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.

The obturator nerve originates from the lumbar plexus and innervates sensation in the thigh and movement of the adductor muscle group of the hip. Reports on physical therapy for patients with obturator nerve injuries have been limited due to insufficient injuries, and there have been no reports on rehabilitation after neurotmesis. Furthermore, there are no reports on the status of activities of daily living (ADL) and details of physical therapy in patients with paralysis of the adductor muscle group. In this study, we reported on a patient with adductor paralysis due to obturator neurotmesis, including the clinical symptoms, characteristics of ADL impairment, and effective movement instruction. The patient is a woman in her 40\'s who underwent laparoscopic total hysterectomy, bilateral adnexectomy, and pelvic lymph node dissection for uterine cancer (grade-2 endometrial carcinoma). During pelvic lymph node dissection, she developed an obturator nerve injury. She underwent nerve grafting during the same surgery by the microsurgeon. Donor nerve was the ipsilateral sural nerve with a 3-cm graft length. Due to obturator nerve palsy, postoperative manual muscle test results were as follows: adductor magnus muscle, 1; pectineus muscle, 1; adductor longs muscle, 0; adductor brevis muscle, 0; and gracilis muscle, 0. On postoperative day 6, the patient could independently perform ADL; however, she was at risk of falling toward the affected side when putting on and taking off her shoes while standing on the affected leg. The patient was discharged on postoperative day 8. Through this case, we clarified the ADL impairment of a patient with adductor muscle palsy following obturator neurotmesis, and motion instruction was effective as physical therapy for this disability. This case suggests that movement instruction is important for acute rehabilitation therapy for patients with hip adductor muscle group with obturator neurotmesis.

Large acetabular paralabral cysts can cause compression of the surrounding neurovascular structures leading to sensory and motor deficits. We present a 68-year-old man with obturator nerve denervation from a paralabral cyst secondary to a labral tear associated with femoroacetabular impingement syndrome. Resolution of symptoms and return to full activities were achieved at 3 months and maintained beyond 1 year through open cyst excision, obturator neurolysis, arthroscopic femoral osteoplasty, and labral repair in the same surgical setting. The patient had a successful clinical outcome, with pain and dysfunction resolution.
Large paralabral cysts may cause obturator nerve compression, which can be successfully treated with open nerve decompression and arthroscopic treatment of labral pathology.

BACKGROUND: Although small bowel obstruction (SBO) is a major complication occurring after abdominal surgery, few reports have described strangulated SBO after pelvic lymphadenectomy (PL). This report describes two cases of strangulated SBO caused by a skeletonized obturator nerve and pelvic vessels after laparoscopic PL during gynecologic surgery.
METHODS: Case 1: A 57-year-old woman with endometrial cancer underwent a laparoscopic semi-radical total hysterectomy with PL. Nine months after the operation, she visited our emergency room complaining about subacute pain spreading in the right groin, right buttock, and dorsal part of the right thigh. She had no abdominal pain. Although her symptoms were not typical, computed tomography (CT) revealed strangulated SBO in the right pelvis. Laparoscopic surgery revealed that the small bowel was ischemic. Then we converted to open surgery. We transected the right obturator nerve and umbilical artery, which constructed an internal hernia orifice in the right pelvis, followed by resection of the ischemic small bowel. Fortunately, during 6-month follow-up, she showed only slight difficulty in walking as a postoperative complication. Case 2: A 62-year-old woman with cervical cancer underwent laparoscopic radical hysterectomy with PL. Six months after the operation, she visited our hospital emergently because of sudden onset of abdominal pain and vomiting. CT showed strangulated SBO. Urgent laparoscopic surgery exhibited the incarcerated small bowel at the right pelvis. Consequently, we converted to open surgery. The terminal ileum was detained into the space constructed by the right umbilical artery. We cut the umbilical artery and performed ileocecal resection. After the surgery, she was discharged with no complication or sequela.
CONCLUSIONS: When examining a patient after PL who complains of severe pain or symptoms, one should consider the possibility of PL-related SBO, even if the pain is apparently atypical for SBO.

We herein report three cases of obturator nerve injury, which is rare in gynecological surgery. In all cases, it was difficult to suture both nerve ends without tension. Therefore, we used a PGA-collagen tube to interpose the nerve defect. After follow-ups of at least seven months, all three patients were able to adduct the hip joint and medial thigh sensations also improved. These results suggest the potential of a PGA-collagen tube in the treatment of obturator nerve injury.

Schwannomas are typically benign tumours of the peripheral nerves. However, they seldom arise from the obturator nerve. We report a case of an uncommon swelling (2.5 × 3.5 cm) in a 65-year-old male cadaver, found during a routine dissection session for first Bachelor of Medicine and Surgery students in the Department of Anatomy, Kasturba Medical College, Manipal, India, in 2019. It was seen originating from the left obturator nerve in the pelvis at the level of the sacral promontory. Histopathological investigation revealed a schwannoma. The hypocellular tumour was arranged in a sweeping fascicle pattern with patches of myxoid degeneration. Obturator schwannomas, though rare, can exist in cadavers, as seen in the present case. Hence, it should be considered as a differential diagnosis for clinical cases of pelvic masses and eliminated only after thorough radiological examination. Knowledge about the existence of such schwannomas is therefore essential.

Obturator nerve injury is an uncommon complication frequently associated with pelvic gynecologic or urologic cancer surgery. It can lead to disability or adversely affect quality of life. Large segmental defects are particularly difficult to manage as the limited mobility of the nerve prevents tension-free direct end-to-end anastomosis. A 36-year-old woman with cervical cancer underwent sentinel lymph node biopsy, laparoscopic radical hysterectomy, and bilateral adnexectomy. During the procedure, the sentinel lymph node (right obturator node) adherent to the obturator nerve was resected together with the nerve segment leaving a 3 cm defect. Immediate laparoscopic obturator nerve repair was performed using an artificial nerve conduit leading to successful recovery. We report this unique case due to rarity of large segmental obturator nerve defects and present laparoscopic nerve repair with artificial nerve conduits as a useful treatment alternative of these important injuries, without nerve donor site morbidity.

Bone cancer metastasis may produce severe and refractory pain. It is often difficult to manage with systemic analgesics. Chemical neurolysis may be an effective alternative in terminally ill patients.
Female terminally ill patient with hip metastasis of gastric cancer in severe pain. Neurolytic ultrasound-guided blocks of the pericapsular nerve group and obturator nerve were performed with 5% phenol. This led to satisfactory pain relief for 10 days, until the patient\'s death.
This approach may be effective and safe as an analgesic option for refractory hip pain due to metastasis or pathologic fracture in terminally ill patients.

The obturator nerve lies deep within the pelvis, and it can be damaged by direct injury during surgery. In this study, nerve conduction was used to confirm an obturator nerve injury in a patient who presented with hip adductor weakness following gynecological surgery for endometrial cancer. A 56-year-old woman complained of weakness in the right adductor muscles after a laparoscopic hysterectomy due to endometrial cancer. Seven days after surgery, the degree of weakness of the right hip adductor was Medical Research Council (MRC) Scale 1; thus, a nerve conduction velocity test was conducted. To obtain the compound muscle action potentials of the obturator nerve, stimulation was performed (1.5 cm inferior and 1.5 cm lateral to the pubic tubercle) with a surface electrical simulator and recording (midpoint of the right medial thigh) of the adductor muscles. The compound muscle action potentials of the right obturator nerve showed lower amplitude (left side: 2.7 mV vs. right side: 0.3 mV) and delayed onset latency (left side: 3.2 ms vs. right side: 2.2 ms). These results indicate a partial right obturator neuropathy. Therefore, nerve conduction could be useful to diagnose an early-stage obturator nerve injury and provide information on the degree of damage.

Objective: Femoral nerve palsy occurs after trauma, surgical procedures and tumors and leads to loss of quadriceps functions, disability and decreased quality of life. The aim of this report was to describe a successful restoration of knee extension by transferring the anterior branch of the obturator nerve to selective branches of the femoral nerve at the thigh level.Methods: We describe a 27-year-old male who had quadriceps femoris muscle paralysis after surgical evacuation for retroperitoneal hematoma five months ago. Since proximal stump of femoral nerve was not accessible, we transferred anterior branch of obturator nerve to selective branches of femoral nerve for reconstruction of quadriceps femoris muscle.Results: After four months, he regained quadriceps muscle strength M3 and began to walk. He achieved full muscle strength (M5) nine months after surgery and was able to walk up-stairs easily 14 months after surgery and atrophy of the quadriceps was improved.Conclusion: The anterior branch of the obturator nerve is an available donor nerve with an excellent functional recovery for the reconstruction of knee extension when proximal stump of femoral nerve is not reachable or the repair needs a long graft.