Le nerf pudendal : morphogenèse, anatomie, physiopathologie, clinique et thérapeutique

Lumbosacral plexus and pudendal nerve magnetic resonance tractography: A systematic review of the clinical applications for pudendal neuralgia

Diffusion tensor imaging (DTI) is commonly used to establish three-dimensional mapping of white-matter bundles in the supraspinal central nervous system. DTI has also been the subject of many studies on cranial and peripheral nerves. This non-invasive imaging technique enables virtual dissection of nerves in vivo and provides specific measurements of microstructural integrity. Adverse effects on the lumbosacral plexus may be traumatic, compressive, tumoral, or malformative and thus require dedicated treatment. DTI could lead to new perspectives in pudendal neuralgia diagnosis and management. We performed a systematic review of all articles or posters reporting results and protocols for lumbosacral plexus mapping using the DTI technique between January 2011 and December 2023. Twenty-nine articles published were included. Ten studies with a total of 351 participants were able to track the lumbosacral plexus in a physiological context and 19 studies with a total of 402 subjects tracked lumbosacral plexus in a pathological context. Tractography was performed on a 1.5T or 3T MRI system. DTI applied to the lumbosacral plexus and pudendal nerve is feasible but no microstructural normative value has been proposed for the pudendal nerve. The most frequently tracking parameters used in our review are: 3T MRI, b-value of 800 s/mm2, 33 directions, 3 × 3 × 3 mm3, AF threshold of 0.1, minimum fiber length of 10 mm, bending angle of 30°, and 3DT2 TSE anatomical resolution. Increased use of DTI could lead to new perspectives in the management of pudendal neuralgia due to entrapment syndrome, whether at the diagnostic, prognostic, or preoperative planning level. Prospective studies of healthy subjects and patients with the optimal acquisition parameters described above are needed to establish the accuracy of MR tractography for diagnosing pudendal neuralgia and other intrapelvic nerve entrapments.

Risk Prediction Model for Radiation-induced Dermatitis in Patients with Cervical Carcinoma Undergoing Chemoradiotherapy

PURPOSE

Radiation-induced dermatitis (RD) is a common side-effect of therapeutic ionizing radiation that can severely affect patient quality of life. This study aimed to develop a risk prediction model for the occurrence of RD in patients with cervical carcinoma undergoing chemoradiotherapy using electronic medical records (EMRs).

METHODS

Using EMRs, the clinical data of patients who underwent simultaneous radiotherapy and chemotherapy at a tertiary cancer hospital between 2017 and 2022 were retrospectively collected, and the patients were divided into two groups: a training group and a validation group. A predictive model was constructed to predict the development of RD in patients who underwent concurrent radiotherapy and chemotherapy for cervical cancer. Finally, the model's efficacy was validated using a receiver operating characteristic curve.

RESULTS

The incidence of radiation dermatitis was 89.5% (560/626) in the entire cohort, 88.6% (388/438) in the training group, and 91.5% (172/188) in the experimental group. The nomogram was established based on the following factors: age, the days between the beginning and conclusion of radiotherapy, the serum albumin after chemoradiotherapy, the use of single or multiple drugs for concurrent chemotherapy, and the total dose of afterloading radiotherapy. Internal and external verification indicated that the model had good discriminatory ability. Overall, the model achieved an area under the receiver operating characteristic curve of .66.

CONCLUSIONS

The risk of RD in patients with cervical carcinoma undergoing chemoradiotherapy is high. A risk prediction model can be developed for RD in cervical carcinoma patients undergoing chemoradiotherapy, based on over 5 years of EMR data from a tertiary cancer hospital.

Pudendal nerve neurolysis outcomes for urogenital and rectal disorders in patients suffering from pudendal nerve entrapment: A systematic review

PURPOSE

Pudendal neuropathy is an uncommon condition that exhibits several symptoms depending on the site of nerve entrapment. This study aims to evaluate the efficacy of pudendal nerve neurolysis (PNN) in improving lower urinary tract symptoms, anal and/or urinary incontinence, and sexual dysfunctions.

MATERIALS AND METHODS

A systematic literature search was performed on 20 May 2023 using Scopus, PubMed, and Embase. Only English and adult papers were included. Meeting abstracts and preclinical studies were excluded.

RESULTS

Twenty-one papers were accepted, revealing significant findings in the field. The study identified four primary sites of pudendal nerve entrapment (PNE), with the most prevalent location likely being at the level of the Alcock canal. Voiding symptoms are commonly exhibited in patients with PNE. PNN improved both urgency and voiding symptoms, and urinary and anal incontinence but is less effective in cases of long-standing entrapment. Regarding sexual function, the recovery of the somatic afferent pathway results in an improvement in erectile function early after neurolysis. Complete relief of persistent genital arousal disorder occurs in women, although bilateral PNN is necessary to achieve the efficacy. PNN is associated with low-grade complications.

CONCLUSIONS

PNN emerges as a viable option for addressing urinary symptoms, fecal incontinence, erectile dysfunction, and female sexual arousal in patients suffering from PNE with minimal postoperative morbidity.

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.

Advances in the therapeutic approach of pudendal neuralgia: a systematic review

CONTEXT

Although pudendal neuralgia (PN) has received growing interest over the last few years, diagnosis remains difficult, and many different therapeutic approaches can be considered.

OBJECTIVES

This article aims to provide an overview of the possible treatments of PN and investigate their efficacies.

METHODS

Utilizing PubMed and ScienceDirect databases, a systematic review was carried out and allowed identification of studies involving patients with PN, as defined by Nantes criteria, and their associated treatments. Relevant data were manually reported.

RESULTS

Twenty-eight articles were selected, totaling 1,013 patients (mean age, 49 years) and six different types of interventions. Clinical outcomes, most frequently quantified utilizing the Visual Analog Scale (VAS), vary greatly with both the therapy and time after intervention (from 100 to <10%). However, neither peri nor postoperative serious complications (grade > II of Clavien-Dindo classification) are reported. Although surgery seems to provide a higher proportion of long-term benefits, identifying the most efficient therapeutic approach is made impossible by the multitude of outcome measurements and follow-up frequencies. It should also be noted that literature is sparse regarding randomized controlled trials with long-term follow-up.

CONCLUSIONS

Although there are a number of modalities utilized for the treatment of PN, there are no current recommendations based on treatment efficacies. This seems to be largely in part caused by the lack of standardization in outcome quantification. Future research in this field should focus on prospective cohort studies with high levels of evidence, aimed at assessing the long-term, if not permanent, benefits of available therapies.

Topical lidocaine-prilocaine cream versus rectal meloxicam suppository for relief of post-episiotomy pain in primigravidae: A randomized clinical trial

OBJECTIVES

To compare the analgesic effect of topical lidocaine-prilocaine (LP) cream and rectal meloxicam suppository on the post-episiotomy pain in primigravidae.

PATIENTS AND METHODS

A randomized open-label clinical trial included primigravidae delivered vaginally with episiotomy. Eligible women were recruited and randomized to topical LP cream on the episiotomy line or rectal meloxicam suppository 15 mg. The intensity of the perineal pain was assessed using a visual analog scale (VAS) immediately, at 6, 12 h and after 5 days post-episiotomy.

RESULTS

One hundred ninety women were enrolled (n = 95 in each arm). No difference between both groups in the VAS scores immediately (mean ± SD: 8.54 ± 1.35 vs. 8.33 ± 1.50, p = 0.419) and 6 h after episiotomy (p = 0.859). However, women in the LP arm were more likely to report lower VAS scores at 12 h and 5 days post-episiotomy (mean ± SD: 1.20 ± 0.50 vs. 5.65 ± 1.65, p = 0.0001; 1.19 ± 0.49 vs. 2.64 ± 1.73, p < 0.001; respectively).

CONCLUSION

Application of topical LP cream after repair of episiotomy in primigravidae seems to substantially alleviate the induced pain with subsequent less need for additional analgesia and more patients' satisfaction.

Persistent genital arousal disorder: Treatment by neurolysis of dorsal branch of pudendal nerve

BACKGROUND

Persistent genital arousal disorder (PGAD) is a woman's perception that she is in a state of sexual arousal, without the ability of arousal to be satisfied by orgasm. It is the hypothesis of this study that PGAD results from a minimal degree of nerve compression of the dorsal branch of the pudendal nerve. If this is true, PGAD could be treated by neurolysis of the dorsal branch of the pudendal nerve.

METHODS

A retrospective chart review from 2010 through 2018, of those women having neurolysis of the dorsal branch of the pudendal nerve for PGAD. The main outcome measures were the pre-operative and post-operative changes in clitoral symptoms (arousal, numbness, pain).

RESULTS

Eight women included in this study were followed more than 26 weeks since surgery (mean = 65, range = 26-144 weeks). Seven of these women had the surgery bilaterally, and each of these had an excellent result, meaning elimination of the arousal symptoms, and the ability to resume normal sexual intercourse. The patient with unilateral decompression of the dorsal branch of the pudendal nerve was the only patient who had some, versus complete improvement in arousal symptoms. Of the seven women that had pain, six had complete relief and one had partial relief. No major surgical complications were observed.

CONCLUSION

The relief of arousal symptoms by neurolysis of the dorsal nerve to the clitoris supports the hypothesis that PGAD is due to a minimal degree of compression of the dorsal branch of the pudendal nerve.

Transischiorectal fossa approach for resection of pudendal nerve schwannoma: case report

Pudendal nerve schwannomas are very rare, with only two cases reported in the English-language literature. The surgical approaches described in these two case reports are the transgluteal approach and the laparoscopic approach. The authors present the case of a patient with progressive pelvic pain radiating ipsilaterally into her groin, vagina, and rectum, who was subsequently found to have a pudendal schwannoma. The authors used a transischiorectal fossa approach and intraoperative electrophysiological monitoring and successfully excised the tumor. This approach has the advantage of direct access to Alcock's canal with minimal disruption of the pelvic muscles and ligaments. The patient experienced complete relief of her pelvic pain after the procedure.

Histological Correlates of Penile Sexual Sensation: Does Circumcision Make a Difference?

INTRODUCTION

The question of whether removal of sensory receptors in the prepuce by circumcision affects sensitivity and/or sexual pleasure is often debated.

AIMS

To examine histological correlates relevant to penile sensitivity and sexual pleasure.

METHODS

Systematic review of the scientific literature on penile structures that might affect sensitivity and sexual sensation. Articles were included if they contained original data on human male penile histology or anatomy. Individual articles, including reference lists, were evaluated. They were then considered in relation to physiological data from articles retrieved by a previous systematic review.

RESULTS

We retrieved 41 publications on penile structure. Considered in the light of 12 reporting physiological measurements, our evaluation finds that sexual response is unlikely to involve Meissner's corpuscles, whose density in the prepuce diminishes at the time of life when male sexual activity is increasing. Free nerve endings also show no correlation with sexual response. Because tactile sensitivity of the glans decreases with sexual arousal, it is unrelated to sexual sensation. Thermal sensitivity seems part of the reward mechanism of intercourse. Vibrational sensitivity is not related to circumcision status. Observations that penile sexual sensation is higher post circumcision are consistent with greater access of genital corpuscles to sexual stimuli after removal of the prepuce. This is based on the distribution of these corpuscles (which are located in the glans) and, in uncircumcised men, the position of the retracted prepuce during intercourse, rather than any change in the number of genital corpuscles. The scientific literature suggests that any sexual effect of circumcised men may depend solely on exposure of the glans and not on the absence of the prepuce.

CONCLUSION

Based on histological findings and correlates of sexual function, loss of the prepuce by circumcision would appear to have no adverse effect on sexual pleasure. Our evaluation supports overall findings from physiological measurements and survey data.

A comparative study on relieving post-episiotomy pain with diclofenac and indomethacin suppositories or placebo

In this study, we compare the prophylactic efficacy of a diclofenac suppository and an indomethacin suppository on decreasing post-episiotomy pain. A total of 90 women with 2nd-degree episiotomy were assigned to receive a single dose of diclofenac suppository (30), indomethacin suppository (30) or placebo (30), according to randomised blocks. The pain was assessed at 1, 2, 4, 6 and 12 hours after receiving analgesia, using the two methods of pain score and visual analogue. This study showed that in the group given diclofenac or indomethacin, at all the assessed hours, the pain measured was considerably less than in the suppository-free group (p < 0.05). Comparing the diclofenac and indomethacin groups, there were only significant differences in the 4 and 12 hour measurements: the diclofenac was more effective than the indomethacin (4th hour), but due to a shorter half-life, the diclofenac group in the 12th hour had more pain (p < 0.05). Diclofenac suppository is recommended at 4-hour intervals for all patients, without internal disorders, to decrease episiotomy pain.

Pudendal schwannoma: A case report and literature review

Schwannomas are benign nerve sheath tumours most often associated with the cranial nerves and the peripheral nerve system of the neck and extremities. Pelvic schwannomas are rare, with only about 25 cases reported. We report the case of a 34-year-old man referred for worsening pain of 10 years duration involving the right testicle and right penile shaft. Magnetic resonance imaging discovered a well-circumscribed pelvic tumour of 3.2 × 2.8 × 3.2 cm. Considering the possible complications involved in exposing the pudendal nerve during surgical resection, we performed an extensive literature search to aid preoperative planning. The most commonly described surgical approach for pelvic schwannomas has been open median laparotomy with transperitoneal dissection. To our knowledge, pudendal schwannomas have never been described in the literature. However, after considering the location and characteristics of the tumour, we chose laparoscopy because it offers the advantages of better visualization of anatomical structures with minimal invasiveness and faster recovery. At the 3-week follow-up, the patient described a significant decrease in pain and normal neurological and urological examinations.

Pelvic floor therapies in chronic pelvic pain syndrome

Chronic pelvic pain syndrome is a poorly understood clinical entity associated with urinary symptoms, pelvic floor dysfunction, and multisystem disorders. Treatment of pelvic floor dysfunction is difficult and often frustrating for the patient as well as for the involved physician. The purpose of this review is to update clinicians on the latest research for the treatment of pelvic floor dysfunction in relation to chronic pelvic pain syndrome.

Where does pelvic nerve injury occur during rectal surgery for cancer?

AIM

Optimal treatment of rectal adenocarcinoma involves total mesorectal excision with nerve-preserving dissection. Urinary and sexual dysfunction is still frequent following these procedures. Improved knowledge of pelvic nerve anatomy may help reduce this and define the key anatomical zones at risk.

METHOD

The MEDLINE database was searched for available literature on pelvic nerve anatomy and damage after rectal surgery using the key words 'autonomic nerve', 'pelvic nerve', 'colorectal surgery', and 'genitourinary dysfunction'. All relevant French and English publications up to May 2010 were reviewed. Reviewed data were illustrated using 3D reconstruction of the foetal pelvis.

RESULTS

The ligation of the inferior mesenteric artery and dissection of the retrorectal space can cause damage to the superior hypogastric plexus and/or hypogastric nerve. Anterolateral dissection in the 'lateral ligament' area and division of Denonvilliers' fascia can damage the inferior hypogastric plexus and efferent pathways. Perineal dissection can indirectly damage the pudendal nerve.

CONCLUSIONS

In most cases, the pelvic nerves can be preserved during rectal surgery. Complete oncological resection may require dissection close to the nerves where the tumour is located anterolaterally where it is fixed and when the pelvis is narrow.

[Management of chronic postoperative pelvic and perineal pain due to parietal somatic nerve damage]

INTRODUCTION

All surgical procedures require an incision with a risk of nerve damage at the site of the scar or as a result of fibrotic scar tissue. The purpose of this article is to describe the management of chronic postoperative pelvic and perineal pain due to parietal somatic nerve damage.

PATIENTS AND METHODS

A comprehensive review of the literature was performed by searching PUBMED for articles on the management of chronic postoperative pelvic and perineal pain due to parietal somatic nerve damage.

RESULTS

Postoperative lesions of parietal somatic nerves (ilioinguinal, iliohypogastric, genitofemoral, pudendal, obturator, femoral) are frequent after pelvic surgery. Clinical examination of the scars (trigger zone) and detailed analysis of the topography and type of pain are essential elements in the analysis of this pain. Infiltration of local anaesthetic at the trigger point or along the nerve has a diagnostic value. Corticosteroid infiltrations and minimally invasive treatments such as pulsed radiofrequency have provided more or less lasting improvement of the symptoms. Surgical nerve release together with resection of fibrosis and removal of prosthetic material provides good long-term results. The surgical approach depends on the nerve concerned and the level of the lesion.

CONCLUSION

The management of chronic postoperative pelvic and perineal pain due to parietal somatic nerve damage is based on local infiltration of anaesthetics and corticosteroids. Nerve release surgery with resection of fibrosis provides the best long-term results.

[Anatomy and physiology of chronic pelvic and perineal pain]

OBJECTIVE

To determine the mechanisms involved in the regulation of pelvic and perineal pain.

MATERIAL AND METHODS

Description of the anatomical pathways mediating nociceptive transmission and the physiological mechanisms of pain control.

RESULTS

The pelvis and perineum do not have the same innervation. The pelvis is innervated by the sympathetic nervous system, while the perineum is innervated by the somatic nervous system via sacral nerve roots (and the pudendal nerve) and the thoracolumbar sympathetic nervous system. Systems of regulation of nociceptive messages are present at all levels of the nervous system. Two of these systems are essential: one situated in the dorsal horns of the spinal cord (gate control) and another supraspinal system (descending inhibitory system). Via a series of filters and amplifiers, the nociceptive message is integrated and analysed in the cerebral cortex, with interconnections with various areas, especially involving memory and emotion.

CONCLUSION

Excessive nociceptive stimulation must be clearly distinguished from dysfunction of pain control systems (for example neuropathic pain). The definition of pain: "unpleasant sensory and emotional experience related to a real or potential tissue lesion or described in terms of such a lesion" clearly indicates that not all pain is inevitably related to a persistent and visible cause. Convergence phenomena identified between nerve pathways of the various systems and pelvic organs account for the possible diffusion of visceral nociceptive messages and interactions between organs. A good knowledge of anatomy is essential to understand the patient's description of the pain, and a good knowledge of the modalities of pain control is essential to correctly adapt treatment strategies (drugs, neurostimulation, psycho-behavioural therapy, etc.).