Laparoscopic Sleeve Gastrectomy: Good Operation, With Limits

Miriam E Tucker

November 09, 2017

WASHINGTON, DC — Two new studies help better characterize the short- and long-term outcomes for laparoscopic sleeve gastrectomy, which in recent years has become the favored and most commonly performed bariatric procedure.

Results from one large database analysis suggest that laparoscopic sleeve gastrectomy is safer than laparoscopic gastric bypass in the short term (30 days), although both procedures appear very safe.

But a separate meta-analysis with data beyond 7 years suggests that between a quarter to a third of patients who have a sleeve gastrectomy may eventually require a revision or experience weight regain.

The two studies were both presented during a "Top-10 Papers" session of the American Society for Metabolic and Bariatric Surgery (ASMBS) at Obesity Week 2017.

"We don't fully know the natural history of the [sleeve] operation yet. It's only been around for the past 8 years," Stacy A Brethauer, MD, a bariatric surgeon at the Cleveland Clinic, Ohio, told Medscape Medical News.

"I think it will take longer for us to fully understand who's going to respond well to it and who's not, and who's going to need additional therapy later on.…We just need to keep following these patients and learn as we go."

About 65% to 70% of bariatric-surgery procedures today in the United States are sleeve gastrectomies, said Dr Brethauer, who is immediate past president of the ASMBS and comoderated the top-10 session. "There's no question it's a highly safe operation. The data say it's safer than the bypass, but if you look at the numbers then bypass is extremely safe as well."

However, regarding his meta-analysis of long-term outcomes, surgery resident Colin Martyn, MD, of Texas Tech University, El Paso, told Medscape Medical News, "Sleeve gastrectomy is a very good operation in the midterm in terms of weight loss, but at 7 years, in terms of excess body weight loss, we're seeing failure to keep that off in about one-fourth of people."

"When we tell people about sleeve gastrectomy we need to tell them here are the short-term outcomes and here are the potential long-term outcomes, because we advertise the sleeve gastrectomy as this great procedure that has fewer immediate short-term complications compared with gastric bypass."

In Large Database, Sleeve Beats Bypass on 30-Day Safety

The 30-day safety data, from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement registry, were presented by Sandhya Kumar, MD, a clinical instructor at the University of California, San Francisco.

This represents the largest bariatric-specific data set available, said Dr Kumar, and includes all cases from accredited centers in the United States and Canada.

Of the 134,142 patients identified with primary laparoscopic sleeve gastrectomy or bypass operations (revisions and open procedures were excluded), 93,062 (69%) underwent sleeve and 41,080 (31%) underwent bypass.

The two groups differed in terms of several variables. The bypass patients were older (45 vs 44 years, < .001), had higher body mass indexes (45 vs 44 kg/m2, < .001), and were more likely to have diabetes (35% vs 23%, < .001), gastroesophageal reflux disease (GERD) (37% vs 29%, < .001) and other comorbidities.

In multivariate models adjusting for the between-group differences, bypass was still associated with significant twofold increased risk for leaks (odds ratio [OR], 2.10; < .001) and major morbidity (OR, 2.20; < .001) and also with an elevated risk for mortality (OR, 1.64; = .001), compared with sleeve gastrectomy at 30 days.

"Long-term weight outcomes, metabolic disease resolution, and risk of GERD progression with laparoscopic sleeve gastrectomy are still under study," Dr Kumar said.

He added: "Ultimately, we feel that [the sleeve] may be a better choice for high-risk candidates, particularly ones with many comorbidities, where the lower risk associated with sleeve may offset some of the higher risks conferred by patient characteristics."

However, discussant Kelvin Higa, MD, of Advanced Laparoscopic Surgery Associates, Fresno, California, pointed out: "I think the fact that we're looking at 30-day outcomes is one of the greatest limitations on the clinical impact of this analysis, in particular as many complications of the sleeve might present in delayed fashion, particularly leaks, so we wouldn't be capturing that at all with this data set."

"We'll be anxious to see whether more long-term data from larger clinical trials will help answer that question," Dr Higa added.

"The Longer One Has a Sleeve Gastrectomy, the Higher the Failure Risk"

In his presentation of the long-term outcomes, Dr Martyn noted that since sleeve gastrectomy has been available for obesity treatment only since 2007, few data beyond 5 years have been obtained.

To overcome that, he and his colleagues performed a meta-analysis of nine studies that included cases with data beyond 7 years.

Primary end points were percent with excess weight loss of less than 50% ("failure") and incidence of sleeve revisions due to excess weight loss less than 50%, GERD, or both.

The nine studies included 2210 patients, of whom 345 completed follow-up. The overall failure rate — due to weight regain, less than 50% excess weight loss, or revision — was 33.9%. At 7 or more years, that failure rate was 27.8% (both < .001).

The overall pooled estimated revision rate was 19.9%, with about 13.7% due to weight regain and 2.9% to GERD. But over 5 or more years, the pooled revision rate was estimated to be 31.2%.

"While sleeve gastrectomy provides comparable short-term outcomes to gastric bypass, our results indicate that the sleeve may not have long-term outcomes that match the short- to midterm data," Dr Martyn noted.

"Our data suggest that the longer one has a sleeve gastrectomy, the higher the risk of failure."

However, he added that because the sleeve gastrectomy is so recent, "the learning curve of the early-adopting surgeons may have contributed to the high rates of long-term failure and revisions.…Decreases in short-term complications have been seen as surgeons become more experienced in sleeve gastrectomy."

Senior author Benjamin L Clapp, MD, also of Texas Tech, El Paso, told Medscape Medical News: "I think when we counsel patients we need to tell them these numbers. 'It's a great operation and you have a 75% chance that everything is going to be great and you'll go home with your sleeve and never need anything else.'

"But these numbers [on failure] are out there, so you have to include that in your decision-making process when doing informed consent with the patient."

But What Exactly Is "Success" or "Failure" for Bariatric Surgery?

Discussant Philip R Schauer, MD, director of the Cleveland Clinic Bariatric and Metabolic Institute, raised another concern about Dr Martyn's paper: the use of greater than 50% excess weight loss as the definition for "success" and any amount less than that as "failure."

"It's a somewhat obsolete definition that fails to recognize that there can be significant health benefits and improvements in quality of life with…20% to 49% of excess weight loss....If you drop the 50% down to 20% to 30%, it will change the failure rate significantly.…It's very important how you communicate these results," Dr Schauer said.  

Indeed, Dr Brethauer told Medscape Medical News that the issue of defining "success" for bariatric surgery is still being worked out. He was lead author of an ASMBS paper on the topic (Surg Obes Relat Dis. 2015;11:489–506).

Some in the field have advocated moving away from use of "excess" weight loss, as opposed to total weight loss, since that leads to confusion when medical professionals use the latter.

Bottom line, he said, "There's no clear definition for 'success' and 'failure' in the literature….We as surgeons are trying to move away from that terminology and more toward long-term outcomes for patients in terms of health and well-being.…I think it's probably inappropriate to use an arbitrary cutoff.

"As long as patients have clinically meaningful weight loss and improvements in their health and quality of life, then that's what we're going for," he concluded.

Dr Brethauer is a speaker for Ethicon and Medtronic. The study authors have no relevant financial relationships. .

Obesity Week 2017. October 31, 2017; Washington, DC. Abstract A101.

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