Yield of early postoperative computed tomography after frontal ventriculoperitoneal shunt placement

Despite being widely used, ventriculoperitoneal (VP) shunt placement is a procedure often associated with complications and revision surgeries. Many neurosurgical centers routinely perform early postoperative cranial computer tomography (CT) to detect postoperative complications (e.g., catheter malposition, postoperative bleed, over-drainage). Because guidelines are lacking, our study aimed to evaluate the yield of early routine postoperative CT after shunt placement for adult hydrocephalus. We retrospectively reviewed 173 patients who underwent frontal VP shunting for various neurosurgical conditions. Radiological outcomes were proximal catheter malposition, and ventricular width in preoperative and postoperative imaging. Clinical outcomes included postoperative neurological outcome, revision surgery because of catheter malposition or other causes, mortality, and finally surgical, non-surgical, and overall morbidity. In only 3 (1.7%) patients did the early routine postoperative CT lead to revision surgery. Diagnostic ratios for CT finding 1 asymptomatic patient who eventually underwent revision surgery per total number to scan were 1:58 for shunt malposition, 1:86 for hygroma, and 1:173 for a cranial bleed. Five (2.9%) patients with clinically asymptomatic shunt malposition or hygroma underwent intervention based on early postoperative CT (diagnostic ratio 1:25). Shunt malposition occurred in no patient with normal pressure hydrocephalus and 2 (40%) patients with stroke. Lower preoperative Evans' Index was a statistically significant predictor for high-grade shunt malposition. We found a rather low yield for early routine postoperative cranial CT after frontal VP-shunt placement. Therefore, careful selection of patients who might benefit, considering the underlying disease and preoperative radiological findings, could reduce unnecessary costs and exposure to radiation.