Effectiveness of hinge craniotomy as an alternative to decompressive craniectomy for acute subdural hematoma

Acute subdural hematoma (ASDH) is a life-threatening condition, and hematoma removal is necessary as a lifesaving procedure when the intracranial pressure is highly elevated. However, whether decompressive craniectomy (DC) or conventional craniotomy (CC) is adequate remains unclear. Hinge craniotomy (HC) is a technique that provides expansion potential for decompression while retaining the bone flap. At our institution, HC is the first-line operation instead of DC for traumatic ASDH, and we present the surgical outcomes.

From January 1, 2017, to December 31, 2022, 372 patients with traumatic ASDH were admitted to our institution, among whom 48 underwent hematoma evacuation during the acute phase. HC was performed in cases where brain swelling was observed intraoperatively. If brain swelling was not observed, CC was selected. DC was performed only when the brain was too swollen to allow replacement of the bone flap. We conducted a retrospective analysis of patient demographics, prognosis, and subsequent cranial procedures for each technique.

Of the 48 patients, 2 underwent DC, 23 underwent HC, and 23 underwent CC. The overall mortality rate was 20.8% (10/48) at discharge and 30.0% (12/40) at 6 months. The in-hospital mortality rates for DC, HC, and CC were 100% (2/2), 21.7% (5/23), and 13.0% (3/23), respectively. Primary brain injury was the cause of death in five patients whose brainstem function was lost immediately after surgery. No fatalities were attributed to the progression of postoperative brain herniation. In only one case, the cerebral contusion worsened after the initial surgery, leading to brain herniation and necessitating secondary DC.

The strategy of performing HC as the first-line operation for ASDH did not increase the mortality rate compared with past surgical reports and required secondary DC in only one case.