Comparison of Elongations Provided by Subcutaneous Pedicle Rhomboid Flap and Z-Plasty in Rat Inguinal Skin

Abstract

The most commonly used technique in the treatment of contracture bands is Z-plasty. The subcutaneous pedicle rhomboid flap is a relatively new flap whose efficiency in the treatment of wide or linear contractures with two or more contracture bands has been demonstrated. This experimental study was planned to compare the lengthening provided by the subcutaneous pedicle rhomboid flap with that provided by the Z-plasty. The lower extremities of 10 male Sprague-Dawley rats were strained by hanging 500 g of weight to create tension lines over both inguinal areas. Z-plasty, with a 1-cm central limb and 60-degree angles, was planned over the inguinal tension line on one side. On the other side, a subcutaneous pedicle rhomboid flap was sketched, with a 1-cm-long axis and inner 60-degree angles located over the tension line. In the Z-plasty technique, triangular flaps were elevated over the muscle, transposed, and sutured. In the subcutaneous pedicle rhomboid flap technique, the flap was incised down to the muscle and freed from the tension line, which was later relieved by relaxation incisions. The resulting defects were then closed by suturing the rhomboid flap in V-Y advancement along the tension line and in Y-V advancement along the relaxation incisions. The final lengthening provided by both techniques was measured, and the results were analyzed statistically. Both techniques were effective in relieving tension over the inguinal areas and in lengthening the tension lines. The lengthening provided by Z-plasties with 1-cm central limbs ranged from 3 to 3.8 cm. The difference between preoperative and postoperative Z-plasty measurements ranged from 2.0 to 2.8 cm (mean +/- SD, 2.43 +/- 0.28 cm). The lengthening provided by the flaps with 1-cm axes ranged from 3.9 to 5.0 cm and the difference in measurements before and after surgery ranged from 2.9 to 4.0 cm (3.27 +/- 0.33 cm). Statistical analysis revealed that the elongation provided by the subcutaneous pedicle rhomboid flap was longer than that provided by Z-plasty (p < 0.0001). The subcutaneous pedicle rhomboid flap technique is a more effective than Z-plasty in lengthening the tension lines in rat inguinal skin.