Post-Thoracotomy Pain Syndrome

Abstract

Post-thoracotomy pain syndrome (PTPS) is characterized by pain that recurs or persists at the incision site or in the dermatomal distribution of intercostal nerves for longer than two months after thoracotomy. Among surgical procedures, thoracotomy is estimated to have some of the highest rates of chronic postoperative pain and subsequent disability. PTPS has wide estimates of incidence (5% to 90%) and approximately half of patients undergoing thoracotomy who develop PTPS will experience impairments in the capacity to perform daily activities. PTPS generally manifests with symptoms of allodynia, dysesthesias, and lancinating pain and is most often attributed to intercostal neuralgia. PTPS may lead to complications that include impaired shoulder function and respiratory dysfunction secondary to decreased depth of breathing, including retention of secretions, and atelectasis. Muscle disruption, chest wall pain with shoulder movement, and myofascial pain may also contribute to shoulder dysfunction in patients with PTPS. Management of PTPS includes treatment with analgesic medications, rehabilitation to preserve and maintain shoulder and respiratory function, and potentially procedures to treat focal and anatomic causes of pain.

Keywords

cancer rehabilitation, chronic pain, epidural analgesia, lung surgery, post-thoracotomy pain syndrome

Synonym
None
ICD-10 Code
G89.12	Acute post-thoracotomy pain
G89.22	Chronic post-thoracotomy pain

Definition

Post-thoracotomy pain syndrome (PTPS) is pain that recurs or persists at the incision site or in the dermatomal distribution of the intercostal nerves for longer than 2 months after thoracotomy. Thoracotomies are used to access intrathoracic contents, such as the lung, esophagus, and heart. The most common indication for a thoracotomy is tumor resection. The classic thoracotomy consists of a posterolateral incision of the thorax, bisection of the latissimus dorsi and serratus anterior, separation of the ribs, disruption of the intercostal nerves, and pleural incision. The thoracotomy is regarded as one of the most painful surgical procedures performed because they involve trauma to pain-sensitive structures, such as multiple muscle layers, fascia, neurovascular bundles, bone, joints, and the parietal pleura. The incidence of PTPS has a wide range (5% to 90%), but on average, approximately 40% to 50% of patients will have chronic postoperative pain. PTPS is mild to moderate in 92% of cases; 50% of patients will have disruption in the capacity to perform daily activities. Sleep disruption occurs in 25% to 30%. Severe, disabling pain is estimated to occur in 3% to 5% of patients with PTPS. Predictive factors for development of PTPS include increased pain 24 hours postoperatively, female gender, pre-operative opiate use, and radiation therapy.

Intercostal neuralgia is the most commonly implicated cause of chronic PTPS. Other factors contributing to pain are outlined in Table 111.1 . Recognizing that local muscle disruption of the serratus anterior and latissimus dorsi results in abnormal scapulohumeral mechanics, shoulder abnormalities are one of the common causes of functional loss after thoracotomy.

Table 111.1

Factors Associated With Post-Thoracotomy Pain

Intercostal neuroma
Rib fracture
Adhesive capsulitis
Infection
Pleurisy
Costochondral dislocation
Costochondritis
Local tumor recurrence
Myofascial pain
Vertebral collapse

See references .

Symptoms

PTPS generally manifests with symptoms of allodynia, dysesthesias, and lancinating pain typically attributed to intercostal neuralgia. In addition, patients may have symptoms of achiness, pleuritic pain, and focal tenderness over the incision site. Shoulder movement, deep breathing, coughing, and lying directly on the affected side can aggravate these symptoms. Pain is frequently aggravated with shoulder maneuvers and direct contact with the incision site. PTPS may also manifest as shoulder dysfunction and sleep disruption due to persistent pain symptoms.

Physical Examination

The examination of the patient with PTPS includes inspection of the incision site and chest wall movement with respiratory excursion. Deep breathing maneuvers to elicit pleuritic pain are another component of the examination. Palpation over the incision site to evaluate for scar adherence, hypersensitivity, or pain in the dermatomal distribution of intercostal nerves is the next component of the examination. The rib cage is disrupted with surgery and must be assessed for persistent fractures, costochondral avulsions, and costochondritis. Assessment of regional musculature for postoperative disruption, atrophy, dyskinesia, and myofascial pain is important. Adhesive capsulitis and shoulder girdle dysfunction are factors in PTPS; therefore, active and passive range of motion of the shoulder and scapulohumeral mechanics should be evaluated. Neurologic examination includes motor testing of the affected extremity compared with the unaffected side, evaluation for scapular winging and dyskinesis, and assessment of the dermatomal distribution of the transected intercostal nerves.

Functional Limitations

PTPS results in daily activity limitations in 50% of those affected. One study identified functional decrement using the 36-item short form health survey in most patients at 4 to 48 weeks postoperatively. Shoulder restriction secondary to chest wall pain, adhesive capsulitis, and disruption of the serratus anterior and latissimus dorsi have been identified in 15% to 33% of post-thoracotomy patients at 1 year. Shoulder restriction may lead to limitations in sleep function, lifting capacity, and full range of motion for activities involving the shoulder girdle. In addition, functional limitations may result from respiratory compromise related to the effects of surgery or underlying pulmonary disease.

Diagnostic Studies

The relevant diagnostic studies to obtain include baseline radiographs of the rib cage to evaluate for bone disruption. In addition, chest radiographs and computed tomography scans can be used to screen for intrathoracic processes, such as pleural adhesions, pneumonia, and recurrence of primary malignant disease. A diagnostic intercostal nerve block can be performed to identify intercostal neuralgia.

Differential Diagnosis