Impact of Thymectomy on Immunity in Infants After Cardiac Surgery

NCT07019857 | Recruiting

• 1 other identifier: RC24_0411
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 2

Brief Summary

Heart surgery in infants typically involves complete removal of the thymus gland to improve access to the heart. However, the thymus plays a key role in developing the immune system in early childhood, especially in the production and maturation of T lymphocytes, which help the body defend itself against infections. The THYMIC study tests the hypothesis that partial removal of the thymus (partial thymectomy) during heart surgery may better preserve the child's immune function compared to total removal (complete thymectomy). The goal is to determine whether this conservative surgical approach could reduce the risk of immune system impairment and infections in the months following surgery. This is a prospective, interventional, single-center study conducted at CHU de Nantes, involving 3 groups of infants:

• One group undergoing heart surgery with complete thymectomy;
• One group undergoing heart surgery with partial thymectomy;
• One control group undergoing heart or non-heart surgery without thymus removal. All infants enrolled will have two blood tests: one taken during their surgery and one taken one year later. These blood tests will quantify immune cells (T, B, NK cells), levels of antibodies, and vaccine responses. Parents will also be asked to fill out a questionnaire to record any infections their child experiences during the year after surgery. By comparing the immune responses and infection rates among the groups, the researchers hope to better understand the long-term effects of thymectomy in infants. The results could support future recommendations to preserve part of the thymus when possible during heart surgery. Participation in the study does not change the medical or surgical care of the child. The decision to perform a partial or complete thymectomy is made by the surgeon based on the child's anatomy. The additional blood samples are small in volume and follow current safety regulations.

Conditions

Congenital Heart Defects; Thymectomy; Immunological Deficiency Syndrome

Keywords

Thymectomy; Cardiac Surgery; Infant; Immunity; Lymphocytes; TRECs; Vaccination; Infection

Outcome Measures

Primary Outcomes (1)

• T-Lymphocyte response

  biological endpoint with absolute quantification of LyTs, LyT subpopulations and TRECs.

  12 months after surgery

Secondary Outcomes (2)

• Humoral response

  12 months after surgery

• Clinical impact

  12 months after surgery

Study Arms (3)

Complete Thymectomy Group

EXPERIMENTAL

Infants undergoing cardiac surgery with cardiopulmonary bypass (CPB), during which a complete thymectomy is performed for surgical access to the heart and great vessels. The extent of thymus resection is determined by the cardiac surgeon intraoperatively, based on anatomical considerations

Diagnostic Test: Blood sample collection at surgery time and 12 months later

Partial Thymectomy Group

EXPERIMENTAL

Infants undergoing cardiac surgery with CPB, during which a partial thymectomy is performed, with an effort to preserve thymic tissue when anatomically feasible.

Diagnostic Test: Blood sample collection at surgery time and 12 months later

Control Group (No Thymectomy

ACTIVE COMPARATOR

Infants undergoing: * Cardiac surgery by thoracotomy without thymectomy (e.g., for aortic coarctation) or * Non-cardiac surgery (e.g., digestive procedures) with complete preservation of the thymus. These patients serve as immunological reference controls

Diagnostic Test: Blood sample collection at surgery time and 12 months later

Interventions

Blood sample collection at surgery time and 12 months later DIAGNOSTIC_TEST

each participant undergoes a blood test 1) at surgery time and 2) 12 months after surgery. These 5mL samples include: * Blood cell count * TREC dosage * Complete Lymphocytes immunophenotyping * Immunoglobulin dosage

Complete Thymectomy Group; Control Group (No Thymectomy; Partial Thymectomy Group

Eligibility Criteria

• Age: Up to 6 Months
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• \- Children aged between 0 and 6 months;
• Born at a gestational age \> 37 weeks' gestation;
• With an indication for cardiac surgery under CEC at Nantes University Hospital;
• Cardiopediatric follow-up planned at Nantes University Hospital;
• Written agreement signed by legal guardians to participate in the study.
• For the control groups:
• Control group A (cardiac surgery without thymectomy):
• Children aged between 0 and 6 months of age;
• Born at a gestational age \> 37 SA;
• Indicated for thoracotomy cardiac surgery at Nantes University Hospital;
• Cardiopediatric follow-up planned at Nantes University Hospital;
• Written agreement signed by legal guardians to participate in the study.
• Control group B (non-cardiac surgery)
• Children aged between 0 and 6 months;
• Born at a gestational age \> 37 SA;

You may not qualify if:

• Gestational age \< 37 SA;
• With a history of cardiac surgery under ECG;
• And/or with heart disease requiring further surgery within 12 months of the 1st surgery (e.g. pulmonary cerclage, systemic pulmonary anastomosis).
• And/or a history of partial or complete thymectomy;
• Receiving long-term immunosuppressive treatment;
• Post-operative follow-up planned in a hospital other than Nantes University Hospital, or moving house planned during the follow-up period;
• parental refusal.
• \- Gestational age \< 37 SA;
• With a history of cardiac surgery under ECG;
• And/or with heart disease requiring further surgery within 12 months of the 1st surgery (e.g. pulmonary cerclage, systemic pulmonary anastomosis).
• And/or a history of partial or complete thymectomy;
• Receiving long-term immunosuppressive treatment;
• Post-operative follow-up planned in a hospital other than Nantes University Hospital, or moving house planned during the follow-up period;
• parental refusal.

Sponsors & Collaborators

• Nantes University Hospital: lead

Study Sites (2)

CHU de Nantes

Nantes, 44093, France

NOT YET RECRUITING

Chu de Nantes

Nantes, 44093, France

RECRUITING

MeSH Terms

Conditions

Heart Defects, Congenital; Immunologic Deficiency Syndromes; Infections

Condition Hierarchy (Ancestors)

Cardiovascular Abnormalities; Cardiovascular Diseases; Heart Diseases; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Immune System Diseases

Study Officials

• Alexis Chenouard, PH

  Nantes University Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Alexis Chenouard, PH

CONTACT

02 44 76 82 21; alexis.chenouard@chu-nantes.fr

Evelyne Gauvard

CONTACT

Evelyne.GAUVARD@chu-nantes.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: three groups according to type of surgery (complete thymectomy, partial thymectomy, control)

Study Record Dates

• First Submitted: June 5, 2025
• First Posted: June 13, 2025
• Study Start: July 25, 2025
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: April 16, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

FR (2)