Massive Brain Swelling and Death After Cranioplasty: A Systematic Review

Although cranioplasty is a common procedure, it may cause a variety of complications. Massive brain swelling after cranioplasty (MBSC) is an unusual complication that has been reported more frequently in recent years. Most of the existing information about this condition is speculative and the cause remains unclear.

A PubMed and Scopus search adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed to include studies reporting patients with MBSC. Different information was analyzed in these cases to describe the characteristics and identify risk factors for MBSC.

The search yielded 19 articles with a total of 26 patients. All studies were case reports and small case series. In most patients, preoperative intracranial hypotension and a considerable degree of sinking of skin flap were identified; this was the only constant finding observed in these cases. In addition, we propose a grading system to estimate the degree of preoperative sinking of skin flap and an algorithm with recommendations to decrease the incidence of MBSC.

MBSC is an unusual, highly lethal, and probably underreported condition. The information gathered in this review indicates that MBSC occurs secondary to a cascade of pathologic events triggered by the bone flap implantation. This evidence suggests that the primary pathologic change is a sudden increase in the intracranial pressure acting on a brain chronically exposed to intracranial hypotension.