Thoracic wall fascial plane blocks: a narrative review for breast, thoracic, and cardiac surgery

Abstract

Thoracic wall surgery is frequently associated with severe and multifactorial postoperative pain, including somatic, visceral, and neuropathic components. Inadequate pain control can impair respiratory function, delay mobilization, prolong hospitalization, and contribute to the development of chronic postsurgical pain. Traditional techniques, such as thoracic epidural and paravertebral blocks, have shown efficacy; however, their complexity and risk profiles limit their widespread use. In recent years, ultrasound-guided fascial plane blocks have gained prominence because of their favorable safety profile, ease of use, and suitability for incorporation into multimodal analgesia strategies. This narrative review provides an overview of the anatomical rationale, mechanisms of action, and clinical applications of fascial plane blocks of the thoracic wall, namely the interpectoral and pectoserratus, serratus anterior, erector spinae, and parasternal intercostal plane blocks. These techniques have demonstrated promising results in breast, thoracic, and cardiac surgeries, with analgesic outcomes comparable to those of conventional methods in many studies. Although evidence suggests a favorable safety profile and potential for opioid-sparing effects, further high-quality research is required to confirm their efficacy across diverse patient populations and surgical contexts. As clinical experience and data continue to accumulate, thoracic wall fascial plane blocks are emerging as important components of modern perioperative pain management strategies.

Background

Postoperative pain after thoracic wall surgery is often severe and multifactorial. It may involve somatic components related to surgical incisions, visceral components due to the manipulation of intrathoracic organs, placement of drains, or neuropathic pain arising from intercostal nerve injury [1]. Inadequately controlled pain can impair pulmonary function, delay mobilization, and contribute to postoperative respiratory and hemodynamic complications, ultimately compromising the overall quality of recovery. Acute postoperative pain is a well-recognized risk factor for the development of chronic postsurgical pain, which can affect 20–60% of patients undergoing thoracic procedures [2, 3]. Historically, regional anesthesia techniques for thoracic wall analgesia have included thoracic epidural anesthesia (TEA), thoracic paravertebral blocks (TPV), and intercostal nerve block. However, their routine use has been limited by technical complexity, risk of complications, and inconsistent success rates [4]. Over the last decade, the advent and widespread adoption of ultrasound-guided fascial plane blocks have transformed thoracic wall analgesia practices. These blocks are increasingly recognized as valuable tools in multimodal analgesia pathways, including enhanced recovery after surgery (ERAS) protocols and procedure-specific postoperative pain management (PROSPECT) guidelines [5–7]. Fascial plane blocks of the thoracic wall have gained popularity because of their favorable safety profile, ease of administration, and potential to reduce opioid consumption. Techniques such as interpectoral (IPP), interpectoral plane and pectoserratus plane (IPP + PSP), serratus anterior plane (SAP), erector spinae plane (ESP), and superficial (S-PIP) and deep parasternal intercostal plane (D-PIP) blocks have shown promising results across a range of surgical settings [8].

In this narrative review, we aimed to provide an overview of the thoracic wall fascial plane blocks, with a particular focus on their anatomical basis, mechanism of action, and clinical applications in breast, thoracic, and cardiac surgeries. Herein, we summarize the current evidence and highlight the evolving practices that are reshaping the field of perioperative analgesia.

Anatomy of the thoracic wall

Within the paravertebral region, the branches project anteriorly toward the sympathetic chain. The thoracic sympathetic chain runs longitudinally along the vertebral column and communicates with the thoracic spinal nerves via the rami communicantes. These sympathetic pathways play a critical role in transmitting visceral pain from the thoracic organs, including the heart, lungs, and pleura, to the central nervous system. Through these connections, nociceptive input from the thoracic viscera is integrated with somatic structures, explaining the referred pain phenomena often observed in clinical settings.

Many studies focusing on the innervation and anatomy of the thorax have described the course of intercostal nerves and their branches [9]. It has been repeatedly emphasized that after emerging from the neural foramen, the thoracic nerves enter the paravertebral region and give rise to dorsal rami. The thoracic dorsal rami provide three distinct branches—medial, intermediate, and lateral (with occasional variations in nomenclature)—that contribute to the cutaneous innervation of the paraspinal dorsal region and motor supply to the associated muscles, similar to the lumbar region [10]. From this point, the intercostal nerve continues its course between the internal and innermost intercostal muscles [9, 11]. Near the midaxillary line, it gives rise to the lateral cutaneous branch, which pierces the internal and external intercostal muscles, as well as the serratus anterior muscle, before emerging superficially. This branch then divides into anterior and posterior divisions that innervate the lateral thoracic wall. The intercostal nerve continues its course between the two intercostal muscle layers and near the sternum, pierces the internal intercostal and pectoralis major muscles to emerge at the surface. It terminates as the anterior cutaneous branch, which divides into medial and lateral divisions that innervate the parasternal region (Fig. 1).

Fig. 1.

Schematic illustration of the thoracic wall anatomy

The efficacy and appropriate indications of any fascial plane block depend on multiple factors, including the extent of spread, specific nerves and branches likely to be blocked, and the presence of adhesions, lesions, or surgical alterations [12]. Therefore, predicting outcomes requires a high level of anatomical knowledge and considerable clinical experience and must be tailored to the patient’s specific condition, such as the presence of adhesions or altered anatomy. For example, awareness that the superficial and deep fascia of the pectoralis major muscle merges superiorly with the clavipectoral and deltopectoral fascia, inferiorly with the rectus abdominis and external oblique muscle fascia around the level of the 5th and 6th ribs, laterally with the superficial fascia of the serratus anterior muscle, and medially with the sternum provides important guidance [13]. Such details can help clinicians anticipate the potential extent of anterolateral thoracic blocks, identify areas where these blocks may be insufficient, and determine the combinations of techniques that may overcome these limitations.

Another important muscle group in which the continuity of fascial planes plays a critical role is the rhomboid muscle [14]. The superior and inferior limits of the rhomboid intercostal block not only determine the inherent restrictions of this technique but also transform it into an advantage by providing a safer and more predictable alternative to blocks such as the erector spinae plane block, which is often less predictable [15–17]. Understanding fascial compartments also guides clinicians in shaping realistic expectations regarding the extent and efficacy of each block. In this section, we will not elaborate on every specific location where a muscle fascia transforms into an aponeurosis or merges with another fascia, as this paper is not a purely anatomical review, and such details are beyond its scope. However, we emphasize that clinicians should reconsider their expectations of fascial plane blocks and base their rationale for combining different blocks on anatomical continuity. Another crucial point is whether the nerves lying within the fascial planes are primarily somatic or motor. This distinction must be carefully considered to avoid selecting blocks for inappropriate indications.

Ultrasound-guided fascial plane blocks of the thoracic wall

Ultrasound-guided fascial plane blocks of the thoracic wall target distinct anatomical planes to provide coverage for anterior, lateral, and posterior chest wall innervation, as summarized in the block distribution and indications illustrated in Fig. 2.

Fig. 2.

Schematic illustration of thoracic wall fascial plane blocks. The illustration shows the sensory coverage and primary indications of commonly used thoracic wall blocks. The color-coded overlay highlights the approximate dermatomal distribution and clinical scenarios where each block is applicable

Interpectoral and interpectoral + pectoserratus plane blocks

The IPP block, formerly known as PECS I [18], was originally described by Blanco et al. [19] and targets the fascial plane between the pectoralis muscles. Also described by Blanco et al. [20], the IPP + PSP block, formerly known as PECS II [18], targets the fascial plane between the pectoralis minor and serratus anterior muscles. For the IPP + PSP block, two injections are performed. The first is similar to the IPP technique, between the pectoralis major and minor muscles at a depth of 1–3 cm, while the second is performed at the anterior axillary line at the level of the fourth rib, between the pectoralis minor and serratus anterior at a depth of 3–6 cm. With the transducer placed at the midclavicular level and angled inferolaterally, the axillary vessels and second rib are identified, then the probe is moved laterally to visualize the pectoralis minor, serratus anterior, and ribs. Approximately total 30 mL of local anesthetic is deposited to complete the block (Fig. 3).

Fig. 3.

Schematic illustration of the injection sites for local anesthetic during ultrasound-guided interpectoral and interpectoral-pectoserratus plane blocks. In the interpectoral block, the local anesthetic is injected between the pectoralis major and pectoralis minor muscles. In the interpectoral + pectoserratus plane block, local anesthetic is first injected between the pectoralis major and minor muscles (step 1), and then between the pectoralis minor and serratus anterior muscles (step 2)

The IPP block targets the lateral and medial pectoral nerves, whereas the IPP + PSP block extends coverage to the intercostobrachial nerve (T2), lateral branches of the T3-T6 intercostal nerves, and long thoracic nerve, providing broader analgesia of the anterolateral chest wall. Both blocks are primarily used for perioperative pain control in breast and chest wall procedures. They can be routinely used as adjuncts to general anesthesia for mastectomy, lumpectomy, and other breast cancer surgeries [21, 22]. They can also be used for esthetic breast procedures, as they help alleviate chest tightness associated with implant placement [23, 24]. These blocks are particularly useful when thoracic epidural or paravertebral blocks are contraindicated or technically difficult.

Serratus anterior plane block

Also described by Blanco et al. [25], the SAP block targets either the superficial or the deeper planes adjacent to the serratus anterior muscle, at the level of the fourth or fifth ribs, in the axillary region (Fig. 4). The superficial approach targets the plane between the latissimus dorsi and the serratus anterior muscles, whereas the deep approach targets the plane underneath the serratus anterior muscle, between this muscle and the underlying rib. Studies show mixed evidence regarding to the efficacy of both approaches [26, 27]. Nevertheless, both approaches seem to cover the lateral cutaneous branches of the intercostal nerves from T2 to T9, long thoracic nerve, and thoracodorsal nerve. The transducer is placed in the mid-axillary line by first identifying the fourth and fifth ribs, then oriented in the coronal plane and slightly tilted posteriorly. At this level, the latissimus dorsi is superficially visualized, with the serratus anterior muscle lying deep over the ribs. Advancing the probe posteriorly helps delineate the fascial plane between these two muscles, which serves as the injection target. The SAP block is achieved with a linear probe (1–4 cm depth) and 20–30 mL of local anesthetic deposited in the fascial plane [25].

Fig. 4.

Schematic illustration of the injection site for local anesthetic during a serratus anterior plane block

Erector spinae plane block

The ESP block, originally described by Forero et al. [28], is a fascial plane block that has gained popularity over the last few years due to its versatility. In the thoracic area, where this block was originally described and is most commonly performed, the most superficial layers consist of the skin and subcutaneous tissue, followed by the trapezius and the rhomboid muscles. Deep to this lies the erector spinae muscle group (iliocostalis, longissimus, and spinalis), which originate from the sacrum, iliac crest, and vertebral processes and extend longitudinally along the spine. The fascial plane targeted for the ESP block lies between the erector spinae muscles and the tips of the transverse processes of the thoracic vertebrae. The transducer is placed in a paramedian sagittal orientation approximately 2 cm lateral to the spinous processes to visualize the transverse process. Using an in-plane cranial-to-caudal approach, the needle is advanced until it contacts the transverse process. Correct placement is confirmed by injecting a small test dose, with spread observed deep to the erector spinae muscle and superficial to the transverse process, followed by administration of 20–30 mL of local anesthetic (Fig. 5).

Fig. 5.

Schematic illustration of an ultrasound-guided erector spinae plane block

After exiting the intervertebral foramen, the spinal nerves are divided into the dorsal and ventral rami. The ventral rami continue anteriorly to form the intercostal nerves, while the dorsal rami supply the posterior thoracic wall. Local anesthetic deposited in the erector spinae plane spreads both cranio-caudally and anteriorly, potentially reaching the ventral and dorsal rami, rami communicants, and variably the paravertebral and epidural spaces. This spread reliably involves the dorsal rami and provides consistent posterior thoracic wall analgesia. However, the spread to the ventral rami and paravertebral space is highly variable and often incomplete, leading to erratic coverage of the anterolateral thorax [29]. This variability explains why the ESP block may provide excellent analgesia for some thoracic procedures but insufficient coverage for others, particularly those relying heavily on ventral rami blockade. Although its precise mechanism of action remains a subject of ongoing investigation, several theories have been proposed. These include the spread of local anesthetic to the dorsal rami and paravertebral space, systemic absorption, immunomodulatory effects, and analgesia mediated through the innervation of fascial layers [30].

Parasternal intercostal plane blocks

The parasternal region is located on the anterior chest wall, immediately lateral to the sternum. The most superficial layers consist of the skin and subcutaneous tissue, followed by the pectoralis major muscle, which is the largest muscle in the anterior chest wall. The intercostal muscles (external and internal) extend toward the sternum and deep to the pectoralis major. Beneath these is the transversus thoracis muscle, which originates from the inner surfaces of the 2nd to 6th costal cartilages and inserts into the posterior surface of the sternum. The sternum is located medially, the costae and intercostal spaces are located laterally and inferiorly, and the pleura and lungs are located in the deepest plane, which constitutes the boundaries of the region. The internal mammary artery (IMA) and vein run approximately 1–2 cm lateral to the sternum between the internal intercostal and transversus thoracis muscles [31, 32]. The superficial and deep parasternal blocks aim to anesthetize the anterior branches of the Th2-6 intercostal nerves. The S-PIP block involves injection of a local anesthetic between the pectoralis major and intercostal muscles, whereas the D-PIP block is performed between the internal intercostal and transversus thoracis muscles (Fig. 6). The characteristics of all the included blocks are summarized in Table 1, highlighting the key distinctions in technique, anatomical targets, and clinical applications.

Fig. 6.

Schematic illustration of the injection sites for local anesthetic during ultrasound-guided superficial and deep parasternal intercostal plane blocks

Table 1.

Regional anesthesia techniques: anatomical target, indications, considerations, and complications

Block	Anatomical target/injection plane	Indications	Considerations	Potential complications
IPP + PSP Block	Between pectoralis major and minor and pectoralis minor and serratus anterior muscles	Breast surgery with axillary dissection, subpectoral implant surgery, minimally invasive cardiac surgery, VATS	Covers pectoral with axillary regions, easy to perform	Hematoma, LA toxicity
SAP Block	Between serratus anterior muscle and ribs	Breast surgery, thoracotomy, VATS rib fractures, Minimally invasive cardiac surgery	Easy to perform	Hematoma, LA toxicity, pneumothorax
ESP Block	Fascia deep to erector spinae muscle over the transverse processes	Thoracic surgery, mastectomy, VATS, rib fractures, cardiac surgery	Less invasive, easy catheterization, shallow learning curve	Rare pneumothorax, LA toxicity
S-PIP and D-PIP Blocks	S-PIP: between pectoralis major and intercostal muscles; D-PIP: between intercostal and transversus thoracis muscles	Sternotomy, cardiac surgery, breast surgery	Superficial: easier and safer; Deep: closer to internal mammarian artery, heart and pleura	Vascular puncture, LA toxicity

Abbreviations: IPP + PSP Interpectoral and pectoserratus plane, SAP Serratus anterior plane, ESP Erector spinae plane, LA Local anesthetic, VATS Video-assisted thoracic surgery, S-PIP Superficial parasternal intercostal plane, D-PIP Deep parasternal intercostal plane

Clinical applications and block selection

Breast surgery

The ERAS and PROSPECT guidelines advocate multimodal analgesia with regional plane blocks to reduce opioid use during breast surgery. Given the complex innervation of the anterolateral chest wall and axilla, the IPP, IPP + PSP, SAP, and ESP blocks have become key techniques, each selected for its specific anatomical coverage and procedural advantages.

Interpectoral plane block and pectoserratus plane block

The IPP block was first applied in lumpectomy, implant placement, and subpectoral reconstruction [19], whereas the IPP + PSP block added axillary and intercostal coverage for more extensive breast surgery [20]. A Cochrane review [33] showed that IPP, IPP + PSP, SAP, and ESP blocks provided marginally better early postoperative pain relief, although this was below the minimum clinically important difference (MCID) [34]. The IPP + PSP block did not significantly lower 24‑h opioid use but extended the time to the first analgesic by 123 min without increasing postoperative nausea and vomiting (PONV), indicating non-inferior analgesia with fewer risks than the TPV block. A meta-analysis of 18 RCTs found a non-significant trend toward opioid sparing and no differences in pain, PONV, or rescue analgesia between the IPP + PSP and TPV blocks, except for a small subgroup advantage in patients without axillary dissection [34, 35].

Subsequent trials comparing the IPP + PSP block with other blocks confirmed their comparable efficacy and added clinical benefits. Lewis et al. [36] demonstrated that IPP and IPP + PSP blocks are non‑inferior to other peripheral techniques (SAP, TPV, ESP blocks) for hospital length‑of‑stay (1.31 vs. 1.17 days; p = 0.15) and opioid use (17.9 vs. 26.1 mg; p = 0.17). A review by Fernández [37] further showed that IPP + PSP block lowers 24‑h pain scores by 39–55%, delays the first analgesic request by 5 h, and reduces opioid consumption by 59% compared to systemic analgesia.

In conclusion, cohort data, meta-analyses, and systematic reviews confirm that IPP and IPP + PSP blocks provide analgesic efficacy comparable to or even superior to both peripheral and central techniques, while offering rapid, low-risk application and consistent opioid-sparing, making them practical candidates for a ‘gold standard’ in breast surgery.

Serratus anterior plane block

The SAP block has emerged as a simple and versatile regional anesthesia technique, primarily applied in thoracic surgery, but also reported in the literature for breast surgery. In a Cochrane review [33], the SAP block matched the TPV block in analgesia for both rest and movement at 2 and 24 h, as well as in recovery quality, time to first analgesic, 24‑h opioid use, and PONV rates, albeit with low certainty of evidence. Qian et al. [38] found no significant difference in the 24‑h total analgesic consumption or pain scores on the first postoperative day. Notably, the SAP block extended the time to the first rescue analgesic by 1.37 h compared with the TPV block.

Both superficial and deep approaches to the SAP block have been previously described. Singh et al. [39] reported no clinically meaningful differences between these techniques in terms of 24-h oral morphine equivalents, pain scores, time to rescue analgesia, or PONV. Accordingly, either approach may be selected based on the practitioner’s preference.

In conclusion, the SAP block provides analgesia comparable to the TPV block, with no meaningful differences between the superficial and deep approaches, making it a practical option for selected breast surgeries, although further high-quality studies are warranted [33, 38, 39].

Erector spinae plane block

The ESP block has been extensively studied, and TPV blocks have been shown to provide comparable- analgesia and have pronounced benefits in both simple and complex breast procedures. In a Cochrane review [33], the ESP block matched the TPV block in reducing both resting and dynamic pain at 2 and 24 h postoperatively, with comparable 24‑h opioid use, time to first analgesic, recovery quality, and PONV rates. The efficacy of the ESP block extends beyond simple breast procedures into complex reconstructions: in latissimus dorsi flap cohorts, it shortened hospital stay by 24 h and reduced intraoperative opioid use by 23 mg morphine milligram equivalent [40], and in a larger mastectomy series, it delivered the shortest postoperative stay (30.6 h) and lowest day 1 opioid consumption (10 mg vs. 18.75 mg epidural and 20 mg systemic) [41].

Collective clinical data underscore the efficacy of ESP blocks across a range of breast surgery populations [42, 43]. Macdonald et al. [44] reviewed 68 studies and found that the ESP block generally provides superior pain relief compared to no block and has comparable efficacy to other regional techniques. The rapid administration of the ESP block, its safety profile, and ease of learning make it an attractive option for reducing postoperative pain, opioid use, and healthcare costs. Shaikh et al. [45] further showed that while ESP block and SAP block yield similar pain scores, ESP block extends the time to first analgesic administration and avoid the higher 24‑h morphine consumption and increased rescue analgesic requirements seen with the SAP block, without compromising patient satisfaction or PONV rates.

In conclusion, the ESP block provides analgesia comparable to that of the TPV block in both simple and complex breast surgeries while reducing hospital stay, opioid use, and rescue doses. Its rapid, low-risk application and superior duration compared to the SAP block establish its role as a key component of multimodal breast surgery pain protocols and a reliable alternative to neuraxial techniques.

Thoracic surgery

Thoracic operations—open thoracotomy, Video-assisted thoracoscopic surgery (VATS), and rib fixation—are highly painful. Although TPV block and TEA have traditionally been used to cover the brachial plexus, T₂–T₆ intercostals, and cervical plexus, ultrasound-guided fascial plane blocks now deliver precise, effective, and lower-risk analgesia [46].

Interpectoral plane block and pectoserratus plane block

IPP and IPP + PSP blocks are routinely paired with other fascial plane blocks to achieve comprehensive multilayered thoracic analgesia [46–48]. In a randomized controlled trial of 40 adults undergoing lobectomy, segmentectomy, or wedge resection, IPP + PSP block reduced 24-h fentanyl consumption (49.0 ± 44.2 µg vs. 104.0 ± 72.7 µg) and reduced 4-h rescue analgesia rates (20% vs. 75%, p < 0.05), with lower numeric rating scale (NRS) scores at 1 and 4 h but no 24-h difference, demonstrating improved intraoperative stability and early postoperative pain control [49]. Furthermore, Yıldırım et al. [50] found that IPP + PSP block and TPV block produced similar static and dynamic pain scores over 24 h after VATS, although IPP + PSP block tended toward higher morphine use (22.49 ± 15.85 mg vs. 14.60 ± 12.18 mg; p = 0.073), and required more rescue analgesia (92.3% vs. 69.2%; p = 0.038) while offering better intraoperative hemodynamics; a case report [51] showed combined IPP + PSP block and SAP block achieved effective “awake” VATS analgesia (median NRS = 2, no rescue in 24 h, mean postoperative NRS = 2). This suggests that combined IPP + PSP block and SAP blocks offer a practical and effective option for both intra- and postoperative pain management in minimally invasive thoracoscopic procedures.

In conclusion, IPP + PSP block reduces opioid use and pain scores in lobectomy, VATS, and other thoracic procedures; provides analgesia comparable to that of TPV block with superior hemodynamic stability; and when combined with a serratus anterior plane block, enables effective awake VATS analgesia.

Serratus anterior plane block

The SAP block has gained increasing attention as a safe and technically straightforward alternative to traditional thoracic analgesic techniques. Makkar et al. [52] found TPV block significantly prolonged time to first rescue analgesia versus SAP block (mean difference [MD], 0.6 h) and reduced 24‑h oral morphine milligram equivalents by 9.73 mg, though TPV block carried risks of pleural puncture (2 cases), hematoma (5 cases), and injection‑site pain (6 cases), whereas SAP block had no block‑related complications. Following these extensive comparisons, Qian et al. [38] found no significant difference in 24‑h total analgesic consumption between the SAP block and TPV block (MD, 2.36 mg), with comparable pain scores at all time points and a significantly shorter time to first rescue analgesia for the SAP block, indicating that the SAP block matches the TPV block in efficacy while offering a simpler, faster, and lower-risk technique. Moreover, continuous SAP block has been evaluated in lung transplant recipients. In a series of 14 lung transplant patients, Luo et al. [53] reported that a continuous SAP block reduced the first-week- cumulative morphine equivalents (11.95 mg) with no catheter-related adverse events, underscoring its safety and efficacy as a fascial plane block for post-transplant acute pain control.

In conclusion, the current evidence indicates that the SAP block provides effective postoperative analgesia with opioid-sparing benefits comparable to those of established thoracic regional techniques. Combining efficacy with shorter procedure times, lower complication rates, and practical ease, it has emerged as a highly viable option in multimodal analgesia protocols for thoracic surgery.

Erector spinae plane block

The ESP block has emerged as an effective and minimally invasive alternative to thoracic paravertebral and epidural techniques, combining reliable analgesia with a strong safety profile. In their systematic review and meta-analysis, Koo et al [54]. Compared the ESP block with systemic analgesia in thoracic surgery patients and found a 17.49 mg reduction in 24-h opioid consumption and significant decreases in resting and dynamic pain scores, although some studies suggest that these effects may partly reflect systemic local anesthetic absorption [55]. Moorthy et al. [56] randomized patients receiving TPV block and ESP catheterization and reported higher QoR-15 scores at 24 and 48 h with ESP block (118 vs. 110; 131 vs. 120) despite similar pain scores, opioid use, respiratory metrics, and complication rates, indicating that the ESP block may enhance subjective recovery without compromising analgesic efficacy.

To further elucidate the regional block comparisons in minimally invasive thoracic surgery, researchers have directly compared various fascial plane approaches to VATS. In a randomized controlled trial, Finnerty et al. [57] compared ESP and SAP blocks in patients who underwent VATS. At 24 h postoperatively, the QoR‑15 score was significantly higher in the ESP group (114 vs. 102; p = 0.02). However, the higher pleurectomy rate in the SAP arm may have confounded these results, warranting a cautious interpretation of their real-world applicability. Subsequently, Taketa et al. [58] evaluated the ESP block versus the TPV block in patients with VATS and found that resting NRS pain scores were significantly lower with the TPV block, whereas dynamic pain scores did not differ between the groups. The TPV block also achieved more extensive parasternal dermatomal spread than the ESP block. These findings suggest that the TPV block may provide superior early resting analgesia and better parasternal coverage than the ESP block during the immediate postoperative period. Additionally, Muhammad et al. [59] found that the ESP block provided statistically superior analgesia, a mean 19.73 mg reduction in oral morphine consumption (below the 30 mg MCID), and a longer time to first analgesic request than the SAP block, with no increase in opioid-related adverse events or block complications [60]. Finnerty et al. [57] noted higher Comprehensive Complication Index scores with SAP block, while Hassan et al. [61] showed that ESP block better preserved forced vital capacity and forced expiratory volume in 1 s at 24 h postoperatively. Collectively, these data indicate that ESP and SAP blocks share comparable efficacy and safety profiles, without one technique clearly outperforming the other.

In conclusion, this extensive body of literature indicates that ESP, SAP, and TPV blocks and TEA deliver comparable postoperative analgesia, opioid sparing, and hemodynamic stability, while the simplicity, faster recovery, and shorter stays of ESP blocks make them particularly advantageous.

Cardiac surgery

Postoperative pain is increasingly recognized as a silent epidemic, with a substantial impact on the quality of life of patients undergoing cardiac surgery [62]. The primary causes of pain are surgical incisions, rib injuries, extraction of the IMA and saphenous vein, sternal retraction, and the use of chest tube drains [63]. ERAS cardiac guidelines recommend perioperative multimodal analgesia [7]. Recently, the 2024 update emphasized, with moderate-quality evidence and expert consensus, that anterior chest wall regional anesthesia techniques should be considered part of multimodal strategies [64]. A recent meta-analysis of nearly 59,000 patients confirmed that opioid-sparing anesthesia incorporating multimodal analgesia and regional blocks, such as the ESP and parasternal blocks, significantly reduced perioperative opioid use, shortened ICU stay and duration of mechanical ventilation, and improved postoperative pain outcomes without increasing the mortality rate [65].

Pain mechanisms in minimally invasive cardiac surgery differ substantially from those in full sternotomy [66]. Mini-thoracotomy pain is primarily driven by intercostal nerve compression or stretching, rib spreading, subperiosteal trauma, intercostal muscle disruption, and multiple pleural/chest tube insertions. These factors generate a predominantly lateral and posterolateral pain pattern, often accompanied by neuropathic features due to intercostal nerve irritation. In this context, fascial plane techniques, such as ESP and SAP blocks, may provide more anatomically appropriate coverage than parasternal blocks.

Cardiac surgery inherently requires systemic anticoagulation, typically with high-dose heparinization for cardiopulmonary bypass [67]. This limits the use of neuraxial and paravertebral blocks due to the risk of neuraxial hematoma or uncontrolled bleeding. Fascial plane blocks offer a safer alternative because they are performed in compressible, superficial tissue planes that are distant from major vascular or neuraxial structures. Current evidence reports very low rates of bleeding or block-related complications with ESP and S-PIP blocks in fully anticoagulated patients, although high-quality prospective safety data remain limited.

Chronic post-surgical pain affects 30–50% of patients and significantly impacts their long-term quality of life [68, 69]. Despite its clear clinical relevance, data on the effects of fascial plane blocks on CPSP are limited. The ESP block has not shown a consistent reduction in chronic pain at 3–6 months postoperatively [70], and long-term outcomes for parasternal blocks remain largely unexplored. Factors such as sternal instability, neuropathic pain components, graft-harvesting techniques, and prolonged chest tube drainage likely contribute to CPSP, independent of acute analgesic strategy. More robust research is needed to clarify whether fascial plane techniques influence the trajectory of CPSP after cardiac surgery.

Analgesic strategies for cardiac surgery differ substantially between pediatric and adult populations because of anatomical, physiological, and procedural factors. Children undergoing cardiac surgery typically experience higher pain sensitivity, limited communication of pain intensity, and greater vulnerability to opioid-related respiratory depression, making regional techniques particularly valuable for opioid-sparing analgesia [63]. However, smaller thoracic dimensions, thinner fascial planes, and variable ossification of the ribs and sternum may alter local anesthetic spread and require careful dose adjustments to avoid toxicity.

Erector spinae plane block

Multiple trials show that ESP block significantly reduce acute postoperative pain scores and opioid consumption after cardiac surgery, including sternotomy and minimally invasive approaches. ESP blocks are associated with lower pain scores in the first 12–24 h postoperatively, delayed need for rescue analgesia, and reduced opioid requirements compared to standard care or other analgesic regimens, and some studies also report shorter ICU and hospital stays [71–74]. In a network meta-analysis, among the fascial plane blocks, the ESP block was found to be the most effective within the first 24 h postoperatively compared with the control group [75]. However, another meta-analysis reported that the ESP block was not associated with significant reductions in pain, opioid requirements, extubation time, or ICU length of stay [76]. These apparent inconsistencies may be partly explained by variability in local anesthetic spread, as the extent and direction of injectate distribution in ESP block can differ considerably between patients and techniques [30]. Although continuous ESP block may reduce hospital length of stay following minimally invasive cardiac surgery [66, 77], ESP block did not significantly decrease the incidence or severity of chronic postsurgical pain [70].

Superficial and deep parasternal intercostal plane blocks

A recent meta-analysis confirmed the efficacy of the S-PIP block compared to controls in median sternotomy [78]. Additionally, studies have shown that catheters placed in the S-PIP may extend these benefits by up to 48 to 72 h postoperatively [79, 80]. A randomized controlled trial directly comparing S-PIP and D-PIP blocks showed no significant difference in 24-h morphine consumption [81]. Consistently, a prospective observational cohort study reported no significant difference in pain scores between the S-PIP and D-PIP groups at 24 and 48 h [82]. Similarly, in a meta-analysis comparing S-PIP and D-PIP blocks, no significant difference was found in 24-h opioid consumption. Furthermore, dermatomal analyses demonstrated comparable sensory coverage of the anterior thorax, confirming that both techniques provided similar analgesic efficacy [83, 84].

However, recent randomized controlled trials have suggested that parasternal blocks may offer limited clinical benefits in cardiac surgery. One study reported no improvement in early postoperative quality of recovery compared with standard care [85], while another demonstrated that single-shot SPIP blocks with liposomal bupivacaine did not reduce opioid consumption or enhance recovery, indicating that more sustained approaches, such as catheter-based or repeated injection techniques may be required [86].

Cadaveric studies have attempted to delineate the anatomical spread of local anesthetics [87]. One study demonstrated that two-level injections achieved superior spread compared with single-level injections in S-PIP [88]. Another cadaveric analysis at the T3–T4 level, using 20 mL of injectate, showed that D-PIP had a more extensive distribution than S-PIP [31]. More recently, multilevel injection techniques (double or triple injections) have been proposed to improve craniocaudal coverage [89]. However, for drain-related pain below the T6 vertebra, a combination of techniques may be more appropriate such as recto-intercostal plane block [90]. Importantly, cadaveric findings do not always translate into clinical efficacy, and caution is required when extrapolating these results [91].

In summary, both the S-PIP and D-PIP blocks provided comparable analgesic efficacy after cardiac surgery. However, S-PIP offers notable advantages: it is technically simpler, safer, and associated with a lower risk of complications, such as pneumothorax, pericardial injury, or myocardial damage. Importantly, D-PIP carries the risk of internal IMA injury, which is of particular concern during CABG when the IMA is used as a graft. As a deeper block, D-PIP poses compression challenges in the event of vascular injury, thereby increasing the risk of bleeding. Performing these blocks before incision appears more reasonable, as it preserves fascial integrity and allows for the early recognition of potential bleeding. Considering its comparable efficacy and favorable safety profile, a superficial approach is a more pragmatic choice in clinical practice.

General strengths and limitations

This review integrates evidence from RCTs, observational studies, meta-analyses, and cadaveric studies on thoracic, cardiac, and breast surgeries, providing a unified perspective on the performance and clinical relevance of fascial plane blocks. By examining diverse surgical populations and techniques, we highlighted consistent themes such as early postoperative pain reduction, opioid-sparing effects, and favorable safety profiles compared with central neuraxial approaches (Table 2). However, several limitations are common to all three clinical areas. Considerable heterogeneity exists in block techniques, anesthetic volumes and concentrations, injection levels, timing of administration, and multimodal analgesic protocols, which limits direct comparability and weakens the generalizability of pooled findings. Long-term outcomes, including CPSP, functional recovery, and patient-reported outcomes, remain insufficiently studied. Moreover, cadaveric spread patterns provide anatomical insight but do not consistently correlate with clinical efficacy, necessitating cautious interpretation. These shared limitations should be considered when applying current evidence to perioperative analgesia planning.

Table 2.

Thoracic wall fascial plane blocks selection according to surgical type

Surgery	Target area	Blocks	Rationale
Breast surgery	Anterior + lateral thorax: T2–T6	IPP + PSP, SAP, ESP	Breast surgery pain is mainly anterior–lateral; IPP and IPP + PSP provide reliable pectoral, intercostal, and axillary coverage with analgesia comparable to TPVB and fewer risks. SAP offers effective lateral chest analgesia, matching TPVB in early outcomes. ESP provides broader spread with comparable analgesia and reduced opioid use and length of stay
Thoracic surgery	Lateral + posterior thorax: T4–T7	ESP, SAP, IPP + PSP	ESP block provides extensive posterior–lateral spread suitable for incisional and visceral pain components. SAP block is often sufficient for lateral port-site pain. IPP + PSP block may be used in combination with SAP block when additional anterior chest wall coverage is required
Cardiac surgery	Anterior sternum: Th2–T6	S-PIP, D-PIP, ESP	S-PIP and D-PIP blocks effectively target the anterior mediastinal region and provide consistent coverage for sternotomy pain. ESP block may offer additional benefit but its anterior spread can be variable. For MICS or chest tube–related pain, SAP or IPP + PSP may be more appropriate due to targeted lateral and anterior dermatomal coverage

Abbreviations: IPP + PSP Interpectoral and pectoserratus plane, SAP Serratus anterior plane, ESP Erector spinae plane, MICS Minimally invasive cardiac surgery, S-PIP Superficial parasternal intercostal plane, D-PIP Deep parasternal intercostal plane, LA Local anesthetic, VATS Video-assisted thoracic surgery

Recent advances and future perspectives in thoracic wall fascial plane blocks

Recent years have seen the introduction of novel fascial plane blocks in the thoracic region, aimed at achieving wider or more targeted spread and more effective analgesia. A key example is the Serratus Posterior Superior Intercostal Plane (SPSIP) Block, first described by Tulgar et al. [92] in 2023. By depositing local anesthetic between the serratus posterior superior and intercostal muscles, SPSIP block can cover both lateral and dorsal branches of the intercostal nerves. Cadaveric studies demonstrated dye spread from C7–T7, while clinical application produced sensory loss from C3–T10, suggesting extensive coverage across the neck, shoulder, and posterior thorax [93, 94]. Another promising technique is the rhomboid intercostal block, where local anesthetic is injected between the rhomboid major and intercostal muscles [16]. This block has shown effective analgesia for thoracic wall and rib fracture pain, targeting both dorsal rami and lateral cutaneous branches. Similarly, the mid-transverse process to pleura block offers a simplified alternative to the paravertebral block, with injection between the transverse process and pleura, enabling spread into the paravertebral and epidural spaces while minimizing technical difficulty and complications [95]. Collectively, these innovations reflect a growing trend toward versatile, ultrasound-guided thoracic fascial plane blocks that expand options for perioperative analgesia.

In parallel, combined block strategies are increasingly employed to overcome the limitations of single techniques. For instance, bilateral S-PIP block combined with either the ESP block or the recto-intercostal plane block has been shown to provide more comprehensive analgesia after sternotomy, effectively addressing both sternal and drain-related pain [96]. Similarly, multiple injections across different fascial planes (e.g., simultaneous superficial and deep SAP block) or the use of long-acting formulations such as liposomal bupivacaine have been proposed to enhance block duration and efficacy [97, 98]. At the same time, advances in imaging technology are driving block refinement. High-resolution ultrasound and MRI have revealed unexpected spread patterns of the ESP block, supporting the use of multiple low-volume, dermatome-specific injections to optimize coverage [99]. Importantly, when performing combined blocks, clinicians must carefully calculate cumulative local anesthetic doses, favor diluted concentrations, and take precautions against systemic toxicity while also considering anatomical factors that may influence local anesthetic spread [100].

Growing evidence supports the feasibility of fascial plane blocks as the primary anesthetic strategy in selected awake or sedated patients undergoing thoracic, breast, and anterior mediastinal procedures. For thoracoscopic surgery, techniques such as SAP block, ESP block, and the recently described SPSIP block have enabled non-intubated VATS by providing broad thoracic dermatomal coverage with only light-to-moderate sedation, particularly in frail or high-risk patients where general anesthesia poses substantial risks. In breast surgery, combinations of IPP + PSP, SAP block, and S-PIP and D-PIP blocks have allowed completion of radical mastectomy and lumpectomy under sedation [13]. Complementary data from anterior chest wall surgery further strengthen this evidence: bilateral bi-level S-PIP block has been successfully used for awake sternal fixation in patients with cervical spine fractures, offering an alternative when airway manipulation is contraindicated [101]. Additionally, a study demonstrated that combining the recto-intercostal fascial plane block with S-PIP can provide T3–T11 anesthesia for awake subxiphoid pericardial window surgery, expanding the applicability of fascial plane blocks to upper abdominal and subxiphoid interventions in high-risk, sedated patients [102]. Although current evidence is largely based on case reports and small feasibility studies, these findings collectively indicate that well-planned fascial plane block combinations may serve as a viable alternative anesthetic option in awake or sedated patients when general or neuraxial anesthesia is undesirable or hazardous.

Conclusions

Thoracic wall fascial plane blocks have emerged as versatile and effective tools for managing postoperative pain across a spectrum of surgical procedures, including breast, thoracic, and cardiac surgeries. These blocks offer comparable analgesic efficacy to traditional neuraxial techniques while providing a more favorable safety profile and greater technical ease. With growing evidence supporting their role in multimodal analgesia, particularly within the ERAS and PROSPECT protocols, they are now considered integral to contemporary perioperative pain strategies. Future studies should focus on optimizing block combinations, refining catheter-based approaches, and standardizing techniques to improve patient outcomes and reduce opioid dependence.

Abbreviations

TEA

Thoracic epidural anesthesia

TPV

Thoracic paravertebral

ERAS

Enhanced recovery after surgery

PROSPECT

Procedure-specific postoperative pain management

IPP

Interpectoral plane

PSP

Pectoserratus plane

SAP

Serratus anterior plane

ESP

Erector spinae plane

S-PIP

Superficial parasternal intercostal plane

D-PIP

Deep parasternal intercostal plane

IMA

Internal mammary artery

RCTs

Randomized controlled trials

PONV

Postoperative nausea and vomiting

NRS

Numeric rating scale

VATS

Video-assisted thoracoscopic surgery

ICU

Intensive care unit

MCID

Minimum clinically important difference

MRI

Magnetic resonance imaging

SPSIP

Serratus posterior superior intercostal plane

Authors’ contributions

Conceptualization, B.D. and E.T.; methodology, A.D.C, S.A., C.K. and S.T.; investigation, E.T., S.T., S.A., Y.G., H.E., C.K., B.D. and A.D.C.; resources, B.D.; data curation, E.T., C.K., B.D. and A.D.C.; writing—original draft preparation, B.D., C.K., E.T., S.A., S.T., H.E., A.D.C., and Y.G.; writing—review and editing, B.D., C.K., E.T., S.A., S.T., Y.G., A.D.C., and H.E.; project administration, B.D. All authors read and approved the final manuscript.

Funding

This research received no external funding.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.