Chronic post-surgical pain

CPSP has become a health priority and has been included in the International Classification of Diseases 11^th Revision (ICD-11), due to the joint efforts of the World Health Organization (WHO) and the International Association for the Study of Pain (IASP). ¹

It is our ambition to reverse the chronic nature of pain for these patients or to prevent the development of chronic post-surgical pain in patients that undergo surgery.

We therefore see a need for:

1. Reverse the chronic nature of pain and/or neuropathy after surgery by showing that a subset of patients have permanent improvement in pain or symptoms of neuropathy without continued treatment
2. Prevent the development of chronic pain one year after surgery with a time-limited treatment

Disease Overview

Definition and symptoms

CPSP, also known as post-operative pain, is a complex disorder in which pain develops or increases in intensity following a surgical procedure and does not dissipate for at least several months.¹ The painful symptoms often relate to the distribution of nerves in the area of the surgery, and therefore the type of pain can depend on the operation itself.²

Epidemiology and risk factors

CPSP is a common complication of surgery, affecting up to 30% of adults undergoing surgical procedures.³ The prevalence of CPSP is estimated at 55 million people across the US and EU, with approximately 2 million new cases per year.^4-10 Patient factors and surgical characteristics affect the risk of developing acute post-surgical pain. Risk factors for CPSP include female gender, psychosocial issues, perioperative pain and type of surgical trauma.^4-10 Neuropathic pain post-surgery is particularly high in operations such as amputation, hernia repair and mastectomy.¹¹

Current management approaches

The management of CPSP is split into two approaches: prevention and treatment.¹² Prevention techniques focus on the surgical procedure and include interventions such as regional anaesthesia and pre-emptive analgesia, although there is controversy regarding their effectiveness.¹² Treatment for CPSP is complex because of the highly heterogeneous patient group; several pharmaceutical therapies are suggested for treatment, but their long-term benefits are questionable.