Flap Survival After Previous Vascular Pedicle Division and Preexisting Scar Formation at the Pedicle Site An Experimental Study

Abstract

Background: We conducted an experimental study to investigate if it would be possible to re-elevate a flap at a standard flap site if its vascular pedicle was mutilated previously and there was a preexisting scar formation at the pedicle site. Materials and Methods: Thirty-five male Sprague-Dawley rats were divided into 3 groups. In the control group (n = 5), animals received a procedure in which unilateral axial pattern abdominal flap was elevated, and then sutured to its original place. The remaining 2 groups underwent 2-stage procedures. In the first stage, scar tissue was created with either a skin incision (group 2, n = 15) or excision (group 3, n = 15) at the prospective pedicle site of the abdominal flap. In the second stage, abdominal flap was raised in 5 rats as a scar-pedicled flap at day 7, day 21, and day 42. Flaps were sutured in their places. Seven days later, flap survival was evaluated. Results: Control flaps had complete survival (day 7, 95.5%; day 21, 94.8%; and day 42, 94.5%). Group 2 and group 3 flaps raised on day 7 (group 2, 65.4%; group 3, 63.9%) and on day 21 (group 2, 65.7%; group 3, 66.7%) showed decreased survival compared to control group flaps (P < 0.05). On day 42, group 1 flaps had better survival when compared to group 2 flaps (82.6% vs 70.0%, P < 0.05). Group 1 flaps showed progressive vascular network formation as evidenced by contrast medium first in the proximal two thirds of the flaps on day 7, and later via visualization of the axial pattern vascular tree on day 42. In group 3, approximately half of the flap was filled with barium contrast and no single pedicle was identified on day 42. Conclusions: Preexisting scar tissue and pedicle division in the pedicle site of a standard flap diminished dimensions of surviving flap when compared to control flaps. Incision-scar-pedicled flaps achieved better survival compared to excision-group flaps, particularly in the late postoperative period. The study findings showed that it may be possible to raise a flap from previously mutilated site secondary to scar formation and pedicle injury.