Bulbar Anastomotic Urethroplasty
Anastomatic urethroplasty is a treatment of choice for bulbar urethral trauma at some centers. It is generally performed for short bulbar strictures of non traumatic origin.
In my practice, I follow the rule of transecting the bulbar urethra only when it is already transected by trauma.
Under spinal anesthesia the patient is placed in lithotomy position. A midline perineal incision is made. The bulbo spongiosis muscle is incised in the midline. The dissection of the bulbo spongy muscle from the urethra is difficult at the site of injury due to fibrosis. The bulbar urethra is mobilized from the corpora cavernosa. A dilator is passed through meatus into the urethra. A firm nodule is felt in the corpora spongiosa at the site of injury and the urethra is transected this level. The spongio fibrotic tissue is excised on the proximal and the distal end of the urethra. The urethra is spatulated on both sides into normal pink urethra upto 1.5 cm. The anastomosis can be performed either with single suture line of interrupted 4 /0 vicryl sutures or in two layers. The first layer picks up urethral mucosa and can be continuous or interrupted. The second layer picks up the corpora spongiosa. A 14 F silastic Foley catheter is introduced into the bladder. The wound is closed in layers with absorbable sutures. I rarely use drain.
The catheter is removed after three weeks.
Anastomotic Urethroplasty for Posterior urethral trauma
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Augmented Urethroplasty (Barbagli)
Guido Barbagli from Arezzo, Italy published his innovative technique of dorsal onlay free graft urethroplasty in the journal of urology in 1996. His technique of urethroplasty has revolutionized the management of urethral strictures world over. We introduced his technique in Pune, India in 1997. Barbagli initially used free prepucial skin graft as a dorsal onlay. Later on he started using buccal mucosa graft.
The indications are as follows:
The required investigation is the ascending urethrogram to demonstrate the site and length of the stricture.
The patient is placed in lithotomy position after spinal anesthesia. Dilute Methylene Blue dye is injected through the meatus into the urethra. The penis and perineum are massaged to push the dye proximally. I apply a 6 F feeding tube as a tourniquet to lightly compress the urethra below the glance penis. A midline perineal incision is made the bulbar urethra is dissected from corpora cavernosa. I place two stay sutures ventrally at 6 O’ Clock position on the facia over corpora spongiosa. These stay sutures allow me to rotate the bulbar urethra to open the urethra exactly at 12 O’ Clock (dorsal) position over a dilator distal to the stricture. The urethra is spatulated through the stricture proximally into normal urethra minimum to a distance of 1.5 cm.
Buccal mucosa graft harvesting : the graft can be taken under general or local anesthesia. A retractor is placed to wide open the jaws. A roller gauze is packed into the pharynx to block aspiration of blood during dissection. The Stensons Duct opening opposite the second upper molar tooth is marked with Methylene Blue. Injury to the duct opening is avoided by making an incision from the angle of mouth towards the lower jaw. Xylocaine with 2% Adrenaline is injected with a fine needle from the angle of mouth to anterior tonsiler pillar below the buccal mucosa. A stay suture is taken at the angle of mouth just inside the vermilion border. Two parallel incisions 1.5 cm apart are made from the angle of mouth to the anterior tonsil pillar. The buccal mucosa graft is harvested. Any injury to the Buccinator muscle is avoided. Bleeders if any are coagulated with bipolar diathermy. Initially I use to close the defect in the buccal mucosa at 3 – 0 chromic catgut continues sutures. Now for last five years, I have rarely closed the wound. The buccal mucosa graft is kept in a bowl of saline to which Gentamycin injection is added. The graft defatting of the graft is performed. Some surgeons perform aggressive defatting to make the graft very thin and transparent. Moderate defatting is sufficient in my opinion. Some surgeons pin down the graft with multiple needles on a silicon block to facilitate defatting. The buccal mucosa graft is transferred to the perineal surgeon. The graft is placed over the corpora cavernosa with mucosa facing towards the lumen. The graft is spread and fixed to the corpora cavernosa. Quilting sutures with absorbable material allow the graft to be fixed to the underlying structures. This prevents collection of seroma below the graft and tiny holes created with the suture material allow the serous fluid to drain. Some surgeons make multiple incisions in the graft similar to skin graft. It allows narrow a graft to cover wider area. I personally do not use it. The edge of the corpora spongiosa is sutured to the buccal mucosa with continuous sutures to the right side. A 14 F silastic catheter is inserted into the bladder. Then the left edge of corpora spongiosa is sutured to the buccal mucosa with continuous sutures. Each stitch incorporates the underlying corpora cavernosa, the buccal mucosa and the corpora spongiosa (three in one stitch). Care must be taken while suturing to avoid inadvertent needle entry into the periurethral catheter.
The success of dorsal onlay buccal mucosa graft urethroplasty depends upon the width of the urethral plate. If the stricture is tight and long, the urethral plate will be too narrow. With a narrow urethral plate (less than 5mm) we can not suture edge of the urethral mucosa to the BMG. If we do this the effective lumen will be 20F. So edge of the corpora spongiosa is sutured to the BMG leaving strips of exposed spongiosa on both sides of the urethral plate. This violates the principle of primary healing and it will heal by secondary intention and may lead to restricture formation.
Ventral Onlay Urethroplasty
In the bulbar region the urethra lies dorsally in the corpora spongiosa. It is possible for us to use the buccal mucosa graft as a ventral onlay and then overclosed the spongiosa to cover the BMG.
Same as Barbagli’s urethroplasty, suitable for obese patients, proximal bulbar strictures, failed dorsal onlay buccal mucosa graft.
Under spinal anesthesia through a midline perineal incision the bulbar urethra is exposed but not mobilized. Methylene Blue dye is injected through the meatus into the proximal urethra. A dilator is passed through the meatus upto the level of the stricture. The bulbar urethra is opened ventrally distal to the stricture. Ventral urethrotomy is performed through the strictured urethra into normal proximal bulbar urethra upto 1.5cm. Methylene Blue stained urethral mucosa helps to identify the narrowed lumen of the urethra. A 1.5cm wide and 6cm long BMG is harvested from the chic and defatting is performed. The BMG is sutured to the urethral mucosa with continuous sutures of 4/0 vicryl on the right side. The mucosal surface of the BMG faces inside towards lumen of the urethra. Then a 14 F silastic Foley catheter is inserted to the bladder. Then the left side of the urethra is sutured to the buccal mucasa with continuous sutures. The corpora spongiosa is over closed with continuous sutures of 4/0 vicryl and taking bite of the buccal mucosa graft. The wound is closed in layers. The catheter is removed after three weeks.
LINGUAL MUCOSA GRAFT
Recently surgeons have started using lingual mucosa from lateral edge of the tongue.
Skin-prepucial, penile, scrotal, Post auricular Wolf Graft(PAWG), SIS, Bioengineered Tissue
Skin-prepucial– whenever urethra needs replacement (substitution) pedicled prepucial skin tube is the first choice. Harvesting of the inner prepucial skin with its blood supply is performed as described by Asopa and Ducket. A stay suture is taken through the glans dorsal to the meatus. A circumcision incision is made on the inner layer of the prepuce 5mm away from the coronal sulcus. This incision is depend upto the Bucks facia at this level the whole penis is degloved upto the base. This dissection leaves the dorsal neurovascular bundle intact on the penis. A second incision is made on the outer surface of the prepuce at the level of the glans. Here the penile skin is degloved again just below the skin. Now the prepuce with its blood supply forms a circular tube between the penile skin and the Bucks facia. This prepucial skin plus facia tube is incised at 6 O’clock towards the base of the penis. Now stay sutures are taken at the junction of the inner and outer prepucial skin at both ends. An incision is made with sharp scissors between these two skin layers. The outer skin can be used as a free graft or as a pedicled graft if required. But most of the times, it is discarded. The inner prepucial skin with its blood supply is rotated around the penile base and is used to form a tube around a 14 Foley catheter. Now this tube is anastomosed proximally and distally to the urethra. The most common use is for bulbar urethral necrosis following posterior urethral trauma. The proximal end of the prepucial tube is anastomosed apex of the prostatic urethra. The distal end is anastomosed to the urethra at the level of distal bulbar portion. The disadvantage of pedicle prepucial tube is that it forms a diverticulam and leads to post micturition dribble. The patient may get anastomotic stricture at both ends of the prepucial tube.
Penile Skin– the next best choice after prepucial skin is penile skin. It is used routinely for the Orandi’s urethroplasty.
Scrotal Skin– is the last choice for urethral substitution. Scrotal skin is thermo labile so it forms a diverticulam once it is turned inside. As it is hair bearing skin (hirsute) it leads to hair ball and stone formation. The skin also becomes soggy as the washerman’s feet are. Scrotal skin is used for Turner Warwick scrotal drop back procedure urethroplasty. Scrotal skin is also used for Blandy – Manmeet Singh urethroplasty.
Post Auricular Wolf Graft (PAWG)– is the skin of choice in patients of BXO where buccal mucosa is not suitable for grafting as the donor site is hidden behind the ears.
SIS– small intestinal submucosa is available as off the shelf replacement for the urethra. SIS provides scaffolding over which the urothelium grows and the SIS is slowly absorbed. I have used SIS for full length urethroplasty in 12 patients. All patients developed restricture. So at the present time, we have stopped using SIS as a substitute for urethroplasty.
Bio Engineered Tissue– with the recent advances in regenerative medicine many labs are developing urethral substitutes in the lab.
Appendix, Rectal Mucosa, Tunica Vaginalis
Appendix– an article was published by Mitrofanoff on the use of appendix for replacement of urethra. A careful appendicectomy is performed without damaging the appendix. The outer peritoneal layer is removed with sharp dissection. the appendix is incised longitudinally. The mucosa of the appendix is carefully excised. The appendicular sub mucosa is now used as a free patch to augment or substitute the urethra. I have used this technique in two patients with gratifying results in desperate situations where options of urethral replacement tissue are limited.
Rectal Mucosa– there are few published reports mostly from China regarding use of rectal and colonic mucosa for reconstruction of long segments of the urethral strictures. I have not used this method till today.
Tunica Vaginalis– I have used the tunica vaginalis in two patients where they had simultaneous hydrocele. The hydrocele sack is opened as in hydrocele repair and part of the tunica vaginalis is rotated to be used as a dorsal onlay graft urethroplasty. Though the patients did well post operatively, I do not favor this option.
Augmented Anastomotic Urethroplasty
If a patient has a long bulbar stricture the original stricture is usually short and tight. The concept is to excise this short and tight stricture and spatulate the urethra on both sides and anastomos the urethra to form flat urethral plate. A buccal mucosa graft is used as patch of augmentation either on ventral or dorsal side. The BMG takes care of the gray urethra on both sides of the stricture. Ultimately the short and tight stricture is excised and the remaining bulbar urethra is augmented achieving good results.
Under anesthesia as in Barbagli’s urethroplasty the bulbar urethra is mobilized and spatulated dorsally. The short and tight segment (less than 1.5cm) of the bulbar urethra is excised. A 1.5cm wide and 6 cm long BMG is spread and fixed on the corpora cavernosa. The ventral urethral plate is reconstituted by anastomosing the proximal and distal urethral ends. The urethral plate is now flat and is sutured to the buccal mucosa graft as in Barbagli’s technique. Rest of the management is similar to Barbagli’s urethroplasty.
Initially, I was enthusiastic and performed many of these procedures. But according to my current concept of not transecting the bulbar urethra for non traumatic strictures has shifted my thinking away from augmented anastomosis.
1. Poor or absent urethral plate e.g. Hypospadias cripple
Hypospadias cripple – these patients have multiple failed hypospadius repairs. They are left with minimal local skin for repair and have multiple strictures and or fistulae in the urethra. They are best dealt with two stage BMG urethroplasty. In the first stage the whole bad urethra is excised with all the scar tissue the penis made straight and its position is checked by intra cavernosal injection of saline. A 2.5cm wide graft of buccal mucosa or two strips of 1.5cm wide buccal mucosa graft are spread and fixed over the corpora cavernosa. The graft is quilted with absorbable sutures. The second stage is performed 3-6 months later. A U incision is made and the buccal mucosa is turned into a tube a 14 F silastic Foley catheter is inserted and the skin is closed with Z-plasties.
Bulbar urethral necrosis/stenosis – seen in patients with prior anastomotic urethroplasties with bulbar urethral transection. If a patient has a history of ED (indicating poor dorsal artery flow), corpus spongiosum dissection (destruction of the circumflex arterial arterial supply to the urethra) and bulbar urethral transection with disruption of the bulbar arterial blood supply can lead to necrosis of the bulbar urethra (blood supply is paired bulbar arteries, circumflex arteries, and retrograde flow from dorsal arteries). Treatment in general requires tubularized well vascularized flaps (skin, prefabricated mucosa, intestine, etc).