trial was reasonable, given the investigators' stated intention of examining the response of patients with mild as well as moderately severe depressive disorder. The organisers could be criticised for failing to stratify the sample to allow a statistical comparison of the two kinds of case, but this is not one of the points raised. The criticism of the investigators' null hypothesis is more difficult to understand because the hypothesis was the usual one, that there would be no differences between treatments. Neither criticism justifies the surprising statement that the trial could be considered unethical. Drs Snaith and Tombs criticise the state of research into treatment for depressive disorders and, it seems, a wider range of psychiatric illness. In doing so, however, they make two contradictory statements-firstly, that it is known that all the therapeutic techniques tested in the trial are known to be effective in the right conditions and, secondly, that the subject is in a state of confusion. In fact there is a substantial body of research into the treatment of depressive disorders from which reasonably clear guidance can be drawn about the use of drug treatment. Less is known about the effects of psychological treatment; hence the National Institute of Mental Health conducted a trial. For other conditions treated by psychiatrists such as anxiety disorders there is research to guide the selection of psychological as well as drug treatment. The editorial gave guidance about the treatment of mild to moderate depressive disorders -essentially that drugs are the first choice, with psychological treatment a second line of treatment in circumstances that were described. The National Institute of Mental Health trial is not perfect in its design but it is an important study that deserves measured consideration. In any case, as noted in the editorial, it is unwise to pass judgment until the full results have been published. M G GELDER
University of Oxford, Warneford Hospital, Oxford OX3 7JX
Coronary artery bypass surgery SIR,-Messrs E W J Cameron and W S Walker present their view of the current state of coronary artery surgery.' At Papworth Hospital in the past year 90% of all patients undergoing isolated coronary artery bypass grafting or combined procedures, including emergencies, received unilateral or bilateral internal mammary grafts. We disagree with most of the authors' contraindications to using the internal mammary artery. There is litle anatomical restriction on its application if both right and left internal mammary arteries and lengthening procedures, where necessary, are used.2 Grafting of the internal mammary artery can be used in patients with crescendo angina (without haemodynamic instability), left ventricular hypertrophy, and left main stem disease with clear long term benefit' and improved early survival in certain subgroups compared with conventional vein grafting.4" Pulmonary hyperinflation rarely, if ever, contraindicates use of the internal mammary artery. We consider the main contraindication to its use to be emergency revascularisation in patients with severe haemodynamic instability who have failed angioplasty or extensive subclavian atheroma. Messrs Cameron and Walker conclude that increasing use of the internal mammary artery is indicated. We believe that this is somewhat cautious and that the use of the internal mammary artery as a graft to the left anterior descending coronary artery should be mandatory." Current discussion centres on whether bilateral internal mammary grafts, either pedicled or free, and other arterial conduits such as the right gastroepiploic offer significant late advantages over a single
1588
internal mammary artery graft to the left anterior descending coronary artery.46 Complete revascularisation at the time of the primary procedure should still be the goal, bypassing stenoses of 70% of the luminal diameter or more and 50% or more in the left main coronary artery. Incomplete revascularisation according to these criteria has clearly been shown to be a primary predictor of recurrent angina and the need for repeated surgery. There is no reason to change such a recommendation other than on the basis of prospective trials similar to those already conducted. The suggestion that the results of run off measurement should guide the surgeon seems to us ill advised because measurements of graft flow or coronary resistance to flow have never been shown to be of practical value. Our approach to coronary artery bypass grafting into the next decade will comprise routine use of the left internal mammary artery and complete revascularisation at the primary procedure. We will increasingly use bilateral, sequential, and free internal mammary grafts and evaluate other autologous arterial conduits. ALAN J BRYAN SIMON W KENDALL STEPHEN R LARGE JOHN WALLWORK
Papworth Hospital,
Cambridge CB3 8RE I Cameron EWJ, Walker WS. Coronary artery bypass surgery. BrMed3' 1990;300:1219-20. (12 May.) 2 Cosgrove DM, Loop FD. Techniques to maximize mammary artery length. Ann Thorac Surg 1985;40:78-9. 3 Cameron A, Davis KB, Green GE, Myers WO, Pettinger M. Clinical implications of internal mammary artery bypass grafts: the coronary artery surgery study experience. Circulation 1988;77:815-9. 4 Kirklin JW, Naftel DC, Blackstone EH, Pohost GM. Summary of a consensus concerning death and ischaemic events
after coronary artery bypass grafting. Circulation 1989; 79(suppl I):81-91. 5 Loop FD, Lytle BW, Cosgrove DM, et al. Influence of the internal mammary artery graft on 10 year survival and other cardiac events. N Engli Med 1986;314:1-6. 6 Loop FD, Lytle BW, Cosgrove DM. New arteries for old. Circulation 1989;79 (suppl I):40-5. 7 Lvtle BW, Loop FD, Cosgrove DM, et al. Fifteen hundred coronary reoperations. Results and determinants of early and late survival. 7 Thorac Cardiovasc Surg 1987;3:847-59.
I Holton A, Tvrer P. Five year outcome in patients withdrawn from long term treatment with diazepam. Br Med7 1990;300: 1241-2. (12 May.) 2 Cowen PJ, Nutt DJ. Abstinence symptoms after withdrawal of tranquillising drugs. Is there a common neurochemical mechanism? Lancet 1982;ii:360-2.
Audit of amniocentesis SIR,-We would like to comment on three points raised in the article by J J Wiener and colleagues.' Firstly, in centres with the necessary skill in ultrasound scanning and with today's real time equipment, it is now routine to investigate raised serum maternal a fetoprotein concentration using high resolution ultrasound alone.2 Indeed, the value of using the blood test to screen for neural tube defects in centres that can offer skilled ultrasound scanning to all women booking at 18 weeks' gestation is questionable. None the less, its value in screening for fetuses with Down's syndrome and associated intrauterine growth retardation may be sufficient reason for retaining it.
Secondly, amniocentesis without direct ultrasonic guidance should be discouraged.2 Amniocentesis under ultrasonic guidance avoids the risk of making contact with the fetus; minimises the chance of traversing the placenta (or at least enables the operator to avoid umbilical cord insertion); and decreases the number of negative attempts, bloodstained taps, and pregnancy loss by factors of three, two, and seven.3 Satisfactory visualisation can be obtained using standard ultrasound machines. Finally, obstetricians should be taught to perform amniocentesis with ultrasonic guidance under the supervision of skilled teachers before performing amniocentesis alone. When obstetricians are familiar with this technique they can learn chorionic villus sampling and other invasive diagnostic techniques.4 J S SMOLENIEC D K JAMES Bristol Maternity Hospital, Bristol BS2 8EG P A SMITH
Southmead Hospital, Bristol BS1O 5NB
Patients withdrawn from benzodiazepines SIR,-Dr Anthony Holton and Peter Tyrer report that 27 of 39 patients withdrawn from long term treatment with diazepam had been prescribed benzodiazepines during the five year follow up period and that 13 had managed to stop the drugs again.' The apparent ability to stop and start such drugs appears to be quite unlike the pattern of dependence which is found in the alcohol dependency syndrome, which may share a common biochemical basis with benzodiazepine dependency.2 In my view this paper underlines the difficulty in assessing dependency on benzodiazepines. Habitual use, even amounting to the patient's perception of inability to discontinue the drugs, does not constitute a physical dependency syndrome. It may be that studies of individuals said to be dependent on benzodiazepines would benefit from recruitment of patients who had experienced distinct withdrawal illnesses including not only affective change but seizures or perceptual abnormalities-symptoms outwith the neurosis for which the drugs were prescribed in the first place. The presence of such symptoms after benzodiazepine withdrawal constitutes the only firm criterion on which the diagnosis of dependency can be made. MARTIN G LIVINGSTON Department of Psychological Medicine, University of Glasgow, Glasgow G12 OAA
1 Weiner JJ, Farrow A, Farrow SC. Audit of amniocentesis from a district general hospital: is it worth it? Br Med J 1990;300: 1243-5. (12 May.) 2 Campbell S, Smith PA, Pearce JM. 'rhe ultrasound diagnosis of neural tube defects and other cranio-spinal abnormalities. Prenatal diagnosis. In: Proceedings of the eleventh study group of the Rosal College of Obstetricians and Gynaecologists. London: Royal College of Obstetricians and Gynaecologists, 1983: 254-7. 3 Working Partv on Amniocentesis. An assessment of the hazards of amniocentesis. Brj Obstet Gynaecol 1978;85:1-41. 4 Nicolaides KH, Soothill PW. Cordocentesis. In: Studd J, ed. Progress in obstetrncs and gynaecology. Vol 7. Edinburgh: Churchill Lisingstone, 1989:123-5.
Consumers in the new NHS SIR,-Professor Rudolph Klein highlighted the need for the consumer's voice to be heard when Working for Patients is implemented. Outpatient and inpatient services must be monitored and quality and provision of treatment must indeed be safeguarded for the population. Professor Klein suggested, however, that community health councils should do this and that they would require access to more specialist skills. Public health consultants are already trained in these skills and better placed to fulfil this function, perhaps in conjunction with community health councils. KATE MACKAY
Department of Public Health Medicinc, Lothian Health Board, Edinburgh I Klcin R. Looking after consumers in the new NHS. Br Med ] 1990;300:1351-2. (26 May.)
BMJ VOLUME 300
16 JUNE 1990
University of Oxford, Warneford Hospital, Oxford OX3 7JX
Coronary artery bypass surgery SIR,-Messrs E W J Cameron and W S Walker present their view of the current state of coronary artery surgery.' At Papworth Hospital in the past year 90% of all patients undergoing isolated coronary artery bypass grafting or combined procedures, including emergencies, received unilateral or bilateral internal mammary grafts. We disagree with most of the authors' contraindications to using the internal mammary artery. There is litle anatomical restriction on its application if both right and left internal mammary arteries and lengthening procedures, where necessary, are used.2 Grafting of the internal mammary artery can be used in patients with crescendo angina (without haemodynamic instability), left ventricular hypertrophy, and left main stem disease with clear long term benefit' and improved early survival in certain subgroups compared with conventional vein grafting.4" Pulmonary hyperinflation rarely, if ever, contraindicates use of the internal mammary artery. We consider the main contraindication to its use to be emergency revascularisation in patients with severe haemodynamic instability who have failed angioplasty or extensive subclavian atheroma. Messrs Cameron and Walker conclude that increasing use of the internal mammary artery is indicated. We believe that this is somewhat cautious and that the use of the internal mammary artery as a graft to the left anterior descending coronary artery should be mandatory." Current discussion centres on whether bilateral internal mammary grafts, either pedicled or free, and other arterial conduits such as the right gastroepiploic offer significant late advantages over a single
1588
internal mammary artery graft to the left anterior descending coronary artery.46 Complete revascularisation at the time of the primary procedure should still be the goal, bypassing stenoses of 70% of the luminal diameter or more and 50% or more in the left main coronary artery. Incomplete revascularisation according to these criteria has clearly been shown to be a primary predictor of recurrent angina and the need for repeated surgery. There is no reason to change such a recommendation other than on the basis of prospective trials similar to those already conducted. The suggestion that the results of run off measurement should guide the surgeon seems to us ill advised because measurements of graft flow or coronary resistance to flow have never been shown to be of practical value. Our approach to coronary artery bypass grafting into the next decade will comprise routine use of the left internal mammary artery and complete revascularisation at the primary procedure. We will increasingly use bilateral, sequential, and free internal mammary grafts and evaluate other autologous arterial conduits. ALAN J BRYAN SIMON W KENDALL STEPHEN R LARGE JOHN WALLWORK
Papworth Hospital,
Cambridge CB3 8RE I Cameron EWJ, Walker WS. Coronary artery bypass surgery. BrMed3' 1990;300:1219-20. (12 May.) 2 Cosgrove DM, Loop FD. Techniques to maximize mammary artery length. Ann Thorac Surg 1985;40:78-9. 3 Cameron A, Davis KB, Green GE, Myers WO, Pettinger M. Clinical implications of internal mammary artery bypass grafts: the coronary artery surgery study experience. Circulation 1988;77:815-9. 4 Kirklin JW, Naftel DC, Blackstone EH, Pohost GM. Summary of a consensus concerning death and ischaemic events
after coronary artery bypass grafting. Circulation 1989; 79(suppl I):81-91. 5 Loop FD, Lytle BW, Cosgrove DM, et al. Influence of the internal mammary artery graft on 10 year survival and other cardiac events. N Engli Med 1986;314:1-6. 6 Loop FD, Lytle BW, Cosgrove DM. New arteries for old. Circulation 1989;79 (suppl I):40-5. 7 Lvtle BW, Loop FD, Cosgrove DM, et al. Fifteen hundred coronary reoperations. Results and determinants of early and late survival. 7 Thorac Cardiovasc Surg 1987;3:847-59.
I Holton A, Tvrer P. Five year outcome in patients withdrawn from long term treatment with diazepam. Br Med7 1990;300: 1241-2. (12 May.) 2 Cowen PJ, Nutt DJ. Abstinence symptoms after withdrawal of tranquillising drugs. Is there a common neurochemical mechanism? Lancet 1982;ii:360-2.
Audit of amniocentesis SIR,-We would like to comment on three points raised in the article by J J Wiener and colleagues.' Firstly, in centres with the necessary skill in ultrasound scanning and with today's real time equipment, it is now routine to investigate raised serum maternal a fetoprotein concentration using high resolution ultrasound alone.2 Indeed, the value of using the blood test to screen for neural tube defects in centres that can offer skilled ultrasound scanning to all women booking at 18 weeks' gestation is questionable. None the less, its value in screening for fetuses with Down's syndrome and associated intrauterine growth retardation may be sufficient reason for retaining it.
Secondly, amniocentesis without direct ultrasonic guidance should be discouraged.2 Amniocentesis under ultrasonic guidance avoids the risk of making contact with the fetus; minimises the chance of traversing the placenta (or at least enables the operator to avoid umbilical cord insertion); and decreases the number of negative attempts, bloodstained taps, and pregnancy loss by factors of three, two, and seven.3 Satisfactory visualisation can be obtained using standard ultrasound machines. Finally, obstetricians should be taught to perform amniocentesis with ultrasonic guidance under the supervision of skilled teachers before performing amniocentesis alone. When obstetricians are familiar with this technique they can learn chorionic villus sampling and other invasive diagnostic techniques.4 J S SMOLENIEC D K JAMES Bristol Maternity Hospital, Bristol BS2 8EG P A SMITH
Southmead Hospital, Bristol BS1O 5NB
Patients withdrawn from benzodiazepines SIR,-Dr Anthony Holton and Peter Tyrer report that 27 of 39 patients withdrawn from long term treatment with diazepam had been prescribed benzodiazepines during the five year follow up period and that 13 had managed to stop the drugs again.' The apparent ability to stop and start such drugs appears to be quite unlike the pattern of dependence which is found in the alcohol dependency syndrome, which may share a common biochemical basis with benzodiazepine dependency.2 In my view this paper underlines the difficulty in assessing dependency on benzodiazepines. Habitual use, even amounting to the patient's perception of inability to discontinue the drugs, does not constitute a physical dependency syndrome. It may be that studies of individuals said to be dependent on benzodiazepines would benefit from recruitment of patients who had experienced distinct withdrawal illnesses including not only affective change but seizures or perceptual abnormalities-symptoms outwith the neurosis for which the drugs were prescribed in the first place. The presence of such symptoms after benzodiazepine withdrawal constitutes the only firm criterion on which the diagnosis of dependency can be made. MARTIN G LIVINGSTON Department of Psychological Medicine, University of Glasgow, Glasgow G12 OAA
1 Weiner JJ, Farrow A, Farrow SC. Audit of amniocentesis from a district general hospital: is it worth it? Br Med J 1990;300: 1243-5. (12 May.) 2 Campbell S, Smith PA, Pearce JM. 'rhe ultrasound diagnosis of neural tube defects and other cranio-spinal abnormalities. Prenatal diagnosis. In: Proceedings of the eleventh study group of the Rosal College of Obstetricians and Gynaecologists. London: Royal College of Obstetricians and Gynaecologists, 1983: 254-7. 3 Working Partv on Amniocentesis. An assessment of the hazards of amniocentesis. Brj Obstet Gynaecol 1978;85:1-41. 4 Nicolaides KH, Soothill PW. Cordocentesis. In: Studd J, ed. Progress in obstetrncs and gynaecology. Vol 7. Edinburgh: Churchill Lisingstone, 1989:123-5.
Consumers in the new NHS SIR,-Professor Rudolph Klein highlighted the need for the consumer's voice to be heard when Working for Patients is implemented. Outpatient and inpatient services must be monitored and quality and provision of treatment must indeed be safeguarded for the population. Professor Klein suggested, however, that community health councils should do this and that they would require access to more specialist skills. Public health consultants are already trained in these skills and better placed to fulfil this function, perhaps in conjunction with community health councils. KATE MACKAY
Department of Public Health Medicinc, Lothian Health Board, Edinburgh I Klcin R. Looking after consumers in the new NHS. Br Med ] 1990;300:1351-2. (26 May.)
BMJ VOLUME 300
16 JUNE 1990
