A computed tomography-based planning tool for predicting difficulty of minimally invasive aortic valve replacement

Area of Science:

• Cardiovascular Surgery
• Medical Imaging
• Surgical Planning

Background:

• Minimally invasive aortic valve replacement (MIAVR) offers benefits like reduced mortality and shorter hospital stays.
• Limited exposure of the aortic annulus is a key challenge in MIAVR.
• Computed tomography (CT) scans are currently used for pre-operative anatomical assessment.

Purpose of the Study:

• To introduce a novel planning prototype for MIAVR that automatically quantifies access angle and distance.
• To assess the association between these quantitative measurements and surgical outcomes.
• To evaluate the prototype's utility in predicting access difficulty.

Main Methods:

• A prototype system was developed for automatic measurement of access angle, distance, and aortic annulus dimensions.
• Measurements were visualized on the chest cage using ISO contours.
• Fourteen patients undergoing MIAVR via ministernotomy were included to assess associations with procedural parameters.

Main Results:

• The mean access angle was 40.3° ± 5.1°.
• Access angle showed a strong association with aortic cross-clamping time (r=0.60, P=0.02) and access difficulty score (ρ=0.57, P=0.03).
• Access angles differed significantly between easy and difficult access groups (P=0.03), while access distance showed no significant outcome association.

Conclusions:

• The access angle is a critical predictor of surgical complexity in MIAVR.
• Automated measurement and visualization of the access angle offer significant clinical value for pre-operative planning.
• This prototype can enhance the safety and efficiency of minimally invasive cardiac procedures.