2 The procedure
2.1.1 Atrial fibrillation is the irregular and rapid beating of the atria. Patients with AF may be asymptomatic or may have symptoms such as fatigue, palpitations and chest pain. They also have an increased risk of thromboembolic stroke. In non-valvular AF, thrombi largely develop in the LAA.
2.1.2 Patients with AF who are considered to be at high risk of thromboembolic stroke are usually treated with anticoagulation therapy. If a patient is unable to tolerate anticoagulation, then surgical obliteration of the LAA through a percutaneous or open approach may be offered.
2.2.1 Thoracoscopic exclusion of the LAA for non-valvular AF for the prevention of thromboembolism is usually carried out with the patient under general anaesthesia, and often alongside other procedures such as radiofrequency or microwave ablation to treat AF. Under thoracoscopic guidance the pericardium is opened and the atrial appendage excluded, usually using staples. A chest drain may be used to allow lung re-expansion. Postoperative transoesophageal echocardiography may be used to confirm exclusion of the LAA.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/guidance/IP/857/overview
2.3.1 A case series of 100 patients treated by thoracoscopic LAA exclusion (n = 85) and epicardial radiofrequency ablation reported cerebrovascular accidents in 2% (2/88) of patients followed up and transient ischaemic attack (TIA) in 2% (2/88) of patients over a mean follow-up of 23 months.
2.3.2 A case series of 15 patients treated by the procedure alone reported an overall stroke rate of 4% per patient-year (95% confidence interval 1.0 to 16) (mean follow-up 42 months). Of these, 1 patient had a fatal stroke 55 months after the procedure.
2.3.3 The Specialist Advisers listed key efficacy outcomes as total exclusion of the LAA with endothelialisation and a demonstrable absence of residual appendage on echocardiography, and prevention of sequelae of thrombus such as stroke or TIA.
2.4.1 Death was reported in 3% (3/100) of patients in the case series of 100 patients (not otherwise described).
2.4.2 Thoracotomy for postoperative bleeding from the LAA was reported in 1 patient in the case series of 15 patients. Intraoperative conversion to mini-thoracotomy to control bleeding was required in 3% (3/100) of patients in the case series of 100 patients.
2.4.3 Conversion to median sternotomy because of severe pleural adhesions was required in 1 patient in a case series of 30 patients; 7% (2/30) of patients required drainage of pneumothorax after removal of chest drains.
2.4.4 Prolonged postoperative air leak and chronic pleuritic pain were each reported in 1 patient in the case series of 15 patients.
2.4.5 Acute subendocardial infarction (recovery within 12 days) was reported in 1 patient in a case series of 81 patients.
2.4.6 The Specialist Advisers listed anecdotal adverse events as incomplete exclusion with residual appendage, and neuralgia from the thoracoscopic port sites.
2.5.1 The Committee considered the prevention of stroke to be the most important efficacy outcome of this procedure. However, its evaluation is complicated by the concomitant use of procedures to ablate AF and the variable use of anticoagulants.
2.5.2 The Committee was advised that new devices are available for this procedure that avoid the use of staples.