Study design and patient population
This longitudinal, prospective, single-center study was approved by the institutional ethical committee. Written informed consent was acquired from all patients or caregivers. Our study was conducted in concordance with the Declaration of Helsinki and its amendments.
We included 55 pediatric and adult patients, who underwent a VC implantation by the same surgeon between September 2018 and March 2021 at our neurosurgical center. In a total of 29 patients, the shuntoscope-guided technique (study group) was used and in 26 patients VC was inserted using conventional free-hand-methods (control group) during that period. The average follow-up (FU) was 19.56 months (SD ±8.76, range 4–33 months).
All patients had a CSF circulatory disorder with a verified indication for placement of a ventricular catheter. Patients were operated in 2 different hospitals but by the same surgeon. Hence, there was no blinded patient randomization but the distribution among the 2 groups was decided according to availability of the shuntoscope during surgery.
The same craniometric points were utilized in both techniques. The Kocher’s point was always used for VC insertion and placement. The Kocher’s point is located 2-3 centimeters lateral to the midline and approximately 11-12 cm posterior to the nasion, or 10-11 cm posterior from the glabella [11, 17, 19]. After skin incision, the burr hole was placed on the mid-pupillary line and just anterior to the coronary suture to avoid any damage to the primary motor cortex.
In the control group, the ventricular catheter was inserted in a 90-degree angle to the cortex and fixed at 5.5 cm from the dura or 6.5 cm from the bone. Uninterrupted CSF flow and prompt filling after pumping of the burr hole reservoir attached to the VC were accepted as a sign of the correct position of the catheter.
In the study group, the incision through the cortex and placement of the ventricular catheter in the body of the lateral ventricle, preferably just before the foramen of monro, was done with the assessment of the camera assisted Shuntoscope (Karl Storz GmbH & Co.KG, Tuttlingen, Germany). To enable passage of the camera through the VC, a small slit incision was applied on the tip of the catheter (Figure 1). After ventriculostomy, the shuntoscope was advanced through the slitted VC tip for intraventricular inspection, orientation, and control of positioning. Ideal position is achieved when the tip of the catheter is just before choroid plexus and not touching the ventricular walls. Finally, the shuntoscope was withdrawn. The extracranial end of the VC was fixed and connected to the drainage system (Video 1).
The utilized shuntoscope encompassed a telescope with a diameter of 1.0 mm and a length of 160.0 mm. The endoscope is semi-rigid with a remote eyepiece and light connection. Fiberoptic light transmission is incorporated. The shuntoscope is linked to a three-chip full HD camera head (Karl Storz GmbH & Co. KG, Tuttlingen, Germany) with a resolution of 1920 - 1080 pixels (parfocal zoom lens, focal length f = 15–31 mm).
Patient characteristics were documented (age, CSF drainage indication, and comorbidities). The mean follow-up (FU) was 19.56 ±8.76 months. Intra- and postoperative complications and revision rates as well as mortality rates were recorded over a period of at least one year after surgery.
A routine post-operative clinical and radiological follow-up examination was performed before discharge. Each patient underwent postoperative imaging (CT-scans in adult patients and MRI scans in pediatric patients) to evaluate the position of the catheter (Figure 2&3). VC position was assessed by an independent neuroradiologist.
Catheter positioning was graded on postoperative imaging using a three-point scale from Hayhurst et al. 2010 . Grade I is described as the optimal position when the catheter tip is floating in the ventricle (Figure 3). Grade II is considered when the catheter tip is touching the choroid plexus or ventricular lining wall. Grade III is considered when the tip is within parenchyma or when it failed to reach the intraventricular space (Figure 4).
Continuous variables were given as mean and standard deviation and categorical variables were given as frequencies and percentages The Mann-Whitney-Test was used for intergroup comparisons. Two-sided level of significance was set at .05. Statistical analysis was performed using SPSS (v26.0, IBM Corp, Armonk, NY).