Consistently, there is a lack of a clear definition of severe hypospadias. The clinically accepted preoperative meatal position to classify the severity of hypospadias but the meatal position would change after VC correction. Therefore, a definite classification can only be completed at intra-operative findings. For patients with residual chordee, transection of the urethral plate is inevitable, and grafts such as buccal mucosa graft and flaps have been used to achieve full correction of the penile curvature [14]. In the present study, we used a stepwise approach to manage the curvature, and severe hypospadias was defined as the residual VC was > 30° after degloving. Of 136 patients who underwent TPIFU, the mean degree of VC was 60 °. The urethral plate was excised in all the cases and dorsal plication was performed in 115(84.56%) patients.
Although surgeons have been making various efforts or modifications to optimize the procedure, managing severe hypospadias is challenging, and the best options for fewer complications are still debated. Notwithstanding the dispute on single-stage versus two-stage repairs is ardent, the purpose of the operation was to provide a tension-free, well-vascularized tubularized neourethra and improve postoperative wound healing [15]. It is believed that the selection of surgical techniques in hypospadias repair is highly based on the patient’s anomaly characteristics and the surgeon’s preferences. In recent years, the shift in interest from one-stage to two-stage repair occurred as superior functional, cosmetic results with fewer complications and a smoother learning curve [16, 17]. The TPIFU is one of the most common techniques for severe hypospadias. Although researchers have made modifications to improve prognosis, the satisfactory complications rate has not been reached [18–20]. Indeed, the complication rates of TPIFU, ranging from 13–91%, vary widely in the literature and across countries[21]. We reviewed the literature and summarised the outcomes of articles published on proximal hypospadias treated with TPIFU, as shown in Table 3[13, 15, 20, 22–34].
Table 3 Literature review of one-stage TPIFU [1–16]
Author; Year
|
No. Patients
|
Age (m)
|
Follow up (m)
|
No. Complications
|
Fistula
|
Urethral stricture
|
Diverticulum
|
Wound dehiscence
|
Others
|
Castan˜o´ n, E,2000[1]
|
42
|
37 (12-108)
|
/
|
16
|
9
|
3
|
2
|
/
|
2
|
Chuang,1995[2]
|
103
|
47(5-168
|
/
|
31
|
25
|
5
|
1
|
/
|
/
|
Cui,2020[3]
|
155
|
21.6(6-144)
|
62.4(3-120)
|
84
|
49
|
26
|
9
|
/
|
/
|
Daboos,2020[4]
|
160
|
54
|
36
|
28
|
12
|
12
|
/
|
4
|
/
|
Dewan,1991[5]
|
189
|
6-120
|
25.1±23.7
|
93
|
65
|
55
|
5
|
/
|
/
|
Ghali,1999[6]
|
148
|
38.4(18-144)
|
23(6-53)
|
48
|
22
|
30
|
7
|
/
|
3
|
Han,2020[7]
|
161
|
14-186
|
13.7(12-17)
|
42
|
25
|
11
|
5
|
/
|
/
|
Hayashi,2001[8]
|
13
|
23(10-36)
|
36(30-44)
|
1
|
1
|
/
|
/
|
/
|
/
|
Huang,2017[9]
|
32
|
11(7-23)
|
23(12-38)
|
6
|
6
|
/
|
/
|
/
|
/
|
Huang,2017[10]
|
65
|
33.6(7-144
|
19(14-30)
|
10
|
10
|
0
|
/
|
/
|
/
|
Lyu,2019[11]
|
40
|
26.2± 13.8
|
12
|
19
|
14
|
4
|
1
|
/
|
/
|
Macgillivray,2002[12]
|
24
|
27.5(21-35)
|
62.5(4-100)
|
10
|
9
|
1
|
/
|
/
|
/
|
Patel,2004[13]
|
14
|
16.8(8-74)
|
170(144-253)
|
3
|
2
|
1
|
/
|
/
|
/
|
Sorber,1997[14]
|
70
|
(6-168)
|
16.7(12-92)
|
16
|
6
|
4
|
/
|
4
|
2
|
Wang,2019[15]
|
320
|
15.1(11-64)
|
40.2(1-156)
|
125
|
53
|
31
|
41
|
/
|
/
|
Zheng,2012[16]
|
25
|
145.4±128.4
|
38.7(22-60)
|
6
|
4
|
4
|
/
|
1
|
/
|
TPIFU, transverse preputial island flap urethroplasty
In the present study, complications were defined as any complaints that required surgical correction, including fistula, urethral stricture, and diverticulum. The complication rate of primary operation was 39%, with fistula (24 patients, 17.6%) being the most common complication, similar to the previous studies[35]. Both fistula and urethral stricture were believed to be related to the poor blood supply to the neourethra and the native urethra[36] Cui et al. suggested that surgeons should protect the vascular pedicle of the inner sheath of the foreskin, ensuring the transverse flap is as thick as possible so that the vascular tissue can be preserved. The marginal skin with poor blood supply at the end of the neourethra must be removed when the neourethra and the native urethra are anastomosed. Compared with the fistula, the urethral stricture is a more distressing complication from the patient’s perspective. The main cause of strictures is the circular scar between the native urethra and the flap, and it may require salvage urethrotomy and even urethral reconstruction[37]. In the present study, 17 patients (12.5%) developed urethral stricture, of which six underwent two or more dilatations, and two underwent open surgical reconstruction. As the urethral stricture is difficult to deal with, researchers have modified the surgical technique. Ferro et al. argued that cutting a wedge and a V-shaped suture at the ends of the flap could help prevent any circumferential suture line, avoiding proximal anastomotic stricture and distal meatal stenosis[38]. Huang et al. modified the TPIFU by performing straightforward and reliable in situ tubularization of the flap, reducing urethral stricture incidence. In our experience, in addition to protecting the blood supply, a tension-free anastomosis between the neourethra and the native urethra is the key point to decreasing the incidence of urethral stricture. An oblique anastomosis should be adopted between the neourethra and the native urethra to increase the area of the anastomotic surface and the blood supply of the anastomosis. As for diverticulum after TPIFU, it was hypothesized that the flap’s lack of attachment to the surrounding tissues makes the neourethra more elastic and thus prone to progressive dilation[39]. In the present study, 12 (9.1%) patients concurrent with diverticula were treated with resection of redundant tissue and multilayer closure. Based on our clinical practice, the incidence of diverticulum was related to the smoothness and elasticity of the preputial island flap (As shown in Fig. 3). Two-stage technique was recommanded for those preputial island flap condition is poor.
In the present study, we proposed a new perspective to evaluate the surgery techniques treating severe hypospadias from the view of operation frequency. Although the TPIFU developed a higher complication and reoperation rate after the primary surgery, the result may be different if we focus on the surgery number to cure the patients. In the present study, 83(61%) patients achieved short-term cured through a single operation, which means more than 50% of patients could be free from the second procedure. On the other hand, TPIFU provides the advantages of minimizing operative trauma, allowing the use of unscarred skin with good vascularity and decreasing the number of hospitalizations, decreasing the infection risk and caregiving burden for parents. As we gain an improved understanding of the interplay of psychological factors of children, including timing in genital awareness, sexual orientation, and body image, more procedures may lead children and parents to develop lower opinions on the repair of hypospadias and worse sexual and psychological results [40]. As the National Center for Children's Health in China, our center has more patient resources and a well-structured educational system, helping doctors overcome the steep learning curve of TPIFU. Snodgrass et al. suggested that to gain expertise from greater volumes of cases, surgeons/teams should be designated for proximal hypospadias repair in each center[41]. Castagnetti et al. argued that surgeon experience is more important than the technique itself[42]. When choosing the type of repair, personal preference, training, and success rate when using a specific technique should be considered as important variables. Every surgeon should develop their own strategy and focus on mastering only a few techniques.
The present study has particular limitations, including the retrospective nature, a small number of patients, and short-term follow-up. The long-term complications such as chordee recurrence and erectile pain did not analyze due to insufficient follow-up duration. Besides, we did not measure uroflow and postvoid residual volume in all patients. Obstructive urinary flow pattern seems common in patients who underwent proximal hypospadias repair, which may remit spontaneously with age. Thus, we believe conservative treatment with watchful observation may avoid unnecessary intervention. Further multicenter studies with larger sample sizes are required. Besides, we will publish a follow-up series to further prospective validate and extend the result of the present study (Trial registration number ChiCTR1900023055).