Megumi Furuya

Efferent Lymphatic Vessel Anastomosis: Supermicrosurgical Efferent Lymphatic Vessel-to-Venous Anastomosis for the Prophylactic Treatment of Subclinical Lymphedema.

BackgroundIn lower extremity lymphedema secondary to pelvic cancer treatments, lymphedema develops despite that the inguinal lymph nodes (LNs) are preserved. Obstruction of the efferent lymphatic vessels of the inguinal LNs causes lower extremity lymphedema, and it is considered a radical treatment to bypass the efferent lymphatic vessel. MethodsEfferent lymphatic vessel anastomosis, supermicrosurgical efferent lymphatic vessel-to-venous anastomosis, was performed on 14 legs with subclinical lymphedema [leg dermal backflow (LDB) stage I]. Efferent lymphatic vessel anastomosis was performed under local anesthesia at the groin region, and an efferent lymphatic vessel of the inguinal LN is anastomosed to a recipient vein. Feasibility and postoperative results were evaluated. ResultsAll 14 efferent lymphatic vessel anastomoses were successfully performed without perioperative complication. All legs could be free from lymphedematous symptoms without perioperative compression at postoperative 1 year. Postoperative LDB stage included LDB stage 0 (n = 8) and LDB stage I (n = 6), which was significantly downstaged compared with preoperative LDB stage (P < 0.001). ConclusionsEfferent lymphatic vessel anastomosis allowed lymph flow bypass after filtration by the superficial inguinal LN through a skin incision along the inguinal crease, and was effective to prevent development of symptomatic lymphedema in subclinical lymphedema cases.

Establishment of supermicrosurgical lymphaticovenular anastomosis model in rat.

Background: Lymphaticovenular anastomosis (LVA) is becoming a choice of treatment for compression‐refractory lymphedema. However, LVA requires highly sophisticated microsurgical technique called supermicrosurgery, and no training model for LVA has been developed. This study aimed to develop and evaluate feasibility of a new LVA model using rat thigh lymphatic vessels. Methods: Ten Sprague‐Dawley rats were used for the study. After preoperative indocyanine green (ICG) lymphography, lymphatic vessels in posteromedial aspect of the thigh were dissected. In right limbs, the largest lymphatic vessel was anastomosed to the short saphenous vein or its branch, and the remaining lymphatic vessels were ligated (LVA group). In left limbs, all lymphatic vessels were ligated (control group). Anastomosis patency was evaluated intraoperatively and at postoperative 7 days. Results: Courses of lymphatic vessels in the thigh were constant; lymphatic vessels run along the short saphenous vein. The mean diameter of lymphatic vessel used for LVA was 0.240 ± 0.057 mm, and the mean diameter of vein was 0.370 ± 0.146 mm. All lymphatic vessels were translucent and very thin like human intact lymphatic vessels. In LVA group, intra‐ and post‐operative anastomosis patency rates were 100% (10/10) based on ICG lymphography. In control group, intra‐ and post‐operative patency rates were 0% (0/10). Conclusions: Rat lymphatic vessels are thin, translucent, and fragile similar to intact human lymphatic vessels. The LVA model uses easily accessible lymphatic vessels in the thigh, and is useful for training of supermicrosurgical LVA.

Ultrasound visualization of the lymphatic vessels in the lower leg.

Identification of lymphatic vessels for lymphaticovenular anastomosis (LVA), which is an effective surgical treatment for obstructive lymphedema, is important. Indocyanine green (ICG) lymphography is useful for that purpose, but is not common in many institutions. Although ultrasound is a very common modality, no research has yet underlined the feasibility of the device to detect the lymphatic vessels.

Triple supermicrosurgical side-to-side lymphaticolymphatic anastomoses on a lymphatic vessel end-to-end anastomosed to a vein.

Lymphatic supermicrosurgery or supermicrosurgical lymphaticovenular anastomosis (LVA), has become a useful treatment option for obstructive lymphedema refractory to conservative treatments. As diameter of a lymphatic vessel is small (around 0.5 mm) and anastomosed lymphatic vessel has a risk of anastomosis obstruction, it is important to create as many bypasses as possible for LVA surgery by combining multiconfiguration anastomoses such as end-to-end (E-E), end-to-side (E-S), side-toend (S-E), and side-to-side (S-S) anastomoses. Sometimes, a lymphatic surgeon faces a situation where there are many lymphatic vessels and one recipient vein in a surgical field; it is challenging to bypass many lymph flows using one vein. To address this challenge, we developed a new technique for maximization of lymph flow bypasses. There were four lymphatic vessels and one recipient vein in a surgical field of a secondary leg lymphedema patient (Fig. 1A). The recipient vein with an intact valve was too far to anastomose directly to any of the four lymphatic vessels. The farthest lymphatic vessel with diameter of 0.55 mm was cut as proximally as possible to transfer to the vein, and to bridge the remaining three lymphatic vessels with diameters of 0.55, 0.65, and 0.70 mm (Fig. 1B). The transferred lymphatic vessel was supermicrosurgically anastomosed to the three lymphatic vessels in a S-S fashion, and to the recipient vein with diameter of 0.50 mm in an E-E fashion (Fig. 1C) using six stitches of 11-0 nylon interrupted sutures. Thus, normograde lymph flow of the transferred lymphatic vessel and both normograde and retrograde lymph flows of the three lymphatic vessels were bypassed into venous circulation with only one recipient vein. Although the method can be applied in limited situations, the method can be a useful option for multiple lymph flow bypasses in a surgical field; multiple S-S lymphaticolymphatic anastomoses allow maximization of lymph flow bypasses using only one vein. Further clinical studies are required to refine procedures and confirm the efficacy of the technique.

Preoperative color Doppler ultrasound assessment of the lateral thoracic artery perforator flap and its branching pattern

The anatomy of the lateral thoracic artery perforator flap remains controversial, but this region is extremely useful as a reconstructive donor site. In this report, we describe the usefulness of the preoperative color Doppler ultrasound evaluation for the harvesting of the lateral thoracic artery perforator flap, and we clarify its branching pattern. Twenty-seven patients underwent the preoperative color Doppler ultrasound assessment before perforator flaps were harvested. We evaluated the branching pattern and the diameter of the flaps by direct observation. All flaps were successfully transferred, and it was found that the branching pattern of the lateral thoracic perforator is divided into three groups: the superficial branch, the medial branch, and the deep branch. Their appearance ratios were 48.1% (13/27), 14.8% (4/27), and 81.5% (22/27), respectively. The lateral thoracic artery perforator flap has a great deal of anatomical variation, and vessels with relatively small diameters compared to those of other flaps. This is why flaps from this region are not currently popular. This study revealed the superiority of the color Doppler ultrasound for preoperative planning of the lateral thoracic artery perforator flap elevation. Furthermore, the branching pattern and the diameters of the different branches were specified.

Relationship Between Lymphedema and Arteriosclerosis: Higher Cardio-Ankle Vascular Index (CAVI) in Lymphedematous Limbs.

BackgroundArteriosclerosis is one of the most important public health issues because it is very common in developed countries and its sequelae are lethal. Lymphatic vessel insufficiency has been reported to be associated with atherogenesis. Lymphedema seems to affect progression of arteriosclerosis, but no clinical study has been reported. MethodsForty-eight limbs of 24 female patients with pelvic cancer-related lower extremity lymphedema (LEL) were evaluated. Cardio-ankle vascular index (CAVI), an indirect estimate of the arterial stiffness, was measured in each limb. Cardio-ankle vascular index was compared according to known arteriosclerosis risk factors including age (younger than 65 years vs 65 years), body mass index (BMI; <25 vs 25 kg/m2), hypertension (HT), diabetes mellitus, hyperlipidemia (HL), and smoking, as well as according to LEL-related factors including duration of LEL (<5 years vs 5 years), pelvic irradiation, leg cellulitis, LEL index (<250 vs 250), and leg dermal backflow (LDB) stage (LDB stage 0/I vs LDB stage II/III/IV/V) using univariable analyses and multivariable analysis. ResultsUnivariable analyses revealed statistically significant differences in CAVI between lower BMI and higher BMI [7.19 (0.75) vs 8.36 (1.24), P < 0.01], HT (−) and HT (+) [7.25 (0.81) vs 8.17 (1.29), P < 0.01], HL (−) and HL (+) [7.19 (0.74) vs 8.06 (1.27), P < 0.01], and lower LDB stage and higher LDB stage [6.87 (0.65) vs 7.76 (1.05), P < 0.01]. Multivariable analysis revealed statistically significant differences in CAVI between lower BMI and higher BMI (P < 0.01), shorter duration of LEL and longer duration of LEL [7.21 (1.04) vs 7.71 (0.97), P = 0.04], and lower LDB stage and higher LDB stage (P = 0.04) ConclusionsHigher BMI, longer duration of LEL, and higher LDB stage were independent factors associated with higher CAVI in pelvic cancer-related LEL.

The half notching method for Flow-through lymphaticovenular anastomosis

Lymphaticovenular anastomosis (LVA) has been known as an effective treatment for lymphedema. In LVA surgery, it is important to make as many bypasses as possible to maximize its treatment efficacy. Flow-through LVA (FT-LVA), in which two ends of a cut lymphatic vessel are anastomosed to a Y-shaped branched vein, is useful to increase the number of bypasses for a beginner lymphatic surgeon; both ends are anastomosed in an end-to-end fashion that is the easiest anastomosis type. However, after a lymphatic vessel is cut, sometimes cut ends become shorter and go among into surrounding tissues or go far away from recipient veins. In this situation, clipping vessels before cutting is useful to fix them, but it can make difficult to sew them due to smaller working space especially for surgeons with less experience of supermicrosurgery. To address this challenge, we developed a new method, half notching method, for FT-LVA. There are a lymphatic vessel and two venous branches prepared for FT-LVA. First, a half width of the lymphatic vessel is incised using microscissors; a notched site is determined based on lengths and locations of recipient veins. Second, the veins and both proximal and distal sides of the notched lymphatic vessel wall are stitched to venous branches to approximate them (Fig. 1). Then, the lymphatic vessel is completely transected with microscissors. In the state that all lymphatic vessels and veins are in a point, they exist within a field of vision.