Pilot Study Evaluates Use of Virtual Reality in Planning Endovascular Repair of Splenic Artery Aneurysms

March 21, 2018—Researchers from Stanford University Medical Center aim to improve outcomes in splenic artery aneurysm (SAA) repair by employing virtual reality (VR)–based visualization tailored to individual patient anatomies. Sharing findings at the 2018 Society of Interventional Radiology Annual Scientific Meeting in Los Angeles, Zlatko Devcic, MD, described a VR platform's ability to enable computed tomography (CT) reconstructions to be experienced as three-dimensional objects that can be moved and manipulated by a user wearing a VR viewer. Using VR, physicians participating in the study accurately identified inflow and outflow arteries associated with SAAs and were more confident in their conclusions than when viewing the CT reconstructions on a flat screen.

The goal of the application is to enhance the operator's understanding of spatial relationships such as those between an aneurysm and its adjacent arteries.

As detailed in the study abstract, the investigators reconstructed the preprocedural CT angiography images of 14 patients with 17 SAAs who had undergone endovascular repair. True 3D (EchoPixel, Inc.) was the VR visualization software system used, and AquariusNet (TeraRecon) was used for standard volume-rendering image interpretation. There were 17 inflow and 22 outflow arteries associated with the SAAs included in the study.

The investigators measured the accuracy of three radiologists in identifying the inflow and outflow arteries associated with the aneurysms using each method. The radiologists also ranked improvements in their confidence on a scale of 1 to 4 when using VR compared to the standard method. The overall sensitivity, accuracy, and positive predictive value for VR was similar to that of standard rendering: 91.3%, 89.7%, 84% versus 88.9%, 88.9%, 84.6%, respectively (P = .14). However, the ability to view and manipulate images in true three-dimensions using VR markedly improved operator confidence on the four-point scale (71% = 3, 21% = 4).

While noting the particular difficulty of treating SAAs due to their intricate nature and anatomic variations, Dr. Devcic commented to Endovascular Today that he sees the potential for VR evaluation as having wide-ranging applicability, particularly for physicians newer to the learning curve of a procedure.

In an SIR announcement regarding the study, Dr. Devcic elaborated, “Preoperative planning is possibly the most important step towards successfully treating a patient, so the value of VR cannot be understated. This technology gives us a totally different way to look at that structure and safely plan our approach to patient care.”

Based on these results, continued study of VR applications is planned at Stanford, where the investigators hope to determine whether the technology can help reduce procedural time and thereby radiation exposure and contrast use.