Arterialized venous flaps for reconstructing soft-tissue defects of the extremities

Retrograde Free Venous Flaps for Extremity Reconstruction: A Roadmap

Background and Objectives: Retrograde free venous flaps represent a separate entity among free venous flaps: their physiology is still unclear, but they provide an immediate visible refill after reconnection, with a similar behaviour to conventional flaps. Therefore, the dimensions and the indications of these flaps can be extended beyond what was previously believed, and they can be easily customized, including with respect to tendons and nerves. Nevertheless, they are still debated and regarded as unsafe. Materials and Methods: From 2012 to 2019, we performed 31 retrograde free venous flaps on 31 patients to reconstruct hands, digits, and in one case the heel. All the flaps were arterialized in a retrograde manner; the donor site was the forearm in 28 cases, the foot in 2 cases, and the calf in 1 case. We recorded the size, vein architecture, donor site, donor artery, donor morbidity, function for composite and non-composite flaps, immediate complications, late complications, survival rate, and the number of revisions. We recorded the hand function when appropriate. A total of 10 flaps were also intraoperatively studied with indocyanine green to monitor their hemodynamical behaviour. Results: All the patients were followed for an average of 8 months (6−15). The flap dimensions ranged from 6 cm2 to 136 cm2. All the flaps, except two that had complete necrosis, survived. Two flaps had partial necrosis. There was no correlation between necrosis and the size of the flap, with one case of necrosis and one of partial necrosis in the small flaps (<10 cm2). None of the cases with partial necrosis needed a new flap. Two flaps developed a late arterio-venous shunt that was ligated. Conclusions: The retrograde free venous flaps proved to be a useful tool for complex reconstructions of the hand and extremities. They can provide a large island of pliable skin and composite tissue with tendons and nerves, but surgeons must be aware of some caveats.

Multiple simultaneous venous flow-through free flap salvage for multifinger revascularisations

A 22-year-old man presented with traumatic crush-avulsion injuries to the left index, ring and small fingers resulting in complex soft tissue loss and acute three-finger ischaemia. The patient underwent immediate revascularisation and soft tissue resurfacing of the three digits using three separate venous flow-through free flaps performed in a single-stage operation. Continued follow-up after 9 months confirmed successful salvage of these three digits. Multiple simultaneous venous flow-through free flaps can be considered as a viable alternative reconstructive modality for traumatic multi-digit ischaemia where both graft-based digital artery reconstruction and soft tissue coverage are required for multiple digits.

Reverse Flow Shunt Restricted Arterialized Venous Free Flap

Several technical modifications have been described to avoid complications of venous flaps. The authors describe a technical variation of the venous flap to reduce the risk of venous congestion and the likelihood of shunting, thus increasing venous flap reliability.

USE of arterialized saphenous vein venous flow-through flaps as a temporizing measure for hand salvage in contaminated wounds presenting with limb ischemia: A case series

BACKGROUND

Vascular injuries resulting in limb ischemia are traditionally treated acutely with autologous or prosthetic bypass grafts. Traumatic contaminated injuries with soft tissue and vascular segmental loss are challenging as prosthetic bypasses are at risk of erosion, infection, and occlusion; and autologous bypasses are at risk of desiccation, blow-out, infection, and clotting. We propose a novel approach to these injuries by using arterialized saphenous vein venous flow-through free flaps (S-VFTF) as an autologous bypass, and present the results of its application in a series of cases.

METHODS

Spanning 2008 to 2015, four patients presenting with large contaminated crush/avulsion wounds with vascular injury underwent hand revascularization with S-VFTF, allowing the contaminated wounds to be serially debrided. Definitive soft tissue reconstruction was performed once the wound was considered clean. The S-VFTF skin paddle was de-epithelialized and the soft tissue defect covered with a free latissimus dorsi flap or a rectus abdominis myocutaneous flap.

RESULTS

All ischemic limbs were successfully reperfused and there were no take backs for perfusion issues. All S-VFTF remained patent at discharge and final follow-up. No partial or complete finger/hand amputations were required. All definitive coverage free flap survived with no complications.

CONCLUSION

The two-stage reconstruction presented may help reconstructive and vascular surgeons consider alternatives to traditional vascular reconstruction methods. This technique avoids an exposed vascular graft in an extensively contaminated open wound. It allows the surgeon to perform thorough and sufficient debridement of the wound, preventing definitive reconstruction in a not yet declared zone of injury.

Systematic Review and Meta-Analysis of Unconventional Perfusion Flaps in Clinical Practice

BACKGROUND

Although unconventional perfusion flaps have been in clinical use since 1975, many surgeons are still deterred from using them, because of some reports of high necrosis rates.

METHODS

The authors performed a systematic review and meta-analysis of all articles written in English, French, German, Spanish, and Portuguese on the clinical use of unconventional perfusion flaps and indexed to PubMed from 1975 until July 15, 2015.

RESULTS

A total of 134 studies and 1445 patients were analyzed. The estimated survival rate of unconventional perfusion flaps was 89.5 percent (95 percent CI, 87.3 to 91.3 percent; p < 0.001). Ninety-two percent of unconventional perfusion flaps (95 percent CI, 89.9 to 93.7 percent; p < 0.001) presented complete or nearly complete survival. Most defects mandating unconventional perfusion flap reconstruction were caused by trauma (63.6 percent), especially of the hand and fingers (75.1 percent). The main complication of all types of flaps was a variable degree of necrosis (7.5 percent of all unconventional perfusion flaps presented marginal necrosis; 9.2 percent and 5.5 percent had significant and complete necrosis, respectively). There was a positive correlation between the rate of postoperative infection and the need for a new flap (Pearson coefficient, 0.405; p = 0.001). Flaps used to reconstruct the upper limb showed better survival than those transferred to the head and neck or to the lower limb (p < 0.001).

CONCLUSION

Unconventional perfusion flaps show high survival rates and should probably be used more liberally, particularly in the realm of upper limb reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Revascularization of Arterialized Venous Flaps through a Total Retrograde Reverse Blood Flow: Randomized Experimental Trial of Viability

Background:

Arterialized venous flaps (AVFs) have been used for reconstruction of soft tissue defects throughout the body. Several different revascularization models have been performed, but venous drainage through the arterial system has not been studied. In our total retrograde reverse blood flow (TRRBF) perfusion model, the arterial blood flow enters through the venous system and venous drainage exits through the arterial system.

Methods:

We developed a novel experimental model in rabbit ears to evaluate the capacity of TRRBF perfusion pattern to allow AVF viability. The ears were assigned to 3 groups: group 1, total devascularization without revascularization (n = 3); group 2, TRRBF (n = 12); and group 3, conventional AVF (n = 12). The ears were observed during a 30-day follow-up period, and clinical serial assessment of edema, cyanosis, and necrosis was performed. Tissue oxygenation was determined at the beginning and end of the follow-up. Histological analysis was performed.

Results:

Necrosis was found in 3/3 (100%) ears in group 1, 3/12 (25%) in group 2, and 0/12 (0%) in group 3 (95% CI, 0.505–0.994; P = 0.0001). In group 2, edema was higher (5/12, 41.66%) than in group 3 (0/12, 0%) (95% CI, 0.0135–0.65; P = 0.041). Cyanosis and venous congestion was of greater intensity and duration in group 2 than in group 3 (10.33 ± 4.51 vs 4.5 ± 2.06 d).

Conclusions:

Although evolution is torpid and prolonged in ears with TRRBF, 9/12 (75%) survived, suggesting that TRRBF can be used as a rescue method.

The physiology, microcirculation and clinical application of the shunt-restricted arterialized venous flaps for the reconstruction of digital defects

Reconstruction of digital defects using the venous flap offer several advantages but remained unpopular owing to levels of venous congestion rates. We performed animal studies to test the hypothesis that an arterio-venous shunt increases pressure for peripheral flap perfusion and decreases venous congestion. Using an abdominal adipofascial flap model in six male Sprague-Dawley rats, microcirculation was modified as follows: type I - arterial flap; type II - flow-through arterio-venous flap (AVF); and type III - shunt-restricted AVF. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type II flaps, blood flow oscillated without a dominant direction and came to a standstill. In type III flaps, blood flowed proximally in a reverse direction whereas distally, flow was similar to type I flaps. In a clinical series, 21 patients received a total of 22 shunt-restricted AVFs. All 22 clinical flaps survived; four flaps suffered epidermolysis but recovered without full thickness loss.

Microsurgical arterialization of degloving injuries of the upper limb

The authors describe a technique in which a microsurgical anastomosis between an artery and a vein in an afferent direction (through a vein graft, when necessary) of a degloved flap is used to revascularize or arterialize the flap. In 3 difficult cases, there was substantial salvage of flap tissue.

Use of a sequential two-in-one free arterialised venous flap for the simultaneous reconstruction of two separate defects on the foot

A sequential free arterialised venous flap carrying two flaps nourished by a single venous pedicle was designed for the simultaneous reconstruction of two separate soft tissue defects on the dorso-medial aspect of the foot. These two defects were separated by approximately 3.5 cm, exposing the extensor hallucis longus tendon and first tarso-metatarsal joint. Superficial epidermolysis was noted postoperatively in the smaller flap. Nonetheless, flap survival was uneventful with no further surgery required, and the patient was discharged 7 days after surgery. Three months after the surgery, the patient was satisfied with the result and no morbidity was evident at the donor site. The sequential flap is not a new flap category, but we are unaware of any previous report of a free arterialised venous flap in the form of a sequential flap. We demonstrate the clinical value of this type of flap design for selected cases. The benefits and possible pitfalls of the sequential free arterialised venous flap are discussed.

Use of an arterialized venous flap for resurfacing a circumferential soft tissue defect of a digit

Circumferential defects of digit are uncommon but present a challenging problem to the clinician. The use of simple skin grafts tends to cause tendon adhesions and can limit digital range of motion. The use of local skin flaps, such as a cross-finger flap, is limited by the considerable skin loss in a defect that is circumferential in nature. Other options have included the use of reversed forearm flap or some free tissue transfer. We report a case in which the circumferential defect of an index finger, measuring 6 cm around the digit and 3 cm long, is resurfaced by the use of a free arterialized venous flap raised from the volar forearm skin.

Use of a venous flap from an amputated part for salvage of an upper extremity injury

The authors describe a patient in whom a large arterialized venous flap was harvested from a nonreplantable part after partial hand amputation. A 9 x 6-cm segment of dorsal hand skin was transplanted acutely in an artery-vein-vein fashion to cover exposed bone, joints, and reconstructed tendons. The flap provided durable coverage, and at 1 year the patient regained 94% total active motion at the index finger and 99% total active motion at the long finger. Salvage of component parts such as a venous flap and extensor tendons avoided additional procedures for coverage and staged tendon reconstructions.

Venous free flaps for reconstruction of skin defects of the hand

Twenty-one cases of skin defects of the hand were treated with venous flaps. According to type, nine flaps were arterialised flaps (A-A), five were (A-V), and seven were (V-V) type. Venous flaps can be used up to 8 x 3 cm in size or even bigger if the number of veins anastomosed is increased. The main advantage of venous flaps is that they can also be used for simultaneous reconstruction of circulation in digits.

Dorsalis pedis tendocutaneous delayed arterialized venous flap in hand reconstruction

We report two patients whose acute soft-tissue and tendon defects in the hand were treated with a dorsalis pedis tendocutaneous delayed arterialized venous flap between 1994 and 1997. The surviving surface area was 100 percent in both patients. The flap sizes were 10 x 10 cm and 6 x 6 cm. At 2 weeks postoperatively, active flexion and passive extension commenced, and progressive resistance exercises were performed for an additional 5 weeks. Flaps showed a similar color match and skin texture compared with the normal skin of the hand. Advantages of the tendocutaneous delayed arterialized venous flap are that a larger flap can be obtained than when using a pure venous flap or arterialized venous flap; the survival rate of the arterialized venous flap increases, which permits the use of a composite flap; the main artery of the donor site is preserved; thin, nonbulky tissue is used; and elevation is easy, without deep dissection. The disadvantages are the two-stage operation, donor-site scarring, and weak extension of the toes.

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.

Free arterialised venous forearm flaps for intraoral reconstruction

In 29 patients, the intraoral defect after excision of an oral squamous cell carcinoma was repaired with an arterialised venous forearm flap. In all cases, a flap of skin and fat with a superficial vein passing through it was raised from the flexor surface of the right forearm. After the flap had been sutured into the intraoral defect, the original distal end of the vein was anastomosed to an artery and the original proximal end to a vein. Fifteen (52%) of the flaps survived completely, six (21%) had superficial epithelial loss or some marginal necrosis and eight (27%) became completely necrotic. Areas of partial loss developed slowly and formed stable granulation tissue. The flap donor sites were either closed primarily (n = 20) or were covered with a split thickness skin graft (n = 9). There were no functional problems of the donor forearms. These results contrast with the high success rates achieved with orthodox free radial forearm flaps. Further research into venous flaps is essential.