Have Endovascular Advances Reinvented Limb Salvage Expectations?
In the early 1980s, LoGerfo opened the window of limb salvage in critical stages of diabetic atherosclerosis by fighting the misconception of microangiopathy that had previously prevented attempts to bypass arterial lesions in diabetic foot.1 He produced evidence that revascularization of distal diabetic arterial occlusions can be successful. This evidence in turn gave a fundamental push to expand and improve techniques of distal bypass.2,3
Physicians then applied the same techniques for the treatment of non-diabetic atherosclerosis to diabetic atherosclerosis. At this time, the concept of critical limb ischemia (CLI) emerged and limb salvage was the expected goal. Soon we saw that long-term results of distal revascularization in patients with diabetes were not inferior when physicians measured them in terms of limb salvage. This boosted the practice of distal bypass for diabetic arterial lesions.
Subsequently, researchers observed that following distal bypass in patients with diabetes, physicians could salvage limbs despite the vessels’ reocclusion. Consequently, bypass patency rates have been consistently lower than limb salvage rates over
the years as reported in the literature.
How Endovascular Approaches Have Evolved Over The Years
In the last 10 years, improvements in techniques and materials helped us to extend the endovascular approach to distal vessels successfully. In addition to the efficacy of the endovascular approach, it is a simpler technique for various specialists to master and patients widely prefer an endovascular approach to bypass surgery. These factors, among others, have helped in the consequential widespread applications and indications for endovascular techniques.
Today, most centers routinely perform femoral, popliteal and tibial endovascular interventions. Accumulated data supports this practice and shows evidence of the immediate efficacy of these interventions.4 The effect of this phenomena and the current trend of its practice have pushed the endovascular approach further distally, so much so that sometimes surgeons perform single tibial interventions in patients with diabetes and CLI.5-7
Most studies on revascularization procedures today insist on either limb salvage or major amputation-free survival as the primary efficacy endpoint. Ulcer healing is seldom considered to be a criterion for success.8
To this endpoint, results may appear exceptional (generally over
a 95 percent limb salvage rate) despite very poor outcomes in terms of patency of the recanalized vessels (generally below 50 percent). In addition, while the literature always claims a near 100 percent limb salvage rate, there is a consistently high number of “minor amputations” (reportedly up to 48.6 percent) cited alongside of this figure.9
We experience the same outcome in our center, where the endovascular approach to the ischemic diabetic foot leads to a 96 percent one-year limb salvage rate despite a 76 percent to 86 percent targeted vessel patency rate according to the technology (PTA/stent versus endoluminal laser assisted atherectomy) vascular surgeons have applied.