Abstract
Background Preoperative mapping of lymphatic vessels for lymphovenous anastomosis (LVA) surgery is frequently performed by indocyanine green (ICG) lymphography solely; however, other imaging modalities, such as ultrasound (US), might be more efficient, particularly for Caucasian patients. We present our preoperative assessment protocol, experience, and approach of using US for locating optimal LVA sites.
Methods Fifty-six (16 males) lymphedema patients who underwent LVA surgery were included in this study, 5 of whom received two LVA operations. In total, 61 LVA procedures with 233 dissected lymphatic vessels were evaluated. Preoperative US was performed by the author S.M. 2 days before intraoperative ICG lymphography. Fluid-predominant lymphedema regions were scanned more profoundly. Skin incisions followed preoperative US and ICG lymphography markings. Detection of lymphatic vessels was compared between ICG lymphography and the US by using the intraoperative verification under the microscope with 20 to 50x magnification as the reference standard.
Results Among the dissected lymphatic vessels, 83.3% could be localized by US, and 70% were detectable exclusively by it. In all, 7.2% of US-detected lymphatic vessels could not be found and verified intraoperatively. Among the lymphatic vessels found by US, only 16% were apparent with ICG before skin incision. In total, 23.2% of the dissected lymphatic vessels could be visualized with ICG lymphography preoperatively. Only 9.9% of the lymphatic vessels could be found by ICG alone.
Conclusion High-frequency US mapping accurately finds functional lymphatic vessels and matching veins. It locates fluid-predominant regions for targeted LVA surgeries. It reveals 3.6 times as many lymphatic vessels as ICG lymphography. In our practice, it has an integral role in planning LVA procedures.
Keywords
lymphedema - lymphovenous anastomosis - ultrasound - ICG - indocyanine green - supermicrosurgery
