Letter: Contactless Ultrasonic Cavitation for the Prevention of Shunt Obstruction in Hydrocephalus: A Proof-of-Concept Study.

Abstract

To the Editor: We read with great interest the article by Gomez-Gonzalez et al1 regarding a proof of concept concerning contactless ultrasonic cavitation that “has the potential to be used routinely as a noninvasive, preventative cleaning procedure to reduce the likelihood of obstruction-related events in patients with hydrocephalus treated with an implanted shunt.” The authors presented an elegant and novel approach to treatment of shunt obstruction, an all too common issue with which neurosurgeons must deal. Frustratingly, the neurosurgical community has moved forward with many technological improvements, while making limited progress in our biological management of hydrocephalus. Those of us who commonly treat patients with shunts know the failure rate is higher than we would like. However, in many cases, we have no better options. Neurosurgery has historically tried many minimally invasive techniques to reduce the morbidity of shunt revision. As the authors pointed out, there was a flurry of interest in these techniques because endoscopes became small enough to fit down the ventricular catheter and still allow good visualization. When the percutaneous endoscopic recanalization of the catheter (PERC) procedure was first published, there was international interest in the technique.2 We are not aware of any teams using similar techniques on a regular basis anymore. Personal experience with the PERC technique (Dr Trumble was second author on the article) confirmed it was a safe method for proximal shunt revision. However, the location of the obstruction was not consistently at the distal end (along the intraventricular holes) but sometimes along the lumen of the intracranial portion of the catheter. Endoscopic visualization allowed confirmation of location of obstruction, removal, and visualization of cerebrospinal fluid flow after recanalization. Placement of the instrumentation through the Rickham reservoir also allowed manometric confirmation of resumption of cerebrospinal fluid flow after the PERC procedure. We commend Gomez-Gonzalez et al for their novel approach to a common neurosurgical issue and look forward to clinical application of future techniques to improve the treatment of patients with hydrocephalus.