Otmar Gratzl

Preoperative and postoperative auditory and facial nerve function in cerebellopontine angle meningiomas.

Preoperative and postoperative facial nerve and auditory function were reviewed retrospectively in 13 cases of cerebellopontine angle meningiomas. According to their location within the posterior fossa and with special reference to the internal auditory canal, they were classified into a premeatal and a retromeatal group. All the tumors were removed by an otoneurosurgical team by use of a retrosigmoid approach. Postoperative results (1 year after operation) were compared within the two groups with respect to preservation of hearing (normal hearing in 31% and preservation of preoperative hearing in 69% of the cases) and facial nerve function (no or mild postoperative impairment in 69% of the cases). Both preoperative and postoperative impairment of facial nerve and auditory function prevailed in the premeatal group. For preservation of vital vascular and central nervous structures, subtotal resection with consecutive fractionated radiation therapy had to be performed in 30% of the cases. Our results provide substantial evidence that in cerebellopontine angle meningiomas a precise preoperative study of tumor location will assist in improving individual operative strategy and thus postoperative functional results.

Treatment of syringomyelia after posttraumatic paraparesis or tetraparesis.

This retrospective study of 12 patients with syringomyelia related to spinal cord trauma with paraplegia or tetraplegia and secondary progressive neurologic deficits was conducted to evaluate various surgical treatments. Judging by the results of postoperative neuroradiologic examinations, 75% had incomplete reduction of the spinal fracture at the time of initial surgery. The secondary neurologic deterioration occurred within a delay of 146 +/- 16 months and included ascending sensory deficits in 92%, deafferentation pain in 83%, and increased motor weakness in 33%. There was a positive correlation between the severity of symptoms, incomplete reduction of spinal fracture, and the degree of arachnoid scarring in preoperative neuroradiologic examinations. Syringoperitoneal shunting was performed in 83% of patients, and laminectomy with arachnoid lysis and dural grafting were performed in 17%. Pain was improved in 75%, sensory deficits in 25%, and motor weakness in 8%. During the follow-up period of 44 +/- 25 months, 30% of patients with syringoperitoneal shunting required repeated operation for obstruction or infection, whereas the syringomyelia remained collapsed in the two patients with laminectomy with arachnoid lysis and dural grafting, but this did not require additional surgery. In conclusion, laminectomy with arachnoid lysis and dural grafting seems to be a promising alternative treatment for patients with secondary neurologic deterioration after traumatic paraplegia or tetraplegia. Syringoperitoneal shunting may be reserved for patients without severe arachnoid scarring.

Fehler und Gefahren bei der Chirurgie von Kleinhirn-brückenwinkeltumoren

Es werden die Resultate und Komplikationen einer retrospektiven Studie von 92 Patienten vorgestellt, die innerhalb von 1981–1991 eines KleinhirnbrUkkenwinkeltumors wegen Uber einen retrosigmoidalen Zugang von einem neurochirurgischotologischen Team operiert wurden. Das Kollektiv setzte sich aus 73 vestibulAren Schwannomen, 9 Meningeomen, 3 Neurofibromatosen vom Typ 2, 3 Epidermoidzysten und jeweils 1 Lipom, Tuberkulom, HAmangioblastom und Gliom zusammen. Die LetalitAt war insgesamt null. Die Fazialisfunktion ein Jahr postoperativ zeigte sich bei den vestibulAren Schwannomen in 66% als gut (House-Grad I–II) und in 26% als mAssig (House-Grad III–IV), sowie bei den Meningeomen in 76% als gut. Bei den Schwannomen steht die Fazialisfunktion in signifikanter Korrelation zur TumorgrOsse (p = 0,0002). Bei 28% der vestibulAren Schwannome und 100% der Meningeome mit prAoperativ normalem GehOr (Gardner-Klasse I) konnte postoperativ unabhAngig von der TumorgrOsse die HOrfunktion vollstAndig erhalten werden (Gardner-Klasse I). Die weitere postoperative MorbiditAt wird unter Einbeziehung der aktuellen Literatur abgehandelt.

Current status of regional cerebral blood flow measurement in revascularization microneurosurgery of the brain

Treatment of cerebrovascular insufficiency has advanced through introduction of the extracranial-intracranial arterial bypass technique between the superficial temporal artery and a branch of the middle cerebral artery. (1,3,4,14,15) Until now, selection of appropriate candidates as well as assessment of postoperative results have been largely based on clinical criteria and on additional findings obtained from cerebral angiography. (2,10) In previous publications, we have described the preliminary results of pre- and postoperative regional cerebral blood flow studies (rCBF) in patients that underwent extracranial-intracranial bypass surgery for cerebral ischemia. (5,6,11–13) In addition to providing a quantitative increase in cerebral blood flow following bypass surgery, our results have demonstrated that the selection of appropriate candidates could be considerably facilitated by routinely using rCBF studies during the preoperative evaluation of patients. Despite these promising results, it was felt that a more definitive assessment of rCBF studies should await further experience with its application in revascularization microneurosurgery.

Microneurosurgical arterial anastomoses in patients with prolonged reversible ischemic neurologic deficits (PRIND)

During the first symposium on extracranial-intracranial anastomoses in Loma Linda, California,(1) there was almost general agreement that this operation should be performed as a prophylactic measure in patients with a history of transient ischemic attacks (TIA). That this clinical condition still represents the best indication is well supported by an up-to-date review of our own series including 62 operated cases. Those patients with episodes of focal cerebral dysfunction of vascular origin lasting for no longer than 24 hours do show the most promising postoperative results, according to a long-term follow-up study. In order to analyze the therapeutic effect of the microneurosurgical anastomosis on brain blood flow a topical and quantitative evaluation has been carried out. For this purpose the data of clinical investigation, angiography, and measurement of regional cerebral blood flow (rCBF)—were collected and compared for the pre- and postoperative situation.