The Composition of Catheter Encrustations, including the Effects of Allopurinol Treatment

Hedelin, Hans; Eddeland, Allan; Larsson, Laşse; Petersson, S.; Ohman, S

doi:10.1111/j.1464-410x.1984.tb05382.x

Cited by 58 publications

(30 citation statements)

References 9 publications

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“…Susceptibility to encrustation of poly mers used for urethral catheters could also be assessed; silicone and latex with various coatings (silicone, hydrogel or Teflon) being the main materials studied. For ureteric stents, human sterile urine seems however to be a more suitable medium for experimentation [6][7][8][9]11].…”

Section: Discussionmentioning

confidence: 99%

“…Despite advances in biomaterials, stent encrustation causing luminal blockage remains K ARC F R its have studied long-term indwelling urethral catheters in patients with chronic urinary infections; in vitro experi ments have mainly been based on the crystallization pro cess induced by the addition of enzyme urease [6][7][8][9]. However, double-J ureteric stent encrustations frequently occur in sterile urine, and stone patients seem particularly prone to this complication.…”

Section: Introductionmentioning

confidence: 99%

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Double-J Ureteric Stent Encrustations: Clinical Study on Crystal Formation on Polyurethane Stents

Robert¹,

Boularan

Sandid³

et al. 1997

Urol Int

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Objective: To evaluate the crystalline composition of encrustations on double-J ureteric stents in order to prevent their formation on the base of urolithiasis prophylaxis. Patients: 40 patients had a polyurethane double-J ureteric stent inserted between June 1994 and March 1995. Group 1 comprised 22 stone formers whose stents were placed in support of endourological treatment or extracorporeal shock wave lithotripsy of renal or ureteric calculi. Group 2 comprised 18 patients whose stents were inserted for advanced and obstructive malignancy (n = 8) or as an adjunct to reconstructive surgery or endourological techniques (n = 10). After removal, stents were examined for encrustation and obstruction. A biochemical semiquantitative analysis was performed for deposits > 5 mg, and smaller sediments were examined with a polarizing optical microscope. Results: The incidence of encrustation was significantly higher (p = 0.009) for stone formers. In addition, in this group indwelling times of encrusted and obstructed stents were significantly shorter (p = 0.03 and 0.02, respectively). No particular relationship was found between the incidence of encrustation and indwelling times for stone formers. Conversely, for patients without urolithiasis, indwelling times were significantly longer for encrusted or obstructed stents than for unaffected ones (p = 0.05 and 0.02, respectively). Biochemical and optical analyses of encrustations mainly revealed calcium oxalate, calcium phosphate and ammonium magnesium phosphate. Calcium oxalate was the main crystalline phase, especially in the absence of urinary infection. Conclusion: Calcium oxalate represents the principal component of double-J ureteric stent encrustations. Thus, prophylaxis of encrustation may consist of preventive measures usually applied in cases of recurrent idiopathic calcium oxalate urolithiasis.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Double-J Ureteric Stent Encrustations: Clinical Study on Crystal Formation on Polyurethane Stents

Robert¹,

Boularan

Sandid³

et al. 1997

Urol Int

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“…Naturally occurring deposits consist of ammonium magnesium orthophosphate hexahydrate (NH4MgP04 * 6H,O), which forms the mineral struvite, (Hukins et al, 1983) and calcium phosphate (Hedelin et al, 1984) which is present as a very poorly crystalline form of the mineral hydroxyapatite (Ca,(PO,),OH) (Cox et al, 1986). Struvite is formed when the urine is infected by bacteria (mainly Proteus) which secrete the enzyme urease; this enzyme catalyses the hydrolysis of urea in the urine to ammonium hydroxide and carbon dioxide (NH,),CO + 3 H 2 0 --t 2NHl + 2 0 H -+ C 0 2…”

Section: Introductionmentioning

confidence: 99%

An Automated Technique for in Vitro Assessment of the Susceptibility of Urinary Catheter Materials to Encrustation

Cox

Hukins

Davies

et al. 1987

Engineering in Medicine

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An automated technique has been developed for assessing the extent to which existing or potential materials for the construction of indwelling catheters become encrusted during exposure to infected urine. In this technique the enzyme urease is added to artificial urine containing albumin in a reaction vessel which contains the samples to be tested. Controlled replacement of reactants leads to appreciable formation of encrusting deposits which adhere firmly to the surface of the test samples. Deposits have the same chemical composition as those which encrust catheters in vivo.

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“…Infections with this organism result in the formation of extensive crystalline biofilms on the catheters that can block the flow of urine from the bladder (28). The crystalline material, composed of magnesium and calcium phosphates, precipitates out of solution under the alkaline conditions generated by the P. mirabilis urease enzyme (5,13,20). The obstruction of the flow of urine through the catheter can induce serious complications.…”

mentioning

confidence: 99%

Ultrastructure of Proteus mirabilis Swarmer Cell Rafts and Role of Swarming in Catheter-Associated Urinary Tract Infection

et al. 2004

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Proteus mirabilis is a common cause of catheter-associated urinary tract infection (C-UTI). It blocks indwelling urethral catheters through the formation of extensive crystalline biofilms. The obstruction of urine flow can induce episodes of pyelonephritis, septicemia, and shock. P. mirabilis exhibits a type of motility referred to as swarming, in which multicellular rafts of elongated, hyperflagellated swarmer cells form and move rapidly in concert over solid surfaces. It has been suggested that swarming is important in the pathogenesis of C-UTI. In this study we generated a set of stable transposon mutants deficient in swarming and used them to assess the role of swarming in the migration of P. mirabilis over urinary catheters. Swarming was found to be essential for migration over all-silicone catheters. Swarming-deficient mutants were attenuated in migration over hydrogel-coated latex catheters, but those capable of swimming motility were able to move over and infect these surfaces. A novel vapor fixation technique for the preparation of specimens and scanning electron microscopy were used to resolve the ultrastructure of P. mirabilis multicellular rafts. The flagellar filaments of P. mirabilis were found to be highly organized during raft migration and were interwoven in phase to form helical connections between adjacent swarmer cells. Mutants lacking these novel organized structures failed to swarm successfully. We suggest that these structures are important for migration and formation of multicellular rafts. In addition, the highly organized structure of multicellular rafts enables P. mirabilis to initiate C-UTI by migration over catheter surfaces from the urethral meatus into the bladder.Indwelling bladder catheterization is a convenient way to manage the problems of urinary retention and incontinence that afflict so many elderly and disabled people. The catheter, however, forms a bridge along which bacteria can pass from a contaminated external environment into a vulnerable body cavity. Even with meticulous nursing care, all patients undergoing catheterization for longer than a month will develop urinary tract infections (16). The number of catheterized patients is so large that catheter-associated urinary tract infections (C-UTI) are the most common infections acquired in hospitals and other health care facilities (29).Proteus mirabilis poses particular problems in the care of patients undergoing long-term indwelling bladder catheterization. Infections with this organism result in the formation of extensive crystalline biofilms on the catheters that can block the flow of urine from the bladder (28). The crystalline material, composed of magnesium and calcium phosphates, precipitates out of solution under the alkaline conditions generated by the P. mirabilis urease enzyme (5,13,20). The obstruction of the flow of urine through the catheter can induce serious complications. Urine either leaks around the outside of the catheter causing patients to become incontinent or is retained in the bladder resulting ...

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The Composition of Catheter Encrustations, including the Effects of Allopurinol Treatment

Cited by 58 publications

References 9 publications

Double-J Ureteric Stent Encrustations: Clinical Study on Crystal Formation on Polyurethane Stents

Double-J Ureteric Stent Encrustations: Clinical Study on Crystal Formation on Polyurethane Stents

An Automated Technique for in Vitro Assessment of the Susceptibility of Urinary Catheter Materials to Encrustation

Ultrastructure of Proteus mirabilis Swarmer Cell Rafts and Role of Swarming in Catheter-Associated Urinary Tract Infection

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