Evaluation of risk factors and treatment options in patients with ureteral stricture disease at a single institution

Verapamil inhibits inflammation and promotes autophagy to alleviate ureteral scar by regulation of CaMK IIδ/STAT3 axis

BACKGROUND

Ureteral stricture (US) is a pathological stenosis in the urinary tract characterized by increased collagen synthesis and inflammation. Autophagy activation has been shown to ameliorate tissue fibrosis and protect against fibrotic diseases. Verapamil has beneficial therapeutic benefits on fibrotic disorders. The pharmacological effects of verapamil on fibroblast autophagy in US and the underlying mechanism need to be investigated further.

METHODS

US patients were recruited to isolate scar tissues, hematoxylin-eosin (HE) and Masson trichrome staining were performed to analyze histopathological changes. The US animal model was established and administered with verapamil (0.05 mg/kg) in the drinking water. Transforming growth factor (TGF)-β1 was adopted to facilitate collagen synthesis in fibroblasts. The mRNA and protein expressions were examined by qRT-PCR, western blot, immunofluorescence and immunohistochemistry. ELISA was adopted to measure interleukin (IL)-1β and IL-6 levels. Molecular interaction experiments like dual luciferase reporter and chromatin immunoprecipitation (ChIP) assays were performed to analyze the interaction between signal transducers and activators of transcription 3 (STAT3) and RNA polymerase II associated factor 1 (PAF1).

RESULTS

Herein, our results revealed that verapamil activated TGF-β1-treated fibroblast autophagy and inhibited inflammation and fibrosis by repressing Ca2+⁄calmodulin-dependent protein kinase II (CaMK II) δ-mediated STAT3 activation. Our following tests revealed that STAT3 activated PAF1 transcription. PAF1 upregulation abrogated the regulatory effect of verapamil on fibroblast autophagy and fibrosis during US progression. Finally, verapamil mitigated US in vivo by activating fibroblast autophagy.

CONCLUSION

Taken together, verapamil activated TGF-β1-treated fibroblast autophagy and inhibited fibrosis by repressing the CaMK IIδ/STAT3/PAF1 axis.

Outcomes of Robot-assisted Appendiceal Ureteroplasty From a Multi-institutional Experience

OBJECTIVE

To evaluate the viability of robot-assisted appendiceal ureteroplasty as an innovative surgical approach for the reconstruction of ureteral strictures in cases where traditional methods are unsuitable.

METHODS

We conducted a retrospective review of 14 patients who underwent robot-assisted appendiceal ureteroplasty for right-sided ureteral stricture disease at three academic centers between March 2018 and November 2022. Patients were selected based on stricture characteristics, tissue quality, and the need for tissue transfer techniques. Surgical outcomes, including stricture-free rates, renal function, and complication rates, were analyzed.

RESULTS

The median patient age was 63years, with a balanced gender distribution. The median stricture length was 4.75 cm. The majority of strictures were located in the proximal ureter (50%). Surgical approaches included appendiceal onlay flaps (71.4%) and interposition flaps (28.6%). The median operative time was 268 minutes, with an average estimated blood loss of 75 mL. Postoperatively, ureteral patency was achieved in 92.9% of patients. Two patients (14.3%) experienced urinary tract infections requiring readmission. There was no significant change in serum creatinine levels postoperatively. Hydronephrosis grade significantly improved following surgery (P = .025).

CONCLUSION

Robot-assisted appendiceal ureteroplasty is a safe and effective technique for managing ureteral strictures. It offers a high success rate with minimal complications, making it a valuable addition to the urologic surgeon's armamentarium for complex ureteral reconstructions.

A Forgotten Double-J Ureteric Stent as the Core of a Bladder Stone: A Case Report and Literature Review

BACKGROUND Double-J (D-J) ureteric stents are widely applied in urological operations as they play a vital role in maintaining postoperative functionality of the patient's urinary system and thereby accelerating recovery. D-J stent encrustation may occur due to prolonged retention and lead to secondary complications. We report the case of a forgotten D-J stent that gradually formed into a bladder stone. CASE REPORT A 54-year-old man was referred to the Urology Department due to intermittent hematuria, left flank pain, and lower urinary tract symptoms that persisted for 2 weeks. His history was significant for undergoing left ureterolithotripsy followed by the implantation of an ipsilateral D-J stents 2 years ago in a local hospital. The patient did not follow-up regularly or actively seek medical attention for his urinary tract symptoms. Computed tomographic urography revealed a hyperdense tubular object protruding from the left distal ureter to the bladder. The patient underwent cystolithotripsy, left ureteric stent removal, and left ureteroscopy to clear away the bladder stone and its D-J stent core. CONCLUSIONS Formation of bladder stones secondary to prolonged indwelling D-J stent and its encrustation is not uncommon in developing countries where the level of public education is low. Prompt D-J stent removal can prevent complications associated with its retention and avoid unnecessary secondary procedures. Endoscopic urologic procedures are safe and feasible management options, and doctor-to-patient communication is vital for a better prognosis.

[Update on ureteral reconstruction 2024]

Ureteral strictures can occur along the entire course of the ureter and have many different causes. Factors involved in the development include, among other things, congenital anomalies, iatrogenic injuries during endoscopic as well as open or minimally invasive visceral surgical, gynecological, and urological procedures as well as prior radiation therapy. Planning treatment for ureteral strictures requires a detailed assessment of stricture and patient characteristics. Given the various options for ureteral reconstruction, various methods must be considered for each patient. Short-segment proximal strictures and strictures at the pyeloureteral junction are typically surgically managed with Anderson-Hynes pyeloplasty. End-to-end anastomosis can be performed for short-segment proximal and middle ureteral strictures. Distal strictures are treated with ureteroneocystostomy and are often combined with a Boari and/or Psoas Hitch flap. Particularly, the treatment of long-segment strictures in the proximal and middle ureter remain a surgical challenge. The use of bowel interposition is an established treatment option for this, offering good functional results but also potential associated complications. Robot-assisted surgery is increasingly becoming a minimally invasive treatment alternative to reduce hospital stays and optimize postoperative recovery. However, open surgical ureteral reconstruction remains an established procedure, especially after multiple previous abdominal operations.

Evaluation of risk factors, treatment options, and prognostic-related factors in patients with benign ureteral strictures: An 8-year single-center experience

OBJECTIVES

To investigate the etiology, therapeutic effect, and prognosis-related factors of benign ureteral strictures.

METHODS

We analyzed the date of 142 patients with benign ureteral strictures from 2013 to 2021. Ninety-five patients received endourological treatment and 47 patients underwent reconstruction. Preoperative, intraoperative, and postoperative information were compared and analyzed. Symptomatic improvement and radiographic blockage alleviation defined therapeutic success.

RESULTS

Stone-related factors caused 85.2% of cases. The overall success rate of endourological treatment was 51.6% versus 95.7% of reconstruction (p < 0.01). However, endourological treatment was better in terms of postoperative hospital stay time, operation time, and intraoperative blood loss (p < 0.001). In endourological group, patients with stricture length ≤2 cm, mild-to-moderate hydronephrosis, proximal or distal stricture had a higher success rate. Multivariate regression analysis showed that the surgical method was the only independent risk factor affecting success and recurrence. Reconstruction success rate was higher than endourological treatment (p = 0.001, OR 0.057, 95% CI (0.011-0.291)), and recurrence rate was also lower (p = 0.001, HR 0.074, 95% CI (0.016-0.338)). No obvious recurrence was seen in reconstruction, and the median recurrence time in endourological treatment was 51 months.

CONCLUSIONS

Stone-related factors are an important cause of benign ureteral strictures. Reconstruction is the gold standard treatment due to its high success rate and low recurrence rate. Endourological therapy is also preferred as the initial treatment in proximal or distal ureter with length ≤2 cm and mild-to-moderate hydronephrosis. Further close follow-up is required after treatment.

Predictors of Ureteral Strictures after Retrograde Ureteroscopic Treatment of Impacted Ureteral Stones: A Systematic Literature Review

BACKGROUND

The stricture-formation rate following ureteroscopy ranges from 0.5 to 5% and might amount to 24% in patients with impacted ureteral stones. The pathogenesis of ureteral stricture formation is not yet fully understood. It is likely that the patient and stone characteristics, as well as intervention factors, play a role in this process. In this systematic review, we aimed to determine the potential factors responsible for ureteral stricture formation in patients having impacted ureteral stones.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria, we conducted systematic online research through PubMed and Web of Science without a time restriction, applying the keywords "ureteral stone", "ureteral calculus", "impacted stone", "ureteral stenosis", "ureteroscopic lithotripsy", "impacted calculus", and "ureteral strictures" singly or in combination.

RESULTS

After eliminating non-eligible studies, we identified five articles on ureteral stricture formation following treatment of impacted ureteral stones. Ureteral perforation and/or mucosal damage appeared as key predictors of ureteral stricture following retrograde ureteroscopy (URS) for impacted ureteral stones. Besides ureteral perforation stone size, embedded stone fragments into the ureter during lithotripsy, failed URS, degree of hydronephrosis, nephrostomy tube or double-J stent (DJS)/ureter catheter insertion were also suggested factors leading to ureteral strictures.

CONCLUSION

Ureteral perforation during surgery might be considered the main risk factor for ureteral stricture formation following retrograde ureteroscopic stone removal for impacted ureteral stones.

Effect of 3D laparoscopic surgery for ureteral stricture

OBJECTIVE

To investigate the efficacy and safety of 3D laparoscopic surgery for ureteral stricture.

METHODS

There were 47 patients with ureteral stricture and treated with 3D laparoscopic surgery from December 2017 to December 2020, and comprehensive analysis of relevant clinical data. Among the patients with ureteral stricture, there were 31 males and 16 females, 28 were left-sided and 19 were right-sided, aged 20-78 years, with an average age of 43 years; the number of upper and middle ureteral stricture cases was 34, and the lower ureteral stricture was 13, with a stricture length of 0.5-4.0 cm; all patients had different degrees of hydronephrosis before surgery, and the degree of separation of the renal collecting system before surgery was 36.19±4.09 mm. Preoperative serum creatinine was 82.00±35.49 μmol/L. Patients with upper and middle ureteral stricture underwent 3D laparoscopic ureteral stricture resection plus ureter end anastomosis, and patients with lower ureteral stricture underwent 3D laparoscopic ureteral bladder reimplantation.

RESULTS

All patients had successful surgery, with an operative time of 132.87±27.64 min, an estimated intraoperative bleeding volume of 58.94±22.29 ml, a postoperative hospital stay of 7.81±1.74 days, and no complications such as intestinal injury and abdominal hemorrhage occurred; the ureteral stent tube was removed 8-12 weeks after the operation, and the follow-up was 3-36 months, with a mean of 18.98±11.36 months. The patients' hydronephrosis was reduced or disappeared, and the symptoms such as back pain and swelling were effectively relieved. The degree of separation of the renal collecting system was 15.28±3.26 mm and the creatinine value was 72.38±29.20 μmol/L on postoperative reexamination, which were statistically significant compared with those before surgery (P<0.05).

CONCLUSION

3D laparoscopic ureteral stricture resection plus ureter end anastomosis or 3D laparoscopic ureteral bladder reimplantation for ureteral stricture is safe and effective, with few complications and rapid postoperative recovery.

Comprehensive endoscopic management of impacted ureteral stones: Literature review and expert opinions

Treatment of urolithiasis, a benign disease, requires high efficacy and safety. Endoscopic treatment of impacted ureteral stones remains a challenging procedure for urologists, despite recent remarkable advances in surgical technology in treatment of urolithiasis. The success rate of endoscopic treatment in patients with impacted stones is reported to be lower than that in patients with nonimpacted stones. Moreover, the presence of stone impaction is associated with high rates of intraoperative and postoperative complications. The best management for patients with impacted ureteral stones should therefore be devised based on the latest knowledge and techniques. The present review focuses on the preoperative prediction of stone impaction, the safest and most effective endoscopic surgical procedures, and the most appropriate management for postoperative ureteral strictures. We overview comprehensive endoscopic management for impacted ureteral stones based on literature review and expert opinions.

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.

Surgical and radiological predictive factors for ureteric stricture formation in patients treated with ureteroscopy for ureteric stones

BACKGROUND

Ureteric stricture is a potential complication of impacted ureteric stones. This study investigates surgical and radiological factors that could predict ureteric stricture formation after ureteroscopic treatment of impacted ureteric stones.

MATERIALS AND METHOD

Intraoperative and radiological data for patients who underwent ureteroscopic treatment of ureteric stones impaction over a 5-year period were reviewed retrospectively. Patients who had previous ureteroscopic treatment or strictures were excluded.

RESULTS

Between January 2014 and May 2019, 1,340 patients presented as emergency renal colic secondary to ureteric stones. A total of 297 ureteroscopy procedures were performed for impacted calculi. The mean age was 53 years. The stricture rate was 3.3%. Analysis of radiological and surgical factors revealed that the degree of hydronephrosis, residual fragments and intraoperative ureteric injury were significant predictors for stricture formation (p = 0.018, 0.01 and 0.02, OR = 10, 47 and 1776, respectively). None of the other factors significantly predicted ureteric stricture formation.

CONCLUSION

Our study found the presence of severe hydronephrosis, residual stone fragments after surgery and intraoperative ureteric injury are significant predictive factors for ureteric stricture formation. The high-risk patients should be monitored with routine postoperative renal ultrasound.

Impact of radiation on the incidence and management of ureteroenteric strictures: a contemporary single center analysis

BACKGROUND

Ureteroenteric stricture incidence has been reported as high as 20% after urinary diversion. Many patients have undergone prior radiotherapy for prostate, urothelial, colorectal, or gynecologic malignancy. We sought to evaluate the differences between ureteroenteric stricture occurrence between patients who had radiation prior to urinary diversion and those who did not.

METHODS

An IRB-approved cystectomy database was utilized to identify ureteroenteric strictures among 215 patients who underwent urinary diversion at a single academic center between 2016 and 2020. Chart abstraction was conducted to determine the presence of confirmed stricture in these patients, defined as endoscopic diagnosis or definitive imaging findings. Strictures due to malignant ureteral recurrence were excluded (3 patients). Statistical analysis was performed using chi squared test, t-test, and Wilcoxon Rank-Sum Test, logistic regression, and Kaplan-Meier analysis of stricture by cancer type.

RESULTS

65 patients had radiation prior to urinary diversion; 150 patients did not have a history of radiation therapy. Benign ureteroenteric stricture rate was 5.3% (8/150) in the non-radiated cohort and 23% (15/65) in the radiated cohort (p =  < 0.001). Initial management of stricture was percutaneous nephrostomy (PCN) in 78% (18/23) and the remaining 22% (5/23) were managed with primary retrograde ureteral stent placement. Long term management included ureteral reimplantation in 30.4% (7/23).

CONCLUSIONS

Our study demonstrates a significant increase in rate of ureteroenteric strictures in radiated patients as compared to non-radiated patients. The insult of radiation on the ureteral microvascular supply is likely implicated in the cause of these strictures. Further study is needed to optimize surgical approach such as utilization of fluorescence angiography for open and robotic approaches.

Long-term Follow Up of Ileal Ureteral Replacement for Complex Ureteral Strictures: Single Institution Study

OBJECTIVE

To report our 16-year experience with ileal ureter interposition for complex ureteral stricture. Ureteral reconstruction continues to evolve to include less invasive techniques to successfully manage ureteral stricture. However, long, complex, obliterative and especially radiated ureteral strictures are not amenable to less invasive techniques and may require Ileal ureter interposition.

MATERIALS AND METHODS

Retrospective review of a single institution's ureteral reconstruction database was performed. Demographics, operative details, success rate, complication rate, and length of follow-up were noted. Unilateral replacements utilized ileal ureteral interposition. Success rate was defined as no need for further open intervention.

RESULTS

Between 2003 and 2019, 188 ureteral reconstructions were performed, of which 46 required ileal ureter interposition. Of these 46 patients, 10 required bilateral reconstruction. Average age was 53 years, 26 (57%) were female. The average stricture length was 9.1 cm (2-20 cm). Stricture etiology included iatrogenic causes (n = 24, 52%), radiation causes (n = 12; 26%), vascular disease (n = 3; 7%), and idiopathic retroperitoneal fibrosis (n = 3; 7%). Forty-three surgeries were performed by open abdominal approach; 3 were performed robotically. The average length of operation was 412 minutes, blood loss 417 mL and LOS was 10 days. At mean follow up of 4.4 years (1-16 years), overall success rate was 83%, with 17% (n = 8) patients requiring subsequent major surgery (5 successful ureteral revision, 3 nephrectomy) and 11 (24%) patients experiencing a major complication.

CONCLUSION

In our long-term follow up of over 4 years, ileal ureteral interposition remains a successful option for complex ureteral strictures in properly selected patients.

Minimal-invasive management of urological complications after kidney transplantation

Kidney transplantation represents the gold standard treatment option for patients with end-stage renal disease. Improvements in surgical technique and pharmacologic treatment have continuously prolonged allograft survival in recent years. However, urological complications are frequently observed, leading to both postoperative morbidity and putative deterioration of allograft function. While open redo surgery in these patients is often accompanied by elevated surgical risk, endoscopic management of urological complications is an alternative, minimal-invasive option. In the present article, we reviewed the literature on relevant urological postoperative complications after kidney transplantation and describe preventive approaches during the pre-transplantation assessment and their management using minimal-invasive approaches.

Buccal ureteroplasty for recurrent extended strictures and obliterations of distal ureter

At the current stage of development of urology, selection of the surgical method for cases of severe obstructive diseases of the upper urinary system remains a challenge. This study aimed to explore the results of application of a buccal graft (BG) to remedy extended recurrent strictures and obliterations of the distal ureter. Seven patients with the mentioned diseases had undergone surgery: for six of them, the method of choice was complete BG ureteroplasty, one had onlay ureteroplasty. One intervention was laparoscopic, the remaining surgeries were open. The length of the replaced ureteral defect was 5–8 cm. In five cases, the flap was additionally vascularized with the iliac muscle, in one we used omentum tissue, in another — both the iliac muscle and the omentum. There were no fatalities registered, nor severe complications as per the Clavien–Dindo classification. The patients were followed-up for 4–18 months; as of today, no recurrence cases were identified. Control examinations showed complete patency of the neoureter and good vascularization of the BG. Thus, this method can be an option in cases disallowing distal ureter restoration with tissues of the patient's own urinary tract or segments of the gastrointestinal tract.

Roles Played by Biomarkers of Kidney Injury in Patients with Upper Urinary Tract Obstruction

Partial or complete obstruction of the urinary tract is a common and challenging urological condition caused by a variety of conditions, including ureteral calculi, ureteral pelvic junction obstruction, ureteral stricture, and malignant ureteral obstruction. The condition, which may develop in patients of any age, induces tubular and interstitial injury followed by inflammatory cell infiltration and interstitial fibrosis, eventually impairing renal function. The serum creatinine level is commonly used to evaluate global renal function but is not sensitive to early changes in the glomerular filtration rate and unilateral renal damage. Biomarkers of acute kidney injury are useful for the early detection and monitoring of kidney injury induced by upper urinary tract obstruction. These markers include levels of neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemotactic protein-1, kidney injury molecule 1, N-acetyl-b-D-glucosaminidase, and vanin-1 in the urine and serum NGAL and cystatin C concentrations. This review summarizes the pathophysiology of kidney injury caused by upper urinary tract obstruction, the roles played by emerging biomarkers of obstructive nephropathy, the mechanisms involved, and the clinical utility and limitations of the biomarkers.

Dosimetric Predictors of Genitourinary Toxicity From a Phase I Trial of Prostate Bed Stereotactic Body Radiation Therapy

PURPOSE

Our purpose was to analyze dose-volume parameters associated with genitourinary (GU) toxicity from a phase I clinical trial of prostate bed stereotactic body radiation therapy.

METHODS AND MATERIALS

Patients were treated in escalating dose levels of 35, 40, and 45 Gy, over 5 fractions. Data from all 26 patients enrolled in the protocol were analyzed using multiple dose-volume cut points for multiple GU organs at risk. Univariate logistical regression and Fisher exact test were used to assess statistical significance associated with incidence of toxicity.

RESULTS

The median follow-up was 36 months for all patients. Acute GU toxicity was mild and resolved spontaneously. Eight out of 26 patients (30.7%) developed late GU toxicity of grade 2 or higher. Two patients developed grade 3 ureteral stenosis, 1 in the 35 Gy arm and the other in the 45 Gy arm. Three patients developed grade 2 or higher hematuria/cystitis, and 3 developed grade 2 or higher incontinence. Incidence of grade 3 ureteral stenosis was related to the absolute volume of bladder wall receiving greater than 20, 25, and 30 Gy (P < .01). Grade 2 cystitis and hematuria were related to the volume of bladder wall receiving 20 Gy less than 34% and 35 Gy less than 25% (18.8% vs 60% and 23.8% vs 80%, respectively, P < .05). Incontinence was related to mean urethral dose less than 35 Gy and 25 Gy (4.3% vs 66.7% and 0% vs 37.5%, respectively, P < .05) and volume of urethra receiving 35 Gy less than 24% (8.3% vs 50%, P < .05).

CONCLUSIONS

This is the first analysis to report dose-volume thresholds associated with late GU toxicity in patients receiving prostate bed stereotactic body radiation therapy. We recommend limiting the bladder wall receiving 25 Gy to less than 18 cubic centimeters to reduce the risk for late grade 3 ureteral stenosis.

Post ureteroscopic stone surgery ureteral strictures management: a retrospective study

PURPOSE

To share experience in managing ureteral strictures following ureteroscopic lithotripsy.

METHODS

Ninety five patients diagnosed as ureteral strictures after ureteroscopic lithotripsy between January 2013 and January 2018 were included. 53 received endourological treatment, 34 underwent reconstruction, 6 underwent nephrectomy for severe renal impairment, and 2 chose routine ureteral stent replacement. Therapeutic success was defined as absence of clinical symptoms and radiologic relief of obstruction.

RESULTS

The follow-up time ranged from 13 to 57 months, with a median time of 24. It lasted more than 13 months in all patients, exception for 2 nephrectomies. Two patient groups including 69 endourological procedures and 37 reconstructions were used to compare therapeutic effects and complications. The overall success rate was 60.9% (42/69) in endourological intervention vs. 97.3% (36/37) in reconstruction (p < 0.001), while 74.4% (29/39) patients with stricture less than 1 cm and 68.8% (33/48) patients with mild-to-moderate hydronephrosis achieved success in endourological group. All except 1 failure appeared within the first year postoperatively. Subgroup analyses for endourological procedures revealed significant differences in the success rate of different stricture lengths and hydronephrosis (p = 0.004 and p = 0.043). Multivariate Cox regression analysis indicated that reconstruction was significantly related to a more successful outcome, compared with endourological procedures (HR 0.052, 95% CI 0.007-0.394, p = 0.004).

CONCLUSION

Reconstruction performs better than endourological procedures in surgical outcome. Endourological procedure provides an acceptable success rate in patients with stricture shorter than 1 cm and slight hydronephrosis. Most stricture recurrence appeared within the first year postoperatively.

Chronic, Gross Hematuria Caused by Idiopathic Ureteric Stricture

An otherwise healthy, 10-year-old boy presented with chronic, gross hematuria. This persisted daily for 5 years despite extensive multidisciplinary workup with renal biopsy and resulted in severe iron deficiency anemia. The extensive workup and requirement for routine follow-up, investigations, and procedures led to significant psychosocial distress for the patient. Initially, it was thought the patient had a nutcracker phenomenon, but on closer inspection of his ureters, an idiopathic, unilateral ureteric stricture was discovered and, after 8 weeks of stenting, resulted in complete resolution of the hematuria. Importantly, the patient's psychosocial distress resolved after resolution of the hematuria and with the closure that came with a diagnosis.

Ureteroureteral anastomosis for endometriosis involving the ureter: Case series and literature review

Introduction:

The purpose of this study was to review operative management of endometriosis involving the ureter.

Materials and methods:

Retrospective case series of three patients undergoing resection of ureteral endometriosis with ureteroureterostomy for endometriosis involving the ureter by minimally invasive gynecologic surgeons between 2007 and 2018 at a large academic medical center in the Northeastern United States. A literature review was conducted to find cases with a similar approach.

Results:

Three cases of ureteral endometriosis surgically managed at our institution with ureteroureteral anastomosis were identified. Ureteral endometriosis was identified preoperatively by hydroureteronephrosis on imaging. Intrinsic ureteral endometriosis was confirmed by pathology in two cases; extrinsic endometriosis was grossly visualized in one case. Operative times ranged from 300 to 387 min. Estimated blood loss ranged from 150 to 250 mL. There were no intraoperative complications. A total of 151 cases with a similar approach were described in the literature. Recurrence of obstructive uropathy occurred in 11 cases.

Conclusion:

Ureteral endometriosis is a rare complication with several management options. Ureterectomy with ureteroureterostomy has been described in the literature and in three cases at our institution with low complication rates and rare stricture formation. This technique can be successful in the management of ureteral endometriosis and warrants further investigation.

The Morbidity of Ureteral Strictures in Patients with Prior Ureteroscopic Stone Surgery: Multi-Institutional Outcomes

PURPOSE

Nephrolithiasis is an increasingly common ailment in the United States. Ureteroscopic management has supplanted shockwave lithotripsy as the most common treatment of upper tract stone disease. Ureteral stricture is a rare but serious complication of stone disease and its management. The impact of new technologies and more widespread ureteroscopic management on stricture rates is unknown. We describe our experience in managing strictures incurred following ureteroscopy for upper tract stone disease.

MATERIALS AND METHODS

Records for patients managed at four tertiary care centers between December 2006 and October 2015 with the diagnosis of ureteral stricture following ureteroscopy for upper tract stone disease were retrospectively reviewed. Study outcomes included number and type (endoscopic, reconstructive, or nephrectomy) of procedures required to manage stricture.

RESULTS

Thirty-eight patients with 40 ureteral strictures following URS for upper tract stone disease were identified. Thirty-five percent of patients had hydronephrosis or known stone impaction at the time of initial URS, and 20% of cases had known ureteral perforation at the time of initial URS. After stricture diagnosis, the mean number of procedures requiring sedation or general anesthesia performed for stricture management was 3.3 ± 1.8 (range 1-10). Eleven strictures (27.5%) were successfully managed with endoscopic techniques alone, 37.5% underwent reconstruction, 10% had a chronic stent/nephrostomy, and 10 (25%) required nephrectomy.

CONCLUSIONS

The surgical morbidity of ureteral strictures incurred following ureteroscopy for stone disease can be severe, with a low success rate of endoscopic management and a high procedural burden that may lead to nephrectomy. Further studies that assess specific technical risk factors for ureteral stricture following URS are needed.

miR-140-5p-mediated regulation of the proliferation and differentiation of human dental pulp stem cells occurs through the lipopolysaccharide/toll-like receptor 4 signaling pathway

Human dental pulp stem cells (DPSCs) are oral mesenchymal stem cells with potential to differentiate into various cell types. Recent studies of DPSCs have focused on microRNAs (miRNAs), a class of small noncoding RNAs that play crucial roles in regulating DPSC phenotypes. In the current study, the expression of miR-140-5p was significantly decreased during lipopolysaccharide (LPS)-mediated differentiation of DPSCs in vitro. Overexpression of miR-140-5p enhanced proliferation of DPSCs and inhibited DPSC differentiation, whereas suppression of miR-140-5p produced the opposite effect. Moreover, the expression of toll-like receptor 4 (TLR-4), a critical regulator of DPSCs, was negatively correlated with the levels of miR-140-5p. A luciferase reporter analysis confirmed that miR-140-5p could regulate TLR-4 by directly binding to the 3'-untranslated region (3'-UTR) of the TLR4 mRNA. Additionally, we suppressed TLR-4 expression by treating cells with a TLR-4 inhibitor, CLI-095, and demonstrated that the effect of the miR-140-5p inhibitor on DPSC proliferation and differentiation could be partially reversed by blocking TLR-4. Taken together, our data suggest that miR-140-5p is a novel miRNA that regulates DPSC proliferation and differentiation.

Contemporary management of ureteral strictures

Ureteral stricture disease is a luminal narrowing of the ureter leading to functional obstruction of the kidney. Treatment of strictures is mandatory to preserve and protect renal function. In recent times, the surgical management of ureteral strictures has evolved from open repair to include laparoscopic, robotic and interventional techniques. Prompt diagnosis and early first line intervention to limit obstructive complications remains the cornerstone of successful treatment. In this article, we discuss minimally invasive, endo-urological and open approaches to the repair of ureteral strictures. Open surgical repair and endoscopic techniques have traditionally been employed with varying degrees of success. The advent of laparoscopic and robotic approaches has reduced morbidity, improved cosmesis and shortened recovery time, with results that are beginning to mirror and in some cases surpass more traditional approaches.

Level of evidence: Not applicable for this multicentre audit.

Loss of Renal Function After Retrograde Ureteral Placement of an Allium Stent for Severe Ureteral Stricture

Background: Ureteral strictures are a recurrent chronic condition that leads to severe side effects and poor quality of life. Management of ureteral stricture is a great challenge for urologists and no specific guidelines exist. Retrograde Allium^® ureteral stent (AUS) is a newly developed ureteral stent to treat either bulbar urethral or ureteral stenosis.

Case Presentation: We describe a case of a 74-year-old Caucasian adult male presenting with a severe ureteral stricture secondary to an ureteroscopy for stone disease. Treatment with retrograde AUS placement produced a complete loss of renal function after 36 months, probably because of the development of a long achalasic stretch of the ureter.

Conclusions: AUS is a new and promising device for the treatment of ureteral stenosis. However, a lack of standardization of the technique recommends a close instrumental follow-up after the procedure to decide the optimal time for stent removal.

Ureteroscopy-Assisted Laparoscopic Segmental Resection of Ureteral Stricture with a Modified Flank Position: Clinical Experience

PURPOSE

To share the surgical technique that possesses the advantage of a perioperative ureteroscope without position change, which allows for a laparoscopic segmental resection of the ureteral stricture to be performed more precisely.

PATIENTS AND METHODS

Between 2006 January and 2015 December, 10 patients with a ureteral stricture received a laparoscopic segmental resection and ureteroureterostomy in our clinical institute. The etiology included stone, endometriosis, crossing vessel, and idiopathic benign ureteral polyp. With the advance of bilateral lower extremities extended and abducted, 1 assistant used a ureteroscope as a direct guide to the precise location of the stricture affected ureter. Thus, the surgeon was able to perform a more specific resection without an unnecessary excision, which may have compromised the blood supply or increased the tension at anastomosis.

RESULTS

Five patients received the traditional transperitoneal laparoscopic approach, whereas the other 5 patients received a ureteroscopy-assisted laparoscopic segmental resection and ureteroureterostomy. The operating time appears to be no different between the two groups (124 minutes versus 142 minutes, P = .351), and, thus, no additional time is consumed for the ureteroscope procedure. After at least 1 year of follow-up, only 1 patient in the traditional laparoscopic group suffered from recurrence. One patient had a right ureteral stricture due to stone impaction, where with the advantage of a ureteroscope guide without change position, the operator was able to make a limited excision at the affected location. No complications related to the decubitus and bilateral leg in the extended position were noted.

CONCLUSIONS

Ureteroscopy-assisted laparoscopic segmental resection of the ureter without a change in position is a feasible and safe procedure when dealing with a refractory ureter stricture. Although it is convenient, the surgeon should be aware of possible pressure sores at the dependent part.

Clinical factors associated with postoperative hydronephrosis after ureteroscopic lithotripsy

Purpose

This study aimed to determine the predictors of ipsilateral hydronephrosis after ureteroscopic lithotripsy for ureteral calculi.

Materials and Methods

From January 2010 to December 2014, a total of 204 patients with ureteral calculi who underwent ureteroscopic lithotripsy were reviewed. Patients with lack of clinical data, presence of ureteral rupture, and who underwent simultaneous percutaneous nephrolithotomy (PNL) were excluded. Postoperative hydronephrosis was determined via computed tomographic scan or renal ultrasonography, at 6 months after ureteroscopic lithotripsy. Multivariable analysis was performed to determine clinical factors associated with ipsilateral hydronephrosis.

Results

A total of 137 patients were enrolled in this study. The mean age of the patients was 58.8±14.2 years and the mean stone size was 10.0±4.6 mm. The stone-free rate was 85.4%. Overall, 44 of the 137 patients (32.1%) had postoperative hydronephrosis. Significant differences between the hydronephrosis and nonhydronephrosis groups were noted in terms of stone location, preoperative hydronephrosis, impacted stone, operation time, and ureteral stent duration (all, p<0.05). On multivariable analysis, increasing preoperative diameter of the hydronephrotic kidney (adjusted odds ratio [OR], 1.21; 95% confidence interval [CI], 1.12–1.31; p=0.001) and impacted stone (adjusted OR, 3.01; 95% CI, 1.15–7.61; p=0.031) independently predicted the occurrence of postoperative hydronpehrosis.

Conclusions

Large preoperative diameter of the hydronephrotic kidney and presence of impacted stones were associated with hydronephrosis after ureteroscopic stone removal. Therefore, patients with these predictive factors undergo more intensive imaging follow-up in order to prevent renal deterioration due to postoperative hydronephrosis.