Air-filled microballoon manometry for use in anorectal physiology.

Manometry is fundamental to anorectal physiology but the water-filled manometric systems commonly used have several disadvantages. To investigate the 'new' air-filled microballoon system, we compared it with a standard water-filled equivalent by measuring sphincter length, maximum resting pressure (MRP) and maximum voluntary contraction pressure (MVC) in 44 patients using the station pull-through technique. A good correlation was found for all three parameters (Spearman correlation coefficient rs: sphincter length = 0.86, MRP = 0.86 and MVC = 0.94, P less than 0.001). Repeat studies in 15 patients showed excellent reproducibility (rs: sphincter length = 0.97, MRP = 0.96 and MVC = 0.97, P less than 0.001). Air-filled microballoon manometry gives results similar to a water-filled microballoon system and has many advantages.