TUNICA VAGINALIS FOR CORRECTING PENILE CHORDEE IN A RABBIT MODEL: IS THERE A DIFFERENCE IN FLAP VERSUS GRAFT?

Recurrent ventral curvature after corporoplasty with tunica vaginalis flap

INTRODUCTION AND OBJECTIVE

Optimal means to correct ventral curvature (VC) is debated. Our preferred technique for curvature greater than 45° is corporoplasty using tunica vaginalis flap (TVF). We describe our complications with TVF for ventral lengthening.

METHODS

Forty-four boys who underwent ventral lengthening with a corporoplasty with TVF were identified in a prospective database for proximal hypospadias repair by a single surgeon from 2008 to 2021. Corporotomy was performed by incising the tunica albuginea of the corpora cavernosa transversely at the point of maximum curvature. Harvested TVF was tailored to the size of the corporotomy and anastomosed to the edges of the tunica albuginea and on laid to the corporal defect with the mesothelial side of the TVF abutting the erectile tissue.

RESULTS

Median age at surgery was 1.0 years (IQR 0.72-1.82). Median follow-up time was 4.9 years (IQR 2.6-8.0). Thirteen patients (27%) were older than 10 years of age at last follow up (median 13.3, range 10-20). Twenty-two boys (50%) received preoperative testosterone. The most common location of the meatus after degloving was penoscrotal (41%). Median VC after degloving was 90° (IQR 80-100). The urethral plate was transected in 43/44 (98%) of boys, improving median VC to 60° (IQR 40-60). After corporotomy, the median longitudinal distracted distance was 15 mm (IQR 12-17). Urethral reconstruction was most commonly achieved with the transverse island preputial flap technique or its modifications (39/44; 89%). Erections were reported in 42 boys (95%). None developed corporal diverticula, and two patients (4.5%) had ascended testis associated with TVF harvest. Seven percent of boys had recurrent ventral curvature (RVC; 3/44). Median RVC was 30° (IQR 30-45). One patient had RVC at the penoscrotal junction (not at site of prior corporoplasty) identified 11 years post operatively at age 15, and underwent dorsal plication. The other 2 patients were diagnosed less than 1 year post operatively. Both patients received testosterone due to small glans size, had double-face tubularized transverse island preputial flap as urethral and ventral skin coverage, and had endocrine and genetic consultation. Both had scarring of the preputial flap and of the corporoplasty. Scar excision and superficial transverse incisions on the tunica albuginea corrected RVC.

CONCLUSIONS

The five-year outcome of ventral penile lengthening using TVF for corporoplasty is favorable with 7% of boys with RVC, and 4.5% with ascended testes associated with TVF harvest. None developed corporal diverticula.

Evaluation of Bi-Layer Silk Fibroin Grafts for Penile Tunica Albuginea Repair in a Rabbit Corporoplasty Model

The use of autologous tissue grafts for tunica albuginea repair in Peyronie's disease and congenital chordee is often restricted by limited tissue availability and donor site morbidity, therefore new biomaterial options are needed. In this study, bi-layer silk fibroin (BLSF) scaffolds were investigated to support functional tissue regeneration of tunica albuginea in a rabbit corporoplasty model. Eighteen adult male, New Zealand white rabbits were randomized to nonsurgical controls (NSC, N = 3), or subjected to corporoplasty with BLSF grafts (N = 5); decellularized small intestinal submucosa (SIS) matrices (N = 5); or autologous tunica vaginalis (TV) flaps (N = 5). End-point evaluations were cavernosography, cavernosometry, histological, immunohistochemical, and histomorphometric assessments. Maximum intracorporal pressures (ICP) following papaverine-induced erection were similar between all groups. Eighty percent of rabbits repaired with BLSF scaffolds or TV flaps achieved full rigid erections, compared to 40% of SIS reconstructed animals. Five-minute peak erections were maintained in 60% of BLSF rabbits, compared to 20% of SIS and TV flap reconstructed rabbits. Graft perforation occurred in 60% of TV group at maximum ICP compared to 20% of BLSF cohort. Neotissues supported by SIS and BLSF scaffolds were composed of collagen type I and elastin fibers similar to NSC. SIS and TV flaps showed significantly elevated levels of corporal fibrosis relative to NSC with a corresponding decrease in corporal smooth muscle cells expressing contractile proteins. BLSF biomaterials represent emerging platforms for corporoplasty and produce superior functional and histological outcomes in comparison to TV flaps and SIS matrices for tunica albuginea repair.

Tunica vaginalis graft for recurrent urethrocutaneous fistula repair after hypospadias surgery

OBJECTIVES

To evaluate the outcomes of recurrent urethrocutaneous fistula repair using tunica vaginalis graft as an intermediate protective layer.

METHODS

We retrospectively reviewed the data of 45 children with recurrent urethrocutaneous fistula who underwent tunica vaginalis graft repair between February 2011 and January 2019. The repair was carried out at least 6 months after a previous fistula repair. Follow up at an outpatient clinic was scheduled on a weekly basis for 1 month, then monthly for 6 months and then annually. During follow up, every patient was evaluated by history taking. The site of repair and the act of micturition were inspected. Urine analyses together with culture and sensitivity tests were carried out if required. Successful repair was defined as the absence of recurrence, with good force and caliber of the urinary stream.

RESULTS

This study included 45 patients with recurrent urethrocutaneous fistula who were managed with a tunica vaginalis graft as a second layer. The mean age of patients was 6.7 ± 2.8 years. The mean postoperative hospital stay was 5.5 ± 0.7 days. The repair was successful for 43 (95.6%) patients, and urethrocutaneous fistula recurrence was reported for two (4.4%) patients, which were repaired after 6 months. In all patients, the cosmetic appearance of the penis was satisfactory without torsion or ventral chordee.

CONCLUSION

Tunica vaginalis graft is a simple and fast procedure that is highly effective as a protective second layer for recurrent urethrocutaneous fistula repair.

Can a graft be placed over a flap in complex hypospadias surgery? An experimental study in rabbits

Purpose:

To develop a rabbit experimental study to test the hypothesis that surgical repair of hypospadias with severe ventral curvatures might be completed in one stage, if a graft, such as buccal mucosa, could be placed over the tunica vaginalis flap used in corporoplasty for ventral lengthening, with the addition of an onlay preputial island flap to complete the urethroplasty.

Materials and methods:

The experimental procedure with rabbits included a tunica vaginalis flap for reconstruction of the corpora after corporotomy, simulating a ventral lengthening operation. A buccal mucosa graft was placed directly on top of the flap, and the urethroplasty was completed with an onlay preputial island flap. Eight rabbits were divided into 4 groups, sacrificed at 2, 4, 8 and 12 weeks postoperatively, and submitted to histological evaluation.

Results:

We observed a large number of complications, such as fistula (75%), urinary retention (50%) and stenosis (50%). There were two deaths related to the procedure. Histological evaluation demonstrated a severe and persistent inflammatory reaction. No viable tunica vaginalis or buccal mucosa was identified.

Conclusions:

In this animal model, the association of a buccal mucosa graft over the tunica vaginalis flap was not successful, and resulted in complete loss of both tissues.

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.

Onlay foreskin flap anastomosed directly to the tunica albuginea: a short-term experimental study in rabbits

INTRODUCTION

In severe hypospadias, urethral plate division is necessary for curvature correction. To configure the new urethra, an approach has been described using a foreskin flap directly anastomosed in an 'onlay' fashion to the tunica albuginea of the corpora cavernosa. Results suggest that it is possible to use the corpus cavernosum albuginea as the posterior wall of the neourethra without the need of a dorsal graft.

OBJECTIVE

The present experimental study aimed to evaluate the histological characteristics and healing pattern of this procedure.

STUDY DESIGN

Sixteen New Zealand male rabbits were divided into two groups of eight animals. Eight animals underwent 1-cm longitudinal dorsal incision of the penile urethra and the edges were anastomosed to the tunica albuginea (Group 1). Eight other animals underwent complete excision of 1.0 cm of penile urethra. Urethroplasty was performed using a foreskin flap directly anastomosed as an onlay to the albuginea, as shown in the figure (Group 2). Sacrifice and histological assessment was performed 2, 4, 8 and 12 weeks postoperatively.

RESULTS

In Group 1, a mild inflammatory process was noted that became almost imperceptible at 12 weeks. Fibrosis was mild at all stages in this group. Over time, a regenerative epithelium covered the corpus cavernosum. Immunohistochemistry using specific CK-7 and CK-20 confirmed the presence of urothelium. No complications were microscopically detected in this group. Group 2 presented with a more intense inflammatory infiltrate, which also resolved over time. Fibrosis was slightly more intense in this group, especially in animals that had urethral strictures. Group 2 presented with three fistulas, two were associated with urethral stricture. Histological evaluation showed the presence of epithelization over the albuginea, which turned out to be similar to the normal urothelium over time and was confirmed by immunohistochemistry. Non-keratinized stratified squamous epithelium of the foreskin flap showed good integration to the urethra.

DISCUSSION

Microscopic analysis showed that inflammation, fibrosis and complications were similar to previous studies. At 12 weeks there was a well-developed epithelium similar to normal urethra, which was confirmed by immunohistochemistry; this was similar to what occurs in the TIP technique, as previously demonstrated. It was hypothesized that the epithelium regeneration developed from the urethral edges, as demonstrated in other experimental studies.

CONCLUSION

The albuginea was covered by mature urothelium after 12 weeks, which presumably grew from the urethral edges. The foreskin flap onlay that was directly anastomosed to the albuginea completely integrated and constituted the roof of the neourethra.

A critical analysis of the surgical outcomes for the treatment of Peyronie's disease

Peyronie’s disease (PD) is a relatively common condition, which can impair sexual function and result in emotional and psychological distress. Despite an abundance of minimally invasive treatments, few have confirmed efficacy for improving penile curvature and function. Surgical therapies include many different techniques and are reserved for patients with stable disease of ⩾12 months’ duration. We searched PubMed for all articles from 1990 to the present relating to the surgical management of PD. Preference was given to recent articles, larger series, and those comparing various techniques and/or materials. Outcomes were subsequently analysed and organised by surgical technique and the graft material used. Available surgical techniques include plication/corporoplasty procedures, incision and grafting (I&G), and placing a penile prosthesis with or without adjunctive procedures. Although several surgical algorithms have been reported, in general, plication/corporoplasty procedures are reserved for patients with adequate erectile function, simple curvatures of <60°, and with no deformities (hour-glass, hinge). I&G are reserved for complex curvatures of >60° and those with deformities. Penile prostheses are indicated for combined erectile dysfunction and PD. Overall outcomes show high rates of improved curvature and patient satisfaction, with mildly decreased erectile function with both plication and the I&G procedure (I&G >plication) and decreases in penile length (plication >I&G). Surgical management of PD remains an excellent treatment option for patients with penile curvature precluding or impairing sexual activity. Surgical algorithms are available to assist treating clinicians in appropriately stratifying surgical candidates. Additional research is needed to identify optimal surgical techniques and materials based on patient and disease characteristics.

Ventral corporal body grafting for correcting severe penile curvature associated with single or two-stage hypospadias repair

PURPOSE

The literature on small intestinal submucosa for chordee correction in children is scarce. We reviewed our experience with 1 ply SIS for ventral corporal body grafting in cases of severe ventral penile curvature associated with proximal hypospadias in children.

MATERIALS AND METHODS

From 04-2001 to 12-2007, 58 boys with proximal hypospadias and severe ventral curvature underwent single layered SIS graft to the corporal bodies to correct chordee. In 43 patients the surgery was done in the first stage of a planned 2-stage procedure. Fifteen patients underwent a 1-stage chordee correction with SIS and tubularized transverse preputial flap urethra.

RESULTS

Mean follow-up was 4.8 years. A straight phallus with good cosmesis was achieved in 57/58 patients. In 51/58 patients an artificial erection was performed in the operating room as part of a second stage procedure or for complications associated with the one stage urethroplasty. One patient needed a second procedure to correct the curvature (chordee was over-corrected and needed a ventral Nesbitt plication). In fifteen patients that underwent a 1-stage genital reconstruction, the neourethral meatus was left in the lower part of the glans in 8 patients and at the coronal sulcus in 7.

CONCLUSIONS

Corporal body grafting with single layer SIS is a viable option for correction of severe chordee associated with corporal body disproportion. SIS is a material with reliable results, easy availability and no donor site associated morbidity. As a result of penile elongation with a graft, simultaneous island flap urethroplasty became difficult in many patients.

Demonstration of postoperative effectiveness in ventral lengthening using a tunica vaginalis flap for severe penile curvature with hypospadias

OBJECTIVES

To evaluate the postoperative effectiveness of ventral lengthening with a tunica vaginalis flap. Correcting penile curvature is an essential step in proximal hypospadias surgery. It is logical to lengthen the ventral radius using a graft; however, penile curvature would recur owing to a graft contracture with inadequate vascularization. Although a tunica vaginalis is considered a suitable material to be used as a flap instead of a graft, clinical application of this technique is uncommon. Information regarding the usefulness and effectiveness of this procedure is required.

METHODS

Between 2003 and 2008, we repaired 146 patients with hypospadias and the urethral plate was transected in 39 patients because of severe curvature. Significant severe curvature persisting even after transection of the plate was corrected with ventral corporeal lengthening procedures using a tunica vaginalis flap in 15 patients and postoperative results were evaluated.

RESULTS

Straight penile erection was identified in all 15 boys at home by their parents. In 7 of the 15 boys, artificial erection was performed at the time of additional surgery; 5 degrees of curvature was found in 2 patients and 0 degree in 5.

CONCLUSIONS

At the second session of surgery, we observed that penile straightening was maintained without recurrence of curvature. Additionally, the area in which the tunica vaginalis flap was placed on the ventrum did not contract. Therefore, lengthening the ventral aspect using a tunica vaginalis flap might be an important alternative for correction of severe penile curvature in hypospadias surgery.

Ventral penile lengthening versus dorsal plication for severe ventral curvature in children with proximal hypospadias

PURPOSE

The 2 main approaches to correct severe ventral curvature are dorsal plication of the corpora and ventral corporeal lengthening by tunica albuginea patching. Controversy persists since neither technique has been proved to be superior to the other with respect to initial or long-term outcome. However, to our knowledge a direct comparison of outcome of these 2 procedures has not been previously reported.

MATERIALS AND METHODS

A retrospective review of the records of 100 consecutive patients who underwent repair of penoscrotal or more proximal defects from 1996 to 2004 was performed. Children were divided into 2 groups, including group 1-32 who underwent a ventral penile lengthening procedure and group 2-68 who underwent dorsal plication. Meatal location, preoperative testosterone stimulation, severe ventral curvature (greater than 45 degrees) at the beginning of operation and after degloving, proximal ventral dissection, urethral plate transection and recurrent ventral curvature were compared between the 2 groups.

RESULTS

Mean age was 17 months (range 9 to 56) in patients with ventral penile lengthening and 17.8 months (range 10 to 58) in patients with dorsal plication. Mean followup was 65 (range 29 to 120) and 62 months (range 30 to 116), respectively. Of the 32 group 1 children 30 (93.7%) had penoscrotal or more proximal hypospadias vs 57 of the 68 (83.8%) in group 2. Three of the 32 children who underwent ventral penile lengthening had recurrent ventral curvature vs 19 of the 68 who underwent dorsal plication (9.4% vs 27.9%, p = 0.03). On multivariate analysis dorsal plication remained significantly associated with recurrent ventral curvature independently of the other factors (OR 4.56, 95% CI 1.14-18.28, p = 0.03).

CONCLUSIONS

Dorsal plication was more often associated with recurrent ventral curvature compared to ventral penile lengthening on univariate and multivariate analysis. Future studies adjusting for proximal ventral dissection and urethral plate transection are necessary to further elucidate the role of each technique in the correction of severe ventral curvature in children with proximal hypospadias.

Current concepts in hypospadias surgery

Anatomical anomalies in hypospadias are an abnormal ventral opening of the urethral meatus, abnormal ventral curvature of the penis and abnormal distribution of the foreskin around the glans with a ventrally deficient hooded foreskin. The techniques of hypospadias surgery continue to evolve. The current standard of care for hypospadias repair includes not only a functional penis adequate for sexual intercourse and urethral reconstruction offering the ability to stand to urinate, but also a satisfactory cosmetic result. Tubularized incised plate repair has been the mainstay for distal hypospadias. In cases of proximal hypospadias, one-stage repairs such as the Duckett repair or the Koyanagi repair have been well established, while two-stage repairs remain important alternatives. Whether dorsal plication or ventral lengthening should be used to correct penile curvature is still controversial, and long-term results are required. Efforts have been made in this decade to improve cosmetic appearance, constructing a slit-like meatus or performing foreskin reconstruction, and to prevent onerous complications.

Outcome Analysis of Severe Chordee Correction Using Tunica Vaginalis as a Flap in Boys With Proximal Hypospadias

PURPOSE

There is ongoing controversy regarding optimal treatment for severe ventral curvature. It has been suggested that ventral corporeal lengthening may be associated with recurrent curvature and erectile dysfunction. To further assess these issues we reviewed our experience with ventral penile lengthening for correcting the severe ventral curvature associated with proximal hypospadias.

MATERIALS AND METHODS

We reviewed the records of 38 boys with severe hypospadias and congenital ventral curvature greater than 45 degrees who were treated at our institution from 1995 to 2004 with placement of a flap or graft in the corporeal bodies to straighten the phallus. Of the patients 21 had perineal and 17 had penoscrotal hypospadias, including 22 with associated penoscrotal transposition and/or bifid scrotum and 6 with ambiguous genitalia. Testosterone stimulation before surgery was given in 11 children at surgeon discretion.

RESULTS

Median age at surgery was 15 months. The urethral plate was divided in 94.7% of patients. A tunica vaginalis flap was used alone in 23 cases and associated with dura, pericardium or small intestinal submucosa in 8, 2 and 1, respectively. The remaining 4 patients underwent ventral grafting alone, including lyophilized dura in 1, pericardium in 1 and dermis in 1. Urethral reconstruction was achieved by the transverse island flap technique or 1 of its modifications in 34 children. Four boys underwent a 2-stage procedure. Followup available on 35 of 38 patients was 1 to 11 years (median 5.3). Recurrent ventral curvature in 5 of 35 patients was mild in 1 and clinically significant, requiring re-intervention, in 4. Four of 9 patients (44.4%) who underwent corporeal grafting with lyophilized dura had recurrent ventral curvature vs 1 of 23 (4.3%) who had a tunica vaginalis flap (chi-square 5.14, p = 0.02). At last followup straight erections were documented by patients and/or parents in 30 of 35 children (85.7%).

CONCLUSIONS

The short-term outcome of ventral penile lengthening using tunica vaginalis flap alone for correcting severe chordee is favorable with a 95% success rate. Dural grafts were associated with a higher risk of recurrent ventral curvature compared to tunica vaginalis flaps. Although most of our patients were not yet adults, when chordee and erectile dysfunction may become apparent, we believe that tunica vaginalis flap repair is a good option for correcting severe ventral curvature.

Proximal Hypospadias With Severe Chordee: Single Stage Repair Using Corporeal Tunica Vaginalis Free Graft

PURPOSE

We report the results of corporeal tunica vaginalis free graft for single stage correction of severe chordee in children with proximal hypospadias.

MATERIALS AND METHODS

A total of 18 children with proximal hypospadias and severe chordee underwent tunica vaginalis free graft for correction of chordee and urethroplasty. The graft was anastomosed to the ventral surface of the corpus cavernosum to correct severe penile curvature without dorsal plication of the corpus cavernosum. Single stage urethroplasty was then performed. In cases where the urethral plate was too short for urethral reconstruction a transverse preputial island flap was used for single stage urethroplasty. If the incised urethral plate did not have a well vascularized and supple appearance or the prepuce was not sufficient for phallic coverage, we transected the urethral plate and staged urethroplasty was done.

RESULTS

Mean followup was 27.5 months. In 13 patients ventral chordee was corrected using tunica vaginalis free graft without transecting the urethral plate, and urethroplasty was performed in 1 stage. In 3 patients the urethral plate was transected and a transverse preputial island flap was used for single stage urethroplasty. In 2 patients the urethral plate was transected and interposed with dermal graft and tunica vaginalis free graft, followed by staged urethroplasty. There was mild residual chordee in 2 cases. One child had a urethrocutaneous fistula at 2 weeks postoperatively, and 1 presented with obstructive pattern uroflowmetry due to meatal stenosis.

CONCLUSIONS

In this preliminary report the majority of patients with proximal hypospadias and severe chordee were successfully treated with single stage repair using tunica vaginalis free graft for correction of severe chordee.

Graft Materials in Peyronie's Disease Surgery: A Comprehensive Review

OBJECTIVE

To discuss the currently used graft materials in Peyronie's surgery.

METHODS

A MEDLINE search was conducted till the end of September 2006 on the surgical treatment of Peyronie's disease, and all aspects of the graft materials used for Peyronie's surgery were examined.

RESULTS

Currently available interposing graft materials may be classified in three categories: autologous tissues, extracellular matrix (ECM) tissues, and synthetic materials. Each grafting material in these categories has its own advantages and drawbacks in terms of tissue properties, antigenicity, availability, and cost-effectiveness. Saphenous vein grafts are the most widely used among autologous grafts, with acceptable functional outcomes in the long term. Other graft materials include tunica vaginalis, fascia lata, rectus fascia, and buccal mucosa, with variable results. Despite numerous advantages in terms of tissue compatibility, the major drawback of autologous grafts is tissue harvesting that to morbidities and longer operative durations. For this reason, the use of readily available ECM tissues as the products of tissue engineering is recommended by some authors. Among ECM grafts, cadaveric and bovine pericardia have satisfactory mid-term outcomes. However, longer follow-ups with an adequate number of patients are lacking. On the other hand, recent evidence suggests that small intestinal submucosa may be associated with high rate of operative failure and complications. Generally, synthetic materials are no longer used in grafting procedures in Peyronie's surgery because of their antigenicity and inappropriate functional properties. For prosthesis surgery, pericardia as well as autologous rectus fascia grafts are probably the most suitable graft materials because of their suitable tissue characteristics that satisfy the mechanical demands of the prosthesis.

CONCLUSION

Saphenous vein grafting from autologous tissues and pericardium from ECM tissues have satisfactory results. However, further research and clinical studies are needed in order to determine the optimal graft material.

Correction of Penile Curvature by Rotation of the Corpora Cavernosa: A Case Report

AIM

We report on the corporal rotation technique, customized for the management of ventral curvature in patients without hypospadias.

METHODS

A male patient with ventral curvature of 90 degrees was operated on. The neurovascular bundle was mobilized for a short distance at the point of maximum curvature. The corpora cavernosa were approximated to each other in the dorsal midline by suturing pairs of longitudinal parallel incisions. To avoid urethral narrowing, minimal dissection was used to develop the groove on either side of the corpus spongiosum, to release it from its attachment to the rotated corpora cavernosa.

RESULTS

Full correction of the curvature was achieved, without shortening, erectile dysfunction, or micturition problems.

CONCLUSION

Corporal rotation can be applied for the correction of ventral penile curvature in patients with and without hypospadias, without sacrificing penile length.

Single-layer small intestinal submucosa or tunica vaginalis flap for correcting penile chordee

OBJECTIVE

To evaluate the use of single-layer small intestinal submucosa (SIS) and tunica vaginalis flap (TVF) for covering defects in the ventral surface of the tunica albuginea to correct severe penile chordee.

MATERIALS AND METHODS

In all, 24 New Zealand white rabbits had a rectangular area excised from the ventral surface of tunica albuginea. In 12 rabbits TVF was used to cover the defect and in the remaining animals single-layer SIS was used. Animals were killed in groups of four at 2-, 6- and 12-week intervals after surgery. Before death in the 12-week group, an artificial erection was induced and cavernosography performed. Transverse sections of the penis at the graft site were stained with haematoxylin and eosin and Masson's trichrome, and examined microscopically.

RESULTS

None of the animals developed haematoma or bleeding. The mean operative duration for TVF and SIS grafts were 56 and 29 min, respectively (P < 0.001). At the time of autopsy, there was no contracture in any of the rabbits. Of the 8 rabbits assessed, all had a straight rigid erection and cavernosography showed evidence of an intact corporal veno-occlusive mechanism. Histologically at 6 and 12 weeks, the mesothelial layers of the TVF and the SIS graft were completely replaced by well-collagenized tissue similar to that of normal tunica albuginea, with no inflammatory infiltrate.

CONCLUSIONS

Both the TVF and single-layer SIS graft are viable comparable options for corporal body grafting. The 'off-the-shelf' availability, significantly quicker operation and absence of donor site morbidity make single-layer SIS better than TVF for correcting chordee.

4 LAYER VERSUS 1 LAYER SMALL INTESTINAL SUBMUCOSA FOR CORRECTION OF PENILE CHORDEE: EXPERIMENTAL STUDY IN A RABBIT MODEL

PURPOSE

We evaluated the use of 4 vs 1 layer small intestinal submucosa (SIS) for covering defects in the ventral surface of the tunica albuginea to correct severe chordee.

MATERIALS AND METHODS

A total of 18 New Zealand white rabbits underwent implantation of a 10 x 5 mm SIS graft following excision of a rectangular area in the ventral surface of the tunica albuginea. In 9 rabbits 4 layer SIS was used to cover the defect and in the remaining animals 1 layer SIS was used. The animals were sacrificed at 2, 6 and 12-week intervals postoperatively, respectively. The surface area of the grafts was measured and the percent of contracture was calculated. Transverse sections of the penis at the graft site were stained with hematoxylin and eosin, and Masson's trichrome, and examined microscopically.

RESULTS

: None of the animals had hematoma or bleeding. At autopsy contracture was not seen in any of the rabbits with 1 layer SIS. On the contrary, there was 21% and 25% contracture at 6 and 12 weeks, respectively, in the 4 layer SIS group. At 12 weeks the 1 layer SIS graft was completely replaced by well collagenized tissue similar to that of normal tunica albuginea without inflammatory infiltrate, while the multilayer SIS graft was replaced by dense fibrous tissue with areas of chronic inflammation and other focal areas of calcification.

CONCLUSIONS

Four layer SIS undergoes contracture and calcification when used to cover defects in the tunica albuginea. On the other hand, 1 layer SIS can be safely and reliably used for corporeal grafting.

Single layered small intestinal submucosa in the repair of severe chordee and complicated hypospadias

PURPOSE

Severe ventral chordee often accompanies proximal hypospadias. We describe our experience with single layered small intestinal submucosa (SIS), a commercially available, acellular, collagen based biomaterial, in the repair of severe chordee as part of a multistage approach to the repair of proximal hypospadias.

MATERIALS AND METHODS

Between 2001 and 2002, 9 boys with proximal hypospadias (penoscrotal to perineal) and severe ventral chordee (greater than 40 degrees) underwent SIS grafting to correct the curvature. In each case the urethral plate was transected at the point of maximal curvature, the defect in the corporal bodies was measured, and the SIS graft was cut 2 mm wider around the perimeter of the defect and sutured into place. Skin resurfacing of the ventral penis was performed in standard fashion using Byars flaps. Recurrence of chordee was assessed by an artificial penile erection test at the time of stage 2 reconstruction.

RESULTS

Of the 9 boys 8 underwent a planned 2-stage repair with subsequent urethroplasty 6 to 12 months after the initial stage 1 chordee repair. Median age at stage 1 repair of the 8 boys was 9 months. Native meatus location was penoscrotal in 6 boys, mid scrotal in 1 and perineal in 1. A 14 month-old boy underwent 1-stage chordee correction with SIS and a transverse preputial island tube graft urethroplasty for penoscrotal hypospadias. There were no perioperative medical or surgical complications related to use of SIS for chordee repair. Median age of the 8 boys at stage 2 repair was 18 months. At stage 2 the graft site was supple and smooth without significant scarring. All chordee correction has remained durable with followup ranging from 16 to 21 months. Postoperative complications occurred in 3 cases, including meatal stenosis requiring meatoplasty, subcoronal fistula requiring repair and complete breakdown of the neourethra in the single stage repair case.

CONCLUSIONS

Although this study includes a small population of patients and has limited followup, our favorable experience with single layer SIS suggests that it is a safe and effective, commercially available material for corporal body grafting to correct severe chordee as part of a multistage surgical approach to repair complex hypospadias. A larger series of patients with longer followup is necessary to determine if the chordee correction remains durable. Our experience is insufficient to judge its efficacy in single stage repairs.

Successful Use of Tunica Vaginalis Grafts for Treatment of Severe Penile Chordee in Children

PURPOSE

Prior reports have suggested that tunica vaginalis free grafts for the treatment of chordee are associated with a high failure rate and residual curvature. We reviewed our experience with tunica vaginalis free grafts for the treatment of severe chordee associated with scrotal and perineal hypospadias.

MATERIALS AND METHODS

The records of 25 children with scrotal or perineal hypospadias associated with severe ventral chordee requiring a corporal graft to straighten the phallus treated from 1996 to 2001 were reviewed. Of the cases 5 were reoperative due to prior failed urethroplasty and residual chordee. All patients undergoing primary surgery received testosterone treatment preoperatively. Dermis was used in 3 patients, small intestinal submucosa in 3 and a free graft of tunica vaginalis in the remaining 19. One child had 2 tunica grafts placed at the same setting to correct the chordee.

RESULTS

Patient age ranged from 5 months to 16 years (median 8 months). All patients have been followed for a minimum of 1 year and a maximum of 5 years. All patients completed stage 2 repair of the hypospadias at which artificial erection was performed to detect residual ventral curvature. In only 1 patient with a prior failed hypospadias repair was there evidence of recurrent chordee after tunica vaginalis graft placement. This patient was treated with a dorsal plication at the time of urethroplasty. No other patient had evidence of residual or recurrent chordee.

CONCLUSIONS

In our hands, tunica vaginalis grafting of the corpora has produced excellent results. It is a readily available material and easy to harvest in patients who require extensive perineal dissection at the first operation. Long-term followup of these children as they progress through puberty is needed.