Sinking skin syndrome in a decompressive craniectomy series: Clinical and radiological features

BACKGROUND: The sinking skin syndrome (SSS) is a particular complication after a decompressive craniectomy (DC). It still remains a poorly understood and underestimated entity. METHODS: Retrospective case series of craniectomized patients with and without SSS. Clinical and radiological features (DC diameter, shape of craniectomy flap, and midline deviation) were described and relative volumes of intracranial loss were quantified. RESULTS: Twenty-seven patients (63% with SSS). The most common indication for DC was traumatic brain injury: 48.15%. The p50 diameter of DC was 12.8 cm for patients with SSS and 11.1 cm for patients without (Z score = 0.32). DC area was 81.5 cm(2) for patients with SSS and 71.43 cm(2) for patients without the syndrome (Z score = 0.61). According to the shape of the craniectomy flap, we classified our patients as: «same level» (51.8%), «sunken» (25.9%), and «extracranial herniation» (14.8%). Two patients (7.4%) had paradoxical herniation. Midline deviation was present in 12 (70.6%) patients with SSS. The 3(rd) ventricle volume average was 1.2 cc for patients with SSS versus 2.35 cc for patients without (Z score = 0.04). About 94.11% of patients (16 out of 17) clearly improved after replacement of the cranial defect. CONCLUSION: In our series, low 3(rd) ventricle volumes had a good relation with SSS. The presence of a sunken flap does not guarantee SSS per se and we propose the following radiologic description: A = sunken, B = same level, C = extracranial herniation, and D = paradoxical. Replacement of the skull defect is the main treatment.