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The Spine Blog

Friday, March 28, 2014

Duration of Surgery: Independent Risk Factor for Complications?

“There are good fast surgeons and bad fast surgeons, but there’s no such thing as a good slow surgeon.” This aphorism seems to be supported by Dr. Kim and colleagues’ recent paper looking at the correlation between duration of surgery for one level lumbar fusion and complications. While duration of surgery has been found to be a risk factor for complications in many surgical disciplines, it had not been evaluated in spine surgery. As such, this group from Chicago used the National Surgical Quality Improvement Program (NSQIP) database to determine the association between operative duration and complications in one level lumbar fusion. They included over 4500 patients undergoing one level lumbar fusion, including posterolateral fusion, XLIF, ALIF, PLIF or TLIF, with or without instrumentation. Patients undergoing multilevel fusion, revision fusion, or pelvic instrumentation were excluded. The authors did not comment about decompression, but there is no indication that patients undergoing decompression as well as fusion were excluded. The duration of surgery was classified as under 2 hours, 2-3 hours, 3-4 hours, 4-5 hours, and greater than 5 hours, and the correlation between duration of surgery and complications within 30 days of surgery was determined. The univariate analysis indicated that duration of surgery was associated with increased overall complications, medical complications, and surgical complications. In the multivariate analyses—the details of which are somewhat unclear—the authors reported that increasing operative duration was associated with overall complication rate, medical complications, superficial infection, and DVT. The other complications tended to only be significantly related to operative time in cases over 5 hours in length. Based on these data, the authors concluded that operative duration is an independent risk factor for complications and could be considered as a quality metric.


Common sense indicates that minimizing operative time while still performing safe and effective surgery should always be a goal, and this and other studies support this. However, the data presented in this database analysis does not strongly support the conclusion that operative duration is a strong, independent predictor of complications. Not surprisingly, increased operative time was associated with age, BMI, gender, inpatient admission, infected or contaminated cases, medical comorbidity, and increased complexity of cases. While the authors performed a multivariate analysis that likely controlled for some of these factors, which covariates were included in the models was not reported. Additionally, posterolateral fusion, XLIF, ALIF, PLIF, and TLIF were also analyzed together, and fusion technique is clearly related to both operative time and complications. Other factors such as performing a simultaneous decompression, hospital or surgeon volume, indications for surgery, having had prior lumbar decompression, and having a perioperative complication (i.e. durotomy, misplaced hardware, etc.) were not included in the analysis, and all of these factors can affect both surgical duration and complications. These and other unmeasured confounders likely played a greater causative role in generating complications than did the actual duration of surgery. Given these issues, the authors’ conclusion that duration of surgery is a useful quality metric is probably not supported by the data. A more thorough analysis controlling for the many potential confounders would be necessary to make such a conclusion, and these other data points are likely not included in the NSQIP database. For now, surgeons should strive to operate as efficiently as is safe, and duration of surgery should not be considered a quality metric on which surgeons are evaluated. If surgeons became incentivized to operate faster, it seems unlikely that outcomes would improve.


Please read Dr. Kim’s article on this topic in the March 15 issue. Does this article change how you perceive the need for efficiency in the OR? Let us know by leaving a comment on The Spine Blog.

Adam Pearson, MD, MS

Associate Web Editor