Effect of short-term ischemia on microcirculation and wound healing of adipocutaneous flaps in the rat

Abstract Purpose Composite flaps used in reconstructive surgery may intra- and postoperatively suffer from hypoperfusion and/or ischemia-reperfusion influencing wound healing. We aimed to follow-up the effect of ischemia on adipocutaneous flaps' wound healing and microcirculation. Methods In anesthetized rats groin flaps were formed bilaterally. In Control group the flaps were repositioned and sutured back. In Ischemia-Reperfusion (I/R) group before repositioning and suturing the flap pedicles were clamped for 60 minutes. Laser Doppler (LD) fluxmetry and temperature probes were applied on the cranial, central and caudal flap regions before/after preparation and ischemia, re-suturing, and on the 1st-3rd-5th-7th-14th postoperative days, before the final examinations and biopsies for histology. Results Flaps' skin temperature quickly recovered after repositioning. LD values were lower in the I/R group, reaching a significant level by the 3rd postoperative day, and remained lowered till the 14th day. The magnitude of alterations differed in the flap regions. Histologically normal wound healing process was seen, except for some I/R flaps, where hypertrophized mammary glands were found. Conclusions Short-term ischemia could influence flap microcirculation and wound healing, and may result in hypertrophized mammary glands. Laser Doppler could be used to evaluate intra- and postoperative microcirculatory changes and may have significance in predicting complications.

Intra and postoperative evaluations of microcirculation and micro-rheological parameters in a rat model of musculocutaneous flap ischemia-reperfusion

PURPOSE:To examine how the ischemia-reperfusion injury of latissimus dorsi-cutaneous maximus (LDCM) musculocutaneous flap affects the microcirculatory (flap's skin surface) and hemorheological parameters, and whether an intraoperative deterioration would predictively suggest flap failure in the postoperative period.METHODS: Ten healthy male rats were subjected to the study. In Group I the left flap was sutured back after 2-hour, while the contralateral side was right after its elevation. In Group II the same technique was applied, but the pedicle of the left flap was atraumatically clamped for 2-hour. The contralateral side was left intact. On the flap skin surface laser Doppler tissue flowmetry measurements were done before and after and during the protocols applied in the groups. Microcirculatory and hemorheological examinations were done postoperatively.RESULTS: The microcirculatory parameters significantly decreased during immobilization and ischemia. Afterwards, all the regions showed normalization. In the retrospective analysis there was a prominent difference between the microcirculatory parameters of necrotic and survived flap during the early postoperative days (1-3) in Group II. Erythrocyte aggregation and deformability showed only slight differences.CONCLUSIONS: Two-hour ischemia and reperfusion caused deterioration in latissimus dorsi-cutaneous maximus flap microcirculation. Predicting the possible postoperative complication, the intraoperative laser Doppler measurement can be informative.

Analysis of effect isoxsuprine hydrochloride and nicotine in the Transverse Rectus Abdominis Myocutaneous flap (TRAM) in rats

PURPOSE: To evaluate the effects of isoxsuprine and nicotine on TRAM. METHODS: Forty eight 48 Wistar rats distributed into four Groups (n=12). All rats received medication managed daily for 20 days: saline solution (SA), nicotine solution (NI), isoxsuprine solution (IS) and nicotine solution (NI) + isoxsuprine solution (IS). On day 21st the rats were submitted to the caudally based, right unipedicled TRAM flap and after 48 hours, made the macroscopic evaluation of the surface of the flap, photographic documentation and collection of material for histology. Data from macroscopic evaluation were analyzed by ANOVA and microscopic evaluation by Kruskal-Wallis test, with significance level of 5%. RESULTS: In the macroscopic evaluation of isoxsuprine Group retail presented absolute numbers: final area (p=0.001*) and viable area (p=0.006*) with the highest values; necrosis (p=0.001*) had the lowest value. Microscopic examination revealed no significant findings in the study of TRAM under the action of isoxsuprine and nicotine to the percentage of necrosis in the left and right cranial and caudal regions. CONCLUSIONS: There was significant improvement in viability of TRAM using the isoxsuprine solution alone. No influence using nicotine alone and in association with isoxsuprine. .