Surgery or endovascular therapy for chronic limb-threatening ischemia
N Engl J Med. 2022 Dec 22;387(25):2305–2316. doi: 10.1056/NEJMoa2207899. Epub 2022 Nov 7.
Farber A, Menard MT, Conte MS, Kaufman JA, Powell RJ, Choudhry NK, Hamza TH, Assmann SF, Creager MA, Cziraky MJ, Dake MD, Jaff MR, Reid D, Siami FS, Sopko G, White CJ, van Over M, Strong MB, Villarreal MF, McKean M, Azene E, Azarbal A, Barleben A, Chew DK, Clavijo LC, Douville Y, Findeiss L, Garg N, Gasper W, Giles KA, Goodney PP, Hawkins BM, Herman CR, Kalish JA, Koopmann MC, Laskowski IA, Mena-Hurtado C, Motaganahalli R, Rowe VL, Schanzer A, Schneider PA, Siracuse JJ, Venermo M, Rosenfield K, BEST-CLI Investigators
Background: Patients with chronic limb-threatening ischemia (CLTI) require revascularization to improve limb perfusion and thereby limit the risk of amputation. It is uncertain whether an initial strategy of endovascular therapy or surgical revascularization for CLTI is superior for improving limb outcomes.
Methods: In this international, randomized trial, we enrolled 1,830 patients with CLTI and infrainguinal peripheral artery disease in two parallel-cohort trials. Patients who had a single segment of great saphenous vein that could be used for surgery were assigned to cohort 1. Patients who needed an alternative bypass conduit were assigned to cohort 2. The primary outcome was a composite of a major adverse limb event—which was defined as amputation above the ankle or a major limb reintervention (a new bypass graft or graft revision, thrombectomy or thrombolysis)—or death from any cause.
Results: In cohort 1, after a median follow-up of 2.7 years, a primary-outcome event occurred in 302 of 709 patients (42.6%) in the surgical group and in 408 of 711 patients (57.4%) in the endovascular group (hazard ratio, 0.68; 95% confidence interval [CI], 0.59 to 0.79; P<0.001). In cohort 2, a primary-outcome event occurred in 83 of 194 patients (42.8%) in the surgical group and in 95 of 199 patients (47.7%) in the endovascular group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06; P=0.12) after a median follow-up of 1.6 years. The incidence of adverse events was similar in the two groups in the two cohorts.
Conclusions: Among patients with CLTI who had an adequate great saphenous vein for surgical revascularization (cohort 1), the incidence of a major adverse limb event or death was significantly lower in the surgical group than in the endovascular group. Among the patients who lacked an adequate saphenous vein conduit (cohort 2), the outcomes in the two groups were similar. (Funded by the National Heart, Lung, and Blood Institute; BEST-CLI ClinicalTrials.gov number, NCT02060630.)
Pulsed electric field ablation versus radiofrequency thermal ablation in murine breast cancer models: anticancer immune stimulation, tumor response, and abscopal effects
J Vasc Interv Radiol. 2024 Mar;35(3):442–451.e7. doi: 10.1016/j.jvir.2023.11.021. Epub 2023 Nov 30.
Pastori C, Nafie EHO, Wagh MS, Mammarappallil JG, Neal RE II
Purpose: To compare the immune response and survival after size-matched radiofrequency (RF) ablation and a proprietary form of pulsed electric field (PEF) ablation in murine tumors.
Material and methods: Orthotopically inoculated EMT6 or 4T1 murine tumors received sham, RF ablation or PEF ablation. 4T1 tumor ablations included subgroups with intraperitoneal checkpoint inhibition immunotherapy (αPD-1). Blood was collected for cytokine profiling and flow cytometry. Tumor size was measured and survival was monitored. Tumor samples were processed for histology, immunohistochemistry, flow cytometry, and cytokine profiling. Lungs were collected from 4T1-bearing mice for hematoxylin and eosin histology to assess metastatic spread and abscopal effect induced by ablation.
Results: PEF elicited distinct immunomodulatory effects, with clear differences in serum and tumor cytokine profiles compared with RF ablation, including intratumoral downregulation of vascular endothelial growth factor, hypoxia-inducible factor 1α, c-MET, interleukin-10, Ki67, and tumor necrosis factor-α (all P < .05). PEF increased innate immune activation, with enhanced recruitment of dendritic cells, M1 macrophages and natural killer cells coupled with a reduction in M2 macrophages and myeloid-derived suppressor cells (all P < .05). Concurrently, PEF strengthened adaptive immunity compared with RF ablation, characterized by increased antigen-specific T-cells and decreased regulatory T-cells (all P < .05). PEF stalled tumor growth and increased survival at the end of the study (≥4× versus RFA). Finally, PEF promoted an abscopal effect of clearing metastases in the lungs, which was stronger in combination with αPD-1 than with PEF alone.
Conclusions: The proprietary form of PEF used in this study evoked a preferential immunostimulatory profile versus RF ablation thermal ablation in mice, with implications for enhancing the therapeutic effectiveness of checkpoint inhibition immunotherapy for immunotherapy-unresponsive tumors.
