Factors Associated with the Development of Chronic Post-Sternotomy Pain: A Case-Control Study

Abstract

OBJECTIVE The aim of the present study was to investigate the factors associated with chronic post-sternotomy pain in heart surgery patients.METHODS Between January 2013 and February 2014, we evaluated 453 patients with >6 months post-sternotomy for cardiac surgery at a surgical outpatient clinic. The patients were allocated into a group with chronic post-sternotomy pain (n=178) and a control group without pain (n=275). The groups were compared for potential predictors of chronic post-sternotomy pain. We used Cox proportional hazards regression to determine which independent variables were associated with the development of chronic post-sternotomy pain.RESULTS In total, 39.29% of the patients had chronic poststernotomy pain. The following factors were significantly associated with chronic post-sternotomy pain: (a) use of the internal thoracic artery in coronary bypass grafting (P=0.009; HR=1.39; 95% CI, 1.08 to 1.80); (b) a history of antidepressant use (P=0.0001; HR=2.40; 95% CI, 1.74 to 3.32); (c) hypothyroidism (P=0.01; HR=1.27; 95% CI, 1.03 to 1.56); (d) surgical wound complication (P=0.01; HR=1.69; 95% CI, 1.08 to 2.63), and (e) patients on disability benefits or scheduled for a consultative medical examination for retirement (P=0.0002; HR=2.05; 95% CI, 1.40 to 3.02).CONCLUSION The factors associated with chronic poststernotomy pain were: use of the internal thoracic artery; use of antidepressants; hypothyroidism; surgical wound complication, and patients on disability benefits or scheduled for a consultative examination.

Chronic Poststernotomy Pain

“…7,35 Wound complications, including infection, mediastinitis, keloid formation, and wound dehiscence, have been linked to the development of chronic poststernotomy pain. 35 Increased risk is conferred with minor superficial wound infections, as well as more severe, deeper infections including mediastinitis. Major sternal wound infection, including sternal dehiscence, occurs in approximately 2% of patients following median sternotomy.…”

“…These changes are likely the cause of the development of chronic pain in patients with wound complications. 35 Likewise, poor sternal healing may contribute to the development of chronic pain. Sternal pseudoarthrosis and sternal nonunion occur in up to 1% of patients following median sternotomy and are characterized by cessation of both the periosteal and endosteal healing responses after 3 months.…”

“…Hypothyroidism is thought to contribute to neuropathic pain, although the exact mechanism remains unclear. 35 Demyelination, aminoglycan deposition, and regional hypoxia leading to muscle spasms have all been postulated as reasons for the association between hypothyroidism and chronic pain development. 49,50 Like other forms of chronic pain, concomitant mood disorders including depression and anxiety increase the risk of chronic pain following sternotomy.…”

“…In addition, patients receiving disability or other secondary gain may be more likely to experience chronic pain, or at least report it. 35 Patients with preoperative pain states, especially those prescribed opioids, as well as patients with angina also seem more likely to develop chronic pain. 9 Undoubtedly, genetic predisposition toward the development of neuropathic injury and chronic pain exists and plays a role in poststernotomy pain.…”

Rationale and design of influence of volatile anesthesia versus total intravenous anesthesia on chronic postsurgical pain after cardiac surgery using Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials criteria assessment: study protocol for a prospective randomized controlled trial

“…Cardiac surgery remains one of the most common forms of major surgery, with over 2 million patients undergoing this procedure worldwide each year [1]. Many patients develop chronic postsurgical pain (CPSP) which persists in the anterior thorax after median sternotomy [1].…”