Reconstruction of anterior urethra in hypospadias by buried skin strip method

RECONSTRUCTION OF ANTERIOR URETHRA IN HYPOSPADIAS BY BURIED SKIN STRIP METHOD A SIMPLIFIED A N D IMPROVED TECHNIQUE

By J. C. MUSTARD]~,M.B., Ch.B., F.R.C.S.

From the Nuffield Department of Plastic Surgery, Oxford, and the Plastic Surgery Unit, Royal Infirmary, Glasgow THE number of operations devised in the past hundred years by generations of able surgeons for reconstructing the anterior urethra in hypospadias, after correction of the ventral curvature, is in itself adequate demonstration of the difficulty of devising a simple yet uniformly successful technique. It is not the present writer's intention merely to erect one further monument along this hypospadiac Appian Way, but rather to show how, by the use of a simple device, one of the earliest published methods--the use of the buried skin strip so lucidly described and illustrated by Duplay in his paper of I88o--may produce consistently good results without the exercise of any extraordinary skill or dexterity, and in a minimum of time. In the method described by Duplay a strip of skin on the ventral aspect of the penile shaft was isolated from the lateral skin by means of two parallel incisions some 5 to 7 mm. apart running proximally from the glans to within a few millimetres of the reposed urethral opening. Lateral flaps were fashioned and widely undermined so that they could be brought together over the central skin strip. An extensive surface of contact of the two flaps was obtained by the use of single silver wire sutures passed from side to side through the flaps and held in place by lead clips, the flaps being protected from the clips and closer apposition being obtained by interposing the end portion of a sound between the clips and the skin surface ; a procedure clearly shown by the illustrations here reproduced from Duplay's original article (Fig. r). The method, which he developed from his original operation (r874) in which he had formed a urethral tube from the central skin, fell into disuse, although it was mentioned by Cecil in I936 ; but to Marion and Perard (r942) and later to Denis Browne (~949) must go the credit for resurrecting Duplay's original technique. Denis Browne, using the same type of single stop sutures with malleable dips, and with individual beads instead of sounds, completed the junction of the reconstructed urethra with the original urethra at the time of the reconstruction operation, diverting the urinary stream by means of a perineal urethrostomy, thus saving any secondary closure. In Denis Browne's own hands this modified operation of Duplay's has given extremely good results, with only three cases of fistula formation in a series of fifty. This very satisfactory minimal proportion of cases complicated by fistula formation has not, however, been attained in the writer's own series, nor in that of several colleagues and others with whom he has personally discussed the matter. Smith and Blackfield (r952), discussing Denis Browne's results, reached the conclusion t h a t " a significant incidence of fistula: is to be expected in most hands." i66

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C FIG. I

A~ Central skin strip with lateral flaps outlined and with central sound in position to assist skin strip forming into a tube. B, Showing silver sutures, lead clips, and protecting lengths of old sounds on skin surfaces. C~ Cross section to show buried skin strip--lateral protecting sounds not shown. A: B, and C are reproduced from Duplay, S. (188o).

Arch. gdn. Mdd., ~4~, 257.

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Failure to obtain a water-tight urethra in one operation has been experienced in as high as 30 per cent. of cases in individual series, owing to the formation of one or more fistula: at the site of the transfixing sutures. Such small fistulm rarely prove difficult to close at a subsequent stage, but the objective of a foolproof one-stage closure is no longer attained. Tbe fistulm may be produced by pressure of the beads on the skin, either by too tight application of the beads and collars holding the flaps together or--even when an initial slack has been left, and a dorsal slit is made--by undue o~dema of the lateral flaps producing tightness between the beads with subsequent necrosis of tissue beneath them. In some cases uncomplicated by such ~edema or necrosis the fistulm have resulted from leakage of urine alongside the catheter and into the newly reconstructed urethra. Such leakages, even of minor quantities of urine, because of the fact that the sutures bridge across the apex of the new urethra, almost invariably lead to ultimate persistence of the suture track, with leakage of urine through this small opening when the urinary stream is eventually allowed to flow under full pressure through the new urethra. It seemed reasonable to the writer, in view of his own and the experiences of others, to devise a method of holding the two lateral skin flaps in the desired wide apposition by some means other than by passing sutures through them at a site affording such an invitation to fistula formation. A simple clamp was accordingly designed, on the paper-clip principle, which would fulfil the requirements of the operation safely and satisfactorily. The clamp was constructed of I mm. thick perspex sheet so that the skin flaps could be kept under inspection in their entirety and had a controlled spring action allowing the pressure of the blades of the clamp on the two flaps to be adjusted to suit each case. Several models of different design, but embodying the same basic principle, have been tried out, and it is believed that the final model (Fig. 2) is the simplest to produce and to use. OPERATIVE TECHNIQUE

The urinary stream is first diverted by a perineal urethrostomy, using a Malecot catheter of suitable size, and cutting down on the catheter by diathermy. The subsequent steps of making a U-shaped incision, excising two small triangles of skin from the glans, and undermining the lateral skin flaps widely and for some distance proximally are illustrated in Fig. 3, A and B. The edges of the lateral flaps are sutured together, using medium silk, at intervals of about 3 to 4 mm.mtaking onlya small bite of each skin edge--and one end of each suture is left long. A few sutures are inserted to pin down the flaps to the denuded triangles on the glans (Fig. 4). At least two sutures, passing through skin only and not into the dissected space beneath, should be inserted proximal to the junction of the lateral flap edges (Figs. 4 and 5). When all the sutures are in position they are grasped in one or more long-bladed forceps (Fig. 5) and, the screw catch on the clamp having been opened, the penis is laid in position in the clamp, the line of sutures being passed along the open slot (Fig. 6). Each suture is now gently pulled on, bringing the skin flaps into the space between the blades of the clamp. When the suture is sufficiently tightened, as shown by a tendency of the flaps to blanch if the pull is increased, the suture is

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C FIG. 2 Writer's clear acrylic hypospadias damp. A, Side view. B, From below, showing slots for sutures. C, End view showing screw adjustment. (A later model has a removable screw and dispenses with the hinge.)

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k B FIG. 3 Dissection of lateral skin flaps leaving ventral skin strip. A, Showing line of incision (dotted line) and two triangles (stippled) on glans to be excised. B, Skin flaps undermined extensively both laterally and in midline proximal to L urethral opening, A

/

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FIG. 4 ]Ventral view showing skin flaps sutured to glans and to each other at edges. Note sutures inserted proximal to incision line--see text.

J ",

FIG. 5 As in Fig. 4 lateral view. Sutures held in forceps.

FIG. 6 Sutures being slid along gap between two blades of clamp--cf. Fig. 2, C. (Screw open.)

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pressed home into one of the tapering slots and cut off short (Fig. 7, B). It is important to put the flaps on a slight disto-proximal stretch to get m a x i m u m length of urethra. The hinged screw is now swung into place and the blades of the clamp are

f A

B FIG. 7 Transverse section showing penis resting in clamp and skin flaps drawn down between blades of latter by pulling on sutures and pressing these into slots. A, With screw closed up. B, With screw open.

tightened until the skin flaps begin to blanch. The screw is then loosened sufficiently to allow of disappearance of any such blanching (Fig. 7, A). Finally, a Gamgee pad is fixed to the abdominal wall by adhesive strapping and the clamp fastened to this (Fig. 8).

FIG. 8 Clamp in position on penis, showing method of fixation to pad on abdomen.

Post-operative Management.--Within twenty-four hours the flaps become dark and discoloured, but continue to blanch slightly on compression, and after a few days the discoloration passes off and the normal pink colour of the skin is regained. Between seven and ten days after operation the skin-edge sutures begin to cut through and about the ninth day the clamp either becomes completely free or may be removed with division of the few remaining sutures. The perineal catheter may be left in situ for a further two days for added security, but experience

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would appear to show that it is not by any means prejudicial to sound healing if it is removed at the time of freeing of the clamp, or even earlier. The urethrostomy opening closes in a few days spontaneously. COMMENT

The majority of the earlier cases of the series had had the ventral curvature corrected and the skin defect covered by the use of a modified Ombredanne type of preputial flap. It was found that this gave a very loosely attached skin strip which tended to buckle into folds, one of which usually bulged out of the distal opening of the new urethra, causing some spreading and diversion of the urinary stream. This was absent in later cases, in which at the suggestion of Mr E. W. Peet a Blair type of correction was used. In this technique the two preputial flaps meet in the ventral midline and give a skin strip fixed to the penile shaft, without any tendency to folding. The clamp used for the first two cases operated on was of a very elementary type and did not have any rounding of the proximal edges of the clamp blades ; nor were the penis and clamp prevented from twisting by being fixed to an abdominal pad, and in one of these cases the sharp, right-angled proximal corner of the clamp dug into the lateral flap on one side as the penis twisted round, causing a small point of necrosis with a resulting fistula. Subsequent alteration in design with flaring outwards in a gradual curve of the offending corners of the clamp has resulted in a complete absence of any such complication in any subsequent case. Using the redesigned clamp, a series of twelve cases was operated on: in one case an early uncontrollable post-operative ha~morrhage from the glans and corpora gave rise to the formation of large clots between and beneath the flaps with almost complete failure to achieve union of the flaps. Apart from this last case, no fistula has arisen in any of the other twelve cases treated by the technique described. It was observed early in the series that the pressure of the clamps reduced the gross, and at times alarming, oedema which the penile skin shows after any operative trauma. Further, the discoloration of the flaps disappeared in general more rapidly in these cases than in those in which a clamp was not used. Diversion of the urinary stream by a posterior urethrostomy is not universally regarded as a satisfactory procedure; and in the cases of hypospadias operated on in this department, both by this and by other methods, leakage of urine past the catheter, even without blockage of this last, has occurred on a number of occasions - - a n experience shared by other operators in this field. Such leakage of urine has had no apparent ill-effect on the outcome of the operation when the flaps are apposed by a d a m p - - n o vulnerable stitch tracks being in the vicinity of the leaking urine--and indeed in two cases in which the catheter ceased to function for one or other reason within twenty-four hours of operation and in which almost the whole of the urine was voided through the newly constructed channel, the pressure of the clamps was apparently sufficiently great to prevent any extravasation whatsoever and an uneventful convalescence took place in both cases. In one case, in fact, the catheter was mistakenly removed by the house surgeon eighteen hours post-operatively, after he had attempted to syringe it clear, and all the urine passed through the new urethra from then on, only a small proportion escaping through the urethrostomy opening.

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Encouraged by these two experiences the writer decided to dispense with the posterior urethrostomy and on four occasions drained the urine by means of a simple Jacques rubber catheter introduced into the bladder via the external urethral opening and laid along the skin strip before this last was buried by the lateral flaps. It was found that the catheter tended to be extruded about the fourth or fifth day, and from then on urine was voided along the new urethral channel --without any pain. In one of the cases, however, a boy of 4 years of age with a very tiny, under-developed penis, the lateral skin flaps were so thin that the catheter could be seen through them and the pressure of the catheter against one of the flaps at its thinnest part gave rise to a small area of devitalisation which, possibly in conjunction with a moderately severe inflammatory reaction due t o infection by Streptococcus hcemolyticus (Group A), gave rise, two days after removal of the clamp, to a small breakdown and fistula formation. Infection apart, such pressure necrosis might well have been avoided if a dorsal slit had been used in this case, but in all the cases operated on it was found entirely unnecessary to make any dorsal relaxing slit, as is necessary with the bead and collar technique, and the complication encountered in this experimental departure from the writer's routine operative procedure was not foreseen until the damage was done. It should be here emphasised that although it was not found necessary to carry out a dorsal slit in any of the cases described, the writer would state categorically that if circumstances warranted it he would have no hesitation in carrying out the procedure to obviate any tightness, particularly in a small penis. It appears to be unnecessary in most cases however, and complete healing is thereby accelerated with earlier discharge of the patient from hospital. Contraction of the dorsal scar is a rare late sequel of a dorsal-slit procedure, but nevertheless it does occur. Further experience may show that an extensive dorsal slit may, in fact, allow simple non-self-retaining catheterisation to be used instead of posterior urethral drainage, and the experiment must undoubtedly be tried--at least once--of dispensing with a catheter completely. The original technique was returned to after the four experimental cases, and successful results without fistula formation were achieved in all cases. SUMMARY A simplified technique is described whereby reconstruction of the anterior urethra was carried out both in children and in adults, using a lightweight transparent clamp to appose the lateral skin flaps over a buried skin strip. A defect in the original design of the clamp and a later experimental technique without using a posterior urethrostomy are described. In these two phases (six cases) complications are shown to have arisen in two cases. A series of twelve cases carried out by the standard technique described in the paper is reported with only one case (complicated by massive clot formation) in which successful fistula-free reconstruction of the anterior urethra was not obtained by a one-stage operation. I wish to extend my grateful thanks to Professor T. P. Kilner of the NuffieM Department of Plastic Surgery, Oxford, in whose department the majority of the eases were operated on, for his continued encouragement and constructive criticism, and to Mr E. IV. Peer for his co-operation with a number of the cases and his extremely helpful advice.

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REFERENCES

BLAIR,V. P., and BYARS, L. T. (I938). 3:. UroL, 40, 814. BROWNE, DENIS (1949). Proc. R. Soc. Med., 42, 466. CECIL, A. B. (1936). In Cabot, H., " M o d e r n Urology," 3rd ed., vol. i, sec. 2, p. i i 5. L o n d o n : Henry Kimpton. DUPLAY, SIMON (1874). Arch. gdn. Mdd., 133 , 513 . -(188o). Arch. gdn. Mdd., 145 , 257. MARION, G., and PERARD,J. (1942). " Technique des op6rations pLastiques sur la vessie et sur l'ur6tre." Paris : Masson et cie. SMITH, D. R., and BLACKFIELD,H. M. (1952). Surgery, 6, 885. Hypospadias clamps as described in this article and made to the writer's design may be obtained on order (four sizes) from Messrs Charles F. Thackray Ltd., 38 Welbeck Street, London, V¢'.I. I am grateful to Messrs A. C. Stewart, Ltd., Thornliebank, Glasgow, for technical advice and assistance,