Fibrous encapsulation of the peritoneal catheter in peritoneal shunt: Case report

Fatal ventriculoperitoneal shunt occlusions diagnosed at autopsy

The placement of a ventriculoperitoneal (VP) shunt is frequently used in the management of chronic hydrocephalus. Failure of the shunt may occur due to physical obstruction, which is a recognized complication. Autopsy examination of deceased individuals with chronic disability is often not performed, which contributes to the difficulty in determining the frequency of mortality from VP shunts. Examination, when it does occur, should focus on the patency and positioning of the shunt, and this evaluation is especially important when the cause of death is poorly defined. In this report, we describe two cases of death caused by obstruction of VP shunts documented at autopsy. The first death was determined to be secondary to cerebellar edema with uncal and tonsillar herniation after posterior left VP shunt occlusion. The second was due to VP shunt occlusion resulting in diffuse cerebral edema and ventricular enlargement with compression and hemorrhage of the cerebellar tonsils and medulla.

Inflammation and obstruction of distal catheter slits in ventriculoperitoneal shunts: likely role of graphite

OBJECTIVE

Tissue reactions that contribute to obstruction of peritoneal catheters in ventriculoperitoneal shunt systems are not well characterized. Several recent rapid obstructions in children prompted a retrospective quality assurance review.

METHODS

The authors conducted a detailed investigation of 22 surgically explanted peritoneal shunt catheters and 8 autopsy cases with documented distal shunt obstruction. Patients' medical histories were reviewed, and the catheters and/or tissues were subjected to conventional histological and immunohistochemical evaluations. In addition, 3 cases were subjected to electron microscopic examination including elemental analysis.

RESULTS

The majority of symptomatic obstructions were associated with distal slit catheters (17 slit, 3 open-end, and 2 unknown type). Among the autopsy cases, deaths were attributed to shunt failure in 2 cases of slit catheter obstruction, 1 case of open-end catheter obstruction, and 1 case of catheter withdrawal from the peritoneal cavity. The early tissue response consisted of a predominantly T lymphocyte accumulation with phagocytosis of graphite particles by macrophages. This is associated with proliferation of fibroblasts, mesothelial cells, and blood vessels, which can grow through the slits and occlude the catheter lumen. As the inflammation subsides after approximately 1 year, the tissue plug becomes collagenized and calcified.

CONCLUSIONS

This study, supported by experimental literature in other organ systems, indicates that graphite used to coat the slit openings of distal catheters from ventriculoperitoneal shunts likely predisposes to obstruction. Neurosurgeons and manufacturers should consider the potential negative consequences of this shunt design. The authors concur with previous recommendations that slit-valve distal catheters should not be used for ventriculoperitoneal shunting unless they can be proven safe and efficacious in a controlled trial.

Laparoscopic Resection of Advanced Colorectal Cancer in a Patient with Lumboperitoneal Shunt

A 78-year-old woman with lumboperitoneal (LP) shunt was diagnosed with advanced cancer of the ascending colon. Laparoscopic right hemicolectomy was performed without manipulating the catheter. The patient's postoperative course was uneventful, with no shunt-related complications or neurological deficit. The number of patients with cerebrospinal fluid (CSF) shunt who require abdominal surgery has been increasing. There are only few studies on laparoscopic surgery for patients with LP shunt, and the safety of pneumoperitoneum in the CSF shunt remains controversial. Consistent with other studies, we considered that pneumoperitoneum with a pressure of 10 mmHg has few negative effects. Our recommendations are as follows: (1) during colorectal resection, laparoscopic surgery can be performed without routine manipulation of the shunt catheter; (2) altering the location of the port is necessary to prevent both damage to the shunt tube during surgery and wound infection postoperatively; and (3) laparoscopic surgery is superior to laparotomy because it is associated with reduced surgical site infections and postoperative adhesions. However, laparoscopy should be performed at least 3 months after the construction of CSF shunt.