Wrap-around arterialized venous flap for salvage of an avulsed finger

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.

Microsurgery in 46 cases with total hand degloving injury

OBJECTIVE

To summarize the characteristics of total hand degloving injury and investigate the curative effect of microsurgery.

METHODS

A total of 46 patients with total hand degloving injury were enrolled in this study. The injury classification and treatment methods were as follows: Type I (11 cases), treated by replantation of the gloved skin; Type II (6 cases), treated by reconstruction using thumb wrap-around flap and second toe; Type III (4 cases), treated by reconstruction using bilateral second toe with dorsal foot flap; Type IV (9 cases), treated by replantation in situ or reconstruction; Type V (16 cases), treated by replantation or abdominal flap reconstruction.

RESULTS

Of the patients who received Type I treatment, five completely survived, whereas eight had finger necrosis. In Type II, both the reconstructed fingers and hand flaps survived. For four patients who received Type III treatment, eight reconstructed fingers survived. In Type IV, two patients with reconstructed fingers survived, whereas the six with replantation in situ had necrosis of the partial palmar or hand dorsum skin. In Type V, nine patients with reconstructed fingers survived, and five cases with abdominal skin flap reconstruction and one case with anterolateral femoral flap survived. The restoration of hand appearance and function was the best in patients who received replantation. For reconstruction cases, however, the hand function was recovered to the basic self-care level. In cases with abdominal flap reconstruction, the hand function showed poor recovery.

CONCLUSION

Total hand degloving injury can be classified into different types according to the injury degree. The appropriate microsurgical treatment based on these types can produce better curative effect.

Clinical applications of venous flaps in the reconstruction of hands and fingers

In recent years, the venous flap has been highly regarded in microsurgical and reconstructive surgeries, especially in the reconstruction of hand and digit injuries. It is easily designed and harvested with good quality. It is thin and pliable, without the need of sacrificing a major artery at the donor site, and has no limitation on the donor site. It can be transferred not only as a pure skin flap, but also as a composite flap including tendons and nerves as well as vein grafts. All these advantages make it an optimal candidate for hand and digit reconstruction when conventional flaps are limited or unavailable. In this article, we review its classifications and the selection of donor sites, update its clinical applications, and summarize its indications for all types of venous flaps in hand and digit reconstruction.

Optimizing the arterialized venous flap

BACKGROUND

Outcome of arterialized venous flaps is quite varied. The authors' initial experiments showed that a good vascular bed contributes significantly to survival of the flap. In continuation of these experiments, this study aimed to understand the influence of architectural variations on flap outcome.

METHODS

Fasciocutaneous flaps were designed on the ears of New Zealand rabbits, and the animals were randomized into four groups having flaps that used the larger anterior marginal vein (1.3 mm) or the smaller central vein (0.6 mm) for arterial inflow, with or without isolation of the flap from its bed with a silicone sheet. Flaps were observed for area of flap survival and vasculature was assessed by microangiography.

RESULTS

Using the smaller central vein for arterial inflow (n = 15), arterialized venous flaps had an excellent outcome, with good flap survival in 100 percent of the animals (survival of >85 percent of flap area), and a mean flap survival area of 99.4 +/- 1.6 percent. Even when neovascularization was prevented by isolation of the flaps (n = 14), 92 percent of central vein flaps showed good survival, with a mean flap survival area of 93.3 +/- 7.3 percent, which was significantly better than that of anterior marginal vein flaps (n = 22), which showed good flap survival in only 27 percent of the animals (mean flap survival area, 76.4 +/- 12.1 percent).

CONCLUSIONS

Survival of arterialized venous flaps is optimized by using smaller-caliber veins for inflow and reserving larger-caliber veins for outflow. This regulates inflow and avoids high blood pressure, and arterialized venous flaps behave as physiologic flaps do, by not relying on neovascularization for survival.

Finger-level avulsion-type injuries

Fifty-nine avulsed fingers were managed between May 1986-December 2004. Of 59 cases, 39 (66%) were treated with microsurgical techniques, and the remaining 20 cases (34%) were treated in the conventional manner. Follow-up time varied between 9-18 years. All cases were classified according to the Kay-Wolff classification. Replantation was done in 26 fingers, and revascularization in 13 fingers. The survival rate was 100% in the revascularization cases, and 80.7% in the replantation cases. The total active range of motion was more than 90 degrees in the interphalangeal joints in 48% of cases, and sensory recovery was good in 38% of cases (between 4-10 mm, static two-point discrimination test). Although the data show that avulsion injuries can be treated successfully by microsurgical techniques, functional results are not as successful. However, the decision for surgery at times is determined by nonmedical factors such as the patient's age, occupation, economic situation, and level of motivation.

Clinical application of the retrograde arterialized venous flap

Retrograde arterialized venous flaps were applied to skin and soft-tissue defects in 13 patients with an average age of 34.4 years. Ten defects were located on the hand, and three on the lower leg. All flaps were harvested from the flexor aspect of the forearm; they ranged in size from 2 x 1 to 11 x 7 cm. There was venous congestion with superficial epidermolysis in six flaps, but not in the other seven. Partial skin necrosis in two of the lower-extremity flaps necessitated secondary skin grafts. Our results suggest that retrograde perfusion enhances blood flow in the periphery of arterialized venous flaps and gives good results in terms of flap survival, especially on the upper extremity.

Retrograde arterialized venous flap: an experimental study

An experimental model was established to study circulation in retrograde arterialized venous flaps (RAVF). Venous flaps measuring 7 x 4 cm with a matching venous system were harvested from both forearms of 10 fresh human cadavers. In each trial, both flaps were simultaneously perfused with heparinized human blood driven by a pulsatile circulation model. In each trial there was one flap with retrograde perfusion, and one flap with antegrade perfusion. Clinical assessment, measurement of outflow, and angiographic examination with digitally assisted assessment after 3 h of perfusion showed better results for retrograde perfusion in 8 of the 10 trials. This study indicates that blood circulation in the periphery of arterialized venous flaps can be enhanced by retrograde arterialization.

Use of "spare parts" in mutilated upper extremity injuries

Management and treatment of complex mutilated upper extremity injuries often can be challenging and at times seemingly formidable. A reconstructive surgeon's ability to mobilize, transpose, and transfer tissues has allowed not only closure of complex wounds but also restoration of function and form. Use of "spare parts" from an otherwise unsalvageable limb represents the ultimate form of reconstruction that probes the creative mind and challenges the reconstructive knowledge of the surgeon. In this article, the authors review and discuss the use of various "spare parts" in the treatment of mutilating hand injuries.

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.