Keywords
diabetic foot ulcers - hanging pedicle - microvascular reconstruction - free tissue
transfer
Diabetic foot ulcers (DFUs) are a severe complication of diabetes with significant
morbidity, mortality, and health care costs.[1] Despite advances in wound care and limb revascularization, many patients still undergo
amputation, increasing 5-year mortality rates by up to 80%.[2]
[3] While numerous treatment modalities exist for this challenging pathology, limb salvage
remains the ultimate goal.
Given their complex nature, DFU treatment requires a multidisciplinary approach to
optimize nutritional status, comorbidities, and local wound care while providing appropriate
footwear and patient education.[2] Revascularization procedures and antibiotics should be implemented when appropriate.
If these measures fail, microsurgical free-tissue transfer can be considered in suitable
candidates, with consistently high rates of flap survival and long-term salvage.[1]
[3]
[4]
Microvascular reconstruction in the diabetic patient warrants thorough preoperative
evaluation and perioperative management to mitigate risk factors that increase flap
failure.[1]
[2]
[3] Concomitant atherosclerotic disease, which further complicates reconstruction, can
be overcome by using end-to-side anastomoses to preserve distal blood flow and minimize
vascular spasm, harvest of a long pedicle to escape the zone of inflammation, and
utilization of supermicrosurgery in the absence of adequate major recipient vessels.[4]
[5] Though successful, these methods are limited by technical difficulty, surgeon expertise,
and available technology. Additionally, these procedures are time-consuming and can
result in added incisions in an already ischemic limb with healing difficulties.
To decrease operative time and minimize the number of incisions and risk of wound
healing complications, we suggest the use of the “hanging” free flap for the reconstruction
of chronic lower extremity diabetic ulcers. Following patient optimization and adequate
wound debridement, our reconstruction involves standard free flap harvest, end-to-end
microsurgical anastomosis, and inset. Following flap inset, we cover the “hanging”
pedicle with a skin graft instead of making extraneous incisions within the undisturbed
soft tissues or tunnels that can compress the vessels ([Fig. 1] and [Video 1]). While the flap incorporates, the exposed pedicle is protected with a soft dressing.
After incorporation, the patient undergoes a second-stage surgery in 4 to 6 weeks
which entails pedicle division, flap inset revision, and end-to-end reconstruction
of the recipient vessel. We have utilized this technique to reconstruct 10 patients
so far. Patients (ages 41 to 57) had prolonged history of diabetes complicated by
chronic stage 3 lower extremity ulcers. Defects ranged between 18 and 23 cm2 and were located over the distal third of the leg or the foot. Defects were reconstructed
using the first dorsal metacarpal artery perforator, radial forearm, and anterolateral
thigh free flaps. All patients underwent successful flap division ([Figs. 2] and [3]) with 100% flap survival rate. One patient developed partial necrosis of the distal
tip of the flap that was managed conservatively.
Fig. 1 “Hanging” pedicle immediately postoperatively, covered with skin graft.
Fig. 2 Wound following incorporation, pedicle division, and flap revision.
Fig. 3 Pictorial representation of the extracorporeal pedicle reconstruction.
Video 1 Video detailing original wound following debridement, radial forearm harvest, “hanging
pedicle” overlying flap coverage, subsequent coverage of pedicle with skin graft,
and immediate postoperative result.
Free tissue transfer to reconstruct poorly vascularized lower extremity DFU remains
the cornerstone for limb salvage in diabetic patients. Besides decreasing the number
of incisions on diabetic patients, our novel technique utilizing the “hanging” pedicle
simplifies flap monitoring and inset. Furthermore, it allows reconstruction of recipient
vessels to reestablish distal blood flow. There is no substantial increase in operative
skill required to incorporate our technique into surgical practice.
