Tunica vaginalis onlay urethroplasty as a salvage repair

Preliminary experience using a tunica vaginalis flap as the dorsal component of Bracka's urethroplasty

OBJECTIVE

To evaluate clinical use of a tunica vaginalis flap as the dorsal component of a two-stage urethroplasty in boys with cripple hypospadias.

PATIENTS AND METHODS

We performed the first stage of a Bracka two-stage urethroplasty, using a tunica vaginalis flap as the dorsal component in six boys with cripple hypospadias. We analysed their clinical characteristics and the results of this technique.

RESULTS

The mean (range) age of the boys was 57 (34-120) months. The mean (range) number of previous procedures the boys had undergone was 4 (3-5). At the 6-month follow-up, all the boys presented significant fibrosis of the dorsal graft rendering it unusable for tubularisation.

CONCLUSIONS

Exposure to the external environment seems to induce retraction and fibrosis of the tunica vaginalis. We believe one should be very cautious about using tunica vaginalis as the dorsal component of a two-stage urethroplasty, as significant fibrosis might well render the flap unusable.

Histopathological characteristics of buccal mucosa transplants in humans after engraftment to the urethra: a prospective study

PURPOSE

Histopathological changes in buccal mucosa transplants after engraftment to the urethra and exposure to urine remain nebulous. We investigated histopathological changes in buccal mucosa transplants integrated into the urethra in humans.

MATERIALS AND METHODS

We prospectively evaluated 22 patients with recurrent urethral stricture after buccal mucosa urethroplasty between November 2012 and October 2013. All patients underwent repeat buccal mucosa urethroplasty performed by a single surgeon. Intraoperatively we harvested a sample of the integrated buccal mucosa transplant previously engrafted to the urethra, a sample of healthy urethra, a sample of freshly harvested buccal mucosa from the contralateral inner cheek and a sample of fibrotic tissue from the area of the current stricture. A dedicated uropathologist performed meticulous histopathological examination of all tissue samples using hematoxylin and eosin staining. Preoperative clinical data were also collected on all patients.

RESULTS

The mean interval from previous to current buccal mucosa urethroplasty was 22.2 months (range 4.1 to 76.0). Mean stricture length at repeat urethroplasty was 52.7 mm (range 30.0 to 70.0). Histopathological characteristics of the integrated buccal mucosa transplants were completely preserved in all patients, consisting of thick sheets of stratified nonkeratinized squamous epithelium with a stratum spinosum. Transplants were not partially or entirely overgrown with urothelium.

CONCLUSIONS

Buccal mucosa transplants retain their histopathological characteristics and are not overgrown with urothelium after urethral engraftment and urine exposure in humans. These findings may explain the superiority of buccal mucosa transplants on the outcome of substitution urethroplasty compared to that of other materials.

Tunica Vaginalis Pedicle Flap for Reconstruction of Anterior Urethral Stricture

OBJECTIVE

To evaluate the intermediate-term clinical efficacy and success rate of tunica vaginalis (TV) pedicle flap for reconstruction of bulbo-penile urethral stricture.

METHODS

We assessed the medical records of 15 male patients who had undergone TV pedicle flap urethroplasty for reconstruction of anterior urethral stricture between January 2006 and December 2011. The surgical outcome was assessed by comparison of four parameters including the maximum flow rate (Qmax ), international prostate symptom score (IPSS), residual urine (RU) and quality of life (QOL) in all patients pre- and postoperatively. Moreover, pre- and postoperative retrograde urethrography films were compared in all patients. t-test was used for data analysis.

RESULTS

The mean patient age was 38.1 ± 9.3 years (range: 25-55), mean stricture length was 4.2 ± 1.1 cm (range: 3-6.1 cm), and the mean follow up time was 14.6 ± 1.9 months (range: 12-18) months. There was a statistically significant difference between Q(max) , IPSS, RU and QOL pre- and postoperatively (P < 0.01). The clinical success rate in this study was 86.6% (13/15). The early complication was one case of wound infection and subsequent wound dehiscence, one case of hematoma formation in another patient, which did not have any influence in the long-term clinical outcome.

CONCLUSION

At intermediate-term follow up, TV pedicle flap urethroplasty has a high clinical success rate with low complication. However, a large clinical trial with long-term follow up is needed to confirm the result.

Dorsal tunica vaginalis graft plus onlay preputial island flap urethroplasty: experimental study in rabbits

OBJECTIVE

To assess the use of tunica vaginalis graft plus onlay preputial island flap in urethral reconstructive surgery in rabbits through histopathology.

MATERIAL AND METHODS

We developed an experimental model of urethroplasty that resembles one-stage complex hypospadias surgery with divided urethral plate. The tunica vaginalis graft is dorsally placed to recreate the urethral plate and the internal preputial island flap is placed onlay to complete the urethroplasty. Sixteen animals were divided into four equal groups and sacrificed at 2, 4, 8 and 12 weeks after surgery, the penis being sent for histopathological evaluation.

RESULTS

There were no deaths related to the procedure or wound breakdown; all rabbits voided spontaneously after surgery. Two urethrocutaneous fistulae were found. Microscopically, good tissue integration was observed, the tunica vaginalis mesothelium was gradually replaced by a more stratified epithelial lining, similar to the urothelial lining of the native urethra. The stratified squamous non-keratinized lining of the internal preputial island flap also changed into a thinner epithelial lining with only 4-5 cell layers. Two urethral diverticula were found.

CONCLUSION

A tunica vaginalis graft placed dorsally plus an onlay internal preputial island flap was shown to be a successful technique for urethroplasty in an animal model.

Interim outcome of the single stage dorsal inlay skin graft for complex hypospadias reoperations

PURPOSE

Despite high success rates for primary hypospadias repair, some cases require multiple procedures for ultimate reconstruction. We report our experience with single stage dorsal inlay urethroplasty using skin grafts for complex reoperations.

MATERIALS AND METHODS

A total of 31 patients (mean age 13.8 years) with failed previous hypospadias surgery were included in the study. Indications included fistulas, strictures, diverticula and repair breakdown. The urethral plate had been removed or was severely scarred in all patients. A free penile or groin skin graft was sutured and quilted to the corpora cavernosa, guaranteeing sufficient blood supply. The neourethra was tubularized and covered with a tunica vaginalis or dartos flap, followed by glanuloplasty. Outcome analysis included urethrograms, urethral ultrasound and flow measurements.

RESULTS

Foreskin was used in 15 cases, penile skin in 12 and inguinal skin in 4. Average graft length was 3.92 cm. A total of 20 patients required glanuloplasty with a skin graft extended to the tip of the glans. After a mean followup of 30.71 months 5 patients underwent redo surgery, for a complication rate of 16.1%. Urethral stricture of the proximal anastomosis was the most frequent finding.

CONCLUSIONS

This single stage approach using dorsal skin grafts is a reliable method to create a substitute urethral plate for tubularization. Complication rates are equivalent to those of staged procedures. Foreskin should be used as a graft donor site to optimize the outcome if available. This approach represents a safe option for reoperations even if the urethral plate or midline penile skin is grossly scarred.

Urethroplasty using a bovine pericardium graft: an experimental study using normal urethras from dogs

The use of bovine pericardium as a urethral patch to substitute a ventral segment of canine urethras was studied. Healing, epithelial growth, urethral permeability, fistulas, and calcification were analyzed. Thirty male mongrel dogs of medium and large size underwent resection of a ventral segment of the medial urethra measuring 2.0 x 0.5 cm, which was replaced with a bovine pericardium graft, treated with buffered glutaraldehyde and preserved in formaldehyde. Two running sutures of polygalactin 5-0 were applied, one on each side of the patch. The corpus spongiosum was closed with uninterrupted suture and the skin with interrupted suture of polygalactin 5-0. Six months later, the animals were examined and sacrificed under anesthesia. Retrograde urethrograms showed that the urethral healing was complete in six of the 30 animals, without stenosis, fistulas or dilations. Microscopic examination showed complete epithelization of these six urethras. The remaining 24 animals presented urethrocutaneous fistulas without stenosis, demonstrated by urethral catheterism using a 10-Fr plastic catheter. These data show that a successful urethral reconstruction of the penile urethra was possible in only 20% of the operated animals. Infection and leakage may be the cause of the urethrocutaneous fistulas present in 80% of cases. Further studies are necessary to determine whether such fistulas are avoidable. If they are, the bovine pericardium may well be an option in the treatment of urethral lesions in dogs.

Tube-onlay-tube tunica vaginalis flap for proximal primary and reoperative adult hypospadias

PURPOSE

We describe the surgical technique of and report the results in the first 20 patients who underwent combined onlay-tube construction of a tunica vaginalis flap.

MATERIALS AND METHODS

We repaired 20 cases of proximal primary (8) and repeat (12), adult hypospadias using a tube-onlay in 4, an onlay-tube in 3, a tube-onlay-tube in 9 and an onlay-tube-onlay in 4. In 15 patients contralateral tunica vaginalis was used as a blanket wrap. Three to 6 months postoperatively after obtaining informed consent retrograde urethrography, cystourethroscopy, uroflowmetry and urethral biopsy were done in 20, 17, 10 and 13 patients, respectively.

RESULTS

No fistula or diverticulum developed. Complications occurred in 3 patients (15%), including urethral stricture, meatal stenosis and urethral stricture, and meatal regression and urethral stricture in 1 each. All strictures occurred in the distal urethra in reoperative cases. At long-term followup there was no recurrent stricture or meatal stenosis after internal urethrotomy and dilation. Urethral biopsy in all 13 patients showed a stratified epithelium indistinguishable from native urethra. The reasons for delayed presentation include perceiving hypospadias as a normal variation (paribor or cut by angels), losing hope for a cure after multiple failed repairs, being told by urologists that repair is futile and pressure by wives for cosmetic or fertility reasons.

CONCLUSIONS

The place of tunica vaginalis in hypospadias surgery is more than coverage for urethroplasty. It can be successfully used for substitution urethroplasty. As an extension to the principles of the onlay flap and the concept of urethral plate preservation, combined onlay-tube constructions of tunica vaginalis, including a tube-onlay-tube flap, are successfully applicable to proximal hypospadias, especially in reoperative cases. Urothelialization of the tunica vaginalis occurs within months of surgery.