Michael R. Gaab

Traumatic Brain Swelling and Operative Decompression: A Prospective Investigation

Since 1978, decompressive craniotomy was performed according to a standardized protocol. Exclusion criteria were age greater than or equal to 40 years, deleterious primary brain damage, operable space occupying lesions, larger infarctions in CT scan or irreversible brain stem incarceration/ischaemic damage as shown by bulbar syndrome, loss in BAEP or oscillating flow in TCD. Indication was given by progressive intracranial hypertension not controllable by conservative methods, if ICP decompensation was correlated with clinical (GCS, extension spasms, mydriasis) and electrophysiological (EEG, SEP, CCT) deteriorations. 18 patients were decompressed by unilateral. 19 by bilateral craniotomy with large fronto-parieto-temporal bone flap and a dura enlargement by use of temporal muscle/fascia. 37 patients at an age of 18 +/- 7 (4-34) years were operated 5 h-10 d after trauma. Recovery was surprisingly good: only 5 died, 2 due to an ARDS; 3 remained vegetative, all others achieved full social rehabilitation or remained moderately disabled. The best predictor of a favourable outcome was an initial posttraumatic GCS greater than or equal to 7. These in younger patients with delayed posttraumatic decompensation before irreversible ischaemic damage occurs.

Endoscopic aqueductoplasty: technique and results.

OBJECTIVE The purpose of this study was to determine the safety and efficacy of endoscopic aqueductoplasty in patients with hydrocephalus caused by aqueductal stenosis. The controversy of third ventriculostomy and aqueductoplasty is discussed. METHODS A series of 17 patients who underwent endoscopic aqueductoplasty is reported. Rigid rod-lens scopes were used for inspecting the aqueductal entry and performing balloon aqueductoplasty. With the aid of a 2.5-mm flexible endoscope, the aqueduct and fourth ventricle were explored and aqueductal membranous obstructions were perforated. Third ventriculostomies were performed simultaneously in nine patients. One aqueductal stent was inserted. In six patients, frameless computerized neuronavigation was used for an accurate approach to the aqueduct. The average duration of the endoscopic procedures was 59 minutes (range, 25-100 min). RESULTS There was no endoscopy-related mortality. Surgical complications included an asymptomatic fornix contusion and two injuries to the aqueductal roof, which resulted in permanent diplopia due to dysconjugate eye movement (one patient) and transient trochlear palsy (one patient). In addition, two patients developed transient dysconjugate eye movements, and one patient had an asymptomatic epidural hematoma. Eleven patients showed improvement in their symptoms. The conditions of five patients were unchanged. One patient died of stroke 1 month after the operation. No patient required shunting. The ventricles decreased in size in nine patients and were unchanged in the remaining eight patients. CONCLUSION Endoscopic aqueductoplasty is an effective alternative to third ventriculostomy for the treatment of hydrocephalus caused by short aqueductal stenosis. However, longer follow-up periods are necessary to evaluate long-term aqueductal patency after aqueductoplasty.

Endoscopic observation of a slit-valve mechanism in a suprasellar prepontine arachnoid cyst: case report.

OBJECTIVE AND IMPORTANCE There are several theories regarding the genesis of arachnoid cysts. However, controversy continues over what mechanisms are involved in the formation of the cysts. CLINICAL PRESENTATION A 6-year-old female patient presented with precocious puberty. The results of a neurological examination were unremarkable. Magnetic resonance imaging revealed a large suprasellar prepontine arachnoid cyst. INTERVENTION An endoscopic ventriculocystostomy via a right frontal burr hole was performed. During inspection of the cyst, we clearly observed a slit-valve mechanism that was obviously responsible for the formation and enlargement of the cyst. The valve was formed by an arachnoid membrane surrounding the basilar artery. Synchronous with pulsation, the valve opened and closed rapidly. CONCLUSION A slit-valve mechanism seems to be at least one factor of the genesis of suprasellar prepontine arachnoid cysts.

Incidence of complications in neuroendoscopic surgery

ObjectiveThis study was undertaken to determine the complication rate in intracranial endoscopic neurosurgery.ResultsThe complications in our series of endoscopic intracranial procedures for the treatment of hydrocephalus, colloid and arachnoid cysts, as well as intraventricular tumors, were analyzed.ConclusionAlthough the complication rate in endoscopic neurosurgery is low, severe, rarely even life-threatening, complications may occur. The complication rate decreases markedly with surgical experience, indicating a steep learning curve.

Endoscopic treatment of cerebrospinal fluid pathway obstructions.

OBJECTIVE This article describes our endoscopic techniques developed for the treatment of various obstructions of cerebrospinal fluid pathways. METHODS Blocked cerebrospinal fluid pathways result in ventricular dilation in front of the obstruction, which may cause acute or chronic symptoms of hydrocephalus. The traditional treatment is insertion of a shunt. Because of the high failure rate in the long term, shunts should be avoided whenever possible. RESULTS Our techniques of septum pellucidum fenestration, third ventriculostomy, lamina terminalis fenestration, temporal ventriculostomy, foraminoplasty of the foramen of Monro, aqueductoplasty, aqueductal stenting, and retrograde aqueductoplasty for trapped fourth ventricle are presented. CONCLUSION Neuroendoscopic techniques can effectively treat obstructive hydrocephalus by restoration of the obstructed cerebrospinal fluid pathway or creating a bypass into the ventricles or subarachnoid spaces.

Endoscopic resection of colloid cysts.

COLLOID CYSTS OFTEN cause cerebrospinal fluid pathway obstruction, which results in ventricular enlargement that provides sufficient space for endoscopy. Because of further improvement of endoscopic instrumentation and hemostasis, colloid cysts often can be resected completely via an endoscopic approach. This article describes our endoscopic technique as developed for the removal of colloid cysts located in the third ventricle.

Endoscopic aqueductoplasty in the treatment of aqueductal stenosis

ObjectiveEndoscopic aqueductoplasty is an option in the treatment of obstructive hydrocephalus caused by aqueductal stenoses. We report on our experience with this endoscopic technique, focussing on indications, operative technique, and results.MethodsA series of 39 endoscopic aqueductoplasties was performed in 33 patients harbouring a hydrocephalus caused by aqueductal stenosis. In 13 patients, a third ventriculostomy was simultaneously performed. There was no endoscopy-related mortality. One aqueductoplasty had to be abandoned. In 7 patients, reclosure of the restored aqueduct required an endoscopic revision. In 25 patients (76%), the hydrocephalus-related symptoms resolved or improved. The condition was unchanged in 8 patients. Four patients needed to be shunted. The ventricles decreased in size in 22 patients (67%), were larger in 2, and unchanged in the remaining 9 patients.ConclusionEndoscopic aqueductoplasty is a treatment option in patients with hydrocephalus caused by membranous aqueductal stenosis. Unfortunately, the reclosure rate is higher than initially expected. More experience and longer follow-up are necessary to determine the value of endoscopic aqueductoplasty in the treatment of hydrocephalus caused by aqueductal stenosis.

Chronic subdural hematoma—Craniotomy versus burr hole trepanation

The authors present a series of more than 200 surgical procedures for chronic subdural hematoma in a 5-year-period. Clinical presentation and neurosurgical treatment were regarded with a special focus on the surgical technique. Between March 2003 and July 2008, 193 patients (113 male and 80 female, mean age 72.5 yrs [range 26–97 yrs]) suffering from chronic subdural hematoma were retrospectively analyzed. One-hundred-fifty-one craniotomies and 42 burr holes were performed. Forty-two craniotomy patients (27.8%) in contrast to 6 burr hole patients (14.3%) required surgical revision. A craniectomy was performed as an ultima ratio after at least 2 prior evacuations in 3 cases. Chronic subdural hematoma is a disease of the elderly. A craniotomy seems to possess a higher rate of recurrence of the chronic subdural hematoma so that a burr hole evacuation should be preferred. Craniectomy might be a good therapeutic option in complicated recurrent chronic subdural hematomas.

Water jet dissection in neurosurgery: experimental results in the porcine cadaveric brain.

OBJECTIVEWater jet dissection is currently under investigation as a new tool for use in neurosurgical procedures. The safety of this instrument has already been demonstrated. However, precise data demonstrating highly accurate tissue dissection in the brain in combination with vessel preservation are still missing. METHODSIn this study, 50 porcine cadaveric brains were dissected with the use of several nozzle types (80–150 in &mgr;m diameter, coherent straight or helically turned jet) and several levels of water jet pressure (1–40 bars). The dissection characteristics in various brain regions and the basilar artery were evaluated morphologically. RESULTSThe best results regarding reliable function, dissection accuracy, and the correlation of water jet pressure with dissection depth were obtained with the 120-&mgr;m Helix Hydro-Jet nozzle. An almost linear relationship of pressure increase with dissection depth was demonstrated. The dissection depth varied significantly up to threefold, depending on the area investigated (greatest resistance was in the brainstem, followed by hemispheres and then the cerebellum). Vessels including the basilar artery resisted pressure up to 15 bars in most cases, whereas the basilar artery was dissected significantly more often with higher pressure. CONCLUSIONThe results indicate that 1) use of the water jet enables very precise and reliable brain parenchyma dissection with vessel preservation under conditions corresponding to the clinical situation, and 2) the nozzle type and water jet pressure must be selected carefully according to the brain area and tissue targeted. This study provides the morphological basis for further research with the use of the water jet technique in the brain. The water jet’s characteristics may make this device a useful addition to the neurosurgical armamentarium.

Continuous intrathecal infusion of baclofen in patients with spasticity caused by spinal cord injuries

Abstract.The aim of this study was to determine the efficacy and safety of intrathecal baclofen therapy delivered by a programmable pump for the chronic treatment of spinal spasticity. Twelve patients with intractable spasticity caused by spinal cord injuries underwent implantation of a programmable continuous infusion pump after significant reduction in spasticity following an intrathecal test bolus of baclofen. No deaths or new permanent neurological deficits occurred following surgery or chronic intrathecal baclofen therapy. The follow-up (12 months) shows a reduction in rigidity in the lower limb of 2.0 points on the Ashworth scale and in the upper limb of 1.2 points. Muscle spasms were reduced from a mean preoperative score of 2.8 to a mean postoperative score of 1.0. In two cases, we observed postoperative catheter dislocation, a complication which could be corrected surgically. This study demonstrates that chronic intrathecal baclofen infusion is a safe and effective form of treatment of intractable spasticity in patients with spinal cord injury. There is considerable reduction in the risk of infection in view of the fact that interrogation and programming of the implanted programmed pumps is noninvasive.