Minimally Invasive Gynecological Surgery

21. Neurophysiology and Minimal Invasive Laparoscopic Therapy

Marc Possover1, 2  


Possover International Medical Center, Zuerich, (CH), Switzerland


Division of Gynecology & Neuropelveology, University of Aarhus, Aarhus, Denmark

Marc Possover


21.1 Introduction

21.2 The Neuropelveological Diagnosis: A Combination of Different Knowledge ()

21.3 The Laparoscopy: The Tool of Choice in Neuropelveology

21.4 Control to Sensoric Functions of the Pelvic Nerves and Plexuses: New Therapeutic Options for Urge Amount of Patients

21.5 The LION Procedure to the Pudendal Nerve to Treat Motor Pelvic Dysfunctions

21.6 Recovery of Pelvic Motor Functions in Spinal Cord Disorders

21.7 Conclusion


21.1 Introduction

The pelvis is not only the anatomical site of various organs such as the bladder, the rectum, and the reproductive organs, but also contains the pelvic nerves. Only the pelvic nerves and plexuses enable the central nervous system the necessary control to the sexual functions, storage and elimination of urine and feces, and movement and sensation in the pelvis and the legs. Therefore, damages to these nerves lead to multiple following conditions:

·               Sexual dysfunction (e.g., impotence), digestive disorders (especially constipation), and bladder dysfunction (especially overactive bladder).

·               Difficulty walking and standing and difficulty moving the toes.

·               Nerve disorders such as sciatica (pain that radiates from the buttocks to the toes), vulvodynia, vaginal pain, pudendal neuralgia, prostate pain, chronic prostatitis, penile and testicular pain, coccygodynia (tailbone pain), abdominal pain, and pain on urination.

Awareness that pathologies of the pelvic nerves may exist is still lacking and incidences are widely underestimated. Many patients suffering from pelvic nerve conditions only receive medication to treat the symptoms. Consequently, treatment frequently fails to address the root cause of the problems. Neurophysiological investigations to the pelvic nerves and plexuses are not especially developed. Neurosurgical instruments and classical surgical microscopy have been introduced but are unsuitable for surgical interventions performed deep in the pelvis. The posterior surgical approach used by neurosurgeons is not suitable for the treatment of pelvic nerve disorders; in fact, they may result in even more nerve damage. Most medical specialties often neglect the pelvic nerves and a medical specialty devoted exclusively to pelvic nerve disorders has been lacking until now. The neuropelveology— the medical specialty that deals with the pathologies and functional disorders of the pelvic nerves and plexuses—closes this gap (Possover 2010a2011).

21.2 The Neuropelveological Diagnosis: A Combination of Different Knowledge (Possover and Forman)

In most pelvic pain syndromes, the main symptom is low abdominal pain and the main objective of treatment is to control it. Not only gynecologic, dermatologic, or urological conditions may induce pelvic pain but also central or peripheral neuropathic conditions. Patient’s history and clinical examination must combine gynecological, urological, and neurological aspects of pain. The way of thinking for a proper neuropelveological diagnosis does not focus first on diagnosis of possible pelvic pathology, but on neurologic pathways of pain information to the central nervous system. The second step consists of determination of the level of the lesion (below, in, or above the pelvis), whereas the last step focuses on the determination of a possible etiology. Because several parallel nerve systems do exist, an absolute knowledge of pelvic neuroanatomy is mandatory. Pathologies of the sympathetic systems may induce visceral pelvic pain, whereas pelvic somatic nerve conditions may induce neuropathic pains. Sacral radiculopathies may induce abnormal sensation not only in the posterior surfaces of the lower limb, the pudendal (=genito–perineo–anal areas) areas, the vulva (vulvodynia), the tailbone (coccygodynia), and the buttock according with the sacral dermatomes (Fig. 21.1), but also dysfunctions of the lower limb, bladder, terminal intestine, and sexual functions. In massive neurogenic lesions of the sacral plexus, loss of strength in hip extension, knee flexion, and dorsal plantar flexion of the foot can also be detected. A precise anamnesis, with a clinical examination that includes a neurologic, gynecologic, urologic, and proctologic examination, permits determination of the neurologic level of the lesion in the majority of patients. A key in neuropelveological diagnosis are the external genital organs: deep vaginodynia correspond to irritation of the inferior hypogastric plexus and have therefore characters of visceral pain accompanied by vegetative symptoms. Combination of anterior vulvodynia with groin pain (with or without irradiations in the tight) orients the diagnosis to pathology of the genitofemoral nerve (or of the lumbar plexus). A pathology of the pudendal nerve (Alcock’s canal syndrome) always combined vulvodynia, perineal and perianal pain. The combination of pudendal pain with “nongynecological pains,” such as sciatica, gluteal, and low-back pains, orients the diagnosis to a pathology of the sacral plexus—sacral radiculopathy. Further pain irradiations in the anterior part of the tight (lumbar dermatomes) correspond generally to pathology of the spinal cord and/or column.


Fig. 21.1

Neuropelveologic assessment of dermatomes and trigger points of the pelvic nerves. L5 fifth lumbar root, S sacral nerve root, PN pudendal nerve, SN sacral nerve roots, GFNgenitofemoral nerve

21.3 The Laparoscopy: The Tool of Choice in Neuropelveology

Because of the anatomical location of the nerves within the pelvis (near major pelvic blood vessels), classical pelvic nerve surgery is very invasive and risky, especially for massive blood loss and nerves damages. Open pelvic surgery is laborious and cumbersome. Laparoscopy overcomes all of the limitations. High-resolution video cameras provide necessary magnification and microneurofunctional procedures. Thanks to these developments, all pelvic nerves and plexuses are now easily accessible for morphologic (Possover 2004a; Possover et al. 2007a) and functional (Possover et al. 2004) exploration by laparoscopy (Fig. 21.2). In addition to evaluating the disease status and making functional assessments, laparoscopic examination of the pelvic nerves also makes it possible to identify and to treat potential causes of functional disorders and neuropathic pain (Possover 2010b): neurofunctional procedures, such as nerve decompression (relief of pressure), neurolysis (release of a nerve sheath), nerve reconstruction, or implantation of stimulation electrodes in direct contact to nerves for postoperative neuromodulation (Possover et al. 2007bc), can be done in optimal conditions by laparoscopy.


Fig. 21.2

Laparoscopic dissection of the left sacral plexus (supracardinal portion). SN sciatic nerve, LST lumbo-sacral trunk, S sacral nerve root

21.4 Control to Sensoric Functions of the Pelvic Nerves and Plexuses: New Therapeutic Options for Urge Amount of Patients

Pudendal pain, proctalgia, coccygodynia, vulvodynia, and pudendal neuralgia are all pain situations reported as “chronic pelvic pain”. All these pain situations occur in 7–24 % of the population and are associated with impaired quality of life and high healthcare costs. Anoperineogenital pain are frequent complaint usually not only as a result of common and easily recognizable organic disorders such as anal fistula, thrombosed hemorrhoids, genitoanal cancer, or other dermatologic pathologies but can also occur under circumstances in which no organic cause can be found. Such pain syndromes are then poorly understood, with little research evidence available to guide their diagnosis and treatment. Also, lumbar pain with irradiations in the legs without any real spinal etiology is frequently treated by medical treatments on long-term or unnecessary surgeries; pelvic origins of such pain are very rarely evocated. Endopelvic lesions are less well known and because their diagnosis is difficult and surgical approach remained difficult and invasive, these etiologies are mostly managed by symptomatic treatments. In general, the number of patients suffering from pelvic nerve disorders is grossly underestimated. In the international literature, also the prevalence of pelvic nerve damage is estimated to be low. This is in stark contrast to clinical reality: both bladder and bowel dysfunctions and neurogenic pain after pelvic surgeries are seen every day in many doctors’ offices around the world. This may be due to a lack of awareness of the existence of such diseases and to the complexity of the pelvic nerve anatomy. In our experience, the most frequent etiologies for pelvic nerve irritation or even damages are:

·               Deeply infiltrative sciatic nerve (plexus sacralis endometriosis as part of a parametric endometriosis or as an isolated condition) (Possover et al. 2011)

·               Surgical nerves damages, especially surgeries with mesh implantation (Possover 2009; Possover and Lemos 2011)

·               Vascular compression syndrome of the pelvic nerves

·               More seldom, pelvic nerve conditions such as schwannomas (Possover 2013a) and pathologies of the sacral bone

Procedures of laparoscopic nerve decompression have proven safe and effective. They are reported to achieve remarkable pain relief in 62 % of patients with postoperative nerve damage, in 78 % of patients with endometriosis involving the pelvic nerves, and in more than 80 % of patients with pelvic nerve compression by varicose veins in the pelvic area.

In axonal nerve pathologies, or in event of failure of the classical peripheral nerve surgical techniques, the neuromodulation is a well-known option to control both neural pain and dysfunctions of the lower intestinal and urinary tract. The surgical procedure is designed to implant an electrode in contact to the injured nerve proximal to the lesion, which is connected to a pacemaker that produces continuous low-level electrical current. The LION procedure to pelvic nerves in pain situation is only indicated in neurogenic nerves damages (axonal lesion) that represent only a small percent of indications.

21.5 The LION Procedure to the Pudendal Nerve to Treat Motor Pelvic Dysfunctions

Urinary and fecal dysfunctions affects millions of women and men all over the world and this condition encompasses overactive bladder, urinary/fecal incontinence, chronic constipation, and urination difficulties due to obstructions of the urinary tract or due to neurological central or peripheral nerve diseases. Continence and micturition/defecation involve a balance between urethral/anal closure and detrusor/rectal muscle activity. Disorders or troubles of coordination of both functions are responsible for bladder and intestinal dysfunctions.

The most common types of urinary disorders especially in women is stress urinary incontinence that is caused by loss of support of the urethra, which is usually a consequence of damage to pelvic support structures as a result of childbirth. Behind behavior changes and pelvic floor training, treatment focuses on the surgical reconstruction of the normal pelvic anatomy using techniques of vaginal repair or sling procedures. In all other conditions, treatments target on efferent effects by using neuroregulator pharmacotherapies with two aims: the first to reduce high vesical pressures (to avoid retrograde reflux) and the second to restore normal micturition. So alpha blockers target on reduction urethral pressure, whereas antimuscarinics and parasympathomimetic drug respectively reduce or active detrusor contractility. Despite the fact that pharmacological treatments are currently first therapeutic options, adherence on long term is low because of side effects and patient tolerability often challenging (Abrams et al. 2000). Also, intradetrusor injections of botulinum toxin A constitute a powerful treatment of overactive bladder in patients being able and willing to return for frequent postvoid residual evaluation (risk for infections) and to perform self-catheterization if necessary (elevated postvoid residuals). Elevated postvoid residuals responsible for urinary tract infections and repetition of injections for life lead to discontinuation of treatment (Kantartzis and Shepherd 2012). Electrical stimulation of the pelvic nerves has emerged as an alternative and attractive treatment for refractory cases of urinary disorders, as well those due to a hypo- or a hypercontractility of the detrusor and/or of the sphincter, as those due to trouble of urethra-vesical coordination (Tanagho and Schmidt 1988; van Kerrebroeck 1998). Pelvic nerve neuromodulation has been proven effective and is today an established treatment option for patients refractory to or intolerant of conservative treatments for urinary disorders. The method, known as the LION procedure (Laparoscopic Implantation ONeuroprothesis), allows the surgeon to place an electrode directly on the pelvic nerves of interest. Neuromodulation is absolutely minimal invasive and preserves the anatomical integrity of the pelvic nerves, the lower urinary, and intestinal tracts and can be readily reversed. In the technique of Sacral Nerve Neuromodulation, implantation of the stimulation’s electrode can be obtained by percutaneous puncture technique. However, behind the fact that most gynecologists are not familiar with such techniques, SNM present several important inconvenience and disadvantages (Possover 2014a). Behind technical aspects, SNM present two major problems:

·               Not all pelvic nerves and plexuses are suitable for puncture techniques, only the superficial nerves outside the pelvis or below the pelvic floor.

·               SNM do not offer etiologic treatment; once neuromodulation is indicated, possible etiologies are omitted. Conservative treatment options and SNM should be classically considered before surgical options are considered. However, when any etiological treatment may exist, even a surgical one, medical and neuromodulative treatment options should be only considered after such an etiologic treatment option has failed. When no etiology can be found, patient’s disorders are classified as “idiopathic” or “nonneurogenic.” However, some etiologies can only be diagnosed by laparoscopy: so deeply infiltrating endometriosis of the bladder, vesicointestinal adhesions, endometriosis/fibrosis/vascular entrapment of the sacral nerve roots or of the pudendal nerve are all conditions that can induce such urinary disorders, but can only be diagnosed and treated by laparoscopy (Possover and Forman 2012). Etiologic treatment is then not only the treatment of choice but also avoids unnecessary costs for symptomatic treatment options on long term. When by laparoscopy no any etiology can be found, the procedure can be directly used for placement of an electrode to the nerve(s) of interest.

The LION procedure to the sacral plexus (Fig. 21.3) has the advantage to enable neuromodulation of all sacral nerve roots involved in bladder and rectal functions with only one multipolar lead and one pacemaker (Possover 2010c).


Fig. 21.3

LION procedure to the left sacral plexus. R rectum, PM pyriform muscle, S sacral nerve root

Because of failure of SNM in some patients suffering from incontinence and/or overactive bladder, trying to optimize the results of pelvic nerve neuromodulation, pudendal nerve stimulation (PNS) has been proposed as a logical alternative in those patients who fail to respond to SNM and successfully tested. Indeed, because the pudendal nerve rises from S2, S3, and S4, PNS activates afferent innervation over these three sacral segments, thereby providing increased afferent input for best inhibition of bladder and rectum (treatment of OAB). Pudendal efferent stimulation also activates the external urethral and external anal sphincters as well as the levator ani muscles, providing improvement of urinary and anal–fecal incontinence without activation of other fibers present in the sacral nerve roots. PNS also provides a potential modulative effect on bladder voiding function and improvement of sexual functions. Since the pudendal nerve (PN) directly innervates much of the pelvic floor, it is believed to be more optimal stimulation site for treatment of both urinary and anal–fecal incontinence as well as bladder overactivity (Spinelli et al. 2005), with few undesired side effects comparing to SNM and in some nonneurogenic disorders (Peters et al. 2005) may be explained by the more selective stimulation of nerve fibers innervating the external urethral and external anal sphincter muscles. There is no doubt that PNS is the better option for treatments of most frequent bladder disorders: PNS is no longer an alternative after failure of SNM, but has to be proposed in first line instead SNM. Main reasons why PNS has not replaced SNM until now are not problems with indication or efficacy, but technical difficulties. The anatomical location of the nerve, deep inside the pelvis and in proximity to major pelvic vessels, makes implantation by percutaneous puncture techniques extremely difficult and very dangerous. The PNS can be obtained by transgluteal puncture technique assisted by electrophysiological guidance. Location of leads below the pelvic floor by lacking anchoring to fix anatomical structures and permanent exposition to external traumas while sitting, intercourse, or walking exposes for lead migration and cable rupture. The LION procedure is the only technique that enables placement of a lead to the endopelvic portion of the PN by minimal invasive approach (Possover 2014b). Gynecologists are trained in laparoscopic surgery and for most of them, the LION procedure to the pelvic nerves especially to the PN may not present major surgical difficulties; only the anatomical way for exposure the PN must be learned. LION procedures are suitable for day-surgery, take less than 30 min for the entire procedure, while no special instrumentations or equipments (X-rays, electrophysiological guidance, etc.) or training in percutaneous puncture techniques are required, just classical OR instrument setup for laparoscopy.

21.6 Recovery of Pelvic Motor Functions in Spinal Cord Disorders

Spinal cord injury (SCI) dramatically changes the life of the affected person. The loss of control of skeletal muscles and sensations below the injury, together with serious disturbances in autonomic nervous system functions, produce a profound deterioration in the quality of life and loss of autonomy. In view of trends in the epidemiology of SCI, it is becoming increasingly important to develop treatment strategies that can enhance recovery motor function, walking in particular, following SCI. Because a complete biological cure for spinal cord injuries is not foreseeable in the near future, electronic devices that help the victim’s recover some functions are urgently needed. None of the previously available devices was able to control both pelvic organ function and leg movements. The LION procedure is actually the only minimal invasive technique of electrode implantation that enables selective placement of electrodes under control of the view and in direct contact to the endopelvic portion of the lumbosacral nerves (Possover et al. 2010; Possover 2004b). Because separate electrodes are placed to the sciatic and femoral nerves, re-education with electrical controlled muscles eccentric actions and FES-assisted locomotor training can be started few weeks after implantation. Nerve stimulation has major advantages compared to electrical muscles stimulation to induce a more harmonious movement with less fatigue effect. Because electrodes are connected to a rechargeable pacemaker, FES-training and continuous pelvic nerve neuromodulation are both feasible on long term. Both kind of stimulation may induce a building of muscle mass that constitute a major prevention effect to formation of decubitus lesions (Mawson et al. 1993). More than that, previous researches have also suggested that exogenously applied weak electric fields around damaged axons have a role to play in facilitating axonal regeneration, possibly by providing neurotropic guidance to the growing axons (Lu et al. 2008). Other experimental studies also indicated that electrical stimulation can lead to significant functional recovery more due to alternate synaptic pathways (McCaig et al. 2000). In a recent study, we reported on recovery of sensory and supraspinal control of leg movements in four peoples with chronic paraplegia treated by FES-assisted locomotor training and continuous low-frequency pelvic nerves neuromodulation (Possover 2013b). This finding suggests that such a form of rehabilitation may induce changes that affect the central pattern generator and allows supra- and infraspinal inputs to engage residual spinal pathways. Low-frequency neuromodulation of the pelvic nerves has the advantage to provide continuously such afferent inputs without need of active participation of the patient. All these information create a “need for reconnection/regeneration” resulting in a potential neural plasticity and secondary improved functional abilities. Therefore, motivation, re-education of SCI peoples and probably peripheral nerves stimulation will be essential in rehabilitation of peoples with SCI.

21.7 Conclusion

All of these new diagnostic and treatment options are the result of our pioneering work in the multidisciplinary field of neuropelveology. At the beginning, we started with laparoscopic nerve sparing techniques in gynecology. After a short time, it became obvious that laparoscopy is not only an optimal tool for learning and teaching pelvic neuroanatomy but also offers a unique approach to the pelvic nerves. From that point, neuropelveology has overstepped the limits of the gynecology and has opened new ways not only in clinical medicine but also in neuroscience researches. The main dilemma is that knowledge required in neuropelveology is dispersed into completely different specialty areas, which usually have nothing in common. The way is not easy because laparoscopic surgeries to the pelvic nerves require in-depth knowledge of the neuroanatomy of the pelvis and a great deal of expertise in advanced laparoscopic and neurosurgical procedures. Nevertheless, considering the large number of patients who can benefit from this new field of medicine, teaching in the field of neuropelveology should be mandatory for doctors in training.


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