JAP  Volume 7 Issue 1 Feature


Table 5: List of investigations commonly performed prior to TAVI Assessment


Investigations


Left ventricular function, Severity of stenosis, Other valvular functions


Aortic annulus diameter (to determine transcathter)


Transthoracic ot transoesophageal echocardiography (TTE or TOE)


TTE, TOE or CT angiogram


Detect coronary artery disease Coronary angiography Anatomy of access vessels


Table 7: Advantages of general anaesthesia Advantages of general anaesthesia


• Patient immobility – facilitates positioning of valve prosthesis • Neuromuscular blockade –control of respiratory movement • Allows use of intraoperative TOE – aids continuous visualisation of aortic valve.


• Secure airway with tracheal tube • Favourable for patients who may not tolerate supine position for a long duration


• Facilitates surgical repair of vascular access site.


remodelling or haemodynamic instability, warranting further intervention. Incorrect valve sizing may result in annulus rupture and cardiovascular collapse during deployment. Perforation of the right ventricle by a transvenous pacing wire or perforation of the aorta by a catheter is likely to result in pericardial bleeding and cardiac tamponade.


Neurological complications Stroke is one of the most feared complications following TAVI. Embolisation from native calcified valve leaflets is thought to be the main causative factor. Although clinically silent embolism is noted in 73 percent,10


permanent neurological deficit.11 protection devices have reported encouraging results.12,13


Acute kidney injury Acute kidney injury is reported in six percent of patients following TAVI with 1.8 percent requiring temporary renal replacement.11 The cause is often multi-factorial – both patient-related (diabetes, hypertension, pre-existing) and procedure-related (hypotensive episodes, radiocontrast agent, embolisation of calcific debris) factors are likely to contribute. Adequate preoperative and postoperative hydration, maintenance of renal perfusion pressure and avoidance of nephrotoxic drugs are the main strategies to preserve kidney function. Complications of TAVI are listed in Table 8.


Conclusion TAVI is an emerging less-invasive approach to surgical AVR and


there is a growing body of evidence to support the benefits of TAVI in selected high-risk patients. Minimising surgical trauma by avoiding median sternotomy, cardiopulmonary bypass and cardioplegic cardiac arrest is the rationale behind TAVI. A number of studies have compared the outcomes of TAVI with


standard medical treatment and surgical AVR. Of note is the PARTNER trial, in which high-risk patients were randomised to either surgical


28 www.japractice.com


Table 6: Advantages of ‘local anaesthesia with conscious sedation’ compared with general anaesthesia.


Advantages of local anaesthesia with conscious sedation


• Relatively less haemodynaemic instability; less intraoperative requirement of catecholamines


• Ability to monitor neurologic status during the procedure (because of risk of stroke)


Iliofemoral or CT angiography


• Early recovery • Early mobility • Shorter hosputal stay • High-risk patients like thosewith chronic pulmonary disease could benefit as complications like prolonged ventilation is avoided.


Table 8: Complications of TAVI Intra-operative complications


• Myocardial ischaemia or infaraction • Conduction block • Cardiac arrhythmia • Rupture of aortic root or annulus • Cardiac tamponade (RV or LV perforation)


• Paravalvular regurgitation • Valave embolisation or migration • Access femoral arterial injury


Post-operative complications


• Delirium • Seizure • Stroke • LV pseudo-aneurysm • Bleeding requiring re-invention


• Acute kidney injury


AVR or TAVI. Although there was slight increase in peri-procedure risks (stroke and vascular complications) in the TAVI group at 30 days,14 this was compensated by similar mortality rate and symptomatic improvement in both groups at two years follow-up.15


The same


investigators randomised another group of high-risk ‘inoperable’ patients to either TAVI or standard medical therapy including balloon valvuloplasty. There was significant improvement in quality of life and decreased mortality rate in the TAVI group both at two year follow- up.17


A recent evidence-based analysis has concluded that TAVI is


cost-effective for those patients who could not undergo surgery.18 As technologies continue to develop, the technique is gradually


only about 4.5 percent of patients suffer from A few small trials using embolic


evolving to be used in younger patient age groups with severe comorbidities.19


Cardiothoracic anaesthetists will continue to play a


major participative role in developing the standard of care for this high-risk patient group. ■


JAP 2013: 1: 24-29


Dr Stephen T Webb Dr Webb is a Consultant in


Anaesthesia & Intensive Care at Papworth Hospital NHS Foundation Trust in Cambridge. Dr Webb trained in anaesthesia and


intensive care medicine in Northern Ireland and Cambridge before being appointed as Consultant in Intensive Care & Anaesthesia at Papworth Hospital in 2008. His clinical and research interests lie in cardiothoracic anaesthesia, cardiothoracic intensive care and patient safety.


Dr Gokulnath Rajendran Specialist Trainee in Anaesthesia at Papworth Hospital.


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