A hybrid omental-parietal peritoneal fibrous sheath: a case report of an unreported cause of recurrent ventriculoperitoneal shunt failure

BackgroundHydrocephalus often requires surgical cerebrospinal fluid diversion, and ventriculoperitoneal (VP) shunting remains one of the most widely used treatments. Distal catheter obstruction is a common cause of ventriculoperitoneal (VP) shunt malfunction. Typical abdominal mechanisms include omental wrapping, adhesions, catheter migration, perforation, and cerebrospinal fluid (CSF) pseudocyst formation. Obstruction caused by a parietal peritoneum–anchored fibrous sheath has rarely been described.Case descriptionA 30-years-old man underwent VP shunt placement for communicating hydrocephalus after surgery for intracerebral hemorrhage. He subsequently developed recurrent shunt dysfunction and underwent two distal catheter revisions at an outside hospital within 1 month, with only transient improvement. On admission to our institution, he presented with a tense decompressive craniectomy defect and progressive ventriculomegaly. Abdominal computed tomography showed that the distal catheter coursed toward the right subphrenic region without obvious fluid accumulation. Diagnostic laparoscopy revealed dense omental adhesions and, more importantly, a complete fibrous sheath encasing the distal catheter and fixed to the parietal peritoneum. The sheath formed a blind-ended cavity that isolated the catheter tip and side holes from the absorptive peritoneal surface. No evidence of active shunt infection was identified. Laparoscopic sheath release, distal catheter revision, and repositioning of the catheter away from the abdominal wall restored CSF drainage. Postoperative imaging showed reduced ventriculomegaly and resolution of external brain herniation.ConclusionThis case illustrates a rare mechanism of distal VP shunt failure caused by hybrid omental–parietal peritoneal fibrous sheath formation. Laparoscopy is valuable for diagnosis, functional confirmation, sheath release, and strategic catheter repositioning.