Micro-arteriovenous fistula in patients with lower limb lymphedema

Background@#A micro-arteriovenous fistula (AVF) is a minute, short shunt between an artery and a vein that does not pass through a capillary. We investigated the association between micro-AVFs and lymphedema using computed tomography angiography (CTA) and venous blood gas analysis. @*Methods@#In 95 patients with lower limb lymphedema, the presence or absence of early venous return (EVR) was compared between patients with primary and secondary lymphedema. Furthermore, we investigated the difference in the timing of edema onset in patients with secondary lymphedema with or without EVR using CTA. In 20 patients with lower limb lymphedema with confirmed early EVR in a unilateral lower limb, the partial pressure of oxygen (PO2) was compared between the lower limb with EVR and the contralateral lower limb. @*Results@#Secondary lymphedema with or without EVR occurred at an average of 36.0±59.3 months and 93.5±136.1 months, respectively; however, no significant difference was noted. PO2 was 57.6±11.7 mmHg and 44.1±16.4 mmHg in the EVR and non-EVR limbs, respectively, which was a significant difference (P=0.005). @*Conclusions@#EVR and venous blood gas analysis suggested the presence of micro-AVFs in patients with lower extremity edema. Further research is warranted to examine the cause of micro-AVFs, to advance technology to facilitate the confirmation of micro-AVFs by angiography, and to improve lymphedema by ligation of micro-AVFs.

Indocyanine green fluorescence videoangiography for reliable variations of supraclavicular artery flaps

BACKGROUND: Pedicled flaps are useful for reconstructive surgery. Previously, we often used vascularized supraclavicular flaps, especially for head and neck reconstruction, but then shifted to using thoracic branch of the supraclavicular artery (TBSA) flaps. However, limited research exists on the anatomy of TBSA flaps and on the use of indocyanine green (ICG) fluorescence videoangiography for supraclavicular artery flaps. We utilized ICG fluorescence videoangiography to harvest reliable flaps in reconstructive operations, and describe the results herein. METHODS: Data were retrospectively reviewed from six patients (five men and one woman: average age, 54 years; range, 48–60 years) for whom ICG videoangiography was performed to observe the skin perfusion of a supraclavicular flap after it was raised. Areas where the flap showed good enhancement were considered to be favorable for flap survival. The observation of ICG dye indicated good skin perfusion, which is predictive of flap survival; therefore, we trimmed any areas without dye filling and used the remaining viable part of the flap. RESULTS: The flaps ranged in size from 13×5.5 cm to 17×6.5 cm. One patient received a conventional supraclavicular flap, four patients received a TBSA flap, and one patient received a flap that was considered to be intermediate between a supraclavicular flap and a TBSA flap. The flaps completely survived in all cases, and no flap necrosis was observed. CONCLUSIONS: The TBSA flap is very useful in reconstructive surgery, and reliable flaps could be obtained by using ICG fluorescence videoangiography intraoperatively.

A simple calculation for the preoperative estimation of transverse rectus abdominis myocutaneous free flap volume in 2-stage breast reconstruction using a tissue expander

BACKGROUND: Flap volume is an important factor for obtaining satisfactory symmetry in breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) free flap. We aimed to develop an easy and simple method to estimate flap volume. METHODS: We performed a preoperative estimation of the TRAM flap volume in five patients with breast cancer who underwent 2-stage breast reconstruction following an immediate tissue expander operation after a simple mastectomy. We measured the height and width of each flap zone using a ruler and measured the tissue thickness by ultrasound. The volume of each zone, approximated as a triangular or square prism, was then calculated. The zone volumes were summed to obtain the total calculated volume of the TRAM flap. We then determined the width of zone II, so that the calculated flap volume was equal to the required flap volume (1.2×1.05×the weight of the resected mastectomy tissue). The TRAM flap was transferred vertically so that zone III was located on the upper side, and zone II was trimmed in the sitting position after vascular anastomosis. We compared the estimated flap width of zone II (=X) with the actual flap width of zone II. RESULTS: X was similar to the actual measured width. Accurate volume replacement with the TRAM flap resulted in good symmetry in all cases. CONCLUSIONS: The volume of a free TRAM flap can be straightforwardly estimated preoperatively using the method presented here, with ultrasound, ruler, and simple calculations, and this technique may help reduced the time required for precise flap tailoring.