Unilateral CryptorchidismORCANCT02235623
Orchidopexy Randomized Clinical Assessment
A study testing Single-stage Fowler-Stephens orchidopexy (FSO) and Two-stage Fowler-Stephens orchidopexy (FSO) in people with Unilateral Cryptorchidism, run by Boston Children's Hospital at 1 site in United States.
Trial summary
This is a randomized trial designed to evaluate testicular outcomes after a single stage versus a two-stage surgical procedure to fix an undescended, one-sided testicle located in the abdomen. Also to determine and compare the costs, surgical complications and the health related quality of life for the two procedures. Read more about this study
- Who is it for?
- Ages 4 to 36 months, men only
- Conditions the study is for
- Unilateral Cryptorchidism
- What is being tested?
- Single-stage Fowler-Stephens orchidopexy (FSO) and Two-stage Fowler-Stephens orchidopexy (FSO)
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 66 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2014to 31 Dec 2030
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 36 months
- Men only
- No healthy volunteers
- Child
Who may be able to join
- Boys age 4 months to 36 months
- Undergoing diagnostic laparoscopy for unilateral non-palpable testis, who are found at laparoscopy to have an abdominal undescended testis, in whom a Fowler-Stephens Orchiopexy would be appropriate.
Who cannot join
- Age > 36 months
- Age < 4 months
- Bilateral cryptorchidism
- Solitary testis
- Findings at laparoscopy for which Fowler-Stephens Orchiopexy would not be indicated
- Intra-operative mobility of the intra-abdominal testis such that, with no (or minimal) mobilization, the testis is able to reach the contralateral internal ring, without dividing the spermatic vessels.
- Assessment of whether a single stage primary orchidopexy will be performed, is entirely at the discretion of the attending surgeon.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Vera Rodic, MPH contact
United States1 site, 1 recruiting
- Recruiting
Boston Children's Hospital
Boston, Massachusetts, 02115
Badar Omar, BA, 617-919-6354, Badar.Omar@childrens.harvard.edu
Caleb P Nelson, MD, MPH
About this study
Official title: Randomized Trial of One Stage vs Two Stage Orchidopexy for Abdominal Undescended Testis
This is a randomized trial designed to evaluate testicular outcomes after a single stage versus a two-stage surgical procedure to fix an undescended, one-sided testicle located in the abdomen. Also to determine and compare the costs, surgical complications and the health related quality of life for the two procedures. Testicular outcomes will be measured using a scrotal ultrasound 6-12 months after the procedure (after the second stage procedure for those randomized to a 2 stage surgery).
- Conditions
- Unilateral Cryptorchidism
- Being tested
- Single-stage Fowler-Stephens orchidopexy (FSO), Two-stage Fowler-Stephens orchidopexy (FSO)
- Keywords
- Laparoscopic Surgery, Orchiopexy
- Medical subject headings
- Cryptorchidism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Single-stage Fowler-Stephens orchidopexy (FSO)Procedure or surgery
Two-stage Fowler-Stephens orchidopexy (FSO)Procedure or surgery
| Study group | Role | What they receive |
|---|---|---|
| Stage 1- Single-stage Fowler-Stephens orchidopexy (FSO) | Other | Stage 1 single surgery to clip the vessels to the testis, divide the spermatic vessels and bring the testis into the scrotum. Receives: Procedure: Single-stage Fowler-Stephens orchidopexy (FSO) |
| Stage 2- Two-stage Fowler-Stephens orchidopexy (FSO) | Other | Stage 2 2 surgeries: 1st surgery-Clip vessels to testis. 2nd surgery done 6-12 months later, divide the spermatic vessels and bring the testis into the scrotum. Receives: Procedure: Two-stage Fowler-Stephens orchidopexy (FSO) |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the volume of the operated testis via ultrasound measurements.
To evaluate the volume of the operated testis at 6-12 months after single-stage Fowler-Stephens orchidopexy (FSO) (6-12 months after two- stage FSO), as determined by ultrasound measurements. This will be compared to the intra-operative testicular measurements done during the laparoscopy.
Measured: 6-12 months after final FSO surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Sep 2014 (estimated)
- Study startAug 2014
- Primary completion31 Dec 2030 (estimated)
- Study completion31 Dec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Unilateral CryptorchidismStudies of the same condition, open and under way.
- More trials run by Boston Children's HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 66 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Boston Children's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Caleb Nelson, Boston Children's Hospital
- Investigators
- Caleb P Nelson, MD, MPH, Principal investigator, Boston Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02235623
- Sponsor's protocol ID
- P00008033
- Acronym
- ORCA
- Status last verified
- Apr 2026
- First submitted
- 2 Sep 2014
- Last updated
- 15 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 15 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Trial of One Stage vs Two Stage Orchidopexy for Abdominal Undescended Testis
- ClinicalTrials.gov ID
- NCT02235623
- Acronym / sponsor ID
- ORCA / P00008033
- Conditions
- Unilateral Cryptorchidism
- Keywords
- Laparoscopic Surgery, Orchiopexy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 66 participants (estimated)
- Lead sponsor
- Boston Children's HospitalUniversity, hospital or other
- Study start
- Aug 2014
- Primary completion
- 31 Dec 2030 (estimated)
- Study completion
- 31 Dec 2030 (estimated)
- First posted
- 10 Sep 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a randomized trial designed to evaluate testicular outcomes after a single stage versus a two-stage surgical procedure to fix an undescended, one-sided testicle located in the abdomen. Also to determine and compare the costs, surgical complications and the health related quality of life for the two procedures. Testicular outcomes will be measured using a scrotal ultrasound 6-12 months after the procedure (after the second stage procedure for those randomized to a 2 stage surgery).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Stage 1- Single-stage Fowler-Stephens orchidopexy (FSO) | Other | Procedure: Single-stage Fowler-Stephens orchidopexy (FSO)Stage 1 single surgery to clip the vessels to the testis, divide the spermatic vessels and bring the testis into the scrotum. |
| Stage 2- Two-stage Fowler-Stephens orchidopexy (FSO) | Other | Procedure: Two-stage Fowler-Stephens orchidopexy (FSO)Stage 2 2 surgeries: 1st surgery-Clip vessels to testis. 2nd surgery done 6-12 months later, divide the spermatic vessels and bring the testis into the scrotum. |
Who may qualify
- Ages
- 4 to 36 months
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- Boys age 4 months to 36 months
- Undergoing diagnostic laparoscopy for unilateral non-palpable testis, who are found at laparoscopy to have an abdominal undescended testis, in whom a Fowler-Stephens Orchiopexy would be appropriate.
Key exclusion criteria (7 listed)
- Age > 36 months
- Age < 4 months
- Bilateral cryptorchidism
- Solitary testis
- Findings at laparoscopy for which Fowler-Stephens Orchiopexy would not be indicated
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Single-stage Fowler-Stephens orchidopexy (FSO) | Procedure or surgery | Stage 1- Single-stage Fowler-Stephens orchidopexy (FSO) |
| Two-stage Fowler-Stephens orchidopexy (FSO) | Procedure or surgery | Stage 2- Two-stage Fowler-Stephens orchidopexy (FSO) |
Primary outcome
To evaluate the volume of the operated testis via ultrasound measurements.
Time frame: 6-12 months after final FSO surgery
To evaluate the volume of the operated testis at 6-12 months after single-stage Fowler-Stephens orchidopexy (FSO) (6-12 months after two- stage FSO), as determined by ultrasound measurements. This will be compared to the intra-operative testicular measurements done during the laparoscopy.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Apr 2026.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Vera Rodic, MPH contact
Caleb P Nelson, MD, MPH principal investigator
Boston Children's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Single-stage Fowler-Stephens orchidopexy (FSO) and Two-stage Fowler-Stephens orchidopexy (FSO) in people with Unilateral Cryptorchidism, run by Boston Children's Hospital at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Badar Omar, BA (617-919-6352, Badar.Omar@childrens.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To evaluate the volume of the operated testis via ultrasound measurements. (time frame: 6-12 months after final FSO surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Apr 2026.