Can we predict the incidence of high-grade Clavien-Dindo complications in patients with forgotten encrusted stents undergoing endourologic management?

Objective:Ureteral stents are customarily inserted to facilitate urinary drainage,but they come with their own glitches of being forgotten and/or encrusted leading to serious consequences.The present study aimed to report the complications in patients with forgotten and encrusted stents according to the Clavien-Dindo system specific to urological procedures and identify the factors leading to high-grade(Clavien-Dindo Grade 4A or above)complications.Methods:The hospital records of patients with forgotten encrusted double-J stents over a period of 8 years were reviewed.The parameters recorded included patient demographics,indwelling time,need for percutaneous nephrostomy,hemodialysis,urine culture,blood culture,total blood counts,serum creatinine,radiologic findings,management techniques,number of surgical interventions,modified Clavien-Dindo complications,follow-up,and mortality,if any.Results:Forty patients were included in the study.The median age was 52(range 6-85)years.Of the total,25(62.5%)patients had a“significant”stent load;31(77.5%)had renal failure or acute kidney injury on presentation;19(47.5%)patients had sepsis at presentation.Among the patients presented with sepsis,11(57.9%)patients demonstrated a positive urine culture;and 7/11(63.6%)patients exhibited pan-resistant organisms.Twelve out of 40(30.0%)patients in our series developed high-grade Clavien-Dindo complications.On univariate analysis,sepsis at presentation(p=0.007),stent load(p=0.031),diabetes(p=0.023),positive urine culture(p=0.007),and stent indwelling time of more than 1 year(p=0.031)were found to be significant.On multivariate logistic regression analysis,sepsis at presentation(p=0.017)and positive urine culture(p=0.016)were significant predictors for high-grade complications.Conclusion:It is prudent to identify specific risk factors,namely sepsis at presentation and positive urine culture to triage and optimize these patients before surgical management.

Fe-Si-Mn-Oxyhydroxide Encrustations on Basalts at East Pacific Rise near 13°N:An SEM-EDS Study

Fe-Si-Mn-oxyhydroxide encrustations at the East Pacific Rise （EPR） near 13°N were analyzed using the scanning electron microscope （SEM） with an energy dispersive spectrometer （EDS）. These encrustations are mainly composed of amorphous Fe- Si-Mn-oxyhydroxides forming laminated, spherical, porous aggregates with some biodetritus, anhydrite, nontronite, and feldspar particles. Anhydrite particles and nontronite crystals in the Fe-Si-Mn-oxyhydroxide encrustations imply that the Fe-Si-Mn-oxyhy- droxide may have formed under relatively low- to high-temperature hydrothermal conditions. The Fe-Si-Mn-oxyhydroxide encrusta- tions on pillow basalts are 1-2mm thick. The growth rate of ferromanganese crusts in the survey area suggests that these encrusta- tions are an unlikely result of hydrogenic deposition alone having a hydrothermal and （Fe/Mn ratio up to 7.7 and Fe/（Fe＋Mn＋A1） ratio exceeding 0.78） hydrogenic origin （0.22 Fe/Mn ratio close to the mean value of 0.7 for open-ocean seamount crusts）. The varying Fe/Mn ratios indicate that the Fe-Si-Mn-oxyhydroxide encrustations have formed through several stages of seafloor hydrother- malism. It is suggested that, at the initial formation stage, dense Fe-Si-oxyhydroxides with low Mn content deposit from a relatively reducing hydrothermal fluid, and then the loose Fe-Si-Mn-oxyhydroxides deposit on the Fe-Si-oxyhydroxides. As the oxidation degree of hydrothermal fluid increases and Si-oxide is inhibited, Mn-oxide will precipitate with Fe-oxyhydroxides.

Successful treatment of encrusted cystitis:A case report and review of literature

BACKGROUND Encrusted cystitis(EC)is a chronic inflammation of the bladder associated with mucosal encrustations.Early diagnosis and optimal treatment are not well established.Here,we report a case of EC successfully treated with com-bination therapy.CASE SUMMARY A 27-year-old man presented with frequency,urgency,dysuria,gross hematuria and suprapubic pain for 2 mo.He was diagnosed with EC based on characteristic calcifications of the bladder wall(most of them were struvite),cystoscopy and histopathological examination.He was cured after combined therapy of elimination of encrustations,bladder instillation of hyaluronic acid and injection of botulinum-A neurotoxin into bladder submucosal tissue.CONCLUSION Bladder instillation of hyaluronic acid and injection of botulinum-A neurotoxin into the bladder submucosal tissue can be used for treatment of EC.

Development of a hybrid photoacoustic and optical monitoring system for the study of laser ablation processes upon the removal of encrustation from stonework

In the context of this work,a prototype hybrid photoacoustic(PA)and optical system for the on-line monitoring of laser cleaning procedures is presented.The developed apparatus has enabled the detection of MHz frequency range acoustic waves generated during the laser ablation process.The intrinsically generated PA signals combined with high resolution optical images provide the opportunity to follow the cleaning process accurately and in real time.Technical mock-ups have been used to demonstrate the potential of this novel technique with emphasis given to applications that refer to the restoration of Cultural Heritage(CH)surfaces.Towards this purpose,the real time monitoring of the laser assisted removal of unwanted encrustation from stonework has been achieved using IR and UV wavelengths.This novel approach has allowed for the precise determination of the critical number of laser pulses required for the elimination of the encrustation layer,while highlighting the dominant ablation mechanisms according to the irradiation wavelength.The promising results obtained using the prototype hybrid PA and optical system can open up new perspectives in the monitoring of laser cleaning interventions,promoting an improved restoration outcome.

Epi- and endobiont faunal communities on an Egyptian Mediterranean rocky shore: species composition and their competition for space

The exposed calcareous rocky area of the Abu Qir Headland,east of Alexandria,Egypt which range from coarse grains,through pebbles,cobbles,and boulders to rocky platforms,was signifi cantly colonized by sclerobionts(epibionts and endobionts).The epibiont species diversity was comparatively higher than that of endobionts.Epibiont communities included bryozoans(the anascan-grade cheilostome Bifl ustra savartii),serpulid(Hydroides elegans,Spirobranchus cf.tetraceros,Vermiliopsis striaticeps and Protula or Apomatus)and spirorbid(Spirorbis)wormtubes,and balanoid barnacles(Amphibalanus amphitrite,Balanus trigonus,and Perforatus perforatus).The cheilostome bryozoan colonies,which developed extensive sheets,proliferated on the study rocky shore either encrusting the bioeroded basement directly,or encrusting other epilithic taxa,particularly balanoid barnacles and serpulid worms.Encrusters displayed a remarkable marginal competitive interaction(overgrowth and stand-off)for space on the study rocky shore.On the other hand,endobionts were not well represented on the studied rocky shore exposure.It was possible to identify three ichnotaxa:Gastrochaenolites,Maeandropolydora,and Finichnus.The fi ndings documented represent a signifi cant contribution to our knowledge of sclerobionts composition,sequence of their colonization and/or bioerosion,and their mutual relationships on the intertidal rocky shore of the Abu Qir Headland.

Endoscopic treatment of urothelial encrusted pyelo-ureteritis disease:A case series

BACKGROUND Urothelial encrusted pyelo-ureteritis disease is an infrequent condition and there is no unified surgical treatment and reference standard to consult.We have used a minimally invasive endoscopic method to treat three such cases,which yielded excellent results.CASE SUMMARY The first case was a 45-year-old man who had unilateral ureteropelvic junction(UPJ)atresia and contralateral stenosis and was treated by double endoscopic surgery using an anterograde percutaneous nephroscope coupled with a rigid retrograde ureteroscope.The second case was a 12-year-old boy who received a percutaneous nephroscopy on one side and a percutaneous nephroscopy with a rigid ureteroscope on the other side due to the presence of bilateral UPJ stenosis.The third case was a 32-year-old woman with bilateral lower ureteral stricture treated using a rigid retrograde ureteroscope.Endoscopic surgeries were successfully performed on all the three patients.Varying degrees of encrustation and erosion of the urothelium were observed during the operation.The calcified layer composition analysis showed magnesium ammonium phosphate or carbonate apatite.Two patients achieved a good prognosis.CONCLUSION Minimally invasive endoscopic treatment for urothelial encrusted pyelo-ureteritis disease can yield better results.

A New Biomaterial for Urinary Catheters

Several studies argue that an ideal biomaterial for urinary catheters is utopian. Based in literature review it seems to be true. However, research advances: the biomaterial itself, new designs, new coatings, associated drugs, etc. Once implanted and interacting with urine, two old problems persist: encrustation and bacterial colonization. In this context, an extracellular product from bacterial synthesis on sugarcane molasses biomaterial has been studied in several experimental and clinical studies. Based on its high biocompatibility, the aim of this study is to evaluate its performance in an in vivo model as an endourologic prosthesis implanted in the bladder of Wistar rats. We evaluate physical, chemical and biological phenomena in comparison to an already established biomaterial, polyurethane. Even though it is not a finished product, the sugarcane biopolymer presented similar performance compared to polyurethane in several analyzed parameters and has an important characteristic: low cost.

Forgotten Ureteral Stents in a Tertiary Hospital in Accra and a Review of Endourological Management of Upper Urinary Tract Pathologies in the West Africa Sub-Region

Background: Forgotten ureteral stent is defined as prolong indwelling ureteral stent whose function is no longer desired. Ureteral stents are used in the management of upper urinary tract pathologies. Prolonged indwelling ureteral stents may be complicated by urosepsis or renal failure, encrustation, stone formation, spontaneous fracture which may either be retained or voided in the urine (stenturia). Hitherto, these complications were managed by open procedures alone in our center. We report our recent experience in endourology with the management of three cases of forgotten ureteral stents with durations of ten years and two years (two cases) and review endourological practice in West Africa. Conclusion: Although encrusted stents can be managed successfully by minimally invasive approaches in the majority of cases, the best treatment is prevention. Urology units should have preferably an electronic stent register such that when the time for removal is due, the patient's name and details are flagged red. If electronic register is not available, then a hard paper/book register should be made to prevent situations of forgotten stents. Also, efforts must be made to improve endourological services in the West Africa subregion to allow patients to have the benefit of endourology in the management of upper urinary tract pathologies including that of stones originating from an encrusted or fractured forgotten ureteral stent.

Continental island from the Upper Silurian (Ludlow) Sino-Korean plate

Recent field studies on Upper Silurian stratigraphy and paleontology in the Inner Mongolia Autonomous Region (for short Inner Mongalia) near Bater Obo (=Bateaobao) resulted in the discovery of a small continental island with fossil invertebrates preserved as encrusters (stromatoporoids and corals) attached directly to a rocky shore surface and buried by silty clay mud. The Bater island (named herein) is 610 m ×200 m in size and composed of Ordovician igneous rock (diorite). Limestone strata dating from the Ludlow Epoch (about 420 Ma) surround the island and dip away from the igneous core in a radial pattern. The encrusting fossils occur on the sheltered (south and southeast) side of the island, whereas the north side was exposed to stronger wave activity based on a basal conglomerate unit composed of diorite boulders. This is the first record of an ancient island in China and the first report worldwide of stromatoporoids as members of a rocky-shore community. The island clearly shows distinct windward

Foraminiferal micro-buildups(“reefs”)in the Wuchiapingian basin facies of the basal Zechstein carbonates in western Poland

Encrusting foraminifers locally can play an essential reef-forming role such as in the Carnian fossiliferous Hallstatt Limestones of Austria where a dense succession of hardgrounds occurs with numerous small buildups(up to 2 cm high)composed of sessile foraminifers.Similar foraminiferal micro-buildups occur in a 10-cm-thick bed in the basinal facies in the basal Zechstein(Upper Permian)strata in the Radlin 60 borehole,in western Poland.Foraminiferal micro-buildups of presumably columnar habit account for up to a half of the volume.The growth of columns was interrupted by hiatal surfaces,although usually the growth of columns was restored afterwards.In the upper part of the bed with foraminiferal micro-buildups,the foraminiferal encrustations become visibly less abundant,and in most cases,they have a shape of less regular masses.The bed with foraminiferal micro-buildups abounds in closely spaced discontinuity(hiatal)surfaces,occasionally encrusted by foraminifers.Tubular foraminifers in the bed with foraminiferal micro-buildups are accompanied by various encrusting organisms,possibly microbes;they are grouped under the name Palaeonubecularia.In the intercolumnar spaces,common Midiella sp.occur.During deposition,the conditions were mostly suboxic,and various types of ferruginous morphs,common in the lower part of the bed,suggest that dysoxic-anoxic interfaces produced various microaerophilic environments for iron-bacteria.The environmental conditions during the deposition of the upper part of the bed were very similar to those characterizing the starved basin environment in which the bioclastic-peloidal and oncoidal sediments in the Zechstein Limestone have been formed.In turn,the lower part of the bed registers the transition from normal(=not starved)marine conditions,with a clear chemocline,to the starved basin conditions.The deposition of the bed was coeval with the Kupferschiefer deposition based on the correlation ofδ13C curves,which implies that the previous stratigraphical concept of basal Zechstein strata has to be re-evaluated.

In vitro study on infectious ureteral encrustation resistance of Cu-bearing stainless steel

Cu-bearing stainless steel has been found to have obvious inhibition performance against encrustation in vitro. This study was aiming to further investigate the inhibitory effect of a Cu-bearing stainless steel（316 L-Cu SS） on the infectious encrustation based on its antimicrobial activity. The encrustation in presence of bacteria, antibacterial performance, urease production and Ca and Mg precipitation were examined by scanning electron microscopy, antibacterial assay, enzyme-linked immunosorbent assay and inductively coupled plasma-mass spectrometry, respectively. It was found that 316 L-Cu SS could inhibit the formation of bacterial biofilm due to the release of Cu^（2＋） ions and then decrease the urease amount splitting by bacteria, which produced a neutral environment with pH around 7. However, more encrustations coupled with bacterial biofilms on the surface of comparison stainless steel（316 L SS） with an alkaline environment were recorded. It can thus be seen that the 316 L-Cu SS highlights prominent superiority against encrustation in the presence of microorganisms.

In vitro and in vivo studies on bacteria and encrustation resistance of heparin/poly-L-lysine-Cu nanoparticles coating mediated by PDA for ureteral stent application

Ureteral stents are commonly utilized as a medical device to aid the flow of urine.However,biofilm formation and encrustation complications have been clinical problems.To overcome this challenge,heparin/poly-L-lysine-copper(Hep/PLL-Cu)nanoparticle was immobilized on a dopamine-coated polyurethane surface(PU/NPs).The stability and structural properties of the nanoparticles were characterized by Zeta potential,poly dispersion index,transmission electron microscopy,atom force microscopy and contact angle.The surface composition,antibacterial potency,encrustation resistance rate and biocompatibility of PU/NPs were investigated by scanning electron microscope,X-ray photoelectron spectroscopy,antibacterial assay and MTS assay,respectively.In addition,the antiencrustation property was studied by implanting coated NPs stents in the rat bladder for 7 days.It was shown that the size and distribution of Hep/PLL-Cu nanoparticles were uniform.PU/NPs could inhibit Proteus mirabilis proliferation and biofilm formation,and exhibit no cytotoxicity.Less encrustation(Ca and Mg salt)was deposited both in vitro and in vivo on samples,demonstrating that the NPs coating could be a potential surface modification method of ureteral material for clinical use.

In vivo study on heparin/poly-L-lysine-copper coating for surface functionalization of ureteral stent

Polyurethane(PU)ureteral stents are used in clinics to maintain the ureteral patency.Due to biofilm formation and encrustation complications,long-term clinical usage has been limited.It is therefore necessary to develop an effective response to this unmet medical need.A heparin/poly-L-lysine/copper(NPs)coating was developed in our previous work that showed the effect of preventing infection and encrustation in vitro.In this work,a further study was conducted by grafting NPs on clinical ureteral stents that then were implanted into the infectious bladders of Wistar rats to investigate the effects of nanoparticles on bacterial growth and crystal deposition in vivo.It was found that decreased numbers of adherent microbes,urease amount splitting by bacteria,and deposited crystals were observed on the NPs stents with significant differences in comparison with PU stents.Besides,histological analysis showed that the NPs stents decreased the host tissue inflammation in close relation to the decrease biofilm formation and encrustation after 28 days of implantation.