Biliary Stent Blockage with Bacterial Biofilm

Abstract

Clogging of endoscopic stents necessitates their replacement in many patients with malignant obstructive jaundice and limits their use in benign strictures. We studied the basic mechanism of clogging to find ways to prevent it. We did light and electron microscopy studies of blocked and functioning stents, which were prepared so that organic structures would be preserved. The material blocking the lumina was composed of a matrix of bacterial cells and their fibrillar anionic extracellular products. Crystals of calcium bilirubinate, calcium palmitate, and cholesterol were embedded within this matrix. Bacterial cells were attached to the stent surface by a fibrillar matrix, suggesting that the initial event in stent clogging is the development of an adherent bacterial biofilm. Bacterial enzyme activity (beta-glucuronidase and phospholipase) leads to the deposition of crystals. The use of antibacterial plastics in the manufacture of stents may reduce bacterial adhesion and stent clogging.

The effect of indwelling endoprosthesis on stone size or fragmentation after long-term treatment with biliary stenting for large stones

“…We know that the sphincter of Oddi acts as a mechanical barrier, preventing the regression of the duodenal contents. The breakdown of this barrier with sphincterotomy or transpapillary insertion of an endoprosthesis results in microbial infection of the bile by ascending infection [8,11,17]. Additionally the presence of a foreign body in the biliary system has been proven to facilitate bacterial adhesion and biofilm formation [11].…”

Pancreatic Cancer: Stenting versus Surgery

“…The polysaccharide matrix protects the bacte ria from the host defense mechanisms and from toxic sub stances such as antibiotics, biocides, and surfactants. It is most likely that this layer is the first step in the clogging process [16][17][18]. Crystals of calcium bilirubinate, calcium palmitate and cholesterol are embedded within the matrix and the bacteria are attached to the stent surface by a fibrillar matrix.…”

“…Several vari ables may be involved: bile flow, bile composition, bacte rial contamination and endoprosthesis characteristics such as length, shape, design, position, size, number and material (polyethylene and other similar polymers). At tempts at manipulating all of these have been made in stones consisting mainly of calcium bilirubinate with some calcium palmitate and unidentified organic materi al together with bacteria [16][17][18][19] (table 3). Bacteria form biofilms by polysaccharide production, which cements the bacterial cell to the surface and mediates adhesion to sister cells.…”

“…Many experts do not use sphincterotomy for stent inser tion unless insertion of two stents is planned. Stent occlusion may occur from 1 week to over 15 months after placement, with a mean of about 5 months [16][17][18][19][20][21][22][23][24][25][26] and patients can present with malaise, low-grade fever or mild disturbance of liver enyzmes. Several vari ables may be involved: bile flow, bile composition, bacte rial contamination and endoprosthesis characteristics such as length, shape, design, position, size, number and material (polyethylene and other similar polymers).…”

“…The predictability of occlusion, with its serious compli cation of sepsis, mitigates in favor of planned removal and replacement at approximately 4-month intervals [1][2][3], The variability of stent survival, however, would sup port the conservative approach of close clinical follow-up to anticipate early symptoms of biliary obstruction or cholangitis [24][25][26], vitro [16][17][18][19][20][21][22] with little impact on clinical practice al though a newly developed Teflon stent ( fig. 3) shows promise [23].…”