How Fluorescence Angiography Can Clarify Treatment Options For Patients With PAD

Mark Snyder, DPM, FACFAS

How Fluorescence Angiography Can Clarify Treatment Options For Patients With PAD

Mark Snyder, DPM, FACFAS

October 2016

This author provides insights on how fluorescence angiography helped prevent a hallux amputation in an 80-year-old patient.

Technology is advancing and giving us tools to facilitate better outcomes in surgery. I have been utilizing SPY Elite technology (Novadaq Technologies) to assist me in my medical decisions. For years, vascular surgeons have told me they had done all they could and we should “go ahead and see what happens during the amputation or wound debridement.” However, regardless of our skills as great surgeons, if the microvasculature is poor, it is common that the wound will dehisce. This puts the patient at risk for multiple procedures.

What if we could see the level of amputation that would be necessary for optimal healing? Fluorescence angiography gives you that tool. SPY technology uses an imaging agent of indocyanine green (ICG), which the Food and Drug Administration approved in 1959. The liver metabolizes ICG and it is safe for patients with impaired kidneys. Indocyanine green is contraindicated in patients with iodine sensitivity. Indocyanine green binds to the plasma protein and travels to the area to be evaluated. Utilizing the near-infrared laser and camera device intraoperatively, we can see the small vessel blood flow.

A Closer Look At The Patient Presentation

An 80-year-old Hispanic male with peripheral arterial disease (PAD) presented to the hospital. He had a previous endovascular procedure performed by his cardiologist. I consulted for an amputation of the hallux.

The patient had a necrotic hallux with full thickness necrotic wound at the fifth metatarsal base and a wound at the heel. Prior to SPY technology, I would have proceeded with the amputation and possible debridement of the wound. I would have waited for the amputation to fail, which may have subsequently prompted a below-the-knee amputation. However, instead of placing this patient at risk of multiple failed procedures, I utilized fluorescence angiography to make a definitive treatment plan.

The patient went into the OR for evaluation of wounds on March 18, 2016. I injected ICG (2.5 mg/mL in 4mL) and performed SPY imaging of the hallux and necrotic foot wounds.

This allowed discussion with the cardiologist about trying to increase the blood flow to the patient’s peroneal artery for the best outcome. The cardiologist was able to use this information and focus his time on opening that vessel during his endovascular procedure.

I planned a subsequent visit to the OR for a planned hallux amputation and wound debridement with repeat SPY imaging. However, the plan changed and I made an intraoperative decision to debride all wounds and use an acellular dermal matrix (DermaACELL, LifeNet Health/Novadaq Technologies) over the wounds along with VAC Therapy (KCI). I utilized the SPY Elite technology after surgical debridement. Doing so allowed me to avoid the amputation. I again utilized the SPY imaging after graft placements.

Note that if I planned a transmetatarsal amputation, it would have failed. Using the SPY technology helped me identify the lack of uptake along the arcuate artery.

In Conclusion

I feel fluorescence angiography will become the gold standard in preoperative planning for wound care and amputations. I have incorporated this technology in all my amputation procedures and have had great success with only one wound dehiscence caused by lack of adherence by the patient.

This technology gave me the ability to salvage the foot of a patient, who most likely would have had multiple surgical trips to the operating room. Overall, this saves the patient time and ensures the best surgical outcome.