SLR - November 2018 - Nicole S. Zahn
Lower-Extremity Salvage with Thoracodorsal Artery Perforator Free Flap in Condition of Symmetrical Peripheral Gangrene
Reference: Soo Yeon Lim, Gyeong Hoe Kim, Il Hoon Sung, Dong Woo Jang, Jung Soo Yoon, Youn Hwan Kim, and Sang Wha Kim. Lower-Extremity Salvage with Thoracodorsal Artery Perforator Free Flap in Condition of Symmetrical Peripheral Gangrene. BioMed Research International. Volume 2018, Article ID 6508607.
Scientific Literature Review
Reviewed By: Nicole S. Zahn, DPM
Residency Program: Bethesda Memorial Hospital, Boynton Beach, FL
Podiatric Relevance: Symmetrical peripheral gangrene is devastating, has a mortality rate of more than 40 percent and its cause is poorly understood. Half of the patients who survive will require amputation of the affected extremities. Disseminated intravascular coagulation is present in 85 to 100 percent of cases, and the lower extremities are most often affected. After a period of nonsurgical management, major reconstructive procedures are required for limb salvage with aims to retain functional length of the limbs for preservation of function. Reconstruction with free flaps can be extremely effective in this regard.
Methods: Ten thoracodorsal artery perforator free flaps were performed in six patients with symmetrical peripheral gangrene between the dates of January 2007 and February 2016. All patients were in shock accompanied by disseminated intravascular coagulation. After the patient’s general condition had stabilized and necrotic areas demarcated, radical debridement and amputation was performed, after which, negative pressure wound therapy was applied. Wounds subsequently underwent serial debridement every 24 to 48 hours to ensure wound stability and health. All patients then underwent computed tomography angiography to confirm vascularity and to locate viable recipient vessels. All defects were reconstructed using thoracodorsal arterial perforator free flaps and after insetting of the flap into the defect, microanastamosis was performed and venous return was checked. Donor sites were then closed primarily, or a split-thickness skin graft was applied. Intravenous prostaglandin was administered for 14 days postoperatively.
Results: A total of 10 amputations with reconstruction via thoracodorsal artery perforator free flaps were performed in six patients; eight of which were transmetatarsal and two Lisfranc. Flap size varied from 7 x 11 cm to 25 x 15 cm. The mean pedicle length of the flaps was 8.5 cm. All TDAP flaps included one perforator except for one chimeric flap including a 4 x 4 cm LD muscle flap. The recipient vessels used were located above the ankle level away from the zones of injury. The anterior tibial vessels were used in five cases and posterior tibial vessels in the five others. Final ambulation states and late complications were evaluated in outpatient clinics during the follow-up period. Ambulatory states were evaluated by the Functional Ambulation Classification (FAC) in outpatient clinics. All of the patients were able to walk alone. Three were able to walk independently at FAC level 6 using foot orthoses and footwear, and one could walk independently on level surfaces at FAC level 5. The remaining two patients could walk independently at FAC level 4 using walking aids. The average FAC level was 5.2.
Conclusions: There are no specific preventions or treatments for symmetrical peripheral gangrene. As a result, amputation is often inevitable due to the irreversibly necrotic tissue that can cause secondary infection. Past efforts have been made to preserve the length of the limb by distal amputation depending on available soft-tissue coverage. After minimal bony amputation, reconstruction with the thoracodorsal free flap was performed and found to be successful in foot salvage in patients with symmetrical peripheral gangrene.