Posthemispherectomy hydrocephalus: Results of a comprehensive, multiinstitutional review

Abstract

SUMMARY Purpose Hemispherectomy surgery for medically intractable epilepsy is known to cause hydrocephalus in a subset of patients. Existing data regarding the incidence of, and risk factors for developing, post-hemispherectomy hydrocephalus has been limited by the relatively small number of cases performed by any single center. Our goal was to better understand this phenomenon and to identify risk factors that may predispose patients to developing hydrocephalus after hemispherectomy surgery. Methods Fifteen pediatric epilepsy centers participated in this study. A retrospective chart review was performed on all available patients who had hemispherectomy surgery. Data collected included surgical techniques, etiology of seizures, prior brain surgery, symptoms and signs of hydrocephalus, timing of shunt placement and basic demographics. Key findings Data were collected from 736 patients who underwent hemispherectomy surgery between 1986 and 2011. Forty-six patients had pre-existing shunted hydrocephalus and were excluded from analysis, yielding 690 patients for this study. One hundred sixty-two patients (23%) required hydrocephalus treatment. The timing of hydrocephalus ranged from the immediate post-operative period to 8.5 years after surgery, with 43 patients (27%) receiving shunts more than 90 days after surgery. Multivariate regression analysis revealed anatomic hemispherectomies (OR 4.1, p<0.0001) and previous brain surgery (O.R. 1.7, p=0.04) as independently significant risk factors for developing hydrocephalus. There was a trend towards significance for the use of hemostatic agents (O.R. 2.2, p=0.07) and the involvement of basal ganglia or thalamus in the resection (O.R. 2.2, p=0.08) as risk factors. Significance Hydrocephalus is a common sequela of hemispherectomy surgery. Surgical technique and prior brain surgery influence the occurrence of post-hemispherectomy hydrocephalus. A significant portion of patients develop hydrocephalus on a delayed basis, indicating the need for long-term surveillance.

Etiology associated with developing posthemispherectomy hydrocephalus after resection-disconnection procedures

“…The blood supply to the choroid plexus was not interrupted during the operation, and use of large volumes of hemostatic agents was discouraged when using our hemispherectomy technique. 15 Other components of the perioperative protocol were designed to reduce infections, as previously described. 17 Antibiotic agents (cefazolin or, for allergic patients, clindamycin or vancomycin) were administered intravenously prior to skin incision and were continued postoperatively as noted above.…”

“…8,13,16,20 Previous studies, including a recent multicenter collaborative project involving different hemispherectomy techniques, have identified type of procedure and previous operations as factors associated with developing posthemispherectomy hydrocephalus. 6,14,15 However, these reports were unable to clearly identify possible links with clinical variables that might suggest mechanisms for developing hydrocephalus after a particular hemispherectomy procedure.…”

“…Given prior findings, we concentrated on a single, firsttime resection-disconnection hemispherectomy operation Etiology associated with developing posthemispherectomy hydrocephalus after resection-disconnection procedures using a standardized perioperative protocol including use of ventriculostomy catheters to control for prior surgeries and operative techniques. 12,15 Based on clinical experience, we hypothesized that etiology would be the most important factor associated with developing posthemispherectomy hydrocephalus requiring CSF shunts when using our resection-disconnection procedure.…”

“Compensated hyperosmolarity” of cerebrospinal fluid and the development of hydrocephalus

“…It is well documented that osmotic gradients play a significant part in the regulation of brain water and CSF volume (Hochwald et al, 1974;Wald et al, 1976;Orešković et al, 2002;Maraković et al, 2010;Jurjević et al, 2012). Because of this, it has been presumed that without significant obstruction or stenosis of the CSF system, all pathological processes in which an increase of CSF osmolarity (the osmotic load of CSF) takes place should lead to an increase in CSF volume, and consequently should cause hydrocephalus (Krishnamurthy et al, 2009;Orešković and Klarica 2010; what speaks in favor the most recent multiinstitutional studies of hydrocephalus as a consequence of hemispherectomy surgery for medically intractable epilepsy treatment (Lew et al, 2013).…”

Complete prefrontal lobe isolation surgery for recurrent epilepsy: A case report

“…However, they are considered palliative as they may reduce seizure frequency or severity, but do not stop seizure activity (19). A previous study observed that hemispheric and posterior quadrantic disconnection achieved the same rates of seizure control as epileptogenic focus resection in patients with intractable epilepsy (20). Disconnection is achieved by surgical incision to achieve isolation of the epileptogenic foci (21).…”