A mathematical model and deduction describing the basic rules of hemodynamics of the multi-territory flap in the early stage
10.3760/cma.j.cn114453-20200924-00513
- VernacularTitle:跨区供血皮瓣早期血流动力学基本规律理论研究
- Author:
Youlun TAO
1
;
Maochao DING
;
Shanshan XI
;
Yihua MAO
;
Jianhong WANG
;
Shucai ZHANG
;
Buqing CHANG
;
Yunjia HAO
;
Jiaqiang FAN
;
Shiming FENG
;
Zaiyi ZHANG
;
Aiguo WANG
Author Information
1. 徐州市中心医院骨科，徐州医科大学徐州临床学院，徐州 221009
- Keywords:
Hemodynamics;
Multi-territory flap;
Blood flow;
Theoretical model
- From:
Chinese Journal of Plastic Surgery
2022;38(7):814-820
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the basic rules of hemodynamics of the multi-territory flap in the early stage.Methods:In this paper, based on the prototype of the free flaps and vascularized pedicled transpositional flaps. The angiosome theory was applied as a basis to systematically analyze the blood flow pathway, the resistance network, and the series or parallel connection mode between each resistance network within the flap, according to the knowledge of fluid mechanics and current pathway, and finally the mathematical model was used for deduction.Results:Based on the model, it can be concluded that a dynamic flow balance can be achieved in the arteries and veins of the multi-territory flap in the early stage and the flap could be divided into four areas: the effective microcirculation zone, the venous stasis zone, the relative ischemic zone and the absolute ischemic zone. And the following inferences can be drawn: (1) The blood supply to the vascular pedicle is constant by pressure rather than by flow. (2) The resistance of the flap varies by the position or the relative position of the arterial vascular pedicle and venous vascular pedicle. (3) The flow velocity decrease gradually from the pedicle to the distal end. (4) The main factors that lead to distal flap necrosis vary depending on the region in which they are located: the venous stasis zone is mainly due to obstructed venous return, and the relative and absolute ischemic zones are mainly due to insufficient arterial blood supply.Conclusions:The basic rules and characteristics of hemodynamics of the multi-territory flap in the early stage can be well explained by this theoretical model, the pedicled artery and vein of the flap can achieve a dynamic balance of flow, and the blood flow gradually decreases from the pedicle to the distal end. The survival range of the flap depends on the pressure difference between the artery and vein as well as the resistance of the blood flow path in the flaps. The distal necrotic area of the flap can be divided into venous stasis area and arterial insufficiency area.
