Evaluation of healing at urethral anastomotic site by pericatheter retrograde urethrogram in patients with urethral stricture.

INTRODUCTION: Stricture urethra has been always a surgical challenge. Different opinions regarding time require healing at anastomotic site after urethroplasty, so various strategies are there regarding time for post-operative catheter removal. In this study, healing was assessed by pericatheter retrograde urethrogram (PUG) before the catheter removal.
MATERIALS AND METHODS: Prospective study was conducted from January 2006 to December 2009. Twenty eight cases of short-segment urethral stricture (<2 cm) who underwent urethroplasty were included and divided into two groups depending upon etiology; post-traumatic group (road traffic accident/straddle type injury) and iatrogenic stricture group (due to prolong catheterization/after cystoscopy/Faulty Foleys balloon placement). Post-operative PUG was done on 14(th) post-operative day in all patients for healing assessment. Extravasation of dye on PUG was taken as anastomotic leak. If the patient had not showed extravasation, the catheter was removed. Otherwise it was kept further for next one week and again PUG was done for healing assessment.
RESULTS: Extravasation of dye was noted in 4 patients (33%) of iatrogenic group and 14 patients (87.5%) of the post-traumatic group on 14(th) post-operative day PUG. (P ≤ 0.05). The decision to remove catheter was depended upon PUG finding and it was safe, no complication was developed in any patient.
CONCLUSION: Iatrogenic strictures have better healing than post-traumatic stricture in the post-operative period. PUG is a safe and simple procedure and can guide about safe removal of catheter in the post-operative period.

INTRODUCTION

Urethroplasty is a common procedure performed for stricture urethra. This disease involves young age group, mainly between 20 and 40 years.[12] These patients need long hospital stay in post-operative period that leads to the absence from the workplace and increase socioeconomic burden. The major hindrance for mobility and a reason for a hospital stay in the post-operative period is presence of urinary catheter. Traditionally, post-operative catheter removal is done on 21st day after urethroplasty.[345] Still there is some controversy existing about the best feasible time of proper healing and how to assess it by simple procedures.[6] There is a difference in the duration of anastomotic healing according to the type of procedure performed, but whether there is any significant difference in duration of healing at the anastomotic site according to etiology of short-segment stricture urethra is still a dilemma.[7] Pericatheter retrograde urethrogram (PUG) is well described but not accepted widely. In this study, for assessment of healing we had used PUG and assessed that any specific etiological cause play any role in healing. Usually anastomotic healing of urethroplasty is assessed by micturating cystourethrogram after the catheter removal. This procedure required catheter removal; however, with pericatheter retrograde urethrogram [PUG], there is no need for catheter removal and if inadequate healing is found, the option to keep the catheter continues without risk of reinsertion trauma that is present in case of the MCU. PUG allows adequate urethral assessment and healing before the removal of indwelling catheter.[8]

MATERIAL AND METHODS

This prospective study was conducted at our institute, from January 2006 to December 2009 after approval of institutional ethics committee. All patients with short-segment (<2 cm) stricture urethra were included. Long-segment stricture and stricture due to infective pathology were excluded. Patients were divided into two groups according to their etiology; (1) Post-traumatic group i.e. stricture due to road traffic accident or straddle type injury. Sixteen patients were enrolled in this group (2) iatrogenic group i.e. stricture due to prolonged catheterization or after cystoscopy or due to faulty technique of Foleys insertion (urethral rupture due to Foleys balloon). Twelve patients were enrolled in this group. All cases underwent all routine investigations including complete hemogram and urine culture. Preoperative assessment of the stricture was done by the retrograde urethrogram and micturating cystourethrogram (RGU/MCU). These patients had undergone end to end urethroplasty (all with perineal approach) by the single operating surgeon.

The standard surgical technique of excision and anastomosis was applied while the patient was carefully positioned in exaggerated lithotomy. A midline vertical perineal incision was given (for posterior urethral stricture progressive perineal approach was used) and adequate urethral mobilization was done. After the removal of the scar and fibrotic tissue, the proximal end of urethra was spatulated in the position of 12 o’clock and the distal end of urethra was also spatulated in the opposite direction. Anastomosis of the two ends of the urethra was performed mucosa to mucosa on a urethral catheter.

On 14th post-operative day PUG was performed for all patients. During PUG a 5 Fr infant feeding tube was inserted up to one cm into the urethra by the side of indwelling Foley's catheter. 5 ml of contrast (Urografin 76%) diluted with 5 ml of normal saline injected by infant feeding tube and urethrogram was taken. Extravasation of dye on PUG was taken as anastomotic leak. [Figure 1a] If the patient had not showed extravasation at the anastomotic site [Figure 1b] on the 14th day, the catheter was removed otherwise it was kept further for next week and again pericatheter retrograde urethrogram PUG was done on the 21st day in the remaining patients. Patients were assessed for any discomfort, any other urinary complain, infection, during or after the PUG. All urethrogram were examined by a radiologist for any extravasation.

Figure 1

(a) Pericatheter retrograde urethrogram (PUG) on 14th post-operative day shows extravasation of dye from anastomotic site, (b) PUG on 14th post-operative day shows no extravasation of dye

RESULTS

Twenty eight male patients [mean age; 32 ± 13 years] of short-segment urethral stricture (<2 cm on the MCU and confirmed intraoperatively) were enrolled in the study. In iatrogenic group, 6 out of 12 patients had posterior urethral stricture while in the post-traumatic group, 9 out of 16 patients had posterior urethral stricture. All patients had undergone for excision of stricture urethra with end to end anastomosis.

On 14th post-operative day PUG was performed. Four (33%) patients in the iatrogenic group and fourteen (87.5%) patients in the post-traumatic group showed extravasation of dye [P < 0.05]. There was no extravasation on the 21st day in all 4 patients of iatrogenic group and 12 patients of post-traumatic group. Only two patients of post-traumatic group had extravasation of dye on the 21st day for which catheter was kept to continue for another 1 week and then removed on the 28th post-operative day. Subsequently, MCU was performed which was suggestive of normal healing. There was no complication after pericatheter retrograde urethrogram and/or removal of catheter after PUG (especially poor urinary stream, urinary retention or infection).

DISCUSSION

Short-segment urethral strictures [<2 cm] are best treated by end to end anastomotic urethroplasty, but there is some controversy that exists about time to remove per urethral catheter in post-operative period.[46] Many authors removed the catheter from10th post-operative day to 21st post-operative day according to type of stricture repair, 10-14th day in anastomotic and 21 or more for graft repair.[67] Santucci et al. found 1% extravasations rate in 168 patients with anastomotic urethroplasty for bulbar stricture after post-operative catheter for 14 days.[5] Hosam et al. reported 17% extravasations with very early catheter removal i.e. 3rd post-operative day and they assessed leakage by post-operative MCU in patients with late catheter removal.[6]

In our series total extravasations rate is high i.e. 64.2% on the 14th day, which was reduced to 11.11% on 21st day; however, in iatrogenic group extravasation was only in 33.33% cases as compared to post-traumatic group who had 87.5%, which was assessed by pericatheter retrograde urethrogram. It was suggestive that healing is delayed in patients who developed a stricture due to external trauma. The reason for this difference is not known exactly but may be due to mechanism of injury i.e. the scarring process of spongy erectile tissue in corpus spongiosum underlies the urethral epithelium that results in stricture and in some cases, the scarring process extends through the tissues of the corpus spongiosum and into adjacent tissues. Contraction of this scar reduces the urethral lumen. In iatrogenic group there is partial-thickness or full-thickness involvement but with minimal fibrosis in the spongy tissue, while in post-traumatic group, inflammation and fibrosis involving tissues outside the corpus spongiosum [Figure 2a and b].

Figure 2

[Adopted from Jordan GH: Management of anterior urethral stricture disease. Probl Urol 1987;1:199-225 from Campbell Walsh 10th ed. pp 968 publisher - Elsevier]. Showing depth of urethral injury, (a) In iatrogenic stricture, partial-thickness involvement and no or minimal fibrosis outside (b) In post-traumatic group, inflammation and fibrosis involving tissues outside the corpus spongiosum

Balogunand Lee SC stated that pericatheter retrograde urethrogram is the most useful radiological diagnostic method to evaluate the timing of the removal of catheter after urethroplasty without the fear of re-catheterization.[89] We found similar results in our study that pericatheter retrograde urethrogram is safe and reliable method for assessment of urethral anastomotic healing without the need for catheter removal. In this study it was found that etiology plays important role in the healing process. There is a high probability of healing (P < 0.05) in iatrogenic stricture [66.7%] on the 14th day as compared to post-traumatic stricture group [12.5%].

CONCLUSION

Healing at the anastomotic site depends upon multiple factors and one of them is its etiology. Iatrogenic strictures have better healing in the post-operative period than post-traumatic stricture. PUG is a safe and simple procedure. PUG can guide about safe removal of catheter in the post-operative period.