Q&A: The Patient Safety Implications of Overlapping Surgeries

This member only article appears in the January issue of Patient Safety Monitor Journal.

A study published in The Journal of the American Medical Association made headlines this November, announcing that overlapping surgeries didn’t increase the risk of postop complications. This study, and several others like it that came out in 2017, suggests the practice may not be as risky as some have feared.
The study reviewed the cases of 2,275 patients who underwent neurosurgical procedures at the same hospital: 43% had the surgeon stay with the patient for the entire procedure, while 57% had the primary surgeon perform two procedures in different operating rooms.
In the 90 days following their operations, there wasn’t any difference in morbidity, mortality, or worsened outcome measures between the two groups. That said, the study did find the overlapping surgeries were notably longer than the consecutive surgeries.
The practice of overlapping surgeries came into the public eye in 2016 after the Boston Globe came out with a lengthy exposé into the practice. There’s been heated debate on the subject ever since.
PSMJ spoke with Bradley T. Truax, MD, principal consultant of the Truax Group, about the safety and best practices around overlapping surgeries. Truax is board-certified in both neurology and internal medicine and has been involved in patient safety for more than 25 years.
Q: What’s an “overlapping” surgery?
First, note the difference between “concurrent” surgery and “overlapping” surgery. No one condones “concurrent” surgery (where critical parts may overlap).

Overlapping surgery is where a surgeon is present for the entire “critical portion” of the surgery and then moves to another case and lets a resident, fellow, or surgical assistant finish the first case.
Q: What are your thoughts on overlapping surgeries? And do the findings in this study match your experience?
There are now at least eight studies that show no excess morbidity or mortality from overlapping surgery (OS) versus one study (the Canadian study) that showed increased complications with overlapping surgery. But the studies are problematic.
First is the problem with “big data.” Adverse events related to overlapping surgery are not common. Quite frankly, most cases in which overlapping surgery is done proceed without incident.
As a result, studies which look at large volumes of cases comparing overlapping with non-overlapping cases will never be able to detect which adverse events are the result of overlapping surgery. The latter cases will simply be “diluted out” in the big series.

The only way you could find that is if you take all the cases with complications and do a root cause analysis on each of them, and then decide if OS contributed to it or was a root cause. Obviously, that’s very time and resource intensive, and there’s very few people who are going to do all that. Theoretically you might do it on a small population, maybe all your hip replacements and just look at all the people who got an SSI. Then do a root cause analysis to tie down whether that infection was due to a prolonged procedure and was the prolonged procedure because it was an OS as opposed to a non-OS.
Another problem is that even when adjustments are made (such as use of propensity score weighting in the Howard study) it’s almost impossible to get away from selection bias. There’s something that makes these surgeons decide, “Oh, I’m going to do this case as a non-overlapping case.” And sometimes it’s pretty obvious: maybe the patient has a whole bunch of medical comorbidities and they didn’t want to do an overlapping in that case. But you can’t always tell that, and certainly not from the administrative data. And even if you’re doing chart review you can’t tell why the surgeon decided do it as an overlapping surgery or not.

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