Biomedical subjects

Ahmed A Shokeir

Publications and source records attributed to Ahmed A Shokeir.

At least 19 recordsLinked to original sources

PubMed2007

Post-percutaneous nephrolithotomy extensive hemorrhage: a study of risk factors.

PURPOSE: We identified risk factors predicting severe bleeding due to percutaneous nephrolithotomy. MATERIALS AND METHODS: Computerized data on 2,909 patients who underwent a total of 3,878 percutaneous nephrolithotomy procedures between January 1995 and December 2005 were retrospectively reviewed. Data on patients who experienced severe bleeding requiring angiographic renal embolization were compared with those on other patients using univariate and multivariate analyses. We tested the characteristics of patients, kidneys and stones together with details of the operative procedure and surgeon experience. RESULTS: Severe bleeding complicated a total of 39 procedures (1%) in 25 males and 14 females with a mean age of 50.7 +/- 12.6 years. Associated morbidity included shock in 6 patients and perirenal hematoma in 4. Renal angiography revealed pseudoaneurysm in 20 patients, arteriovenous fistula in 9, the 2 lesions in 8 and arterial laceration in 2. Bleeding could be controlled with superselective embolization in 36 patients (92.3%). Followup was available on 33 patients (mean 21 +/- 15 months). Renal function was stable in all patients except 3 who had a post-embolization increase in serum creatinine, of whom all had a solitary kidney and none required renal replacement therapy. Significant risk factors for severe bleeding were upper caliceal puncture, solitary kidney, staghorn stone, multiple punctures and inexperienced surgeon. CONCLUSIONS: Percutaneous nephrolithotomy should be performed by an experienced endourologist in patients at risk for severe bleeding, such as those with a solitary kidney or staghorn stones.

Adult↗

PubMed2006

Outcome of percutaneous nephrolithotomy: effect of body mass index.

OBJECTIVE: The surgical management of renal and upper ureteral calculi presents unique challenges in obese patients. We reviewed our recent experience with percutaneous nephrolithotomy (PNL) in obese patients to determine the safety and outcome of this procedure in such group of patients. PATIENTS AND METHODS: The surgical records of 1121 patients treated with PNL between 2000 and 2004 were reviewed. Patients were stratified into four groups according to the World Health Organization classification of body mass index (BMI): <25 (average), 25-29.9 (overweight), 30-39.9 (obese), and >40 kg/m(2) (morbidly obese). The outcomes of PNL in these four groups were compared. RESULTS: A total of 1287 procedures were performed on 1155 renal units (1.1 procedures per renal unit). The overall stone-free rate was 85.1% and the mean hospital stay was 3.3+/-2.6 d. Major complications were seen in 72 patients (6.4%). No statistically significant differences were found in decrease in haemoglobin concentration, hospital stay, and complication rate among the four study groups. The need for auxiliary procedures and stone-free rates were comparable. CONCLUSIONS: PNL in obese and morbidly obese patients yields a stone-free rate that is comparable to that achieved in nonobese patients. The complication rate and length of hospital stay are also similar.

Adolescent↗

PubMed2006

Eosinophilic cystitis simulating invasive bladder cancer: a real diagnostic challenge.

OBJECTIVES: To report our experience with eosinophilic cystitis (EC) presented as invasive bladder cancer. MATERIALS AND METHODS: We recently treated three patients with bladder masses mimicking neoplasms and biopsy proved the diagnosis of EC. Data from our three patients were presented. RESULTS: There were two females and one male with ages of 14, 43 and 38 years. All the three patients had irritative bladder symptoms, suprapubic pain and hematuria. Bladder mass was detected by pelvic examination in the three patients and confirmed by radiologic tests and cystoscopy. In one patient, the mass caused bilateral hydroureteronephrosis while the upper tract was normal in the other two. Elevated serum leukocytes was evident in the three cases while peripheral eosinophilia was observed in one. Biopsy showed EC in all the three patients who were treated by transurethral resection of the lesions followed by a combination of corticosteroids, antibiotics and antihistaminics. All patients experienced marked improvement during a follow-up duration up to 30 months. CONCLUSION: EC is a rare disease. In addition to symptoms of frequency, dysuria, hematuria and suprapubic pain, the disease may present with a bladder mass mimicking invasive bladder cancer. Resection of the lesion is mandatory with systemic treatment of corticosteroids, antihistaminics and antibiotics. Early detection and prompt treatment usually result in a good prognosis.

Adolescent↗

PubMed2006

Pediatric live-donor kidney transplantation in Mansoura Urology & Nephrology Center: a 28-year perspective.

Our objective was to evaluate our overall experience in pediatric renal transplantation. Between March 1976 and March 2004, 1,600 live-donor kidney transplantations were carried out in our center; 216 of the patients were 18 years old or younger (mean age 12.9 years). There were 136 male patients and 80 female patients. The commonest causes of end-stage renal disease (ESRD) were renal dysplasia (22%), nephrotic syndrome (20%), hereditary nephritis (16%), and obstructive uropathy (16%). Of the donors, 94% were one-haplotype matched and the rest were identical. Pre-emptive transplantation was performed in 51 (23%) patients. Triple-therapy immunosuppression (prednisone + cyclosporine + azathioprine) was used in 78.2% of transplants. Rejection-free recipients constituted 47.7%. Hypertension (62%) was the commonest complication. A substantial proportion of patients (48%) were short, with height standard deviation score (SDS) less than -1.88. The overall infection rate was high, and the majority (53%) of infections were bacterial. The graft survival at 1 year, 5 years and 10 years were 93.4%, 73.3% and 48.2%, respectively, while the patients' survival at 1, 5 and 10 years were 97.6%, 87.8% and 75.3%, respectively. Despite long-term success results of pediatric renal transplantation in a developing country, there is a risk of significant morbidity.

Adolescent↗

PubMed2006

Colonic perforation during percutaneous nephrolithotomy: study of risk factors.

OBJECTIVES: To identify the risk factors implicated in colonic perforation during percutaneous nephrolithotomy. METHODS: From 1985 to 2004, 5039 percutaneous nephrolithotomy procedures were performed in our center. Colonic perforation complicated 15 procedures (0.3%). The patient files were retrospectively reviewed for detection of preoperative risk factors as shown by multivariate statistical analysis. The operative details and postoperative course were also studied to determine the time and mode of diagnosis of colonic injury and treatment strategies and outcome. RESULTS: All injuries were retroperitoneal. The mean patient age was 57 +/- 8.4 years. Of the 15 patients, 11 were men and 4 were women. The left side was affected in 10 patients (66.6%). The right side was injured only in those with horseshoe kidneys or with recurrent disease. Colonic perforation complicated lower caliceal puncture in 12 procedures (80%) and complicated upper caliceal punctures in those with horseshoe kidneys or chronic colonic distension. Significant independent risk factors were advanced patient age and the presence of a horseshoe kidney. The diagnosis was established intraoperatively in 5 patients and postoperatively in 10, 5 of whom presented with colocutaneous fistula. The diagnosis was confirmed with abdominal computed tomography or opacification of the colon during antegrade or retrograde pyelography. Conservative treatment was successful in all but 2 patients who required colostomy. CONCLUSIONS: Significant independent risk factors for colonic perforation during percutaneous nephrolithotomy were advanced patient age and the presence of a horseshoe kidney. Early diagnosis and proper treatment represent the key to minimizing patient morbidity and avoiding serious complications.

Adult↗

PubMed2006

Prognostic factors of success of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal stones.

OBJECTIVES: To evaluate the factors that affect the success rate of extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stones. PATIENTS AND METHODS: Between January 2000 and December 2003, 427 patients with single or multiple renal stones (< 30 mm, largest diameter) underwent ESWL monotherapy using Storz SL 20 lithotriptor. The results of treatment were evaluated after 3 months of follow-up. Treatment success was defined as complete clearance of the stones or presence of clinically insignificant residual fragments < 4 mm. The success rate was correlated with the characteristics of the patients, conditions of the urinary tract and stone features. RESULTS: At 3-month follow-up, the overall success rate was 333/427 (78%). Repeat treatment was needed in 226 patients (53.1%). Post-ESWL auxiliary procedures were required in 36 patients (8.4%). Post-ESWL complications were recorded in 16 patients (3.7%). Of the 10 prognostic factors studied, 5 had a significant impact on the success rate, namely: renal morphology, congenital anomalies, stone size, stone site and number of treated stones. Other factors including age, sex, nationality, stone nature (de novo or recurrent) and ureteric stenting had no significant impact on the success rate. CONCLUSIONS: The success rate of ESWL for the treatment of renal stones could be predicted by stone size, location and number, radiological renal features and congenital renal anomalies.

Adolescent↗

PubMed2006

Treatment of renal stones in children: a comparison between percutaneous nephrolithotomy and shock wave lithotripsy.

PURPOSE: We compared the results of percutaneous nephrolithotomy and shock wave lithotripsy for the treatment of 1 to 2 cm renal stones in children. MATERIALS AND METHODS: The study included 166 children with renal stones 1 to 2 cm. A total of 75 patients (82 kidneys) were treated with percutaneous nephrolithotomy and 91 (93 kidneys) were treated with shock wave lithotripsy. Mean followup was 31 +/- 10 months (range 6 to 84). Both groups were compared regarding stone-free rate, re-treatment rate, complications and incidence of stone recurrence. RESULTS: Both groups were comparable regarding preoperative characteristics. Of the units treated with percutaneous nephrolithotomy 4 (4.9%) were associated with minor complications. Stone-free rate after a single session of percutaneous nephrolithotomy was 86.6% (71 units), and the remaining 11 kidneys with residual stones were successfully treated with repeat percutaneous nephrolithotomy in 7 and shock wave lithotripsy in 4. Therefore, a total of 78 units (95%) were stone-free after percutaneous nephrolithotomy monotherapy, and the overall stone-free rate at 3 months was 100%. Of the patients undergoing shock wave lithotripsy 1 (1.1%) had development of steinstrasse and was successfully treated with ureteroscopy. The overall re-treatment rate after shock wave lithotripsy was 55%. A total of 79 units (84.9%) were stone-free after shock wave lithotripsy monotherapy, whereas 7 (7.5%) with no gross response to treatment were treated with percutaneous nephrolithotomy and 7 with insignificant stones less than 4 mm were followed. Therefore, the overall stone-free rate at 3 months was 92.5%. The differences in stone-free rates and re-treatment rates significantly favored percutaneous nephrolithotomy, while the incidence of complications and stone recurrence at last followup were not significantly different between the groups. CONCLUSIONS: For treatment of 1 to 2 cm renal stones in children percutaneous nephrolithotomy is better than shock wave lithotripsy, yielding higher stone-free and lower re-treatment rates.

Adolescent↗

PubMed2006

Iatrogenic infections in urological practice: concepts of pathogenesis, prevention and management.

In this paper we review the pathogenesis, prevention and management of iatrogenic infection in urological practice. A systematic literature search was conducted using MEDLINE. The topics discussed include the commonest home-care, outpatient, endourologic and open surgical procedures. In addition, we discuss iatrogenic urinary infections associated with special situations, including urinary diversion, urologic prostheses, diabetes mellitus, dialysis, kidney transplantation and complicated urinary tract infections (UTIs). The findings of the literature review are as follows. Prophylactic antibiotics are not recommended with clean intermittent catheterization. With prolonged catheterization, antibiotics should not be used unless symptoms of pyelonephritis or septicemia become apparent. With transrectal prostate biopsy, infection can be prevented by rectal cleansing, use of smaller needles and administration of antimicrobial prophylaxis before and after the procedure. With ureteral stents, antibiotics should be restricted to patients with clinical signs of infection and high-risk patients. Infections after transurethral resection of the prostate can be prevented by avoiding risk factors and using perioperative antibiotics. In endourological procedures, antibiotic prophylaxis is indicated in cases of infected stones, preoperative UTIs or prolonged procedures. Antibiotics are not recommended for clean wounds, as prophylaxis for clean-contaminated wounds or as therapy for contaminated and dirty wounds. In patients with urinary diversion, the objective is to prevent pyelonephritis by avoiding both reflux and obstruction of the upper urinary tract. In patients with urological prostheses, the most important measure to overcome iatrogenic infection is prevention. In dialysis patients, iatrogenic infections can be prevented by the development of new catheter materials that are less susceptible to biofilms. In kidney transplant recipients, iatrogenic infections can be prevented by treating all types of infection prior to transplantation and by using peri- and postoperative prophylactic antibiotics.

Communicable Disease Control↗

PubMed2006

Noninvasive treatment of benign prostatic hyperplasia. Where do we stand in 2005.

Noninvasive treatment of lower urinary tract symptoms LUTS due to benign prostatic hyperplasia BPH includes self-management and medical treatment. Self-management should be encouraged as an initial step for all men with uncomplicated LUTS/BPH. It consists of 3 elements, namely: education and reassurance, lifestyle modification of fluid intake and concurrent medical therapy and finally behavioral interventions including management of post-void dribbling and bladder retraining. If self-management fails, medical or surgical interventions are required. Further, research is required to define and test the effectiveness of self-management either as a primary intervention or to augment existing medical therapies. Benign prostatic hyperplasia patients in need of rapid onset of symptom relief and those with small prostates benefit from the use of alpha-blockers. Although 5-alpha-reductase inhibitors 5 ARIs provide symptomatic benefits, the onsets of these are slower than those observed with the alpha-blockers. Amongst available therapies, only 5 ARIs have been shown to reduce the risk of acute urine retention AUR and BPH-related surgery compared to placebo. The Medical Therapy of Prostatic Symptoms MTOPS Study provides rational basis for combined alpha-blockers plus 5 ARIs in patients with a high index of disease progression prostate volume >30 g and prostate-specific antigen >1.6 ng/ml. Preliminary studies suggest that anticholinergics could be safe in LUTS/BPH and can help to alleviate irritative bladder symptoms due to overactive bladders commonly associated with BPH.

Adrenergic alpha-Antagonists↗

PubMed2005

Routine insertion of ureteral stent in live-donor renal transplantation: is it worthwhile?

OBJECTIVES: To evaluate the impact of the routine use of double-J stents in live-donor renal transplantation at a single institute from a prospective randomized study. METHODS: A total of 100 patients were prospectively randomized into two groups of 50 patients each. Group 1 received a routine double-J silicone ureteral stent and group 2 did not. A standard Lich-Gregoir ureteroneocystostomy was performed in both groups. In group 1, the patients were scheduled for stent removal after 2 weeks. RESULTS: Both groups were comparable in terms of age, sex, ischemia time, number of renal arteries, and time to diuresis. In group 1, two grafts were lost in the early postoperative period and those patients were excluded from the final analysis. None of our patients in either group had developed a ureteral stricture at a mean follow-up of 10.8 +/- 3.6 months. In the stented group, 2 patients developed a urinary leak, but no leakage was reported in the nonstented group (P = 0.14). Although 19 patients in group 1 (39.6%) had a urinary tract infection, only 9 in group 2 (18%) showed evidence of a positive urine culture (P = 0.02). The presence of a ureteral stent and female sex were the independent predictors of postoperative urinary tract infection on multivariate analysis. The mean serum creatinine at discharge was 1.2 +/- 0.3 mg% and 1.2 +/- 0.4 mg% in groups 1 and 2, respectively (P = 0.2). CONCLUSIONS: The results of our study have shown that routine ureteral stent insertion has no impact on the rate of vesicoureteral leakage or obstruction in live-donor renal transplantation, whereas it is significantly associated with an increased incidence of urinary tract infection. Stenting should be limited to patients with a pathologic and/or defunctionalized bladder.

Adult↗

PubMed2005

Postnatal unilateral pelviureteral junction obstruction: impact of pyeloplasty and conservative management on renal function.

OBJECTIVES: To study the effect of pyeloplasty and conservative management on renal function in children with pelviureteral junction obstruction. METHODS: This prospective study included 65 children postnatally diagnosed with unilateral pelviureteral junction obstruction. On the basis of the patients' symptoms and technetium-99m diethylenetriamine pentaacetic acid renal isotope scan findings, symptomatic patients or those with split function of the corresponding kidney of 40% or less were assigned to group 1 (n = 35) and underwent pyeloplasty. Asymptomatic patients with split function greater than 40% (group 2, n = 30) were treated conservatively. Patients who showed deterioration of renal function underwent pyeloplasty. The effect of both lines of treatment on renal function was evaluated. RESULTS: After pyeloplasty, group 1 had improvement in the glomerular filtration rate (GFR) in 30 (85.7%), stabilization in 2 (5.7%), and deterioration in 3 (8.6%) patients. In group 1, the comparison between the mean value of the baseline GFR (17.1 +/- 7.7 mL/min) and its mean value at follow-up (28 +/- 6.3 mL/min) showed an increase of statistical significance (P <0.01). In the group 2 patients, conservative treatment resulted in improvement in the GFR in 12 (40%), stabilization in 3 (10%), and deterioration in 15 (50%) patients. In group 2, no significant difference was found between the mean baseline GFR (29.8 +/- 9.8 mL/min) and its mean value at follow-up (31.2 +/- 5.6 mL/min). CONCLUSIONS: In patients with postnatal pelviureteral junction obstruction, early pyeloplasty is recommended if the corresponding GFR is 40% or less. Conservative management in patients with better function resulted in deterioration of renal function in 50%. Should this policy of treatment be chosen, meticulous follow-up is mandatory.

Child↗

PubMed2005

Extracorporeal shock wave lithotripsy monotherapy for treatment of patients with urethral and bladder stones presenting with acute urinary retention.

OBJECTIVES: To present our experience with extracorporeal shock wave lithotripsy (ESWL) monotherapy for the treatment of patients with urethral and bladder stones presenting with acute urinary retention. METHODS: A total of 64 patients (62 male and 2 female) with urethral or bladder stones underwent ESWL monotherapy. All patients presented to the emergency department with acute urinary retention. The mean patient age was 40 +/- 13.2 years (range 11 to 74). The exclusion criteria were urethral strictures, associated bladder growths detected by pelvic ultrasonography, and bladder stones larger than 25 mm in the largest diameter. After fixation of a Foley catheter, ESWL monotherapy was performed with a Storz SL 20 lithotriptor. The catheter was removed after confirmation of stone fragmentation. RESULTS: Fine fragmentation was obtained and uncomplicated spontaneous evacuation occurred without the need for adjuvant procedures in 60 patients. Four patients developed acute urinary retention due to urethral stone impaction. In 3 patients, the urethral catheter was successfully refixed, and an additional session of ESWL resulted in fine fragmentation of the stones, with spontaneous evacuation after catheter removal. In the remaining patient, the stone could not be pushed into the bladder and crushing was performed endoscopically. CONCLUSIONS: ESWL monotherapy is safe and effective for the treatment of urethral and bladder stones in patients with no other causes of infravesical obstruction.

Acute Disease↗

PubMed2005

Treatment of complete staghorn stones: a prospective randomized comparison of open surgery versus percutaneous nephrolithotomy.

PURPOSE: We studied the role of open surgery versus percutaneous nephrolithotomy (PCNL) in the treatment of complete staghorn stones in a prospective randomized manner. MATERIALS AND METHODS: A total of 79 patients with 88 complete staghorn stones, defined as filling the entire collecting system or at least 80% of it, were prospectively randomized for PCNL (43) or open surgery (45). Intraoperative and postoperative morbidity, operative time, hospital stay, and stone clearance at discharge home and followup were compared for both methods. Patients with significant residuals in both groups were subjected to extracorporeal shock wave lithotripsy (Dornier Medical Systems, Inc., Marietta, Georgia) on an outpatient basis. Followup was completed for all cases with a mean duration +/- SD of 4.9 +/- 2.5 months (range 3 to 14). Renal function was evaluated by Tc-mercaptoacetyltriglycine renogram before and after treatment in both groups. RESULTS: Intraoperative complications in terms of bleeding requiring blood transfusion, and pleural, vascular or ureteral injuries were recorded in 7 patients (16.3%) in the PCNL and 17 (37.8%) in the open surgery groups, a difference of significant value (p <0.05). Major postoperative complications including massive hematuria requiring blood transfusion, septicemia, urinary leakage and wound infection were observed in 8 patients (18.6%) in the PCNL group and in 14 (31.1%) in the open surgery group, a difference of no significant value. PCNL was associated with shorter operative time (127 +/- 30 vs 204 +/- 31 minutes, p <0.001), shorter hospital stay (6.4 +/- 4.2 vs 10 +/- 4.2 days, p <0.001) and earlier return to work (2.5 +/- 0.8 vs 4.1 +/- 1 weeks, p <0.001). On the other hand both treatment groups were comparable in regard to stone-free rates at discharge home (49% vs 66%) and at followup (74% vs 82%). At followup renal function improved or remained stable in 91% and 86.7% in the PCNL and open surgery groups, respectively. CONCLUSIONS: PCNL is a valuable treatment option for complete staghorn stones with a stone-free rate approaching that of open surgery. Moreover, it has the advantages of lower morbidity, shorter operative time, shorter hospital stay and earlier return to work.

Adult↗

PubMed2005

Surgical complications in live-donor pediatric and adolescent renal transplantation: study of risk factors.

UNLABELLED: To report the surgical complications among our pediatric and adolescent renal transplants and to analyze the different factors that may influence the occurrence of such complications. METHODS: A total of 250 pediatric and adolescent renal transplants were included in this study. Of these patients, there were 154 boys and 96 girls with a mean age of 15.4+/-3.7 yr (range 5-20 yr). All patients received their kidneys from living donors. Four patients underwent renal retransplantation. Surgical complications were reported and their incidence was correlated with several pretransplant, technical and post-transplant risk factors by both univariate and multivariate analyses. The impact of surgical complications on graft and patient survival was computed using the Kaplan-Meier technique. RESULTS: Among the 250 patients, 35 surgical complications were encountered in 33 patients. These complications included urinary leakage in 10 patients, ureteric stricture in 11 patients, complicated lymphocele in eight patients, hematoma necessitating surgical exploration in two patients, wound dehiscence in one patient, stone of the graft ureter in one patient and renal artery stenosis in two patients. The incidence of urological complications (ureteral stenosis, urinary leakage and stone disease) was 8.8% and vascular complications 0.8%. Small ureteric leakage (four patients) was treated by endourologic techniques, whereas leaks associated with ureteral necrosis required open revision. Endourologic treatment was attempted in early and mild cases of ureteric obstruction. In late and severe cases, surgery was performed. On univariate analysis, the factors that significantly affected the incidence of surgical complications were recipient's age, lower urinary tract abnormalities, the type of primary urinary recontinuity, the time to diuresis, and height and weight of the patients. On multivariate analysis, the type of primary urinary continuity was the only factor that sustained statistical significance. Neither patient nor graft survival was affected by the occurrence of surgical complications. CONCLUSION: Primary urinary continuity is the only risk factor that affects the incidence of surgical complications among pediatric and adolescent live donor renal transplants, with the extravesical technique of Lich-Gregoir providing the best results. Surgical complications in pediatric and adolescent renal transplantation can be minimized if basic principles of careful transplant techniques are used. Prompt identification and treatment of any complication is paramount to graft and patient survival.

Adolescent↗

PubMed2005

Determinants of graft survival in pediatric and adolescent live donor kidney transplant recipients: a single center experience.

To study the independent determinants of graft survival among pediatric and adolescent live donor kidney transplant recipients. Between March 1976 and March 2004, 1600 live donor kidney transplants were carried out in our center. Of them 284 were 20 yr old or younger (mean age 13.1 yr, ranging from 5 to 20 yr). Evaluation of the possible variables that may affect graft survival were carried out using univariate and multivariate analyses. Studied factors included age, gender, relation between donor and recipient, original kidney disease, ABO blood group, pretransplant blood transfusion, human leukocyte antigen (HLA) matching, pretransplant dialysis, height standard deviation score (SDS), pretransplant hypertension, cold ischemia time, number of renal arteries, ureteral anastomosis, time to diuresis, time of transplantation, occurrence of acute tubular necrosis (ATN), primary and secondary immunosuppression, total dose of steroids in the first 3 months, development of acute rejection and post-transplant hypertension. Using univariate analysis, the significant predictors for graft survival were HLA matching, type of primary urinary recontinuity, time to diuresis, ATN, acute rejection and post-transplant hypertension. The multivariate analysis restricted the significance to acute rejection and post-transplant hypertension. The independent determinants of graft survival in live-donor pediatric and adolescent renal transplant recipients are acute rejection and post-transplant hypertension.

Adolescent↗

PubMed2005

Magnetic resonance imaging as a sole method for the morphological and functional evaluation of live kidney donors.

OBJECTIVE: To evaluate gadolinium-enhanced dynamic magnetic resonance imaging (MRI) as the sole method for the anatomical and functional assessment of potential live-kidney donors. SUBJECTS AND METHODS: The study included 50 consecutive kidney donors; in addition to routine donor evaluation, the kidney was imaged with Gd-enhanced dynamic MRI, which was also used for selectively determining the glomerular filtration rate (GFR) of each kidney. All donors had a m99Tc-mercaptoacetyltriglycine (MAG3) renal scan as the reference standard to measure GFR. The anatomical results of MRI were compared with the findings at donor nephrectomy, and the GFR estimated from MRI compared with that from MAG3 scintigraphy. RESULTS: MR angiography had 100% sensitivity, 94% specificity and 96% overall accuracy for detecting the number of renal arteries, and 100% sensitivity, 98% specificity and 98% overall accuracy for the number of renal veins. There was a close correlation (r = 0.54, P < 0.01) between the GFR of each kidney estimated by MRI or MAG3. For the right and left kidneys the mean isotope clearance was not significantly different from that of mean MRI clearance. MR urography allowed visualization of the urinary tract and the detection of any abnormality. CONCLUSION: Gd-enhanced dynamic MRI can provide accurate information about the anatomy of the urinary tract and vasculature of the kidney, and can be used to accurately estimate the selective GFR of each kidney. Therefore, we recommend MRI as a single imaging diagnostic method for assessing potential live kidney donors.

Adult↗

PubMed2004

Diagnosis of noncalcareous hydronephrosis: role of magnetic resonance urography and noncontrast computed tomography.

OBJECTIVES: To evaluate the role of magnetic resonance urography (MRU) and noncontrast computed tomography (NCCT) in the diagnosis of noncalcareous hydronephrosis when excretory urography (intravenous urography) is either contraindicated or inconclusive. METHODS: A total 108 consecutive patients with noncalcareous hydronephrosis were included in this study. In all patients, intravenous urography was either contraindicated or could not determine the diagnosis. In all patients, calculus obstruction was excluded by NCCT and all underwent heavily T2-weighted MRU. The final definitive diagnosis was established by retrograde or antegrade ureterography, endoscopy, or open surgery and was considered the reference standard for the diagnosis of obstruction. Normal kidneys in patients with unilateral obstruction were considered the reference standard for the absence of obstruction. The results of MRU were compared with those of NCCT regarding sensitivity, specificity, and overall accuracy. RESULTS: Of the 108 patients, 5 had bilateral obstruction and the remaining 103 had unilateral obstruction. Of the latter group, 5 had a solitary kidney; therefore, the total number of renal units was 211 (113 obstructed and 98 normal units). Ureteral strictures were identified by NCCT in 15 (28%) of 54 and by MRU in 45 (83%) of 54 patients. Bladder, ureter, or prostate tumors causing ureteral obstruction could be diagnosed in one half of the 54 patients with such tumors by NCCT (27 of 54) and in all but 2 patients by MRU (52 of 54). Both NCCT and MRU could identify all extraurinary causes of obstruction. Overall, of the 113 kidneys with noncalculus obstruction, the cause could be identified by MRU in 102 (sensitivity of 90%) and by NCCT in 47 (sensitivity of 42%), a difference of statistically significant value in favor of MRU (P <0.001). The specificity of T2-weighted MRU and NCCT was 100% and 99%, respectively (not a statistically significant difference). The overall accuracy of T2-weighted MRU and NCCT was 95% and 68%, respectively (P <0.001). CONCLUSIONS: In patients with ureteral obstruction in whom intravenous urography is not helpful and after NCCT has excluded stone disease, heavily T2-weighted MRU is a sensitive and specific method in the identification of the cause of obstruction.

Adult↗

PubMed2004

Percutaneous nephrolithotomy in treatment of large stones within horseshoe kidneys.

OBJECTIVES: To present our experience with percutaneous nephrolithotomy (PCNL) in the treatment of large stones within horseshoe kidneys. METHODS: The study included 34 patients with 45 stone-bearing horseshoe kidneys treated by PCNL in one center. The indications for PCNL were large stone burden (greater than 2 cm) in 10 kidneys (22.2%), multiple complex stones in 22 (48.9%), staghorn stones in 3 (6.7%), and failed extracorporeal shock wave lithotripsy (ESWL) in 10 kidneys (22.2%). All PCNL procedures were performed in a standard one-session technique with fluoroscopic guidance. Procedures were evaluated for intraoperative and postoperative complications, use of auxiliary procedures (second-look PCNL, ureteroscopy, and ESWL), and length of hospital stay. Moreover, the stone-free rate was calculated at discharge from the hospital and 3 months later. In addition, we assessed the need for secondary intervention during a mean follow-up of 75 +/- 16 months (range 6 to 108). RESULTS: The stone burden ranged from 264 to 2408 mm(2) (mean 664 +/- 153). Access to the horseshoe kidneys was supracostal in 10 (22.2%) and subcostal in 35 kidneys (77.8%). A single tract was used in 37 (82%), and two tracts were created in the remaining 8 kidneys (18%). Major complications were seen in six PCNL procedures (13.3%) and included significant hematuria requiring blood transfusion in three, septicemia in one, ureteral obstruction in one, and colonic injury in one. All complications were successfully treated. Auxiliary procedures were required in 12 patients (35.3%) and included ureteroscopy in 1, second-look PCNL in 3, and ESWL to fragment residual caliceal stones in 8 patients. The mean hospital stay was 4 +/- 1.9 days (range 3 to 12). The stone-free rate was 82% at discharge and 89% at 3 months. During the course of follow-up, 19 patients (56%) developed stone recurrence and were successfully treated with ESWL in 8 and PCNL in 11. CONCLUSIONS: PCNL is a safe and effective procedure in the treatment of large stones within horseshoe kidneys.

Adolescent↗