Histological analysis of the papilla after endoscopic papillary balloon dilation.

BACKGROUND/AIMS: Endoscopic papillary balloon dilation is an effective procedure in the management of bile duct stones and is believed to preserve the papillary function. The papillary architecture is also considered to be preserved. However, little is known about the effects of balloon dilation on papillary structure. The present study was conducted to elucidate these effects.

METHODOLOGY

Since May 1994, endoscopic papillary balloon dilation was performed in 467 patients (407 patients for removal of bile duct stone, 57 for insertion of stent and 3 for baby cholangioscope). Of those, histological examinations were undertaken in 10 patients. The indications of endoscopic papillary balloon dilation were bile duct stone removal in 2 patients, stent insertion in 8. The specimens were obtained 2 to 63 weeks after endoscopic papillary balloon dilation during surgical operation in 6 patients and autopsy in 4 patients. Serial sections through the papilla were stained by hematoxylin and eosin and Masson's trichrome. The specimens were also obtained from 4 patients without biliary disease as control.

RESULTS

No smooth muscle disruption nor architectural distortion was observed except for one patient who had mild disruption of smooth muscle caused by a biliary drainage tube. However, mild to moderate inflammation and fibrosis were seen in 9 patients and in 8, respectively.

CONCLUSIONS

The papillary architecture is not affected by endoscopic papillary balloon dilation. This may imply that endoscopic papillary balloon dilation preserves papillary function.