Complications of endoscopic third ventriculostomy in previously shunted patients.

OBJECTIVE: Endoscopic third ventriculostomy (ETV) is considered to be a safe and effective treatment in selected patients as an initial treatment for obstructive hydrocephalus and at the time of shunt malfunction in previously shunted patients. We compared the outcome and complications of ETV between patients with newly diagnosed hydrocephalus and those with previous shunting procedures. METHODS: A retrospective review of patients undergoing ETV from 1996 to 2004 at Alberta's Childrens Hospital and Foothills Medical Centre was completed. Patient data included symptoms at clinical presentation, cause of hydrocephalus, age at initial shunt, number of previous shunt revisions, age at ETV, complications, and subsequent shunting procedures performed. RESULTS: A total of 131 patients were identified with a minimum follow-up duration of 1 year; 71 (82.5%) of 86 patients who underwent ETV as a primary procedure and 36 (80%) of 45 patients who had ETV at the time of shunt malfunction were shunt-free at the last follow-up evaluation. Patients younger than 1 year old who underwent ETV were more likely to require an additional procedure for control of their hydrocephalus (P < 0.01). Serious complications after ETV occurred more frequently in patients who presented at the time of shunt malfunction (14 of 45 patients, 31%) compared with patients who underwent primary ETV (seven of 86 patients, 8%) (P = 0.02). Previously shunted patients with a history of two or more revisions (P = 0.03) and who experienced a serious complication at the time of ETV (P = 0.01) were more likely to require shunt replacement. CONCLUSION: ETV is an effective treatment both in selected patients with newly diagnosed hydrocephalus and in patients with a previous shunting procedure who are presenting with malfunction. Complications of ETV occur more frequently in previously shunted patients than in patients treated for newly diagnosed hydrocephalus, and care must be taken in the selection and treatment of these patients.

Optimizing epilepsy surgery with intraoperative MR imaging.

PURPOSE: The surgical treatment of medically intractable temporal lobe epilepsy includes the resection of temporal lobe structures. Although the reported seizure-free outcomes are highly variable, there is growing evidence that the extent of resection of the mesiotemporal lobe directly correlates with seizure control. METHODS: A moveable, high-field intraoperative magnetic resonance (MR) system was used to monitor and optimize the resection of the amygdala and hippocampus in 14 epilepsy patients. Fourteen patients with intractable seizures of temporal lobe origin underwent standard preoperative investigations including MR imaging, EEG telemetry, single-photon emission computed tomography, and neuropsychologic and sodium amytal testing. Anterior temporal lobectomy was performed on 10 patients, whereas four were treated with selective amygdalohippocampectomy. Intraoperative electrocorticography was applied as required. For all procedures, the objective was to resect the amygdala completely, and hippocampus to the posterior margin of the brainstem. RESULTS: Interdissection intraoperative MR imaging taken when optimal resection was thought to have been achieved revealed residual unresected amygdala or hippocampus in seven of 14 patients. An unexpected acute hematoma was found in one patient. At 17 months' follow-up, 13 (93%) of 14 patients are seizure free or have significantly improved seizure control. CONCLUSIONS: The mobile high-field intraoperative MR system provides high-resolution images without restriction on surgical instruments or techniques. The ability to identify and resect residual mesial temporal lobe targets before craniotomy closure is of potentially tremendous value in optimizing seizure control.