Urethrocutaneous Fistula After Hypospadias Repair in children: Analysis of Risk Factors – Re-visit

DISCUSSION

Low complication rates are anticipated with an optimal hypospadias repair, resulting in a normal penis in terms of aesthetics and function, both urination and sexually ^4,5.The issue of postoperative sequelae of hypospadias surgery and related risk factors has long been a fascinating topic for pediatric urologist to research and debate ⁶. One of the most prevalent after repair of hypospadias consequences, urethrocutaneous fistula, is a huge problem for both the surgeon and the children  ⁷.

After the correction, 19.9% of the patients in this research had urethrocutaneous fistula.The incidence rate is in the middle of prior research estimates, which range from 6.2% to 38.8%. ^7–9

According to research published by The American Academy of Pediatrics, paediatric genital operations should be accomplished between the ages of six and eighteen months ¹⁰.

By the age of six months, most newborns have developed a decent tolerance for anesthesia and surgery. They are potty trained and aware of their genitalia by the age of 18 months. Some urologists have a preference to operate the child at four months for hypospadias treatment due to the short time of healing, less scar, and the assumption that it is at ease for the newborns to overcome the operation stress ¹¹.

Because of ignorance, illiteracy, and financial constraints, the average age of hospital admission in underdeveloped nations is greater than in rich countries. As a result, whenever the patients are taken to the hospital, which is normally after the age of four years, they are operated on ¹².

AS patients less than two years old who underwent primary repair 11 (22.4%) patient developed UCF, the age group between  2-4 years old 9 (18.4%) developed UCF and the age group more than 4 yeaes old 29 (59.2%) developed UCF . This data revealed that the age is non significant factor for developing fistula (P-0.904) which correlates to Chung et al.³

(P-0.299).In contrast Duarsa¹³ showed that the age is a significant factor fro developing UCF (P-0.015). Also Sheng ¹⁷ discovered that the age is non significant factor for developing fistula. 

Of the 49 patient who developed UCF post repair, 24 patient (49%) developed fistula within 2 years. Chung et al.³ reported that 47 (74.6%)  developed fistula within 1 month.   Opposite to expectations our study revealed that 13 (26.5%) patient developed fistula after 4 years which interpreted as most patients came when they were already at the age of more than 4 years old. This age demographics shows that early awareness of the disease is still low.

The incidence rate is in the middle of prior research estimates, which range from  6.2% to 38.8%. ^7–9 After the correction, 19.9% of the patients in this research had urethrocutaneous fistula. The frequency of fistulas differs from surgeon to surgeon., Kass and Bolong ¹⁴ stated just one patient (0.48 %) developing a fistula in 206 patients of hypospadias operations. Sarhan ⁴ discovered 47 cases (9.4%) with fistulae development out of 500 hypospadias procedures. As shown in Korean research, out of 212 hypospadias procedures, ¹⁵ it was reported that 42 cases (19.8%) with fistulas formation, whereas Hwang ¹⁶ stated that 16 cases (31.4%) with fistulas formation out of 51 hypospadias procedures. Chung et al.³ revealed that 63 patients (21.4%) out of 294 developed fistula.  Sheng ¹⁷ discovered 39 patients (32.5%) with fistulae out of 120 hypospadias procedures. Recently, Duarsa¹³reported that 15.27% of patients  developed urethrocutaneous fistula after the repair.

In the univariate analysis, the type of hypospadias had a statistically significant impact on the result (P-0.006). So, each hypospadias site was studied separately, and the results indicated that no other factors had a major impact on the surgery's outcome in multivariate analysis (P<0.001).The types of hypospadias in this study are significantly correlated to the development of fistula as in Chung et al.’s ³ study which shows that distal hypospadias have better outcome and lower risk of fistula compared to proximal cases (P<0.001). On the contrary,Duarsa¹³ shows type of hypospadias is not significant factor (P-0.102).Sheng ¹⁷ did not take the site of hypospadias into cosideration as a risk factor for developing urethrocutaneous fistula.

There is no single procedure which is suitable for all patients.  .With the advancement of surgical techniques, it is unsurprising that the urethroplasty technique is not significantly linked to the risk of developing fistula.  In the univariate analysis, the method of correction had a statistically significant impact on the result (P-0.766), however, in multivariate analysis the method of correction was not significant for developing fistula (P-0.556).Duarsa¹³showed that the type of hypospadias repair was not significantly linked to the development of fistula  (P-0.102) in contrast to Chung et al.’s ³ study which revealed that distal hypospadias have lower risk of fistula compared to proximal cases

(P-0.006), while Sheng ¹⁷ did not depend on method of correction as a risk factor for developing fistula.

For splint size there is no statistically significant difference between the groups with p-value (p-0.118) in this study as opposed to Duarsa¹³whoclaimed that splint size is a significant risk factor for developing fistula (P-0.023), and it is possible that a larger splint size,  would increase the risk of post operative hematoma and wound infection. Chung et al. ³ & Sheng ¹⁷ did no mention splint size as a risk factor.

Sheng ¹⁷ discovered that the chance of development fistulas following hypospadias correction is linked to the length of the urethral defects and previous urethral operations. However, an analysis of the length of the urethral defects and previous urethral operations as a possible risk has never been discussed previously in any research, thus further researches on the relation of the length of the urethral defects and previous urethral operations should be implemented in the future.

So, our results indicated that only site of hypospadias had a major impact on the surgery's outcome.The types of hypospadias in this study are significantly correlated to the development of fistula as in Chung et al.’s ³ study which shows that distal hypospadias have better outcome and lower risk of fistula compared to proximal cases. On the contrary,Duarsa¹³ shows type of hypospadias is not significant factor while age and splint size are. Sheng ¹⁷ discovered that the chance of development fistulae following hypospadias correction is linked to the length of the urethral defects and previous urethra operations, but not to age, surgical technique, kind of surgical intervention, chordae extent, or other variables.

It's unclear why some individuals get urethrocutaneous fistula while others don't. A crucial element is assumed to be surgical technique, while a regional deficiency in the growth hormones might have a role ¹⁸.

Hormonal treatment has been advocated to minimise the formation of fistulas, although the outcomes have been variable. Additionally, several aspects of postoperative care, such as the usage of specific kinds of dressings and operative materials, wound condition, and the antibiotic, should be deemed ¹⁶.

These postoperative characteristics were of limited data in our analysis but might be substantial hazard factors; thus, we wish to include them in our follow up investigations. Because there were so many variables to examine and the analysis is so challenging, there were only some researches on peri-operative risk factors for the formation of the fistulas. Even though our research study had shortcomings and drawbacks, it may be beneficial to physician considering hypospadias correction. To corroborate our preliminary findings in this comparatively small case study, more research with various study designs will be required.

CONCLUSION

After hypospadias correction, the likelihood of urethrocutaneous fistula formation is related to the site of hypospadias (greater in the proximal hypospadias). The type of hypospadias procedure, the suture utilized, and the method used were not linked to the formation of fistulas.