Microvascular distal foot arterialization with flow through free flaps for salvage of the no-option foot

Abstract

Patients with chronic limb-threatening ischemia, advanced foot wounds, and no pedal revascularization targets often face amputation. Deep vein arterialization has significant drawbacks. We report three cases using flow-through free flaps with microvascular distal foot arterialization to salvage ischemic feet with complex wounds. All flaps survived. Patients achieved wound healing and ambulation. Two maintained perfusion at 3 and 6 years. One required transmetatarsal amputation at 14 months but remains ambulatory. This technique provides a novel salvage option for the “no-option” foot by combining soft tissue coverage and selective arterialization of small distal veins, avoiding complications of deep vein arterialization and offering durable perfusion.

Traditional revascularization is often ineffective or impossible in patients with severe pedal vascular disease lacking arterial targets. Approximately 20% of patients with chronic limb-threatening ischemia (CLTI) fall into this “no-option” group, with high rates of major amputation.1, 2, 3

Deep vein arterialization (DVA) has been used to treat lower extremity wounds in otherwise high-functioning patients.4, 5, 6, 7 However, DVA can cause chronic limb edema and cardiac strain. Only 53.4% of patients achieve full wound healing, and 46.7% require reintervention.⁸

For patients with extensive wounds and exposed tendon or bone, flap reconstruction is contraindicated because surrounding tissue perfusion is required for healing.⁹ DVA alone is often insufficient. In these cases, guillotine transmetatarsal amputation (TMA) is commonly performed, but it carries a prolonged healing time and osteomyelitis risk.

In 2020, we introduced a novel technique combining flow-through free flap coverage and selective distal foot venous arterialization at the microvascular level, achieving rapid, complete healing and preserving ambulation in a patient with a Wound, Ischemia, and foot Infection (WIfI) grade 3 plantar forefoot wound¹⁰ (Fig). At 6 years, the patient remains ambulatory. This report expands upon that single case with two additional patients undergoing microvascular distal foot arterialization for limb salvage.

Fig.

Schematic of the vascular “plumbing” of the case, demonstrating a free muscle flap anastomosed end-to-side (ETS) to the bypass vessel, and a flow-through artery anastomoses end-to-end to the dorsal vein to the first webspace after lysis of venous valves. Reproduced from Effendi M, Ha AY, Felder JM 3rd. Foot salvage with selective arterialization of pedal venosomes. PRS Global Open 2020; 8:e2612. Licensed under CC BY 4.0.

Case reports

Patient selection

Candidates were those requiring free flap wound coverage with no feasible traditional revascularization options. They typically presented with Global Limb Anatomic Staging System (GLASS) P1/P2 perfusion and WIfI grade 2 or 3 wounds. A preserved dorsal venous arch was essential, favoring patients with plantar wounds. Candidates had in-line arterial flow to the ankle via a compliant vessel and no significant arterial calcification, as determined by imaging, physiologic testing, or intraoperative findings. Those suitable for TMA were excluded. Valve lysis depended on vein size: small veins required none; larger veins (>2 mm) underwent retrograde dilator passage or direct excision via venotomy if valves visibly impeded flow. Outflow vein patency was presumed clinically; future cases may benefit from preoperative duplex ultrasound to confirm dorsal venous system integrity and optimize planning. All cases were managed within a multidisciplinary limb salvage program involving vascular surgery, plastic and reconstructive surgery, podiatry, and wound care. Free flaps were performed by a microsurgeon. Anastomoses were performed with either 4× loupe magnification or an operating microscope, and 8-0 nylon suture was used for all vascular repairs.

Cases, technique, and outcomes

Videos are provided with further details of each patient’s course (Supplementary Videos 1 and 2, online only).

Patient 1

A 48-year-old diabetic man with CLTI presented with a WIfI grade 3 plantar forefoot ulcer with osteomyelitis. Ten years earlier, he underwent popliteal to distal posterior tibial (PT) bypass using a saphenous vein graft. Angiography revealed severe trifurcation disease and chronic total occlusion of anterior tibial, PT, and peroneal arteries. Pedal angiography demonstrated a GLASS P1 foot with largely absent dorsal circulation and no further targets for arterial revascularization. Stenosis of the origin of the bypass was treated with angioplasty, complicated by intimal dissection, and then stented. Perfusion to the foot was still clinically inadequate, with progressive gangrene within the wound, and pallor of the first webspace. A partial medial rectus flap was chosen, perfused by the medial branch of the deep inferior epigastric artery with the lateral branch used for outflow as a flow-through vessel. The flap artery and vein were anastomosed end-to-side (ETS) to the distal saphenous vein graft bypass and PT vena comitantes at the ankle, respectively. The flap was inset after debridement. The dorsal foot veins supplying the first webspace were divided proximally, reflected medially, and anastomosed to the flow-through artery of the flap. This arteriovenous anastomosis achieved arterialization of the forefoot, with resolution of the ischemic tissue changes. Revascularization achieved was durable at 10 months postoperatively, with Doppler examination demonstrating arterialized signals throughout the dorsal forefoot (Supplementary Video 1, online only). There was no chronic edema or venous engorgement of the foot noted. Six years after flap creation, the patient remains ambulatory with no additional surgical procedures performed on the left lower extremity (Supplementary Video 1, online only).

Patient 2

A 72-year-old diabetic man with CLTI had a worsening WIfI grade 3 lateral plantar ulcer with osteomyelitis and superficial dry gangrene of the dorsal toes. Angiography demonstrated trifurcation disease with chronic total occlusions of the anterior tibial and peroneal vessels. Angioplasty of the PT resulted in improved runoff but a GLASS P1 foot with absent dorsal circulation.

A radial forearm free flap was used. ETS anastomosis was performed between the radial artery and the PT artery at the ankle, along with their venae comitantes. Because the radial artery does not have significant side branches that can be used for end-to-end arterialization, the medial marginal vein of the foot was divided proximally, transposed medially towards the radial artery, and anastomosed ETS to the radial artery. Although not a classic flow-through flap, the radial artery also served as the arterialization conduit. At 7 months, the wound had healed with restored foot perfusion. Postoperative Doppler examination demonstrated strong arterialized signals throughout the foot. However, at 14 months, the patient developed distal wet gangrene requiring TMA. Notably, arterialization was successful and maintained for over 1 year; the subsequent TMA was performed for a new wound unrelated to the original reconstruction. PT artery runoff remained patent. At 4 years, the TMA site is healed, and the patient ambulates with a walker.

Patient 3

A 60-year-old diabetic female smoker presented with infrarenal aortic occlusion and dry gangrene of the hallux and first ray. Despite aortic endarterectomy and aortobifemoral bypass, she had single-vessel PT runoff and poor perfusion, with cyanosis and 7-second capillary refill. Excision of the gangrenous ray resulted in minimal bleeding from the surrounding viable tissues, and the dorsalis pedis was noted to be chronically occluded within the wound. Wound reconstruction of the first ray amputation site was performed using a latissimus dorsi free flap ETS to the posterior tibial artery at the ankle. The serratus anterior branch of the thoracodorsal artery was used to arterialize a midline dorsal foot vein that fed the remaining distal dorsal subcutaneous venous arch of the foot. Venous valves were mechanically disrupted. At 7 months, the foot was well-healed with normal color and capillary refill and strong arterialized signals throughout the foot and toes. At 3 years, the foot remains free of wounds, and the patient ambulates independently (Supplementary Video 2, online only).

Written consent was obtained from all patients for publication of case details, photographs, and videos.

Discussion

In cases of unreconstructable distal arterial disease, surrounding tissues often cannot support healing—even if a flap survives. Our solution both reconstructs the wound and provides durable arterial reconstruction via microvascular arterialization of the venous system. This technique is most applicable to patients with plantar forefoot wounds, preserved ankle-level inflow, and nonreconstructible distal arterial disease. All three cases involved patients who otherwise would have required below-knee amputation due to plantar wound locations that ruled out successful TMA. In two of the patients, residual ischemia would have made healing of any partial foot amputation unlikely.

This technique allows the entire foot to be salvaged apart from what has already undergone necrosis, an improvement to a TMA. The forefoot, which is the most ischemic area and most subject to new wound formation, is selectively arterialized, which provides durable revascularization. This reduces the likelihood of new wound formation in the forefoot, which is traditionally the argument for performing a TMA.

Our technique of selective distal superficial venous arterialization offers several advantages over standard DVA. By using a smaller-caliber arterial inflow from the flap, we avoid the edema and pain often associated with high-flow arterialization of the entire dorsal venous arch. This approach also eliminates the need for prosthetic conduits, which have high early failure rates, and instead targets perfusion to the distal forefoot tissues most in need of revascularization. Adequate inflow and intact distal dorsal foot veins are necessary; thus, we limited inclusion to patients with an ankle pulse and excluded those with significant arterial calcification near the ankle. Limitations include the small sample size, lack of follow-up imaging, and reliance on Doppler exams rather than angiography, which was not clinically justifiable given the stable result. Broader application is currently limited by low awareness among vascular surgeons. We hope this report promotes further study of this promising technique.

Funding

None.

Disclosures

None.

Appendix (online only)

Supplementary Video 1

Patient 1, foot salvage with selective arterialization of the venous system.

Supplementary Video 2

Patient 3, arterialization of midline dorsal foot.