Choke vessels, vascular anastomosis between adjacent angiosome, play an important role in flap expansion and survival. Here we established a flap model with single and multiple perforators to detect and compare the changes in choke vessels, discuss the effect of hemodynamics on the vascular morphology, and explore the underlying mechanism.
One hundred mice (7–8 weeks) were subjected to a “choke zone” surrounded by 4 perforators on their backs. Delayed surgery was performed by the ligation of 1, 2, or 3 perforators to establish flap models. The blood flow of the choke zone was measured by laser Doppler flowmetry preoperatively and 6 hours and 1, 3, 5, and 7 days. The morphological changes of choke vessels in the choke zone were observed by gross and histological analyses. Levels of angiogenesis-related markers such as endothelial nitric oxide synthase (eNOS), metalloproteinase 2, hypoxia-inducible factor 1α (HIF-1α), and intercellular adhesion molecule 2 (ICAM-2) were detected by Western blotting and enzyme-linked immunosorbent assay.
Blood flow and microvascular count were obviously increased postoperatively and peaked and were maintained for 1 week (P < 0.01). Meanwhile, the diameters of the choke vessels expanded. The eNOS level was increased at 7 days (P < 0.05); however, the enzyme-linked immunosorbent assay results showed that the HIF-1α and ICAM-2 levels were decreased at 7 days.
(1) The delayed surgery that kept a single perforator had the greatest impact on the choke zone. (2) Changes in choke vessels were closely related to the shear stress caused by enhanced blood perfusion after surgery. (3) Choke vessel growth was regulated by eNOS, metalloproteinase 2, HIF-1α, and ICAM-2.
From the *Department of Human Anatomy, of Wenzhou Medical University, Wenzhou, Zhejiang Province, China;
†Department of Human Anatomy of, North Sichuan Medical College, Nanchong, Sichuan Province, China; and
‡Medical College of Lishui College, Lishui, Zhejiang Province, China.
Received December 7, 2017, and accepted for publication, after revision August 6, 2018.
Y.M. and H.L. have made the same contributions to this study and should thus be listed as the co–first authors.
This research was supported by Zhejiang Provincial Natural Science Foundation of China (LY14H150009), Wenzhou Science and Technology Plan Project (Y20160184), and the National Natural Science Foundation of China (31371214).
Conflicts of interest and sources of funding: none declared.
This article has not been published in any other journal or presented in any meetings. All authors have approved the manuscript and agree with submission to Annals of Plastic Surgery.
Reprints: Shixin Chen, MD, Medical College of Lishui College, Lishui 323000, Zhejiang, China. E-mail: email@example.com; Yihua Mao, MD, Department of Human Anatomy, Wenzhou Medical University, Zhongxin North Road, Wenzhou 325035, Zhejiang, People's Republic of China. E-mail: firstname.lastname@example.org.