Research of effects of radiotherapy on flep survey in experimental rat transversus rectus abdominis musculocutaneous (tram) flap model.

ABSTRACTIntroduction&Objective: There is no standard protocol for time of starting radiotherapy treatment and effects of radiotherapy on transversus rectus abdominis musculocutaneous flap which is a otogen tissue used in breast reconstruction. Objective of this experimental study is to research effects of radiotherapy on TRAM flap survey done under general anesthesia and timing of radiotherapy after surgery.Material&Methods: Research is made on 56 Sprague-Dawley albino male rats weighing 250-500 grams. Rats separated into 7 groups based on the computer made randomization list (computer generated randomization program). All groups except for 1st and 2nd had 4x4 cm superior epigastric artery based island flap released. Nothing is done to 1st group as it is control group. 2nd group was exposed to radiotherapy on first day with no surgical procedures. Only surgical procedure (TRAM flap release) applied to 3rd group being the sham group. Groups 4-7 was released TRAM flap and given radiotherapy on postoperative 10th day to group 4, 20th day to group 5, 30th day to group 6 and 40th day to group 7 respectively. 8 weeks after radiotherapy groups sacrificed. Obtained tissue samples examined histopathologically. Collagenization, fibrosis, inflammation, focal hyalinization, and skin thickness was evaluated during histopathological exam.Results: Histopathologic evaluation showed that inflammation, fibrosis, collagenization, and focal hyalinization was decreased significantly in group 6 and 7 compared to other groups as control group being the reference group. As there was no necrosis of any parts of the flaps necrosis was excluded from histopathological and statistical parameters.Conclusion: Based on the histopathologic and statistical data for single dose radiotherapy applied to experimental rat TRAM flaps, it is being thought that flap survey is affected negatively during first 30 days, effected less on 40th day. Again based on the histopathologic and statistical data, earliest day for radiotherapy administration is 40 days or approximately 6 weeks postoperatively.Keywords: TRAM flap, TRAM flap and radiotheraphy, breast cancer