Robotic-Assisted Resection of a Benign Schwannoma of the Obturator Nerve: A Rare Case.

BACKGROUND Neurilemmomas are rare tumors derived from the Schwann cells that comprise the peripheral nerve sheaths. They have a slow growth and rarely display malignancy. Early diagnosis is rare, and the treatment consists by surgical resection. Although robotic-assisted surgery is commonly used for treating retroperitoneal diseases, there are few reports of resection of retroperitoneal and pelvic schwannoma through robotic-assisted surgery. In the present study, we reported a case of complete excision of a benign retroperitoneal schwannoma of the obturator nerve by robotic-assisted surgery. CASE REPORT A 51-year-old woman was referred by her gynecologist for left pelvic discomfort of a 3-month duration. The physical examination was normal, but a computerized tomography scan of the abdomen and pelvis showed an expansive pelvic lesion in the topography of the left iliac vessels, a hypodense contrast enhancement measuring 4.6×3.4 cm. Magnetic resonance imaging showed an extraperitoneal lesion located medially and inferiorly to the left external iliac vessels, with a size of 4.9×3.7 cm, and of probable neural etiology. Surgical resection of the tumor was recommended because of the diagnostic hypothesis of obturator nerve schwannoma. CONCLUSIONS This case showed that retroperitoneal neurilemmomas are difficult to diagnose owing to a lack of specific symptoms, and the best treatment is complete tumor resection. The use of robotic techniques gives greater dexterity to the surgeon, since it provides high-definition 3-dimensional vision, which can make the removal of retroperitoneal tumors susceptible to minimally invasive resection in a safe and effective way.

Uterine Fibroid-Induced Compressive Neuropathy of Lumbar Plexus and Obturator Nerve.

Introduction: Uterine fibroids are the most common gynecologic tumors in reproductive-aged women with a prevalence of up to 80%. Symptoms can range from heavy vaginal bleeding and bulk symptoms to, less frequently, deep vein thrombosis and bowel obstruction. Case Description: A 32-year-old female patient presented with acute-onset of right groin and knee pain, and difficulty ambulating. A large posterior uterine fibroid was found to be compressing branches of the lumbar plexus, including the obturator nerve. The patient underwent gynecologic evaluation and an urgent laparoscopic myomectomy. Postoperatively, she had significant improvement in neurologic symptoms. She continued physical therapy for residual mild paresthesia and pain with prolonged ambulation. Discussion: Large pelvic masses such as uterine fibroids should be considered on the differential diagnosis for acute-onset non-gynecologic symptoms such as compressive neuropathy, which require urgent evaluation and possible surgical management.

Effect of obturator nerve block during transurethral resection of bladder tumors on the disease recurrence, progression and surgery outcomes.

OBJECTIVE: In our study, we aimed to evaluate the effect of the obturator nerve block (ONB) on the operation time, duration of hospital stay, complete resection, presence of muscle tissue in the pathology, second resection, recurrence, and progression, when applied in addition to spinal anesthesia in patients with primary bladder lateral wall tumor and Transurethral Resection of Bladder Tumor (TURBT) was planned. MATERIALS AND METHODS: Seventy patients with bladder lateral wall tumors were included in the study. In addition, ONB was applied to 35 of the patients who underwent spinal anesthesia. The two groups were compared in terms of obturator reflex development, perforation, complete resection, presence of muscle tissue in pathology samples, need for second resection, need for second resection due to inadequate muscle tissue, and 1 year recurrence and progression rates. RESULTS: When the two groups were compared for obturator reflex and bladder perforation, both were found to be lower in the ONB group (p = 0.002, p = 0.198, respectively). The rate of complete resection and the presence of muscle tissue in the pathology samples were higher in the ONB group (p = 0.045, p = 0.034, respectively). The rates of second resection and second resection due to inadequate muscle tissue were found to be higher in the group without ONB (p = 0.015, p = 0.106, respectively). In the 1-year follow-up, the recurrence rate was significantly lower in the ONB group (p < 0.001), while there was no significant difference between the progression rates (p = 0.106). CONCLUSION: In our study, we found out that ONB applied in addition to spinal anesthesia increases the rate of complete and muscle tissue resection by decreasing the obturator reflex, and causes a significant reduction in the need for second resection and tumor recurrence.

Obturator Nerve Block for Transurethral Resection of Bladder Tumors.

Background: Bladder tumors are identified and treated using a surgical procedure called as transurethral resection of bladder tumors (TUR-BT). During TUR-BT resection, stimulation of the obturator nerve may cause violent adductor muscle spasms. The "obturator reflex," as this disorder is known, generally causes the legs to move inadvertently (leg jerking). Since this condition can cause several complications, it is preferable to avoid it. Objective: In this study, we investigated the effectiveness of spinal anesthesia combined with obturator nerve block or general anesthetic without muscle relaxant in preventing adductor muscle spasm during TUR-BT procedures. Methods: Forty consecutive patients were enrolled in a prospective observational evaluation and divided into two groups. Patients in Group I underwent spinal anesthesia along with an obturator nerve block, while those in Group II underwent general anesthesia without a neuromuscular relaxant. The following details were recorded: time for obturator block performance, the severity of the motor blockade, the length of the procedure in both groups because a probable adductor spasm might make it more difficult. The level of the surgeon's pleasure was noted throughout the surgery. Additionally, the patient's satisfaction and any issues that may have arisen were documented (the incidence of vascular puncture, hematoma, nerve damage, and visceral injury was noted). Results: Block performance time in Group I was 4.8±0.5 minutes, whereas it was 5.0±0.3 minutes in Group II. The ease of access for the two groups was the same. Group I demonstrated increased patient and surgeon satisfaction with a general anesthesia without neuromuscular relaxants and an obturatorius nerve block. Mean surgical time did not differ between the groups.There were no complications in either group. Conclusion: During such operations, routine use of ONB in combination with spinal anaesthetic or general anesthetic without a neuromuscular blocker can enhance oncological outcomes for patients, reduce complication rates, and extend the period of time spent living without disease.

Increased Plasma Ignition Distance Practice may Prevent the Obturator Reflex Occurrences and Compare of its Effectiveness Versus Obturator Block: A Prospective, Randomized, Controlled Study.

OBJECTIVE: To compare the ability of the obturator nerve block (ONB) and increased plasma ignition distance practice (IPDP) techniques to inhibit obturator nerve reflex (ONR) occurring with bipolar transurethral resection of the bladder. METHODS: Sixty patients who had a tumor placed at the lateral sidewall or had a tumor in another part of the bladder along with the lateral wall were randomly enrolled. Cystoscopic and ultrasonographic examinations and a computerized tomography scanning of the urinary bladder were used to determine the ONB side. Group 1 consisted of patients who had the ONB procedure. Group 2 consisted of patients who had IPIDP. The severity of the ONR was classified as severe, mild, and very mild. The study's primary endpoint was ONR occurrences and successful completion of the surgery. The secondary endpoints were bleeding and bladder perforation. RESULTS: There was a significant difference in the occurrence of ONR between the two groups (P = 0.0011). However, there was no significant difference between the two groups in the ability to resect the tumor and complete the surgery (P = .764). There was no correlation between the ONR and the tumor size (P = 0.478). CONCLUSION: Our study concluded that both ONB and IPIDP have comparable results, especially in resecting tumors and completing the operation. IPIDP has some advantages over ONB, such as shorter operative time, lower total costs, and less trained personnel requirements.

Outcome of transurethral resection of bladder tumour under spinal anaesthesia combined with obturator nerve block in Sri Lanka.

PURPOSE: Transurethral resection of bladder tumour (TURBT) is done under general anaesthesia (GA) with muscle relaxation to prevent obturator jerk and bladder perforation. TURBT under spinal anaesthesia (SA) with obturator nerve block (ONB) may prevent the obturator jerk while eliminating the disadvantages of GA. OBJECTIVES: To assess the outcome of TURBT under SA and ONB. METHODS: Patients undergoing TURBT for lateral wall tumours from 01.11.2017 to 30.10.2020 were prospectively studied. Anterior branch of obturator nerve with plain Bupivacaine was blocked with the guidance of an ultrasound scan and a nerve stimulator. Significant obturator jerk which necessitated conversion to GA was defined as failed ONB. RESULTS: Out of 72 patients with mean age of 66.7 years underwent ONB, 61 (84.7%) were men. Fifty two (72.2%) had unilateral and 20 (27.8%) had bilateral blocks. Sixty one (84.7%) patients had no obturator jerk whereas 5 (7%) had a mild jerk which did not preclude safe resection. Six patients (8.3%) had a failed ONB requiring conversion to GA. None had a bladder perforation requiring laparotomy, developed neurovascular injury or anaesthetic toxicity and only one patient required intensive care monitoring. CONCLUSION: SA with anterior branch of ONB is an effective and safe alternative to GA with muscle relaxation for TURBT although a randomized trial is necessary to determine the true efficacy and safety over the other.

Systematic Review and Meta-Analysis of Inguinal Versus Classic Obturator Nerve Block.

Obturator nerve block (ONB) has been widely applied in transurethral resection of bladder tumor and knee surgery to prevent serious complications such as bladder perforation or to improve the quality of anesthesia during knee surgery. The classic/pubic and inguinal ONB methods are the two primary approaches used. The classic and inguinal ONB methods are two techniques for anesthetizing the obturator nerve, and each method may result in different respective outcomes. We aimed to compare the efficacy of the classic and inguinal methods. We presumed the inguinal approach to be an overall superior technique because it was recently invented and has been reported to provide numerous benefits. This study included randomized controlled trials comparing classic and inguinal approaches to ONB. Two independent investigators extracted study-level data for a random-effects meta-analysis of the comparison between the classic approach and inguinal approaches. We identified five studies comprising 312 patients. The pooled results revealed a higher success rate (risk ratio, 1.15; 95% confidence interval [CI], 1.04-1.27), fewer puncture attempts (mean difference, -0.84; 95% CI, -1.55 to -0.12), and shorter procedure time (mean difference, -28.87; 95% CI, -47.19 to -10.54) for patients given inguinal ONB. The inguinal approach is, overall, the superior method for performing the ONB procedure. The inguinal method resulted in a higher success rate, fewer puncture attempts, and shorter procedure time.

Effectiveness and Safety of a Modified Technique of Transvesical Obturator Nerve Block to Avoid Adductor Contractions during Transurethral Resection of Bladder Tumors.

INTRODUCTION: The aim of the study was to evaluate the effectiveness of a modified transvesical obturator nerve block (ONB) in the prevention of obturator nerve reflex and consecutive bladder perforations (BPs) during transurethral resection of bladder tumors (TURBTs). MATERIALS AND METHODS: A retrospective analysis of all patients resected in 2014-2015 due to a bladder tumor of the lateral walls, including a follow-up period until December 2018, was performed. Two groups were defined: in the first group, all patients underwent TURBT with a modified transvesical ONB. The second group underwent conventional TURBT with intermittent resection. Primary endpoints were the rates of adductor contractions and BPs. RESULTS: Ninety-four out of 1,145 resected patients presented with tumors on the lateral wall of the bladder and a complete dataset including a long-term follow-up. Thirty-six patients were treated in the ONB group, and 58 patients comprised the control group. The median age in the 2 groups was 70.8 and 71.8 years in the first and second groups, respectively. Adductor spasms were reported in 8.33 versus 25.86% (p = 0.057) and perforation in 2.78 versus 17.24% (p = 0.047) in groups 1 and 2, respectively. After a median follow-up of 32.5 months, there was no significant difference in recurrence rates (52.78 vs. 51.72%, p = 0.672). In a subgroup analysis, lower perforation rates were recorded for the ONB group in patients with tumors <3 cm (0/30 vs. 8/46, p = 0.076) and in patients with unifocal tumors (0/12 vs. 5/23, p = 0.141). DISCUSSION/CONCLUSION: The simplified approach of transvesical ONB demonstrated in this study appears to be an inexpensive, safe, effective, and simple-to-use technique.

Peritoneal Retraction Pocket Defects and Their Important Relationship with Pelvic Pain and Endometriosis.

OBJECTIVE: The objective of this video is to demonstrate different clinical presentations of peritoneal defects (peritoneal retraction pockets) and their anatomic relationships with the pelvic innervation, justifying the occurrence of some neurologic symptoms in association with these diseases. DESIGN: Surgical demonstration of complete excision of different types of peritoneal retraction pockets and a comparison with a laparoscopic retroperitoneal cadaveric dissection of the pelvic innervation. SETTING: Private hospital in Curitiba, Paraná, Brazil. INTERVENTIONS: A pelvic peritoneal pocket is a retraction defect in the surface of the peritoneum of variable size and shapes [1]. The origin of defects in the pelvic peritoneum is still unknown [2]. It has been postulated that it is the result of peritoneal irritation or invasion by endometriosis, with resultant scarring and retraction of the peritoneum [3,4]. It has also been suggested that a retraction pocket may be a cause of endometriosis, where the disease presumably settles in a previously altered peritoneal surface [5]. These defects are shown in many studies to be associated with pelvic pain, dyspareunia, and secondary dysmenorrhea [1-4]. Some studies have shown that the excision of these peritoneal defect improves pain symptoms and quality of life [5]. It is important to recognize peritoneal pockets as a potential manifestation of endometriosis because in some cases, the only evidence of endometriosis may be the presence of these peritoneal defects [6]. In this video, we demonstrate different types of peritoneal pockets and their close relationship with pelvic anatomic structures. Case 1 is a 29-year-old woman, gravida 0, with severe dysmenorrhea and catamenial bowel symptoms (bowel distension and diarrhea/constipation) that were unresponsive to medical treatment. Imaging studies were reported as normal, and a laparoscopy showed a posterior cul-de-sac peritoneal pocket infiltrating the pararectal fossa, with extension to the lateral border of the rectum. Case 2 is a cadaveric dissection of a posterior cul-de-sac peritoneal pocket infiltrating the pararectal fossa, with extension to the pelvic sidewall. After dissection of the obturator fossa, we can observe that the pocket is close to the sacrospinous ligament, pudendal nerve, and some sacral roots. Case 3 is a 31-year-old woman, gravida 1, para 1, with severe dysmenorrhea that was unresponsive to medical treatment and catamenial bowel symptoms (catamenial bowel distention and diarrhea). Imaging studies were reported as normal and a laparoscopy showed left uterosacral peritoneal pocket infiltrating the pararectal fossa in close proximity to the rectal wall. Case 4 is a cadaveric dissection of the ovarian fossa and the obturator fossa showing the proximity between these structures. Case 5 is a 35-year-old woman, gravida 0, with severe dysmenorrhea that was unresponsive to medical treatment, referring difficulty, and pain when walking only during menstruation. A neurologic physical examination revealed weakness in thigh adduction, and the magnetic resonance imaging showed no signs of endometriosis. During laparoscopy, we found a peritoneal pocket infiltrating the ovarian fossa, with involvement in the area between the umbilical ligament and the uterine artery. This type of pocket can easily reach the obturator nerve. Because the obturator nerve and its branches supply the muscle and skin of the medial thigh [7,8], patients may present with thigh adduction weakness or difficulty ambulating [9,10]. Case 6 is a cadaveric dissection of the sacrospinous ligament and the pudendal nerve from a medial approach, between the umbilical artery and the iliac vessels. Case 7 is a 34-year-old woman, gravida 1, para 1, with severe dysmenorrhea and catamenial bowel symptoms as well as deep dyspareunia. The transvaginal ultrasound showed focal adenomyosis and a 2-cm nodule, 9-cm apart from the anal verge, affecting 30% of the bowel circumference. In the laparoscopy, we found a posterior cul-de-sac retraction pocket associated with a large deep endometriosis nodule affecting the vagina and the rectum. In all cases, endometriosis was confirmed by histopathology, and in a 6-month follow-up, all patients showed improvement of bowel, pain, and neurologic symptoms. CONCLUSION: Peritoneal pockets can have different clinical presentations. Depending on the topography and deepness of infiltration, they can be the cause of some neurologic symptoms associated with endometriosis pain. With this video, we try to encourage surgeons to totally excise these lesions and raise awareness about the adjacent key anatomic structures that can be affected.

Anatomic Study of the Bifurcation of the Obturator Nerve: Application to More Precise Surgical/Procedural Localization.

BACKGROUND: This anatomic study aimed to more precisely locate the bifurcation of the obturator nerve in relationship to the obturator foramen. Such information might improve outcomes in neurotization or other procedures necessitating exposure of the obturator nerve and could increase success rates for obturator nerve blockade. METHODS: Fourteen sides from fresh-frozen cadaveric specimens were used in this study. Dissection of the obturator nerve was performed, and its bifurcation into anterior and posterior branches was documented and classified. Measurements of these branches were also performed. Bifurcations of the obturator nerve were classified as type I when proximal to the obturator foramen, type II when inside the obturator foramen, and type III when distal to the obturator foramen. RESULTS: Type I, type II, and type III obturator nerve bifurcations were observed in 14.3%, 64.3%, and 21.4% of sides, respectively. In type I nerves, the mean distance from the bifurcation of the obturator nerve to the obturator foramen was 15.8 mm, and in type II nerves the mean was 14.0 mm. The mean diameter of the main trunk, anterior branch, and posterior branch was 3.74 mm, 2.64 mm, and 2.28 mm, respectively. CONCLUSIONS: Bifurcation of the obturator nerve can occur proximally, distally, or inside the obturator foramen. Therefore using imaging modalities such as ultrasound is strongly recommended for identifying the main trunk or anterior and posterior branches of the obturator nerve before surgery or other procedures aimed at this nerve due to such anatomic variations.

Obturator Intraneural Ganglion Cysts: Joint Connected and Underdiagnosed.

BACKGROUND: Intraneural ganglion cysts of the obturator nerve are rare. Our aim is to review cases of obturator intraneural ganglion cysts at our institution and those reported in the literature. METHODS: We reviewed all cases evaluated by the senior author. A literature search was performed using the PubMed database and Google Scholar with the following terms: "obturator cyst," "obturator intraneural ganglion cyst," and "obturator intraneural ganglia." All cases underwent a retrospective review. Patient demographic data, including age, sex, and presenting signs and symptoms were recorded. Imaging studies were re-evaluated by 2 musculoskeletal radiologists experienced in the diagnosis of intraneural ganglion cysts. RESULTS: We identified 2 cases of obturator intraneural ganglia at our institution; both were connected to the hip joint. We found 4 cases that were clearly diagnosed as intraneural ganglia in the literature, of which only 1 was recognized by the original authors as being joint connected, but based on our reinterpretation, 3 of 4 were joint connected. An additional 9 cases identified in the literature did not definitely report the nerve-cyst relationship, but based on our reinterpretation, were believed to be intraneural; 8 were joint connected. CONCLUSIONS: We believe that obturator intraneural ganglion cysts adhere to the principles of the unifying articular theory. They arise from the anteromedial hip joint and extend into an articular branch and can reach the parent obturator nerve. Surgery should address the hip disease and/or the articular branch connection. Not appreciating the pathoanatomy of these cysts can lead to persistent or recurrent cysts.

Anatomical study of the innervation of posterior knee joint capsule: implication for image-guided intervention.

BACKGROUND AND OBJECTIVES: Peripheral nerve block is an important component of the multimodal analgesia for total knee arthroplasty. Novel interventional techniques of ultrasound-guided nerve block supplying the posterior knee joint capsule require knowledge of the innervation of the posterior capsule. The objectives of this cadaveric study were to determine the course, frequency, and distribution of the articular branches innervating the posterior knee joint capsule and their relationships to anatomical landmarks. METHODS: Fifteen lightly embalmed specimens were meticulously dissected. The origin of articular branches was identified, their frequency recorded, and the course documented in relation to anatomical landmarks. The capsular distribution of articular branches was documented and a frequency map generated. RESULTS: In all specimens, articular branches from the posterior division of the obturator and tibial nerves were found to supply the posterior capsule. Additionally, articular branches from common fibular nerve and sciatic nerve were found in eight (53%) and three (20%) specimens, respectively. The capsular distribution of tibial nerve spanned the entire posterior capsule. The posterior division of obturator nerve supplied the superomedial aspect of the posterior capsule overlapping with the tibial nerve. The superolateral aspect of the posterior capsule was innervated by the tibial nerve and, when present, the common fibular/sciatic nerves. CONCLUSIONS: Frequency map of the course and distribution of the articular branches and their relationship to anatomical landmarks form an anatomical basis for peripheral nerve block approaches that provide analgesia to the posterior knee joint capsule.

Obturator Neuromodulation with Laparoscopic Placement of an Obturator Lead for the Treatment of Intractable Opioid-Dependent Chronic Pelvic Pain due to Obturator Neuralgia.

Chronic pelvic pain (CPP) is a common condition in women that can have a devastating effect on quality of life. Some of the most severe forms of CPP are related to peripheral nerve injuries, causing persistent neuropathic pain. We present a case of a young woman with severe opioid-dependent chronic pelvic and right groin pain due to obturator neuralgia. She had failed amultitude of treatments, including multiple medications, manual physical therapy, nerve blocks, surgical neurolysis, and spinal cord stimulation, without significant benefit. She underwent a trial of peripheral neuromodulation of the obturator nerve with laparoscopic placement of a quadripolar lead. During the 6-day trial, she experienced almost complete relief of her pain; therefore, she underwent permanent implantation of an intermittent pulse generator. Over the next 6 months, she was completely weaned off chronic opioids. At 23 months postimplantation, she had essentially no pain and was no longer receiving any analgesic, antidepressant, or membrane-stabilizing medications.

Neurofibroma involving obturator nerve mimicking an adnexal mass: a rare case report and PRISMA-driven systematic review.

BACKGROUND: Pelvic masses are a common gynecologic problem, and majority of them are diagnosed as ovarian tumors finally. Sometimes, it is hard to distinguish the origin of these pelvic masses. The following case is a solitary neurofibroma arising from the right-side obturator nerve, which was impressed as a right-side ovarian tumor initially. We reported this case, and also performed a PRISMA-driven systematic review to summary the similar cases in the literature. This review includes image, molecular and pathological findings and outcome of neurofibroma. CASE PRESENTATION: A 33-year-old woman with a regular menstrual period denied any symptoms or signs. During her physical check-up, image examination revealed a right-side heterogeneous pelvic mass; it was suggestive of a complex of right-side ovarian tumor. A provisional diagnosis of retroperitoneal pelvic mass, probably a benign ovarian tumor, was made. Excision of the right-side pelvic mass was performed. We sent the specimens for frozen pathology, which indicated neurofibroma and lipomatous tumor and that the possibility of liposarcoma cannot be excluded. A segment of the obturator nerve was attached to the tumor and was severed. A right-side obturator nerve tear during tumor excision was observed, and a neurosurgeon was consulted for obturator nerve grafting and repair. The patient complained of mild weakness and paresthesia affecting the right leg, and we consulted a rehabilitation doctor for neuron injury. The patient's recovery was uneventful, and she was discharged eight days after the drain was removed. Further rehabilitation treatment was arranged. CONCLUSION: A neurofibroma is an uncommon pelvic retroperitoneal tumor, and it can be misdiagnosed as an adnexal mass. To our knowledge, this is a rare case of a solitary neurofibroma arising from the obturator nerve. It usually does not have any neurological deficit. We present this case to demonstrate that pelvic neurofibroma can be mistaken for an adnexal mass. This fact should be borne in mind during the diagnosis process.

Obturator Internus Muscle Endometriosis with Nerve Involvement: a Rare Clinical Presentation.

STUDY OBJECTIVE: To describe our surgical approach in a rare case of deep infiltrating endometriosis of the obturator internus muscle with obturator nerve involvement. DESIGN: A step-by-step surgical explanation using video and literature review (Canadian Task Force Classification III). SETTING: Endometriosis can be pelvic or rarely extrapelvic and is classically defined as the presence of endometrial glands and stroma outside the uterine cavity [1,2]. Pain along the sensitive area of the obturator nerve, thigh adduction weakness and difficulty in ambulation are extremely rare presenting symptoms [2-4]. PATIENT: We report a case of a 32-year-old patient who presented with cyclic leg pain in the inner right thigh radiating to the knee caused by a cystic endometriotic mass in the obturator internus muscle with nerve retraction. The patient provided informed consent to use the surgical video. Institutional review board approval was obtained. INTERVENTIONS: Pelvic magnetic resonance imaging was performed and confirmed a nodular lesion of about 2.3 cm with high signal on T1WI and T2WI and without fat suppression on T2FS inside the right obturator internus muscle, suggesting an endometriotic lesion (Fig. 1). Surgical removal of the mass was performed using the laparoscopic approach. A normal pelvic cavity was found, and the retroperitoneal space was dissected. A mass located within the right obturator internus muscle, below the right iliac external vein, behind the corona mortis vein, and lateral to the right obturator nerve was identified. The whole region was inflamed, and the nerve was partially involved. Dissection was performed carefully with rupture of the tumor, releasing a chocolatelike fluid (Fig. 2), and the cyst was removed. Pathology examination was consistent with endometriosis. Patient improvement was observed, with pain relief and improved ability for right limb mobilization. No recurrence of endometriosis was found at the follow-up visit 6 months later. MEASUREMENTS AND MAIN RESULTS: The obturator nerve is responsible for motor and sensitive innervation of the joins and internal muscles of thigh and knee as well as the innervation of skin in the internal thigh. Pain along the sensitive area of the obturator nerve at the time of menstruation, thigh adduction weakness, difficulty ambulating, or paresthesia can be presenting symptoms with the involvement of the obturator nerve [5]. Besides paresthesia, our patient presented all the symptoms. The suspected diagnosis of obturator internus muscle endometriosis with retraction of the obturator nerve was confirmed by laparoscopic surgery and pathological examination of the excised tissue. To our knowledge, only 4 cases of endometriosis involving the obturator nerve have been described (according to MEDLINE searched in January 2017) [5-8]. The laparoscopic approach provided an excellent access to the retroperitoneal space, allowing fine dissection of the obturator nerve and the surrounding structures with complete removal of the cystic mass. CONCLUSION: We report a rare case of endometriosis with a single mass located inside the right obturator internus muscle with neuronal involvement of the obturator nerve. The fundamental role of laparoscopy was clearly demonstrated for the diagnosis and treatment of our patient.

Immune response in peripheral axons delays disease progression in SOD1G93A mice.

BACKGROUND: Increasing evidence suggests that the immune system has a beneficial role in the progression of amyotrophic lateral sclerosis (ALS) although the mechanism remains unclear. Recently, we demonstrated that motor neurons (MNs) of C57SOD1G93A mice with slow disease progression activate molecules classically involved in the cross-talk with the immune system. This happens a lot less in 129SvSOD1G93A mice which, while expressing the same amount of transgene, had faster disease progression and earlier axonal damage. The present study investigated whether and how the immune response is involved in the preservation of motor axons in the mouse model of familial ALS with a more benign disease course. METHODS: First, the extent of axonal damage, Schwann cell proliferation, and neuromuscular junction (NMJ) denervation were compared between the two ALS mouse models at the disease onset. Then, we compared the expression levels of different immune molecules, the morphology of myelin sheaths, and the presence of blood-derived immune cell infiltrates in the sciatic nerve of the two SOD1G93A mouse strains using immunohistochemical, immunoblot, quantitative reverse transcription PCR, and rotating-polarization Coherent Anti-Stokes Raman Scattering techniques. RESULTS: Muscle denervation, axonal dysregulation, and myelin disruption together with reduced Schwann cell proliferation are prominent in 129SvSOD1G93A compared to C57SOD1G93A mice at the disease onset, and this correlates with a faster disease progression in the first strain. On the contrary, a striking increase of immune molecules such as CCL2, MHCI, and C3 was seen in sciatic nerves of slow progressor C57SOD1G93A mice and this was accompanied by heavy infiltration of CD8+ T lymphocytes and macrophages. These phenomena were not detectable in the peripheral nervous system of fast-progressing mice. CONCLUSIONS: These data show for the first time that damaged MNs in SOD1-related ALS actively recruit immune cells in the peripheral nervous system to delay muscle denervation and prolong the lifespan. On the contrary, the lack of this response has a negative impact on the disease course.

A South Indian cadaveric study on obturator neurovascular bundle with a special emphasis on high prevalence of 'venous corona mortis'.

Surgical procedures in the pelvic region are very challenging because of the complex anatomy of this region. "Corona mortis" is a term used to describe retro-pubic anastomosis between the obturator and external iliac vessels. It is considered as a key structure as significant haemorrhage may occur if the vessels are cut accidentally during pelvic surgeries. Earlier studies have documented a high frequency of venous anastomosis compared to its arterial counterpart. The objective of our study was to document the prevalence of venous corona mortis in South Indian human adult cadaveric pelvises. We conducted this study on 73 cadaveric pelvic halves. Out of the 73 hemi pelvises, 36 were normal without any variations of the obturator vessels while 37 hemi pelvises (51%) showed the presence of abnormal obturator vessels which proves to be a very high incidence in terms of variations. Out of the 37 hemi pelvises, 25 (68%) showed the presence of 2 obturator veins, out of which 1 was normal and the other was an abnormal obturator vein. 8 hemi pelvises (22%) had only abnormal obturator vein. Most of the abnormal obturator veins drained into the external iliac vein, while two veins drained into inferior epigastric veins. Venous corona mortis is said to be frequently encountered during surgery and is considered to be as important as arterial corona mortis in its clinical implications. Individual evaluation of this risky anatomical structure should be done prior to any surgical interventions.

Obturator nerve block transurethral surgery for bladder cancer: comparison of inguinal and intravesical approaches: prospective randomized trial.

AIM: Transurethral resection of bladder tumors close to these areas may stimulate the obturator nerve, causing violent adductor contraction and possible inadvertent bladder perforation. To avoid this reaction, local anesthetic blockade of the obturator nerve as it passes through the obturator canal is effective in stopping adductor spasm during spinal anesthesia. METHODS: Forty-one patients undergoing (transurethral resection of bladder tumor) TUR-BT with spinal anesthesia who required (obturator nerve block) ONB were included in the study. After spinal anesthesia, ONB was performed with an inguinal approach (group 1) (n = 21) or an intravesical approach (group 2) (n = 20). In this study, we used 10 ml of 2 % lidocaine to perform the ONB. RESULTS: The mean age of patients was 60.8 ± 7.5 years. The groups were not different with regards to age, tumor localization and tumor size. There were two bladder perforations in group 1 and six perforations in group 2 (p = 0.130). However, the efficacy of ONB was significantly higher in inguinal approach group compared to intravesical approach group (p = 0.032). CONCLUSION: Obturator nerve block plays an additive role on the quality of analgesia for bladder surgery. Our data suggests that identification of the obturator nerve with ultrasound is easy and the block can be assessed by observing avoidance of bladder spasm.

Bilateral obturator neuropathy after transobturator vaginal sling: a case report.

Transobturator tape procedure is a popular and effective minimally invasive technique to treat stress urinary incontinence. We report a case of transient obturator neuropathy caused by transobturator tape placement for stress urinary incontinence. Findings on physical examination were significant for bilateral obturator neuropathy resulting in significant motor deficit, prompting removal of the sling to avoid the potential of prolonged or permanent morbidity. There was immediate complete resolution of neuropathy with the return of motor function after surgical removal of the sling.