gms | German Medical Science

Objective: Decompressive hemicraniectomy (DHC) is a treatment option in impending malignant cerebral infarction and refractory ICP elevation. A craniectomy diameter of 12cm has been widely accepted as the minimum size for effective decompression. However, complete hemispheric exposure extending from the sagittal sinus to the temporal base, and from the frontal sinus to the transverse sinus is frequently advocated and thought to be superior to smaller craniectomies. At the same time, the benefit of additional decompression is unclear.

Method: We reviewed a total of 74 patients undergoing DHC from 2008 to 2013 at our institution, where complete clinical data sets and computed tomography (CT) scans were available. Among other parameters, the maximum anterior-posterior diameter of the craniectomy defect was measured, and patients were dichotomized accordingly (<18cm and ≥18cm). Complications immediately attributable to the surgical procedure (contusion/hemorrhage, transverse/sagittal sinus violation, frontal sinus/mastoid violation), duration of surgery, the need for additional or permanent CSF drainage during hospitalization (lumbar drain, EVD, shunt), and GOS after 3 months were recorded.

Results: Baseline demographics (age, sex, GCS on admission, underlying pathology) were comparable in both groups, as was the duration of surgery and the rate of immediately related surgical complications. With smaller craniectomies, the need for additional or permanent CSF drainage did not increase, but a trend toward better outcome in patients with smaller craniectomies was observed (p=0.06). Subcategorization into groups with small (12-15cm), middle (15-20cm) and large (>20cm) craniectomies as well as estimation of decompression surface (<180cm² vs ≥180cm²) provided comparable results.

Conclusions: If the lower threshold of 12cm for DHC size is observed, complete hemispheric exposure is not superior to smaller craniectomies, but may be associated with a worsening in outcome.