Vascular Decompression of Trigeminal and Facial Nerves in the Posterior Fossa under Endoscope-Assisted Keyhole Conditions.

OBJECTIVE: The aim of this study was to determine the use and safety of the endoscope as an adjunct during trigeminal and facial nerve decompression procedures performed under keyhole conditions in the posterior fossa. METHOD: We performed 67 surgeries in 65 patients with symptomatic trigeminal and facial nerve compression syndromes. The diagnosis was made mainly on the basis of clinical history, examination, and magnetic resonance imaging scans. Surgery was performed in all cases under endoscope-assisted keyhole conditions. The follow-up was 1 week postoperatively, 6 months, and then yearly up to 7 years. All 34 patients with trigeminal neuralgia received preoperative medication treatment and experienced failure with it. Eighteen patients out of 30 with hemifacial spasm had been previously treated with botulinum toxin injections. One patient suffered from both trigeminal neuralgia and facial spasm, because of a megadolichobasilar and vertebral artery with compression of both cranial nerves. RESULTS: Sixty-four of the 65 patients became symptom free after surgical treatment; one revision surgery was necessary because of disappearance of the decompression muscle piece. No mortalities or minor morbidities were observed in this series. CONCLUSION: A precise planned keyhole craniotomy and the simultaneous use of the microscope and the endoscope render the procedure of the decompression less traumatic.

Endoscope-assisted removal of colloid cysts of the third ventricle.

Colloid cysts are benign space-occupying lesions, which arise from the velum interpositum or the choroid plexus of the third ventricle and are able to produce symptomatic obstruction of the foramina of Monro with resultant hydrocephalus. In our department, we have operated on colloid cysts routinely in an endoscope-assisted microsurgical manner via a key-hole approach. During a period of 10 years, 28 microsurgical resections of colloid cysts of the third ventricle were performed. Seven patients demonstrated colloid cysts inside the third ventricle with obstruction of the right foramen Monro, two patients demonstrated cysts with obstruction of the left foramen Monro. Twelve patients suffered from cysts inside the third ventricle with obstruction of both foramina Monro and five patients demonstrated cysts lying into the third ventricle without obstruction of the foramina. In 21 patients no preoperative therapy was performed outside. Three patients had received shunt systems before in other hospitals, two patients received aspiration of the cysts under stereotactic conditions and two patients received external ventricular drains. Total removal of the cyst was achieved in all patients (100%). No patient received a second operation, because none had a recurrent cyst. All cysts were removed with the cyst wall. Overall clinical improvement was achieved in a long-standing period between 6 and 83 months in 27 (96%) patients. In one patient (4%) the psychomotor disturbance was unchanged and no patient deteriorated. From the microsurgical point of view, the combination of keyhole surgery under endoscopic visual control using preexisting anatomical windows offers an effective minimally invasive approach.

Endoscope-assisted microsurgery for tumors of the septum pellucidum: surgical considerations and benefits of the method in the treatment of four serial cases.

Neoplasms that primarily originate from the septum pellucidum are extremely rare. Generally the septum pellucidum is involved in direct extension of tumors that arise from the neighboring structures, principally the corpus callosum. Endoscope-assisted techniques form a useful adjunct to common microsurgical procedures to completely remove intraventricular lesions. There are two main advantages of endoscope-assisted surgery over common microsurgical techniques: reduction of superficial brain retraction with less iatrogenic trauma to the neighboring structures and inspection of hidden corners depict simultaneously anatomical details which are not precisely visible in the zoomed and thus light-reduced beam of the microscope. Four patients with septum pellucidum tumors underwent surgery by a transcallosal approach. In all four patients the endoscope-assisted microsurgery technique was used to remove the tumor. In one of the four patients neuronavigation was additionally used for guidance. Complete tumor excision was achieved in all patients. The histological findings showed pilocytic astrocytoma in two cases, one subependymoma and one neurocytoma, respectively. There were no postoperative complications. Endoscope-assisted microsurgery provides maximum efficiency to remove the septum pellucidum tumors with minimum invasiveness.

[Coincidence of an epidural hematoma and epidural metastases during thoracic epidural anaesthesia]. / Koinzidenz eines epiduralen Hämatoms und epiduralen Metastasengewebes bei thorakaler Epiduralanästhesie.

In the present report we describe a case of epidural hematoma with paraplegia subsequent to preoperative thoracic epidural catheter insertion. The hematoma co-localized with epidural metastases unknown at the time of catheter insertion. In addition to the description of the exact interventions, the conditions enabling early diagnosis and therapy of the described complication are discussed. Furthermore, we discuss the necessity of preoperative examinations if an epidural anaesthesia is planned.

Transoral transclival removal of anteriorly placed cavernous malformations of the brainstem.

BACKGROUND: The natural history of brain stem cavernous malformations is unfavorable because of their high hemorrhage rate and resulting neurological deterioration among patients. However, direct surgery of intrinsic and anteriorly situated cavernomas is hazardous and leads to a bad postoperative outcome because of trauma to lateral and dorsally situated eloquent areas of the brain stem. METHODS: We review the cases of two patients with symptomatic cavernous malformations of the anterior brain stem and describe the usefulness of a transoral-transclival approach. A 23-year-old man developed progressive hemihypaesthesia and paraesthesia, hemiparesis with gait ataxia, dysarthria, dysphonia, and dysphagia. A 38-year-old woman suffered from an acute onset of vertigo with nausea and vomiting, diplopia, and paraesthesia of the left hand and foot. In both patients, computed tomography demonstrated the presence of brain stem hemorrhage, because of cavernous malformation. Magnetic resonance imaging showed a close proximity of the lesions to the pia mater only on the ventral surface of the brain stem. RESULTS: In both patients, the cavernomas could be safely approached and completely resected via a transoral transclival route. Three months after surgery, neurological examination revealed marked neurological improvement. The 23-year-old patient showed slight gait ataxia, no hemiparesis, no cranial nerve palsies; the 38-year-old woman demonstrated no neurological symptoms except for minimal motor dysfunction of the left hand. In both cases, under perioperative prophylactic antibiotics, no meningitis was observed. The patients could subsequently return to their previous employment. CONCLUSION: The transoral transclival approach for ventrally situated brain stem cavernomas allows a largely atraumatic resection of the lesion.

The influence of surgical experience on the rate of intraoperative aneurysm rupture and its impact on aneurysm treatment outcome.

BACKGROUND: The influence of surgical experience on the result of aneurysm surgery remains unclear. To determine the impact of surgical experience we considered the occurrence of intraoperative aneurysm rupture (IAR) during microneurosurgery for intracranial aneurysms as an objective factor that could be evaluated. METHODS: A retrospective study was performed on 379 consecutive patients with 490 cerebral aneurysms operated upon from 1989 to 1995. RESULTS: IAR occurred in 6.7% of aneurysms and 8.7% of patients. There was a direct inverse relationship between the annual caseload of the surgeon and the risk of IAR. New neurological deficits (NND) occurred in 21% of patients with IAR, which accounts for 1.8% of NND in all patients with aneurysms. CONCLUSION: Although there seems to be a direct relationship between surgical experience and the risk of IAR, the impact on the overall treatment outcome of cerebral aneurysms is rather limited.

Bovine pericardium for duraplasty: clinical results in 32 patients.

Bovine pericardium has been widely used for grafts in cardiac surgery and seems to have suitable properties for use as a dural graft. We report on the use of solvent-preserved, gamma-sterilized Tutoplast bovine pericardium for dural grafts in 32 patients undergoing cranial and spinal operations with the objective of clinically assessing this material and technique by a retrospective analysis. All available records were reviewed and information regarding the indication for grafting, complications, and outcome were collected and analyzed for all patients. Indications for grafting included tethered cord myelolysis, closure of lumbosacral myeloceles, Chiari decompression, posterior fossa craniotomy, supratentorial craniotomy, and trauma. Outcomes were excellent in 31 patients; the one poor outcome was unrelated to surgical closure. The dural graft was not intended for outcome in any patient. Bovine pericardium was found to be a flexible and easily suturable, safe and cost-effective material for duraplasty. These results confirm the excellent suitability of Tutoplast bovine pericardium for dural substitution.

Brain tissue pO2 related to SjvO2, ICP, and CPP in severe brain injury.

The aim of this report is to present first experience in comparing the course of brain tissue oxygen pressure values (PtiO2) to changes in jugular vein oxygen saturation (SjvO2), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) after severe brain injury. PtiO2 monitoring was done using a polarographic Clark type microcatheter (LICOX pO2 probe) (GMS, Kiel, Germany) with a diameter of 0.5 mm and a sensitive area 7.9 mm long inserted in a right frontal position. The microcatheter was connected to a LICOX pO2 device. A fiber-optic catheter was used to measure SjvO2 and placed into the right internal jugular vein. The ICP monitoring was performed with a fiber-optic intraparenchymal device (Camino Laboratories, San Diego, Calif.) inserted in a left frontal position. Consistent correlations could be noticed between reduced PtiO2 and higher ICP and lower CPP levels. However, the absolute value of a single SjvO2 data point seemed to be less relevant diagnostically than its trend over a period of time. Owing to their experience, the authors suppose that PtiO2 monitoring will be a very important and reliable tool in the treatment of brain injury in the future, especially in its correlation to ICP and CPP.

Tightness of duraplasty in rabbits: a comparative study.

OBJECTIVE: The purpose of this study was to test, in rabbits, the tightness of seven dural substitution materials commonly used in neurosurgery, i.e., Lyodura (B. Braun Melsungen AG, Melsungen, Germany), Tutoplast dura (Tutogen Medical, Inc., Parsippany, NJ), Tutoplast fascia lata (Tutogen Medical, Inc.), autologous periosteum, Neuropatch (B. Braun Melsungen AG), Dacron (E.I. du Pont de Nemours and Co., Wilmington, DE), and Ethisorb (Ethicon, Inc., Somerville, NJ). METHODS: Duraplasties were performed with sutures alone or were additionally fixed with fibrin glue. Leakage pressures were assessed by infusion of artificial cerebrospinal fluid, containing sodium fluorescein, into the cisterna magna and detection of fluorescence using a charge-coupled display camera with background substraction, 3 days, 3 weeks, or 3 months after surgery. RESULTS: Three days after implantation, the mean tightness values of duraplasties with Lyodura or Neuropatch were significantly higher (P = 0.007) than the values for the other substitutes. A significant improvement of tightness with increasing implantation time could be demonstrated for autologous periosteum (P = 0.0063). Improvement of tightness with the use of fibrin glue could be proven only for the heterologous grafts (P = 0.0071). The tightness values for Neuropatch fixed only with sutures were similar to those for the best heterologous substitutes implanted with additional fibrin glue. Lyodura, Tutoplast dura, and Neuropatch demonstrated favorable implantation characteristics; they were thin, flexible, and easily suturable. Neither adhesions to the brain nor space-occupying scars were noted. CONCLUSION: These results confirm the excellent suitability of Lyodura and Neuropatch for dural substitution.

Migratory activity of human glioma cell lines in vitro assessed by continuous single cell observation.

A new migration assay, the time-lapse individual cell migration assay (TIM-assay), was developed, which allows the observation of cells over 24 h under controlled conditions. Using this technique, the migratory behavior of 8 human glioblastoma cell lines in vitro was studied. Special features are simultaneous documentation of migratory parameters of individual cells, i.e., migration velocities and migration paths of individual cells. Migration velocity for cell populations of the same cell line ranged from 0 to 24 microm/h. The migration paths were examined for being directional. Two thirds of all cells showed directional migration. Migration paths were further classified according to visual judgements for being linear, oscillating or mixed. The migration index had a mean of 91%. The presented TIM-assay allows the assessment of several new parameters. that may be useful to identify subgroups of gliomas with different biological characteristics.

Intracranial endoscopy.

Since 1910, when Lespinasse [73] in Chicago was the first surgeon to use an endoscopic device for the treatment of a neurologic disease, various methods of endoscopy have evolved into accepted diagnostic and therapeutic adjuncts of modern neurosurgery. Nevertheless, until recently technical shortcomings of the available endoscopes have prevented the widespread use of neuroendoscopy. However, now, at the end of the 20th century, endoscopes can be regarded as some of the most important instruments for the development of microneurosurgery into the 3rd millennium. The aim of this review of intracranial endoscopy in neurosurgery, which admittedly might not be completely objective in the authors' personal assessment of various endoscopic techniques, is first to depict the historical evolution of neuroendoscopy, second to describe the technical equipment used in intracranial endoscopic neurosurgery, third to characterize the most frequent endoscopic methods in brain surgery, and fourth to indicate how neuroendoscopy might develop in the near future. It will be shown that this ongoing evolutionary process in neuroendoscopy was only possible with the mutual influence of improved diagnostic techniques, increased microanatomical knowledge, refined neurosurgical instrumentation--especially the introduction of the surgical microscope, and endoscopic diagnostic and therapeutic strategies.

Endoscopic third ventriculostomy: outcome analysis of 100 consecutive procedures.

OBJECTIVE: Endoscopic third ventriculostomy (ETV) has been shown to be a sufficient alternative in the surgical treatment of occlusive hydrocephalus. To elucidate the ongoing discussion of timing, indication, and surgical technique, a retrospective analysis of 100 consecutive ETVs was conducted. METHODS: One hundred ETVs were performed in 95 patients (43 female and 52 male patients). Their age ranged from 3 weeks to 77 years (mean age, 36 yr). Hydrocephalus was caused by aqueductal stenosis in 40 patients, space-occupying lesions in 42, and intraventricular or subarachnoid hemorrhage in 8. One patient had postinflammatory hydrocephalus, and four patients had occlusive hydrocephalus of unknown origin. In 33 cases, surgery was performed using stereotactic guidance. RESULTS: ETV was accomplished in 98 of 100 cases. The overall success rate was 76%. Patients with benign space-occupying lesions and nontumorous aqueductal stenosis had the highest success rates, which were 95 and 83%, respectively. Complications were arterial bleeding in one case, venous bleeding in three cases, intracerebral bleeding in one case, and infection in one case. There were no permanent morbidities or mortalities. CONCLUSION: ETV is most effective in treating uncomplicated occlusive hydrocephalus caused by aqueductal stenosis and space-occupying lesions. ETV is still effective in two-thirds of the patients with previous infections or intraventricular bleeding. Patients who have previously undergone shunting and who have occlusive hydrocephalus should undergo ETV at the time of shunt failure, with immediate ligation or removal of the shunt device. In selected cases of distorted anatomy or impaired visual conditions, stereotactic guidance is helpful.

Postoperative pain therapy after lumbar disc surgery.

OBJECT: This study was undertaken to determine whether a special postoperative pain administration of tramadol and diclofenac provides any benefits in patients who underwent microsurgical lumbar discectomy. METHODS: The study consisted of 60 patients undergoing microsurgical lumbar discectomy. Patients were randomly divided into two groups based on the postoperative pain management: 1) Group A (n = 30); no standardized pain therapy; these patients received on demand different analgesics and at variable dosages which were selected by the neurosurgeons; 2) Group B (n = 30); standardized pain therapy with specific dosages of tramadol and diclofenac in regular time intervals during the first 48 hours after surgery. After surgery follow-up data from a special standardized questionnaire were obtained for all 60 patients during the first 48-72 postoperative hours. The patients were asked for course and intensity of pain as well as about some specific circumstances of clinical therapy after surgery. The postoperative pain intensity of patients treated with the special combination of tramadol and diclofenac was significantly diminished (24 hours after surgery: p = 0.0002, 48 h: p = 0.0047, 72 h: p = 0.0034) in relation to the group without standardized pain therapy. Similarly, the frequency of breakthrough pain was significantly reduced (24 h: p = 0.0001, 48 h: p = 0.003, 72 h: p = 0.004). CONCLUSIONS: The results suggest that the application of tramadol and diclofenac during the first 48 hours after lumbar microdiscectomy results in a reduction in postoperative pain without complications. We suggest that the use of this combination can be a beneficial adjunct to lumbar disc surgery.

Endoscopic neurosurgery and endoscope-assisted microneurosurgery for the treatment of intracranial cysts.

OBJECTIVE: Different endoscopic techniques have been introduced into neurosurgery, but accepted terminology and definitions are still missing. We propose a terminology based on whether the endoscope is used alone or in conjunction with an operating microscope and on whether the route of surgical manipulations is through or outside the endoscope. Accordingly, procedures are categorized into endoscopic neurosurgery (EN), endoscope-assisted microneurosurgery (EAM), and endoscope-controlled microneurosurgery (ECM). METHODS: We treated 36 patients with intracranial arachnoid cysts (ACs) and intraventricular cysts endoscopically. The patients ranged in age from 4 months to 69 years (mean age, 31 yr). The follow-up period ranged from 6 to 44 months (mean follow-up duration, 14 mo). The indications were hydrocephalus in 17 patients, focal neurological deficits in 4 patients, progressive nonlocalizing symptomatology in 13 patients, and space occupation in 2 asymptomatic patients. EN was used in 14 cases, EAM in 15 cases, and ECM in 7 cases. RESULTS: The overall success rate was 70%. Nine patients (25%) had unchanged symptomatology, and the condition of two patients (5%) deteriorated. The best success rates were achieved in patients with intraventricular cysts (89%) and posterior fossa ACs (78%). Symptomatic improvement was best achieved in patients with hydrocephalus or focal neurological deficits (81%). CONCLUSION: Different endoscopic techniques (i.e., EN, EAM, and ECM) provide sufficient treatment of selected intracranial cysts. Our data suggest that intraventricular cysts and suprasellar ACs should be approached using EN whereas posterior fossa and sylvian ACs may be more effectively treated using a combined technique (EAM or ECM).

Endoscopic treatment of mesencephalic ependymal cysts: technical case report.

OBJECTIVE: To evaluate the results of different neuroendoscopic surgical procedures for the treatment of mesencephalic ependymal cysts. METHODS: The clinical records of five patients treated for symptomatic mesencephalic ependymal cysts were retrospectively studied. Two patients had been operated on using an endoscope-assisted microsurgical technique and three patients using a pure endoscopic procedure. RESULTS: Adequate fenestration of the cysts was achieved in all of the patients. Two of the patients were symptom-free, and the other three had improved significantly after a mean follow-up duration of 14 months. There was no surgical morbidity. CONCLUSION: Mesencephalic ependymal cysts can be treated adequately, resulting in a low morbidity rate, using neuroendoscopy or endoscope-assisted microsurgery. This specific surgical technique is presented.

Cerebral blood flow velocities after subarachnoid haemorrhage in relation to the amount of blood clots in the initial computed tomography.

In 72 patients with acute subarachnoid haemorrhage (SAH) the relationship between the amount of subarachnoid blood clots detected by initial cranial computed tomography (CCT) up to 48 hours after bleeding and the later development of vasospasm, established by blood flow velocity measurement with transcranial Doppler ultrasound (TCD) was investigated. The serial Doppler examinations started within the first 72 hours after SAH and were carried out every second day up to three weeks. Each Doppler recording was accompanied by a neurological examination. Patients classified as Hunt and Hess grade V were excluded from the study. All patients with remarkable brain oedema in CCT or with intracranial pressure above 25 mmHg were also excluded. Because of the well known age-dependence of vasospasm after SAH, two age groups were formed. A statistically significant correlation (p > 0.05) between blood flow velocities and blood load after SAH was not found. The mean age of the investigated 72 individuals was 48.9 years (14 up to 76 years). 47 patients were younger than 56 years. Linear regression analysis indicated a correlation with a quite low significance level (r = 0.350, p < 0.025) between TCD blood flow velocities and blood load in CCT in these younger subjects. No significant correlation (p > 0.05) between these two variables could be established in the 25 patients older than 55 years. In a second step an intra-individual comparison of side-to-side differences in TCD and CCT was made. There were no significant differences in blood flow velocities between subjects with or without side-to-side differences in cisternal blood load. It is concluded that the amount of blood visible on initial CCT after SAH is not a powerful predictor of cerebral blood flow velocities measured by TCD.

Sensitivity and specificity of MRA in the diagnosis of neurovascular compression in patients with trigeminal neuralgia. A correlation of MRA and surgical findings.

The published rates of operatively confirmed neurovascular compression as the cause for trigeminal neuralgia range from 10% to nearly 100%. High-definition magnetic resonance angiography (MRA) was performed in 27 consecutive patients (in 6 cases with 3D reconstructions) to show neurovascular compression preoperatively. The MRA findings were compared with the relationship between the Vth nerve and the surrounding vessels at surgery. In 23 patients MRA showed present neurovascular compression in accordance with surgical findings (18/27 in complete accordance of type and side of vessel, site and direction of compression). One woman had no neurovascular compression either on MRA or intraoperatively. One MRA prediction of neurovascular compression was false, and two results were false negative. The sensitivity of MRA was therefore 88.5% but the specificity only 50%, if surgical findings are the reference. In one patient with right trigeminal neuralgia MRA revealed bilateral neurovascular compression of the Vth nerves. Therefore, the overall specificity of MRA might be below 50%. In one patient with multiple sclerosis, the decision to operate was markedly influenced by the clear finding of neurovascular compression on MRA. The patient has been free from trigeminal pain for 149 weeks after microvascular decompression. In 6 patients, 3D reconstructions of the MRA data were performed. The images helped in 3D visualisation of the operation, but did not yield new information about the nature of the vessels revealed, or the site, direction or side of the neurovascular compression.

The supraorbital keyhole approach to supratentorial aneurysms: concept and technique.

BACKGROUND: Anterior surgical approaches to the base of the brain have always required relatively large craniotomies, most larger than the lesion itself. Especially in aneurysm surgery, the size of the lesion is not always proportionate to the extent of brain exposure. The improvement of surgical techniques and diagnostic imaging, as well as the introduction of neuroendoscopy and new surgical instruments, enable us now to treat various intracranial lesions through small keyholes. In particular, cerebral aneurysms, because of their anatomic characteristics, are apt to be treated by the keyhole approach. The supraorbital keyhole approach has the broadest field of indications, although its technical aspects have not yet been evaluated. METHODS: The concept and technique of the supraorbital keyhole approach are presented in detail. We conducted a retrospective study in which we evaluated the technical aspects of the supraorbital keyhole approach considering the indications, limitations, and complications of this approach as well as new instrumentation in surgery of supratentorial aneurysms. RESULTS: The use of 139 supraorbital keyhole approaches for 197 aneurysms is described. Multiple aneurysms have been treated by one approach in 38 patients. Clipping of the aneurysm was performed in 94% and wrapping in 6% of patients. Eighteen aneurysms were contralateral to the approach. In four patients, intraoperative accidental aneurysm rupture occurred. There were no approach-related complications. CONCLUSIONS: The supraorbital keyhole approach offers equal surgical possibilities with less intraoperative accidental rupture and less approach-related morbidity as conventional approaches in the treatment of supratentorial aneurysms.