Ahmed M. Harraz

Tissue engineering and stem cells: Basic principles and applications in urology

To overcome problems of damaged urinary tract tissues and complications of current procedures, tissue engineering (TE) techniques and stem cell (SC) research have achieved great progress. Although diversity of techniques is used, urologists should know the basics. We carried out a literature review regarding the basic principles and applications of TE and SC technologies in the genitourinary tract. We carried out MEDLINE/PubMed searches for English articles until March 2010 using a combination of the following keywords: bladder, erectile dysfunction, kidney, prostate, Peyronies disease, stem cells, stress urinary incontinence, testis, tissue engineering, ureter, urethra and urinary tract. Retrieved abstracts were checked, and full versions of relevant articles were obtained. Scientists have achieved great advances in basic science research. This is obvious by the tremendous increase in the number of publications. We divided this review in two topics; the first discusses basic science principles of TE and SC, whereas the second part delineates current clinical applications and advances in urological literature. TE and SC applications represent an alternative resource for treating complicated urological diseases. Despite the paucity of clinical trials, the promising results of animal models and continuous work represents the hope of treating various urological disorders with this technology.

Risk factors of hospital readmission after radical cystectomy and urinary diversion: analysis of a large contemporary series

To determine the incidence, risk factors and causes of hospital readmission in a large series of patients who underwent radical cystectomy (RC) and urinary diversion.

Toward a Standardized System for Reporting Surgical Outcome of Pediatric and Adolescent Live Donor Renal Allotransplantation

PURPOSE There is a lack of a standardized reporting methodology for surgical complications of pediatric renal transplantation. We applied Martin criteria and the modified Clavien-Dindo classification in pediatric renal transplantation. MATERIALS AND METHODS We retrospectively reviewed the charts of 447 patients 20 years or younger who underwent renal transplantation between March 1976 and January 2011. Martin criteria were fulfilled and complications were graded according to the modified Clavien-Dindo classification. For early complications grades I and II were considered low grade and III to V high grade. A similar grading system was adopted for late complications. RESULTS A total of 84 early complications (18.5%) occurred in 77 transplant recipients (17%). Of grade I complications 37 (8.1%) were asymptomatic lymphoceles. Grade II complications were observed in 2 patients (0.4%). Grade IIIa complications included aspiration of hematoma (1 case), percutaneous nephrostomy fixed for ureteral obstruction (3), percutaneous tube drain for symptomatic lymphoceles (7) and antegrade ureteral stenting for ureteral leakage (6). Grade IIIb complications included exploration for wound dehiscence (1 case), revision of ureterovesical anastomosis (8), marsupialization of lymphoceles (4), hemorrhage (3) and vascular thrombotic accidents (6). Graft nephrectomy (grade IVa) complications occurred in 2 transplant recipients. Among 4 mortalities (grade V) only 1 patient died due to surgical complications. On multivariate analysis delayed graft function was the only predicator of high grade surgical complications (p = 0.005). High grade surgical complications affected recipient but not graft survival. CONCLUSIONS Using a standardized, high quality reporting methodology is feasible in pediatric renal transplantation. However, consensus should be sought regarding medical complications and a grading system should be developed for reporting of late complications.

Changes in Differential Renal Function after Pyeloplasty in Children

PURPOSE Previous series showed controversial differential renal function outcomes after pyeloplasty in children. However, they were limited by study power, methodology and lack of comparable end points. We determined the status of differential renal function after pyeloplasty in children in what is to our knowledge the largest series to date. MATERIALS AND METHODS After excluding patients with renal anomalies, solitary kidney or bilateral pyeloplasty from analysis, we retrospectively identified 196 younger than 18 years who were treated with pyeloplasty between May 2002 and January 2010 and had preoperative and postoperative renal scintigraphy available. Primary outcome measures were greater than 5% improvement in baseline differential renal function and baseline weighted differential renal function at last followup. Clinical variables predicting outcome measures were determined using univariable and multivariable analyses. RESULTS During a median followup of 12 months, mean ± SD differential renal function improved from 35.8% ± 10% to 38.7% ± 11% (p <0.001). In the poor and intermediate groups baseline differential renal function improved, while in the good group function was static postoperatively (p <0.001). The linear regression model showed that only baseline differential renal function explained the variance in baseline weighted differential renal function (β = -0.393, p <0.001). In the Cox proportional hazards model baseline differential renal function (less than 35% HR 3.196, p <0.001 and 35% to 40% HR 2.733, p = 0.002) and cortical thickness (HR 2.114, p = 0.029) were the only predictors of a greater than 5% improvement in postoperative differential renal function. CONCLUSIONS Renal function improves after pyeloplasty in children. Baseline differential renal function and cortical thickness predict improvement after surgery.

Sildenafil citrate as a medical expulsive therapy for distal ureteric stones: A randomised double-blind placebo-controlled study.

Abstract Objective: To study the effect of sildenafil citrate on spontaneous passage of distal ureteric stones (DUS). Patients and methods: This was a randomised double-blinded placebo-controlled study of 100 patients with DUS. Inclusion criteria were: male, age 18–65 years, normal renal function, and a single radiopaque unilateral DUS of 5–10 mm. Patients were randomly allocated into two equal groups, one that received placebo and the other that received 50 mg sildenafil citrate once daily. Both investigators and patients were masked to the type of treatment. Patients self-administered the medication until spontaneous passage of the DUS. In patients where there was uncontrolled pain, fever, an increase in serum creatinine of >1.8 mg/dL, progressive hydronephrosis or no further progress after 4 weeks, a decision was taken for further treatment. Results: In all, 47 and 49 patients were available for analysis in both the placebo and sildenafil citrate groups; respectively. Both groups were comparable for age and stone characteristics. Spontaneous expulsion occurred in 19 of 47 patients (40.4%) in the placebo group and in 33 of 49 (67.3%) in the sildenafil citrate group (P = 0.014). The mean time to stone expulsion was significantly shorter in the sildenafil citrate group (P < 0.001). A multivariable Cox proportional hazards model showed that receiving sildenafil citrate was the only independent factor that had a significant impact on stone passage with a hazard ratio of 2.7 (95% confidence interval 1.5–4.8; P < 0.001). Conclusion: Sildenafil citrate enhances spontaneous passage of 5–10 mm DUS.

Renal function evaluation in patients undergoing orthotopic bladder substitution: a systematic review of literature.

Renal function (RFn) after orthotopic bladder substitution (OBS) is a critical point to be assessed. We performed a systematic review of MEDLINE for full length peer reviewed English articles from the year 2000 till January 2013. We included only original articles and excluded reviews, editorials and replies and abstracts presented in conferences. The outcome is formulated in research questions; what is the status of RFn after OBS? Which is better, the direct free‐refluxing or anti‐refluxing ureteroileal anastomosis (UIA) techniques? Studies reporting RFn as secondary outcome were also reported. A total of 129 publications were reviewed for full text and only 41 were included in this review. All studies were of low level of evidence and grade of recommendations. Only 3 randomized controlled trials were included and were of poor quality. Renal function after OBS was poorly described in the literature with no universal definition about RFn deterioration or outcome with no consensus on the best evaluation method. Urinary obstruction, chemotherapy and pyelonephritis appeared significant factors but with insufficient evidence. There is a universal trend to use the free refluxing technique for UIA to avoid complications of anti‐refluxing techniques. However, the anti‐reflux technique proved acceptable outcome in experienced hands. There is marked heterogeneity and underestimation of RFn evaluation among reported outcomes after OBS with most publications reporting the incidence of UIA and pyelonephritis with paucity reporting absolute figures about RFn measurements. In conclusion, urinary tract obstruction remains the main factor of RFn deterioration after OBS. Methods evaluating RFn, definitions of RFn outcome and factors predicting it are poorly studied in the literature and the current evidence is relatively weak to draw solid conclusions. Further well‐designed studies and consensus about method of assessment and definitions of RFn are warranted.

Impact of the type of ureteroileal anastomosis on renal function measured by diuretic scintigraphy: long-term results of a prospective randomized study

To determine the long‐term effects of the direct refluxing‐type ureteroileal anastomosis technique with those of an antireflux technique on individual renal units, using diuretic scintigraphy in a prospectively randomized study.

Critical Analysis of Outcome After Open Dismembered Pyeloplasty in Ectopic Pelvic Kidneys in a Pediatric Cohort

OBJECTIVE To evaluate the functional and morphologic outcome after open pyeloplasty for ureteropelvic junction obstruction (UPJO) in ectopic pelvic kidneys. MATERIALS AND METHODS A retrospective review of all patients who underwent open pyeloplasty in ectopic pelvic kidneys was conducted. Records were evaluated with respect to age at presentation, preoperative imaging, surgical details, and postoperative course. Patients were followed up regularly for functional and morphologic outcome. Success was defined as symptomatic relief and radiographic improvement of obstruction at the last follow-up. RESULTS Between 1995 and 2010, 680 patients with primary UPJO underwent open dismembered pyeloplasty at our center. Of these patients, 43 (6.3%) had UPJO in ectopic pelvic kidneys. No perioperative complications were encountered in the study group. Mean follow-up was 42 months (range, 18-90 months), and 5 patients were lost to follow-up. The overall success rate was 82.6%. Postoperative hydronephrosis was improved in 20 (52.6%), stable in 11 (29%), and worsened in 7 (18.4%). Postoperative renal function was improved in 12 (31.6%), stable in 19 (50%), and deteriorated in 7 (18.4%). Redo pyeloplasty was required in 4 patients and secondary nephrectomy in 3. Preoperative differential renal function and surgeon experience were statistically significant predictors of improvement in renal function after pyeloplasty. CONCLUSION Open pyeloplasty for UPJO in ectopic pelvic kidneys is feasible, but varying degrees of hydronephrosis and radiologic obstruction persist after pyeloplasty that could be attributed to anatomy-related pelvocaliectasis, and so regular follow-up is warranted in this subpopulation.

Long-term outcome of grafts with multiple arteries in live-donor renal allotransplantation: Analysis of 2100 consecutive patients.

Abstract Purpose:To analyse the long-term outcome in relation to multiple graft arteries (MGA) in live-donor renal transplantation, and assess its effect on graft and patient survival. Patients and methods: Between March 1976 and November 2009, a total of 2100 live-donor renal transplants were carried out at our centre. Patients were stratified according to the number of graft arteries into two groups, i.e. MGA (two or more arteries; 237 patients) and single-graft artery (SGA; 1863 patients). Variables assessed included patient demographics, site of vascular anastomosis, ischaemia time, onset of diuresis, delayed graft function, acute tubular necrosis (ATN), acute rejection, vascular and urological complications. Moreover, long-term patient and graft survival were compared among both groups. Patients were followed up for a mean (SD) of 112 (63) months. Results: Grafts with MGA were associated with a prolonged ischaemia time (P = 0.001) and ATN (P =0.005). Vascular thrombosis (arterial and venous) had a higher incidence in MGA (2.5%) than SGA (0.6%) (P = 0.01). Both groups were not significantly different for the onset of diuresis, acute rejection and urological complications (P = 0.16, 0.23 and 0.85, respectively). Graft and patient survival were comparable in both groups. The mean (SD) 1-, 5-, 10- and 20-year graft survival rates (%) for MGA were 96.1 (1.26), 86.6 (2.39), 61.3 (4.42) and 33.8 (7.23), and 97.5 (0.36), 86.8 (0.84), 66.0 (1.35) and 37.3 (2.76) for SGA (P = 0.54). Conclusions: Although there was a higher incidence of prolonged ischaemia time, ATN and vascular thrombosis in live-donor renal transplants with MGA, it did not adversely affect patient or graft survival. The early, intermediate- and long-term follow-up showed an outcome comparable to that in patients with SGA.

Is there a way to predict failure after direct vision internal urethrotomy for single and short bulbar urethral strictures

Abstract Objective: To identify patient and stricture characteristics predicting failure after direct vision internal urethrotomy (DVIU) for single and short (<2 cm) bulbar urethral strictures. Patients and methods: We retrospectively analysed the records of adult patients who underwent DVIU between January 2002 and 2013. The patients’ demographics and stricture characteristics were analysed. The primary outcome was procedure failure, defined as the need for regular self-dilatation (RSD), redo DVIU or substitution urethroplasty. Predictors of failure were analysed. Results: In all, 430 adult patients with a mean (SD) age of 50 (15) years were included. The main causes of stricture were idiopathic followed by iatrogenic in 51.6% and 26.3% of patients, respectively. Most patients presented with obstructive lower urinary tract symptoms (68.9%) and strictures were proximal bulbar, i.e. just close to the external urethral sphincter, in 35.3%. The median (range) follow-up duration was 29 (3–132) months. In all, 250 (58.1%) patients did not require any further instrumentation, while RSD was maintained in 116 (27%) patients, including 28 (6.5%) who required a redo DVIU or urethroplasty. In 64 (6.5%) patients, a redo DVIU or urethroplasty was performed. On multivariate analysis, older age at presentation [odds ratio (OR) 1.017; P = 0.03], obesity (OR 1.664; P = 0.015), and idiopathic strictures (OR 3.107; P = 0.035) were independent predictors of failure after DVIU. Conclusion: The failure rate after DVIU accounted for 41.8% of our present cohort with older age at presentation, obesity, and idiopathic strictures independent predictors of failure after DVIU. This information is important in counselling patients before surgery.