PHILADELPHIA – In surgery for small-bowel obstruction, laparoscopy is more likely to result in bowel injury than is open surgery but with ultimately better outcomes overall. This means that surgeons should proceed with “considerable caution” when performing minimally invasive surgery in the small bowel, researchers at University of Toronto reported during the annual meeting of the American Surgical Association.
In explaining the rationale for the study, Dr. Behman said, “Several studies have shown that over the last several years [that] the utilization of laparoscopic techniques for adhesive small-bowel obstruction has become increasingly common. However, these procedures have some inherent challenges.” Those technical challenges include introducing the trocar into an abdomen filled with distended bowel, trying to manipulate the distended bowel with laparoscopic bowel graspers, and the potentially ischemic bowel wall, he said.
The University of Toronto researchers performed a population-based retrospective cohort study of 8,584 patients in the Ministry of Health Ontario database from 2005 to 2014. The primary outcome was a composite, consisting of bowel repair, including operative billing codes for either via intraoperative enterotomy or suture repair of the intestine, or bowel resection. Secondary outcomes were serious complications and 30-day mortality.
During the study period, the share of SBO procedures performed laparoscopically increased from 4% in 2005 to 14.3% in 2014, Dr. Behman said.
“Patients in the laparoscopic group were slightly younger, had a lower overall comorbidity burden, and tended to be treated at larger hospitals and hospitals without teaching designations,” Dr. Behman said. Specifically, the average age of the 673 patients who had laparoscopy was 63 years vs. 67 years for the 7,911 open-procedure patients. As for comorbidities, 9% and 50% in the laparoscopic group were healthy and low users and high and very high users, respectively, vs. 7% and 57% of the open-procedure group.
The incidence of any bowel intervention was 53.5% in the laparoscopic group vs. 42% in the open group, Dr. Behman said. After a multivariable regression analysis, the researchers determined the following factors raised a patient’s odds of having a bowel intervention: older age; female sex; having had an after-hours procedure; and having had the procedure earlier in the study period. “However, even after [the researchers adjusted] for all of these covariates, the variable in our model that was most significantly associated with a bowel intervention was having had a laparoscopic procedure, with an odds ratio of 1.6,” Dr. Behman said.
When analyzing secondary outcomes, the researchers found that laparoscopy was associated with a lower risk of 30-day mortality (OR, 0.6) and serious complication (OR, 0.8). “So, there does appear to be a direct trade-off with laparoscopy probably having better clinical outcomes, but also being a risk factor for bowel intervention,” Dr. Behman said. So the researchers preformed a secondary analysis that divided the cohort into four subgroups: laparoscopy with and without bowel intervention; and open surgery with and without bowel intervention.
“The next question we wanted to ask was, in patients that are at high risk of a laparoscopic bowel injury, is an open approach or early conversion to open beneficial?” Dr. Behman said. “To put this another way, is it more important to avoid a bowel intervention or to avoid the morbidity associated with an open procedure?”
The secondary analysis confirmed that laparoscopic patients had lower rates of serious complications: in those without bowel intervention, 5% for laparoscopy vs. 10% for open; and in those who had a bowel intervention, 15% for laparoscopy vs. 22% for open. However, those who had an open procedure without a bowel intervention had lower complication rates than did those who had a laparoscopic operation with a bowel intervention, Dr. Behman said, “suggesting that perhaps the bowel intervention is a greater driver of serious complications than having an open procedure.”
These findings can inform patient selection, Dr. Behman added. “In light of the fact that laparoscopic approaches are likely associated with a greater risk of bowel intervention, appropriate caution should accompany these procedures,” he said. “In patients who are at high risk for a bowel intervention, an open approach or early conversion to a laparotomy should be considered.”
In his discussion of the study,, of Wayne State University, Detroit, asked if the study accounted for timing of surgery, the etiology of laparoscopic-related bowel interventions, and if serosal tears were included as bowel injuries. Dr. Behman said that the study did include timing of surgery in the initial analysis and found it to be a nonfactor. However, the database did not specify the causes for bowel resections or reasons for conversions.
Dr. Behman and Dr. Diebel reported having no financial disclosures
The complete manuscript of this study and its presentation at the American Surgical Association’s 137th Annual Meeting, April 2017, in Philadelphia, is to be published in the Annals of Surgery pending editorial review.