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. 2026 Jan 22;18(1):e102065.
doi: 10.7759/cureus.102065. eCollection 2026 Jan.

Initial Design of a Self-Retracting Trocar for Distal Ventriculoperitoneal Catheter Insertion

Jacques Lara-Reyna  1 , Grant Ganpat  2 , Michael Larson  2 , Caleb Lee  2 , Brendan Mason  2 , Kalyani Nair  2 , Julian J Lin  1
Affiliations

Initial Design of a Self-Retracting Trocar for Distal Ventriculoperitoneal Catheter Insertion

Jacques Lara-Reyna et al. Cureus. .

Abstract

Background Laparoscopic access, assisted by a general surgeon, is the most commonly used technique for inserting a distal catheter during ventriculoperitoneal shunt placement. This study introduces a novel single-use trocar designed for peritoneal access, combining engineering analyses to ensure performance and safety. Methods We presented the design and bench evaluation of this new trocar concept. A Pugh matrix evaluated material and feature optimization, while failure mode and effect analysis (FMEA) identified risks such as blade dulling and spring failure. Finite element analysis (FEA) confirmed the structural integrity of the trocar. Results The FEA confirmed the structural integrity of the trocar, demonstrating high load capacities of 1655.3 N for the shaft, 503.4 N for the cannula, and 2799.12 N for the handle with minimal deformation and a high safety margin. The prototype features a sharp blade with an automatically retractable blunt tip to reduce tissue trauma and a cannula with a side slit for catheter insertion. Using sausage casing to simulate the peritoneum, sharpness testing showed a breakthrough force of 2.98 N compared to 2 N for the Versastep trocar (Medtronic, Minneapolis, MN). Conclusions The assessment and conceptualization of this new trocar showed reliability, a low risk of component failure, and good sharpness performance after multiple laboratory tests. The self-retractable tip provides a safety profile during insertion into the peritoneal cavity. Further testing in vivo is needed.

Keywords: cerebrospinal fluid; hydrocephalus; peritoneum; shunt; trocar.

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Conflict of interest statement

Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Trocar system with the dull shaft (dark gray) inside the retractable sharp blade shaft (light gray), cannula with a slit on the side (blue), and the system’s handle (white)
Image credits: authors of this article.
Figure 2
Figure 2. Mechanism used to test blade sharpness
The system is positioned over a scale and zeroed. The sausage casing is placed between two clamps, and the mechanism exerts a force against the tip of the system. Image credits: authors of this article.
Figure 3
Figure 3. Initial prototype demonstrating the concept of using a spring under the handle that will provide retractability of the sharp shaft after insertion of the system
Image credits: authors of this article.
See this image and copyright information in PMC

References

    1. Age-specific global epidemiology of hydrocephalus: systematic review, metanalysis and global birth surveillance. Isaacs AM, Riva-Cambrin J, Yavin D, et al. PLoS One. 2018;13:0. - PMC - PubMed
    1. Distal shunt placement in pediatric ventriculoperitoneal shunt surgery: an international survey of practice. Ruf L, Greuter L, Guzman R, Soleman J. Childs Nerv Syst. 2023;39:1555–1563. - PMC - PubMed
    1. Burge S. The Systems Engineering Tool Box. Rugby, UK: Burge Hughes Walsh Limited; 2009. Pugh matrix; pp. 1–15.
    1. Burge S. The Systems Engineering Tool Box. Rugby, UK: Burge Hughes Walsh Limited; 2010. FMEA; pp. 1–11.
    1. History of hydrocephalus and its treatments. Lifshutz JI, Johnson WD. Neurosurg Focus. 2001;11:0. - PubMed