gms | German Medical Science

Objective: Hydrocephalus (HC) due to compression/occlusion of the fourth ventricle is a common complication in patients with cerebellar hematoma or ischemic infarction in the posterior fossa. Acute HC often needs to be treated by external cerebrospinal fluid drainage. Nevertheless, some patients develop a progression to shunt-dependency, even after surgical decompression of the fourth ventricle. Up to date, the rate of chronic hydrocephalus in posterior fossa infarction/bleeding is not well known. Therefore, we conducted a retrospective analysis at our institution and analyzed the rate of acute and chronic HC after surgical treatment of cerebellar hematomas and infarction.

Methods: We retrospectively reviewed a consecutive series of patients who underwent necrosectomy in cerebellar infarction or hematoma evacuation between 01/2010 and 10/2017. The preoperative CT scans were analyzed for compression of the fourth ventricle, signs of acute HC and concomitant intraventricular hemorrhage (IVH). Follow-up CT scans were analyzed for persisting HC.

Results: Seventy-five patients (33 with cerebellar infarction and 42 with cerebellar hematoma) were identified (39m, 36f). Mean age was 68.6 years (28-89). In 71 patients (95%), acute HC due to compression/occlusion of the fourth ventricle was seen on preoperative CT scans. IVH was detected in 24 patients (32%). To secure liquor circulation, an EVD was placed in 42 patients (54.7%), whereof 18 (24%) were diagnosed with cerebellar hematoma and intraventricular hemorrhage. Postoperative CT scans documented a successful decompression of the fourth ventricle in 50 patients (67%). Afterwards eight patients with prior EVD received an LD (10.6%), while 3 patients (4.0%) were treated with an LD in the first place. Chronic HC was diagnosed in 8 patients (10.6%). However, only two patients (2.7%) without intraventricular hemorrhage required VPS (one with cerebellar infarction, one with bleeding), the complication occurred more often in patients with intraventricular hemorrhage, which was treated successfully by VPS (n=4; 5.3%) or endoscopic third ventriculostomy (n=2; 2.7%).

Conclusion: Acute HC is a common finding in cerebellar infarction and hemorrhage. Despite surgical decompression of the blocked cerebrospinal fluid pathways, temporary external cerebrospinal fluid drainage is required in more than 50% of the patients during the acute phase. On the other hand, the rate of permanent shunt-dependency is low but raises with the finding of intraventricular blood.