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

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.

Current role of neuromodulation in bladder pain syndrome/interstitial cystitis

Neuromodulation is recommended by major international guidelines as a fourth-line treatment in bladder pain syndrome/interstitial cystitis (BPS/IC) patients after failure of behavioural, oral and intravesical pharmacological treatments, including hydrodistension. A non-systematic review of studies identified by electronic search of MEDLINE was performed with no time limitation. A narrative synthesis of the existing evidence regarding the results of sacral, tibial and pudendal nerve stimulation in the management of BPS/IC was developed. Neuromodulation in pelvic chronic pain disorders, including BPS/IC, is a useful tool for refractory patients to conventional treatments. Sacral neuromodulation may be effective in patients with BPS without Hunner's lesions, and the effect seems to be maintained in the mid- and long-term. Posterior tibial nerve stimulation can be offered to patients with BPS/IC in the context of a multidisciplinary approach. When pudendal neuralgia is suspected, selective pudendal nerve stimulation has a high response rate. The aetiology of the pain can influence the outcomes in the mid- and long-term of the different neuromodulation approaches, thus careful diagnosis is recommended.

Bilateral electrical pudendal nerve stimulation as additional therapy for lower urinary tract dysfunction when stage II sacral neuromodulator fails: a case report

Background

Sacral neuromodulation (SNM) has become an effective therapy for patients with lower urinary tract dysfunction (LUTD) who do not respond to conservative treatment. However, an effective treatment strategy for patients who fail SNM has not yet been identified. An option for LUTD is needed when the clinical response to the SNM diminishes.

Case presentation

A 51-year-old Chinese man presented to an outpatient clinic complaining of difficulty in urination for > 3 years. The patient also complained of urinary frequency and urgency, accompanied by perineal discomfort. He was diagnosed with LUTD based on his symptoms and previous examinations. The patient underwent sacral neuromodulation with a permanent implantable pulse generator (IPG) (provided free of charge by Chengnuo Medical Technology Co., Ltd.; General Stim, Hangzhou, China) in the left buttock, as he participated in the company’s clinical trial to test the long-term effects of IPG. He reported loss of efficacy of the device 3 months after the implantation. We performed bilateral electrical pudendal nerve stimulation (EPNS) therapy for him. After 2 weeks of treatment, he began to report smooth voiding within 2 h after EPNS, and a moderate improvement in urinary frequency, urgency, and perineal discomfort. After 4 weeks of EPNS, the patient reported > 50% improvement in his urination, evaluated with the short form of the International Consultation on Incontinence Questionnaire for Male Lower Urinary Tract Symptoms. He reported smooth voiding, moderate improvements in urinary frequency and urgency, and the disappearance of the perineal discomfort. He also reported improved sleep and erections. The patient was discharged after 8 weeks of EPNS treatment.

Conclusion

EPNS could be an option as an additional therapy for patients with LUTD who have failed SNM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00808-5.

Neuromodulation of the Pudendal Nerve Assisted by 3D Printed: A New Method of Neuromodulation for Lower Urinary Tract Dysfunction

Electrical stimulation of peripheral nerves by implanted electrodes is an effective treatment for certain pelvic floor diseases. As well as intravesical electrical stimulation, this predominantly includes stimulation of the sacral nerve, tibial nerve, and pudendal nerve. The pudendal nerve is one of the main nerves that stimulate pelvic floor muscles, external urethral meatus, and the anal sphincter and pelvic organs, and it may have effects on frequent urination, urgency, dysuria, and perineal pain. It is difficult to locate because of its anatomical course, however, leading to difficulties fixing the electrode, which increases the difficulty of pudendal nerve electrical stimulation in clinical practice. In the current study 3D printed navigation was used to solve these problems. Combined with autopsy data and patient pelvic and nerve data, a personalized design was generated. Neural modulation of the pudendal nerve was achieved by implanting the lead with the guidance of 3D printed navigation. 3D printed navigation can maximize the phase II conversion rate, reduce the difficulty of surgery, shorten the operation time, reduce damage to additional organs and blood vessels, and increase the accuracy of electrode implantation, and it can be performed while the patient is awake. It is an accurate, reversible, efficient, and minimally invasive surgery.

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 selective pudendal neuromodulation for neurogenic bladder: a review of literature

This study presents an alternative technique for neuromodulation in cases where percutaneous sacral implantation is difficult or has previously failed. We aimed to describe a novel technique of selective placement of an electrode over the pudendal nerve (PN), via laparoscopic approach in a patient with urinary retention who previously failed sacral neuromodulation (SNM) treatment.