A new endoscopic minimal invasive approach for pudendal nerve and inferior cluneal nerve neurolysis: An anatomical study

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.

Origin, course, and distribution of the posterior femoral cutaneous nerve and the spatial relationship among its branches

This study aimed to elucidate the origin, course, and distribution of the branches of the posterior femoral cutaneous nerve, considering the segmental and dorsoventral compositions of the sacral plexus, including the pudendal nerve. The buttocks and thighs of five cadavers were analyzed bilaterally. The branches emerged from the sacral plexus, which was divided dorsally to ventrally into the superior gluteal, inferior gluteal, common peroneal, tibial, and pudendal nerves. It descended lateral to the ischial tuberosity and comprised the thigh, gluteal, and perineal branches. As for the thigh and gluteal branches, the dorsoventral order of those originating from the sacral plexus corresponded to the lateromedial order of their distribution. However, the dorsoventral boundary was displaced at the inferior margin of the gluteus maximus between the thigh and gluteal branches. The perineal branch originated from the ventral branch of the nerve roots. In addition, the pudendal nerve branches, which ran medially to the ischial tuberosity, were distributed in the medial part of the inferior gluteal region. These branches should be distinguished from the gluteal branches; the former should be classified as the medial inferior cluneal nerves and the latter as the lateral ones. Finally, the medial part of the inferior gluteal region was distributed by branches of the dorsal sacral rami, which may correspond to the medial cluneal nerves. Thus, the composition of the posterior femoral cutaneous nerve is considered necessary when considering the dorsoventral relationships of the sacral plexus and boundaries of the dorsal and ventral rami.

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.

Retroperitoneal Causes of Genitourinary Pain Syndromes: Systematic Approach to Evaluation and Management

INTRODUCTION

Women with pelvic pain commonly report pain in their ovaries, vagina, uterus, or bladder. These symptoms may be caused by visceral genitourinary pain syndromes but also may be caused by musculoskeletal disorders of the abdomen and pelvis. Understanding neuroanatomical and musculoskeletal factors that may contribute to genitourinary pain is important for evaluation and management.

OBJECTIVES

This review aims to (i) highlight the importance of clinical knowledge of pelvic neuroanatomy and sensory dermatomal distribution of the lower abdomen, pelvis, and lower extremities, exemplified in a clinical case; (ii) review common neuropathic and musculoskeletal causes of acute and chronic pelvic pain that may be challenging to diagnose and manage; and (iii) discuss female genitourinary pain syndromes with a focus on retroperitoneal causes and treatment options.

METHODS

A comprehensive review of the literature was performed by searching the PubMed, Ovid Embase, MEDLINE, and Scopus databases using the keywords "chronic pelvic pain," "neuropathy," "neuropathic pain," "retroperitoneal schwannoma," "pudendal neuralgia," and "entrapment syndromes."

RESULTS

Retroperitoneal causes of genitourinary pain syndromes have substantial overlap with common conditions treated in a primary care setting. Thus, a comprehensive and systematic history and physical examination, with focused attention to the pelvic neuroanatomy, is key to establishing the correct diagnosis. In the clinical case, such a comprehensive approach led to the unexpected finding of a large retroperitoneal schwannoma. This case highlights the intricacy of pelvic pain syndromes and the complex nature of their possible overlapping causes, which ultimately affects treatment planning.

CONCLUSION

Knowledge of the neuroanatomy and neurodermatomes of the abdomen and pelvis, in addition to understanding pain pathophysiology, is critical when evaluating patients with pelvic pain. Failure to apply proper evaluation and implement proper multidisciplinary management strategies contributes to unnecessary patient distress, decreased quality of life, and increased use of health care services. Khalife T, Hagen AM, Alm JEC. Retroperitoneal Causes of Genitourinary Pain Syndromes: Systematic Approach to Evaluation and Management. Sex Med Rev 2022;XX:XXX-XXX.

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.

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.

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

BACKGROUND

Pudendal and cluneal nerve entrapment can cause a neuropathic pain syndrome in the sensitive areas innervated by these nerves. Recently, a new endoscopic minimal invasive approach for pudendal and inferior cluneal nerve neurolysis has been published in a cadaver study. The aim of our study was to describe the feasibility of this new approach and to evaluate the clinical outcome.

METHODS

Fifteen patients underwent the ENTRAMI technique. The Numeric Pain Rating Scale (NPRS) and Patient Global Impression of Change (PGIC) were recorded at baseline and at 3 and 6 months after surgery.

RESULT

The average duration of intervention (skin to skin) was 139 min (range 50-270 min) for bilateral pudendal neurolysis and/or cluneal neurolysis and 113 min (range 100-130 min) for unilateral pudendal and/or cluneal neurolysis. No perioperative blood loss occurred. At 3 months, 50% of patients declared a more than 30% improvement of their PGIC, increasing to 57% at 6 months; 31% reported more than 90% improvement of PGIC at 6 months. Overall reduction of the average maximal NPRS score was from 9 (range 7-10) to 6 at 3 months (range 0-10; p value < 0.05) and to 5 at 6 months (range 0-10; p value < 0.05). There were no postoperative complications.

CONCLUSIONS

The ENTRAMI technique is feasibly in patients suffering from pudendal and/or cluneal neuralgia and preliminary results are promising.

CLINICAL TRIAL NUMBER

NCT03883178.

The ENTRAMI technique: Endoscopic transgluteal minimal invasive technique for implantation of a pudendal electrode under full visual control: A cadaver study

AIM

The aim of this article is to describe a minimal invasive trans gluteal endoscopic approach to implant a pudendal electrode for neuromodulation under full visual control.

METHODS

Eight trans gluteal approaches were performed on four cadavers. The sacral transforaminal percutaneous technique was performed to implant the electrode. The electrode was then picked up and placed under visual control next to the pudendal nerve.

RESULTS

The first trocar was placed in the upper lateral quadrant of the gluteal region. The 0° optical system was used to help with the pneumodissection to identify the sciatic nerve. At that point a second 3 mm trocar was placed to insert a dissecting grasping forceps. In some cases, a second 3 mm trocar was placed. A step by step dissection, based on anatomical findings, was necessary to be able to locate the pudendal nerve. The electrode, which was placed percutaneously and transforaminal through S3 or S4, was picked up and placed under full visual control next to the pudendal nerve, slightly entering the Alcock's canal. The electrode was placed in an ideal manner, meaning that all 4-contact points of the electrode are in parallel and in contact with the targeted nerve. The electrode was fixed in that ideal position at the level of the sacrospinous ligament. After placement of that electrode, an X-ray of the pelvic area was done.

CONCLUSIONS

The ENTRAMI technique allows optimal pudendal electrode placement under full visual control and should now be tested in a clinical setting.