Introduction:
This article provides the lawyer and other uninitiated readers with an introduction to the principles and practice of cardiac surgery. Medico-legal problems relating to consent, professional competence, supervision of trainees and peri-operative care are outlined. Liability issues in three cardiac operations - valve surgery, aortic surgery and coronary artery bypass grafts - are discussed.
History and background:
The year 1953 was a significant landmark for patients with heart disease - it was then that John Gibbon performed the first successful 'open heart' procedure in the world using cardiopulmonary bypass (the heart/lung machine). It was rightly hailed as a breakthrough - the downside was that only one of his first four patients survived. Things have changed dramatically in the intervening half century - expected survival for the operation he performed (closure of an atrial septal defect (hole in the heart) is now 100%.
Cardiac surgery is part of the legally defined specialty of cardiothoracic surgery - essentially anything within the chest. Training covers surgery for the heart and great vessels (including the aorta), lungs, oesophagus and mediastinum. Some surgeons focus solely on cardiac surgery, some on thoracic surgery (lungs, oesophagus and mediastinum) while some have a mixed cardiothoracic practice. Cardiac surgery is performed for both congenital (meaning 'born with') heart disease and acquired heart disease - this article will focus on cardiac surgery for acquired heart disease in adults.
Perfusion/cardiopulmonary bypass:
Surgery is referred to as 'open' heart surgery if cardio- pulmonary bypass is used and 'closed' if it is not. Cardiopulmonary bypass is a machine that does the work of the heart and lungs, thus allowing the surgeon to stop the heart and carry out the intended procedure. It essentially consists of an artificial lung and a pump. However, the technology is complex and a perfusionist manages the bypass circuit; they have their own professional body: The Society of Clinical Perfusion Scientists of Great Britain and Ireland.
There are a number of potential medicolegal issues with regard to perfusion.
Preparation of the circuit:
The perfusionist has to prime the circuit with a 'cocktail' of fluid. Errors in priming have lead to serious injury or death of the patient. As the circuit will be connected directly to the patient's arterial system, it is important that all air is evacuated from the circuit before starting the circulation. Any bubbles of gas or particulate matter could cause injury to any of the patient's organs.
Intra-operative perfusion:
The perfusionist has to adjust the flow of gas into the artificial lung to maintain the normal levels of oxygen and car- bon dioxide in the patient. They also have to ensure that there is sufficient volume in the 'reservoir' of the circuit - if the volume falls to low, air could be pumped into the patient's circulation causing stroke or other serious injury.
Temperature:
The temperature of the patient will be adjusted (using the heat exchanger in the circuit) depending on the surgeon's operative strategy. It is important that the patient is neither cooled nor re-warmed too quickly - injury, particularly to the brain, can occur.
The Team:
While the cardiac surgeon is the leader of the team, good teamwork is the key to the successful outcome of the patient - an error by any member can have serious consequences. The team includes the referring cardiologist who is responsible for carrying out the appropriate investigations and making an accurate diagnosis (and from the medico- legal point of view, the one to give reports on condition and prognosis as they are responsible for follow-up). The medical and nursing staff in the ward are responsible for preparing the patient for theatre. In theatre, the team consists of the consultant surgeon plus one or two assistants (depending on the operation).
The anaesthetist is a key member of the team. Cardiothoracic anaesthesia is a subspecialty and the anaesthetists have their own professional body: the Association of Cardiothoracic Anaesthetists. These anaesthetists will have an assistant (either an anaesthetic trainee or a trained anaesthetic nurse/Operating Department assistant). There is a perfusionist and a 'scrub' nurse plus a 'floor/runner' nurse. The average cardiac operation lasts about four hours and so extra staff are needed as back up.
Medico-legal issues occasionally arise with regard to delegation of all or part of the procedure to more junior members of the team. This most often involves surgical trainees - in the past, 'would be' cardiac surgeons trained first in general surgery and then undertook a six-year program of training in cardiothoracic surgery. This was essentially an apprenticeship (no formal assessments) with increasing delegation as training progressed. From 1 August 2007, the Royal Colleges' Intercollegiate Training Committee has set out a clearly defined competence-based curriculum. In future, therefore, trainees will not under- take any part of the procedure without supervision unless they have been signed off as competent.
Another issue is that of a consultant undertaking a new procedure - although many of the operations in cardiac surgery are standard, there have been a number of recent major developments and consultants have had to learn new procedures.
General issues:
A number of issues are common to all cardiac operations.
Consent:
Both the Department of Health and the General Medical Council have produced clear guidelines on consent for surgery - it is a process and not a 'one-off ' signing of a consent form. In best practice the process should begin with a discussion with the consultant surgeon responsible, in advance of admission for surgery. It should include an explanation of the condition and the natural history of the disease process (without surgery). The details of the proposed operation should be explained and an indication of the expected benefits and outcome given (cardiac surgery has an extensive international evidence base for surgery).
Cardiopulmonary bypass:
The role of the perfusionist has been noted above.
â-- Postoperative bleeding: Patients have to be fully anti-coagulated (the blood thinned so it does not clot in the bypass machine) during surgery - this process has to be reversed at the end. Sometimes it is difficult and bleeding is a well-recognized postoperative problem.
â-- Myocardial protection: While the heart is stopped during the procedure, it does not have a blood supply. It is there- fore important that the surgeon uses an appropriate strategy to limit damage to the heart - a not uncommon point in 'Particulars of Claim' is that of 'inadequate myocardial protection'. This is a difficult question as there is no set standard of practice.
â-- Brain damage: Another area that generates claims is that of brain injury following surgery - it is multifactorial in aetiology. Another problem is that, during open heart surgery, the heart is full of air. This air must be removed from the heart at the end of the procedure or air bubbles could travel to the brain causing damage. Inadequate 'de-airing' is another source of claims.
Intensive care:
All patients have a period of 'intensive care' following cardiac surgery. Each patient has an individual nurse who has particular skills in caring for patients in this area.
â-- Medical cover: There is no set pattern in the UK of providing medical cover for intensive care - traditionally this was undertaken by the consultant surgeon assisted by their team, with much of the care delegated to an experienced surgical trainee. The consultant anaesthetist was usually involved with particular regard to management of the respiratory system. Out-of-hours care is a particular thorny issue - the European Working Time Directive now limits the working hours of trainees and this has put significant strain on the traditional pattern of trainees providing resident experienced surgical and anaesthetic cover.
â-- Chest re-opening: Patients are not uncommonly quite unstable and on occasions (particularly in response to sudden bleeding) the patient has to have their chest opened in intensive care. It is a standard of care that all units will have facilities to enable this to happen as soon as possible but the time involved and the personnel responsible are a matter of intense debate at present.
â-- Intra-aortic balloon pump: Often the patient's circulation requires more support than can be provided by drugs. One option is to insert a 'balloon pump' into the descending aorta (main body artery) through the femoral (leg) artery. As many of the patients with heart disease also have disease in their peripheral arteries, ischaemia of the leg is not uncommonly associated with an intra-aortic balloon pump and can lead to amputation. This may generate a medico-legal claim but does not necessarily indicate a breach of duty of care.
â-- Infection: All patients after cardiac surgery are vulnerable to infection - partly because their immune system is functioning less well after major surgery (and cardiopulmonary bypass) and partly because they have invasive intra-arterial and intravenous lines used for monitoring (these lines act as a source of entry for skin bacteria). For this reason, all patients receive prophylactic antibiotics prior to bypass - it is important that these antibiotics have circulated around the body and are in the tissues before the operation starts or they are ineffec- tive.There is no set standard regimen for antibiotic pro- phylaxis.
Incision: median sternotomy:
The standard incision used to approach the heart is the median sternotomy - the sternum (breastbone) is split down the middle using a mechanical saw. In most cases it heals afterwards uneventfully but when it doesn't it causes major problems, often leading to a claim. Underlying structures can be damaged during the sawing process. The innominate vein lies immediately under the top of the sternum damage to it during sawing is a rare but well recognized complication and there is no fail-safe way of preventing it. It is usually repaired without consequence but this has been the subject of a claim. Some patients come back for re-operation; part of the healing process after the first part of the operation is the scar tissue that forms around the heart. This may cause adherence between the heart and the back of the sternum - the heart can be dam- aged directly at sternal re-entry. For this reason, many surgeons would use the femoral (leg) artery to connect the patient to the heart/lung machine. However, femoral bypass carries its own specific complications and has generated medico-legal claims.
Acquired adult heart surgery - specific operations:
Coronary artery bypass grafts (CABG)
In ischaemic heart disease the blood supply to the heart muscle is restricted by blockages inside the coronary arteries. The surgeon uses a conduit to bypass the narrow area in the coronary artery. For the main artery on the front of the heart a 'spare' artery (the left internal mammary artery [LIMA]) from behind the breastbone is used - this is a standard of care. Although a matter of debate, the standard method for the other arteries is to use segments of vein from the lower leg - these have side branches that have to be clipped or tied.
â-- Sudden bleeding postoperatively is a recognized complication but can lead to a claim if there is an adverse outcome. A recent (unsuccessful) case9 was based on res ipsa loquitor - if the side branch bled, it hadn't been secured adequately.
â-- Recurrent angina: some grafts fail immediately or in the early period after surgery - sometimes related to the quality of the conduit or the target vessel but sometimes for technical reasons. Graft failure is not necessarily a breach of duty.
Valve surgery:
Although the heart has four valves, it is the two on the left which usually need surgical attention. The left ventricle is the main pumping chamber of the heart and its function is to pump blood around the body. As a pump it has an inlet valve (mitral) and an outlet valve (aortic). Medico-legal issues can arise in relation to:
â-- consent - the patient needs to be well-informed to be able to choose an appropriate prosthesis;
â-- damage to surrounding structures during implantation - the commonest problem relates to the electrical wiring system of the heart. If it is damaged, a pacemaker will be needed. The back of the heart can tear or disrupt during a mitral valve replacement. Neither are necessarily indications of poor surgical technique;
â--valve dysfunction - technical problems are seen on occasion and ideally an echocardiogram would be performed in the operating theatre. It is good practice to perform an echocardiogram before discharge;
â-- infection (known as endocarditis) - a dreaded complication which can appear early, and so presumably due to infection in theatre (all patients should receive prophylactic antibiotics), or late - the issue of prophylactic antibiotics for dental treatment is currently provoking much controversy.
Aortic surgery:
The aorta is the main body artery - it arises from the heart and passes up to the neck before turning to pass through the chest into the abdomen. Cardiac surgeons deal with the part in the chest. The aorta is prone to dilatation (aneurysm) or dis- section (a process in which the inner lining tears and allows blood into the middle layers of the aorta). Both these processes can lead to rupture and sudden death. Surgery is sometimes undertaken prophylactically or as an emergency. Failure to refer for surgery could be a breach of duty. Aortic surgery carries significant risks (especially in the emergency situation) of brain damage and spinal cord ischaemia leading to paralysis.
Professional organization and scrutiny of performance:
The Society for Cardiothoracic Surgery for Great Britain and Ireland is the professional organization for cardiac surgeons. Individual surgeons have their own web page within the international collaboration CTS Net. The Society holds a list of surgeons who undertake medico-legal work and can be contacted by e-mail. However, it is important to note that this list is held by the Society to facilitate contact between solicitors and surgeons and inclusion on this list does not in any way imply any endorsement by the Society.
Cardiac surgeons have led the way in collecting data on their performance - the Society began collecting (albeit very crude) data in 1977. Believing it was important to pro- vide information to patients, the Society has collaborated with the Healthcare Commission, the press and patient groups in the development of a public database. A recent review of the unit in Oxford by the Healthcare Commission commented: 'there is no other specialty that has collected as much data, in as much detail as cardiac surgery. The diligence of this group of surgeons has resulted in a high level of scrutiny of their performance in a way that is not currently possible for any other surgical specialty.'
When things go wrong it is important that lawyers find an expert witness [http://www.xproexperts.co.uk] with the appropriate background and experience who is able to comment upon, and possibly testify as to the issues at hand.
Cardiac surgeons have demonstrated their desire to provide the highest quality care. However, the number of people involved, the complex nature of the work, the technology used and the variability of patients in their individual risk for cardiac surgery mean that mortality and morbidity can never be eliminated. Medico-legal claims will continue to be an inescapable aspect of practice.
This article provides the lawyer and other uninitiated readers with an introduction to the principles and practice of cardiac surgery. Medico-legal problems relating to consent, professional competence, supervision of trainees and peri-operative care are outlined. Liability issues in three cardiac operations - valve surgery, aortic surgery and coronary artery bypass grafts - are discussed.
History and background:
The year 1953 was a significant landmark for patients with heart disease - it was then that John Gibbon performed the first successful 'open heart' procedure in the world using cardiopulmonary bypass (the heart/lung machine). It was rightly hailed as a breakthrough - the downside was that only one of his first four patients survived. Things have changed dramatically in the intervening half century - expected survival for the operation he performed (closure of an atrial septal defect (hole in the heart) is now 100%.
Cardiac surgery is part of the legally defined specialty of cardiothoracic surgery - essentially anything within the chest. Training covers surgery for the heart and great vessels (including the aorta), lungs, oesophagus and mediastinum. Some surgeons focus solely on cardiac surgery, some on thoracic surgery (lungs, oesophagus and mediastinum) while some have a mixed cardiothoracic practice. Cardiac surgery is performed for both congenital (meaning 'born with') heart disease and acquired heart disease - this article will focus on cardiac surgery for acquired heart disease in adults.
Perfusion/cardiopulmonary bypass:
Surgery is referred to as 'open' heart surgery if cardio- pulmonary bypass is used and 'closed' if it is not. Cardiopulmonary bypass is a machine that does the work of the heart and lungs, thus allowing the surgeon to stop the heart and carry out the intended procedure. It essentially consists of an artificial lung and a pump. However, the technology is complex and a perfusionist manages the bypass circuit; they have their own professional body: The Society of Clinical Perfusion Scientists of Great Britain and Ireland.
There are a number of potential medicolegal issues with regard to perfusion.
Preparation of the circuit:
The perfusionist has to prime the circuit with a 'cocktail' of fluid. Errors in priming have lead to serious injury or death of the patient. As the circuit will be connected directly to the patient's arterial system, it is important that all air is evacuated from the circuit before starting the circulation. Any bubbles of gas or particulate matter could cause injury to any of the patient's organs.
Intra-operative perfusion:
The perfusionist has to adjust the flow of gas into the artificial lung to maintain the normal levels of oxygen and car- bon dioxide in the patient. They also have to ensure that there is sufficient volume in the 'reservoir' of the circuit - if the volume falls to low, air could be pumped into the patient's circulation causing stroke or other serious injury.
Temperature:
The temperature of the patient will be adjusted (using the heat exchanger in the circuit) depending on the surgeon's operative strategy. It is important that the patient is neither cooled nor re-warmed too quickly - injury, particularly to the brain, can occur.
The Team:
While the cardiac surgeon is the leader of the team, good teamwork is the key to the successful outcome of the patient - an error by any member can have serious consequences. The team includes the referring cardiologist who is responsible for carrying out the appropriate investigations and making an accurate diagnosis (and from the medico- legal point of view, the one to give reports on condition and prognosis as they are responsible for follow-up). The medical and nursing staff in the ward are responsible for preparing the patient for theatre. In theatre, the team consists of the consultant surgeon plus one or two assistants (depending on the operation).
The anaesthetist is a key member of the team. Cardiothoracic anaesthesia is a subspecialty and the anaesthetists have their own professional body: the Association of Cardiothoracic Anaesthetists. These anaesthetists will have an assistant (either an anaesthetic trainee or a trained anaesthetic nurse/Operating Department assistant). There is a perfusionist and a 'scrub' nurse plus a 'floor/runner' nurse. The average cardiac operation lasts about four hours and so extra staff are needed as back up.
Medico-legal issues occasionally arise with regard to delegation of all or part of the procedure to more junior members of the team. This most often involves surgical trainees - in the past, 'would be' cardiac surgeons trained first in general surgery and then undertook a six-year program of training in cardiothoracic surgery. This was essentially an apprenticeship (no formal assessments) with increasing delegation as training progressed. From 1 August 2007, the Royal Colleges' Intercollegiate Training Committee has set out a clearly defined competence-based curriculum. In future, therefore, trainees will not under- take any part of the procedure without supervision unless they have been signed off as competent.
Another issue is that of a consultant undertaking a new procedure - although many of the operations in cardiac surgery are standard, there have been a number of recent major developments and consultants have had to learn new procedures.
General issues:
A number of issues are common to all cardiac operations.
Consent:
Both the Department of Health and the General Medical Council have produced clear guidelines on consent for surgery - it is a process and not a 'one-off ' signing of a consent form. In best practice the process should begin with a discussion with the consultant surgeon responsible, in advance of admission for surgery. It should include an explanation of the condition and the natural history of the disease process (without surgery). The details of the proposed operation should be explained and an indication of the expected benefits and outcome given (cardiac surgery has an extensive international evidence base for surgery).
Cardiopulmonary bypass:
The role of the perfusionist has been noted above.
â-- Postoperative bleeding: Patients have to be fully anti-coagulated (the blood thinned so it does not clot in the bypass machine) during surgery - this process has to be reversed at the end. Sometimes it is difficult and bleeding is a well-recognized postoperative problem.
â-- Myocardial protection: While the heart is stopped during the procedure, it does not have a blood supply. It is there- fore important that the surgeon uses an appropriate strategy to limit damage to the heart - a not uncommon point in 'Particulars of Claim' is that of 'inadequate myocardial protection'. This is a difficult question as there is no set standard of practice.
â-- Brain damage: Another area that generates claims is that of brain injury following surgery - it is multifactorial in aetiology. Another problem is that, during open heart surgery, the heart is full of air. This air must be removed from the heart at the end of the procedure or air bubbles could travel to the brain causing damage. Inadequate 'de-airing' is another source of claims.
Intensive care:
All patients have a period of 'intensive care' following cardiac surgery. Each patient has an individual nurse who has particular skills in caring for patients in this area.
â-- Medical cover: There is no set pattern in the UK of providing medical cover for intensive care - traditionally this was undertaken by the consultant surgeon assisted by their team, with much of the care delegated to an experienced surgical trainee. The consultant anaesthetist was usually involved with particular regard to management of the respiratory system. Out-of-hours care is a particular thorny issue - the European Working Time Directive now limits the working hours of trainees and this has put significant strain on the traditional pattern of trainees providing resident experienced surgical and anaesthetic cover.
â-- Chest re-opening: Patients are not uncommonly quite unstable and on occasions (particularly in response to sudden bleeding) the patient has to have their chest opened in intensive care. It is a standard of care that all units will have facilities to enable this to happen as soon as possible but the time involved and the personnel responsible are a matter of intense debate at present.
â-- Intra-aortic balloon pump: Often the patient's circulation requires more support than can be provided by drugs. One option is to insert a 'balloon pump' into the descending aorta (main body artery) through the femoral (leg) artery. As many of the patients with heart disease also have disease in their peripheral arteries, ischaemia of the leg is not uncommonly associated with an intra-aortic balloon pump and can lead to amputation. This may generate a medico-legal claim but does not necessarily indicate a breach of duty of care.
â-- Infection: All patients after cardiac surgery are vulnerable to infection - partly because their immune system is functioning less well after major surgery (and cardiopulmonary bypass) and partly because they have invasive intra-arterial and intravenous lines used for monitoring (these lines act as a source of entry for skin bacteria). For this reason, all patients receive prophylactic antibiotics prior to bypass - it is important that these antibiotics have circulated around the body and are in the tissues before the operation starts or they are ineffec- tive.There is no set standard regimen for antibiotic pro- phylaxis.
Incision: median sternotomy:
The standard incision used to approach the heart is the median sternotomy - the sternum (breastbone) is split down the middle using a mechanical saw. In most cases it heals afterwards uneventfully but when it doesn't it causes major problems, often leading to a claim. Underlying structures can be damaged during the sawing process. The innominate vein lies immediately under the top of the sternum damage to it during sawing is a rare but well recognized complication and there is no fail-safe way of preventing it. It is usually repaired without consequence but this has been the subject of a claim. Some patients come back for re-operation; part of the healing process after the first part of the operation is the scar tissue that forms around the heart. This may cause adherence between the heart and the back of the sternum - the heart can be dam- aged directly at sternal re-entry. For this reason, many surgeons would use the femoral (leg) artery to connect the patient to the heart/lung machine. However, femoral bypass carries its own specific complications and has generated medico-legal claims.
Acquired adult heart surgery - specific operations:
Coronary artery bypass grafts (CABG)
In ischaemic heart disease the blood supply to the heart muscle is restricted by blockages inside the coronary arteries. The surgeon uses a conduit to bypass the narrow area in the coronary artery. For the main artery on the front of the heart a 'spare' artery (the left internal mammary artery [LIMA]) from behind the breastbone is used - this is a standard of care. Although a matter of debate, the standard method for the other arteries is to use segments of vein from the lower leg - these have side branches that have to be clipped or tied.
â-- Sudden bleeding postoperatively is a recognized complication but can lead to a claim if there is an adverse outcome. A recent (unsuccessful) case9 was based on res ipsa loquitor - if the side branch bled, it hadn't been secured adequately.
â-- Recurrent angina: some grafts fail immediately or in the early period after surgery - sometimes related to the quality of the conduit or the target vessel but sometimes for technical reasons. Graft failure is not necessarily a breach of duty.
Valve surgery:
Although the heart has four valves, it is the two on the left which usually need surgical attention. The left ventricle is the main pumping chamber of the heart and its function is to pump blood around the body. As a pump it has an inlet valve (mitral) and an outlet valve (aortic). Medico-legal issues can arise in relation to:
â-- consent - the patient needs to be well-informed to be able to choose an appropriate prosthesis;
â-- damage to surrounding structures during implantation - the commonest problem relates to the electrical wiring system of the heart. If it is damaged, a pacemaker will be needed. The back of the heart can tear or disrupt during a mitral valve replacement. Neither are necessarily indications of poor surgical technique;
â--valve dysfunction - technical problems are seen on occasion and ideally an echocardiogram would be performed in the operating theatre. It is good practice to perform an echocardiogram before discharge;
â-- infection (known as endocarditis) - a dreaded complication which can appear early, and so presumably due to infection in theatre (all patients should receive prophylactic antibiotics), or late - the issue of prophylactic antibiotics for dental treatment is currently provoking much controversy.
Aortic surgery:
The aorta is the main body artery - it arises from the heart and passes up to the neck before turning to pass through the chest into the abdomen. Cardiac surgeons deal with the part in the chest. The aorta is prone to dilatation (aneurysm) or dis- section (a process in which the inner lining tears and allows blood into the middle layers of the aorta). Both these processes can lead to rupture and sudden death. Surgery is sometimes undertaken prophylactically or as an emergency. Failure to refer for surgery could be a breach of duty. Aortic surgery carries significant risks (especially in the emergency situation) of brain damage and spinal cord ischaemia leading to paralysis.
Professional organization and scrutiny of performance:
The Society for Cardiothoracic Surgery for Great Britain and Ireland is the professional organization for cardiac surgeons. Individual surgeons have their own web page within the international collaboration CTS Net. The Society holds a list of surgeons who undertake medico-legal work and can be contacted by e-mail. However, it is important to note that this list is held by the Society to facilitate contact between solicitors and surgeons and inclusion on this list does not in any way imply any endorsement by the Society.
Cardiac surgeons have led the way in collecting data on their performance - the Society began collecting (albeit very crude) data in 1977. Believing it was important to pro- vide information to patients, the Society has collaborated with the Healthcare Commission, the press and patient groups in the development of a public database. A recent review of the unit in Oxford by the Healthcare Commission commented: 'there is no other specialty that has collected as much data, in as much detail as cardiac surgery. The diligence of this group of surgeons has resulted in a high level of scrutiny of their performance in a way that is not currently possible for any other surgical specialty.'
When things go wrong it is important that lawyers find an expert witness [http://www.xproexperts.co.uk] with the appropriate background and experience who is able to comment upon, and possibly testify as to the issues at hand.
Cardiac surgeons have demonstrated their desire to provide the highest quality care. However, the number of people involved, the complex nature of the work, the technology used and the variability of patients in their individual risk for cardiac surgery mean that mortality and morbidity can never be eliminated. Medico-legal claims will continue to be an inescapable aspect of practice.