Table of Contents
Shunt disconnection
Shunt disconnection is defined as any discontinuity, including a tear or complete separation between the catheter and valve.
Etiology
Shunt disconnection may be caused by fractures resulting from biomechanical stress as the patient grows, degradation of the catheter itself, calcification of the catheter, and scar tissue formation, which may promote shear stress on the catheter 1) 2).
Diagnosis
see Shunt Evaluation.
Ventriculoperitoneal shunt disconnection
Complications
Mechanical problems can be caused by disconnection of the parts of the shunt system, breakage of the tubing, and obstructions at either end of the tubing (especially glialependymal tissue in the brain)
Shunt disconnection has not been always represented a shunt malfunction. Many patients with disconnected shunt may be independent from shunt system, and it can be a good chance for patient to remove the shunt system 3).
Distal catheter disconnection or break with increasingly sophisticated shunts 4).
BioGlide snap-design ventricular catheters
Are prone to disconnection. Continued vigilance and specific imaging are important. Catheter removal after disconnection may be difficult. Elective removal prior to disconnection in asymptomatic children has not been performed 5).
It has been determined from nine reports of disconnected catheters requiring revision surgery, that the listed ventricular catheters may become detached from the snap base assembly after implantation and that this condition may increase the need for emergency revision surgery. There have been no reports of patient death or permanent serious injury as a result of this issue.
Consequences for a patient with failure of a ventricular catheter may include: nausea, vomiting, headache, lethargy, change in mental status, seizures, visual disturbance, and other more serious conditions. Patients with questions are encouraged to talk with their physician or contact Medtronic Neurosugery at 1-805-571-8400, Monday – Friday, 8 a.m. to 5 p.m. CDT. Physicians with medical questions related to this issue or Medtronic therapies should contact Medtronic at 1-800-328-0810, Monday – Friday, 8 a.m. to 5 p.m. CDT.
Any adverse reactions experienced with the use of this product, and/or quality problems can also be reported to the FDA’s MedWatch Program by phone at 1-800-FDA-1088, by Fax at 1-800-FDA-0178, by mail at MedWatch, HF-2, FDA, 5600 Fishers Lane, Rockville, MD 20852-9787, or on the MedWatch website at www.fda.gov/medwatch.
Rughani et al., reviewed the CT scans of 10 patients with an intact and functioning snap-shunt system to characterize the normal appearance of the snap-shunt connection. On CT scans the distance between the radiopaque portion of the ventricular catheter and the radiopaque portion of the reservoir dome measures an average of 4.72 mm (range 4.6-4.9 mm, 95% CI 4.63-4.81 mm). In the authors' patient with a fractured ventricular catheter, this interval measured 7.8 mm, and in the patient with a disconnection it measured 7.7 mm. In comparison with the range of normal values, a radiolucent interval significantly greater than 4.9 mm should promptly raise concern for a disconnected or fractured shunt in this system. This measurement may prove particularly useful when serial imaging is not readily available 6).
