Deep vein Arterialization in patients with critical “non-revascularizable” limb ischemia.
We are familiar with the poor quality of life and elevated mortality of patients with chronic limb-threatening ischemia (CLTI). In its last stages (nearly terminal), revascularization (either surgical or endovascular) has been shown to reduce amputation incidence.
However, similarly to heart disease and other vascular scenarios, there are cases with complex anatomy (no arterial targets for distal runoff or suitable conduits for surgical bypass) such that will exclude them from revascularization and catalogue them as non-revascularizable (reaching 20% of patients with critical limb ischemia).
The concept of deep vein arterialization was introduced as a surgical procedure over 100 years ago. However, it presented numerous complications, being ‘steal phenomenon’ one of the most common. Its transcatheter alternative allows us to create an arteriovenous fistula proximal to the affected segment with the use of a self-expanding covered stent (endovascular valvotomy will establish arterial blood flow into the venous system of the foot, limiting steal phenomenon) and restore oxygenated blood to the pedal veins.
The PROMISE II was a single arm, multicenter, prospective study, carried out in the US to assess the safety and efficacy of transcatheter deep vein arterialization. It included patients with critical limb ischemia, Rutherford class 5 (local gangrene) or 6 (extensive gangrene), and also patients with chronic diabetes (dialyzed via autologic vessels or peritoneal dialysis). It excluded patients with systemic infection, rapidly deteriorating wounds, or advance cardiac failure. A Limflow device was used for the procedure (with DAPT before and after procedure).
Primary end point was amputation free survival (above the ankle) at 6 months. Secondary end point included primary patency, assisted primary patency or secondary patency, Rutherford class change and target lesion healing. Primary end point was compared against a pre-specified performance goal (54%).
Between December 2019 and March 2022, 105 patients were enrolled, mean age was 70, 31.4% were women and 42.8% were Black, Hispanic or Latin. Most were diabetic and hypertensive. 74.3% had already had index limb revascularization, while 18.1% were on dialysis.
Arterialization was successful in 99% of cases, being the posterior tibial the most common crossing (75.2%), followed by the peroneal (19%). Mean procedure duration was 199 minutes and less than 2% presented contrast induced nephropathy.
According to Bayesian analysis, the posterior probability of amputation-free survival at 6 months was 66.1%, exceeding the performance goal of 54% by 0.993, which exceeded the pre-specified threshold. There was 87.1% survival and limb salvage rate was 76%. The subgroup of dialysis patients presented 36.8% incidence of amputation free survival, compared against non-dialysis patients with 72.7%. Also, mortality was higher in this subgroup (36.2% vs 8.6%).
Read also: When Is It Best to Fracture a Bioprosthesis in TAVR?
At 6 months, primary patency was 25.9%, assisted primary patency 45.4% and secondary patency 64.2%. Rutherford class was reduced in 42% of cases and as regards wounds, 25% were completely healed and 51% were in the process of healing. There were no serious adverse events.
Conclusions
Arterialization showed favorable results at 6 months, which makes it a promising option for patients previously considered untreatable. However, nearly three quarters of these patients required new interventions to maintain secondary patency. At short term, there were no congestive venous events, which should be reassessed at long term. We still have to carefully select patients, seeing as the dialysis population did not show promising results.
Dr. Omar Tupayachi.
Member of the Editorial Board of SOLACI.org.
Original Title: Transcatheter Arterialization of Deep Veins in Chronic Limb-Threatening Ischemia.
Reference: Shishehbor, Mehdi H et al. “Transcatheter Arterialization of Deep Veins in Chronic Limb-Threatening Ischemia.” The New England journal of medicine vol. 388,13 (2023): 1171-1180. doi:10.1056/NEJMoa2212754.
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