HoloDIEP-Faster and More Accurate Intraoperative DIEA Perforator Mapping Using a Novel Mixed Reality Tool.

BACKGROUND:  Microsurgical breast reconstruction using abdominal tissue is a complex procedure, in part, due to variable vascular/perforator anatomy. Preoperative computed tomography angiography (CTA) has mitigated this challenge to some degree; yet it continues to pose certain challenges. The ability to map perforators with Mixed Reality has been demonstrated in case studies, but its accuracy has not been studied intraoperatively. Here, we compare the accuracy of "HoloDIEP" in identifying perforator location (vs. Doppler ultrasound) by using holographic 3D models derived from preoperative CTA.

METHODS:  Using a custom application on HoloLens, the deep inferior epigastric artery vascular tree was traced in 15 patients who underwent microsurgical breast reconstruction. Perforator markings were compared against the 3D model in a coordinate system centered on the umbilicus. Holographic- and Doppler-identified markings were compared using a perspective-corrected photo technique against the 3D model along with measurement of duration of perforator mapping for each technique.

RESULTS:  Vascular points in HoloDIEP skin markings were -0.97 ± 6.2 mm (perforators: -0.62 ± 6.13 mm) away from 3D-model ground-truth in radial length from the umbilicus at a true distance of 10.81 ± 6.14 mm (perforators: 11.40 ± 6.15 mm). Absolute difference in radial distance was twice as high for Doppler markings compared with Holo-markings (9.71 ± 6.16 and 4.02 ± 3.20 mm, respectively). Only in half of all cases (7/14), more than 50% of the Doppler-identified points were reasonably close (<30 mm) to 3D-model ground-truth. HoloDIEP was twice as fast as Doppler ultrasound (76.9s vs. 150.4 s per abdomen).

CONCLUSION:  HoloDIEP allows for faster and more accurate intraoperative perforator mapping than Doppler ultrasound.