Percentage Of Flap Survival Research Articles

The post-traumatic reconstruction of nail bed defects using a homodigital dorsal adipofascial reverse flap

Nail bed defects (NBDs) of the distal phalanx, are common and remain challenging to reconstruct. This study aimed to evaluate the clinical outcome of these post-traumatic injuries treated using a homodigital dorsal adipofascial reverse flap (HDARF). Sixteen patients, averaging 43-years-old, were retrospectively reviewed, who underwent the aforementioned procedure from February 2018 to December 2019. Range of motion of the distal interphalangeal (DIP) joint, static Weber’s 2-point discrimination sensibility of the pulp, the percentage of nail adherence, complications, patient’s satisfaction, subsequent nail regrowth, and flap survival were evaluated upon follow-up. At 26 months average follow-up, the percentage of flap survival was 100%. Complete regrowth of the nail was reported in 11 cases (69%), on average 4.7 months after surgery. A total absence of ungual regrowth was noted in 5 cases (31%). The mean static Weber’s 2-point discrimination value of injured finger was 4.25 mm, reconstructed fingers’ mean range of motion for the DIP joint was 75 degrees. Patient satisfaction was graded as very satisfying in 11 cases (69%), satisfying in 4 cases (25%), and disappointing in 1 case (6%). The HDARF is a good alternative for the management of NBDs of fingers and thumb. It yielded functionally and aesthetically acceptable results with low donor site morbidity. Level of evidenceIV.

Effect of intraoperative vasopressor use on free flap outcome following major head-and-neck reconstructive surgeries

Introduction: Major head-and-neck surgeries involving wide excision of the tumor usually necessitate reconstruction with free flaps for tissue cover. Even with meticulous fluid management with crystalloids, colloids, albumin, blood, and blood products, many patients become hemodynamically unstable and require the use of vasopressors perioperatively. Objectives: The purpose of this analysis was to assess the safety, role, and present-day trends of the use of vasopressor agents in free flap surgeries and to find any relation of graft rejection or failure of flap surgeries or postoperative complications with perioperative use of such agents. Methods: Reviewing the literature regarding the usage of vasopressors in head-and-neck free flap surgeries, percentage of flap survival, thrombosis of the artery, venous edema, and need for revision surgery were analyzed. Most of the published data had shown that optimizing hemodynamic stability with vasopressors had a more beneficial effect on overall flap perfusion and minimized the complications of iatrogenic fluid overload. The common conclusion was that perioperative vasopressor administration was not detrimental to free flap survival. Conclusion: Based on available data, it is concluded that perioperative use of vasopressors does not adversely affect free flap outcome in patients undergoing head-and-neck reconstructive surgeries and could even be beneficial considering the avoidance of complications of liberal intravenous fluid administration.

Study of Different Therapeutic Agents for the Prevention of Ischemia Reperfusion Injury in Free Skin Flap

Background: In clinical practice a certain fraction of skinflap transfers fail invariably because of ischemia-reperfusioninjury. This study was designed to develop experimental modelof ischemia-reperfusion injury in rat skin flap to investigatethe effect of certain pharmacological agents on prevention orreducing ischemia-reperfusion injury.Methods: A “4x6” cm hemi epigastric skin flap of adultalbino rat was raised and subjected to 8 hours of ischemiathen reperfusion for 48 hours. A total of 40 flaps were studiedand divided randomly into 5 groups. 15 minutes prior toreperfusion, all flaps (except group I) were infused by saline,Vitamin C, Heparin, and Monoclonal antibody LY-6G togroups II, III, IV and V respectively. After 2 days, macroscopicevaluation of flap survival, histological study of neutrophilinfiltration, and biochemical tissue enzymes assay wereperformed.Results: All flaps survived completely in sham group Iwith minimal neutrophilia while the mean percentage of flapnecrosis in control group II was 90.5% with massive neutrophilia.The mean percentage of flap survival were 71, 80,and 84 percent in groups III, IV, and V respectively. Neutrophilcount of flap tissue showed significant reduction as comparedwith control flaps. Tissue enzymes assay showed stable levelof superoxide dismutase activity in flaps pretreated by drugscompared to control group. Caspase-3 enzyme activity showedvariable decrements in flaps pretreated with the differentdrugs when compared with control flaps.Conclusion: The use of certain pharmacological agentscould significantly reduce the effect of ischemia-reperfusioninjury on skin flaps.

Effects of Morroniside on the Viability of Random Skin Flaps in Rats

ABSTRACTObjective: The purpose of our experiment was to determine whether morroniside can improve the survival of ischemic skin flaps in rats. Methodology: A total of 40 male Sprague-Dawley rats were randomly divided into two groups (control group and treatment group). Modified McFarlane flaps were performed (causally based, 9 cm × 3 cm). The percentage of survival of each flap was calculated. Flap blood flows were measured by Laser-Doppler flowmeter. Flap vasculature was assessed by angiography after Lead oxide-gelatin injection. Vascular endothelial growth factor (VEGF) was evaluated by immunochemistry. Superoxide Dismutase (SOD) level and malondiadehyde (MDA) content were determined using assay kits. Results: At the seventh postoperative day, the morroniside-treated rats showed a higher percentage of flap survival than the control rats. Flap perfusion and the level of vascular endothelial growth factor were significantly elevated in the morroniside-treated group. In the treatment group, the distal section of the flap was nearly saturated with contrast agent, while in the control group, the contrast agent perfused only half of the flap. In the treatment group, morroniside administration significantly increased SOD level and reduced MDA content. Conclusion: Morroniside can enhance ischemic flap survival.

Optimization of an Arterialized Venous Fasciocutaneous Flap in the Abdomen of the Rat.

Although numerous experimental models of arterialized venous flaps (AVFs) have been proposed, no single model has gained widespread acceptance. The main aim of this work was to evaluate the survival area of AVFs produced with different vascular constructs in the abdomen of the rat. Fifty-three male rats were divided into 4 groups. In group I (n = 12), a 5-cm-long and 3-cm-wide conventional epigastric flap was raised on the left side of the abdomen. This flap was pedicled on the superficial caudal epigastric vessels caudally and on the lateral thoracic vein cranially. In groups II, III, and IV, a similar flap was raised, but the superficial epigastric artery was ligated. In these groups, AVFs were created using the following arterial venous anastomosis at the caudal end of the flap: group II (n = 13) a 1-mm-long side-to-side anastomosis was performed between the femoral artery and vein laterally to the ending of the superficial caudal epigastric vein. In group III (n = 14), in addition to the procedure described for group II, the femoral vein was ligated medially. Finally, in group IV (n = 14), the superficial caudal epigastric vein was cut from the femoral vein with a 1-mm-long ellipse of adjacent tissue, and an end-to-side arterial venous anastomosis was established between it and the femoral artery. Seven days postoperatively, the percentage of flap survival was 98.89 ± 1.69, 68.84 ± 7.36, 63.84 ± 10.38, 76.86 ± 13.67 in groups I-IV, respectively. An optimized AVF can be produced using the vascular architecture described for group IV.

Upper and middle third auricular reconstruction with a peninsular conchal flap

Background: Traumatic or iatrogenic full thickness auricular defects can be reconstructed in many ways. The defects exceeding 2 cm require challenging reconstruction techniques. The reconstruction options for those should include an- terior and posterior skin envelope repair with cartilaginous content. Providing color and texture match, while maintaining anatomic landmarks, should be considered. The outcomes of patients in which we used a peninsular conchal axial pattern flap (PCF) to reconstruct the composite defects of the auricle were outlined in this case series. Materials and Methods: Five patients with different etiologies were evaluated and operated with PCF between March 2012 and January 2015. The ages of the patients ranged from 21 to 91 years with a median age of 80. The mean follow-up period was 16.8 months. In PCF, the conchal subpart of the auricle was elevated as an axial pattern composite flap relied on the anastomotic connections between the superficial temporal artery and the posterior auricular artery. Donor sites were left to secondary healing. The statistical assessment was carried out with the Mann-Whitney U test. Results: The median age of the patients was 80 (21-91) years. The median percentage of flap survival was 100,00. The median operation duration was 92,00 minutes. Donor site epithelialization was 21 and 20 days in the first two patients, with a median of 20,5 days. In the latter three patients, a silver-containing dressing material was used prophylactically to suppress contamination by skin bacteria, which led to a decrease of the length of healing time to a median of 11,00 days, with a range of 3,00. Conclusion: PCF offers a one-stage procedure and can be used in the reconstruction of defects of the auricle exceeding 2 cm. The use of axial pattern peninsular conchal flap is recommended to all of our colleagues.

The Effects of Vasonatrin Peptide on Random Pattern Skin Flap Survival

A lot of methods have been intensively investigated to improve random skin flap survival. Decreasing inflammation and alleviating tissue injury have been reported to be effective in improving survival ratio. Vasonatrin peptide (VNP) is a chimera of atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP). The current study demonstrates that VNP possesses the venodilating actions of CNP, the natriuretic actions of ANP, and the unique arterial vasodilating actions not associated with either ANP or CNP. However, its effects on skin flap survival have not been previously reported. Sprague-Dawley rats, weighing 220 to 260 g, were randomly divided into 2 groups, namely, the VNP-treated group and the control group. Rectangular random dorsal skin flaps measuring 3 × 9 cm including the panniculus carnosus were elevated, then the flaps were sutured into their original places. In the VNP group, 0.1 mg/kg of VNP was administered intravenously (IV) after surgery and then daily for 3 days. In the control group, 1 mL/kg of saline was administered IV after surgery and then daily for 3 days. To observe the effects of VNP, blood perfusion, histopathological examination, the inflammatory mediators (tumor necrosis factor α, interleukin 1β, and interferon γ), and biochemical analysis (malondialdehyde, glutathione, and myeloperoxidase) were detected and the flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area. The viability measurements showed the percentage of flap survival was increased in the VNP-treated group (76.53% ± 6.36%) as compared with the control group (61.12% ± 4.92%) (P < 0.05), and the histological and biochemical assays corroborated the data. The blood perfusion of flaps in the VNP-treated group was higher than the control group (P < 0.05). The inflammatory mediators (tumor necrosis factor α, interleukin 1β, and interferon γ) were significantly lower in the VNP-treated group than the control group (P < 0.05). This study found that VNP, which could elevate the tissue blood perfusion and mitigate the tissue damage and inflammatory reaction, is associated with a higher percentage of survival random pattern skin flap area.

The Effect of Hemodynamic Remodeling on the Survival of Arterialized Venous Flaps

ObjectiveTo evaluate the effect of hemodynamic remodeling on the survival status of the arterialized venous flaps (AVFs) and investigate the mechanism of this procedure.Materials and MethodsTwo 7 x 9 cm skin flaps in each rabbit (n=36) were designed symmetrically in the abdomen. The thoracoepigastric pedicle and one femoral artery were used as vascular sources. Four groups were included: Composite skin grafts group and arterial perfusion group were designed in one rabbit; AVF group and hemodynamic remodeling group by ligation of the thoracoepigastric vein in the middle were outlined in another rabbit. Flap viability, status of vascular perfusion and microvasculature, levels of epidermal metabolite and water content in each group were assessed.ResultsHighly congested veins and simple trunk veins were found using angiography in the AVF group; while a fairly uniform staining and plenty of small vessels were observed in the hemodynamic remodeling group. The metabolite levels of the remodeling group are comparable with those in the arterial perfusion group. There was no statistically significant difference in the percentage of flap survival between the arterial perfusion group and hemodynamic remodeling group; however, significant difference was seen between the AVF group and the hemodynamic remodeling group.ConclusionsUnder the integrated perfusion mode, the AVFs are in an over-perfusion and non-physiological hemodynamic state, resulting in unreliability and unpredictability in flap survival; under the separated perfusion mode produced by remodeling, a physiological-like circulation will be created and therefore, better flap survival can be expected.

Effect of Topically Applied Minoxidil on the Survival of Rat Dorsal Skin Flap

Flap necrosis still is a challenging problem in reconstructive surgery that results in irreversible tissue loss. This study evaluated the effect of topically applied minoxidil on angiogenesis and survival of a caudally based dorsal rat skin flap. For this study, 24 male Wistar rats were randomly divided into three groups of eight each. A caudally based dorsal skin flap with the dimensions of 9×3cm was raised. After elevation of the flaps, they were sutured back into their initial positions. In group 1 (control group), 1ml of isotonic saline was applied topically to the flaps of all the animals for 14days. In group 2, minoxidil solution was spread uniformly over the flap surface for 7days after the flap elevation. In group 3, minoxidil solution was applied topically to the flap surface during a 14-day period. On day 7 after the flap elevation, the rats were killed. The average area of flap survival was determined for each rat. Subdermal vascular architecture and angiogenesis were evaluated under a light microscope after two full-thickness skin biopsy specimens had been obtained from the midline of the flaps. The lowest flap survival rate was observed in group 1, and no difference was observed between groups 1 and 2. Compared with groups 1 and 2, group 3 had a significantly increased percentage of flap survival (P<0.05). Intense and moderate angiogenesis also was observed respectively at the proximal and distal areas of the flaps in group 3. The results of this experiment seem to show that the early effect of minoxidil is vasodilation and that prolonged use before flap elevation leads to angiogenesis, increasing flap viability. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Improvement of Prearterialized Venous Flap Survival with Delay Procedure in Rats

The purpose of this experimental study is to investigate the improvement in flap survival of prearterialization with delay procedure in venous flaps in rats. The transverse superficial inferior epigastric flap was utilized. Forty-six rats were randomized into four groups: group 1 as arterialized venous flaps, group 2 as venous flaps of prearterialization with delay procedure, group 3 as arterial perfusion venous flap, and group 4 as venous perfusion venous flap. Direct observation, histological analysis, and vascular perfusion examination by Indian ink injection were performed for flap assessment. The percentage of flap survival was 41.6 +/- 2.4%, 98.0 +/- 1.8%, 89.5 +/- 1.0%, and 11.3 +/- 0.8% in these four groups, respectively. Significant differences were noted between groups ( P < 0.05) except for between group 2 and group 3 ( P > 0.05). Vascular perfusion studies revealed that the Indian ink filled the entire flaps of group 2 in comparison with partially filled flaps in other groups. Histological examination showed more small vessels were observed through all layers of the flaps as well as dilated superficial veins in group 2 than those in other groups. In conclusion, prearterialization with delay procedure can improve the viability of the flap, and this method may be a strategy for flap prefabrication based on the venous network.

S109 – N-2 MPG in Groin Flaps Subjected to Vein Occlusion

Objectives In a prior communication, we showed that ischemic rat groin flaps exposed to the free radical scavenger N-2 mercaptopropionylglycine (MPG) at the time of arterial and venous occlusion had a higher rate of survival than untreated flaps. In this study, the objective is to test the efficacy and timing of administration of MPG in salvaging rat groin flaps subjected to venous occlusion alone. Methods Randomized controlled trial. Main outcome is mean percentage of flap survival at 7 days. 30 mature Sprague-Dawley rats were randomized to 3 groups based on timing of treatment with MPG: 1- flap raised, no MPG, no venous occlusion (sham group); 2- flap raised, no MPG, 10-hour period of venous occlusion (control group); 3- flap raised, MPG after 10 hours venous occlusion (post-reperfusion group). Results There was no statistical difference noted in mean survival of venous occluded flaps when comparing the control and post-reperfusion groups, after 7 days. Specifically, the mean flap survival in the control group at 7 days was 10.9% (median 0%, range 0–100%). The mean flap survival in the post-reperfusion group was 14.6% (median 0%, range 0–100%). The mean flap survival in the sham group was 90.0% (median 100%, range 0–100%). Conclusions Post-reperfusion MPG administration is not helpful for flaps subjected to venous occlusion alone. The free-radical scavenger activity of MPG is potentiated within the tissues prior to vein occlusion. Potential applications for free flap salvage would need further study.

Intraoperative use of dynamic infrared thermography and indocyanine green fluorescence video angiography to predict partial skin flap loss

Inadequate perfusion is the most common cause of partial flap loss in reconstructive surgery. Intraoperative monitoring of flap perfusion may prevent such loss. This study compared indocyanine green fluorescence angiography (ICG-FA) and dynamic infrared thermography (DIRT) in their ability to predict intraoperatively the percentage of flap survival in a caudally based McFarlane flap in 10 male Wistar rats. The intraoperative images of both techniques were subjectively and objectively analysed. The percentage of flap survival, as judged from the digital colour photographs 7 days post-operatively, was 69 ± 3%. Objective analysis of flap survival based on intraoperative DIRT and ICG-FA (74 vs 63%, respectively) correlated quite well with the subjective measurements (75 ± 2 vs 59 ± 4%, respectively). However, intraoperative ICG-FA images underestimated flap survival by 6–10%, while intraoperative DIRT images overestimated the flap survival by 5–6%. The authors conclude that intraoperative use of ICG-FA and DIRT can provide valuable information on areas with inadequate perfusion as long as their limitations are respected.

Effect of Celecoxib on Fasciocutaneous Flap Survival and Revascularization

To study the effect of celecoxib (Celebrex; Pfizer, Cambridge, Mass) on (1) primary ischemic time and (2) revascularization of fasciocutaneous free flaps in a rat model. In the ischemia study, 50 male Sprague-Dawley rats were divided into 2 groups of 25 rats each, a control group and a celecoxib group. Five rats in each treatment group were exposed to ischemic times of 4, 6, 8, 10, and 12 hours. Survival of the flap was assessed 7 days after reversal of the ischemia. Probit curves and the critical ischemic time were calculated. In the revascularization study, 30 male Sprague-Dawley rats were divided into 2 groups of 15 rats each. One group was fed celecoxib, while the other was fed a normal diet. All rats had a 3 x 6-cm fasciocutaneous flap based on the inferior epigastric artery elevated and exposed to 2 hours of primary ischemia. The flap was then sutured back into the wound bed. Each of these groups was then divided into 3 groups of 5 rats whose pedicles were divided on postoperative day 5, 6, or 7. Percentage survival of the flap was measured 7 days later. In both parts of the study, the experimental group was fed celecoxib, 1500 ppm, throughout the interoperative period. In each animal, a 3 x 6-cm ventral fasciocutaneous groin flap based on the left superficial epigastric artery was elevated. In the ischemia study, respective flap survival rates from the control and celecoxib groups at the various ischemic times were as follows: 4 hours, 100% and 100%; 6 hours, 80% and 100%; 8 hours, 80% and 80%; 10 hours, 60% and 60%; and 12 hours, 20% and 10%. The median lethal ischemic times were 9.7 and 9.6 hours, respectively. There was no statistical difference in flap survival between the celecoxib and control groups. In the revascularization study, ligation of the flap pedicle on day 5, 6, or 7 did not result in any difference in the percentage of flap survival among the 3 groups. Celecoxib appears to have no deleterious effect on free tissue transfer survival or healing, as evidenced by revascularization in a fasciocutaneous free flap model.

Hemoglobin-Based Oxygen Carrier Does Not Improve Survival of Ischemic Rat Island Groin Flaps

Reducing reperfusion injury to skin flaps is an effective means to improve the survival of the flap. By enhancing oxygen delivery to the microcirculation within the flap, ischemia–reperfusion injury should be decreased, improving the flap's survival. This study evaluated the effects of a hemoglobin-based oxygen carrier (Oxyglobin) on the development of necrosis and survival of ischemic rat island groin flaps. Sprague-Dawley rats were randomly assigned to one of three treatment groups. A groin flap was elevated on each rat and subjected to 9 h of ischemia. Rats in group I were given an intravenous infusion of 0.9% saline prior to elevation of the skin flap. Rats in group II were given an intravenous infusion of Oxyglobin prior to elevation of the skin flap. Rats in group III were given a low-dose intravenous infusion of Oxyglobin following the 9 h of ischemia, just prior to reperfusion. The flaps were monitored for 7 days postoperatively for necrosis. The percentage of flap necrosis was recorded at the end of 7 days. All rats were euthanized at the completion of the study and the flaps were harvested for histopathological analysis. No significant difference was noted in the survival of the flaps or the degree of necrosis in the rats treated with Oxyglobin compared to the control group. Thus, pre-reperfusion treatment with Oxyglobin did not improve the percentage of flap survival, or the degree of severity of necrosis in rat groin flaps subjected to 9 h of ischemia.

Pharmacologic enhancement of rat skin flap survival with topical oleic acid.

This study was instituted to investigate in a rat model the effect of topical coadministration of the penetration enhancer oleic acid (10% by volume) and RIMSO-50 (medical grade dimethyl sulfoxide, 50% by volume) on rat skin flap survival. A rectangular abdominal skin flap (2.5 x 3 cm) was surgically elevated over the left abdomen in 40 nude rats. The vein of the flap's neurovascular pedicle was occluded by placement of a microvascular clip, and the flap was resutured with 4-0 Prolene to its adjacent skin. At the end of 8 hours, the distal edge of the flap was reincised to gain access to the clips and the clips were removed. After resuturing of the flap's distal edge to its adjacent skin, the 40 flaps were randomly divided into four groups. Group 1 (control) flaps were treated with 5 g of saline, group 2 (dimethyl sulfoxide) flaps were treated with 2.7 g of dimethyl sulfoxide (50% by volume), group 3 flaps (oleic acid) were topically treated with 0.45 g of oleic acid (10% by volume), and group 4 (dimethyl sulfoxide plus oleic acid) flaps were treated with a mixture of 0.45 g of oleic acid (10% by volume) and 2.7 g of dimethyl sulfoxide (50% by volume) diluted in saline. Each flap was topically treated with 5 ml of drug-soaked gauze for 1 hour immediately after clip removal to attenuate reperfusion injury. Thereafter, drug was applied topically once daily for 4 more days. Digital photographs of each flap were then taken on day 6 and the flaps were then harvested. The percentage of skin survival in each flap was determined by computerized morphometry and planimetry. The mean surviving area of group 3 (oleic acid-treated flaps) was 23.60 +/- 4.19 percent and was statistically higher than that in group 1 (control, saline-treated flaps) at 7.20 +/- 2.56 percent. The mean surviving area of group 2 (dimethyl sulfoxide-treated flaps) at 18.00 +/- 5.23 percent and group 4 (oleic acid- and dimethyl sulfoxide-treated flaps) at 9.90 +/- 3.44 percent did not achieve statistically higher mean surviving areas than controls. A topical solution of oleic acid (10% by volume) caused a statistically significant increase in the survival of rat abdominal skin flaps relative to controls. Dimethyl sulfoxide and the two experimental drugs together did not increase the percentage of flap survival when given as a single 5-ml dose released from a surgical sponge at reperfusion for 1 hour and then daily for a total of 5 days. The reasons for the lack of response are unknown but may have included the technical difficulty of delivering an adequate dose of dimethyl sulfoxide topically and immiscibility between dimethyl sulfoxide and oleic acid. Further studies may be warranted.

Increased tissue survival in experimental skin flaps in mast cell-deficient rats.

The role of mast cells and their principal mediator, histamine, in surgical skin flap survival was investigated using mast cell-deficient (Ws/Ws); their congenic littermates wild-type (+/+), and Wistar rats. A standardized dorsal skin flap was raised and sutured back into position, and 6 days later the percentage of flap survival was assessed. Moreover, endogenous histamine concentration in the dorsal skin during the surgical preparation was determined using in vivo microdialysis technique together with high performance liquid chromatography-fluorometry. Accumulation of skin flap myeloperoxidase (MPO) (reflecting leucocyte recruitment) was determined spectrophotometrically. The experimental skin flaps in genetically mast cell-deficient rats exhibited increased tissue survival and showed little accumulation of MPO and rather low and stable level of histamine output in comparison with skin flaps in the wild-type (+/+) littermates or normal Wistar rats. Antihistamine treatment inhibited but did not prevent leucocyte recruitment in the skin flaps post-surgery in +/+ and Wistar rats. It is suggested that mast cell derived histamine plays an important role in leucocyte recruitment in skin flaps. However, mast cell-independent factors should be taken into consideration and needs further investigation as even in mast cell-deficient animals there was some accumulation of leucocytes and tissue necrosis in the skin flaps post-surgery.

Effect of photodynamic therapy on revascularization of fasciocutaneous flaps.

Photodynamic therapy (PDT) may be used as an adjuvant intraoperative treatment to improve locoregional control. PDT has been shown both to delay wound healing and to have a deleterious effect on flap survival after a primary ischemic insult. This delay in wound healing may make the flap dependent on its pedicled blood supply for a prolonged period. Long-term flap loss may be experienced. The effect of PDT on flap revascularization, with subsequent dependence on its vascular pedicle, is evaluated. Randomized controlled trial using a rodent model. A rat fasciocutaneous flap was used. Study groups were as follows: group I received no treatment; group II received treatment with 630-nm light; groups IH and IV were given Photofrin (in group III, loupes without a fiberoptic light source were used for flap elevation, and in group IV, light source was employed); and group V was given Photofrin and 630-nm light. Primary ischemic times of 2 or 4 hours were used. Vascular pedicles were ligated on postoperative day (POD) 5, 6, or 7, and percentage of flap survival was evaluated 7 days later. With 2 hours of ischemia, revascularization was decreased in the PDT group on POD 6 (P < .05) and on day 7 (P < .005) when compared with the other groups. With 4 hours of ischemia, revascularization was decreased in the PDT group on PODs 5 (P < .001), 6 (P < .01), and 7 (P < .005). Intraoperative PDT decreases revascularization of a rat fasciocutaneous flap.

Postischemic flap washout with hydroxyethyl starch (HAES) and its beneficial effect on the no-reflow phenomenon in rat skin island flaps

This study investigated the possible effect of hydroxyethyl starch (HAES) as a postischemic perfusion washout on survival of skin flaps. Forty-eight, male, Sprague-Dawley rats were used in this experiment. A 4×6 cm unilateral island skin flap based on the superficial inferior epigastric artery and vein was raised. The femoral neurovascular bundle supplying the flap pedicle was also dissected free. The flaps were divided into four groups, each consisting of 12 rats. Group 1 (Nonishemic control); Group 2 (Control) – no perfusion washout; Group 3 (Saline) – postischemic washout with normal saline solution; Group 4 (HAES) – postischemic washout with hydroxyethyl starch 10% (HAES) solution. The flaps were subjected to 11 hours of warm ischemia. Thirty minutes prior to the completion of the ischemic period, the flaps were perfused with normal saline solution in group 3 and with HAES in group 4. The percentage of flap survival was assessed on postoperative day 7. Statistical analysis was performed using the Student’s t-test. Flap survival rates for Group 4 (HAES) were significantly greater than Group 2 (Control nonperfusion washout) and Group 3 (saline solution) (p<0.001). This is the first study to investigate the effect of HAES on skin flap survival based on the results, HAES solution may be useful in clinical practice.

Effects of environmental stress on tissue survival and neutrophil recruitment in surgical skin flaps in relation to plasma corticosterone levels in the rat.

Because glucocorticoid treatment can improve the survival of surgical skin flaps, we examined the influence of environmental stress on skin flap survival in the rat. Female Sprague-Dawley rats. Dexamethasone (1 mg/kg i.p.). A standardized dorsal skin flap was raised and sutured back into position, and six days latter the percentage of flap survival was assessed. Corticosterone in rat plasma was measured using radioimmuno assay, and skin flap myeloperoxidase accumulation (reflecting neutrophil recruitment) was determined spectrophotometrically. Skin flap survival decreased gradually during a 10 day acclimatization period after transportation of the animals from the supplier, and plasma corticosterone levels were increased during the first 5 days of acclimatization compared to day 7 and 10. Dexamethasone treatment of rats accustomed to their new environment for 10 days increased flap survival to a level close to that observed in animals operated at day 1 after arrival. Flap surgery induced pronounced neutrophil recruitment into flap tissue, and this cell accumulation was greatly reduced in both the dexamethasone treated rats and in rats with elevated corticosterone levels. Skin flap survival in rats exposed to environmental stress may be significantly increased as compared to animals accustomed to their new environment for one week, possibly as a consequence of anti-inflammatory actions exerted by stress-induced elevations in plasma corticosterone. These findings emphasize the importance of strictly controlling environmental stress factors in studies of inflammation and tissue damage after surgical skin trauma.

Evaluation of a continuous systemic infusion of iloprost, a stable PGI-2 analog, on the survival of experimental skin flaps.

Numerous investigators have attempted to enhance the survival of ischemic experimental skin flaps using various pharmacologic manipulations. Recently, the authors' laboratory demonstrated the beneficial effect of iloprost, a stable PGI2 analogue, as a post-ischemic perfusion washout, in improving the survival of ischemic skin flaps. The rat unilateral abdominal skin flap, based on the superficial epigastric vessels, was utilized in this study involving 30 animals. The animals were divided into three different treatment groups, with ischemic periods of 16 and 18 hr. Perfusion washouts were performed at the completion of the various ischemic periods. Alzet osmotic pumps were used to deliver a continuous systemic infusion of iloprost for 7 days postoperatively. The groups consisted of the following: Group 1 (single ILO)--perfusion washout with iloprost only; Group 2 (continuous LD ILO)--low-dose systemic iloprost infusion (0.066 mcg/kg/min) and perfusion washout with iloprost; and Group 3 (continuous HD ILO)--high-dose systemic iloprost infusion (0.1 mcg/kg/min) and perfusion washout with iloprost. The percentage of flap survival was assessed on postoperative day 7. Skin flaps of the animals receiving the continuous systemic infusion of iloprost were noted to have varying percentages of survival, while skin flaps undergoing perfusion washout only were found to have either complete survival using a continuous systemic infusion of iloprost, compared to iloprost perfusion washout alone. In addition, the hypotensive side effects of systemic iloprost infusion limit its use in the rat skin-flap model.