Efficacy of Magnetic Resonance urography in detecting crossing renal vessels in children with ureteropelvic junction obstruction.

INTRODUCTION: An aberrant or accessory crossing renal vessel (CV) leading to the lower pole of the kidney is the most common extrinsic cause of uretero pelvic obstruction(UPJ) obstruction in a child and young adolescent.There is still controversy regarding there functional significance in obstruction Preoperative identification of such vessels may influence surgical management. OBJECTIVE: First aim is to determine the value of magnetic resonance (MR) urography in detecting crossing vessels in children with UPJ obstruction,comparing the data with postoperative findings and the second one is to evaluate morphologic and functional parameters in these hydronephrotic kidneys. MATERIALS AND METHODS: Between June 2009 and December 2012 we retrospectively reviewed MR urography records of one hundred and nine children with unilateral hydronephrosis at the University Children's Hospital. 68 (62.4%) were male and 41 (37.6%) were female,median age was 6.5 ± 5.7. Of the total number of patients, 30 (27%) underwent pyeloplasty, while 79 (72.5%) did not. The age at surgery ranged from 0.3 to 18 years (median 6.6 years). The indication for surgery was based on standard criteria (obstructed renal transit time with or without altered renal function of vDRF < 40%), and did not depend on the presence or absence of a crossing vessel.Consensus reviewes of the MR urography studies were compared with surgical findings. RESULTS: A crossing vessel (CV) was found upon surgery in 9 (33%) of 30 kidneys.On MRU, there was no crossing vessel in 21 kidneys, confirmed at surgery in 18. A crossing vessel was detected with MRU in 9 kidneys and confirmed at surgery in 6. Thus, the sensitivity of MRU was 66.7%, the specificity was 85.7%, the positive predictive value was 66.7%, the negative predictive value was 85.7% and the accuracy was 80%. There was no statistically significant difference in the detection of crossing vessels between MR urography and surgery (p = 0.004 and p < 0.01 respectively). Overall, MRU and surgery showed good agreement (κ = 0.524). CONCLUSION: Based on our results we suggest that MR urography is a reliable and safe diagnostic tool to determine crossing vessels in selected children with UPJ obstruction. Thus, MRU can substitute for other imaging modalities and provide detailed information about the morphology and function of the affected kidney KEY WORDS: Children, Crossing renal vessels, Hydronephrosis, Ureteropelvic function obstruction.

Refluxing megaureter for the Mitrofanoff channel using continent extravesical detrusor tunneling procedure.

PURPOSE: We present a variation on the continent procedure using the refluxing megaureter for the Mitrofanoff channel, and its results. MATERIALS AND METHODS: The Mitrofanoff procedure using the refluxing megaureter was performed in 35 patients (valve bladder syndrome 15, neurogenic bladder 10, non-neurogenic bladder 10) between 1995 and 2001. Mean patient age was 5.9 years. In 5 patients the distal segment of the megaureter was used after nephrectomy, and in 30 patients the proximal segment of the megaureter was simultaneously reimplanted unilaterally. The distal segment of the megaureter was inserted under the detrusor close to the native hiatus, pulled through the tunnel between the unresected detrusor and the mucosa, and subsequently brought to the abdominal wall. The ureterovesical junction was left intact. RESULTS: In all of our patients we obtained sufficient length and good vascularization of both ureteral segments. Satisfactory tunnel length was achieved in 29 patients. In 6 cases the tunnel was elongated by dissection of the detrusor. Median followup was 37 months. Three patients had development of stenosis at the stoma level, which resolved with minimal revision at the ureter-skin level. Minimal leakage occurred in 3 patients, all of whom were successfully treated with anticholinergics. On routine followup no patient had signs of reflux recurrence in the reimplanted ureter. CONCLUSIONS: The results of our variant procedure expand the number of patients who may benefit from use of the ureter for the Mitrofanoff channel.

Dorsal dartos flap for preventing fistula in the Snodgrass hypospadias repair.

OBJECTIVE: To evaluate the importance of urethral covering using vascularized dorsal subcutaneous tissue for preventing fistula in the Snodgrass hypospadias repair. PATIENTS AND METHODS: The study included 67 children (aged 1-11 years) who had hypospadias repaired between April 1998 and May 2003, including 51 with distal and 16 with midshaft hypospadias. In all children, a standard tubularized incised-plate urethroplasty was followed by reconstruction of new surrounding urethral tissue. A longitudinal dartos flap was harvested from excessive dorsal preputial and penile hypospadiac skin, and transposed to the ventral side by a buttonhole manoeuvre; it was sutured to the glans wings around the neomeatus, and to the corpora cavernosa over the neourethra. Thus the neourethra was completely covered with well-vascularized subcutaneous tissue. RESULTS: At a mean (range) follow-up of 21 (6-65) months, the result was successful, with no fistula or urethral stenosis, in all 67 children. CONCLUSION: We suggest that urethral covering should be part of the Snodgrass procedure. A dorsal well-vascularized dartos flap, buttonholed ventrally, is a good choice for preventing fistula. Redundancy of the flap and its excellent vascularization depends on the harvesting technique.

'Pseudospongioplasty' in the repair of a urethral diverticulum.

OBJECTIVES: To describe a technique for repairing urethral diverticula which includes neourethral reconstruction and increasing the mechanical support of the neourethra. PATIENTS AND METHODS: Between February 1995 and May 2000, 267 patients with proximal hypospadias underwent a one-stage penile skin longitudinal flap urethroplasty. The overall postoperative complication rate was 20%; a diverticulum formed in 24 patients (9%) and in all it was repaired. Diverticulectomy was carried out by de-epithelialization of excess diverticular skin, so that two subcutaneous vascularized tissue wings could be created. After re-establishing distal urethral patency and neourethral closure, the de-epithelialized diverticular wings were folded and overlapped to form a mechanical support for the neourethral ventral wall; this procedure was termed 'pseudospongioplasty'. RESULTS: There were no recurrences of diverticulum or any fistula formation. The only complication was urethral stenosis in two cases, which was successfully resolved by internal urethrotomy. CONCLUSION: Re-establishing patency and providing mechanical support are essential when repairing a urethral diverticulum. Our technique with pseudospongiosal tissue reconstruction during the repair represents a good alternative or addition to other techniques.

Detrusorectomy with rectus muscle hitch and backing.

PURPOSE: Bladder autoaugmentation is a procedure that includes detrusoromyotomy or detrusorectomy with an aim to release intact urothelium, which then prolapses and increases bladder capacity and compliance. Covering of the prolapsed urothelium usually is done by using deepithelialized pedicled colonic or gastric patch. The authors present their first experiences with detrusorectomy using rectus muscle for hitch and backing. METHODS: Between August 1999 and February 2002, autoaugmentation was performed in 19 patients (12 girls and 7 boys) aged 4 to 12 years (median, 8). All patients had a neurogenic bladder with small capacity and poor compliance. Detrusorectomy usually involves the whole upper half of the bladder to achieve regular shape of the huge prolapsed urothelium. Both rectus muscles are dissected from their anterior and posterior sheaths. Urothelium is sutured to the muscle at several points to prevent its retraction and shrinkage. This way, bladder is fixed and hanged on rectus muscles. RESULTS: Follow-up was 6 to 35 months (median, 21). The new bladder capacity was increased in all patients and ranged from 190 to 411 ml (median, 313). All patients had clinical improvement and better compliance. CONCLUSIONS: Detrusorectomy with rectus muscle hitch and backing is a safe and simple procedure. However, long-term results are needed to define value of this procedure.

Bladder autoaugmentation with rectus muscle backing.

PURPOSE: Bladder autoaugmentation is a procedure which includes detrusoromyotomy or detrusorectomy to release intact urothelium which than prolapses and increases bladder capacity and compliance. The prolapsed urothelium is usually covered with de-epithelialized pedicled colonic or gastric patch. We present our initial experience with bladder autoaugmentation using rectus muscle backing. MATERIALS AND METHODS: Between August 1999 and December 2000 autoaugmentation was performed in 4 girls and 3 boys 4 to 11 years old (median age 8). All patients had neurogenic bladder with small capacity and poor compliance. The technique is performed using an extraperitoneal approach through either an inferior midline longitudinal or transverse incision. The procedure is started with a semi-filled bladder to find the right plane and then continues with an almost empty bladder to avoid severe injury of the prolapsed urothelium. Both rectus muscles are dissected from the anterior and posterior sheaths and sutured to detrusor edges. Urothelium is sutured to the muscle at several places to prevent its retraction and shrinkage. Thus, the bladder is fixed and hangs on rectus muscles, that is the anterior abdominal wall. RESULTS: Followup was 10 to 25 months (median 16). Bladder capacity at 6 months postoperatively increased in all patients, and ranged from 162 to 368 ml. (median 266). All patients had clinical improvement, decreased hydronephrosis, no vesicoureteral reflux and better compliance. CONCLUSIONS: Bladder autoaugmentation with rectus muscle backing is a safe and simple procedure. Rectus muscle is a good alternative to other backing materials.