Decompressive Craniectomy Is Not an Independent Risk Factor for Communicating Hydrocephalus in Patients With Increased Intracranial Pressure

BACKGROUND: It was recently suggested that communicating hydrocephalus is an almost universal finding after hemicraniectomy and that early cranioplasty may prevent the need for permanent cerebrospinal fluid diversion in these patients. OBJECTIVE: To conduct a study in an attempt to verify these findings. METHODS: The medical records of all patients who underwent decompressive craniectomy for medically refractory elevated intracranial pressure between 2001 and 2009 were retrospectively reviewed. Patients with subarachnoid hemorrhage, intraventricular hemorrhage, or head trauma were excluded. Hydrocephalus was classified as internal or external and as clinically significant or asymptomatic. RESULTS: The patient population consisted of 17 patients, 8 men and 9 women, with a median age of 44 years (range, 27-53 years). Etiologies included malignant middle cerebral artery territory infarction in 12 patients, hemorrhagic transformation of ischemic cerebrovascular accident in 2 patients, dural sinus thrombosis in 2 patients, and hemorrhagic cerebrovascular accident in 1 patient. The extent of craniectomy ranged from a large bone flap in 4 patients to a standard hemicraniectomy in 13 patients. Two patients died and 1 was lost to follow-up during the acute stage. The remaining 14 patients underwent cranioplasty after a median interval of 21 days (range, 3-42 days). In none of these patients did clinically significant hydrocephalus develop requiring cerebrospinal fluid diversion. Asymptomatic extra-axial cerebrospinal fluid collections developed in 2 patients that resolved spontaneously after cranioplasty. CONCLUSION: Our results suggest that, contrary to some beliefs, hydrocephalus does not frequently occur after decompressive craniectomy.