Clinical efficacy of transverse preputial island flap urethroplasty for single-stage correction of proximal hypospadias: a single-centre experience in Chinese patients

Hypospadias is one of the most common congenital urinary malformations in children [1]. Proximal hypospadias refers to a urinary meatus that is located at the shaft of the penis near the scrotum, the junction of the penis and scrotum, or the perineal area [2]. Hypospadias is a serious condition, and surgery is the only treatment for proximal hypospadias, although it is associated with a difficult technique and high postoperative complication rate. Despite decades of surgical improvement, there is currently no single procedure that can perfectly solve all of the problems associated with the proximal type of hypospadias [3]. A high incidence of postoperative complications is still a major challenge for paediatric urologists.

At present, there are two types of operations for proximal hypospadias, single or two-stage surgery, and the choice of operation is still controversial. Long CJ et al. found that single-stage surgery led to a higher incidence of postoperative complications than two-stage surgery [4]. However, recent studies have also shown that the complication rate of two-stage surgery was higher than expected, reaching as high as 30–68%, and with the improvements in surgery technology, single-stage surgery did not lead to an increase in the incidence of postoperative complications and can reduce the number of operations needed [5, 6]. This study retrospectively analysed the clinical data of patients receiving transverse preputial island flap urethroplasty for single-stage correction of proximal hypospadias in our hospital in the past 10 years, and we summarized our clinical experience over these 10 years.

This research was approved by the ethics committee of our hospital and strictly abides by the principles of the Helsinki Declaration (the code of ethical approval for scientific research projects, 2019 Ethical Scientific Research Approval No. 2005).

All 155 patients, aged 6 months to 12 years old, weighing 6.8 kg–55.8 kg, underwent transverse preputial island flap urethroplasty for single-stage correction; there were 50 cases of a urinary meatus in the proximal penile body, 84 cases of a urinary meatus in the penile scrotum junction, and 21 cases of a urinary meatus in the perineum. The median operation time was 2.8 h (2.3 h - 3.9 h), the median length of postoperative hospital stay was 15 d (12 d – 29 d), and the median follow-up time was 5.2 years (3 months − 10 years). A total of 92 (59.3%) postoperative complications occurred, and 41 (26.5%) patients underwent reoperation. There were 49 patients (31.6%) with urinary fistula; among them, 7 healed by themselves, and 42 were cured after reoperation. Urethral stricture occurred in 26 cases (16.8%), of which 22 patients were cured after urethral dilatation, and 4 patients were cured after reoperation. There were 9 patients (5.8%) with urethral diverticulum after operation, all of whom were cured after reoperation. There were 8 patients (5.2%) with urinary tract infection, all of whom were cured by medical treatment. There were no cases of chordee recurrence or infravesical obstruction after surgery (Table 1).

The family members’ satisfaction with the cosmetic appearance of the penis were as follows: the satisfaction score for the urinary meatus was 2 (1–3), with a satisfaction rate of 85.2% (132/155); the satisfaction score for the glans appearance was 2 (0–3), with a satisfaction rate of 87.7% (136/155); the satisfaction score for the appearance of the foreskin of the penis was 2 (1–3), with a satisfaction rate of 92.3% (143/155); and the satisfaction score for the overall penis shape was 2 (1–3), with a satisfaction rate of 89.0% (138/155).

Hypospadias is one of the most common congenital structural malformations in the urinary system, with the second highest incidence among all such malformations. According to Springer’s latest global multicentre epidemiological survey, the incidence rate of this condition in Asia has risen to 0.6–110/10,000, and the southeast coast is in a high-incidence area [1]. Proximal hypospadias is a serious type of the condition that is often combined with severe chordee. It is difficult to correct the malformation, and there are still many postoperative complications after surgery. After many years of development, both the operative skills for treating proximal hypospadias and the cure rate have greatly improved [9], but there is no perfect surgical method to avoid postoperative complications [2]. Controversy still exists with regard to the choice of single-stage or two-stage surgery. Many scholars have found that as long as the surgical technique was mature, the postoperative complications of single-stage surgery would not exceed that of two-stage surgery; single-stage surgery can reduce the number of surgeries to one and reduce the burden on the patients and the pain of a second operation. Singal AK et al. reported a summary of 136 patients with proximal hypospadias who underwent transverse preputial onlay island flap urethroplasty for single-stage correction over 7 years, and the results showed that single-stage operations could provide reliable functional results [10]. The study by Emir H et al. showed that the mature technique of single-stage surgery for proximal hypospadias was desirable for achieving good results and recovery satisfaction [11]. Castagnetti M et al. found that single-stage surgery for proximal hypospadias did not increase the overall incidence of postoperative complications compared with two-stage surgery [12]. We used the single-stage transverse preputial island flap urethroplasty method to treat proximal hypospadias. After more than 10 years of development, we have accumulated some experience and have reported this experience as follows.

Urinary fistula is the most common complication after surgery and can occur anywhere in the proximal anastomosis. The cause is related to poor blood supply to the newly formed urethra or poor blood effusion [13‐16]. We summarized our recommendations as follows: 1) pay attention to protecting the vascular pedicle of the inner sheath of the foreskin and ensure that the transverse flap is as thick as possible so that the vascular tissue can be preserved. The length of the vascular pedicle is based on the diameter of the penis, and there must be no tension from the root of the vascular pedicle when the flap is transferred. 2) When the newly formed urethra and the original urethra are anastomosed, the marginal skin with poor blood supply at the end of the newly formed urethra must be removed. An oblique anastomosis should be adopted to increase the area of the anastomotic surface and the blood supply of the anastomosis. 3) At the end of surgery, we routinely placed a rubber drainage strip from the outside of the scrotum to the ventral urethral anastomosis of the penis. This tube can fully drain the blood, provide effusion to the penile corpus cavernosum and create good conditions for wound healing.

Urethral stricture is another common complication after surgery for hypospadias [17, 18]. The cause is related to the thickness of the urethral stent tube, local inflammation, scars, etc. [19] Mild urethral stricture can be relieved after multiple urethral dilatations, but a severe urethral stricture requires repeat urethroplasty [20]. Our experience is that the urethra should be routinely expanded 2 weeks after catheter removal, and the situation determines the frequency of the dilation. Early postoperative urethral dilatation is an important measure to prevent and treat urethral stricture. Most children with urethral stricture were cured after urethral dilatation. Only some patients with severe stenosis and one patient who also had urethral diverticulum needed another surgery.

Satisfaction of the family members with the appearance of the child’s penis after urethroplasty is also a goal pursued by our urologists. We completely removed ventral fibrosis during the operation, and if necessary, the penile dorsal folding method was used to completely correct chordee. During follow-up, there were no cases of recurrent chordee in our department for nearly 10 years. The PPPS questionnaire is widely used to assess postoperative penile appearance scores [7, 8, 12]. We used the PPPS questionnaire to assess the parents’ satisfaction with the appearance of the penis. The parents’ satisfaction rates with the urinary meatus, glans appearance, shaft skin appearance and general appearance were 85.2, 87.7, 92.3 and 89.0%, respectively. This shows that the parents’ overall satisfaction rate was high, and a satisfactory appearance evaluation can be obtained through the one-stage operation.

This study has some limitations. First, this is a single-centre study with a small sample size. Therefore, further multicentre studies with larger sample sizes are required. Second, the study was a retrospective study without a control group.

Proximal hypospadias is a serious condition that is often combined with severe chordee, and transverse preputial island flap urethroplasty for single-stage correction is an effective surgical procedure for treating this condition. During the operation, more attention should be given to protecting the blood supply of the vascular pedicle in the foreskin, completely correcting chordee and using rubber drainage strip. The use of postoperative care and disinfection should also be strengthened.