Yield of early postoperative computed tomography after frontal ventriculoperitoneal shunt placement

Abstract

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.

Ultrasound-Guided Insertion of the Ventricular Catheter in Ventriculoperitoneal Shunt Surgery: Evaluation of Accuracy and Feasibility in a Prospective Cohort

“…Lower preoperative EI values, equivalent to smaller ventricle width, have been associated with shunt malpositioning in the freehand cohort. 10 There was no association between preoperative EI values, and shunt positioning in the US cohort, similar to the results of other studies. 7 In some studies, occipital position of VPS has been inferior to frontal position regarding patency and functioning of the shunt.…”

“…Patients with stroke or tumor had higher rates of malposition than patients with normal-pressure hydrocephalus, probably due to the fact that the former leads to a distorted anatomy, making freehand VPS placement more difficult. 10 Underlying disease has not been significantly associated with malposi-tioning in our US cohort. This might be explained by the fact that US-G helps navigate the catheter correctly into the ventricle, even if the ventricular anatomy is distorted or the ventricles are very small.…”

“…8,9 An association between location of the shunt and correct positioning of the proximal catheter was not observed in the two cohorts. 10 Operation time was shorter in the US cohort. An explanation might be that patients from the freehand cohort who were operated on before 2014 underwent a mini-laparotomy for abdominal VPS placement.…”

“…The data of the freehand cohort have been collected for a different study published in 2018. 10 The primary outcome was the accuracy of proximal catheter placement. This was assessed through a computed tomography (CT) scan performed 3 to 5 days postoperatively.…”

Intraoperative Ultrasound Guided compared to Stereotactic Navigated Ventriculoperitoneal Shunt Placement: Study Protocol for a Randomized Controlled Study

“…The position of the proximal ventricular catheter is important since it in uences possible malfunction of the VPS as well as shunt survival (4)(5)(6)(7). With freehand placement rates of malpositioned VPS are still high (around 20%) (8).…”