Comprehensive analysis of tubularized incised-plate urethroplasty in primary and re-operative hypospadias.

OBJECTIVE: To retrospectively review our experience of the tubularized incised-plate (TIP) urethroplasty over the last 4 years. PATIENTS AND METHODS: From 1998 to December 2001, 133 patients (mean age 7 years, sd 4, range 1-22), had a TIP urethroplasty by one surgeon for primary (103) and re-operative (30) hypospadias; the defects included 106 (79%) distal and mid-shaft, and 27 (21%) posterior shaft. The neourethra was covered by a subcutaneous flap in 66 (50%) patients or by corpus spongiosa (spongioplasty) in 31 (23%), with no cover in the remaining 36 (27%). In the last 20 patients (15%) a modified meatoplasty was used; the site and size of the new meatus was predetermined on the glans around a suitable catheter before any incision. Urethral stents were not used after repair in 39 (29%) patients, and regular meatal dilation was used only in patients with voiding difficulty and obvious tendency to stenosis. The presence of complications requiring re-operation and overall general appearance were recorded. RESULTS: The mean (sd) follow-up was 10 (5) months; there were 24 complications in 20 patients (15%), including a small fistula in 12 (9%), complete disruption of the repair in 4 (3%), meatal stenosis in seven (5%) and neourethral stricture in one (0.8%). Complications were not significantly different between primary and re-operative cases, and unaffected by the use of the stents. On univariate analysis complications were significantly higher with running than interrupted sutures, in repairs in the first 2 years of the study, in patients with posterior hypospadias, and in those with no neourethral coverage. However, the last two factors were the only significant independent risk factors in a multivariate analysis. Regular urethral dilatation was indicated in 43 patients (32%). Modified meatoplasty was associated with a significantly lower requirement for regular dilatation (P < 0.05) and no meatal stenosis. In the 113 complication-free patients the operation gave an excellent cosmetic appearance with a vertical slit meatus on the tip of conical glans in 110 (97%); there was slight meatal retraction in the remaining three patients. CONCLUSION: The TIP repair is a reliable method for treating both distal and proximal penile shaft hypospadias, is suitable for both primary and re-operative cases, and is more versatile than other repairs. Covering the neourethra with a flap or spongioplasty significantly improves the results. Regular urethral dilatation is required in a third of patients but modified meatoplasty obviates the need for regular dilatation and eliminates the risk of meatal stenosis.

Late renal functional and morphological evaluation after non-operative treatment of high-grade renal injuries in children.

OBJECTIVE: To assess the long-term results in children with high-grade renal trauma who were managed without surgery, as such treatment was initially successful but little is known about the late ipsilateral renal function and morphology. PATIENTS AND METHODS: The study included 13 children (nine boys and four girls; mean age 8 years, sd 5) with high-grade renal injury who were managed without surgery between 1997 and 2001, and followed for a mean (sd, range) of 3 (2, 0.5-7) years. The trauma was caused by a motor-car accident in five and falling from a height in eight children, and was on the right in 10 and on the left in three. There was gross and microscopic haematuria in 10 and three patients, respectively. The trauma was graded according to the American Association for Surgery of Trauma, with grades III, IV and V renal injury in six, four and three children, respectively. All patients were treated initially by observation; one required super-selective embolization because of continuing haemorrhage. Three children with progressive urinary extravasation were treated with a percutaneous tube drain and JJ stent for 6 weeks. Patients were discharged after a mean (sd) hospital stay of 9 (6) days. Ultrasonography then showed resolving haematoma in all patients with a mean (sd) size of 7 (2) cm(2). At the last follow-up patients were re-evaluated by a clinical examination, renal scintigraphy and computed tomography angiography. RESULTS: None of the children was hypertensive nor had any abnormality on urine analysis; all had normal serum creatinine levels, and scintigraphy and angiography showed normal contralateral kidneys in all. Ipsilateral abnormalities were detected in 12 patients, and included a single scar in five, multiple scars in six and a cystic lesion with multiple septa in one. There was no vascular complication or hydronephrosis, and no significant functional loss, with all affected kidneys having a split function of 41-50% at the last follow-up. CONCLUSION: Although there is no late functional loss there are residual morphological changes in almost all children with high-grade renal injury. This study provides objective support for the non-operative management of high-grade renal injury in children, but a prolonged follow-up is warranted to assess the risk of progression of these abnormalities.

On multiobjective oligopoly.

Multiobjective oligopoly models are constructed. The objectives of the first two models are to maximize profits and to maximize sales. In the third model the objectives are to maximize profits and to minimize risk. Giving more weight to risk minimization decreased the profits. In all three models, we found that the weight of profit maximization has to be higher than a given threshold. Again they require that the weight of profit maximization has to be higher than a certain value.

Healing of unstented tubularized incised plate urethroplasty: an experimental study in a rabbit model.

OBJECTIVE: To develop a rabbit model to study the temporal healing taking place after an unstented tubularized incised plate urethroplasty (TIPU). MATERIALS AND METHODS: The study comprised 13 New Zealand white rabbits (3-4 kg); the ventral wall of the penile urethra was excised to create a hypospadias-like defect. A vertical incision was made in the dorsal urethral plate and the incised urethra tubularized. Two animals were killed at 2 days and two at 5 days after surgery, and the remainder killed at 2, 6 and 12 weeks (three each). A retrograde urethrogram was taken at autopsy. Serial sections of the penis were stained with haematoxylin and eosin, and Masson trichrome for microscopy. RESULTS: There were no deaths related to the procedure and all animals voided spontaneously. Retrograde urethrograms showed no fistulae or stricture. Microscopic examination at 2 and 5 days showed partial coverage of the incision with regenerating urothelium. At 2 weeks there was full-thickness urothelium with a mild inflammatory reaction. At 6 and 12 weeks, remodelling of the peri-urethral connective tissue with minimal fibrosis completed the healing. CONCLUSION: The mechanism of healing of the incised urethral plate involves normal urothelial regeneration into the depth of the incised defect, which explains the gain in urethral diameter after TIPU. Urine flow, during normal voiding, might be responsible for keeping the incised plate open during urothelial regeneration. A urethral stent was not necessary for normal healing in this model.

Ureteroneocystostomy in children with posterior urethral valves: indications and outcome.

PURPOSE: Ureteroneocystostomy in children with posterior urethral valves represents a surgical challenge. We reviewed our experience with this procedure to assess its indications and outcome. MATERIALS AND METHODS: Between 1996 and January 2000, 106 children with posterior urethral valves were treated of whom 20 (19%) underwent ureteroneocystostomy at a mean age plus or minus SD of 5 +/- 2.6 years. Indications for surgery were recurrent urinary infections despite adequate valve ablation in 14 patients of whom 7 had persistent reflux in 12 renal units and 7 had obstruction in 11 ureterovesical junctions. The remaining 6 patients were initially treated with high loop diversion and obstruction was confirmed in 9 ureterovesical junctions by the Whitaker test. Bladder function was assessed by videourodynamics before surgery. Transureteroureterostomy was performed in 7 ureters, and 25 ureters were tailored and reimplanted using the combined intravesical and extravesical approach, including a psoas hitch in 18 (72%). RESULTS: Mean followup plus or minus SD was 2.3 +/- 1 years. Obstruction and reflux occurred in 1 (4%) and 9 (36%) ureteroneocystostomies, respectively. Obstruction was successfully managed by repeat surgery. Patients with reflux were maintained on chemoprophylaxis. No patient required repeat surgery and reflux did not resolve spontaneously in any. Reflux occurred in all ureteroneocystostomies without a psoas hitch (100%) and in 2 with a hitch (10%) (p <0.004). Dilatation of the upper tracts persisted in all patients. In 2 patients end stage renal disease developed. The remaining 18 patients had serial sterile urine cultures and with a mean serum creatinine plus or minus SD of 0.8 +/- 0.3 mg.%. CONCLUSIONS: Ureteroneocystostomy is indicated for patients with persistent obstruction after high diversion or those with persistent reflux or obstruction and recurrent infections despite adequate valve ablation and a stable bladder. However, the procedure is associated with a high rate of postoperative reflux. Psoas hitch has a significant role in prevention of reflux.

Posterior urethral valves: does young age at diagnosis correlate with poor renal function?

OBJECTIVES: To determine whether young age at presentation is associated with poor renal function in patients with posterior urethral valves (PUVs). Previous studies have indicated that a young age at diagnosis is an adverse prognostic factor for patients with PUVs. METHODS: Fifty-three children with PUVs were diagnosed between January 1998 and March 2000. The patients included 25 infants with a median age of 3 months (group 1) and 28 children with a median age of 3.5 years (group 2). No statistically significant difference was present between the two groups regarding presenting symptoms, incidence of hydronephrosis, bilateral vesicoureteral reflux, presence of popoff mechanisms, or number of positive urinary cultures at presentation. Primary valve ablation was carried out in all patients. The median follow-up period for groups 1 and 2 was 19 and 18.5 months, respectively (P <0.05). RESULTS: The percentage of serum creatinine deviation greater than the normal age-reference range was calculated for each patient at diagnosis and at the last follow-up visit. The median percentage of serum creatinine deviation at presentation was 190% for group 1 and 22% for group 2 (P >0.05). The median percentage of serum creatinine deviation at the last follow-up visit was nil for group 1 and 10% for group 2 (P <0.009). Persistently dilated upper tracts were noted in 48% and 86% of patients in groups 1 and 2, respectively (P <0.004). CONCLUSIONS: In contrast to the findings of previous studies, we provide evidence of a less favorable outcome with delayed presentation of PUVs relative to those diagnosed in the first year after birth in respect to renal function and upper tract dilation.

A single-centre long-term outcome analysis of artificial urinary sphincter placement in children.

OBJECTIVE: To retrospectively evaluate the outcome of artificial urinary sphincter (AUS) placement in 79 children, with a mean follow-up of 12.5 years. PATIENTS AND METHODS: A total of 89 children had an AUS placed between 1977 and 1994; complete data were obtained for 79 (63 boys and 16 girls). The indication for AUS placement was urinary incontinence caused by sphincteric deficiency with a stable bladder. Before and after surgery, all patients underwent ultrasonography, voiding cysto-urethrography and urodynamics. Logistic regression was used to assess the factors influencing the outcome. RESULTS: The mean (range) age at surgery was 11.7 (3-18) years. The cause of incontinence was a neuropathic bladder in 74 patients and bladder exstrophy in five. At a mean (range) follow-up of 12.5 (5-22) years, 63 of 79 patients (80%) had an intact AUS. The AUS was removed in 16 patients (20%) because of erosion at a mean (range) of 5.6 (1-11) years after insertion; there were 0.035 revisions per patient-year. Of 63 patients with an AUS in place, 57 (90%) are completely dry and 36 (57%) are using clean intermittent catheterization. Thirteen patients (20%) developed bladder instability during the follow-up, which was managed by anticholinergics in eight, spinal cord de-tethering in three and enterocystoplasty in two. Hydronephrosis occurred in 12 of 126 renal units (10%) that improved after enterocystoplasty or anticholinergics. The overall 10-year survival of the AUS was 79% (78% for early models and 80% for the AMS800); the survival was not affected by age, sex, model, previous bladder neck surgery, augmentation cystoplasty or intermittent catheterization. Bladder exstrophy was associated with lower AUS survival, as four of the five patients affected had the AUS removed secondary to erosion (P = 0.014). CONCLUSION: In children the AUS has a 79% 10-year survival and gives a 90% continence rate. Bladder instability after AUS placement can be managed with anticholinergics or enterocystoplasty. The AUS is not a justifiable treatment option for patients with bladder exstrophy.

High resolution ultrasound characterization of early allograft hemodynamics in pediatric living related renal transplantation.

PURPOSE: Allograft vascular thrombosis occurs in 5% to 10% of pediatric renal transplants. The hemodynamics of renal allograft immediately after implantation is unclear. High resolution Doppler ultrasound of the renal allograft performed in the operating room after incision closure is an effective and objective method to advance our understanding of baseline renal allograft hemodynamics, and identify unsuspected vascular complications early enough to ensure prompt surgical repair. MATERIALS AND METHODS: Between September 1998 and July 2000 high resolution, color power Doppler ultrasound was prospectively performed on 21 living related renal transplants in the operating room immediately after incision closure. Each ultrasound described allograft anastomotic blood flow, direction of diastolic flow, parenchymal perfusion and resistive indexes. RESULTS: There were 20 (95%) allografts with good power Doppler perfusion that had satisfactory immediate function with no vascular complications at 9 to 26-month followup. Initially, anastomotic turbulence was described in 15 (71%) allografts, and resistive indexes were abnormal in 8 (38%). Turbulence and abnormal resistive index normalized in all allografts by 1-month followup. Ultrasound of 1 allograft identified unsuspected poor perfusion and reversal of diastolic flow in the operating room after incision closure. In another allograft in which a 4-hour post-transplant ultrasound was compared with the baseline study in the operating room an unsuspected thrombosis of the right common iliac vein was confirmed. CONCLUSIONS: Good parenchymal perfusion and forward diastolic flow after renal reperfusion correlated well with immediate graft function. Initial turbulence and abnormal resistive index in the presence of favorable perfusion are misleading and not independent predictors of graft function. Ultrasound performed in the operating room identified 2 unsuspected major vascular complications facilitating prompt surgical correction.

Tunica vaginalis for correcting penile chordee in a rabbit model: is there a difference in flap versus graft?

PURPOSE: We compared tunica vaginalis applied as a flap versus a graft for covering defects in the ventral tunica albuginea in a rabbit model. MATERIALS AND METHODS: We used 18 New Zealand White rabbits in the study. The urethra was mobilized off of the corpus cavernosum. A defect was created in the ventral aspect of the tunica albuginea by excising a 1 x 0.5 cm. rectangular area. The defect was covered by the testicular surface of tunica vaginalis as a vascularized flap in 9 animals and as a graft in 9. At 2, 6 and 12-week intervals 3 animals per group were sacrificed. Transverse sections of the penis at the repair site were stained with hematoxylin and eosin, and Masson's trichrome for microscopy. RESULTS: Autopsy revealed no contracture in any of the tunica vaginalis flaps. In contrast, the tunica vaginalis grafts had contracted by a mean of 22% (range 20% to 25%) at 2, 38% (range 30% to 44%) at 6 and 42% (range 38% to 48%) at 12 weeks. Microscopic examination of the tunica vaginalis flaps showed evidence of an intact blood supply and viable cremasteric muscle layer but no evidence of necrosis. Collagen remodeling and maturation was noted at 12 weeks. In tunica vaginalis grafts there was evidence of necrosis of all tunica vaginalis layers at 2 weeks with granulation tissue and active fibrosis at the periphery. At 6 and 12 weeks most necrotic tissue was replaced by fibrosis. Osseous metaplasia was identified in 1 graft at 12 weeks. CONCLUSIONS: The optimal use of tunica vaginalis for correction of chordee is as a flap rather than as a free graft. Grafts were associated with significant necrosis and contracture, of which neither was associated with flaps.

Long-term outcome analysis of low pressure rectal reservoirs in 33 children with bladder exstrophy.

PURPOSE: The augmented valved rectum and double folded rectosigmoid bladder represent 2 modifications of ureterosigmoidostomy. Both procedures improve continence by lowering the reservoir pressure. We present the outcome of these techniques on the upper urinary tract, continence, metabolic profile, linear growth and bone density. MATERIALS AND METHODS: Between March 1987 and May 1997, 22 boys and 11 girls with bladder exstrophy underwent urinary diversion to a low pressure rectal reservoir. Patient age at surgery ranged from 2 to 13 years (mean 5.4). The augmented valved rectum technique was used in 18 cases and the double folded rectosigmoid bladder method was used in 15. Serial followup ultrasounds were obtained and voiding proctography was performed 1 year postoperatively in all patients. Supine height was measured at last followup in all cases. Serum electrolytes, arterial blood gases, the results of which were plotted on an acid base nomogram, and bone density using dual energy x-ray absorptiometry were measured in all patients. Prophylactic alkalization was administered to all patients. RESULTS: Mean followup is 66 months (range 24 to 148). All patients are continent during the daytime with an emptying frequency of 3 to 5 times, and all are continent at night. No patient experienced pyelonephritis or clinical acidosis. The upper urinary tract was either improved or stabilized in 64 of 66 renal units. No patient had reflux to the upper urinary tract. All patients had normal serum creatinine, sodium, potassium, calcium and phosphorus. Hyperchloremia was noted in 19 of the 33 patients (57%), and arterial blood gases showed subclinical metabolic acidosis in 18 (55%). Supine height measurements at last followup revealed that 19 of the 33 patients (57%) had decreased linear growth (below 3rd percentile). All patients had significant reduction in bone density, and mean for age corrected bone density was 70% (standard deviation 10.9%). Both groups (augmented valved rectum and double folded rectosigmoid bladder) were comparable in regard to age, sex and followup duration. There was no statistically significant difference between the groups in any parameter measured. CONCLUSIONS: The augmented valved rectum and double folded rectosigmoid bladder provide preservation of the upper urinary tract with excellent continence rates. However, prophylactic alkalization and functional isolation of the reservoir do not prevent the long-term metabolic consequences. Subclinical metabolic acidosis and decreased linear growth are to be anticipated in more than 50% of patients. Moreover, significant bone demineralization is to be expected in all of these patients.

Complete repair of bladder exstrophy: preliminary experience with neonates and children with failed initial closure.

PURPOSE: The surgical repair of bladder exstrophy remains challenging for the pediatric urologist. We present our preliminary experience with complete primary repair of exstrophy in neonates and children with failed initial closure. MATERIALS AND METHODS: Between November 1998 and April 1999, 9 boys and 2 girls with bladder exstrophy underwent complete repair. This procedure was performed in the first 72 hours of life in 4 boys and at age 3 months in 1 girl. Complete repair with osteotomy was performed after failed initial closure in 5 boys and 1 girl at a mean age of 28 months (range 15 to 36). The bladder and urethra were closed in continuity and epispadias was repaired by total penile disassembly. All patients were kept in a spica cast for 3 weeks. Ureteral stents and suprapubic tube were removed 10 and 14 days, respectively, after surgery. Ultrasound was performed preoperatively and every 3 months postoperatively, voiding cystourethrography was done 6 to 12 months after surgery. RESULTS: Mean followup is 14 months (range 12 to 17). All repairs were successful including 1 case of penile scrotal duplication. Concomitant augmentation was done in 2 girls due to a small bladder plate. Complete closure resulted in hypospadias in 3 of the 9 boys. No patient had dehiscence or fistula. Serial followup ultrasound revealed no hydronephrosis and normal renal growth. Febrile urinary tract infection occurred in 1 case 2 months after surgery and was managed conservatively. Bladder capacity was 200 and 270 ml., at 6 months, respectively, in the 2 patients with an augmented bladder and both are dry on intermittent catheterization. The 4 patients in whom the closure was performed at birth are voiding with dry intervals with mean bladder capacity of 75 cc at 1 year (range 60 to 90). The 5 older children had a mean bladder capacity of 120 cc (range 70 to 150) at 6 months, of whom 2 are completely continent and 3 have 1 to 3 hours of dry intervals. CONCLUSIONS: Complete repair of bladder exstrophy is feasible in neonates and children after failed initial closure with minimal morbidity. There is no short-term evidence of worsening reflux or hydronephrosis. Longitudinal followup with adequate recording is required for continence evaluation. This technique may minimize the future need of bladder neck reconstruction and augmentation in patients with exstrophy.

Double folded rectosigmoid bladder with a new ureterocolic antireflux technique.

PURPOSE: We present a new method of urinary diversion to the rectum. MATERIALS AND METHODS: Between 1992 and 1995 a new surgical procedure was used in 32 women, 20 men and 12 children 3 to 60 years old (mean age plus or minus standard deviation 35.4 +/- 2.2). The main indication for diversion was invasive bladder carcinoma. Surgery entailed creation of an S-shaped double folded rectosigmoid reservoir with implantation of the ureters via an extramural serous lined antireflux technique. RESULTS: One patient died of a massive pulmonary embolism postoperatively. Followup ranged from 6 to 36 months (mean 19.2 +/- 7.0). During the observation period 6 patients died of local recurrence and/or distant metastasis within 8 months. Of the patients 57 are currently evaluable. All patients are continent during the day with an emptying frequency of 2 to 4 times. Nocturnal enuresis was observed in 4 children who responded favorably to imipramine hydrochloride therapy. Upper urinary tract function was maintained or improved in 95% of the patients. No clinical evidence of acidosis was observed, since all patients were kept on prophylactic oral alkalization. CONCLUSIONS: The procedure can circumvent some of the inherent disadvantages of ureterosigmoidostomy and is a good alternative to orthotopic bladder substitution when the urethra cannot be used.