Identification of the ilioinguinal and iliohypogastric nerves during open inguinal hernia repair: a nationwide register-based study

BACKGROUND

Chronic pain remains prevalent after open inguinal hernia repair and nerve-handling strategies are debated. Some guidelines suggest sparing nerves that are encountered; however, the nerve identification rates are unclear. This study aimed to investigate the nerve identification rates in a register-based nationwide cohort.

METHODS

This study was reported according to the RECORD guideline and used prospective, routinely collected data from the Danish Hernia Database, which was linked with the National Patient Registry. We included patients ≥ 18 years old, undergoing Lichtenstein hernia repair with information on nerve handling of the iliohypogastric and ilioinguinal nerves.

RESULTS

We included 30,911 open hernia repairs performed between 2012 and 2022. The ilioinguinal nerve was identified in 73% of the repairs and the iliohypogastric nerve in 66% of repairs. Both nerves were spared in more than 94% of cases where they were identified. Female patient sex, emergency and recurrence surgery, general anesthesia, medial and saddle hernias, and large defect size all result in lower nerve identification rates for both nerves.

CONCLUSION

The Ilioinguinal nerve was recognized in 73% of cases, while the iliohypogastric nerve was recognized in 66% with almost all identified nerves being spared during surgery. Several pre- and intraoperative factors influenced identification rates of the ilioinguinal and iliohypogastric nerve.

Efficacy and safety of ilioinguinal neurectomy in open tension-free inguinal hernia repair: A meta-analysis of randomized controlled trials

BACKGROUND

There is still controversy surrounding routine ilioinguinal neurectomy in open tension-free inguinal hernia repair.

METHOD

PubMed, Cochrane Library and EMBASE databases were searched for randomized controlled trials of ilioinguinal neurectomy in open tension-free inguinal hernia repair. Revman 5.3 software was used for meta-analysis.

RESULT

Meta-analysis revealed that the incidence of severe pain on the first postoperative day was lower in the ilioinguinal neurectomy group (ING) than in the ilioinguinal nerve preservation group (INPG) [P < 0.0001]. The incidence of no pain in the first month postoperatively [P = 0.0004], the incidence of no pain in the sixth months postoperatively [P < 0.00001], and the numbness incidence in the first month postoperatively [P = 0.001] in the ING was higher than that in the INPG. There was no significant difference in the incidence of severe pain in the first month postoperatively [P = 0.20], the numbness incidence in the sixth postoperative month [P = 0.05], the hypoesthesia incidence in the first [P = 0.15] and sixth [P = 0.85] postoperative months between the two groups.

CONCLUSION

Ilioinguinal neurectomy in open tension-free inguinal hernia repair can better prevent postoperative pain.

Innervation of the scrotum by the anterior division of the obturator nerve - a rare variation

The scrotum is supplied by ilioinguinal, genital branch of genitofemoral, perineal branch of the posterior cutaneous nerve of the thigh and the posterior scrotal branches of the pudendal nerve. We report an extremely rare innervation of the anterior part of the scrotum by the anterior division of the right obturator nerve. The genital branch of genitofemoral nerve did not reach the scrotum. The ilioinguinal nerve did not supply the scrotum. The anterior division of the obturator nerve gave a branch which ascended superomedially in the thigh, crossed superficial to the spermatic cord and communicated with the right ilioinguinal nerve. As it crossed the spermatic cord, it gave a scrotal branch which descended over the spermatic cord and ramified to supply the anterior part of the scrotum. Knowledge of this variation could be important to anaesthesiologists, urologists and surgeons in general.

Ultrasound-guided microwave ablation in the treatment of inguinal neuralgia

Chronic groin pain can be due to a variety of causes and is the most common complication of inguinal hernia repair surgery. The etiology of pain after inguinal hernia repair surgery is often multifactorial though injury to or scarring around the nerves in the operative region, namely the ilioinguinal nerve, genital branch of the genitofemoral nerve, and the iliohypogastric nerve, is thought to be a key factor in causing chronic post-operative hernia pain or inguinal neuralgia. Inguinal neuralgia is difficult to treat and requires a multidisciplinary approach. Radiologists play a key role in the management of these patients by providing accurate image-guided injections to alleviate patient symptoms and identify the pain generator. Recently, ultrasound-guided microwave ablation has emerged as a safe technique, capable of providing durable pain relief in the majority of patients with this difficult to treat condition. The objectives of this paper are to review the complex nerve anatomy of the groin, discuss diagnostic ultrasound-guided nerve injection and patient selection for nerve ablation, and illustrate the microwave ablation technique used at our institution.

Postmortem evaluation of neuromuscular damages more extensive than the surgical intervention area after iliac crest bone graft

Several complications may occur following iliac bone grafting, one of the common sites for autologous bone harvesting. Of these, it is difficult to localize the damage in neurological complications due to the presence of several nerves in a similar distribution area with variations among individuals. To minimize these complications, conventional clinical anatomical studies using normal human cadavers have estimated the theoretical neurological damage area corresponding to the surgical intervention area. We report a case of neuromuscular damage in a 93-year-old woman who had an iliac crest defect after a bone graft, based on the virtual and physical dissections with histological confirmations.In this study, the patient was confirmed to have severe neuromuscular complications with major complications including a hernia protruding through the iliac defect. One of the two ilioinguinal nerves was extracted with the hernia sac through the iliac defect, and its distal part was completely damaged. The iliohypogastric nerve, which was far from the defect foramen, also showed remarkable fibrosis and demyelination, affected by the degeneration of the transversus abdominis muscles.The present anatomical findings show that the area of eventual neuromuscular damage should be estimated to larger than the conventionally predicted area of direct nerve damage, which is usually concomitant with the surgical intervention area.

Is it possible to identify the inguinal nerves during hernioplasty? A systematic review of the literature and meta-analysis of cadaveric and surgical studies

Purpose

Patients who undergo inguinal hernioplasty may suffer from persistent postoperative pain due to inguinal nerve injuries. The aim of this systematic review and meta-analysis was to provide comprehensive data on the prevalence (identification rates), anatomical characteristics, and ethnic variations of the ilioinguinal (IIN), the iliohypogastric (IHN) and the genital branch of the genitofemoral (GNF) nerves.

Methods

The systematic literature search was conducted using the PubMed, Scopus and Web of Science databases.

Results

A total of 26 articles (5265 half-body examinations) were included in this study. The identification rate of the IIN was 94.4% (95% CI 89.5–97.9) using a random-effects model. Unweighted multiple regression analysis showed that study sample size (β = − 0.74, p = .036) was the only statistically significant predictor of lower prevalence. The identification rates of the IHN and GNF was 86.7% (95% CI 78.3%–93.3%) and 69.1% (95% CI 53.1%–83.0%) using a random-effects model, respectively. For those outcomes, a visual analysis of funnel and Doi plots indicated irregularity and provided evidence that larger studies tended to have lower identification rates. In terms of the synthesis of anatomical reference points, there was a large and statistically significant amount of heterogeneity for most outcomes.

Conclusions

The identification rates of the inguinal nerves in our study were lower than reported in literature. The lowest was found for GNF, suggesting that this nerve was the most difficult to identify. Knowledge regarding the anatomy of the inguinal nerves can facilitate their proper identification and reduce the risk of iatrogenic injury and postoperative pain.

Incidence of chronic groin pain following open mesh inguinal hernia repair, and effect of elective division of the ilioinguinal nerve: meta-analysis of randomized controlled trials

PURPOSE

Chronic post-operative groin pain is a substantial complication following open mesh inguinal hernia repair. The exact cause of this pain is still unclear, but entrapment or trauma of the ilioinguinal nerve may have a role to play. Elective division of this nerve during hernia repair has been proposed in an attempt to reduce the incidence of chronic groin pain.

METHODS

We performed a meta-analysis of nine randomized controlled trials comparing preservation versus elective division of the ilioinguinal nerve during this operation.

RESULTS

A substantial proportion of patients having open mesh inguinal hernia repair experience chronic groin pain when the ilioinguinal nerve is preserved (estimated rate of 9.4% at 6 months and 4.8% at 1 year). Elective division of the nerve resulted in a significant reduction of groin pain at 6-months post-surgery (RR 0.47, p = 0.02), including moderate/severe pain (RR 0.57, p = 0.01). However, division of the nerve also resulted in an increase of subjective groin numbness at this time point (RR 1.55, p = 0.06). At 12-month post-surgery, the beneficial effect of nerve division on chronic pain was reduced, with no significant difference in the rates of overall groin pain (RR 0.69, p = 0.38), or of moderate-to-severe groin pain (RR 0.99, p = 0.98) between the two groups. The prevalence of groin numbness was also similar between the two groups at 12-month post-surgery (RR 0.79, p = 0.48).

CONCLUSIONS

Routine elective division of the ilioinguinal nerve during open mesh inguinal hernia repair does not significantly reduce chronic groin pain beyond 6 months, and may result in increased rates of groin numbness, especially in the first 6-months post-surgery.

Surgical experience of laparoscopic retroperitoneal triple neurectomy for a patient with chronic neuropathic inguinodynia

BACKGROUND

Neuropathic inguinodynia following inguinal hernia repair sometimes becomes a disabling disease. We report a case of successful surgical treatment of chronic refractory neuropathic pain after inguinal hernia by laparoscopic retroperitoneal triple neurectomy.

CASE PRESENTATION

A seventy-year-old male who underwent right-side inguinal hernia repair using the Lichtenstein method revisited our hospital with inguinodynia 16 months after surgery. After a thorough assessment, the patient was diagnosed with neuropathic pain based on the following: 1) dermatomal mapping suggested ilioinguinal and iliohypogastric nerve problems, 2) pain was evoked by specific movement, 3) the site of maximum pain was slightly changed at every physical examination, and 4) no evidence of recurrence or meshoma was observed on MRI. Conservative therapies were ineffective. Surgical intervention using laparoscopic retroperitoneal triple neurectomy was performed 4 months after treatment initiation. In the lateral recumbent position, a three-port method was used. The ilioinguinal and iliohypogastric nerves and the genital branch of the genitofemoral nerves were identified and resected. Although a residual nerve emerged from L2/3 toward the inguinal region, the nerve remained in situ. Pain assessment 3h after surgery revealed that pain was decreased but remained. Reoperation involving resection of the residual nerve was performed on the same day. Although another type of mild pain appeared 3 months after surgery, the patient resumed normal life, without any restrictions.

CONCLUSIONS

Laparoscopic retroperitoneal triple neurectomy is useful for treating refractory neuropathic pain. The diagnosis of neuropathic pain via thorough preoperative assessment is vital for procedure success because the procedure would not be effective for other types of pain.

Utility of ultrasound-guided transversus abdominis plane block for day-case inguinal hernia repair

BACKGROUND

The transversus abdominis plane (TAP) block is a regional anesthesia technique that effectively reduces the pain intensity and use of analgesia in abdominal surgery. The aim of this study was to determine the utility of the ultrasound-guided TAP block in improving the efficacy of the ultrasound-guided ilioinguinal/iliohypogastric nerve (IIN/IHN) block for intraoperative anesthesia and postoperative pain control in day-case inguinal hernia repair (IHR).

METHODS

We conducted a descriptive study of patients undergoing elective primary unilateral open IHR. Fifty-nine patients were divided into two groups according to the anesthetic technique used: ultrasound-guided TAP block plus ultrasound-guided IIN/IHN block (TAP group) vs. ultrasound-guided IIN/IHN block alone (IIN/IHN group). The outcome measures were the adequacy of anesthesia during surgery and postoperative analgesia.

RESULTS

Four patients (12.5%) in the TAP group and 10 patients (37.0%) in the IIN/IHN group experienced inadequate anesthesia and needed systemic sedation (P < 0.05). No significant differences in additional local anesthetic volume were found between the two groups. Patients in the TAP group reported lower pain scores at the end of surgery (0.4 ± 0.8 vs. 2.1 ± 2.5, P < 0.01), at 2 hours after surgery (0.8 ± 1.3 vs. 3.0 ± 2.2, P < 0.01), at discharge (1.4 ± 1.2 vs. 4.3 ± 2.2, P < 0.01), and at 24 hours (1.5 ± 1.1 vs. 4.5 ± 2.3, P < 0.01).

CONCLUSIONS

The combination of the TAP and IIN/IHN blocks is associated with better intraoperative anesthesia and lower postoperative pain scores compared with the IIN/IHN block alone.

Successful treatment for patients with chronic orchialgia following inguinal hernia repair by means of meshoma removal, orchiectomy and triple-neurectomy

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Refractory orchialgia following inguinal hernia repair is challenging complication.

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There has been no established surgical treatment for orchialgia.

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We report a case treated by aggressive surgical intervention for orchialgia.

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The detailed preoperative assessment is important to distinguish the sort of pain.

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Triple neurectomy should be considered in patients with neuropathic orchialgia.

Introduction

Orchialgia following inguinal hernia repair is rare complication and still challenging since there has been no established surgical treatment because of complexity of nerve innervation to the testicular area. Herein we report a case of postoperative orchialgia following Lichtenstein repair, which was successfully treated by mesh removal, orchiectomy and triple neurectomy.

Case presentation

A 65-year-old man was referred to our department because of chronic right orchialgia following Lichtenstein hernia repair. He walked with a limp and was unable to walk a long distance. Physical examination revealed the presence of meshoma in the groin area and hypoesthesia in the anterior skin of the right scrotum. His right testis was completely atrophic and located not in the scrotum but in the subcutaneous regions of right groin. He was diagnosed as both neuropathic and nociceptive orchialgia and underwent meshoma removal, triple-neurectomy, and orchiectomy to address these issues. Pathological examination revealed that meshoma was integrated with the structures of the spermatic cord, leading to foreign-body reaction and fibrosis around the genital branch of genitofemoral nerve. The resected right testis was completely-scarred without ischemic changes. Orchialgia disappeared immediately after operation and he was able to walk without a limp.

Discussions

It is important to distinguish between nociceptive and neuropathic orchialgia. Neuroanatomic understanding is essential to guide treatment options. Orchiectomy is an option but should be reserved for refractory cases with evidence of nociceptive pain accompanied by anatomical changes.

Conclusions

Triple neurectomy should be considered in patients with neuropathic orchialgia.