Sciatic Foramen Research Articles

Ultrasound Localization of the Sacral Plexus Using a Parasacral Approach

In this report, we describe the feasibility of locating the sacral plexus nerve using a parasacral approach and an ultrasound-guided technique. The parasacral region using a curved probe (2-5 MHz) was scanned in 17 patients in search of the medial border of the ischial bone and the lateral border of the sacrum, which represent the limit of the greater sciatic foramen. In addition, attempts were made to identify the piriformis muscles and the gluteal arteries. The sacral plexus was identified at the level of the sciatic foramen as a round hyperechoic structure. The gluteal arteries were identified in 10 of 17 patients, but we failed to positively identify the piriformis muscle in any patient. To confirm localization of the sacral plexus, an insulated needle attached to a nerve stimulator was advanced and, in each case, a sacral plexus motor response was elicited (plantar flexion-12, dorsal flexion-1, hamstring muscle stimulation-3, gastrocnemius muscle stimulation-1-not recorded) at a current between 0.2 and 0.5 mA. No complications were observed. This report confirms the feasibility of using ultrasound to locate the sacral plexus using a parasacral approach.

Sciatic hernia: laparoscopic transabdominal extraperitoneal repair with plug and patch

Sciatic hernia is a rare pelvic floor hernia that occurs through the greater or lesser sciatic foramen. Sciatic hernias often present as pelvic pain, particularly in women, and diagnosis can be difficult. Transabdominal and transgluteal operative approaches, including laparoscopic repair, have been reported. We show a laparoscopic technique using a plug of human allogeneic dermal matrix and lightweight polypropylene extraperitoneal patch avoiding fixation. The patient had significant improvement of her symptoms and no complications at 12 months follow-up.

Bilateral high division of the sciatic nerve: incidence and clinical implications in Nigeria.

Introduction: The sciatic nerve (L4-S3) comprised of the tibial and common fibular (peroneal) components contained in the same epineural sheath usually leaves the pelvis via the greater sciatic foramen beneath the piriformis muscle. They usually separate in the lower thigh above the popiteal fossa. Variations in this arrangement have been reported. We noted one such variation in our study. Materials / Methods: The gluteal region and posterior thigh of 26 cadavers were dissected over a two session period (2004/05 and 2005/06) with emphasis on the sciatic nerves and its related structures. Results: One out of the twenty-six had the sciatic nerve dividing into its two main branches in the pelvis and the common peroneal passing over the piriformis muscle as it enters the posterior thigh. Conclusion: High division of the sciatic nerve is seen in 3.8% of Nigerians and could predispose to injury during intragluteal injection, may be the cause of piriformis syndrome, sciatica, failed sciatic nerve block in anesthesia and predispose to injury during posterior hip operations. Keywords: Sciatic nerve, high division, nerve injury, nerve block.Tropical Journal of Medical Research Vol. 11 (2) 2007: pp. 12-13

An Unusual Presentation of Infantile Fibrosarcoma in a Male Newborn

We describe a 10-day-old male presenting with drop foot and immobility in his right leg; no abnormality in physical examination had been found upon delivery or discharge. Magnetic resonance imaging showed a pelvic mass with an extension to the great sciatic foramen. Fine-needle aspiration biopsy revealed congenital infantile fibrosarcoma. He was started on vincristine, actinomycin-D, cyclophosphamide chemotherapy. However, he died soon after the second cycle due to veno-occlusive disease of the liver. Differential diagnosis of drop foot and immobility in lower extremity must include infiltrating neoplasms in pelvis.

A unique variation of the sciatic nerve

The normal course of the sciatic nerve out of the pelvis is through the greater sciatic foramen, below the inferior border of piriformis muscle and descends between the greater trochanter and the ischial tuberosity (Williams, 1995). There is evidence for anatomical variations of the course or level of division of the sciatic nerve (Pokorny et al., 2006). Variations of the anatomy of the sciatic nerve may be responsible for complications related to total hip arthroplasties.

Ureterosciatic Hernia Causes Obstructive Uropathy

Obstructive uropathy can be caused by urolithiasis, fibrotic ureteral stricture, inflammatory ureteritis with polyp formations, ureteral malignancy and various forms of external compression. Ureteral herniation is a relatively rare cause of obstructive uropathy and has been reported with herniation sites including inguinal canal, femoral canal and sciatic foramen. Most ureteral herniations occur in the inguinal area. In the literature, previous cases of sciatic ureter have been treated with observation in asymptomatic patients or with surgery in patients with obstructive uropathy or clinical symptomatology. We report the case of a 91-year-old female with asymptomatic hydronephrosis of the left kidney due to extremely rare ureterosciatic herniation. Her global renal function was acceptable. As she was elderly and a poor surgical candidate, watchful waiting was recommended after discussion with the patient and her family.

Ureteral Sciatic Hernia: A Case Report

A ureteral hernia that occurs through the sciatic foramen is very rare. We present a case of a ureteral sciatic hernia with hydronephrosis. Intravenous urography (IVU) showed the presence of a curved, laterally displaced ureter, and computed tomography (CT) clearly depicted the herniated ureter through the sciatic foramen. The patient was treated transiently with a double J catheter.

An unusual case of a ureteric hernia into the sciatic foramen causing urinary sepsis: successfully treated laparoscopically

We present the rare case of a ureteric hernia into the sciatic foramen. The presentation was that of a 59-year-old woman with urinary tract sepsis associated with an acute deterioration of renal function. The hernia was successfully repaired laparoscopically.

Fibromatosis (desmoid tumor) in the urogenital system

Fibromatosis refers to a group of rare tumors characterized by benign proliferation of fibroblasts [1]. The unique feature of fibromatosis is the often poorly circumscribed nature of the growth and infiltration of surrounding organs, often leading to incomplete removal. This report describes two such cases of pelvic fibromatosis. A 16-year-old girl presented with a history of marked lower urinary tract symptoms of 1-year duration, which culminated in acute urinary retention. A general physical examination was unremarkable. Abdominal examination revealed vague fullness in the suprapubic region. Digital rectal examination revealed a hard mass in the right paravaginal area, which was also visible in the right gluteal region. Her routine biochemical and hematological tests were normal. Ultrasound of the abdomen revealed a pelvic mass. Magnetic resonance imaging (MRI) showed a large mass occupying the pelvis (Fig. 1); the plane between the mass and the lateral pelvic wall was ill defined. Extension of the mass was seen in the right gluteal region through the sciatic foramen and right ischiorectal fossa. The mass was compressing the rectum and displacing the uterus anteriorly. The urinary bladder was also compressed. Fine-needle aspiration cytology of the mass suggested a spindle cell tumor, and debulking surgery was planned. During surgery the mass was found to occupy the whole pelvic region and removal was done piece by piece, leading to near total excision of the mass. A 40-year-old woman presented with a history of lower urinary tract symptoms and dyspareunia. Routine tests were ⁎ Corresponding author. Tel.: +91 172 2756321 (O); fax: +91 172 2744401. E-mail address: santoshsp1967jaimatadi@yahoo.co.in (S. Kumar).

The tip of the iceberg: a giant pelvic atypical lipoma presenting as a sciatic hernia

BackgroundThis case report highlights two unusual surgical phenomena: lipoma-like well-differentiated liposarcomas and sciatic hernias. It illustrates the need to be aware that hernias may not always simply contain intra-abdominal viscera.Case presentationA 36 year old woman presented with an expanding, yet reducible, right gluteal mass, indicative of a sciatic hernia. However, magnetic resonance imaging demonstrated a large intra- and extra-pelvic fatty mass traversing the greater sciatic foramen. The tumour was surgically removed through an abdomino-perineal approach. Subsequent pathological examination revealed an atypical lipomatous tumour (synonym: lipoma-like well-differentiated liposarcoma). The patient remains free from recurrence two years following her surgery.ConclusionThe presence of a gluteal mass should always suggest the possibility of a sciatic hernia. However, in this case, the hernia consisted of an atypical lipoma spanning the greater sciatic foramen. Although lipoma-like well-differentiated liposarcomas have only a low potential for recurrence, the variable nature of fatty tumours demands that patients require regular clinical and radiological review.

Establishment of normal values for tibial somatosensory evoked potentials

Normal values for tibial somatosensory evoked potentials (SEPs) have been reported by several authors, although subject factors, such as height, age or gender, have not been fully considered. We aimed to establish standard values fully considering subject factors using multivariate analysis for tibial SEPs, including the P15 component which we reported previously as a new stable component generated at the greater sciatic foramen. We examined SEPs following left tibial nerve stimulation in 65 normal subjects of various ages, and performed multiple regression analysis using height, age (age 20) 2 and gender as predictor variables. We objectively selected the latency or interval parameters with less intersubject variability as the standard parameters. As a result, P15 was clearly identified in all of the subjects and is promising as a new parameter to evaluate the proximal segment of the tibial nerve. Among three cortical bipolar derivations investigated, the Cz′–Cc lead gave the most constant and stable P38 component. The latencies of the N8o (N8 onset), P15 (P15 peak), N21, N30 and P38o/P38 in the Cz′–Cc lead, as well as the intervals between them were selected as standard parameters. We established nomograms to find the normal limit values of each parameter.

The level of the sciatic nerve division and its relations to the piriform muscle

The sciatic nerve, as the terminal branch of the sacral plexus, leaves the pelvis through the greater sciatic foramen beneath the piriform muscle. Afterwards, it separates into the tibial and the common peroneal nerve, most frequently at the level of the upper angle of the popliteal fossa. Higher level of the sciatic nerve division is a relatively frequent phenomenom and it may be the cause of an incomplete block of the sciatic nerve during the popliteal block anesthesia. There is a possibility of different anatomic relations between the sciatic nerve or its terminal branches and the piriform muscle (piriformis syndrome). The aim of this research was to investigate the level of the sciatic nerve division and its relations to the piriform muscle. It was performed on 100 human fetuses (200 lower extremities) which were in various gestational periods and of various sex, using microdissection method. Characteristic cases were photographed. Sciatic nerve separated into the tibial and common peroneal nerve in popliteal fossa in 72.5% of the cases (bilaterally in the 66% of the cases). In the remainder of the cases the sciatic nerve division was high (27.5% of the cases) in the posteror femoral or in the gluteal region. Sciatic nerve left the pelvis through the infrapiriform foramen in 192 lower extremities (96% of the cases), while in 8 lower extremities (4% of the cases) the variable relations between sciatic nerve and piriform muscle were detected. The common peroneal nerve penetrated the piriform muscle and left the pelvis in 5 lower extremities (2.5% of the cases) and the tibial nerve in those cases left the pelvis through the infrapiriform foramen. In 3 lower extremities (1.5% of the cases) common peroneal nerve left the pelvis through suprapiriform, and the tibial nerve through the infrapiriform foramen. The high terminal division of sciatic nerve (detected in 1/3 of the cases), must be kept in mind during the performing of popliteal block anesthesia. Although very rare, anatomical abnormalities of common peroneal nerve in regard to piriform muscle are still possible.

Quantitative analysis of uterosacral ligament origin and insertion points by magnetic resonance imaging.

To estimate the percentage of healthy women in whom the uterosacral ligaments are identifiable on standard magnetic resonance imaging (MRI) scans and to determine origin points from the genital tract and insertion points on the pelvic sidewall. Eighty-two asymptomatic women (mean +/- standard deviation age 53 +/- 12 years; mean parity 2.5, range 0-7) volunteered for this study. They were eligible if the most dependent vaginal wall point lay at least 1 cm above the hymenal ring remnant during a Valsalva maneuver. Axial proton density MRI of the entire pelvis was analyzed at 5-mm intervals. All results were referenced to the ischial spine. We determined the visibility of the uterosacral ligaments and located their origins from the genital tract and their insertion points on the pelvic sidewall. Uterosacral ligaments were visible in 61 (87%) of 70 analyzable scans. They extended over a mean craniocaudal distance of 21 +/- 8 mm (range 10-50). Three regions of origin were found: cervix alone, cervix and vagina in the same section, and vagina alone. Thirty-three percent, 63%, and 4% of 254 identified origin points were from these three areas, respectively. Of 259 uterosacral insertion points, 82% overlaid the sacrospinous ligament/coccygeus muscle complex, 7% the sacrum, and 11% the piriformis muscle, the sciatic foramen, or the ischial spine. Although uterosacral ligament morphology was similar bilaterally, its craniocaudal extent was greater on the right side. In healthy women, the uterosacral ligament origin and insertion points exhibited greater anatomic variation than their name would imply.

Intérêt de la voie d’abord transglutéale sous contrôle tomodensitométrique dans les procédures radiologiques interventionnelles percutanées

Purpose To assess the CT-guided transgluteal approach for percutaneous interventionnal image guided procedures. Materiel and Methods CT guided transgluteal approach through the greater sciatic foramen was used for diagnostic procedure (CT guided needle biopsy of presacral masses n=5) or percutaneous treatment (aspiration n=4, and drainage n=10) in 19 patients, mean age 58 year (age range 20-86). Results No technical failure occurred. A histological diagnostic was obtained in all diagnostic procedures. The success rate for therapeutic procedures was 87% and allowed to postpone surgery in 2 cases. In 2 patients a small pelvic hematoma occurred after catheter placement, but remained without consequence. Recurrences of collection occurred in 2 cases, one treated medically and the other surgically. Two patients suffered from transient deep pelvic pain, which resolved after catheter removal. Conclusion CT-guided percutaneous transgluteal procedures may be successfully performed in patients who cannot undergo trans-perineal, trans-rectal or trans-vaginal approach and is a safe and effective diagnostic and therapeutic option.

CT-guided transgluteal drainage of deep pelvic abscesses: indications, technique, procedure-related complications, and clinical outcome.

Deep pelvic abscesses may present a unique challenge for percutaneous drainage because of numerous overlying structures, which preclude safe percutaneous access. These structures include the pelvic bones, intestine, bladder, iliac vessels, and gynecologic organs. Use of the transgluteal approach to drain these abscesses can circumvent these obstacles and provide a useful surgical alternative or a temporizing measure. The transgluteal approach requires a thorough understanding of the anatomy of the sciatic foramen region and associated anatomic structures. The ideal approach for transgluteal access is to insert the catheter as close to the sacrum as possible, at the level of the sacrospinous ligament. Transgluteal drainage can be performed with the tandem-trocar technique or the Seldinger technique. Modifications of the procedure are needle aspiration not followed by catheter placement, use of the angled gantry technique, bilateral transgluteal drainage, combined anterior and posterior drainage, and drainage of necrotic pelvic masses. The transgluteal approach is a useful option in pediatric patients. Daily catheter care is essential for successful percutaneous catheter therapy. Although pain has been cited as a common complication of the technique, this complication can be minimized with judicious use of analgesia and a meticulous technique. Other complications are hemorrhage and catheter malposition.

Innervation of the female levator ani muscles

Objective: The objective of this study was to characterize the innervation of the human female levator ani muscles. Study Design: Detailed dissections of the peripheral innervation of the iliococcygeal, pubococcygeal, puborectal, and coccygeal muscles were performed in 12 fresh-frozen female cadavers (aged, 32-100 years) with the use of transabdominal, gluteal, and perineal approaches. Both the pudendal nerve and the sacral nerve roots that enter the pelvis from the cephalic side were followed from their origin at the sacral foramina to their termination. Pelvic floor innervation was described with reference to fixed bony landmarks, particularly the coccyx, the ischial spine and the inferior pubis. Photographs were taken, and nerve biopsies were performed to confirm the gross findings histologically. Biopsy specimens were stained with Masson's trichrome. Results: In each dissection, a nerve originated from the S3 to S5 foramina (S4 alone, 30%; from S3 and S4, 40%; from S4 and S5, 30%), crossed the superior surface of the coccygeal muscle (3.0 ± 1.4 cm medial to the ischial spine [range, 1.0-4.2 cm]), traveled on the superior surface of the iliococcygeal muscle innervating it at its approximate midpoint, and continued on to innervate both the pubococcygeal and puborectal muscles at their approximate midpoint. The pudendal nerve originated from the S2 to S4 foramina, exited the pelvis through the greater sciatic foramen, traversed Alcock's canal, and branched to innervate the external anal sphincter, the external urethral sphincter, the perineal musculature, the clitoris, and the skin. Despite specific attempts to locate pudendal branches to the levator ani, none could be demonstrated. Nerve biopsy specimens that were obtained at gross dissection were confirmed histologically. Conclusion: Gross dissections suggest that the female levator ani muscle is not innervated by the pudendal nerve but rather by innervation that originates the sacral nerve roots (S3-S5) that travels on the superior surface of the pelvic floor (levator ani nerve). Because definitive studies (eg, nerve transection or neurotracer studies) cannot be performed in humans, further studies that will use appropriate animal models are necessary to confirm and extend our findings. (Am J Obstet Gynecol 2002;187:64-71.)

Percutaneous drainage of abdominal abcess

The mortality in undrained abdominal abscesses is high with a mortality rate ranging between 45 and 100%. The outcome in abdominal abscesses, however, has improved due to advances in image guided percutaneous interventional techniques. The main indications for the catheter drainage include treatment or palliation of sepsis associated with an infected fluid collection, and alleviation of the symptoms that may be caused by fluid collections by virtue of their size, like pancreatic pseudocele or lymphocele. The single liver abscesses may be drained with ultrasound guidance only, whereas the multiple abscesses usually require computed tomography (CT) guidance and placement of multiple catheters. The pancreatic abscesses are generally drained routinely and urgently. Non-infected pancreatic pseudocysts may be simply observed unless they are symptomatic or cause problems such as pain or obstruction of the biliary or the gastrointestinal tract. Percutaneous routes that have been described to drain pelvic abscesses include transrectal or transvaginal approach with sonographic guidance, a transgluteal, paracoccygeal–infragluteal, or perineal approach through the greater sciatic foramen with CT guidance. Both the renal and the perirenal abscesses are amenable to percutaneous drainage. Percutaneous drainage provides an effective and safe alternative to more invasive surgical drainage in most patients with psoas abscesses as well.

PERCUTANEOUS NEPHROLITHOTOMY OF A PELVIC KIDNEY: A POSTERIOR APPROACH THROUGH THE GREATER SCIATIC FORAMEN

No AccessJournal of UrologyCLINICAL UROLOGY: Case Reports1 Jul 2001PERCUTANEOUS NEPHROLITHOTOMY OF A PELVIC KIDNEY: A POSTERIOR APPROACH THROUGH THE GREATER SCIATIC FORAMEN JAMES D. WATTERSON, ANTHONY COOK, RIKI SAHAJPAL, JOHN BENNETT, and JOHN D. DENSTEDT JAMES D. WATTERSONJAMES D. WATTERSON More articles by this author , ANTHONY COOKANTHONY COOK More articles by this author , RIKI SAHAJPALRIKI SAHAJPAL More articles by this author , JOHN BENNETTJOHN BENNETT More articles by this author , and JOHN D. DENSTEDTJOHN D. DENSTEDT Financial interest and/or other relationship with Boston Scientific, Cook Canada and Phillips Petroleum. More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(05)66114-9AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "PERCUTANEOUS NEPHROLITHOTOMY OF A PELVIC KIDNEY: A POSTERIOR APPROACH THROUGH THE GREATER SCIATIC FORAMEN." The Journal of Urology, 166(1), pp. 209–210 References 1 : Laparoscopic surgery for urolithiasis: pyelolithotomy, calyceal diverticulectomy and treatment of stones in a pelvic kidney. J Endourol2000; 14: 829. Google Scholar 2 : Laparoscopic pyelolithotomy in a pelvic kidney: a case report and review of the literature. J Soc Laparoendosc Surg1997; 1: 163. Google Scholar 3 : Drainage of pelvic abscesses through the greater sciatic foramen. Radiology1986; 158: 487. Google Scholar From the Departments of Urology and Radiology, University of Western Ontario, London, Ontario, Canada© 2001 by American Urological Association, Inc.FiguresReferencesRelatedDetails Volume 166Issue 1July 2001Page: 209-210 Advertisement Copyright & Permissions© 2001 by American Urological Association, Inc.Keywordsnephrostomy, percutaneousurinary calculikidneyMetricsAuthor Information JAMES D. WATTERSON More articles by this author ANTHONY COOK More articles by this author RIKI SAHAJPAL More articles by this author JOHN BENNETT More articles by this author JOHN D. DENSTEDT Financial interest and/or other relationship with Boston Scientific, Cook Canada and Phillips Petroleum. More articles by this author Expand All Advertisement PDF downloadLoading ...

CROHN'S DISEASE PRESENTING AS LEFT GLUTEAL ABSCESS

SUMMARYAlthough abscesses and fistulae are common complications of Crohn's disease, the gluteal area is a rare site for abscess formation. The abscess results from extension of pus through the fascial plains of the pelvis and through the greater sciatic foramen into the gluteal area. This is the first reported left gluteal abscess due to Crohn's disease as pus extends across the midline to the left side. The clinical picture can be misleading and diagnosing the source of infection may be difficult. Incision of this abscess without identifying the source of infection will result in enterocutaneous fistula. Ultrasound guided aspiration of the abscess as well as treatment of metabolic deficiencies and septicaemia before definitive surgical treatment of the bowel disease will reduce the morbidity and mortality of this rare complication. The clinical picture, management of this complication and review of the literature are discussed.

CT-Guided transgluteal drainage of deep pelvic abscesses in children: selective use as an alternative to transrectal drainage.

The transgluteal approach to abscess drainage through the greater sciatic foramen has been described in adults, but this route has not been as extensively studied in children. We performed CT-guided transgluteal percutaneous abscess drainage in seven children and assessed the results of drainage and catheter tolerance. Transgluteal catheters are well tolerated by children, and the transgluteal route is an effective approach to selected pelvic abscesses in children.