Case Report: Case report. Anastomositis on the 1st day after OAGB.

Introduction

Obesity is one of the most pressing public health challenges today.¹ Its prevalence continues to rise globally, with millions of individuals facing the burden of related comorbidities such as type 2 diabetes, cardiovascular disease, and gastroesophageal reflux. Surgery is the most effective treatment.² Among surgical approaches, one-anastomosis gastric bypass (OAGB) is increasingly performed due to its technical simplicity and favorable weight-loss results compared with restrictive procedures. Nevertheless, postoperative complications remain a significant concern. Strictures, anastomotic leakage, and inflammatory changes at the anastomotic site are well-documented^3–5 and can impair recovery or necessitate reintervention. Endoscopic balloon dilatation⁶ is effective and allows same day discharge but has risks like perforation or bleeding. Early complications affecting the gastrojejunal anastomosis within the first postoperative days are rarely reported. Such cases provide an opportunity to better understand the pathophysiology of anastomotic inflammation and to explore whether conservative treatment strategies can avoid invasive procedures. The present case describes an episode of acute anastomositis developing on the first day after OAGB and highlights successful resolution with medical therapy alone.

Case presentation

The patient is a 38-year-old male. Height 170 cm, weight 121 kg, BMI 41.86 kg/m². On June 23, 2025, he was admitted to the Professor Oral Ospanov Surgery Center⁷ for planned surgical treatment due to morbid obesity. His medical history included diabetes, hyperlipidemia, hypertension, hyperuricemia, GERD, and gastritis. On June 24, 2025, he underwent a planned laparoscopic FundoRing one-anastomosis gastric bypass.⁸ Fundoplication (Fundoring) was performed because the patient had GERD.⁹ The operation proceeded as planned without technical difficulties. A 1.5-meter distance was established from the ligament of Treitz. A manual single-layer end-to-side anastomosis was performed using Stratafix 3/0 suture. Operation time was 133 minutes. The operation ended at 10:30 am, after which the patient was in the recovery room.

At 2:00 pm, the patient was transferred to the ward. At 4:00 pm, in the presence of the attending physician, he was allowed to drink water in small sips without dysphagia. At 9:13 pm, the patient reported a single episode of vomiting, after which no further complaints were noted. At 7:30 am the following day, the patient began to report belching and was treated with 2 ml of cerulin intramuscularly. Given persistent complaints, an abdominal ultrasound and an X-ray of the esophagus and stomach were performed at 10:30 am. Radiological assessment demonstrated obstruction at the anastomotic site ( Figure 1). Video gastroduodenoscopy confirmed anastomositis, and conservative therapy was initiated.

Figure 1. X-ray with contrast demonstrating anastomotic obstruction.

Conservative treatment included aminocaproic acid 100 ml + 50 ml 0.5% novocaine + 1 ml adrenaline + 8 ml (32 mg) dexamethasone per os for 2 days. Additionally, dexamethasone 16 mg + 200 ml sodium chloride 0.9% intravenously on day 1, and dexamethasone 8 mg + 200 ml sodium chloride 0.9% intravenously on day 2. Parenteral nutrition consisted of Oliclinomel No. 4-550 E, 1500 ml per day for 2 days. Antibacterial therapy included Meropenem 1000 mg in 100 ml sodium chloride 0.9% intravenously and Metrid 0.5%, 100 ml intravenously. A proton pump inhibitor (40 mg) was administered intravenously once daily.

At 5:36 am the following day, the patient reported no complaints. After the morning round at 07:30, oral intake was resumed. On June 27, 2025, follow-up video gastroduodenoscopy showed a patent anastomosis. The patient was discharged the same day at 2 pm with recommendations. On September 19, 2025, follow-up revealed no complaints, no heartburn, no dysphagia, and a weight of 101 kg (-20 kg).

Discussion

Anastomotic complications remain one of the most challenging aspects of bariatric surgery. While strictures are well-documented and typically occur weeks after surgery, early manifestations of anastomositis within 24 hours are rarely described. In this case, the patient presented with early postoperative vomiting and belching, confirmed by imaging and endoscopy as anastomositis.

Conservative therapy using corticosteroids, anti-inflammatory agents, antibiotics, and parenteral nutrition proved sufficient for clinical and endoscopic resolution. This approach minimized risks associated with invasive interventions such as balloon dilation, which, although effective, carries risks of perforation, bleeding, and recurrence.

The successful outcome suggests that in select cases of early anastomositis, noninvasive therapy can be considered as a first-line treatment. However, more data and clinical experience are needed to establish standardized protocols. Future studies should compare conservative versus interventional strategies for early anastomotic complications to optimize patient outcomes.

Conclusion

This clinical observation demonstrates that inflammation at the anastomotic site can occur as early as the first day after surgery. Conservative management, including hormonal, antibacterial, and supportive therapy, resulted in favorable outcomes without the need for endoscopic or surgical intervention. Early recognition and timely conservative treatment may reduce risks and promote faster recovery.