Transversus Thoracis Muscle Plane Block for Sternotomy Pain in Cardiac Surgery

NCT ID: NCT04596163

Last Updated: 2023-07-13

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 86 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-10-15
• Study Completion Date: 2023-04-22

Brief Summary

Sternotomy pain is usually significant after cardiac surgery. Analgesic options for sternotomy in cardiac surgery are often limited. Poorly controlled acute pain is an important factor to development of chronic postsurgical pain. The transversus thoracis muscle plane (TTP) block is a novel technique that provides analgesia to anterior chest wall. A double-blinded RCT is conducted to assess the efficacy of applying TTP block as an adjunct to analgesia in cardiac surgery.

Detailed Description

Chronic postsurgical pain (CPSP) is defined as the persistence of pain at surgical site or referred area, at least 3 months following the surgical procedure. CPSP after median sternotomy is not uncommon after cardiac surgery. The reported incidence ranges from 28% to 56% up to 2 years postoperatively. A number of factors can contribute to the variation in incidence, including the variations in presentation of chronic post-sternotomy pain and under-reporting from patients. Given the nature of cardiac surgery and considerable anxiety of patients at perioperative period, patients would tend to live with the chronic pain and rationalize it as a normal consequence of the surgery. Patients therefore may not report any symptoms, resulting in a delay in diagnosis of chronic post-sternotomy pain.

The mechanisms for development of CPSP after sternotomy are not fully known. The up-regulation, activation and neural sensitization during the acute pain phase are important factors to the development of chronic pain. Causes of pain from sternotomy include neuropathy from anterior intercostal nerves entrapment or injury during surgical dissection and internal mammary artery harvesting, musculoskeletal injury from surgical incision and dissection, sternal fracture or incomplete bone healing, and development of sternal wound infections. Poorly controlled acute pain in the perioperative period can trigger central sensitization, a stepwise modification of spinal pain pathways involving protein synthesis and synaptic strength, which can lead to hyperalgesia and chronic pain. Therefore, good perioperative acute pain control not only provides postoperative pain relief, but also prevents occurrence of chronic pain.

In most centres, opioids such as fentanyl and morphine are used mainly for the management of acute pain after cardiac surgery. However, perioperative opioids are known to be associated with dose-dependent side effects such as nausea and vomiting, pruritis, respiratory depression, postoperative chronic opioid use and increased risk of chronic pain. Multimodal approach such as the use of NSAIDs may not be optimal after cardiac surgery due to the risk of bleeding and renal failure. Regional analgesia has opioid-sparing effect and seems to be a good choice for perioperative anaglesia. Regional techniques such as thoracic epidural and paravertebral blocks have been described but they are not ideal due to the potential complications from systemic heparinization in cardiac surgery. Erector spinae plane (ESP) block was reported to decrease perioperative morphine consumption and early postoperative pain score. However, the transverse process tip is not always easy to visualize on ultrasound, especially in obese patients, resulting in variation in ESP block efficacy.

Transversus thoracis muscle plane (TTP) block covers the anterior branches of intercostal nerves T2 to T6. It has been described in cardiac surgical patients that provides analgesia for sternotomy. TTP block is a superficial block and therefore is relatively safe when compared with thoracic epidural and paravertebral nerve block during heparinization. The investigators hypothesized that pre-emptive TTP block can provide effective perioperative analgesia and prevent the occurrence of CPSP in cardiac surgical patients requiring median sternotomy. A prospective, double-blinded randomized controlled trial was conducted to assess the analgesic efficacy of TTP block in open cardiac surgery.

Conditions

Pain, Postoperative; Surgical Wound; Cardiac Event

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Intervention

Ultrasound guided Regional block using 0.25% levobupivacaine (local anaesthetic agent) 20ml (50mg) on each side of the sternum over 1-2 minutes after general anaesthesia before surgery.

Group Type: ACTIVE_COMPARATOR

Transversus thoracis muscle plane block

Intervention Type: PROCEDURE

After general anaesthesia, transversus thoracis plane (TTP) block, a kind of regional block will be performed near both sides of the sternum under ultrasound guidance using either levobupivacaine or normal saline to both groups of patients. The end point for injection is the fluid spread along the plane just superficial to the transversus thoracis muscle, together with the downward displacement of the pleura.

Control

Ultrasound guided Regional block using 20ml of 0.9% normal saline on each side of the sternum after general anaesthesia before surgery.

Group Type: PLACEBO_COMPARATOR

Transversus thoracis muscle plane block

Intervention Type: PROCEDURE

After general anaesthesia, transversus thoracis plane (TTP) block, a kind of regional block will be performed near both sides of the sternum under ultrasound guidance using either levobupivacaine or normal saline to both groups of patients. The end point for injection is the fluid spread along the plane just superficial to the transversus thoracis muscle, together with the downward displacement of the pleura.

Interventions

Transversus thoracis muscle plane block

After general anaesthesia, transversus thoracis plane (TTP) block, a kind of regional block will be performed near both sides of the sternum under ultrasound guidance using either levobupivacaine or normal saline to both groups of patients. The end point for injection is the fluid spread along the plane just superficial to the transversus thoracis muscle, together with the downward displacement of the pleura.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• Elective CABG, aortic valve repair/replacement, mitral valve repair/replacement, or combined CABG/valve procedure

Exclusion Criteria

• emergency surgery
• redo surgery
• history of thoracotomy or mastectomy
• history of chronic pain or regular analgesic use (except paracetamol and NSAID)
• history of psychiatric illnesses or illicit drug use
• renal failure with eGFR <30ml/min or on renal replacement therapy
• mortality or require re-sternotomy within 24h after operation
• intraoperative use of remifentanil
• unable to provide informed consent

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Chinese University of Hong Kong

OTHER

Sponsor Role: lead

Responsible Party

WONG MAN KIN

Honorary Clinical Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Henry Man Kin Wong, MBChB

Role: PRINCIPAL_INVESTIGATOR

Chinese University of Hong Kong

Locations

Prince of Wales Hospital

Hong Kong, , Hong Kong

Countries

Hong Kong

Other Identifiers

2020.371-T

Identifier Type: -

Identifier Source: org_study_id