Surgical Treatment of Upper Urinary Tract Lithiasis in Conakry

Introduction: The management of urinary lithiasis in our settings has long been conventional surgery. The recent introduction of endoscopy of the upper urinary tract represents a major advance in our department. The aim was to contribute to the study of the treatment of lithiasis of the upper urinary tract in Conakry and to report on our initial experience of ureteroscopy in Conakry. Methodology: This is a prospective descriptive study lasting one year, from January 1 to December 31, 2022, carried out at the Urology Department of the Ignace Deen National Hospital and at the PERCHIN Urological Clinic. The study included all patients treated surgically for lithiasis of the upper urinary tract who met the selection criteria. Results: The study included 57 patients. The mean age was 30 years, with extremes of 20 and 73 years;the most represented age group was 31 to 40 years, followed by 20 to 30 years with 29.9% and 26.3% respectively. Males predominated in 36 cases (63.15%), with a M/F sex ratio of 1.71. Left-sided renal colic was the most common, at 75.43% (n=43), and right-sided renal colic at 40.35%, associated with digestive signs at 43.85%. 77.19% had normal creatinine levels before surgery, versus 22.81% with elevated creatinine levels, i.e. 15.78% improvement in renal function after surgery. Urinary tract infection was found in 47.36%, and Escherichia coli in 31.57%, followed by staphylococcus aureus in 8.77%. Overall, 82.45% of patients had organic damage to the kidneys or ureters. Right ureterohydronephrosis was noted in 56.14%, followed by left hydronephrosis in 26.32%. Open surgery was predominant in 52.63% of cases, with endoscopic surgery (URS) accounting for a significant 47.36% during the study period. The endoscopic treatment used was laser ureteroscopy. In our study, 73.68% underwent drainage of the upper excretory tract, including 64.91% with a JJ catheter. The average length of stay was 07 days, with extremes of 02 and 28 days, and 81.4% of patients who underwent URS had a length of stay of less than 4 days. Conventional surgery had the highest complication rate (14.28%). The stone free rate for the two surgical treatment methods (open and endoscopic surgery) was 73% and 92.59%.

Segmental ureteroileal conduit resection for the treatment of distal upper urinary tract recurrence of bladder cancer fol lowing cystectomy

Segmental ureterectomy is less invasive than radical nephroureterectomy and results in nephron preservation and satisfactory tumor control.This study was to determine the feasibility of segmental ureteroileal conduit resection(SUICR) for patients with distal upper urinary tract recurrence of bladder cancer following radical cystectomy.Four patients with high-grade distal upper urinary tract recurrence underwent SUICR 15-108 months after radical cystectomy.The surgical technique details of SUICR,operative results,and follow-up outcomes are reported.The median operation time was 280 min,and estimated blood loss was less than 100 ml One patient suffered from ileus 5 days after surgery and was managed conservatively.Histopathologic evaluation showed high-grade stages pTa-pT1 diseases for these patients,and ureteral margins were all negative.No patient suffered from tumor recurrence,with a median follow-up of 39 months.SUICR preserved the ipsilateral renal unit and conformed to oncological principles during surgery.The oncological outcome was satisfactory for these properly selected patients.This technique provides a valid alternative to nephroureterectomy for patients with imperative indications and high-grade upper urinary tract recurrence of bladder cancer following radical cystectomy.

Oncological impact of different distal ureter managements during radical nephroureterectomy for primary upper urinary tract urothelial carcinoma

BACKGROUND The current standard surgical treatment for non-metastatic upper urinary tract urothelial carcinoma(UTUC)is radical nephroureterectomy(RNU)with bladder cuff excision(BCE).Typically,BCE techniques are classified in one of the following three categories:An open technique described as intrasvesical incision of the bladder cuff,a transurethral incision of the bladder cuff(TUBC),and an extravesical incision of the bladder cuff(EVBC)method.Even though each of these management techniques are widely used,there is no consensus about which surgical intervention is superior,with the best oncologic outcomes.AIM To investigate the oncological outcomes of three BCE methods during RNU for primary UTUC patients.METHODS We retrospectively analyzed the data of 248 primary UTUC patients,who underwent RNU with BCE between January 2004 to December 2018.Patients were analyzed according to each BCE method.Data extracted included patient demographics,perioperative parameters,and oncological outcomes.Statistical analyses were performed using chi-square and log-rank tests.The Cox proportional hazards regression model was utilized to identify independent predictors.P<0.05 was considered statistically significant.RESULTS Of the 248 participants,39.9%(n=99)underwent intrasvesical incision of the bladder cuff,38.7%(n=96)EVBC,and 21.4%(n=53)TUBC.At a median followup of 44.2 mo,bladder recurrence developed in 17.2%,12.5%,and 13.2%of the cases,respectively.Cancer-specific deaths occurred in 11.1%,5.2%,and 7.5%of patients,respectively.Kaplan-Meier survival curves with a log-rank test highlighted no significant differences in intravesical recurrence-free survival,cancer-specific survival,and overall survival among these approaches with P values of 0.987,0.825,and 0.497,respectively.Multivariate analysis showed that the lower ureter location appears to have inferior intravesical recurrence-free survival(P=0.042).However,cancer-specific survival and overall survival were independently influenced by tumor stage(hazard ratio[HR]=8.439;95%con
dence interval:2.424-29.377;P=0.001)and lymph node status(HR=14.343;95%CI:5.176-39.745;P<0.001).CONCLUSION All three techniques had comparable outcomes;although,EVBC and TUBC are minimally invasive.While based upon rather limited data,these findings will support urologists in blending experience with evidence to inform patient choices.However,larger,rigorously designed,multicenter studies with long term outcomes are still required.

Dynamic Renal Scintigraphy in Diagnosis of Upper Urinary Tract Obstruction in Transplanted Kidney

Nuclide renal dynamic imaging was performed on 88 transplanted kidney. Two kinds of renal scintigraphic characteristics were identified in recipients with supravesical obstruction of the graft. First, the regular type was characterized by radioactivity defect area in kidney parenchyma during early uptake period followed by ureteropelvic retention. Second, the tubular type was typified by cortical retention and attenuation in collecting system during the whole test period with a special sign of “hollow kidney”. Non obstructive dilated calyces showed similar signs as the regular type. Acute rejection reaction and tubule necrosis demonstrated obstructive time activity curves. However, the radioactivity retention appeared in cortex. It was suggested that dilated calyces and obstructive renogram might not be reliable evidence for upper urinary tract obstruction. The signs of radioactivity attenuation in kidney parenchyma during early uptake period followed by ureteropelvic retention may be more valuable for the evaluation. As for tubular obstruction, specified “hollow kidney” was the characteristic sign which is helpful for the diagnosis.

Etiological Aspects of the Dilatation of the Upper Urinary Tract at University Hospital of Gabriel Toure

Introduction: The dilatation of the upper urinary tract, signs in the vast majority of cases the presence of a ureteral obstacle. The etiologies are diverse. Mali is a country where urinary schistosomiasis is endemic. Repeated infestation may result in long-term ureteropelastic dilatation secondary to stenotic sequelae. The objective is to study the causes of dilatations of the upper urinary tract. Materials and Methods: This is a prospective study of 12 months, from October 2010 to September 2011, performed in the urology department of Gabriel Toure University Hospital in Bamako. The parameters studied were: age, sex, reason for consultation, medical history, urinary analysis, etiological diagnosis, management, evaluation of renal failure. Result: In 12 months, we collected 50 cases of dilatations of the upper urinary tract representing 0.66% of all consultations. The average age of our patients was 35 years old. The sex ratio was 2.13 in favor of men. A history of urinary schistosomiasis was found in 25 patients or 50%. Low back pain was the most common reason for consultation, 76%. The renal and bladder ultrasonography performed in all 50 patients in our series found bilateral dilatation in 68% of patients and unilateral dilation in 32% of cases. Urinary tract infection with Escherichia coli was found in 53% of cases. Ureterovesical reimplantation was performed in 40% of cases. Conclusion: The dilatation of the upper urinary tract, consequence of an anatomical or functional obstruction, constitutes a rather frequent pathology and constituted 10% of the surgical acts of our service. Etiologies are diverse: congenital and acquired. Open surgery gives good results, but the introduction of innovative minimally invasive surgical technique is necessary.

Primary Tumors of the Upper Urinary Tract: Report of 4 Cases

Primary tumors of the upper urinary tract are rarely reported in the literature. We thus report here four cases of primary tumors of the upper urinary tract that were difficult to diagnose, in three women and one man. Preoperative diagnosis was established in only two cases requiring a nephro-ureterectomy. The other two cases were surprisingly diagnosed during anatomopatho- logical examination. Preoperative diagnosis was a pyonephrosis in one case and a renal failure resulting from stenosis of the pelvic ureter in the other. Despite modern methods, primary tumors of the upper urinary tract remain difficult to diagnose.

Lymphoepithelioma-like carcinoma of the upper urinary tract: A systematic review of case reports

BACKGROUND Lymphoepithelioma-like carcinomas(LELCs)are rare,malignant epithelial tumors,generally considered a subtype of squamous cell carcinoma.LELCs are undifferentiated and can occur in multiple tissues,although LELCs in the urinary tract are extremely rare.As such,evidence does not provide clinicians with guidelines for the best practices.Even though this is a rare disease,it is associated with high morbidity and mortality.Therefore,we must learn to differentiate LELC types and identify risk factors for early identification.AIM To develop an evidence base to guide clinicians treating primary LELCs of the upper urinary tract(UUT-LELC).METHODS We performed a systematic review of all reports on UUT-LELC from the first published case in 1998 until October 2019,according to the PRISMA.A database was then developed by extracting data from previously published reports in order to analyze interactions between clinical characteristics,pathological features,interventions and outcomes.Survival was analyzed using Kaplan–Meier estimates,which were compared using log rank tests.RESULTS A total of 28 previously published cases were identified for inclusion.The median age was 72 years with a male to female ratio of 4:3.Pure type LELCs were most common with 48.3%(n=14),followed by 37.9%(n=11)predominant LELCs and 3.4%(n=1)focal LELCs.Epstein-Barr virus testing was negative in all cases.Fourteen patients received radical nephroureterectomy(RNU)-based intervention.Twenty-three patients survived with no evidence of further metastasis,although six died before the median 18 mo follow-up point.Survival analysis suggests pure histological subtypes,and patients who receive complete tumor resection have more favorable prognoses.As always in cancer care,early identification generally increases the probability of interventional success.CONCLUSION The most effective treatment for UUT-LELC is RNU-based therapy.Since cases are few in number,case reporting must be enhanced and publishing encouraged to both save and prolong lives.

Multi-modality imaging review of congenital abnormalities of kidney and upper urinary tract

Congenital abnormalities of the kidney and urinary tract(CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis(bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number(agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography(US) is typically the first imaging performed as it is easily available, noninvasive and radiation free used both antenatally and postnatally. Computed tomography(CT) and magnetic resonance imaging(MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.

Risk factors of concurrent urinary sepsis in patients with diabetes mellitus comorbid with upper urinary tract calculi

BACKGROUND Urinary sepsis is frequently seen in patients with diabetes mellitus(DM)complicated with upper urinary tract calculi(UUTCs).Currently,the known risk factors of urinary sepsis are not uniform.AIM To analyze the risk factors of concurrent urinary sepsis in patients with DM complicated with UUTCs by logistic regression.METHODS We retrospectively analyzed 384 patients with DM complicated with UUTCs treated in People’s Hospital of Jincheng between February 2018 and May 2022.The patients were screened according to the inclusion and exclusion criteria,and 204 patients were enrolled.The patients were assigned to an occurrence group(n=78)and a nonoccurrence group(n=126).Logistic regression was adopted to analyze the risk factors for urinary sepsis,and a risk prediction model was established.RESULTS Gender,age,history of lumbago and abdominal pain,operation time,urine leukocytes(U-LEU)and urine glucose(U-GLU)were independent risk factors for patients with concurrent urinary sepsis(P<0.05).Risk score=0.794×gender+0.941×age+0.901×history of lumbago and abdominal pain-1.071×operation time+1.972×U-LEU+1.541×U-GLU.The occurrence group had notably higher risk scores than the nonoccurrence group(P<0.0001).The area under the curve of risk score for forecasting concurrent urinary sepsis in patients was 0.801,with specificity of 73.07%,sensitivity of 79.36%and Youden index of 52.44%.CONCLUSION Sex,age,history of lumbar and abdominal pain,operation time,ULEU and UGLU are independent risk factors for urogenic sepsis in diabetic patients with UUTC.

Beyond prostate, beyond surgery and beyond urology: The “3Bs” of managing non-neurogenic male lower urinary tract symptoms

Lower urinary tract symptoms(LUTS),consisting storage,voiding and postmicturition symptoms,is a comprehensive definition involving symptoms that may occur due to several causes.Instead of simply focusing on the enlarged prostate,more attention has to be paid to the entire urinary tract as well as multiple system comorbidities.Therefore,prostate surgery alone does not necessarily provide adequate management and cross-disciplinary collaborations are sometimes required.Based on current literature,this paper proposes the“3Bs”concept for managing non-neurogenic male LUTS,namely,“beyond prostate”,“beyond surgery”and“beyond urology”.The clinical application of the“3Bs”enables urologists to carry out integrated,individualized and precise medical care for each non-neurogenic male LUTS patient.

Who needs further evaluations to diagnose upper urinary tract urothelial cancers among patients with abnormal findings by enhanced CT?

Objective:We evaluated who would need further evaluations such as retrograde pyelography(RP)and/or ureteroscopy to diagnose upper urinary tract urothelial cancers(UUTUCs)when abnormal findings for the upper urinary tract(UUT)were detected by enhanced computed tomography(CT).Methods:We retrospectively analyzed 125 patients who underwent enhanced CT for various reasons and had abnormal findings for the UUT.Patients whose tumors were suspected to be of extraureteral origin were excluded.All patients received RP and/or ureteroscopy to evaluate the UUTUCs.Results:The median age of the 125 patients was 70 years and gross hematuria(26.4%)was the most frequently observed symptoms.RP,ureteroscopy and both were performed for 121,59 and 55 patients,respectively.CT revealed tumor-like lesions in 58 patients and the other patients had non-tumor-like lesions.UUTUCs were found in 43(34.4%)of the 125 patients.All of them had tumor-like lesions on CT.In 58 patients who had tumor-like lesions on CT,univariate and multivariate analyses revealed that tumor diameter and tumor enhancement were significant predictive factors for UUTUCs.ROC curve analysis of enhanced CT to diagnose UUTUCs revealed that a tumor diameter of 18 mm was the best cutoff point.The sensitivity,specificity and accuracy were 90.0%,98.8% and 92.7% for RP and 95.5%,100% and 97.1%for ureteroscopy,respectively.Both of them had high sensitivity,specificity and accuracy.Conclusion:We should decide to evaluate the UUT according to the tumor diameter on enhanced CT.When we evaluate the UUT in patients with tumor diameters of less than 20 mm,ureteroscopy is recommended.

Upper Urinary Tract Calculi in Senegal: A Comparative Study between Open Surgery and Endoscopy, a Review of 89 Cases

Objective: The aim was to assess the place of endourologic intervention in our practice and compare it to open surgery in the management of upper urinary tract calculi in Senegal. Patients and Methods: This was a retrospective study conducted at both the Principal and Grand Yoff Hospitals of Dakar from January 2009 to December 2013 in which 89 patients with upper urinary tract calculi were mobilized. All patients with symptomatic upper urinary tract colic symptoms were included. Results: Eighty-nine were followed up during the study period, 63 men and 36 women (sex of ratio 1.2). The average age was 44 years with extremes 22 - 75 years. Forty two patients, including 28 men and 14 women (sex ratio 1: 2) were treated with open surgery. The mean age was 42.75 years (4 - 75 years). The average duration of hospitalization after open surgery was 8 days (4 - 60 days). The mean stone size in open surgery was 23 mm (5 mm - 45 mm). Complications noted were: 2 cases of urinomas (4.76%), 1 case of lower back fistula (2.38%), 1 case of renal pelvis fistula (2.38%) and 1 case (2.38%) of infection. Forty seven patients including 35 men (55.6%) and 12 women (46.2%) were treated by endourology. The average length of hospital stay was 2 days (2 d - 3 d). The average stone size treated by endourology was 13 mm (5 mm - 40 mm). No complications were observed in this group. The cost of open surgery was a third of that of endourology. Conclusion: Endoscopic surgery, as is observed from industrialized countries occupies a prominent place in the treatment of upper urinary tract calculi in Senegal;however, the only limiting factor encountered is the cost which remains out of reach for patients and burdening the budgets of our hospitals with limited means.

Selection of staged or synchronous percutaneous nephrolithotomy for treatment of bilateral upper urinary tract calculi

Objective To evaluate the decision process to perform staged or synchronous bilateral percutaneous nephrolithotripsy ( PCNL) in the treatment of bilateral upper urinary tract calculi. Methods Patients with an indication for bilateral PCNL were enrolled in the study

Laparoscopic nephroureterectomy for upper tract urothelial carcinoma-Update

Upper urinary tract urothelial carcinomas(UTUCs)are uncommon and account for only 5%e10%of urothelial carcinomas.Pyelocaliceal tumors are about twice as common as ureteral tumors.Sixty percent of UTUCs are invasive at diagnosis.Radical nephroureterectomy,including the excision of the distal ureter and bladder cuff is standard of care for treatment of localized UTUCs,because of the high potential for recurrence,multifocality,and progression.Since first laparoscopic nephroureterectomy(LNU)was introduced by Clayman et al.in 1991 and improvement of laparoscopic technique and equipment,LNU has been reported to be equivalent to conventional open method.We reviewed the current literature of patients with UTUCs treated by LNU focusing on technical aspects,peri-operative and oncological outcomes.Laparoscopic radical nephroureterectomy offers the advantages of minimally invasive surgery without deteriorating the oncological outcome for treatment of UTUCs.Indications tend to increase as operator skills increase.Indications for laparoscopic or open nephroureterectomy are in principle the same.The basic requirement for laparoscopic surgery in UTUCs is to achieve benefits of minimal invasive surgery and maintain oncologic principles.

Non-invasive evaluation of lower urinary tract symptoms(LUTS)in men

Lower urinary tract symptoms(LUTS)are common in males over the age of 40 years old and are likely to increase with an aging population.Currently urodynamic studies are the gold standard to determine the aetiology of voiding dysfunction and LUTS.However,due to its invasive nature,a great number of non-invasive ultrasound based investigations have been developed to assess patients with symptomatic LUTS.The clinical application of noninvasive tests could potentially stratify patients who would require more invasive investigations and allow more precise patient directed treatment.A PubMed literature review was performed and we will discuss the non-invasive investigations that have been developed thus far,focusing on bladder wall and detrusor wall thickness(BWT&DWT),ultrasound estimated bladder weight(UEBW)and intravesical prostatic protrusion(IPP).

Obstructive uropathy: Overview of the pathogenesis, etiology and management of a prevalent cause of acute kidney injury

Obstructive uropathy is defined as the structural or functional interruption of urinary outflow at any level in the urinary tract.It is regarded as one of the most prevalent causes of acute kidney injury(AKI),accounting for 5%–10%of cases.Acute severe obstruction of the urinary tract is a potentially threatening situation for the kidneys and therefore requires prompt identification and management to relieve obstruction.The aim of the present article is to review and synthesize available evidence on obstructive uropathy,providing a clinical guideline for clinicians.A literature review on obstructive uropathy in the context of AKI was performed,focusing on the least clarified aspects regarding diagnosis and management.Recent literature searching was conducted in English and top-level evidence articles including systematic reviews,metanalyses and large series were prioritized.Acute obstruction of the urinary tract is a diagnostic and therapeutical challenge that may lead to important clinical complications together with direct structural and hemodynamic damage to the kidney.Early recognition of the leading cause and its exact location is essential to ensure prompt urinary drainage together with the most suitable drainage technique selection.A multidisciplinary approach,including urologists,nephrologists,and other medical specialties,is best suited to correctly manage concomitant hemodynamic changes,fluid and electrolyte imbalances,and other related issues.Obstructive uropathy is one of the leading causes of AKI.Recognition of patients suitable for early diversion and feasibility or adequate selection of the indicated technique is sometimes challeng-ing.A thorough understanding of the physiopathology behind the development of urinary obstruction is vital for correct diagnosis and management.

Renal papillary necrosis with urinary tract obstruction:A case report

BACKGROUND Renal papillary necrosis(RPN)is a rare disease.It is difficult to distinguish RPN with urinary tract obstruction from upper urinary tract occupying lesions.We reported a case of RPN and made a definite diagnosis largely based upon its endoscopic characteristics.CASE SUMMARY A 75-year-old woman presented with right flank pain,visible hematuria and a body temperature greater than 39℃.Laboratory investigations revealed leukocytosis with 12.7×10/L white blood cells and 93.6%neutrophils.Blood creatinine was 333 umol/L.Ultrasonography showed hydronephrosis of the right kidney and a right distal ureteric lesion.After urgent placement of right ureteral double J stent and treatment with antibiotics,the patient’s symptoms and the blood abnormalities improved rapidly.Computed tomography urography showed the presence of multiple occupying lesions in the right pelvis.The endoscopic ureteroscopy revealed that renal papillary necrosis and the subsequent migration of sloughed papillae into the upper ureter and calyces.The sloughed papillae appeared like“cottons”,which were whitish,soft,and irregularly-shaped without blood supply.In addition,the necrotic and sloughed renal papillae were removed by flexible ureteroscopy to prevent further obstruction.Pathological examination found that infarcted renal papillae were associated with inflammatory exudation.Three months after discharge,follow-up computed tomography urography showed no obvious lesions in the renal pelvis.CONCLUSION This case revealed the endoscopic features of RPN.In addition,flexible ureteroscopy proves to be vital in diagnosis and treatment of RPN.

Rare primary lymphoepithelioma-like carcinoma of the renal pelvis

Lymphoepithelioma-like carcinoma(LELC)is a rare,malignant epithelial tumour which can arise within the upper urinary tract.This letter adds to a previous systematic review and cumulative analysis of 28 published upper urinary tract-LELC cases which provided insight into this disease;however,the current evidence does not provide clinicians with clear guidelines due to its rarity.Therefore,the aim was to report a new case of renal pelvis LELC presented in our hospital.In this instance,we were able to report treatment experience and longterm follow-up results.This patient presented with hypertension and haemturia which initiated further investigation.While ultrasound identified an hypechoic mass,no malignant cells were detected using cytological testing.Abdominal magnetic resonance imaging identified a slightly enhanced mass in the left renal pelvis with no evidence of lymph node metastasis.Ureteroscopic tumor biopsy suggested the existence of urothelial carcinoma,hence,laparoscopic radical left nephroureterectomy with bladder cuff excision was performed.Through patientpractitioner consultations,we decided to adopt a"watch and wait"approach after radical nephroureterectomy rather than administering chemotherapy.Although,we would encourage clinicians to record and publish cases to garner insight into this type of malignant disease.

Management of BPH then 2000 and now 2016-From BPH to BPO

The diagnosis and treatment of benign prostatic obstruction(BPO)is based on a number of well-known lower urinary tract symptoms(LUTS)feared by all ageing males with functional testes.The ascent of modern urology turned this disease from lethal into an annoying but treatable health problem in the previous century.We are able to relieve the great majority of patients from their bothersome symptoms to a respectable quality of life by medication or removal of the obstructive part of the enlarged prostate.We can be proud of some progress made in the new millennium to reach a correct diagnosis and subsequent choice of treatment aiming for quality of life and cost-efficiency for public health.Still it remains symptomatic treatment and we expect the new generation of urologists to close some gaps in our knowledge on the regulation of prostatic growth to focus on prevention and elimination of the disease in the foreseeable future.

Magnetic resonance urography in the diagnosis of urinary tract obstruction after renal transplantation

OBJECTIVE: To evaluate magnetic resonance urography (MRU) in the diagnosis of urinary tract obstruction after renal transplantation. METHODS: A total of 31 patients with suspected urinary tract obstruction after renal transplantation were examined, and the results were compared with those from surgery and B-ultrasound examination. RESULTS: The urinary tract after renal transplantation was clearly shown using MRU, and all patients were clearly diagnosed by MRU. Imaging results were consistent with those from surgery. CONCLUSIONS: MRU is suitable for detecting urinary tract obstruction after renal transplantation. It is a alternative method for IVP and CT in patients with renal function impairment and uremia.