A Prospective Study of Patients with Hypoplastic Left Heart Syndrome (HLHS) Following Stage II Surgical Palliation

  • Study type:

    Observational What is this?

    Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.

Study IDs

  • Site IRB:

    • Rochester, Minnesota: 12-002887
  • NCT ID:

    NCT01708863
  • Sponsor Protocol Number:

    12-002887

About this study

Hypoplastic left heart syndrome (HLHS) is a severe form of congenital heart disease that consists of multiple obstructions to flow through the left heart and aorta, as well as hypoplasia of the left ventricle. Most patients require a three-stage surgical protocol starting within days of birth. Stage I of this process is the Norwood reconstruction (within the first few days of life), Stage II (usually required within 3-8 months) involves creation of a direct connection between the patient's superior vena cava and the pulmonary arterial confluence (bidirectional Glenn anastomosis), and the last stage is creation of a Fontan circulation (typically within the first 2-4 years). This "single ventricle" approach requires the right ventricle to perform as the only circulatory pump for the entire body.

Our long-term goal is to develop regenerative strategies to strengthen and augment the right ventricular muscle of the single-ventricle heart following surgical palliation in HLHS patients. To determine the safety and feasibility of a cell-based therapeutic intervention at the Stage II surgery, we aim to document the natural history of post-surgical care in HLHS patients having undergone standard of care with protocol specific follow-up over the course of a 6-month period.

This prospective study will document the natural history in patients with HLHS after planned Stage II surgical palliation with a focus on cardiovascular parameters within 6 months following surgery in 10-20 patients.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion Criteria:

  • Up to 18 months of age
  • Undergoing planned Stage II Glenn palliative surgery
  • History of successful modified Norwood procedure utilizing a RV-PA shunt
  • Written informed consent can be obtained from both parents and/or legal guardians, unless one parent is not reasonably available

Exclusion Criteria:

  • Severe chronic diseases, extra-cardiac syndromes, or cancer
  • The following conditions within 15 days prior to the date of the Stage II Glenn surgery:
    • Cardiogenic shock
    • Pulmonary hypertension requiring chronic medical therapy (e.g. supplemental oxygen, vasodilator)
    • Arrhythmia that required medication for control
  • Any documented infection requiring treatment with IV antibiotics, and/or current infection being treated with antibiotics
  • The following complications of their congenital heart disease:
    • Any condition requiring urgent, or unplanned procedure 15 days prior to Stage II Glenn surgery
  • Tricuspid repair and/or aortic arch repair at the time of Stage II Glenn surgery
  • Length of hospitalization of more than 60 days for Stage I Norwood procedure
    • Chylothorax requiring dietary modifications
    • Seizure or neurological injury
    • Moderate to severe tricuspid regurgitation prior to Stage II Glenn surgery
    • History of extracorporeal membrane oxygenator (ECMO) support

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Timothy Nelson, M.D., Ph.D.

Open for enrollment

Karen Krucker R.N.

(507)255-4774

Krucker.Karen@mayo.edu