Initial Three-Year Review of Transcatheter Aortic Valve Replacement (TAVR) Program Launch at a Tertiary Academic Community Hospital

Initial Three-Year Review of Transcatheter Aortic Valve Replacement (TAVR) Program Launch at a Tertiary Academic Community Hospital Tara Stansbury, Research Scholar Raymond Singer, MD Lehigh Valley Physicians Group - Cardiac Thoracic Surgery Abstract This study reviews the outcomes of the 225 Transcatheter Aortic Valve Replacement Procedures that were performed over the past three years at Lehigh Valley Health Network. It was performed as a retrospective chart review to evaluate the mortality and stroke rates for patient demographics such as age, gender, and various comorbidities. Patients performed better with decreasing comorbidities and a low percentage required pacemaker implantation after surgery. This study shows that TAVR procedures can be performed safely at a tertiary academic community hospital with excellent outcomes compared to the PARTNER trials and commercial roll-out studies. Introduction Severe Aortic Stenosis (AS) is the narrowing or obstruction of the aortic valve that results in fatigue, shortness of breath, and, in extreme cases, hospitalization or death.1 In the past, surgical aortic valve replacement (SAVR), which requires a sternotomy and cardiopulmonary bypass, was the only option for patients with this condition. During this procedure, the cardiothoracic surgeon opens the chest, removes the aortic valve and replaces it with a prosthetic valve.2 Many patients with aortic stenosis, however, are considered inoperable or high-risk due to age, frailty, and other comorbidities. These patients, often denied surgical aortic valve replacement (SAVR), are alternatively being considered for the less invasive transcatheter approach.3 Transcatheter aortic valve replacement (TAVR) is a transformative procedure that avoids the need for conventional open-heart aortic valve replacement in high-risk patients.3 These patients now have the option of TAVR, a less invasive procedure that uses a sheath to implant the prosthetic valve into the existing aortic valve. The catheter is fed into either the groin (transfemoral) or the chest (transapical) and then guided through the blood vessel into the aorta.4 The transfemoral approach is more common, however, the transapical approach is performed if the patient has coronary artery disease.2 Although the procedure is considered less invasive, it has not yet been cleared for low-risk patients. In order to be considered high-risk, the patient must have several comorbities that prevent him or her for being a viable candidate for surgical aortic valve replacement.4 The Food and Drug Administration approved TAVR in 20115 and shortly after on May 16, 2012, the team of cardiologists and cardiothoracic surgeons at Lehigh Valley Health Network (LVHN) started performing this innovative procedure.6 Three years later, 225 procedures have been performed with great success. The purpose of this analysis was to assess the outcomes of all the TAVR procedures conducted at LVHN, a tertiary academic community hospital, over the past three years. Mortality rates and stroke rates were evaluated based on certain patient demographics such as age, sex and relevant comorbidities. A study was also conducted to determine the rate of pacemaker implantation. Methodology A retrospective chart review was performed with approval of the Lehigh Valley Health Network Department of Surgery as a quality improvement (QI)/process improvement (PI) project with permission to report in the literature using the SQUIRE guidelines. The TAVR procedure was performed 225 times over the course of three years in patients with severe aortic stenosis. These patients were deemed inoperable, or high-risk, for surgical aortic valve replacement during the TAVR clinic and were therefore considered to be good candidates for the TAVR procedure. Age, gender, comorbidities, patient mortality, stroke, and pacemaker implantation were determined by reviewing the patient records. All patients were evaluated to determine the mortality and stroke rates. Only patients without pacemakers prior to surgery were evaluated to determine the rate of pacemaker implantation after surgery. The comparison data from the PARTNER Trials was taken from the study, “Clinical Outcomes at 1 Year Following Transcather Aortic Valve Replacement.”4 Results A review of the first 3 years shows 225 TAVR procedures were performed, 134 Trans-Femoral (TF), 91 Trans-Apical (TA). The patient population was 120 men and 105 women, age ranging from 50 to 99, 41 of whom were less than 75 years old, 96 were 75 to 84 years old, 81 were 85 to 94 years old, and 1 was greater than 95 years old. Overall in-hospital mortality was 4 (1.78%); 30-day mortality 7 (3.11%); 60-day mortality 8 (3.56%); 1-year mortality 27 (12%). Complications included stroke 11 (4.89%), need for pacemaker 41 (21.81%). The 4 in-hospital deaths were due to stroke (1), liver failure (1), cardiac failure (1), and hemorrhage (1). Regrettably, some of the patient demographics only contained a few individuals for LVHN in comparison to the many STS/AVT Registry patients. Otherwise, the LVHN results compared favorably to the PARTNER trials and other commercial roll-out studies. Figure 1: A comparison of the LVHN and STS/ACC TVT Registry4 Mortality rates for the various patient conditions and comorbidities. Figure 2: A comparison of the LVHN and STS/ACC TVT Registry4 Stroke rates for the various patient conditions and comorbidities. Discussion The purpose of this study was to assess the outcomes of all the TAVR procedures that were performed over the past three years. Out of 26 conditions, only 3 of LVHN’s mortality rates were higher than those of the STS/ACT registry and out of 23 conditions, 15 of LVHN’s stroke rates were higher than those of the STS/ACT registry. The low percentage of pacemaker implantation indicates that the patients often return to normal rhythm after surgery, which allows for an easier recovery. Pacemaker implantation requires an additional procedure that requires a longer stay for the patient and additional bills that are unfavorable for both the hospital and the patient. In general, patients performed better with lower age, higher left ventricular ejection fraction (LVEF%), zero to moderate COPD, lower creatinine levels, and no preoperative atrial fibrillation. The transfemoral approach has overall better outcomes. This is most likely because patients undergoing the transapical approach often have coronary artery disease. Patients with less comorbidities, and therefore lower STS Prom %, had overall better outcomes. Altogether, these results confirm that TAVR procedures can be performed safely at a tertiary academic community hospital with excellent outcomes compared to the PARTNER trials and commercial roll-out studies. Factors predicting success include an existing high volume of interventional cardiology and cardiac surgical program, documented quality outcomes, a hybrid operating room, and the ability for the interventional cardiologists and cardiac surgeons to work as a collaborative team. The limitation to this study includes the low number of patients (225) at LVHN in comparison to the high number of patients in the PARTNER trials (12,182). Some of the demographics were underrepresented (e.g. only 1 patient over 95 years old) so, some of the statistics may be considered invalid. Another limiting factor is that not all patients receive the same brand of valve. While most of the patients received the Edwards SAPIEN valves, some patients received the Medtronic CoreValve. It is difficult to determine whether patients performed superior with one valve or the other because so few patients received the Medtronic CoreValve. For future work, it would be more beneficial to determine the mortality and stroke rates with a larger patient population and compare the different demographics between the two types of valves. References: Carabello, B. (2013). How Does the Heart Respond to Aortic Stenosis: Let Me Count the Ways. Circulation: Cardiovascular Imaging, 858-860. Walther, T., Simon, P., Dewey, T., Wimmer-Greinecker, G., Falk, V., Kasimir, M., . . . Mack, M. (2007). Transapical Minimally Invasive Aortic Valve Implantation: Multicenter Experience. Circulation. 3. Rodés-Cabau J, Webb JG, Cheung A, et al. Transcatheter Aortic Valve Implantation for the Treatment of Severe Symptomatic Aortic Stenosis in Patients at Very High or Prohibitive Surgical Risk: Acute and Late Outcomes of the Multicenter Canadian Experience. J Am Coll Cardiol. 2010;55(11):1080-1090. doi:10.1016/j.jacc.2009.12.014. 4. Holmes, D., Brennan, J., Rumsfeld, J., Dai, D., O’Brien, S., Vemulapalli, S., . . . Mack, M. (2015). Clinical Outcomes at 1 Year Following Transcatheter Aortic Valve Replacement. JAMA, 313(10), 1019-1026. 5. U.S. Food and Drug Administration. (2013, September 6) Retrieved July 9, 2014, from http://www.fda.gov/MedicanDevices/ProductsandMedicalProcedures/DeviceApprovalsandClearances/Recently-ApprovedDevices/ucm/280840.htm 6. Singer, M.D.,R. (2015, May 3). Trans-Catheter Aortic Valve Replacement (TAVR) Surgery, Retrieved July 16, 2015

Surgical Treatment of Multiple Vein Graft Aneurysms in 72 Year Old Man

Abstract The rarity of saphenous vein graft aneurysms following coronary artery bypass graft surgery presents an interesting case, as seen in a 72 year-old gentleman who underwent his third bypass surgery for an aneurysmal graft. Information regarding the case was gathered using the Lehigh Valley Health Network medical databases. The 8 cm aneurysmal portion of the graft was resected successfully and replaced with a CryoVein. Following surgery the patient had relief of symptoms and recovered well. It was determined that the patient had two true aneurysms present, making surgery a necessity in this specific case. Introduction Saphenous vein graft (SVG) aneurysms following coronary artery bypass grafting (CABG) are rare but fatal complications that frequently require surgical repair.1 We address a rare surgical case regarding an individual requiring a third sternotomy involving two SVG aneurysms with thrombus, 22 years following CABG. Information was gathered retrospectively using the LVHN database. Case Report In November of 2013, a 72 year-old man, a former smoker with a previous history of hypertension, hyperlipidemia, coronary artery disease, myocardial infarction, and coronary artery bypass graft surgery, was readmitted for a third sternotomy to resect a giant vein graft aneurysm forming on the right coronary artery (RCA) graft that had grown to a diameter of 8 cm. An additional aneurysm of 5 cm was also present on the circumflex vein graft. The patient had undergone coronary artery bypass graft (CABG) surgery in 1991, with his first redo CABG occurring in 2007. At that time, the vein graft aneurysm measured 4 cm but was not resected during the second bypass graft procedure to the left anterior descending (LAD) and circumflex arteries. Five years later, in 2013, the patient returned after a syncope episode and presented at the hospital with an enlarged aneurysm of the RCA vein graft, measuring 8 cm and a 5 cm aneurysm of the circumflex vein graft. A transesophageal echocardiogram (TEE) was performed, showing the presence of the aneurysms and as a result, inflow obstruction from the inferior and superior vena cava due to small atrial chamber size. The patient was scheduled for surgery in November and discharged from the hospital. At the time of surgery, the patient received general anesthesia, and a skin incision was made right below the clavicle to expose the axillary artery, through which the patient was heparinized. An 8 mm Hemashield conduit was anastomosed onto the right axillary artery and connected to the arterial line. A left groin incision was made to expose the femoral vein on the left side. This vein was cannulated with a 24 French venous cannula from Edwards Medical Supplies Inc. The patient was opened through a median sternotomy with an oscillating saw following the removal of previous surgical wires. A retractor was inserted into the mediastinum after the substernal structure was dissected. Upon opening, the vein graft aneurysm from the RCA was clearly visible and easily palpated. The aneurysm was first dissected off of adhesions, pleural tissue, and the right atrium. The ascending aorta was partly visible at this time, but it was a fairly short view. A segment of 3 to 4 cm of vein graft that was not aneurysmal was identified prior to the extremely aneurysmal portion. A right angle dissector was used to get around the normal caliber of the vein graft. The dissection continued along with the aneurysm out along the diaphragmatic surface of the heart, where the native RCA became visible on top of the vein graft aneurysm. The aneurysm had grown over the years causing tenting and migration of the native RCA to occur. There was clear anastomosis and it was followed, causing movement further distally into the heart itself. The distal PDA that appeared to be of reasonable caliber was dissected out. At this time the CryoVein was prepared, and the vein was incised to shape it. Using a beating heart on-pump technique, the distal PDA was opened with a 1.5 mm shunt for bleeding control, and the vein was anastomosed to the arteriotomy. The vein graft was sized to the original vein graft of the RCA and was clamped proximally. A punch hole was made in the vein graft for proximal anastomosis. With the vein graft still clamped, the proximal neck of the vein graft aneurysm was cut into and disconnected from the normal segment of the old vein graft. After sewing over the cut end of the old graft, it could then be laid into the vein graft aneurysm after removing all thrombus and grommet material. The entire venous graft aneurysm was compressed and most of the aneurysmal wall was resected. There was a second aneurysm of the vein graft by the diaphragmatic surface of approximately 4 to 5 cm in diameter. This was resected in its entirety and disconnected from the native coronary artery. The native coronary artery was completely occluded and so the artery was clipped and divided. The patient was then weaned off of cardiopulmonary bypass without difficulties, protamine was given, cannulas removed and hemostasis was achieved. Following surgery the patient did have pneumomedtastinum that resolved and a resolved left pleural effusion as a result of surgery over the five- day period before discharge. Upon discharge the patient had an improved blood pressure and was recovering well. Discussion After CABG, aneurysms of SVGs are a rare complication that can occur from a few days to over 21 years after surgery.2 Aneurysms can present as either true aneurysms or pseudoaneurysms. A relative distinction has been determined, that true aneurysms typically present as late complications of bypass surgery,3 while pseudoaneurysms may occur early after initial surgery at the anastomotic site.4 It has been determined that our patient developed two true aneurysms following both bypass graft procedures. True aneurysms have been found to occur more commonly in the body of the graft, present more than 5 years following bypass and are a result of vein graft necrosis, hypertension, trauma at harvest or implantation, or progressive atherosclerosis and thrombosis.5 Our patient presented with a single syncope episode, which is a common symptom presenting with SVG.2 CT and CT with contrast were used to show the extent of the aneurysm and its relation to and impact on surrounding structures. In a study from the Annals of Thoracic Surgery using 15 patients’ data, 25% had SVG aneurysms to the right coronary artery graft and 19% had the same to the circumflex coronary artery graft, which were the second and third highest locations of aneurysmal sites.6 In the same study, patients with previous histories of myocardial infarctions and hyperlipidemia were more at risk to develop SVG aneurysms,6 which were previous health factors for our patient. True aneurysms have been found to commonly form in the body of the vein graft as a result of chronic degeneration by vascular injury from hyperlipidemia and progression of atherosclerosis.7,8 With complications presenting as a result of compression from the aneurysmal graft, surgical intervention for this patient was required. Surgical correction was necessary due to previous heart history, multiple aneurysms, possibility for rupture, and presence of thrombus within the aneurysm. Aneurysms of SVGs are frequently unknown until symptoms arise or the discovery is made coincidentally with other medical testing. Patients with increased risk factors for SVG aneurysms should follow-up with physicians around the 10-year mark post surgery to check for aneurysm formation. References: 1Drummer E, Furey K, Hollmann J. Rupture of a saphenous vein bypass graft during coronary angioplasty. Br Heart J. 1987;58:78-81. 2Mayglothling J, Thomas MP, Nyzio JB, et al. Aneurysm of aortocoronary saphenous vein graft: case report and literature review. Heart Surg Forum. 2004;55:587-588. 3Liang BT, Antman EM, Taus R, et al. Atherosclerotic aneurysms of aortocoronary vein grafts. Am J Cardio. 1988;61:185-188. 4Le Breton H, Pavin D, Langanay T, et al. Aneurysm and pseudoaneurysms of saphenous vein coronary arter bypass grafts. Heart. 1998;79:505-508. 5Bramlet DA, Behar VS, Ideker RE. Aneurysm of a saphenous vein bypass graft associated with aneurysms of native coronary arteries. Cathet Cardiovasc Diagn. 1982;8:489-4. 6Sareyyupoglu, B, Schaff HV, Ucar I, et al. Surgical treatment of saphenous vein graft aneurysms after coronary artery revascularization. Ann Thorac Surg. 2009;88:1801-1805. 7Poll LW, Sadra B, Rühlow S, et al. Thrombosis of a large saphenous vein graft aneurysm leading to acute myocardial infarction 21 years after coronary artery bypass grafting: role of cardiac multi-slice computed tomography. Interact CardioVasc and Thorac Surg. 2011;12:284-286. 8Kalimi R, Palazzo RS, Graver LM. Giant aneurysm of saphenous vein graft to coronary artery compressing right atrium. Ann Thorac Surg. 1999;68:1433-1437

Cannulation of the Axillary Artery for Cardiopulmonary Bypass: Safeguards and Pitfalls.

BACKGROUND: The ascending aorta is the customary site for arterial cannulation for cardiopulmonary bypass. Favorable experience at our institution and elsewhere using axillary artery cannulation in treating type A aortic dissections has caused us to broaden our indications for using this site for arterial cannulation for cardiopulmonary bypass. METHODS: Medical records, operative notes, and perfusion records were reviewed in all patients in whom the axillary artery was cannulated directly or by a graft for cardiopulmonary bypass from January 1, 2000 through August 30, 2002. RESULTS: Seventy-five patients underwent axillary artery cannulation during the 32-month interval. Eleven patients had ascending aortic dissections, 20 had extensively diseased ascending aortas, and 44 were individuals undergoing repeat cardiac procedures. The right axillary artery was used in 72 patients and the left in 3. In 16 patients the artery was cannulated directly, and in 59 the arterial cannula was inserted into a prosthetic graft that had been anastomosed to the axillary artery. Axillary artery cannulation was satisfactory in 95% (71 of 75) of the cases in which it was used. CONCLUSIONS: Cannulation of the axillary artery for cardiopulmonary bypass is a dependable approach for procedures including reoperations, aortic dissections, and extensively diseased ascending aortas