Resumen de Shape modified radial artery adipo fascio cutaneous perforator flap. An observational anatomical vascular analysis & prospective randomised control clinical study
Title of thesis: shape modified radial artery adipo fascio cutaneous perforator flap. An observational anatomical vascular analysis & prospective randomised control clinical study.
Key words: Digital subtraction angiography, Computed tomography, Magnetic resonance imaging, Traditional radial forearm free flap, Shape modified radial forearm free flap, Distal perforator, Proximal perforator, Pedicle length, Scar Score, Quality of life questioner, Square centimetre.
Background: Radial forearm free flap with all its present day modifications is the workhorse of soft tissue reconstruction in head and neck. Although there are several advantages, it requires the sacrifice of a major artery of forearm. There are several modifications of harvesting a forearm flap based on perforator principles. A clear understanding of vascular anatomy of individual perforators relative to its vascular territory and flow characteristics is essential for both flap harvest and design. The purpose of this study was to demonstrate and determine the location, size and vascular territory of radial artery cutaneous perforators and further application of this knowledge of distal and proximal cutaneous perforators in achieving reliable shape modifications of radial forearm free flap in reconstruction of head and neck defects.
Materials and Methods:
Anatomical/Cadaveric study:
12 fresh human cadavers and 24 cadaveric forearms were dissected to determine the total number, location, size and vascular territory of radial artery adipo-facio cutaneous perforator. The cutaneous territory of distally dominant perforators was analyzed using methylene blue injections and three-dimensional computed tomographic angiogram to determine the vascular network.
Clinical Study:
15 patients with various head and neck defects following oncological resections were reconstructed with shape modified adipo-fascio cutaneous free forearm flap. All these patients were prospectively followed for donor site healing, motor and sensory nerve deficit. Function and quality of life questioner was used for donor site assessment.
Results:
In the 12 fresh human cadavers and 24 forearm specimens, a total of 222 perforators were dissected for an average of 18.5 radial artery perforators per forearm. Of the total 222 perforators dissected 118 were smaller than 0.5mm in diameter (53.15%) these were not clinically significant. 104 perforators were greater than 0.5mm in diameter (46.84%) these were clinically significant. Of the 222 radial artery perforators dissected, 127 perforators (57.20%) were radially distributed and 95 perforators (42.79%) had ulnar distribution. A total of 90 perforators (40.54%) were identified on distal side (radial styloid) and 132 perforators (59.45%) were identified on proximal side (lateral epicondyle). Mean number of perforators on radial side was 10.6 and 7.9 on ulnar side, a comparison of both using student t paired test gives a P value of 0.006, which was statistically significant. Comparison of mean number of perforators on the distal side was 7.5 and proximal side was 11.0, Student Paired t test gives a P value of 0.003, which was statistically significant. Comparison of mean diameter of perforators between the distal side (1.11) and proximal side (0.86), side using Student Paired t test gives a P value of 0.01 which was statistically significant. A chi square test was done to compare mean diameter of perforators on distal side, which were more than 1mm (80%) and less than 1mm (20%) and on proximal side more than 1mm (35.6%) and less than 1mm (64.4%). Chi square value of 42.406 was obtained, degree of freedom value was 1 and P value of <0.001 was achieved which was found to be highly significant. Methylene blue injections into the proximal part of radial artery demonstrated clusters both in proximal and distal forearm and also cutaneous territory of flap. Three-dimensional computed tomographic angiography reveals a network of linking vessels found to communicate between adjacent perforators and running parallel to radial artery.
Large network of linking vessels could be found between fascia and dermis, which also explains the ability to harvest forearm flap at the supra-fascial level. A total of 15 patients were reconstructed with shape modified radial forearm flap following oncologic resections. Wound healing in all 15 patients was good, with scar assessment fairing better than traditional radial forearm flap. There was no sensory or motor nerve deficit. Although pedicle length was comparatively shorter in shape modified radial forearm flap, there was no problem in anastomosing to neck vessels.
Statistical Analysis:
Statistical Package for Social Sciences [SPSS] for Windows, Version 22.0. Released in 2013.Armonk, NY: IBM Corp. was used to perform statistical analyses.
Descriptive Statistics:
Descriptive analysis of all the explanatory and Outcome parameters was done using frequency and proportions for categorical variables, whereas in Mean and SD for continuous variables.
Inferential Statistics:
Independent Student t Test was used to compare the mean Flap Dimensions (in Sq.cm), Pedicle Length (in cm), Duration of Follow-up, Scar assessment & Quality of Life [QoL] scores between 2 groups.
Chi Square Test was used to compare the presence of Sensory and Motor deficit between 02 groups.
The level of significance [P-Value] was set at P<0.05.
Conclusion: Increase in knowledge of vascular territory of radial artery cutaneous perforators with regards to numbers, size, location, and cutaneous territory can lead to expanded use of radial forearm flap based on either distal or proximal perforator alone, without sacrificing the radial artery. Shape modified technique for harvesting radial forearm flap allows primary closure of donor site. Donor site is better healed and shows a predicted pattern, which is functionally and aesthetically good.
