Comparing Different Postconditioning Cycles After Ischemia Reperfusion Injury in the Rat Skin Flap

Abstract

Ischemic postconditioning is a useful manipulation to reduce the undesirable effects of ischemia-reperfusion (I/R) injury. The beneficial results of this phenomenon against I/R injury have been seen in several flap models. However, there are no published works comparing different postconditioning (post-con) cycles in skin flaps. In this study, we investigated the effectiveness of different post-con cycles in a skin flap model. Epigastric island flap (6 × 3 cm) model which was based on the left superficial epigastric artery and vein was used, and complete 6 hours of ischemia was generated by occlusion of the pedicle. Forty male Wistar rats were allocated into 5 groups (n = 8 in each group). Group 1 (sham group): the elevated skin flap was repositioned without an episode of ischemia. Group 2 (control group): skin flap was elevated and 6 hours of complete ischemia was induced by clamping the pedicle. Group 3 (post-con 1): After ischemia, post-con was performed by 6 cycles of 15 seconds of repeated I/R periods. Group 4 (post-con 2): After ischemia, post-con was performed by 6 cycles of 30 second of repeated I/R periods. Group 5 (post-con 3): After ischemia, post-con was performed by 6 cycles of 60 second of repeated I/R periods. Flap viability was assessed 1 week after the surgical procedure, the necrotic area of the skin flap was measured using image analysis on the computer. The area of flap necrosis was statistically significant between the control and post-con group 4 and group 5, and no statistically significant difference was obtained between the control and post-con group 3. Groups 4 and 5 demonstrated lesser area of flap necrosis than the control group and group 4 was superior to group 5. The results revealed that the post-con applied by means of 6 cycles of 30 seconds yields the best protection against I/R injury in the rat skin flap model.

The Value of Postconditioning in Plastic and Reconstructive Surgery: A Systematic Review

“…Based on the results of the published articles (►Tables 1-4), rats and mice 9,10,17,[19][20][21][23][24][25][26][27][28][29][30][31][32] are the common animal models used for the study of post-con. There are also several other animal models undertaken as flap models, which were not widely used in experimental studies, including pigs 18 and rabbits.…”

“…Reperfusion injury by abrupt restoration of circulation after the prolonged ischemia has long been a big problem in plastic and reconstructive surgery. 9 Multiple therapeutic strategies have been proposed in an attempt to attenuate I/R injury, 22,34,35 among which the post-con procedure is the one that has been investigated as the most promising protocol. post-con was first described in 1996, which involves intermittent cycle reperfusion after ischemic insult.…”

“…Recently, the post-con strategy has also been introduced in plastic and reconstructive surgery, aiming to relieve the I/R injury and salvage the ischemic flaps. 9,10,[17][18][19][20][21][22][23][24][25] The initially protective effect of post-con in skin flaps 9,10,17 and muscle flaps [18][19][20] has been reported in I/R animal models and remote or pharmacological post-con has also been developed as alternatives in amelioration of I/R injury. 18,[21][22][23][24][25] Compared with the clinical limitations of preconditioning (pre-con), which exerts its effects primarily during ischemic injury, post-con exerts its effect after ischemic injury, and therefore, post-con can be easily applied to ischemic tissue as an "after-injury strategy" 10 and may be a more valuable technique in plastic and reconstructive surgery.…”

Beneficial effects of Xuebijing injection on random skin flap survival in rats

“…Flap necrosis, however, remains a grand challenge in the postoperative period and is responsible for failure of operation. According to previous studies [19,20], I/R injury, neutrophil infiltration, and inflammation may account for flap necrosis.…”

Effects of diammonium glycyrrhizinate on random skin flap survival in rats: An experimental study

“…Therefore, it is crucial to prevent partial necrosis in order to enhance survival of the skin flap. Previous studies have found that ischemia-reperfusion injury and inflammation are critical in partial necrosis (15,16). In addition, certain studies have confirmed that VEGF promotes revascularization (17,18), thus enhancing the survival of skin flaps.…”