Heinz Fankhauser

Cyst of the ligamentum flavum: report of six cases.

Six cases of cyst of the ligamentum flavum with compression of a lumbar nerve root are reported. All patients exhibited recurrent back pain and sciatica. Investigation included computed tomography, myelography, or both. The correct diagnosis was reached before operation in only half the patients. High-resolution computed tomography performed in the four last patients outlined the cystic lesion with its low-density center. Surgical excision was performed in all patients. Microscopic examination showed a dense fibrous cyst arising from the ligamentum flavum. The lumen contained myxoid or necrotic material, but no epithelial lining. Cysts of the ligamentum flavum must be considered in the differential diagnosis of causes of sciatica. A firm radiological diagnosis may, at present, still require myelography combined with high-resolution computed tomography. Differentiation from synovial or ganglion cysts of the spine is discussed.

Appropriateness of Indications for Surgery of Lumbar Disc Hernia and Spinal Stenosis

Study Design This prospective study examines the appropriateness of indications for surgery of herniated intervertebral disc and spinal stenosis in patients undergoing surgery in a university hospital setting. Objective To evaluate the appropriateness of surgery using explicit criteria developed by an expert panel in the United States. Summary of Background Data The use of surgery for herniated intervertebral disc and spinal stenosis varies widely within and among countries. It has been postulated that the main reason for treatment failure is poor selection of condidates for the procedure. Methods The authors prospectively evaluated appropriateness of surgical indications for herniated lumbar intervertebral disc or spinal stenosis in 328 consecutive patients undergoing the operation in two university neurosurgery departments. Outcome was measured 1 year after surgery by a standardized interview. Results Indications for surgery were considered to be appropriate or equivocal in 202 (62%) patients and inappropriate in 126 (38%). Among the 126 inappropriate procedures, 66 were so rated because of insufficient activity restriction before the procedure. One year after surgery, 74% of the patients perceived the results of the operation as good or very good. Conclusions Appropriateness as measured by the criteria established by the American panel identified a large percentage of day-to-day practice in the two surgical units as inappropriate. However, use of criteria that include new findings about lack of efficacy of bed rest probably would lower this percentage. Criteria of appropriateness of medical and surgical procedures, developed through the panel process, need to be updated regularly.

Computed Tomography of the Postoperative Intervertebral Disc and Lumbar Spinal Canal : Investigation of Twenty - five Patients after Successful Operation for Lumbar Disc Herniation

Twenty-five patients with good outcome after operation for lumbar disc herniation underwent unenhanced computed tomography (CT) and plain radiography of the lumbar spine before, 5 to 7 days after, and 6 to 7 weeks after the operation to define the radiological features of the postoperative disc and spinal canal. After operation, the center of the disc appears hypodense. The anterior and lateral borders remain sharply delimited, but in 44% of the cases the posterior border shows an image suggesting the persistence of disc herniation. In 84% of the cases, there are major changes in the spinal canal with complete occlusion of the extradural space on the operated side by a heterogeneous material the attenuation value of which ranged between those of cerebrospinal fluid and disc. The outline of the dural sac and of the nerve root is lost. This aspect did not significantly change between the 1st and the 6th postoperative week, except for the disappearance of any air within the canal and a slight movement on the dural sac toward the operated side. From these major radiological modifications found in asymptomatic postoperative patients, it is concluded that positive CT in patients with the failed back surgery syndrome has limited value. Myelography is preferred as the primary neuroradiological investigation.

Biodistribution of boron sulfhydryl for boron neutron capture therapy in patients with intracranial tumors

The biodistribution of boron sulfhydryl (BSH) was evaluated for boron neutron capture therapy of brain tumors. A selective boron delivery to the neoplasm is a prerequisite for successful therapy. The uptake of BSH after intravenous administration was analyzed in neoplastic and normal tissues in 61 patients undergoing craniotomies for intracranial tumors. The patients received 10 to 100 mg of BSH/kg (5-50 mg of 10B/kg) body weight, 2 to 72 hours before surgery. The tumor boron concentrations ranged from 0.2 ppm (micrograms/g) in a low-grade glioma to 19.5 ppm in a high-grade glioma. The tumor to blood boron ratio rose above 1 in 15 of 24 high-grade intracerebral tumors, 18 h or more after BSH infusion. The boron concentration in high-grade tumors was heterogeneous. Low-grade intracerebral tumors showed a low boron concentration with a tumor to blood ratio below 1. Extracerebral tumors, mainly meningiomas, showed boron concentrations comparable with high-grade tumors, with a tumor to blood ratio above 1 in 10 of 17 patients. The boron concentrations in skin and muscle compared roughly with the blood values. Boron did not enter normal brain in any significant amount. In high-grade tumors, tumor to brain ratios were above 2. Low boron concentrations in normal brain make BSH safe for a Phase I normal tissue tolerance study. Computed tomographic contrast enhancement was evaluated to tumor boron uptake for 30 patients. Tumor enhancement on computed tomography does not permit the prediction of individual tumor boron concentrations; however, the absence of a contrast enhancement was always associated with low boron uptake.

Extreme lateral lumbar disc herniation: clinical presentation in 178 patients.

SummaryA retrospective analysis of clinical characteristics of 178 consecutive patients with extreme lateral lumbar disk herniation, amongst 3047 patients operated on for herniated lumbar disc, is presented. The level specific incidence of extreme lateral disc herniation (ELLDH) ranged from a low of 4.5% at L 4–5 to peak of 17.4% at L 3–4 although the largest number of ELLDH occurred at L 4–5 and L5-S1 for a total number of 139 cases (78.1%). 43.6% of all L3 radiculopathies were caused by an L 3–4 ELLDH, whereas only 4.4% of all L 5 radiculopathies were caused by an L 5-S 1 ELLDH.Leg pain, either of the sciatic or the femoral type, was the first and dominant clinical symptom of radiculopathy, but pain radiation occurred not always in the appropriate dermatomal segment. ELLDH at upper levels (L 2–3 and L 3–4) caused usually none or only minor low back signs (76.2%), whereas ELLDH at lower levels more often caused moderate or major lumbar symptoms and signs (59.6%). Positive femoral nerve traction test with upper ELLDH showed a high frequency (84.4%) and reliability and is therefore an important clinical parameter in this situation. Motor deficits occurred more often (78.8%) than sensory deficits (46.6%), were usually of the monoradicular type and were therefore a more reliable clinical sign than sensory disturbances.

Microsurgical anatomy and operative technique for extreme lateral lumbar disc herniations

SummaryThe anatomy of the lateral aspect of the lumbar spine and our lateral microsurgical technique for extreme lateral lumbar disc herniations (ELLDH) is described. This study was based on the microdissection of 4 cadavers, on the morphometric evaluation of these as well as 6 dried cadaver spines and 8 lumbar CT scans, and on the use of this technique on over 200 cases.Level dependent changes in the posterior arch cause a shift of the disc space distally relative to the facet joint, an increasing amount of bone to overlie the intervertebral foramen, and a decreasing amount of working space within the exposure in the caudal direction. Therefore, more bone removal from the lateral aspect of the pars interarticularis and supero-lateral aspect of the facet joint is required in the lower lumbar spine. When the exposed ligamentum flavum is resected, the dorsal root ganglion is seen and access to the herniation and disc space is achieved. Level dependent changes in the pedicles and transverse processes lead to an alteration in the course and relationships of the nerves, thereby influencing the pathophysiology of and surgical technique for the ELLDH. The operative target is the lateral aspect of the pars interarticularis and not the intertransverse space as has been previously described.Our techniques allows for the early identification of the nerve with minimal risks of injury to it, to the adjacent vessels and to the structural integrity of the facet joint and pars interarticularis.

Biodistribution of Boron Sulfhydryl (BSH) in Patients with Intracranial Tumors

The therapeutic as well as the undesired effects of Boron Neutron Capture Therapy (BNCT) largely depends upon the absolute and relative 10B concentrations in tumors and in normal tissues and body fluids. Our present work on BSH in patients with intracranial neoplasms has been prompted by crucial questions regarding: tumor levels, tumor-to-normal tissue ratios, variations between different tumors, variations inside the same tumor, correlation between histology and 10B levels, time course of BSH uptake, pharmacokinetics of BSH, Temptative answers to some of these questions have been worked out for animals and experimental animal tumor models. For humans, Hatanaka et al. [2] have published boron concentrations measured at the time of re-operation and actual BNCT in 60 patients. Eleven to 17 hrs after intra-arterial or intravenous administration of 40 to 80 mg of 10B/kg as BSH, 26 glioblastoma patients yielded a median 10B concentration in the tumor of approximately 15 ppm and a median tumor-to-blood ratio of 1.1. In 13 cases of anaplastic astrocytomas the values were comparable with a median tumor concentration of approximately 22 ppm and a tumor-to-blood ratio of 1.4. In 4 cases of astrocytomas grade I-II, the median concentration dropped to around 5 ppm and the tumor-to-blood ratio remained always below 0.6. Beside Hatanaka’s findings, the literature contains only anecdotal data on the situation in humans [1,4,5].

Borocaptate Sodium (BSH) Pharmacokinetics in Glioma Patients

In a previous communication we have reported the results of a biodistribution study of intravenous borocaptate sodium (BSH) administered to 28 patients undergoing craniotomy for various intracranial tumors10. The measured boron concentrations in tumor, blood, and normal cranial tissues led to the tentative conclusion 1) that BSH readily enters most malignant intracerebral tumors, 2) that some retention of the drug occurs in these tumor, leading to an improvement of the tumor-to-blood ratio over the first 18 hours, and possibly later, and 3) that BSH is virtually excluded from normal brain.

Osseous metastases from a benign intraventricular meningioma

SummaryThe authors report a case of a 6 month-old male presenting with increasing head circumference and a large benign intraventricular meningioma which was grossly removed at the initial surgery. Twenty-four months later, the patient returned with subcutaenous and osseous metastatic lesions at the site of the previous craniotomy, revealing the same histology as the original tumour. The presentation, pathology and management of this unique case are discussed.

Update on Biodistribution of Borocaptate Sodium (BSH) in Patients with Intracranial Tumors

The use of borocaptate sodium (BSH) for Boron Neutron Capture Therapy (BNCT) has been studied since 1968. BSH has shown differential accumulation in rodent tumor models both subcutaneously and intracerebrally implanted. BSH administration to humans for BNCT has also been reported [1,2,3,4], including at this symposium [see report by D. Haritz]. In 1990, we presented the biodistribution of BSH in 28 patients with various intracranial tumors [5]. This compound showed accumulation in most high grade intracerebral tumors and low grade extracerbral tumors with a variable kinetic; a delay of at least 12 hours after administration was usually necessary to obtain a positive tumor to blood ratio. In order to obtain more substantial information on the distribution pattern, and to determine an adequate dose to be given before neutron radiation, we have extended this investigation to a larger number of patients.