Technical Considerations and Pitfalls of BASILICA: Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction

First-in-Human Dedicated Leaflet Splitting Device for Prevention of Coronary Obstruction in Transcatheter Aortic Valve Replacement

BACKGROUND

Coronary artery obstruction is a life-threatening complication of transcatheter aortic valve replacement (TAVR) procedures. Current preventive strategies are suboptimal.

OBJECTIVES

The aim of this study was to describe bench testing and clinical experience with a novel device that splits valve leaflets that are at risk for causing coronary obstruction after TAVR, allowing normal coronary flow.

METHODS

The ShortCut device was initially tested in vitro and preclinically in a porcine model for functionality and safety. The device was subsequently offered to patients at elevated risk for coronary obstruction. Risk for coronary obstruction was based on computed tomography-based anatomical characteristics. Procedure success was determined as patient survival at 30 days with a functioning new valve, without stroke or coronary obstruction.

RESULTS

Following a successful completion of bench testing and preclinical trial, the device was used in 8 patients with failed bioprosthetic valves (median age 81 years; IQR: 72-85 years; 37.5% man) at 2 medical centers. A total of 11 leaflets were split: 5 patients (63.5%) were considered at risk for left main obstruction alone, and 3 patients (37.5%) were at risk for double coronary obstruction. All patients underwent successful TAVR without evidence of coronary obstruction. All patients were discharged from the hospital in good clinical condition, and no adverse neurologic events were noted. Procedure success was 100%.

CONCLUSIONS

Evaluation of the first dedicated transcatheter leaflet-splitting device shows that the device can successfully split degenerated bioprosthetic valve leaflets. The procedure was safe and successfully prevented coronary obstruction in patients at risk for this complication following TAVR.

Risk Assessment of Coronary Obstruction During Transcatheter Aortic Valve Replacement: Insights From Post-BASILICA Computed Tomography

OBJECTIVES

The aim of this study was to examine the predictive value of preprocedural computed tomography (CT)-based risk stratification of coronary obstruction during transcatheter aortic valve replacement (TAVR) on the basis of geometric measurements on postprocedural CT.

BACKGROUND

Proper patient selection for additional procedures to prevent coronary obstruction during TAVR has not been adequately evaluated.

METHODS

Pre- and postprocedural computed tomographic scans of 28 patients treated using bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) and TAVR were analyzed. Using the postprocedural computed tomographic images, threatened coronary obstruction (TCO) was defined as: 1) ostial obstruction (adherence of the transcatheter heart valve [THV] to the coronary ostium with leaflet extension above the ostium); and/or 2) sinus sequestration (THV adherence to the sinotubular junction [STJ] with leaflet extension above the STJ) and was substratified into complete and incomplete types.

RESULTS

A total of 51 leaflets were evaluated (88% surgical tissue valves) after excluding leaflets not visible on CT (n = 5). On postprocedural CT, complete TCO was observed in 25.4% (13 of 51 leaflets). On preprocedural CT, leaflets were at high risk for complete TCO (incidence 53%) if the virtual THV-to-coronary distance (VTC) was <3.0 mm, or if the virtual THV-to-STJ distance (VTSTJ) was <1.0 mm with STJ height - leaflet length <0 mm (leaflet-STJ mismatch). Leaflets were at low risk (incidence 0%) if the VTC was ≥3 mm and VTSTJ was ≥3.0 mm or STJ height - leaflet length was ≥+2.0 mm. Of 28 leaflets treated using BASILICA, complete TCO was seen in 35.7% (n = 10), due to sinus sequestration (100%) with coexisting ostial obstruction (30%). Actual coronary events occurred in 7.1% (n = 2) because of leaflet prolapse, corresponding to an absolute risk reduction by BASILICA of 29% (P = 0.021).

CONCLUSIONS

Risk assessment of coronary obstruction after TAVR may improve with a multiparametric approach incorporating VTC, VTSTJ, and leaflet-STJ mismatch. BASILICA appeared to reduce actual coronary events even in leaflets with anticipated coronary obstruction.