Mechanical Dilation Using Nylon Monofilament Aids Multisite Lymphaticovenous Anastomosis Through Improving the Quality of Anastomosis.

Lymphaticovenous anastomosis (LVA) is now a common treatment for lymphedema. It is important to create as many bypasses as possible to maximize the efficacy of LVA. We have developed a method whereby nylon monofilaments are placed inside the vessel lumen to act as dilators. We refer to this technique as mechanical dilation (MD) to distinguish it from intravascular stenting. In this study, we investigated the efficacy of the conventional supermicrosurgery technique performed with and without MD as a treatment for lower limb lymphedema. The LVA was performed using conventional supermicrosurgery alone in 10 patients (group without MD) and in combination with MD in another 10 patients (group with MD). The mean number of successful LVAs performed per hour was significantly higher in the group with MD than in the group without MD (1.42 ± 0.16 vs 1.14 ± 0.15; P < 0.05). The mean amount of improvement in the lower extremity lymphedema index was significantly greater in the group with MD than in the group without MD (7.34 ± 1.57 vs 4.41 ± 1.53; P = 0.003 < 0.05). A statistically significant correlation was found between the number of successful LVAs and amount of improvement in lymphedema (r = 0.449, P = 0.047 < 0.05). Our findings suggest that use of MD does not shorten the operating time or increase the number of LVAs that can be performed but may make it possible to increase the number of successful LVAs that can be performed between vessels with a diameter of less than 0.3 mm. Use of MD could increase the improvement rate of lymphedema to a greater extent than that achieved by conventional microsurgery alone.