Each year, about 250,000 Americans undergo sleeve gastrectomy, one of the most common weight-loss operations in the United States. For most patients, recovery is uneventful. But for a small share—between 1% and 3% in routine cases, and as many as 1 in 10 in revision surgeries—the procedure can leave behind a gastric leak, in which fluid escapes from the stomach and forms an abscess.

Treating those leaks can be a long process. Doctors usually rely on endoscopic internal drainage, threading a small plastic tube called a double-pigtail stent through the stomach wall so the fluid can drain. But the devices typically used are built for bile ducts, not for the oddly shaped cavities created by gastric leaks.