Benefits of laparoscopic over open colectomy decrease with operative time

Major Finding: The rates of complications and death postoperatively were lower with the laparoscopic approach if the operation lasted 3 hours or less, but not if it lasted longer.

Data Source: A retrospective cohort study of 4,273 cases of laparoscopic or open right colectomy for cancer.

Disclosures: Dr. Bailey disclosed no relevant conflicts of interest.



PHOENIX – The longer a laparoscopic colectomy for cancer takes, the less its advantages over an open colectomy in terms of morbidity and mortality, researchers reported at the annual meeting of the American Society of Colon and Rectal Surgeons.

A team led by Dr. Matthew Bailey, a surgery resident at the University of Kentucky in Lexington, queried the National Surgical Quality Improvement Program (NSQIP) database to identify more than 4,000 patients undergoing right colectomy because of colorectal malignancy.

Dr. Timothy Geiger

Results showed that compared with their peers having an open operation lasting 3 hours or less, patients having a laparoscopic operation of this duration were less likely to develop complications and to die. However, when the operations lasted more than 3 hours, there was no longer any significant difference.

Within the laparoscopic group, patients were more likely to have a procedure lasting longer than 3 hours if they had recently received radiation therapy, were morbidly obese, or had peripheral vascular disease.

"We recommend that surgeons consider an open approach if the patient has risk factors for an operative duration greater than 3 hours," Dr. Bailey said. "We also recommend surgeons consider conversion to an open approach when it is anticipated that a laparoscopic right colectomy will exceed 3 hours."

Dr. Walter Peters of Columbia (Mo.) Surgical Associates, who comoderated the session, asked, "Were the laparoscopic procedures lasting more than 3 hours concentrated in a few institutions, or were they spread across the entire NSQIP database?"

The investigators did not assess the institutional distribution, and it may not be possible to tease that information out of NSQIP, Dr. Bailey replied.

Session attendee Dr. Eric Haas, of Colorectal Surgical Associates in Houston asked what percentage of patients had a conversion from laparoscopic to open procedures and whether analyses were conducted according to intention to treat.

"NSQIP unfortunately does not allow you to discern that, there’s no CPT [Current Procedural Terminology] code for conversion," Dr. Bailey said. "We can only assume that cases that were converted laparoscopic to open were most likely ultimately coded as open. So there was no way to perform an intent-to-treat analysis."

Dr. Haas also noted that surgeon experience with laparoscopy may have played a role. "In my own experience, certainly at the beginning of the learning curve phase, I would take 3, maybe 4 hours. And the one risk factor that you can’t put [in analyses] is surgeon," he said. "So were these 3-hour cases because of the learning curve, or were they true 3-hour cases because of the patient factors?"

The NSQIP database captures the surgeon who dictates the operative report and the level of training, the highest-level resident involved, and the specialty of the surgeon (although colorectal surgery is not among the options), according to Dr. Bailey. Still, it is generally not possible to determine who did all or most of the operation.

"We did look at operative time, and it was around 138 minutes, plus-minus, for a laparoscopic right colectomy, with the reported literature being around 187 minutes. So I’m not sure if the reported literature is dated or if, in these over 200 hospitals across the nation, this is realistic of current practice trends," he said.

"The study shows that patients are probably going to have increased complications with longer surgery, whether it’s laparoscopic or open," Dr. Timothy Geiger of Vanderbilt University Medical Center, Nashville, Tenn., the session’s other comoderator, said in an interview. "It was a good study, but it needs a little bit more in-depth look, especially at things like redosing of antibiotics, whether that is done in an appropriate manner. But otherwise, it’s a great kind of intro for us to look at this."

Giving some background to the research, Dr. Bailey noted, "The use of laparoscopy in colon cancer has been shown to be equivalent to open surgery in survival and oncologic outcomes. The question of whether operative time negatively impacts laparoscopic outcomes compared to open surgery outcomes requires further investigation if we are to endorse a laparoscopic approach regardless of procedure length. We postulated that there is an operative duration where the benefits of a laparoscopic approach are negated."

The investigators analyzed data from the NSQIP database for the years 2005 through 2010, identifying patients who had a right colectomy for cancer and excluding those treated on an emergent basis, or having secondary procedures other than enterolysis or mobilization of the splenic flexure.

Analyses were based on 2,141 patients in the laparoscopic group and 2,132 patients in the open group. Procedures lasted longer than 3 hours in 18% of the former and 11% of the latter.

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