7229 Eus performed without luminal water filling is as accurate for staging depth of invasion in gastric carcinoma.

Abstract

Presently endoscopic ultrasound (EUS) is the most accurate modality for T staging of gastric carcinoma. Two acoustic coupling techniques are used: (1) balloon-inflation alone, and (2) luminal water filling plus balloon-inflation. Not filling the gastric lumen with water may have the advantages of improved comfort for the patient, and a reduced risk of aspiration. However effect of omitting luminal water on the accuracy of gastric cancer staging has not been evaluated. AIM: To determine if the non-luminal filling technique was as accurate as the conventional waterfilled lumen technique in the T staging of gastric carcinoma. METHODS: Preoperative EUS was performed on 26 consecutive patients (aged 30-89 years, median 64 years) with gastric carcinoma by two experienced operators, using a radial echoendoscope (GF-UM200, 7.5-12 MHz, Olympus Co. Ltd, Singapore). The non-luminal filling technique (HKY) and the water-filled lumen technique (YKG) were used in 14 and 12 patients respectively. In the water-filled lumen procedures, 200-300 ml water was pumped into the stomach. The findings were prospectively correlated with histology of the resected specimens. RESULTS: Of the 26 tumors, 3 were pathologic (p) T1, 2 pT2, 15 pT3 and 6 pT4. The overall concordance of EUS T stage with p T stage was 90% for stages pT1 to pT3, while 5 of the 6 pT4 tumors were understaged as T3. Four of the 5 pT4 tumors were impassable antropyloric tumors, and the inability to assess the full length of the tumours was probably the reason for the understaging. The non-water-filled lumen technique was 100% accurate for T staging of pT1 to pT4 tumors versus 80% for the water-filled lumen technique (p = not significant). CONCLUSIONS: Omission of luminal water filling did not reduce the accuracy of EUS in the T staging of gastric carcinoma. This may improve patient safety and comfort.