Risk factors for migration of retrievable covered expandable metallic stent in patients with persistent benign ureter strictures.

PURPOSE: The purpose of this study is to evaluate the incidence, risk factors, and salvage management of retrievable covered expandable metallic stent (RCEMS) migration in patients with persistent benign ureter strictures. MATERIALS AND METHODS: A retrospective study was performed on 117 consecutive patients who underwent implantation of RCEMS. Univariate and multivariate analyses were used to identify prognostic factors for stent migration, including stricture location and length, hydronephrosis-cortex ratio, ureteral dilation, and the diameter of the narrowest portion of the stricture. RESULTS: Stent migration occurred in 22 (19.5%) of 113 patients who met inclusion criteria. Of the 22 patients, 16 (72.7%) had ordinary ureteral stricture, 3 (13.6%) had stricture in transplanted kidneys, and 3 patients (13.6%) had ureter stricture in orthotopic neobladders. The mean creatinine for the entire cohorts showed significant improvement (p = 0.038). Multivariate analysis identified the following prognostic factors for migration: distal ureteral stricture (p = 0.006), patients who underwent balloon dilation (p = 0.003), hydronephrosis-cortex ratio ≧10 (p = 0.017), larger diameter of wasting of RCEMS (p < 0.001), and patients with a shorter stricture length (p = 0.006). Salvage management was required in 4 of the 22 patients. The strictures in the remaining 18 patients improved with observation. CONCLUSIONS: Stent migration is more likely to occur in patients with the five prognostic factors mentioned above. Our study developed a nomogram to predict stent migration in patients with ureteral strictures treated using RCEMS.

Risk Factors for Failure of Endoscopic Balloon Dilatation of Primary Obstructive Megaureter: Single-Center 12-Year Experience with 123 Cases.

Purpose: To review our experience with >100 patients with primary obstructive megaureter (POM) undergoing endoscopic balloon dilatation (EBD) and a follow-up of up to 12 years and determine potential risk factors for failure. Our hypothesis is that EBD allows for long-term treatment in >80% of patients, and its effectiveness decreases in more severe cases. Methods: This is a retrospective study of 123 consecutive patients (131 ureters) undergoing EBD from 2009 to 2021. Indications for EBD included symptoms, worsening dilatation, and/or renal function impairment. Clinical characteristics, complications, and outcomes, including those in the patients with >5-year follow-up, were described. Preoperative and intraoperative markers of severity chosen a priori were tested as risk factors for failure. Failure was defined as the need for ureteral reimplantation after EBD. Results: EBD was feasible in 121 of 123 (98%) patients, regardless of age. After a median follow-up of 38 (9-143) months, EBD was effective in 84.5% of cases. Failures generally occurred in the 1st year after EBD and were seldom associated with permanent loss of renal function. Of the 66 patients with follow-up >5 years, EBD was effective in 56 patients. No preoperative characteristic proved to be a risk factor for failure. The intraoperative absence of a ring was the only significant risk factor for failure, odd ratio 117.86 (95% confidence interval 6.27-2215.84). Conclusions: EBD was feasible and definitive treatment in 85% of our cases, regardless of age. Since this study did not identify preoperative factors to help the clinicians in patient selection, we consider EBD a viable initial procedure in all patients with POM who require surgical intervention, especially in infants.

Percutaneous Nephroureteral Stent Placement and Antegrade Forceps Biopsy of Ureteral Obstruction.

PURPOSE: To evaluate the feasibility of percutaneous transluminal ureteral biopsy (PTUB) combined with percutaneous nephroureteral stent placement for ureteral obstruction under fluoroscopy. MATERIALS AND METHODS: From September 2011 to July 2021, 37 patients (27 men and 10 women; median age, 65.0 years) who experienced ureteroscopic biopsy failure or refused or were unable to undergo ureteroscopic biopsy underwent PTUB for ureteral obstruction during nephroureteral stent placement under fluoroscopic guidance. Data on technical success, early adverse events, and radiation dose were collected. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy (OA) of PTUB were analyzed. RESULTS: The technical success of PTUB was 89.2%, with a mean irradiation dose of 76.9 mGy·cm2 ± 12.2. A total of 67.6% (25/37) of the cases were correctly diagnosed with malignancy, whereas 8 cases were confirmed to be true negatives. There were 4 false negatives and no false positives. PTUB had a sensitivity, specificity, PPV, NPV, and OA of 86.2% (25/29), 100% (8/8), 100% (25/25), 66.7% (8/12), and 89.2% (33/37), respectively. Eleven patients (29.7%) experienced Grade 1 adverse events (transient aggravated hematuria). CONCLUSIONS: PTUB appears to be a safe and effective alternative to ureteroscopic biopsy for ureteral obstruction.

The Current Status of Palliative Care, Hospice, and End-of-Life Health Care Utilization in Patients With Malignant Ureteral Obstruction.

INTRODUCTION: Malignant ureteral obstruction is associated with a poor prognosis, with a median survival of 3 to 7 months. These patients are ideal candidates for concurrent palliative care services, consistent with American Society of Clinical Oncology guidelines. We aimed to characterize palliative care, hospice, and end-of-life health care utilization in patients with malignant ureteral obstruction. METHODS: Patients ≥ 18 years old at our institution and diagnosed with malignant ureteral obstruction between May 2014 and August 2020 were retrospectively identified and pertinent data extracted. Palliative care, hospice, and end-of-life health care utilization was described, and factors associated with each were assessed with logistic regression models. Overall survival was assessed with Cox proportional hazard regression models. RESULTS: One hundred fifteen patients qualified for analysis; 39.1% (45/115) utilized palliative care and spent a median of 12.5 days (IQR 3-52 days) on nonhospice palliative care. On adjusted analysis Black ethnicity (aOR 3.44, 95% CI: 1.08-10.94) was associated with palliative care utilization. Of the patients, 53.9% (62/115) utilized hospice. The median time from hospice initiation to death was 12 days (IQR 5-23 days). On adjusted analysis, prior extirpative surgery (aOR 3.63, 95% CI 1.01-13.05) and palliative care utilization (aOR 4.38, 95% CI 1.70-11.31) were associated with hospice utilization. Median survival following diagnosis was 141 days (IQR 37.5-442.5). Of the patients, 43.0% (37/86) had high end-of-life health care utilization. On multivariable analysis, only hospice (aOR 0.03, 95% CI 0.01-0.14) was associated with less end-of-life health care utilization. CONCLUSIONS: Palliative care is underutilized in malignant ureteral obstruction. Hospice, but not palliative care utilization, was associated with decreased end-of-life health care utilization.

Management Patterns of Male Urethral Stricture Disease among Urologists: What Do the Guidelines Say? What Do Urologists Do?

Background: The aim of the present study is to evaluate and analyze the daily clinical practice for male urethral stricture disease (MUSD) among urologists. Methods: Considering the latest guidelines on urethral stricture disease, a survey was developed regarding the various treatment options and preferences in different sites of male urethral stricture disease. The survey was sent to urologists via e-mail and phone application. Results: A total of 266 urologists completed the survey and were included in the final analysis. In regard to workplace, 62 (23.3%), 58 (21.8%), 71 (26.7%), and 75 (28.2%) respondents worked in university hospitals, training and research hospitals, state hospitals, and private practice hospitals, respectively. In regard to the diagnostic method used in male urethral strictures, 88.7% of the participants would choose uroflowmetry + postvoiding residual (UF + PVR), and 64.6% would choose retrograde urethrography (RUG). Direct vision internal urethrotomy (DVIU) was the most frequently chosen method in penile urethral strictures (PUS), being chosen by 72.9%. Direct vision anterior internal urethrotomy was the most common method for both ≤2 cm and >2 cm strictures, 63.1%, and 30.8%, respectively. The most preferred graft for augmentation urethroplasty was buccal mucosa (75.8%). Endoscopic incision/resection (transurethral resection (TUR)) is the most frequently applied treatment method for posterior urethral/vesicourethral anastomotic strictures (86.4%). Conclusions: The present study clearly shows that most urologists still prefer DVIU and urethral dilatation to urethroplasty in MUSD, which contradicts current guidelines. Urologists should be encouraged to perform urethroplasty and/or refer patients to experienced centres for recurrent MUSD (AU)

Outcomes following Exchange and Upsizing of Malfunctioning Small-Caliber Double-J Ureteral Stents.

PURPOSE: To determine the effectiveness of exchange and upsizing of malfunctioning small-caliber double-J (JJ) ureteral stents. MATERIALS AND METHODS: Thirty-one patients with malfunctioning cystoscopically placed small-caliber (6 or 7 F) JJ stents underwent transurethral (n = 28) or transrenal (n = 3) exchange and upsizing to a large-caliber (10 F) JJ stent from 2013 to 2022. Ureteral obstruction was malignant in 20 patients (65%) and benign in 11 (35%). Fifteen patients (48%) presented with persistent hydroureteronephrosis and 16 patients (52%) with worsening hydronephrosis. Acute kidney injury (AKI) was present in 19 patients (61%) at the time of stent malfunction. Therapeutic success was defined as resolution of hydronephrosis and AKI, if present. RESULTS: JJ stent exchange and upsizing was technically successful in 31 patients (100%) with no immediate adverse events. Therapeutic success was achieved in 27 patients (87%). During follow-up (median, 97 days; IQR, 32-205 days), 2 patients who initially achieved therapeutic success had stent malfunction, requiring conversion to percutaneous nephrostomy drainage (2/27, 7%). CONCLUSIONS: Exchange and upsizing to large-caliber JJ stents can relieve urinary obstruction and resolve AKI in patients with malfunctioning small-caliber JJ stents. Large-caliber JJ stents should be considered as a salvage option for patients who wish to continue internal drainage and avoid percutaneous nephrostomy.

Wunderlich syndrome secondary to ureteropelvic junction obstruction.

Wunderlich syndrome (WS) is defined as a rare spontaneous renal hemorrhage. It mostly occurs with concomitant diseases without trauma. It usually presents with the Lenk triad and is diagnosed in emergency departments with the effective use of advanced imaging modalities such as ultrasonography, computerized tomography, or magnetic resonance imaging scanning. In the management of WS, conservative treatment, interventional radiology, or surgical procedures are decided according to the patient's condition and treated appropriately. Conservative follow-up and treatment should be considered in patients whose diagnosis is stable. If diagnosed late, the progression can be life-threatening. As an interesting case of WS, a 19-year-old patient was presented with hydronephrosis due to ure-teropelvic junction obstruction. Spontaneous renal hemorrhage without a history of trauma is presented. The patient, who presented to the emergency department with the sudden onset of flank pain, vomiting, and macroscopic hematuria was imaged by computed tomography. The patient could be followed and treated conservatively for the first 3 days, and on the 4th day, his general condition deteriorated, and he underwent selective angioembolization and then laparoscopic nephrectomy. WS is a serious, life-threatening emer-gency, even in young patients with benign conditions. Early diagnosis is mandatory. Delays in diagnosis and non-energetic approaches can lead to life-threatening situations. In hemodynamically unstable non-malignant cases, the decision for immediate treatment, such as angioembolization and surgery, should be taken without hesitation.

Calycosin pretreatment enhanced the therapeutic efficacy of mesenchymal stem cells to alleviate unilateral ureteral obstruction-induced renal fibrosis by inhibiting necroptosis.

Bone marrow-derived mesenchymal stem cells (MSCs) show antifibrotic activity in various chronic kidney diseases. Here, we aimed to investigate whether Calycosin (CA), a phytoestrogen, could enhance the antifibrotic activity of MSCs in primary tubular epithelial cells (PTECs) induced by TGF-ß1 and in a mouse model of unilateral ureteral obstruction (UUO). We found that MSCs treatment significantly inhibited fibrosis, and CA pretreatment enhanced the effects of MSCs on fibrosis in vitro. Consistent with the in vitro studies, MSCs alleviated tubular injury and renal fibrosis in mice after UUO, and CA-pretreated MSCs resulted in more significant improvements in tubular injury and renal fibrosis than MSCs after UUO. Moreover, MSCs treatment significantly inhibited necroptosis by repressing the elevation of MLKL, RIPK1, and RIPK3 in PTECs treated by TGF-ß1and in mice after UUO, and CA-pretreated MSCs were superior to MSCs in alleviating necroptosis. MSCs significantly reduced TNF-α and TNFR1 expression induced by TGF-ß1 in PTECs and inhibited TGF-ß1, TNF-α, and TNFR1 expression induced by UUO in mice. These effects of MSCs were significantly enhanced after CA pretreatment. Therefore, our results suggest that CA pretreatment enhances the antifibrotic activity of MSCs by inhibiting TGF-ß1/TNF-α/TNFR1 signaling-induced necroptosis.

Nicorandil and Bone Marrow-derived Mesenchymal Stem Cells Therapeutic Effect after Ureteral Obstruction in Adult Male Albino Rats.

BACKGROUND: Chronic kidney disease is a global health problem for which renal fibrogenesis is the final treatment target. OBJECTIVE: In our work, we have highlighted two new strategies, nicorandil and Bone marrow-derived mesenchymal stem cells (BM-MSCs), as effective in reversing renal fibrosis induced by partial unilateral ureteral obstruction (PUUO). METHODS: The current study included 96 male albino rats randomly divided into four groups, with 24 rats per group; Group I, the control group; Group II, PUUO, where two-thirds of the left ureter was entrenched in the psoas muscle; Group III, same surgical procedure as in Group II for 7 days, and then the rats received 15 mg/kg/day nicorandil once daily for 21 days; and Group IV, same surgical procedure as in Group II for 7 days, and then rats were given 3 × 106 of labeled MSCs injected intravenous, and left for 21 days. Blood and kidney tissues were collected for biochemical, histological, and molecular analyses. RESULTS: Both the nicorandil and BM-MSCs treatment groups could ameliorate kidney damage evidenced by inhibition of MDA elevation and total antioxidant capacity reduction caused by PUUO. Also, there was a significant reduction observed in TNF, TGF, IL6, collagen I, and α-SMA in addition to improvement in histological examination. However, a significant difference was found between the BM-MSCs and nicorandil-treated groups. CONCLUSION: Our results suggest that BM-MSCs and nicorandil improved renal fibrosis progression through their antiapoptotic, anti-inflammatory, and antifibrotic effects in male albino rats subjected to PUUO, with BM-MSCs being more effective compared to nicorandil.

Carvacrol preserves antioxidant status and attenuates kidney fibrosis via modulation of TGF-ß1/Smad signaling and inflammation.

Chronic kidney disease (CKD) with diverse aetiologies is emerging as a challenging kidney disorder associated with inflammation and interstitial fibrosis. Carvacrol (CVL) is a bioactive monoterpenoid found abundantly in oregano, thyme, and bergamot, having diverse pharmacological benefits. However, the effect of CVL against fibrotic changes in the kidneys is poorly defined. In the current study, a robust mouse model of renal fibrosis induced through unilateral ureteral obstruction (UUO) is used to investigate the anti-fibrotic activity of CVL. The mice were treated with two different oral doses of CVL (25 mg kg-1 and 50 mg kg-1 body weight) for 14 consecutive days. The UUO induction resulted in impaired renal function, severe histological damage, and collagen deposition in the obstructed kidney. Our findings revealed profound activation of transforming growth factor-ß1 (TGF-ß1) and NF-κB (p65) signaling along with the downregulation of antioxidant proteins, nuclear factor-erythroid factor 2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), and superoxide dismutase (SOD) in the obstructed kidney. CVL administration markedly recovered antioxidant proteins and kidney histological changes. In addition, CVL blunted the NF-κB (p65) phosphorylation and reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and cyclooxygenase 2 (COX-2) compared to the UUO control group. CVL also alleviated the increased fibrotic protein levels of TGF-ß1, pSmad2/3, collagen I, collagen III, fibronectin, and myofibroblast activation and epithelial-mesenchymal transition (EMT) markers, including alpha-smooth muscle actin (α-SMA), E-cadherin, and vimentin in the kidneys. Findings from in vitro study also confirmed that CVL inhibits the EMT process in TGF-ß1 stimulated renal tubular epithelial cells (NRK 52E cells). Collectively, our findings indicate that CVL administration attenuates kidney fibrosis by targeting oxidative stress and inflammation.

Ureterorenoscopic (URS) Lithotripsy and Balloon Dilation Cause Acute Kidney Injury and Distal Renal Tubule Damage: A Prospective Study.

Ureterorenoscopy (URS) is believed to be a safe and effective procedure for treating ureteral stones or ureteral strictures. Rapidly increasing intrarenal pressure during URS may have a negative impact on the kidney, but its effect on renal function is not well known. The aim of this study was to evaluate whether URS balloon dilation or lithotripsy could cause acute kidney injury (AKI), which was evaluated using urine neutrophil gelatinase-associated lipocalin (NGAL), and renal tubular damage, which was evaluated using urine α-glutathione S-transferase (GST) and πGST. This prospective study included 207 patients with a mean age of 53.8 years between September 2012 and June 2013. Four groups were included: the ureteral stricture group (group 1), the ureteral stone group (group 2), and two control groups. URS increased urine NGAL (uNGAL) levels on days 1 and 14 in both groups, and only elevated uGST levels were noted on day 14 after URS lithotripsy (URS). On day 14, the difference between low-grade and high-grade hydronephrosis was significant in group 1 (p < 0.001) compared to that in group 2 (p = 0.150). Multivariate logistic regression analysis revealed that age, baseline estimated glomerular filtration rate (eGFR), and stone size > 1.0 cm were associated with the complete recovery of hydronephrosis after URS on day 14. Patients with ureteral stones with preserved renal function had more AKI than those with impaired renal function. However, there was no significant difference in URS-related AKI between the ≤1 cm and >1 cm subgroups. In addition, urine αGST and πGST levels were both significantly higher in the stone > 1 cm subgroup than in the ≤1 cm subgroup. In conclusion, URS laser lithotripsy and balloon dilatation resulted in AKI and renal tubular damage on day 14, although post-URS double-J (DBJ) stenting was performed in every patient.

Ureteral Strictures Following Ureteroscopy for Kidney Stone Disease: A Population-based Assessment.

PURPOSE: As the prevalence of urolithiasis increases and ureteroscopy is used more frequently, the risks of uncommon complications such as ureteral stricture may become more notable. Our objective is to assess the rate and associated risk factors of ureteral stricture formation in patients undergoing ureteroscopy. MATERIALS AND METHODS: Utilizing the IBM MarketScan research database, we evaluated data from 2008 to 2019 and compared ureteral stricture rates and their management following ureteroscopy to subjects who had shock wave lithotripsy. Shock wave lithotripsy was used as a comparison group to represent the rate of stricture from stone disease alone. A third group of those having both shock wave lithotripsy and ureteroscopy was included. Patients and secondary procedures were identified using Current Procedural Terminology, and International Classification of Diseases-9 and -10 codes. RESULTS: A total of 329,776 patients received ureteroscopy, shock wave lithotripsy, or shock wave lithotripsy+ureteroscopy between 2008 and 2019. Stricture developed in 2.9% of patients after ureteroscopy, 1.5% after shock wave lithotripsy, and 2.6% after shock wave lithotripsy+ureteroscopy. In the multivariable model, rates of stricture were 1.7-fold higher after ureteroscopy vs shock wave lithotripsy (OR:1.71, 95% CI 1.62-1.81). Preoperative hydronephrosis, age, prior stones/intervention, and concurrent kidney and ureteral stones were associated with increased risk of stricture. Of those with strictures incurred after ureteroscopy, 35% required drainage, 21% had endoscopic intervention, 4.8% required reconstructive surgery, and 1.7% underwent nephrectomy. CONCLUSIONS: Ureteral stricture rate after ureteroscopy of nearly 3% was higher than expected and approximately twice the rate attributable to stone disease alone. Factors associated with the stone as well as instrumentation were found to be risk factors. The morbidity of stricture disease following ureteroscopy was significant.

Comparison between Antegrade versus Retrograde Ureteral Stent Placement for Malignant Ureteral Obstruction.

PURPOSE: To compare the technical success of antegrade uteral stent (AUS) and retrograde ureteral stent (RUS) placements in patients with malignant ureteral obstruction (MUO) and to determine the predictors of technical failure of RUS. MATERIALS AND METHODS: This study retrospectively included 61 AUS placements (44 patients) performed under fluoroscopic guidance and 76 RUS placements (55 patients) performed under cystoscopic guidance in patients with MUO from January 2019 to December 2020. Technical success rates of the 2 techniques were compared using inverse probability of treatment weighting (IPTW) analysis. Logistic regression was used to identify predictive factors for technical failures. RESULTS: Technical success was achieved in 98.4% of the AUS group and 47.4% of the RUS group. After stabilized IPTW, the technical success rate was higher in the AUS group than in the RUS group (adjusted risk difference, 49.4%; 95% confidence interval [CI], 35.4%-63.1%). The independent predictors for technical failure of the RUS procedure were age of ≥65 years (odds ratio [OR], 5.56; 95% CI, 1.73-21.27), ureteral orifice invasion (OR, 4.21; 95% CI, 1.46-13.46), and extrinsic cancer (OR, 15.58; 95% CI, 2.92-111.81). CONCLUSIONS: The technical success rate of AUS placement was higher than that of RUS placement in patients with MUO. RUS failure was associated with age of ≥65 years, cancer with ureteral orifice invasion, and extrinsic ureteral obstruction.

Analysis of long-term effect of ureteral balloon dilatation combined with internal and external drainage tube in the treatment of benign ureteral stricture.

PURPOSE: There are few reports about balloon dilatation combined with internal and external drainage tube in the treatment of ureteral stricture under interventional therapy. The aim of the study is to explore the safety, effectiveness and long-term efficacy of this treatment strategy. MATERIALS AND METHODS: It is a retrospective and observational study. From October 2013 to October 2016, 42 patients with benign lower ureteral stricture received interventional treatment. Balloon dilatation combined with internal and external drainage tube implantation were used. There were 25 male patients and 17 female patients. There were 7 cases (16.7%) with congenital ureteral stricture, 12 cases (28.6%) with inflammation, 15 cases (35.7%) with ureteral stricture after lithotomy or lithotripsy, and 8 cases (19.0%) with ureteral stricture after pelvic or abdominal surgery. After the drainage tube was removed, B ultrasound, enhanced CTU or IVP of urinary system were reexamined every six months. The follow-up time was 12-60 months. RESULTS: The age was 52.9 ± 11.6 years. The length of ureteral stricture was 1.1 ± 0.5 cm. 42 patients completed interventional treatment, the technical success rate was 100%, no ureteral perforation, rupture or other complications were identified. Preoperative urea nitrogen 9.2 ± 2.3 mmol/L and creatinine 175.8 ± 82.8umol/L. Urea nitrogen and creatinine were 3.8-9.1 mmol/L and 45.2-189.6 umol/L when removing the drainage tube. There were significant differences in the levels of urea nitrogen and creatinine before and after tube removal (P < 0.05). The ureteral patency rate was 100% at 6 months, 93% at 12 months, 83% at 18 months, 79% at 24 months, 76% at 30 months and 73% at 36-60 months. The overall success rate was 73%. Multivariate Cox regression analysis showed that stenosis length was a risk factor for postoperative patency (P < 0.05). CONCLUSION: Balloon dilatation combined with internal and external drainage tube implantation in the treatment of benign lower ureteral stricture is safe and effective.

Non-surgical management of vesicoureteral junction obstruction: a case report.

OBJECTIVE: To report the case of a pediatric patient with bilateral hydronephrosis due to vesicoureteral junction obstruction (VUJO) that was treated non-surgically and to discuss the approach of this anomaly. CASE DESCRIPTION: A 25-month-old boy was referred without complaints for consultation due to prenatal ultrasound showing kidneys with cysts. He was under antibiotic prophylaxis. No family history of kidney disease and/or inherited disorders was reported. Renal ultrasound (RUS) at 2 days of life showed bilateral hydronephrosis, thus ruling out the possibility of kidney cystic disease. Dynamic renal scintigraphy (DTPA) showed marked retention of the marker in the pyelocaliceal system bilaterally, with little response to diuretic drug. He was maintained under antibiotic prophylaxis, when a new RUS showed bilateral ureteral dilatation, abrupt stenosis in the ureterovesical transition region (0.2 cm caliber), moderate bilateral hydronephrosis, and slight renal cortical thickness, confirming the diagnosis of VUJO. At 2 years and 10 months of age, DTPA showed hydronephrosis and ureteral stasis in both kidneys secondary to stenosis at the vesicoureteral junction (VUJ) level, with preservation of kidney function and slow degree of emptying. We opted for a non-surgical approach. RUS at 10 years of age showed significant improvement of all parameters, with ureteral transverse diameter of 9 mm, preserved VUJ, and age-appropriate bilateral kidney development. COMMENTS: VUJO is a major cause of prenatal hydronephrosis and can trigger a deterioration of kidney function. Its treatment is still controversial but should take into account the importance of clinical follow-up and serial imaging evaluation.

Longitudinal Outcomes from Conservative Management of Cervical Cancer Associated Ureteral Obstruction.

OBJECTIVE: To identify predictors of hydronephrosis (HN) resolution and HN treatment failure. HN is a common comorbid condition with cervical cancer (CCa). Treatments for CCa continue to improve and long-term management strategies of HN are becoming increasingly necessary. METHODS: A query of a single hospital (2004 - 2019) ICD-9 and CPT codes was made to develop a cohort of CCa patients with HN. A retrospective review was performed. The effects of patient, renal/HN, and cancer covariates on time to HN treatment failure, treatment complications and time to HN resolution were evaluated using logistic regression and competing risk Cox regression models. RESULTS: Of the 1670 women treated for CCa during the study period, 179 (10.7%) developed HN (n = 72 (40%) bilateral), 78 (44%) at time of CCa diagnosis and 101 (56%) as a result of treatment, of which 145 (81%) underwent initial treatment with a PCN (n = 77, 53%) or US (n = 68, 47%). Complication rates were similar between PCN (56%) and US (61%) when adjusting for treatment time. Initial treatment failure was more likely with US vs PCN (HR 3.2, P <0.01). HN resolution (n = 32, 22%) without reconstruction was predicted by HN concurrent with CCa diagnosis (HR 3.1, P <0.01) and bilateral HN (HR 0.2, P <0.01). CONCLUSION: CCa associated HN has a resolution rate of only 19% at 12 months. Those presenting with HN after CCa treatment are less likely to resolve without reconstruction. PCN and US have similar complication rates but initial US placement has a nearly three times increased risk of failing than PCN.

A nomogram to predict stricture-free survival in patients with ureteral stricture after balloon dilation.

BACKGROUND: Balloon dilation is a commonly used minimally invasive endourological treatment of ureteral stricture, but the postoperative recurrence rate is relatively high. And factors contributing to recurrence after treatment are poorly understood. Herein, we sought to develop a novel clinical nomogram to predict ureteral stricture-free survival in patients suffering from ureter stricture and performed balloon dilation. METHODS: The nomogram was established based on a retrospective analysis of 321 patients who received endoscopic balloon dilation alone for ureter strictures from January 2016 to January 2020 in Sun Yat-sen Memorial Hospital using the Cox regression model. Perioperative clinical data and disease outcomes were analyzed. The primary endpoint was the onset of ureteral re-stricture after ureter balloon dilation. Discrimination of the nomogram was assessed by the concordance index (C-index) and the calibration curve. The results were internally validated using bootstrap resampling. RESULTS: Overall, 321 patients with a median follow-up of 590 days were enrolled in the study, among which 97 patients (30.2%) developed recurrence of ureteral stricture during follow-up. Five variables remained significant predictors of ureteral re-stricture after multivariable analyses: stricture nature (P < 0.001), urinary nitrite (P = 0.041), CKD (P = 0.005), stent retention time (P < 0.001), and balloon size (P = 0.029). The calibration craves for the probability of 1-, 3-, and 5-years stricture-free survival (SFS) presented satisfied with the consistency of nomogram prediction and actual observation. The C-index of the model was 0.74 (95% CI 0.70-0.79). CONCLUSIONS: Our study developed the first nomogram to effectively predict stricture-free survival in patients suffering from ureter stricture after balloon dilation. It is helpful to identify the optimal patients with ureter stricture for balloon dilation and improve treatment outcomes. However, further external validation of the nomogram is warranted.

Comparative study of renal drainage with different ureteral stents subject to extrinsic ureteral obstruction using an in vitro ureter-stent model.

BACKGROUND: To compare the efficacy of different ureteral stents subject to extrinsic ureteral obstruction (EUO), in a controlled in vitro stented ureter experiment. METHODS: We employ an in vitro ureter-stent experimental set-up, with latex tubing simulating flexible ureters attached to vessels simulating renal units and bladders. The flow behavior of five ureteral stents-polymeric 8F, tandem 6F, tandem 7F, endopyelotomy and metal-was tested under a ureteral deformation configuration of 40°, with 2000 g external force over a 3.5 cm length of the ureter. A constant fluid flow was applied through the ureter-stent configurations, and pressure fluctuations in the renal unit were monitored. We considered a renal unit pressure of 10 cmH2O or flow discontinuation in the bladder as stent failure. Urine containing debris was mimicked by use of a colloidal solution. RESULTS: Of all assessed ureteral stents, under EUO conditions, only the single 8F stents remained patent throughout the length of the experiment. All other stents-tandem 6F and 7F, single 7F, metal and endopyelotomy-displayed limitations. CONCLUSIONS: Tandem and metal stents show no superiority over large luminal polymeric stents for EUO treatment in this in vitro model. Larger luminal stents offer excellent resistance to external pressure and allow adequate colloidal flow. The need for frequent exchange and bladder irritation should also be considered in the choice of stent configuration for treatment of kidney drainage under EUO.

Time dependant functional and morphological recovery of the kidney after relief of obstruction in patients with impacted ureteral stones.

OBJECTIVES: To assess the course of functional and morphological recovery of the kidney following the relief of obstruction with ureteral JJ stent in cases with unilateral impacted stones. MATERIALS AND METHODS: A total of 42 adult patients who were admitted to our clinic with unilateral obstructing impacted ureteral stones requiring JJ stent placement were included in the study. The course of functional recovery was assessed by evaluating the serum creatinine levels, renal resistive index (RRI) values and urinary levels of kidney injury molecule-1, neutrophil gelatinaseassociated lipocalin as well as microalbumin before at 1 day, 1 week and 4 weeks after JJ stent placement. Course of morphologic recovery was evaluated by evaluating the degree of hydronephrosis, kidney size, perirenal straining and ureteral diameter. RESULTS: Our results showed that all relevant parameters began to decrease after 24 hours and continue to normalize during 1 week evaluation; majority of these variables indicating the functional and morphological recovery were in normal range after 4 weeks. Decompression of the obstructed kidneys with JJ stent placement in patients with impacted ureteral stones was found to be effective enough with recovery of normal renal functional and morphological status after a minimum time period of 4 weeks. Morphological recovery of affected kidneys following JJ stenting was obtained with a significant difference between baseline and 1-month evaluation findings (p = 0.001, p < 001, p < 001, respectively). KIM-1 excretion began to decline to normal levels after 4 weeks (3.52 ± 0.99 ng/ml versus 2.84 ± 0.66 ng/ml, p < 0.001). The same findings were observed for the urinary excretion levels of NGAL, which normalized at the 1-month evaluation (604.55 ± 140.28 ng/ml versus 596.87 ± 80.17 ng/ml p = 0.895). Urinary microalbumin excretion levels however remained high even until 1-month follow-up with a statistically significant difference when compared with the normal excretion values (p < 0.001). There was a statistically significant difference in RRI values between baseline and 1-month follow-up findings in obstructed kidney (p < 0.001). CONCLUSIONS: Elective management of the obstructing impacted ureteral stone(s) will be safer with limited risk of infective complications after functional and morphological normalization in such kidneys following 4 weeks of JJ stent placement.