Preliminary study of ultrasound-guided ilioinguinal-iliohypogastric nerve block in performing low ligation of the spermatic vein

Abstract

Background

Varicocele is the most prevalent condition in andrology. Current microscopic surgical techniques have demonstrated precise efficacy and are associated with numerous advantages. However, anesthesia protocols vary considerably across institutions, and achieving rapid recovery has become a major focus of research. Precision nerve block anesthesia represents a growing trend in the evolution of anesthetic techniques for varicocele surgery. The application of ultrasound (US)-guided ilioinguinal and iliohypogastric nerve blocks during low ligation of the spermatic vein, along with innovative anesthetic strategies, facilitates the performance of this procedure as ambulatory surgery—marking a novel advancement in the field. This paper aimed to evaluate the safety, convenience and efficacy of US-guided ilioinguinal-iliohypogastric nerve block (ILNB) in performing low ligation of the spermatic vein, and the novel anesthetic approach for low ligation of the spermatic vein as an ambulatory surgery was introduced.

Methods

Sixty-nine patients diagnosed with varicocele were enrolled in this study from March 2021 to August 2021, and all patients underwent low ligation of the spermatic vein. The patients were randomly divided into the conventional anesthesia group (CA: spinal anesthesia) or ILNB group. The ILNB group underwent real-time US guidance to examine the area around the ilioinguinal nerve (deep iliac circumflex artery) and the transverse abdominal muscle plane. When the effects of anesthesia were insufficient, sufentanil was administered intravenously as a supplementary anaesthesia. All surgeries were performed under a microscope by the same surgical group. The demographic characteristics, visual analogue scale (VAS) scores, recovery speed (duration until discharge postoperative period), postoperative adverse events, and medical costs in each group were recorded.

Results

Twenty-one patients received conventional anesthesia, while Forty-eight patients received the novel anesthesia method. There was no significant difference in demographic characteristics between the two groups. All patients achieved full recovery, and no postoperative adverse events, including bleeding, haematoma, or surgical site infection, were observed in any of the groups. Compared with those in the CA group, patients in the ILNB group had comparable postsurgical VAS scores, and the hospital expenses were lower.

Conclusions

Patients in the ILNB group under US guidance were successfully anesthetized according to the requirements for undergoing microscopic low ligation during varicocele surgery. This novel method was proven to be both safe and effective and merits widespread application. US-guided ILNB for low ligation of the spermatic vein was considered “ambulatory surgery”. Compared with previous “ambulatory surgeries” under spinal anesthesia, the length of hospital stay was shorter for patients undergoing low ligation of the spermatic vein under ILNB: it was also safe and reliable and more precise, and the cost was lower. In addition to the advantages of significantly lower medical costs, this approach can shorten the hospitalization duration and save medical resources.

Highlight box.

Key findings

• This study focuses on ultrasound (US)-guided ilioinguinal and iliohypogastric nerve blocks during low ligation of the spermatic vein.

What is known and what is new?

• Microsurgical varicocelectomy under a microscope is an important method for treating varicocele, and improving anesthesia methods is a key factor in accelerating postoperative recovery for these patients.

• US-guided precise nerve block techniques represent a novel anesthesia approach.

What is the implication, and what should change now?

• Precise local nerve block anesthesia under US guidance satisfied the anesthesia requirement for performing microscopic low ligation of varicocele surgery, and this method was proven to be both safe and effective and merits widespread application.

Introduction

Primary varicocele is common in urological diseases, and the incidence rate is approximately 10–15% in young adults. Patients often suffer from scrotal swelling and pain, which can lead to male infertility by reducing the quality of semen (1). The indications to remove a varicocele include relief of pain, reducing the risk of testicular atrophy, and treating or preventing infertility (2). There are many clinical treatments for varicocele, and surgical interventions are often needed to improve semen quality and reduce clinical symptoms if other factors are excluded. At present, the mainstream surgical methods include traditional open surgery, laparoscopic high ligation and microscopic low ligation (3). Based on the surgical approach, local anatomy, surgical trauma and clinical short- and long-term results, the technique of ligation of the spermatic vein under a microscope is characterized by more careful dissection, less trauma, less postoperative adverse events, less relapse and rapid recovery; however, most patients still suffer from the disadvantages of general anesthesia or spinal anesthesia (4), including systemic inflammatory status, oxidative stress, delayed awakening, nausea, vomiting, whole spinal anesthesia and abnormal spinal nerve block. At the same time, a longer hospital stay, greater cost and heightened perioperative anxiety, such as anxiety and fear, are associated with this technique. In particular, concerning the method of anesthesia, the anxiety subscores of patients who underwent general anesthesia were found to be markedly higher than those of patients who underwent regional anesthesia (5).

In recent years, some scholars have performed local anesthesia or nerve block (6,7), their researches have demonstrated that patients got local anesthesia or nerve block anesthesia experienced comparable pain relief, lower medical cost, shortened hospital stay compared with that getting general anesthesia (8-10). However, these methods are mainly carried out based on theoretical anatomical locations, which aren’t precise enough, when anatomical variations occur, satisfied anesthetic effect cannot be obtained, thus supplementary anesthesia or an extended scope of anesthesia is often required. Based on the concepts of rapid rehabilitation, precise anesthesia and analgesia technology, the combination of ultrasound (US)-guided regional anesthesia, comprehensive analgesia technology and microsurgery technology, a surgical model of “ambulatory surgery” for varicocele operations with an US-guided precise regional anesthesia technique was proposed and tested. We present this article in accordance with the STROBE reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-289/rc).

Methods

Patients

Sixty-nine patients with unilateral varicocele who visited the Department of Urology from March to August 2021 were enrolled in the present study. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the medical ethics committee of The Second Affiliated Hospital, Army Medical University (No. 2021-study-105-01) and informed consent was obtained from all patients.

Inclusion criteria

(I) Patients with perineum or testicular discomfort and edema exhibited clinically significant symptoms, and these symptoms had substantially impaired their quality of life; conservative treatment was ineffective, and other causes were ruled out. (II) Patients with at least three semen tests revealed abnormalities. (III) Patients in which US revealed grade I, II or III varicocele with a significant decrease in testosterone levels, excluding other diseases. (IV) Patients in which the volume of affected testicular decreases by more than 20% in comparison with that of the healthy side. (V) Patients older than 18 years. (VI) Patients who were able to fully understand the doctor’s instructions and the possible risks of regional anesthesia or spinal anesthesia.

Exclusion criteria

(I) Patients with varicocele diagnosed by US or physical examination as grade I, but without significant symptom or getting relief with medication. (II) Patients with recurrent varicocele. (III) Patients with grade II varicoceles that improved with medication. (IV) Patients with abnormal blood coagulation function or serious basic diseases who were unable to tolerate surgery. (V) Patients with a past history of inguinal surgery. (VI) Patients who were allergic to amide local anesthetic. (VII) Patients with bilateral varicoceles. (VIII) Patients with a haematoma or skin infection in the inguinal region. (IX) Patients with a history of lumbar surgery.

Group

The patients were randomly assigned to each group according to a random number table. All participants were informed of the advantages and risks of each anesthesia method in detail and were divided into the conventional anesthesia (CA) or ilioinguinal-iliohypogastric nerve block (ILNB) group randomly, and informed consent was obtained. The demands of patients selecting another group after being informed the study will be satisfied.

Operative procedure for the ILNB group

Abdominal wall fat thickness was measured in all patients. Under US (linear array probe, 6–18 MHz, Figure 1), the deep iliac circumflex artery and transverse abdominal muscle space were used as anatomical markers. Moreover, 60 mg ropivacaine and 200 mg lidocaine in 20 mL of mixture were injected around the deep iliac circumflex artery and the plane of the transverse abdominal muscle to observe drug diffusion via US (Figure 2). The entire transverse abdominal muscle surface was intermittently examined to determine drug diffusion according to the extent of swelling of the surrounding tissue (Video 1). After 5 minutes, for patients with visual analogue scale (VAS) scores ≥5, 5 µg of sufentanil was injected intravenously, and 0.2 mg of dexmedetomidine + 50 mL of normal saline was infused via a mechanical infusion pump at a rate of 5 mL/h. For patients with thick abdominal wall fat in the inguinal region, anesthetics were administered at the inner ring of the inguinal canal under US guidance to block the peripheral nerve of the spermatic cord and reduce discomfort. After anesthesia, the skin (approximately 2–3 cm long), subcutaneous tissue and aponeurosis of the external oblique muscle in the groin area were cut, the cremaster muscle and internal and external fascia of the spermatic cord were opened, the thickened spermatic cord vein was identified, the arteriovenous and lymphatic vessels were carefully distinguished under the microscope, and the spermatic vein was ligated and cut. The operative region was pressed by a salt bag (weighted 500 mg) for 4 hours to help reliving discomfort of post-operation.

Figure 1.

Probe position and orientation.

Figure 2.

Ultrasound image of the precise nerve block technique. Red arrow: puncture needle; blue arrow: deep iliac circumflex artery; yellow arrow: ilioinguinal nerve on the surface of the transverse abdominal muscle; green arrow: inferior iliac nerve; purple arrow: intestinal contents.

Video 1.

Download video file ^{(12.3MB, mp4)}

Anesthesia procedure steps.

Operative procedure for the CA group

Patients in the CA group underwent conventional spinal anesthesia. Anesthesia was performed by an experienced anesthetist who administered ropivacaine (AstraZeneca AB, 20–25 mg) at the puncture site (L3–L4 or L2–L3, usually 8–9 cm long) prior to surgery. After anesthesia, surgery was performed as described for the ILNB group. For patients with a VAS score ≥5, 5 µg of sufentanil was injected intravenously, and 0.2 mg of dexmedetomidine + 50 mL of normal saline was infused by a mechanical infusion pump at a rate of 5 mL/h.

Outcome assessment

Demographic information, including age and body mass index (BMI), was collected. Preoperative and operative variables, including the varicocele side, varicocele grade, duration of anesthesia and surgery, were recorded. Complications such as bleeding, hematoma, local anesthetic poisoning, local hematoma, puncture site infection, nerve injury (pain, numbness) and incision infection related to the surgery were evaluated. Additionally, the duration until discharge and VAS pain scores at the 1st, 2nd and 4th hours postoperative period were recorded. In addition, the total medical expense and the medical cost for anesthesia were compared between the groups.

VAS pain scores

A VAS was used at 1, 2 and 4 hours after the operation. Patients with postoperative VAS scores greater than 3 points were given one oral lefetamine oral analgesic agent. The patients resumed a normal diet after the operation, and sandbags were continually used outside the hospital for 2–4 hours. The patients were recommended to rest for 2–3 days.

Statistical analysis

The sample size was estimated by power analysis, which was based on the data obtained in the early stage, it was estimated ILNB group led to 35% decrease (δ) in the time to discharge, while the deviation (s) was estimated to be 35%, the power (β) was set to be 90% and the α level was 0.05, putting into the formula $n=2{\left[\frac{\left(t_{\alpha }+t_{\beta }\right)s}{\delta }\right]}^2$, $n=2{\left[\frac{\left(19.6+1.28\right)\times 0.35}{0.35}\right]}^2$. Based on these, a sample size greater than or equal to 21 in each group seems to be appropriate. Statistical analyses were performed using SPSS software, version 18.0 (SPSS Inc., Chicago, IL, USA). Numerical data was compared using the independent-samples t-test. For categorical data, it was analysed using the Chi-squared test. P<0.05 was used to indicate statistical significance.

Results

The CA method was used for 21 patients, while the novel anesthesia method was used for 48 patients. There was no significant difference in demographic characteristics between the two groups (Table 1). All patients achieved full recovery, and no postoperative adverse events, including bleeding, haematoma, or surgical site infection, were observed in any of the groups. The hospital stay was shorter and recovery was faster in the ILNB group (Table 2). Compared with those in the CA group, patients in the ILNB group had comparable postsurgical VAS scores. There was no significant difference in the proportion of patients who needed to use sufentanil or dexmedetomidine, resulting in a significantly lower medical cost. There was no significant difference in operation time or anesthesia time between the two groups (Table 3).

Table 1. Demographic characteristics.

Demographic characteristics	CA group	ILNB group	P value
Age (years)	23±3	22±2	0.43
BMI (kg/m2)	23.42±1.47	21.32±1.68	0.57
Varicocele side	21	48	0.49
Left	17	41
Right	4	7
Grade of varicocele	21	48	0.44
I	3	5
II	5	9
III	13	34

Data are presented as mean ± standard deviation or n. BMI, body mass index; CA group, conventional anesthesia group; ILNB group, ilioinguinal-iliohypogastric nerve block group.

Table 2. Time and postoperative adverse events.

Surgical indicators	CA group	ILNB group	P value
Duration of anesthesia (min)	33±3	31±4	0.67
Duration of surgery (min)	32±3	31±2	0.58
Time to discharge (hours)	7±1	4±2	0.048
Bleeding	0	0	<0.001
Haematoma	0	0	<0.001
Incision infection	0	0	<0.001
Anesthetic poisoning	0	0	<0.001
Puncture site infection	0	0	<0.001
Nerve injury	0	0	<0.001

Data are presented as mean ± standard deviation or n. CA group, conventional anesthesia group; ILNB group, ilioinguinal-iliohypogastric nerve block group.

Table 3. VAS score and cost.

VAS score and cost	CA group	ILNB group	P value
VAS score (points)	4±2	5±1	0.22
1st hour	5±1	5±1	0.12
2nd hour	4±1	3±1	0.24
4th hour	2±1	2±1	0.11
Supplementary anaesthesia	4	8	0.73
Cost in anesthesia (Chinese Yuan)	3,245±376	546±75	0.01
Total cost (Chinese Yuan)	7,848±490	3,478±159	0.02

Data are presented as mean ± standard deviation or n. CA group, conventional anesthesia group; ILNB group, ilioinguinal-iliohypogastric nerve block group; VAS, visual analogue scale.

Discussion

Varicocele ligation has a well-documented efficacy on improving abnormal semen quality and testicular pain caused by varicocele (8-10), but traditional surgical methods require spinal anesthesia or general anesthesia. Some scholars have attempted to use regional nerve blocks, but this method involves estimating the needle entry point by examining the body surface (11). The effect of this method is often poor due to anatomical variation. Hence, the efficacy of this method remains uncertain. The spermatic vein is mainly innervated by the inferior iliac nerve, the ilioinguinal nerve and the reproductive branch of the genitofemoral nerve. These nerves branch mainly downwards towards the periphery, between the internal oblique muscles and the transverse abdominal muscles, and below the aponeurosis of the external oblique muscles (12). The main branch is located on the inner side of the anterior superior iliac spine and around the deep iliac circumflex artery. The external oblique muscle, internal oblique muscle, transverse abdominal muscle (13), deep circumflex iliac artery and surrounding US imaging allows clear visualization of anatomical structures (14). Under the guidance of US, the structures of nerves and blood vessels can be observed directly, and the positive aspects or advantages of US-guided nerve block or fascial block, as a more precise and safe technique, the spread of local anesthetics after injection, direct control of needling, the spread of LA, and avoidance of intravascular injection (artery in the nearness of nerves), enhances the success rate of nerve block localization, lowers the risk of postoperative adverse events, and decrease the need for local anesthetics.

However, variations in the ilioinguinal and iliohypogastric nerves from patient to patient may lead to incomplete nerve block (15). Therefore, the use of sufentanil combined with dexmedetomidine is beneficial for improving the anesthetic effect. Moreover, our study showed that the main factors affecting the anesthetic effect and the operation time were the subcutaneous fat thickness of the abdominal wall fat and the grade of the varicocele. The thicker the abdominal wall fat of the inguinal region is, the more difficult it is to identify the nerve structures (16), the more difficult it is to accurately deliver anesthetic agents into the fascial plane. In the ILNB group of our study, patients with a high BMI experienced prolonged anesthesia duration by 15% compared to those with a low BMI. The patients got unsatisfied local anesthesia felt pain, and can’t well cooperate with doctor during surgery, we doctors need to administer additional anesthetic, which led to prolonged operation duration. In contrast, the more obvious the varicocele is, the easier it is to find the nerve structures under the microscope, and the shorter the surgical time, for patients with none-obvious varicocele, doctors need to take more time to locate the nerve structures, which results in an extended surgical duration.

With precise US-guided nerve block, this method can be used to ligate the varicocele under a microscope. Compared with the CA method, this method is characterized by minimal invasiveness, rapid recovery, and cost-effectiveness and no ureter-related discomfort. This study showed that there was no need to change the method of anesthesia in patients, and none of the patients experienced postoperative complications requiring readmission to the hospital for further treatment. Rather, this method allowed patients to leave the hospital the same day of the surgery; it was highly effective with minimal discomfort, it did not affect their diet or activities, and the whole hospital stay averaged only 4 to 5 hours; however, for patients who received CA, their recovery time was much longer. These results are highly significant for novel coronavirus pneumonia. The corona virus pneumonia was one of the main reasons why we conducted this study. We believe that our novel approach could help facilitate broader adoption of ambulatory surgery models. Compared with that in the past, the length of hospital stay was shorter for the ILNB group under US guidance (classifying as an “ambulatory surgery”) than it was for the ILNB group under the previous spinal anesthesia. Therefore, the use of US guidance in procedures can significantly reduce healthcare costs.

The technique of US-guided nerve block has been widely used in clinical practice, and the effect of anesthesia has been clinically demonstrated. Based on anatomy and imaging, the use of precise nerve block under US has made some clinical operations easier and less invasive, and ligation under a microscope has also been proven to be characterized by minimal trauma, a low recurrence rate, few complications and quick recovery. In this study, we effectively combine these methods, and this study is the first to test this novel approach in the treatment of varicocele. The final results confirmed its notable benefits in promoting recovery and minimizing costs.

This study also had several limitations. First, the postoperative follow-up time was insufficient, long-term effects were not studied, The research background of this article was during the most severe period of the novel coronavirus, when the exposure time in the hospital was required to be minimized, and after the subsequent epidemic situation improved, further sample enrollment was not possible. After the control of the novel coronavirus epidemic, patients were no longer limited to a certain hospital. Second, the sample size is small and lacks the support of more data. This is the attempt of our next work, including comparing the “precise nerve block” with the classic local anesthesia.

Conclusions

Precise local nerve block anesthesia under US guidance satisfied the anesthesia requirement for performing microscopic low ligation of varicocele surgery, and this method was proven to be both safe and effective and merits widespread application. However, more multicentre, large-sample clinical studies should be performed in the future.

Supplementary

The article’s supplementary files as

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the medical ethics committee of The Second Affiliated Hospital, Army Medical University (No. 2021-study-105-01) and informed consent was obtained from all patients.

Data Sharing Statement

Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-289/dss

tau-14-10-2995-dss.pdf ^{(57.2KB, pdf)}

DOI: 10.21037/tau-2025-289