Minimally Invasive Approaches for Lumbosacral Plexus Schwannomas.

BACKGROUND AND OBJECTIVES: Lumbosacral plexus schwannomas (LSPSs) are benign, slow-growing tumors that arise from the myelin sheath of the lumbar or sacral plexus nerves. Surgery is the treatment of choice for symptomatic LSPSs. Conventional retroperitoneal or transabdominal approaches provide wide exposure of the lesion but are often associated with complications in the abdominal wall, lumbar or sacral plexus, ureter, and intraperitoneal organs. Advances in technology and minimally invasive (MIS) techniques have provided alternative approaches with reliable efficacy compared with traditional open surgery. We describe 3 MIS approaches using tubular retractor systems according to the lesion level. METHODS: This was a multicenter, retrospective observational cohort study to evaluate the use of MIS tubular approaches for surgical resection of LSPSs. We included 23 lumbar and upper sacral plexus schwannomas. Clinical presentation, spinal level, surgical duration, degree of resection, days of hospitalization, pathological anatomy of the tumor, approach-related surgical difficulties, and outcomes were collected. RESULTS: The posterior oblique approach was used in 43.5% of the cases, the transpsoas approach in 39.1%, and the transiliac in 17.4%. The mean operative time was 3.3 hours, and the mean hospitalization was 2.5 days. All tumors were WHO grade 1 schwannoma. Postoperative MRI confirms gross total resection in 91.3% of the patients. No patient requires instrumentation. The pros and cons of each approach were summarized. CONCLUSION: The MIS approaches adapted to the lumbar level may improve surgeons' comfort allowing a safe resection of retroperitoneal LSPS.

Surgical and oncologic outcomes in dogs with malignant peripheral nerve sheath tumours arising from the brachial or lumbosacral plexus.

Malignant peripheral nerve sheath tumours (MPNST) of a plexus nerve or nerve root cause significant morbidity and present a treatment challenge. The surgical approach can be complex and information is lacking on outcomes. The objective of this study was to describe surgical complication rates and oncologic outcomes for canine MPNST of the brachial or lumbosacral plexus. Dogs treated for a naïve MPNST with amputation/hemipelvectomy with or without a laminectomy were retrospectively analysed. Oncologic outcomes were disease free interval (DFI), overall survival (OS), and 1- and 2-year survival rates. Thirty dogs were included. The surgery performed was amputation alone in 17 cases (57%), and amputation/hemipelvectomy with laminectomy in 13 cases (43%). Four dogs (13%) had an intraoperative complication, while 11 dogs (37%) had postoperative complications. Histologic margins were reported as R0 in 12 dogs (40%), R1 in 12 dogs (40%), and R2 in five dogs (17%). No association was found between histologic grade and margin nor extent of surgical approach and margin. Thirteen dogs (46%) had recurrence. The median DFI was 511 days (95% CI: 140-882 days). The median disease specific OST was 570 days (95% CI: 467-673 days) with 1- and 2-year survival rates of 82% and 22% respectively. No variables were significantly associated with recurrence, DFI, or disease specific OST. These data show surgical treatment of plexus MPNST was associated with a high intra- and postoperative complication rate but relatively good disease outcomes. This information can guide clinicians in surgical risk management and owner communication regarding realistic outcomes and complications.

Elimination of Lumbar Plexus Injury by Changing the Entry Point and Traction Direction of the Psoas Major Muscle in Transpsoas Lateral Lumbar Spine Surgery.

Background and Objectives: The lateral approach is commonly used for anterior column reconstruction, indirect decompression, and fusion in patients with lumbar degenerative diseases and spinal deformities. However, intraoperative lumbar plexus injury may occur. This is a retrospective comparative study to investigate and compare neurological complications between the conventional lateral approach and a modified lateral approach at L4/5. Materials and Methods: Patients with a lumbar degenerative disease requiring single-level intervertebral fusion at L4/5 were included and categorized into group X and group A. Patients in group X underwent conventional extreme lateral interbody fusion, while those in group A underwent a modified surgical procedure that included splitting of the anterior third of the psoas muscle, which was dilated by the retractor on the anterior third of the intervertebral disc. The incidence of lumbar plexus injury, defined as a decrease of ≥1 grade on manual muscle testing of hip flexors and knee extensors and sensory impairment of the thigh for ≥3 weeks, on the approach side, was investigated. Results: Each group comprised 50 patients. No significant between-group differences in age, sex, body mass index, and approach side were observed. There was a significant between-group difference in intraoperative neuromonitoring stimulation value (13.1 ± 5.4 mA in group X vs. 18.5 ± 2.3 mA in group A, p < 0.001). The incidence of neurological complications was significantly higher in group X than in group A (10.0% vs. 0.0%, respectively, p < 0.05). Conclusions: In our modified procedure, the anterior third of the psoas muscle was entered and split, and the intervertebral disc could be reached without damaging the lumbar plexus. When performing lumbar surgery using the lateral approach, lumbar plexus injury can be avoided by following surgical indication criteria based on the location of the lumbar plexus with respect to the psoas muscle and changing the transpsoas approach to the intervertebral disc.

Surgical Management of Lumbosacral Plexus Tumors.

BACKGROUND: Lumbosacral plexus tumors are uncommon, and because of their deep location and proximity to critical nerves subserving lower extremity function, understanding surgical approaches and short-term outcomes is important. METHODS: In a retrospective case series of lumbosacral plexus tumor surgeries performed from May 2000 to July 2021 by a single neurosurgeon, demographic information, clinical presentation, imaging studies, and operative outcomes were analyzed. RESULTS: A total of 42 patients with mean age of 48.3 years (range, 16-84 years) underwent surgery for a lumbosacral plexus tumor. Patients presented with leg pain (n = 25; 59.5%), followed by back/flank pain (n = 5; 11.9%), abdominal/pelvic pain (n = 5; 11.9%), leg weakness (n = 5; 11.9%), and leg numbness (n = 3; 7.1%). The most common tumor pathology was schwannoma (n = 20; 50.0%) followed by neurofibroma (n = 9; 22.5%). A retroperitoneal approach was used in all cases. Gross total resection was achieved in 23 (54.8%) patients, and only 1 (2.4%) patient exhibited symptomatic tumor recurrence after subtotal resection of a malignant tumor. Mean follow-up was 33.1 months (range, 1-96 months). Postoperatively, patient neurological status remained unchanged or improved (n = 37; 88.1%). Complications were infrequent, with 4 (9.5%) patients experiencing new sensory symptoms and 1 patient (2.4%) experiencing new anticipated motor weakness after en bloc resection of a malignant tumor. CONCLUSIONS: Indications for surgery include pain and/or neurological symptoms attributable to the lesion or large size if asymptomatic. Careful study of preoperative imaging is necessary to determine the best approach. Intraoperative nerve stimulation is essential to preserve function and guide extent of resection in benign tumors.

Exposure of the Lumbosacral Plexus by Using the Pararectus Approach: A Technical Note.

BACKGROUND: Surgical exploration of the lumbosacral plexus is challenging. Previously described approaches reach from invasive open techniques with osteotomy of the ilium to laparoscopic techniques. OBJECTIVE: To describe a novel surgical technique to explore lumbosacral plexopathies such as benign nerve tumors or iatrogenic lesions of the lumbosacral plexus in 4 case examples. METHODS: We retrospectively evaluated 4 patients suffering from pathologies or injuries of the lumbosacral plexus between 2017 and 2019. The mean follow-up period after surgery was 23.5 (range 11-52) months. All patients underwent neurolysis of the lumbosacral plexus using the single incision, intrapelvic, extraperitoneal pararectus approach. RESULTS: In all patients, the pathology of the lumbosacral plexus was successfully visualized, proving feasibility of the extraperitoneal pararectus approach for this indication. There were no major complications, and all patients recovered well. CONCLUSION: The pararectus approach allows excellent visualization of the lumbar plexus and intrapelvic lesions of the femoral and sciatic nerves.

Minimally invasive management for multifocal pelvic retroperitoneal malignant paraganglioma: a neuropelveological approach.

BACKGROUND: Pheochromocytoma and Paraganglioma (PGL) are rare neuroendocrine tumors, with an estimated incidence of about 0.6 cases per 100.000 person/year. Overall, 3-8% of them are malignant. These tumors are characterized by a classic triad of symptoms (headaches, palpitations, profuse sweating) due to hypersecretion of catecholamines. Despite several advantages of minimally invasive surgery (MIS) for PGL debulking, the surgical approach is not standardized yet. In this scenario, we aimed to report a case of a multiple recurrent PGL with metastatic retroperitoneal localization involving the pelvic sidewall, excised with MIS. CASE PRESENTATION: We performed complete laparoscopic-assisted neuronavigation (LANN technique) with isolation of the sacral routes and the sciatic nerve to obtain complete exposure of the main anatomic landmarks. Robotic surgery was used to perform neurolysis of sacral plexus, and partial resection of left splanchnic nerves was needed. After the resection of the first mass, extensive neurolysis of all sacral routes, obturator nerve, pudendal nerve till the entrance of the pudendal (Alcock) canal, and sciatic nerve was performed. Finally, the mass was identified after trans gluteal incision and dissection of the maximum gluteal muscle, and a partial resection of the superior gluteal nerve and slicing of the sciatic nerve were needed to obtain a radical excision of the mass. Then neurorrhaphy of the sectioned nerve fibers of the superior gluteal nerve was performed, and nerve protection was obtained using a collagen nerve wrap. After 18 months of follow-up, the patient is free of disease at the MRI imaging and 123I-metaiodobenzylguanidine scintigraphy. CONCLUSIONS: Minimally invasive gynecological surgery with neuropelveological approach could be considered as a feasible option in case of multifocal pelvic retroperitoneal malignant paraganglioma of the pelvic side wall.

Surgical Treatment of Vertical Shear Pelvic Fracture Associated with a Lumbosacral Plexus Injury through the Lateral-Rectus Approach: Surgical Techniques and Preliminary Outcomes.

OBJECTIVE: To examine the surgical techniques and preliminary outcomes of the lateral rectus approach (LRA) for treating vertical shear (VS) pelvic fracture associated with lumbosacral plexus (LSP) injury. METHODS: This study was a retrospective trial. From August 2010 to October 2017, 29 patients with VS pelvic fractures involving LSP injury who were treated with the LRA were included in this study. The patients were 18-61 years old, with a mean age of 36.2 years. All patients underwent neurolysis, open reduction, and internal fixation (ORIF) through the LRA. The fracture reduction was evaluated using the Matta criteria, and the neural recovery was evaluated by muscle strength grading proposed by the British Medical Research Council (BMRC). RESULTS: All 29 patients underwent the surgery successfully. The mean operating time was 155.2 ± 32.1 min (range: 105-220 min). The mean operative blood loss was 1021.4 ± 363.4 mL (range: 400-2000 mL). All patients were followed-up for at least 24 months (mean, 32.8 ± 13.5 months; range: 24-96 months). According to the Matta criteria, there were 17 excellent cases, nine good cases, and three fair cases in 29 patients. The ratio of excellent-to-good cases was 89.66%. According to the criteria of the Nerve Injuries Committee of the British Medical Research Council (BMRC), the recovery of nerve and muscle strength achieved to M5 (full recovery of neurological symptoms) was 14 cases, M4 (fine recovery of neurological symptoms), seven cases; M1, M2, and M3 (partial recovery of neurological symptoms), five cases, and M0 (no recovery of neurological symptoms), three cases. CONCLUSIONS: LRA is a safe and feasible surgical approach for treating VS pelvic fractures with LSP injury, which can be used to perform nerve exploration and release from the front, reduce the fracture, and fix it with the anterior iliac plates and/or sacroiliac screws.

Shamrock Lumbar Plexus Block for Hip Hemiarthroplasty in a High Risk Elderly Patient with Hip Fracture.

Hip fractures in the geriatric population are associated with high morbidity and mortality rate. Early surgical fixation is of major importance, as it is one of the factors that contribute to patient optimization. However, these patients usually present a high burden of comorbidities, including aortic stenosis that could affect their treatment. Despite major advances in anesthetic and surgical techniques, severe aortic stenosis remains an independent, important risk factor for patients undergoing anesthesia for noncardiac surgery. In these patients, general and/or neuraxial anesthesia should be avoided; peripheral nerve blockade is a viable option. This article presents a 96-year-old hip fracture patient with severe aortic stenosis and aspiration pneumonia that successfully underwent hip hemiarthroplasty under peripheral nerve blockade as sole anesthesia.

Effects of thigh extension on the position of the femoral nerve: application to prone lateral transpsoas approaches to the lumbar spine.

Some authors have suggested that thigh extension during the prone lateral transpsoas approach to the lumbar spine provides the theoretical advantage of providing posterior shift of the psoas muscle and plexus and is responsible for its lower rates of nerve injury. We aimed to elucidate the effects of surgical positioning on the femoral nerve within the psoas muscle via a cadaveric study. In the supine position, 10 fresh frozen adult cadavers had a metal wire secured to the pelvic segment of the femoral nerve and then extended proximally along with its L2 contribution. Fluoroscopy was then used to identify the wires on the femoral nerves in a neutral position and with the thigh extended and flexed by 25 and 45°. Additionally, a lateral incision was made in the anterolateral abdominal wall to mimic a lateral transpsoas approach to the lumbar spine, and measurements were made of the amount of movement in the vertical plane of the femoral nerve from neutral to then 25 and 45° of thigh flexion and extension. On fluoroscopy, the femoral nerves moved posteriorly at a mean of 10.1 mm with thigh extension. Femoral nerve movement could not be detected at any degree of this range of flexion of the thigh. Extension of the thigh to about 30° can move the femoral nerve farther away from the dissection plane by approximately one centimeter. This hip extension not only places the femoral nerve in a more advantageous position for lateral lumbar interbody fusion procedures but also helps to promote accentuation of lumbar lordosis.

Relation of the lumbosacral trunk to the sacro-iliac joint.

This study aims to evaluate the relation between the lumbosacral trunk (LT) and the sacro-iliac joint (SIJ). In forty anatomic specimens (hemipelves) a classical antero-lateral approach to the SIJ was performed. The SIJ was marked at the linea terminalis (reference point A). Reference point B was situated at the upper edge of the interosseous sacro-iliac ligament. The length of the SIJ (distance A to B) and the distance between point A and the ventral branch of the fourth (L4) and fifth (L5) lumbar spinal nerves at the linea terminalis were measured. The SIJ had a mean length of 58.0 mm. The ventral branch of L5 was located closer to the SIJ in very long SIJs (mean length: ≥ 6.5 cm; mean distance: 9.8 mm) compared to very short joints (≤ 5 mm; mean distance: 11.3 mm). For the ventral branch of L4, very long SIJs had a mean distance of 7 mm and very short joints an average distance of 9.7 mm between point A and the nerve branch. A safe zone of approximately 1 cm to 2 cm (anterior to posterior) is present on the sacral surface (lateral to medial) for safe fixation of plates during anterior plate stabilization of the SIJ. Pelves with a shorter dorsoventral diameter of the most superior part of the SIJ apparently give more space for inserting plates.

Dorsal Root Entry Zone Lesioning: Systematic Review

Introduction Dorsal root entry zone (DREZ) leasioning (DREZ-otomy) is considered an effective treatment for chronic pain due to spinal cord injuries, brachial and lumbosacral plexus injuries, postherpetic neuralgia, spasticity, and other conditions. The objective of the technique is to cause a selective destruction of the afferent pain fibers located in the dorsal region of the spinal cord. Objective To identify and review the effectiveness and the main aspects related to DREZ-otomy, as well as the etiologies that can be treated with it. Methods The PubMed, MEDLINE and LILACS databases were used as bases for this systematic review, having the impact factor as the selection criteria. The 23 selected publications, totalizing 1,099 patients, were organized in a table for systematic analysis. Results Satisfactory pain control was observed in 70.1% of the cases, with the best results being found in patients with brachial/lumbosacral plexus injury (70.8%) and the worst, in patients with trigeminal pain (40% to 67%). Discussion Most of the published articles observed excellent results in the control of chronic pain, especially in cases of plexus injuries. Complications are rare, and can be minimized with the use of new technologies for intraoperative monitoring and imaging. Conclusion DREZ-otomy can be considered a great alternative for the treatment of chronic pain, especially in patients who do not tolerate the side effects of the medications used in the clinical management or have refractory pain.

Surgical Neuropelviology: Combined Sacral Plexus Neurolysis and Laparoscopic Laterally Extended Endopelvic Resection in Deep Lateral Pelvic Endometriosis.

OBJECTIVE: Surgical demonstration of combined sacral plexus neurolysis and laparoscopic laterally extended endopelvic resection for deep lateral infiltrating endometriosis. DESIGN: Video showing principles of neurolysis and laparoscopic laterally extended endopelvic resection applied to endometriotic surgery. SETTING: University tertiary referral center. Deep infiltrating endometriosis is an underestimated disease with real medical and clinical issues, recently classified as central pelvic endometriosis and lateral pelvic endometriosis further divided into superficial and deep according to the structures' involvement [1]. The surgical removal of endometriotic foci remains the standard treatment. A wide knowledge of neuroanatomy and high skills in minimally invasive surgery are required to manage this challenging surgical scenario [2]. INTERVENTIONS: New surgical approach for deep lateral infiltrating endometriosis based on the principles of lateral extended endopelvic resection and neuropelviologic surgery [3,4]. The patient was a 35-year-old woman, para 1, with neuropathic pain radiating to the left leg and a cyclic menstrual disorder. A laparoscopically assisted neuronavigation and subsequent neurolysis allowed the identification of the lateral nodule without damage to the autonomic pelvic innervation [1]. Then, a complete resection of the internal vascular compartment was required to obtain a radical endometriotic eradication. Shaving and bladder resection were also performed to complete removal of the endometriotic foci. CONCLUSION: The association of neuroanatomic knowledge and surgical oncologic principles applied to minimally invasive surgery should be considered to ensure an adequate surgical radicality and clinical benefit in patients with deep infiltrating endometriosis.

Surgical Management of Symptomatic Lumbar, Sacral, and Lumbosacral Plexus Tumors: a Peripheral Nerve Unit Experience.

OBJECTIVE: Data concerning the surgical treatment of lumbosacral plexus tumors (LSPTs) is scarce. This study aims to present our experience with a series of 19 patients surgically treated for symptomatic LSPTs at our institution. METHODS: This is a retrospective study of 19 patients surgically treated for symptomatic LSPTs from 2011 to 2019. Clinical data were retrieved from medical records and consisted of age, gender, clinical presentation, location of the lesion, surgical approach, final histopathologic diagnosis, follow-up time, outcomes, and complications. RESULTS: Nineteen surgical procedures were conducted. Thirteen patients were female and six, male. The median age of patients was 45 years (range 20 to 63 years). No patients harbored genetic syndromes. Surgical treatment appears to be correlated to the reduction of pain in patients with peripheral nerve sheath tumors (PNSTs), as assessed by visual analog scale (VAS). Sixteen patients did not present with new-onset deficits during follow-up (84.2%), two of whom recovered from their preoperative deficit. Four patients presented with postoperative weakness. The histopathological diagnoses were 11 schwannomas, four neurofibromas, three metastases, and one lymphoma. CONCLUSIONS: LSPTs are rare. When surgical treatment is indicated, it usually requires multidisciplinary management. Surgery appears to be effective concerning the reduction of pain in PNSTs and may also recover neurological deficits. Iatrogenic neurological deficits are an evident risk, such that intraoperative multimodal monitoring should always be performed if available. In lesions involving the sacral plexus, we found it to be indispensable.

Excision of deep endometriosis nodules of the parametrium and sacral roots in 10 steps.

OBJECTIVE: To present 10 consecutive, standardized, and reproducible surgical steps allowing complete excision of deep endometriosis nodules infiltrating the parametrium and sacral roots. DESIGN: Surgical video presenting the 10 surgical steps. Local institutional review board approval was not required for this video article, because the video describes a technique and the patient cannot be identified whatsoever. SETTING: Endometriosis Center. PATIENTS: Patients undergoing excision of deep endometriosis nodules of the parametrium and sacral roots. INTERVENTION: The excision of deep endometriosis infiltrating the parametrium down to the sacral roots may be performed following 10 steps: complete ureterolysis and removal of ureteral stenosis; opening of the pararectal space in contact with the rectum in a sagittal plane; dissection caudally toward the rectovaginal space, section of the rectovaginal nodule in two separate blocks infiltrating the rectum and vagina, respectively, all the way down to the levator ani muscles; dissection of the presacral space and identification of the superior hypogastric plexus and hypogastric nerve; transverse incision of the peritoneum at the level of the promotorium, extended laterally above the origin of the hypogastric vessels; anterograde dissection of the hypogastric artery and identification of the hypogastric vein; anterograde dissection of the hypogastric vein and opening of Okabayashi space, followed by identification and, when required, ligation of hypogastric vein tributaries; dissection is extended behind the venous network with identification of the pyriform muscles and sacral roots S2, S3, and S4; anterograde dissection of the nerve network and inferior hypogastric plexus, up to the posterior limits of the deep endometriosis nodule; and excision of the deep endometriosis nodule from the posterior limit to the inferior limit in contact with the sacral roots, which should be released or shaved, then to the lateral limit in contact with the pyriform muscle and lateral pelvic wall. Additional steps may be required to remove adjacent infiltration of the vagina, rectum, bladder, or ureters. The movie does not reflect a similar approach in cases of isolated nodules of the sciatic nerves involving a specific lateral dissection plane between the external iliac vessels and the iliopsoas muscle. MAIN OUTCOME MEASURES: Description of 10 successive surgical steps. RESULTS: The 10-step procedure already has been employed in 70 women with deep endometriosis of the parametria involving sacral roots, in whom sensory or motor complaints were not completely relieved by continuous amenorrhea provided by contraceptive pill intake or gonadotropin-releasing hormone analogs. Baseline complaints included somatic pain (85.7%), severe bladder dysfunction (10%), or hydronephrosis (24.3%). Main localizations concerned sacral roots (95.7%), sciatic nerves (7.1%), mid/low rectum (87.1%), and bladder (21.4%). Operative time was 224 ± 94 minutes. Among postoperative complications, we recorded rectovaginal fistulae (14.3%), urinary tract fistulae (4.3%), and bladder dysfunction at 3 weeks (22.9%) and 12 months (5.7%) after the surgery. CONCLUSIONS: Laparoscopic excision of deep endometriosis nodules of the parametria involving the sacral roots is a challenging procedure, requiring good anatomic and surgical skills. Teaching such a complex procedure is a delicate task. By following 10 sequential steps, the surgeon may reduce the risk of hemorrhage originating from the hypogastric venous network, preserve as much as possible autonomic nerves and organ function, and successfully excise deep endometriosis nodules. However, transection of the internal iliac artery and vein should not be systematic, as it may adversely affect the vascular supply of the pelvis. Transection of small pelvic splanchnic nerves should be performed only if they actually are included in fibrous nodules, as it may be followed by sexual, bladder, and rectal dysfunction or perineal sensory effects. Although the 10 steps attempt to standardize the surgical approach in a challenging localization of deep endometriosis, they are not mandatory and their use should be individualized.

A systematic review of nerve-sparing surgery for high-risk prostate cancer.

INTRODUCTION: We provide a systematic analysis of nerve-sparing surgery (NSS) to assess and summarize the risks and benefits of NSS in high-risk prostate cancer (PCa). EVIDENCE ACQUISITION: We have undertaken a systematic search of original articles using 3 databases: Medline/PubMed, Scopus, and Web of Science. Original articles in English containing outcomes of nerve-sparing radical prostatectomy (RP) for high-risk PCa were included. The primary outcomes were oncological results: the rate of positive surgical margins and biochemical relapse. The secondary outcomes were functional results: erectile function (EF) and urinary continence. EVIDENCE SYNTHESIS: The rate of positive surgical margins differed considerably, from zero to 47%. The majority of authors found no correlation between NSS and a positive surgical margin rate. The rate of biochemical relapse ranged from 9.3% to 61%. Most of the articles lacked data on odds ratio (OR) for positive margin and biochemical relapse. The presented results showed no effect of nerve sparing (NS) on positive margin (OR=0.81, 0.6-1.09) or biochemical relapse (hazard ratio [HR]=0.93, 0.52-1.64). A strong association between NSS and potency rate was observed. Without NSS, between 0% and 42% of patients were potent, with unilateral 79-80%, with bilateral - up to 90-100%. Urinary continence was not strongly associated with NSS and was relatively good in both patients with and without NSS. CONCLUSIONS: NSS may provide benefits for patients with urinary continence and significantly improves EF in high-risk patients. Moreover, it is not associated with an increased risk of relapse in short- and middle-term follow-up. However, the advantages of using such a surgical technique are unclear.

Lateral Interbody Fusion at L4/5: Management of the Transitional Psoas.

OBJECTIVE: Managing retraction of the lumbar plexus is critical to safely perform lateral lumbar interbody fusion (LLIF) via the transpsoas approach. Occasionally, a transitional psoas is encountered at L4/5 and has been postulated to be a contraindication to transpsoas LLIF. A case series of patients with transitional psoas who underwent L4/5 LLIFs is presented. METHODS: This retrospective review assessed 79 consecutive patients who underwent L4/5 LLIF during a 24-month period. Preoperative imaging was reviewed, and patients were classified into 2 groups: normal psoas or transitional psoas. Intraoperative features and outcomes were compared between groups. RESULTS: Seventy-nine patients underwent L4/5 LLIFs, of whom 23 had transitional psoas anatomy and 56 had normal psoas anatomy. Among patients with transitional psoas, the center of the psoas was a mean (range) of 11.2 (5.2-26.6) mm in front of the center of the vertebral body compared with 2.0 (0-4) mm in the normal psoas group. The mean (range) retraction time was similar between groups (10.8 [6.7-14.9] minutes in the transitional psoas group vs. 11.0 [7.8-15.0] minutes in the normal psoas group). No permanent motor injuries occurred in either group, and no differences in length of stay or preoperative or postoperative Oswestry Disability Index scores were found between the groups. The protocol for L4/5 LLIF in patients with transitional psoas anatomy is described. CONCLUSIONS: Transitional psoas anatomy is frequently encountered in surgical candidates for L4/5 LLIF. Through careful identification of the lumbar plexus and judicious retraction, the transpsoas LLIF can safely be performed in these patients.

A study to improve identification of the retroperitoneal course of iliohypogastric, ilioinguinal, femorocutaneous and genitofemoral nerves during laparoscopic triple neurectomy.

BACKGROUND: Laparoscopic triple neurectomy is an available treatment option for chronic groin pain, but a poor working knowledge of the retroperitoneal neuroanatomy makes it an unsafe technique. OBJECT: Describe the retroperitoneal course of iliohypogastric, ilioinguinal, lateral femoral cutaneous and genitofemoral nerves, to guide the surgeon who operates in this region. METHODS: Fifty adult cadavers were dissected resulting in 100 anatomic specimens. Additionally, 30 patients were operated for refractory chronic inguinal pain, using laparoscopic triple neurectomy. All operations and dissections were photographed. Measurements were made between the nerves of the lumbar plexus and various landmarks: interneural distances in a vertical midline plane, posterior or anterior iliac spine and branch presentation model. RESULTS: The ilioinguinal and iliohypogastric nerves were independent in 78% (Type II) and separated by an average of 2.5 ± 0.8 cm. In surgery study, only 38% were recognized as Type II and at a significantly greater distance (3.5 ± 1.2 cm, p < 0.001). The distance between ilioinguinal and lateral femoral cutaneous nerves was also greater during surgery, with statistical significance (5.1 ± 1.5 versus 4.2 ± 1.5, p < 0.005). The distance of the nerves to their bone references were not statistically different. The genitofemoral nerve emerged from the psoas major muscle in 20% as two separate branches (Type II), regardless of the study. The lateral femoral cutaneous nerve had a mean distance of 0.98 ± 1.6 cm medial to the anterior superior iliac spine. CONCLUSION: The identification of the IH, II, FC and GF nerves is essential to reduce the rate of failures in the treatment of CGP. The frequent anatomical variations of the lumbar plexus nerves make knowledge of their courses in the retroperitoneal space essential to ensure safe surgery. The location of the nerves in the LTN is distorted by up to 1 cm. regarding references in the cadavers.

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

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

Extended anterolateral transiliac approach to the sacral plexus.

The approach to the sciatic plexus and lateral part of the sacrum is difficult. A subperitoneal anterolateral approach can be extended by sectioning the iliac bone above the acetabulum and lowering it toward the external part of the iliac wing and buttock. This transiliac anterolateral approach exposes the lumbosacral trunk, first sacral foramina and sciatic plexus to the origin of the sciatic trunk. Exposure can be extended upward by subperitoneal lumbotomy, downward by opening the ischiorectal fossa, or outward by trochanterotomy. This approach was used 18 times by one of the authors (FHD) for resection of 13 malignant tumors and 5 plexus releases. Procedure time was 3-6hours, with 500-4,000ml blood loss. The approach systematically enabled surgical objectives to be met. There was 1 septic complication that healed after debridement.