Computerized endoscopic balloon manometry to detect esophageal variceal pressure

Measuring the variceal pressure is important in predicting esophageal variceal bleeding. However, current noninvasive methods of measuring variceal pressure have not gained wide popularity. We have developed a computerized endoscopic balloon manometry (CEBM) system to detect variceal pressure. The aims of the study were to test the in-vitro accuracy of CEBM and to evaluate the clinical reliability and feasibility of this method.

The CEBM system, comprising an esophageal variceal manometer and a computer, records variceal pressure and manometry images simultaneously. In the in-vitro study, variceal models were fixed inside an artificial esophagus, into which an endoscope with transparent balloon was inserted for intraluminal pressure measurement. The artificial varix was filled with water and connected to a water column to modulate the intraluminal pressure. This CEBM system was tested blindly in variceal models with different intraluminal pressures. CEBM was also used to measure variceal pressure in 23 patients with liver cirrhosis and esophageal varices, and the results were compared with the hepatic venous pressure gradient (HVPG).

In the in-vitro study, the measured intraluminal pressure correlated significantly with the actual intraluminal pressure for different diameters (R > or = 0.993, P < 0.001). Variceal pressure measurements with CEBM were technically successful in 23 patients. Regression analysis showed a good correlation between variceal pressure measured with CEBM and the HVPG (R = 0.858, P < 0.001).

Our preliminary results indicate that CEBM is feasible and accurate. CEBM may become a more reliable method for detecting variceal pressure.