Protocol Adaptation of Optical Coherence Tomography in Lower Limb Arteries Revascularization

Lesion Eccentricity Plays a Key Role in Determining the Pressure Gradient of Serial Stenotic Lesions: Results from a Computational Hemodynamics Study

PURPOSE

In arterial disease, the presence of two or more serial stenotic lesions is common. For mild lesions, it is difficult to predict whether their combined effect is hemodynamically significant. This study assessed the hemodynamic significance of idealized serial stenotic lesions by simulating their hemodynamic interaction in a computational flow model.

MATERIALS AND METHODS

Flow was simulated with SimVascular software in 34 serial lesions, using moderate (15 mL/s) and high (30 mL/s) flow rates. Combinations of one concentric and two eccentric lesions, all 50% area reduction, were designed with variations in interstenotic distance and in relative direction of eccentricity. Fluid and fluid-structure simulations were performed to quantify the combined pressure gradient.

RESULTS

At a moderate flow rate, the combined pressure gradient of two lesions ranged from 3.8 to 7.7 mmHg, which increased to a range of 12.5-24.3 mmHg for a high flow rate. Eccentricity caused an up to two-fold increase in pressure gradient relative to concentric lesions. At a high flow rate, the combined pressure gradient for serial eccentric lesions often exceeded the sum of the individual lesions. The relative direction of eccentricity altered the pressure gradient by 15-25%. The impact of flow pulsatility and wall deformability was minor.

CONCLUSION

This flow simulation study revealed that lesion eccentricity is an adverse factor in the hemodynamic significance of isolated stenotic lesions and in serial stenotic lesions. Two 50% lesions that are individually non-significant can combine more often than thought to hemodynamic significance in hyperemic conditions.

Peripheral arterial disease treatment planning using noninvasive and invasive imaging methods

With the growing prevalence and mortality of peripheral arterial disease, preoperative assessment, risk stratification, and determining the correct indication for endovascular and open surgical procedures are essential for therapeutic decision-making. The effectiveness of interventional procedures is significantly influenced by the plaque composition and calcification pattern. Therefore, the identification of patients for whom endovascular treatment is the most appropriate therapeutic solution often remains a challenge. The most commonly used imaging techniques have their own limitations and do not provide findings detailed enough for specific, personalized treatment planning. Using state-of-the-art noninvasive and invasive imaging modalities, it is now possible to obtain a view, not only of the complex vascular anatomy and plaque burden of the lower extremity arterial system, but also of complex plaque structures and various pathologic calcium distribution patterns. In the future, as these latest advancements in diagnostic methods become more widespread, we will be able to obtain more accurate views of the plaque structure and anatomic complexity to guide optimal treatment planning and device selection. We reviewed the implications of the most recent invasive and noninvasive lower extremity imaging techniques and future directions.

Optical Coherence Tomography Contribution Assessment in the Revascularization of Long Femoropopliteal Occlusive Lesions (TASC C and D): A Randomized Trial

BACKGROUND

Endovascular treatment has become the first-line revascularization technique for femoropopliteal lesions. This technique lacks reliable and accurate morphological control of the arterial segment treated. Intraoperative 2-dimensional angiogram consumes iodinated contrast media and increases X-ray exposure; this subsequently provides no 3-dimensional information on the quality of the revascularization completed, what could explain some of the early and late failures of the technique. We evaluated whether intraoperative optical coherence tomography (OCT) control in addition to standard angiogram could improve the primary patency rate at 12 months in comparison to standard angiogram alone in patients with occlusive femoropopliteal lesions.

METHODS

The tomography by optical coherence in femoral artery trial is a multicentric, prospective, randomized, controlled, and single-blind study including patients with long de novo occlusive femoropopliteal lesions. The randomization will be achieved in 2 balanced groups of patients after crossing successfully the lesion: group 1 with intraoperative OCT control in addition to standard angiogram and group 2 with standard angiogram alone. The randomization will be stratified by center. The protocol has been submitted and approved by a French ethic's committee under reference number CPP2019-12-098. The study has been registered under the reference number NCT04434586 on the Web site of clinicaltrials.gov.

RESULTS

The primary outcome of the study is the primary patency at 12 months. The number of patients who need to be treated is 166 (83 in each group) considering 5% of no workable data. Symptoms' improvement, target lesion revascularization, target vessel revascularization, quality-of-life questionnaires, cost utility, and cost effectiveness will be analyzed as secondary end-point variables at 12 months.

CONCLUSIONS

The present study is to evaluate the potential benefit for patients on the result of endovascular revascularization of long occlusive femoropopliteal lesion at 12 months when using intraoperative OCT control.