Novel Utilization of Ultrasound Guidance for Ventriculoperiotoneal/Ventriculoatrial Shunt Injection

Learning Objectives Ventriculoperitoneal/Ventriculoatrial shunt injection using Tc99m-DTP to assess for shunt malfunction is a commonly utilized procedure at our institution. However on many occasions, it is difficult to initially palpate and identify the shunt bubble to access the shunt utilizing the butterfly needle. In our experience, this has been due to excess subcutaneous adipose tissue or an unusual shape of the shunt bubble. This can lead to the physician blindly injecting the radiotracer, most often resulting in a subcutaneous injection and a nondiagnostic exam.

We present a new policy we have instituted at our institution for the last 2 years. When we encounter a shunt bubble we cannot palpate we utilize a readily available portable ultrasound 15 mHz linear transducer to follow the shunt tubing from it's craniotomy site to the shunt bubble. We then mark the skin at this location and use the butterfly needle to access the shunt bubble. We verify the location by aspirating CSF and then inject the radiotracer into the bubble. We have utilized this technique on 6 shunts with 100% success, 5 VP shunts and 1 VA shunt. Ultrasound guided VP/VA shunt injection is a valuable technique for accessing difficult to palpate shunt bubbles.

Research Support Our literature search did not reveal any prior reports of ultrasound guidance for shunt injection.