Estimation of Lower Abdominal Flap Survival in Rabbit Model Using Laser Doppler Flowmetry Value

ABSTRACT

Microsurgery has developed over the last three decades to become a routine surgical operation and it's indications for autogenous tissue transplant have been increased. Despite of initial success rate ranging from 80 to 95 percent, the compromise of vascular pedicle causing flap loss has been still one of the serious complications in the microsurgery. As the success of re-exploration is inversely proportional to the time elapsed till the clinical recognition of vascular complication after operation, early detection of perfusion compromise is an important determinant of flap salvage. In this sense, the laser doppler flowmetry has been widely used as an objective monitoring system for the flap survival. This study was designed to investigate the critical time point of flap survival and to estimate the variation of flow value measured by laser doppler flowmetry. Sixteen New Zealand white rabbits weighed from 1.5 kg to 2 kg were used. The lower abdominal island flap(10 5 cm) based on the superficial epigastric pedicle was elevated and repositioned again. The flow values were checked before the flap elevation, immediately after the flap elevation. And thereafter, they were also checked before and after the ligation of pedicle at the 6th, 8th, 10th, 12th, 14th and 16th day of experimental period. After a preliminary study, additional 5 rabbits on each 14th and 16th experimental day were included in the same experimental procedure. The LD value in each point was measured with the laser doppler flowmetry and it was taken as the value of LD at the experimental time. After that, LD ratio(D/C) was obtained by calculating the ratio of LD value(D) after pedicle ligation to that(C) before pedicle ligation in each experimental period. The flap necrosis was noted from the 6th postoperative day to the 12th postoperative day after the pedicle ligation. On the 14th day after the operation, flap survival was noticed after the pedicle ligation. In the group of flap necrosis, LD ratio(D/C) from the 6th day to the 12th postoperativ