Geometric analysis of the V-Y advancement flap and its clinical applications.
BACKGROUND
Geometry is fundamental in the comprehension of local flap design. The purpose of this study was to discuss the differences between the V-Y advancement flap and other local flaps, understand its geometry, and analyze its clinical applications.


METHODS
The analysis was based on qualitative measurements of an injury, taking into consideration the following dimensions: largest diameter, shortest diameter, and depth. Standardization of the flap design consisted of directing its advancement over the shortest diameter and making the V base match the size of the largest diameter. The flap was analyzed in two planes: the horizontal plane includes the V-Y design and the vertical plane includes the flap pedicle. The height of the flap can be obtained by simple trigonometry, taking into consideration the largest diameter and alpha angle in the horizontal plane. In the vertical plane, where the pedicle and pivot plane are positioned, for known shortest diameter and depth, the final depth of the pivot plane can be calculated using Pythagoras' principles.


RESULTS
This analysis was applied to 25 patients with adequate skin coverage at follow-up. A correction factor was added to reduce the overdeepening of the vertical plane calculations. The final concepts for clinical application in the classic deep pedicle V-Y flap design are to calculate the length of the V by modifying the alpha angle and to move the pivot plane deeper to accomplish optimal flap movement.


CONCLUSIONS
Using these principles, tension-free closure of the Y and appropriate advancement of the flap are obtained.
Andrades
Patricio R
PR
Department of Clinical Epidemiology, Clinical Hospital J. J. Aguirre, University of Chile School of Medicine, Santiago, Chile. patomed@tutopia.com
Calderon
Wilfredo
W
Leniz
Patricio
P
Bartel
German
G
Danilla
Stefan
S
Benitez
Susana
S
D006801:Humans; D016014:Linear Models; D008433:Mathematics; D008875:Middle Aged; D013524:Surgical Flaps