Joel C. Hutcheson

APPENDICOVESICOSTOMY: THE MITROFANOFF PROCEDURE—A 15-YEAR PERSPECTIVE

PURPOSE Appendicovesicostomy was introduced in the United States in 1982 at our hospital. It has become the most popular alternate continence channel for catheterization. We reviewed the experience of 1 surgeon with appendicovesicostomy during a 15-year period. MATERIALS AND METHODS We retrospectively reviewed the operative reports and clinical records of 50 consecutive patients in whom appendicovesicostomy was performed by 1 surgeon between 1982 and 1998. The underlying diagnosis was myelomeningocele in 31 cases, bladder exstrophy in 6, the prune-belly syndrome in 2, posterior urethral valves in 2 and other disorders in 10. Mean patient age at surgery was 13.1 years (range 4 months to 25 years) and mean followup was 4.3 years (range 3 months to 16.3 years). RESULTS Of the 50 patients 96% continue to catheterize the appendicovesicostomy. Stomal stenosis developed in 5 cases (10%) and other complications included stricture and appendiceal perforation in 2 each. Eight patients (16%) required appendicovesicostomy revision at a median of 7.3 months (range 1 month to 5.8 years) after the initial procedure. Median time to revision for stomal stenosis was 13 months (range 1 month to 5.8 years). Appendicovesicostomy continence was achieved in 49 patients (98%). CONCLUSIONS Our series demonstrates the successful long-term outcome and durability of appendicovesicostomy in children. Careful adherence to technique at initial surgery helps ensure a high long-term success rate.

LONG-TERM FOLLOWUP OF ENDOSCOPIC INCISION OF URETEROCELES: INTRAVESICAL VERSUS EXTRAVESICAL

PURPOSE Endoscopic incision was performed as the initial therapy for ureteroceles in children presenting to our institutions between 1985 and 1990. To assess the long-term efficacy of this treatment modality we reevaluated the outcome of these patients. MATERIALS AND METHODS Parameters reviewed included patient age at surgery, position of the ureterocele, a duplex system, preoperative and postoperative reflux, and the need for additional operations. Statistical analysis consisted of chi-square and Wilcoxons rank sum tests. RESULTS Of the patients 22 had intravesical and 22 had extravesical ureteroceles. Average age at initial surgery was 1.9 +/- 3.7 years with average followup of 7.2 +/- 3.1 years. A second operation was required in 18 cases (41%), which was significantly more likely for an extravesical ureterocele (18% versus 64%, p = 0. 002), a duplex system (p = 0.026) or preoperative reflux (p = 0.02). Second operations included reimplantation in 13 cases, upper pole partial nephrectomy in 7, total nephroureterectomy in 3, bladder neck reconstruction in 3 and lower pole pyeloplasty in 3. The only secondary operations performed for intravesical ureteroceles were reimplantation in 3 cases and upper pole nephrectomy in 1. New onset reflux developed in 14 of 27 patients (52%) postoperatively, including 7 with intravesical and 7 with extravesical ureteroceles. None required a second open operation. CONCLUSIONS With extended followup the percentage of patients requiring open surgery after endoscopic incision of ureteroceles increased from our original report of 27% to 41% (p = 0.166). Only 18% of cases with an intravesical ureterocele required a subsequent operation compared to 64% with an extravesical ureterocele (p = 0.002). The reduction in size of the obstructed ureter following endoscopic decompression facilitated successful reimplantation. Endoscopic puncture permits definitive treatment in the majority of children by at most a single incision, open operation at the bladder level.

THE DECOMPENSATED DETRUSOR III: IMPACT OF BLADDER OUTLET OBSTRUCTION ON SARCOPLASMIC ENDOPLASMIC RETICULUM PROTEIN AND GENE EXPRESSION

PURPOSE Regulation of calcium ion homeostasis has a significant role in smooth muscle contractility. The sarcoplasmic endoplasmic reticulum, calcium, magnesium, adenosine triphosphatase (SERCA) is a regulatory ion pump that may have a role in the functional outcome after outlet obstruction. We investigate what correlation if any existed between SERCA protein and gene expression, and the contractile properties in the same bladder. MATERIALS AND METHODS Standardized partial bladder outlet obstructions were created in adult New Zealand white rabbits, which were divided into control, sham operated and obstructed groups. Muscle strip studies subcategorized the obstructed group into compensated (force greater than 50% of control) and decompensated (force less than 50% of control). Microsomal membrane and total RNA fractions were prepared from the same bladder tissue. Membrane proteins were used for Western blot analysis using a SERCA specific monoclonal antibody, and total RNA was assessed with Northern blot analysis. RESULTS The relative intensities of signals for the Western and Northern blots demonstrated a strong correlation between protein and gene expression. Furthermore there was a strong association between the loss of SERCA messenger RNA and protein expression and loss of bladder function. CONCLUSIONS Bladder contractility after outlet obstruction is influenced in part by smooth muscle cell ability to maintain calcium homeostasis via SERCA. The loss of SERCA protein expression is mediated by down-regulation in gene expression in the same bladder. These data suggest that smooth muscle ion pump gene expression is in part mechanically (pressure work) regulated.

The use of vesicostomy as permanent urinary diversion in the child with myelomeningocele.

PURPOSE Treatment of the child with myelomeningocele presents the urologist with many challenges. While vesicostomies are usually used for temporary bladder drainage until continent reconstruction is performed, we have a population of postpubertal patients with myelomeningocele in whom vesicostomies have been preserved. We review our experience with these older children. MATERIALS AND METHODS A search of our database of 350 patients with myelodysplasia identified 23 with urinary diversion accomplished by permanent vesicostomy. Those who had undergone vesicostomy after age 11 years were designated as group 1. Those who received a vesicostomy early in life that was maintained post puberty were designated as group 2. Indications for vesicostomy, upper tract status before and after vesicostomy, recurrent infections and complications were noted. Upper tract status was determined by serial ultrasounds during routine followup. RESULTS Group 1 was comprised of 5 patients with mean age at vesicostomy of 17 years and a mean followup interval of 5.2 years. Group 2 was comprised of 18 patients with mean age of vesicostomy at 2.6 years and mean followup interval of 13 years. Hydronephrosis resolved in all children from both groups. Vesicostomy revision was required in 1 patient secondary to prolapse. Other complications included mild prolapse that did not require revision, stenosis requiring revision 5 months after the initial procedure and an early bilateral ureterovesical obstruction that resolved. Of the patients 33% had recurrent upper tract calculi. CONCLUSIONS While the goal of achieving urinary continence is well worth striving for in the child with myelomeningocele, it is not realistic for all patients. We believe that permanent cutaneous vesicostomy is an acceptable alternative that the reconstructive surgeon should consider. This reliable and simple technique ensures safe decompression of the upper urinary tracts, while avoiding the complications of urinary diversion using segments of bowel.

ECTOPIC AND UNDESCENDED TESTES: 2 VARIANTS OF A SINGLE CONGENITAL ANOMALY?

PURPOSE We compared pathological findings in ectopic and undescended testis to determine whether the pathological evidence supports the hypothesis that the 2 conditions are variants of the same congenital anomaly. MATERIALS AND METHODS We identified 24 boys with ectopic testis not in the superficial inguinal pouch of Denis Browne. Seven boys were excluded from study due to unavailable clinical records for 3, contralateral undescended testis in 2 and inadequate biopsy specimens in 2. Pathological findings of ectopic testis in the remaining 17 patients were compared with those of age matched patients with unilateral undescended testis. Total germ cell count, testicular volume, patency of the processus vaginalis and epididymal abnormalities were compared. Data were analyzed using the Wilcoxon matched pairs signed rank and Fishers exact tests. RESULTS No difference was noted in total germ cell count (p = 0.33), testicular volume (p = 0.1475), processus vaginalis patency (p = 0.0854) or epididymal abnormalities (p = 1.00) in the 2 groups. Of the 24 boys (8%) with ectopic testis 2 also had a contralateral undescended testis. CONCLUSIONS Similar pathological findings in ectopic and undescended testes as well as the association of ectopic testis with a contralateral undescended testis suggest that ectopic and undescended testes are variants of the same congenital anomaly. Thus, boys with ectopic testis may have an increased incidence of subfertility and testicular malignancy. This spectrum of abnormal testicular position, and its range of pathological conditions and complications may appropriately be called the undescended testis sequence.

THE DECOMPENSATED DETRUSOR V: MOLECULAR CORRELATES OF BLADDER FUNCTION AFTER REVERSAL OF EXPERIMENTAL OUTLET OBSTRUCTION

PURPOSE Calcium ion homeostasis has a significant role in smooth muscle function. Its regulation requires complex storage and release mechanisms via ion pumps and channels located within intracellular storage sites (sarcoplasmic reticulum) and at the plasma membrane. We have previously reported a dramatic loss of the 2 major sarcoplasmic reticulum proteins sarcoplasmic endoplasmic reticulum calcium magnesium adenosine triphosphatase (SERCA2) and the ryanodine sensitive ion channel, also called the ryanodine receptor, after outlet obstruction. In our current study we investigated the correlation of the expression of these 2 major sarcoplasmic reticulum components with bladder function recovery after the reversal of outlet obstruction. METHODS AND METHODS Standard partial bladder outlet obstruction was created in adult New Zealand White rabbits. Voiding patterns were monitored 2 and 4 weeks postoperatively, and rabbits were selected for outlet obstruction reversal based on a voiding pattern consistent with a decompensated state, as indicated by a frequency of greater than 30 voids daily and an average voided volume of less than 4 cc. Bladder biopsy was done when outlet obstruction was reversed. Voiding performance was monitored postoperatively and the animals were sacrificed 2 weeks later. Voiding patterns and muscle strip studies enabled us to define 2 functional outcome categories after reversal, namely normal versus minimally improved. Microsomal membrane protein fractions were prepared from the same bladder tissues before and after reversal, and probed by Western blot analysis for SERCA2 and ryanodine receptor expression. RESULTS Western blot analysis revealed a major loss of SERCA2 and ryanodine receptor expression at the time of reversal and biopsy. In 65% of bladders obstruction reversal resulted in a normalized voiding pattern with a recovery of ryanodine receptor expression that was 15% to 65% of control values. In contrast, in the 35% of bladders with persistent voiding symptoms there was minimal recovery of ryanodine receptor expression. SERCA2 expression increased slightly in each group after reversal but did not differ in bladders with normalized versus improved function. CONCLUSIONS Bladder decompensation is highly associated with a loss of sarcoplasmic reticulum function. Furthermore, the decompensated detrusor recovers function after obstruction reversal, which is associated with the recovery of these sarcoplasmic reticulum components.

The anatomical approach to inguinal orchiopexy

PURPOSE Achieving a scrotally positioned testis with no iatrogenic atrophy is the primary goal of the surgical treatment of cryptorchidism. The success rate is associated with preoperative testicular position and the technique used. Our success rate with inguinal orchiopexy for abdominal testis is higher than those previously published and may be due to our anatomical approach to retroperitoneal dissection. We review the relevant anatomy and discuss the surgical technique of inguinal orchiopexy. MATERIALS AND METHODS We researched and reviewed the relevant technical and anatomical literature on inguinal orchiopexy, and describe the anatomical approach to orchiopexy in detail. RESULTS An understanding of the retroperitoneal fascial layers is the key to understanding surgery of the retroperitoneum. Dividing the internal spermatic fascia is required for the surgeon to separate the processus vaginalis from the vas and vessels. CONCLUSIONS The average age of children undergoing cryptorchid surgery has decreased dramatically during the last 40 years. In such young patients extensive mobilization of the vas and vessels may be accomplished through a relatively small incision. We believe that our success rate with inguinal orchiopexy for abdominal testis is associated with our anatomical approach to retroperitoneal dissection.

AMIODARONE INDUCED EPIDIDYMITIS IN CHILDREN

PURPOSE Amiodarone is an antiarrythmic agent, which is often successfully used when all other antiarrythmics have failed. Sterile epididymitis is a recognized complication of treatment in adults, occurring in up to 11% of patients. To date there have been no reported cases of amiodarone induced epididymitis in children. We present a previously unrecognized cause of epididymitis in boys. MATERIALS AND METHODS The medical records, including radiographic imaging, pathology and operative reports, of 2 postpubertal boys who had sterile epididymitis after prolonged therapy with amiodarone were reviewed. RESULTS In both cases the onset of scrotal pain and subsequent evaluation led to diagnosis of epidydimitis. Amiodarone was determined to be the cause, and cessation of the drug resulted in symptom resolution in 1 case. CONCLUSIONS While it remains uncertain, the pathophysiology of amiodarone induced epididymitis is likely related to its high concentration in testicular tissue. Recognition that amiodarone is a rare but significant cause of epididymitis in children is important to prevent unnecessary surgery in high risk patients. Amiodarone induced epididymitis in children tends to be a self-limited process and of secondary importance to the serious cardiac disease. Whereas discontinuing amiodarone risks sudden cardiac death, a reduction in dosage or temporary cessation of the drug may result in rapid resolution of the epididymitis.

The Fate of Urinary Bladder Smooth Muscle After Outlet Obstruction—A Role for the Sarcoplasmic Reticulum

In response to outlet obstruction, the human bladder is capable of undergoing an adaptive response.39,45,51 Similar findings have been observed in a rabbit model of partial bladder outlet obstruction. Compensatory hypertrophy can be defined as a bladder that has developed increased mass, wall thickness, and can generate greater pressures to overcome the increased outlet resistance with a non-existent or minimal post void residual urine. While muscle strips from such a bladder may generate the same or slightly less force using in vitro studies, the increase in total bladder wall muscle mass allows the compensated bladder to empty to completion. However, in some instances, bladder decompensation sets in, characterized by less efficient contractile performance and increasing post void residuals.39 In general, bladder wall decompensation and the increasing post void residual urine have a relatively slow and insidious clinical onset with the patient gradually noticing changes in their voiding pattern. At its clinical extreme, bladder decompensation may result in acute urinary retention,39 although this occurs rarely in the United States. Bladder outlet obstruction managed surgically still leaves up to 30% of patients with persisting complaints of lower urinary tract symptoms despite successful removal of the anatomic obstruction.27 It is not known which changes take place in the lower urinary tract that can account for these observations.

THE DECOMPENSATED DETRUSOR IV: EXPERIMENTAL BLADDER OUTLET OBSTRUCTION AND ITS FUNCTIONAL CORRELATION TO THE EXPRESSION OF THE RYANODINE AND VOLTAGE OPERATED CALCIUM CHANNELS

PURPOSE Calcium ion homeostasis has a significant role in smooth muscle function. Its regulation requires complex storage and release mechanisms via ion pumps and channels located within intracellular storage sites (sarcoplasmic reticulum) and at the plasma membrane. A prominent component of the sarcoplasmic reticulum is the ryanodine sensitive ion channel which releases calcium from the sarcoplasmic reticulum into the cytosol. At the level of the plasma membrane the voltage operated calcium channel (dihydropyridine sensitive) serves to allow an influx of extracellular calcium. Our prior studies have shown a loss of sarcoplasmic endoplasmic reticulum Ca++Mg++ATPase expression following outlet obstruction. In this study we correlate ryanodine and voltage operated calcium channel protein expression with bladder function following partial outlet obstruction. MATERIALS AND METHODS Standardized partial bladder outlet obstructions were created in adult New Zealand white rabbits, which were divided into control, sham operated and obstructed groups. Muscle strip studies further subcategorized the obstructed group into compensated (force greater than 50% of control) and decompensated (force less than 50% of control) and were correlated with in vivo determinations of voiding frequency and voided volumes. Microsomal membrane protein fractions were prepared from the same bladder tissue and were used for Western blot analysis using specific monoclonal antibodies. RESULTS Increased voiding frequency and decreased voided volumes correlated with the definitions of compensated and decompensated. The Western blots revealed a near disappearance of ryanodine expression in the decompensated group with minimal changes in the expression of the voltage operated calcium channel. CONCLUSIONS Bladder performance as measured in vivo and in vitro after outlet obstruction is influenced in part by smooth muscle cell ability to maintain calcium homeostasis via the sarcoplasmic reticulum. Bladder decompensation is highly associated with a loss of sarcoplasmic reticulum function with lesser changes taking place in those calcium regulatory proteins at the plasma membrane.