Who is in the operating room during surgery?
The surgical team present during a heart operation are: The cardiovascular surgeon, who leads the surgical team and performs the key parts of the surgery. Assisting surgeons, who follow the direction of the cardiovascular surgeon. A cardiovascular anaesthesiologist, who gives the medicines that make you sleep during the surgery (called anaesthesia). The anaesthesiologist makes sure that you get the right amount of medicines throughout the surgery and monitors the ventilator, a machine which breathes for you during surgery. A perfusion technologist, who operates the heart-lung machine. Cardiovascular theater nurses, who are specially trained to assist in heart surgery.
Having a General Anaesthetic
The exact type of anaesthetic you are given depends on the procedure you are having. For most operations, anaesthesia is started by injecting a drug into your vein. Within seconds you will fall asleep and won’t wake up again until after your operation is completed. This is known as the ‘induction’ of anaesthesia. It is also possible to bring about anaesthesia with anaesthetic gases, breathed through a face mask. Your anaesthetist will decide what is best for you and will stay with you during the operation.
To keep you asleep, you will be given a mixture of oxygen and anaesthetic gases through a flexible tube put into your windpipe. This part of anaesthesia is known as ‘maintenance’.
During the operation, you will be connected to machines that monitor the activity of your heart and other bodily organs. Your anaesthetist will keep a close check on your heart rate, blood pressure, and the amount of oxygen in your bloodstream.
What is a heart-lung machine?
The heart-lung machine is also called a cardiopulmonary bypass machine. It takes control of blood flow around the body during the operation by replacing the heart’s pumping action and by adding oxygen to the blood. This helps the heart to remain stationary for the operation, which is necessary when the heart has to be opened (open heart surgery). Because the heart-lung machine takes over the work of the heart, a surgeon can more easily operate as the heart is not moving or full of blood.
How does the heart-lung machine work?
The heart-lung machine carries blood from the right side of the heart (the right atrium) to a reservoir within the machine called an oxygenator. Inside the oxygenator, oxygen is bubbled through the blood allowing it to enter into red blood cells. This causes the blood to turn from dark (oxygen-poor) to bright red (oxygen-rich). A filter then removes the air bubbles from the oxygen-rich blood, and the blood travels back to the body’s main blood vessel, called the aorta. The aorta supplies the newly oxygenated blood to rest of the body in a continuous process of blood circulation. Specially trained technicians called perfusion technologists (blood flow specialists) make sure that the heart-lung machine does its job properly during the surgery.
The heart-lung bypass machine provides a very safe and effective service which can take over the work of the heart and lungs for hours. However, your surgeon will try to limit the time that you spend on the machine to ensure that your body returns to is normal physiological function as soon as possible.
Mini cardiopulmonary bypass
This is also a heart-lung machine but in a miniature form. It guarantees a higher percentage of red cells (especially for patients of small statue and weight) and is equipped with biocompatible surfaces both of which can help to protect the function of your kidneys, especially for high risk operations.
Mini cardiopulmonary bypass is associated with reduced bleeding following the operation, and possibly, a lower transfusion rate and lower incidence of peripheral thromboembolic events.
What are cooling techniques?
Cooling techniques help the surgeon to increase the amount of time they can operate on the heart without damaging it. Cool temperatures help to reduce the activity (metabolism) of the heart’s tissues. The heart may be cooled in 2 ways:
- Blood is cooled as it passes through the heart-lung machine. In turn, the cooled blood lowers total body temperature.
- Cold salt-water (saline) is poured over the heart.
It is usually necessary to inject a special potassium solution (called cardioplegia) into the heart which speeds up the process of stopping the heart from beating (moving) therefore enabling the surgeon to start performing the operation.
Mini and endoscopic access surgery
Mini sternotomy (vertical incision made in the centre of the chest)
Mini sternotomy is a specialised technique which uses a small vertical incision along the skin in the centre of the chest in order to open the sternum (breastbone). The advantage of this technique is that it produces better cosmetic results without causing risk to the way the surgery is performed. Unlike the conventional sternotomies which extend for a length of 25-30cm and cause an extensive length of tissue damage, mini sternotomy has a length of only 10-15cm and preserves the skin and underlying tissues.
Mini sternotomy leaves the patient with a smaller scar that is located lower than a conventional scar. It can enable the patient to wear a lower neck line garment without fear of the scar showing, and it is often well hidden on men with chest hair or within women’s cleavage. The full cosmetic outcome can be assessed after a period of 3 months when the incision is almost fully healed and incorporated into the patients’ body.
Mini and endoscopic conduit harvesting (Radial artery and leg vein removal)
Minimaly invasive conduit harvesting is a technique used to remove the radial artery from your forearm or the long saphenous vein from your leg using less invasive techniques, so that it can be used as a graft for bypassing the diseased coronary artery of your heart. Conventional techniques involve a long vertical cut which must be made deep into the leg tissues to expose the artery or the vein.
The conventional procedures of harvesting arteries and veins (long incisions) have high rate of complications which can include cellulitis, blood clots, neuralgia and ischemic sequelae, delayed in wound healing, necrosis and infections. These post operative complications are frequently associated with peripheral vascular artery disease, obesity, diabetes, female sex, preoperative steroid treatment, and anaemia. In addition to complications, the patient may experience discomfort from the leg wound that may restrict their mobilisation during the first 6 weeks following the operation.
Minimally invasive – endoscopic conduit harvesting is an advanced method of artery or vein removal, which has a low complication rate and excellent cosmetic results. The artery or vein is removed with the help of special surgical instruments and specialist surgical techniques which ensure that the quality of the removed vein is maintained. This method also ensures that trauma to the patients’ forearms or legs is minimised and blood loss is restricted to an absolute minimum. Patients can put weight on their leg and use their hands on the first day following their operation and mobilise free from the discomfort of long painful leg scars. Healing of the small wounds is complete after 3 months and the cosmetic outcome is very pleasing .
Fully endoscopic arterial and vein harvesting reduces the number of small incisions required to remove the vein, leaving only 2-3 small scars. However, it requires the use of special “single use” equipment at an additional cost to enable the surgical team to harvest the arteries and veins with direct vision. The cosmetic and functional result of this method is the most superior of all techniques used for peripheral arteries and veins harvesting.
- Mid-term outcomes for Endoscopic versus Open Vein Harvest: a case control study. Kirmani BH, Barnard JB, Mourad F, Blakeman N, Chetcuti K, Zacharias J. J Cardiothorac Surg. 2010 May 28;5:44.
- Is it safe to perform endoscopic vein harvest? Tennyson C, Young CP, Scarci M. Interact Cardiovasc Thorac Surg. 2010 Apr;10(4):625-9.
- 2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines.Society of Thoracic Surgeons Blood Conservation Guideline Task Force,Ferraris VA, Brown JR, Despotis GJ, Hammon JW, Reece TB, Saha SP, Song HK, Clough ER; Society of Cardiovascular Anesthesiologists Special Task Force on Blood Transfusion, Shore-Lesserson LJ, Goodnough LT, Mazer CD, Shander A, Stafford-Smith M, Waters J; International Consortium for Evidence Based Perfusion, Baker RA, Dickinson TA, FitzGerald DJ, Likosky DS, Shann KG. Ann Thorac Surg. 2011 Mar;91(3):944-82.
- International Consortium For Evidence-Based Perfusion
- Multimedia Manual of Cardiothoracic Surgery. Cardiopulmonary bypass collection.
- Perfusion Line