Analytical assessment of the learning curve for preoperative planning of lymphovenous anastomosis using ultrahigh frequency ultrasound

Ultrasound (US) imaging is useful for identifying functional lymphatic vessels and suitable veins for lymphovenous anastomosis (LVA). However, its accuracy depends on the experience of the examiner. The aim of this study was to assess the learning curve for preoperative planning of LVA using ultrahigh frequency US (UHFUS).

Plastic surgeons from our department were asked to perform for the first time an US examination for preoperative planning of LVA (month 0). Data of the following US examinations were also periodically collected for two years (months 1, 3, 6, 12 and 24) and statistically analyzed. The results were also compared with the examinations of 3 experts in UHFUS.

At least one vein was accurately identified in all US examinations and with the highest level of confidence since the beginning (p 0.001). The lymphatic vessels correctly identified per incision progressively increased during the follow up: 33.3%, 41.7%, 83.3%, 100%, 100%, respectively (p 0.004).

From month 3 onwards, the efficiency of the US examination increased, and after 6 months, the time decreased. Suitable veins for LVA can be located since the first US examinations, so even for a beginner, it is useful to incorporate US into preoperative planning. The assessment of the lymphatic vessels required more time: after 3 to 6 months, they can be accurately identified, and after 1 year, they were found in more complex cases, with complete confidence and the examinations began to be comparable with the experts.