Robotic resection of an obturator schwannoma with preservation of normal nerve fascicles and function.

An asymptomatic pelvic tumor was incidentally found in a 27-year-old man. A CT-guided needle biopsy with a pathologic examination confirmed the diagnosis of a benign schwannoma. We describe the complete robotic resection with the conservation of normal fascicles. The postoperative course was uneventful. No neurological deficit occurred, and the electromyogram was normal 6 weeks and 7 months later.

The Evolution and Technique of Nerve-Sparing Retroperitoneal Lymphadenectomy.

The evolution of retroperitoneal lymph node dissection technique and associated template modifications for nonseminomatous germ cell tumors have resulted in significant improvement in the long-term morbidity. Through the preservation of sympathetic nerves via exclusion from or prospective identification within the boundaries of resection, maintenance and recovery of antegrade ejaculation are achieved. Nerve-sparing strategies in early-stage disease are feasible in most patients. Postchemotherapy, select patients can be considered for nerve preservation. This article describes the anatomic and physiologic basis for, indications and technical aspects of, and functional and oncologic outcomes reported after nerve-sparing retroperitoneal lymphadenectomy in testicular cancer.

Retroperitoneal anatomy of the iliohypogastric, ilioinguinal, genitofemoral, and lateral femoral cutaneous nerve: consequences for prevention and treatment of chronic inguinodynia.

PURPOSE: Chronic inguinodynia is one of the most frequent complications after groin herniorrhaphy. We investigated the retroperitoneal anatomy of the iliohypogastric, ilioinguinal, genitofemoral, and lateral femoral cutaneous nerve to prevent direct nerve injury during hernia repairs and to find the most advantageous approach for posterior triple neurectomy. METHODS: We dissected the inguinal nerves in 30 human anatomic specimens bilaterally. The distances from each nerve and their entry points in the abdominal wall were measured in relation to the posterior superior iliac spine, anterior superior iliac spine, and the midpoint between the two iliac spines on the iliac crest. We evaluated our findings by creating high-resolution summation images. RESULTS: The courses of the iliohypogastric and ilioinguinal nerve are most consistent on the anterior surface of the quadratus lumborum muscle. The genitofemoral nerve always runs on the psoas muscle. The entry points of the nerves in the abdominal wall are located as follows: the iliohypogastric nerve is above the iliac crest and lateral from the anterior superior iliac spine, the ilioinguinal nerve is with great variability, either above or below the iliac crest and lateral from the anterior superior iliac spine, the genital branch is around the internal inguinal ring, the femoral branch is either cranial or caudal to the iliopubic tract, and the lateral femoral cutaneous nerve is either medial or lateral to the anterior superior iliac spine. CONCLUSION: Nerve injury during inguinal hernia repairs can be avoided by taking the topographic anatomy of the inguinal nerves into consideration. The most advantageous plane to look for the iliohypogastric and ilioinguinal nerve during posterior neurectomy is on the anterior surface of the quadratus lumborum muscle. For the surgical treatment of severe chronic inguinodynia, especially after posterior open or endoscopic mesh repair (TAPP/TEP), the retroperitoneoscopic or open retroperitoneal approach for posterior triple neurectomy can be considered.

[Anatomy and physiology of autonomic pelvic innervations].

Autonomic innervation is responsible for the correct function of the organs in the pelvis. Retroperitoneal surgery is associated with trauma of the nerve structures. For this reason a detailed knowledge of topographic anatomy of the pelvis is needed, when surgery for oncological diseases or endometriosis is performed. Faster recovery, decrease of the number of postoperative complications and a better quality of life are the result of the nerve-sparing approach.

Post-chemotherapy nerve-sparing laparoscopic retroperitoneal lymph node dissection in stage IIB testicular cancer.

We report our experience of extraperitoneal nerve-sparing laparoscopic retroperitoneal lymph node dissection after chemotherapy. Six patients were diagnosed with non-seminomatous germ cell tumor after orchiectomy and clinical stage IIB disease. Nerve-sparing laparoscopic retroperitoneal lymph node dissection was carried out for residual retroperitoneal tumors after cisplatin-based chemotherapy. The median tumor diameter was 2.95 cm before chemotherapy and 1.95 cm after chemotherapy. A modified left (n=1), right (n=1) and bilateral (n=4) template for the dissection area was used. Surgery was successfully completed in all patients and no conversion to open surgery was necessary. Median operative time was 394 min (range 212-526 min). Median blood loss was 75 mL (range 10-238 mL). The overall complication rate was 33.3% (2/6). Two patients had prolonged lymphatic leakage (grade I), which was managed conservatively. Antegrade ejaculation was preserved in all six patients. The histopathological findings showed that two patients had mature teratoma and four patients had necrotic tissue. After a median follow up of 30 months (range 24-36), no recurrence of disease was observed. We can conclude that extraperitoneal nerve-sparing laparoscopic retroperitoneal lymph node dissection for residual tumors after chemotherapy is a feasible operation. The oncological outcomes need to be confirmed in a certain number of patients with longer follow up.

The lumbosacral plexus: anatomic considerations for minimally invasive retroperitoneal transpsoas approach.

PURPOSE: The minimally invasive transpsoas approach can be employed to treat various spinal disorders, such as disc degeneration, deformity, and lateral disc herniation. With this technique, visualization is limited in comparison with the open procedure and the proximity of the lumbar plexus to the surgical pathway is one limitation of this technique. Precise knowledge of the regional anatomy of the lumbar plexus is required for safe passage through the psoas muscle. The primary objective of this study was to determine the anatomic position of the lumbar plexus branches and sympathetic chain in relation to the intervertebral disc and to define a safe working zone. The second objective was to compare our observations with previous anatomical studies concerning the transpsoas approach. METHODS: A total of 60 lumbar plexus in 8 fresh cadavers from the Department of Anatomy were analyzed in this study. Coronal and lateral X-Ray images were obtained before dissection in order to eliminate spine deformity or fracture. All cadavers were placed in a lateral decubitus position with a lateral bolster. Dissection of the lumbar plexus was performed. All nerve branches and sympathetic chain were identified. Intervertebral disc space from L1L2 to L4L5 was divided into four zones. Zone 1 being the anterior quarter of the disc, zone 2 being the middle anterior quarter, zone 3 the posterior middle quarter and zone 4 the posterior quarter. Crossing of each nervous branch with the disc was reported and a safe working zone was determined for L1L2 to L4L5 disc levels. A safe working zone was defined by the absence of crossing of a lumbar plexus branch. RESULTS: No anatomical variation was found during blunt dissection. As described previously, the lumbar plexus is composed of the ventral divisions of the first four lumbar nerves and from contributions of the sub costal nerve from T12. The safe working zone includes zones 2 and 3 at level L1L2, zone 3 at level L2L3, zone 3 at level L3L4, and zone 2 at level L4L5. No difference was observed between right and left sides as regards the relationships between the lumbar plexus and the intervertebral disc. CONCLUSION: We observed some differences concerning the safe working zone in comparison with other cadaveric studies. The small number of cadaveric specimens used in anatomical studies probably explains theses differences. The minimally invasive transpsoas lateral approach was initially developed to reduce the complications associated with the traditional procedure. The anatomical relationships between the lumbar plexus and the intervertebral disc make this technique particularly risky a L4L5. Alternative techniques, such as transforaminal interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF) or anterior interbody fusion (ALIF) should be used at this level.

Safe working zones using the minimally invasive lateral retroperitoneal transpsoas approach: a morphometric study.

PURPOSE: The minimally invasive lateral retroperitoneal transpsoas approach is a recent technique developed for lumbar interbody fusion and discectomy. The proximity of the retroperitoneal vessels and ventral nerve roots to the surgical pathway increases the risk of injury to these anatomical structures. A precise knowledge of the regional anatomy of the lumbar plexus is required for safe passage through the psoas muscle. Preoperative examination of the axial MRI images will allow the surgeon to observe the neural structures at the operative levels and confirm that abdominal vessels do not obstruct the lateral disc space. The objective of this study was to determine the anatomic position of the ventral nerve roots and the retroperitoneal vessels in relation to the vertebral body in the degenerative spine and to delineate a safe working zone using magnetic resonance imaging (MRI). METHODS: We retrospectively evaluated lumbar spine MRI in 78 patients (from L1-L2 to L4-L5). The total number of lumbar vertebrae measured was 304 levels. Sagittal MRI sections were used to measure disc height (anterior, middle, posterior). Axial MRI sections were used to measure the sagittal and transversal vertebral endplate diameters, the overlap between ventral nerve roots and the posterior border of the lower endplate of the vertebral body, and the overlap between the retroperitoneal vessels and the anterior border of the lower endplate of the vertebral body. The safe zone was subsequently calculated. It was defined as the relative lower endplate vertebral body sagittal diameter that is anterior to the nerve root and is posterior to the retroperitoneal vessels. RESULTS: The safe working zone was 75.3% of the lower endplate of the vertebral body sagittal diameter at L1-L2, 59.5% at L2-L3, 51.9% at L3-L4 and 37.8% at L4-L5 levels. This area significantly decreases from L1-L2 to L4-L5 (p < 0.05). Compared with L1-L2, L2-L3 levels, the more anterior position of the nerve root and the more posterior position of the retroperitoneal vessels at the L4-L5 level causes a significant reduction of this area. Compared with the L3-L4 level, we observed that the safe zone decrease was simply secondary to the more anterior position of the nerve roots at the L4-L5 level. CONCLUSION: Preoperative planning and safe zone delineation are a simple method to assess the relative position of neural and vascular anatomic structures in relation to the surgical area. This method can help spine surgeons to prevent perioperative complications.

Trajectory of the main sensory and motor branches of the lumbar plexus outside the psoas muscle related to the lateral retroperitoneal transpsoas approach.

OBJECT: The minimally invasive lateral retroperitoneal transpsoas approach is increasingly used to treat various spinal disorders. Accessing the retroperitoneal space and traversing the abdominal wall poses a risk of injury to the major nervous structures and adds significant morbidity to the procedure. Most of the current literature focuses on the anatomy of the lumbar plexus within the substance of the psoas muscle. However, there is sparse knowledge regarding the trajectory of the lumbar plexus nerves that travel along the retroperitoneum and abdominal wall muscles in relation to the lateral approach to the spine. The objective of this study is to define the anatomical trajectories of the major motor and sensory branches of the lumbar plexus that are located outside the psoas muscle. METHODS: Six adult fresh frozen cadaveric specimens were dissected and studied (12 sides). The relationship between the retroperitoneum, abdominal wall muscles, and the lumbar plexus nerves was analyzed in reference to the minimally invasive lateral retroperitoneal approach. Special attention was given to the lumbar plexus nerves that run outside of psoas muscle in the retroperitoneal cavity and within the abdominal muscle wall. RESULTS: The skin and muscles of the abdominal wall and the retroperitoneal cavity were dissected and analyzed with respect to the major motor and sensory branches of the lumbar plexus. The authors identified 4 nerves at risk during the lateral approach to the spine: subcostal, iliohypogastric, ilioinguinal, and lateral femoral cutaneous nerves. The anatomical trajectory of each of these nerves is described starting from the spinal column until their termination or exit from the pelvic cavity. CONCLUSIONS: There is risk of direct injury to the main motor/sensory nerves that supply the anterior abdominal muscles during the early stages of the lateral retroperitoneal transpsoas approach while obtaining access to the retroperitoneum. There is also a risk of injury to the ilioinguinal, iliohypogastric, and lateral femoral cutaneous nerves in the retroperitoneal space where they travel obliquely during the blunt retroperitoneal dissection. Moreover, there is a latent possibility of lesioning these nerves with the retractor blades against the anterior iliac crest.

Topography of the lumbar sympathetic trunk in normal lumbar spines and spines with spondylophytes.

BACKGROUND: Degenerative processes of the lumbar spine may change the position of the sympathetic trunk which might cause failure of sympathetic blocks owing to inadequate distribution of local anaesthetic. METHODS: The retroperitoneal spaces of 56 cadavers [24 males and 32 females; 79 (10) yr] embalmed with Thiel's method were investigated by dissection. The course of the lumbar sympathetic trunk (LST) was documented from the diaphragmatic level to the linea terminalis. Topography of the large vessels and the psoas muscle was documented. In the case of spondylophytes, the location or direction of displacement of the trunk was regarded with special interest. RESULTS: The LST entered the retroperitoneal space at the level of the vertebral body of L2 in 70 of the 112 sides and showed the most consistent relationship with the medial margin of the psoas muscle at intervertebral disc level L2/3. On 11 spines with spondylophytes, the sympathetic trunk was dislocated to the most ventrolateral point of the spondylophyte in 12 cases, in six cases dorsolaterally, and in one case ventromedially. The more the sympathetic chain departed at the vertebral body level, the more the body developed a concavity by loss of height. CONCLUSIONS: Spondylophytes influenced the location of the LST and the distribution of the local anaesthetic. The local anaesthetic should wash around the spondylophyte to reach all possible locations of the chain. The medial margin of the psoas muscle was confirmed to be a consistent reference point at intervertebral disc level L2/3.

Neural entrapment during uterosacral ligament suspension: an anatomic study of female cadavers.

OBJECTIVE: To describe retroperitoneal neural structures at risk during uterosacral ligament suspension and to estimate risk of neural injury based on uterosacral ligament suspension suture placement technique. METHODS: Uterosacral ligament suspension was performed in 10 unembalmed female cadavers. In each cadaver, bilateral uterosacral ligament suspension sutures were placed using different techniques, as described in the literature. Distances from the ischial spine and instances of neural entrapment were recorded. Biopsy specimens of the deepest (most dorsal) tissue that each suture traversed were immunostained with a nerve-specific (S100) antibody, and the largest nerve diameter was recorded. RESULTS: Median location of sutures relative to the ischial spine did not differ significantly by suture technique. Portions of sacral nerve roots were encircled by uterosacral ligament suspension sutures in seven cadavers. There were no instances of nerve entrapment when sutures were placed while tenting the ligament with an Allis clamp, although these sutures contained a less substantial purchase of connective tissue. In six cadavers, sacral nerves were encircled by sutures placed using a dorsal and posterior arc, regardless of the needle size. In one instance, only the larger CT-1 needle encircled sacral nerve roots. S100 immunostaining confirmed gross findings, with nerve tissue in all specimens (diameter 30-1,225 micrometers). Mean nerve diameter was significantly larger in biopsy specimens in which entrapment was noted grossly (472 micrometers compared with 108 micrometers; P<.001). CONCLUSION: Sacral nerve roots are the most vulnerable neural structures during uterosacral ligament suspension. Suture placement directly into the uterosacral ligament with a dorsal and posterior needle arc results in a higher risk of nerve entrapment compared with ventral tenting of the ligament.

Surgical anatomy of the retroperitoneal spaces, Part IV: retroperitoneal nerves.

We present surgicoanatomical topographic relations of nerves and plexuses in the retroperitoneal space: 1) six named parietal nerves, branches of the lumbar plexus: iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous, obturator, femoral. 2) The sacral plexus is formed by the lumbosacral trunk, ventral rami of S1-S3, and part of S4; the remainder of S4 joining the coccygeal plexus. From this plexus originate the superior gluteal nerve, which passes backward through the greater sciatic foramen above the piriformis muscle; the inferior gluteal nerve also courses through the greater sciatic foramen, but below the piriformis; 3) sympathetic trunks: right and left lumbar sympathetic trunks, which comprise four interconnected ganglia, and the pelvic chains; 4) greater, lesser, and least thoracic splanchnic nerves (sympathetic), which pass the diaphragm and join celiac ganglia; 5) four lumbar splanchnic nerves (sympathetic), which arise from lumbar sympathetic ganglia; 6) pelvic splanchnic nerves (nervi erigentes), providing parasympathetic innervation to the descending colon and pelvic splanchna; and 7) autonomic (prevertebral) plexuses, formed by the vagus nerves, splanchnic nerves, and ganglia (celiac, superior mesenteric, aorticorenal). They include sympathetic, parasympathetic, and sensory (mainly pain) fibers. The autonomic plexuses comprise named parts: aortic, superior mesenteric, inferior mesenteric, superior hypogastric, and inferior hypogastric (hypogastric nerves).

Radical pancreatoduodenectomy combined with retroperitoneal nerve, lymph, and soft-tissue dissection in pancreatic head cancer.

BACKGROUND: Recent studies have revealed that the reason for the low surgical resection rate of pancreatic carcinoma partly lies in its biological behavior, which is characterized by neural infiltration. This study aimed to investigate the clinical significance of radical pancreatoduodenectomy combined with retroperitoneal nerve, lymph, and soft-tissue dissection for carcinoma of the pancreatic head. METHODS: Forty-six patients with pancreatic head cancer were treated in our hospital from 1995 to 2005. The patients were divided into two groups: radical pancreatoduodenectomy combined with retroperitoneal nerve, lymph and soft-tissue dissection (group A, n = 25) and routine Whipple's operation (group B, n = 21). There were no significant differences between the two groups in relation to age, gender and preoperative risk factors, and perioperative conditions, pathological data and survival rates were studied. RESULTS: There were no significant differences in tumor size, surgical procedure time, postoperative complications, and time of hospitalization. However, the number and positive rate of resected lymph nodes in group A were significantly higher than those in group B (P < 0.05). The 1- and 3-year survival rate in group A were 80% and 53%, respectively, which was higher than those in group B (P < 0.05). There were significant differences in the survival rates between patients with and without nerve infiltration in group A (P < 0.05). CONCLUSIONS: Radical pancreatoduodenectomy combined with retroperitoneal nerve, lymph and soft-tissue dissection, can effectively remove the lymph and nerve tissues that were infiltrated by tumor. Meanwhile, this method can reduce the local recurrence rate so as to improve the long-term survival of patients.

Laparoscopic retroperitoneal lymph node dissection: description of the nerve-sparing technique.

INTRODUCTION: Laparoscopic retroperitoneal lymph node dissection (RPLND) is associated with a more favorable postoperative recovery and decreased morbidity compared with open RPLND. To date, laparoscopic RPLND is used as a diagnostic tool for patients with clinical Stage I nonseminomatous germ cell tumor and as a diagnostic and therapeutic tool for patients with low-volume Stage II nonseminomatous germ cell tumor after chemotherapy. In an effort to further expand the therapeutic implications for laparoscopic RPLND, we describe a nerve-sparing technique for laparoscopic RPLND. TECHNICAL CONSIDERATIONS: In all cases, a four-port transperitoneal approach was used to perform a unilateral nerve-sparing technique. Laparoscopic nerve-sparing RPLND requires complete exposure of the retroperitoneum, similar to the standard procedure. A stepwise surgical approach is required for prospective identification of the sympathetic trunk and postganglionic nerve fibers. Identification and division of the lumbar veins is required for complete mobilization of the vena cava to facilitate dissection of the postganglionic nerves on the right side as they course dorsal to the vena cava. Meticulous dissection was required for preservation of the postganglionic nerves in the interaortocaval and para-aortic regions. CONCLUSIONS: Laparoscopic nerve-sparing RPLND is technically feasible. Performance of laparoscopic nerve-sparing RPLND decreases the potential morbidity associated with the standard laparoscopic technique further and may help expand the therapeutic potential for this minimally invasive procedure.

Iatrogenic injury to the ilioinguinal and iliohypogastric nerves in the groin: a case report, diagnosis, and management.

A case of right-sided ilioinguinal and iliohypogastric neuralgia following laparoscopic repair in a 52-year-old man is presented. Significant pain persisted despite conservative measures and was successfully treated with resection of the ilioinguinal and iliohypogastric nerves in the retroperitoneal space. The anatomy, mechanisms of injury, and management of postherniorrhaphy neuropathy are reviewed.

Surgical treatment of clinical stage A nonseminomatous testis cancer.

Until clinical staging improves, patients presenting with clinical stage A nonseminomatous testis cancer should be offered the option of initial nerve-sparing RPLND versus surveillance. Either method of management may be successful in the individual patient. We feel each patient with clinical stage A disease must be informed of alternative methods of management and be allowed to choose the method of management that he feels best suits his needs in terms of risk benefit.

[Studies on retroperitoneal lymph node dissection concerning postoperative ejaculatory function in patients with testicular cancer].

This study was done to explore the appropriate procedure of retroperitoneal lymph node dissection (RLND) to preserve ejaculatory function. The relation between postoperative ejaculatory function and area dissected at RLND was investigated in 47 patients with testicular cancer. The patients were divided into 5 groups according to the retroperitoneal area dissected. Group 1 (38 patients) underwent bilateral RLND, group 2 (3 patients) and 3 (2 patients) right unilateral RLND, and group 4 (2 patients) and 5 (2 patients) left unilateral RLND. The vertical limits of the dissected area were similar in all groups, namely renal pedicle and bifurcation of common iliac artery. The lateral limits were bilateral ureters in group 1, right border of aorta and right ureter in group 2, left border of aorta and left ureter in group 4, and vena cava and left ureter in group 5. Group 3 was similar to group 2, but the paraaortic region at the root of inferior mesenteric artery was also dissected. All patients in group 1 had dry ejaculation. Thirty patients in this group were examined for seminal emission and none of them could demonstrate seminal emission. Normal antegrade ejaculation was seen in group 2 and 4 patients, but retrograde ejaculation was recognized in group 3. Inability of seminal emission ws confirmed in group 5 patients. When consideration is given to the function of retroperitoneal sympathetic nerves, our results suggest that unilateral RLND without impairing superior hypogastric plexus should be adopted to preserve ejaculatory function.

Nerve-preserving bilateral retroperitoneal lymphadenectomy: anatomical study and operative approach.

In a study of the sympathetic trunk in 18 cadavers a new anatomical approach for modified bilateral retroperitoneal lymphadenectomy was developed, which is characterized by unilateral preservation of the L3 ganglion and the fibers arising from this ganglion. Furthermore, the sympathetic trunk and its lumbar branches were dissected, including the connections between the right and left sympathetic trunks arising from the L3 and L4 ganglia. On the right side the fibers were found dorsal to the inferior vena cava from where they pass into the aortocaval zone. Caudal to the inferior mesenteric artery these fibers communicate with the left para-aortic fibers. The precise topographic inter-relationship between the L2 and L3 ganglia was studied; the lower margin of the L3 ganglion was located 1 cm. cranial to the origin of the inferior mesenteric artery. Based on these findings a modified operative technique was developed for stages B1 and B2 testicular tumors. With the help of this modification it should be possible to preserve ejaculatory function in 50% of the patients who undergo an operation for small retroperitoneal tumors. However, this modification can be justified only if the recurrence rate is not higher than that with radical bilateral lymphadenectomy.