Minimally Invasive Aortic Valve Replacement

Submitted by April Meyer, University of Saint Francis

Tags: aortic valve replacement aortic valves

Minimally Invasive Aortic Valve Replacement

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Over the past couple years; technology has grown in many ways. In the medical field, physicians are constantly trying to improve how they perform surgery. Performing surgeries that are most beneficial for the patient are becoming more common. As a cardiovascular nurse, it is important to understand how the newest technology and procedures will affect the patient care and outcomes, as well as being able to educate their patient. There will be an increasing number of minimally invasive aortic valve replacements being performed by cardiovascular surgeons in the near future.

Understanding how the new approach to minimally invasive aortic valve replacement will affect the patient and nursing care. The new, cutting edge technology of minimally invasive procedures is overall beneficial for the patient. Also, the patient satisfaction rate with this surgery is another key point. As a nurse, the job is always geared towards improving quality of care.

Knowing the difference between the methods of surgical interventions is important as a cardiovascular nurse. Aortic valve replacement has been performed on patients for over half a century. The new aortic valve surgeries are less invasive than the traditional methods, and the advantages seem to outweigh the disadvantages. With minimally invasive surgery the scar will be smaller, which will cause less damage to the patient’s body image than with the traditional cardiovascular surgeries. This procedure will not take as much time for the surgeon to perform. Therefore, the patient will require less time under general anesthesia. Additional advantages of having a patient with minimally invasive aortic valve replacement include greater comfort level, the decrease in scarring, and the quicker recovery.

Skills and associated knowledge that are not used in everyday practice can be forgotten. As a nurse, it is vitally important to understand the anatomy and physiology of the cardiovascular system. The left ventricle of the heart ejects blood through the aortic valve to the aorta. Then, the blood travels and branches off into other arteries in order to perfuse the body’s vital organs. The aorta is a major artery in the body. The aortic valve is the most important valve in the body. If there are complications, then this can cause severe problems for the patient.

The aortic valve is the valve in the left ventricle of the heart. The left ventricle contracts and, the aortic valve opens. Blood is then pushed to the rest of the body. The aortic valve has three cusps. The three aortic cusps are half moon-shaped. In about ten percent of hearts are aortic cusps equal in size. In two-thirds of patients’ hearts, the right cusp is larger than the other two aortic cusps. Each cusp has a free edge and a closing edge. The free edge and closing edge meet in the center of each cusp forming a mound or nodule of Arantius. Lunulae are a crescent-shaped area between the free and closing edges on the aortic valve. The lunulae are where the cusps come together during valve closure. It can increase in size with age. The diameter of the aortic annulus is equal to the diameter of the ascending aorta (Fuster, O’Rourke, Walsh, & Poole-Wilson, 2008, p. 62).

If a patient has severe complications with the heart, a valve replacement will be necessary. “Aortic stenosis is an obstruction to outflow of blood from the left ventricle (LV), which may be at the valve, above the valve (supravalvular), or below the valve (subvalvular)” (Fuster, O’Roubke, Walsh, Poole-Wilson, 2008, p. 1697). Another, aortic valve conditions, is valve regurgitation is when there is improper closure or malformation of cusps causing leaking or back flowing of blood. (Eisner & Topol, 2000, p. 127). These are two of the most common types of complications that can occur with the aortic valve. If these disorders become severe they will be treated with surgery.

According to Senagore, the patient will be put under general anesthesia. The surgeon will then clamp the aorta and stop the heart. The aortic root is cut, open and the valve is removed. The surgeon will suture in the aortic rim and into the replacement valve. The patient will be sized for a new valve before insertion. The new valve is sutured in, and the heart is deaired. The cross clamp is removed and then the heart is started again. This is the general process of aortic valve replacement (Senagore, 2004, p. 104).

There are two main types of valves used for a valve replacement. Mechanical valve is a man-made valve. The disadvantage is the patient has to be on anticoagulation therapy while the mechanical valve is in place. Biological tissue valve is used from a pig or cow heart valves. Anticoagulation medications are not needed for biological tissue valve replacements. The disadvantage of the biological valves is that do not last as long as the mechanical valves. The decision between which valve will be taken into consideration by the physician as well as the patient based on the patient’s age and lifestyle.

According to Senagore, following the patients valve replacement surgery they will be in the intensive care unit (ICU) (2004, p.106). The patient will be weaned off the ventilator. They will have chest tubes draining blood accumulated from the surgery. They are put on prophylactic antibiotics. The patient normally stays in the ICU for three days, and then is discharged after a week from the surgery. Other care that is given to the patient is wound care. The patient’s overall health will become better after the surgery (Spenagore, 2004, p. 106).

According to Senagore for traditional aortic valve replacement, “There is a 3-5% hospital mortality associated with aortic valve replacement. There is an average survival rate of five years in 85% of patients suffering from aortic stenosis that undergo aortic valve replacement” (2004, p. 106). If the patient has a reoperation, it is normally because the patient has a biological tissue valve and it has been worn out. The percentage of complications and death is fairly low with aortic valve replacement.

In an interview with Douglas Gray, M.D., F.A.C.S, he explained how he performed minimally invasive aortic valve replacements. Dr. Gray makes a small incision on the right side of the chest. He is performing minimally invasive aortic valve replacements on his patients unless it is contraindicated for the patient (personal communication, November 13, 2012)

According to Cohn, minimally invasive aortic valve replacement is the new progressing surgery. This new approach has become one of the most debated topics with cardiovascular surgeons today. Understanding the process behind minimally invasive valve replacement surgery is the key to a greater understanding of the effects on the patient. The surgeon starts by making a skin incision or lower ministernal incision of six to eight centimeters. The incision starts from the xiphoid process upward. Then surgeon cuts to the intercostals space to the patient’s right. It is important to make sure to avoid the septal artery. If the surgeon makes an incision in to the left atrium, they may injure the septal artery. The septum will then be opened and retracted. The valve replacement will then be performed in the traditional way. After the aortic valve is replaced, the septum and right atrium are closed. The patient will be taken off bypass (as seen below in Figure 1) after being defibrillated and the intracardiac air is removed. A transesophageal echocardiogram will be done to confirm that all air has been removed. Air can be removed by aspirating the ascending aorta and filling the heart. Another important tip is having carbon dioxide (CO2) in the field; this can help remove air. The patient will then be extubated. They will only spend one day in the ICU. Most patients go home after four to six days post-operatively. It is important for the nurse to understand how the procedure is performed, so they can explain to their patients what will be happening during surgery (Cohn, 2001).

Is minimally invasive surgery really better? According to Cohn, it is said that there is less blood utilization, less of a hospital stay, and less cost to the patient. Shorter hospital time is necessary, and recovery and a rehabilitation center is less likely with minimally invasive aortic valve replacement. It is remarkable that the patient has had decreased blood utilization with aortic valve replacement. In the first 100 patients, there was a decrease in pain and a quicker return to work for patients. In minimally invasive aortic valve replacement, patients stated there was a faster return to their normal activities of daily living (Cohn, 2001).

It is important for the cardiovascular nurse to understand the benefits of this procedure. They need to know what concerns patients may have with this procedure. Most patients are concerned about how their body will be affected after the procedure. No patient wants to have a large scar in the middle of their chest, and with this procedure there is less of a scar. Patients, particularly women, are worried about their body image after open heart surgery. There seems to be a trend, that patients of the younger generation are more worried about the scar than elderly patients. With minimally invasive aortic valve replacement, patients will be able to wear shirts and cloths that will not reveal their scar. This could be the most persuasive argument in convincing patients to having minimally invasive aortic valve replacement surgery performed.

There is a greater risk with patients that have had traditional aortic valve replacements as compared to the minimally invasive approach. “They found a greater incidence of post-operative [atrial fibrillation] AF than in the mini-invasive group (35.3% versus 24% in the standard group.)” (Corbi, Rahmati, Donal, Lanquetot, Jayle, Manu, & Allal, 2003, p. 138). In Table 1 below, displays complications that can arise from cardiovascular surgery. Among this list, there is anything from atrial fibrillation (as discussed above) to death. According to this study, there were no deaths related to minimally invasive aortic valve replacement, while there was a 5.7% mortality rate with the traditional approach to aortic valve replacement. There are factors that weigh in these statistics, such as there being over twice as many patients in the traditional aortic valve replacement. Patients should be aware various complications of the traditional aortic valve replacement and the benefits of the minimally invasive approach. (Corbi, Rahmati, Donal, Lanquetot, Jayle, Manu, & Allal, 2003).

According to Cicala, recovering from aortic valve replacement takes longer than minimally invasive surgery (1998, p. 147). The patient will wake up in the ICU with multiple tubes. The physician will still have an endotracheal tube in the patient’s throat to help them breath. The tube will be removed several hours after they wake up and breathing efficiently. There will be IVs and a central line in the patient. Most people that have endured traditional aortic valve replacement surgery find that it is difficult to cough and take death breaths due to the incisional chest pain. Due to this inability to deep breath and cough, the patient is at a much higher risk for developing pneumonia. On day three or four, the tubes will be removed and the patient is encouraged to walk the halls. The patient will have to splint their abdominal and chest wall with a pillow in order get out of bed, cough, or sneeze. This is done to prevent the incision from reopening (Cicala, 1998, p. 147).

Pain management in aortic valve replacement patients is a crucial part of the assessment for a nurse working in cardiovascular care. Patients with open heart surgery typically experience more post-operative pain than minimally invasive aortic valve replacement. If the patient’s pain is well managed, then there will be a better chance of a quick recovery. If the patient is experiencing a high level of pain, then they will have lack of motivation to move.

According to Muth and Bellenir, some surgeons are set in their ways and refuse to update their methods (2002). As a patient, would you want the surgeon to do a procedure they have done for years, or something they have done for only a month or two? Not many people want to be the guinea pig for new procedures. Just like every other procedure, aortic valve replacement, there are risks. The risk/benefit analysis is based on age, general health conditions, and their cardiac health. Regardless of the benefits, there is always a risk of dying during surgery (Muth & Bellenir, 2002, p. 243).

According to Benway, Benedict, and Boldt, “In 1960 the first aortic valve replacement surgery was performed with a mechanical valve” (2012). Experience also plays a major role in deciding between minimally invasive and traditional aortic valve replacement. If the patient has a traditional aortic valve replacement, the cardiovascular surgeon will have more experienced with performing the procedure. In addition, the nurse will be more knowledgeable about how to take care of the patient.

Aortic valve replacement is a new and progressive surgery that will be performed increasingly in the near future. The patient that receives minimally invasive aortic valve replacement will have less pain, and less post-operative complications. Patients that receive minimally invasive approach will have less self-esteem issues because their scar will be small. Dr. Gray noticed his patients were more satisfied with the minimally invasive approach. This procedure has a lower mortality rate than traditional aortic valve replacements. The patient that has minimally invasive aortic valve replacement surgery will spend less time in the hospital. The patient will be able to return to their normal activities of daily living sooner. Therefore, the patient will be less likely to have any complications after the surgery. Patients that have received minimally invasive aortic valve replacement surgeries are more likely to be satisfied with their health care experience. This will be accepted by surgeons more in the future. The minimally invasive approach to surgeries will be done not only for aortic valves, but for other procedures. Surgeons know that less invasive procedures tend to produce fewer complications. Therefore, minimally invasive procedures are a better overall choice.

Reference

  1. Bellenir, K., & Muth, A.S, (2002). Surgery sourcebook. Detroit, MI: Omnigraphics, Inc. Benway, R., Benedict, L., & Boldt, M., (2012). History. Retrieved from: http://www.pages.drexel.edu/~rjb56/history.htm
  2. Cicala, R. (1998). The heart disease sourcebook. Los Angeles, CA: Lowell House
  3. Cohn, L. (2001). Minimally invasive valve surgery. Journal of Cardiac Surgery, 16(3), 260-265
  4. Corbi, P., Rahmati, M., Donal, E., Lanquetot, H., Jayle, C., Menu, P., & Allal, J. (2003). Prospective comparison of minimally invasive and standard techniques for aortic valve replacement: initial experience in the first hundred patients. Journal of Cardiac Surgery, 18(2), 133-139.
  5. D. Gray, personal communication, November 13, 2012
  6. Dimarakis, I., Stefanou, D., Yarham, G., Mulholland, J., & Anderson, J. (2008). Total miniaturized cardiopulmonary bypass: the next step in minimally invasive aortic valve replacement. Perfusion, 23(5), 275-278.
  7. Eisner, M. D., & Topol, E. J., (2000). Cleveland clinic heart book. New York NY: CMD
  8. Fuster, V., Walsh, R.A., O’Rourke, R.O., & Poole-Wilson, P., (Eds.). (2008). Hurst’s the heart (12th ed.). New York, NY: Mc Graw Hill Medical
  9. Senagore, A.J., (2004). The gale encyclopedia of surgery: A guide for patients and caregivers Farmington Hills, MI: Thomson Gale