The implications of the anatomy of the nerves and vessels in the treatment of rectosigmoid endometriosis.

Endometriosis is a common benign gynecological disease characterized by the presence of endometrial glands and stroma outside the uterus. It can be defined as endometrioma, superficial peritoneal endometriosis or deep infiltrating endometriosis (DIE) depending on the location and the depth of infiltration of the organs. In 5%-12% of cases, DIE affects the digestive tract, frequently involving the distal part of the sigmoid colon and rectum. Surgery is generally recommended in cases of obstructive symptoms and in cases with pain that is non-responsive to medical treatment. Selection of the most optimal surgical technique for the treatment of bowel endometriosis must consider different variables, including the number of lesions, eventual multifocal lesions, as well as length, width and grade of infiltration into the bowel wall. Except for some major and widely accepted indications regarding bowel resection, established international guidelines are not clear on when to employ a more conservative approach like rectal shaving or discoid resection, and when, instead, to opt for bowel resection. Damage to the pelvic autonomic nervous system may be avoided by detection of the middle rectal artery, where its relationship with female pelvic nerve fibers allows its use as an anatomical landmark. To reduce the risk of potential vascular and nervous complications related to bowel resection, a less invasive approach such as shaving or discoid resection can be considered as potential treatment options. Additionally, the middle rectal artery can be used as a reference point in cases of upper bowel resection, where a trans mesorectal technique should be preferred to prevent devascularization and denervation of the bowel segments not affected by the disease.

Robotic assisted laparoscopy for deep infiltrating endometriosis.

Deep infiltrative endometriosis is a condition affecting up to 15 % of women of childbearing age, defined by extra uterine location of endometrial like tissues. The symptoms of endometriosis range from severe dysmenorrhea to infertility, chronic pelvic pain, bowel dysfunction and urinary tract involvement to name the most common. Endometriosis has an impact on the quality of life of patients, with personal and social consequences. Although medical treatment is indicated in the first instance, surgery may be necessary. Standard laparoscopy has become the gold standard for this surgery. However, surgery for deep infiltrative endometriosis is known to be highly complex, and the significant development of robotic assistance in recent years has had an impact on the evolution of surgical practice. This comprehensive review of the literature provides an overview of the contributions of robotic surgery in the field of endometriosis and gives an insight into the next steps in its development.

Intraoperative near-infrared fluorescence imaging can identify pelvic nerves in patients with cervical cancer in real time during radical hysterectomy.

PURPOSE: Radical hysterectomy combined with pelvic lymphadenectomy is the standard treatment for early-stage cervical cancer, but unrecognized pelvic nerves are vulnerable to irreversible damage during surgery. This early clinical trial investigated the feasibility and safety of intraoperative near-infrared (NIR) fluorescence imaging (NIR-FI) with indocyanine green (ICG) for identifying pelvic nerves during radical hysterectomy for cervical cancer. METHODS: Sixty-six adults with cervical cancer were enrolled in this prospective, open-label, single-arm, single-center clinical trial. NIR-FI was performed in vivo to identify genitofemoral (GN), obturator (ON), and hypogastric (HN) nerves intraoperatively. The primary endpoint was the presence of fluorescence in pelvic nerves. Secondary endpoints were the ICG distribution in a nerve specimen and potential underlying causes of fluorescence emission in pelvic nerves. RESULTS: In total, 63 patients were analyzed. The ON was visualized bilaterally in 100% (63/63) of patients, with a mean fluorescence signal-to-background ratio (SBR) of 5.3±2.1. The GN was identified bilaterally in 93.7% (59/63) of patients and unilaterally in the remaining 4 patients, with a mean SBR of 4.1±1.9. The HN was identified bilaterally in 81.0% (51/63) of patients and unilaterally in 7.9% (5/63) of patients, with a mean SBR of 3.5±1.3. ICG fluorescence was detected in frozen sections of a nerve specimen, and was mainly distributed in axons. No ICG-related complications were observed. CONCLUSION: This early clinical trial demonstrated the feasibility and safety of NIR-FI to visualize pelvic nerves intraoperatively. Thus, NIR-FI may help surgeons adjust surgical decision-making, avoid nerve damage, and improve surgical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04224467.

Impact of nerve-sparing posterolateral parametrial excision for deep infiltrating endometriosis on postoperative bowel, urinary, and sexual function.

OBJECTIVE: To evaluate the functional outcomes of nerve-sparing surgery for deep infiltrating endometriosis (DIE) with or without posterolateral parametrectomy. METHODS: A multicenter, observational, retrospective, cohort study was performed including all symptomatic women who underwent nerve-sparing laparoscopic excision of DIE and preoperative and postoperative assessment of functional outcomes through validated questionnaires between April 2019 and March 2020. Women with posterolateral parametrial DIE (P-group) and women with no parametrial involvement (NP-group) were compared in terms of preoperative and postoperative functional outcomes related to pelvic organs assessed through validated questionnaires (KESS and GIQLI for bowel function, BFLUTS for urinary function, and FSFI for sexual function); pain symptoms at 3-month follow up assessed through an 11-point visual analogue scale (VAS) for dyschezia, dysmenorrhea, dyspareunia and chronic pelvic pain; surgical outcomes; and rate of urinary voiding dysfunction at 3-month follow up. RESULTS: One-hundred patients were included: 69 in the P-group and 31 in the NP-group. Preoperative and postoperative values of questionnaires, pain symptoms, and postoperative complication rates were comparable between the two groups, except for postoperative dyspareunia and sexual dysfunction, which were statistically higher in the P-group. Only patients in the P-group experienced urinary voiding dysfunction, but no statistical significance was reached (P = 0.173). CONCLUSION: Posterolateral parametrectomy for DIE appears to be associated with a higher risk of postoperative dyspareunia and sexual dysfunction.

Embryological Development and Topographic Anatomy of Pelvic Compartments-Surgical Relevance for Pelvic Lymphonodectomy.

BACKGROUND: The oncological outcome of surgery for the treatment of pelvic malignancies can be improved by performing pelvic lymphonodectomy. However, the extent and regions of lymph node harvest are debated and require profound knowledge of anatomy in order to avoid collateral damage. METHODS: The embryological development and topographic anatomy of pelvic compartments in relation to pelvic lymphonodectomy for rectal, uterine, and prostate cancer are reviewed. Based on pre-dissected anatomical specimens, lymph node regions and drainage routes of the posterior and urogenital pelvic compartments are described in both genders. Anatomical landmarks are highlighted to identify structures at risk of injury during pelvic lymphonodectomy. RESULTS: The ontogenesis of urogenital and anorectal compartments and their lymphatic supply are key factors for adequate lymphonodectomy, and have led to compartment-based surgical resection strategies. However, pelvic lymphonodectomy bears the risk of injury to somatic and autonomic nerves, vessels, and organs, depending on the regions and extent of surgery. CONCLUSION: Embryologically defined, compartment-based resection of pelvic malignancies and their lymphatic drainage routes are based on clearly delineated anatomical landmarks, which permit template-oriented pelvic lymphonodectomy. Comprehensive knowledge of pelvic anatomy, the exchange of surgical concepts between specialties, and minimally invasive techniques will optimize pelvic lymphonodectomy and reduce complications.

Re-exploring the pelvic neuroanatomy from a new perspective and a potential guidance for TaTME: a "bottom-up" approach.

Neuro-anatomy of the perineum has gained renewed attention due to its significance in the transanal procedures for rectal cancer (eg TaTME). Surgeons embarking on this technique must have sophisticated knowledge and a precise anatomical understanding of the perineum before proceeding with this reversed rectal approach. We report anatomical observations deriving from a relevant experience in the colorectal surgery field. The collective multicenter experience of the present study is clinically relevant and based on the rectal and transanal resections performed in colorectal centers of excellence from Greece, UK, and Italy over the last 10 years (2011-2020). From the original anatomical and intraoperative observations derived from collective cases operated by this multicenter group of colorectal surgical centers in three European countries, data were retrieved and analyzed in collaboration with specialist researchers of human anatomy and interpreted for their clinical significance and potential use for preoperative planning and intraoperative guidance during TaTME. This descriptive article demonstrates in detail the neurogenic pathways encountered in the perineum and pelvic cavity during transanal procedures. Specific anatomical and topographic implications are also included serving as a guide for colorectal surgeons to perform a nerve-sparing procedure. transanal approach for rectal excision offers new insights into the complex pelvic and perineal neuroanatomy while the procedure itself remains a challenge for surgeons. Preoperative anatomical planning and 3D reconstruction may help in anticipating technical difficulties, resulting in more precise surgical dissections and decreased postoperative complications.

Pelvic Neuroanatomy: An Overview of Commonly Encountered Pelvic Nerves in Gynecologic Surgery.

OBJECTIVE: This video tutorial identifies key anatomic landmarks useful in identifying the path of the most commonly encountered pelvic nerves in benign gynecologic surgery. DESIGN: This is a narrated overview of commonly encountered pelvic nerves during benign gynecology, their origin, sensory, and motor function, as well as sequelae related to injury. SETTING: The unintended injury of pelvic neural connections can be a complication of any pelvic surgery, however, surgery for malignancy or endometriosis may increase the likelihood of encountering these nerves. The majority of focus surrounding surgical nerve injury, however, relates to patient positioning [1]. Injury to the pelvic nerves can lead to lifelong sexual, bladder, and defecatory dysfunction [2]. INTERVENTIONS: We review the Genitofemoral, Lateral Femoral Cutaneous, Ilioinguinal, Obturator, Superior and Inferior Hypogastric nerves, Pelvic Splanchnic nerves, and the Sacral nerves. Surgical illustrations are used (Fig. 1) alongside real-time narrated video to help viewers recognize the normal course of commonly encountered pelvic nerves at the time of gynecologic surgery (Figs2-3). CONCLUSION: The surgical management of complex pelvic disease can unfortunately carry significant patient morbidity [3]. The neural pathways traveling through the pelvis via the hypogastric nerves are responsible for proprioception, vaginal lubrication, and proper functioning or the urethral and anal sphincters [4]. Sparing these nerves during pelvic surgery, and especially when anatomic planes are distorted by pelvic disease, requires surgical expertise and an immense understanding of pelvic neuroanatomy [4,5]. Preservation of the pelvic neural pathways is necessary to deliver the best patient outcomes while minimizing unwanted surgical complications. This video tutorial also highlights the origin of these nerves, their anatomic location, procedures in which these nerves may be encountered, and what sequelae occur from their unintended injury.

Novel Neurostimulation of Autonomic Pelvic Nerves Overcomes Bladder-Sphincter Dyssynergia.

The disruption of coordination between smooth muscle contraction in the bladder and the relaxation of the external urethral sphincter (EUS) striated muscle is a common issue in dysfunctional bladders. It is a significant challenge to overcome for neuromodulation approaches to restore bladder control. Bladder-sphincter dyssynergia leads to undesirably high bladder pressures, and poor voiding outcomes, which can pose life-threatening secondary complications. Mixed pelvic nerves are potential peripheral targets for stimulation to treat dysfunctional bladders, but typical electrical stimulation of pelvic nerves activates both the parasympathetic efferent pathway to excite the bladder, as well as the sensory afferent pathway that causes unwanted sphincter contractions. Thus, a novel pelvic nerve stimulation paradigm is required. In anesthetized female rats, we combined a low frequency (10 Hz) stimulation to evoke bladder contraction, and a more proximal 20 kHz stimulation of the pelvic nerve to block afferent activation, in order to produce micturition with reduced bladder-sphincter dyssynergia. Increasing the phase width of low frequency stimulation from 150 to 300 µs alone was able to improve voiding outcome significantly. However, low frequency stimulation of pelvic nerves alone evoked short latency (19.9-20.5 ms) dyssynergic EUS responses, which were abolished with a non-reversible proximal central pelvic nerve cut. We demonstrated that a proximal 20 kHz stimulation of pelvic nerves generated brief onset effects at lower current amplitudes, and was able to either partially or fully block the short latency EUS responses depending on the ratio of the blocking to stimulation current. Our results indicate that ratios >10 increased the efficacy of blocking EUS contractions. Importantly, we also demonstrated for the first time that this combined low and high frequency stimulation approach produced graded control of the bladder, while reversibly blocking afferent signals that elicited dyssynergic EUS contractions, thus improving voiding by 40.5 ± 12.3%. Our findings support advancing pelvic nerves as a suitable neuromodulation target for treating bladder dysfunction, and demonstrate the feasibility of an alternative method to non-reversible nerve transection and sub-optimal intermittent stimulation methods to reduce dyssynergia.

[Nerve sparing techniques in deep endometriosis surgery to prevent urinary or digestive functional disorders: Techniques and results: CNGOF-HAS Endometriosis Guidelines]. / Les techniques de préservation nerveuse dans la chirurgie de l'endométriose profonde pour prévenir les séquelles fonctionnelles urinaires et digestives : modalités techniques et résultats. RPC Endométriose CNGOF-HAS.

OBJECTIVES: To evaluate the feasibility and functional urinary and digestive results of nerve sparing techniques in endometriosis surgery. METHODS: A research on the medline/pubmed database using specific keywords (nerve sparing, endometriosis, pelvic nerves) identified 7 publications among about 50 whose purpose was to describe the feasibility, the techniques and the functional results of nerve preservation in this indication. Among them there are: 2 uncontrolled retrospective studies, 3 prospective non-randomized studies, a meta-analysis and a review of the literature. RESULTS: Nerve preservation requires a perfect knowledge of the anatomy of the pelvic autonomic system. The laparoscopic approach is preferred by the different authors due to its anatomical advantage. The feasibility of this technique seems to be demonstrated despite certain limitations in the different studies and depending of the retroperitoneal extension of the lesions. When feasible, it is likely to significantly improve postoperative urinary function (urinary retention) compared to a conventional technique. It is observed no difference regarding digestive function. CONCLUSIONS: Nerve sparing in this indication is a technique the feasibility of which has been demonstrated and is subject to the topography and extent of the disease. In the absence of invasion or entrapment of pelvic autonomic nerves by endometriosis, this technique improves postoperative voiding function (NP3). During pelvic surgery for endometriosis, it is recommended to identify and preserve autonomic pelvic nerves whenever possible (GradeC).

Total mesorectal excision for cancer: histological and immunohistochemical evidence of nerve removal and risk-factor analysis.

AIM: Whether or not nerve-sparing rectal-cancer surgery can effectively prevent removal of the pelvic autonomic nerves has not been substantiated microscopically. We aimed to analyse the quality of nerve preservation in female patients by quantifying residual nerve fibres in total mesorectal excision specimens, to analyse pro-erectile function of the nerve fibres removed and to determine risk factors for pelvic denervation. METHOD: Serial transverse sections from female patients, 64 ± 18 years of age, were studied after the mesorectal fascia was inked and studied histologically [using anti-S100 and anti-neuronal nitric oxide synthase (nNOS) antibodies]. Nerve fibres located within 1 mm of the inked surface were counted and analysed according to type of surgery, tumour location, pT stage, circumferential resection margin and the necessity for a posterior colpectomy. RESULTS: Twelve specimens were analysed. Per specimen, the mean number of nerve-fibre sections outside the mesorectum was 5.3 ± 3.6 (range: 1-12). The mean number of fibres per specimen was 6.4 ± 4.1 in patients having a low-rectal tumour and 4.4 ± 2.9 in those with mid or higher rectal tumours (P = 0.42). The mean number of fibres was higher (9.2) for T4 tumours than for T2/T3 tumours (5.0 ± 3.5), but this difference was not statistically sigmificant (P = 0.25). Patients having abdominoperineal excision, a posterior colpectomy or a circumferential resection margin of less than 1 mm had significantly more nerve fibres in the specimen (10.6 ± 1.9 vs 4.4 ± 2.8; P = .041). Fibres localized at the anterolateral rectum corresponded to branches of the neurovascular bundle, expressing rich pro-erectile activity (positive anti-nNOS immunostaining). CONCLUSION: The neurovascular bundle is a key risk zone for pelvic denervation during total mesorectal excision. Abdominoperineal excision, posterior colpectomy and an invaded circumferential resection margin are associated with perineal denervation.

Sensory innervation of the guinea pig colon and rectum compared using retrograde tracing and immunohistochemistry.

BACKGROUND: Neurons in lumbar and sacral dorsal root ganglia (DRG) comprise extrinsic sensory pathways to the distal colon and rectum, but their relative contributions are unclear. In this study, sensory innervation of the rectum and distal colon in the guinea pig was directly compared using retrograde labeling combined with immunohistochemistry. METHODS: The lipophilic tracer, DiI, was injected in either the rectum or distal colon of anesthetized guinea pigs, then DRG (T6 to S5) and nodose ganglia were harvested and labeled using antisera for calcitonin gene-related peptide (CGRP) and transient receptor potential vanilloid 1(TRPV1). KEY RESULTS: More primary afferent cell bodies were labeled from the rectum than from the distal colon. Vagal sensory neurons, with cell bodies in the nodose ganglia comprised fewer than 0.5% of labeled sensory neurons. Spinal afferents to the distal colon were nearly all located in thoracolumbar DRG, in a skewed unimodal distribution (peak at L2); fewer than 1% were located in sacral ganglia. In contrast, spinal afferents retrogradely labeled from the rectum had a bimodal distribution, with one peak at L3 and another at S2. Fewer than half of all retrogradely labeled spinal afferent neurons were immunoreactive for CGRP or TRPV1 and these included the larger traced neurons, especially in thoracolumbar ganglia. CONCLUSIONS & INFERENCES: In the guinea pig, both the distal colon and the rectum receive a sensory innervation from thoracolumbar ganglia. Sacral afferents innervate the rectum but not the distal colon. Calcitonin gene-related peptide immunoreactivity was detectable in fewer than half of afferent neurons in both pathways.

Pelvic intraoperative neuromonitoring during robotic-assisted low anterior resection for rectal cancer.

While the oncological outcome of patients with rectal cancer has been considerably improved within the last decades, anorectal, urinary and sexual functions remained impaired at high levels, regardless of whether radical surgery was performed open or laparoscopically. Consequently, intraoperative monitoring of the autonomic pelvic nerves with simultaneous electromyography of the internal anal sphincter and manometry of the urinary bladder has been introduced to advance nerve-sparing surgery and to improve functional outcome. Initial results suggested that pelvic neuromonitoring may result in better functional outcomes. Very recently, it has also been demonstrated that minimally invasive neuromonitoring is technically feasible. Because, to the best of our knowledge, pelvic neuromonitoring has not been performed during robotic surgery, we report the first case of robotic-assisted low anterior rectal resection combined with intraoperative monitoring of the autonomic pelvic nerves.

Pathophysiologic explanation for bladder retention in patients after laparoscopic surgery for deeply infiltrating rectovaginal and/or parametric endometriosis.

OBJECTIVE: To investigate pathophysiologic mechanisms involved in bladder retention after surgery for rectovaginal deeply infiltrating endometriosis (DIE). DESIGN: Retrospective case study. SETTING: Tertiary referral unit. PATIENT(S): All patients who presented at our center over the last 5 years with bladder retention developed after laparoscopic surgery for rectovaginal or parametric DIE. INTERVENTION(S): To assess the mechanisms involved in the pathogenesis of this complaint, we performed a step-by-step workup including patient history, clinical neuropelveologic assessment, cystoscopy, and video-urodynamic testing with pelvic floor electromyography and rectomanometry. MAIN OUTCOME MEASURE(S): Patient Perception of Bladder Condition, International Prostate Symptom Score, and the short-form version of the Urogenital Distress Inventory questionnaires. RESULT(S): Forty-seven patients were investigated in this study. Mean (±SD) interval from the surgery was 9.5 years (±4.3; range, 7-15 years). Eighteen patients developed acute paralytic motor bladder atony and 5 acute neurogenic bladder atony. Twenty-four patients developed chronic neurogenic bladder atony. The first symptom of chronic bladder retention was reduction of urinary frequency (after 5 years on average). The most frequent complaints that made patients aware of difficulties in voiding were a weak urinary stream (appearing on average 7 years after the procedure) and the need for Valsalva or Crede maneuver (on average 9 years after the procedure). CONCLUSION(S): Segmental rectum resection with parametric resection exposes the most patients to the risk of bladder motor paralytic retention. However, the most frequent etiology seems to be chronic myogenic destruction secondary to chronic bladder overdistention. Patients after surgery for DIE require a long follow-up, with particular attention paid to postvoid residual volumes.