Undescended testes
Key points
3% term infants, 33% preterm
2% of all testes ascend
80% palpable
If impalpable: 50% inguinal, 40% abdominal, 10% absent
Pathophysiology
Gubernaculum develops 8-12 weeks
Testicular descent: Abdominal phase 8-15 weeks, Inguinoscrotal phase 25-35 weeks
Hormones:
Insulin-like hormone 3 produced by Leydig cells: Swelling of gubernaculum during abdo phase
Testosterone: Regression of cranial suspensory ligament
Calcitonin gene-related peptide: Gradient to guide gubernaculum
PPV obliterates when testis is descended, starting bottom to top
Enzymes and cellular activities adapted to work at 33C - higher temps in UDT
Thought to be environmental factors e.g. Oestrogen exposure
No definite genetic cause
Associations
Maternal oestrogen exposure
Prader-Willi - Paternal 15q11-q13 deletions, Excessive weight gain, Hypogonadism, Learning difficulties
Klinefelter's
Kallmann syndrome
Gastroschisis/Exomphalos/CDH/Bladder extrophy
Prune belly
Hypospadias
41% of Cerebral palsy - due to hypertonic cremaster
History and Examination
If testis is impalpable in groin, examine femoral area, perineum and base of penis, contralateral hemiscrotum
For babies with bilateral impalpable - Investigate for DSD - Karyotype, FISH, LH, FSH, Testosterone
Histology
Histopathologic differences become much more pronounced after 2 years of life and are increased with delayed orchiopexy
Peritubular fibrosis
Seminiferous tubule atrophy
Decreased / absent spermatogenesis - impaired gonocyte transformation
Sertoli cells may demonstrate granular cell change
Radiology
USS is useful in overweight patients
MRI - poor sensitivity and predictive values
Management of retractile testes
1/3 retractile testes become ascending, 1/3 descend, 1/3 stay retractile (Agarwal J Urol 2006), associated with growth spurts
Need to follow up yearly till resolved or until puberty
If fully ascended, do not wait until puberty to perform orchidopexy, as no difference in fertility if watch and wait (van Brakel 2014 J Ped Surg)
Hormonal therapy only marginally more effective than placebo
Can give HCG in Prader Willi
Outcomes of orchidopexy
Atrophy rate <5%
Ascent rate 2%
Unilateral UDT - normal fertility - 80-90% paternity rate
Bilateral UDT + ascended - 6x risk of infertility compared to population - paternity rate 45-65%
2-8x higher risk of malignancy
10% of testicular cancers have hx of UDT
If left in abdomen - seminoma most likely. If successful orchidopexy - 63% are germ cell tumours
1% Malignancy rate if left inguinal, 5% if abdominal
If remnant is left, 15% contain testicular tissue, but only 1 cancer has been reported
Patients with 1 testis do not need to avoid contact sports, but should avoid motorbikes
Standard scenario
Infant with unilateral undescended testis
ORCHESTRA study & BJS open Meta-Analysis suggest no difference in atrophy rates before or after age 1
Possibly better fertility with earlier orchidopexy
Balance against risk of general anaesthetic <1 year of age
Reasonable to operate around age 1
EUA + open orchidopexy - open external ring + divide cremaster
If impalpable - place laparoscope
If testis visible - 1st stage Fowler-Stephens - clip and divide vessels
If remnant/nubbin - excise +/- fix contralateral testis
If vas and vessels blind ending - no further action +/- fix contralateral testis
If vas and vessels going through internal ring - groin exploration + proceed
In all cases of impalpable testis the fate of the testicular tissue must be positively identified - it cannot be left in the abdomen
In some cases epididymis descends separate to the testis
In this situation the abdomen should be explored up to the origin of the gonadal vessels to identify the body of the testis
Special scenario - Post pubertal UDT
Rogers et al examined post pubertal UDT specimens - no spermatogenesis seen and 2 cancers found
Orchidectomy recommended, but post pubertal inguinal UDT can be preserved + biopsied if patient insists and agrees to regular examination
Special scenario - Alternative procedures
Shehata technique 2016 (1st stage laparoscopic orchidopexy where the vessels are not divided, the testis is pexed to opposite abdominal wall to allow vessel lengthening over 6 months) - Reviewed in 34 boys in 2019 - no atrophy, 3 slipped traction sutures
Do not perform Fowler-Stephens if previous groin exploration as the gubernaculum blood supply will be disrupted
Microvascular orchidopexy - divide and anastomose to inferior epigastrics
Meta-analysis 2018 (Yu et al) - 2 stage laparoscopic is better than single stage in terms of success and atrophy rate - 2 stage FSO - 87% success rate, atrophy rate 10%
Page edited by Mrs Charnjit Seehra BSc November 2024
References
Holcomb and Ashcraft’s Pediatric Surgery, 7th edition, 2020, Chapter 51
(Tasian GE et al. Age at orchiopexy and testis palpability predict germ and Leydig cell loss: clinical predictors of adverse histological features of cryptorchidism. J Urol. 2009 Aug;182(2):704-9. doi: 10.1016/j.juro.2009.04.032. Epub 2009 Jun 17. PMID: 19539332.)
Agarwal PK, Diaz M, Elder JS. Retractile testis--is it really a normal variant? J Urol. 2006 Apr;175(4):1496-9. doi: 10.1016/S0022-5347(05)00674-9. PMID: 16516034.
van Brakel J et al. Fertility potential in a cohort of 65 men with previously acquired undescended testes. J Pediatr Surg. 2014 Apr;49(4):599-605. doi: 10.1016/j.jpedsurg.2013.09.020. Epub 2013 Oct 3. PMID: 24726121.
Paediatric Surgical Trainees Research Network (PSTRN); Organizing and Writing Group:. Timing of orchidopexy and its relationship to postoperative testicular atrophy: results from the ORCHESTRA study. BJS Open. 2021 Jan 8;5(1):zraa052. doi: 10.1093/bjsopen/zraa052. PMID: 33609392; PMCID: PMC7893476.
Allin BSR, Paediatric Surgery Trainees Research Network et al. Systematic review and meta-analysis comparing outcomes following orchidopexy for cryptorchidism before or after 1 year of age. BJS Open. 2018 Feb 5;2(1):1-12. doi: 10.1002/bjs5.36. PMID: 29951624; PMCID: PMC5952379.
NHS England Paediatric orchidopexy for undescended testis Commisioning guide 2015
Contini G et al. Cystic Dysplasia of the Rete Testis: Case Report and Systematic Review of the Literature. Front Pediatr. 2022 May 18;10:898038. doi: 10.3389/fped.2022.898038. PMID: 35664872; PMCID: PMC9158335.