Outcomes of emergency endovascular versus open repair for abdominal aortic aneurysm rupture

Purpose@#Ruptured abdominal aortic aneurysm (rAAA) is one of the most common aortic emergencies in vascular surgery and is associated with high operative mortality and morbidity rates despite recent treatment advances. We evaluated operative mortality risks for the outcomes of emergency endovascular aneurysm repair (eEVAR) vs. open repair in rAAA. @*Methods@#Twenty patients underwent eEVAR (n = 12) or open repair (n = 8) for rAAA between 2016 and 2020. We adopted the EVAR first strategy since 2018. Primary endpoints included in-hospital mortality and 1-year survival. The outcome variables were analyzed with Fisher exact, Mann-Whitney test, and linear by linear association. The Kaplan-Meier method was used to estimate survival. @*Results@#There were 13 males (65.0%) and the median age of the study cohort was 78.0 years (range, 49–88 years). Inhospital mortality occurred in 7 patients (35.0%); 5 (50.0%) in the early period and 2 (20.0%) in the later period of this series. According to the procedure type, 4 (50.0%) and 3 (25.0%) in-hospital mortalities occurred in the open repair and eEVAR patients, respectively. In 6 patients (50.0%), eEVAR was performed on unfavorable anatomy. The 1-year survival of eEVAR vs. open repair group was 75% ± 12.5% and 50% ± 17.7%, respectively. On univariate analysis, preoperative highrisk indices, postoperative acute renal failure requiring dialysis, pulmonary complications, and prolonged mechanical ventilation were associated with higher operative mortality. @*Conclusion@#The current data showed relatively superior outcomes with eEVAR vs. open repair for rAAA, even in some patients with unfavorable anatomy supporting the feasibility, efficacy, and safety of EVAR first strategy.

Outcomes of emergency endovascular versus open repair for abdominal aortic aneurysm rupture

Purpose@#Ruptured abdominal aortic aneurysm (rAAA) is one of the most common aortic emergencies in vascular surgery and is associated with high operative mortality and morbidity rates despite recent treatment advances. We evaluated operative mortality risks for the outcomes of emergency endovascular aneurysm repair (eEVAR) vs. open repair in rAAA. @*Methods@#Twenty patients underwent eEVAR (n = 12) or open repair (n = 8) for rAAA between 2016 and 2020. We adopted the EVAR first strategy since 2018. Primary endpoints included in-hospital mortality and 1-year survival. The outcome variables were analyzed with Fisher exact, Mann-Whitney test, and linear by linear association. The Kaplan-Meier method was used to estimate survival. @*Results@#There were 13 males (65.0%) and the median age of the study cohort was 78.0 years (range, 49–88 years). Inhospital mortality occurred in 7 patients (35.0%); 5 (50.0%) in the early period and 2 (20.0%) in the later period of this series. According to the procedure type, 4 (50.0%) and 3 (25.0%) in-hospital mortalities occurred in the open repair and eEVAR patients, respectively. In 6 patients (50.0%), eEVAR was performed on unfavorable anatomy. The 1-year survival of eEVAR vs. open repair group was 75% ± 12.5% and 50% ± 17.7%, respectively. On univariate analysis, preoperative highrisk indices, postoperative acute renal failure requiring dialysis, pulmonary complications, and prolonged mechanical ventilation were associated with higher operative mortality. @*Conclusion@#The current data showed relatively superior outcomes with eEVAR vs. open repair for rAAA, even in some patients with unfavorable anatomy supporting the feasibility, efficacy, and safety of EVAR first strategy.

Guidelines for Transcatheter Aortic Valve Replacement in Korea: Past Obstacles and Future Perspectives

BACKGROUND: Analyses of the efficacy and safety of transcatheter aortic valve replacement (TAVR) in most countries have been based on outcomes obtained in accordance with national practice guidelines and monitoring protocols. The purpose of this study is to share our experience regarding the process for establishing guidelines and monitoring protocols for the use of TAVR in Korea, in the hopes that it may be helpful to others undergoing a similar process in their own country. METHODS: The Korean guidelines for TAVR were established on June 1, 2015 in through a tri-party agreement involving the Department of Health and Welfare, the Korean Society of Thoracic and Cardiovascular Surgery and the Korean Society of Cardiology. We agreed to monitor the guidelines transparently and to exchange opinions regarding amendments or continuation of its contents after 3 years of monitoring. RESULTS: The monitoring meetings were not held as regularly as agreed, and monitoring was also made difficult by insufficient and incomplete data. Nevertheless, during the meetings, measures to improve the monitoring process were discussed, and accordingly, an agreement was made to continue the monitoring process, with the aim of completing data collection by 2018. CONCLUSION: Compliance with guidelines is critical for assessing the efficacy and safety of TAVR. Moreover, the TAVR monitoring process must be properly conducted for an accurate evaluation to be made. Any country planning to introduce TAVR may encounter difficulties with regards to the optimal initiation strategy and subsequent monitoring. Nevertheless, continued efforts should be made to persuade the government and the corresponding medical societies to facilitate the optimal application of TAVR.

Stress-Induced Cardiomyopathy Presenting as Shock

Stress-induced cardiomyopathy has become a more recognized and reported entity. It can be caused by emotional or physical stress, which causes excessive catecholamine release. Typically, the clinical course is benign with conservative treatment being effective. However, stress-induced cardiomyopathy can be fatal. A 41-year-old female presented with cardiogenic shock followed by sudden back pain. Initial echocardiographic finding showed severely decreased ejection fraction with akinesia at all mid-to-apical walls with relatively preserved basal wall contractility. The coronary artery was intact on coronary angiography. Cardiac resuscitation and extra-corporeal membrane oxygenation was needed to manage the cardiogenic shock. Recovery was complete after 2 weeks.

Single and Multiple Valve Surgery in Native Valve Infective Endocarditis

BACKGROUND: Surgical treatment of infective endocarditis (IE) remains a challenge, especially in cases of multiple valve surgery. We evaluated the clinical outcomes of native valve IE and compared the outcomes of single valve surgery with those of multiple valve surgery. MATERIALS AND METHODS: From 1997 to 2011, 90 patients underwent surgery for native valve IE; 67 patients with single valve surgery (single valve group) and 23 patients with multiple valve surgery (multiple valve group). The mean follow-up duration was 73.1+/-47.4 months. RESULTS: The surgical mortality in the total cohort was 4.4%. The overall survival (p=0.913) and valve-related event-free survival (p=0.204) did not differ between the two groups. The independent predictor of postoperative complications was New York Heart Association class (p=0.001). Multiple valve surgery was not a significant predictor of surgical mortality (p=0.225) or late mortality (p=0.936). Uncontrolled infection, urgent or emergency surgery, and postoperative complications were identified as independent predictors of valve-related morbidity, excluding multiple valve surgery (p=0.072). CONCLUSION: In native valve IE, multiple valve surgery as a factor was not an independent predictor of mortality and morbidity. The number of surgically corrected valves in native IE seems to be unrelated to perioperative and long-term outcomes.

Deep Vein as a Graft Conduit / 대한혈관외과학회지

Infected vascular lesion, including aortic graft infection, is one of the most challenging fields in vascular surgery. The primary treatment objectives are to remove the infected graft material and to re-establish vascular continuity with an extra-anatomic bypass or in situ graft replacement. Despite significant progress in perioperative care and antimicrobial therapy, mortality and morbidity remain high. The great saphenous veins are gaining wide popularity as acceptable native vascular grafts, but in terms of flow capacity, their small caliber may be unsuitable for immediate replacement of arterial flow. Superficial femoral popliteal vein grafts are excellent conduits for infected aortic, peripheral arterial and central venous lesion, in terms of feasible harvesting, resistance to infection, serving immediate high postoperative flow and long-term durability. Surgery using the superficial femoral vein (SFV) graft is neither time-consuming nor dangerous. A delicate preoperative and intraoperative surgical plan is mandatory, and future studies regarding the long-term patency, appropriate clinical indication and safety issue of the SFV graft in peripheral vessel reconstruction are warranted.

Preoperative Extracorporeal Membrane Oxygenation for Severe Ischemic Mitral Regurgitation: 2 case reports

Indication for extracorporeal membrane oxygenation (ECMO) has been extended as the experience of ECMO in various clinical settings accumulates and the outcome after ECMO installation improves. We report two cases of successful mitral valve surgery for severe ischemic mitral regurgitation in patients on ECMO support for cardiogenic shock which developed upon coronary angiography.

The In-hospital Clinical Outcomes of Extracorporeal Life Support after Adult Cardiovascular Surgery / 대한흉부외과학회지

BACKGROUND: We analyzed the clinical results and the factors for survival of patients who underwent extracorporeal life support system after adult cardiovascular surgery. MATERIAL AND METHOD: We retrospectively reviewed the medical record of 44 patients (1.6% of the total adult cardiovascular surgical cases) who underwent the use of a ventricular assisted device or extracorporeal membrane oxygenation from January 2002 to August 2008. There were 32 (72.7%) males and their mean age was 61.7+/-14.9 (range: 20~73) years old. The mean duration of extracorporeal life support system was 5.3+/-3.0 (range: 1~12) days. RESULT: Of these 44 patients, 24 (54.5%) patients were successfully weaned from the extracorporeal device. Eighteen (40.9%) survivors were able to be discharged from the hospital. Complications were noted in 38 patients (86.4%). An emergency operation, no usage of a concomitant intraaortic balloon pump and major complications during use of the extracorporeal life support system such as bleeding, flow instability and renal failure were identified as significant risk factors for poor survival on univariated analysis. Owing to educational support and a continuous renal replacement therapy system, the clinical outcomes of these patients have improved since 2006. On multivariated analysis, renal failure and bleeding during extracorporeal life support were significant risk factors for poor survival. CONCLUSION: Although using extracorporeal life support systems after adult cardiovascular surgery revealed acceptable clinical results, determining the optimal treatment strategy and further well designed larger studies are needed to improve the survival rate of patients who undergo extracorporeal life support after adult cardiovascular surgery

Short- and Long-Term Results of Triple Valve Surgery: A Single Center Experience

Triple valve surgery is usually complex and carries a reported operative mortality of 13% and 10-yr survival of 61%. We examined surgical results based on our hospital's experience. A total of 160 consecutive patients underwent triple valve surgery from 1990 to 2006. The most common aortic and mitral valve disease was rheumatic disease (82%). The most common tricuspid valve disease was functional regurgitation (80%). Seventy-four percent of the patients were in New York Heart Association (NYHA) class III and IV. Univariate and multivariable analyses were performed to identify predictors of early and late survival. Operative mortality was 6.9% (n=11). Univariate factors associated with mortality included old age, preoperative renal failure, postoperative renal failure, pulmonary complications, and stroke. Of them, postoperative renal failure and stroke were associated with mortality on multivariable analysis. Otherwise, neither tricuspid valve replacement nor reoperation were statistically associated with late mortality. Survival at 5 and 10 yr was 87% and 84%, respectively. Ninety-two percent of the patients were in NYHA class I and II at their most recent follow-up. Ten-year freedom from prosthetic valve endocarditis was 97%; from anticoagulation-related hemorrhage, 82%; from thromboembolism, 89%; and from reoperation, 84%. Postoperative renal failure and stroke were significantly related with operative mortality. Triple valve surgery, regardless of reoperation and tricuspid valve replacement, results in acceptable long-term survival.

Development of Porcine Pericardial Heterograft for Clinical Application(Tensile Strength-thickness) / 대한흉부외과학회지

BACKGROUND: Bioprosthetic devices for treating cardiovascular diseases and defects may provide alternatives to autologous and homograft tissue. We evaluated the mechanical and physical conditions of a porcine pericardial bioprosthesis treated with Glutaraldehyde (GA), Ethanol, or Sodium dodecylsulfate (SDS) before implantation. MATERIAL AND METHOD: 1) Thirty square-shaped pieces of porcine pericardium were fixed in 0.625%, 1.5% or 3% GA solution. 2) The tensile strength and thickness of these and other bioprosthesis, including fresh porcine pericardium, fresh human pericardium, and commercially produced heterografts, were measured. 3) The tensile strength and thickness of the six treated groups (GA-Ethanol, Ethanol-GA, SDS only, SDS-GA, Ethanol-SDS-GA and SDS-Ethanol-GA) were measured. RESULT: 1) Porcine pericardium fixed in 0.625% GA the thinnest and had the lowest tensile strength, with thickness and tensile strength increasing with the concentration of GA solution. The relationship between tensile strength and thickness of porcine pericardium increased at thicknesses greater than 0.1 mm (correlation-coefficient 0.514, 0<0.001). 2) There were no differences in tensile strength or thickness between commercially-produced heterografts. 3) Treatment of GA, ethanol, or SDS minimally influenced thickness and tensile strength of porcine pericardium, except for SDS alone. CONCLUSION: Porcine pericardial bioprosthesis greater than 0.1 mm thick provide better handling and advantageous tensile strength. GA fixation did not cause physical or mechanical damage during anticalcification or decellularization treatment, but combining SDS-ethanol pre-treatment and GA fixation provided the best tensile strength and thickness.

Development of Porcine Pericardial Heterograft for Clinical Application(Microscopic Analysis of Various Fixation Methods) / 대한흉부외과학회지

BACKGROUND: Various experimental trials for the development of bioprosthetic devices are actively underway, secondary to the limited supply of autologous and homograft tissue to treat cardiac diseases. In this study, porcine bioprostheses that were treated with glutaraldehyde (GA), ethanol, or sodium dodecylsulfate (SDS) were examined with light microscopy and transmission electron microscopy for mechanical and physical imperfections before implantation. MATERIAL AND METHOD: 1) Porcine pericardium, aortic valve, and pulmonary valve were examined using light microscopy and JEM-100CX II transmission electron microscopy, then compared with human pericardium and commercially produced heterografts. 2) Sections from six treated groups (GA-Ethanol, Ethanol-GA, SDS only, SDS-GA, Ethanol-SDS-GA and SDS-Ethanol-GA) were observed using the same methods. RESULT: 1) Porcine pericardium was composed of a serosal layer, fibrosa, and epicardial connective tissue. Treatment with GA, ethanol, or SDS had little influence on the collagen skeleton of porcine pericardium, except in the case of SDS pre-treatment. There was no alteration in the collagen skeleton of the porcine pericardium compared to commercially produced heterografts. 2) Porcine aortic valve was composed of lamina fibrosa, lamina spongiosa, and lamina ventricularis. Treatment with GA, ethanol, or SDS had little influence on these three layers and the collagen skeleton of porcine aortic valve, except in the case of SDS pre-treatment. There were no alterations in the three layers or the collagen skeleton of porcine aortic valve compared to commercially produced heterografts. CONCLUSION: There was little physical and mechanical damage incurred in porcine bioprosthesis structures during various glutaraldehyde fixation processes combined with anti-calcification or decellularization treatments. However, SDS treatment preceding GA fixation changed the collagen fibers into a slightly condensed form, which degraded during transmission electron micrograph. The optimal methods and conditions for sodium dodecylsulfate (SDS) treatment need to be modified.

Neuroprotective Effect of Phenytoin and Hypothermia on a Spinal Cord Ischemic Injury Model in Rabbits / 대한흉부외과학회지

BACKGROUND: Spinal cord ischemic injury during thoracic and thoracoabdominal aortic surgeries remains a potentially devastating outcome despite using various methods of protection. Neuronal voltage-dependent sodium channel antagonists are known to provide neuroprotection in cerebral ischemic models. This study was designed to compare the neuroprotective effects of phenytoin with those of hypothermia in a rabbit model of spinal cord ischemia. MATERIAL AND METHOD: Spinal cord ischemia was induced in New Zealand white rabbits by means of infrarenal aortic cross clamping for 25 minutes. Four groups of 8 animals each were studied. The control group and the hypothermia group received retrograde infusion of saline only (22degrees C, 2 mL/min); the normothermic phenytoin group and the hypothermicphenytoin group received retrograde infusion of 100 mg of phenytoin at different rectal temperatures (39degrees C and 37degrees C, respectively) during the ischemic period. The neurologic function was assessed at 24 and 72 hours after the operation with using the modified Tarlov criteria. The spinal cords were harvested after the final neurologic examination for histopathological examination to objectively quantify the amount of neuronal damage. RESULT: No major adverse effects were observed with the retrograde phenytoin infusion during the aortic ischemic period. All the control rabbits became severely paraplegic. Both the phenytoin group and the hypothermia group had a better neurological status than did the control group (p<0.05). The typical morphological changes that are characteristic of neuronal necrosis in the gray matter of the control animals were demonstrated by means of the histopathological examination, whereas phenytoin or hypothermia prevented or attenuated these necrotic phenomena (p<0.05). The number of motor neuron cells positive for TUNEL staining was significantly reduced, to a similar extent, in the rabbits treated with phenytoin or hypothermia. Phenytoin and hypothermia had some additive neuroprotective effect, but there was no statistical significance between the two on the neurological and histopathological analysis. CONCLUSION: The neurological and histopathological analysis consistently demonstrated that both phenytoin and hypothermia may afford significant spinal cord protection to a similar extent during spinal cord ischemia in rabbits, although no significant additive effects were noticed.

Removal of alpha-Gal Epitopes in Aortic Valve and Pericardium ofPig Using Green Coffee Bean alpha-Galactosidase / 대한흉부외과학회지

BACKGROUND: It is currently thought that tissue valve degeneration is related to an animal's immune response, which is mainly due to cell surface alpha-Gal epitopes. Cell surface alpha-Gal epitopes are known to be degraded by the enzyme called green coffee bean alpha-galactosidase. It is also well known that alpha-Gal epitopes are immunologically stained by Griffonia Simplicifolia isolectin type B4. We know that many commercially available tissue valves are made of aortic valves and pericardial tissue of pig. So, we investigated whether alpha-Gal epitopes of the aortic valve and pericardial tissue of a pig can be removed by green coffee bean alpha-galactosidase, and we did so by comparing immunologic staining of the tissues before and after the enzyme treatment. MATERIAL AND METHOD: After treating fresh porcine aortic valve and pericardial tissue with green coffee bean alpha-galactosidase at concentrations of 0.5 unit/mL, 1.0 unit/mL, 2.0 unit/mL, respectively, under the condition of pH 6.5, temperature 4degrees C and 24 hours of incubation, each sample was stained with Griffonia Simplicifolia isolectin type B4 immunofluorescent labeling. We then examined whether the alpha-Gal epitopes were reduced or abolished in each consecutive concentration of green coffee bean alpha-galactosidase by comparing the degree of the Griffonia Simplicifolia isolectin B4 staining in each sample. RESULT: In the pig aortic valve tissue, a 1.0 unit/mL concentration of green coffee bean alpha-galactosidase at pH 6.5, 4degrees C and reaction for 24 hours was enough for complete removal of alpha-Gal epitopes from the cell surface on the immunostaining with Griffonia Simplicifolia isolectin B4. On the other hand, more alpha-Gal epitopes were present in the pig pericardial tissue on Griffonia Simplicifolia isolectin B4 staining before the enzyme treatment, and 1.0 unit/mL of galactosidase was not sufficient for complete removal of alpha-Gal from the tissue. 2.0 units/mL of green coffee bean alpha-galactosidase was needed to completely remove the alpha-Gal epitopes from the pericardial tissue on immunostaining. CONCLUSION: The alpha-Gal epitopes of the pig's aortic valve and pericardial tissue were successfully stained with Griffonia Simplicifolia isolectin B4. We could remove nearly all the alpha-Gal epitopes using green coffee bean alpha-galactosidase at the concentration of 1.0 unit/mL in the aortic valve of pig, and 2.0 unit/mL was need to nearly completely remove all the alpha-Gal epitopes in the pericardial tissue of pig under the condition of pH 6.5, 4degrees C and 24 hours of reaction time. In the near future, removal of alpha-Gal epitopes in the pig's aortic valve and pericardial tissue will become a powerful tool for the improvement of the tissue valve durability. It needs to be determined if alpha-galactosidase treated pig tissue is immune to human anti-Gal antibody or anti-Gal monoclonal antibodies.

Influence of Cerebral Protection Methods in Thoracic Aortic Surgery Using Hypothermic Circulatory Arrest / 대한흉부외과학회지

BACKGROUND: Protection of the brain is a major concern during thoracic aortic surgery using hypothermic circulatory arrest (HCA). This study compares the surgical outcomes of two different cerebral protection methods in thoracic aortic surgery using HCA: retrograde cerebral protection (RCP) and antegrade cerebral protection (ACP). MATERIAL AND METHOD: We retrospectively reviewed data on 146 patients who underwent thoracic aortic surgery from May 1995 to February 2007 using either RCP (114 patients, Group 1) or ACP (32 patients, Group 2) during HCA. There were 104 dissections (94 acute and 10 chronic) and 42 aneurysms (41 true aneurysms and 1 pseudoaneurysm), and all patients underwent ascending aortic replacement. There were 33 cases of hemiarch replacement, 5 of partial arch replacement, and 21 of total arch replacement. RESULT: The two groups were similar in preoperative and operative characteristics, but Group 2 had more elderly (over 70 years old) patients (34.4% vs. 10.5%), more coronary artery diseases (18.8% vs. 4.4%), more total arch replacements (46.9% vs. 5.3%) and longer HCA time (50+/-24 minutes vs. 32+/-17 minutes) than Group 1. The operative mortality was 4.4% (5/114) and 3.1% (1/32), the incidence of permanent neurologic deficits was 5.3% (6/114) and 3.1% (1/32), and the incidence of temporary neurologic deficits was 1.8% (2/114) and 9.4% (3/32) in Groups 1 and 2, respectively. There were no statistical differences between the two groups in operative mortality, postoperative bleeding, or neurologic deficits (permanent and temporary). CONCLUSION: The early outcomes of aortic surgery using HCA were favorable and showed no statistical difference between RCP and ACP. However, the ACP patients endured longer HCA times and more extended arch surgeries. ACP is the preferred brain protection technique when longer HCA time is expected or extended arch replacement is needed.

Short Term and Midterm Surgical Results for Infective Endocarditis: Does Wide Debridement and Reconstruction Affect the Post Operative Mortality and Morbidity? / 대한흉부외과학회지

BACKGROUND: We present here the early and midterm surgical results for infective endocarditis and we especially focus on the effect of aggressive reconstruction or root implantation after wide debridement. MATERIAL AND METHOD: Between January 1995 and Jun 2006, we enrolled 79 adult infective endocarditis patients who underwent surgical treatment. There were 63 and 16 native and prosthetic valve endocarditis cases, respectively. They included 27 cases of culture negative endocarditis. With performing valve replacement or repair, 28 of the patient underwent a more aggressive surgical option, for example, aortic root replacement or reconstruction, or heart base reconstruction etc. RESULT: There were statistical relationships between the in-hospital mortality and staphylococcal infection, urgent-based operation and operation during the active phase of endocarditis. Wide debridement and aggressive reconstruction were not related to either the post operative mortality or the early morbidity. Culture negative endocarditis was not related to the postoperative mortality and morbidity. CONCLUSION: Physicians must pay attention to patients' medical treatment during the preoperative period of the infective endocarditis. If surgery is considered for treating infective endocarditis, it should be performed before the downhill course of the disease so that the surgical outcome is improved. Wide debridement and more aggressive reconstruction are also warranted.

Small Aortic Annulus in Aortic Valve Replacement; Comparison between Aortic Annular Enlargement Group and Patient-prosthesis Mismatch Group / 대한흉부외과학회지

BACKGROUND: The effect of patient-prosthesis mismatch (PPM) on the clinical outcome following aortic valve replacement (AVR) remains controversial. This study compared the surgical outcomes of AVR between patients with a patient-prosthesis mismatch and those having undergone an aortic annular enlargement. MATERIAL AND METHOD: Six hundred and twenty seven adult patients, who underwent AVR with stented bioprosthetic or mechanical valves, between January 1996 and February 2006, were evaluated. PPM was defined as an indexed effective orifice area (iEOA) < or =0.85 cm2/m2, and severe if the iEOA < or =0.65 cm2/m2. PPM was present in 103 (16.4%, PPM group) patients, and severe in 11 (1.8%, SPPM group). During the period of the study, 21 patients underwent an AVR with annular enlargement (AE group). RESULT: The mean iEOA of the AE group was larger than that of the PPM group (0.95 vs. 0.76 cm2/m2, p=0.00). The AE group had longer CPB, ACC and operation times than the PPM group, and showed a tendency toward higher operative mortality (14.3% vs. 2.9%, p=0.06). The SPPM group had higher AV pressure gradients (peak/mean) than the AE group (72/45 mmHg vs. 38/25 mmHg, p=0.02/0.06) and suffered more AV related events (AV reoperation or severe aortic stenosis)(45.5% vs. 9.5%, p=0.03). LV masses were not regressed in the patients who experienced an AV related event. CONCLUSION: During AVR in patients with a small aortic annulus, annular enlargement should be carefully applied taking into account the high risk of operative mortality due to annular enlargement and co-morbidities of patients. Aortic annular enlargement; however, should be considered as an alternative method in patients expected to have a severe PPM after an AVR.

Surgery for Myocardial Bridging: A report of two cases / 대한흉부외과학회지

Most myocardial bridgings are found incidentally without symptoms, but myocardial bridging may induce symptoms such as angina, myocardial infarction, and ventricular arrythmia. In a patient who has symptoms despite of proper medication, stent insertion, supra-arterial myotomy or coronary artery bypass grafting have been applied without a definite guideline of treatment. We report two surgical cases of myocardial bridging with a review of the literature.

Angiographic Results of Radial Artery Grafts that are Used for Myocardial Revascularization / 대한흉부외과학회지

BACKGROUND: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other grafts with retrospective manner. MATERIAL AND METHOD: From January 2001 to June 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month (2~110 month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. RESULT: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p<0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. CONCLUSION: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

Risk Factor Analysis for Spinal Cord and Brain Damage after Surgery of Descending Thoracic and Thoracoabdominal Aorta / 대한흉부외과학회지

BACKGROUND: Surgery of descending thoracic or thoracoabdominal aorta has the potential risk of causing neurological injury including spinal cord damage. This study was designed to find out the risk factors leading to spinal cord and brain damage after surgery of descending thoracic and thoracoabdominal aorta. MATERIAL AND METHOD: Between October 1995 and July 2005, thirty three patients with descending thoracic or thoracoabdominal aortic disease underwent resection and graft replacement of the involved aortic segments. We reviewed these patients retrospectively. There were 23 descending thoracic aortic diseases and 10 thoracoabdominal aortic diseases. As an etiology, there were 23 aortic dissections and 10 aortic aneurysms. Preoperative and perioperative variables were analyzed univariately and multivariately to identify risk factors of neurological injury. RESULT: Paraplegia occurred in 2 (6.1%) patients and permanent in one. There were 7 brain damages (21%), among them, 4 were permanent damages. As risk factors of spinal cord damage, Crawford type II.III (p=0.011) and intercostal artery anastomosis (p=0.040) were statistically significant. Cardiopulmonary bypass time more than 200 minutes (p=0.023), left atrial vent catheter insertion (p=0.005) were statistically significant as risk factors of brain damage. Left heart partial bypass (LHPB) was statistically significant as a protecting factor of brain (p=0.032). CONCLUSION: The incidence of brain damage was higher than that of spinal cord damage after surgery of descending thoracic and thoracoabdominal aorta. There was no brain damage in LHPB group. LHPB was advantageous in protecting brain from postoperative brain injury. Adjunctive procedures to protect spinal cord is needed and vigilant attention should be paid in patients with Crawford type II.III and patients who have patent intercostal arteries.

Risk Factor Analysis for Operative Death and Brain Injury after Surgery of Stanford Type A Aortic Dissection / 대한흉부외과학회지

BACKGROUND: Surgery for Stanford type A aortic dissection shows a high operative mortality rate and frequent postoperative brain injury. This study was designed to find out the risk factors leading to operative mortality and brain injury after surgical repair in patients with type A aortic dissection. MATERIAL AND METHOD: One hundred and eleven patients with type A aortic dissection who underwent surgical repair between February, 1995 and January, 2005 were reviewed retrospectively. There were 99 acute dissections and 12 chronic dissections. Univariate and multivariate analysis were performed to identify risk factors of operative mortality and brain injury. RESULT: Hospital mortality occurred in 6 patients (5.4%). Permanent neurologic deficit occurred in 8 patients (7.2%) and transient neurologic deficit in 4 (3.6%). Overall 1, 5, 7 year survival rate was 94.4, 86.3, and 81.5%, respectively. Univariate analysis revealed 4 risk factors to be statistically significant as predictors of mortality: previous chronic type III dissection, emergency operation, intimal tear in aortic arch, and deep hypothemic circulatory arrest (DHCA) for more than 45 minutes. Multivariate analysis revealed previous chronic type III aortic dissection (odds ratio (OR) 52.2), and DHCA for more than 45 minutes (OR 12.6) as risk factors of operative mortality. Pathological obesity (OR 12.9) and total arch replacement (OR 8.5) were statistically significant risk factors of brain injury in multivariate analysis. CONCLUSION: The result of surgical repair for Stanford type A aortic dissection was good when we took into account the mortality rate, the incidence of neurologic injury, and the long-term survival rate. Surgery of type A aortic dissection in patients with a history of chronic type III dissection may increase the risk of operative mortality. Special care should be taken and efforts to reduce the hypothermic circulatory arrest time should always be kept in mind. Surgeons who are planning to operate on patients with pathological obesity, or total arch replacement should be seriously consider for there is a higher risk of brain injury.