Augmented Reality for Lymphovenous Anastomosis Planning Based on ICG Lymphography Anatomy of the Healthy Limb.

Background: When indocyanine green lymphography (ICG-L) fails to display a linear pattern, preoperative planning for lymphovenous anastomosis (LVA) becomes challenging. Given the anatomical symmetry of lymphatics in extremities, the healthy limb can serve as a template for the affected one. This study introduces an accessible technique that uses augmented reality (AR) to mirror the lymphatic anatomy of the unaffected limb onto the affected side to assist in surgical planning.

Methods: Twelve patients with unilateral secondary lymphedema of the upper or lower extremity (Stage II or less) were included. After standard ICG-L mapping, the unaffected limb was photographed when it showed a linear lymphatic pattern. The image was mirrored and superimposed onto the affected limb using an AR smartphone app to guide incision planning for LVA. Volume reduction and clinical outcomes were measured postoperatively.

Results: A total of 39 LVAs were successfully performed at the planned locations, with 100% intraoperative accuracy. No modifications or extensions of incisions were needed. Patients experienced an average operative time of 142.5 min. Volume excess was reduced by 47% over a follow-up period of 3-24 months, with a notable reduction in episodes of cellulitis and improvements in symptoms and quality of life.

Conclusions: "Mirror the lymph" is a reliable, low-cost AR-based planning method for identifying lymphatic vessels in patients with unilateral lymphedema when ICG-L mapping shows early dermal backflow. This technique improves surgical precision and efficiency and offers an innovative tool for resource-limited settings.