Single-stage repair of hypospadias using longitudinal dorsal island flap: Single-surgeon experience with 102 cases

Dorsal midline incision: A versatile technique for correction of meatal stenosis during hypospadias repair

Objectives:

To our knowledge, the incidence of congenital meatal abnormalities associated with hypospadias varies from 9.6% to 31%, of which meatal stenosis is the most common, affecting 9.1–16.7% of patients. Traditionally, meatal stenosis has been dealt with by meatal dilatation, although ventral meatotomy until the normal urethra is encountered has also been used. Here, we report the outcome of a technique where, during hypospadias repair, a dorsal midline incision was performed instead of a ventral urethral incision, starting at the narrow meatus and subsequently extending proximally to treat the meatal stenosis.

Methods:

Patients having distal hypospadias with meatal stenosis were included in this study. In this technique, a dorsal midline incision was extended until normal calibre urethra was encountered. Patients with chordee >15°, proximal hypospadias, redo cases, glans width <14 mm, where separation of the skin from the underlying urethra was not possible and with a follow-up of less than three months were excluded from the study. A total of 73 patients were operated on using this technique. Results were assessed with regards to urethrocutaneous fistula (UCF) and stricture formation.

Results:

Five (6.85%) patients developed UCF: one (5%) in the subcoronal group, two (8.0%) in the distal penile group and two (14.3%) in the mid-penile hypospadias group. Postoperatively, only one patient had meatal stenosis.

Conclusion:

We think hypospadiac meatal stenosis is best treated by a dorsal midline incision, as it does not lead to a proximal shift of the meatus, and this defect heals by re-epithelisation without significant scarring, which in turn decreases the possibility of UCF. That is why the fistula rate in our study was 6.85%, which is lower than in various published series.

Dorsal vertical island flap urethroplasty in children with hypospadias: a single center’s experience 75 patients

Objective

To assess the results and complications of dorsal vertical island flap (DVIF) urethroplasty.

Methods

A total of 175 children were operated on for hypospadias. Out of these, 41 with proximal hypospadias with severe chordee required two-stage urethroplasty. In 18 babies with glanular hypospadias, a meatal advancement and glanuloplasty procedure was done. In 25 babies with mid-penile and distal penile hypospadias, tubularized incised urethral plate (TIP) urethroplasty was the option. 16 babies with unhealthy urethral plate and chordee were chosen for dorsal vertical tube urethroplasty after excision of the urethral plate. The rest of the 75 babies with proximal, mid-penile or distal penile hypospadias with no or minimal chordee after degloving and poor urethral plate were chosen for DVIF urethroplasty. These 75 babies with DVIF were followed up from 3 months to 5 years to assess complications such as urethrocutaneous fistula, meatal stenosis, glans dehiscence, megalourethra or urethral diverticulum, stricture, and penile torsion/rotation.

Results

A total of 75 patients with proximal, mid-penile, or distal penile hypospadias in whom DVIF was used during the study period were included. The mean age was 3.7 years, ranging from 8 months to 14 years. Fourteen patients developed complications (18.6%). The most common complication was urethrocutaneous fistula, which was seen in seven (9.3%) patients. Glans dehiscence was seen in five patients (6.6%), and one had meatal stenosis with diverticulum formation. Skin necrosis was observed in one patient. In 61 patients, stream was good, with no torsion, and good cosmetic appearance was observed.

Conclusions

DVIF is a good alternative to TIP in mid-penile and distal penile hypospadias. Our early experience with DVIF urethroplasty showed an acceptable rate of complications and good cosmetic results.

Repair of urethral defects with polylactid acid fibrous membrane seeded with adipose-derived stem cells in a rabbit model

AIM

The aim of this study is to evaluate the capacity of polylactid acid (PLA) fibrous membrane seeded with allogeneic rabbit adipose tissue-derived stem cells (ADSCs) to repair urethral defects in a rabbit model.

MATERIALS AND METHODS

Rabbit ADSCs were harvested and phenotypically characterized. Twenty-four New Zealand male rabbits with 5-mm urethral mucosal defects were randomly divided into two groups. They underwent urethroplasty either with PLA fibrous membrane seeded with ADSCs (group A) or blank PLA fibrous membrane (group B). At 4 and 6 weeks after urethroplasty, the urethral grafts were collected and analyzed grossly and histologically. The incidence rate of urethrostenosis was measured.

RESULTS

The adipose tissue-derived cells in monolayer culture showed a typical morphology of mesenchymal stem cells (MSCs). They were positive for the MSC marker CD44 but negative for lineage markers CD45 and CD105. Six weeks after surgery, the incidence rate of urethrostenosis in group A was significantly lower than that in group B (p < 0.05). In group A, the ADSC-seeded grafts showed a normal urethral architecture with a thickened muscle layer. In contrast, the newly developed urethra in group B demonstrated a fewer number of urothelial layers and scarce or no smooth muscle cells.

CONCLUSION

The PLA scaffold seeded with ADSCs is effective in urethral regeneration in a rabbit model. ADSCs may represent a promising source of seed cells for urethral tissue engineering.

CR, Mauney JR. Acellular bi-layer silk fibroin scaffolds support tissue regeneration in a rabbit model of onlay urethroplasty

Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a rabbit model of urethra repair. A bi-layer silk fibroin matrix was fabricated by a solvent-casting/salt leaching process in combination with silk fibroin film casting to generate porous foams buttressed by homogeneous silk fibroin films. Ventral onlay urethroplasty was performed with silk fibroin grafts (Group 1, N = 4) (Width×Length, 1×2 cm²) in adult male rabbits for 3 m of implantation. Parallel control groups consisted of animals receiving small intestinal submucosa (SIS) implants (Group 2, N = 4) or urethrotomy alone (Group 3, N = 3). Animals in all groups exhibited 100% survival prior to scheduled euthanasia and achieved voluntary voiding following 7 d of initial catheterization. Retrograde urethrography of each implant group at 3 m post-op revealed wide urethral calibers and preservation of organ continuity similar to pre-operative and urethrotomy controls with no evidence of contrast extravasation, strictures, fistulas, or stone formation. Histological (hematoxylin and eosin and Masson's trichrome), immunohistochemical, and histomorphometric analyses demonstrated that both silk fibroin and SIS scaffolds promoted similar extents of smooth muscle and epithelial tissue regeneration throughout the original defect sites with prominent contractile protein (α-smooth muscle actin and SM22α) and cytokeratin expression, respectively. De novo innervation and vascularization were also evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Following 3 m post-op, minimal acute inflammatory reactions were elicited by silk fibroin scaffolds characterized by the presence of eosinophil granulocytes while SIS matrices promoted chronic inflammatory responses indicated by mobilization of mononuclear cell infiltrates. The results of this study demonstrate that bi-layer silk fibroin scaffolds represent promising biomaterials for onlay urethroplasty, capable of promoting similar degrees of tissue regeneration in comparison to conventional SIS scaffolds, but with reduced immunogenicity.

Assessment of outcome in hypospadias surgery - a review

Hypospadias is a challenging field of urogenital reconstructive surgery with different techniques being currently used. Modern surgery claims that it is possible to create a functionally and cosmetically normal penis. Continuous re-evaluation and assessment of outcome may have a major impact on future clinical practice. Assessment of outcome includes: complication rate, cosmetic appearance of the penis, functional outcome (micturition, sexuality), and psychological factors such as quality of life and psychosexual life. This article briefly reviews current strategies of outcome assessment. Somehow in the future, we will be able to give an accurate estimation of the long-term consequences of being born with hypospadias.