Morphological changes in bile ducts following preoperative biliary stenting.

Objectives: To analyze the morphological changes in bile ducts following endobiliary stent insertion, and consequent technical problems encountered at surgery.

Methods: Data on bile duct morphology--gross (luminal diameter and wall thickness) and microscopic (histological changes in bile duct wall graded semiquantitatively)--and operative parameters related to bile duct dissection (grade of difficulty in dissection) were collected prospectively in 31 consecutive patients undergoing pancreatico-duodenectomy. These data were compared between patients who had undergone preoperative endoscopic biliary stent placement (n=17) and those who had not (n=14).

Results: Mean duration of stenting before surgery was 34 (range 10-120) days. Stented ducts were significantly narrower (luminal diameter 9 [7-12] mm vs. 17.5 [8-23] mm; p=0.0001) and had thicker walls (2.3 [1.3-3.5] mm vs. 1.85 [0.8-2.2] mm; p=0.004) compared to non-stented ones. On microscopy, stented ducts had advanced grades of submucosal gland hypertrophy, fibrosis and inflammatory cell infiltrate. Difficulty in bile duct dissection was encountered more often in patients who had been stented than in those without stents, though the difference was not statistically significant.

Conclusion: Endobiliary stent placement results in significant morphological and fibroproliferative inflammatory changes in bile ducts, making dissection difficult.