Ventriculoperitoneal shunting after aneurysmal subarachnoid hemorrhage: analysis of the indications, complications, and outcome with a focus on patients with borderline ventriculomegaly.

Abstract

The goals of this study were to investigate the risk factors, indications, complications, and outcome for patients with ventriculoperitoneal shunts (VPSs) after subarachnoid hemorrhage and to define a subgroup eligible for future prospective studies designed to clarify indications for placement of a VPS. Clinical characteristics of 236 prospectively evaluated patients with subarachnoid hemorrhage and 6 months of follow-up were analyzed. Hydrocephalus was estimated by the relative bicaudate index (RBCI) measured on computed tomographic scans at the time of shunting. Patients were divided into three groups by ventricle size: Group 1 included 121 patients with small ventricles (RBCI <1.0), Group 2 included 88 patients with borderline ventricle size (RBCI 1.0-1.4), and Group 3 included 27 patients with markedly enlarged ventricles (RBCI >1.4). Initially, 86 patients (36%) underwent ventriculoperitoneal shunting: 19 in Group 1 (16%), 43 in Group 2 (49%), and 24 in Group 3 (90%). Indications for placement of a VPS, risk factors, and outcome differed markedly by group. Four patients (3% of those not initially shunted) developed delayed hydrocephalus requiring a VPS, including one in Group 2 (2%). The 6-month shunt complication rate was 13%. Evaluation of patients in Group 2 indicated that functional status was an important factor in selecting candidates for shunting, and that patients receiving shunts and shunt-free patients demonstrated improvement in functional status during follow-up. Although we currently use a proactive shunting paradigm for posthemorrhagic hydrocephalus, this report demonstrates that a conservative approach to patients with borderline ventricle size (i.e., RBCI of 1.0-1.4) and normal intracranial pressure should be evaluated in a prospective randomized trial.