PERSISTENCE OF PEDICLE BLOOD-FLOW UP TO 10 YEARS AFTER FREE MUSCULOCUTANEOUS TISSUE TRANSFER

The hypothesis of whether or not flap perfusion remains persistent thr ough its vascular pedicle up to 10 pears after free tissue transfer wa s tested. Since 1982, more than 1,000 free tissue transfers have been performed at this institution. Of these, 40 patients were selected wit h comparable posttraumatic soft-tissue defects of the lower leg and su rgical repair by a latissimus dorsi myocutaneous free flap. All patien ts had a postoperative course free of complications. Measurements of f lap perfusion were started in groups 1 through 4 (each 10 patients) 3 to 5 weeks, 5 to ? months, 4 to 6 years, and 8 to 10 years after free tissue transfer, respectively. Quantitative measurements of local flap perfusion were performed by means of the hydrogen clearance technique (Ameda, Switzerland) at definite sites intracutaneously and subcutane ously within the flap's skin paddle as well as in the adjacent intracu taneous and subcutaneous skill of the surrounding soft tissue. Simulta neously, the vascular pedicle of the flap was visualized by a duplex s canner (Toshiba, Japan). In each group nine measurements were performe d before (phase A), during (phase B), and after closing the pedicle (p hase C) by manual compression. Each measurement took about 10 minutes. Statistical evaluation of the obtained values was achieved by the Man n-Whitney U test and the Wilcoxon signed rank test. Local flap perfusi on showed no statistical differences for phase A and C in all four gro ups of patients. In phase B, however, a statistically highly significa nt (p < 0.01) absence of local flap perfusion was registered in all fo ur groups at the site of the flap's skin paddle. No statistically sign ificant alterations of intracutaneous and subcutaneous blood flow was found in the surrounding soft tissue. In our clinical-experimental set ting, flap perfusion persisted by means of its vascular pedicle even 1 0 years after free tissue transfer. Our findings support the importanc e of an intact vascular pedicle for permanent flap survival after free tissue transfer.