NATIONAL HARBOR, Md.—Surgeons who perform more robotic bariatric surgeries have shorter operative times than those who perform fewer such procedures, according to new research led by surgeons at Henry Ford Health System, in Detroit.
Reviewing records from nearly 5,000 patients undergoing primary robotic Roux-en-Y gastric bypass in the state of Michigan, investigators divided surgeons into terciles based on their annual volumes. Operative times were significantly longer among low- versus high-volume surgeons, although the mean difference was 18 minutes (168 vs. 152 minutes; P<0.001). Rates of concurrent hiatal hernia repair, cholecystectomy, and conversion to open surgery were similar between low- and high-volume surgeons.
At 30 days, overall complication rates were similar between low- and high-volume surgeons, including for leaks or perforations, obstructions, infections, hemorrhage, and venous thromboembolism. However, the investigators observed a higher rate of emergency department visits among patients operated on by low- versus high-volume surgeons (16.8% vs. 12.4% of cases; P=0.004), as well as higher rates of hospital readmission (6.5% vs. 4.4%; P=0.025). These findings were presented by Mouhammad Halabi, MD, a research fellow at Henry Ford, at the 2025 annual meeting of the American Society for Metabolic and Bariatric Surgery.
“Robotic surgery is increasingly being adopted in bariatric surgery,” Dr. Halabi said. “While these procedures are generally considered safe, outcomes can vary depending on surgeon experience and case volumes, particularly in the initial learning curve. In the case of robotic gastric bypass, performance and consistency typically stabilize at around 30 cases.”
Dr. Halabi and colleagues used the Michigan Bariatric Surgery Collaborative registry to review records from all patients (n=4,700) receiving bypass from 2008-2024. To ensure they were analyzing cases from proficient surgeons, they excluded those with fewer than 30 lifetime robotic RYGB cases. Tercile 1, the low-volume group, included 10 surgeons who performed 596 procedures (mean surgeon case volume, 63). Tercile 2 included 10 surgeons performing 1,373 procedures (mean surgeon case volume, 143). Tercile 3, the high-volume arm, included nine surgeons performing 2,731 procedures (mean surgeon case volume, 356).
Compared with the high-volume surgeons, low-volume surgeons operated on slightly older patients (45 vs. 44 years; P=0.042) and on more individuals with Medicaid coverage (27.9% vs, 23.1%; P=0.013); hyperlipidemia (48.7% vs. 41.6%; P=0.001); diabetes (36.2% vs. 30.1%; P=0.003); a prior venous thromboembolism (11.6% vs. 5.1%; P<0.001); and liver disease (12.5% vs. 5.7%; P<0.001).
“In summary, our analysis showed that surgeon volume is primarily associated with improvements in operative efficiency,” Dr. Halabi said. “Importantly, at 30 days, no differences in complications were noted. So, after achieving proficiency, low-volume surgeons can achieve clinical outcomes comparable to high-volume surgeons.”
During the discussion, some attendees questioned whether researchers had compared surgeons’ complication rates using the robot compared with straight stick laparoscopy (they didn’t) and cautioned defining the term proficiency as 30 cases.
A camp of surgeons believes in the volume–outcome relationship, that the more cases a person does the better the outcomes, Shanu N. Kothari, MD, the chair of surgery for Prisma Health in Greenville, South Carolina, told General Surgery News. Another camp believes volume should never be a surrogate for quality, and to look directly at outcomes. “There’s an assumption that if you’re a higher volume surgeon, you’re automatically better,” said Dr. Kothari, who moderated the session, and the authors applied that to a threshold of 30 cases.
However, what’s unknown from the data presented is if the high-volume surgeons use the robot 100% of the time and the low-volume surgeons only use the robot some of the time, have difficulties gaining access to an OR containing a robot due to demand, or whether they practice in a rural area with fewer patients, he said. It’s also unclear whether the readmissions were for something simple such as rehydration or a technical complication like anastomotic leak or bleeding.
“We don’t have enough granular data to draw strong conclusions from that portion,” he said.
Oliver Varban, MD, a minimally invasive and bariatric surgeon at Henry Ford and a senior study author, told General Surgery News that his group has data on the reasons for readmission and plans to analyze the information. It also would be interesting to evaluate outcomes among surgeons’ robotic and laparoscopic cases, he said.
“What I was most intrigued by this study is that complication rates—especially severe complications such as bleeding and leak—were similar between high- and low-volume surgeons,” Dr. Varban said. “Sure, operative efficiency is better among higher-volume surgeons, but I was expecting lower-volume surgeons to have more complications, and they didn’t. Robotic surgery ‘leveled the playing field’ for gastric bypass.”
Drs. Halabi, Kothari, and Varban reported no relevant financial disclosures.
This article is from the November 2025 print issue.
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