Reoperative Cardiac Surgeries: The Inception of an Institutional Database

Abstract The success of an initial cardiac surgery promotes longer survival rates among patients who may live long enough to require further surgical intervention. Unfortunately these reoperations are associated with higher risks. Retrospective analysis is successful in identifying risk factors that promote better patient stratification and surgical management. The Lehigh Valley Health Network has a high volume of reoperation records that can be converted into a microcomputer database on the institutional level. This research strives to begin the first model of this database intended to compute meaningful and concrete statistical data. Background In an effort to compile information regarding cardiothoracic surgery on an international scale, the Society of Thoracic Surgeons (STS) began the STS National Database in 1989 (Shahian et al., 2013). This project served as a stepping-stone towards providing data for clinical research that would surface any overlooked complications and generate concrete evidence for improving the quality of surgeries and patient outcomes (Edwards, Clark, & Schwartz, 1994). The continuous innovations in cardiothoracic surgery call for constant revision of the data collection and algorithms within the database. For example, STS recently renovated its “Procedure Type” input to include immediate surgeries, terminated plans, and the relatively new transcatheter valve procedure. STS graciously provides free resources, including training guides, user-friendly software, and analogous data collection worksheets (Shahian et al., 2013). Several questions can be answered through analysis of an established network that exists within a database. The STS National Database has provided data to identify risk factors associated with reoperative surgery (Jamieson et al., 1999). At the institutional level, a recent study tested for the effects of previous Coronary Artery Bypass Grafting (CABG) on redo surgery for valves by using a 10-year volume of 1,000+ patients (Breglio et al., 2013). With precision comes the ability to hone in on specific postoperative instances and factors most likely associated with those outcomes (Vivacqua et al., 2011). With the proper structure and sample size, the Lehigh Valley Health Network (LVHN) has the materials and potential to create a database and can examine the patient pool as a whole and generate meaningful statistics. The Cardiothoracic Department within LVHN contains an extensive history of cases that, if correctly compiled, may provide key insight into readmitted-patient risk factors associated with specific operations. Due to the positive results of initial cardiac surgeries, patients survive long enough to develop more complications that require a reoperation (Balsam et al., 2010). The mortality risk increases with each cardiac surgery for a single patient, and constructing a database of this caliber will both neatly organize the retrospective data for generating meaningful statistics and draw LVHN towards the platform of the groundbreaking STS Database and becoming a major contributor to the international effort. Past work from Research Scholars within the department regarded the quantitative study of past surgical patients cases, and presently we are striving towards preparing these cases for database construction and future statistical analysis. Methodology Upon literature review of reoperative cardiac surgeries, a hybridized microcomputer database was constructed with Microsoft Access (Friedrichsen, 2010). The design was specialized to capture important information that could be conveniently extracted from given patient records. Presently LVHN has records of redo patients from the Cedar Crest and Muhlenberg campuses, and this project constructed the first version of the database and recorded information from 2009 and 2010 with a resultant sample size of 122 patients. Published database studies are typically of ≥10 year volumes, and therefore this study should be further innovated and supplemented in order to obtain an acceptable amount of information. Thus far, the database captures patient medical and surgical histories, perioperative cardiac conditions, the type of reoperation itself, and the postoperative outcomes. The framework of Microsoft Access allows one to design a form with which the user can enter data that translates into a corresponding table. While every preexisting condition may have a specificity to the patient, general categories have been shown to be powerful tools for examining multiple records as a whole (Jones et al., 2001). The database form included the following operative information: Patient name, Medical Record Number (MRN), Surgeon, hospital campus, age (years), weight (pounds), height (inches), cardiac surgical history, history of smoking, drinking, drug abuse, Diabetes Mellitus, dyslipidemia, dialysis, hypertension, Endocarditis, lung disease, renal insufficiencies, Coronary Artery Disease, previous valve surgery and valve operated on, other cardiac interventions, NSTEMI (Non-ST Segment Elevation Myocardial Infarction), STEMI, angina, heart failure, cardiogenic shock, arrhythmia, ejection fraction, valve etiologies and lesions, other diseases, presence of a ventricular assist device, type of redo surgery, postoperative outcomes, and mortality (within 30 days of redo). Categories were inputted as a discrete number, free-response text, or binary true/false for appropriate categories. Data analysis was performed by exporting information into Microsoft Excel. Gender stratification was utilized as this has been one of the previously recognized risk factors in certain reoperative cardiac surgeries (Lytle et al., 1986). Results The database currently contains the information of 122 patients including all redo cardiac patients from 2009 and 2010 from both Cedar Crest and Muhlenberg. Of the current pool, females (n=44, 36.1%) had an average age of 68 ± 13 years and morality rate of 9.09% (n=4). Males (n=78, 63.9%) were at a mean age of 69 ± 11 years and morality rate of 3.85% (n=3). The order of most frequent preoperative conditions for both genders were hypertension (n=105, 86.1%), Coronary Artery Disease (n=98, 80.3%), hyperlipidemia (n=91, 74.6%), history of smoking (n=66, 54.1%), Diabetes Mellitus (n=50, 41.0%), history of drinking (n=42, 34.4%), and renal insufficiencies (n=34, 27.9%). All other conditions were frequencies below 10%. 48 patients (39.3%) had a prior valve surgery. Most preexisting conditions were extracted from transcripts taken by Physician Assistants and Catheter Lab Reports. Conditions regarding cardiac physiology and performance were recorded by Cardiac Anesthesiologists and Cardiothoracic Surgeons. Of the procedures performed, the CABG procedure and valve replacements and repairs were dominant. Operations that were categorized as “other” were underrepresented in this investigation, including Ascending Aortic Aneurysm repair, Septal Myectomy, root reconstruction, tumor removal, and specific revascularization procedures. Categorization of operations for females (Figure 1) and males (Figure 2) were developed with a systematic approach by creating networks. Figure 1. Categorization of Redo Operations for Females Figure 1. The networks described correspond to the findings within the database for 2009 and 2010. Each initial node corresponds to the first cardiac surgery the patient underwent (as denoted by a ratio out of 44). Edges leading to subsequent nodes are weighted in order to emphasize which reoperations are of a higher occurrence. Final nodes correspond to the actual reoperation that was performed at Lehigh Valley Heath Network. Ratios within these nodes correspond to the frequency within that subcategory. Figure 1. Categorization of Redo Operations for Males Figure 2. The architecture of the male network was constructed in a similar hierarchical manner. Considering the edge weights, there are visible differences in operation frequencies between genders. Additionally, the free-text response capability of Microsoft Access allows one to enter any postoperative outcomes that may be specific to the patient. Using a counting function, the program can determine how many times a specific outcome arises, and this may be an indication of common outcomes from specific operations. If programmed correctly and categorized efficiently, one can set up a relationship within Microsoft Access that allows for recording the frequency of certain outcomes for a specific redo. Figure 3. Most Common Postoperative Outcomes Frequency of Postoperative Outcomes (Females) Acute Blood Loss Anemia Atrial Fibrillation Pleural Effusions Atelectasis Thrombocytopenia Other Notable Occurrences: Arrhythmia, Acute Renal Issues, Respiratory Insufficiency, Seizure Frequency of Postoperative Outcomes (Males) Acute Blood Loss Anemia Atelectasis Atrial Fibrillation Acute Renal Issues Atrial Fibrillation Volume Overload Thrombocytopenia Other Notable Occurrences: Respiratory Insufficiency, Arrhythmia, Pleural Effusions, Seizures Figure 3. Outcomes are listed in descending order. Separating this data by gender shows differences in postoperative patient conditions. Due to the small sample size, it is difficult to presently confirm any significant risk factors associated with mortality. At this time, there are underlying themes present within the failed reoperations. For example, females who did not survive the reoperation after 30 days underwent some form of revascularization operation and may have had a substantial and established disease, such as lung disease or endocarditis. Similarly, the males who did not survive were also at a critical state prior to a revascularization surgery, including history of angina, myocardial infarction, cardiogenic shock, or other risk statuses. In almost all cases of postoperative results, patients were under ventilator-dependent respiratory failure, which may serve as an indicator that pulmonary status is vital to risk stratification if additional data also presents this motif. Conclusion Creating a database of this institutional caliber has, thus far, proven to be an indispensible tool for efficiently harvesting retrospective data and utilizing mathematical modeling to identify odds and trends. Beginning this new research with a mature Database will accelerate the process for compiling data and, once the patient sample size is sufficiently large, generate meaningful statistics. Differences in ratios between categorical variables can then be tested for using a two-tailed Fischer’s Exact Test with a Contingency Table to determine significance (Breglio et al., 2013). Thus far we have noted gender differences in necessary reoperations and the outcomes of those reoperations. However, further classification may be necessary so as to not generalize findings or establish conclusions prematurely. The relationship function within Microsoft Access would allow for this type of intricate analysis. Additionally, further database form renovation may be necessary once medical records start transcribing recently developed procedures, such as the transcatheter aortic valve replacement (TAVR) (Shahian et al., 2013). This may make the institutional database a great tool for analyzing this new procedure once enough cases have been recorded. The database would already be established, and the data analysis can be performed and broadcasted quickly, putting the Lehigh Valley Health Network at the forefront of research in the TAVR procedure. This database is at the preliminary model stage and carries great implications if supported and completed gradually over time. Comments/Acknowledgements Special thanks to Dr. James Wu for his guidance and invaluable insight, Heather Geist, a fellow research scholar for assistance with database completion, Dr. Phillips for additional help, and the rest of the surgical team here at LVHN-Cedar Crest. References Balsam, L. B., Grossi, E. A., Greenhouse, D. G., Ursomanno, P., Deanda, A., Ribakove, G. H., … Galloway, A. C. (2010). Reoperative valve surgery in the elderly: predictors of risk and long-term survival. The Annals of Thoracic Surgery, 90(4), 1195–200; discussion 1201. doi:10.1016/j.athoracsur.2010.04.057 Breglio, A., Anyanwu, A., Itagaki, S., Polanco, A., Adams, D. H., & Chikwe, J. (2013). Does prior coronary bypass surgery present a unique risk for reoperative valve surgery? The Annals of Thoracic Surgery, 95(5), 1603–8. doi:10.1016/j.athoracsur.2013.01.073 Edwards, F. H., Clark, R. E., & Schwartz, M. (1994). Coronary artery bypass grafting: The Society of Thoracic Surgeons National Database experience. The Annals of Thoracic Surgery, 57(1), 12–19. doi:10.1016/0003-4975(94)90358-1 Friedrichsen, L. (2010). Microsoft Access 2010: Illustrated Introductory (p. 256). Cengage Learning. Retrieved from http://books.google.com/books?hl=en&lr=&id=aRk9AAAAQBAJ&pgis=1 Jamieson, W. R. E., Edwards, F. H., Schwartz, M., Bero, J. W., Clark, R. E., & Grover, F. L. (1999). Risk stratification for cardiac valve replacement. National Cardiac Surgery Database. The Annals of Thoracic Surgery, 67(4), 943–951. doi:10.1016/S0003-4975(99)00175-7 Jones, J. M., O’kane, H., Gladstone, D. J., Sarsam, M. A., Campalani, G., MacGowan, S. W., … Cran, G. W. (2001). Repeat heart valve surgery: risk factors for operative mortality. The Journal of Thoracic and Cardiovascular Surgery, 122(5), 913–8. doi:10.1067/mtc.2001.116470 Lytle, B. W., Cosgrove, D. M., Taylor, P. C., Gill, C. C., Goormastic, M., Golding, L. R., … Loop, F. D. (1986). Reoperations for Valve Surgery: Perioperative Mortality and Determinants of Risk for 1,000 Patients, 1958–1984. The Annals of Thoracic Surgery, 42(6), 632–643. doi:10.1016/S0003-4975(10)64597-3 Shahian, D. M., Jacobs, J. P., Edwards, F. H., Brennan, J. M., Dokholyan, R. S., Prager, R. L., … Grover, F. L. (2013). The society of thoracic surgeons national database. Heart (British Cardiac Society), 99(20), 1494–501. doi:10.1136/heartjnl-2012-303456 Vivacqua, A., Koch, C. G., Yousuf, A. M., Nowicki, E. R., Houghtaling, P. L., Blackstone, E. H., & Sabik, J. F. (2011). Morbidity of bleeding after cardiac surgery: is it blood transfusion, reoperation for bleeding, or both? The Annals of Thoracic Surgery, 91(6), 1780–90. doi:10.1016/j.athoracsur.2011.03.10

Observed Behavioral Effects of Medical Treatment for Type B Aortic Dissections

Observed Behavioral Effects when Medically Treating Type B Aortic Dissections Jordan Williams, James Wu, M.D. July 21, 2014 Abstract This study sought to identify possible behavioral effects from treatment of Type B aortic dissections with antihypertensive medications. A retrospective study of 104 patient records and charts was performed searching for eleven different behavioral effects compiled from listed side effects of five different classes of antihypertensive medications. This resulted in 57 patients with observed behavioral effects, and 47 patients with no observed behavioral effects. The median age of the patient population was 68 ± 16 years. Of the 57 patients with observed behavioral effects, the most frequent symptom seen was anxiety and restlessness. Although it was not possible in this study to prove an exact cause and effect relationship between the antihypertensive medications and the behavioral effects, this study is still significant. The pattern of behavioral symptoms identified in this study, as well as the lack of statistically sound research in this area, create a need for further randomized controlled studies in order to possibly improve patient outcomes by identifying other aspects of needed treatment. Introduction A Stanford Type B aortic dissection is an event where the wall of the descending aorta tears, diverting blood from the true lumen, into a newly created false lumen (Kouchoukos, Blackstone, Hanley, & Kirklin, 2013). Over time this can lead to an aortic aneurysm, and possibly even a rupture of the aorta. Type B dissections are further classified as complicated and uncomplicated. Complicated dissections are those that involve spinal cord, renal and/or visceral ischemia, as well as aortic rupture (Moulakakis , et al., 2014), while uncomplicated dissections involve none of the aforementioned events. Complicated dissections usually require surgical intervention, by an endovascular stent graft or open surgical repair. The accepted treatment of uncomplicated Type B aortic dissections continues to be medical treatment utilizing antihypertensive medications. There are many types of antihypertensive medications used in treatments today, including anti-adrenergic (including alpha and beta blockers), diuretics, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARB), and drugs that are formed from combinations of all these types (Medications for Treating Hypertension, 2009). With the exception of the diuretics, all of the drugs described act on specific neurological pathways, for example ARB drugs block the angiotensin II receptor, thereby inhibiting angiotensin II from causing an increase in blood pressure. Due to the fact that these drugs act to decrease blood pressure, changes in the patient’s perfusion may occur, especially if the patient was hypertensive before being diagnosed with the dissection. This change in perfusion then may result in a change in behavior, as the patient’s brain tissue is not receiving and exchanging the same amount of material over time as before. Because most of the prescribed antihypertensive medications act on neurological pathways, the drugs may also cause behavioral effects simply due to their mechanism of action. Patients may describe feeling, “dizzy” or “lightheaded”, among other symptoms, and in some cases may begin acting restlessly or even violently. A literature review utilizing the key words “type B dissection”, “behavioral effects” and “medical treatment” revealed no studies done on the behavioral effects of treating Type B aortic dissections with antihypertensive medications. Furthermore this search revealed that there were no studies performed that compared the behavioral effects of different classes of antihypertensive medications being used to treat Type B aortic dissections (Chan, Lai, & Wright , 2014). A literature search using the key words “antihypertensive medication” and “behavioral effects” did result in articles published in the 1980’s and 1990’s, on the behavioral effects of various hypertensive medications. Most of these studies focused on the behavioral effects of one class of antihypertensive medication (Bird, Blizard, & Mann, 1990; Blumenthal , et al., 1988; Callender, Hodsman, Hutcheson, Lever, & Robertson, 1983; Conant , et al., 1989; McAnish & Cruickshank, 1990). However as one summary article stated, while these articles generally found no negative impacts on behavior, most of the articles utilized a patient sample of less than 20. (Muldoon, Manuck, Shapiro, & Waldstein, 1991). Therefore due to this finding, and the lack of research on the behavioral effects of treating type B aortic dissections medically, there is a need for further studies involving antihypertensive medications and their behavioral effects, especially when used to treat Type B aortic dissections. The purpose of this study was to observe possible behavioral consequences of treating Type B aortic dissections medically, in order to determine the frequency of these behavioral consequences, and thus stimulate interest in further research involving randomized controlled trials. Methods This study was a retrospective study initially involving 244 patients selected from the hospital database. Patients were sorted based off of the following inclusion criteria: (1) Patient had to have Type B aortic dissection (versus Type A), (2) Patient had to be treated medically versus surgically, and (3) Patient could not have any history of behavioral disorders (stroke, dementia, etc.) before being treated for their Type B dissection. Of the 244 initial patients, 109 were found to present with type B aortic dissections. Of these 109, 104 patients were treated medically and did not have any major behavioral disorders prior to hospital treatment. These patients’ medical records were then examined to determine if any behavioral changes after administration of antihypertensive medications could be observed. These changes were entered into a database, using the following selection options: anxiousness/restlessness, depression, disorientation, dizziness/lightheadedness, fatigue, hallucinations, headache, nausea, none found, shakes , slurred/garbled speech and syncope. These categories were selected from common side effects listed for the major classes of antihypertensive medications found on Harvard Medical School’s health publication site (Medications for Treating Hypertension, 2009). If a new behavioral category, not seen in prior patients was discovered while reviewing the patients’ charts, this was added to the category set as well. Behavioral effects for each patient were only recorded if they didn’t present with those symptoms prior to hospitalization. For example, if a patient had a history of fatigue and then experienced fatigue, nausea, and dizziness while being treated, then only nausea and dizziness were recorded. A histogram was then constructed to show the relative frequency of the behavioral effects observed, along with a pie chart that compared the number of patients with behavioral effects found to the number of patients that had not observed behavioral effects. Results Table 1 Summary of Patient Demographics Total Patients with Medically Treated Type B Aortic Dissection 104 Number with Behavioral Effects 57 Number of Males 67 Number of Females 37 Date Range 2004-2014 (10 Years) Age Range 21-94 (73 years) Median Age 68 ± 16 years Number of Deaths 10 Figure 1 This figure displays the frequency of a given behavioral effect seen in the study population Figure 2 This figure depicts the relative amount of patients in which behavioral effects found, and patients in which no effects were found These results show that the patients in this study were mostly in their upper 60’s. From the histogram (Figure 1), it can be seen that of the behavioral effects observed, anxiousness/restless had the highest frequency. However it can also be observed that 45% of the patients did not present with any behavioral effects (Figure 2). It is also interesting to note that no events of depression or syncope were observed in the patient population (Figure 1). Conclusion This study revealed that while almost half of the patients observed did not present with any behavioral effects, the other half presented most frequently with “anxiousness/restlessness”. These results are interesting because the fact that half of the patients did not present with any behavioral effects, seems to possibly concur with the findings of the studies performed twenty years prior on hypertensive medications, which either found no negative effect on behavior or possibly found a positive effect. However as stated before, these studies are advanced in age, utilized very small sample sizes, and were note done on patients being treated for type B dissections. Therefore their results could be unduly biased. For the patients that did respond to the antihypertensive medications with some form of behavioral effect, the fact that the top three frequencies of behavioral effect were anxiety and restlessness, along with nausea and fatigue, could indicate areas where patients would need more medication or other treatment. Even though this study utilized a cohort of 104 patients, it was still performed at one location, and thus results could still be skewed based on the patient population surrounding the hospital. Also because this study was retrospective in nature, exact cause and effect cannot necessarily be proven between the antihypertensive medication and the behavioral effects. Based on these findings, randomized controlled trials need to be performed in order to better understand the effects of hypertensive medications on behavior in hypertensive only patients. These results can then be used to study effects that may or may not present themselves in treating Type B aortic dissections medically. In conclusion, this and other studies could greatly enhance the treatment of people with Type B aortic dissections, by identifying critical needs of the patient that might currently be ignored. References Bird, A., Blizard , R., & Mann, A. (1990). Treating hypertension in the older person: an evaluation of the association of blood pressure level and its reduction in cognitive performance. Journal of Hypertension, 147-52. Retrieved from http://www.druglib.com/abstract/bi/bird-as_j-hypertens_19900200.html Blumenthal , J., Madden, D., Krantz, D., Light, K., McKee, D., Ekelund, L., & Simon, J. (1988). Short-term behavioral effects of beta-adrenergic medications in men with mild hypertension. Clinical Pharmacology and Therapeutics, 429-35. Retrieved from http://www.ncbi.nlm.gov/pubmed/3356086 Callender, J., Hodsman, G., Hutcheson, M., Lever, A., & Robertson, J. (1983). Mood Changes during captopril therapy for hypertension. A double-blind pilot study. Hypertension, 90-93. Retrieved from http://hyper.ahajournals.org/content/5/5_Pt_2/III90.short Chan, K. K., Lai, P., & Wright , J. M. (2014). First-line beta-blockers versus other anithypertensive medications for chronic type B aortic dissection. Cochrane Database of Systematic Reviews . doi:DOI: 10.1002/14651858.CD010426.pub2 Conant , J., Engler , R., Janowsky, D., Maisel, A., Gilpin, E., & LeWinter, M. (1989). Central Nervous System side effects of beta-adrenergic blocking agents with high and low lipid solubility . Journal of Cardiovascular Pharmacology , 656-661. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/2471005 Kouchoukos, N., Blackstone, E., Hanley, F., & Kirklin, J. (2013). Kirklin/Barratt-Boyes Cardiac Surgery, 2 Vol Set. Elsevier Health Sciences. Retrieved 2014 McAnish , J., & Cruickshank, J. (1990). Beta-Blockers and Central Nervous System Side Effects. Pharmacology and Therapeutics , 163-197. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/1969642 Medications for Treating Hypertension. (2009, August). Harvard Women\u27s Health Watch. Retrieved from http://www.health.harvard.edu/newsletters/Harvard_Womens_Health_Watch/2009/August/Medications-for-treating-hypertension Moulakakis , K., Mylonas , S., Dalainas, I., Kakisis, J., Kotsis, T., & Liapis, C. (2014). Management of complicated and uncomplicated acute type B dissection. A systematic review and meta-analysis. Annals of Cardiothoracic Surgery, 234-246. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052408/ Muldoon, M. F., Manuck, S. B., Shapiro, A. P., & Waldstein, S. R. (1991). Neurobehavioral effects of antihypertensive medications. Journal of Hypertension, 549-559. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/167945

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

Outcomes of Convergent Ablation Procedure using a Cryo-balloon Catheter for Treatment of Atrial Fibrillation

Outcomes of Convergent Ablation Procedure using a Cryo-balloon Catheter for Treatment of Atrial Fibrillation Rosalie Mattiola, Bryan Auvil, James K. Wu, MD, Gregory Altemose, MD, From the Division of Cardiothoracic Surgery, Department of Surgery, Lehigh Valley Health Network, Allentown, Pennsylvania. BACKGROUND Traditional catheter based treatment for atrial fibrillation (AF) uses radiofrequency as a source of energy for the ablation of atrial tissue. This is an endocardial (inside the heart) technique. The success rate of this technique at one year is around 50-60%1. In the last three years, a novel technology using a combined/hybrid trans-diaphragmatic surgical epicardial (outside the heart) ablation with endocardial (inside the heart) ablation techniques have had one-year success rates close to 80%2. This is called the Convergent Procedure (CP) 3. The CP can be done with either radiofrequency ablation (RF), or with a cryo-balloon catheter to create the endocardial lesion set. The cryo-balloon technique may be a preferred approach, as it creates improved endocardial coverage of the pulmonary veins. Limited data is available on the cryo-balloon technique for CP. OBJECTIVE To evaluate the effectiveness and patient outcomes of utilizing the cryo-balloon ablation technique in the setting of the Convergent Procedure(CP). METHODS From October 2013 to May 2015, thirty-one AF patients underwent the convergent procedure with cryo-balloon endocardial ablation at LVHN. Patients were managed postoperatively medically with amiodarone, steroids, anticoagulants, and anti-inflammatories. Follow-up visits occurred 1 month, 3 months, 6 months, and 12 months after the surgery. Most (89%) patients received an implantable monitoring device that was interrogated at each visit for arrhythmias. Medical records were reviewed to determine pre-operative comorbidities and post-operative outcomes. Descriptive statistics were utilized to analyze the data. RESULTS Of the atrial fibrillation patients undergoing a convergent procedure with a cryo-balloon, 30% suffered from paroxysmal AF; 70% from persistent or chronic AF. Arrhythmia-free survival after the convergent procedure using a cryo-balloon catheter, including repeat ablation was 92% three months post-operatively and 89.5% six months post-operatively. One patient required a repeat ablation post-operatively. There were no deaths. Major complications included one patient experiencing pericardial effusion and one with hemoperitoneum. CONCLUSIONS This study of 31 patients suggests that the use of a cyro-balloon catheter for endocardial ablation during the convergent procedure is a viable method to eliminate the recurrence of persistent atrial fibrillation and arrhythmias. Further study is warranted that obtains a larger sample size of CP patients and allows more time between operation and follow-up data collection. Other data should be collected on the time efficiency of the cryo-balloon versus radiofrequency technique. KEYWORDS Atrial fibrillation, Catheter ablation, Hybrid ablation, Cryo-ablation, Cryo-balloon catheter, Outcomes ACRONYMS AF= Atrial fibrillation; CP= Convergent Procedure; RF= Radiofrequency; ACT= Activated clotting time Introduction Atrial fibrillation (AF) is the most common abnormal heart rhythm, effecting approximately 2.2 million individuals in the United States4. AF can be treated medically, and/or by means of shocking the heart back into rhythm via cardioversion(s) and/or by ablating electrical tissue of the posterior heart. Patients with AF whom experience persistent symptoms even after receiving the above treatments are considered appropriate candidates for the hybrid epicardial/endocardial-ablating convergent procedure (CP). Traditionally, ablations utilize radiofrequency (RF) energy as a means to cauterize the electrical tissue of the heart. The epicardial portion of the convergent procedure uses this such technique. However, for the second portion of the procedure, it may be more effective to utilize a cryo-balloon catheter to freeze the endocardial tissue rather than cauterizing it with a RF source. The endocardial segment of the CP is conducted by an electrophysiologist who feeds a catheter thru the femoral artery to the posterior aspect of the heart. The RF catheter tip requires approximately 30 small burns around the pulmonary veins to isolate all electrical conduction that could disturb the heart’s sinus rhythm. The cryo-balloon catheter requires only 8-14 lesions to freeze the electrical tissue around the pulmonary veins. Figure 1: Radiofrequency Endocardial Ablation8 Figure 2: Cryo-balloon Endocardial Abaltion11 Figures 1 and 2 show cross sections of the heart exposing the left atrium and interior pulmonary vein ostia. The first figure depicts the radiofrequency circumferential mapping process while the second figure animates cryo-balloon occlusion in one of the pulmonary vein ostium. Methods Study Population Between October 2013 and May 2015, thirty-seven AF patients underwent the convergent procedure at Lehigh Valley Hospital at Cedar Crest in Allentown, Pennsylvania. The cryo-balloon technique was used on 31 of those 37 patients to isolate the endocardium. RF ablations were applied to the other 6 patients. Patients met criteria to undergo the convergent procedure if they experienced symptomatic AF for an extended period of time, and/or if they had a history of failed medical therapies, cardioversions or traditional ablations for treatment of AF. Patients were excluded from the study if they were administered RF ablations during the endocardial portion of their CP. Ablation Procedure The Convergent Procedure is divided into two parts; epicardial and endocardial. The epicardial portion is performed by a cardiothoracic surgeon. To begin, general anesthesia is induced and maintained throughout the entire case. An esophageal temperature probe is placed and the patient is prepped and draped in the usual sterile fashion. A small incision is made in the midline, approximately 2 cm below the xiphoid process. The surgeon then enters the peritoneal cavity using a modified Hassan technique. Two additional 5-mm trocars are placed in the midclavicular line, on either side. This is done under direct palpation. The abdomen is then insufflated with carbon dioxide to achieve a pneumoperitoneum. The surgeon identifies the falicform ligament and creates a pericardial window in the central tendon of the diaphragm. Next, the surgeon guides the nContact cannula into the pericardial space and removes the 5-mm trocars. The posterior aspect of the left atrium is then ablated with a radiofrequency device for 90 seconds per ablation in a linear fashion from the left pulmonary veins to the right pulmonary veins. A double lesion set is created. The nContact cannula is then flipped to access and ablate the anterior surface of the right and left pulmonary veins. Total lesions range from 16 to 23. Finally, a drain is placed into the pericardial space and exited out one of the 5-mm trocar sites. The fascia and skin are repaired in the usual fashion. The case is then turned over to an electrophysiologist for the endocardial portion. The electrophysiologist begins by assuring the groin area is clipped, prepped and draped in the usual sterile fashion. Local anesthesia is applied to the groin and a transseptal catheterization is performed under fluoroscopic and hemodynamic guidance. A one-puncture transseptal access is performed using a Brockenbrough needle assembly with a long sheath. Once the catheter is across the atrial septum, heparin is immediately infused and dosed to maintain an activated clotting time (ACT) of \u3e 300 seconds. CT levels are assessed every 15 minutes throughout the procedure. Next, right femoral vein access is obtained for catheter placement. The vessel is accessed using the modified Seldinger technique. Similarly, left femoral vein access is obtained for electrode placement. Then, right internal jugular vein access is obtained for coronary sinus catheter placement. Using an Intracardiac echocardiography (ICE), a catheter is then advanced into the right atrium. An echocardiography is used to guide the transseptal puncture, guide catheter positioning, measure the diameter of the pulmonary vein ostia, ensure proper contact between the ablation catheter and the endocardium, measure pulmonary venous blood flow velocity before and after ablation, and identify esophagus location relative to posterior left atrium. At the conclusion of the procedure, ICE imaging is used to ensure there is no evidence of pericardial effusion. After the catheter enters the right atrium, electrophysiologic testing is performed and measurements of basic intervals and refractory periods are obtained. Catheters are positioned in the high right atrium, right ventricular apex, left atrium and His-bundle region for pacing and recording. Arrhythmia induction protocols include programmed stimulation without acute drug testing. A shell of the pulmonary veins and the left atrium was made prior to surgery using the EnSite Velocity10 3-D mapping system. The anatomy of the pulmonary veins are determined in this manner. A 20mm Achieve circular mapping catheter is then positioned within each of the individual pulmonary vein ostia. Pulmonary vein potentials are determined in all four veins. The electrophysiologist ensures the occlusion of each pulmonary vein and then employs a “freeze-thaw-freeze” strategy which ultimately delivers two lesions per vein. Occlusion is determined by repeat contrast pulmonary venography and lack of color flow via ICE imaging. The cryo-balloon is inflated with a liquid refrigerant (liquid nitrogen). The refrigerant evaporates and scars the tissue of the occulted pulmonary vein, thus Figure 3: Cryo-balloon catheter5 eliminating any electrical conduction that could interfere with electrical currents in the atria and cause atrial fibrillation6. The Arctic Front Advance 23mm or 28mm cyro-balloon ablation catheter is positioned at the ostium of the left superior pulmonary vein, left inferior pulmonary vein, right superior pulmonary vein and right inferior pulmonary vein. Each vein receives a 1 to 3 lesions which results in the isolation of each respective vein. The total lesion time ranges from 1353 to 2674 seconds. Figure 4: Complete Pulmonary Vein Isolation This image depicts the shell of the pulmonary veins of a LVHN CP patient. The grey area represents electrical isolation on scarred tissue. Postoperative managementPatients were restarted on their normal medication after the procedure. Additionally, at least 77% of the patients received the following medical therapy; an anticoagulant (heparin, coumadin, eliquis) and an anti-inflammatory (colchicine) administered 6-12 hours after the operation. An intravenous steroid (salumedrol; methoprednisolin) administered for 2-3 days post-operatively and amiodarone taken for 6-8 weeks to manage lingering arrhythmias. To thoroughly record both asymptomatic and symptomatic arrhythmia episodes, 89% of the patients received remote monitoring devices (41% Lifewatch EM, 8 % ILR, 22% PPM-dual, 7 % ICD-Dual 11% Holter, 11% None). Figure 5: Implantable Monitoring Devices Follow Up Patients were seen in the office at 1 month, 3 month, 6 month, and 12 month intervals when applicable. At each visit, monitoring devices were interrogated and/or echocardiograms were administered to determine heart rhythm. Recurrent arrhythmias were defined as episodes lasting greater than 1 minute or accounting for greater than a 2% burden as recorded by a monitoring device. Medications were also adjusted and other therapies were scheduled as needed. Results Table 1: Study Population Demographics Characteristic Subjects N 31 Age (years), mean (range) 66 (40-81) Sex:Male, n (%) 23 (74.2) Paroxysmal AF, n (%) 9 (30) Persistent AF, n (%) 22 (70) Hypertension, n (%) 23 (74.2) Obesity, n (%) 8 (25.8) Congestive Heart Failure, n (%) 9 (29) Current/Past Tobacco Use, n (%) 14 (48.3) Sleep Apnea, n (%) 11 (34.4) Pacemaker, n (%) 7 (22.6) Previous Ablation, n (%) 13 (38.7) Previous Cardioversion, n (%) 17 (54.8) Family Hist. HD, n (%) 13 (43.3) N = population size; SD = standard deviation; n= number; AF= atrial fibrillation; HD= heart disease The patients were between the ages of 40 and 81 at the time of the procedure. The average age was 66 years old. Male patients defined 67.5% of the study population. All patients were of white race. Patients had either paroxysmal, persistent, or longstanding persistent (chronic) AF. 76.6% (23/30) of patients were in sinus rhythm at every follow up. At 3 months, 100% (26/26) of patients were free of atrial fibrillation while 92% (23/25) of patients that received the full convergent procedure were arrhythmia-free. Six months after their operation, 94.7% (18/19) of patients were AF-free while 89.5% (17/19) were arrhythmia-free. Twelve month post-operative data was only available for 6 patients. All of these patients (100%) were arrhythmia and AF- free. Table 2: Post-operative outcomes AF-free Arrhythmia-free 3 months 100% 92% 6 months 94.7% 89.5% 12 months 100% 100% Heart rhythm was determined by interrogating monitoring devices and/or by administering echocardiograms. A total of 5 patients did experience recurrent arrhythmias after the convergent procedure using a cryo-balloon catheter. Three out of five experienced post-operative recurrent atrial flutter and were cardioverted back into sinus rhythm. One of these three patients only received endocardial ablations due to liver adhesions, leaving the surgeon to abort the epicardial portion of the CP. One patient experienced symptomatic atrial tachycardia and received another traditional ablation along with cardioversions. One patient experienced irregular rhythm after an epicardial-only ablation. This patient received endocardial ablation 3 months later, but did experienced recurrent atrial fibrillation without palpitations before returning to sinus rhythm. Overall, 3.2% (1/30) of patients required repeat ablation and 12.9% (3/30) required post-operative cardioversion due to recurrent arrhythmias. Figure 6: Post-operative Therapies in response to Recurrent Arrhythmia Analysis Literature Review Literature on the convergent or “hybrid ablation” procedure is heavily concentrated on radiofrequency ablation for both epicaridal and endocardial segments. A Polish study found 72.2% (13/18) of their patients in sinus rhythm 6 months after the procedure and 80% (8/10) in sinus rhythm after 12 months2. Civello, et al., reports 89% of their patients (93/104) in sinus rhythm approximately 6 months post- operatively7. Gehi, et al., reports a 12-month arrhythmia free survival of 70.5% and a repeat ablation rate of 6%3. Traditional radiofrequency catheter ablation alone has much lower success rates. A 43 patient study reports 56.5% in normal sinus rhythm using antiarrhythmic drugs six months after the ablation1 . Another endocardial-only radiofrequency ablation study provides 12 month results of 68% arrhythmia-free survival9. Figure 7: Success of Convergent Procedure using Cryo-balloon catheter Discussion Procedural Complications Overall, procedural complications were very limited. A total of two patients (6.4%) experienced adverse-effects from the operation. Although several measures are taken to avoid effusion including administering anti-inflammatory drugs, one patient experienced pleural effusion 4 days post-operatively. This patient required reoperation for drain insertion. He recovered and was discharged the next day. The other patient experienced hemoperitoneum with a hematoma around on the trocar sites secondary to their anticoagulated state following surgery. The patient was re-operated on and had hematomas evacuated with suction and controlled with cautery. The patient was discharged 4 days after the convergent procedure and recovered successfully. There were no procedural mortalities, no atrioesophogeal fistulas, and no pericardial tamponade. Table 3: Major Complications N 31 Procedural Mortality Atrioesophageal fistula Pericardial effusion 1 Pericardial tamponade Bleeding 1 Total 2 (6.4%) Study Limitations The study included only patients with symptomatic AF. This was a retrospective study of the effectiveness of cryo-balloon ablation for eliminating the recurrence of AF. No quality of life surveys were collected. A control group of RF ablations was not studied; rather the control group statistics were represented from previous literature. Furthermore, time posed a great limitation on this study as the convergent procedure has only been performed for two years in the Lehigh Valley Hospital. Many patients underwent their CP less than a year before the conduction of study. Thus, limited follow-up data was available. Conclusions This retrospective review of a cohort of 31 patients suggests that the use of a cyro-balloon catheter for endocardial ablation during the convergent procedure is a viable method to eliminate the recurrence of persistent atrial fibrillation and arrhythmias. A literature review of radiofrequency ablation convergent procedures offers success rates very close to the cryo-balloon rates described in this study. However, these studies contained a much larger sample size and occurred over a significantly longer time period. For this reason, further study is warranted that obtains a larger sample size of CP patients and allows more time for follow-up data collection. Other data should be collected on the time efficiency of the cryo-balloon versus radiofrequency technique. Because the RF catheter requires the electrophysiologist to administer more than 28 burns around the circumferences of each pulmonary vein, while the heart is beating, while the patient is breathing, it is difficult to ensure proper contact of catheter to tissue and to ensure equal distance between each burn so that the entirety of the tissue is electrically isolated. In comparsion, once a cryo-balloon is positioned in the opening of a pulmonary vein and occlusion is confirmed, it is inflated with liquid nitrogen one to three times. The use of a cryo-balloon catheter is simpler, faster and usually ensures complete electrical isolation with no missed tissue. The efficiency of the procedure can lead to more patients scheduled for operation, and better outcomes with greater quality of life overall. Additionally, lesser recurrence of arrhythmias correlates with lower costs for the patient and hospital. The more effective the convergent procedure, the lower amount of repeat ablations, cardioversions and medication required. References 1. JR Edgerton , et al. (2008). Minimally invasive pulmonary vein isolation and partial autonomic denervation for surgical treatment of atrial fibrillation. The Annals of Thoracic Surgery, 86, Vol 1, 35-39. 2. M Zembala, et al. (2012). Minimally invasive hybrid ablation procedure for the treatment of persistent atrial fibrillation: one year results. Kardiologia Polska; 70, 8: 819–828 3. Gehi et al. (2013). Hybrid epicardial-endocardial ablation using a pericardioscopic technique for the treatment of atrial fibrillation. The Heart Rhythm Society, 10, No 1, 22-28. 4. Mayo Foundation (2015). Atrial Fibrillation. Mayo Foundation for Medical Education and Research. Retrieved from http://www.mayoclinic.org/diseases-conditions/atrial-fibrillation/basics/definition/CON-20027014 6. Medtronic (2014). Arctic Front Advance Cardiac CryoAblation Catheter. Medtronic. 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