The current increasing use of decompressive craniectomy (DC) carries the implicit appearance of complications due to alterations in both intracranial pressure and in the hydrostatic-hemodynamic equilibrium.
Numerous complications may arise after DC, including contusion or hematoma expansion, epilepsy, herniation of the cortex through a bone defect, cerebrospinal fluid leakage through the scalp incision, infection, subdural effusion, hydrocephalus and “syndrome of the trephined”. Several hydrocephalus predictors were identified; these included DC, distance from the midline, hygroma, age, injury severity, subarachnoid or intraventricular hemorrhage, delayed time to craniotomy, repeated operation, and duraplasty. However, results differed among studies. The impact of DC on hydrocephalus remains controversial 1).
Expansion of contusions, new subdural and epidural hematomas contralateral to the decompressed hemisphere, and external cerebral herniation typify the early perioperative complications of decompressive craniectomy for TBI. Within the 1st week following decompression, CSF circulation derangements manifest commonly as subdural hygromas.
Paradoxical herniation following lumbar puncture in the setting of a large skull defect is a rare, potentially fatal complication that can be prevented and treated if recognized early. During the later phases of recovery, patients may develop a new cognitive, neurological, or psychological deficit termed syndrome of the trephined. In the longer term, a persistent vegetative state is the most devastating of outcomes of decompressive craniectomy. The risk of complications following decompressive craniectomy is weighed against the life-threatening circumstances under which this surgery is performed. 2).
Among the factors studied, only the presence of mydriasis with absence of pupillary reflex, scoring 4 and 5 in the Glasgow Coma Scale, association of intracranial lesions and diversion of midline structures (DML) exceeding 15mm correlated statistically as predictors of poor prognosis 3).
Paradoxical brain herniation represents a rare manifestation, included in “trephine syndrome”, extremely critical but with relatively simple treatment.
Among 13 patients with contralateral epidural hematoma (CEDH) following DC, all but 1 patient were younger than 60 years of age. In 10 patients (77%) with CEDH, the contralateral calvarial fracture involved more than 1 bone plate. Comparatively, contralateral calvarial fracture involving more than 1 bone plate was noted in 21 patients (35.6%) without CEDH. After multiple logistic regression analysis, only age (p = 0.008, odds ratio [OR] = 0.916, 95% confidence interval [CI] = 0.858-0.987) and number of fracture-involved bone plate (p = 0.006, OR = 10.971, 95% CI = 2.02-59.70) remained independently associated with CEDH development following DC, and CEDH development rate increased by 8.4% with every 1-year decrease in age.
Age and number of fracture-involved bone plate are significant risk factors for CEDH development following DC. Involvement of 2 or more bone plates of contralateral calvarial skull fracture in young adult may prompt an immediate postoperative computed tomography scan to detect the occurrence of CEDH, irrespective of the operative findings and neurological status. This may prevent devastating neurological consequence of CEDH and improve therapeutic outcome 4).