Significant Improvement In Flap Survival Research Articles

The outcome of prostaglandin‐E1 and dextran‐40 compared to no antithrombotic therapy in head and neck free tissue transfer: Analysis of 1,351 cases in a single center

Free tissue transfer has become a popular technique for soft tissue defect reconstruction in head and neck cancer ablation. Although high success rates and good reliability of free flaps are proven, microvascular thrombosis is still the most critical issue for microsurgeons. Pharmacological antithrombotic agents are widely used but their efficacy is still debated. In this study, we analyzed whether prostaglandin-E1 (PGE1) and dextran-40 can improve the outcomes compared to no antithrombotic therapy at all. We retrospectively reviewed 1,351 free flaps performed for head and neck reconstruction after cancer ablation. Three groups defined were 232 flaps received PGE1, 283 flaps received dextran-40, and 836 received no antithrombotic therapy. The demographics of these three groups indicated no statistical differences. The results showed that flap survival revealed no significant difference among PGE1, dextran-40, and control group (P = 0.734). There was a tendency to hematomas in PGE1 group (P = 0.056) when compared with other two groups. Dextran-40 significantly increased flap failure rate in high-risk patients with diabetes mellitus (P = 0.006) or hypertension (P = 0.003), when compared with PGE1 and control group. These results revealed antithrombotic therapy with PGE1 and dextran-40 do not determine a significant improvement in flap survival.

The Effect of Calcium Channel Blockers on Smoking-Induced Skin Flap Necrosis

Calcium channel blockers have been shown experimentally to reverse many of the effects of nicotine. The purpose of this study was to assess the effect of calcium channel blockers on smoking-induced skin flap necrosis. Forty male albino Wistar rats were divided into four groups. Groups A, B, and C were treated in a controlled smoking chamber for 20 minutes daily for 21 days. On day 14, caudally based dorsal skin flaps (3 x 10 cm) were created. On days 14 through 21, group B animals received verapamil (20 mg/kg/day) by gavage. Group C received nifedipine (10 mg/kg/day). On day 21, standardized photographs were taken and flap survival areas determined. Urine cotinine concentrations were measured on days 14 and 21. The mean cotinine level at surgery was 161 ng/ml in group A (smoking), 149 ng/ml in group B (verapamil), and 168 ng/ml in group C (nifedipine). These differences were not statistically significant. Cotinine concentration at surgery for group D (no smoking) was less than 10 ng/ml. The mean flap survival in group D was 79.1 percent, compared with 63.7 percent in group A (p = 0.003). The mean flap survival in group B (verapamil) was 72.8 percent, compared with 73.7 percent in group C (nifedipine). Both values were significantly greater than in group A (p = 0.04 and p = 0.008, respectively). In this study, enteral calcium channel blockers were associated with a statistically significant improvement in flap survival compared with untreated animals with an equivalent smoke exposure. Calcium channel blockers may reduce perioperative risk in active smokers who require skin flap surgery.

Effect of Aspirin and Heparin on Random Skin Flap Survival in Rats

BACKGROUND Aspirin and heparin are commonly given to patients undergoing microvascular procedures to increase flap survival and patency, yet there is scant information concerning the effect these flaps have on nonmicrovascular flaps. OBJECTIVE The objective was to obtain baseline values concerning the effect of aspirin and heparin on the viability of standardized flap tissues. METHODS AND MATERIALS One hundred rats were divided into five groups receiving high-dose aspirin, low-dose aspirin, high-dose aspirin in combination with heparin, and heparin alone and the final group were controls. The viability of the tissue was measured at 1 week by fluorescein florescence. RESULTS There was significant improvement in flap survival in the high-dose aspirin and high-dose aspirin combination groups. CONCLUSIONS It appears that high-dose aspirin increases survival of ischemic flap tissue irrespective of the presence of microvascular anastomosis and may be of clinical benefit in all flap surgery.

Effect of Hyaluronic Acid on Random-Pattern Flaps in Rats

Hyaluronic acid is a common component of the extracellular matrix, has many medical applications, and is widely used as a soft tissue filler in patients who simultaneously or eventually undergo cosmetic procedures to the areas treated. The objective was to study the effect of hyaluronic acid on wound healing and viability of random-pattern flaps in rats. Twenty-six male rats were randomly divided into two groups. A cephalically based random dorsal flap was used-14 rats received hyaluronic acid to the bed of the flap immediately after surgery; 12 served as controls. After 1 week, flap survival was evaluated by fluorescein fluorescence. A t-test statistical analysis of survival relationships was performed. Flap viability in hyaluronic acid-treated rats was slightly better than in controls (average flap length survival 46.7 and 40.6 mm, respectively; p<.2). Although hyaluronic acid had a slight beneficial effect on flap viability, no significant improvement in flap survival was shown. The lack of any deleterious effect of hyaluronic acid on relatively ischemic tissues is further evidence of its harmless effect during surgical intervention. Further studies should be performed to clarify the potential benefit of hyaluronic acid on random flaps. The authors have indicated no significant interest with commercial supporters.

Effect of Aspirin and Heparin on Random Skin Flap Survival in Rats

Aspirin and heparin are commonly given to patients undergoing microvascular procedures to increase flap survival and patency, yet there is scant information concerning the effect these flaps have on nonmicrovascular flaps. The objective was to obtain baseline values concerning the effect of aspirin and heparin on the viability of standardized flap tissues. One hundred rats were divided into five groups receiving high-dose aspirin, low-dose aspirin, high-dose aspirin in combination with heparin, and heparin alone and the final group were controls. The viability of the tissue was measured at 1 week by fluorescein fluorescence. There was significant improvement in flap survival in the high-dose aspirin and high-dose aspirin combination groups. It appears that high-dose aspirin increases survival of ischemic flap tissue irrespective of the presence of microvascular anastomosis and may be of clinical benefit in all flap surgery. The authors have indicated no significant interest with commercial supporters.

Evaluation of Flashlamp-Pumped Pulsed-Dye Laser (585 nm) in Nonsurgical Delay of Dorsal Rat Cutaneous Flaps

This study evaluated the efficiency of a flashlamp-pumped pulsed-dye laser operating at 585 nm in the delay of a caudally based, 10 x 3-cm dorsal rat skin flap. Two different laser treatment patterns (only longitudinal borders and the entire surface of the proposed flap) for two different fluences (6 J/cm and 8 J/cm) were compared with an acute untreated control flap as well as two surgical delay methods (incision of longitudinal borders and incision of longitudinal borders plus flap undermining). Twelve male Sprague-Dawley rats were used in each of seven groups. Two additional rats were used for histologic evaluation and two rats were used for in vivo real-time video monitoring studies. Two weeks after delay procedures, the flaps were raised and sutured on the primarily closed flap donor area. After 5 days, the length of flap survival was measured. The effects of the laser on the cutaneous vasculature and perfusion were assessed by intravenous fluorescein injection, histologic analysis, microangiography, and in vivo real-time video monitoring. No statistically significant improvement in flap survival was observed in any of the laser treatment groups. The overall findings indicate that the flashlamp-pumped pulsed-dye laser operating at 585 nm did not penetrate deep into skin and coagulate the subdermal plexus with tested laser settings and did not induce the delay phenomenon.

Enhancement of dorsal random-pattern skin flap survival in rats with topical lidocaine and prilocaine (EMLA): Enhancement of flap survival by EMLA

Various topical pharmacologic agents have been investigated for their efficacy in preventing or reversing skin flap ischemia. Most of these studies have focused on agents that act on the vascular smooth muscles to cause vasodilatation and improve circulation in the flap. Most of local anesthetics relax vascular smooth muscle and produce peripheral vasodilatation. Topical lidocaine administration was shown that it was an effective and prompt resolution of mechanically induced vasospasm. The topical analgesia cream, EMLA is a mixture of the substances lidocaine and prilocaine. EMLA causes a biphasic vascular response comprising initial blanching and vasoconstriction (maximal after 1.5 h of application) and late erythema and vasodilatation at application times longer than 3 h. To investigate the effect of EMLA on random flap survival, 40 rats were divided in 2 groups of 20 animals. Caudally based random pattern skin flaps were elevated on dorsa of the rats in 10 x 3 cm dimensions. In group 1 which was the treatment group, topical EMLA was applied and covered with Opsite for 1 week whereas in group 2 which was the control group, carrier for EMLA was applied to the flaps. At the end of treatment period, the areas of flap necrosis were measured and percentages of flap survivals were calculated. The mean percentages of flap survivals in group 1 and 2 were 81.2 +/- 1.2 percent and 58.7 +/- 2.3 percent, respectively. Topically administered EMLA might lead to a significant improvement in flap survival. In addition, it is safe, cost-effective, easily applied, and clinically available.

Timing, Magnitude, and Utility of Surgical Delay in the TRAM Flap: I. Animal Studies

Surgical delay is an effective technique, but the precise timing of the delay effect and the required extent of the delay procedure are uncertain. We endeavored to study [Illegible Text] survival as a function of the duration of the delay period in a rat transverse rectus abdominis myocutaneous (TRAM) flap model. Two specific delay procedures (limited and extensive) were utilized, and flap survival was assessed after delay periods of 3, 7, 10, 14, 21, and 30 days (n ≥ 7, all groups). A delay of 7 days or greater resulted in statistically significant improvement in flap survival in all groups. The delay effect appeared to be maximal at 14 days, and in the extensive delay group, a 14-day delay resulted in statistically greater flap survival than a 7-day delay. Improvement in flap survival was greater when an extensive delay procedure was used. Although the model system has limitations, the rat TRAM flap appears to be a suitable model for the study of the delay phenomenon. Possible clinical correlations are addressed in part II.

Timing, magnitude, and utility of surgical delay in the TRAM flap: I. Animal studies.

Surgical delay is an effective technique, but the precise timing of the delay effect and the required extent of the delay procedure are uncertain. We endeavored to study flap survival as a function of the duration of the delay period in a rat transverse rectus abdominis myocutaneous (TRAM) flap model. Two specific delay procedures (limited and extensive) were utilized, and flap survival was assessed after delay periods of 3, 7, 10, 14, 21, and 30 days (n > or = 7, all groups). A delay of 7 days or greater resulted in statistically significant improvement in flap survival in all groups. The delay effect appeared to be maximal at 14 days, and in the extensive delay group, a 14-day delay resulted in statistically greater flap survival than a 7-day delay. Improvement in flap survival was greater when an extensive delay procedure was used. Although the model system has limitations, the rat TRAM flap appears to be a suitable model for the study of the delay phenomenon. Possible clinical correlations are addressed in part II.

The effect of Prostacyclin on experimental random pattern flaps in the rat.

Abstract In a controlled experimental study of the survival of random pattern flaps in rats it has been found that pre-treatment with prostacylin prior to raising the skin flaps did not improve flap survival. However, if treatment was begun at the commencement of the operation and continued afterwards, there was a significant improvement in flap survival compared with the viability predicted by intravital dye injection. Possible explanations of these findings are discussed and the suggestion put forward that in addition to reducing platelet adherence and vasoconstriction PGI 2 may also stimulate the formation of new capillaries in ischaemic areas. This hypothesis requires further investigation.

The effects of streptokinase on ischemic flaps

Prolonged ischemic periods may inhibit success in microsurgical procedures. Impairment of fibrinolytic activity could be a factor contributing to this problem. Ischemic epigastric flaps in the rat were used as a model to measure the potential of streptokinase to improve blood flow and tissue survival. A moderate but statistically significant improvement in flap survival was observed and is felt to be due to the enhancement of fibrinolytic activity previously impaired by ischemia. Saline irrigation alone in control animals was found to be detrimental to flap survival. Streptokinase might prove beneficial when dealing with an ischemic replant or free flap.

The effect of prostacyclin on experimental random pattern flaps in the rat

In a controlled experimental study of the survival of random pattern flaps in rats it has been found that pre-treatment with prostacylin prior to raising the skin flaps did not improve flap survival. However, if treatment was begun at the commencement of the operation and continued afterwards, there was a significant improvement in flap survival compared with the viability predicted by intravital dye injection. Possible explanations of these findings are discussed and the suggestion put forward that in addition to reducing platelet adherence and vasoconstriction PGI 2 may also stimulate the formation of new capillaries in ischaemic areas. This hypothesis requires further investigation.