Description of the condition
Undescended testes is a common problem in boys and is defined as failure of testis to reach a scrotal position (Acerini 2009).The prevalence of undescended testes at birth has been reported to be 9% to 30% in preterm males and 4% to 5% of full-term males (Acerini 2009; Hutson 2007). The undescended testes can be found in any location along the line of descent of testis (e.g. lower pole of the kidney to the superficial inguinal pouch). Depending on the severity of the maldescent, undescended testes are commonly discussed as "palpable" or "impalpable". Palpable undescended testes are located in the superficial inguinal pouch or in the inguinal canal. Impalpable undescended testes may be in the inguinal canal or in the abdomen proximal to the deep inguinal ring. It has been estimated that only about 20% of undescended testes are at the deep inguinal ring or proximal to that. If left untreated, testis in an undescended location is prone to possible complications like histological changes leading to subfertility, increased risk of malignancy, trauma and torsion (Hutson 2007). Prompt recognition and treatment of undescended testes has been recommended in order to optimise long term testicular function since progressive damage to germ cells has been convincingly proven beyond the age of two years (Ong 2005).
Description of the intervention
Treatment of undescended testes is aimed at relocating the affected testis in its anatomically appropriate scrotal position in a timely manner to prevent the sequelae and complications including subfertility and testicular cancer (Hutson 2007; Pettersson 2007). The current standard treatment for undescended testes is surgical (orchiopexy). In recent literature, an increase in both the incidence of undescended testes and surgical correction for the same has been reported (Acerini 2009; Mandat 1992). The increase in the incidence is likely to be due an increased awareness and hence an increase in detection during the first year of life (Acerini 2009). Surgical correction of undescended testes is thus one of the commonest interventions to be performed in children. Various surgical techniques are currently practiced (Aycan 2006; Cortesi 1976; Esposito 2003; Jallouli 2009; Park 2010). The comparative efficacy of these techniques has not been evaluated using meta-analytic techniques. In addition, hormonal therapy is also used for stimulating testicular descent (Jallouli 2009; Zivkovic 2006; Zucchini 1996).
Surgical treatment (orchiopexy)
Surgical correction of undescended testes was first performed in 1877 by Annandale (Fischer 2005). The surgical technique was further refined through the contributions of Schuller, Bevan and Lattimer (Park 2010). The basic principles underpinning orchiopexy include separation of the processus vaginalis from the cord structures, achieving adequate cord length and anchoring the testis in a subdartos pouch within the scrotum. A success rate of 90% has been reported for this technique for all undescended testes except the high abdominal ones (Park 2010). Fowler and Stephens described a technique of dividing the testicular vessels in order to enable testes with short vessels to be brought down to the scrotum (Fowler 1959). This technique relies on the development of collateral circulation through the cremasteric artery and the artery to the vas deferens. The success of this procedure was reported to be about 70%, failure was due to an ischaemic loss of the testis. This procedure is now done as a two-stage procedure with some improvement in the testicular survival (Elyas 2010). In the 1970s, laparoscopy was first used to locate the impalpable testis (Cortesi 1976). The use of laparoscopy has had a significant impact on the management of the high intra-abdominal testis (Gatti 2007) and lead to a resurgence in the popularity of the Fowler-Stephens orchiopexy both as a single-stage and a two-stage procedure.
Human chorionic gonadotropin (HCG), human menopausal gonadotropin, and gonadotropin releasing hormone (GnRH) analogue have been reported to effect the descent of testis in a child with undescended testis (Aycan 2006; Dixon 2007; Esposito 2003; Giannopoulos 2001). If hormonal therapy is used, it is typically commenced in the neonatal period (Dixon 2007) but has also been reported to induce descent at a later age (Esposito 2003).The reported success rates are as high as 60% (Aycan 2006; Giannopoulos 2001) when a combination of HCG and luteinising hormone releasing hormone (LH) have been used whereas success rates between 25% to 35% have been reported by others (Esposito 2003). A 20% response was noted in bilateral undescended testes (Dixon 2007). Beneficial effects of hormonal therapy on the contralateral testis have also been reported (Zivkovic 2006). On the other hand, a high incidence of side effects has also been reported (Cortes 2000; Thorsson 2007).
There has been an ongoing debate over the optimal age of intervention for undescended testes (Hutson 2007; Ong 2005; Thorup 2009). Some authors believe that early surgical correction (between three and six months) prevents histological changes which could reduce fertility or increase malignancy risk (Hutson 2007), while others believe that correction up to two years of age prevents long-term complications (Thorup 2009). Traditionally, surgical interventions have been delayed beyond six months due to a higher incidence of complications of orchiopexy in early infancy
How the intervention might work
The aim of interventions in children with undescended testes is to achieve a viable testis in a scrotal position at an optimal age. Germ cell development is an active process that continues till about four years after birth (Ong 2005). It is known that testes in an undescended location are prone to progressive histological damage resulting in a possible decrease in the germ cells (Ong 2005). Maturation of neonatal gonocytes into spermatogonia is an active process that extends to up to four years of age (Ong 2005). Timely relocation of the testis in a scrotal position can halt further damage to the germ cells (Tasian 2009; Thorup 2009). A 2% risk/month of severe germ cell loss and 1% risk/month of Leydig cell depletion for each month a testis remains undescended, and a 50% greater risk of germ cell depletion in nonpalpable testes has been reported, thus emphasising the need for early relocation of an undescended testis (Tasian 2009). At the same time, early relocation of undescended testes appeared to have no effect on the risk of malignancy or sperm extraction (Pike 1986; Wiser 2009).
Surgery is currently recommended before the age of two years (Hutson 2007; Thorup 2009) and this is believed to decrease the chance of impact on germ cell maturation. Hormonal therapy is commenced in the newborn period to induce testicular descent (Dixon 2007). Hormonal therapy has also been used after surgical correction since it may have beneficial effects on germ cell maturation in the operated as well as the contralateral testis (Zivkovic 2006).
Why it is important to do this review
In reported literature, hormonal therapy and surgical correction have been used with varying successes (Ong 2005; Park 2010). Hormonal therapy has also been used as an adjunct to surgical correction (Jallouli 2009; Zivkovic 2006). The precise role of either modality (surgical and hormonal) of therapy needs to be clarified on the backdrop of the possible benefits and harms.
Overall, robust comparisons between hormonal therapy and surgical correction, between various surgical approaches and between different recommended ages of correction will provide useful information for clinicians and policy makers to tailor the clinical practice and also design future research studies.