1332. Preliminary Investigation of Shunt Mechanical Failure and Disconnection.

Authors: MILES HUDSON; Carolyn Harris; Caden Nowak; Richard Garling, MD; Sulmaz Zahedi (southfield, MI)

Introduction: Hydrocephalus is a common neurological disorder due to excess production or decreased absorption of cerebrospinal fluid. Ventricular shunting is the gold standard for patient care and allows for CSF homeostasis. Approximately 85% of patients will require a revision of their shunt within 10 years due to various reasons. Very few investigations have been conducted on mechanical shunt disconnections which some studies have shown to account for as high as 15% of all shunt revisions.


Methods:Electronic medical records of 108 patients presented with shunt revision surgery at CHM were reviewed. 

Mechanical stress testing was completed utilizing the Instron 8500 plus control doc. Stress testing was conducted under various loading angles and positions. 

Trails:

#1 90 degree cyclic loading sutured
#2 90 degree cyclic loading integrated
#3 Parallel ramp loading sutured 
#4 Parallel ramp loading sutured 
#5 Parallel ramp loading integrated unitized
#6 Stretching of catheter

Results:

Number of Shunts VP VA LP LA Other Total
99 20 6 4 8 137

Total Revisions: 800

Average number of revisions per patient: 7.4 revisions

Number of Disconnections VP VA LP LA Other Total
40 9 3 4 4 60


Revisions due to disconnection: 7.5%


Mechanical Stress Testing:

Integrated Catheters: Reached maximum # of cycles
Standard Catheters: Failed before maximum # of cycles

Parallel loading tests:
Nurolon: Failed
Silk: Passed
Integrated: Passed

Conclusion:

Shunt disconnections are responsible for 7.5% of shunt revision surgeries at CHM. Increasing the use and availability of integrated catheters may lower the number of disconnections. The development of catheters with greater mechanical integrity as well as the development of new connection methods may be the best option to significantly reduce shunt disconnections and patient rehospitalizations.