Surgical approaches for pudendal nerve entrapment: insights from a systematic review and meta-analysis.

BACKGROUND: Pudendal nerve entrapment (PNE) is an underdiagnosed condition affecting a spectrum of pelvic functions, primarily pain, as outlined by Nantes diagnostic criteria. Although numerous surgical decompression techniques are available for its management, consensus on efficacy and safety is lacking. This study conducts a systematic review and meta-analysis to assess the efficacy and complication rates of the main surgical decompression techniques. METHODS: A comprehensive literature search was conducted in PubMed®, Embase®, Web of Science®, and ClinicalTrails.gov® on 19th of April 2023. Initial screening involved title and abstract evaluation, with subsequent retrieval and assessment of abstracts and full-text articles. Studies assessing pain outcomes before and after surgical release of the pudendal nerve were included. Studies without full-text, focusing on diagnostic methods or with outcomes relating solely to LUTS, digestive symptoms, or sexual dysfunction, were excluded. Risk of bias assessement was conducted using the National Institute of Health (NIH) Study Quality Assessment tool. Studies were categorized based on three surgical techniques: perineal, transgluteal, and laparoscopic transperitoneal. Random-effects meta-analysis with subgroup analysis were used. Meta-regression analyses were conducted to investigate the influence of covariates on the observed outcomes. RESULTS: Nineteen studies, comprising 810 patients, were included. The overall significant pain relief rate across all techniques was estimated at 0.67 (95% CI 0.54 to 0.78) with considerable heterogeneity (I2 = 80.4%). Subgroup analysis revealed success rate for different techniques: laparoscopic (0.91, 95% CI 0.64 to 0.98), perineal (0.69, 95% CI 0.52 to 0.82), and transgluteal (0.50, 95% CI 0.37 to 0.63). The laparoscopic technique exhibited a complication rate of 16.0%. Meta-regression indicated that patient age and median follow-up significantly influenced outcomes. CONCLUSION: While comparing surgical techniques is challenging, this meta-analysis highlights important outcome differences. The laparoscopic technique appears most promising for pain improvement. However, the study also emphasizes the need for further robust, long-term research due to significant heterogeneity across studies and prevelent risk of bias. PROSPERO database: CRD42023496564.

Nerve transfer for restoration of lower motor neuron-lesioned bladder, urethral and anal sphincter function. Part 4: Effectiveness of the motor reinnervation.

In pilot work, we showed that somatic nerve transfers can restore motor function in long-term decentralized dogs. We continue to explore the effectiveness of motor reinnervation in 30 female dogs. After anesthesia, 12 underwent bilateral transection of coccygeal and sacral (S) spinal roots, dorsal roots of lumbar (L)7, and hypogastric nerves. Twelve months postdecentralization, eight underwent transfer of obturator nerve branches to pelvic nerve vesical branches, and sciatic nerve branches to pudendal nerves, followed by 10 mo recovery (ObNT-ScNT Reinn). The remaining four were euthanized 18 mo postdecentralization (Decentralized). Results were compared with 18 Controls. Squat-and-void postures were tracked during awake cystometry. None showed squat-and-void postures during the decentralization phase. Seven of eight ObNT-ScNT Reinn began showing such postures by 6 mo postreinnervation; one showed a return of defecation postures. Retrograde dyes were injected into the bladder and urethra 3 wk before euthanasia, at which point, roots and transferred nerves were electrically stimulated to evaluate motor function. Upon L2-L6 root stimulation, five of eight ObNT-ScNT Reinn showed elevated detrusor pressure and four showed elevated urethral pressure, compared with L7-S3 root stimulation. After stimulation of sciatic-to-pudendal transferred nerves, three of eight ObNT-ScNT Reinn showed elevated urethral pressure; all showed elevated anal sphincter pressure. Retrogradely labeled neurons were observed in L2-L6 ventral horns (in laminae VI, VIII, and IX) of ObNT-ScNT Reinn versus Controls in which labeled neurons were observed in L7-S3 ventral horns (in lamina VII). This data supports the use of nerve transfer techniques for the restoration of bladder function.NEW & NOTEWORTHY This data supports the use of nerve transfer techniques for the restoration of bladder function.

Combined Decompression of Pudendal and Inferior Cluneal Nerves for Entrapment Neuralgias Using Transperitoneal Robotic Laparoscopy: Feasibility and Our Four-Step Technique.

OBJECTIVE: To demonstrate the feasibility of a combined decompression of pudendal and inferior cluneal nerves for entrapment syndrome using a transperitoneal robotic laparoscopy. DESIGN: Demonstration of our 4-step technique with narrated video footage. SETTING: Pudendal and inferior cluneal neuralgias caused by an entrapment syndrome are both responsible for perineal pain [1]. Although more precise data are lacking, these 2 neuralgias are frequently associated. Failure of surgical pudendal nerve decompression in the early 2000 has driven to discover the entity of a potential entrapment syndrome of the posterior cutaneous nerve of the tight and its inferior cluneal branches between the ischium bone and the sacrotuberous ligament [2]. The corresponding neuralgia is responsible for a neuropathic pain to a more posterior part of the perineum and the thigh, without any neurovegetative symptom. In case of failure of medical treatment, surgery can be proposed using an invasive open transgluteal approach as a standard treatment [3-5]. INTERVENTIONS: Transperitoneal robotic laparoscopy for a mini-invasive releasing of both pudendal and inferior cluneal nerves, following a 4-step technique: 1. Opening of the peritoneum between the external iliac vessels and the umbilical ligament 2. Dissection of the internal iliac and pudendal arteries up to the pudendal nerve 3. Section of the sacrospinous ligament and release of the pudendal nerve 4. Section of the sacrotuberous ligament and release of the inferior cluneal nerve CONCLUSION: Previously, pudendal and inferior cluneal neuralgias have been managed with an invasive open transgluteal surgery. Here, we demonstrate the feasibility of a mini-invasive transperitoneal robotic laparoscopy, with a standardized 4-step surgical technique. VIDEO ABSTRACT.

Anatomical Relationships of the Sciatic Nerve and Pudendal Nerve to the Ischial Spine as They Exit the Greater Sciatic Foramen.

OBJECTIVE: Deep gluteal syndrome is a clinical condition in which discomfort may arise due to the pathoanatomy of the subgluteal space. We conducted an anatomical exploration to categorize the relationship of the piriformis muscle, sciatic nerve (SN), and pudendal nerve (PN) to the ischial spine (IS) and sacrospinous ligament. METHODS: We analyzed 22 cadavers. The piriformis muscle, SN, and PN were exposed through either a transgluteal approach or a gluteal flap. The relationship of the neural structures to the IS, sacrospinous ligament, and ischial bone as they exit the greater sciatic foramen was observed, and the exit zones were classified as zone A, medial to the IS (entirely on sacrospinous ligament); zone B, on the IS; and zone C, lateral to the IS (entirely on ischial bone). RESULTS: The SN was observed either in zone B or zone C in all specimens. The PN was found to be in either zone A or zone B in 97.6% of specimens. The most common combinations were SN in zone B and PN in zone A (type I), and SN in zone C and PN in zone B (type II). CONCLUSIONS: The results from this study show clear anatomical differences in the SN-PN relationship, which may play a role in pain seen in deep gluteal syndrome. Moreover, classification of the SN-IS and PN-IS relationships described in this article will help describe different pathologies affecting the deep gluteal area.

First case-series of robot-assisted pudendal nerve release: technique and outcomes.

OBJECTIVE: Pudendal Nerve Entrapment (PNE) may determine chronic pelvic pain associated with symptoms related to its innervation area. This study aimed to present the technique and report the outcomes of the first series of robot-assisted pudendal nerve release (RPNR). PATIENTS AND METHODS: 32 patients, who were treated with RPNR in our centre between January 2016 and July 2021, were recruited. Following the medial umbilical ligament identification, the space between this ligament and the ipsilateral external iliac pedicle is progressively dissected to identify the obturator nerve. The dissection medial to this nerve identifies the obturator vein and the arcus tendinous of the levator ani, which is cranially inserted into the ischial spine. Following the cold incision of the coccygeous muscle at the level of the spine, the sacrospinous ligament is identified and incised. The pudendal trunk (vessels and nerve) is visualized, freed from the ischial spine and medially transposed. RESULTS: The Median duration of symptoms was 7 (5, 5-9) years. The median operative time was 74 (65-83) minutes. The median length of stay was 1 (1-2) days. There was only a minor complication. At 3 and 6 months after surgery, a statistically significant pain reduction has been encountered. Furthermore, the Pearson correlation coefficient reported a negative relationship between the duration of pain and the improvement in NPRS score, - 0.81 (p = 0.01). CONCLUSIONS: RPNR is a safe and effective approach for the pain resolution caused by PNE. Timely nerve decompression is suggested to enhance outcomes.

Clinical usefulness of quantitative thermal sensory testing in the diagnosis and surgical treatment of women with pudendal neuropathy.

BACKGROUND: The aim of this study, conducted on women with pudendal neuropathy, was to evaluate the usefulness of quantitative thermal sensory testing (QTST) in the diagnosis, surgical management, and prognosis of the disease. METHODS: The study was conducted on 90 women with pudendal neuropathy. QTST in pudendal nerve sensory innervation territory was realized before and more than 24 months after operative pudendoscopy on most patients. Cold and warm thresholds were evaluated together with a search for qualitative anomalies. The diagnostic value of QTST was assessed by comparing baseline data with normative values previously derived from 41 presumably healthy women. The effect of operative pudendoscopy on thermal sensitivity was tested by comparing preoperative and postoperative measurements. Assessment of the long-term prognostic value of QTST was based on "surgical success" defined as a VAS pain level less than 4 at least 2 years after surgery. RESULTS: The existence of qualitative anomalies, like anesthesia, allodynia, dysesthesia, radiation, and dyslocalization, was clearly indicative of pudendal neuropathy. The presence of after sensation and "out of limit" values of skin temperature and cold detection threshold were also helpful for diagnosing the disease. Surgery reduced qualitative anomalies but had no positive effect on QTST thresholds. QTST measurements had no real prognostic value but other factors like constipation and abnormal perineal descent were predictive of surgical success. CONCLUSION: For women with pudendal neuropathy, QTST can be considered a useful, non-invasive tool in the diagnosis, and management of the disease, but it cannot predict satisfactorily long-term outcome of operative pudendoscopy.

Right laparoscopic pudendal release + neurostimulator prosthesis (LION procedure) in pudendal neuralgia.

AIM: Pudendal neuralgia is a highly disabling entity with complex diagnostic and controversial treatment results. Surgical neurolysis has been shown to be the most effective treatment. Sacral root neurostimulation or posterior tibial nerve stimulation are used to rescue patients who either have not responded to surgery or have worsened after an initial improvement. METHODS: Given the excellent visualization of the pudendal nerve during laparoscopic pudendal release, we propose to combine this procedure with neurostimulation, taking advantage of the possibility of in situ placement of the electrode. The abdominal cavity is accessed laparoscopically through four ports, and after identifying and releasing the pudendal nerve a neurostimulation electrode is placed next to the nerve and is connected to a generator located in a subcutaneous pocket. RESULTS: This procedure has been performed in one patient with a satisfactory result. CONCLUSIONS: Laparoscopic pudendal release with neurostimulator prosthesis is an experimental technique that can be promising for the treatment of pudendal neuralgia.

The "Possover-LION Procedure" to the Pelvic Somatic Nerves in People With a Spinal Cord Injury.

OBJECTIVE: To demonstrate the technique of laparoscopic implantation of neuroprosthesis to the pelvic somatic nerves for recovery of voluntary walking motion in some patients with chronic spinal cord injuries. DESIGN: Video. SETTING: Tertiary referral unit specialized in advanced gynecologic surgery and neuropelveology. INTERVENTIONS: The technique of laparoscopic implantation of electrodes on the pelvic nerves-the LION (Laparoscopic Implantation of Neuroprothesis) procedure-was introduced by Possover in gynecology more than 15 years ago for the treatment of refractory pelvic neuropathic pain and bladder dysfunctions. From this first indication, further applications were developed, especially in the field of parapleology. The "Possover-LION" procedure consists of a laparoscopic implantation by transperitoneal approach of 4 stimulation lead electrodes to the sciatic, pudendal, and femoral nerves on both sides in those with a spinal cord injury. The femoral nerves are identified laterally to the psoas muscles, whereas exposure of the sciatic and pudendal nerves is obtained by blunt dissection of the lumbosacral space, laterally to the external iliac vessels. The lead electrodes are simply placed in direct contact to the nerves, while the retroperitoneal loop of cables prevents from dislocation. Finally, all cables are connected to a multichannel generator implanted in paraumbilical position, fixed to the abdominal fascia. CONCLUSION: The LION procedure allows the stimulation of the pelvic somatic nerves for recovery of a voluntary electrically assisted walking motion in approximately 70% of patients with chronic complete or incomplete spinal cord injury.

Surgeon-administered ilio-inguinal and pudendal nerve blocks for major vulval surgery: An observational study with visual analogue pain scoring.

Surgical excision of the groin and vulva is a painful procedure. Traditionally following general or regional anaesthesia, local anaesthetic was infiltrated around the wound. Thedistribution varied and the somatic pain control was not reliable. Inspired by the success of the application of peripheral nerve blocks for postoperative pain control with open abdominal procedures, we introduced blockade of the ilioinguinal nerve (IIN) and pudendal nerve (PN) into our vulval surgery to assess the requirement for parenteral and oral analgesia in the postoperative period. This is an observational study of all patients undergoing major vulval and/or related groin surgery. Sampling biopsies were excluded. Levobipuvicaine 0.25% (2.5 mg/ml) or 0.5% (5 mg/ml) was used for and dosage was calculated based on the patient's weight with no more than 2 mg/kg. For example, using 0.25% of levobupivacaine (2.5 mg/ml) for a 70 kg patient, 56 ml is administered divided into 4, giving 14mls at each site (2 sites abdominally for IIN block and 2 sites for pudendal block). Eighteen women were included in the analysis. Median age was 67 (range 34-81) years and thirteen (72%) were >60 years. Visual analogue scores (VAS) ranged from 0 to 3 for seventeen patients from day 0 to day 1 and fifteen patients from day 2 to day 5. Two patients had pain scores >4 on one or more postoperative days: one had chronic arthralgia and one had received a lower volume of bupivacaine. This observational study demonstrates that ilioinguinal and pudendal nerve LA blocks may be a valuable addition to the multimodal postoperative analgesic pathway for women undergoing major surgical excision in the vulva and groin.

Is pudendal nerve entrapment a potential cause for weak ejaculation?

Ejaculatory dysfunction is one of the most common complaints of patients with sexual disorders. While it encompasses several ejaculatory disorders, weak ejaculation is seldom described in the literature. Since the pudendal nerve is the main nerve of ejaculation, we aim to hypothesize that pudendal nerve entrapment could be a cause of weak ejaculation, and that pudendal nerve release could contribute to the improvement of the ejaculatory stream. We presented two cases suffering from a weak ejaculatory stream and sensation of incomplete semen emptying, accompanied with clinical features of pudendal nerve entrapment. Both cases improved after pudendal nerve block and then laparoscopic transperitoneal pudendal release, with a sustained amelioration of the ejaculatory stream after 3 weeks of surgery. Pudendal canal entrapment is therefore a potentially curable cause for weak ejaculation.

Pudendal nerve block: a safe, simple and effective approach in surgical proctological patients.

BACKGROUND: Pudendal nerve block (PNB) is commonly used in pudendal neuralgia (PN) and, as anesthesiological technique, in obstetrical and urological procedures. The purpose of this retrospective study was to compare the efficacy of PNB with other anesthesiolocal techniques in proctological surgery. METHODS: A total of 362 patients were seen from a 22-month-time interval. Surgical indication was placed after a conservative therapy. Seventy-eight patients underwent surgery: 42 with spinal anesthesia with PNB and 36 with PNB alone according to their anatomical characteristics. All the patients underwent PNB in lithotomy position and with a perirectal approach. The success rate of PNB was evaluated in postoperative pain control with the VAS score, after the first and the second evacuation. The follow-up also included a third check on the seventh day after surgery. RESULTS: In postoperative period, the mean VAS score found after the first evacuation in patients undergoing PNB was 2.66, after the second evacuation was 1.55, while the VAS score on the seventh day was 0.38. The mean VAS score in the group who underwent spinal anesthesia and PNB were respectively 3.71 and 1.80 after the first and second evacuation. The VAS score calculated on the seventh day was 0.50. There were no statistically significant differences in the VAS score between the 2 groups (P>0.05). CONCLUSIONS: PNB may be a valid alternative to spinal anesthesia in proctological patients. PNB has proven to be both safe and effective technique.

Expanded Perineal Coverage With Combined Pudendal and Inferior Cluneal Nerve Blocks: A Case Report.

The pudendal nerve (PN) block is an effective regional technique for providing analgesia to the perineum. However, when the surgical site involves dermatomal areas lateral to the PN dermatome, additional blocks are necessitated. We present a case report of a 6-year-old female who presented for surgical resection of widespread condylomata accuminata involving the perineum and buttocks. Analgesia was achieved using a combined PN and inferior cluneal nerve block. To our knowledge, this is the first report of this combined technique used for perioperative analgesia.

Sensate total clitoris reconstruction via microneurovascular dorsal foot web space flap with pudendal nerve coaptation.

Revision surgery after gender-affirming genitoplasty is becoming more and more common as more patients gain access to surgical treatment. The complexity of genitoplasty and extensive dissection of delicate tissues predisposes patients to necrosis of the flap(s) employed, which can leave patients with complications ranging from poor aesthetics to total lack of genital sensation. The purpose of this report is to detail the revision surgery of a 32-year-old transgender woman who underwent vaginoplasty at an outside institution and presented to our clinic for clitoral reconstruction following necrosis and near-total loss of the neoclitoris. Physical exam showed extensive necrosis, and 3-Tesla magnetic resonance (MRI) revealed significant scarring of the pudendal nerve branches at the level of the pubic symphysis. Healthy nerve was identified at the level of the right inferior pubic ramus, and total clitoral reconstruction with an innervated first dorsal web space free flap anastamosed to the deep inferior epigastric vessels was performed. Complications included donor site cellulitis with partial loss of the skin graft and formation of hypertrophic scar tissue. This was treated 6 months postoperatively with excision of scar tissue in the webspace and placement of an additional full-thickness skin graft. At follow-up, the patient reported tactile and erogenous sensation of the neoclitoris itself and subjective satisfaction with the aesthetic outcome. Our results provide evidence that this flap is a feasible option to create an aesthetic and sensate neoclitoris in the setting of previous neoclitoral necrosis. This case report also describes the novel use of 3-Tesla MRI in target selection for nerve coaptation.

Anatomical feasibility of peripheral nerve transfer to reestablish external anal sphincter control - cadaveric study.

PURPOSE: Motor deficits affecting anal sphincter control can severely impair quality of life. Peripheral nerve transfer has been proposed as an option to reestablish anal sphincter motor function. We assessed, in human cadavers, the anatomical feasibility of nerve transfer from a motor branch of the tibialis portion of the sciatic nerve to two distinct points on pudendal nerve (PN), through transgluteal access, as a potential approach to reestablish anal sphincter function. METHODS: We dissected 24 formalinized specimens of the gluteal region and posterior proximal third of the thigh. We characterized the motor fascicle (donor nerve) from the sciatic nerve to the long head of the biceps femoris muscle and the PN (recipient nerve), and measured nerve lengths required for direct coaptation from the donor nerve to the recipient in both the gluteal region (proximal) and perineal cavity (distal). RESULTS: We identified three anatomical variations of the donor nerve as well as three distinct branching patterns of the recipient nerve from the piriformis muscle to the pudendal canal region. Donor nerve lengths (proximal and distal) were satisfactory for direct coaptation in all cases. CONCLUSIONS: Transfer of a motor fascicle of the sciatic nerve to the PN is anatomically feasible without nerve grafts. Donor nerve length was sufficient and donor nerve functionally compatible (motor). Anatomical variations in the PN could also be accommodated.

Pudendal Neurolysis: 6-Step Laparoscopic Approach.

OBJECTIVE: To demonstrate the safety and feasibility of the laparoscopic approach to perform pudendal neurolysis in a case of pudendal nerve entrapment syndrome [1-3]. DESIGN: A video tutorial that highlights the laparoscopic steps to performing pudendal neurolysis, with a focus on the main anatomic landmarks [4,5]. SETTING: A tertiary care regional hospital. INTERVENTIONS: This video shows a 6-step approach to laparoscopic pudendal neurolysis for the treatment of pudendal nerve entrapment between the sacrospinous and sacrotuberous ligaments [2,6-8]. Step 1: Identification of the umbilical artery. Step 2: Dissection and development of the lateral paravesical space until the pelvic floor. Step 3: Identification of the arcus tendineus of the endopelvic fascia. Step 4: Identification of the ischial spine and the sacrospinous ligament covered by the coccygeus muscle. Step 5: Coagulation and section of the coccygeus muscle and the sacrospinous ligament. Step 6: Medialization of the pudendal nerve until its entrance into the Alcock canal. CONCLUSION: This video demonstrates the safety, feasibility, and reproducibility of laparoscopic pudendal neurolysis in 6 steps. A minimally invasive approach is adequate to treat the pudendal compression until the Alcock canal [2].

Laparoscopic treatment of pudendal nerve and artery entrapment improves erectile dysfunction in healthy young males.

Erectile dysfunction (ED) is increasingly becoming more common in young healthy males and is attributed mainly to psychogenic causes in these patients. Recent studies have reported that ED could be secondary to pudendal nerve or artery entrapment. This perspective assessed the efficacy of laparoscopic pudendal nerve and artery decompression in young patients suffering from refractory ED, associated to a pudendal nerve entrapment syndrome. After excluding patients with psychological ED and venous leakage, five young male patients with a history of both ED and pudendal nerve entrapment syndrome diagnosed based on the Nantes criteria were recruited. Pudendal nerve and artery release was performed using a laparoscopic transperitoneal approach. International Index for Erectile Function (IIEF-5) and erectile hardness score (EHS) improved significantly in all patients, 3 months after surgery. Pudendal nerve and artery entrapment could be therefore a reversible cause of ED in young healthy males, and its treatment by laparoscopic pudendal nerve and artery decompression seems to be safe and effective.