Parenteral testosterone therapy’s effect on penile size before hypospadias surgery

INTRODUCTION

Hypospadias is a birth defect that is associated with three anomalies of the penis

1. Opening of urethral orifice on ventral surface

2. Ventral curvature of the penis

3. Dorsally hooded prepuce.^[1,2]

Hypospadias is the most common congenital defect, which affects 0.3–0.7% of all live male births.^[3]

Hypospadias is most likely caused by a combination of factors.^[4]

The aim of hypospadias repair is to achieve excellent functional and cosmetic results.^[5] Anthropometry of the penis particularly the biometrics of the glans penis is an important consideration before hypospadias repair.^[6] Studies have shown that small glans diameter measuring <14 mm (mm) is associated with glans dehiscence following hypospadias repairs.^[7,8] It has been hypothesized that increasing the size and girth of the penis preoperatively may lead to a larger surgical site, thus reducing intraoperative and postoperative complications of the hypospadias corrective surgery.

To enlarge phallus size, temporary stimulation with testosterone or dihydrotestosterone cream has been used. However, the results were inconsistent, but its absorption was also variable.^[9] This observation has made surgeons administer parenteral testosterone to increase the glans diameter before hypospadias repair.^[10,11] Testosterone is the peripherally acting androgen causing growth and development of the external genitalia and secondary sexual characters. The effect is more pronounced on the genitals as a result of higher expression of androgen receptors.

MATERIAL AND METHODS

This prospective study was conducted at the Department of Urology, Dr. S.N Medical College, Jodhpur, from September 2019 to March 2021. A total of 20 patients with hypospadias were included in this study of ages between 6 months and 18 years.

RESULTS

Type of hypospadias

Of 20 cases, 10 were of distal (three coronal, four subcoronal, and three distal penile), seven were of middle (five midshaft and two proximal penile), and three were of proximal hypospadias (three penoscrotal) [Figure 1].

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Figure 1:

Types of hypospadias.

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Penile dimensions

The mean stretched penile length was 2.45 ± 0.82 cm. It increased to 3.52 ± 0.56 cm. The mean increase in penile length was 1.07 ± 0.23 cm (P < 0.001) [Table 1], [Figure 2].

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Figure 2:

Penile dimensions before and after testosterone injection.

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Table 1: Penile dimensions before and after injection.

Mean values	Stretched penile length (cm)	Glans diameter (cm)	Diameter at base of penis (cm)
Pre-injection	2.45±0.82	1.82±0.42	1.28±0.18
Post-injection	3.52±0.56	2.83±0.28	2.20±0.32
Difference	1.07±0.23	1.01±0.46	0.92±0.12
P value	<0.001	<0.001	<0.001

The mean of transverse diameter of the glans was 1.82 ± 0.42 cm which increased to 2.83 ± 0.28 cm. The increase was statistically significant (P < 0.001).

The diameter at the base of penis was 1.28 ± 0.18 cm which increased to 2.20 ± 0.32 cm. The difference was statistically significant (P < 0.001).

Two patients developed mild pubic hair, after two doses of injection. There were no parents reported cases of acne or aggression.

DISCUSSION

Testosterone increases size of the penis in prepubertal males due to its androgenic effects. This effect is beneficial for the surgical repair of hypospadias because a larger penile size makes correction easier and less risky.^[12]

One study that administered human chorionic gonadotropin (hCG) to children over 5 weeks found that hCG produces disproportionate penile enlargement and decreases the severity of hypospadias.^[13] However, the use of hCG lacked a treatment protocol and there were wide variations in response.

Topical application of testosterone has also been found effective in increasing penile length and glans circumference.^[14] The drawback of topical testosterone is that the results of its use are inconsistent due to variable absorption. Concerns over absorption and potential side effects after local application led to the use of injectable slowly releasing testosterone for pre-operative genital stimulation.

In a study conducted by Ahmad et al., 23 patients aged between 6 months and 10 years; preoperatively, testosterone was given deep intramuscularly in three doses at 4, 3, and 2 weeks before reconstructive surgery at the dose of 2 mg/kg body weight and concluded that parenteral testosterone can be safely used to improve the surgical outcome of hypospadias repair.^[15]

In our study, the effect of intramuscular testosterone on penile growth from the day of injection to the day of operation was statistically significant (P < 0.001). The mean increase in penile length was 1.07 ± 0.23 cm. There was an increase in transverse glans diameter of 1.01 ± 0.46 [Table 1]. The texture and vascularity of penile skin also improved. This increased transverse length is helpful particularly in proximal hypospadias. Negligible side effects were noted in the form of development of pubic hair in two patients.

CONCLUSION

Penile augmentation with parenteral testosterone is associated with an increase in phallus size and diameter with few adverse effects. The vascularity of penile skin also improved. Thus, parenteral testosterone can be safely used to improve the results of hypospadias surgery.