Contrast-enhanced ultrasound for assessing pre-operative lymphatic vessel function and post-operative anastomotic patency in lymphatic-venous anastomosis: a retrospective observational study.

Rationale And Objectives: Lymphedema represents a significant global health challenge, severely impacting patient quality of life. Lymphatic-venous Anastomosis （LVA） is commonly employed as an effective intervention for patients with lymphedema. However, existing imaging tests for localizing lymphatic vessels exhibit various limitations; Consequently, there is a need for a more effective comprehensive method that can be employed for both preoperative localization of lymphatic vessels and postoperative patency assessment.

Methods: Under local anesthesia, Contrast-enhanced Ultrasound (CEUS) was utilized to assess lymphatic vessel function and localize it prior to LVA in eight patients with refractory lymphedema following breast cancer surgery. High-frequency Ultrasound was employed for the localization of superficial vein. One-week post-surgery, CEUS was performed on all patients to assess the patency of anastomoses, and to evaluate surgical outcomes based on the number of visible patent anastomoses, anastomotic patency rates, and other indicators.

Results: Prior to surgery, 68 pooled lymphatic vessels were visualized in eight patients, six of them exhibited tortuous and dilated. Lymphatic vessels with uniform internal diameter and intact continuity were selected for preoperative localization of LVA. Postoperatively, the anastomoses were clearly visualized and demonstrated a relatively high patency rate (26/41,63.2%). The patent anastomoses underwent "spider-like" changes. The internal diameters of the collecting lymphatic vessels were narrower post-operation compared to pre-operation measurements. Furthermore, six months after surgery, the internal diameters of the collecting lymphatic vessels of the affected limbs had decreased, with the maximum reduction reaching 11 cm.

Conclusion: The cases in this study underscore the utility of CEUS in both preoperative assessment and localization of LVA and postoperative evaluation of anastomotic patency. This could represent a new technique that might supersede traditional methods such as Indocyanine Green (ICG) and become a routine assessment tool after LVA.