A minimally invasive, endoscopic transgluteal procedure for pudendal nerve and inferior cluneal nerve neurolysis in case of entrapment: 3- and 6-month results. The ENTRAMI technique for neurolysis

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.

Unidentified Branches of the Posterior Femoral Cutaneous Nerve and Persistent Neuropathy

The posterior femoral cutaneous nerve (PFCN) is an extensive nerve with numerous collateral branches which provide cutaneous innervation to 2/3^rds of the posterior thigh, the infragluteal fold, as well as the lateral anal region, scrotum, and labia majora through its inferior cluneal and pudendal nerve branches. It has been noted in multiple studies that patients can experience persistent PFCN neuropathy after surgery for decompression of known collateral branches. In this study, we used 17 formaldehyde (7 male and 10 female) perfused cadavers obtained from Hershey Medical Center’s donor program to study the branching patterns of the PFCN. As a result, we found that 41% of individuals have an unidentified proximal branch of PFCN that recurs over the inferolateral border of the gluteus maximus, suggesting other areas of potential compression or nerve entrapment that could lead to persistent PFCN neuropathy that’s not improved after treatment for sciatic, pudendal, or inferior cluneal neuralgia. We hope these findings allow clinicians to modify current surgical techniques and improve patients’ post-operative quality of life.

Diagnosis and treatment of pudendal and inferior cluneal nerve entrapment syndrome: a narrative review

AIM

Pudendal and inferior cluneal nerve entrapment can cause a neuropathic pain syndrome in the sensitive areas innervated by these nerves. Diagnosis is challenging and patients often suffer several years before diagnosis is made. The purpose of the review was to inform healthcare workers about this disease and to provide a basis of anatomy and physiopathology, to inform about diagnostic tools and invasive or non-invasive treatment modalities and outcome.

METHODS

A description of pudendal and inferior cluneal nerve anatomy is given. Physiopathology for entrapment is explained. Diagnostic criteria are described, and all non-invasive and invasive treatment options are discussed.

RESULTS

The Nantes criteria offer a solid basis for diagnosing this rare condition. Treatment should be offered in a pluri-disciplinary setting and consists of avoidance of painful stimuli, physiotherapy, psychotherapy, pharmacological treatment led by tricyclic antidepressants and anticonvulsants. Nerve blocks are efficient at short term and serve mainly as a diagnostic tool. Pulsed radiofrequency (PRF) is described as a successful treatment option for pudendal neuralgia in patients non-responding to non-invasive treatment. If all other treatments fail, surgery can be offered. Different surgical procedures exist but only the open transgluteal approach has proven its efficacy compared to medical treatment. The minimal-invasive ENTRAMI technique offers the possibility to combine nerve release with pudendal neuromodulation.

CONCLUSIONS

Pudendal and inferior cluneal nerve entrapment syndrome are a challenge not only for diagnosis but also for treatment. Different non-invasive and invasive treatment options exist and should be offered in a pluri-disciplinary setting.

A Comprehensive Review of Cluneal Neuralgia as a Cause of Lower Back Pain

Lower back pain (LBP) is one of the most common presenting complaints in clinical adult medical patients. While most often diagnosed as "nonspecific mechanical" in etiology, several lesser known, rarer causes of LBP exist, some of which can even cause neuropathic pain. One of these infrequent causes, cluneal neuralgia (CN), is associated most often with damage or entrapment of the cluneal nerves, particularly the superior cluneal nerve (SCN) and/or the middle cluneal nerve (MCN). These nerves supply sensation to the posterior lumbar and buttock area. However, the LBP caused by CN is often difficult to recognize because it can mimic radiculopathy or sacroiliac joint (SIJ) pain or lead to symptoms in the legs. This makes CN significantly important for clinicians and surgeons to include in their differential. A thorough history proves beneficial in the diagnostic workup, as many risk factors for CN have been reported in the literature. If a CN diagnosis is made, several effective conservative measures can alleviate patients' pain, such as nerve blocks, peripheral nerve stimulation, or high frequency thermal coagulation. Additionally, surgical treatments, such as CN release or endoscopic decompression, have resulted in fantastic patient outcomes. The purpose of the present investigation is to investigate the existing literature about CN as a cause for LBP, consider its epidemiology, discuss its pathophysiology and risk factors, elucidate its clinical presentation and diagnosis, and examine the various treatment modalities that have been reported across the world.

Recommendations on the management of pudendal nerve entrapment syndrome: A formalised expert consensus

BACKGROUND

Since the development and publication of diagnostic criteria for pudendal nerve entrapment (PNE) syndrome in 2008, no comprehensive work has been published on the clinical knowledge in the management of this condition. The aim of this work was to develop recommendations on the diagnosis and the management of PNE.

METHODS

The methodology of this study was based on French High Authority for Health Method for the development of good practice and the literature review was based on the PRISMA method. The selected articles have all been evaluated according to the American Society of Interventional Pain Physicians assessment grid.

RESULTS

The results of the literature review and expert consensus are incorporated into 10 sections to describe diagnosis and management of PNE: (1) diagnosis of PNE, (2) patients advice and precautions, (3) drugs treatments, (4) physiotherapy, (5) transcutaneous electrostimulations (TENS), (6) psychotherapy, (7) injections, (8) surgery, (9) pulsed radiofrequency, and (10) Neuromodulation. The following major points should be noted: (i) the relevance of 4+1 Nantes criteria for diagnosis; (ii) the preference for initial monotherapy with tri-tetracyclics or gabapentinoids; (iii) the lack of effect of opiates, (iv) the likely relevance (pending more controlled studies) of physiotherapy, TENS and cognitive behavioural therapy; (v) the incertitudes (lack of data) regarding corticoid injections, (vi) surgery is a long term effective treatment and (vii) radiofrequency needs a longer follow-up to be currently proposed in this indication.

CONCLUSION

These recommendations should allow rational and homogeneous management of patients suffering from PNE. They should also allow to shorten the delays of management by directing the primary care.

SIGNIFICANCE

Pudendal nerve entrapment (PNE) has only been known for about 20 years and its management is heterogeneous from one practitioner to another. This work offers a synthesis of the literature and international experts' opinions on the diagnosis and management of PNE.

Pilot study: pudendal neuromodulation combined with pudendal nerve release in case of chronic perineal pain syndrome. The ENTRAMI technique: early results

INTRODUCTION AND HYPOTHESIS

Chronic perineal pain syndrome due to pudendal nerve impingement is difficult to diagnose and to treat. All the known treatment options leave room for improvement considering the outcome. Early neuromodulation of the pudendal nerve after its surgical release could improve outcomes.

OBJECTIVES

The aim of the study was to evaluate the potential beneficial effect of pudendal neuromodulation combined with release surgery using the ENTRAMI technique (endoscopic transgluteal minimally invasive technique).

STUDY DESIGN

This is a single-center prospective descriptive study. Between March 2019 and March 2020, 16 patients (2 males, 14 females) were included. Data were collected at baseline and 1 month after surgery.

METHODS

Patients eligible for inclusion had chronic perineal pain for at least 3 months in the area served by the pudendal nerve. We combined pudendal nerve release with neuromodulation.

RESULTS

At 1 month, the numeric pain rating scale (NPRS) dropped from 9.5 at baseline to 3.5 (p = 0.003). Seventy-six percent of patients showed a global impression of change (PGIC) of > 50% at 1 month, and optimal treatment response (PGIC ≥ 90%) was found in 41% of patients.

LIMITATIONS

The drawback of our study was that it was not randomized or blinded. The peripheral nerve evaluation lead (PNE) used could only be implanted for 1 month because of infection risk and is also prone to dislocations and technical failures.

CONCLUSION

Pudendal nerve liberation by the ENTRAMI technique combined with short-term pudendal neuromodulation seems feasible and promising in treating patients with chronic perineal pain. Clinical trial number: NCT03880786.

Laparoscopic transperitoneal pudendal nerve and artery release for pudendal entrapment syndrome

INTRODUCTION

Pudendal nerve and artery entrapment is an underdiagnosed pathology responsible of several urinary, sexual and anorectal complaints. The aim of our study was to evaluate safety and feasibility of laparoscopic transperitoneal pudendal nerve and artery release in a large retrospective cohort of patients with pudendal nerve entrapment syndrome with both a short and long-term follow-up. Technical details and outcomes are also reported.

METHODS

A series of 235 patients with pudendal syndrome underwent laparoscopic transperitoneal pudendal canal release between June 2015 and February 2020. Operative data were recorded prospectively for all patients. A complete history, pain visual analog scale (VAS) for perineodynia, and three scores evaluating the main symptoms (USP, IIEF-5, PAC-SYM) were obtained before and at least 24 months after surgery for 32 patients only. Post-operative complications were also evaluated using Clavien-Dindo classification at regular interval.

RESULTS

The mean operating time per side was 33.9 ± 6.8 min and the average hospital stay was 1.9 ± 0.3 days. Blood loss was 20 cc ± 10 cc with no patients needing transfusion. The only significant per-operative complication was hemorrhage (600 ml) in one patient induced by a pudendal artery laceration, successfully treated by laparoscopic suturing. Post-operative complications were noted in 18.7% of patients with no serious Clavien-Dindo complications. Perineodynia VAS dropped from 6.8 ± 0.9 to 2.2 ± 1.8 after surgery (p < 0.001). Mean IIEF-5 scores significantly improved one month after the surgery (15.2 vs 19.3, p = 0.036). Mean USP scores significantly improved for the dysuria domain (4.2 vs 1.6, p = 0.021) but not for stress urinary incontinence (3.9 vs 4.1, p = 0.082) or overactive bladder symptoms (14.1 vs 13.8, p = 0.079). Mean PAC-SYM scores significantly improved after the procedure (1.8 vs 1.1, p < 0.001).

CONCLUSION

A complete laparoscopic pudendal nerve and artery release, from the sciatic spine through the Alcock's canal, is a fast and safe surgery with promising functional results. A large prospective trial is needed to validate such an approach.

Endoscopic trans gluteal minimal-invasive approach for nerve liberation (ENTRAMI technique) in case of pudendal and/or cluneal neuralgia by entrapment: One-year follow-up

BACKGROUND

Chronic neuropathic perineal pain syndrome is a collective term that encompasses several diagnoses. In patients where the neuropathic pain syndrome is caused by pudendal or cluneal nerve entrapment, surgical release can be proposed if other measures have failed. The aim of this study is to evaluate the clinical outcome of patients suffering from pudendal and/or cluneal nerve entrapment at 1 year after this minimal invasive surgery, which is based on the open trans gluteal approach who has proven its efficacy compared to medical treatment in a randomized control trial.

METHODS

Patients eligible for inclusion had chronic perineal neuropathic pain for at least 3 months in the area served by the pudendal and/or cluneal nerve, refractory to conservative measurements. Patients met all five of the Nantes criteria.

RESULTS

Fifteen patients underwent the ENTRAMI technique. At 1 year after surgery, overall reduction of the average maximal Numeric Pain rating Scale (NPRS-score) was from 9 (range, 7-10) at baseline to 5 (range, 0-10; P-value <.05). At 1 year 73% of patients declared to have a "good treatment response" (patient global impression of change [PGIC] >30%) and optimal treatment response (PGIC ≥90%) was found in 40% (P-value <.05). No complications were recorded.

CONCLUSION

This study clearly shows that the technique is feasible with promising long-term results in a difficult to manage patient group.