Ischemia and reperfusion in skin flaps: effects of mannitol and vitamin C in reducing necrosis area in a rat experimental model (original) (raw)

The Effect of Topical Vitamin A and E on Ischemic Random Skin Flap Survival

WORLD JOURNAL OF PLASTIC SURGERY, 2019

BACKGROUND Ischemia of skin flaps is an important complication in reconstructive surgery. This study evaluated the efficacy of topical vitamins A and E on improving flap survival. METHODS Twenty-four white-albino male rats were randomly divided into two groups of treatment and control. Standard rectangular, distally based dorsal random pattern skin flap was elevated. Intra-peritoneal cephazoline was administered to prevent any unexpected infection. No pharmaceutical agent was administered for the control group, but pure vaseline ointment. In treatment group, vaseline plus vitamins A and E were administrated daily after surgery for 10 days. The rats were evaluated on the 10 th day after surgery for viable and necrotic portions of the flaps. RESULTS The mean values of necrosis in the flaps were 625±189.56 and 920.00±247.31 in the treatment and control groups, respectively. Vaseline plus vitamins increased flap survival significantly. CONCLUSION Topical vitamins A and E may be effective pharmaceutical agents to increase viability of random skin flaps in rats. They can be added to vasoactive topical agents to reach better results.

Involvement of reactive oxygen species in post-ischaemic flap necrosis and its prevention by antioxidants

British Journal of Plastic Surgery, 1991

In attempts to substantiate the possible participation of reactive oxygen species, and the signilicance of the xanthhre oxidase system in both post-ischaemic reperfusion necrosis of the island flap and distal necrosis of the pedicle flap, and to develop oew pharmacological measures for salvaging ilap necrosis, a series of experiments were made using an island flap model and a random-pattern flap model in rats. The results were as follows: (1) Epoxysuccinyl derivative (E&c), allopurhrol and L-SOD salvaged post-ischaemic reperfusion necrosis of the island flaps; (2) E-64c and allopurhrol did not salvage anticipated necrosis of the distal region of random flaps but L-SOD did; (3) tissue SOD activity did not reflect the fate of the island flap, but did of the distal region of the random flap. These results demonstrated a possible involvement of ROS in both post-ischaemic necrosis of island flaps and distal necrosis of random flaps. However, xanthine oxidase was signitlcant in producing ROS only in the former.

Transferring the protective effect of remote ischemic preconditioning on skin flap among rats by blood serum

Journal of Plastic Surgery and Hand Surgery, 2019

The aim of this study was to show whether the protective effect of remote ischemic preconditioning (RIPC) on flaps can be transferred among different individuals with the transfusion of blood serum. Blood serum was taken from rats without any procedure (Group x), rats 1 hour (Group y) and 24 hours (Group z) after performing RIPC and the remaining rats were divided into six groups. While the random pattern skin flap was performed only in the back region in Group 1, and it was performed 1 hour (Group 2) and 24 hours (Group 3) after induction RIPC. Flap surgery was performed after the intravenous injection of serum obtained from Group x in Group 4, from Group y in Group 5, and from Group z in Group 6. After 7 days, the ratios of viable areas in the flaps of the remaining rats were calculated. When the viable area ratios in the flaps to the whole flap area were calculated, it was found out that the viable area ratios in Group 2 (61.6%), Group 3 (75.6%) and Group 6 (74.2%) were statistically significantly higher compared to Group 1 (51.5%), Group 4 (52.6%) and Group 5 (58.7%), that viable area ratios in Groups 3 and 6 were statistically significantly higher compared to Group 2, and that there was no difference between Groups 3 and 6. This study showed that RIPC forms a protective effect on the flaps and that this effect could be transferred among individuals with blood serum.

Comparison of blood flow and cell function in ischemic skin flaps

Journal of Surgical Research, 1984

Cellular function and blood flow in acute, steroid-treated, and surgically delayed random skin flaps have been examined. In these studies, the period following flap elevation could be divided into early (O-2 hr), intermediate (4-6 hr), and late (12 hr) periods of &hernia, based on the cutaneous blood flow and cellular function measured by thallium-201 uptake. There was a close correlation (r = 0.98, 2 hr) between blood flow and cellular function during the early period of ischemia which became worse with time (r = 0.78, 12 hr). Blood flow studies demonstrated a significant difference (P < 0.05) between the early and intermediate periods of &hernia which was abolished by surgical delay. Improvement in cellular function was accomplished by improved blood flow in the surgically delayed flaps, while steroidtreated flaps enhanced cellular metabolism by another mechanism. Cellular function approximated blood flow during the early and immediate period of ischemia. Steroids may augment cellular function without improving blood flow, while surgical delay improves cellular function by improving blood flow.

Glutathione disulphide as a marker of reperfusion injury in ischaemic skin flaps

British Journal of Plastic Surgery, 1995

Estimation of the oxidised form of glutathione (GSSG) in an ischaemic/reperfused organ is frequently employed as an indicator of oxidative stress created by the production of oxygen free radicals during the reperfusion period. The time course of oxidative stress and tissue damage in 19 ischaemic/reperfused guinea-pig island skin flaps was evaluated. No-flow ischaemia was induced in the flaps for 6 h in 7 animals, and for 8 h in 9 animals (a further 3 animals served as controls without ischaemia). Arterial and venous blood samples were obtained directly from the flap pedicle at baseline, 10,30, and 60 min following reperfusion. Results suggest that a second focus of oxidative injury, possibly mediated by activated neutrophils, contributes to the overall process of reperfusion injury. Plasma levels of GSSG allow for a more sensitive quantification of oxidant stress within reperfused ischaemic flaps, and may serve as a useful tool in skin flap research.

Increased survival of skin flaps by scavengers of superoxide radical

FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 1987

Elevation of rat abdominal skin flaps, followed by ligation and division of the left inferior neurovascular pedicle, resulted in only a 40% survival of the area normally perfused by the ligated artery and vein. Superoxide dismutase (SOD) (EC 1.15.1.1) administered i.v. (20,000 U/kg) 30 min before flap elevation increased survival to 52%. SOD derivatized with polyethylene glycol, which increases circulating half-life, was more effective, increasing survival to 80%. This protective effect resulted from the catalytic activity of the derivatized enzyme because inactivation by treatment with H2O2 eliminated its effect on skin flap survival. An equimolar mixture of Desferal and MnCl2, which catalyzes the dismutation of O2- in vitro, improved survival to 72%. Desferal-Fe3+, which lacks in vitro SOD activity, or Mn2+ alone did not affect the survival of skin flaps, but Desferal alone was nearly as effective as the Desferal-Mn2+ mixture. This effect of Desferal may result from acquisition of...

2016_Novel skin chamber for rat ischemic flap studies in regenerative wound repair.pdf

Background: In plastic surgery, skin flap is an important approach to reconstructive wound repairs. The rat dorsal skin flap is a clinically relevant and popular animal model to investigate and evaluate flap survival and necrosis. Nonetheless, flap survival is often unstable with unpredictable outcomes, regardless of previous attempts at design modification. Methods & Results: In the present study, we report a novel flap chamber that provides stable and reproducible outcomes by separating the dorsal skin flap from its surrounding skin by in situ immobilization. The flap chamber blocks circulation that disturbs flap ischemia from both basal and lateral sides of the flap tissue. Demarcation of skin necrosis is macroscopically evident on the flap and supported by distinct changes in histological architecture under microscopic examination. The utility of the novel skin flap chamber is further proven by applying it to the examination of flap survival in streptozotocin-induced diabetic rats with an increase in skin necrosis. The flap chamber also affords size modifications where a narrower flap chamber increases ischemia and provides manipulable therapeutic windows for studying cell therapies. Accordingly, intradermal injection of endothelial cells 3 days before flap ischemia significantly increases the survival of skin flaps. Conclusions: The novel flap chamber not only may stabilize the skin flap and provide reproducible outcomes that overcome the shortfalls of the traditional ischemic flap but also may afford size modifications that support research designs and test therapeutic approaches to regenerative repair.

The Effect of Antioxidants on Ischemia-Reperfusion Injury in Flap Surgery

Antioxidants, 2019

Flap surgery has wide use in plastic surgery in the closure of tissue defects. In spite of the major advances in plastic surgery in the past years, flap surgery is still associated with significant mortality. Ischemia-reperfusion (I/R) injury, which is a complex injury associated with flap blood flow, is one of the most important causes of flap failure. The main pathophysiology underneath I/R injury is associated with reactive oxygen species, which can be prevented by certain antioxidant applications. Antioxidants have been widely used in flap surgery and I/R injury previously. There have been a lot of articles showing positive effects of antioxidants on I/R injury. In this chapter, we focus the mechanism of I/R injury and how antioxidants can able to diminish the damage, moreover demonstrating the effect of certain antioxidants on I/R injury that has been investigated previously.

The effects of montelukast on random pattern skin flap survival: An experimental study in rats

Current Therapeutic Research-clinical and Experimental, 2008

Background: A variety of methods to improve skin flap survival, including the use of pharmacologic agents, have been intensively investigated. Decreasing neutrophil-mediated inflammation and tissue injury has been reported to be effective in improving flap survival. Montelukast is a selective reversible cysteinyl leukotriene receptor-1 antagonist that has been found to have protective effects against renal ischemia reperfusion injury and burn-induced oxidative injury of the skin in rats. However, its effects on skin flap survival have not been previously reported.Objective: The aim of this study was to investigate the effects of montelukast on neutrophil-mediated random pattern skin flap survival.Methods: Male Sprague-Dawley rats weighing 230 to 250 g were randomly divided into 2 groups—the montelukast-treated group and the control group. Caudally based rectangular random pattern skin flaps 3 × 9 cm were elevated on the backs of the rats. The flaps were sutured into their original places. In the montelukast group, 1 mL of solution containing 10 mg/kg montelukast was administered intraperitoneally (IP) 30 minutes before surgery and then daily for 6 days. In the control group, 1 mL of saline was administered IP 30 minutes before surgery and then daily for 6 days. To observe the effects of montelukast, myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration, was measured from extracted skin tissue 12 hours after flap elevation. Flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area.Results: Sixteen rats (mean [SD] weight, 240.6 [6.6] g) were equally divided between the 2 groups. All rats survived throughout the study period. Mean (SD) MPO activity in flap tissue was significantly lower in the montelukast group than in the control group (14.57 [2.33] vs 21.28 [4.86] U/g protein; P = 0.005). The percentage of necrotic flap area was significantly lower in the montelukast group than in the control group (17.17 [7.95] vs 37.51 [10.72]; P = 0.001).Conclusion: This small, experimental, in vivo animal study found that montelukast was associated with both lower MPO activity and a lower percentage of necrotic random pattern skin flap area. Future studies are needed to clarify these findings.