In Search of Ideal Analgesia: Classical and Deep Rectus Sheath Block in Laparoscopic Cholecystectomy

Abstract

Background

Laparoscopic cholecystectomy (LC) is the gold standard of treatment for symptomatic cholelithiasis. Despite its minimally invasive nature, LC is still associated with moderate postoperative pain that may delay early mobilization, oral intake, and discharge while increasing the need for opioids. Within ERAS protocols, multimodal analgesia using regional techniques has become increasingly important. The rectus sheath block (RSB) is considered a useful option for controlling the somatic pain component related to the periumbilical port site.

Materials and Methods

A narrative literature review was conducted using PubMed, Scopus, and Google Scholar to identify studies published up to 2026. The analyses included prospective randomized and non-randomized studies, retrospective case series, anatomical investigations, and expert recommendations. In addition to the classical RSB, the deep rectus sheath block (DRSB) was evaluated as a potentially relevant technique for addressing not only somatic but also peritoneum-related pain.

Results

Classical RSB, performed by injecting local anesthetic between the rectus abdominis muscle and the posterior rectus sheath, provides effective analgesia in the periumbilical port area, reduces postoperative pain intensity, and decreases opioid consumption during the first 24 h after LC compared with wound infiltration or systemic analgesia alone. DRSB, which targets the preperitoneal plane between the posterior rectus sheath and parietal peritoneum, has shown promising analgesic effects in isolated clinical reports after LC and epigastric hernia repair, with possible benefits for peritoneum-related pain. However, the current evidence for DRSB remains limited to case reports and small case series, and its exact mechanism of action is still debated.

Conclusion

RSB is a valuable component of multimodal analgesia for LC, with a demonstrated opioid-sparing effect and favorable safety profile under ultrasound guidance. DRSB appears promising, but remains experimental. Further well-designed randomized trials are needed to define its indications, optimal technique, and role in standardized analgesic protocols for LC.

Introduction

Over the past few decades, laparoscopic cholecystectomy (LC) has become the standard procedure for symptomatic cholelithiasis and most benign gallbladder pathologies. Despite its minimally invasive nature, LC is associated with pronounced pain during the first hours and days after surgery. It has a mixed somatic–visceral character.¹ The somatic component is caused by trauma to the anterior abdominal wall in the area of the trocar ports, especially the periumbilical port, whereas visceral pain is related to stretching and irritation of the parietal peritoneum by pneumoperitoneum, traction on the gallbladder and diaphragm, and manipulations in the region of the hepatoduodenal ligament.² Although laparoscopic cholecystectomy is associated with less postoperative pain than open surgery, clinically significant pain remains common. Moderate-to-severe postoperative pain has been reported near 30% of patients during the first 24 hours after surgery, and inadequate pain control may delay mobilization, prolong hospital stay, increase opioid requirements, and negatively affect patient satisfaction and recovery.¹

Current PROSPECT recommendations emphasize the need for multimodal analgesia, including systemic non-opioid analgesics (paracetamol, NSAIDs) and lidocaine infusions, and among regional techniques suggest subcostal transversus abdominis plane block (TAPB), erector spinae plane block (ESPB), or paravertebral block as “second-line” methods for patients with an anticipated high level of pain or an increased risk of opioid-related complications.³ However, these recommendations do not yet reflect the rapid development of fascial blocks of the anterior abdominal wall targeting the rectus sheath and the preperitoneal space. Current PROSPECT recommendations are based primarily on techniques supported by a larger volume of procedure-specific evidence. The absence of rectus sheath block (RSB) from these recommendations does not necessarily indicate ineffectiveness but rather reflects the limited number of high-quality studies, heterogeneity of available protocols, and uncertainty regarding its comparative benefit relative to other regional analgesic approaches.

The RSB belongs to the fascial blocks of the anterior abdominal wall and consists in the injection of a local anesthetic into the space between the posterior rectus sheath and the rectus abdominis muscle itself, with the aim of blocking the anterior branches of the intercostal nerves Th7-Th12.⁴ This approach provides analgesia of the skin and muscles in the area of midline and paramedian incisions – in the context of LC, primarily around the umbilical port, which is often the most painful site.⁵

With the advent of ultrasound-guided techniques, RSB has evolved from a relatively “blind” method with a high risk of inaccurate needle placement into a precise and safe procedure that allows real-time visualization of all layers of the anterior abdominal wall, needle position, and the spread of the local anesthetic.⁶

In parallel, the concept of the deep rectus sheath block (DRSB) has emerged, in which the local anesthetic is injected not above the posterior sheath but into the preperitoneal space beneath the posterior fascia of the rectus sheath but above the parietal peritoneum.^7,8 This space is the immediate “neighbor” of the parietal peritoneum, which opens the possibility of a more pronounced effect on the peritoneum-related component of pain characteristic of LC.⁹

In light of the growing interest in opioid-sparing strategies and ERAS approaches, it is important to critically analyze the role of both classical and deep rectus sheath blocks in the context of laparoscopic cholecystectomy, including their potential benefits, limitations, and safety.

The emergence of DRSB has generated interest because it is hypothesized to extend the analgesic effects of classical RSB beyond somatic abdominal wall pain and potentially influence peritoneum-related pain pathways.^7–9 If confirmed, such an effect could represent a clinically meaningful advance in postoperative pain management after laparoscopic cholecystectomy.^1–3 However, the anatomical basis, mechanisms of action, and clinical effectiveness of DRSB remain incompletely understood.^7–9 Therefore, a critical comparison of the available evidence on classical RSB and DRSB is necessary to define their respective roles, limitations, and future research priorities in laparoscopic cholecystectomy.^5,7

The aim of this narrative review is to integrate the available anatomical, experimental, and clinical data on rectus sheath block in LC, with a particular emphasis on comparing classical and deep techniques, as well as discussing their place in current multimodal analgesia protocols.

Materials and Methods

Review Design

This study was conducted as a narrative review rather than as a systematic review or meta-analysis. This approach was selected for several reasons.

1. Heterogeneity of available studies. Studies on the rectus sheath block in LC differ substantially in design (randomized and non-randomized prospective studies, retrospective case series, case reports), patient characteristics, block technique (volume and concentration of local anesthetic, unilateral or bilateral performance, combination with other blocks), timing of the intervention (pre-incisional, at the end of surgery, intraoperative laparoscopic-guided approach), and outcome measures (VAS at rest/movement, opioid consumption, quality of recovery, length of hospital stay, etc).

2. Limited number of studies on DRSB. For DRSB, the literature consists mainly of isolated case reports and small series without standardized protocols or large randomized trials.^10–12 Under these conditions, performing a formal meta-analysis would be methodologically inappropriate.

3. Need for detailed anatomical and technical description. The anatomy of the rectus sheath, preperitoneal and retroperitoneal interfascial spaces, the specifics of sonographic landmarks (“railroad track sign,” “hypoechoic triangle”), and modifications of the RSB/DRSB technique are crucial for clinical interpretation but fall beyond the scope of a typical systematic review, which predominantly focuses on numerical endpoints.^13,14

4. Early stage of technique development. The DRS block is at the stage of conceptual formation, with ongoing discussions regarding terminology (“deep rectus sheath block” vs “anterior transversalis fascia block”), anatomical substrates, and mechanisms of action.^15,16 This situation is better suited to a flexible narrative description rather than rigid inclusion/exclusion criteria of a systematic review.

Thus, the narrative approach allows the integration of clinical, anatomical, and technical aspects; critical appraisal of conflicting data; and the development of a practice-oriented perspective on the role of RSB/DRSB in LC, which was the primary aim of this review.

Search Strategy and Selection of Sources

A literature search was conducted in the PubMed, Scopus, and Google Scholar databases up to 2025 using the following combinations of keywords:

• “rectus sheath block” and “laparoscopic cholecystectomy”;

• “deep rectus sheath block” and “preperitoneal block” and “cholecystectomy”;

• “rectus sheath block” and “abdominal surgery”;

• “preperitoneal local anesthetic” and “abdominal wall”;

• “transversus abdominis plane” and “rectus sheath” and “laparoscopy.”

A total of 168 records were initially identified through database searching and manual screening of reference lists. After removal of duplicates and exclusion of publications not directly relevant to laparoscopic cholecystectomy, rectus sheath block techniques, or perioperative analgesia, 74 articles were considered eligible for full-text evaluation. Finally, 60 publications were included in the narrative synthesis, comprising randomized controlled trials, prospective observational studies, retrospective case series, anatomical investigations, technical reports, systematic reviews, and guideline documents. The following were included in the analysis:

• prospective randomized studies of RSB/DRSB in LC;

• prospective non-randomized studies evaluating RSB in LC;

• retrospective case series of DRSB in LC and other abdominal surgeries;

• anatomical, cadaveric, and imaging studies (CT, MRI, and contrast-enhanced ultrasound) investigating the spread of local anesthetic in RSB/DRSB.

• PROSPECT recommendations and other expert documents related to the management of pain after LC.

Publications were excluded if they focused exclusively on open abdominal procedures without providing anatomical or technical information relevant to laparoscopic surgery, lacking sufficient methodological description, or duplicated previously published datasets.

Due to the narrative nature of the review, a formal risk-of-bias assessment using validated instruments (eg., RoB 2 or ROBINS-I) was not performed. Nevertheless, each study was qualitatively appraised regarding sample size, adequacy of randomization, blinding procedures, comparability of study groups, completeness of outcome reporting, and consistency of conclusions with the presented data. Attention was paid to methodological limitations that could affect the strength and generalizability of the reported findings.

Results

Anatomical and Pathophysiological Rationale for the Use of Rectus Sheath Block in LC

At the level of the umbilicus, the anterior abdominal wall is formed by the skin, subcutaneous tissue, aponeuroses of the external and internal oblique and transversus abdominis muscles, rectus abdominis muscle within its sheath, transversalis fascia, and parietal peritoneum. Above the arcuate line, the posterior wall of the rectus sheath is well developed and consists of aponeurotic layers of the internal oblique and transversus abdominis muscles; below the arcuate line, the posterior sheath is absent, and the rectus abdominis muscle lies directly against the transversalis fascia and preperitoneal fat.¹⁷ Segmental intercostal nerves Th7-Th12, as well as the iliohypogastric and ilioinguinal nerves, after leaving the intercostal spaces, enter the plane between the internal oblique and transversus abdominis muscles, where they form a neural plexus of this layer of the abdominal wall. From there, they give off the lateral and anterior cutaneous branches that pass through the rectus sheath to the skin of the anterior abdominal wall¹⁶ (Figure 1). The anterior branches at the level of the umbilicus are the main targets of the classical RSB.

Figure 1.

Innervation of the abdominal wall and schematic distribution of the thoracoabdominal nerves. (a) Level of entry of the thoracolumbar nerves into the transversus abdominis plane (TAP). (b) Formation of the TAP and plexuses of the rectus sheath (RS). (c) Termination of the nerves and innervation of the parietal peritoneum (PP) and anterior abdominal wall. (Reproduced from Sonawane et al¹⁶ © Wolters Kluwer Health, Inc. Distributed under the terms of the Creative Commons Attribution License, CC BY 4.0).

Abbreviations: ARS, anterior rectus sheath; PRS, posterior rectus sheath; RAM, rectus abdominis muscle; TAM, transversus abdominis muscle; IOM, internal oblique muscle; EOM, external oblique muscle; AC, abdominal cavity; PP, parietal peritoneum; TF, transversalis fascia; PPS, preperitoneal space; SF, subcutaneous fat/superficial fascia; DCIV, deep circumflex iliac vessels; AAL, anterior axillary line; MAL, midaxillary line; PAL, posterior axillary line; DIEV, deep inferior epigastric vessels.

The parietal peritoneum lining the inner surface of the abdominal wall is innervated both by somatic branches of the lower intercostal and lumbar nerves and by autonomic fibers (via the phrenic and celiac plexuses), which determines its high sensitivity to pain, pressure, touch, friction, cutting, and temperature.⁹ In contrast, the visceral peritoneum lacks distinct somatic innervation and predominantly perceives stretch and ischemia.

Postoperative pain after LC has several components:^18,19

• Somatic pain in the area of the trocar ports, especially the periumbilical port, where a larger incision is made for gallbladder extraction.

• Peritoneum-related pain: associated with stretching of the parietal peritoneum by pneumoperitoneum, contact with instruments, irrigation, and instillation of solutions.

• Referred shoulder–diaphragmatic pain – due to irritation of the diaphragmatic peritoneum and involvement of the phrenic nerve (n. phrenicus).

Classical RSB, by injecting local anesthetic between the posterior rectus sheath and the rectus abdominis muscle, blocks the anterior cutaneous branches of the intercostal nerves, providing somatic analgesia in the periumbilical and midline ports, but only partially affects peritoneum-related pain^5,20 (Figure 2a and b).

Figure 2.

(a) Ultrasound image of RSB; (b) schematic diagram of ultrasound-guided RSB. (Reproduced from Aboelsuod et al²⁰ © Al-Azhar University (Damietta). Distributed under the terms of the Creative Commons Attribution License, CC BY 4.0).

In contrast, in the deep rectus sheath block, the needle tip is positioned in the preperitoneal space between the posterior fascia of the rectus sheath and parietal peritoneum (or between the transversalis fascia and peritoneum below the arcuate line). Injection of a local anesthetic into this space leads to “dropping” of the peritoneum, its separation, and the spread of the solution along the anterior abdominal wall and into the retroperitoneal interfascial planes^7,21 (Figure 3). This theoretically makes it possible to affect both somatic and peritoneal (conditionally “visceral”) afferents.

Figure 3.

Horizontal line (yellow line): correct location of the local anesthetic in the preperitoneal space between the posterior fascia of the rectus sheath and the parietal peritoneum. N – needle. (Reproduced from Fusco et al⁷ © Edizioni Minerva Medica. Distributed under the terms of the Creative Commons Attribution License, CC BY 4.0).

Thus, the anatomy of the anterior abdominal wall and the innervation of the parietal peritoneum provide a rational basis for the use of both classical and deep rectus sheath blocks in LC, which is directed primarily at the somatic component, while the latter potentially complements it by influencing peritoneum-related pain.

Classical Rectus Sheath Block: Evolution of the Technique

From “Blind” Techniques to Ultrasound Guidance

Historically, RSB was performed using a “blind” technique based on the perception of sequential fascial loss of resistance (LOR) as the needle passes through the anterior sheath, muscle belly, and posterior sheath. This approach was associated with a high risk of inaccurate needle placement: injection too superficially (into the muscle) or too deeply (up to the peritoneum or even intraperitoneally), which reduced the effectiveness of the block and increased the risk of complications.²² In a prospective study, Dolan et al compared the accuracy of RSB performed by resident physicians using the blind LOR technique versus ultrasound guidance. Correct placement of the anesthetic within the rectus sheath was achieved in only 45% of cases with LOR, compared with 89% under ultrasound guidance. As body mass index increased, the accuracy of the “blind” method decreased even further.²² This study became an important argument in favor of the routine use of ultrasound for RSB, especially in patients with obesity or a history of prior laparotomy.

Subsequent anatomical and clinical studies demonstrated that ultrasound imaging allows clear identification of the layers of the anterior abdominal wall, posterior rectus sheath, transversalis fascia, and peritoneum, as well as real-time monitoring of local anesthetic spread, which significantly improves the safety and reproducibility of the block.^13,23

Standard Ultrasound Technique

Standard ultrasound-guided RSB was performed with the patient in supine position. A high-frequency linear probe was placed transversely, approximately 2–3 cm lateral to the midline at the level of the umbilicus. On the ultrasound image, the skin, subcutaneous tissue, rectus abdominis muscle, its anterior and posterior sheaths, deeper transversalis fascia, and sometimes a thin hyperechoic peritoneal line are identified. The needle was inserted in-plane from the lateral side and advanced to the interface between the posterior surface of the rectus abdominis muscle and the posterior sheath. After negative aspiration, a small test volume of fluid was injected, and the formation of an anechoic “pocket” between the muscle and the posterior sheath was observed (a sign of correct placement). A calculated volume of local anesthetic is then administered – usually 10–20 mL on each side.⁶

Onishi et al proposed the use of contrast-enhanced ultrasound by adding a microbubble contrast agent perflubutane (Sonazoid^®) to the local anesthetic solution, which made it possible to clearly assess the spread of the solution in real time and to confirm the correspondence between the area of ultrasound contrast enhancement and the distribution of radiopaque contrast²³ (Figures 4A–D and 5).

Figure 4.

Ultrasound visualization of rectus sheath block (CEUS and B-mode). (A) before RSB: Prior to the block, the rectus abdominis muscle, its sheath, the peritoneum, and intra-abdominal structures are well visualized. (B) during RSB: Perflubutane within the needle lumen is clearly visualized in CEUS mode. (C) after RSB: The local anesthetic (LA) appears as a hyperechoic area in CEUS mode and as a hypoechoic area in B-mode. (D) 5 minutes after RSB: LA is clearly delineated in CEUS mode. In B-mode, the spread of LA is not visualized.(Reproduced from Onishi et al²³ © Springer Nature. Published with permission under STM Permissions Guidelines).

Abbreviations: RSB, rectus sheath block; CEUS, contrast-enhanced ultrasonography; LA, local anesthetic.

Figure 5.

Radiographic image of iohexol distribution after rectus sheath block. The distribution of iohexol extends over the lumbar muscles during rectus sheath block (Reproduced from Onishi et al²³ © Springer Nature. Published with permission under STM Permissions Guidelines).

The most common complications of RSB are the injection of anesthetic outside the rectus sheath and its systemic toxicity, vascular injury (Figures 6A–H), and bowel injury (Figure 7), although their incidence usually does not exceed 2.5%.^24,25

Figure 6.

Rectus sheath hematoma and inferior epigastric vessels. (A) Rectus sheath hematoma. (B) Color Doppler image of the inferior epigastric artery accompanying the rectus sheath hematoma. (C) Color Doppler image showing an inferior epigastric vessel within the rectus abdominis muscle. (D) Color Doppler image showing an inferior epigastric vessel in the deeper portion of the rectus abdominis muscle. (E) Color Doppler image of inferior epigastric vessels adjacent to the posterior aspect of the rectus abdominis muscle; arrowheads indicate the needle trajectory. (F) Color Doppler image showing an inferior epigastric vessel in the superficial portion of the rectus abdominis muscle. (G) Color Doppler image demonstrating multiple inferior epigastric vessels traversing the rectus abdominis muscle. (H) Color Doppler image demonstrating a cluster of inferior epigastric vessels near the posterior aspect of the rectus abdominis muscle. Arrowheads indicate the needle trajectory. Arrows indicate the rectus sheath hematoma. (Reproduced from Kwon et al²⁴ © Wolters Kluwer Health, Inc. Published with permission under STM Permissions Guidelines).

Abbreviation: RA, rectus abdominis muscle.

Figure 7.

The small intestine located in close proximity to the posterior layer of the rectus sheath. If the needle is advanced beyond the posterior rectus sheath in the same direction, bowel injury may occur. Arrowheads indicate the needle trajectory. The arrow indicates the bowel. The asterisk (*) marks the accumulation of local anesthetic. (Reproduced from Kwon et al²⁴ © Wolters Kluwer Health, Inc. Published with permission under STM Permissions Guidelines).

Abbreviation: RA, rectus abdominis muscle.

Access Modifications: Long-Axis and the “Hypoechoic Triangle”

Classically, RSB is performed using transverse (short-axis) scanning. However, several modifications have been proposed for large midline incisions or when broader craniocaudal coverage is required.

• Long-axis rectus abdominis sheath block – The linear probe was placed parallel to the long axis of the rectus abdominis muscle, approximately 3 cm from the midline, creating a “tunnel” of local anesthetic between the muscle and the posterior sheath, with the option of advancing the needle cranially to distribute the solution at the T6-T11 levels²⁶ (Figures 8A–C).

• “Hypoechoic triangle” – Thind et al described a parasagittal plane between adjacent segments of the rectus abdominis muscle above the umbilicus, where the distance between the muscle epimysium and the deep fascia increases and vessels are absent. This “hypoechoic triangle” facilitates correct needle and catheter placement in the appropriate fascial layer and may improve block success¹⁴ (Figure 9A and Figure 9B).

Figure 8.

Ultrasound-guided long-axis rectus sheath block. (A) Position of the probes and needle directions. (B) Ultrasound image with the probe at position 1. (C) Ultrasound image with the probe at position 2. Triangles indicate the needle trajectory. (Reproduced from Peng et al²⁶ © Elsevier Inc. Published with permission under STM Permissions Guidelines).

Abbreviations: RA, rectus abdominis muscle; RAS, rectus abdominis sheath; TA, transversus abdominis muscle; LA, local anesthetic.

Figure 9.

Parasagittal/longitudinal view and in-plane approach within the hypoechoic triangle. (A) Parasagittal/longitudinal (novel approach) view showing adjacent segments of the rectus abdominis (RA) on one side, the tendinous intersection (TI) between the two segments, and the underlying hypoechoic triangle (HT). The boundaries of this real space (as opposed to the potential space in the traditional approach) are a thin fascial layer enveloping the rectus abdominis muscle (F) and the double layer forming its base (transversus abdominis [TA] and peritoneum [P]). (B) In-plane approach with needle tip placement. The bidirectional pattern of spread and the crescent-shaped appearance of the injectate within the hypoechoic triangle are shown. (Reproduced from Thind et al¹⁴ © Wolters Kluwer Health, Inc. Distributed under the terms of the Creative Commons Attribution License, CC BY 4.0).

These modifications have so far only been sparsely described in the context of LC, but demonstrate the potential for further optimization of local anesthetic spread with RSB.

Classical Rectus Sheath Block in Laparoscopic Cholecystectomy: Clinical Studies

The clinical effectiveness of classical RSB in LC has been investigated in a number of prospective randomized, pilot, and retrospective studies, which overall demonstrate its considerable potential as a component of multimodal analgesia, while at the same time highlighting that its effect depends on the type of procedure (single-incision versus standard four-port LC, robotic cholecystectomy), timing of the block, dose of local anesthetic, and combination with other fascial blocks and systemic analgesics.

One of the early studies demonstrating the advantages of RSB in single-incision laparoscopic cholecystectomy (SILC) is a prospective trial by Kamei et al, in which 75 patients with symptomatic cholelithiasis or gallbladder polyps were randomized to standard four-port LC, SILC, or SILC combined with ultrasound-guided bilateral RSB (RSB-SILC; 10 mL of 0.375% ropivacaine on each side before skin incision).²⁷ The groups did not differ in age, BMI, ASA status, duration of surgery, or complication rates; however, in the RSB-SILC group, VAS pain scores were significantly lower at 2 h (compared with both SILC and standard LC) and at 6 hours (compared with SILC), whereas the differences leveled off at 12–24 hours. The frequency of analgesic requests also tended to be lower in the RSB-SILC group, while the single-incision technique alone, without the block, did not show any advantage in terms of pain compared with four-port LC.²⁷ This study convincingly demonstrated that the addition of ultrasound-guided RSB, rather than a reduction in the number of ports, determines the reduction in early postoperative pain in SILC.²⁷

Subsequent studies on SILC focused on optimizing the dose of local anesthetic and combining RSB with systemic analgesia. In a prospective study with a sequential up-and-down design, Fu et al determined the minimum effective dose of ropivacaine for bilateral ultrasound-guided RSB combined with intravenous butorphanol in 24 patients undergoing SILC; success was defined as the absence of significant incisional pain at rest (NRS ≤ 3) during the first 12 hours.²⁸ According on probit analysis, the ED50 and ED95 of ropivacaine were 0.719 mg/kg (95% CI 0.553–0.873) and 0.967 mg/kg (95% CI 0.835–1.91), respectively, which is substantially lower than the doses commonly used in clinical practice. In the “successful” block group, no patient required rescue analgesia, and no signs of systemic local anesthetic toxicity were observed.²⁸ Thus, the authors demonstrated that RSB can provide effective control of incisional pain in SILC through careful titration of the ropivacaine dose, minimizing the risk of toxicity.²⁸

In another prospective randomized study, Fu et al evaluated how the choice of opioid for preventive analgesia modifies the effect of bilateral ultrasound-guided RSB in SILC.²⁹ In 58 patients, all underwent bilateral RSB with 0.5% ropivacaine (20 mL per side) 30 minutes before induction of anesthesia, after which they received either butorphanol 0.02 mg/kg or sufentanil 0.1 µg/kg. The combination of RSB + butorphanol was associated with a lower frequency of requests for additional analgesia (0.76±0.69 vs. 1.4±1.05; p=0.021), significantly lower visceral pain intensity at 2, 6, and 12 hours, and a markedly lower incidence of postoperative nausea and vomiting (PONV) (10.3% vs. 44.8%; p=0.003), while port-site pain was similar between the groups.²⁹ This highlights that even with an identical RSB technique, the choice of concurrent systemic analgesic (κ-agonist vs. μ-agonist) can modify the control of the visceral pain component and the side-effect profile, which is important in the context of ERAS protocols.²⁹

In this context, studies on dexmedetomidine as a systemic adjuvant for multimodal analgesia in LC also deserve attention. In a randomized controlled trial, Ye et al demonstrated that an intravenous infusion of dexmedetomidine at a dose of 0.6 µg/kg before induction of anesthesia maintains hemodynamic stability, reduces the incidence of coughing on emergence, and decreases postoperative pain intensity, as well as the incidence of shoulder pain and the peak rate of PONV in the 6–12–hour interval after surgery.³⁰ Gayathri et al showed that different routes of dexmedetomidine administration (including non-intravenous) have distinct effects on wake-up time, sedative profile, and quality of recovery, while maintaining an acceptable analgesic effect, which underscores the importance of individualizing the choice of adjuvants in regimens where RSB serves as a key regional component.³¹

Not all studies on SILC demonstrate a clear advantage of RSB over simpler methods of local analgesia. In a randomized double-blind trial, Yang et al compared three postoperative analgesic strategies after transumbilical SILC in 59 patients: ultrasound-guided bilateral RSB, conventional wound infiltration with ropivacaine and dexmedetomidine (LAI-I), and infiltration using a specialized injection kit designed to ensure reliable deep anesthetic delivery down to the peritoneum (LAI-II).³² VAS scores during the 2–48 hours after surgery did not differ among the three groups; in the LAI-II group, there was only a trend toward lower VAS scores in the early hours, whereas the frequency of PCIA requests was lower specifically with the use of the injection kit.³² The authors concluded that in SILC, RSB, and conventional port-site infiltration provide comparable analgesic effects, whereas optimized deep infiltration allows a modest reduction in the need for additional analgesia without increasing procedure time.³²

One of the key questions for a standard four-port LC is the optimal timing of the RSB. In a randomized prospective single-center study, Jeong et al compared preoperative (before skin incision) and postoperative (after wound closure) ultrasound-guided RSB in 200 adult patients undergoing elective LC, in which bilateral blocks below the umbilicus and intercostal nerve blocks were performed using 40 mL of 0.25% ropivacaine.³³ Preoperative RSB was associated with a significant reduction in the total requirement for rescue analgesics during the first 24 hours and with lower cumulative analgesic consumption at 1, 9, and 18 hours, converted to fentanyl equivalents; pain intensity was significantly lower only immediately after surgery (0 hours), and did not differ substantially at later time points, with a similar safety profile.³³ Thus, preoperative RSB provides a pronounced preemptive analgesic effect, reducing opioid requirements in LC.³³

Comparisons of RSB with standard local wound infiltration and intraperitoneal instillation of local anesthetics have yielded heterogeneous results. In a prospective study of 75 patients, Gupta et al compared 0.25% ropivacaine for intraperitoneal instillation, bilateral RSB, and standard analgesia with tramadol “on demand”.³⁴ The time to the first dose of tramadol was longest in the RSB group (~16 hours), intermediate with intraperitoneal instillation (~8 hours), and shortest in the control group (~1.7 hours), while total opioid consumption over 48 hours was reduced by 50.3% in the RSB group and by 32.2% in the intraperitoneal instillation group compared with controls. Pain profiles according to VAS and the Prince Henry Hospital Pain Score during the first 6–12 hours were also most favorable in the RSB group, without serious adverse effects.³⁴ The authors consider preemptive RSB was considered a more effective postoperative analgesic strategy after LC than intraperitoneal instillation and was recommended as a priority component of multimodal pain management.³⁴

A similar rationale – but with an emphasis on broad abdominal wall fascial plane block – was demonstrated by Saxena et al, who compared port-site infiltration with local anesthetic versus a combination of subcostal TAPB and bilateral RSB (ultrasound-guided abdominal field blocks, USAFB) in 80 patients undergoing LC.³⁵ In the USAFB group, NRS pain scores over 24 h were significantly lower, and total fentanyl consumption was approximately halved (200±100 µg with port-site infiltration vs. 120±74 µg with USAFB; p<0.0001), with higher patient satisfaction.³⁵ This confirms that combining RSB with a subcostal TAPB provides a stronger somatic analgesic component compared with isolated port-site infiltration.

In a prospective randomized study, Kitamura et al randomized 62 patients undergoing standard four-port LC to ultrasound-guided bilateral RSB or infiltration anesthesia at the umbilical incision with a long-acting local anesthetic.³⁶ VAS pain scores on postoperative days 0–3, the area under the VAS curve, the frequency of additional analgesic use, and length of hospital stay did not differ significantly between groups. On postoperative day 1, there was even a trend toward lower VAS scores in the infiltration anesthesia group.³⁶ Multivariable analysis showed that the main predictor of severe pain (VAS ≥ 5) was a lower intraoperative fentanyl dose rather than the choice of local analgesia technique, leading the authors to a practical conclusion: for most patients after LC, simple umbilical port infiltration with a long-acting anesthetic may be sufficient.³⁶

A similarly equivocal picture regarding the superiority of RSB over combined intraperitoneal and port-site infiltration was observed in a randomized single-blind study by Aboelsuod et al, in which 80 patients after LC were compared with respect to the efficacy of bilateral ultrasound-guided RSB with 0.25% bupivacaine (30 mL) versus a combined technique: intraperitoneal instillation of bupivacaine into the gallbladder bed plus port-site infiltration with the same drug.²⁰ Both strategies provided satisfactory pain control (VAS < 4), but at 16–24 hours RSB was associated with lower VAS scores, a longer interval to first morphine administration (17.16±4.83 vs. 11.8±0.34 hours; p=0.002), and lower total morphine consumption (6.21±0.65 vs. 8.98±0.58 mg; p=0.001), with no difference in adverse events.²⁰ This indicates a certain advantage of RSB in prolonging analgesia and reducing opioid requirements, even when both the ports and the abdominal cavity are treated with local anesthetic.²⁰

In a larger randomized trial of abdominal plane blocks, Wu et al compared three analgesic strategies in 180 patients undergoing three-port LC: port-site infiltration with ropivacaine plus dexmedetomidine alone (LAI), a combination of posterior TAPB with LAI (TL), and a combination of TAPB with bilateral RSB (TR).³⁷ Over 48 h after surgery, no differences were found among the three groups in VAS scores (incisional, visceral, or shoulder pain), time to unassisted ambulation, dezocine consumption, or sleep quality. At the same time, overall satisfaction with analgesia was highest in the LAI group.³⁷ The authors concluded that all three approaches provide a clinically acceptable level of pain control and that the advantages of more complex TAPB+RSB combinations are not always evident against the background of adequate port-site infiltration, especially when dexmedetomidine was used as an adjuvant.

In the context of emergency surgery, Izwan et al, in a pilot prospective randomized study of 138 patients undergoing emergency LC, compared a TAPB+RSB combination with port-site infiltration using the same volume and concentration of ropivacaine.³⁸ Despite an identical total dose of local anesthetic (40 mL of 0.375% ropivacaine), the mean cumulative perioperative opioid dose was significantly lower in the TAPB+RSB group (61.2 mg vs. 115.2 mg morphine equivalent; p<0.05), indicating a potential opioid-sparing effect of combined blocks even in the setting of acute cholecystitis.³⁸

With regard to minimally invasive modifications of cholecystectomy, data on robotic procedures using new abdominal port sites (robotic cholecystectomy using new port sites) are of particular interest. In a prospective randomized trial, Kim et al evaluated the dynamics of superficial, deep abdominal, and shoulder pain after RCNP in 40 women randomized to either bilateral ultrasound-guided RSB (split-injection technique) or a control group.³⁹ In the control group, superficial pain at the main port site predominated only during the first postoperative hour and rapidly decreased to minimal levels; the addition of RSB significantly reduced the intensity of this superficial pain and improved satisfaction with analgesia only during the first hour, without affecting deep or shoulder pain and without reducing total fentanyl consumption over 24 hours (same source).³⁹ The authors emphasized that, in the setting of generally low pain intensity after RCNP, the routine use of RSB may be excessive and not always justified in view of the time required and potential risks.³⁹

A substantial body of research has focused specifically on the role of RSB within combined fascial block regimens. In a retrospective analysis, Selvi et al compared bilateral oblique subcostal TAPB (OSTAP) with a combination of right-sided serratus intercostal plane block (SIPB) and bilateral RSB in 67 patients undergoing LC on the background of standard multimodal analgesia.⁴⁰ NRS pain scores over 24 h were similar in both groups; however, the mean 24-hour tramadol consumption was significantly lower in the SIPB+RSB group (69±50 mg vs. 125±50 mg; p<0.001), as was the frequency of rescue analgesia.⁴⁰ This indicates that incorporating RSB into combined blocks targeting both somatic and visceral components of pain can reduce opioid requirements without compromising pain control.⁴⁰

In a prospective randomized controlled trial, Yoon et al compared a combination of right-sided lateral and subcostal TAPB plus bilateral RSB (RS-TAP) with a regimen without RSB that included bilateral TAPB and right-sided subcostal TAPB (Bi-TAP) in 88 patients.⁴¹ The primary endpoint was VAS over 48 h (0, 12, 24, 48 h); secondary endpoints included rescue analgesic use, IV-PCA consumption, patient satisfaction, sleep quality, and the incidence of adverse effects. No statistically significant differences were found between the groups for any of these outcomes, and the frequency of adverse events was likewise comparable.⁴¹ The authors concluded that adding RSB to an optimized TAPB regimen does not improve formally measured pain intensity or sleep quality; however, both strategies provide a clinically acceptable level of analgesia.⁴¹

Several studies have shown that including RSB in combined plane blocks can improve not only pain perception but also “hard” physiological parameters and overall quality of recovery. In a prospective randomized trial of 189 patients, Karaarslan et al demonstrated that the combination of bilateral RSB with subcostal TAPB (OSTAP) not only reduced VAS pain scores at all time points (30 min, 2, 8, and 24 h) and tramadol requirements (median 0 mg vs. 84 mg in the control group) but also significantly decreased the mechanical power of ventilation and increased QoR-15 scores, thereby improving the quality of recovery after LC.⁴²

A similar trend was observed in a randomized controlled trial by Ramkiran et al, which compared three strategies in 61 patients: a combination of right-sided subcostal TAPB with bilateral RSB (OSTAP+RSB), isolated OSTAP, and standard port-site infiltration with bupivacaine.⁴³ The combined OSTAP+RSB approach provided the lowest VAS scores both at rest and during movement over 2–24 hours, as well as the lowest cumulative 24-hour tramadol dose (60±69.9 mg vs. 119.1±82.8 mg with OSTAP and 182.5±59.1 mg with port-site infiltration), without any block-related complications.⁴³ This supports the notion that multicomponent fascial blocks incorporating RSB have the greatest potential for reducing opioid requirements.⁴³

In a more recent randomized trial of 49 patients, Mo et al compared two regimens, both of which included bilateral RSB but differed by the additional block performed: either a subcostal TAPB or an external oblique intercostal block (EOIB).⁴⁴ The EOIB+RSB combination resulted in lower sufentanil consumption at 24 and 48 hours and higher QoR-15 scores compared with TAPB+RSB, without an increased incidence of complications.⁴⁴ At the same time, in a letter to the editor, Sun and Feng pointed out several methodological limitations of this study (lack of data on surgeons’ experience, a questionably justified efficacy threshold for opioid consumption, and uneven distribution of sufentanil dosing), which may exaggerate the reported superiority of EOIB+RSB.⁴⁵ Thus, although RSB within the EOIB+RSB combination shows potential for improving analgesia and recovery quality, interpretation of these findings requires caution in light of the methodological nuances.

Additional evidence for the advantages of RSB-containing combination regimens over simple local infiltration was provided by Gangadhar et al, who compared a right-sided EOIB combined with left-sided RSB (EOIB+RSB) versus port-site infiltration with bupivacaine in 70 patients undergoing LC.⁴⁶ The combined block produced significantly lower resting VAS scores during the first 12 h, a smaller proportion of patients requiring tramadol (14.3% vs. 65.7%; p<0.001), a longer time to first analgesic request, and fewer analgesic doses over 24 h, along with a lower incidence of nausea/vomiting and higher patient satisfaction.⁴⁶

On the other hand, a retrospective study by Manıcı et al showed that RSB may not be inferior to the more proximal ESPB in terms of pain control and opioid requirements. In 44 patients undergoing LC, bilateral ESPB at the T7-T8 level with 20 mL of 0.25% bupivacaine on each side was compared with bilateral ultrasound-guided RSB using the same volume and concentration of anesthetic, performed at the end of surgery; all patients received morphine.⁴⁷ Mean 24-hour morphine consumption was similar in the ESPB and RSB groups (6.29±1.73 mg vs. 6.60±3.41 mg; p=0.717); VAS scores, the incidence of PONV and shoulder pain were also comparable, and no serious complications were recorded.⁴⁷ This confirms that conventional RSB remains a technically simpler yet sufficiently effective alternative to ESPB within a multimodal analgesic regimen.⁴⁷

Another important aspect of combined regimens is the effect of additional blocks on the visceral component of pain when RSB has already been performed. In a randomized controlled trial by Kwon et al, all patients undergoing LC received bilateral RSB for somatic pain control, while ESPB at the T7 level was added only in the intervention group to assess whether it provided additional visceral analgesia.⁴⁸ In a conceptually similar prospective randomized study by Lee et al, all patients underwent pre-incisional bilateral RSB to minimize somatic pain, after which a thoracic paravertebral block (TPVB) was administered either before the incision (pre-TPVB) or after wound closure (post-TPVB).⁴⁹ Pre-TPVB in combination with RSB was associated with significantly lower postoperative opioid consumption compared with post-TPVB, with similar pain scores over 24 h (same source). Both studies highlight that, in contemporary protocols, RSB is often regarded as the “baseline standard” for somatic pain control, to which more proximal blocks (ESPB and TPVB) are added for targeted modulation of the visceral component and reduction of opioid requirements.

A separate group consisted of studies comparing different combinations of peripheral blocks with RSB without detailed reference to a specific type of LC. In a large prospective trial, Haitov Ben Zikri et al randomized 189 patients to one of four regimens: TAPB, subcostal TAPB, combined subcostal TAPB+TAPB, or subcostal TAPB+RSB; in all cases, 0.25% bupivacaine with dexamethasone was used.⁵⁰ In the entire cohort, pain intensity on the VAS decreased from 3.6±3.2 points at 30 minutes to 0.9±2.0 points at 24 hours, without significant differences among the four groups; however, combined blocks (subcostal TAPB+TAPB and subcostal TAPB+RSB) reduced the total number of prescribed analgesics (2.3–2.5 drugs per patient vs. 2.7–2.8 with isolated TAP techniques, p=0.024).⁵⁰ No complications were observed during the first 24 hours. Taken together with the data of Wu et al, this suggests that adding RSB to already effective TAP blocks does not always result in a marked reduction in the subjective intensity of pain but may optimize analgesic therapy by reducing its overall volume or the need for opioids.^37,50

A systematic review of clinical studies on RSB in laparoscopic and robotic cholecystectomy allowed several general conclusions to be drawn. First, in SILC and conventional LC, ultrasound-guided bilateral RSB significantly reduces early postoperative incisional pain and opioid requirements compared with no regional analgesia or systemic analgesia alone.^20,27,33,34 Second, when compared with simpler techniques, local port-site infiltration, intraperitoneal instillation, or their combination, RSB does not always demonstrate a clear advantage in terms of VAS scores, although it often provides a longer interval to the first opioid dose and lower total analgesic consumption, particularly in regimens that include both RSB and TAPB.^{20,32,35–38} Third, the most pronounced opioid-sparing effect of RSB is seen as part of combined fascial blocks (TAPB+RSB, OSTAP+RSB, SIPB+RSB, EOIB+RSB), which simultaneously target the somatic and visceral components of pain and may improve not only pain intensity but also recovery quality and physiological parameters (QoR-15, mechanical power of ventilation).^{38,40,42–44,46,50} Fourth, RSB is at least no worse than ESPB in terms of pain control and opioid requirements after LC, while remaining a technically simpler and safe alternative, whereas the addition of proximal blocks (ESPB, TPVB) on the background of an already performed RSB is used mainly to target visceral pain and to achieve a preemptive effect.^47–49 Finally, dose-finding studies on ropivacaine and the choice of concomitant opioids (butorphanol vs. sufentanil), as well as studies using dexmedetomidine as an adjuvant (both for infiltration and systemic administration), indicate that RSB may serve as a key tool in dose-sparing strategies for local anesthetics and systemic analgesics without increasing the risk of toxicity and with improvements in hemodynamic and recovery profiles.^28,30,31,37

Importantly, the overall quality of evidence remains variable. Many available studies are single-center trials with relatively small sample sizes, heterogeneous analgesic protocols, and differences in block timing, local anesthetic regimens, and outcome assessment methods.^{5,20,32,36,37,41} Several investigations demonstrated statistically significant reductions in opioid consumption despite only modest or inconsistent differences in pain scores, raising questions regarding the clinical magnitude of benefit.^{20,32,36,37,50} Furthermore, direct comparisons between RSB and other regional techniques remain limited, preventing robust conclusions regarding comparative superiority.^41,47,50 Therefore, although the cumulative evidence supports a beneficial role for RSB, the certainty of evidence should generally be regarded as low-to-moderate rather than high.^{5,20,32,36,37,41,47,50}

Overall, clinical evidence indicates that classical RSB is an important and versatile component of multimodal analgesia in LC. Its benefit is particularly evident in settings with more intense somatic pain (SILC, conventional LC without additional blocks) when used in a preemptive manner and in combination with other plane blocks. At the same time, the existence of studies that do not demonstrate an advantage of RSB over simple port-site infiltration underscores the importance of individualizing the analgesic strategy, taking into account the type of procedure, concomitant blocks, available resources, and the patient’s risk profile as well as the need for further high-quality randomized trials with standardized endpoints to clearly define the place of RSB among other analgesic techniques in LC.

Deep Rectus Sheath Block in Laparoscopic Cholecystectomy

Anatomical and Pathophysiological Basis of the DRS Block

Classical RSB involves injecting a local anesthetic between the posterior layer of the rectus sheath and the rectus muscle itself to block the anterior cutaneous branches of the intercostal nerves, thereby providing somatic analgesia in the midline area but having virtually no effect on peritoneal/visceral pain.²⁴ In contrast, the DRSB targets the space between the posterior layer of the sheath (or the transversalis fascia) and the parietal peritoneum – the preperitoneal interfascial space, which, according to anatomical and radiological studies, is directly continuous with the retroperitoneal interfascial space (anterior pararenal, perirenal, and posterior pararenal compartments).^7,8 Owing to the continuity of the transversalis fascia, this space is anatomically connected with the fascia of the quadratus lumborum and psoas major muscles, which theoretically creates conditions for the spread of local anesthetic to the regions traversed by sympathetic and visceral fibers.⁸ According to the proponents of this technique, this may explain the ability of DRSB to modulate visceral nociception.

Evolution of the Deep Rectus Sheath Block Concept

Initially, preperitoneal injection of local anesthetic was regarded as a complication of classical RSB, associated with accidental puncture of the posterior rectus sheath and partial perforation of the peritoneum.²⁴ Subsequently, an Italian group demonstrated that targeted injection of local anesthetic into the preperitoneal space can provide wide diffusion along the parietal peritoneum and produce pronounced analgesia in the midline abdominal area.⁷

Further development of the concept included a description of the combination of DRSB with classical RSB in an elderly female patient undergoing laparotomy as “awake surgery” without general anesthesia: the deep block provided control of visceral pain, whereas the superficial RSB controlled somatic pain, which made it possible to avoid general anesthesia in a very high-risk patient.¹² A case series of epigastric hernias demonstrated the feasibility of using DRSB in combination with spinal anesthesia for open hernioplasty without postoperative opioid use.¹¹

An important step was the detailed description of the ultrasound-guided DRSB technique with needle positioning beneath the posterior rectus sheath and visualization of “dropping” of the parietal peritoneum during injection of the local anesthetic, confirming a preperitoneal rather than intramuscular or subfascial location of the injectate.²¹ At the same time, a number of authors questioned the anatomical rationale for visceral analgesia with DRSB, emphasizing the complex combined innervation of the parietal peritoneum and the possibility of explaining the block effect, in particular, by spread of the injectate within the transversus abdominis plane and the transversalis fascia (the so-called “anterior transversalis fascia block”).^15,16

Thus, the concept of DRSB continues to evolve, and its mechanisms remain a matter of debate. However, accumulated clinical observations provide a basis for extrapolating this technique to LC.

Technique of Performing DRS Block During Laparoscopic Cholecystectomy

Two main technical variants of DRS block have been described for LC: laparoscopically guided (intraoperative, under camera control);¹⁰ Ultrasound-guided transperitoneal or transcutaneous approach at the end of the procedure.²¹

Laparoscopically Guided DRS Block

In the classical case described by Marrone et al¹⁰ the block was performed after completion of the main stage of LC, but before desufflation of the pneumoperitoneum. Under laparoscopic guidance, the surgeon introduced a needle through the anterior abdominal wall at the projection of the lateral edge of the rectus sheath slightly above the umbilical level. Initially, the tip of the needle was positioned within the rectus muscle, which was accompanied by characteristic “bulging” of the deep part of the sheath due to the spread of a test volume of solution within the deep sheath (the “yellow star” sign on the laparoscopic image). The needle was then advanced under direct visualization through the posterior sheath until separation of the parietal peritoneum and filling of the preperitoneal space were observed; on video this corresponded to the appearance of a second, more superficial bulging (two “stars”)¹⁰ (Figure 10A). After negative aspiration, a selected volume of local anesthetic (for example, ropivacaine or bupivacaine at a concentration appropriate for fascial plane blocks) was injected.

Figure 10.

Rectus sheath block and preperitoneal infiltration: laparoscopic and ultrasonographic views. (A) Laparoscopic images obtained during pneumoperitoneum show injection at the lateral end of the rectus abdominis muscle, with spread first within the deep rectus sheath (one yellow star) and then into the preperitoneal space after detachment of the parietal peritoneum (two yellow stars). (B) Postoperative ultrasound demonstrates the injected solution within the deep rectus sheath (one yellow star) and a lateral hypoechoic area consistent with preperitoneal dissection (two yellow stars), although after resolution of the pneumoperitoneum the peritoneum itself is no longer clearly distinguishable. (Reproduced from Marrone et al¹⁰ © Wolters Kluwer Health, Inc. Published with permission under STM Permissions Guidelines).

According to the control sonography of the abdominal wall performed immediately after pneumoperitoneum deflation (Figure 10B), ultrasound revealed the rectus abdominis muscle together with its anterior and posterior sheaths. The injected solution is visible at the level of the deep rectus sheath (marked with a yellow star). Additionally, a hypoechoic “bubble” was seen slightly caudal and lateral, presumably corresponding to the preperitoneal layer of separation beneath the deep sheath (marked with two yellow stars), which had been previously observed during laparoscopy. Although the parietal peritoneum was confirmed to be intact, during ultrasound examination after resolution of the pneumoperitoneum, when the visceral organs again lay against the abdominal wall, the peritoneum was no longer clearly visible. This may create a false impression of the perforation.

After 6 h, the initially injected volume of the solution at the level of the deep rectus sheath was no longer visualized (Figure 11A). The previously described hypoechoic “bubble” (preperitoneal) (two yellow stars) remained visible, assuming a more flattened shape and extending laterally toward the attachment of the lateral abdominal wall muscles (Figure 11B). A biphasic spread of the solution was confirmed: first, within the space of the deep rectus sheath and subsequently in the preperitoneal space with lateral distribution toward the attachment of the lateral abdominal muscles (Figure 11C).¹⁰

Figure 11.

Follow-up sonography of the abdominal wall and anatomical representation. (A) Medial sonographic view 6 h after injection showing residual preperitoneal collection (yellow stars). (B) Lateral sonographic view demonstrating lateral extension of the residual preperitoneal collection (yellow stars). (C) Enlarged sonographic and schematic views illustrate the relationship between the rectus muscle, deep sheath, parietal peritoneum, and preperitoneal space. (Reproduced from Marrone et al¹⁰ © Wolters Kluwer Health, Inc. Published with permission under STM Permissions Guidelines).

From a clinical standpoint, the patient did not require opioids in the early postoperative period; pain intensity on the visual analog scale remained low both at rest and during coughing, which allowed early mobilization and discharge within the standard timeframe without any signs of pain chronification.¹⁰

Ultrasound-Guided DRS Block

In another clinical case, a 31-year-old female patient with obesity and concomitant anemia underwent bilateral DRSB at the end of LC under ultrasound guidance. A high-frequency linear transducer was placed transversely slightly above the umbilicus to identify the layers of the anterior abdominal wall: skin, subcutaneous tissue, rectus abdominis muscle, posterior rectus sheath, transversalis fascia, and the hyperechoic line of the parietal peritoneum. The needle was inserted in-plane from lateral to medial, with the tip initially positioned beneath the posterior rectus sheath, and then advanced deeper until the characteristic “dropping” of the peritoneum appeared upon injection of 1–2 mL of normal saline. After confirming correct placement, 10 mL of 0.375% ropivacaine was injected on each side (total volume, 20 mL), with real-time visualization of the solution spread in the preperitoneal space⁵¹ (Figures 12a and Figure 12b). In the postoperative recovery room, the patient required only a single rescue dose of morphine 3 mg intravenously and subsequently received only oral paracetamol.⁵¹ No signs of hypotension, muscle weakness, local anesthetic systemic toxicity, or intra-abdominal bleeding were observed.

Figure 12.

Preperitoneal local anesthetic injection. (a) Ultrasonography of the rectus abdominis muscle with visualization of the rectus sheath. (b) Injection of local anesthetic (LA) beneath the deep rectus sheath into the preperitoneal space with visualization of the parietal peritoneum. A V-shaped spread of local anesthetic illustrates the opening of the interfascial plane. (Reproduced from Marrone et al⁵¹ © Wolters Kluwer Health, Inc. Distributed under the terms of the Creative Commons Attribution License, CC BY 4.0).

In a letter to the editor of the Saudi Journal of Anaesthesia, the use of a similar ultrasound-guided preperitoneal infiltration at the level of the rectus sheath was described as an adjunct to standard analgesia for LC; the authors emphasized the relative simplicity of the technique for experienced clinicians and its potential as an alternative to TAP and ESP blocks.⁵²

The summarized technical recommendations include the use of a high-frequency linear probe, scanning along the midline and paraumbilical lines, choosing a level above the umbilicus, where the posterior rectus sheath is well developed, careful aspiration before injection, slow administration of the solution with continuous visualization of peritoneal “dropping” and adherence to the maximum safe doses of local anesthetics, especially when combining DRSB with TAPB, ESPB, or other fascial plane blocks.^7,15,21

Clinical Outcomes

The evidence for the use of DRSB in LC is currently limited to individual clinical cases and small case series. Despite the small sample size, the available data demonstrate a marked opioid-sparing effect and good tolerability of the procedure. In all reported cases, the use of a DRSB block in LC was associated with the following:^10,52,53 low levels of postoperative pain during the first 24 hours; Minimal opioid requirements (a single low rescue dose or complete avoidance of opioids) absence of documented serious complications related to the block; Good tolerability and technical feasibility under both laparoscopic and ultrasound guidance.

At the same time, caution is warranted given the limited number of reports, absence of randomized controlled trials, and potential risk of complications inherent to interventions in the preperitoneal space (peritoneal perforation, bleeding, systemic local anesthetic toxicity).^24,54

Synthesis of Current Evidence

The body of evidence reviewed in this manuscript demonstrates a clear difference in the maturity and certainty of data available for classical RSB and DRSB. For classical RSB, multiple randomized controlled trials and several systematic reviews consistently support its ability to reduce early postoperative pain and opioid consumption after laparoscopic cholecystectomy, particularly in single-incision procedures and when incorporated into multimodal analgesic protocols.^{5,20,27,33,34,55}

Nevertheless, the magnitude of benefit is not uniform across studies. While several investigations reported superior analgesia and lower opioid requirements compared with standard care, other randomized trials found outcomes comparable to port-site infiltration or alternative regional techniques.^{20,32,35–38,41,47} These discrepancies likely reflect differences in surgical approaches, timing of block administration, multimodal analgesic regimens, outcome definitions, and study design. Therefore, the current evidence supports RSB as an effective component of multimodal analgesia, but not as a universally superior technique.

In contrast, the evidence supporting DRSB remains preliminary. Current knowledge is derived almost exclusively from anatomical studies, technical reports, case reports, and small case series.^{7,10–12,21,51–53} Although these publications suggest a potential role for controlling peritoneum-related pain and reducing opioid requirements, the absence of controlled comparative studies precludes definitive conclusions regarding efficacy, safety, and clinical indications. Consequently, DRSB should currently be regarded as an investigational technique requiring further validation (Table 1).

Table 1.

Representative Clinical Studies Evaluating Rectus Sheath Block in Laparoscopic Cholecystectomy

Study	Design	Sample Size	Intervention	Comparator	Main Findings
Aboelsuod et al20	RCT	80	Bilateral RSB	Intraperitoneal + wound infiltration	Reduced morphine requirements
Kamei et al27	RCT	75	Bilateral RSB in SILC	SILC or standard LC	Lower early postoperative pain
Fu et al28	Dose-finding study	24	Bilateral RSB	None	Defined ED50 and ED95 for ropivacaine
Fu et al29	RCT	58	RSB + butorphanol	RSB + sufentanil	Lower visceral pain and PONV
Jeong et al33	RCT	200	Preoperative RSB	Postoperative RSB	Lower opioid consumption
Gupta et al34	RCT	75	Bilateral RSB	Intraperitoneal LA or control	Lowest opioid use and pain scores
Saxena et al35	RCT	80	Bilateral RSB + subcostal TAP block	Port-site infiltration	Lower opioid consumption and pain scores
Kitamura et al36	RCT	62	Bilateral RSB	Umbilical infiltration	No significant differences
Wu et al37	RCT	180	TAPB + RSB	TAPB or infiltration	Similar pain outcomes
Izwan et al38	RCT	138	TAP + RSB	Port-site infiltration	Lower opioid consumption
Kim et al39	RCT	40	Bilateral RSB	Control	Reduced early postoperative pain
Selvi et al40	Retrospective	67	SIPB + bilateral RSB	OSTAP block	Lower tramadol consumption
Yoon et al41	RCT	88	TAP + RSB	Bilateral TAP block	No additional analgesic benefit
Karaarslan et al42	RCT	189	OSTAP + RSB	Control	Lower pain and improved QoR-15
Ramkiran et al43	RCT	61	OSTAP + RSB	OSTAP or infiltration	Lowest tramadol consumption
Mo et al44	RCT	49	EOI + bilateral RSB	TAP + bilateral RSB	Lower opioid use and improved recovery
Gangadhar et al46	RCT	70	EOIB + RSB	Port-site infiltration	Reduced analgesic requirements and pain scores
Manıcı et al47	Retrospective	44	Bilateral RSB	Bilateral ESPB	Similar opioid consumption and pain scores
Marrone et al10	Case report	1	DRSB	None	Feasible with excellent analgesia
Petroni et al52	Case report	1	DRSB	None	Excellent analgesia without additional opioid requirements

Discussion

The evidence synthesized in our review confirms that RSB is an effective component of multimodal analgesia for LC, primarily by reducing somatic pain at the umbilical and accessory port sites, decreasing opioid consumption, and improving the quality of recovery within the first 12–24 h after surgery. These findings are consistent with the results of a recent systematic review and meta-analysis by Jeffries et al, which demonstrated a statistically significant reduction in pain intensity during the first 2–12 h following abdominal procedures and a reduction in 24-hour morphine equivalent consumption in patients receiving RSB compared with standard analgesia.⁵⁵

The results of individual randomized trials in LC generally demonstrate a moderate yet clinically appreciable analgesic effect of RSB compared with port-site infiltration with local anesthetic or opioid-based systemic analgesia alone: reduced pain intensity at rest and on coughing, decreased analgesic requirements, better early mobilization, and higher patient satisfaction scores.^34,56 A comprehensive systematic review by Abdildin et al also showed that RSB reduces postoperative pain intensity and opioid consumption in patients undergoing various abdominal procedures, although the effect is most pronounced during the early postoperative hours.⁵

At the same time, the available data are characterized by substantial heterogeneity in terms of the type of surgery, port level, doses and types of local anesthetics, timing of block administration, and the pain-control strategies used in the control groups. In a number of studies, RSB did not demonstrate superiority over wound infiltration or intraperitoneal administration of local anesthetic, particularly when an adequately aggressive multimodal analgesic regimen was employed in the control group.⁵⁷ In a network meta-analysis that included a broad range of abdominal fascial blocks, it was shown that although RSB is superior to no block, its ranking relative to other techniques remains unstable and the overall quality of evidence is moderate.⁵⁸ This supports the notion that the effectiveness of RSB in LC depends substantially on technical details of its performance and on the context of the surrounding multimodal analgesia.

Comparisons of RSB with other fascial plane blocks indicate that this technique is not less effective and is potentially preferable in certain situations. In a retrospective study by Manıcı et al, RSB was found to be non-inferior to the ESPB with respect to 24-hour opioid consumption after LC, with pain scores and analgesic requirements likewise showing no differences.⁴⁷ According to a meta-analysis by Hamid et al, RSB demonstrates a favorable safety profile and the ability to reduce pain intensity and opioid requirements in patients undergoing various types of laparoscopic procedures, placing it on a par with TAP and QL blocks as a component of ERAS protocols.⁵⁶

In contrast, current PROSPECT recommendations for LC focus primarily on subcostal TAP/OSTAP and ESP blocks, whereas RSB has not been included among the “core” techniques because of the limited volume of high-quality studies specifically on cholecystectomy and the considerable heterogeneity of the available data.³ In the context of these recommendations, the findings of our review indicate that RSB may be considered as an alternative or adjunct to the recommended blocks, particularly in situations where ESP or TAP blocks are technically challenging (obesity, spinal deformities, limited feasibility of lateral access) or when there is a need for targeted analgesia of the periumbilical ports.

Studies evaluating the combined fascial plane blocks deserve particular attention. A randomized controlled trial by Yoon et al showed that combining TAPB with RSB in LC results in lower pain scores and reduced opioid consumption compared with TAP block alone, supporting an additional contribution of RSB to the control of somatic pain at the umbilical port site.⁴¹ Combining RSB with other anterolateral blocks (TAPB, OSTAP, EOIB) within a multimodal analgesic regimen allows more precise targeting of different components of postoperative pain and contributes to a reduction in overall opioid exposure.^46,59 Our review confirms that it is the multimodal approach including RSB, rather than an isolated regional technique, that has the greatest potential for optimizing recovery.

A recent trend is the emergence of the concept of DRSB or preperitoneal RSB, which involves the injection of local anesthetic into the interfascial plane between the posterior rectus sheath and peritoneum. Anatomical and ultrasound studies by Fusco et al demonstrated a fundamentally different spread pattern of injectate with DRSB compared with classical RSB, with formation of a V-shaped cleft in the preperitoneal space and a potential effect on peritoneal branches.⁷ Isolated clinical reports, including that of Marrone et al in a patient after LC, indicate a pronounced analgesic effect of DRSB with a reduction in both somatic and, probably, peritoneal components of pain.⁵³ Additional reports on preperitoneal block in LC and other anatomical studies suggest a possible relationship between this technique and transversalis fascia block, which further fuels the discussion on the mechanisms by which DRSB influences visceral pain.^10,53

Despite the appealing concept of DRSB as a “bridge” between classical RSB and blocks targeting the peritoneum and posterior abdominal wall, the current evidence remains very limited and is represented mainly by isolated clinical case reports and small series. This does not allow definitive conclusions to be drawn regarding its true role in LC, particularly in view of the hypothetical rather than proven mechanism of its effect on visceral pain, and the conclusions of some anatomical studies about an “anatomical mismatch” between the expected area of blockade and the innervation zones of the gallbladder. Therefore, DRSB should currently be regarded as a promising experimental technique, and its use should be restricted to centers with a high level of ultrasound expertise and within the framework of clinical studies.

Importantly, the current level of evidence is insufficient to support incorporation of DRSB into routine perioperative analgesic pathways or ERAS protocols for laparoscopic cholecystectomy. Before such recommendations can be made, adequately powered randomized controlled trials demonstrating reproducible clinical benefit, safety, and superiority or non-inferiority compared with established regional techniques are required.

Safety issues related to RSB and DRSB are crucial for integrating these techniques into ERAS standards. A systematic review and meta-analysis by Hamid et al did not identify a substantial increase in the incidence of serious complications with RSB; however, reports of hematomas, peritoneal perforation, and potentially dangerous systemic toxic reactions to local anesthetics in the context of fascial plane blocks mandate caution, especially in patients with coagulopathy and those receiving antithrombotic therapy.⁵⁶ Guidelines on bleeding risk with peripheral nerve blocks emphasize the need for an individualized assessment of the benefit-risk ratio, taking into account block depth, the presence of major vessels, and the feasibility of compression in the event of a hematoma.⁶⁰ Given that, in DRSB, the needle is advanced directly into the preperitoneal space, the theoretical risk of intra-abdominal injury is higher than with classical RSB, which further limits the appropriateness of routine use of this technique without adequate training and standardization.

Clinical Take-Home Message

Current evidence supports ultrasound-guided RSB as a useful component of multimodal analgesia for laparoscopic cholecystectomy, particularly for reducing early postoperative somatic pain and opioid consumption. The greatest benefit appears to be observed in single-incision procedures and when RSB is incorporated into combined fascial plane block strategies. However, superiority over optimized local infiltration techniques has not been consistently demonstrated. Therefore, selection of RSB should be individualized according to surgical approach, available expertise, and institutional analgesic protocols. In contrast, DRSB should currently be regarded as an investigational technique pending validation in adequately powered comparative studies.

Limitations

This narrative review has several limitations related to the available evidence on RSB and DRSB, and the design of the review itself. The most recent systematic review and meta-analysis by Jeffries et al, which included randomized studies of RSB in various abdominal procedures, demonstrated only a moderate, albeit statistically significant, opioid-sparing effect, and reduction in postoperative pain intensity against a background of pronounced clinical and statistical heterogeneity.⁵⁵ Similar conclusions regarding protocol heterogeneity, small sample sizes, different technical modifications of RSB, and concomitant analgesic regimens were drawn in the broader meta-analysis by Abdildin et al, which included patients undergoing different types of abdominal surgery.⁵ Accordingly, the data on LC summarized in this review are based predominantly on small single-center studies with heterogeneous multimodal analgesia protocols, which limits the possibility of formulating strict, universally applicable recommendations.

The evidence for DRSB is currently limited. Only isolated clinical observations (case reports) and small case series of DRSB use in LC and other procedures on the anterior abdominal wall have been published, which have shown encouraging results in terms of pain control and low opioid requirements, but do not allow assessment of long-term effectiveness, rare complications, or impact on long-term outcomes. An additional limitation is the lack of standardized nomenclature and a unified description of the target interfascial plane, as illustrated by publications in which the same technique is described either as a “deep rectus sheath block” or as a variant of an “anterior transversalis fascia block”.^15,16

Furthermore, most studies have focused on short-term endpoints (VAS scores, opioid consumption, length of hospital stay), whereas data on long-term outcomes, the incidence of chronic postoperative pain, and the impact of RSB/DRSB on ERAS-oriented metrics (time to mobilization, return to usual activity, and quality of recovery) remain fragmented. Finally, even with a favorable safety profile of ultrasound-guided RSB/DRSB, the potential risk of intra-abdominal complications and systemic local anesthetic toxicity must be considered, as highlighted by a large retrospective series and expert reviews on fascial plane blocks of the anterior abdominal wall.^24,54

Future Research Directions

In view of the above limitations, future studies should aim to improve the quality and external validity of evidence based on RSB in LC. The primary task was to conduct large multicenter randomized controlled trials comparing RSB (as monotherapy and in combination with other anterior abdominal wall blocks) with contemporary standards of multimodal analgesia, as formulated, in particular, in the PROSPECT recommendations.³ Such studies should employ unified general anesthesia protocols, standardized pain assessment tools, and clearly defined, clinically relevant endpoints, including quality of recovery, time to discharge, incidence of nausea/vomiting, and chronic postoperative pain.

A promising direction is further investigation of combined regional analgesia regimens in which RSB is combined with TAPB, OSTAP, SIPB, and EOIB to achieve optimal control of both somatic and peritoneally mediated pain. Existing data already indicate that such strategies may provide a more pronounced reduction in pain intensity, an opioid-sparing effect, and improvements in the quality of recovery and respiratory mechanics (QoR-15, mechanical power of ventilation) compared with the isolated use of RSB or simple port-site infiltration. Further studies should clarify the optimal combinations of blocks, doses, and volumes of local anesthetics, as well as the impact of these strategies on functional and economic endpoints.

With regard to DRSB, priority should be given to prospective anatomical, imaging, and clinical studies that would allow an unambiguous description of the target interfascial plane, the pattern of local anesthetic spread, and the correlation between the sonographic appearance and the clinical effect. It would be appropriate to combine clinical studies with CT/MRI to validate the hypothesis of a possible effect of DRSB on retroperitoneal interfascial planes and, consequently, on the peritoneally mediated component of pain.

Conclusions

Rectus sheath block appears to be a safe and useful component of multimodal analgesia for laparoscopic cholecystectomy, particularly for reducing early postoperative somatic pain and opioid consumption. The strongest evidence is available for single-incision laparoscopic cholecystectomy, whereas findings in standard multi-port laparoscopic cholecystectomy are more heterogeneous. Evidence for robotic-assisted laparoscopic cholecystectomy remains limited, and extrapolation of current findings to robotic procedures should be made with caution.

From a clinical perspective, RSB may be considered when enhanced postoperative analgesia and opioid-sparing strategies are desired, particularly in SILC. In contrast, deep rectus sheath block should currently be regarded as an investigational technique. Although preliminary reports suggest potential benefits, available evidence is insufficient to support its routine incorporation into perioperative analgesic pathways or ERAS protocols. At present, DRSB should be considered only within research settings or prospective clinical studies. Future high-quality comparative trials are needed to better define the role of both techniques across different laparoscopic approaches.

Funding Statement

The authors declare that no financial support has been received for the research and/or publication of this article.

Data Sharing Statement

Data sharing is not applicable to this article, as no new data were created or analyzed in this study.

Consent for Publication

Informed consent was not required as this study does not involve human participants.

Author Contributions

All authors made a significant contribution to the work reported, in the conception, study design, execution, acquisition of data, analysis and interpretation; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as potential conflicts of interest.