Mid-term outcomes of Shockwave intravascular lithotripsy in the IVLIAC Registry for the treatment of calcified iliac occlusive disease

Objective: The aim of this study was to evaluate safety and efficacy of intravascular lithotripsy (IVL) treatment in calcified iliac arteries and explore a new approach to determining whether to stent or not to stent calcific iliac vessels. Methods: All consecutive patients who underwent IVL (Shockwave Medical) for calcified iliac arteries from February 2021 to May 2024 at four centers were included. Indication for IVL was Rutherford category ≥3 in iliac lesions with moderate-to-severe calcification and was based on a new algorithm: IVL as stand-alone therapy ± provisional stenting in case of stenosis, or IVL as vessel preparation for planned stenting in cases of chronic total occlusion. The primary endpoint was primary patency; assisted primary patency, secondary patency, and freedom from iliac complications were also analyzed. Clinical and procedural data were compared between two groups: IVL stand-alone therapy (IVL ONLY) vs IVL with adjunctive stenting (IVL + STENT). Indication for IVL ONLY was based on adjunctive completion assessments (extravascular ultrasound and translesional gradient pressure). A Cox regression univariate analysis between cases with or without target lesion revascularization was performed. Results: In total, 100 iliac arteries were treated in 86 patients (52 male; mean age, 74 ± 9 years). Median follow-up was 20 months (range, 1-45 months). Critical limb ischemia was present in 55% of the patients, the majority of whom (75%) had severe calcifications (180°-360°). The mean target lesion length was 40.95 ± 29.25 mm with a mean stenosis of 84% ± 10% (12 chronic total occlusions). Technical success was 99%. The target lesions were treated with IVL ONLY in 77% of cases, whereas IVL + STENT was employed in the remaining 23% of the cases (provisional stenting, 11%; planned stenting, 12%). Mean residual stenosis was 14.95% ± 14% at final angiogram. Extravascular ultrasound with improved imaging (bi-triphasic in place of monophasic/blunted ipsilateral common femoral artery waveform), and/or decreased translesional gradient pressure (mean, −71%) were detected in all IVL ONLY cases. Primary patency and assisted primary patency at 24 months were 95% (95% confidence interval, 85.1%-98.1%) and 98% (95% confidence interval, 92%-99.5%), respectively, whereas secondary patency was 100%. Primary patency showed no statistically significant difference (P = 24) between the IVL ONLY and IVL + STENT groups. There was one iliac rupture and no distal embolization. Longer target lesions (P = 24) were significantly related to target lesion revascularization. Conclusions: IVL is a safe and effective treatment option for calcific iliac occlusive disease. This multicenter experience shows promising mid-term results in terms of primary patency despite the very low stenting rate, preserving future treatment options. Further studies are needed to confirm these findings.