Intercostal Nerve Cryoablation Versus Epidural Analgesia for Nuss Repair of Pectus Excavatum

Rationale: The minimal invasive Nuss procedure is currently considered the treatment of choice for pectus excavatum. This procedure is usually associated with severe postoperative pain as great forces are employed on the thoracic cage to correct the sternal depression. Pain is the main limiting factor for early discharge. Epidural analgesia is currently considered gold standard for postoperative pain treatment. Alternative pain management strategies (e.g., patient-controlled analgesia and paravertebral nerve block) have also been described but fail in accomplishing adequate prolonged post-operative pain management. Alternatively, continuous use of opioids comes with side-effects like severe nausea, urinary retention and obstipation. Intercostal nerve cryoablation seems a promising novel technique for postoperative analgesia. Prior studies comparing intercostal cryoablation to other pain treatment modalities after pectus excavatum repair through the minimal invasive Nuss procedure report promising results, but pose significant limitations (e.g., small sample size, retrospective nature with non-matched patient groups or considerable confounders).

Objective: Primary objective of the current study is to determine the impact of intercostal nerve cryoablation on postoperative length of hospital stay compared to standard pain management of young pectus excavatum patients treated with the minimal invasive Nuss procedure.

Study design: The study protocol is designed for a single center, prospective, unblinded, randomized clinical trial.

Study population & intervention: Intercostal nerve cryoablation will be compared to thoracic epidural analgesia in young pectus excavatum patients (i.e., 12-24 years of age) treated with the minimal invasive Nuss procedure. Block randomization, including stratification based on age (12-16 years and 17-24 years) and sex, with an allocation ratio of 1:1 will be performed.

Main study parameters/endpoints: Postoperative length of hospital stay will be recorded as the primary endpoint. Secondary outcomes include: 1) pain intensity; 2) operative time; 3) opioid usage; 4) complications, including neuropathic pain; 5) creatine kinase activity; 6)intensive care unit admissions; 7) readmissions; 8) postoperative mobility; 9) health related quality of Life; 10) days to return to work/school; 11) number of postoperative outpatient visits and 12) hospital costs.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The risks for study participants are negligible as the cryoablation technique has already been effectively used in the Nuss procedure without any serious side effects. Also, participants will be monitored daily by nursing staff and surgeons while admitted to the hospital. Burden associated with participation in the current study consists of completion of several questionnaires preoperatively and postoperatively.

Inclusion criteria

• Patients undergoing the minimal invasive Nuss procedure for surgical repair of pectus excavatum.
• Young patients (12-24 years of age) according to the definition used by the World Health Organization. This cut-off point is chosen to create a more homogenous patient sample, as the thoracic cage is fully matured by the age of 24, in size and density, which will have an effect on postoperative pain.

Exclusion criteria

• A chest wall deformity other than pectus excavatum;
• Opioid use in the 3 months prior to surgery;
• Pain syndrome (e.g., fibromyalgia) or neuropathic pain prior to surgical repair of pectus excavatum;
• Connective tissue disease (e.g., Marfan syndrome, Ehlers-Danlos syndrome);
• Previous thoracic surgery or pectus excavatum repair;
• Contraindication for intercostal nerve cryoablation or thoracic epidural analgesia (e.g., patient refusal, infection at the site of cannulation, uncontrolled systemic infection, bleeding diathesis, increased intracranial pressure, mechanical spine obstruction);
• Psychiatric disease currently receiving treatment;
• Not mastering the Dutch language;
• Participation in another clinical trial that may interfere with the current trial.