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.

Obturator Nerve Injury in Robotic Pelvic Surgery: Scenarios and Management Strategies

BACKGROUND

Obturator nerve injury (ONI) is an uncommon complication of pelvic surgery, usually reported in 0.2-5.7% of cases undergoing surgical treatment of urological and gynecological malignancies involving pelvic lymph node dissection (PLND).

OBJECTIVE

To describe how an ONI may occur during robotic pelvic surgery and the corresponding management strategies.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed video content on intraoperative ONI provided by robotic surgeons from high-volume centers.

SURGICAL PROCEDURE

ONI was identified during PLND and managed according to the type of nerve injury.

RESULTS AND LIMITATIONS

The management approach varies with the type of injury. Crush injury frequently occurs at an advanced stage of PLND. For a crush injury to the obturator nerve caused by a clip, management only requires its safe removal. Three situations can occur if the nerve is transected: (1) transection with feasible approximation and tension-free nerve anastomosis; (2) transection with challenging approximation requiring certain strategies for proper nerve anastomosis; and (3) transection with a hidden proximal nerve ending that may initially appear intact, but is clearly injured when revealed by further dissection. Each case has different management strategies with a common aim of prompt repair of the anatomic disruption to restore proper nerve conduction.

CONCLUSIONS

ONI is a preventable complication that requires proper identification of the anatomy and high-risk areas when performing pelvic lymph node dissection. Prompt intraoperative recognition and repair using the management strategies described offer patients the best chance of recovery without sequelae.

PATIENT SUMMARY

We describe the different ways in which the obturator nerve in the pelvic area can be damaged during urological or gynecological surgeries. This is a preventable complication and we describe how it can be avoided and different management options, depending on the type of nerve injury.

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.

[Analysis of the results of laser destruction of the articular branch of the obturator nerve in elderly and senile patients with degenerative coxarthrosis.]

The aim of the study was to analyze the results of the use of laser destruction of the articular branch of the obturator nerve in elderly and senile patients with degenerative coxarthrosis. The results of treatment of 34 patients over 65 years of age with symptomatic degenerative diseases of the hip joint (HJD) and somatic contraindications for total hip arthroplasty have been prospectively studied. In the study group, in the period from 2017 to 2019, laser destruction of the articular branch of the obturator nerve (970 nm, frequency 9 Hz and power 3 W in a total dose of 100 J) was carried out. The average follow-up was 12 months. To assess the effectiveness of surgical treatment, the dynamics of the pain syndrome in the hip joint was analyzed according to the visual analogue scale, the quality of life according to the SF-36 questionnaire, the functional state of the hip joint according to the W.H.Harris scale and the presence perioperative surgical complications. As a result, it was found that the use of laser destruction of the articular branch of the obturator nerve in degenerative coxarthrosis in elderly and senile patients (if total hip arthroplasty was not possible) made it possible to significantly reduce the level of preoperative pain syndrome, restore the quality of life and improve the functional state of patients with low risks of surgical complications.

Minimally Invasive Therapies for Osteoarthritic Hip Pain: a Comprehensive Review

PURPOSE OF REVIEW

Osteoarthritis (OA) is a highly prevalent cause of chronic hip pain, affecting 27% of adults aged over 45 years and 42% of adults aged over 75 years. Though OA has traditionally been described as a disorder of "wear-and-tear," recent studies have expanded on this understanding to include a possible inflammatory etiology as well, damage to articular cartilage produces debris in the joint that is phagocytosed by synovial cells which leads to inflammation.

RECENT FINDINGS

Patients with OA of the hip frequently have decreased quality of life due to pain and limited mobility though additional comorbidities of diabetes, cardiovascular disease, poor sleep quality, and obesity have been correlated. Initial treatment with conservative medical management can provide effective symptomatic relief. Physical therapy and exercise are important components of a multimodal approach to osteoarthritic hip pain. Patients with persistent pain may benefit from minimally invasive therapeutic approaches prior to consideration of undergoing total hip arthroplasty. The objective of this review is to provide an update of current minimally invasive therapies for the treatment of pain stemming from hip osteoarthritis; these include intra-articular injection of medication, regenerative therapies, and radiofrequency ablation.

Contralateral Obturator Nerve to Femoral Nerve Transfer for Restoration of Knee Extension After Acute Flaccid Myelitis: A Case Report

CASE

A 7-year-old boy presented with left femoral and obturator nerves (ONs) palsy after an asthmatic attack with a viral prodrome, and his right lower limb was unaffected. He was diagnosed with acute flaccid myelitis (AFM) after positive spinal magnetic resonance imaging findings. After contralateral ON to femoral nerve transfer (CONFNT), his left quadriceps was reinnervated at 5.5 months, full knee extension was recovered at 14 months, and good functional outcomes were achieved at 31 months.

CONCLUSIONS

This first clinical report on CONFNT demonstrated a feasible good alternative in treating young patients with AFM with unilateral L2-L4 palsy and short duration of deficit.

Cooled Radiofrequency Neurotomy of the Articular Sensory Branches of the Obturator and Femoral Nerves - Combined Approach Using Fluoroscopy and Ultrasound Guidance: Technical Report, and Observational Study on Safety and Efficacy

BACKGROUND

Chronic hip joint pain is a common condition with an estimated prevalence of 7% in men and 10% in women, in a population sample aged over 45. Conservative treatment can include physical therapy, weight loss, a variety of pharmacologic agents ranging from nonsteroidal antiinflammatory drugs (NSAIDS) to opioids, and intraarticular injections with various substances. Definitive treatment of hip pain, however, has primarily centered on hip arthroplasty.

OBJECTIVE

We describe a novel anterior approach to cooled radiofrequency (RF) hip denervation under combined ultrasound (US) and fluoroscopy guidance to avoid the neurovascular femoral bundle and reach proper landmarks.

STUDY DESIGN

Retrospective chart review of consecutive cases.

SETTING

Interventional Pain Management urban private practice.

METHODS

Data on 52 RF ablations of the hip in 23 patients were retrospectively collected. RF ablation was conducted with patient supine and under guidance of fluoroscopy and US. While fluoroscopy was used to place RF probes to appropriate landmarks, sole purpose of using US was to avoid femoral neurovascular bundle. Data were collected on needle placement, stimulation parameters, and short- and long-term complications.

RESULTS

A total of 62 patients underwent 2 diagnostic blocks. Fifty-two of them had greater than 50% relief and agreed to RF ablation. Until now, the ablation was conducted in 23 patients. There were no adverse events, except one case of neuritis. Expectedly, the needle approach to the lateral articular branches of the femoral nerve was easily achieved with more than a 1 cm passage distance from the femoral nerve in all 52 RF cases (median 2.5 range 1-3.5 cm). Placement of the second trocar to the incisura acetabuli was more challenging; in 21 RF cases the passing distance was less than 1 cm (range 0.5 to 1.9 cm, median 0.8). Motor stimulation (2 Hz) at less than 1 V was positive for the obturator nerve in 26 cases, which resulted in electrode repositioning more laterally (2-5 mm). Change in the pain scores was from the baseline 7.61 ± 1.2 to 2.25 ± 1.4 after the RF ablation (P < 0.01). The time interval of pain relief was much longer for RF ablation.

LIMITATIONS

Limitations of this retrospective, observational study include lack of blinding and absence of a comparator group. We did not attempt to wean opioids in our patient population.

CONCLUSIONS

An anterior needle approach to the lateral articular branches of the femoral and obturator nerves, and subsequently RF denervation of these nerves, is a safe procedure when US needle guidance is combined with identification of landmarks using fluoroscopy.

KEY WORDS

Chronic hip pain, radiofrequency ablation, hip denervation.

A systematic review and meta-analysis of single-incision mini-slings (MiniArc) versus transobturator mid-urethral slings in surgical management of female stress urinary incontinence

BACKGROUND

To assess the current evidence of effectiveness and safety of single-incision mini-slings (MiniArc) versus transobturator midurethral slings in the management of female stress urinary incontinence (SUI).

METHODS

A systematic search was performed from the electronic databases including PubMed, EMBASE, and Cochrane Library by November 2017. Using RevMan5.3 statistical software, the primary outcomes including subject and objective cure rates at 6 to 24 months follow-up were evaluated. Meanwhile, analysis was also performed for comparing the secondary outcomes such as peri- and postoperative complications, operative data, and quality of life.

RESULTS

Six randomized controlled trials (RCTs) and 6 retrospective cohort studies involving 1794 patients with SUI were analyzed based on the inclusion criteria. On the basis of our analysis, MiniArc was proven to have a noninferior clinical efficacy compared with transobturator midurethral slings with respect to the objective cure rate (risk ratio [RR] = 0.98, 95% confidence interval [CI] 0.94-1.03, P = .43) and subjective cure rate (RR = 0.97, 95% CI 0.91-1. 04, P = .38). In addition, pooled analysis showed that MiniArc had significantly lower postoperative pain scores (mean difference [MD] = -1.70, 95% CI -3.17 to -0.23, P = .02) and less postoperative groin pain (RR = 0.42, 95% CI 0.18-0.98, P = .04). Moreover, the MiniArc group also had a significantly shorter operation time (MD = -6.12, 95% CI -8.61 to -3.64, P < .001), less blood loss (MD = -16.67, 95% CI -26.29 to -7.05, P < .001), shorter in-patient stay (MD = 1.30, 95% CI -1.74 to -0.86, P < .001), and less urinary retention risk (RR = 1.15, 95% CI 0.46-2.87, P = .77). However, overall evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MiniArc compared with transobturator slings.

CONCLUSIONS

This meta-analysis indicates that MiniArc is an effective method treating SUI. When compared with transobturator slings, it not only has a similar high cure rates, but also is associated with shorter operation time, less blood loss, more favorable recovery time, lower postoperative pain scores, less postoperative groin pain, less urinary retention, and absence of a visible wound. However, the findings of this study should be further confirmed by well-designed prospective RCTs with a larger patient series.

Robotic Resection of a Symptomatic Parasitic Leiomyoma From the Obturator Fossa

STUDY OBJECTIVE

To demonstrate a technique for robotically resecting a parasitic leiomyoma from the obturator fossa.

DESIGN

Case report and a step-by-step video demonstration of resection of a symptomatic parasitic leiomyoma (Canadian Task Force classification III).

SETTING

Tertiary referral center in New Haven, Connecticut.

INTERVENTIONS

This 48-year-old Caucasian female had undergone a previous total abdominal hysterectomy for uterine leiomyomas. She presented to her primary care provider with lower back pain radiating to the right groin and with a burning sensation on the medial aspect of the inner thigh. She denied any decrease in leg muscle strength. Pelvic magnetic resonance imaging revealed a 3.3-cm mass in the obturator fossa compressing the obturator nerve. She was subsequently referred to gynecologic oncology for resection of the mass, and was brought to the operating room for robotic resection. Once retroperitoneum on the right pelvic sidewall was explored, ureterolysis was performed. The external iliac artery and vein were then mobilized medially to access the obturator fossa. The mass was visualized at the sidewall. Safe resection of the obturator fossa mass requires identification of the obturator nerve. The specimen was resected off the right pelvic sidewall with traction-countertraction, gentle wiping, and grasping-tenting techniques. It was then placed in a laparoscopic bag and removed from the peritoneal cavity in a contained manner. The procedure was performed without any complications. The patient had an uneventful postoperative course and was discharged to home on postoperative day 0. Pathology revealed a benign leiomyoma. The patient was symptom-free at her 4-week postoperative visit.

CONCLUSION

Robotic resection of a symptomatic retroperitoneal mass in the obturator fossa was successfully performed, with resulting resolution of obturator neuropathy. Parasitic leiomyomas should be considered in the differential diagnosis for a patient presenting with an intraperitoneal or retroperitoneal mass with a history of previous surgery for leiomyomas.

Incidental injury and repair of obturator nerve during laparoscopic pelvic lymphadenectomy

OBJECTIVE

To demonstrate a surgical video wherein left obturator nerve was iatrogenically injured during pelvic lymphadenectomy and repaired immediately with laparoscopic epineural end-to-end tension free anastomosis.

METHODS

This is a step-by-step demonstration of an incidental injury and laparoscopic repair of left obturator nerve during pelvic lymphadenectomy. The patient was a 59year-old Hispanic female who was found to have endometrial adenocarcinoma. She was referred to our division for laparoscopic staging during which left obturator nerve was iatrogenically injured. After completion of left pelvic lymphadenectomy, proximal and distal cut ends of the obturator nerve were identified. Careful inspection revealed that the nerve was transected cleanly without any fraying of the edges. Tension-free reattachment of the edges seemed possible without further mobilization of the nerve since the resected part was approximately 5mm. The obturator nerve edges were oriented and stay sutures were placed in order to perform tension-free anastomosis. Epineural end-to-end coaptation was completed with 5-0 polypropylene sutures [1,2].

RESULTS

Postoperatively, the patient did not exhibit any clinically apparent loss of adductor function or any other neurologic deficiency and was discharged home on postoperative day one. Over 6months of follow-up, the patient experienced no residual neuropathy or deficit in the left thigh.

CONCLUSION

Laparoscopic repair of a transected obturator nerve during gynecologic surgery is feasible. In this case, immediate repair of the damaged nerve by an experienced laparoscopic gynecologic surgeon did not result in any neurologic deficit postoperatively.

Transection of the obturator nerve by an electrosurgical instrument and its immediate repair during laparoscopic pelvic lymphadenectomy: a case report

Obturator nerve injury seldom occurs in gynecologic surgery. However, gynecologic oncologic surgery, including pelvic lymph node dissection, increases the risk of this type of injury. Microsurgical techniques are usually performed for the repair of the nerve injury. Herein the authors report a case of obturator nerve injury caused by an electrosurgical instrument during laparoscopic pelvic lymphadenectomy, and its prompt repair by laparoscopic procedure in a 44-year-old patient with cervical cancer.

Combined ultrasound and fluoroscopic guidance for radiofrequency ablation of the obturator nerve for intractable cancer-associated hip pain

Management of pain from skeletal metastases is notoriously difficult. Case reports and case series have described radiofrequency ablation of the obturator nerve branches to the femoral head for treatment of intractable hip pain. Ablation of the obturator branches to the femoral head is technically difficult because of bony and vascular anatomy, including close proximity of the femoral vessels. Here we present the case of a 79-year-old woman with intractable right hip pain and inability to ambulate secondary to metastatic non-small cell lung cancer in the femoral head and acetabulum, treated with thermal radiofrequency ablation of the obturator and femoral nerve branches to the femoral head. Ablation of the obturator nerve was done via anterior placement of the radiofrequency needle under combined ultrasound and fluoroscopic guidance, passing the radiofrequency needle between the femoral artery and femoral vein. Real-time ultrasound guidance was used to avoid vascular puncture. Thermal radiofrequency ablation resulted in sustained pain relief, and resumption in the ability of the patient to ambulate. From this case we suggest that an anterior approach to the obturator nerve branches to the femoral head may be technically feasible using combined ultrasound and fluoroscopic guidance to avoid vascular puncture.

The role of neurolytic obturator nerve block to relieve pain due to cancer and osteoarthritis

Neurolytic obturator nerve block have been performed successfully to relieve pain due to osteolytic metastases of pelvic bone since 1981 in our Pain Clinic. The analgesic effect of one block lasts from three to four months and can be repeated as required. Following the block the patient can go home one hour later. In 2008 we started to perform the neurolytic obturator nerve block to relieve pain due to degenerative osteoarthritis of hip joint. It is a good choice for those patients, who are not enough fit to be operated, or during the waiting time of hip replacement surgery.

Obturator Nerve Entrapment

OBJECTIVE

Obturator neuralgia consists of pain radiating from the obturator nerve territory to the inner thigh.

METHODS

We report a case of idiopathic obturator neuralgia resulting from compression of the obturator nerve in the obturator canal, causing a case of nerve entrapment syndrome. The pain was characterized by its localization in the inguinal region and anterointernal side of the thigh, going down to the internal side of the knee. It was worse when standing or in a monopodal stance. Walking caused pain and a limp.

RESULTS

The diagnosis was confirmed by an analgesic block. The analgesic was infiltrated using a posterior approach and computer-assisted tomography, allowing the quality and specificity of the infiltration to be judged.

CONCLUSION

We describe, for the first time, a treatment of obturator neuralgia by a minimally invasive laparoscopic approach. This involved an obturator nerve neurolysis and section of the internal obturator muscle and the obturator membrane.

Vaginale Revision bei Irritation des N. obturatorius nach Burch-Kolposuspension

Irritation of the obturator-nerve within colposuspension is a possible complication because of topographic proximity between obturator-nerve and operating-field. The main symptoms are weakness of the adductor muscles, sensory disturbance of thigh till paralysis and pain in the operating- field early after surgery. Too lateral fixing of the sutures in the pectineal ligament above the obturator-channel can cause compression of the obturator-nerve. Precocious intervention is a precondition for complete remission of symptoms, retropubic revise of surgery is evident. The method outlined here describes vaginal access for re-surgery with lateral colpotomy and dissection of the proximal colposuspension s suture. In this way a recurrent laparotomy with additional trauma of the operating-field can be avoided. In the case described here, this method led to the patients complete remission.

Laparoscopic injury and repair of obturator nerve during radical prostatectomy

A 61-year-old man with bilateral Gleason score 7 (3+4) clinical Stage T1c prostate cancer was treated with laparoscopic bilateral pelvic lymphadenectomy and radical prostatectomy. The left obturator nerve was inadvertently transected during left obturator lymph node dissection and repaired by laparoscopic reapproximation.

Successful intramuscular neurotization is dependent on the denervation period. A histomorphological study of the gracilis muscle in rats

To characterize the extent to which reinnervation potential depends on the duration of denervation, intramuscular neurotization of the gracilis muscle was performed either immediately or 2, 4, 6, and 8 weeks after transection of the obturator nerve. For neurotization, the sciatic nerve was split into three fascicle groups and fixed intramuscularly. Muscle morphology after 6 weeks of regeneration was identified with anti-myosin immunohistochemistry and NADH staining. Newly formed motor endplates were characterized using acetylcholinesterase staining and electron microscopy. Wet muscle weight ratio indicated the functional state of synapses. Depending on the denervation period, three levels of regenerative outcome were evident. Best results were seen after immediate neurotization or after 2 weeks of denervation. Regeneration, although at a significantly lower level, also occurred after denervation periods of 4 and 6 weeks. Regeneration following neurotization after 8 weeks of denervation was negligible. Quantity and quality of motor endplate formation depended on the denervation period. Thus, in special clinical situations intramuscular neurotization within a distinct time window provides a good reconstructive option.

Muscle Flap Mass Preservation with End-to-Side Neurorrhaphy: An Experimental Study

The authors examined the preservation of rat gracilis muscle flap mass after motor and sensory end-to-side neurorrhaphy. The rat gracilis muscle flap model was designed based on a previous study. Twenty-four Sprague-Dawley rats were divided into three groups. In Group 1 (n = 8), the flap was denervated by transecting the obturator nerve. In Group 2 (n = 8), the flap was reinnervated by coapting the proximal saphenous nerve to the distal obturator nerve. In Group 3 (n = 8), the flap was reinnervated by coapting the motor branch of the femoral nerve to the distal stump of the obturator nerve. At 6 months postoperatively, the gracilis muscle flaps were examined, harvested, and weighed individually. Results showed that the flaps with motor nerve reinnervation retained good bulk, with a weight of 634.0 +/- 65.1 gm, which was statistically significantly higher than the denervated group (457.5 +/- 125.3 gm, p < 0.01). However, muscle mass preservation in the sensory reinnervated group (606.9 +/- 209.1 gm) was not significantly different, compared to the denervated group. Histology revealed atrophic changes in the denervated group, compared to the sensory and motor-reinnervated groups. The authors concluded that muscle mass can be preserved by end-to-side nerve repair. Motor nerve reinnervation is able to better arrest atrophic changes of the muscle flaps.

Results of termino-lateral neurorrhaphy to original and adjacent nerves

In this comprehensive investigation, we studied three different neurorrhaphy models in an attempt to elucidate the potential of termino-lateral nerve repair to original and adjacent nerves. In experimental group 1, the peroneal nerve was sectioned and then attached to the posterior tibial nerve in a termino-lateral fashion. In experiment group 2, the motor nerves to the gastrocnemius muscle were sectioned and then attached to the posterior tibial nerve in a termino-lateral fashion. In experimental group 3, the obturator nerve (L2-4) was sectioned and attached to the sciatic nerve (L4-6) in a termino-lateral fashion. For the control in each group, the same type of nerve used in each respective group was transected without repair. Experimental groups 1 and 2 showed viable axons in the peroneal nerve distal to the neurorrhaphy site. Experimental group 3 showed no viable axons at these sites. No regeneration was observed in the transected nerve without repair in all three control groups. This study suggests that termino-lateral neurorrhaphy is a viable means of repairing damaged nerves if the distal segment of the sectioned nerve is reattached to its original trunk distal to its original branch point. However, the results from experimental group 3 demonstrate that termino-lateral neurorrhaphy cannot be used to repair nerves when the donor and recipient nerves originate from different spinal cord levels.

Mechanoreceptors in collateral knee ligaments: an animal experiment

The mechanoreceptors in the collateral ligaments of the knee joint in rat hindlimbs were studied. In group II (n=10) the femoral and obturator nerves were sectioned. In both groups III and V (n=20) the sciatic nerve was sectioned. In group V (n=10) the sectioned sciatic nerve was sutured 4 weeks after sectioning. In group IV (n=10) all three nerves were sectioned. Group I (n=10) served as control. After 4 months all animals were killed. The ligaments of the knee joint were preserved and stained with gold chloride, paraffin-embedded and cut in sagittal serial sections. The results showed that 4 months after partial or total denervation of the limb, there was necrosis and a decrease in the number of mechanoreceptors, which was dependent upon the severity and site of the lesion. After suture of the sciatic nerve the increase in mechanoreceptors suggested a regenerative process.

Femoral and obturator neuropathies

Femoral, saphenous, and obturator neuropathies have diverse causes, many of which are iatrogenic. They have overlapping, but distinct, clinical features. Electrodiagnostic testing can distinguish between these disorders and others in the differential diagnosis. Imaging studies may demonstrate the origin of the neuropathy in some cases. Conservative treatment is usually sufficient, but occasionally surgical exploration of the affected nerve is indicated.

[Peroperative reconstruction of the obturator nerve of the minor pelvis]

Author presents a case report of 28-year-old female with the successful and immediate repair of the obturator nerve by sural graft, when was damaged during gynecological operation.

Benign schwannoma of the obturator nerve: a case report

We describe a schwannoma of the obturator nerve in a woman 66 years old. It was diagnosed only postoperatively because of the aspecificity of the symptoms. The difficulty of making a correct diagnosis during surgery is discussed, and the potential serious consequences of total excision of the nerve are described.

Microsurgical selective peripheral neurotomy in the treatment of spasticity in cerebral-palsy children

Spasticity represents the most handicapping sequelae of cerebral palsy in children. In this study, 28 children with spastic cerebral palsy were treated over the last 4 years by microsurgical selective peripheral neurotomy: 28 times the posterior tibial nerve for spastic foot deformity, 3 times the ulnar and median nerves for spastic flexion of wrist and fingers, 2 times the sciatic nerve for spastic knee flexion associated with spastic foot deformity and 3 times obturator nerves for spastic adductors. Results on spasticity with follow-up ranging from 3 to 48 months were as follows: spastic foot deformity was corrected in all patients with pure spasticity, 2 out of the 3 children with ulnar and median neurotomy improved, knee flexion and hip adduction were improved in the other 5 patients. Selective peripheral neurotomy is an effective procedure in the treatment of segmental harmful spasticity after failure of a well-conducted conservative treatment associating physiotherapy and antispasmodic medications. It must be performed before the fixed deformities and other orthopedic complications arise.

Percutaneous radiofrequency destruction of the obturator nerve for treatment of pain caused by coxarthrosis

Pain and restriction of movements in the hip joint due to coxarthrosis are common causes of patients' visits to their doctors. During the past few years, endoprosthetic surgery has been the most common surgical method for the treatment of this disease. Endoprosthetic operation is contraindicated for some patients in view of their excessive body weight or the presence of concurrent somatic diseases. In order to eliminate pain due to coxarthrosis, we have developed a new operation--percutaneous radiofrequency destruction of the obturator nerve--carried out at the point of its exit from the small pelvis through the obturator canal.

Comparison of muscle mass preservation in denervated muscle and transplanted muscle flaps after motor and sensory reinnervation and neurotization

The gracilis muscle model was used either as a denervated muscle in situ or as a transplanted flap in 273 rats to compare the trophic effects of muscle reinnervation and neurotization using sensory and motor nerves. The average gracilis muscle flap weighed 626 +/- 94 mg at the time of the initial procedure. Experimental muscles were examined 6 months following the procedure. In denervated, nontransplanted muscles, both motor nerve reinnervation and neurotization resulted in significantly preserved muscle mass, averaging 570 +/- 69 and 521 +/- 116 mg, respectively, compared with the denervated control average of 178 +/- 22 mg (p < 0.05). Sensory nerve reinnervation and neurotization produced much smaller trophic effects (p > 0.05). In transplanted gracilis free flaps, however, only direct reinnervation with motor or sensory nerves resulted in improved bulk preservation, with average weights of 313 +/- 83 and 327 +/- 91 mg compared with the control average of 201 +/- 76 mg (p < 0.05). Neither sensory nor motor neurotization was significantly effective in the free-flap model (p > 0.05). These data suggest that transplantation may alter the response of muscle to reinnervation.

Reinnervation of the rectum with a somatic nerve: a canine study

The purpose of this communication was to evaluate the possibility of rectal stimulation through nerve autografting. Eleven mongrel dogs were studied. The abdomen was opened under anesthesia. The obturator nerve was cut at its entrance into the obturator foramen and was embedded in a tunnel within the musculature of the rectal wall. Six months later, the abdomen was re-opened and bilateral pelvic ganglionectomy was done to denervate the rectum. As the urinary bladder was also denervated subsequent to the pelvic ganglionectomy, cystostomy was performed. Two bipolar electrodes were applied to the obturator nerve. The effects of electrostimulation were evaluated under basic conditions after urecholine and atropine administration and after xylocaine topical application to the obturator nerve. After bilateral pelvic neurectomy, the basic rectal pressure dropped (P < 0.05) and there was no response to urecholine or to atropine injection. Obturator nerve electrostimulation induced evoked potentials within the nerve as well as rectal pressure rise (P < 0.001); the former was abolished with xylocaine topical application to the nerve and the latter with atropine administration. Microscopic examination revealed that the Schwann cells and axons grew in the connective tissue between the rectal muscle bundles. In conclusion, reinnervation of the denervated rectum using a somatic nerve implant is possible. To our knowledge this study is the first to show "smooth' muscle excitability by stimulation of a somatic nerve implant.

[Schwannoma of the obturatorius nerve as differential diagnosis in cystic adnexa tumors]

We report on a case of benign retroperitoneal schwannoma involving the obturator nerve. Discussing the difficulties of diagnosis and treatment the following became clear: 1.) Clinical examination, ultrasound and computed tomography are not helpful to differentiate a retroperitoneal schwannoma from a cystic ovarian tumour; this problem can perhaps be overcome by MR imaging. 2.) The diagnosis should be borne in mind in cases of retroperitoneal tumours of unclear origin. Appropriate surgery is necessary to avoid nerve damage and paralysis.

Obturator nerve injury: a review of management options

Obturator nerve injury in obstetrics/gynecology and gynecologic oncology is thought to be infrequent. The reported consequences of this injury vary in severity and management options have not been well described. The functional anatomy, dual adductor muscle innervation, and inconstant accessory obturator nerve presence help explain variable outcome following neurotmesis. Intraoperative management centers around epineurial repair with surgical loupe magnification. With the assistance of postoperative physiotherapy this approach leads to satisfactory results.

Trophic regulation of acetylcholinesterase isoenzymes in adult mammalian skeletal muscles

This work addresses the physiological regulation of skeletal muscle acetylcholinesterase (AChE) isoforms by examining endplate-enriched samples from adult rat gracilis muscles 48 h after: low-intensity treadmill exercise; obturator nerve transection; nerve impulse conduction blockade by tetrodotoxin; acetylcholine (ACh) receptor (AChR) inactivation by alpha-bungarotoxin; and, addition of obturator nerve extracts to muscles in organ culture. Results document the important role(s) of functional AChRs and ACh-AChR interactions in the differential control of individual AChE isoenzymes. A theoretical model based on these and other findings considers that: AChR activation by spontaneously released ACh is the only neural factor required for the maintenance of G1 + G2 AChE; the amount of A12 AChE is determined by the combined effects of ACh and another neurogenic substance; although mechanisms intrinsic to myofibers control normal levels of G4 AChE, enhanced production of this isoform is initiated through increasing the frequency of ACh-AChR interactions.

[Resection of the obturator nerve for analgesic treatment of degenerative-deforming changes of the hip joint]

Resection of the obturator nerve in hip joint arthritis can eliminate or decrease pain depending on the obturator nerve share in the hip joint innervation. From 1986 to 1988 34 obturator neurectomies were performed in painful hip arthritis patients with temporary or permanent contraindications for hip arthroplasty. In 21 from 30 patients followed-up at least 3 months partial or total relief of pain was found. Extrapelvic obturator neurectomy technique and indications for this procedure were presented.

Intrapelvic obturator neurectomy in cerebral palsy

Results of 202 obturator neurectomies including 190 intrapelvic and 8 extrapelvic obturator neurectomies in 100 patients were evaluated. Obturator neurectomy, intrapelvic in particular, yielded gratifying results in properly selected patients. It controlled adductor spasticity, scissoring, improved perineal care and helped the patients in sitting and early ambulation. Pre- and post-operative intensive physiotherapy was necessary to get maximum benefit of the surgery. Poor motor status, low IQ, athetosis and inadequate post-operative care had adverse effect on final outcome.

Femoral obturator and sciatic neurectomy with iliacus and psoas muscle section for spasticity following spinal cord injury

The treatment of severe refractory spasticity following spinal cord injury may raise challenging therapeutic problems. Classical approaches involve various types of myelotomies, rhizotomies and intrathecal injections of neurolytic substances. Alternative approaches include percutaneous rhizotomies and, more recently, the possible use of electrical stimulation of the spinal cord. Certain cases, however, may not be amenable to commonly accepted techniques. An operative technique is presented which involves a suprapubic incision for an infraperitoneal approach to a femoral and obturator neurectomy and an incision of the iliacus and psoas muscles bilaterally. This may be followed, when indicated, by a bilateral infragluteal section of the sciatic nerves. This technique offers a viable surgical alternative to the treatment of spasticity following spinal cord injury in cases where other traditional methods are contraindicated or have failed.

Clinical and electromyographic evaluation of obturator neurectomy in severe spasticity

Obturator neurectomy was performed in 35 patients with severe spasticity of the lower limbs. Immediate release of excessive spasticity in the adductor group of muscles was observed and confirmed by E.M.G. In most cases, a beneficial reduction of spasticity in other groups of muscles in the lower limbs was also observed. As a result, rehabilitation of the patients was improved.

Insufficiency of the hip adductor after anterior obturator neurectomy in 42 children with cerebral palsy

Forty-two children with cerebral palsy treated between 1970 and 1982 for correction of adduction and internal rotation of the hip were studied. According to the combined procedures and the effects of surgical manipulations, two groups were evaluated. The results of release of the adductor longus and gracilis without anterior obturator neurectomy were satisfactory when combined with proximal release of medial hamstrings. Hypertonicity in hip adduction was relieved. In cases of loss of function of the adductor brevis with anterior obturator neurectomy, the results were not satisfactory, and hyperabduction of the hip was inadequate. The adductor brevis plays an important role in stability of the hip.

Obturator-nerve palsy resulting from intrapelvic extrusion of cement during total hip replacement. Report of four cases

Obturator neuropathy is an infrequently identified complication of total hip replacement that may cause debilitating pain. There have been isolated reports of this complication in the literature, but only one case has been published in which intrapelvic cement was the causative agent. We are describing the cases of four patients with obturator neuropathy after total hip replacement, documented by electromyography and attributed to intrapelvic extension of cement. In each patient the source of the symptoms was not initially apparent. In three of the patients the extruded cement and obturator nerve were explored surgically. One of the three patients was improved by obturator neurectomy. Of the other two patients, both treated by excision of cement, only one was improved. The fourth patient was not treated. Persistent pain in the groin and thigh, intrapelvic cement visible on plain roentgenograms, and adductor weakness after total hip replacement suggest that this complication has occurred. Electromyography can confirm the presence of obturator neuropathy. Based on this limited series, excision of the extruded cement and preservation of the nerve should be attempted only when the nerve is grossly normal and functional as determined by electrical stimulation at the time of surgical exploration; otherwise, obturator neurectomy should be considered.

[Blockade of the obturator nerve in transurethral electroresection of urinary bladder tumors]

Stimulation of obturator nerve during transurethral electroresection causes violent adductor muscle contraction, and is a major cause of inadvertent bladder perforation. General anesthesia with muscle relaxants is often required when the bladder tumor is in the area where the obturator nerve passes in close proximity to the inferolateral bladder wall. Recently obturator nerve block under spinal anesthesia during transurethral surgery have been reported in several papers, but the blockade is not completely reliable. Obturator nerve block using electrostimulator (neutracer) and insulated electroneedle (pole needle) was performed in 25 patients with bladder tumors during transurethral electroresection from October 1980 to December 1981. We herein describe the technique and results of local obturator nerve blockade. Use of neutracer and pole needle makes the obturator nerve block a completely reliable, safe and easy procedure.

Adductor tenotomy-obturator neurectomy

A 3.7-year follow-up study of 25 cerebral palsied children with 41 adductor tenotomies and obturator neurectomies showed significant improvement in hip abduction and acetabular development.

The obturator nerve block. Preventing damage of the bladder wall during transurethral surgery

During transurethral electroresection in the posterolateral bladder neck, trigone and posterior urethra, unintentional contractions of the thigh-adductor muscles may occur due to irritation of the obturator nerve. The sudden displacement of the bladder wall against the cutting loop may cause a perforation of the bladder. The authors describe the topographic relation of the bladder wall to the passage of the obturator nerve in the minor pelvis. The technique of obturator nerve block by local anaesthesia is described and its efficacy is demonstrated in 21 patients.

Hip adductor transfer compared with adductor tenotomy in cerebral palsy

In a ten-year study in patients with cerebral palsy, fifty patients had ninety-eight adductor transfers and fifty-two patients had 102 adductor tenotomies with or without obturator neurectomy. The groups were similar with regard to severity of their disease, age, and associated concomitant surgery. Results were evaluated in three ways: functional change, change in passive motion of the hip, and change in stability of the hip. Our data support the view that although the adductor transfer operation takes longer and is associated with a higher incidence of postoperative drainage, the over-all improvement is greater and is maintained better than that after adductor tenotomy with or without neurectomy. The transferred muscle provides greater pelvic stability, decreases hip-flexion contractures, and reduces instability of the hip.

[Spasm of the adductor muscles, pre-dislocation and dislocations of the hip joints in children and adolescents with cerebral palsy. Clinical observations on aetiology, pathogenesis, therapy and rehabilitation. Part I: The effect of open myotenotomy of the gracilis muscle and of the long and short adductor muscles in connection with total extrapelvine resection of the obturator nerve, on the hip joints and static function (author's transl)]

Spasm and contraction of the adductor muscles involve, on the one hand, danger in respect of the development of a dislocation of the hip, and are a serious impediment to a walking ability on the other. Hence, surgery is often necessary. The article reports on the results of consequent weakening of the adductor muscles as a result of open myotenotomy in association with complete extrapelvine resection of the obturator nerve. 27 patients were subjected to surgery--in most cases bilaterally--at an age between 2 years and 5 months and 18 years, with a follow-up period of up to 15 years. The study does not include patients with spastic dislocation of the hip in whom this method was applied on the non-dislocated side and on the dislocated side in combination with iliopsoas tenotomy. This method makes it possible to achieve regression of existing defective positions of the hip joints. In a few cases, the valgus position of the neck of the femur was corrected to some extent. In two patients it was not possible to prevent the progress of a developing dislocation of the hip. These results show that, whereas the adductor muscles represent an essential factor for the occurrence of a spastic dislocation of the hip, other forces are most probably also involved. In the majority of cases, results were favourable in respect of the static function, although in some cases the success became evident after several years only, especially in mentally retarded patients and in apathetic individuals. Important for therapeutic success is the follow-up. The principles of its therapy are thoroughly discussed. Surgery is indicated only in special cases. Indications must be observed very strictly, since the risk of excessive weakening of the adductor muscles should not be underestimated.

Multiple sclerosis and surgery

Five patients with multiple sclerosis showed deterioration following operation and anaesthesia. In every case the change was associated with pyrexis due to infection. No correlation was found between aggravation and any anaesthetic agent used.

[Indications and technics of trans-obturator by pass]

Starting from a clinical case in which a trans-obturator by-pass was necessary, the most recent findings as regards the technique of this and its indications are reviewed. The procedure is to be considered a valid alternative in cases of ischaemic revascularization when the usual Scarpa triangle route cannot be used.