Harnableitung und Dickdarm

[Tissue engineering in reconstructive urology]

The term tissue engineering incorporates various techniques for the production of replacement tissues and organs. In urology tissue engineering offers many promising possibilities for the reconstruction of the urinary tract. Currently, buccal mucosa and urothelial cells are most commonly used for tissue engineering of the urinary tract. Various materials have been tested for their suitability as tissue scaffolds. The ideal scaffold, however, has not yet been found. In addition to material sciences and cell culture methods, surgical techniques play an important role in reconstructive urology for the successful implantation of tissue engineered transplants.

Pediatric surgical complications of major genitourinary reconstruction in the exstrophy-epispadias complex

PURPOSE

Urinary continence is the goal of exstrophy-epispadias complex (EEC) reconstruction. Patients may require a continent urinary diversion (CUD) if they are a poor candidate for bladder neck reconstruction or are receiving an augmentation cystoplasty (AC) or neobladder (NB). This study was designed to identify the incidence of surgical complications among various bowel segments typically used for CUD.

METHODS

A prospectively kept database of 1078 patients with EEC at a tertiary referral center from 1980 to 2012 was reviewed for major genitourinary reconstruction. Patient demographics, surgical indications, perioperative complications, and outcomes were recorded.

RESULTS

Among reviewed EEC patients, 134 underwent CUD (81 male, 53 female). Concomitant AC was performed in 106 patients and NB in 11. Median follow up time after initial diversion was 5 years. The most common CUD bowel segments were appendix and ileum. The most common surgical complications after CUD were small bowel obstruction, post-operative ileus, and intraabdominal abscess. There was a significantly increased risk in the occurrence of pelvic or abdominal abscess when colon was used as a conduit compared to all other bowel segments (OR=16.7, 95% CI: 1.16-239) and following NB creation compared to AC (OR=39.4, 95% CI: 3.66-423). At postoperative follow-up, 98% of patients were continent of urine via their stoma.

CONCLUSION

We report the largest series to date examining CUD in the EEC population. The increased risk of abdominal and pelvic abscesses in patients who receive a colon CUD and undergo NB compared to AC indicates that while surgical complications following major genitourinary reconstruction are rare, they do occur. Practitioners must be wary of potential complications that are best managed by a multi-disciplinary team approach.

Urologic complications of major genitourinary reconstruction in the exstrophy-epispadias complex

OBJECTIVE

To present the authors' experiences with urologic complications associated with various techniques used to create a continent stoma (CS), augmentation cystoplasty (AC), and neobladder in the exstrophy-epispadias complex (EEC) population.

METHODS

Retrospective review of medical records of patients who underwent CS with or without bladder augmentation were identified from an institutional review board-approved database of 1208 EEC patients. Surgical indications, tissue type, length of hospital stay, age, preoperative bladder capacity, prior genitourinary surgeries, postoperative urological complications, and continence status were reviewed.

RESULTS

Among the EEC patients reviewed, 133 underwent CS (80 male, 53 female). Mean follow-up time after initial continent stoma was 5.31 years (range: 6 months to 20 years). Appendix and tapered ileum were the primary bowel segments used for the continent channel and stoma in the EEC population. The most common stomal complications in this population were stenosis, incontinence, and prolapse. Seventy-nine percent of EEC CS patients underwent AC primarily done with sigmoid colon or ileum. Eleven patients (8%) underwent neobladder creation with either colon or a combination of colon and ileum. Bladder calculi, vesicocutaneous fistula, and pyelonephritis were the most common non-stomal complications. Stomal ischemia was significantly increased in Monti ileovesicostomy compared to Mitrofanoff appendicovesicostomy in classic bladder exstrophy patients (p = 0.036). Furthermore, pyelonephritis was more than twice as likely in colonic neobladder than all other reservoir tissue types in the same cohort (OR = 2.53, 95% CI: 1.762-3.301, p < 0.001).

CONCLUSIONS

To the best of the authors' knowledge, this is the largest study examining catheterizable stomas in the exstrophy population. While Mitrofanoff appendicovesicostomy is preferred to Monti ileovesicostomy because it is technically less challenging, it may also confer a lower rate of stomal ischemia. Furthermore, even though ileum or colon can be used in AC with equally low complication rates, practitioners must be wary of potential urologic complications that should be primarily managed by an experienced reconstructive surgeon.