Ureteral stent versus no ureteral stent for ureteroscopy in the management of renal and ureteral calculi

BACKGROUND

Ureteroscopy combined with laser stone fragmentation and basketing is a common approach for managing renal and ureteral stones. This procedure is associated with some degree of ureteral trauma. Ureteral trauma may lead to swelling, ureteral obstruction, and flank pain and may require subsequent interventions such as hospital admission or secondary ureteral stent placement. To prevent such issues, urologists often place temporary ureteral stents prophylactically, but the value of doing so remains unclear.

OBJECTIVES

To assess the effects of postoperative ureteral stent placement after uncomplicated ureteroscopy.

SEARCH METHODS

We performed a comprehensive search using multiple databases (the Cochrane Library, MEDLINE, Embase, Scopus, Google Scholar, and Web of Science), trials registries, other sources of grey literature, and conference proceedings, up to 01 February 2019. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included trials in which researchers randomised participants undergoing uncomplicated ureteroscopy to placement of a ureteral stent versus no ureteral stent.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data from the included studies. We performed statistical analyses using a random-effects model. We rated the certainty of evidence (CoE) according to the GRADE approach.

MAIN RESULTS

Primary outcomesStenting may slightly reduce the number of unplanned return visits (16 trials with 1970 participants; very low CoE), but we are very uncertain of this finding.Pain on the day of surgery as measured on a visual analogue scale (scale 0 to 10; higher values reflect more pain) is probably similar (mean difference (MD) 0.32 higher, 95% confidence interval (CI) 0.13 lower to 0.78 higher; 4 trials with 346 participants; moderate CoE). Pain on postoperative days 1 to 3 may show little to no difference (standardised mean difference (SMD) 0.25 higher, 95% CI 0.32 lower to 0.82 higher; 8 trials with 683 participants; low CoE). On postoperative days 4 to 30, stented participants may experience more pain (8 trials with 903 participants; very low CoE), but we are very uncertain of this finding.Stenting may result in little to no difference in the need for secondary interventions (risk ratio (RR) 1.15, 95% CI 0.39 to 3.33; 10 studies with 1435 participants; low CoE); this corresponds to three more interventions per 1000 participants (95% CI 13 fewer to 48 more).Secondary outcomesStenting may reduce the need for narcotics (7 trials with 830 participants; very low CoE), but we are very uncertain of this finding.Rates of urinary tract infection (UTI) up to 90 days are probably not substantially different (RR 0.94, 95% CI 0.59 to 1.51; 10 trials with 1207 participants; moderate CoE); this corresponds to three fewer infections per 1000 participants (95% CI 23 fewer to 29 more).Ureteral stricture rates up to 90 days may be slightly reduced (14 trials with 1625 participants; very low CoE), but we are very uncertain of this finding.Rates of hospital admission may be slightly reduced (RR 0.70, 95% CI 0.32 to 1.55; 13 studies with 1647 participants; low CoE). This corresponds to 15 fewer admissions per 1000 participants (95% CI 33 fewer to 27 more).

AUTHORS' CONCLUSIONS

Findings of this review illustrate the trade-offs of risks and benefits faced by urologists and their patients when it comes to decision-making about stent placement after uncomplicated ureteroscopy for stone disease. We noted that both desirable and undesirable effects were small in absolute terms, with findings based mostly on low and very low CoE. The main issues reducing our confidence in research findings were study limitations (mostly risk of performance and detection bias) and imprecision. We were unable to conduct any of the preplanned subgroup analyses, in particular those based on stone size, stone location, and use of ureteral dilation, which may be important effect modifiers. Given the importance of this question, higher-quality and sufficiently large trials are needed to better inform decision-making.

The Protective Effect of Melittin on Renal Fibrosis in an Animal Model of Unilateral Ureteral Obstruction

Renal fibrosis is the principal pathological process underlying the progression of chronic kidney disease that leads to end-stage renal disease. Melittin is a major component of bee venom, and it has anti-bacterial, anti-viral, and anti-inflammatory properties in various cell types. Thus, this study examined the therapeutic effects of melittin on the progression of renal fibrosis using the unilateral ureteral obstruction (UUO) model. In addition, the effects of melittin on inflammation and fibrosis in renal fibroblast cells were explored using transforming growth factor-β1 (TGF-β1). Histological observation revealed that UUO induced a considerable increase in the number of infiltrated inflammatory cells. However, melittin treatment markedly reduced these reactions compared with untreated UUO mice. The expression levels of inflammatory cytokines and pro-fibrotic genes were significantly reduced in melittin-treated mice compared with UUO mice. Melittin also effectively inhibited fibrosis-related gene expression in renal fibroblasts NRK-49F cells. These findings suggest that melittin attenuates renal fibrosis and reduces inflammatory responses by the suppression of multiple growth factor-mediated pro-fibrotic genes. In conclusion, melittin may be a useful therapeutic agent for the prevention of fibrosis that characterizes the progression of chronic kidney disease.

Use of Corticosteroids for Urinary Tuberculosis Patients at Risk of Developing Ureteral Obstruction

A 77-year-old man with urinary tuberculosis developed post renal anuria two days after starting an anti-tuberculosis drug regimen. He had bilateral hydronephrosis, and his right kidney was radiologically diagnosed to be non-functioning. A transurethral catheter was placed in the left ureter. No improvement in the ureteral stricture was noted during the initial three weeks of treatment; however, the stricture did thereafter improve after the commencement of oral prednisolone. In cases of urinary tuberculosis, ureteral stricture can deteriorate and result in ureteral obstruction during anti-tuberculosis treatment. Pre-emptive administration of corticosteroids may be beneficial for preventing such stricture in patients with a pre-existing ureteral lesion.

Routine intraoperative ureteric stenting for kidney transplant recipients

BACKGROUND

Major urological complications (MUCs) after kidney transplantation contribute to patient morbidity and compromise graft function. The majority arise from the vesicoureteric anastomosis and present early after transplantation. Ureteric stents have been successfully used to treat such complications. A number of centres have adopted a policy of universal prophylactic stenting, at the time of graft implantation, to reduce the incidence of urine leaks and ureteric stenosis. Stents are associated with specific complications and some centres advocate a policy of only stenting selected anastomoses.

OBJECTIVES

To examine the benefits and harms of routine ureteric stenting to prevent urological complications in kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register (up to 8 January 2013) through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

All RCTs and quasi-RCTs were included in our meta-analysis.

DATA COLLECTION AND ANALYSIS

Four reviewers assessed the studies for quality against four criteria (allocation concealment, blinding, intention-to-treat and completeness of follow-up). The primary outcome was the incidence of MUCs. Further outcomes of interest were graft and patient survival and the incidence of adverse events (urinary tract infection (UTI), haematuria, irritative symptoms, pain and stent migration). Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Seven RCTs (1154 patients) of low or moderate quality were identified. The incidence of MUCs was significantly reduced (RR 0.24, 95% CI 0.07 to 0.77, P = 0.02, NNT 13) by universal prophylactic stenting. This was dependent on whether the same surgeon performed, or was in attendance, during the operations. Two patients lost their grafts to infective urinary tract complications in the stented group. UTIs, in general, were more common in stented patients (RR 1.49, 95% CI 1.04 to 2.15) unless the patients were prescribed cotrimoxazole 480 mg/d: in which case the incidence was equivalent (RR 0.97, 95% CI 0.71 to 1.33). Stents appeared generally well tolerated, although studies using longer stents (≥ 20 cm) for longer periods (> 6 weeks) had more problems with encrustation and migration.

AUTHORS' CONCLUSIONS

Routine prophylactic stenting reduces the incidence of MUCs. Studies comparing selective stenting and universal prophylactic stenting, whilst difficult to design and analyse, would address the unresolved quality of life and economic issues.

Ureteral stricture formation in laparoscopically procured living donor kidney transplantation

INTRODUCTION

To identify the incidence of and risk factors for ureteral stricture formation in laparoscopically procured living donor kidney transplantation (LLDKT).

MATERIALS AND METHODS

An IRB approved retrospective review of our institution's living donor database was performed. Patients were divided into two cohorts, those with ureteral strictures requiring procedural intervention and those without evidence of ureteral strictures. Analysis was limited to those patients with at least 1 year of follow up.

RESULTS

Of the 584 LLDKT's performed at our institution since June 1999, 510 had at least 1 year of follow up. Four hundred and ninety-six patients had no evidence of stricture disease (97.2%) while 14 (2.8%) developed clinically significant ureteral strictures. The incidence of delayed graft function was higher in the stricture group (21% versus 3%, p < 0.0001) while the intraoperative placement of a ureteral stent was associated with decreased incidence of ureteral strictures (21% of the stricture group received stents compared to 58% in the no stricture group, p = 0.006). In multivariable logistic regression models, delayed graft function was strongly associated with the development of clinically significant ureteral stricture disease (OR 19.3; 95% CI 3.59, 104.2; p = 0.001) while the placement of intraoperative ureteral stents was protective against ureteral stricture formation (OR 0.09; 95% CI: 0.02, 0.49; p = 0.005).

CONCLUSION

Delayed graft function and nonuse of ureteral stents are associated with the development of ureteral strictures following LLDKT.

[Strategy in preventing of uretero-intestinal anastomosis strictures in patients with low-pressure intestinal neobladder]

Ureteroileal stenoses occur in 1.2-20% patients with neobladders. They constitute a serious clinical complication since, as every obstruction of urine flow from the kidney. Ureteroileal stenoses develop usually within firs 6 to 12 months following the extended urological procedure such as radical cystectomy with the creation of ileal orthotopic neobladder. Ureteroileal stenosis belongs to the most difficult complications after creation of ileal neobladder. The experience of our clinic between 2001 and 2011 covers 3500 cases of patients with bladder cancer. 226 patients underwent cystectomy, 120 were treated with urinary diversion m. Bricker and 106 underwent low pressure ileal neobladder modo Studer. Ureters anastomosed with the intestine Michalowskis way of a flap. The authors performed 344 ureteroileal anastomoses, 212 ureteroileal anastomoses with the ileal neobladder modo Studer and 11 stenoses were detected, in 5 patients one-side, in 3 bilateral. In our practice there was altogether 11 detected stenoses which constitutes 5.18%. Based on our experience, in the course of radical removal of the bladder during the preparation of the least possible damage the blood supply ureter, ureter prior to implantation should be checked for leaks, catheter should be made of soft material. The performance of the left ureter to carry out the right side of the mesentery, be careful not without angulation. In the course of the uretero-intestinal anastomosis should not be stitched in place to destroy the vascular anastomosis of ureter to intestine anastomosis and the same should be done without tension. Protect the integrity of the anastomosis, aseptic oncology. Uretero-intestinal anastomosis performed without anti-reflux protection.

[The usefulness of the polymeric "double J" catheter in ureteropelvic junction stenting after laparoscopic pyeloplasty]

OBJECTIVES

The aim of the study was to evaluate both the effectiveness of ureteropelvic junction stenting with the use of a polymeric "double J" stent after laparoscopic pyeloplasty, as well as intra- and postoperative complications of the procedure.

MATERIAL AND METHODS

From October 2001 to November 2010 laparoscopic pyeloplasty was performer in 150 patients with primary UPJO. In all cases an attempt has been made to insert the stent into the operated kidney before the operation. All but one operations were performed using a transperitoneal approach. Anderson-Hynes pyeloplasty was carried out in 85 cases, Y-V plasty in 61 cases and Fenger plasty in 2 patients. Open conversion was performer in two cases.

RESULTS

In 13 cases the complications observed in the postoperastive period were connected with the polymeric stent. In 12 patients the obstruction of the stent lead to massive urinary leakage and in 3 cases from this group urinoma developed. Urinoma was also observed in a patient, who was left without stenting because of the difficulties in inserting the stent to the operated kidney. In 10 cases the stent was successfully replaced but in 3 cases the placement of a percutaneous nephrostomy tube was necessary. It was left in place for 3 weeks.

CONCLUSIONS

Our data indicate, that the stent obstruction is the main cause of postoperative complications in patients after laparoscopic pyeloplasty. So far no better method of upper urinary tract drainage after laparoscopic pyeloplasty has been worked out. Experimenting with various types of stents has been of no avail.

Management of ureteral complications in renal transplantation: prevention and treatment

Urinary anastomotic complications following renal transplantation cause significant patient morbidity. In ureteric reconstruction, different techniques are used to reduce complications (such as leakage or obstruction). In this study, we suggested two aspects of management of the complications of ureteral anastamosis: ureteral spatulation more than 10 mm for prevention and percutaneous nephrostomy and balloon dilatation as the first steps of treatment. A sequential double-blind random trial with 170 kidney transplant recipients was performed, dividing the patients into two groups: group 1 patients had ureteral spatulation length ≤ 10 mm (70 recipients) and group 2 patients had ureteral spatulation ≥ 10 mm (100 recipients). In patients with ureteral stenosis, percutaneous nephrostomy (PCN) and balloon dilatation were used as the first step of treatment. The mean age was 44 ± 4.2 years. Before and after removing the double J stent, ureteral complications that needed surgical intervention occurred in 16/70 recipients in group 1 (20.3%) and in eight/100 recipients in group 2 (8%). There is a significant difference between the two groups (P < 0.05). PCN and balloon dilatation were performed in 24 patients with ureteral stenosis. Eleven patients had a good response and 13 patients underwent surgical procedures (in four of theses patients, ileal interposition was used for repairing the ureteral defects). In conclusion, ureteral spatulation more than 10 mm in prevention of ureteral stenosis and use of PCN and balloon dilatation in the first step of treatment of ureteral obstruction should be the management choice for these patients.

Antifibrotic properties of relaxin: in vivo mechanism of action in experimental renal tubulointerstitial fibrosis

This study examined the efficacy and in vivo mechanism of action of the antifibrotic hormone, relaxin, in a mouse model of unilateral ureteric obstruction (UUO). Kidney fibrosis was assessed in recombinant human gene-2 relaxin-treated animals maintained for 3 and 9 d after UUO. Results were compared with untreated and unoperated animals (d 0). Total collagen, collagen subtypes (I, IV), TGF-β2 production, mothers against decapentaplegic homolog 2 (Smad2) phosphorylation, myofibroblast differentiation, mitosis, and apoptosis were all progressively increased by UUO (all P<0.05 vs. d 0 group at d 3 and d 9), whereas TGF-β1 production was increased and vascular endothelial growth factor expression (angiogenesis) decreased at d 9 (both P<0.05 vs. d 0). A progressive increase in matrix metalloproteinase (MMP)-2 after UUO suggested that it was reactive to the increased fibrogenesis. Conversely, MMP-9 was decreased at d 9, whereas its inhibitor tissue inhibitor of metalloproteinase-1 progressively decreased after UUO. Human gene-2 relaxin pretreatment of animals from 4 d prior to UUO ameliorated the increase in total collagen, collagen IV, Smad2 phosphorylation, and myofibroblasts at both time points (all P<0.05 vs. untreated groups) and inhibited TGF-β2 production and cell proliferation (both P<0.05 vs. untreated groups) with a trend toward normalizing vascular endothelial growth factor expression at d 9, with no effect on TGF-β1 production or apoptosis. The relaxin-mediated regulation of MMPs and tissue inhibitor of metalloproteinases in this model was not consistent with its antifibrotic properties. The beneficial effects of relaxin were lost when treatment was stopped. These findings establish that relaxin can inhibit both early and established phases of tubulointerstitial fibrosis, primarily by suppressing cell proliferation, myofibroblast differentiation, and collagen production. Not all of these effects paralleled changes to TGF-β-Smad signaling.

[Probability of development of "steinstrasse" depending on the number of extracorporeal shock wave lithotripsy in ureteral stones]

One of the complications of extracorporeal shock wave lithotripsy (ESWL) is the urethral obstruction by large stone fragments and formation of "steinstrasse". The present study aims at the investigation of the probability of development of "steinstrasse" depending on the number of ESWL sessions in urethral stone treatment. 162 patients with urinary tract stone disease having urethral stones were included in the present study. Based on the results of the present study it is stated, that the probability of formation of "steinstrasse" increases along with the number of ESWL sessions. Therefore, in such cases more intensive follow-up is necessary after ESWL for prompt detection of "steinstrasse" formation and prevention of possible complications.

[Effect of Astragalus mongholicus on expression of transforming growth factor- beta1 in SD rats with unilateral ureteral occlusion]

OBJECTIVE

To study the effect of Astragalus mongholicus (AM) on the expression of transforming growth factor-beta1 (TGF-beta1) in SD rats with unilateral ureteral occlusion (UUO) and to elucidate the mechanisms underlying the renoprotective effects of AM.

METHOD

Fifty-four Sprague-Dawley rats were randomly divided into 4 groups: sham-operation group, the UUO group and AM treatment group. After administration of AM (10 g kg(-1) d(-1)) for 3, 7 and 14 days, the dynamic histological changes of renal interstitial tissues were observed and renal damage including tubular impairment and interstitial fibrosis were quantified on HE and Masson stained tissue sections. The expression of TGF-beta1 and alpha-smooth muscle actin (alpha-SMA) was measured by immunohistochemistry staining sections. The mRNA of TGF-beta1 and alpha-SMA were reverse transcribed and quantified by real-time PCR. The expression of TGF-beta1 protein were assessed by Western blot.

RESULT

Renal damage was exacerbated and the expression of alpha-SMA and TGF-beta1 were all significantly increased in UUO group compared with those of sham-operation group (P<0.05) at each time point. Tubular impairment and interstitial fibrosis were alleviated, and up-regulations of expressions of TGF-beta1 and alpha-SMA were significantly suppressed by AM treatment (P<0.05).

CONCLUSION

AM can ameliorate renal interstitial fibrosis induced by UUO in vivo. The mechanisms of its antifibrotic effects might be related with the down-regulation of TGF-beta1 expression and suppression of tubular epithelial myofibroblast transdifferentiation in the progress of renal interstitial fibrosis.

[Effect of Astragalus mongholicus on expression of connective tissue growth factor in kidney of SD rats with unilateral ureteral obstruction]

OBJECTIVE

To study the effect of Astrangalus mongholicus (AM) on the expression of Connective Tissue Growth Factor (CTGF) in SD rats with Unilateral Ureteral Obstruction (UUO) and elucidate the mechanism underlying the renorotective effects of AM.

METHODS

36 Sprague-Dawley rats were randomly divided into 3 groups: sham-operation group (Sham), UUO group (UUO) and UUO + AM group (AM). After administration of AM (10 g/kg x d) for 7 and 14 days, the dynamic histological changes of renal interstitial tissues were observed and renal damage including tubular impairment and interstitial fibrosis were quantified on HE and Masson stained tissue sections. The expressions of CTGF and alpha-smooth muscle actin (alpha-SMA) were measured by immunohistochemistry staining sections. The mRNA of CTGF and alpha-SMA were reversely transcribed and quantified to real-time PCR. The expression of CTGF protein was assessed by Western blot.

RESULTS

Renal damage was exacerbated and the expressions of alpha-SMA and CTGF significantly increased in UUO group compared with those of Sham group (P < 0.05) at each time point. Tubular impairment and interstitial fibrosis were alleviated, and up-regulations of expressions of CTGF and alpha-SMA were significantly depressed by AM treatment (P < 0.05).

CONCLUSIONS

AM can ameliorate renal interstitial fibrosis induced by UUO in rats. The mechanism of its antifibrotic effects may be related to the down-regulation of CTGF expression, following suppression of tubulo-epithelial mesenchymal transdifferentation in renal intersitial progress.

Cobalt protoporphyrin attenuates rat obstructive nephropathy: role of cellular infiltration

OBJECTIVES

Renal interstitial inflammation is closely related to the progressive renal fibrosis. It has been reported that heme oxygenase-1 (HO-1) induction attenuated renal fibrosis in obstructive nephropathy. To elucidate the antifibrogenic mechanisms of HO-1, we examined the effect of HO-1 induction on renal interstitial inflammation.

METHODS

Adult male rats underwent unilateral ureteral obstruction (UUO). The rats were pretreated with cobalt protoporphyrin (CoPP, a potent HO-1 inducer; 15 or 50 mg/kg) subcutaneously on the day -6 and -1 before UUO. Sham-operated rats served as controls. Renal interstitial fibrosis, macrophage and T cell infiltration were immunohistochemically assessed on the day 5 after UUO. Gene expressions of HO-1 and profibrogenic molecules were determined by real-time reverse transcriptase-polymerase chain reaction.

RESULTS

CoPP dose-dependently induced HO-1 activity, protein, and messenger RNA (mRNA) expression in the renal cortices. CoPP significantly attenuated the renal fibrosis in a dose-dependent manner. Gene expressions of transforming growth factor-beta and extracellular matrix proteins were upregulated in UUO and were attenuated by CoPP. CoPP markedly inhibited T cell infiltration. Unexpectedly, it enhanced macrophage influx dose dependently. Double immunostaining of macrophage and HO-1 showed that CoPP elicited HO-1 overexpression in infiltrating macrophages, whereas UUO alone did not.

CONCLUSIONS

HO-1 induction protected against the renal interstitial fibrosis in rat obstructive nephropathy. It is suggested that inhibition of T cell influx is, at least in part, involved in the protection. Increased macrophages that overexpress HO-1 may play an important role in attenuating renal fibrosis.

Ureterstriktur nach extrakorporaler Stoßwellenlithotripsie

Extracorporeal shock wave lithotripsy (ESWL) is considered a very safe and noninvasive procedure for the treatment of urolithiasis. Achievements in the technical development of recent decades resulted in a continuous reduction of side effects. One of our patients, a woman with cystinuria, developed a temporary ureteral stricture after several sessions of ESWL. Encouraged by this observation we set out to explore--based on a MEDLINE literature search--published reports of more severe side effects observed in modern ESWL therapy. Besides hydronephrosis and renal colic the most common side effects were renal and perirenal hematomas in up to 4% in the larger series. Uncommon extrarenal complications are described mostly in case reports, which are also outlined in this report. The injury of visceral organs (liver, spleen, gut, pancreas) was published most frequently. A rupture or dissection of an abdominal aortic aneurysm as an outstanding serious complication was also reported several times. Taking obvious and well-known contraindications into consideration and carefully preparing the patients for the therapy (i.e., checking hemostasis, drug history), ESWL is a very safe procedure with a low risk of serious complications. Yet, postoperative clinical and ultrasound monitoring seems to be essential especially with respect to the increasing numbers of outpatient procedures.

Renal pelvis flap—guide for ureteral spatulation and handling during dismembered pyeloplasty

INTRODUCTION

To present a technical modification of the classic dismembered pyeloplasty technique. We have implemented it in 112 pyeloplasties performed during the past 15 years.

TECHNICAL CONSIDERATIONS

The technical modification is based on a renal pelvis flap kept undetached from the ureteropelvic junction, and consequently from the ureter, until near completion of the new ureteropelvic anastomosis. This flap is used for ureteral handling (a "no touch" technique) during pyeloplasty and also serves as a very reliable guide for lateral ureteral spatulation, preventing ureteral twisting and subsequent misalignment of the de novo ureteropelvic junction. We experienced early complications in 4 patients (3.6%). Two patients had excessive urinary leakage from the ureteropelvic anastomosis because of misplacement of a Nelaton retroperitoneal tube drain. We have used soft Penrose drains for retroperitoneal drainage since. Two other patients needed reoperation because of a redundant renal pelvis and ureter consequent to a remnant high anastomosis and insertion of the ureter to the renal pelvis with subsequent kinking and obstruction. No other early or late complications attributable to obstruction of the anastomosis resulting from devascularization or misalignment between the ureter and renal pelvis were encountered.

CONCLUSIONS

Modification of the classic pyeloplasty technique has proved relatively easy and reliable in our experience. With the increasing popularity of the laparoscopic approach for pyeloplasty, the described technical modification may become useful for laparoscopic handling of the ureter.

Angiotensin receptor blockade decreases fibrosis and fibroblast expression in a rat model of unilateral ureteral obstruction

PURPOSE

Unilateral ureteral obstruction is characterized by histopathological changes including interstitial fibrosis, fibroblast specific protein expression, tubular atrophy and apoptosis, and macrophage infiltration. Angiotensin II has been implicated in some of these changes. We examined the effect of angiotensin blockade on markers of renal injury, including fibroblast specific protein expression, fibrosis, apoptosis and macrophage infiltration. We used losartan, an angiotensin II antagonist, in a unilateral ureteral obstruction model and studied animals 3 weeks after unilateral ureteral obstruction, a time at which renal damage is well established.

MATERIALS AND METHODS

Rats underwent unilateral ureteral obstruction and were given either drinking water or losartan for 21 days. Kidneys were harvested and examined for fibrosis (trichrome and the Sircol assay for collagen), apoptosis (TUNEL), and fibroblast specific protein expression and macrophage infiltration (immunohistochemistry).

RESULTS

Unilateral ureteral obstruction was found to induce fibrosis, apoptosis, fibroblast expression and macrophage in the obstructed kidney. Losartan significantly decreased apoptosis and macrophage infiltration in the obstructed kidney. It also decreased fibrosis, as measured by either trichrome staining assessed by a pathologist, the Sircol assay for collagen or fibroblast specific protein expression. However, approximately 50% of the changes were not affected by the current treatment, suggesting that other factors contribute to renal damage in unilateral ureteral obstruction.

CONCLUSIONS

We observed the direct contribution of angiotensin II to both apoptotic and cellular transition processes (epithelial mesenchymal transition) and fibrosis in unilateral ureteral obstruction. Because these processes are active not only in unilateral ureteral obstruction, but also in other renal diseases, the value of angiotensin II blockade as an important part of the antifibrotic armamentarium has been confirmed.

Attenuation of renal fibrosis by curcumin in rat obstructive nephropathy

OBJECTIVES

To test whether curcumin has a protective action against interstitial inflammation and the development of renal fibrosis in obstructive nephropathy. We also tested whether inhibition of nuclear factor kappa-B (NF-kappaB) and activator protein-1 (AP-1) by curcumin is involved in these mechanisms.

METHODS

Adult male rats underwent unilateral ureteral obstruction. The rats were treated with curcumin (200 mg/kg/day or 800 mg/kg/day), NF-kappaB inhibitor pyrrolidine dithiocarbamate (PDTC; 200 mg/kg/day), or vehicle by gavage. Sham-operated rats served as controls. Seven days after unilateral ureteral obstruction, the activity of NF-kappaB and AP-1 was examined by electrophoretic mobility shift assay using nuclear protein extracts from the renal cortex. Gene expression of chemokines and pro-fibrotic molecules was determined by real-time reverse transcriptase-polymerase chain reaction. Macrophage infiltration and collagen III accumulation in the cortical interstitium was examined immunohistochemically.

RESULTS

Both curcumin and PDTC significantly attenuated interstitial macrophage influx and renal fibrosis. Ureteral occlusion activated both NF-kappaB and AP-1-DNA binding. Curcumin and PDTC significantly inhibited NF-kappaB activity, but not AP-1. Gene expression of chemokines and pro-fibrotic molecules was upregulated in unilateral ureteral obstruction that was attenuated by either curcumin or PDTC.

CONCLUSIONS

Curcumin protected against the renal interstitial inflammation and fibrosis elicited by ureteral occlusion. Inhibition of the NF-kappaB-dependent pathway is at least in part involved in the mechanisms, but AP-1 inhibition is unlikely to be involved in the beneficial effects of curcumin.

Routine intraoperative ureteric stenting for kidney transplant recipients

BACKGROUND

Major urological complications (MUCs) after kidney transplantation contribute to patient morbidity and compromise graft function. The majority arise from the vesico-ureteric anastomosis and present early after transplantation. Ureteric stents have been successfully used to treat such complications. A number of centres have adopted a policy of universal prophylactic stenting, at the time of graft implantation, to reduce the incidence of urine leaks and ureteric stenosis. Stents are associated with specific complications and some centres advocate a policy of only stenting selected anastomoses.

OBJECTIVES

To examine the benefits and harms of routine ureteric stenting to prevent urological complications in kidney transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library), MEDLINE, EMBASE, reference lists of articles, books and abstracts and contacted companies, authors and experts to identify relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

All RCTs and quasi-RCTs were included in our meta-analysis.

DATA COLLECTION AND ANALYSIS

Four reviewers assessed the trials for quality against four criteria (allocation concealment, blinding, intention-to-treat and completeness of follow-up). The primary outcome was the incidence of MUCs. Further outcomes of interest were graft and patient survival and the incidence of adverse events (urinary tract infection (UTI), haematuria, irritative symptoms, pain and stent migration). Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Seven RCTs (1154 patients) of low or moderate quality were identified. The incidence of MUCs was significantly reduced (RR 0.24, 95% CI 0.07 to 0.77, P = 0.02, NNT 13) by universal prophylactic stenting. This was dependent on whether the same surgeon performed, or was in attendance, during the operations. Two patients lost their grafts to infective urinary tract complications in the stented group. UTIs, in general, were more common in stented patients (RR 1.49, 95% CI 1.04 to 2.15) unless the patients were prescribed cotrimoxazole 480 mg/d: in which case the incidence was equivalent (RR 0.97, 95% CI 0.71 to 1.33). Stents appeared generally well tolerated, although trials using longer stents (>/= 20 cm) for longer periods (> 6 weeks) had more problems with encrustation and migration.

AUTHORS' CONCLUSIONS

Routine prophylactic stenting reduces the incidence of MUCs. Trials comparing selective stenting and universal prophylactic stenting, whilst difficult to design and analyse, would address the unresolved quality of life and economic issues.

The potency of KUL-7211, a selective ureteral relaxant, in isolated canine ureter: comparison with various spasmolytics

We compared the potency of a selective ureteral relaxant KUL-7211 (beta(2)/beta(3)-adrenoceptor agonist; (-)-2-[4-(2-{[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino}ethyl)phenyloxy]acetic acid) with those of various spasmolytics on contractions in isolated canine ureteral preparations. Drug effects were evaluated on the tonic contraction induced by KCl (80 mM) and on spontaneous, 1x10(-5) M phenylephrine-, and 1x10(-6) M PGF(2alpha)-induced rhythmic contractions in isolated canine ureteral preparations using a functional experimental technique. The potencies (pD(2) value) of the following drugs were compared: KUL-7211, tamsulosin (an alpha(1A/1D)-adrenoceptor antagonist), prazosin (an alpha(1)-adrenoceptor antagonist), verapamil (a Ca(2+)-channel blocker), butylscopolamine (a nonselective muscarinic antagonist), and papaverine (a phosphodiesterase inhibitor). The rank order of relaxing potencies against KCl-induced tonic contraction was KUL-7211 (6.60)>tamsulosin(5.90)>verapamil(5.70)>papaverine(4.88)>prazosin (4.54). The rank order of potencies for reductions in spontaneous rhythmic contractions was KUL-7211 (6.80)>verapamil(6.12)>papaverine(5.05). Conversely, high concentrations of the two alpha-adrenoceptor antagonists (tamsulosin and prazosin) and of butylscopolamine enhanced the spontaneous contractions, although at low concentrations (up to 1x10(-6) M) they had no significant effects. For suppression of spasmogen-induced rhythmic contractions, the rank order of potencies was, against phenylephrine-induced contractions: KUL-7211 (6.95)>tamsulosin(6.26)>prazosin(5.68)>verapamil(5.64)>papaverine (5.03), and against PGF(2alpha)-induced contractions: KUL-7211 (7.05)>verapamil(6.70)>papaverine (5.27). Our results suggest that in dogs, the beta(2)/beta(3)-adrenoceptor agonist KUL-7211 is the most efficacious ureteral relaxant among the spasmolytics tested against various contractions. Possibly, KUL-7211 might be useful for promoting stone passage and relieving ureteral colic in urolithiasis patients.

Pentoxifylline Attenuates Tubulointerstitial Fibrosis by Blocking Smad3/4-Activated Transcription and Profibrogenic Effects of Connective Tissue Growth Factor

Pentoxifylline (PTX) is a potent inhibitor of connective tissue growth factor (CTGF), but its underlying mechanism is poorly understood. Here, it was demonstrated that PTX inhibited not only TGF-beta1-induced CTGF expression but also CTGF-induced collagen I (alpha1) [Col I (alpha1)] expression in normal rat kidney fibroblasts (NRK-49F) and alpha-smooth muscle actin expression in normal rat kidney proximal tubular epithelial cells (NRK-52E). Furthermore, PTX attenuated tubulointerstitial fibrosis, myofibroblasts accumulation, and expression of CTGF and Col I (alpha1) in unilateral ureteral obstruction kidneys. The mechanism by which PTX reduced CTGF in NRK-49F and NRK-52E was investigated. Activation of Smad3/4 was essential for TGF-beta1-induced CTGF transcription, but PTX did not interfere with TGF-beta1 signaling to Smad2/3 activation and association with Smad4 and their nuclear translocation. However, PTX was capable of blocking activation of TGF-beta1-induced Smad3/4-dependent reporter as well as CTGF promoter, suggesting that PTX affects a factor that acts cooperatively with Smad3/4 to execute transcriptional activation. It was found that PTX increased intracellular cAMP and caused cAMP response element binding protein phosphorylation. The protein kinase A antagonist H89 abolished the inhibitory effect of PTX on Smad3/4-dependent CTGF transcription, whereas dibutyryl cAMP and forskolin recapitulated the inhibitory effect. In conclusion, these results indicate that PTX inhibits CTGF expression by interfering with Smad3/4-dependent CTGF transcription through protein kinase A and blocks the profibrogenic effects of CTGF on renal cells. Because of the dual blockade, PTX potently attenuates the tubulointerstitial fibrosis in unilateral ureteral obstruction kidneys.

Upper urinary tract complications in pregnant women with an ileal conduit. Lessons learned from two cases

We describe the occurrence of severe upper urinary tract complications during pregnancy in two women with an ileal conduit. The first patient developed several episodes of left pyelonephritis throughout the duration of her pregnancy but never received proper antibiotic prophylaxis. Intravenous urography performed after delivery documented bilateral staghorn kidney stones and a non-functioning left kidney. The second patient developed severe left loin pain and a high temperature during the fourth month of pregnancy after discontinuing antibiotic prophylaxis. An MRI urogram demonstrated compression of the ureter by the foetus. Symptoms were relieved as soon as the antibiotic prophylaxis was resumed and the pain remained under control with the occasional use of paracetamol until delivery. Based on these observations it appears that the left upper urinary tract may be more prone to dilatation in pregnant patients with an ileal conduit and antibiotic prophylaxis is mandatory throughout the duration of the pregnancy in order to minimize the risk of severe upper urinary tract complications.

The Rho-ROCK system as a new therapeutic target for preventing interstitial fibrosis

The small GTPase Rho is involved in cell-to-substratum adhesion and cell contraction. These actions of Rho mediated by downstream Rho effectors such as Rho-associated coiled-coil forming protein kinase (ROCK) may be partly responsible for the progression of renal interstitial fibrosis. A body of evidence has been accumulated with regard to the involvement of the Rho-ROCK signaling pathway in the development of fibrotic lesions in various organs including the kidney. Tubulointerstitial fibrosis is a final common pathway to the eventual structural desolation of kidneys, and therefore is an important therapeutic target to cure or reverse the progressive functional deterioration. In this review, we will highlight the possible involvement of the Rho-ROCK signaling pathway in the pathogenesis of tubulointerstitial fibrosis and discuss the therapeutic approach toward tubulointerstitial fibrosis by the inhibition of the Rho-ROCK pathway.

Prolonged stenting does not prevent obstruction after TIP repair when the glans was deeply incised

PURPOSE

To evaluate whether prolonged postoperative stenting may reduce the risk of obstruction of the neourethra after TIP repair with deep glanular incision.

METHODS

In a 1-year period 27 patients were operated for penile hypospadias using the TIP technique described by Snodgrass. In contrast to a previous study with 8 - 10 days of postoperative catheter drainage, the indwelling transurethral catheter was kept in place for 12 - 14 days. Deep incision of the urethral plate up to the tip of the glans is the most remarkable surgical detail, resulting in a meatus on top of the glans but in a defect on the dorsal rim of the neomeatus as well. After 3 - 6 months 22 patients were re-investigated during an outpatient visit using a scheme to describe the position of the neomeatus. Uroflowmetry was also performed. Information in three toddlers was gained by phone and 2 patients were lost to follow-up.

RESULTS

Two patients returned with significant obstruction including an urethrocutaneous fistula in one. In contrast to the good assessment by parents and compared to the early appearance after catheter removal a change in meatal position was observed in the majority of patients. Only 6 patients presented with an unchanged meatal position whereas in 16 patients the meatus lost its oval or slit-like shape as well as its position on the tip of the glans. However, despite one obstructive meatus in the coronal position 15 patients showed a sufficient size and position of the meatus underneath the tip of the glans. Uroflowmetry revealed reduced peak-flow values (mean: 8.1 ml/s) in some of the 9 patients evaluated.

CONCLUSIONS

Our data indicate that prolonged stenting does not give better results in those TIP repairs, in whom the urethral plate was incised across the rim of the neomeatus. The early excellent aspect of the glans after stent removal is often impaired by partial closure of the glans incision with a short-term change in size and position of the meatus. To prevent this, the rim of the meatus during reconstruction should be kept completely epithelialised.

Ureteral replacement using small-intestinal submucosa and a collagen inhibitor in a porcine model

PURPOSE

Small-intestinal submucosa (SIS) has been successful as an onlay graft in ureteral repair, but tubularized segment interposition of SIS has been unsuccessful. Our objective was to evaluate whether a type I collagen inhibitor, halofuginone, would prevent stricture formation in tubularized SIS interposition.

MATERIALS AND METHODS

We performed either laparoscopic partial ureteral excision followed by an SIS onlay graft (N = 5) or complete laparoscopic ureteral excision followed by an SIS interposition graft (N = 7) in domestic pigs. Animals received either no (N = 3), low-dose (N = 5), or high-dose (N = 4) halofuginone. Animals had ureteral stenting for 2 weeks after surgery and were permitted to survive for 6 or 9 weeks. An intravenous urogram (IVU) was performed prior to sacrifice. Kidneys were examined grossly and histologically.

RESULTS

One animal that received an onlay graft died of an unrelated illness. The remaining four ureteral onlay animals, including one control and two low-dose and one high-dose pig, had grossly normal kidneys at harvest. The IVU was normal in the control and high-dose animal but showed delayed excretion with mild hydroureteronephrosis in the low-dose animals. Pathologic examination of the SIS site revealed circumferential reepithelialization with inflammation and mild fibrosis. All seven tubularized interposition graft kidneys demonstrated either severe hydroureteronephrosis (N = 5) or renal atrophy (N = 2), and all had complete obstruction on IVU. Pathologic examination revealed a stenotic ureteral lumen with extensive surrounding inflammation and fibrosis.

CONCLUSIONS

An SIS onlay graft was successful in the porcine model of ureteral injury. Halofuginone, a type I collagen inhibitor, did not demonstrate a significant beneficial effect in this technique. Ureteral tubularized interpositions with SIS are unsuccessful and not improved by halofuginone.

Y-neobladder: an easy, fast, and reliable procedure

OBJECTIVES

To describe the operative technique of a new, Y-shaped, ileal neobladder and report the clinical and functional outcomes to add a contribution to the most discussed issues about orthotopic neobladders, in particular related to the problem of the prevention of strictures of ureteral-neobladder anastomoses.

METHODS

Between January 1999 and June 2002, 50 patients (41 men and 9 women) underwent radical cystectomy and Y-shaped orthotopic neobladder reconstruction. The following parameters were considered: operative time, complications, and functional outcomes (evaluated with voiding chart and a questionnaire analyzing continence). Urodynamic studies were performed in the first 20 patients.

RESULTS

The operative time for neobladder reconstruction was 15 to 20 minutes. No severe complications or significant metabolic complications were recorded. Only 1 case of unilateral stricture of the ureteral-neobladder anastomosis was recorded (1% of renal units); the stricture was easily treated with a retrograde endoscopic approach. Daytime and nighttime continence was good or satisfactory in 90% and 85% of patients, respectively. One year after surgery, the average maximal neobladder capacity was 390 mL, and the average pressure at maximal capacity was 15 cm H2O.

CONCLUSIONS

The ileal Y-shaped orthotopic neobladder had good functional outcomes comparable to most popular orthotopic neobladders. Moreover, the surgical technique of the Y-neobladder is easy, rapid, and reliable. In particular, the Y-neobladder seemed to reduce, in our experience, the occurrence of strictures at the ureteral-neobladder anastomosis, because it permits a perfectly aligned anastomosis without mobilization of the ureters.

[Use of ureteral stents in patients with kidney transplantation]

The aim of the study was to determine indications for application of ureteral stents for draining urinary tracts of the renal transplant, after low-invasive surgical interventions, for timing drainage, prevention and correction of complications. Ureteral stent insertion for management of urological complications after transplantation of the kidney was made in 36 patients (25 of them have ureteral stricture, 11 had ureteral necrosis). Low-invasive operations were made in 28 patients, open reconstructive plastic operations were conducted in 12 patients. According to 6-12 follow-up of the stented patients, recurrent ureteral stricture was detected only in 4 patients (11.1%). The stricture was corrected transcutaneously by antegrade ureteral stenting. It is concluded that stenting of the urinary tracts of the transplanted kidney in the treatment of urological complications--necrosis and ureteral stricture--in the course of low-invasive roentgenoendoscopic and open reconstructive-plastic operations raises treatment efficacy and prevents recurrent stricture.

Impact of ureteral stent diameter on symptoms and tolerability

BACKGROUND AND PURPOSE

Indwelling double-pigtail ureteral stents are frequently associated with debilitating symptoms. A randomized study was performed to evaluate the effect of stent diameter (4.7F v. 6F) on symptoms and tolerability.

PATIENTS AND METHODS

Between February and October 2000, 46 consecutive patients undergoing ureteroscopy for stone disease were randomly assigned to receive either a 4.7F (group I) or a 6F (group II) ureteral stent following the procedure. The patients were asked to leave their stents in place for minimum of 7 days. Pain and irritative urinary symptoms in the two groups were compared according to a scale ranging from 0 (none) to 5 (severe). The two groups were also compared for stone size and location, rigid v. flexible ureteroscopy, anesthesia, stent migration, and ureteral dilation.

RESULTS

There were no differences between the groups in terms of pain (P = 0.28) or irritative symptoms (P = 0.37). There was a tendency for stents in group I to migrate distally and dislodge more often than those in group II (32% v 10%).

CONCLUSIONS

When stent insertion following ureteroscopy is deemed necessary, a minimum diameter of 6F is recommended.

[The renal protective effect of selective cyclooxygenase-2 inhibitor on obstructive nephropathy]

OBJECTIVE

To observe the effect of selective cyclooxygenase-2 (COX-2) inhibitor-meloxicam on the progression of tubulointerstitial fibrosis in rats with unilateral ureteral obstruction (UUO).

METHODS

UUO rats were treated with meloxicam (M), indomethacin (I) or vehicle alone (U) for 4 weeks. Using reverse transcription-polymerase chain reaction (RT-PCR), we examined the mRNA expressions of transforming growth factor (TGF)-beta receptor-1 and 2 in left kidney from rats with UUO. Immuno-precipitation and immunohistochemistry analysis were carried out to investigate the protein level of TGF-beta(1). Tubulointerstitial fibrosis was quantified by Masson's staining. Similar studies were performed in another group of rats with sham operation (C).

RESULTS

mRNA expressions of TGF-beta receptor-1 and 2 were markedly increased in Group U compared with those in Group C. Both meloxicam and indomethacin inhibited their expressions to a different degree (P < 0.01), but the effect of meloxicam was more significant. Meloxicam decreased the protein level of TGF-beta(1) (P < 0.01), while indomethacin had no such effect. Compared with Group C, there appeared tubulointerstitial fibrosis in the kidney of rats with UUO. The lesion was aggravated by indomethacin, but remarkably attenuated by meloxicam.

CONCLUSIONS

In summary, selective COX-2 inhibitor-meloxicam has a salutary effect on the tubular and interstitial response to UUO. TGF-beta and its receptor approaches partly explain some of the mechanism.

Steinstrasse after extracorporeal shockwave lithotripsy: aetiology, prevention and management

OBJECTIVE

To determine the causes of steinstrasse, methods of prevention and treatment strategies.

PATIENTS AND METHODS

Fifty-two patients with steinstrasse were identified and treated: all patients were initially treated conservatively but when there was obstruction, infection or no progression of the stone fragments, further treatment was used, ranging from repeated extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrostomy (PCN), endoscopic manipulations and finally open surgery, depending on the degree of obstruction, infection, renal function and response to each kind of therapy.

RESULTS

Conservative management was successful in 25 patients (48%), repeated ESWL in 12 (23%), PCN in 10 (19%), ureteroscopy in three (6%) and open surgery in two (4%).

CONCLUSION

As many patients, and particularly those with larger stones, are treated by ESWL, the risk of developing steinstrasse will increase, with associated patient discomfort, infection or impaired renal function. The optimum selection of cases (aiming to pulverize the stones rather than fragment them) and accurate stone targeting are essential to minimise the development of steinstrasse. The meticulous follow-up of patients with steinstrasse should prevent any loss of renal function. When there is obstruction and/or infection or renal damage, active treatment is indicated, of which ESWL and PCN are the most effective, with ureteroscopy and open surgery reserved for difficult cases.

Protective effect of vitamin E on the response of the rabbit bladder to partial outlet obstruction

PURPOSE

There is increasing evidence that ischemia/reperfusion is a major etiological factor in the progression of bladder dysfunction after partial outlet obstruction. If this evidence is correct, treatment with an antioxidant should be beneficial in rabbits subjected to partial outlet obstruction. We designed the current study to determine if diets high in alpha-tocopherol protected the rabbit bladder against dysfunction induced by partial outlet obstruction.

MATERIALS AND METHODS

A total of 32 rabbits were separated into 4 groups of 8. Groups 1 and 2 were placed on a diet enriched with 1,000 IU/kg. alpha-tocopherol, and groups 3 and 4 were fed a regular diet containing 44 IU/kg. alpha-tocopherol. After 4 weeks partial outlet obstruction was created in groups 1 and 3, while groups 2 and 4 underwent sham operation. After 4 weeks of obstruction the rabbits were anesthetized and the bladders were rapidly excised. Four longitudinal strips obtained from the bladder body were used for contractility studies. The balance of the bladder body was separated between muscle and mucosa. Each section was frozen and stored at -70C for analysis of malondialdehyde as a measure of peroxidation and for alpha-tocopherol concentrations.

RESULTS

Feeding rabbits a diet high in alpha-tocopherol resulted in significant protection against the development of contractile dysfunction after partial outlet obstruction. The protective effect of alpha-tocopherol was related to significantly decreased malondialdehyde and significantly increased tissue concentrations of alpha-tocopherol.

CONCLUSIONS

These data indicate that a major etiology of bladder dysfunction secondary to partial outlet obstruction is related to free radical generation and resultant membrane lipid peroxidation.

Genetically modified bone marrow-derived vehicle cells site specifically deliver an anti-inflammatory cytokine to inflamed interstitium of obstructive nephropathy

In this study, we used genetically modified bone marrow-derived CD11b(+)CD18(+) vehicle cells to deliver IL-1 receptor antagonist (IL-1ra) for treatment of inflamed renal interstitium in an animal model of unilateral ureteral obstruction (UUO). Vehicle cells that expressed the ICAM-1 ligands, CD11b and CD18, were obtained from bone marrow cells of DBA/2j mice and adenovirally transduced with the IL-1ra gene or glucocerebrosidase (GC) gene ex vivo. In kidneys treated to develop UUO, levels of ICAM-1, IL-1 beta, and IL-1R expression increased within 3 days compared with contralateral untreated kidneys in the same mice. Similarly, the macrophage infiltration in the cortical interstitium increased after 3 days in UUO kidneys, but not untreated kidneys. After UUO developed, DBA/2j mice were injected i.v. with either IL-1ra(+) vehicle cells (IL-1ra-treated mice) or GC(+) vehicle cells (GC-treated mice) at 24 h after UUO. Six days after the injection of these vehicle cells, marked increase of CD11b(+) IL-1ra(+) vehicle cells was observed in the ICAM-1-positive interstitium of UUO kidneys from IL-1ra-treated mice. In contrast, no CD11b(+) IL-1ra(+) cells appeared in ICAM-1-negative contralateral kidneys from these mice. Furthermore, the infiltration of macrophages (p < 0.001), expression of ICAM-1 (p < 0.005), and presence of alpha-smooth muscle actin (p = 0.005) in the interstitium of UUO kidneys were significantly decreased in IL-1ra-treated mice compared with GC-treated mice. These findings suggest that IL-1 may contribute to the development of renal interstitial injury and that our method can deliver a functioning gene encoding an antiinflammatory cytokine gene specifically at that site by interacting with local adhesion molecules.

Antibody to transforming growth factor-beta ameliorates tubular apoptosis in unilateral ureteral obstruction

BACKGROUND

Unilateral ureteral obstruction (UUO) is characterized by progressive renal atrophy, renal interstitial fibrosis, an increase in renal transforming growth factor-beta (TGF-beta), and renal tubular apoptosis. The present study was undertaken to determine the effect of a monoclonal antibody to TGF-beta (1D11) in UUO.

METHODS

Mechanical stretch was applied to tubular epithelial cells (NRK-52E) by a computer-assisted system. Three doses of 1D11 (either 0.5, 2, or 4 mg/rat) were administered to rats one day prior to UUO and every two days thereafter, and kidneys were harvested at day 13. Fibrosis was assessed by measuring tissue hydroxyproline and mRNA for collagen and fibronectin. Apoptosis was assessed with the terminal deoxy transferase uridine triphosphate nick end-labeling assay. TGF-beta levels were determined by bioassay. Western blot and immunostaining were used to identify proliferating cell nuclear antigen (PCNA), p53, bcl-2, and inducible nitric oxide synthase (iNOS).

RESULTS

Stretch significantly induced apoptosis in NRK-52E cells, which was accompanied by an increased release of TGF-beta; 1D11 (10 microg/mL) totally inhibited stretch-induced apoptosis. Control obstructed kidney contained 20-fold higher TGF-beta as compared with its unobstructed kidney; 1D11 neutralized tissue TGF-beta of the obstructed kidney. Control obstructed kidney exhibited significantly more fibrosis and tubular apoptosis than its unobstructed counterpart, which was blunted by 1D11. In contrast, 1D11 significantly increased tubular proliferation. p53 immunostaining was localized to renal tubular nuclei of control obstructed kidney and was diminished by 1D11. In contrast, bcl-2 was up-regulated in the 1D11-treated obstructed kidney. Total NOS activity and iNOS activity of the obstructed kidney were increased by 1D11 treatment.

CONCLUSION

The present study strongly suggests that an antibody to TGF-beta is a promising agent to prevent renal tubular fibrosis and apoptosis in UUO.

The efficacy and safety of synchronous bilateral extracorporeal shock wave lithotripsy

PURPOSE

Bilateral renal calculi have traditionally been managed by staged extracorporeal shock wave lithotripsy (ESWLdagger) due to concern about bilateral obstruction. We evaluated the safety and efficacy of synchronous bilateral ESWL in a large series of patients treated at our institution to determine the safety and efficacy of this controversial technique in what is to our knowledge the largest series to date.

MATERIALS AND METHODS

We retrospectively evaluated the records of 120 patients with a mean age of 48 years who underwent bilateral synchronous ESWL between 1987 and 1996. Of the patients 71 (59%) were male. Average followup was 21 months. ESWL was performed using a Dornier HM3 lithotriptor in all cases. Intraoperative technique and postoperative factors were analyzed using the Pearson product moment correlation, the 2-tailed t test and multiple regression analysis.

RESULTS

Mean stone size was 13 and 15 mm. on the left and right sides, respectively. There was an average of 1.7 stones per renal unit. After 1 treatment 72 of the 120 patients (60%) were stone-free bilaterally, while 72% and 73% of left and right renal units, respectively, were also stone-free. Mean creatinine was similar preoperatively and postoperatively (1.46 and 1.41 mg./dl., respectively, p = 0.73). There was 1 or more complications in 18 cases. The majority of complications were minor with no long-term morbidity or death and there was no case of bilateral obstruction or renal failure. Additional procedures were required in 19 patients (16%) due to significant residual stone disease or obstruction during followup. Multiple regression analysis revealed that only patient age, a right ureteral stent and the number of shocks correlated with the complication rate. Stone size and number independently increased the probability of treatment failure and a repeat procedure (p <0.05). Patients with stones 20 mm. or greater were at particularly high risk for treatment failure and additional procedures. A total of 27 of the 35 patients (77%) with residual calculi and 13 of the 19 (68%) requiring additional procedures were in this high risk subgroup.

CONCLUSIONS

Bilateral synchronous ESWL is safe and effective monotherapy for bilateral urolithiasis. No patient had bilateral obstruction or renal failure and no deterioration of renal function was detected at followup. Knowing which patient populations are at higher risk for failure or complications may guide decision making.

Steinstrasse: a comparison of incidence with and without J stenting and the effect of J stenting on subsequent management

OBJECTIVE

To analyse the effect of ureteric stenting on the incidence of steinstrasse and its effects on the subsequent management of steinstrasse.

PATIENTS AND METHODS

Four hundred adult patients with a unilateral stone burden (mean diameter 1.5-3.5 cm) were randomly allocated into two groups; in group 1, patients had a J stent inserted before extracorporeal shock wave lithotripsy (ESWL) and group 2 did not. Before randomization, the patients had normal renal function and no evidence of ureteric obstruction on intravenous urography. All patients underwent ESWL, with the shock waves delivered first to the most dependent part of the calculi. Patients who developed steinstrasse were identified and the effect of the size of the calculi and the presence of a J stent on the incidence and level of the steinstrasse, on the time of diagnosis, the size of the major stone fragment, associated presenting symptoms and effect on subsequent management were compared between the groups.

RESULTS

Patients developed steinstrasse in both groups, with 12 (6%) and 26 (13%) in groups 1 and 2, respectively (significantly different, P<0.05). The incidence of steinstrasse depended on the size of the calculus, regardless of whether a J stent was present, being 2.6% and 56% for a burden of 1.5-2.0 cm and 3.1-3.5 cm, respectively (P<0.001). There was no difference in the presenting symptoms in the two groups. The steinstrasse was in the lower third of the ureter in eight of 12 patients in group 1 and in 16 of 26 (62%) in group 2. The steinstrasse resolved spontaneously in seven patients in group 1 and in 12 (46%) in group 2 (P<0.11). Similarly, J stenting had no effect on the subsequent treatment modalities to resolve steinstrasse.

CONCLUSION

The use of J stenting before lithotripsy significantly lowers the incidence of steinstrasse in patients with a stone burden of 1.5-3.5 cm. The incidence of steinstrasse increases with the size of the calculi, whether or not a J stent is present; J stenting has no apparent effect on the mode of presentation or the subsequent management of steinstrasse.

The role of ureteral stent placement in the prevention of Steinstrasse

BACKGROUND AND OBJECTIVE

Steinstrasse constitutes a potentially serious complication of extracorporeal shock-wave lithotripsy (SWL). Ureteral stent placement has been used to prevent Steinstrasse after fragmentation of larger stones. However, particularly more recently, its preventive efficacy has been questioned. The aim of this study therefore was to analyze the role of ureteral stent placement in the prevention of Steinstrasse.

METHODS

We analyzed data of 1087 patients who had been treated with a Wolf Piezolith 2300 in the General Infirmary in Leeds/UK for stones ranging from 10 to 95 mm in diameter.

RESULTS

The incidence of Steinstrasse was 6.3%. The likelihood was significantly correlated with the stone size and was significantly less in patients with stones >20 mm if a stent had been inserted prior to SWL. Moreover, in these patients, the risk of acute clinical symptoms in the event of Steinstrasse was greatly reduced, and the treatment could be continued safely in the majority of cases (86%). Treatments of the Steinstrasse itself with SWL resulted in its clearance in most of the cases (78%). It was always possible to clear even extended persistent Steinstrasse by laser lithotripsy.

CONCLUSION

These results provide a clear indication for the pre-SWL insertion of a ureteral stent in patients with stones >20 mm in diameter. In the event of Steinstrasse, SWL of the collection should be tried before more invasive endourologic procedures are considered.

A mucosal apposition technique for ureteroneocystostomy after renal transplantation in cats

Renal transplantation is a successful treatment for terminal renal failure in cats. However, in the initial clinical study, there was a frequent occurrence of obstruction of the implanted ureter at the bladder wall or stoma. This resulted in the use of a modified "drop-in" technique that had proved effective in the prevention of obstruction in five normal cats. When applied to renal transplant recipients, ureteral obstruction was reduced, but continued to occur. The modified "drop-in" technique was abandoned and replaced with a technique that apposed the cut edge of the ureteral mucosa to the torn edge of the bladder mucosa. This technique is recommended as it has prevented ureteral obstruction in six successive cases. Prevention of ureteral obstruction, and the required corrective surgery, markedly reduces patient morbidity and mortality, length of hospitalization, and expense to the client.

Use of a single stent for double ureter support in transplantation

A technique for draining both ureters of renal allografts with a single stent is described. The method simplifies the endoscopic removal of the stent.

Trial of intravesical versus extravesical ureteroneocystostomy in renal transplant recipients

We carried out a trial to evaluate the complication rate of intravesical (LP) versus extravesical (Lich) ureteroneocystostomy in recipients of renal transplantation. Ureteric stenosis was the predominant complication in the LP technique, which was more difficult to correct. Complications by the Lich technique were urinary leaks, which were managed successfully by prolonged bladder drainage. We conclude that the Lich technique is simpler to perform and avoids the complication of ureteric stenosis, and should therefore be the procedure of choice for ureteric implantation in recipients of renal transplants.

Primary use of a double J silicone ureteric stent in renal transplantation

Vesicoureteric leakage and obstruction are the commonest urological complications after renal transplantation. A retrospective analysis of our initial experience using a double J silicone ureteric stent showed that primary splinting of the vesicoureteric anastomosis eliminated these complications, whereas their combined incidence was 13.6% in the non-stented patients. The presence of the stent was not associated with increased risks of urosepsis.

[Transurethral ureterolithotripsy with rigid ureteroscope--efficacy of balloon dilation of ureteral orifice and intramural ureter]

In order to minimize the late complications of transurethral ureterolithotripsy with a rigid ureteroscope such as distal ureteral stricture or vesicoureteral reflux, we have performed a balloon dilation of the ureteral orifice and the intramural ureter prior to insertion of a rigid ureteroscope in 62 cases with ureteral calculi between October 1986 and December 1991. A 7F balloon dilator (Bard Co. USA) was cystoscopically inserted into the ureter over a 0.038 inches Radifocus guide wire (Terumo Co., Japan) and then, a balloon was inflated to 15F size with saline using a 10 ml disposal syringe. Thereafter, an 11.5F rigid ureteroscope (Wolf Co., Germany) was inserted instead of a balloon dilator. The stone was disintegrated and removed by ultrasonic lithotripter, electrohydraulic lithotripter and/or basket forceps. The stone was removed completely in 45 cases (72.6%) and incompletely in 10 (16.1%). In 7 cases (11.3%), the stone removal was failed. Long-term follow up with an excretory urography obtained at 6 months or later in 31 cases showed no distal ureteral stricture. Voiding cystography was performed in 33 cases at a mean 2.8 months postoperatively and no vesicoureteral reflux was observed. In control group, 309 cases were treated with transurethral ureterolithotripsy without dilation of the ureteral orifice and the intramural ureter between the same period. A complete removal was achieved in 262 cases (84.8%) and an incomplete removal in 16 (5.2%). 31 (10%) was failed. Distal ureteral stricture due to this procedure was found in 3 cases (2.1%) in 141 long term followed up cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[The use of the double-J catheter as urinary obstruction prophylaxis in lithiasis]

Our experience in the use of the double-J catheter in the prevention and treatment of urinary obstruction in stone disease is presented. This retrospective study spans the period January, 1985 to June 1989. Fifty-five double-J catheters were placed in 51 patients (catheter replacement was required in 4). Catheter placement was done antegradely in 17, retrogradely in 34 and intraoperatively in 4 cases. The indications were for treatment post-ESWL in 45 patients, stone remnants following percutaneous nephrolithotomy in 1, post-ureteroscopy in 2, and after open surgery in 2 patients. Complications were observed in 24% of the cases, hematuria being the most common complication. The foregoing agrees with the 20-40% complication rate reported in the literature. Thus, we can conclude that the double-J catheter is well-tolerated and is a simple yet useful endourologic tool in the prevention and treatment of urinary obstruction in stone disease.

Urological complications of renal transplantation: the impact of double J ureteric stents

In a 10 year series of 350 consecutive renal transplant operations, the overall urological complication rate was 7.7%. During this period double J stents were introduced and were used either in the treatment of actual urological complications or as a prophylactic measure to protect ureters which had been damaged at retrieval. A total of 34 double J stents were used in 33 patients. The indications were: ureteric obstruction (n = 13), urinary leak (n = 5), short transplant ureter anastomosed using an extravesical ureteroneocystostomy (n = 10) and ureteric injury at the time of organ retrieval (n = 6). Thirty-two double J stents were inserted at open operation and two were inserted by an antegrade method after percutaneous nephrostomy. Improvement in renal function occurred in 16 out of the 18 cases of urological complications. No kidneys were lost and there were no deaths as a direct result of these complications. In a number of cases the insertion of a double J stent was the only treatment, thus eliminating the need for more complex surgery. All 16 patients who had a ureteric stent inserted as a prophylactic measure at the time of transplantation made uncomplicated postoperative recoveries. Urinary tract infection was relatively common (27%) after double J stent insertion, but other complications were rare. In conclusion, double J stents have proved to be a useful adjunct in the management of renal transplant related urological complications.

Extracorporeal shock wave lithotripsy for large renal calculi: the role of ureteral stents. A randomized trial

Ureteral stents reduce complications after extracorporeal shock wave lithotripsy (ESWL*) and contribute to successful stone passage. However, some reports note complications that are attributed to indwelling ureteral stents. We randomized 64 patients with large renal calculi (stone burden more than 200 mm.2) for in situ treatment or treatment with a prophylactically inserted stent. We used a 6Ch round stent with single-coiled ends or a triangular shaped stent with double-coiled ends. Patients were treated with a Siemens Lithostar lithotriptor. After 3 months we evaluated the results of treatment and post-ESWL morbidity. Of the in situ group (23 patients) treatment complications consisted of fever in 3, pyelonephritis in 1 and steinstrasse in 3. After 3 months 8 patients (35%) were free of stones. Of the stented population (41 patients) treatment complications consisted of fever in 7, pyelonephritis in 1, steinstrasse in 6 and bladder discomfort in almost half of the patients. Stent calcification and stent migration were also seen in 7 and 10 patients, respectively. Calcified stents had been in situ longer than noncalcified stents. The round stents migrated and calcified more often than the more rigid triangular stents. After 3 months 18 of the stented patients were stone-free (44%). We conclude that ureteral stents do not reduce post-ESWL complications. They are clearly associated with morbidity and do not improve stone passage markedly. Therefore, patients with a stone burden of more than 200 mm.2 should be treated in situ without auxiliary stenting.

Non-antireflux versus antireflux ureteroneocystostomy in adults

A retrospective analysis of ureteric reimplantation in adults showed that a high proportion (71%) had been treated by non-antireflux procedures. Analysis of the ureteroneocystostomy success rate in aetiological groups where either antireflux or non-antireflux techniques were used indicated the superiority of antireflux surgery in the prevention of reflux. The risk of stenosis at the site of anastomosis was equal in both groups. No significant difference in the preservation of renal function was detected in the 2 groups. It was concluded that antireflux procedures offered no advantage over non-antireflux ureteric reimplantation in adults.