Early and Two-year Outcomes after Sutureless and Conventional Aortic Valve Replacement: a Nationwide Population-based Study

Background@#We compared early and 2-year clinical outcomes of sutureless aortic valve replacement (SAVR) with conventional aortic valve replacement (CAVR) in a nationwide study based on claims data. @*Methods@#From December 2016 to November 2018, 3,173 patients underwent bioprosthetic aortic valve replacements. SAVR and CAVR were performed in 641 and 2,532 patients, respectively. Propensity score-matched analysis was performed in 640 patient pairs. @*Results@#Operative mortality rate was 2.8% without significant differences between the SAVR (3.4%) and CAVR (2.3%) groups (P = 0.324). There were no significant differences in postoperative morbidities between the groups except for permanent pacemaker (PPM) implantation. PPM implantation rate was significantly higher in the SAVR (3.8%) than in the CAVR group (0.9%) (P < 0.001). One- and two-year overall survival was 89.1% and 87.5%, respectively, without significant differences between the groups (SAVR group vs. CAVR group = 89.9% and 90.5% vs. 87.2% and 88.7%, respectively; P = 0.475). There were no significant differences in the cumulative incidence of cardiac death, stroke, aortic valve reoperation and infective endocarditis between the groups. Cumulative PPM implantation incidence at 6 months in the CAVR was 1.1%, and no patient required PPM implantation after 6 months. In the SAVR, the cumulative PPM implantation incidence at 0.5, one, and two years was 3.9%, 5.0% and 5.6%, respectively. The cumulative PPM implantation rate was higher in the SAVR group than in the CAVR group (P < 0.001). @*Conclusion@#Early and 2-year clinical outcomes between SAVR and CAVR were not different except for a high rate of permanent pacemaker implantation in the SAVR group.

Early and Two-year Outcomes after Sutureless and Conventional Aortic Valve Replacement: a Nationwide Population-based Study

Background@#We compared early and 2-year clinical outcomes of sutureless aortic valve replacement (SAVR) with conventional aortic valve replacement (CAVR) in a nationwide study based on claims data. @*Methods@#From December 2016 to November 2018, 3,173 patients underwent bioprosthetic aortic valve replacements. SAVR and CAVR were performed in 641 and 2,532 patients, respectively. Propensity score-matched analysis was performed in 640 patient pairs. @*Results@#Operative mortality rate was 2.8% without significant differences between the SAVR (3.4%) and CAVR (2.3%) groups (P = 0.324). There were no significant differences in postoperative morbidities between the groups except for permanent pacemaker (PPM) implantation. PPM implantation rate was significantly higher in the SAVR (3.8%) than in the CAVR group (0.9%) (P < 0.001). One- and two-year overall survival was 89.1% and 87.5%, respectively, without significant differences between the groups (SAVR group vs. CAVR group = 89.9% and 90.5% vs. 87.2% and 88.7%, respectively; P = 0.475). There were no significant differences in the cumulative incidence of cardiac death, stroke, aortic valve reoperation and infective endocarditis between the groups. Cumulative PPM implantation incidence at 6 months in the CAVR was 1.1%, and no patient required PPM implantation after 6 months. In the SAVR, the cumulative PPM implantation incidence at 0.5, one, and two years was 3.9%, 5.0% and 5.6%, respectively. The cumulative PPM implantation rate was higher in the SAVR group than in the CAVR group (P < 0.001). @*Conclusion@#Early and 2-year clinical outcomes between SAVR and CAVR were not different except for a high rate of permanent pacemaker implantation in the SAVR group.

The Impact of an Attending Intensivist on the Clinical Outcomes of Patients Admitted to the Cardiac Surgical Intensive Care Unit after Coronary Artery Bypass Grafting

Background@#We aimed to investigate the associations of critical care provided in a cardiac surgical intensive care unit (CSICU) staffed by an attending intensivist with improvements in intensive care unit (ICU) quality and reductions in postoperative complications. @*Methods@#Patients who underwent elective isolated coronary artery bypass grafting (CABG) between January 2007 and December 2012 (the control group) were propensity- matched (1:1) to CABG patients between January 2013 and June 2018 (the intensivist group). @*Results@#Using propensity score matching, 302 patients were extracted from each group. The proportion of patients with at least 1 postoperative complication was significantly lower in the intensivist group than in the control group (17.2% vs. 28.5%, p=0.001). In the intensivist group, the duration of mechanical ventilation (6.4±13.7 hours vs. 13.7±49.3 hours, p=0.013) and length of ICU stay (28.7±33.9 hours vs. 41.7±90.4 hours, p=0.018) were significantly shorter than in the control group. The proportions of patients with prolonged mechanical ventilation (2.3% vs. 7.6%, p=0.006), delirium (1.3% vs. 6.3%, p=0.003) and acute kidney injury (1.3% vs. 5.3%, p=0.012) were significantly lower in the intensivist group than in the control group. @*Conclusion@#A transition from an open ICU model with trainee coverage to a closed ICU model with attending intensivist coverage can be expected to yield improvements in CSICU quality and reductions in postoperative complications.

Outcomes and Patency of Complex Configurations of Composite Grafts Using Bilateral Internal Thoracic Arteries

Background@#It is generally agreed that using a bilateral internal thoracic artery (BITA) composite graft improves long-term survival after coronary artery bypass grafting (CABG). Although the left internal thoracic artery (LITA)-based Y-composite graft is widely adopted, technical or anatomical difficulties necessitate complex configurations. We aimed to investigate whether BITA configuration impacts survival or patency in patients undergoing coronary revascularization. @*Methods@#Between January 2006 and June 2017, 1,161 patients underwent CABG at Seoul National University Bundang Hospital, where the standard technique is a LITA-based Y-composite graft with the right internal thoracic artery (RITA) sequentially anastomosed to non-left anterior descending (LAD) targets. Total of 160 patients underwent CABG using BITA with modifications. Their medical records and imaging data were reviewed retrospectively to investigate technical details, clinical outcomes, and graft patency. @*Results@#Modifications of the typical Y-graft (group 1, n=90), LITA-based I-graft (group 2, n=39), and RITA-based composite graft (group 3, n=31) were used due to insufficient RITA length (47%), problems using LITA (28%), and target vessel anatomy (25%). The overall 30- day mortality rate was 1.9%. Among 116 patients who underwent computed tomography or conventional angiography at a mean interval of 29.9±33.1 months postoperatively, the graft patency rates were 98.7%, 95.3%, and 83.6% for the LAD, left circumflex artery, and right coronary artery territories, respectively. Patency rates for the inflow, secondary, and tertiary grafts were 98.2%, 90.5%, and 80.4%, respectively. The RITA-based graft (group 3) had the lowest patency rate of the various configurations (p<0.011). @*Conclusion@#LITA-based Y composite graft, showed satisfactory clinical outcomes and patency whereas modifications of RITA- based composite graft had the lowest patency and 5-year survival rates. Therefore, when using RITA-based composite graft, other options should be considered before proceeding atypical configurations.

Subclinical Hypothyroidism Affects the Long-Term Outcomes of Patients Who Undergo Coronary Artery Bypass Grafting Surgery but Not Heart Valve Surgery

Background@#The aim of this study was to determine the associations between subclinical hypothyroidism (SCH) and long-term cardiovascular outcomes after coronary artery bypass grafting (CABG) or heart valve surgery (HVS). @*Methods@#We retrospectively reviewed and compared all-cause mortality, cardiovascular mortality, and cardiovascular events in 461 patients who underwent CABG and 104 patients who underwent HVS. @*Results@#During a mean±standard deviation follow-up duration of 7.6±3.8 years, there were 187 all-cause deaths, 97 cardiovascular deaths, 127 major adverse cardiovascular events (MACE), 11 myocardial infarctions, one unstable angina, 70 strokes, 30 hospitalizations due to heart failure, 101 atrial fibrillation, and 33 coronary revascularizations. The incidence of all-cause mortality after CABG was significantly higher in patients with SCH (n=36, 55.4%) than in euthyroid patients (n=120, 30.3%), with a hazard ratio of 1.70 (95% confidence interval, 1.10 to 2.63; P=0.018) after adjustment for age, sex, current smoking status, body mass index, underlying diseases, left ventricular dysfunction, and emergency operation. Interestingly, low total triiodothyronine (T3) levels in euthyroid patients who underwent CABG were significantly associated with increased risks of all-cause mortality, cardiovascular mortality, and MACE, but those associations were not observed in HVS patients. Both free thyroxine and thyroid-stimulating hormone levels in euthyroid patients were not related with any cardiovascular outcomes in either the CABG or HVS group. @*Conclusion@#SCH or low total T3 might be associated with a poor prognosis after CABG, but not after HVS, implying that preoperative thyroid hormonal status may be important in ischemic heart disease patients.

Clinical Outcomes of Surgical Repair with a Composite Graft for Abdominal Aortic Aneurysm Accompanied by Iliac Artery Aneurysm

Background@#Iliac artery aneurysm is frequently found in patients undergoing surgical repair of an abdominal aortic aneurysm. The use of commercial bifurcated grafts is insufficient for aorto-biiliac replacement with complete iliac artery aneurysm resection. We evaluated the effectiveness of handmade composite grafts for this purpose. @*Methods@#A total of 233 patients underwent open surgery for abdominal aortic aneurysm between 2003 and 2019, including 155 patients (67%) treated with commercial grafts and 78 patients (33%) treated with handmade composite grafts. Their operative characteristics, postoperative outcomes, and late outcomes were retrospectively reviewed. @*Results@#The early mortality rate did not differ significantly between the groups. On average, the handmade composite graft technique took approximately 15 minutes longer than the commercial graft technique (p=0.037). Among patients who underwent elective surgery, no significant differences between the conventional and composite groups were observed in the major outcomes, including red blood cell transfusion volume (2.8±4.7 units vs. 3.1±4.7 units, respectively; p=0.680), reoperation for bleeding (2.7% vs. 3.1%, respectively; p>0.999), bowel ischemia (0% vs. 1.6%, respectively; p=0.364), and intensive care unit stay duration (1.9±6.6 days vs. 1.6±2.4 days, respectively; p=0.680). The incidence of target vessel occlusion also did not differ significantly between groups. @*Conclusion@#The increased technical demand involved with handmade composite grafting did not negatively impact the outcomes. This technique may be a viable option because it overcomes problems associated with commercial grafts.

Risk Factor Analysis of Extended Opioid Use after Coronary Artery Bypass Grafting: A Clinical Data Warehouse-Based Study / 대한의료정보학회지

OBJECTIVES: A clinical data warehouse (CDW) is part of our hospital information system, and it provides user-friendly ‘data search and extraction’ interfaces for query composition. We carried out a risk factor analysis for the extended use of opioids after coronary artery bypass grafting (CABG), taking advantage of the CDW system. METHODS: From 2015 to 2017, clinical data from 461 patients who had undergone either isolated or concomitant CABG were extracted using the CDW; the extracted data included baseline patient characteristics, various examination results, and opioid prescription information. Supplementary data that could not be extracted with the CDW were collected via manual review of the electronic medical records. RESULTS: Data from a total of 447 patients were analyzed finally. The mean patient age was 66.8 ± 10.9 years, 332 patients (74%) were male, and 235 patients (53%) had diabetes. Among the 447 patients, 90 patients (20.1%) took some type of opioid at the 15th postoperative day. An oral rapid-acting agent was the most frequently used opioid (83%). In the risk factor analysis for extended opioid use, duration of operation was the only significant risk factor (odds ratio = 1.004; 95% confidence interval, 1.001–1.007; p = 0.008). CONCLUSIONS: Longer operation time was associated with the risk of extended opioid use after CABG. CDW was a helpful tool for extracting mass clinical data rapidly, but to maximize its utility, the data should be checked carefully as they are entered in the system so that post-processing can be minimized. Further refinement of the clinical data input and output interface is warranted.

Comparison of Radiofrequency Ablation and Cryoablation for the Recovery of Atrial Contractility and Survival

BACKGROUND: Limited comparative data are available on the efficacy of cryoablation versus radiofrequency ablation in patients with atrial fibrillation. This study aimed to compare radiofrequency ablation and cryoablation with regard to clinical outcomes and the restoration of sinus rhythm or atrial contractility. METHODS: A total of 239 patients who underwent surgical ablation between August 2003 and December 2016 at our institution were included. The patients were divided into 2 groups according to the energy device that was used (group A: n=140, radiofrequency ablator; group B: n=99, cryoablator). Echocardiographic data, overall survival, and major cardiovascular and cerebrovascular event (MACCE)-free survival were compared between the 2 groups. RESULTS: At 1 year of follow-up, the atrial contractility recovery rate was 32.2% (19 of 59) in group A and 48.8% (21 of 44) in group B. In addition, cryoablation was found to be a predictive factor for the recovery of atrial contractility (cryoablation vs. radiofrequency ablation: odds ratio, 2.540; 95% confidence interval, 1.063–6.071; p=0.036). The left ventricular ejection fraction was significantly higher in group B (53.1%±11.5% vs. 59.1%±6.3%, p=0.001). The median follow-up duration was 36 months. The 5-year overall survival rate was 80.1%±3.6% in group A and 92.1%±2.9% in group B (p=0.400). The 5-year MACCE-free survival rate was 70.3%±4.0% in group A and 70.9%±5.6% in group B (p=0.818). CONCLUSION: Cryoablation was associated with a higher atrial contractility restoration rate and better left ventricular function than radiofrequency ablation. However, no significant relationship was observed between the energy source and overall or MACCE-free survival.

Beyond the Role of CD55 as a Complement Component

The complement is a part of the immune system that plays several roles in removing pathogens. Despite the importance of the complement system, the exact role of each component has been overlooked because the complement system was thought to be a nonspecific humoral immune mechanism that worked against pathogens. Decay-accelerating factor (DAF or CD55) is a known inhibitor of the complement system and has recently attracted substantial attention due to its role in various diseases, such as cancer, protein-losing enteropathy, and malaria. Some protein-losing enteropathy cases are caused by CD55 deficiency, which leads to complement hyperactivation, malabsorption, and angiopathic thrombosis. In addition, CD55 has been reported to be an essential host receptor for infection by the malaria parasite. Moreover, CD55 is a ligand of the seven-span transmembrane receptor CD97. Since CD55 is present in various cells, the functional role of CD55 has been expanded by showing that CD55 is associated with a variety of diseases, including cancer, malaria, protein-losing enteropathy, paroxysmal nocturnal hemoglobinuria, and autoimmune diseases. This review summarizes the current understanding of CD55 and the role of CD55 in these diseases. It also provides insight into the development of novel drugs for the diagnosis and treatment of diseases associated with CD55.

Mid-Term Results of Minimally Invasive Direct Coronary Artery Bypass Grafting

BACKGROUND@#Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients.@*METHODS@#All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data—including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention—were collected.@*RESULTS@#The mean age of the patients was 69.4±11.1 years and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in the intensive care unit and in the hospital were 1.5 and 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of 85.3%±0.09% and a 5-year MACCE-free survival rate of 72.8%±0.1%. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at 9.7±10.8 months postoperatively.@*CONCLUSION@#MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.

Mid-Term Results of Minimally Invasive Direct Coronary Artery Bypass Grafting / 대한흉부외과학회지

BACKGROUND: Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients. METHODS: All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data—including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention—were collected. RESULTS: The mean age of the patients was 69.4±11.1 years and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in the intensive care unit and in the hospital were 1.5 and 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of 85.3%±0.09% and a 5-year MACCE-free survival rate of 72.8%±0.1%. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at 9.7±10.8 months postoperatively. CONCLUSION: MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.

Prediction of Intimal Tear Site by Computed Tomography in Acute Aortic Dissection Type A

BACKGROUND AND OBJECTIVES: Preoperative identification of intimal tear site in acute type A dissection will help procedural planning. The objective of this study was to determine the key findings of computed tomography (CT)-based prediction for tear site and compare the accuracy between radiologists and surgeons. SUBJECTS AND METHODS: Multi-detector CT (MDCT) images from 50 patients who underwent surgical repair of type A aortic dissection were retrospectively reviewed by 4 cardiac surgeons with limited experience or by 3 radiologists specialized in cardiovascular imaging. Surgical findings of intimal tear site were used as references. RESULTS: In surgical findings, the locations of intimal tear that were identified in 43 patients included aorta (n=25), ascending with arch (n=7), and arch only (n=11). The rest were retrograde dissections from the tear of descending aorta. Key CT findings that were most frequently found were defect in the intimal flap shadow (30.0+/-4.0 patients/reviewer, accuracy 87.0+/-11.7%) and differential filling of false lumen by phase and location (9.4+/-2.9 patients/reviewer, 84.8+/-10.4%). Surgeons predicted tear site (75.0+/-7.7% vs. 86.7+/-1.2%, p=0.055) and specified flap defect (80.5+/-10.3% vs. 95.7+/-7.4%, p=0.073) with lower accuracy than radiologists. CONCLUSIONS: With MDCT imaging, well-educated surgeons could be accurate in three fourths of cases. There was room for improvement through experience. Considering the substantial possibility of inaccuracy, critical decisions on CT images should be made through thorough reviewing by as many experienced radiologists and surgeons as possible.

Pulmonary Thromboembolism - A Complication after Surgical Repair of a Chronic Femoral Arteriovenous Fistula / 대한내과학회지

Rarely, an arteriovenous fistula (AVF) can follow a femoral arterial puncture for cardiovascular catheterization. Surgical repair has been suggested as the standard treatment. We report a 66-year-old woman with a pulmonary thromboembolism as a complication of surgical repair of a chronic femoral AVF. We believe that the repair of the AVF led to a sudden decrease in venous blood flow, leading to thrombus formation at the site of damaged endothelium. Therefore, doctors should consider all possible complications that can arise from a sudden change in blood flow as a result of repairing a chronic AVF.

Current Trend of Robotic Thoracic and Cardiovascular Surgeries in Korea: Analysis of Seven-Year National Data

BACKGROUND: Robotic surgery is an alternative to minimally invasive surgery. The aim of this study was to report on current trends in robotic thoracic and cardiovascular surgical techniques in Korea. METHODS: Data from the National Evidence-based Healthcare Collaborating Agency (NECA) between January 2006 and June 2012 were used in this study, including a total of 932 cases of robotic surgeries reported to NECA. The annual trends in the case volume, indications for robotic surgery, and distribution by hospitals and surgeons were analyzed in this study. RESULTS: Of the 932 cases, 591 (63%) were thoracic operations and 340 (37%) were cardiac operations. The case number increased explosively in 2007 and 2008. However, the rate of increase regained a steady state after 2011. The main indications for robotic thoracic surgery were pulmonary disease (n=271, 46%), esophageal disease (n=199, 34%), and mediastinal disease (n=117, 20%). The main indications for robotic cardiac surgery were valvular heart disease (n=228, 67%), atrial septal defect (n=79, 23%), and cardiac myxoma (n=27, 8%). Robotic thoracic and cardiovascular surgeries were performed in 19 hospitals. Three large volume hospitals performed 94% of the case volume of robotic cardiac surgery and 74% of robotic thoracic surgery. Centralization of robotic operation was significantly (p<0.0001) more common in cardiac surgery than in thoracic surgery. A total of 39 surgeons performed robotic surgeries. However, only 27% of cardiac surgeons and 23% of thoracic surgeons performed more than 10 cases of robotic surgery. CONCLUSION: Trend analysis of robotic and cardiovascular operations demonstrated a gradual increase in the surgical volume in Korea. Meanwhile, centralization of surgical cases toward specific surgeons in specific hospitals was observed.

Wrapping of an Ascending Aortic Aneurysm with the Multiple Boot-Straps Technique in a Patient Undergoing Off-Pump Coronary Artery Bypass Grafting

Ascending aortic aneurysms are usually treated with graft replacement under cardiopulmonary bypass. However, if a candidate for off-pump coronary artery bypass grafting has an enlarged ascending aorta, surgeons may consider wrapping it without cardiopulmonary bypass. Here, we report a 78-year-old female who underwent successful wrapping of the ascending aorta concomitant with off-pump coronary artery bypass grafting, using a new wrapping technique that involves multiple bootstraps.

Sternal Healing after Coronary Artery Bypass Grafting Using Bilateral Internal Thoracic Arteries: Assessment by Computed Tomography Scan

BACKGROUND: This study aimed to investigate sternal healing over time and the incidence of poor sternal healing in patients undergoing coronary artery bypass graft (CABG) surgery using bilateral internal thoracic arteries. MATERIALS AND METHODS: This study enrolled 197 patients who underwent isolated CABG using skeletonized bilateral internal thoracic arteries (sBITA) from 2006 through 2009. Postoperative computed tomography (CT) angiography was performed on all patients at monthly intervals for three to six months after surgery. In 108 patients, an additional CT study was performed 24 to 48 months after surgery. The axial CT images were used to score sternal fusion at the manubrium, the upper sternum, and the lower sternum. These scores were added to evaluate overall healing: a score of 0 to 1 reflected poor healing, a score of 2 to 4 was defined as fair healing, and a score of 5 to 6 indicated complete healing. Medical records were also retrospectively reviewed to identify perioperative variables associated with poor early sternal healing. RESULTS: Three to six months after surgery, the average total score of sternal healing was 2.07+/-1.52 and 68 patients (34.5%) showed poor healing. Poor healing was most frequently found in the manubrium, which was scored as zero in 72.6% of patients. In multivariate analysis, the factors associated with poor early healing were shorter post-surgery time, older age, diabetes mellitus, and postoperative renal dysfunction. In later CT images, the average sternal healing score improved to 5.88+/-0.38 and complete healing was observed in 98.2% of patients. CONCLUSION: Complete sternal healing takes more than three months after a median sternotomy for CABG using sBITA. Healing is most delayed in the manubrium.

Change of Proximal Descending Aortic False Lumen after Conventional Repair of Acute Type I Dissection: Is It Always Unfavorable?

BACKGROUND: Some patients show favorable changes in the descending aortic false lumen after conventional repair of acute type A dissection, although the incidence of favorable changes has been reported to be low. We aimed to investigate the incidence of positive postoperative changes in the false lumen and the factors associated with positive outcomes. METHODS: In 63 patients who underwent surgery for type A acute dissection as well as serial computed tomography (CT) scanning, morphological parameters were compared between the preoperative, early postoperative (mean interval, 5.4 days), and late CT scans (mean interval, 31.0 months) at three levels of the descending thoracic aorta. RESULTS: In the early postoperative CT images, complete false lumen thrombosis and/or true lumen expansion at the proximal descending aorta was observed in 46% of the patients. In the late images, complete thrombosis or resolution of the proximal descending false lumen occurred in 42.9% of the patients. Multivariate analysis found that juxta-anastomotic false lumen thrombosis was predictive of favorable early changes, which were in turn predictive of continuing later improvement. CONCLUSION: Even after conventional repair without inserting a frozen elephant trunk, the proximal descending aortic false lumen showed positive remodeling in a substantial number of patients. We believe that the long-term prognosis of type A dissection can be improved by refining surgical technique, and particularly by avoiding large intimal tears at the anastomosis site during the initial repair.

Robot-Assisted Cardiac Surgery Using the Da Vinci Surgical System: A Single Center Experience

BACKGROUND: We report our initial experiences of robot-assisted cardiac surgery using the da Vinci Surgical System. METHODS: Between February 2010 and March 2014, 50 consecutive patients underwent minimally invasive robot-assisted cardiac surgery. RESULTS: Robot-assisted cardiac surgery was employed in two cases of minimally invasive direct coronary artery bypass, 17 cases of mitral valve repair, 10 cases of cardiac myxoma removal, 20 cases of atrial septal defect repair, and one isolated CryoMaze procedure. Average cardiopulmonary bypass time and average aorta cross-clamping time were 194.8+/-48.6 minutes and 126.1+/-22.6 minutes in mitral valve repair operations and 132.0+/-32.0 minutes and 76.1+/-23.1 minutes in myxoma removal operations, respectively. During atrial septal defect closure operations, the average cardiopulmonary bypass time was 128.3+/-43.1 minutes. The median length of stay was between five and seven days. The only complication was that one patient needed reoperation to address bleeding. There were no hospital mortalities. CONCLUSION: Robot-assisted cardiac surgery is safe and effective for mitral valve repair, atrial septal defect closure, and cardiac myxoma removal surgery. Reducing operative time depends heavily on the experience of the entire robotic surgical team.

Clinical Results of Cardiovascular Surgery in the Patients Older than 75 Years

BACKGROUND: The balance of the risks and the benefits of cardiac surgery in the elderly remains a major concern. We evaluated the early and mid-term clinical results of patients aged over 75 years who underwent major cardiovascular surgery. METHODS: Two hundred and fifty-one consecutive patients, who underwent cardiac surgery at Seoul National University Bundang Hospital between July 2003 and June 2011, were included in this study (mean age, 78.7+/-3.4 years; male:female=130:121). Elective surgery was performed in 112 patients, urgent in 90, and emergency in 49. RESULTS: Early mortality was 12.7% (32/251). Follow-up completion was 100%, and the mean follow-up duration was 2.8+/-2.2 years. Late mortality was 24.2% (53/219). There were 283 readmissions in a total of 109 patients after discharge. However, the reason for readmission was related more to non-cardiac factors (71.3%) than to cardiac factors. The overall survival estimates were 79.2% at the 1-year follow-up and 58.4% at the 5-year follow-up. Patients who underwent elective surgery had a lower early mortality rate (elective, 4.5%; urgent, 13.3%; emergency, 30.6%) and better overall survival rate than those that underwent urgent or emergency surgery (p <0.001). CONCLUSION: The timing of cardiac surgery was found to be an independent risk factor for early and late mortality. Thus, earlier referral and intervention may improve operative results. Further, comprehensive coordinated postoperative care is needed for other comorbid problems in aged patients.

The Anti-calcification Effect of Dithiobispropionimidate, Carbodiimide and Ultraviolet Irradiation Cross-linking Compared to Glutaraldehyde in Rabbit Implantation Models

BACKGROUND: Glutaraldehyde (GA) is a widely used cross-linking agent for improving mechanical properties and resistance to enzymatic degradation of collagenous tissue, but it has several drawbacks such as calcification and cytotoxicity. The aim of this study was to find the alternative effective cross-linking methods to GA. MATERIALS AND METHODS: Bovine pericardium was processed with GA with ethanol+octanol and glycine detoxification, and polyethylene glycol (PG) space filler, dimethyl 3,3'-dithiobispropionimidate (DTBP), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) treatment, and the physical fixation of ultraviolet irradiation were done. The biologic material properties of variously treated pericardial tissues were assessed by biochemical, mechanical and histological tests. Treated pericardial tissues were also implanted subcutaneously or intramuscularly into the rabbit for 10 weeks to assess the xenoreactive antibody response of immunoglobulin G and M, their anti-calcification effect. RESULTS: The biochemical and mechanical properties of EDC fixed pericardial tissues were comparable to the GA fixed tissue. The cytotoxicity was lowest in space filler treated GA fixed group. In rabbit subcutaneous or intramuscular implantation models, decellularization, space filler, EDC treatment group showed significantly lower calcium content than GA only and DTBP treatment group (p<0.05, analysis of variance). The titer of anti Galalpha1-3Galbeta1-4GlcNAc-R antibodies did not change in the postimplantation serial enzyme-linked immunosorbent assay. Hematoxylin and eosin and von Kossa staining showed that decellularization, space filler, EDC, and ultraviolet treatment had less inflammatory cell infiltration and calcium deposits. CONCLUSION: The decellularization process, PG filler, and EDC treatments are good alternative cross-linking methods compared to GA only fixation and primary amine of DTBP treatment for cardiovascular xenograft preservation in terms of the collagen cross-linking stability and in vivo anti-calcification effects.