Diagnostic criteria for Buerger's disease: International Consensus of VAS - European Independent Foundation in Angiology/Vascular Medicine.

Buerger's disease (BD) remains a debilitating condition and early diagnosis is paramount for its effective management. Despite many published diagnostic criteria for BD, selective criteria have been utilized in different vascular centers to manage patients with BD worldwide. A recent international Delphi Consensus Study on the diagnostic criteria of BD showed that none of these published diagnostic criteria have been universally accepted as a gold standard. Apart from the presence of smoking, these published diagnostic criteria have distinct differences between them, rendering the direct comparison of patient outcomes difficult. Hence, the expert committees from the Working Group of the VAS-European Independent Foundation in Angiology/Vascular Medicine critically reviewed the findings from the Delphi study and provided practical recommendations on the diagnostic criteria for BD, facilitating its universal use. We recommend that the 'definitive' diagnosis of BD must require the presence of three features (history of smoking, typical angiographic features and typical histopathological features) and the use of a combination of major and minor criteria for the 'suspected' diagnosis of BD. The major criterion is the history of active tobacco smoking. The five minor criteria are disease onset at age less than 45 years, ischemic involvement of the lower limbs, ischemic involvement of one or both of the upper limbs, thrombophlebitis migrans and red-blue shade of purple discoloration on edematous toes or fingers. We recommend that a 'suspected' diagnosis of BD is confirmed in the presence of a major criterion plus four or more minor criteria. In the absence of the major criterion or in cases of fewer than four minor criteria, imaging and laboratory data could facilitate the diagnosis. Validation studies on the use of these major and minor criteria are underway.

Experimental swine models for perforator flap dissection in reconstructive microsurgery.

BACKGROUND: Perforator flaps account for a fraction of reconstructive procedures despite their growing popularity. Specific microsurgical skills are required for successful harvesting of perforator flaps, which are difficult to attain through direct operating room training. Cadaver and small animal dissection cannot simulate human perforator dissection, lacking either bleeding and vessel feedback or providing too small calibers. Thus, we have developed and refined over the last ten years five perforator flaps models in living pig, described their harvesting technique and provided evidence for their effectiveness as perforator flap training models. METHOD: CT angiography data from ten living pigs was used for detailed examination of the integument's vascular anatomy. Microsurgical techniques were used to standardize and harvest the perforator flaps in acute models. The same operator-assistant team, with no prior perforator flap harvesting experience, raised all flaps in a sequential manner, one animal per day, during a 7 weeks timespan. Porcine flaps were compared to human counterparts in terms of vessel caliber, dissection times. Immediate flap survival was measured as duration of perforator pulsation after completion of flap harvesting, measured every 10 minutes for up to two hours. RESULTS: Five perforator flaps were standardized, based on the deep cranial epigastric, thoracodorsal, lateral intercostal, cranial gluteal and dorsal cervical arteries and the operative technique was described in detail. Mean pig perforator size was 1.24±0.36 mm and mean pedicle diameter was 2.78±0.8 mm, which matched closely the human calibers for each flap. Total harvesting time increased 22.4% between the first two experiments due to a more cautious approach following the lack of perforator pulsation in all flaps in the first experimental animal. A total decrease of 44.4% harvesting time between second and last experiment was observed, as expected with all repetitive surgical procedures. Post-operative perforator pulsation time revealed a steep learning curve, with no or short-term pulsatile perforators in the first five pigs, followed by a 275% increase in total perforator pulsation time between 5th and 6th experimental animal. Based on these findings we provide a description of the most common mistakes, their consequences and gestures which can be trained using the pig perforator flaps, in order to overcome these mistakes. CONCLUSION: These five pig perforator flap models provide a fast and efficient learning tool to develop perforator flap harvesting skills safely. Surgical training using these five experimental models offers a similar hands-on perforator flap dissection experience as with human tissue, based on the similar sized calibers of both perforators and pedicles with their human counterparts.

An International Delphi Consensus on Diagnostic Criteria for Buerger's Disease.

BACKGROUND: Buerger's disease (BD) remains a debilitating condition. Despite multiple published diagnostic criteria for BD, none is universally accepted as a gold standard. METHODS: We conducted a 2-round modified Delphi consensus study to establish a consensus on the diagnostic. The questionnaire included statements from several commonly used diagnostic criteria for BD. Qualitative and quantitative analysis methods were performed. An agreement level of 70% was applied. RESULTS: Twenty nine experts from 18 countries participated in this study. Overall, 75 statements were circulated in Round 1. Of these, 28% of statements were accepted. Following comments, 21 statements were recirculated in Round 2 and 90% were accepted. Although more than 90% of the experts did not agree that the diagnosis of BD can be based only on clinical manifestation, none of the nonclinical manifestations of BD were agreed as a part of the diagnostic criteria. There was an agreement that a history of tobacco consumption in any form, not necessarily confined to the current use, should be a part of the diagnostic criteria of BD. The history of thrombophlebitis migrans, even if not present at presentation, was accepted as a clue for BD diagnosis. It was also agreed that discoloration of the toes or fingers could be included in the diagnostic criteria of BD. Experts agreed that histology results could differentiate BD from atherosclerosis obliterans and other types of vasculitis. The presence of corkscrew collaterals on imaging and burning pain reached the agreement at the first round but not at the second. There was no consensus regarding age cut-off, the requirement of normal lipid profile, and normal blood glucose for BD diagnosis. CONCLUSIONS: The present study demonstrated discrepancies in the various published diagnostic criteria for BD and their selective utilization in routine clinical practice worldwide. We propose that all published diagnostic criteria for BD be re-evaluated for harmonization and universal use.

Dataset of the vascular e-Learning during the COVID-19 pandemic (EL-COVID) survey.

This dataset supports the findings of the vascular e-Learning during the COVID-19 pandemic survey (the EL-COVID survey). The General Data Protection Regulation (GDPR) of the European Union was taken into consideration in all steps of data handling. The survey was approved by the institutional ethics committee of the Primary Investigator and an online English survey consisting of 18 questions was developed ad-hoc. A bilingual English-Mandarin version of the questionnaire was developed according to the instructions of the Chinese Medical Association in order to be used in mainland People's Republic of China. Differences between the two questionnaires were minor and did affect the process of data collection. Both questionnaires were hosted online. The EL-COVID survey was advertised through major social media. All national and regional contributors contacted their respective colleagues through direct messaging on social media or by email. Eight national societies or groups supported the dissemination of the EL-COVID survey. The data provided demographics information of the EL-COVID participants and an insight on the level of difficulty in accessing or citing previously attended online activities and whether participants were keen on citing these activities in their Curricula Vitae. A categorization of additional comments made by the participants are also based on the data. The survey responses were filtered, anonymized and submitted to descriptive analysis of percentage.

Vascular e-Learning During the COVID-19 Pandemic: The EL-COVID Survey.

BACKGROUND: The corona virus disease (COVID-19) pandemic has radically changed the possibilities for vascular surgeons and trainees to exchange knowledge and experience. The aim of the present survey is to inventorize the e-learning needs of vascular surgeons and trainees as well as the strengths and weaknesses of vascular e-Learning. METHODS: An online survey consisting of 18 questions was created in English, with a separate bilingual English-Mandarin version. The survey was dispersed to vascular surgeons and trainees worldwide through social media and via direct messaging from June 15, 2020 to October 15, 2020. RESULTS: Eight hundred and fifty-six records from 84 different countries could be included. Most participants attended several online activities (>4: n = 461, 54%; 2-4: n = 300, 35%; 1: n = 95, 11%) and evaluated online activities as positive or very positive (84.7%). In deciding upon participation, the topic of the activity was most important (n = 440, 51.4%), followed by the reputation of the presenter or the panel (n = 178, 20.8%), but not necessarily receiving accreditation or certification (n = 52, 6.1%). The survey identified several shortcomings in vascular e-Learning during the pandemic: limited possibility to attend due to lack of time and increased workload (n = 432, 50.5%), no protected/allocated time (n = 488, 57%) and no accreditation or certification, while technical shortcomings were only a minor problem (n = 25, 2.9%). CONCLUSIONS: During the COVID-19 pandemic vascular e-Learning has been used frequently and was appreciated by vascular professionals from around the globe. The survey identified strengths and weaknesses in current e-Learning that can be used to further improve online learning in vascular surgery.

A sequence of flaps and dissection exercises in the living model to improve the learning curve for perforator flap surgery.

INTRODUCTION: The training to learn how to perform perforator flaps requires practice on a living model to optimize dissection and to evaluate outcome. The purpose of this study was to describe a training model that optimizes the use of animals in order to perform the maximum number of exercises per animal. MATERIAL AND METHODS: The sequence has been planned and practiced by the first and last author, recorded perfected and implemented in a two-day surgical course. The sequence was then evaluated by the trainers and the trainees by means of a questionnaire. RESULTS: All students were able to complete the sequence of exercises before the end of the second day except two (8/10) who could not complete one exercise each. The students considered the Deep Superior Epigastric Artery Perforator flap the most difficult to perform, being the most technically demanding. The sequence of exercises was judged either easily reproducible or reproducible by all the students. Two students suggested to postpone the DSEAP flap to the second day, after some training, to optimize the experience with the most challenging and rewarding flap. CONCLUSIONS: The training sequence proposed offers a wide range of exercises and allows four trainees, divided in two teams, to work and learn on the same animal. They can perform a wide range of flaps and also harvest the internal mammary vessels. The living model allows for evaluation of the quality of the surgical performance, judged by the difficulties and complications encountered during dissection, and finally through the feedback of flap perfusion.

Predictors of Clinical Outcome after Reconstruction of Complex Soft Tissue Defects Involving the Achilles Tendon with the Composite Anterolateral Thigh Flap with Vascularized Fascia Lata.

BACKGROUND: The composite anterolateral thigh flap with vascularized fascia lata (ALT-FL flap) for covering complex soft tissue defects involving the Achilles tendon has shown promising results. The age and body mass index (BMI) are important predictors of clinical outcome after surgical treatment of Achilles tendon ruptures. In this study, we investigate whether these also influence the outcome of patients after Achilles tendon reconstruction using the ALT-FL flap. METHODS: Twenty patients (mean age: 55.9 ± 8.7 years) with complex tissue defects involving the Achilles tendon underwent reconstruction with the ALT-FL flap. Both the Achilles tendon Total Rupture Score (ATRS) and the American Orthopaedic Foot and Ankle Society (AOFAS) score were assessed preoperatively and 12 months postoperatively. In addition, postoperative magnetic resonance imaging (MRI) studies and measurements of the ankle range of motion were performed and results compared with existing literature. RESULTS: All flaps survived and MRI studies confirmed complete anatomical integration of the fascia lata as "neotendon" at the recipient site. In our patient cohort, the age did not correlate with the outcome measurements, whereas the BMI showed significant negative correlation with the postoperative ATRS (p < 0.001) and AOFAS scores (p < 0.05). The ATRS and AOFAS scores of all patients improved significantly (p < 0.001). However, obese patients with a BMI of more than 30 kg/m2 achieved significant lower ATRS (p < 0.001) and AOFAS scores (p < 0.01), as well as patients with peripheral artery disease (PAD) (p < 0.05). The mean ankle range of motion after ALT-FL flap reconstruction remained statistical insignificant compared with previous avascular or vascularized tendon repairs of the Achilles tendon. CONCLUSION: The ALT-FL flap enables reconstruction of complex tissue defects involving the Achilles tendon with good functional results. However, the presence of an increased BMI or PAD, but not necessarily the age, proves to be a predictor of poor clinical outcome and therefore should be subject to scrutiny during patient selection.

Surgical treatment in a case of giant macrodystrophia lipomatosa of the forefoot.

Macrodystrophia lipomatosa is a rare, congenital, non-hereditary disease, characterized by local gigantism of the fingers or toes. We report the case of a 37-month-old boy, with no prior past medical history, who presented with a gigantic dystrophy of the left forefoot. The location of the deformity was involving the plantar and dorsal aspect of the foot, and digits 1 to 4. After clinical examination, imaging study assessment, and differential diagnosis considerations, it was established that macrodystrophia lipomatosa was the cause of the deformity. A reconstructive surgical intervention was planned. The hypertrophied tissues were excised, resulting in a reduction in the forefoot's volume. The patient had a favorable postoperative course and ambulation was allowed with a custom-made shoe. The case represents a rare pathological entity with complex diagnostic and therapeutic considerations. As far as treatment options, the surgeon must decide between a reconstructive surgical intervention and amputation.

A sequential assessment of the preservation injury in porcine intestines.

BACKGROUND: Clinical and experimental evidence strongly suggest that ischemia-reperfusion injury after intestinal transplantation has deleterious short- and long-term effects and finding means to reduce ischemia-reperfusion injury is a major research area. The anatomical and physiological similarities between the human and porcine digestive tract favor its use as a preclinical model for translational research. Intriguingly, no systematic appraisal of the development of the intestinal preservation injury in pigs is available. MATERIALS AND METHODS: Intestinal procurement was performed in nine pigs using histidine-tryptophan-ketoglutarate solution as preservation fluid. Ileal biopsies were obtained after 8, 14, and 24 h of static cold storage (SCS), and the preservation injury was assessed morphologically (Chiu score) as well as on the molecular level. Tight junction (zonula occludens, claudin-3 and 4, tricellulin, and occludin) and adherens junctions (E-cadherin) proteins were studied using immunofluorescence and Western blot. RESULTS: Eight hours of SCS induced minimal mucosal changes (Chiu grade 1) that advanced to significant subepithelial edema (Chiu grade 3) after 24 h; progressive Goblet cell depletion was also noted. Apoptosis (studied by cleaved caspase-3 staining significantly increased after 24 h of SCS. Significant molecular changes with decreasing expression of zonula occludens, tricellulin, and occludin were evident already after 8 h of SCS and continuously worsened. Claudin-3 and Claudin-4 and E-cadherin expression remained relatively unaltered during SCS. CONCLUSIONS: Important molecular alterations precede histologic changes during SCS of the porcine intestine and may be used as more sensitive injury markers than histologic changes in intestinal ischemia and transplantation.

Defining Standards in Experimental Microsurgical Training: Recommendations of the European Society for Surgical Research (ESSR) and the International Society for Experimental Microsurgery (ISEM).

BACKGROUND: Expectations towards surgeons in modern surgical practice are extremely high with minimal complication rates and maximal patient safety as paramount objectives. Both of these aims are highly dependent on individual technical skills that require sustained, focused, and efficient training outside the clinical environment. At the same time, there is an increasing moral and ethical pressure to reduce the use of animals in research and training, which has fundamentally changed the practice of microsurgical training and research. Various animal models were introduced and widely used during the mid-20th century, the pioneering era of experimental microsurgery. Since then, high numbers of ex vivo training concepts and quality control measures have been proposed, all aiming to reduce the number of animals without compromising quality and outcome of training. SUMMARY: Numerous microsurgical training courses are available worldwide, but there is no general agreement concerning the standardization of microsurgical training. The major aim of this literature review and recommendation is to give an overview of various aspects of microsurgical training. We introduce here the findings of a previous survey-based analysis of microsurgical courses within our network. Basic principles behind microsurgical training (3Rs, good laboratory practice, 3Cs), considerations around various microsurgical training models, as well as several skill assessment tools are discussed. Recommendations are formulated following intense discussions within the European Society for Surgical Research (ESSR) and the International Society for Experimental Microsurgery (ISEM), based on scientific literature as well as on several decades of experience in the field of experimental (micro)surgery and preclinical research, represented by the contributing authors. Key Messages: Although ex vivo models are crucial for the replacement and reduction of live animal use, living animals are still indispensable at every level of training which aims at more than just a basic introduction to microsurgical techniques. Modern, competency-based microsurgical training is multi-level, implementing different objective assessment tools as outcome measures. A clear consensus on fundamental principles of microsurgical training and more active international collaboration for the sake of standardization are urgently needed.

Mastering Lymphatic Microsurgery: A New Training Model in Living Tissue.

BACKGROUND: Advanced microsurgical techniques have emerged as a promising approach for the treatment of lymphedema, but achieving international standards is limited by a scarcity of adequate training models. The purpose of this report is to describe our in vivo porcine training model for microsurgery. STUDY DESIGN: Five female common-breed pigs (Sus scrofa domesticus) weighing 20 to 28 kg were placed under general anesthesia, and blue patent violet dye was injected to highlight lymphatic structures and prepare the pigs for anatomical exploration and microsurgery. The number and type of patent anastomoses achieved and lymph node flaps created and any anatomical differences between porcine and human vessels were noted, in light of evaluating the use of pigs as a training model for microsurgery in living tissue. RESULTS: Multiple lymphatic-venous anastomoses were created at the site of a single incision made at the subinguinal region, running medial and parallel to the saphenous vessels. Ten multiple lymphatic-venous anastomoses were created in total, and all were demonstrated to be patent. Four lymph node flaps were prepared for lymph node transfer. The superficial lymphatic collector system in the caudal limb of the pig was identified and described with particular reference to the superficial, medial (dominant), and lateral branches along the saphenous vein and its accessory. CONCLUSIONS: The authors present a safe and adaptable in vivo experimental microsurgical porcine model that provides the opportunity to practice several advanced lymphatic microsurgical techniques in the same animal. The ideal lymph node transfer training model can be developed from this anatomical detail, giving the opportunity to use it for artery-to-artery anastomoses, vein-to-vein anastomoses, and lymphatic-to-lymphatic anastomoses.

Leg for life? The use of sartorius muscle flap for the treatment of an infected vascular reconstructions after VA-ECMO use. A case report.

INTRODUCTION: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO(1)) systems are a life-saving option in the treatment of acute respiratory distress syndrome (ARDS(2)), but may be encumbered by severe vascular complications in the groin. PRESENTATION OF CASE: A pregnant woman was admitted with respiratory failure due to H1N1 influenza. VA-ECMO was inserted percutaneously by the intensivists and then accidentally removed by the patient after 8 days. 24h later VA-ECMO was reinstalled with surgical denudation of femoral vessels in another department. 2h later, due to active bleeding and signs of limb ischemia, the patient was referred to our department and emergency trombectomy and patch angioplasty with PTFE were performed. Evolution was further bad with wound infection (Pseudomonas, Proteus), which imposed large debridement, replacing the PTFE patch with 2 parallel venous patches and wound reconstruction through sartorius muscle rotation. The wound underwent negative pressure therapy for 10 days and was skin grafted. The patient recovered under systemic antibiotic and virostatic therapy. DISCUSSION: Major complications of using VA-ECMO devices are related to vascular access, most common bleeding at the puncture site and acute limb ischemia. In the groin, sartorius muscle flap is the most used for vascular coverage and small tissue defect reconstruction because of the ease in harvesting and low donor-site complications. CONCLUSION: Although ischemic complications associated with VA-ECMO are accepted by intensivists under the slogan "leg for life", for the repair of the femoral artery in the presence of groin infection the sartorius muscle remains an efficient solution for limb salvage.

Towards a global understanding and standardisation of education and training in microsurgery.

With an increasing emphasis on microsurgery skill acquisition through simulated training, the need has been identified for standardised training programmes in microsurgery. We have reviewed microsurgery training courses available across the six continents of the World. Data was collected of relevant published output from PubMed, MEDLINE (Ovid), and EMBASE (Ovid) searches, and from information available on the Internet of up to six established microsurgery course from each of the six continents of the World. Fellowships and courses that concentrate on flap harvesting rather than microsurgical techniques were excluded. We identified 27 centres offering 39 courses. Total course length ranged from 20 hours to 1,950 hours. Student-to-teacher ratios ranged from 2:1 to 8:1. Only two-thirds of courses offered in-vivo animal models. Instructions in microvascular end-to-end and end-to-side anastomoses were common, but peripheral nerve repair or free groin flap transfer were not consistently offered. Methods of assessment ranged from no formal assessment, where an instructor monitored and gave instant feedback, through immediate assessment of patency and critique on quality of repair, to delayed re-assessment of patency after a 12 to 24 hours period. Globally, training in microsurgery is heterogeneous, with variations primarily due to resource and regulation of animal experimentation. Despite some merit to diversity in curricula, there should be a global minimum standard for microsurgery training.

Induction of therapeutic neoangiogenesis using in vitro-generated endothelial colony-forming cells: an autologous transplantation model in rat.

BACKGROUND: Accumulating evidence shows the potential of bone marrow-derived endothelial colony-forming cells (bmECFCs) as promising tools for vascular repair. However, knowledge about their in vitro expansion, characterization, and functional behavior is still controversial. We demonstrate the in vitro generation of rat bmECFCs and analyze their ability to promote tissue reperfusion in a chronic hind-limb ischemia model. METHODS: Either in vitro-generated and characterized autologous bmECFCs or placebo was injected into ischemic hind limbs of Sprague-Dawley rats. Tissue perfusion was quantified by laser Doppler, in perfusion units (PU), at days 0, 15, and 30. RESULTS: Rat bmECFCs acquire a typical phenotype (CD34(+)VEGFR2(+)CD133(+)CXCR4(+)CD45(-)), culture, and functional behavior (Dil-ac-LDL+) in vitro. Injection of autologous bmECFCs improves tissue perfusion in ischemic hind limbs (183.5 ± 3.29 PU(bmECFCs/day 30)versus 131 ± 3.9 PU(controls/day 30), P < 0.001). CONCLUSIONS: We conclude that rat bmECFCs promote ischemic tissue reperfusion and their proangiogenic properties are a potential mechanism for this effect.

Improvement of a long random skin flap survival by application of vascular endothelial growth factor in various ways of local administration in a rat model.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a heparin-binding glycoprotein which plays a significant role in angiogenesis and vascular permeability. The effect of various ways of local administration of VEGF on random skin flap survival was studied, using flaps with a relatively high length (L) to width (W) ratio (5:1). MATERIALS AND METHODS: An 1.5 × 7.5 cm dorsal skin flap with the pedicle orientated, centered, and remaining attached between the lower angles of the scapulae was elevated in 45 Wistar rats in different phases, depending on the group. Rats were divided in five groups of nine. In group A, injections of saline were administered, in equally divided spaces, into flap's fascia and transposed to a created skin defect. In group B, injections of VEGF were applied subdermally, in equally divided spaces, within the limits of a predesigned flap, a week prior to flap dissection and transposition. In group C, injections of VEGF were applied into a recipient bed's fascia just before flap raising and transposition. In group D, injections of VEGF were applied subdermally, only in the distal third of the flap and then the flap was transposed to a recipient area. Finally, in group E, injections of VEGF were applied in the flap intrafascially and in equally divided spaces and then again, the flap was transposed to a recipient area. A week after final flap raising and positioning, rats were euthanatised and flaps were excised. Specimens were photographed, measured, put in formalin 10% and were sent for histological and image analysis. RESULTS: Mean flap survival percentage was 35.4% in group A, and 33.7% in group B. In groups C and D, the mean survival area was 56.3% and 80.4%, respectively. In group E, the mean flap survival percentage was 28.3%. Histological analysis demonstrated increased angiogenesis in groups C and D. CONCLUSIONS: VEGF application improved skin flap survival when injected subdermally in the distal third of a random skin flap or into the fascia of a recipient area even though the length-to-width ratio was high.

Atypical venous glomangioma causing chronic compression of the radial sensory nerve in the forearm. A case report and review of the literature.

Extrinsic chronic nerve compression induced by nonendothelium derived vascular tumors is a rare occurrence at the forearm level. We present a case of severe chronic compression of the radial sensory nerve (RSN) caused by an undiagnosed venous glomangioma. The tumor was excised with complete symptoms relief. In the presence of severe nerve compression syndromes in young age, without predisposing comorbidities, atypical extrinsic compression due to vascular tumors should be considered.

VEGF application on rat skin flap survival.

BACKGROUND: Induction of angiogenesis has been shown to be mediated by a number of glycoproteins called growth factors. Growth factors control the growth, differentiation, and metabolism of cells. Vascular endothelial growth factor (VEGF) is believed to be the most potent regulator of this process. The effect of its exogenous administration on the distal third of a long random skin flap was examined. MATERIALS AND METHODS: Eighteen Wistar rats were divided into two groups of nine. Rats were anesthetized, and a skin flap, measuring 1.5 × 7.5 cm, was elevated at their dorsum. The flap was standardized by centering the pedicle between the lower angles of the scapulae and by using a frame with the previously mentioned dimensions. The length of the flap was five times greater than its width. In group A (n = 9), the flap was elevated, one milliliter of normal saline was injected subdermally, at the distal third, and it was sutured back at its original place. In group B (n = 9), the flap was elevated, injections of 10 µg of VEGF were administrated subdermally, at the distal third, and it was again sutured back. Rats were euthanized a week later and flaps were excised. All specimens were measured, photographed, put in formalin 10%, and were sent for image and histological analysis. Image analysis was used both for the estimation of viable area and for the calculation of mean vessel density per mm2. RESULTS: Necrotic areas of the flaps were clearly demarcated within a week's time. In group A, the mean flap survival percentage was 38.9%. In group B, the percentage was 80.4%. Histological analysis demonstrated angiogenesis in group B, with mean vessel density per mm2 being higher in group B than in group A. CONCLUSIONS: Administration of VEGF injections at the distal part of a long random skin flap (length to width ratio 5:1) has been shown to improve the survival rate of the flap and thus contributing to the salvage of greater peripheral segment of the flap. Neovascularization induced by exogenous VEGF seems to be the biological mechanism, which leads to the improvement of flap survival.