gms | German Medical Science

Objective: Hydrocephalus (HC) is the most common surgically treatable neurological disorder in children and can be treated by the implantation of a ventricular shunt (VS). Shunt obstruction due to ventricular catheter (VC) obstruction is one of the primary causes for revisions. VC obstruction can be related to its position in the ventricle. Most VC placements are done freehand using anatomical landmarks. Previous studies showed that the use of neuronavigation and ultrasound (US) increased the accuracy of the VC location and reduced the proximal shunt failure rate in an adult and older children cohort. There was however no analysis of the long-time shunt survival in these patients. Our study evaluates the benefit of intraoperative US guidance during first time VC placement in children by postoperative verification its position and long-term proximal shunt survival. No data exist so far evaluating these parameters in an exclusive pediatric group.

Methods: This is a retrospective cohort study of children with HC treated at the University Hospital of Tuebingen in Germany between April 2009 and October 2015. 89 patients with a postoperative cranial imaging (sonography, MRI) clearly identified the location of VC were included in the final analysis. A scoring system was applied with regard to the location of the tip of the VC.Failures of the shunt system due to a VC obstruction were noted. We divided VC occlusions in early within the first three months and late occlusion between three and 9 months postoperatively.

Results: 63 ventricular catheters (71%) were implanted through a right sided burr hole versus 26 (29%) on the left. 63 patients (71%) received a frontal VC, 26 (29%) had an occipital position. In the first postoperative cranial imaging, 7 (8%) VC tips were close or touching the lateral wall of the ventricle, 20 (22%) close or touching the medial wall and 53 (59%) were positioned in the middle of the intended ventricle. In three cases, the tip of the catheter was located in the foramen of Monroe or within the third ventricle, one was in contralateral side and 5 (6%) were touching tumor tissue, choroid plexus or lying within the 4. ventricle. In 84 of 89 cases (94%), the VC tip was in the intended ventricle. Within the first 9 months 6 patients (6.7%) had a VC occlusion. 4 of these had an early, 2 a late revision. Regarding the point of entry the occlusion rates were the following: 4/26 (15%) of occipital catheters and 3/63 (3%) of frontal catheters. Regarding the initial position the occlusion rate was 2/53 (3.8%) for ideally placed catheters, and 4/35 (11.4%) in not-ideally placed catheters.

Conclusion: US guided VC placement is quick, safe, and has no extra cost. US in experienced hands is as precise as navigated procedures The use of US seems to prolong VC longevity as optimized VC placement was associated to a much lower rate of obstruction. Therefore we strongly recommend US use as a routine tool for VC placements.