Fixed Positioning for Decompressive Hemicraniectomy Provides a Larger Diameter Flap than Nonfixed Positioning: A Single-Institution Experience.

Background: Decompressive hemicraniectomy (DHC) is well established as an effective life-saving intervention. Although literature documents a correlation between mortality and hemicraniectomy flap size, no literature exists demonstrating whether a larger flap may be achieved with 3-pin fixation devices versus nonfixed positioning (e.g., occipital headrest, gel donut). Therefore, positioning for DHC remains the preference of the institution and attending physician.

Methods: Patients undergoing DHC during 2005-2016 were identified using Current Procedural Terminology codes. Inclusion criteria were: operative note available in the electronic medical record and postoperative head computed tomography (hCT). Exclusion criteria were: age <18 years, missing data in electronic medical record, no postoperative hCT performed, and craniectomy not done with intention of performing a hemicraniectomy (i.e., craniotomy converted to craniectomy). Anteroposterior diameter of the hemicraniectomy flap was measured in millimeters on the postoperative hCT. The average diameter was compared between the fixed positioning and nonfixed positioning groups.

Results: Analysis included 522 patients who met inclusion criteria; 363 were in the fixed positioning group, and 159 were in the nonfixed positioning group. The average hemicraniectomy diameter was 132.17 mm in the fixed positioning group, and 129.74 mm in the nonfixed positioning group, which was statistically significant (P = 0.027).

Conclusions: This is the first large-scale single-institution study evaluating whether operative positioning for DHC affects the size of a hemicraniectomy flap. Positioning in 3-point fixation led to a statistically significant larger average diameter compared with nonfixed positioning. This indicates that the risks associated with pin fixation as well as additional time spent in positioning in this fashion are offset by the ability to obtain a larger hemicraniectomy flap, which is associated with decreased mortality.