Venous Flap Research Articles

Clinical application of the reversed pedicled venous flap containing perivenous areolar tissue and/or nerve in the hand

A reversed pedicled venous flap containing perivenous areolar tissue and/or nerve was used to cover traumatic skin defects of seven fingers in six patients. The series consisted of six men, ranging in age from 20 to 57 years (average: 39 years). The reconstructed sites were four dorsal skin defects and three volar skin defects of the finger. The flap was designed on the dorsum of the hand, in such a way as to place a vein at the centre of the flap and not to involve the dorsal metacarpal artery. The flap contained a dorsal vein, perivenous areolar tissue and fascia of the interosseous muscle. Cutaneous nerves were present in three of the seven flaps. The pedicle of the flap was dissected distally to the finger web space and the flap was transferred to the skin defect. The size of the flap ranged from 1.4x4.5 cm to 6.0x7.0 cm. The average length of the pedicle was 1.6 cm. Skin grafting was needed at the donor site in one case (flap size: 6.0x7.0 cm), but primary closure was possible in the remaining cases. Postoperatively, the largest flap showed superficial necrosis, although it survived. The remaining flaps survived completely. This suggests that in a large flap the skin should be attached to the pedicle to prevent congestion. The flap can be elevated without reference to the dorsal metacarpal artery at the ulnar side of the dorsum of the hand. The flap is an effective option to reconstruct skin defects of the finger, especially the little finger.

Pre-expanded arterialised venous free flaps for burn contracture of the cervicofacial region

Despite the fact that arterialised venous flaps provide thin good-quality tissue to repair defects of the face and neck, their clinical applications have been limited by an unstable postoperative course and variable flap necrosis. In an effort to resolve these problems, a tissue-expansion technique has been applied to the arterialised venous flap before flap transfer. Three pre-expanded arterialised venous free flaps have been used to treat post-burn scar contracture of the cervicofacial region. The donor site was confined to the forearm in each case. A rectangular expander was usually placed over the fascia of the flexor muscles in the proximal two-thirds of the forearm. The mean expansion period, volume and flap size were 44 days, 420 cm(3)and 147 cm(2), respectively. There were no complications caused by insertion and expansion. The cervicofacial region was successfully reconstructed, after excision of the post-burn contractures, with pre-expanded arterialised venous flaps, with no marginal necrosis or postoperative instability. Large thin arterialised venous flaps are well matched with the recipient defect in the cervicofacial area and the colour and texture match obtained with forearm tissue produced an aesthetically favourable result. Pre-expanded arterialised venous flaps are another new option for free flap reconstruction of the face and neck.

The effect of pentoxifylline on venous flap survival

An experimental study was performed to determine whether the survival area of a flap can be increased using pentoxifylline in a single-pedicled venous skin flap in the rat. Epigastric island venous skin flaps measuring 1.5×2.5 cm were constructed bilaterally. The experimental group received intraperitoneal injections of pentoxifylline 25 mg/kg daily for 7 days following the operation. This study shows the pentoxifylline had no beneficial effect on single-pedicled venous island skin flap viability in the rat model.

Free Venous Flap for the Reconstruction of Defects in the Fingers or Toes-Case Report and Literature Review

From July 1992 to December 2000, five free venous flaps on four patients have been used to cover various defects in the fingers or toes over exposed tendon, and bones in TSGH and Tzu-Chi general hospital. There were three males and one female, with an average age of 20.2 years (range: 13 to 27 years). The average follow-up was 8.25 months (range: three to 12 months). We used two flap donor sites, the volar aspect of the wrist in one case and the dorsum of the wrist in three cases. The size of the flaps ranged from 3.0×1.0 cm^2 to 4.5×3 cm^2 in size. The average size of the flap used in this series was 3.9×2.1cm^2 in size. Donor sites were closed primarily. Two flow-through venous flaps survived completely and healing has been uneventful. Three flow-through venous flaps demonstrated skin necrosis with viable subcutaneous-tissue layers, possibly because of thrombosis of vessel anastomosis. The raw surface required skin graft. However, the mechanism of survival of the venous flap is still obscure, and the survival rate is relatively unpredictable and unstable. Success seems to be influenced by the donor site, mode of circulation, and flap size as well as patent anastomosis. When the radial side of the index, the ulnar side of the little finger, or distal plantar defect of big toe were injured, it was sometimes difficult to apply a local flap and free flap. The venous flap might be indicated for reconstruction of these small troublesome wounds.

Pre-arterialisation of an arterialised venous flap: clinical cases

Many factors affecting the survival of arterialised venous flaps have been elucidated, both experimentally and clinically. The survival of large arterialised venous flaps has been reported, with varying results. Large arterialised venous flaps with preformed arteriovenous fistulae at the donor sites have been successfully performed in experimental animals. We report the results of repair of skin defects in the extremities with arterialised venous flaps in eight patients. The arteriovenous shunts were created at the donor sites at least 2 weeks before the flaps were harvested. The flap sizes ranged between 4 x 4cm and 9 x 10 cm. Flap survival was between 93% and 100% of the surface area, as shown by digitalised scanning. In addition to the known advantages of venous flaps, such as less bulk, preservation of the main arteries and ease of harvesting, pre-arterialisation makes designing the flap easier due to the noticeable superficial veins. Pre-arterialisation, when used in carefully selected cases, did not prolong the hospital course of the patients.

Effects of some pharmacological agents on the survival of unipedicled venous flaps: an experimental study.

Clinical and experimental studies have been conducted to improve the survival of venous flaps. As a result of these studies, although various survival mechanisms were raised, none obtained satisfactory information. Venous stasis, and the resultant venous thrombosis, is a factor that decreases the survival of venous flaps. In this study, we evaluated the effects of two antiinflammatory agents, etodolac and etofenamate, on the survival of unipedicled venous flaps. In this study, 35 male New Zealand white rabbits (3,500-4,000 g) (70 ears) were used. Perichondrocutaneous flaps, 3 x 4.5 cm in size, were designed and raised, keeping the central veins intact in the middle of venous flap. Central arteries and nerves were ligated and transected both proximally and distally, to prepare unipedicled venous flaps. A silicone sheet was placed between the cartilage tissue and flap, to prevent blood flow and revascularization beneath. The subjects were divided into seven groups, consisting of five rabbits (10 ears). In the negative control group (group I), the single vascular pedicle of venous flaps, central veins were ligated and flaps sutured into their own place as the composite graft. In the positive control group (group II), after venous flaps were prepared, normal saline, 0.2 mL, was given subcutaneously. In the first of five experimental groups (group III), unfractionated heparin (100 U/day) was given subcutaneously. In the second experimental group (group IV), etodolac (5 mg/kg/day) was given subcutaneously. In the third experimental group (group V), etophenamate (5 mg/kg/day) was given orally through a feeding tube. In the fourth experimental group (group VI), parnaparin (5 anti-Xa U/kg/day) was given subcutaneously. In the fifth experimental group (group VII), nadroparin (5 anti-Xa U/kg/day) was given subcutaneously, about 7 days postoperatively. At the eighth postoperative day, surviving areas of venous flaps were measured, and the results were evaluated by Kruskal-Wallis ANOVA and Mann-Whitney U-test (P < 0.05). Biopsies were also taken from the flaps for histological evaluation of border of necrotic tissue. Surviving areas of unipedicled venous flaps were larger in experimental groups than those in negative and positive control group (P < 0.05). However, comparison of the experimental groups demonstrated no statistically significant difference (P > 0.05). We concluded that all pharmacological agents used in the experimental groups succeeded in increasing the survival of unipedicled venous flaps. Survival of the unipedicled venous flap was higher in venous flaps than that of composite graft, clearly showing the importance of the venous pedicle.

血管柄付遊離爪移植の一例

A 19-year-old woman with a deformednail on her little finger for 10 years after trauma is reported. As a severe deformity from infection around the nail occurred frequently, we performed a free vascularized nail graft in order to reconstruct her nail. The third toe was chosen as a donor site, and the nail matrix and plate were sacrificed with two veins attached to the flap. Free skin graft was performed for the donor site. After the nail matrix and plate of the recipient site was resected, the flap were fixed and the two veins of the flap was anastomosed to a digital artery and a vein respectively. No complication due to the arterio-venous shunt after surgery was evident. The nail plate never fell off and the clinical result was excellent. Though arterio-venous anastomosis is not physiological, the venous flap is now recognized as an effective treatment. The procedure described in this paper is considered to be beneficial for cases in which nail reconstruction is necessary.

Treatment of Finger Avulsion Injuries with Innervated Arterialized Venous Flaps

Treatment of Finger Avulsion Injuries with Innervated Arterialized Venous Flaps

A microneurovascular study of the great saphenous vein in man and the possible implications for survival of venous flaps

Cross sections (n = 372) of human long saphenous veins (n = 12) from unsalvageable fresh above knee amputation specimens brought to a trauma centre in a large metropolitan hospital were studied. The veins were harvested longitudinally with an amount of soft tissue equivalent to the diameter of the vein and sectioned at intervals of 5 mm. The sections were stained with haematoxylin and eosin for general study, Van Gieson for better delineation of different coats of the vessel wall and reticulin stain to differentiate between venules and arterioles. The vascular structures within the vein wall and its surrounds were analysed by using analySISpro via a CCD camera attached to a light microscope, with the help of a frame grabber card and image analysis software. Results show that the vein has vasa vasorum within its wall, a capillary network around it, arterioles, venules and the saphenous nerve and its branches with their vascular network a further distance apart. The relevance of the microsurgical anatomy of the saphenous vein and its soft tissue envelope in the survival of venous flaps is discussed.

The venous flap

Venous flaps are flaps vascularized through the venous network located within them; they can either be perfused by venous blood or by the rerouting of the arterial blood through the venous bed of the flap. Experimental research has been conducted on various animal models to study the viability, mechanism of survival, and perfusion physiology of venous flaps. Many surgeons have successfully used venous flaps clinically for emergency wound closure or in planned operations. They can be used with almost the same indications as for the customary fascio-cutaneous and skin flaps, and they have the great advantage of preserving the artery in the donor site. Despite the advantages of using venous flaps, their clinical usage is still looked upon with considerable skepticism. Further research into their use is definitely necessary. In this paper, in order to provide reference material for investigators, the authors review the classification, methods of investigation and experimental designs, and discuss the survival mechanisms of venous flaps.

Microcirculation of a venous flap: an experimental study with microspheres in rabbits.

In recent years, it has been found that maintenance of venous circulation alone may support a small flap with no direct arterial inflow. The clinical application of a venous flap has potential in the field of microsurgery. The purpose of this study was to evaluate the haemodynamics within a pedicled venous flap in rabbits, compared with those of a composite graft. Pedicled venous flaps and composite grafts were raised from the abdominal walls of 30 adult New Zealand rabbits. Flap survival was measured and recorded and blood flow studies with microspheres were done for seven days. The viability of the pedicled venous flaps was much better than that of the composite grafts. At two weeks 24 of the venous flaps (80%) showed more than 75% surviving, but 29 (97%) of the composite grafts had less than 25% surviving. The results suggest that the blood flow through a patent vein maintained in a venous skin flap can provide enough nutrients for the flap to survive during the initial three days until neovascularisation. The venous flap receives more blood flow than a composite graft. We conclude that a venous flap depends on blood supply from the axial vein in addition to neovascularisation to maintain its survival.

Retalho venoso unipediculado transposto comparado ao não transposto: estudo experimental em coelhos

Retalhos venosos são aqueles que apresentam em seu pedículo apenas uma veia, diferente dos retalhos convencionais que são caracterizados por entrada de sangue arterial e saída de sangue venoso. O objetivo deste trabalho foi determinar se a transposição do retalho venoso unipediculado modifica a sua área de sobrevida e vascularização. As orelhas de oito coelhos foram submetidas à realização de retalhos venosos. Dissecou-se um retalho de pele de dois por dois centímetros baseado no pedículo distal da veia marginal anterior. Os retalhos foram divididos em dois grupos: no grupo I(n=8), os retalhos venosos foram levantados e suturados na mesma posição; no grupo II (n=8), os retalhos foram levantados e transpostos 90 graus. Estes dois grupos foram comparados entre si e ao grupo III(n=8), no qual foi realizado enxerto de pele com subcutâneo sobre um leito bem vascularizado. A área média de necrose no grupo I (6,5%) foi significativamente menor que no grupo II (43,75%), e as áreas de necrose dos grupos I e II foram significativamente menor do que no grupo III (88,75%). O estudo angiográfico não mostrou alterações no padrão vascular comparando-se os grupos I e II. A veia marginal anterior foi importante para a sobrevida do retalho. Houve uma maior área de necrose do grupo II, em que foi realizada transposição, em relação ao grupo I.

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.

Transfer of a pedicled venous flap containing perivenous areolar tissue and nerve: an experimental study

In this paper, we evaluated experimentally the feasibility of transferring a pedicled venous flap with perivenous areolar tissue into an ectopic site, and investigated the role of each vein, the perivenous areolar tissue and nerve in the viability of pedicled venous flaps. Three groups of flaps were created using a rabbit-ear model: Group 1 (n= 11), containing perivenous areolar tissue and a draining vein; Group 2 (n= 10), perivenous areolar tissue, a draining vein and nerve; Group 3 (n= 10), only perivenous areolar tissue. Macroscopic, angiographic and histological assessments were performed 14 days after transfer. The total survival areas including superficial necrosis of Groups 1, 2 and 3 were 52.7%, 82.5% and 0%, respectively. There were significant differences in mean survival area and mean total survival area including superficial necrosis between Group 1 and Group 2 (P< 0.05). In contrast, all flaps in Group 3 became necrotic. These data suggest that a preserved vein is the necessary condition, and additional arterial flow through the preserved nerve and a small vascular network within the areolar tissue may play an important role in flap survival.

Clinical use of microsurgically re-anastomosed venous flaps for the immediate reconstruction of intraoral resection defects: D. Klein, A. Kovács, T. Stuckensen Deutsche Zeitschrift für Mund-, Kiefer- und Gesichtschirurgie 1996: 20: 274–7

Clinical use of microsurgically re-anastomosed venous flaps for the immediate reconstruction of intraoral resection defects: D. Klein, A. Kovács, T. Stuckensen Deutsche Zeitschrift für Mund-, Kiefer- und Gesichtschirurgie 1996: 20: 274–7

The Effects of Surgical and Chemical Delay Procedures on the Survival of Arterialized Venous Flaps in Rabbits

The aim of this study was to investigate the efficacy of a surgical delay procedure and a combined surgical and chemical delay procedure on the survival of arterialized venous flaps. Experimental groups included (1) a control group, (2) a surgical delay (4-day and 7-day delay) group, and (3) a combined surgical and chemical (doxazosin mesylate, nitroglycerine patch) delay group. These groups were further divided into subgroups (n = 10) depending on the delay period and the chemical agents. An arterialized venous flap was created on one ear of each rabbit. In the arterialized venous flap, arterial inflow was provided by anastomosis of the central auricular artery to the anterior branch of the central auricular vein and a venous outflow through the anterior marginal vein. In the control group, the arterialized venous flaps without any delay procedure showed complete necrosis of all flaps. In the surgical delay group, the mean percentage survival of arterialized venous flaps was 36.6 percent in the 4-day delay group and 59.7 percent in the 7-day delay group. In the combined surgical and chemical delay group, a 3-day chemical delay followed by a 4-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 81.1 percent in the doxazosin mesylate group, 72.8 percent in the nitroglycerine patch group, and 92.9 percent in a combination group of doxazosin mesylate and nitroglycerine patch. A 3-day chemical delay followed by a 7-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 94 percent in the doxazosin mesylate group, 90.2 percent in the nitroglycerine patch group, and 99 percent in a combination group of doxazosin mesylate and nitroglycerine patch. In conclusion, the surgical delay procedure increased the percentage survival of the arterialized venous flaps in proportion to the delay period. The combination group of surgical and chemical delay procedures had a significantly greater percentage survival than that of the surgical delay group (p < 0.001), and the delay period could be shortened. (Plast. Reconstr. Surg. 102: 1134, 1998.)

The effects of surgical and chemical delay procedures on the survival of arterialized venous flaps in rabbits.

The aim of this study was to investigate the efficacy of a surgical delay procedure and a combined surgical and chemical delay procedure on the survival of arterialized venous flaps. Experimental groups included (1) a control group, (2) a surgical delay (4-day and 7-day delay) group, and (3) a combined surgical and chemical (doxazosin mesylate, nitroglycerine patch) delay group. These groups were further divided into subgroups (n = 10) depending on the delay period and the chemical agents. An arterialized venous flap was created on one ear of each rabbit. In the arterialized venous flap, arterial inflow was provided by anastomosis of the central auricular artery to the anterior branch of the central auricular vein and a venous outflow through the anterior marginal vein. In the control group, the arterialized venous flaps without any delay procedure showed complete necrosis of all flaps. In the surgical delay group, the mean percentage survival of arterialized venous flaps was 36.6 percent in the 4-day delay group and 59.7 percent in the 7-day delay group. In the combined surgical and chemical delay group, a 3-day chemical delay followed by a 4-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 81.1 percent in the doxazosin mesylate group, 72.8 percent in the nitroglycerine patch group, and 92.9 percent in a combination group of doxazosin mesylate and nitroglycerine patch. A 3-day chemical delay followed by a 7-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 94 percent in the doxazosin mesylate group, 90.2 percent in the nitroglycerine patch group, and 99 percent in a combination group of doxazosin mesylate and nitroglycerine patch. In conclusion, the surgical delay procedure increased the percentage survival of the arterialized venous flaps in proportion to the delay period. The combination group of surgical and chemical delay procedures had a significantly greater percentage survival than that of the surgical delay group (p < 0.001), and the delay period could be shortened.

Comparison of two types of arterialized venous forearm flaps for oral reconstruction and proposal of a reliable procedure

The mechanism of survival of venous flaps is not yet completely understood. To determine the conditions for reliable success, in 1996 and 1997 we used arterialized venous forearm flaps for oral reconstruction in patients with neoplastic disease. Building on earlier experience with flow-through flaps, we compared two different designs obeying the following specifications: five so-called arterialized flow-through flaps, elevated from the ulnar flexor side of the forearm, with a single vein for orthograde inflow and outflow, diameter not larger than 2 mm (type 1); and five arterialized flaps with two parallel veins on the proximal side of the flap, also with a diameter of 1-2 mm, to avoid by-passing of flap tissue by 'catching' the blood in the venous/capillary system (type 2). There were nine male and one female patients with a mean age of 55.7 years. We covered defects of the anterior or anterolateral floor of the mouth to avoid folding of the flaps. Microsurgical anastomosis was done to the facial artery, the cranial thyroid artery and the external jugular vein or the facial vein. Average size of the flaps was 23 +/- 7.28 cm2 (type 1) and 25 +/- 5 cm2 (type 2). Four flaps of type 1 showed total or subtotal success and only one was lost because of a haematoma. In comparison with this we saw three losses in type 2 and only one partial and one total success, respectively. Analysis showed regularly occurring problems: there was failure of venous drainage in the lost type 2 flaps one day after microsurgery. In the flow-through flaps and the surviving type 2 flaps which had visible communicating branches between the two veins, the partial by-passing of the arterial input avoided this problem. There was no donor site morbidity after covering with a split-thickness skin graft. It could be shown that survival of arterialized venous forearm flaps is based on a combination of an arteriovenous shunt and capillary blood flow. In conclusion, we define six rules for a reliable venous forearm flap.

Complications in wrap-around-flap donor sites after reconstruction using an arterialized venous flap.

The authors have previously reported on the use of the arterialized venous flap to cover skin defects of the big toe resulting from wrap-around-flap transfers. Nineteen patients who had undergone this procedure were reviewed, to determine the incidence of donor-site complications. Problems identified included delayed wound healing, skin erosion, painful callosity, paresthesia, cold intolerance, and cosmetic appearance However, the functional deficit was not great, and most patients were not troubled by their symptoms. The cosmetic appearance of the donor foot was acceptable in most of the patients.

Expansion of venous flaps: an experimental study in rats

In this study, the effects of controlled tissue expansion on the survival of unipedicled venous flaps were investigated in rats. In three groups of Lewis rats, a 3 x 6 cm unipedicled Lateral thoracic venous flap was studied with group 1 as control group (n = 30) without any manipulation, group 2 (n = 30) where an expander was introduced under the flap area but was not expanded and group 3 (n = 30) in which a 40 ml expander was introduced under the flap area and was expanded over a period of 10 days. Observations included gross and histological examination, reverse microangiography, reverse flow resistance and percentage of survival of flaps. Group 3 (expanded) showed more angiogenesis, a better delineation on microangiography, lower reverse flow resistance and higher survival rates as compared to group 2 (non-expanded). In the control group the survival rate of flaps was the poorest and the flaps showed higher rates of reverse flow resistance. Microangiography was not successful in the control group. In a pilot project prior to this experiment microscopic examination of the Lateral thoracic vein in 10 Lewis rats had confirmed the presence of two or three valves in this vein.