CHAPTER 110
Post-Thoracotomy Pain Syndrome
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 [1–3]. 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 [1–10]. The incidence of PTPS has a wide range (2% to 90%), but on average, approximately 40% of patients will have chronic postoperative pain [2,4]. 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%. Fortunately, severe disabling pain occurs in only 3% to 5% of patients with PTPS [5,6]. Predictive factors for development of PTPS include increased pain 24 hours postoperatively, female gender, preoperative opiate use, and radiation therapy [4,8].
Intercostal neuralgia is the most commonly implicated cause of chronic PTPS [1]. Other factors contributing to pain are outlined in Table 110.1. 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 [7].
Table 110.1
Factors Associated with Post-Thoracotomy Pain [1,4]
Intercostal neuroma
Rib fracture
Adhesive capsulitis
Infection
Pleurisy
Costochondral dislocation
Costochondritis
Local tumor recurrence
Myofascial pain
Vertebral collapse
Symptoms
PTPS generally is manifested with symptoms of allodynia, dysesthesias, and lancinating pain typically attributed to intercostal neuralgia [4]. In addition, patients will have symptoms of achiness, pleuritic pain, and focal tenderness over the incision site [1,4]. Shoulder movement, deep breathing, and lying directly on the affected side can aggravate these symptoms [4]. Pain is frequently encountered with shoulder maneuvers and direct contact with the incision site and can be manifested as shoulder dysfunction and sleep disruption.
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 intercostal nerve pain 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, 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 assessment of the dermatomal distribution of the transected intercostal nerves.
Functional Limitations
PTPS results in daily activity limitations in 50% of those affected [5]. Ochroch and associates [9] identified functional decrement using the 36-item short form health survey (SF-36) 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 has been identified in 15% to 33% of post-thoracotomy patients at 1 year [7]. Shoulder restriction leads to limitations in sleep function, lifting capacity, and full range of motion activities of the shoulder girdle. In addition, functional limitations can be attributed to respiratory compromise related to surgery or underlying pulmonary disease.
Diagnostic Studies
The relevant diagnostic studies 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 pleura-based dysfunction, pneumonia, and recurrence of primary malignant disease. A diagnostic intercostal nerve block can be performed to identify intercostal neuralgia.
