SummaryWe present a woman in her first pregnancy, with known aortic stenosis prior to conception, who successfully underwent regional anaesthesia for an elective Caesarean section using a subarachnoid microcatheter. The anaesthetic management of patients with aortic stenosis requiring noncardiac surgery is a complex and contentious matter, particularly when the situation is compounded by the physiological changes accompanying pregnancy and delivery. This is the first reported use of a subarachnoid microcatheter in such a patient. The choice of technique is discussed and compared with other options for providing anaesthesia. Patients with aortic stenosis are at risk of increased morbidity and mortality when undergoing anaesthesia [1]. Their compensatory left ventricular hypertrophy renders them vulnerable to ischaemia and they are difficult to resuscitate [2]. The added stress of the physiological changes of pregnancy and delivery can result in an unstable situation with maternal mortality being quoted as 17% and a perinatal mortality of 32% [3]. The choice of anaesthetic should be appropriate to the well-being of both mother and fetus. There are very few reports in the literature regarding the anaesthetic management of patients with aortic stenosis requiring delivery by Caesarean section [4][5][6][7] and the successful use of a subarachnoid microcatheter for this procedure has not been previously reported.
Case historyA 21-year-old Asian primigravida, known to have aortic stenosis, presented for an elective Caesarean section at 36 weeks gestation. Prior to conception she had been under review by a cardiologist and at this time she had no cardiac-related symptoms and was otherwise fit and well. She was noted to have an ejection systolic murmur graded 4/6 and a pressure gradient across the valve, estimated by echocardiography, of 48 mmHg. Her electrocardiograph (ECG) was normal.Her pregnancy had progressed uneventfully and, when reviewed by the cardiologist at 16 weeks gestation, she was normotensive, in sinus rhythm and there had been a slight increase in her pressure gradient to 57 mmHg. The echocardiograph showed good left ventricular function with no significant hypertrophy. The decision was made by her consultant obstetrician to deliver the baby by Caesarean section at 36 weeks gestation and she was referred for an anaesthetic opinion.Twenty-four hours prior to surgery she was found to be fit and well, in sinus rhythm, normotensive and with no signs or symptoms of cardiac failure. After a full discussion with the patient and having explained the advantages and disadvantages of both general and regional anaesthesia it was decided to employ a regional anaesthetic technique. It was felt that the use of a spinal microcatheter would allow precise titration of local anaesthetic to effect and thereby minimise physiological changes.Following an overnight fast and routine gastric acid prophylaxis, the patient was transferred to the delivery suite anaesthetic room. A 14 gauge peripheral cannula was inserted under local...