Optimal Vessel Sizing and Understanding Dissections in Infrapopliteal Interventions: Data From the iDissection Below the Knee Study

Abstract

Purpose: To investigate if imaging with intravascular ultrasound (IVUS) yields a more accurate estimate of vessel diameter and the presence of dissections after intervention when treating the infrapopliteal arteries. Materials and Methods: A prospective, single-center study enrolled 20 consecutive patients (mean age 74.1±12.4 years; 12 women) with infrapopliteal disease who were treated with PTA (n=10) or orbital atherectomy (OA) followed by PTA (n=10). The majority of patients were hypertensive and half were diabetic. The overall lesion length was 7.3±6.3 cm, and the diameter stenosis was 80.3%±22.1%. The baseline characteristics did not differ between the groups. Vessel diameters were measured using IVUS from the internal elastic lamina (IEL) to the IEL. IVUS was performed at baseline, post PTA or OA, and post OA+PTA. Quantitative vascular angiography (QVA) and IVUS were analyzed by a core laboratory. Dissections on cine images were categorized based on the National Heart Lung and Blood Institute (NHLBI) classification, while the arc and depth were used to characterize dissections on IVUS images. Results: Mean vessel diameter by QVA was 2.9±0.6 vs 4.0±1.0 mm by IVUS according to the core laboratory (mean difference 1.1±0.9, p<0.001). On angiography, there were 7 dissections after PTA (6 C, 1 D), 1 dissection after OA (1 B), and 2 dissections after OA+PTA (1 A, 1 B; p=0.028 vs post PTA). IVUS uncovered 3.8 times more dissections than seen on angiography. There were 23 dissections after PTA (18 intima, 3 media, 2 adventitia), 12 dissections after OA (8 intima, 1 media, 3 adventitia), and 11 dissections following OA+PTA (7 intima, 1 media, 3 adventitia; p=0.425 vs PTA). Bailout stenting (all due to angiographic dissections ≥C) was necessary in 6 of the PTA cohort and none of the OA+PTA group. Conclusion: In addition to underestimating the infrapopliteal vessel diameter by ~25%, angiography underappreciated the presence and severity of post-intervention dissections vs IVUS, particularly in the OA+PTA group.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

“…Additional IVUS may also be valuable to confirm or identify dissections or residual lumen restrictions not readily apparent on angiography. 174 If a dissection persists, scaffold implantation may be necessary.…”

Intravascular Ultrasound–Guided Interventions for Below-the-Knee Disease in Patients With Chronic Limb-Threatening Ischemia

“…Intravascular ultrasound (IVUS)–guided intervention, a common strategy for coronary and femoropopliteal interventions, 14,15 is used to evaluate the target artery, monitor guidewire position, assess plaque morphology and calcification, measure the precise vessel diameter, and evaluate dissection. 14,16 Moreover, newer high-definition (HD) IVUS provides additional information, with clear images for peripheral interventions. 17 To determine if these benefits of IVUS guidance would translate into improved outcomes for patients requiring BTK EVT, a study was designed to compare CTLI patients who underwent IVUS-guided vs angiography-guided balloon angioplasty.…”

Commentary: Tic-Tack-Save the Toes: Tacking Dissections in the Infrapopliteal Arteries

“…Angiography underestimates the number and, just as importantly, the severity of dissections in PAD interventions when compared with intravascular imaging (IVI). [19][20][21] IVI provides precise measurements of the vessel in question, measurements that are systematically underestimated by operators when judging angiography alone. 19,22 Limited data support the premise that intravascular ultrasound (IVUS) improves long-term primary patency rates in the femoropopliteal segment with the adjunctive use of IVUS compared to angiography alone.…”

“…[19][20][21] IVI provides precise measurements of the vessel in question, measurements that are systematically underestimated by operators when judging angiography alone. 19,22 Limited data support the premise that intravascular ultrasound (IVUS) improves long-term primary patency rates in the femoropopliteal segment with the adjunctive use of IVUS compared to angiography alone. 23 How much better would existing BTK options perform if their sizing was guided by IVI?…”