Retrospective study between duration of postoperative urinary diversion and incidence of complications in the repair of hypospadias in children

Introduction

Hypospadias is a common congenital malformation. The prevalence of hypospadias has a large geographical variation. In Europe, it is 18.61 per 10,000 births (1). It is characterized by an abnormal development of the urethra, foreskin, and ventral aspect of the penis with varying degrees of severity. When treatment is required, the available option is surgical correction, but due to the wide spectrum of presentations and the technical challenges involved in the repair, various surgical techniques have been described, none of them being considered a gold standard.

Regardless of the surgical repair technique, the use of postoperative urinary drainage is controversial, and even though most pediatric urologists prefer urethral catheterization after the intervention, there are no guidelines about urinary diversion type and duration. Traditionally, the most widely used drainage is a transurethral bladder catheter (2,3). However, there is no consensus about how long the stent should be maintained in the postoperative period (4-6).

Classically, longer urinary drainage time has been associated with a decrease in the incidence of urethral complications, especially, fistulas and strictures (2,7). However, in recent years, several studies have shown this might not be true and some authors (4,8) have reduced the length in the number of days of urethral catheterization for the same intervention, even a few consider the possibility of not using a postoperative transurethral catheter in middle hypospadias. On the other hand, although some factors, such as hypospadias severity degree and surgeon’s experience, have been analyzed and associated with the incidence of complications, we found limited data regarding postoperative urinary catheterization duration and its association with the incidence of postoperative complications (9).

Therefore, we consider the need to evaluate our experience in the use of postoperative transurethral catheters in proximal and middle hypospadias repair in recent years, as well as the possible association between the urinary diversion duration and the incidence of complications. We present this article in accordance with the STROBE reporting checklist (available at https://amj.amegroups.com/article/view/10.21037/amj-23-161/rc).

Methods

Patients

This is a retrospective cohort study of the children who underwent proximal and middle (distal penile and midshaft) hypospadias repair in our center between January 2014 and December 2019. Distal hypospadias and reoperations were excluded. There were no other exclusion criteria.

Surgical technique

In the study period, 61 children went through hypospadias repair in our center. Of the patients with middle hypospadias, 38 underwent tubularized incised-plate urethroplasty (TIP) and 9 through urethral advancement (Koff technique). TIP technique is a primary tubularization of the urethral plate, with incision of the posterior wall of the plate, which allows it to hinge forward. In Koff technique, the urethral tube was mobilized proximally in a ratio of 3–4:1 (the ratio of mobilized urethral length to the initial distance between the native meatus and the tip of the glans) then positioned distally after creating wide glans wings. In the 14 patients with proximal hypospadias, a two-stage repair (preputial graft + tubularisation) was performed. During the first stage, the penis is straightened, if it is necessary, a Baskin technique is performed and the urethral plate is substituted with a graft of either genital (prepuce). During the second stage, performed around 6 months later, urethroplasty is accomplished by graft tubularisation. Two senior surgeons with more than 100 cases and 10 years of experience operated all the hypospadias.

Follow‑up and measurements

The study variables are shown in Table 1. The transurethral catheter was maintained in the postoperative period according to the urethroplasty length and the surgeon’s subjective perception about technical difficulties during the procedure (e.g., narrow plate) and was not modified by postoperative results. Nocturnal antibiotic prophylaxis was administered until the catheter was removed and a hydrophobic bacterial uptake dressing covered with sterile gauze and compression bandage was used for a maximum of 10 days, even if the catheter persisted.

Statistical analysis

For data analysis, we classified patients into three groups according to the type of repair they underwent. Statistical analysis was performed with SPSS^® software (IBM, Armonk, NY, USA). A descriptive analysis was performed for all variables and subsequently, normality tests were performed (Shapiro-Wilk test), verifying that the variables to be analyzed did not follow a normal distribution, therefore, the study was continued with non-parametric tests (Man-Whitney U). A difference was considered statistically significant if P<0.05.

Ethical consideration

The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the institutional ethics committee of Reina Sofia University Hospital (No. 08/2020), and individual consent for this retrospective analysis was waived.

Results

The mean age at the time of the surgical intervention was 5.5 years [95% confidence interval (CI): 5.01–6.01]. However, if separated by type of procedure, we observe that the mean age varies. In TIP urethroplasty, it was 5.1 years (95% CI: 4.55–5.66), for urethral advancement it was 4.5 years (95% CI: 4.00–5.11) and for the two-stage (preputial graft + tubularisation) repair group the mean age was higher, with 7.2 years (95% CI: 5.95–8.48) at the time of the intervention. Mean follow-up was 3.1 years and no children were lost to follow-up. Twenty percent of patients had intrauterine growth retardation or were underweight for their age. Five of the 61 patients (8.2%) had congenital heart disease. Twelve of the patients (19.7%) had congenital hydronephrosis that did not require surgical treatment.

In our center, postoperative urinary catheterization for hypospadias repair is performed with a silicone catheter, without a balloon (Cook Medical^â), which is fixed to the glans with a non-absorbable suture. We found data about the caliber of the catheter used in most cases (50 of 61), observing that in 47 patients (77%) a 10 Fr catheter was used, in 2 patients a 12 Fr catheter and in only one case an 8 Fr catheter.

Regarding the time that the urinary catheterization was maintained in the postoperative period, in our patients, we observed a mean of 7.28 days (95% CI: 6.36–8.20) of transurethral bladder catheterization permanence. However, again we found differences when stratifying the analysis by type of procedure. In TIP urethroplasty, the catheter was maintained for a mean of 6.03 days (95% CI: 5.72–6.34), similar to urethral advancement with a mean of 6.22 days (95% CI: 4.85–7.60), while in the two-stage (preputial graft + tubularisation) repair group the urethral drainage was kept for a longer time, with a mean of 11.36 days (95% CI: 8.09–14.63) (Table 2).

During admission, 12 patients (19.7%) presented complications related to catheterization, including episodes of catheter obstruction (9), which resolved with saline wash, and loss of the catheter (3), which required repositioning in the operating room. In total, 93.5% of the patients remained hospitalized until the catheter was removed. Only in 6.5% of the cases the children were discharged with the urinary catheter and this was removed at a later output clinic.

The incidence of complications was 34.2% (13/38) in TIP urethroplasty; 33.3% (3/9) in the urethral advances and 64.3% (9/14) in the two-stage repair group (preputial graft + tubularisation). In Table 3, we can see the distribution of the complications.

Of the patients who presented complications (n=25), 8 required a subsequent surgical reoperation, 5 a minor procedure (dilation, etc.) and 12 were kept under observation, either because reoperation is pending decision or because the complication has little functional impact.

Finally, we analyzed whether there was a difference in the urinary catheterization time between children with and without postoperative complications. In the global group, we observed that the mean days of urethral drainage was 6.22 days (95% CI: 5.74–6.70) for patients without complications and 8.80 days (95% CI: 6.72–10.88) for patients with complications, which means, that children who presented complications in the postoperative period kept the urethral catheter a longer time compared with those who did not have complications, with a statistically significant difference (P=0.005).

However, considering that not all patients had the same degree of hypospadias severity and that not all underwent the same correction technique, we decided to expand the analysis, categorizing into groups by type of procedure (Group 1: TIP urethroplasty; Group 2: urethral advancement; Group 3: two-stage repair, preputial graft + tubularisation). As it can be seen in Table 4, in the three groups, the mean of days of bladder catheterization was higher in children with postoperative complications compared to children without complications, but these differences were not statistically significant (P=0.24, P=0.38, P=0.11, respectively). When we perform multivariate regression, there is no correlation between number of days of urethral catheterization and existence of complications depending on type of intervention performed. (Beta 0.010; P=0.93). Although type of surgical technique is closely related to the existence of complications (Adjusted R²=0.308; P<0.001) (Table 5).

Discussion

Hypospadias is a frequent and complex pathology. The objective of the surgical repair is to achieve an adequate voiding and sexual function (good urethra caliber, distal meatus in the glans, no curvature in erection), with a good aesthetic appearance. Currently, although there are more than 250 repair techniques described, none is considered a gold standard, which partly explains why postoperative complications are frequent, more than 50% in some series (9,10). In our study the rate of complication was 34% for middle hypospadias and 64% for proximal hypospadias. The type and distribution of complications found (Table 3) are similar to those presented in other series (11-13). Almost half of the complications (48%) have not required reoperation for now due to their low functional impact. Then, our results seem to indicate that the probability of complications in the postoperative period of hypospadias is associated with the type of hypospadias and the surgical technique, but not with the number of days that the urethral catheter remains in place.

Postoperative complications do not only depend on the surgical repair technique chosen, there are other factors that can influence its occurrence, including the severity of the hypospadias, the surgeon´s experience and biometric parameters such as the size of the glans and narrow plate urethral, which have been clearly established as prognostic factors for the incidence of postoperative complications (9,10). Moreover, other aspects such as the need of postoperative urinary diversion, its duration and its association with the incidence of complications, have been less studied. Because to this, current guides do not offer precise recommendations on this matter (4).

Nowadays, the use of postoperative drainage is still controversial and even though the majority of pediatric urologists prefer urethral catheterization after hypospadias repair, there are no guidelines on type of catheter that should be used and its duration (2). Supporters of the urethral diversion argue that it reduces urinary retention, postoperative dysuria and serves as support for the urethral plate and the neourethra healing process (5). In 2014, a study evaluated urethral scar healing in urethroplasty rat models, observing that urethral healing follows the same phases of dermal repair with the only difference of a longer duration in each phase (14). Which would support the idea of maintaining the urinary diversion for a long time in the postoperative period. Others authors discourage its use, considering that it increases the risk of infection and patient discomfort, additionally it applies pressure on the suture area that can make healing difficult (2). The truth is, that the decision is at the discretion of the surgical team. In our case, we used a silicone catheter without a balloon, fixed to the glans with a non-absorbable suture, and it was maintained for a mean of 7.28 days (95% CI: 6.36–8.20). This concurs with what have been described in the literature, where the most common diversion in proximal and middle hypospadias repair is a transurethral bladder catheter that is kept between 7 and 10 days (2,15).

The majority of our patients (93.5%) required to stay in the hospital while the catheter was in place, in general, due to poor pain control, discomfort and difficulties in handling the catheter. This is possibly related to the fact that they were older children (100% >2 years), who tend to tolerate worse urethral catheterization. In addition, the number of complications that occurred because of the transurethral catheter permanence (19.6%) is not negligible, even leading to Clavien III complications requiring repositioning of the catheter under general anesthesia. Hence, it seems that increasing the number of days of urinary drainage is not insignificant.

Our aim was to analyze if the urinary diversion duration is associated with the incidence of postoperative complications. The hypothesis was that a longer urethral catheterization permanence time would reduce urethral complications (fistula, stricture) by allowing a “dry” healing process for more days. However, we observed that children who underwent proximal and middle hypospadias repair who presented complications, kept the urinary drainage for an average of 2.5 days longer compared to those who did not present complications, with a statistically significant difference (P=0.005).

Considering our preliminary results, it could be inferred that a longer urethral catheterization period is related with an increase in the incidence of postoperative complications. In this regard, in 2006, Aslan et al. suggested that keeping the urinary catheter for a long time could induce a greater inflammatory reaction, inhibiting healing and promoting fistula formation. However, in their retrospective review they found similar complication rates in the patients with early catheter removal vs. the ones that maintained it for a week (8). In our case, we think that the data may not be conclusive in this matter, because it is possible that the surgeon might have kept the transurethral catheter for more days in more complex hypospadias cases, which are the ones that tend to have more complications.

For this reason, we expanded the analysis. Considering that the hypospadias severity and the surgical technique used were not the same in all patients, and that these factors intervene in the appearance of postoperative complications, we categorized the patients by groups according to the surgical technique used for the repair (9). Observing that the time that urethral diversion was kept in each group was different, being longer in patients with complications compared to patients without complications in all groups. However, in none of these the difference was statistically significant.

In 2017, Scarpa et al. published a series of 44 patients who underwent hypospadias repair using the Snodgrass technique between 2011 and 2013. They compared the removal of the urinary catheter immediately after the intervention vs. 6 days after, concluding that the early removal of urethral catheterization was not associated with an increase in complications, although, the evidence is limited by the small sample size and the lack of randomization (4).

Daher et al. in 2015, compared 3 weeks of bladder catheterization vs. 1 week in the hypospadias repair postoperative period, with the hypothesis that prolonged urinary diversion would reduce the rate of fistulas and meatal stenosis. They noticed that this only occurred in the group of children who underwent Duplay repair, in whom a 3-week catheterization was associated with a lower rate of complications. Nevertheless, this was not reflected in children who underwent other surgical techniques, concluding that more studies were required to confirm this observation (2).

In our patients, when analyzing the data stratified by the surgical technique, it is perceived that those with complications remained with urinary diversion for a longer number of days. Though, in none of the groups the difference was statistically significant. This might be due to the fact that our study has certain limitations, such as, a small sample size and a retrospective nature. Also, as we have already mentioned, it is possible that the difference observed relates to the surgeon´s inclination to keep the transurethral catheter for more days when complications are suspected. Hence, it seems clear that our initial hypothesis is not correct, at least in our study group, since a longer duration of the urinary drainage is not associated with a decrease in postoperative complications.

We do not consider the surgeon’s experience as a confounding factor in the incidence of complications, since throughout the study period the same surgical team was maintained and since the two surgeons both have more than 100 cases and 10 years of experience operated all the hypospadias.

As limitations of our work, we find that it is a retrospective study, with a limited number of patients and only analyzes 3 surgical techniques. With no doubt more studies are required to clarify these observations. One of the limitations of the study is the age at which hypospadias correction was performed. Currently, many surgeons choose to operate under 12 or 18 months of age. Therefore, our results could be altered by this difference with the average age of our patients.

Conclusions

In our study, the urinary diversion duration in hypospadias repair is not significantly related with the incidence of postoperative complications, when the data are analyzed according to the surgical technique used.

More prospective, randomized and controlled studies are needed to elucidate this aspect, since the scientific evidence that we currently have is not conclusive.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://amj.amegroups.com/article/view/10.21037/amj-23-161/rc

Data Sharing Statement: Available at https://amj.amegroups.com/article/view/10.21037/amj-23-161/dss

Peer Review File: Available at https://amj.amegroups.com/article/view/10.21037/amj-23-161/prf

Confilicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://amj.amegroups.com/article/view/10.21037/amj-23-161/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the institutional ethics committee of Reina Sofia University Hospital (No. 08/2020),and individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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