Background: Recently, the usefulness of lymphatic ultrasound has been reported. It is beneficial not only to identify lymphatic vessels but also to evaluate lymphatic degeneration and diagnose lymphedema. We previously proposed D-CUPS (Doppler, Cross, Uncollapsible, Parallel, and Superficial fascia) to identify the lymphatic vessels on ultrasound. The purpose of this study was to clarify the sensitivity of each index of D-CUPS. Methods: We performed a retrospective study of 27 patients (44 limbs, 98 sites) with lower extremity lymphedema, who underwent lymphaticovenous anastomosis (LVA). We performed a lymphatic ultrasound the day before surgery. We used a linear probe commonly used for venous ultrasound (Noblus EUP-L65; Hitachi Medical Corp., Tokyo, Japan). We applied the D-CUPS index to identify the lymphatic vessels on ultrasound. We checked whether lymphatic vessels consistent with preoperative lymphatic ultrasound findings were observed during the LVA. We also calculated the sensitivity of each D-CUPS index. Results: All the 27 patients were women, with a mean age of 59.7 years. Totally, 98 incisions were made (59 incisions on the thigh and 39 incisions on the lower leg). During LVA, lymphatic vessels consistent with the preoperative lymphatic ultrasound findings were observed at all the sites. The sensitivities of each indicator of D-CUPS were 100.0%, 100.0%, 68.4%, 19.4%, and 100.0%, respectively. Conclusion: The sensitivity was 100.0% in D, C, and S. Although each index separately was not perfect, by combining them appropriately, we were able to identify lymphatic vessels with certainty.
Keywords: D-CUPS; ICG; lymphatic ultrasound; lymphedema; sensitivity; ultrasound.