Excerpted from “Transpedal Interventions for Critical Limb Ischemia” by John H. Rundback, MD, and Kevin “Chaim” Herman, MD:
Critical limb ischemia (CLI) represents the most advanced form of peripheral arterial occlusive disease (PAOD), manifested by pain at rest, focal or diffuse foot and ankle ulcerations, or gangrene. The rate of PAOD progression to CLI may approach 25%,1 and these patients have a particularly poor prognosis. For patients with CLI, the natural clinical course over 1 year from the time of diagnosis has been estimated to follow the “rule of quarters,” with approximately one-quarter resolving, one-quarter having persistent CLI and ulceration, one-quarter having undergone major amputation, and one-quarter dying.2,3 Following amputation, nearly half of patients die within 1 year, and half of survivors never ambulate.4 These factors, combined with an epidemic increased prevalence of progression to CLI in elderly, diabetic, and chronic kidney disease patients, make CLI a sizeable and increasing burden on the healthcare system.5,6
Historically, surgical7-9 and endovascular10-15 therapy for CLI have enabled approximately 80% “limb salvage.” Despite recognized risk factors, nearly 80% of patients who undergo major amputation fail to see a vascular specialist or undergo a vascular evaluation for potentially remediable disease.16,17 Referrals for possible revascularization are often late, with resultant patterns of disease that are often challenging for reconstruction. Notably, in this population, there is a high proportion of long-segment and multivessel tibial occlusion, a paucity of well-formed collaterals, dense calcification, and poorly delineated pedal outflow channels. Consequently, traditional methods of antegrade recanalization fail in a high percentage of cases.18
Combined retrograde and antegrade interventions have historical precedent for femoropopliteal revascularization using the initially described “Bolia” technique.19 In these cases, the recanalized channel may be either intraluminal or subintimal, with eventual capture or snare retrieval of a retrogradely passed wire into an antegrade catheter, allowing wire rendezvous and subsequent antegrade intervention. Recent work by others20-25 have demonstrated the ability to extend these “rendezvous” techniques to patients with complex patterns of tibial occlusive disease that either fail or are not amenable to other strategies.
For references from this excerpt and to read more about these techniques, see “Transpedal Interventions for Critical Limb Ischemia.”