UROLOGICAL SURVEY   ( Download pdf )

 

RECONSTRUCTIVE UROLOGY

Bladder growth and development after complete primary repair of bladder exstrophy in the newborn with comparison to staged approach
Borer JG, Gargollo PC, Kinnamon DD, Bauer SB, Khoshbin S, Hendren WH, Peters CA, Diamond DA, Atala A, Chin S, Retik AB
Department of Urology, Children’s Hospital Boston, Boston, Massachusetts, USA
J Urol. 2005; 174 (4 Pt 2): 1553-7; discussion 1557-8

  • Purpose: We assessed bladder growth and dynamics following complete primary repair of bladder exstrophy (CPRE) compared to the staged approach.
  • Materials and Methods: We reviewed the records of 16 boys and 7 girls who underwent CPRE within 3 days of life from 1996 to 2004 and compared them to the records of 8 boys and 6 girls treated with a staged repair from 1979 to 1996. Screening methods included voiding cystourethrogram, radionuclide cystogram and urodynamic study. We estimated growth curves for bladder capacity following repair in each group, and compared percent predicted bladder capacity (PPBC), compliance and detrusor overactivity between the CPRE and staged repair groups following bladder neck reconstruction.
  • Results: Bladder capacity in the staged repair group was 69.8 ml (95% CI 46.7-104.4) immediately after bladder neck reconstruction and increased by 15.0% per year thereafter (95% CI 6.2-24.5, p = 0.002). In the CPRE group bladder capacity was 29.0 ml (95% CI 21.3-39.5) initially and increased by 28.9% per year thereafter (95% CI 17.4-41.5, p <0.001). PPBC started at 45.6% (95% CI 35.7-55.5) and increased 1.2% per year (95% CI -1.1-3.5, p = 0.29) following repair for all genders and surgery groups. Compliance was 124.4% (95% CI 22.6-310.7, p = 0.01) greater in the CPRE group at all times following repair. Detrusor overactivity was present in 0 of 19 patients in the CPRE group and 6 of 13 (46%) in the staged group (exact p = 0.002).
  • Conclusions: Within the CPRE group bladder stability was universal, and sphincter electromyography was normal suggesting no neuromuscular compromise of the pelvic floor. At early followup, our results suggest that PPBC is equivalent irrespective of gender or management. Further objective evaluation is needed in both groups.

Magnetic resonance imaging of pelvic musculoskeletal and genitourinary anatomy in patients before and after complete primary repair of bladder exstrophy
Gargollo PC, Borer JG, Retik AB, Peters CA, Diamond DA, Atala A, Barnewolt CE.
Department of Urology and Radiology, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts, USA
J Urol. 2005; 174 (4 Pt 2): 1559-66; discussion 1566

  • Purpose: We characterize pelvic soft tissue and bony anatomy of patients before and after complete primary repair of exstrophy (CPRE).
  • Materials and Methods: We evaluated 15 measurements on pelvic magnetic resonance imaging (MRI) in patients who underwent CPRE without osteotomy at our institution from 1996 to 2004. MRI protocols included axial, sagittal and coronal fast spin echo proton density sequences. Measurements were compared before and after CPRE using a paired t test, and between patients after CPRE, and age and gender matched controls using linear regression adjusting for the matched case-control groups. Patients older than 3 years with continent intervals longer than 3 hours after CPRE were compared to age and gender matched controls using linear regression.
  • Results: A total of 29 MRIs in 18 patients with exstrophy were available for analysis. Median patient age at postoperative MRI was 25 months (range 4 to 36). The configuration of the post-CPRE pelvis was significantly different from that of controls in all parameters measured including wider symphyseal diastasis (34.5 mm vs less than 1 mm) and more obtuse iliac wing (121 degrees vs 98 degrees), puborectalis (94 degrees vs 49 degrees) and ileococcygeus angles (111 degrees vs 98 degrees). The anatomy of continent patients after CPRE was not significantly different from that of controls in most parameters measured.
  • Conclusions: Comparison of the pelvic anatomy in patients before and after CPRE suggests that after CPRE patients have parameters that more closely approximate, but are still significantly different, from those of control patients. Patients with greater than 3-hour continent intervals after CPRE have anatomic parameters most similar to those of age matched controls.

  • Editorial Comment
    The authors compared their data regarding lower urinary tract function as well as renal function in 16 boys and 7 girls treated with a complete primary repair of bladder exstrophy. Early primary repair is defined as repair within the first 3 days of life; these patients were compared to a group of 8 boys and 6 girls treated with a staged repair in bladder exstrophy. Furthermore the same authors studied MRI findings in 18 of these patients at various intervals after complete primary repair (and in some patients also prior to surgery).
    Bladder capacity, compliance and detrusor overactivity were surrogates for detrusor function in both primary and staged repair groups. The “percent predicted bladder capacity” per individual patient was not different between neither surgical groups nor gender. The conclusion was therefore that bladder capacity is more dependent on intrinsic factors than surgical technique. 72% of female and 86% of male patients did require a bladder neck reconstruction in the long-term follow up after complete primary repair in order to achieve continence. It is therefore speculated that the better results after early primary repair regarding overactivity (none of the patients in the primary repair group did show detrusor overactivity versus 46% in the staged group) may be the result of a decreased bladder outlet resistance.
    The results concerning compliance were also better in the primary repair group, which can be partially explained by decreased outlet resistance. It is a fact that in both groups male patients showed a decline in compliance, which supports the speculation about the role of resistance and bladder function in the long term.
    Apart from bladder function, complete voiding and continence are additional important long-term outcome parameters and it is only partially resolved. Among the anatomical landmarks seen upon endoscopy in adolescence and adults, location of the verumontanum and length and width of the urethral sphincteric segment are important. Even for the most experienced surgeons it is extremely difficult to adequately reconstruct the sphincteric structures within the first few days of life. Good functionality of the earliest possible reconstruction is here hampered by what the surgeon can do with only partially developed and in times invisible structures.
    In an attempt to predict continence in patients with complete primary repair with the same group studied an array of measurements in pelvic MRI using various bone and soft tissue landmarks and angles. It is not surprising that the measurements performed were significantly different from age for most parameters. However, the closer the landmarks and angles of the treated exstrophy patients were compared to normal age- and gender matched controls, the better were the results with regards to continence and bladder capacity. Whether all these measurements can be reduced for practicality e.g. symphyseal diastases and the puborectalis sling angle will have to be proven in larger studies with more patients.
    These 2 papers nicely demonstrate that early reconstruction seems to improve the physiological function of the exstrophy bladder smooth muscle cell. However, some of the sphincteric structures are not sufficiently developed to allow a satisfactory reconstruction in most patients. Furthermore we need to include the reconstruction of the entire bony and muscular pelvis to achieve success with storage, emptying and continence. The liberal and sophisticated use of new imaging techniques can be helpful as in many other parts of reconstructive surgery.

Dr. Arnulf Stenzl &
Dr. Karl-Dietrich Sievert

Department of Urology
Eberhard-Karls-University Tuebingen
Tuebingen, Germany