Week 4: Meta-Analysis and the Da Vinci
This week was really exciting in terms of my clinical immersion experiences. I was able to make some significant progress on my meta-analysis and observe a really interesting cardiac surgery involving a mitral valve repair using the da vinci robot.
Most of this week I spent behind a computer working on my meta-analysis of re-operations of descending aortic aneurysms. After working with the librarian, we narrowed our search to about 500 sources of primary literature. The main inclusion criteria for this meta-analysis involves at least 10 patients who have undergone a second aortic graft replacement of their descending aorta. Other than that, there are no other criteria associated with this study. All patients no matter what age or pre-existing condition are included in the study design. As stated in my week 3 blog post, often times when patients have an aortic aneurysm located somewhere along their aorta (aortic root, aortic arch, ascending aorta, descending aorta, or abdominal aorta etc) and undergo a surgery to repair the aneurysm, a second new or reoccurring aneurysm develops somewhere else along the aorta. In the case of this meta-analysis, we are solely looking at cases of re-operations on the descending aorta which often happens after repair of type A ascending aortic aneurysms. Therefore, after obtaining our initial 500 sources of primary literature, I painstakingly went through each of the paper's abstracts to narrow down the source hits to papers that may be relevant to our specific inclusion criteria. After doing so, we have come up with about 100 sources. With that initial filtering completed, I then began to obtain these articles and sift through the data present in each of the papers to ensure that at least 10 patients from each paper had a re-operation of their descending aorta. I am still working on this process and should be done within the next week so that I can begin pulling out useful information from these studies to compile my data analysis. Essentially, we are looking for a variety of correlative parameters that may be associated with why these patients have to undergo a second aortic graft replacement especially since although this surgery fixes the potentially life-threatening original aneurysm from bursting it does not treat the underlying pathological disease progression that caused the aneurysm development in the first place. The reasoning behind what causes aortic aneurysms is still being studied and therefore this study should help to shed some light on various pre-existing risk factors. Although this has really been a tedious process so far, I am looking forward to getting to the actual data analysis portion of this project, which will be much more fruitful.
Besides my clinical research, I had the opportunity to observe an incredible surgery involving a mitral valve replacement using the da vinci robot. The mitral valve is the valve separating the left atrium from the left ventricle. The attending cardiothoracic surgeon that performs these intricate surgeries is Dr. Sloan Guy, whose last name interestingly enough is my own first name. Using a specialized robot called the Da Vinci (which costs about $2.2 million dollars!!!), Dr. Guy is able to repair the mitral valve completely endoscopically, including cutting, ablating, and stitching the tissue through four ports in the patient's chest with special robotic arms, as shown in the figures below.
What is awesome about this procedure is that you can see everything very clearly as a high resolution camera videotapes the entire procedure that is occurring within the patients chest cavity. Therefore, you get to see exactly what the surgeon is seeing the whole time. Mitral valve repairs are necessary when a patient has a mitral valve prolapse, which is when the leaflets of the valve do not close appropriately leading to regurgitation (or blood back flow) and a lower ejection fraction (percentage of blood that is pumped out of the ventricle). Essentially, the heart is unable to pump blood efficiently without effective valves, which can be very debilitating and potentially life threatening depending on the severity of the mitral valve prolapse. Performing this procedure completely endoscopically using the da vinci robot has proven to drastically lower morbidity (especially since the patient does not require large incisions and an open sternotomy to perform the procedure) and allows surgeons to perform very intricate surgical techniques that may not be entirely possible without this sophisticated technology.
The procedure itself took about five hours long as it involved many meticulous steps. First, four insicisions are made in the chest to setup the four ports that which the robotic arms would be inserted into, then the patient's femoral artery is catheterized to place catheters into the heart and put the patient on bypass while the procedure is being performed. Once these steps are complete, the surgeon then sets up the robotic arms in the ports and begins to use the robot for the rest of the procedure. The robot arms are used to cut open the pericardium, which is the connective tissue layer that covers the heart, to expose the heart itself. Then incisions are made on the side of the left atrium to access the prolapsing mitral valve. To determine exactly where the mitral valve is prolapsing, saline is pumped into the left ventricle to see where back flow occurs through the mitral valve. Once the source(s) of the prolapse are determined, the surgeon using the robot fixes the faulty leaflet(s) using sutures to align them in a specific corrected orientation. Once this is complete, a special ring made out of dacron (which is a hemocompatible polymer) is sutured along the edges of the valve to further keep the valve leaflets in a beneficial orientation to eliminate the prolapse (known as a ring annuloplasty), as shown in the figure below.
If you want to watch this procedure yourself, check out this video link (warning: it is quite gory so do not watch it if you are squeamish!): https://www.youtube.com/watch?v=VZTpJluvdGA.
Stay tuned as I continue my immersion experience. We are over the hump and only have three weeks left! Time is surely flying by and am looking forward to finishing up my project and observing more awesome surgeries in the coming weeks.
Most of this week I spent behind a computer working on my meta-analysis of re-operations of descending aortic aneurysms. After working with the librarian, we narrowed our search to about 500 sources of primary literature. The main inclusion criteria for this meta-analysis involves at least 10 patients who have undergone a second aortic graft replacement of their descending aorta. Other than that, there are no other criteria associated with this study. All patients no matter what age or pre-existing condition are included in the study design. As stated in my week 3 blog post, often times when patients have an aortic aneurysm located somewhere along their aorta (aortic root, aortic arch, ascending aorta, descending aorta, or abdominal aorta etc) and undergo a surgery to repair the aneurysm, a second new or reoccurring aneurysm develops somewhere else along the aorta. In the case of this meta-analysis, we are solely looking at cases of re-operations on the descending aorta which often happens after repair of type A ascending aortic aneurysms. Therefore, after obtaining our initial 500 sources of primary literature, I painstakingly went through each of the paper's abstracts to narrow down the source hits to papers that may be relevant to our specific inclusion criteria. After doing so, we have come up with about 100 sources. With that initial filtering completed, I then began to obtain these articles and sift through the data present in each of the papers to ensure that at least 10 patients from each paper had a re-operation of their descending aorta. I am still working on this process and should be done within the next week so that I can begin pulling out useful information from these studies to compile my data analysis. Essentially, we are looking for a variety of correlative parameters that may be associated with why these patients have to undergo a second aortic graft replacement especially since although this surgery fixes the potentially life-threatening original aneurysm from bursting it does not treat the underlying pathological disease progression that caused the aneurysm development in the first place. The reasoning behind what causes aortic aneurysms is still being studied and therefore this study should help to shed some light on various pre-existing risk factors. Although this has really been a tedious process so far, I am looking forward to getting to the actual data analysis portion of this project, which will be much more fruitful.
Besides my clinical research, I had the opportunity to observe an incredible surgery involving a mitral valve replacement using the da vinci robot. The mitral valve is the valve separating the left atrium from the left ventricle. The attending cardiothoracic surgeon that performs these intricate surgeries is Dr. Sloan Guy, whose last name interestingly enough is my own first name. Using a specialized robot called the Da Vinci (which costs about $2.2 million dollars!!!), Dr. Guy is able to repair the mitral valve completely endoscopically, including cutting, ablating, and stitching the tissue through four ports in the patient's chest with special robotic arms, as shown in the figures below.
 |
| Figure 1: Da Vinci robot arms that go through ports in the patient's chest and the associated control panel that the surgeon uses to maneuver the arms and perform the procedure. Images taken from an online source. |
What is awesome about this procedure is that you can see everything very clearly as a high resolution camera videotapes the entire procedure that is occurring within the patients chest cavity. Therefore, you get to see exactly what the surgeon is seeing the whole time. Mitral valve repairs are necessary when a patient has a mitral valve prolapse, which is when the leaflets of the valve do not close appropriately leading to regurgitation (or blood back flow) and a lower ejection fraction (percentage of blood that is pumped out of the ventricle). Essentially, the heart is unable to pump blood efficiently without effective valves, which can be very debilitating and potentially life threatening depending on the severity of the mitral valve prolapse. Performing this procedure completely endoscopically using the da vinci robot has proven to drastically lower morbidity (especially since the patient does not require large incisions and an open sternotomy to perform the procedure) and allows surgeons to perform very intricate surgical techniques that may not be entirely possible without this sophisticated technology.
The procedure itself took about five hours long as it involved many meticulous steps. First, four insicisions are made in the chest to setup the four ports that which the robotic arms would be inserted into, then the patient's femoral artery is catheterized to place catheters into the heart and put the patient on bypass while the procedure is being performed. Once these steps are complete, the surgeon then sets up the robotic arms in the ports and begins to use the robot for the rest of the procedure. The robot arms are used to cut open the pericardium, which is the connective tissue layer that covers the heart, to expose the heart itself. Then incisions are made on the side of the left atrium to access the prolapsing mitral valve. To determine exactly where the mitral valve is prolapsing, saline is pumped into the left ventricle to see where back flow occurs through the mitral valve. Once the source(s) of the prolapse are determined, the surgeon using the robot fixes the faulty leaflet(s) using sutures to align them in a specific corrected orientation. Once this is complete, a special ring made out of dacron (which is a hemocompatible polymer) is sutured along the edges of the valve to further keep the valve leaflets in a beneficial orientation to eliminate the prolapse (known as a ring annuloplasty), as shown in the figure below.
 |
| Figure 2: Mitral valve repair using the da vinci robot showing the robotic arms suturing the ring annuloplasty on the sides of the mitral valve. Image taken from an online source |
If you want to watch this procedure yourself, check out this video link (warning: it is quite gory so do not watch it if you are squeamish!): https://www.youtube.com/watch?v=VZTpJluvdGA.
Stay tuned as I continue my immersion experience. We are over the hump and only have three weeks left! Time is surely flying by and am looking forward to finishing up my project and observing more awesome surgeries in the coming weeks.
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