Primary Cryoplasty Therapy Provides Durable Support for Limb Salvage in Critical Limb Ischemia Patients with Infrapopliteal Lesions: 12-Month Follow-up Results from the BTK Chill Trial

• Published in: Journal of endovascular therapy 2009-04, Vol.16 (2_suppl), p.19-30
• Main Authors: Das, Tony S., McNamara, Thomas, Gray, Bruce, Sedillo, Gino J., Turley, Brian R., Kollmeyer, Kenneth, Rogoff, Michael, Aruny, John E.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Amputation; Angioplasty, Balloon - adverse effects; Apoptosis; Arterial Occlusive Diseases - complications; Arterial Occlusive Diseases - diagnostic imaging; Arterial Occlusive Diseases - mortality; Arterial Occlusive Diseases - therapy; Catheters; Constriction, Pathologic; Critical Illness; Cryotherapy - adverse effects; Design; Dissection; Heart surgery; Hospitals; Humans; Inflation; Ischemia - diagnostic imaging; Ischemia - etiology; Ischemia - mortality; Ischemia - therapy; Leg - blood supply; Limb Salvage; Male; Mechanical properties; Medical imaging; Middle Aged; Patients; Popliteal Artery - diagnostic imaging; Prospective Studies; Radiography; Severity of Illness Index; Time Factors; Treatment Outcome; United States
• ISSN: 1526-6028; 1545-1550
• DOI: 10.1583/08-2652.1

Purpose: To report the 12-month follow-up data from the prospective 16-center Below-the-Knee (BTK) Chill Trial, which examined the use of primary cryoplasty for BTK occlusive disease in patients with critical limb ischemia (CLI). Methods: The trial included 108 patients (77 men; mean age 73±11 years, range 41–101) with CLI (Rutherford categories 4–6) involving 111 limbs with 115 target infrapopliteal lesions. Angiographic inclusion criteria were reference vessel diameter ≥2.5 mm and ≤5.0 mm and target lesion stenosis ≥50%. The primary study endpoints were acute technical success (the ability to achieve ≤50% residual stenosis and continuous inline flow to the foot) and absence of major amputation of the target limb at 6 months. Secondary endpoints were serious adverse events specifically related to use of primary cryoplasty and absence of major amputation of the target limb at 1, 3, and 12 months. Results: Acute technical success was achieved in 108 (97.3%) of treated limbs, with only 1 clinically significant dissection (≥type C) and 2 residual stenoses >50%; stent placement was required following cryoplasty in only 3 (2.7%) procedures. At 6 months and 1 year, major amputation was avoided in 93.4% (85/91) and 85.2% (69/81) of patients, respectively. Through 1 year, 21% (17/81) of patients underwent target limb revascularization. Rates of major amputation and death at 1 year were 0% for limbs of patients with initial Rutherford category 4; 11.4% and 0%, respectively, for initial category 5; and 40.0% and 31.8% for initial category 6. One-year rates of major amputation and death were 20.4% and 8.8%, respectively, for diabetics, versus 4.0% and 10.7% for non-diabetics. At 1 year, major amputation occurred in 16.7% (2/12) of limbs that were expected to be amputated at the time of treatment. Conclusion: Cryoplasty therapy is a safe and effective method of treating infrapopliteal disease, providing excellent results and a high rate of limb salvage in patients with CLI. Study outcomes through 1 year support the use of cryoplasty as a primary treatment option for patients with CLI secondary to BTK occlusive disease.