College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio.
Independent Computational Modeling Consultant, Maumee, Ohio.
J Reconstr Microsurg. 2024 Jan;40(1):12-22. doi: 10.1055/a-2056-0629. Epub 2023 Mar 16.
The anterolateral thigh free flap is an option for repairing soft tissue defects of the distal lower extremity. This flap uses the descending branch of the lateral circumflex femoral (LCF) artery as the flap vessel. The recipient vessel in these flaps is often the anterior tibial (AT), posterior tibial (PT), or peroneal (P) arteries. Computational fluid dynamic (CFD) evaluation of anastomoses between these vessels can optimize outcomes.
Thirty-eight CFD models were created to model end-to-side (ETS) and end-to-end (ETE) anastomoses for lower extremity reconstruction. Seven out of thirty-eight models represented ETS anastomoses between the LCF and AT arteries with varying anastomotic angles. Nine out of thirty-eight models represented 45-degree ETS anastomoses between varying diameters of the LCF and AT, PT, and P arteries. Nine out of thirty-eight models represented stenosis on the flap vessel and recipient vessel, pre- and post-bifurcation. Nine out of thirty-eight models represented ETE anastomoses, rather than ETS, with varying vessel diameters. Four out of thirty-eight models represented ETE anastomoses with varying regions and levels of stenosis.
Stasis of blood flow in ETS models increased as anastomotic angle increased in a logarithmic relationship ( = 0.918). Flow was optimized overall as flap and recipient vessel diameters approached one another. In ETS models, flap vessel and postbifurcation recipient vessel stenosis were found to substantially increase stasis.
Selection of flap and recipient vessels with similar diameters can optimize outcomes in microvascular anastomoses. In the context of lower extremity reconstruction with the ALT flap, the PT artery can be recommended as a first-line recipient vessel due to its similar vessel caliber to the LCF and relative ease of surgical access compared with the P artery. Avoidance of areas of stenosis is recommended to ensure laminar flow and reduce the operative difficulty associated with performing anastomoses on nonpliable arteries. Striving for increased acuity of anastomotic angles is recommended to optimize the flow in ETS microvascular anastomoses.
股前外侧游离皮瓣是修复远端下肢软组织缺损的一种选择。该皮瓣使用旋股外侧动脉降支（LCF）作为皮瓣血管。这些皮瓣的受区血管通常是胫前动脉（AT）、胫后动脉（PT）或腓动脉（P）。对这些血管吻合术的计算流体动力学（CFD）评估可以优化结果。
创建了 38 个 CFD 模型，以模拟下肢重建的端侧（ETS）和端端（ETE）吻合术。38 个模型中有 7 个代表 LCF 与 AT 动脉之间的 ETS 吻合术，吻合角度不同。38 个模型中有 9 个代表 LCF 和 AT、PT 和 P 动脉的不同直径之间的 45 度 ETS 吻合术。38 个模型中有 9 个代表吻合口前和吻合口后瓣血管和受区血管狭窄。38 个模型中有 9 个代表 ETE 吻合术，而不是 ETS，血管直径不同。38 个模型中有 4 个代表 ETE 吻合术，吻合口部位和狭窄程度不同。
ETS 模型中血流停滞随着吻合角度的对数关系增加而增加（ = 0.918）。当皮瓣和受区血管直径接近时，整体血流得到优化。在 ETS 模型中，发现瓣血管和吻合口后分支受区血管狭窄会大大增加停滞。
选择直径相似的皮瓣和受区血管可以优化微血管吻合术的结果。在使用 ALT 皮瓣进行下肢重建的情况下，由于其与 LCF 相似的血管口径和相对于 P 动脉更容易手术操作，PT 动脉可被推荐为首选受区血管。建议避免狭窄区域，以确保层流并降低在非顺应性动脉上进行吻合术的操作难度。建议努力增加吻合术角度的锐度，以优化 ETS 微血管吻合术的血流。
