The distribution of crystalline material in obstructed stents—In need for intra‐luminal surface modification?

Laube, Norbert; Kleinen, Lisa; Avrutin, Vadym; Böde, Ulla; Meißner, Andreas; Fisang, C.

doi:10.1002/jbm.b.31132

Cited by 9 publications

(7 citation statements)

References 27 publications

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“…In experiments with human urine collected from patients, Griffith et al obtained qualitatively similar results to those obtained with the synthetic urine used in this study [8]. In the clinical routine, approximately 10% of all urinary stones were made up of struvite [29] and originated from infection by bacteria that possessed the enzyme urease [15]. Crystallographic analyses showed that often, human "struvite" stones were not monocrystalline, but a mixture of struvite (MgNH 4 PO 4* 6H 2 O) and carbonate apatite (Ca 10 [PO 4 ] 6* CO 3 ) with trace amounts of calcium oxalate [30]; this made exact classification very complicated.…”

Section: Characterization Of Encrustations: Deposits Resemble In Vivosupporting

confidence: 78%

“…Besides this, there are other factors that account for a change of stents in the daily clinical routine. Laube et al investigated 59 stents that were removed from the patients because of clinically observed "stent obstruction" [15]. This phenomenon is often described by the fact that the urine flow is compromised due to large depositions in the lumen of the stent.…”

Section: Resultsmentioning

confidence: 99%

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Prevention of Encrustation on Ureteral Stents: Which Surface Parameters Provide Guidance for the Development of Novel Stent Materials?

Rebl

Renner²,

Kram

et al. 2020

Polymers

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Encrustations of ureteral stents are one of the biggest problems with urological implants. Crystalline biofilms can occur alone or in combination with bacterial biofilms. To identify which surface parameters provide guidance for the development of novel stent materials, we used an in vitro encrustation system. Synthetic urine with increasing pH to simulate an infection situation was pumped over the polymer samples with adjusted flow rates at 37 °C to mimic the native body urine flow. Chemical surface features (contact angle, surface charge), as well as encrustations were characterized. The encrustations on the materials were analyzed quantitatively (dry mass) and qualitatively using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The aim of this comparative study was to identify crucial surface parameters that might predict the quantity and type of mineral deposits in vitro and provide guidance for the development and screening of new polymer-based biomaterials for ureteral stent design. For the first time, we could identify that, within the range of our polymers, those materials with a slight hydrophilicity and a strong negative zeta potential (around −60 mV) were most favorable for use as ureteral stent materials, as the deposition of crystalline biofilms was minimized.

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Section: Characterization Of Encrustations: Deposits Resemble In Vivosupporting

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Prevention of Encrustation on Ureteral Stents: Which Surface Parameters Provide Guidance for the Development of Novel Stent Materials?

Rebl

Renner²,

Kram

et al. 2020

Polymers

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“…It has to be noted that the novel method does not provide extraction of biofilm deposited on the stent lumen. Laube et al (2008) demonstrated that most (i.e., 75%) of the ureteral stents which seem to be obstructed according to failure of the Seldinger technique (i.e., the failure to introduce a guide wire into the stent lumen), do not show significant intraluminal deposits and, therefore, the biofilm in the inner part of the stent can be regarded as negligible. Furthermore, the luminal biofilm is not in direct contact with the urothelium and rarely responsible for stent dysfunction as the main urine flow occurs outside the ureteral stent ( Yossepowitch et al, 2001 ).…”

Section: Resultsmentioning

confidence: 99%

Extraction of Biofilms From Ureteral Stents for Quantification and Cultivation-Dependent and -Independent Analyses

et al. 2018

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Ureteral stenting is a common surgical procedure, which is associated with a high morbidity and economic burden, but the knowledge on the link between biofilms on these stents, morbidity, and the impact of the involved microbiota is still limited. This is partially due to a lack of methods that allow for a controlled extraction of the biofilms from stents. Development of an appropriate in vitro model to assess prevention of biofilm formation by antimicrobial coatings and biomaterials requires a profound understanding of the biofilm composition, including the involved microbiota. This work describes an analytical pipeline for the extraction of native biofilms from ureteral stents for both cultivation-dependent and -independent analysis, involving a novel mechanical abrasion method of passing stent samples through a tapered pinhole. The efficiency of this novel method was evaluated by quantifying the removed biofilm mass, numbers of cultivable bacteria, calcium content, and microscopic stent analysis after biofilm removal using 30 clinical stent samples. Furthermore, the extraction of in vitro formed Escherichia coli biofilms was evaluated by universal 16S quantitative PCR, a cultivation-independent method to demonstrate efficient biofilm removal by the new approach. The novel method enables effective contamination-free extraction of the biofilms formed on ureteral stents and their subsequent quantification, and it represents a useful tool for comprehensive examinations of biofilms on ureteral stents.

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“…Beim Einbringen von Kathetern oder Stents in den Harntrakt kann es zu einer potentiellen primären (nosokomialen/ iatrogenen) oder zusätzlichen Keimverschleppung kommen; bei längerer Liegezeit fördern die Fremdmaterialien aufgrund ihrer Oberfläche selbst die StruvitKarbonatapatit-Mineralisation [15,18,21]. Ursache ist die zur Bakterienanhaftung optimal geeignete Oberfläche.…”

Section: Introductionunclassified

“…Unter ungüns-tigen Umständen kann sich in Folge einsetzender intra-und peribakterieller Kristallisationsprozesse und subsequenter Bildung makroskopischer Mikrolithe sehr schnell ein komplikationsreicher "kristalliner Bakterienbiofilm" entwickeln, dessen kristalliner Bestandteil bei Harnleiterschienen von den Mineralen Struvit und Karbonatapatit dominiert wird [18]; Kalziumoxalat und Brushit (Kalziumhydrogenphosphat, CaHPO 4 ) treten nur relativ selten auf (. Abb.…”

Section: Introductionunclassified

Harnwegsinfektionen und Urolithiasis

Meißner

Mamoulakis

Laube³

2010

Urologe

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The classic "infection stone" struvite is formed as a result of metabolic activity of urease-positive bacteria from alkaline urine with pH-values above 7.5. Due to improved infection diagnostics and antibiotic therapy, the occurrence of infection-related urinary stones in the western industrialized world decreases, despite the generally increasing prevalence rates of urolithiasis in these societies. Struvite is often associated with other mineral phases. These accessory mineral phases could indicate other, non-infection-related causes of urinary stone formation. Thus, mineral analysis is always recommended. Struvite stones as well as struvite encrustations on urinary tract implants are characterized by rapid growth. The rapid growth-related embedding of urease-positive bacteria in the crystalline material makes the urinary stone a persistent source of recurrent urinary tract infections. According to the German Society of Urology guidelines on urolithiasis, a patient with the diagnosis "infection stone" should be assigned to the "high-risk" patient group. Complete stone and debris removal, as well as a special metaphylaxis strategy are required to initiate successful stone therapy.

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The distribution of crystalline material in obstructed stents—In need for intra‐luminal surface modification?

Abstract: 75% of the "obstructed" stents showed no significant inner deposits. Obstruction of urine transport and failure of Seldinger technique occurred due to other reasons. Thus, coating of the stent's inner surface may be overrated.

Cited by 9 publications

References 27 publications

Prevention of Encrustation on Ureteral Stents: Which Surface Parameters Provide Guidance for the Development of Novel Stent Materials?

Prevention of Encrustation on Ureteral Stents: Which Surface Parameters Provide Guidance for the Development of Novel Stent Materials?

Extraction of Biofilms From Ureteral Stents for Quantification and Cultivation-Dependent and -Independent Analyses

Harnwegsinfektionen und Urolithiasis

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