Overlapping surgery is safe—except in high-risk and CABG patients

Overlapping surgery—in which a surgeon moves from one procedure to the next before the first is finished, leaving junior surgeons and trainees to wrap up the noncritical portions of the surgery—isn’t associated with increased mortality or post-op complications in most cases. But, according to a study published in JAMA Feb. 26, it can raise the risk of adverse events in high-risk patients and those undergoing coronary artery bypass graft (CABG) surgery.

Senior author Anupam B. Jena, MD, PhD, of Harvard Medical School and colleagues said overlapping surgery exists for its benefits, like maximizing the use of a hospital’s top surgeons, increasing access to care and providing important hands-on training for more junior physicians. But there’s also concern that such an approach could yield more adverse outcomes if surgeons are absent at a critical point in the procedure.

“To date, most studies have found no association between overlapping surgery and patient outcomes,” Jena and co-authors wrote. “Prior studies have limitations, however. These include analyzing outcomes at single institutions and focusing on narrow sets of procedures, which limit statistical power and generalizability.”

Jena’s team drew information from a national registry of anesthesia patients for a broader dataset, ultimately including 66,430 operations performed between 2010 and 2018 in their retrospective analysis. Surgeries were either total knee or hip arthroplasties, spine surgeries, CABG or craniotomies, and all patients were followed up with until discharge.

Of all the procedures included in their study, Jena et al. said 8,224—12 percent—were overlapping. After adjusting for confounders, overlapping surgery wasn’t associated with significant differences in in-hospital mortality or complications, which included thromboembolic events, pneumonia, sepsis, stroke, MI and infection.

According to the study, patients involved in overlapping procedures saw a 1.9 percent mortality rate and a 12.8 percent risk of complications—not much different from the 1.6 percent mortality rate and 11.8 percent complication rate observed in nonoverlapping patients. Overlapping surgery was, however, associated with a significantly longer surgery duration, with overlapping procedures lasting an average 204 minutes compared to 173 minutes in nonoverlapping procedures.

The majority of patients didn’t experience any adverse outcomes as a result of overlap, but there were a couple of exceptions to the rule, including high-risk patients and those undergoing CABG. Compared to low-risk patients, high-risk ones saw a 1.2 percent increased risk of mortality and a 2.3 percent higher risk of complications.

Similarly, CABG patients’ mortality rate was higher if their surgery involved overlap (4 percent versus 2.2 percent in nonoverlapping patients).

“This study strengthens the evidence that overlapping surgery is a reasonable practice for many cases,” Jena et al. wrote. “However, prespecified, exploratory subgroup analyses did find a significant association between overlapping surgery and increased complication and mortality risk for high-risk patients. Overall, the study findings suggest that overlapping surgery is likely to be a safe practice for most patients, but the exploratory analyses do suggest potential areas for concern and further investigation.”

The authors acknowledged the notable half-hour increase in surgery duration associated with overlapping procedures could have policy implications, “since the operating room is one of the most expensive parts of any hospital.” It’s estimated running an operating room costs an institution between $30 and $60 per minute.

In an editor’s note, JAMA deputy editor Edward H. Livingston, MD, said Jena and colleagues’ study outlines the relative safety of an important element of the learning process for trainees.

“This work appealed to me because it answered an important, unresolved question: Is surgery safe as practiced in academic environments that balance the needs of safe patient care with those required to train the next generation of surgeons?” he wrote. “The answer appears to be yes.”

Livingston also said the study failed to address the risks associated with concurrent surgery—during which the critical parts of an operation are performed at the same time—when a primary surgeon isn’t present during an important part of the procedure.

“Major complications attributable to concurrent surgery have been highlighted by the news media, yet whether this practice is safe or acceptable remains unresolved and is not addressed in the current study,” the editor wrote. “How that should be addressed was outlined in JAMA previously and requires a precise definition of the critical part of the operation that requires the presence of the attending surgeon.”