What should we do with a discontinued shunt?

Technology-Dependent Children

There are a growing number of medically complex children with implanted devices. Emergency physicians with a basic knowledge of these devices can troubleshoot and fix many of the issues that may arise. Recognition of malfunction of these devices can reduce morbidity and mortality among this special population. In this article, we review common issues that may arise in children with gastrostomy tubes, central nervous system shunts, cochlear implants, and vagal nerve stimulators.

The disconnected shunt: a window of opportunities

INTRODUCTION

Shunt disconnection (SD), or migration of the distal end to extra-peritoneal tissues, may lead to shunt malfunction or be diagnosed incidentally. We present a systematic approach for treatment options that is tailored to each patient's personalized history, CSF physiology, and distribution (MRI), as well as a careful informed consent process.

METHODS

We present two algorithms, for symptomatic and asymptomatic SD. In cases presenting with symptomatic elevated intracranial pressure, a distal shunt revision (DSR), or, in selected patients, an endoscopic third ventriculostomy (ETV), should be performed. In asymptomatic patients, several options exist. The first decision is whether to intervene or follow. When action is recommended, a planned shunt revision is possible. The other option is to externalize the shunt and close it under careful clinical and radiological follow-up. Patients are then stratified to three main groups-those that are not shunt dependent, those that have radiological evidence of obstructed hydrocephalus, and the remaining patients. Patients are accordingly treated by ligation of the shunt without or with an endoscopic third ventriculostomy or with a distal shunt revision.

RESULTS

Twenty-one patients were diagnosed with a shunt disconnection. Seventeen were diagnosed at screening tests, while four were presented with shunt malfunction symptoms. Sixteen incidental cases were followed (3-111 months, 39 ± 37), of which three became symptomatic. One patient had an elective ETV followed by a DSR, and three followed-up patients became symptomatic and thus underwent surgery. All symptomatic patients underwent treatment (5 DSR, 2 ETV).

CONCLUSIONS

Shunt disconnection opens a window of opportunities into better understanding the pathophysiology of the hydrocephalic process in a specific patient. Distal shunt revision or ETV (in selected patients) is indicated in symptomatic cases. In asymptomatic patients, options exist. Choosing between those options mandates a careful individual assessment and a detailed informed consent process.

Late pediatric ventriculoperitoneal shunt failures: a Singapore tertiary institution's experience

OBJECTIVE

The introduction of ventriculoperitoneal shunts changed the way hydrocephalus was treated. Whereas much is known about the causes of shunt failure in the first few years, there is a paucity of data in the literature regarding the cause of late shunt failures. The authors conducted a study to find out the different causes of late shunt failures in their institution.

METHODS

A 10-year retrospective study of all the patients who were treated in the authors' hospital between 2006 and 2015 was conducted. Late shunt failures included those in patients who had to undergo shunt revision more than 5 years after their initial shunt insertion. The patient's notes and scans were reviewed to obtain the age and sex of the patient, the time it took for the shunt to fail, the reason for failure, and the patient's follow-up.

RESULTS

Forty-six patients in the authors' institution experienced 48 late shunt failures in the last 10 years. Their ages ranged from 7 to 26 years (12.23 ± 4.459 years [mean ± SD]). The time it took for the shunts to fail was between 6 and 24 years (mean 10.25 ± 3.77 years). Reasons for failure resulting in shunt revision include shunt fracture in 24 patients (50%), shunt blockage in 14 patients (29.2%), tract fibrosis in 6 patients (12.5%), shunt dislodgement in 2 patients (4.2%), and shunt erosion in 2 patients (4.2%). Postoperative follow-up for the patients ranged from 6 to 138 months (mean 45.15 ± 33.26 months).

CONCLUSIONS

Late shunt failure is caused by the effects of aging on the shunt, and the complications are different from early shunt failure. A large proportion are complications associated with shunt calcification. The authors advocate a long follow-up for pediatric patients with shunts in situ to monitor them for various causes of late shunt failure.

A Case of Discontinued Proximal Limb of a Ventriculoperitoneal Shunt With Patent Fibrous Tract

Radionuclide shuntogram is important in the evaluation of cerebrospinal fluid (CSF) shunts complications such as mechanical failure, malpositioning, pseudocyst, or overdrainage. We present here a case of congenital hydrocephalus and posterior fossa cyst with multiple shunt procedures and revisions with breakage of the proximal tube of the ventriculoperitoneal shunt but preserved CSF drainage through the patent fibrous tract. Careful correlation with SPECT/CT images helped confirm the breakage and exclude CSF leak outside of the tract, which was suspected on planar images.

Is the elapsed time following the placement of a ventriculoperitoneal shunt catheter an individual risk factor for shunt fractures?

In this study, we examined whether the resistance of peritoneal catheters against the retraction force changed over time following shunt placement, and the role of this resistance in shunt fracture is discussed. We investigated peritoneal catheters removed from patients treated with a ventriculoperitoneal shunt because of hydrocephalus; previously, patients underwent shunt revision. The maximum tension, maximum elongation and elongation percentages of the peritoneal catheters were measured. The mean and maximum tension values of the revised peritoneal catheters were increased compared to the unused catheters. The maximum elongation and elongation rates were significantly decreased. The changes in the maximum elongation, elongation rate and tension values were unrelated to the time elapsed after catheter insertion. This finding indicates that the time elapsed following peritoneal catheter placement was not an individual factor based on the strength of the response of the organism to the foreign body and the mechanical trauma exposed in shunt fractures.

Scrotal mass: a rare complication of ventriculoperitoneal shunt

SUMMARY

Ventriculoperitoneal shunts are associated with multiple complications. Among them are disconnection and migration of the tubing into the peritoneal cavity. Here we describe a case of a fractured ventriculoperitoneal shunt which migrated and coiled in the scrotum, masquerading as a scrotal swelling. Removal of the shunt via a scrotal incision was performed concomitantly with repair of the hernia sac.

Disconnected subduroperitoneal shunt catheter induces silent bowel perforation: An unusual complication

We report a case of silent bowel perforation by a fractured subduroperitoneal shunt after surgical shunt revision. A 93-year-old bedridden man experienced transanal prolapse of a shunt catheter after defecation. Upon arrival, the patient showed no fever or acute abdominal signs. Abdominal computed tomography (CT) showed an abandoned shunt catheter in the lower abdomen with rectum perforation. The disconnected catheter was successfully removed from the anus by digital rectal maneuver, and no peritonitis or other complication developed afterward. Such broken shunts no longer provide drainage function, and also pose a risk of migrating into the hollow viscera. Therefore, even in the absence of overt peritoneal signs, disconnected catheters should be removed by laparoscopic or minimal surgery to prevent possible development of this unusual complication. Instances of the rare complication are reviewed, and pathogenesis and treatment of the condition are discussed.