Factors affecting operative time and outcome of carotid endarterectomy in the Vascular Quality Initiative

Abstract

Objective: Prior studies have suggested a relationship between operative (Op) time and outcome after major vascular procedures. This study analyzed factors associated with Op time and outcome after carotid endarterectomy (CEA) in the Vascular Quality Initiative (VQI) registry.

Methods: Elective, primary CEAs without high anatomic risk or concomitant procedures from 2012 to 2015 in the VQI were analyzed (N = 26,327, performed by 1188 surgeons from 249 centers). Multivariable analysis was used to identify patient, procedure, and surgeon factors associated with Op time and major adverse events (MAEs), categorized as either technical (ipsilateral stroke, cranial nerve injury, reoperation) or cardiac (myocardial infarction, congestive heart failure, dysrhythmia requiring treatment, surgical site infection, and death).

Results: The mean CEA Op time in the VQI was 114 minutes, with the mean Op time for individual surgeons ranging from 37 to 305 minutes. Procedural factors and the surgeon's volume were responsible for much of the variation in overall Op time (patient factors that reflected demographics and comorbidities each added 5.9 to 6.8 minutes; procedural factors, such as patch angioplasty and completion duplex ultrasound, each added 5.5 to 16.4 minutes; the lowest quartile of the surgeon's annual case volume added 24 minutes). Chi-pie analysis demonstrated that patient factors accounted for 17% of variability in Op time; procedural factors, 44%; and the surgeon's annual volume, 39%. Increasing Op time was highly associated with increased rates of MAEs (P < .001 for cardiac, technical, and death rates). Based on hierarchical multiple logistic regression, cardiac complications were independently associated with increased Op time (comparing surgeons in highest quartile of Op time with those in the lowest: odds ratio, 2.16 for cardiac MAE; 95% confidence interval, 1.59-2.95; P < .001) but not with the surgeon's annual volume. Technical complications were independently associated with a surgeon's low volume (comparing surgeons with the highest annual case volume by quartile against the lowest: odds ratio, 1.25 for technical MAE; 95% confidence interval, 1.06-1.48; P < .001) but not with Op time.

Conclusions: Op time for elective, primary CEAs varies substantially across surgeons in the VQI. Increased Op time is associated with a surgeon's lower annual CEA volume in addition to patient variables and techniques employed. Cardiac complications after CEA are associated with longer Op time, whereas technical complications are associated with a surgeon's low annual volume.

Fig 1

Distribution of carotid endarterectomy (CEA) operative (Op) time by surgeon. Overall mean Op time, 114.5 minutes; median, 108 minutes; standard deviation (SD), 42.8 minutes; interquartile range, 85 to 136 minutes. The vertical lines represent 95% confidence interval (CI) for each surgeon.

Fig 2

Mean operative (Op) time as a function of the surgeon’s annual volume.

Fig 3

Chi-pie diagram depicting patient, procedure, and surgeon factors associated with variability of operative (Op) time. ASA, American Society of Anesthesiologists class; BMI, body mass index; EEG, electroencephalography.

Fig 4

Cardiac complications, technical complications, and death as a function of operative (Op) time. OR, Operating room; TIA, transient ischemic attack.