Background: Little information is available regarding the relationship between ascending aortic length and acute aortic events. We aim to evaluate whether patients with acute type A aortic dissection (ATAAD) exhibit differential aortic measurements compared to control patients. Methods: Data were collected on patients with ATAAD and control patients who received imaging for unrelated conditions. Propensity score matching was conducted using age, sex, race, body surface area, and hypertension in the logistic model. After matching, 67 patients remained in each group. Aortic morphometry was assessed via computed tomographic angiography. Ascending aortic length was defined as the centerline distance between the sinotubular junction (STJ) and the origin of the brachiocephalic trunk. Results: The mean ascending aortic length was 76.9 ± 15.7 mm (range 36.8 to 115.0 mm) for patients with ATAAD and was 62.0 ± 10.7 mm (range 34.0 to 87.8 mm) for control patients, which was a significant difference (t=-6.4, P<0.001). ATAAD patients had greater diameter at STJ (median: 41.6 vs 30.2 mm, z=7.5, P<0.001) and diameter at PAB (median: 42.3 vs 32.2 mm, z=6.8, P<0.001) compared with controls. A maximum ascending aortic diameter >5.5 cm (at either the PAB or STJ) was present in 12 of 67 cases (18%) and 0 of 67 controls (P<0.001). Conclusions: Ascending aortic length is significantly greater in patients who experienced ATAAD compared to matched controls. Elongation of the aorta may play a role in the pathogenesis of ATAAD, and assessment of ascending aortic length may be valuable as a predictive marker for aortic events.

Background: There is limited data to inform minimum case requirements for training in robotically-assisted coronary artery bypass grafting (RA-CABG). Current recommendations rely on non-clinical endpoints and expert opinion. Objectives: To determine the minimum number of RA-CABG procedures required to achieve stable clinical outcomes. Methods: We included isolated RA-CABG in The Society of Thoracic Surgeons (STS) registry performed between 2014 and 2019 by surgeons without prior RA-CABG experience. Outcomes were approach conversion, reoperation, major morbidity or mortality, and procedural success. Case sequence number was used as a continuous variable in logistic regression with restricted cubic splines with fixed effects. Outcomes were compared between operations performed earlier versus later in case sequences using unadjusted and adjusted metrics. Results: There were 1195 cases performed by 114 surgeons. A visual inflection point occurs by a surgeon’s 10th procedure for approach conversion, major morbidity or mortality, and overall procedural success after which outcomes stabilize. There was a significant decrease in the rate of approach conversion (7.7% and 2.5%), reoperation (18.9% and 10.8%), and major morbidity or mortality (21.7% and 12.9%), as well as an increase in rate of procedural success (72.9% and 85.3%) with increasing experience between groups. In a multivariable logistic regression model case sequences of >10 was an independent predictor of decreased approach conversion (OR 0.27, 95% CI 0.09 to 0.84) and increased rate procedural success (OR 1.96, 95% CI 1.00 to 3.84).