Dieter Voth

Bovine pericardium for duraplasty: clinical results in 32 patients

Abstract 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.

Arachnoid cysts: does surgery improve epileptic seizures and headaches?

During the period from 1985 to 1992 we treated 43 patients with intracranial arachnoid cysts (ACs). In this retrospective study we assessed the outcome of these patients with regard to non-specific symptoms such as headaches and epileptic seizures. Twelve patients had headaches of obscure origin and a mostly temporal located AC. Six of these 12 underwent surgery. After the operation 4 patients (4/6) had no further headaches, two remained unchanged. The other 6 conservatively treated patients (6/12) had further headaches.Ten of the 43 patients had epileptic seizures. One patient dropped out of the survey. Six of the 9 remaining patients had a temporal AC. Four of these 6 underwent surgery; postoperatively the seizure disease of 3 patients (3/6) declined. One patient was unchanged. Two patients with epileptic seizures and a temporal AC did not undergo surgery and both improved. Three patients with seizures had a convex located AC. Two of these 3 underwent surgery. The first patient improved postoperatively, the second patient remained unchanged. There was a reduction in the seizures of the medically treated patient.It remains ambiguous, whether there is a relationship between epileptic seizures and intracranial ACs without obvious intracranial pressure signs. A review of the literature, however, showed mostly positive results concerning the surgical treatment of ACs under conditions of simultaneous epileptic seizures. However, the results largely depend upon the definition of the decline of the seizures with regard to the postoperative follow-up, therefore we must remain skeptical. Therapy guidelines in the future not only depend on the clarification of the pathophysiology of the ACs, but also on a reasonable outcome examination.

Cerebral arachnoid cyst: a lesion of the child's brain.

Abstract39 patients with 42 arachnoid cysts have been reviewed in a retrospective study. All kinds of arachnoid cysts reported in the literature were also found in this study. These consist mainly of congenital primary and posttraumatic secondary cysts. Cysts which cause no major neurological deficits require conservative treatment of symptoms only. Cysts which cause major symptoms because of their space occupying nature, however, require surgical treatment. Craniotomy with removal of membranes to allow free physiological circulation of CSF is the treatment of choice in our hands. Cysto-peritoneal shunting is an alternative procedure for patients in a poor condition. More than 50% (23 out of 39 cases) were younger then 20 years of age, suggesting that these cysts are mainly congenital lesions of the brain.

Fine structural features of the cerebral microvasculature in hydrocephalic human infants: Correlated clinical observations

Four of 30 human cerebral cortex biopsies from infants ranging from four days to about ten years treated for hydrocephalus by shunt operations are described paying special attention to the vascular structures. The biopsy specimens were studied in semi-thin and ultrathin sections. Attention is drawn to the role of pinocytotic vesicles found in capillaries and smaller vessels as a possible transcellular route for the hydrocephalic oedema resolution. No intercellular dehíscences or the so called blisters were observed. With the passage of time, the number of membrane bound vesicles increased and arrays of pinocytotic vesicles were discernible both on the abluminal as well as luminal aspect of the capillary wall. Additionally, larger vacuoles containing electrondense material, apparently undergoing autolysis, were also detected. The basal lamina was of uneven thickness and at places duplicated. Hypertrophic pericytes exhibited remarkable oedamatous changes, increased vesicular or vascular transport, demonstrating pericyte brain-barrier dysfunction. Swelling of the astrocytic end-feet bordering the capillaries was remarkable. These findings indicate that the CSF or oedema fluid is absorbed into the vascular system via a transendothelial pathway.

Antibiotic single-dose prophylaxis of shunt infections

Shunt infections after implantation or revision of a shunt for CSF drainage in hydrocephalic patients are serious complications. In view of their frequency, this study investigated the efficacy of prophylactic administration of a single dose of the antibiotic cefazedone in reducting in the post-operative infection rate.Fifty children of up to 14 years of age suffering from hydrocephalus of various etiologies were treated prophylactically and compared with a similar untreated group.The diagnosis of infection was based mainly on microbiological and clinical observations and investigations. Classical infection parameters were also recorded and evaluated, but played only a secondary role in establishing the diagnosis as they can change post-operatively without an infection being present.The infection rates observed were 6% in the group of patients who received antibiotic treatment prophylactically and 14% in the untreated control group.

Tethered cord after spina bifida aperta: a longitudinal study of somatosensory evoked potentials

Progressive neurological deterioration may occur after meningomyelocele repair. Magnetic resonance imaging almost invariably demonstrates a conus medullaris in an abnormally low position, whether neurological symptoms develop or not. Surgery of a secondary tethered cord is indicated when progression of neurological symptoms is documented. We performed a longitudinal study of posterior tibial nerve somatosensory evoked potentials (SSEPs) in children and adolescents after neonatal meningomyelocele repair. All patients were able to walk. Declining or negative posterior tibial nerve SSEPs were recorded in 15 patients; 14 of these had clinical signs of a secondary tethered cord. After surgery of the tethered cord, the SSEPs improved in 8 of 10 patients. Posterior tibial nerve SSEPs may contribute to the diagnosis of secondary tethered cord. After untethering, the evoked potentials demonstrate recovery of spinal cord function and might help to delineate prognosis.

Arterio-venous malformations in childhood: clinical presentation, results after operative treatment and long-term follow-up

In a series of 182 arterio-venous malformations (AVM) recently published [8] we found 33 children aged 1 to 16 years. In 28 cases, the admitting condition was hemorrhage. For 31 AVMs total excision was possible. We observed one postoperative death accounting for a mortality of 3%. All children but two were followed-up by personal examination. Two were not able to work due to severe neurological deficits and seven had not been able to get into their intended occupation.

Assessment of brainstem function in Chiari II malformation utilizing brainstem auditory evoked potentials (BAEP), blink reflex and masseter reflex

Brainstem dysfunction was evaluated in 67 patients with myelomeningocele and Chiari II malformation using brainstem auditory evoked potentials (BAEP), blink reflex (BR) and masseter reflex (MR). Signs and symptoms related to Chiari II malformation were observed in 18 patients while 49 patients had normal brainstem findings. BAEP and BR showed a higher sensitivity of brainstem involvement than MR (BAEP=1.0, BR=0.83, MR=0.50). BR, and in particular, MR were of higher accuracy (BR=0.52, MR=0.72) than BAEP (0.39) in separating patients with brainstem signs and symptoms related to Chiari II malformation. We feel that this is due to anatomic and physiologic peculiarities of the brainstem structures mediating BR and MR. Our results suggest that brainstem reflexes can support the decision of further treatment.

Masseter reflex and blink reflex abnormalities in Chiari II malformation

Masseter reflex and blink reflex were evaluated in 64 patients with a myelomeningocele and Chiari II malformation. In 46 patients, no brainstem signs or symptoms were present. Brainstem dysfunction related to Chiari II malformation occurred in 18 patients. The masseter reflex was more frequently abnormal in the symptomatic than asymptomatic patients (P = 0.02). Although the blink reflex was similarly affected in the two groups of patients (P > 0.1), it was very sensitive, being abnormal in 83% of symptomatic and 65% of asymptomatic patients. Concomitant abnormality of masseter reflex and the late contralateral blink reflex component (R2c) was almost exclusively found in symptomatic patients and reached the highest significance in separating the two groups (P = 0.002).

Magnetic resonance imaging of dysraphic myelodysplasia

The spinal cord in 56 children and adolescents was examined by magnetic resonance imaging (MRI) many years after neonatal surgery on a meningomyelocele (average age 12 years). In a high percentage of cases, the diagnosis “tethered cord” was made. Associated anomalies were found with a frequency of 21%. Typical findings are presented and the impact of these results on therapy planning is discussed.