Several surgical techniques have been described for the treatment of bulbar urethral strictures, but the goal of modern surgery is to reduce morbidity and obtain the best outcome with the fewest complications; currently, the superiority of one surgical technique over another has not yet been clearly defined [ 1, 2 ].
For short bulbar strictures (< 2 cm) it is traditionally advocated the excision and end-to-end anastomosis, while for longer strictures in the last decade it has been advocated a patch graft urethroplasty using preferably buccal mucosa as gold-standard material of substitution [ 3 ]. However, transecting procedures showed over time a significant incidence of sexual complications, making valid the option of grafting techniques even for short non-obliterative strictures [ 4, 5, 6 ].
Recently, the approach (dorsal vs ventral) to the bulbar urethral lumen and the location of the patch (dorsal vs ventral) have become contentious issues without winners [ 7, 8 ].
We analyzed historical background, advantages and disadvantages of several urethral approaches and graft placements, with the aim of focusing the advantages of the ventral approach.
2. Grafting by the Dorsal approach
The Dorsal approach allows to perform the Dorsal Grafting.
In 1979, Devine [ 9 ] popularised the use of free-skin graft techniques in anterior urethral reconstruction. In 1980, Monseur [ 10 ] first described a new type of urethroplasty, which involved the opening of the urethra along its dorsal surface and fixing the opened urethra over the corpora cavernosa, obtaining thus the regeneration of the urethral mucosa by leaving a catheter in place for a long time . In 1996, Barbagli combined the technique of Devine with that of Monseur and described the first dorsal graft urethroplasty by the dorsal approach [ 11 ] (fig. 1).
The technique has represented a revolution in urethral surgery and it has registered a worldwide diffusion because it offers the advantage of the graft being splayed, fixed and supported by the corpora. Barbagli stated that dorsal grafting by dorsal urethrotomy approach offers a wider augmentation than ventral or dorsal grafting using the ventral-urethrotomy approach [ 12 ].
Over time, the same Barbagli warned that the dorsal access might damage the erectile function and the bulbar arteries when dissection from the corpora needs to be very proximal [ 13 ] ; therefore, he recommended his approach only for selected medium or distal bulbar strictures, whilst for the repair of proximal bulbar strictures the ventral approach would seem more advisable [ 8 ].
Nevertheless, in time, the same Author recognised that dorsal approach may be simpler in the distal bulbar urethra, whereas ventral approach with ventral grafting is more efficacious in the proximal bulbar urethra, where the spongiosum tissue is thick. Moreover, the dorsal urethral mobilisation turned out to be difficult in scarred urethras with marked periurethral fibrosis following prior treatments and an extensive dorsal dissection could cause urethral ischemia. For this reason, Kulkarni e Barbagli have recently elaborated a modified dorso-lateral approach which preserves one lateral vascular supply to the urethra by reducing the urethral mobilization [ 14 ].
In very tight strictures, often the dorsal approach forces to a transecting and graft-augmented anastomotic technique, but even with this procedure the problem of vascular damage after the complete urethral transection is still present. Not in the least, the use of the dorsal approach requires from the surgeon a certain amount of surgical skilfulness and expertise.
3. Grafting by the Ventral approach
The Ventral approach allows to perform dorsal or ventral or dorsal plus ventral grafting.
In 1999, Hayes and Malone suggested in hypospadic surgery an evolution of Snodgrass’s longitudinal incision of the urethral plate, by laying an oral mucosal graft into the incised urethral plate [ 15 ]. After merging these concepts, in 2001 Asopa popularized a similar technique suitable for both penile and bulbar stricture repair : dorsal grafting by the ventral urethrotomy approach [ 16 ] (fig. 2). In 1953, Presman introduced the Ventral grafting by a ventral approach [ 17 ]. In 1996, this technique was revived by Morey and McAninch [ 18 ] (fig. 3). Combining the concept of the Asopa-Dorsal Grafting with the McAninch-Ventral Grafting, in 2008, Palminteri proposed the Dorsal plus Ventral double grafting by ventral approach which allows a sufficient enlargement even in very tight strictures [ 19 ] (fig. 4).
The Ventral approach is easier, quicker, less aggressive and more versatile than dorsal approach. It is easier because it provides a direct access to the urethral lumen and a clear visualisation of the stricture, allowing to preserve as much as possible the urethral plate during the urethral opening. This easiness of accessibility is important and evident, especially in the proximal bulbar tract. Easy technique means easy to teach and easy to learn. In fact, the ventral approach does not require a particular surgical skilfulness and expertise, making the procedure easy even for urologysts without special reconstructive training. Furthermore, easier means quicker, reducing the operative time.
Ventral approach is versatile because, depending on the quality of the urethral plate, it allows you to choose in situ the most adequate technique: one-side dorsal grafting or one-side ventral grafting or two-sided double grafting or transecting and graft-augmented anastomosis or perineostomy.
In the case of dorsal grafting, the procedure seems easier than dorsal grafting by dorsal access because the scarred urethra with marked spongiofibrosis is not mobilized from the corpora. There is less harm for the urethral plate because the space for grafting is created without lifting the two urethral halves from the corpora and thereby the blood supply is guaranteed by the saved circumflex and perforating arteries.
In the case of ventral grafting the clear view of the margins of the urethral plate allows to perform a water-tight graft-anastomosis. In the case of a very narrow urethral plate it is possible to transect and excise a portion of the urethra and perform a graft-augmented anastomosis. On the other hand, in these cases the two-sided dorsal plus ventral double grafting represents a valid alternative to the aggressive anastomotic procedures since, by avoiding the transection of the spongiosum, it preserves the urethral plate [ 19, 20 ]. The aim of double grafting was to maintain the integrity of the urethral vascularity and the urethral length, thus reducing the sexual complications related to the anastomotic techniques [ 4, 5, 21, 22 ]. By avoiding the use of a single wide ventral graft, the double grafting may reduce the possibility of fistula and diverticula. Furthermore, the additional second graft could correct the initial use of a single dorsal graft that was intraoperatively considered to be insufficient for adequate augmentation [ 23 ].
Finally, if necessary, the ventral approach allows to convert intraoperatively a one-stage into a staged procedure, allowing to perform a perineostomy. Basically, the Ventral approach is less aggressive because there is a minimal dissection without a wide and circumferential mobilization of the urethra, thus reducing, in the proximal bulbar strictures, the risk of DE, that has been feared when using the dorsal access. In our daily practice, we often have to deal with cases in which the ventral approach proves to be easier than the dorsal one : obese patients, strictures after failed urethroplasty or radiotherapy, very tight strictures, proximal bulbar strictures.
Some experts complain of a bigger bleeding and a risk of vascular damage when cutting ventrally, but there are no studies showing these problems. Others complain of the risk of graft-weakening with urethral sacculation or fistula. In reality, the abundant ventral spongiosum guarantees a satisfying coverage and support for the graft, and the literature fails to show what above supposed. This probably was a problem in the past, when some surgeons did not cover the graft with the spongiosum.
Anyway, perhaps there is a slight weakening of the augmented urethral floor and this could explain the post-voiding dribbling that we discovered in about 20% of our patients. However, except these minimal complications, it is important to highlight that no patient reported sexual complaints and all reported an improvement in sexual life [24 ]. However, the reduced thickness of spongiosum in the distal bulbar urethra may advise against using this approach in this segment.
Generally, surgeons tend to use techniques that are easy, quick and give excellent outcomes with few complications. The Graft urethroplasty using the ventral approach fully responds to these requisites.