Prevention of unfavourable effects of cigarette smoke on flap viability using botulinum toxin in random pattern flaps: An experimental study

BACKGROUND:

There are numerous clinical and experimental studies reporting unfavourable effects of cigarette smoke on skin flaps.

OBJECTIVE:

To investigate whether unfavourable effects of cigarette smoke on flap survival could be reduced by botulinum toxin type A.

METHODS:

Twenty-eight male Wistar albino rats (15 months of age, mean weight 210 g [range 180 g to 230 g]) were included. They were divided into four groups of seven animals each. The control group underwent the surgical procedure alone. Surgical procedure was performed after administration of botulinum toxin type A in the botulinum toxin (BTX) group, after exposure to cigarette smoke in the cigarette smoke (CS) group, and after BTX type A administration and exposure to CS in the CS+BTX (CS+BTX) group. Random pattern cutaneous flaps (3 cm × 9 cm) were elevated from the dorsum of all rats. Necrosis area was calculated in percentages (%) using Image J computer software. Tissue samples were examined histopathologically.

RESULTS:

The mean necrotic area in the control group (26%) and in the BTX group (21%) were similar (P=0.497), whereas administration of BTX type A significantly decreased flap necrosis area in the rats exposed to CS (the mean necrosis areas were 41.5% in the CS group, and 26% in the CS+BTX group; P<0.001). Histopathological examination findings corroborated the unfavourable effects of CS and preventive effects of BTX type A.

CONCLUSION:

Preoperative administration of BTX significantly enhanced flap viability in the rats exposed to CS. Further human studies are warranted to verify whether BTX type A could be used as an agent to reduce the risk of flap necrosis in patients who smoke.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

Delayed prefabricated arterial composite venous flaps: an experimental study in rabbits

Prefabrication of composite arteriovenous flaps with implantation of an autologous graft (cartilage) or an alloplastic material (porous polyethylene) was studied in 40 rabbits. Abdominal flaps based on bilateral epigastric pedicles were elevated. An ear cartilage graft or a porous polyethylene implant was inserted under the flap. Two weeks after the operation, 10 flaps with cartilage graft and 10 flaps with porous polyethylene were raised, converted to arteriovenous flaps, and resutured in place in the experimental groups. In the other 20 rabbits of the control groups, the flaps (10 with cartilage graft and 10 with porous polyethylene) were raised and resutured in place as conventional axial flaps. At the end of the second and fourth week postoperatively, samples were obtained from the flap tissues (including a part of the graft or implantation material) and were prepared for histologic examination in all rabbits. The viable areas of all flaps were assessed at the end of fourth week after the second operation. The mean survival rates were 99.4%, 99.7%, 99.5%, and 99.8% in the arteriovenous and control flaps prefabricated with cartilage graft and the arteriovenous and control flaps prefabricated with porous polyethylene respectively. The features of wound healing in the experimental and control groups were similar. The study showed that arteriovenous perfusion can nourish a prefabricated flap containing an implanted material (autologous or alloplastic) and these 2-week delayed composite flaps have a similar survival rate to delayed prefabricated conventional axial flaps.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

目的 通过兔股动脉、静脉预构轴型扩张皮瓣的微循环血流晕动态变化、光镜下结构的改变及其成活面积,为预构轴型扩张皮瓣的临床应用提供依据.方法 选择新西兰白兔40只,随机分为4组:预构轴型扩张皮瓣组、预构轴型不扩张皮瓣组、单纯预构轴型皮瓣组及无蒂游离皮瓣组,每组4只,前2组股动脉、静脉移位后,预构轴型扩张皮瓣组、预构轴型不扩张皮瓣组分别在肉膜深面置入容量为50 ml长方形皮肤软组织扩张器,预构轴型扩张皮瓣组7 d后开始注水;无蒂游离皮瓣组为对照组,未采取预构及扩张处理.定期对4组皮肤进行微循环血流量检测,并取样进行光镜观察.预构术后52 d,前3组形成以预构股动静脉血管束为蒂的岛状皮瓣,游离皮瓣组则形成无蒂游离皮瓣后均原位缝合,观察其成活面积.结果 预构轴型扩张皮瓣组较其他组微循环血流量增加,成活面积大[(97.54±2.73)%],光镜下改变显著(P<0.05).结论 扩张术能促进预构轴型皮瓣的血管化进程,明显增大预构轴型皮瓣成活面积,增加其移植的安全性.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

兔股动脉和静脉预构轴型扩张皮瓣的实验观察

Objective To study the microcirculation and structural changes, surviving area of expanded prefabricated flaps. Methods A total of 40 New Zealand rabbits were divided randomly into expanded prefabricated, expender lined, simple prefabricated and free flap groups, each consisting of 10 rabbits. For the expanded prefabricated, expender lined and simple prefabricated groups, after the femoral artery and vein were transplanted into subcutaneous tissues of abdomen, and expanders were implanted into the deeper dartos. The free flap group was a blank control group. For the expanded prefabricated group, the expansion was carried out on 7th day postoperatively. On postoperative day 52, when the expander was fully expanded, island flaps with the prefabricated vessels as the pedicles were formed. The flaps were measured by laser Doppler flowmetry, light microscopy and digital re-cording of survival arca. Results When compared with the other groups, the perfusion volume of mi-crocirculation enhanced, flaps survival improved (97.54±2.73) %, blood capillary were stronger, to-gether with microscopic changes were significant in the expanded prefabricated groups (P<0.05). Conclusion Expandedprefabricated flaps can increase the survival size of the flaps and the safety of flap transplantation.     

Viability and versatility of arterialized venous perfusion flaps and prefabricated flaps: an experimental study in rabbits.

The purpose of this study was to investigate the viability of two types of unconventional flaps: 1) the arterialized venous perfusion (AVP) flap; and 2) the prefabricated flap. Four experimental groups were studied: an AVP flap group with assessment of the viability of single and paired flaps nourished by the same vascular pedicle; a prefabricated flap group with the abdominal flap pedicled on the epigastric artery and vein; a prefabricated flap group in which the flap was supplied by an arterialized vein graft (A-V shunt), and paired flaps of different designs, but based on the same vascular pedicle, were investigated; and a free composite graft group. Survival of the skin flaps exceeded 92 percent in each group, except in the free composite group which showed complete necrosis. Results of the study validated that flap viability was independent of flap size (large or small), type (AVP flap or prefabricated flap), and the number of flaps on each vascular pedicle (single or paired).     

An experimental study of prefabricated flaps using silicone sheets, with reference to the vascular patternization process.

A study of the vascularization process in prefabricated flaps, using silicone sheets, has been undertaken in rat models. It was found that the survival rate of flaps was most stable from 2 to 3 weeks after insertion of the silicone sheet, and that this rate decreased when the silicone sheet remained in place beyond that period. The results are probably due to the decrease of delayed effect. Changes that occurred in the circulation and component blood vessels within the flap over time were studied by microangiography, and were categorized at the following four stages: at less than 1 week from the initial surgery, from 1 week but less than 2 weeks, from 2 weeks but less than 4 weeks, and 4 weeks or more. The component vessels consisted of three types, that is, transferred vessels, original vessels, and newly formed vessels, with the last type further divided into three subtypes, to clarify the timing of the vascular proliferation and dilatation for each of the component vessels.     

Preserving osseous viability in osteocutaneous flap prefabrication: experimental study in rabbits

This study presents a technique that preserves osseous viability in prefabricated osteocutaneous flaps with a soft-tissue vascular carrier, with a pedicled skin flap acting as the vascular carrier to neovascularize a partially devascularized bone segment before its transfer. Using a total of 50 New Zealand White rabbits, two groups were randomized as experimental and control animals. In the experimental group (n = 30), a bipedicled dorsal scapular skin flap was anchored with sutures to the scapular bone, by bringing it into contact with the exposed dorsal surface of the bone after stripping the dorsal muscular attachments. Following 4 weeks of neovascularization, the prefabricated composite flaps were harvested, based on the caudally-based dorsal skin flap, after stripping the ventral muscular attachments of the bone. In the control group (n = 20), non-vascularized scapular bone grafts were implanted under bipedicled dorsal scapular skin flaps with sutures. After 4 weeks, prefabricated composite flaps were harvested, based on the caudally-based dorsal skin flap. In both groups, on day 7 after the second stage, the viability of the bony component of the flaps was evaluated by direct observation, scintigraphy, measurement of bone metabolic activity, microangiography, dye injection study, and histology. Results indicated that the bone segments in the experimental group demonstrated a greater survival than in the control group. The authors conclude that this technique of osteocutaneous flap prefabrication preserves the viability of the bony component with a soft-tissue vascular carrier, in contrast to the conventional method of pre-transfer grafting. The technique may be useful clinically in selected cases.     

Effects of ozone gas on skin flaps viability in rats: an experimental study

Background: The main purpose of this study was to assess the effects of ozone gas on the viability of flaps for reconstruction and to determine the optimum application method. The antioxidant, immunomodulatory, and reperfusion effects of ozone gas have been previously assessed, and successful results have been reported. However, only one study has investigated the effect of ozone gas on flap viability. In the present study, it was hypothesised that the antioxidant and reperfusion effects of ozone gas would enhance flap viability.

Methods: Forty female Wistar rats were randomly divided into four groups of 10 rats each. A cranial-based, 3?×?11?cm modified McFarlane flap including the panniculus carnosus was raised from the dorsum of a rat and re-sutured to its own bed using 3/0 sharp propylene. Group 1 (n?=?10): no pharmacological agent was used after the operation. Group 2 (n?=?10): vegetable (olive) oil group; vegetable-oil-impregnated gauze was used as a dressing for 7 days. Group 3 (n?=?10): Vegetable (olive) oil with ozone peroxide group; vegetable oil with ozone peroxide-impregnated gauze was used as a dressing for 7 days. Group 4 (n?=?10): Hemo-ozone therapy group; hemo-ozone therapy was applied rectally once every day for 7 days. All rats were sacrificed at the end of week 1 and assessed macroscopically and histopathologically.

Results: The proportion of substantive necrosis was less in group 4 than in the other three groups. Survival area ratios were better in groups 2 and 3 than in group 1; however, there was no significant difference between groups 2 and 3. No significant differences in the histopathological scores were observed among the groups.

Conclusion: Ozone gas enhanced flap viability. No differences in flap viability were observed between the vegetable oil and vegetable oil with ozone peroxide groups. The greatest benefit ratios were found in the hemo-ozone therapy group.     

预构皮瓣的研究进展

皮瓣移植是组织缺损修复与再造的主要手段。在过去几十年中，显微外科技术的广泛应用和应用解剖学的兴起，导致了轴型皮瓣的问世。轴型皮瓣概念的形成，突破了随意型皮瓣必须按长宽比例进行设计的经验模式，形成了以解剖学和生理学原理为指导的“科学”模式。而预构皮瓣的出现，则进一步打破了解剖学的限制，在没有知名血管分布的区域也可形成有轴心血管滋养的皮瓣，根据预构皮瓣形成的原理，外科医师可以预先将适当的血管载体转移到所需组织的某一层次，“制造”出合意的可游离或岛状移植的轴型皮瓣，以满足组织畸形和缺损修复与再造的需要。     

The effect of twisting on single and double based perforator flap viability: An experimental study in rats

In this study, the histological and vital effects of rotation on multiple and single based perforator flaps were evaluated. A 6 cm × 6 cm abdominal perforator flap model was used on 80 male rats; half of these received a single‐pedicled flap, and the other half double‐pedicled. The flaps of control subgroups were raised and sutured without rotation. In rotation subgroups 90‐, 180‐, 270‐degree rotations were performed, and rotation effects on flap viability and histological changes were analyzed. Among single‐ and double‐pedicled perforator flaps, respectively, mean survival area was 12.59 cm² and 27.84 cm² in non‐rotated subgroups, 12.49 cm² and 17.06 cm² in 90‐degree rotation subgroups, 5.96 cm² and 9.96 cm² in 180‐degree rotation subgroups, and 1.45 cm² and 1.70 cm² in 270‐degree rotation subgroups. While survival areas of double‐ and single‐pedicled perforator flaps with the same rotation degree showed no statistically significant difference, non‐rotated double‐pedicled perforator flaps had a statistically larger survival area compared to single‐pedicled perforator flap (P = 0.001). In the single‐pedicled flap group, there were no statistical differences between survival flap areas of the non‐rotated subgroup and the 90‐ and 180‐degree rotation subgroups (P > 0.05), but the non‐rotated subgroup had a statistically larger survival area compared to the 270‐degree rotation subgroup (P = 0.003). In double‐pedicled perforator flap group, the control subgroup had a statistically larger flap survival area compared to 90‐degree, 180‐degree, and 270‐degree rotation subgroups (P = 0.004, P = 0.002, P = 0.001). Degenerative histological changes gradually increased in correlation with the rotation angle in both single‐ and double‐pedicled groups. When double‐ and single‐pedicled groups were compared; degenerative histology score displayed no statistical difference between control subgroups and rotated subgroups (P > 0.05). In this rat abdominal propeller perforator flap model, we found that double perforators without pedicle rotation could support larger flap survival when compared to the single pedicle. However, double perforators did not cause an increase of survival area when pedicles were rotated. In the single‐pedicled perforator flap, the flap survival area did not significantly decrease until 180‐degree pedicle rotation. In the double‐pedicled perforator flap, the flap survival area decreased when the degree of rotation increased. The degenerative changes increased in correlation with the rotation degree in both single‐ and double‐pedicled perforator flaps. © 2014 Wiley Periodicals, Inc. Microsurgery 34:464–469, 2014.