Mechanical Shunt Catheter Injury From Repeated Insulin Injections in a Diabetic Patient.

Mechanical failure of a ventriculoperitoneal shunt catheter due to repeated external trauma is an extremely rare complication. We report a 72-year-old male with type 2 diabetes who developed a purely subcutaneous fluid collection along the catheter tract after 4 years of habitual subcutaneous insulin injections near the shunt path. Notably, despite self-administering insulin daily, the patient was completely unaware of the necessity to avoid the catheter pathway, highlighting a critical gap in routine post-operative counseling. He presented with localized abdominal swelling and erythema without systemic infection. Abdominal computed tomography demonstrated a kinked catheter within a subcutaneous fluid collection, whereas the deeper peritoneal course and distal tip remained completely intact. The distal catheter was externalized, and at revision surgery, the fluid collection was completely excised. The shunt system was replaced using an alternative upper abdominal midline approach via the linea alba, remote from the prior injection zone. This case underscores 2 vital lessons: first, proactive patient education regarding injection site rotation away from implanted hardware is essential; second, in patients requiring lifelong daily abdominal injections, neurosurgeons should prioritize alternative entry sites like the linea alba to ensure long-term shunt integrity.