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Updated: Mar 8, 2026

Standardized Technique of Aortic Valve Re-implantation for Valve-sparing Aortic Root Replacement
Published on: December 11, 2017
Use of Historical Surgical Times to Predict Duration of Primary Aortic Valve Replacement
Albert Wu1, Daniel E Rinewalt2, Robert W Lekowski1
1Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA.
Objectives:
To test whether a model using a historical average of a surgeon's surgical times for primary aortic valve replacements is a more accurate predictor of actual surgical times than solely relying on a surgeon's estimate.
Design:
Retrospective review.
Setting:
Single university hospital that serves as a tertiary referral center.
Participants:
All patients undergoing primary aortic valve replacement between October 2008 and September 2014.
Interventions:
None.
Measurements And Main Results:
Estimation biases, calculated as the difference between actual and predicted surgical time, were compared between the surgeon and the model, which included between 2 and 20 cases in the historical average. Kruskal-Wallis analysis of variance was used to compare all values. Pairwise comparisons were made using the Steel-Dwass test to determine whether using more cases in the model resulted in smaller estimation biases. Using the historical model reduced mean overestimation bias from 55.30 minutes to 0.90-to-4.67 minutes. No significant difference was seen based on the number of cases used.
Conclusions:
An uncomplicated model can assist in providing comparatively unbiased estimations of surgical time for aortic valve replacements. The model can rely on a fewer number of cases (eg, 5) and does not benefit from including more cases (eg, 20).
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