Different surgical findings in congenital and acquired undescended testes
Jocelyn van Brakel, Erasmus University Medical Centre, Department of Urology, Room HS-404, PO Box 2040, 3000 CA Rotterdam, The Netherlands. e-mail: firstname.lastname@example.org
Study Type – Therapy (case series)
Level of Evidence 4
What's known on the subject? and What does the study add?
Much is known on the aetiology, natural course and treatment of congenital undescended testes (UDT), but these matters are less clear for acquired UDT and still debated. Several studies have examined anatomical findings in patients with UDT. However, most of these studies do not distinguish between congenital and acquired UDT.
This study describes clinical and surgical differences between congenital and acquired UDT, in which full history was known for all patients. Major differences were found in preoperative testis position as well as intraoperative testis position, patency of processus vaginalis and epididymal anomalies between congenital and acquired UDT.
- • To compare surgical findings in congenital and acquired undescended testes (UDT).
PATIENTS AND METHODS
- • A review of 139 boys with 158 congenital UDT and 69 boys with 84 acquired UDT was performed. The most caudal testicular position preoperatively, testis position at surgery, patency of the processus vaginalis and epididymal anomalies were prospectively recorded.
- • In the congenital group, orchiopexy had been performed at median age (range) 4.9 (1.5–14.6) years, while the median age (range) in the acquired group was 11.9 (3.8–23.3) years. Preoperatively, only congenital UDT were found not palpable or emergent inguinal, while only acquired UDT could be manipulated in an unstable scrotal position. In comparison with congenital UDT, acquired UDT were significantly more often located at the scrotal entrance, 27/158 vs 32/84 respectively (P < 0.001). At surgery anorchia, vanished testis or testes lying intra-abdominally were only registered in the congenital UDT group. Also 37/158 congenital UDT were located in the superficial inguinal pouch vs 52/84 of the acquired UDT (P= 0.04). In congenital UDT the processus vaginalis was wide open in 74/158, while in acquired UDT the processus vaginalis was closed in 46/84 (P < 0.001) and small open in 26/84 (P= 0.04). Epididymal anomalies were more often seen in the congenital UDT group (37%) than in the acquired group (11%).
- • The most caudal position of congenital UDT after manipulation before surgery was at the scrotal entrance. These testes were frequently associated with epididymal anomalies and wide open processus vaginalis. This was in contrast to acquired UDT, which can often be pushed down well below the scrotal entrance and are more likely to be situated in the superficial inguinal pouch, with a normal epididymis and closed processus vaginalis.
Undescended testes (UDT) are one of the commonest genital abnormalities in boys. Two types are distinguished: congenital and acquired UDT [1,2]. One per cent of all boys will have a testis that has not yet descended by 1 year of age . Congenital UDT are testes that have never reached a stable scrotal position. Acquired UDT are testes that used to be in a scrotal position – as diagnosed by a physician – and later have become entrapped outside the scrotum. This is seen in 1–3% of boys during childhood . Much is known of the aetiology, natural course and treatment of congenital UDT, but these matters are less clear for acquired UDT and still debated. Furthermore, even less is known about anatomical differences between the two types of UDT. Several studies have examined anatomical findings in patients with UDT [5–19]. However, most of these studies did not distinguish between congenital and acquired UDT. The aim of the study reported here was to objectify possible clinical and surgical differences between the two types.
PATIENTS AND METHODS
Boys included in this study had at prepubertal age been referred for UDT to the Erasmus University Medical Centre – Sophia Children's Hospital, Rotterdam. The surgical findings were registered in a standardised form. Previous testicular positions were retrospectively collected from medical documentation of the Regional Youth Health Care Institution, the GP or the hospital file to diagnose either congenital or acquired UDT.
CONGENITAL UDT GROUP
These boys participated in a placebo-controlled study of LHRH nasal spray between 1982 and 1985 . They had been operated on by the same paediatric surgeon (FH) if LHRH did not achieve a permanent stable scrotal position.
ACQUIRED UDT GROUP
Acquired UDT is defined as a palpable UDT that had previously descended into a stable scrotal position. At least one medical document had to confirm previous stable scrotal position. Patients referred for acquired UDT between 1982 and 2004 were treated conservatively and examined annually at least until puberty stage P2G2 according to Marshall and Tanner . If spontaneous descent did not occur, operation followed.
DEFINITION OF TERMS
The most caudal testicular position found after admission and confirmed following induction of anaesthesia was classified as (i) not palpable; (ii) emergent inguinal – testis intermittently palpable; (iii) inguinal region; (iv) scrotal entrance; (v) unstable scrotal – testis replaced in non-scrotal position immediately after release.
Boys with retractile testes, i.e. testes that could be manipulated into the scrotum and maintained a stable scrotal position until induction of the cremaster reflex, were excluded.
The testicular location at the time of surgery was classified as (i) absent – either true anorchia or ‘vanished testis’; (ii) intra-abdominal; (iii) inguinal canal; (iv) external annulus; (v) superficial inguinal pouch.
The condition of the processus vaginalis was classified as (i) closed – obliterated to a fibrous string; (ii) small open – small open communication between the peritoneal cavity and tunica vaginalis; (iii) wide open – testis can move freely within the processus vaginalis.
The condition of the epididymis was classified as (i) absent; (ii) partially separated from the testis; (iii) completely separated from the testis; (iv) long loop epididymis and vas.
Data were analysed with SPSS, version 17.0 (SPSS Inc., Chicago, IL, USA). Variables were tested for power to distinguish between congenital or acquired UDT. For preoperative testis position a univariate linear regression analysis was done, and for the intraoperative findings (intraoperative testis position, condition of processus vaginalis and epididymal anomalies) a multivariate analysis. P < 0.05 was considered statistically significant.
The study was reviewed and approved by the Medical Ethical Review Committee at Erasmus University Medical Centre in Rotterdam (MEC number 2004-206).
We analysed findings in 139 boys with congenital UDT (19 bilateral and 120 unilateral) and 69 boys with acquired UDT (15 bilateral and 54 unilateral). In the congenital group, orchiopexy had been performed after diagnosis at median age (range) 4.9 (1.5–14.6) years. Median age (range) in the acquired group was 11.9 (3.8–23.3) years. In 74 cases orchiopexy was performed after Tanner stage P2G2; in 10 before puberty. Most important reasons for earlier operation were inguinal complaints and a clinically present ipsilateral inguinal hernia.
Table 1 shows the characteristics of the two groups. Relevant differences between congenital and acquired UDT can be summarised as follows.
Table 1. Characteristics of the congenital and acquired UDT
|Most caudal testis position before surgery*|| || || || || |
| Not palpable||23 (15)||–|| || || † |
| Emergent inguinal||4 (3)||–|| || || † |
| Inguinal region||104 (66)||7 (8)|| || || |
| Scrotal entrance||27 (17)||32 (38)||0.06||0.02–0.14||<0.001|
| Unstable scrotal||–||45 (54)|| || || † |
|Intraoperative testis position‡|| || || || || |
| No testis§||15 (10)||–|| || || † |
| Intra-abdominal||4 (3)||–|| || || † |
| Inguinal canal||37 (23)||4 (5)|| || ||>0.20|
| External annulus||65 (41)||28 (33)|| || || |
| Superficial inguinal pouch||37 (23)||52 (62)||0.48||0.24–0.96||0.04|
|Processus vaginalis‡|| || || || || |
| Closed||35 (22)||46 (55)||0.17||0.07–0.46||<0.001|
| Small open||49 (31)||26 (31)||0.36||0.14–0.94||0.04|
| Wide open||74 (47)||12 (14)|| || || |
|Epididymis‡|| || || || || |
| Normal||99 (63)||75 (89)|| || || |
| Abnormal||59 (37)||9 (11)|| || || |
| Absent||15 (10)||–|| || || † |
| Partial separation||27 (17)||2 (2)||2.82||0.59–13.4||0.192|
| Complete separation||10 (6)||6 (7)||0.38||0.11–1.33||0.132|
| Long loop||7 (4)||1 (1)|| || ||>0.20|
In 27 boys with unilateral congenital UDT the testis was preoperatively not or intermittently palpable. At surgery of these boys 15 testes were absent, four were located intra-abdominally and eight were lying in the inguinal canal. Acquired UDT were always palpable preoperatively. The most caudal position of 66% of congenital UDT was in the inguinal region; most acquired UDT (54%) could be manipulated into an unstable scrotal position. Testes found at the scrotal entrance were significantly more often acquired UDT (odds ratio [OR] 0.06; 95% CI 0.02–0.14, P < 0.001). The acquired group more often had testes situated in the superficial inguinal pouch (OR 0.48; 95% CI 0.24–0.96, P= 0.04).
In the congenital group the patency of the processus vaginalis was more often small or wide open, i.e. in 78% vs 45% in the acquired group. Acquired UDT had significantly more often a closed or small open processus vaginalis (Table 1). Correlations between the patency of the processus vaginalis and the intraoperative positions are shown in Table 2.
Table 2. Condition of processus vaginalis in relation to intraoperative testis position in 158 congenital UDT and 84 acquired UDT
|Absent||5 (33)||10 (67)||–||15 (100)||–||–||–||–|
|Intra-abdominal||–||–||4 (100)||4 (100)||–||–||–||–|
|Inguinal canal||–||1 (3)||36 (97)||37 (100)||–||–||4 (100)||4 (100)|
|External annulus||15 (23)||17 (26)||33 (51)||65 (100)||10 (36)||12 (43)||6 (21)||28 (100)|
|Superficial inguinal pouch||15 (40)||21 (57)||1 (3)||37 (100)||36 (69)||14 (27)||2 (4)||52 (100)|
|Total||35 (22)||49 (31)||74 (47)||158 (100)||46 (55)||26 (31)||12 (14)||84 (100)|
Epididymal anomalies were more often seen in the congenital UDT group than in the acquired group, 37% vs 11% respectively. Table 3 shows the condition of the epididymis in relation to intraoperative testis position. The higher the intraoperative testis position, the higher is the number of epididymal anomalies. In both groups epididymal anomalies were associated with a patent processus vaginalis, especially a wide open processus vaginalis (Table 4).
Table 3. Condition of epididymis in relation to intraoperative testis position in 158 congenital UDT and 84 acquired UDT
|Absent|| ||15 (100)|| || || ||15 (100)|| || || || || |
|Intra-abdominal||–|| ||2 (50)||–||2 (50)||4 (100)|| || || || || |
|Inguinal canal||16 (43)|| ||11 (30)||5 (13.5)||5 (13.5)||37 (100)||3 (75)||–||1 (25)||–||4 (100)|
|External annulus||47 (72)|| ||13 (20)||5 (8)||–||65 (100)||23 (82)||2 (7)||2 (7)||1 (4)||28 (100)|
|Superficial inguinal pouch||36 (97)|| ||1 (3)||–||–||37 (100)||49 (94)||–||3 (6)||–||52 (100)|
|Total||99 (63)||15 (10)||27 (17)||10 (6)||7 (4)||158 (100)||75 (90)||2 (2)||6 (7)||1 (1)||84 (100)|
Table 4. Epididymal anomalies in relation to patency of the processus vaginalis
|Closed||5 (8.5)||–||5 (7)|
|Small open||13 (22)||5 (56)||18 (26)|
|Wide open||41 (69.5)||4 (44)||45 (66)|
|Totals||59 (100)||9 (100)||68 (100)|
This study aimed at objectifying anatomical differences between congenital and acquired UDT observed at surgery. First we need to address the nature of the two study groups. The congenital group received LHRH nasal spray prior to orchiopexy. It is very unlikely that this hormonal treatment influenced the surgical findings because we found no evidence of stimulation of the hypothalamo-pituitary-gonadal axis and our data did not support the presence of hormonal abnormalities in the cryptorchid boys . Following international recommendations, boys with congenital UDT are operated on before 1 year of age .
In the Netherlands the natural course and treatment options in acquired UDT are still being debated [2,23]. Our acquired UDT study group consisted of boys in whom spontaneous descent failed to occur, mostly until the onset of puberty. Therefore the median age of this group is higher than that of the congenital group. However, the key question here is whether a ‘wait and see approach’ until puberty – with surgery if the testis does not spontaneously descend – is to be preferred over surgery immediately following diagnosis [24,25]. This question falls outside the scope of this paper, but nevertheless we would recommend long-term follow-up studies comparing fertility potential and hormonal functioning between the two approaches.
Apart from differences in preoperative positions, there were indeed differences in surgical findings, supporting the idea that these two types are distinct entities. In the congenital group the most caudal position of the testes before surgery was mainly outside the inguinal canal, but no further than the scrotal entrance. In the acquired group, however, most testes could be manipulated to the scrotal entrance or to an unstable scrotal position. Unfortunately, a similar study by Meij-de Vries et al.  does not document preoperative testes positions. The distribution of intraoperative testis positions significantly differed between the two groups. In the congenital group significantly more testes were lying in the inguinal canal than was the case in the acquired group. This was also reported by Meij-de Vries et al. , whose study, however, distinguished slightly different intraoperative testis locations. Also, in other publications related to acquired UDT, the position of the ascending testes at surgery was more likely to be in the superficial inguinal pouch [10,16,18].
Earlier studies found a patent processus vaginalis in 44–93% of patients with UDT [5,8,11,14]. However, these studies did not distinguish between congenital and acquired UDT and commenting on these rates is of little use because the processus vaginalis status of normal boys is unclear [8,14]. We found the processus vaginalis was more often patent in congenital UDT, notably wide open, than in acquired UDT. To our knowledge three studies clearly distinguishing between congenital and acquired UDT present data on the patency of the processus vaginalis [10,15,19]. One reports similar results but does not distinguish between small open and wide open processus vaginalis . The second found fewer cases of patent processus vaginalis in the congenital group than in the acquired group. They suggested that a patent processus vaginalis could explain the late descend or that testes with a patent processus vaginalis might be more at risk to ascent; however, to our knowledge this is the only study with these findings and different opinion . The third also specifies whether the processus vaginalis is small open or wide open and findings are largely comparable with ours . Furthermore, Clarnette et al.  found a closed processus vaginalis in all acquired UDT, and two other studies – reporting only on acquired UDT – found an incidence of closed processus vaginalis of 45% and 48%, respectively [16,18].
The incidence of epididymal anomalies in boys with UDT was reported to be higher than in boys with a hydrocele/hernia without cryptorchidism [5,7,9,11]. In our study more epididymal anomalies were seen in congenital UDT than in acquired UDT, 31% vs 11% respectively. In the literature, proportions of boys with UDT showing epididymal anomalies range widely [5,7,9–14,17]. For example, in an overview by Elder  they vary from 36% to 79% in boys with UDT. There are two explanations for this wide range. First, most authors did not define the normal epididymis. We classified separation of caput and/or cauda epididymis from the testis or a long looping epididymis as anomalies. A completely attached or a widened mesentery between the body of the epididymis was considered normal, in line with Turek et al. . Second, most studies make no distinction between the two types of UDT. Since acquired UDT by definition have descended normally at an earlier stage, it is plausible to expect fewer anomalies than in congenital UDT, as in our study. Different patient selection could thereby cause this wide range. To our knowledge, only one other study also compared epididymal anomalies in acquired UDT and in congenital UDT . In that study 28% of boys with acquired UDT had epididymal anomalies, vs 46% of boys with congenital UDT who were operated on late due to parents' delay or late referral.
Kucukaydin et al.  and Heath et al.  found that testes in a superficial inguinal position had fewer epididymal anomalies than had other forms of UDT. In our study, most testes in the superficial inguinal pouch were acquired UDT. Those two studies did not distinguish between congenital and acquired UDT. One might speculate, however, that they in part were acquired UDT. This would confirm our finding that epididymal anomalies mostly occur in congenital UDT.
Our data showed that epididymal anomalies were most frequent in patients with a wide open processus vaginalis. An open processus vaginalis is indeed most common in congenital UDT. All studies on the association between epididymal anomalies and the patency of the processus vaginalis report higher incidences of epididymal anomalies in patients with an open, especially wide open, processus vaginalis [5,7,9,11–13].
Finally, although surgical findings between congenital and acquired UDT unmistakably differ, it is debatable whether these two conditions represent two truly different aetiologies or rather a spectrum of anomalies, i.e. congenital UDT, retractile testes and acquired UDT. Retractile testes have been reported to progress to acquired UDT during follow-up. In addition, reduction in germ cells have been reported not only for congenital UDT but also for retractile testes and acquired UDT . Long-term studies of testicular function of the latter testes, which are not always situated in the scrotal environment, might provide more insight into the aetiological differences.
In summary, we found major differences in preoperative testis position as well as intraoperative anatomical findings between congenital and acquired UDT. First, the most caudal testis position in congenital UDT was at the inguinal region or at the scrotal entrance, whereas most of the acquired UDT could often be pushed down well below the scrotal entrance into an unstable scrotal position. Second, at surgery most congenital UDT were found inside or just outside the inguinal canal, whereas acquired UDT were mostly located in the superficial inguinal pouch. Third, congenital UDT were associated with more epididymal anomalies combined with a small open or wide open processus vaginalis in comparison with acquired UDT.
The authors thank Ko Hagoort for editorial assistance.
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