Efficacy of the Arteriovenous Loop for Free Flap Reconstruction in Patients with Complex Limb Trauma: Case Series and Literature Review

Abstract

Background and objectives: Complex limb traumas are commonly treated with microsurgical reconstruction and free flaps. However, complications are frequent in patients affected by a previous trauma or comorbidity, atheromasia and a single valid vessel. Free flap reconstruction is indeed a challenging procedure in complex injuries, which may increase the risk of limb ischemia. The Arteriovenous loop (AVL) technique may be considered an efficient alternative treatment. We herein report our procedure and previous research regarding the AVL method using a two-step reconstruction in cases of complex high-energy limb injuries. Materials and Methods: In this single center retrospective cohort study, all the patients from 2014 to 2018 who underwent to AVL reconstruction were assessed. A total of six patients were included in the study for traumatic limb trauma. The two-stage technique was performed each time. The age and sex of patient, the time between stage one and two, the length of AVL loop and rate of free flap success were evaluated. Results: A total of seven AVL reconstructions were performed. The mean age of patients was 36 years old. Eight free flaps were performed; six free flaps were transferred to the vascular loops. The average time between stage one and two was 13 days. The mean length of the pedicle was 25 cm for the upper limb and 33.7 cm for the lower limb. All the free flaps successfully take root. In one case, a surgical revision was required the second day post-operatory due to venous congestion. Conclusions: AVL is a useful and safe technique in microsurgical reconstruction which will prevent vascular complications. Our investigations suggest the efficacy and feasibility of a two-step intervention in acute post-traumatic events. A single-step procedure should be preferred in chronic situation and oncologic reconstruction.

Keywords: arteriovenous loop; complex limb trauma; free flap; microsurgery.

Figure 1

The Arteriovenous loop (AVL) technique.

Figure 2

All the AVLs performed yielded successful outcomes. In one case, a surgical revision was required the second day post-surgery.

Figure 3

M.E. 50 years old, (a) initial x-ray and (b) clinical status, classified as IIIC G/A score.

Figure 4

Angiography showed ulnar artery avulsion and interruption.

Figure 5

Initial soft tissue reconstruction. ALT free flap was anastomosed end-to-side with radial artery. Gracilis free flap was anastomosed end-to-and with ulnar artery interrupted proximally.

Figure 6

Harvested from great saphenous vein and anastomosed end-to-side with Brachial vein and Artery.

Figure 7

Free flap harvested from contralateral leg (a,b);Fibular pedicle placed near AVL (arrow) (c); AVL bisection at the centre (d); End-to-end fibular peduncle anastomoses on AVL (e); Post-operative x-rays after bone fixation (f).

Figure 8

Patient #4, final outcome.

Figure 9

Post hyperbaric therapy viable tissue was observed but superficial tibial bone necrosis was defined.

Figure 10

First stage of AVL technique, great saphenous vein harvested from contralateral legand attached end-to-side to femoral artery and vein.

Figure 11

The midpart of the AVL (arrow) near the injured zone. Latissimus dorsi free flap was harvested and the pedicle anastomosed end-to-end with AVL. The muscle was covered with a dermal substitute. Final result three months later after skin graft positioning.