Chapter 2 Continued (Part 2)
6 Some technical aspects of hypospadiology
Progressively and over the course of time, surgeons and pediatric urologists have developed an impressive number of techniques for repairing the various forms of hypospadias. When considered globally, it is estimated that more than 300 techniques (including variations) for the correction of hypospadias have been described in literature (Arap & Mitre, 2000).
6.1. Correction of chordee
The choice of of a urethroplasty technique is made after correction of chordee (De Sy, 1996a). Different techniques for normalizing the penis have been described (see Baskin, Duckett & Lue, 1996 ; Hayashi, Kojima, Mizuno et al., 2002). The presence of chordee is generally more easily visible when the penis is erect rather than flaccid, and in young infants this is tested by an artificial erection induced by an injection of physiological serum (Wese et al., 1994). The artificial erection test allows a judgment to be made about the extent of straightening and the length of the operation (Baskin et al., 1996 ; Hayashi et al., 2002).
6.2. Urethroplasty
According to De Sy (1996a), the choice of a particular urethroplasty technique is dependent on physical factors present (e.g., chordee, location and appearance of the urethral meatus, the shape and size of the glans, the quality of ventral skin covering the urethra, length of the urethral plate, quantity of preputial skin available). For Wilcox and Ransley (2000), the available techniques can be synthesized into four large groups.
The techniques for advancing the urethra refer to processes of adjusting the distal extremity of the penis, used in repairing anterior forms of hypospadias, without associated chordee. One of the most popular techniques of urethral advancement was the ‘meatal advancement and glanuloplasty incorporated’ or MAGPI [28], which appeared in the 1980s (Sheldon & Duckett, 1987).
However, the aesthetic results of surgical repair of hypospadias by MAGPI are mixed [29], and pediatric urologists are tending to abandon this technique (Paparel et al., 2001). Other techniques have been proposed for repair of anterior forms of hypospadias, such as the ‘glans approximation procedure’ or GAP [30] (Zaontz, 1988, cited by Gittes, Snyder & Murphy, 1998). There is also a technique known as ‘mobilization of the urethra with advancement’ [31]
(Koff, 1981, cited in Atala, 2002).
The techniques known as tubularization [32] of the urethral plate [33] were described by the pioneers of hypospadias surgery almost a century and a half ago (Duplay, 1874). Somewhat forgotten, they were only rediscovered in the 1980s and then widely popularized during the 1990s (Wilcox & Ransley, 2000).
The general principle of these techniques is, as their name indicates, to use the urethral plate, which, once preserved, can be tubularized upon itself as far as the tip of the glans (Bouhafs, Mege, Dubois et al., 2002 ; Mege, Pelizzo, Dubois et al., 1999).
As the urethral plate is too narrow for tubularisation, a method introduced by Snodgrass (1994) overcomes this limitation: a longitudinal incision along its whole length causes the urethral plate to broaden and it can then be tubularized.
The Snodgrass technique, first used for the repair of anterior hypospadias, was later extended to posterior forms (Cendron & Ellsworth, 1999 ; Snodgrass, 1999 ; Snodgrass & Lorenzo, 2002a ; Sugarman, Trevett & Malone, 1999). The urethroplasty technique of ‘tubularized incised plate urethroplasty’ or TIP [34] is nowadays one of the most popular in surgical repair of hypospadias (Cheng, Vemulapalli, Kropp et al., 2002 ; Snodgrass & Nguyen, 2002b).
The techniques known as ‘vascularised flaps’ consist of the creation of a new urethral tube using various flaps of skin taken directly from the penis. I should mention here the Mathieu technique [35] (modified) for repair of anterior hypospadias (Hoebeke, Boemers & De Jong, 1996 ; Ravasse, Petit & Delmas, 2000).
Other techniques have been proposed when chordee is present, for example ‘transversal preputial pedicle flap’ [36] for the repair of both anterior and median hypospadias (Duckett, 1981, cited in De Sy, 1996b), and also the technique known as ‘tubular transversal preputial pedicle flap’ [37], a technique for complete replacement of the urethra, used for repair of posterior hypospadias (Duckett, 1980, cited in Hayashi, Kojima, Nakane et al., 2003).
The techniques using free grafts from elsewhere on the body, popular throughout a large part of the twentieth century, are no longer recommended except in a minority of cases: extreme posterior forms (e.g., perineal) (Ferro et al, 2002 ; Meyer et al., 2002), and multi-operated hypospadias where the skin from the penis (e.g., preputial skin) is no longer useable (van der Werff & van der Meulen, 2000).
However, I would add that certain current techniques make increasing use of the buccal mucosa [38] for making grafts (Caldamone, Edstrom, Koyle et al., 1998; Hensle, Kearney & Bingham, 2002).
6.3. Reconstruction of the ventral side of the penis
The third stage of surgery refers to reconstruction of the ventral side of the penis (Paparel et al., 2001). This final stage is usually incorporated within current urethroplasty techniques [39]. Reconstruction is carried out by means of three surgical techniques. I mention them here, without going into details:
– remodeling of the urethral meatus (meatoplasty) and the ventral side of the glans (glanuloplasty)
– reconstruction of the mucous collar around the glans. This is a technique which gives the penis an appearance very close to that of a normal circumcised penis (Kolligian & Firlit, 2000)
– a correctly vascularised cutaneous covering
- Possible complications
Although the objectives of hypospadias repair aim to obtain a penis with normal functions of urination, erection and appearance, it is well known that there are a number of possible complications related to this type of surgery (Paparel et al., 2001; Wilcox & Ransley, 2000). Here is an outline of some of them.
7.1. Urethral fistulas
One of the more commonly encountered complications after hypospadias surgery is the urethral fistula. Characterized by an outflowing of urine at the site of the repair on the ventral side of the penis, a urethral fistula is at least an annoyance during urination (Dubois, Pellizo, Nasser et al., 1998). This complication can occur during the first six months following the operation or even several years later. Sometimes, fistulas close themselves spontaneously. However, if this complication persists, it is possible to operate again, according to the severity of the situation (e.g. size of the fistula, multiple fistulas) (Elbakry, 2001; Shankar, Losty, Hopper et al., 2002). Some fistulas which are more complex to close than others require specific surgical procedures (Richter, Pinto, Stock & Hanna, 2003).
7.2. Stenosis of the urethral meatus
A second complication is stenosis of the urethral meatus. Rarer than fistulas, stenoses consist of a shrinking of the urethral meatus, which lessens the stream of urine during urination (Ellsworth et al., 1999). This complication can lead to serious problems due to the difficulty of completely emptying the bladder (e.g. damage to the upper urinary tract, urinary infections). A stenosis can be treated manually by dilatation with the help of a catheter or surgically (a meatotomy) (Wilcox & Ransley, 2000).
7.3. Persistent chordee
A third complication refers to the persistence of chordee. In general, this complication is due to its inadequate correction at the time of the first operation. This complication is becoming less frequent thanks to the development of new surgical techniques in orthoplasty and the potential to check the straightening of the penis throughout the surgery (Wilcox & Ransley, 2000).
7.4. Unsatisfactory aesthetic results
A fourth complication relates to disappointing aesthetic results. The aesthetic quality of the repair can, for example, be compromised by the presence of irregular suture points or an excess of skin on the ventral side of the glans (Paparel et al., 2001). The aesthetic objective (to give the patient a penis with as near normal an appearance as possible) can be also be subject to other complications.
Even after surgery, the urethral meatus may be situated below the apex of the glans or may have a circular form instead of a vertical orientation (slit) (Holland, Smith, Ross & Cass, 2001). With the aim of evaluating the aesthetic results of repair operations, some pediatric urologists have, for example, put forward a ‘system of objective analysis’, using photographic negatives taken at different moments of the intervention (just before, just after and between three months and one year afterwards) (Baskin, 2001).
7.5. Multiple failures
A fifth complication refers to multiple failures in operations carried out on what some authors have called hypospadias ‘cripples’ [40] or ‘disasters’ (Paparel et al., 2001). This terminology refers to boys or men who, even if they have been operated on several times [41], still suffer major functional or aesthetic problems (e.g., badly scarred tissue, persistent chordee or fistulas, stenosis of the meatus) (van der Werff & van der Meulen, 2000).
- Pre-admission and post-operative care
Given that the candidate population for hypospadias surgery is composed mostly of young children, the parents should benefit from a variety of information before giving their consent to the operation to be performed on their child (Ellsworth et al., 1999).
The information given out before admission is notably related to the surgical procedures and their objectives, risks and complications associated with such procedures and the duration of hospitalization. Pre-admission information also concerns post-surgical care (Sanders, 2002).
Parents should be informed that a catheter will probably be left in place for several days following the operation, to drain the urine from the bladder (Mondet, Johanet, Larroquet et al., 1999). They should also know that after the operation the penis will be covered in a specialized dressing, the application of which is recommended for several reasons: to keep the penis stabilized, to allow for the best possible healing of tissues, to ensure sterility of the wound, to reduce the risk of bleeding by keeping a moderated pressure, and to maintain the catheter in the correct position (Searles & Mackinnon, 2001).
Continued here.