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Year : 2022  |  Volume : 27  |  Issue : 6  |  Page : 684-688

Extended ulaanbaatar procedure with preputial skin graft for proximal hypospadias

Visiting Paediatric Surgeon, Park Medical Research and Welfare Society, Kolkata, West Bengal, India

Date of Submission06-Feb-2022
Date of Decision15-May-2022
Date of Acceptance18-Jun-2022
Date of Web Publication11-Nov-2022

Correspondence Address:
Uday Sankar Chatterjee
No. 356/3 Sahid Khudiram Bose Sarani, Kolkata - 700 030, West Bengal
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jiaps.jiaps_26_22

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Background: Two stage urethroplasty for proximal penile hypospadias is time consuming, expensive and; traumatic both for parents and phallus. On the other hand, single stage procedure technically demanding. We would like to describe Extended Ulaanbaatar Procedure (EUP) which is not a two stage procedure. Rather, might be called as 'extended single stage' procedure. In EUP we have done orthoplasty along with urethroplasty with preputial skin graft at same sitting as primary procedure keeping urination diverted through proximal hypospadiac meatus as “controlled fistula” which was closed after six months as secondary procedure.
Methods: We operated on 35 patients of proximal penile hypospadias with moderate to severe chordee. Chordee was excised till correction of curvature. Two distracted cut ends of native plate was bridged with preputial skin graft (PSG) in between. Following that, silastic tube was placed over glandular plate as scaffold, on both cut ends of native plate and PSG. All the urethral plates and PSG were buried with tunica vaginalis flap before glanuloplasty. After six months, proximal “controlled fistula” was closed with scrotal dartos fascia and skin to join distal to proximal urethra.
Results: Vertical meatus in glans was found in 32 patients. One patient had glans dehiscence, two patients had medium sized fistula, another two patients had stenosis in neourethra and six had suture track fistula. Twenty-nine patients had satisfactory curve with good flow in uroflowmetry as per nomogram at sixth month of follow up.
Conclusion: In classic Ulaanbaatar procedure authors do distal urethroplasty and glanuloplsaty in 1st stage following orthoplasty to avoid repeat trauma in glans in repeat procedures. Left over urethroplasty in classic Ulaanbaatar was done in 2nd stage. However, in EUP; we did urethroplasty for full length following orthoplasty as primary procedure. This procedure is less invasive than two staged as we avoided repeat degloving and repeat dissection on operated tissues. Urethroplasty done as primary procedure shunned the need of repeat degloving, decreased the period of morbidity, stay, and cost of surgery. We also avoided problems of urination through not matured, long, neo-urethra. Similarly complications i.e disruption, stenosis in neo-urethra can be managed utilizing the advantages of urinary diversion.

Keywords: Buried strip, chordee, hypospadias, preputial graft, tunica vaginalis, urethroplasty

How to cite this article:
Chatterjee US, Basak D. Extended ulaanbaatar procedure with preputial skin graft for proximal hypospadias. J Indian Assoc Pediatr Surg 2022;27:684-8

How to cite this URL:
Chatterjee US, Basak D. Extended ulaanbaatar procedure with preputial skin graft for proximal hypospadias. J Indian Assoc Pediatr Surg [serial online] 2022 [cited 2022 Dec 7];27:684-8. Available from: https://www.jiaps.com/text.asp?2022/27/6/684/360954

   Introduction Top

Choice of hypospadias surgery swings between stages[1] for proximal hypospadias with moderate-to-severe chordee. Some prefer two-stage procedures, comprising orthoplasty or chordee correction in the first stage, followed by the second stage, for urethroplasty. Two-stage procedures need repeat degloving, longer stay, added cost of surgery as well as increased morbidity. That is why some authors[2] prefer single-stage procedure as they are confident as well as skilled. Nevertheless, it is technically demanding and results did not match the expectations, as complication rates are reported to be as high as 25% to 52% in single-stage procedure.[3],[4]

We would like to present our result of concomitant orthoplasty and urethroplasty done with preputial skin graft (PSG)[5] as inlay buried strip;[6] along with we kept urination diverted through proximal hypospadiac meatus, i.e., “controlled fistula”[7] as primary procedure. We put tunica vaginalis flap (TVF) on reconstruction as a vascularized layer to cover over the buried strip. The buried strip was then allowed to regenerate as a tube on Silastic scaffold. “Controlled fistula” was closed following 6 months as a daycare procedure. In fact, this extended Ulaanbaatar procedure (EUP) is a single-stage cum secondary procedure.

   Methods Top

Since March 2017 to April 2021, we operated on 35 patients, the age ranged from 12 months to 18 years, and all of them were pretreated with local application of testosterone gel for 4 weeks. Institute ethical committee approved this study.

Primary procedure

Foley's catheter was placed in the bladder through hypospadiac meatus for diversion of urine. Following that, parallel incision on both sides of the urethral plate and a half circum-meatal incision at hypospadiac meatus were made to separate it from the rest of the penile skin. PSG was harvested from the junction area of inner and outer skin [Figure 1]a. From that junction, the penis was degloved to get urethral plate as an island up to proximal meatus, free from rest of penile skin. We incised the urethral plate transversely in the middle for correction of chordee. Tissues causing chordee were excised till bluish cavernosa came in sight, and curvature was corrected. Multiple incisions on corpora were necessary in some patients for further correction of chordee. Wide apart cut ends of native urethral plate [Figure 1]b were preserved and bridged with PSG of the prepuce. Harvested PSG was stitched to cavernosal albuginea, as well as to cut ends of native plates [Figure 1]c with 4-0 catgut with cutting needle. 5–6 f Silastic tube, as scaffold, was placed on urethral plates and PSG without tubularization,[7] and a longitudinal “hinging” incision[6],[8],[9] was made over the glandular plate (1b) with No. 11 blade to loosely accommodate the Silastic tube as well as to get vertical meatus at follow-up. Following that, we buried the strips of PSG, urethral plates, and Silastic tube with TVF to boost vascular support [Figure 1]d. TVF was fixed around the urethra and PSG up to the tip of the penis with 4-0 catgut. Glanuloplasty was done with subcuticular stitches with 5-0 polyglactin in cutting needle. Proximal native meatus was refashioned as “controlled fistula”[7] for diversion of urine. Penis was regloved with penile skin with Byars flap. Antibiotics were started at preoperative and continued for 7–10 days.
Figure 1: Harvesting of preputial skin graft (a). Chordee correction done. Distal part of native plate with “Hinging incision” (b). Preputial skin grafted in between two wide apart cut ends of native plate (c). TVF wrap over Silastic tube (d). TVF: Tunica vaginalis flap

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Secondary procedure: Closure of “controlled fistula”

Foley's catheter continued to divert urination through controlled fistula or native hypospadiac meatus for 2 weeks. Silastic tube in neourethra was interchanged with latex tube [Figure 2]a after 3 weeks by “rail–road” method on a suitable guide wire and that latex tube was kept for another 3 weeks for continuous calibration. Following that, we advised regular calibration [Figure 2]b till attainment of adequate caliber of neourethra almost of equal caliber of proximal urethra before the closure of controlled fistula or proximal urethrostomy: usually done after 6 months. In between the period, patients and parents were advised to close “controlled fistula” with fingers' tips to steer urination through neomeatus to assess the adequacy of caliber of neourethra.
Figure 2: Change of Silastic tube with latex tube for continuous calibration (a). Calibration of neourethra with dilator and fistula visible (b). Excess skin around urethral mucosa excised and stoma closure (c). Good-looking glans with vertical meatus and closed urethrostomy (d)

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After 6 months, “secondary procedure” was done to close “controlled fistula” as daycare procedure under local or intravenous anesthesia. For that, balloon catheter was introduced in bladder both through glandular meatus and controlled fistula. Urethral mucosa of controlled fistula was then separated from skin margin and excess skin was excised [Figure 2]c to make urethral mucosa to fall deep to dartos. Following that, the gap was closed with scrotal dartos fascia and skin without tubularization[6],[8] of urethral mucosa unlike as suggested by other authors.[10] It would take less that 20 min, and patients would be discharged on the same day. The catheter was kept for 10–12 days, and patients were advised for regular follow-up with uroflowmetry at 6-month interval.

   Results Top

The mean (range) follow-up period was 20.8 (6–42) months. Two patients were lost in follow-up. Vertical meatus in glans was found in 32 patients [Figure 2]d. One patient had glans dehiscence, two patients had medium-sized fistula [Figure 2]b, another two patients had stenosis in neourethra, and six had suture track fistula. Three patients needed a second operation for repair of glans dehiscence and stenosis before the closure of proximal stoma [Table 1]. Two medium fistulas were repaired along with the closure of proximal stoma. Six suture track fistulas healed following “needling”[11] done.
Table 1: Patients' profile and outcome

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Twenty-nine of 33 patients had a satisfactory curve and flow in uroflowmetry at 6 months. The remaining four gradually gained satisfactory flow in uroflowmetry.

   Discussion Top

Ulaanbaatar procedure was first performed in the capital city of Mongolia. In Ulaanbaatar procedure, Dewan et al.[12] did orthoplasty and distal urethroplasty in the same sitting to achieve better glans with vertical meatus [Figure 2]d by avoiding repeat trauma on glans from two-stage procedure. Idea of Ulaanbaatar procedure was to get symmetric appearance of glans and shaft[12] by avoiding repeat trauma from operative intervention. Dewan et al. did remaining urethroplasty in the second stage without any interference on glans and corona.

In the original Ulaanbaatar procedure, Dewan et al. did orthoplasty and distal urethroplasty partially in the first stage. They anastomosed the bivalved Byars flap on the ventral surface following rotation from the dorsum. They made a tube with the free end of anastomosed preputial skin that needed another suture line. That reconstructed tube with two suture lines was placed in the tunnel made in the glans. The rest of preputial skin was fixed on the ventral surface to be useful to create tube in the second stage. However, Jayanthi et al. modified the classic Ulaanbaatar procedure by creating tube from an island flap of prepuce[13] with single suture line, and tube was placed either in tunnel or in bivalved glans. In the second stage, residual urethroplasty was done with penile skin not with preputial skin. Both procedures did not preserve the native urethral plates. In EUP, we have done orthoplasty as well as full-length urethroplasty as “primary procedure” with divided and retracted native urethral plates at two ends along with PSG as bridge in the gap. Classic[12] and modified[13] Ulaanbaatar procedures are substitution urethroplasty. Neourethra is substituted with preputial and penile skin. However, in EUP, cut ends of native urethral plate are preserved and only the gap in urethral plate was substituted with PSG. Following that, urethral tube regenerated from “buried strip” of native urethral plate and PSG. Hence, EUP is a combination of substitution cum regenerative urethroplasty.[6]

For EUP, we repurposed the principle of “buried strip” urethroplasty,[6],[7] and for that, we found PSG[5] is ideal for its easy harvesting, graft take, and its suppleness. Initially, we used oral mucosal graft (OMG) in EUP similar to other authors[7] for its “excellent” long-term results as claimed by some authors[14] in hypospadias surgery.[15] However, we found less suppleness on regular calibration in neourethra formed with OMG, compared to PSG. Complications such as stricture, chordee, and disruption (possibly due to mucus secretion) were found to be more in OMG urethroplasty. Similarly, other authors also mentioned increased complications in urethroplasty[16] with OMG. Hence, we dropped OMG urethroplasty.

We also wrapped TVF over neourethra to increase vascularity around reconstruction[17],[18] to support the regeneration of buried strip from native plate and PSG. In fact, EUP is basically a regenerative urethroplasty.[6],[8]

Both in classic Ulaanbaatar[12] and in modified Ulaanbaatar procedure,[13] the authors did orthoplasty and distal urethroplasty at the first stage and residual urethroplasty in the second stage. In our procedure, we completed orthoplasty and urethroplasty as primary procedures and kept neourethra on regular calibration to get adequate caliber before the closure of “controlled fistula” as a daycare.

Some complications are mentioned in classic Ulaanbaatar as “pouting skin” (3%) and diverticula (3%), and diverticulum was much higher (26%) in modified Ulaanbaatar along with epididymitis (3%). Those complications were likely to be due back pressure and reflux of infected urine in vas deferens from the resistance of long neourethra of inadequate caliber as per Poiseuille's law. In EUP, it is possible to achieve adequate caliber in long neourethra with both continuous calibration followed by regular calibration before the closure of “controlled fistula.” Hence, those complications, i.e., diverticula, epididymitis, and pouting skin, were not found in EUP. Similarly, it is possible to deal all complications following reconstruction of long urethra previous to the closure of “controlled fistula.” It is easy to correct complications as urine is diverted from long neourethra. This prospect is not in classic and modified Ulaanbaatar procedure. Nevertheless, two patients had stenosis in neourethra due to incomplete calibration, result of communication failure. Disruption of glans and stenosis in neourethra were repaired during the period of urinary diversion.

   Conclusion Top

EUP is akin to single-stage procedure along with later closure of proximal “controlled fistula” as a daycare procedure, as a secondary procedure. That is why EUP is less invasive. In conjunction, we would get chances of patch up of long neourethra, if necessary, and would yield adequate caliber before allowing urine to pass through it. EUP shunned the need of repeat degloving, and EUP decreases the period of morbidity, stay, and cost of surgery.


The authors are grateful to Dr. Moinul Hassan, Prof. Tapan K. Mandal, Prof. Tapas K. Majhi, and Dr. Susanto K. Sen, who have allowed them to do operative procedures on their patients.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Retik AB, Bauer SB, Mandell J, Peters CA, Colodny A, Atala A. Management of severe hypospadias with a 2-stage repair. J Urol 1994;152:749-51.  Back to cited text no. 1
Sadove RC, Horton CE, McRoberts JW. The new era of hypospadias surgery. Clin Plast Surg 1988;15:341-54.  Back to cited text no. 2
DiSandro M, Palmer JM. Stricture incidence related to suture material in hypospadias surgery. J Pediatr Surg 1996;31:881-4.  Back to cited text no. 3
Hollowell JG, Keating MA, Snyder HM 3rd, Duckett JW. Preservation of the urethral plate in hypospadias repair: Extended applications and further experience with the onlay island flap urethroplasty. J Urol 1990;143:98-100.  Back to cited text no. 4
Gangopadhyay AN, Sharma S, Mongha R. Onlay free preputial graft for mid and distal penile hypospadias. J Indian Assoc Pediatr Surg 2005;10:244-7.  Back to cited text no. 5
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Chatterjee US, Chatterjee SK. Regenerative urethroplasty in reoperative hypospadias: Buried strip principle revisited. J Indian Assoc Pediatr Surg 2012;17:63-7.  Back to cited text no. 6
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Das AK, Karmakar S, Mandal TK, Majhi TK, Kashyap V, Bera D, et al. Complex hypospadias reconstruction: Ulaan Baatar technique revisited. Int Surg J 2021;8:3354-8.  Back to cited text no. 7
Chatterjee US, Basu AK, Bhaumik KK, Mitra D. Tubularisation in hypospadias repair: Is it essential or necessary? J Indian Assoc Pediatr Surg 2022;27:508-9.  Back to cited text no. 8
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Bhaumik K, Goswami SM, Konar HL, Basu KS, Das S, Mukherji P, et al. Our experience with tubularised incised plate urethroplasty in various types of hypospadias. J Indian Assoc Pediatr Surg 2003;8:108-12.  Back to cited text no. 9
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Sarkar R, Konar H, Sahabasu K, Saha K, Samanta N. Urethroplasty by midline longitudinal incision of the dorsal wall of urethra at the site of the fistula: A useful adjunct to the conventional method of repair of urethrocutaneous fistula developing after hypospadias surgery. J Indian Assoc Pediatr Surg 2006;11:24-6.  Back to cited text no. 10
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Chatterjee US, Basu AK, Bhaumik K. Needling for suture track fistula. J Indian Assoc Pediatr Surg 2021;26:203-5.  Back to cited text no. 11
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Dewan PA, Erdenetsetseg G, Chiang D. Ulaanbaatar procedure for tubularization of the glans in severe hypospadias. J Urol 2004;171:1263-5.  Back to cited text no. 12
Jayanthi VR, Ching CB, Dajusta DG, McLeod DJ, Alpert SA. The modified Ulaanbaatar procedure: Reduced complications and enhanced cosmetic outcome for the most severe cases of hypospadias. J Pediatr Urol 2017;13:353e1-7.  Back to cited text no. 13
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Chatterjee US, Mandal MK, Basu S, Das R, Majhi T. Comparative study of dartos fascia and tunica vaginalis pedicle wrap for the tubularized incised plate in primary hypospadias repair. BJU Int 2004;94:1102-4.  Back to cited text no. 17
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  [Figure 1], [Figure 2]

  [Table 1]


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