Femoropopliteal Arterial Dissections Following FLEX VP and Balloon Angioplasty Versus Balloon Angioplasty Alone: Intravascular Ultrasound Assessment and Correlation With Angiographic Findings.

BACKGROUND: The Flex VP is a longitudinal micro-incision catheter approved for vessel prepping of femoropopliteal arteries and arteriovenous fistulas. In this study, we evaluated the presence of deep dissections (adventitia) using IVUS in patients undergoing Flex VP followed by angioplasty (PTA) versus PTA alone. METHODS: 17 patients (20 limbs) with femoropopliteal artery (FP) disease were prospectively and consecutively included (10 limbs received PTA followed by 10 limbs that received FLEX VP microincision catheter treatment followed by adjunctive PTA). Dissections post PTA, FLEX VP and FLEX VP+ PTA were evaluated using intravascular ultrasound (iDissection classification) and angiographically (NHLBI classification) by core laboratory. The evaluated segment of the vessel was prespecified at 10 cm at the most severe lesion location. Statistical differences were analyzed between the 2 groups at each appropriate procedural point for dissections, minimal luminal diameter (MLD), minimal luminal area (MLA), and residual stenosis. Statistical significance was determined by a p-value <0.05. RESULTS: Baseline demographics and angiographic variables were similar between the PTA vs FLEX VP + PTA groups with the exception of more males (87.5 % vs 33.3 %, p = 0.0274) and longer treated length (median 300 mm vs 150 mm, p = 0.0240) in the FLEX VP + PTA group. Lesion length, chronic total occlusions, angiographic and IVUS evaluated segment length for dissections, calcium severity and final balloon pressures and inflation duration were all similar between the 2 groups. Angiographic dissections were similar between the 2 groups but the increase in severe dissections from index to post POBA on IVUS (involving the adventitia) were significantly more for PTA when compared to FLEX VP + PTA (0 to 12 and 0 to 1 respectively, p = 0.0353). Bailout stenting was statistically similar for PTA as compared to FLEX VP + PTA per core lab evaluation (50 % vs 20 %, p = 0.3498). Minimal luminal area (MLA) gain by IVUS was similar between the 2 groups following FLEX VP + PTA vs PTA (7.4 mm2 vs 6.5 mm2, p = 0.7250). No serious major adverse events occurred in either group. CONCLUSION: Vessel prepping with the FLEX VP + PTA vs PTA yielded lower rates of adventitial dissections as seen on IVUS. The long-term outcomes of these findings remain unclear.