Keywords
hinge craniotomy - traumatic brain injury - intracranial hypertension
Traumatic brain injury (TBI) and stroke are public health concerns worldwide. It is
estimated that 69 million individuals worldwide suffer a traumatic brain injury each
year.[1] There are approximately 13 million new incident strokes globally each year.[2] Intracranial hypertension significantly contributes to morbidity and mortality in
both TBI and stroke. Raised intracranial pressure (ICP) compromises cerebral blood
flow and is the primary cause of secondary brain injury. The current protocols and
guidelines in TBI and stroke include recommendations for controlling intracranial
hypertension.
Intracranial hypertension is managed through a tiered approach. The multiple tiers
include general measures such as elevation of the head end, medical measures such
as osmotic therapy, and surgical measures. The main surgical procedure to control
ICP has been a decompressive craniectomy (DC). DC is a surgery that involves partial
skull removal and dural opening, allowing additional space for brain expansion and
leading to reduced ICP and subsequent improvement in cerebral perfusion.
Although a commonly used procedure, DC is not a perfect solution to the problem of
intracranial hypertension. Randomized controlled trials of DC in TBI—Trial of Decompressive
Craniectomy for Traumatic Intracranial Hypertension (DECRA) and Randomized Evaluation
of Surgery with Craniectomy for Uncontrollable Elevation of Intracranial pressure
(RESCUEicp)—have shown improvement in mortality following DC but poor functional outcomes.[3]
[4] Similarly, the Hemicraniectomy after middle cerebral artery infarction with life-threatening
edema trial (HAMLET), Decompressive Surgery for the Treatment of Malignant Infarction
of the Middle Cerebral Artery (DESTINY), and Decompressive Craniectomy in Malignant
MCA infarction (DECIMAL) trials of DC in stroke have not demonstrated a significant
benefit5.[5] Current TBI and stroke guidelines suggest using DC for refractory intracranial hypertension.
The procedure is associated with many complications—some of which are unique to DC.
Common complications associated with the procedure include new hematomas, progression
of contusions, superficial and deep wound infections, meningitis, hydrocephalus, subdural
hygromas, and cerebrospinal fluid (CSF) leaks. Patients may also suffer from “syndrome
of the trephined”—a rare and unique complication from a sinking skin flap. The complications
of the procedure are not limited to the primary surgery itself. Following DC, patients
must undergo cranioplasty for replacement of the bone flap. The need for a second
surgery and complications associated with cranioplasty can make the procedure of DC
quite morbid.
Three independent investigators suggested an alternative to DC in 2007: hinge craniotomy
(HC).[6]
[7]
[8] They described the technique of resecuring the bone flap in a noncircumferential
pattern to the skull, allowing it to hinge at one point. This provides space for the
brain to expand through the defect, raising the bone flap. By enabling the bone flap
to remain in situ, there would be minimal cosmetic defect. Once cerebral edema resolves,
the bone flap would fall back into place, limiting the need for a subsequent cranioplasty.
HC has multiple advantages—maintained cerebral protection, avoidance of second surgery,
and avoidance of unique DC-related complications. Numerous studies have demonstrated
adequate control of ICP and comparable outcomes with HC in both TBI and stroke. A
study conducted by Mishra et al[9] in our institute demonstrated no significant differences in outcomes at the end
of 1 year following either HC or DC for TBI and stroke. They also noted a lower rate
of complications with HC compared with DC.
The aim of this video ([Video 1], available in the online version) is to demonstrate the surgical technique of HC
and highlight the nuances in performing the technique appropriately to ensure adequate
decompression.
Video 1 Video describing the steps of performing a hinge craniotomy in a patient with traumatic
acute subdural hematoma.
