Journal of Pediatric Urology (2013) 9, 804e807

Tunica vaginalis flap is superior to innerpreputial dartos flap as a waterproofinglayer for primary TIP repair in midshafthypospadias

Ramesh Babu*, Sekar Hariharasudhan

Pediatric Urology, Sri Ramachandra Medical College and Research Institute, Porur,Chennai 600116, India

Received 30 July 2012; accepted 27 October 2012Available online 25 November 2012

KEYWORDSHypospadias;TIP repair;Inner prepucial dartosflap;Tunica vaginalis flap

* Corresponding author.E-mail address: drrameshbabu1@g

1477-5131/$36 ª 2012 Journal of Pedhttp://dx.doi.org/10.1016/j.jpurol.20

Abstract Aims: The aims of this study are 1. to compare outcome of standard tubularisedincised plate urethroplasty (TIP) repair using dartos flap in distal vs. midshaft hypospadiasand 2. to determine whether tunica vaginalis flap (TVF) is superior to dartos flap in midshafthypospadias in reducing early complications.Methods: All patients who underwent TIP repair between 2004 and 2011 by the same surgeonwere divided into three groups based on type of hypospadias and choice of waterproofinglayer: Group A: Distal hypospadias; inner prepucial dartos flap (n Z 36); Group B: Midshafthypospadias; inner prepucial dartos flap (n Z 26); Group C: Midshaft hypospadias; TVF(n Z 21). Early outcomes were compared between the groups using Fisher’s exact test.Results: There was no significant difference in the age distribution or duration of follow upbetween the groups. There was no significant difference in terms of, glans dehiscence or mea-tal stenosis between the groups. In Group A, 0/36 had ventral skin necrosis and 3/36 (8.3%)developed urethrocutaneous fistula. In Group B, there was significantly higher ventral skinnecrosis (6/26; 23%) and urethrocutaneous fistula (8/26; 30.7%) compared to Group A(p Z 0.04). In Group C, there was significantly less ventral skin necrosis (0/21) and urethrocu-taneous fistula (1/21; 4.7%) compared to group B (p Z 0.03). There was no significant differ-ence in outcomes between Group A and Group C.Conclusion: 1. TIP repair using inner prepucial dartos flap has significantly higher complica-tions when used for midshaft hypospadias compared to distal hypospadias. 2. Tunica vaginalisflap reduces the fistula rate and is superior to inner prepucial dartos flap as a waterproofinglayer for primary TIP repair in midshaft hypospadias.ª 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

mail.com (R. Babu).

iatric Urology Company. Published by Elsevier Ltd. All rights reserved.12.10.022

Tunica vaginalis vs. dartos flap in midshaft hypospadias 805

The use of tubularised incised plate urethroplasty (TIP)

popularized by Snodgrass [1] for distal hypospadias has tions. Outcomes were compared between the groups using

been further extended to midshaft and proximal hypospa-dias repair of late [2,3]. The essential addition that pre-vented fistula rate in this approach was inner prepucialdartos flap [4,5]. Harvesting of this flap usually is notassociated with problems as the excess outer prepuce isoften discarded in distal hypospadias. However in cases ofproximal hypospadias, the outer prepucial skin is of greatimportance, as it forms the ventral skin cover. Wheneverthis vascularity is jeopardized it could theoretically lead toventral skin necrosis, and fistula formation [6,7].

Tunica vaginalis flap (TVF) has been used as an effectivewaterproofing layer in hypospadias and several authors[6,7] have reported better outcomes with TVF whencompared to dartos flap. However these studies have notbeen performed segregating the type of hypospadiasresulting in selection bias. The aims of this study are tocompare outcome of standard TIP repair using dartos flap indistal vs. midshaft hypospadias and to determine whetherTVF is superior to dartos flap in proximal hypospadias inpreventing early complications, like ventral skin necrosisand urethrocutaneous fistula.

Table 1 Observations and outcome following TIP repair;Group A (distal hypospadias with inner prepucial dartosflap); Group B (midshaft hypospadias with inner prepucialdartos flap); Group C (midshaft hypospadias with TVF).

Outcomes Group A(n Z 36)

Group B(n Z 26)

Group C(n Z 21)

Mean age (months) 11.8 12.6 14.6Follow up (months) 18 20 18Ventral skin necrosis 0 6 (23.1%)

(p < 0.05)0

Urethrocutaneousfistula

3 (8.3%) 8 (30.7%)(p < 0.05)

1 (4.7%)

Glans dehiscence 1 (2.7%) 1 (3.8%) 1 (4.7%)Meatal stenosis 3 (8.3%) 1 (3.8%) 1 (4.7%)

Patients and methods

All consecutive patients who underwent TIP repair (agerange: 9e18 months) between 2004 and 2011 by the samesurgeon were divided (prospective, nonrandomized) intothree groups based on type of hypospadias and choice ofwaterproofing layer: Group A: Distal hypospadias (coronaland subcoronal); inner prepucial dartos flap (n Z 36);Group B: Midshaft hypospadias; inner prepucial dartos flap(n Z 26); Group C: Midshaft hypospadias; TVF (n Z 21).Patients with poor urethral plate were considered notsuitable for TIP repair; in addition, hypospadias proximal tomidshaft, and re do cases were excluded.

TIP repair was performed under general anaesthesia andcaudal analgesia using 2.5 � magnifications. After deglov-ing and correcting the chordee fully, the urethral plate wastubularised over a 7F silastic catheter with 7-0 poly-dioxanone subcuticular continuous suture, inverting theurethral plate. A second layer/spongioplasty was addedusing the same suture material in all cases. In Group A and Bclassical inner prepucial dartos flap was used while in GroupC, TVF, as described earlier [6,7,13] was used as a water-proofing layer. Glansplasty was done with polydioxanonesutures. In Group A, the excess dorsal foreskin was excisedwhile in Group B & C, after a dorsal midline slit, the excessdorsal foreskin was transposed ventrally from both sides toprovide skin cover and a circumcised look. Adrenalin wasnot used in any of the patients and a tourniquet was usedonly during glans wings dissection. Compression dressing onto the abdominal wall with antibiotic impregnated gaugewas applied in all cases. Intravenous antibiotics were givenfor 3 doses, followed by prophylactic oral antibiotics.Patients were discharged after 48 h with dressing andcatheter. All patients were put on anticholinergics andlaxatives to prevent bladder spasm and straining. Dressingand the catheter were removed on the 8th day. Fortnightlyfollow up was performed in the initial period, followed by

monthly check up until 1 year to record early complica-

Fisher’s exact test.

Results

Table 1 summarizes the observations and results. There wasno significant difference in the age distribution or durationof follow up between the groups. Premature catheter/dressing removal, due to spasm, soakage or accidentalpulling-out of catheter, were not encountered in any of thepatients. There was no wound infection in any of the studypatients. There was no significant difference in terms of,glans dehiscence or meatal stenosis between the groups.

In Group A (distal hypospadias; dartos flap), 0/36 hadventral skin necrosis and 3/36 (8.3%) developed ure-throcutaneous fistula. In Group B (midshaft hypospadias;dartos flap), there was significantly higher ventral skinnecrosis (6/26; 23%) (Fig. 1) and urethrocutaneous fistula(8/26; 30.7%) (Fig. 2) compared to Group A (p Z 0.04). InGroup C (midshaft hypospadias; TVF), there was signifi-cantly less ventral skin necrosis (0/21) and urethrocuta-neous fistula (1/21; 4.7%) compared to group B (p Z 0.03).There was no significant difference in outcomes betweenGroup A and Group C (pZ 1). There was no morbidity in anyof the patients in group C (testicular ascent or infection oratrophy) due to TVF.

Discussion

Although several techniques of providing vascularised softtissue cover to the neourethra have been described [1e12],it was TIP repair popularized by Snodgrass [1e5] thatrevolutionized the hypospadias outcomes particularly withreference to urethrocutaneous fistula. One of the impor-tant additions which resulted in the improved outcomes ofTIP repair was additional coverage of neourethra by vas-cularised inner prepucial dartos. However this dissectionrequires skill and there are chances that the outer pre-pucial skin becomes hypo vascular due to dartos flap. Incases of distal hypospadias, the ventral skin cover isadequate, excess outer prepucial skin is discarded andtherefore hypovascularity of outer foreskin of no

Figure 1 Ventral skin necrosis in a patient with midshafthypospadias following TIP repair using inner prepucial dartosflap. The ventral skin cover is obtained by rotating the outerdorsal foreskin, which probably gets devascularised whileraising the dartos flap.

Figure 2 Bar chart with dark area representing ure-throcutaneous fistula. X axis denotes groups. Y axis denotesnumber of patients. The fistula rate was significantly higher inGroup B (pZ 0.04) compared to Group A. There was significantreduction in fistula in with use of TVF in Group C (p Z 0.03)compared to Group B. There was no significant difference inoutcomes between Group A and Group C (p Z 1).

806 R. Babu, S. Hariharasudhan

consequence. However in cases of midshaft and proximalhypospadias, there is always insufficient skin and ventralcover is provided by rotating the dorsal outer foreskin. Ifthis gets devascularised while raising the dartos flap,eventually it can result in ventral skin necrosis and can leadto increased incidence of urethrocutaneous fistula [6,7].

In the present study we have compared the outcomes ofstandard TIP repair using dartos flap in distal vs. midshafthypospadias and attempted to determine whether TVF issuperior to dartos flap in midshaft hypospadias in pre-venting early complications, like ventral skin necrosis andurethra cutaneous fistula. Our findings reveal that innerprepucial dartos flap along with TIP repair in distal hypo-spadias did not cause any ventral skin necrosis and thefistula rate was comparable with world literature [5e10];however the ventral skin necrosis and fistula were signifi-cantly higher when dartos flap was used along with TIPrepair in midshaft hypospadias. This complication couldsignificantly be reduced by using TVF instead, in childrenwith midshaft hypospadias.

Several authors [6e8] have reported better outcomeswith TVF when compared to dartos flap. TVF has soundvascularity, as it has a separate blood supply and does notimpair the blood supply of the outer prepucial foreskin.Snow et al. [13], in 1995, were the first to report the use of

tunica vaginalis as interposition graft with reported fistularate of 9%. Similar results have also been reported by otherauthors [14,15].

TVF has been used successfully as a waterproofing layerin previously circumcised patients and recurrent urethracutaneous fistulae [16]. In his recent experience, Snodgrasscould reduce the fistula rate to 0% with the use of TVF [17].Our findings reveal that TVF is superior to dartos flap inmidshaft hypospadias in reducing ventral skin necrosis orurethrocutaneous fistula but in distal hypospadias a clas-sical TIP repair with inner prepucial dartos cover itself issufficient. Further studies with larger numbers are requiredto support or negate the observations.

RB designed and conceived the study; SH materialsupport.

No funding; No conflict of interest.

References

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