Palliation of Gastric Outlet Obstruction

Malignant Gastric Outlet Obstruction

Malignant gastric outlet obstruction (MGOO) is a syndrome caused by intestinal obstruction due to tumor growth in the pyloric region or duodenum ( Fig. 33.1 ). Because of this mechanical obstruction, food and fluids accumulate in the stomach, which results in gastric distention. Patients with MGOO usually present with nausea and vomiting (85%), regurgitation (70%), abdominal pain (65%), and complaints of early satiety. Western studies mainly report pancreatic cancer (51%–73%) as the underlying disease, whereas gastric cancer (31%–69%) is the main cause of MGOO in Asian studies. Other causes for MGOO are bile duct cancer, metastatic disease, duodenal cancer, gallbladder cancer, ampullary cancer, and lymphoma. MGOO can be a clinical diagnosis when a patient with a known advanced gastroduodenal malignancy develops obstructive symptoms due to disease progression. However, at first presentation and when an intervention is considered, adequate imaging (i.e., contrast-enhanced computed tomography [CT] scan) is required to confirm tumor growth in the pyloric-duodenal region, to examine the location, extent, and resectability of the tumor, to look for signs of biliary obstruction, and to exclude a second intestinal obstruction distal to the duodenum. One should also be aware of benign causes of gastric outlet obstruction, such as motility disorders, pancreatic pseudocysts, ulcer-related complications, caustic ingestion, gallstone obstruction (Bouveret's syndrome), Crohn's disease, tuberculosis, or bezoars. Endoscopy can therefore be of additional value in the diagnostic process to examine and sample the gastroduodenal area. Cytological or histological confirmation of malignancy is desirable before a definite surgical or endoscopic intervention is offered to the patient.

Palliative Treatment: Surgical Bypass Versus Endoscopic Stent Placement

Patients with MGOO usually have advanced, unresectable disease with a poor prognosis. A mean survival of approximately 100 days (3.3 months) has been reported in a meta-analysis. Palliative measures should therefore aim for comfort and resolution of obstructive symptoms. Traditionally, patients underwent surgical gastrojejunostomy to bypass the malignant obstruction. Nowadays, endoscopic self-expandable metal stent (SEMS) placement is also a valid treatment option for the palliation of MGOO. Three randomized controlled trials (RCTs) have been published that compared surgical gastrojejunostomy with SEMS placement ( Table 33.1 ). The largest and most recently published trial showed that a surgical gastrojejunostomy (open procedure in 16/18 patients) was superior to endoscopic SEMS placement with regard to long-term relief of symptoms, recurrent obstructive symptoms, and reinterventions. There were no differences in health-related quality of life scores and overall survival. The other two trials did not report significant differences in long-term outcomes between surgical gastrojejunostomy and SEMS placement, but the RCTs all showed clear benefits of SEMS placement in the short term: patients had a more rapid recovery of oral food intake and a shorter hospital stay. SEMS placement also resulted in lower medical costs per patient. Based on these results, the authors of the largest trial recommended SEMS placement only in patients who have a life expectancy of less than 2 months. The better long-term outcomes of surgical gastrojejunostomy in comparison with SEMSs have also been confirmed by more recently published studies, including a meta-analysis. So, because of the better short-term results (faster recovery of oral intake and shorter hospitalization), endoscopic SEMS placement is generally offered as a palliative intervention to patients in poor clinical condition who are unfit for surgery and have a short life expectancy of weeks to a few months.

The Endoscopic Procedure