A Study on the Occurrence and Prevention of Perioperative Stroke after Coronary Artery Bypass Grafting

Cerebral infarction after coronary artery bypass grafting (CABG) is a serious complication and a problem that remains unsolved. We will report the onset of cerebral infarction in CABG patients in our institution, and its cause, preventive method. The subjects of this research were 761 patients who underwent on-pump isolated CABG. Preoperative, intraoperative and postoperative factors, onset of cerebral infarction and atrial fibrillation were investigated. Postoperative cerebral infarction and postoperative atrial fibrillation were recognized in 1.4% and 24% of the patients, respectively. The risk factors for cerebral infarction were carotid artery stenosis, cardiopulmonary bypass time >180 min, postoperative atrial fibrillation, and β-blocker non-use. The risk factors for postoperative atrial fibrillation were 75 or higher years of age, chronic kidney diseases, emergency surgery, cardiopulmonary bypass time >180 min, intraoperative carperitide non-use, intraoperative landiolol hydrochloride non-use, preoperative angiotensin II receptor blockers (ARB) non-use, preoperative calcium antagonist use, preoperative statin use, postoperative β-blocker non-use, and postoperative aldosterone blocker non-use. The results of this study showed that cerebral infarction occurs frequently in patients who have developed atrial fibrillation, and it was considered that perioperative cerebral infarction can be prevented by perioperative β-blocker, carperitide, anticoagulation therapy and adequate extracorporeal circulation. Since preoperative, intraoperative and postoperative drug use is closely involved in the risk factor for postoperative atrial fibrillation, it was considered possible that adequate perioperative drug therapy can prevent atrial fibrillation and onset of cerebral infarction. (This article is a secondary publication of J Jpn Coron Assoc 2014; 20: 91–7.)     

Long Term Results and Predictors of Left Ventricular Function Recovery after Aortic Valve Replacement for Chronic Aortic Regurgitation

Objectives: In most patients with aortic regurgitation (AR), aortic valve replacement (AVR) improves left ventricular (LV) function, but some patients will not have favorable remodeling. Our objectives were to review long term clinical results of AVR for AR and to examine what factors affect the normalization of LV function after AVR for chronic AR.Methods: Between 1989 and 2010, 177 patients underwent isolated AVR for chronic pure AR. The patients were divided into 2 groups based on indexed end-systolic LV diameter (iESD): Group L (iESD) ≧25 mm/m²) (130 patients) and Group S (iESD <25 mm/m²) (47 patients).Results: There was no significant difference between groups in late mortality, freedom from cardiac-related death and rehospitalization for heart failure at late follow up after operation. At postoperative follow-up, 16% of patients had not recovered normal LV systolic function. By means of multivariate analysis, iESD and cardiac index (CI) were independent predictors of recovery of LV function and iESD >26.7 mm/m² and CI <2.71 l/min/m² were the best cut-off values.Conclusions: Early and late surgical results of AVR for chronic AR were good, but for the preservation of postoperative normal LV function, AVR for AR patients should be performed before iESD reaches 26.7 mm/m².     

Aortic Valve Replacement Using a Continuous Suture Technique

A bstract The continuous suture technique has been proposed as an alternate method for aortic valve replacement (AVR). Advantages include a decreased ischemic and bypass time. Despite reports of a low incidence of perivalvular leak, wide use of the continuous suture technique has not been adopted. This report reviews our experience with the continuous suture technique. From January 1984 through November 1991, 181 consecutive patients underwent AVR using the continuous suture technique. The mean age was 61 years (range 6 to 88 years). Diagnoses included pure aortic stenosis (AS) in 41%, aortic insufficiency (Al) in 31%, and a combination of AS and Al in 28%. Fifty-six patients underwent isolated AVR and 125 underwent AVR combined with other procedures. The overall early mortality was 5.5%. Early mortality for isolated AVR was 0% (0/56) and was 8.0% (10/125) for those undergoing concomitant procedures. Late mortality was 4.7% in a mean follow-up of 30 months (range 1 to 86 months). The incidence of perivalvular leak was 2.3% (4/171 operative survivors). Perivalvular leak was mild in two, and moderate in two; none required reoperation. Perivalvular leak developed only in patients whose suture line was not reinforced with glutaraldehyde treated pericardium. The continuous suture technique is a quick and effective method for AVR and results in a low incidence of perivalvular leak.     

Late gadolinium enhancement as a potential marker of increased perioperative risk in aortic valve replacement

OBJECTIVES Risk assessment of patients with aortic stenosis (AS) undergoing aortic valve replacement (AVR) is challenging. We set out to determine the impact of myocardial late gadolinium enhancement (LGE), as detected by cardiovascular magnetic resonance (CMR), on postoperative outcomes following AVR. METHODS A prospective observational study was conducted on patients undergoing CMR using the LGE technique within 1 year of subsequent AVR. Patients were categorized into absent, mid-wall or infarct patterns of LGE by independent observers blinded to all clinical data, and data were collected with regard to 30-day mortality, major adverse cardiac and cerebrovascular events (MACCE) and postoperative complications. RESULTS A total of 63 patients were studied. Twenty-five patients had no LGE; 20 had mid-wall LGE and 18 had an infarct pattern. The incidence of MACCE, cerebrovascular accident (CVA) and heart block were significantly higher in the mid-wall group compared with the other two groups (MACCE: 25 vs. 0 vs. 5%, P = 0.014; CVA: 20 vs. 0 vs. 0%, P = 0.013; heart block: 30 vs. 4 vs. 12%, P = 0.050). Patients with no LGE had no 30-day MACCE events and no deaths up to 2 years of follow-up. CONCLUSIONS The myocardial LGE holds promise as a means of predicting risk prior to AVR for AS.     

Retrograde continuous cold blood cardioplegia for aortic valve surgery

From September 1983 to February 1987, 45 consecutive aortic valve operations were performed using the retrograde continuous cold blood cardioplegia (RCCBC) via the coronary sinus. Except one patient died of stuck valve after aortic and mitral valve replacements, 44 patients were subjected for this study and all survived patients were symptomatically improved. They were divided into two groups according to the aortic cross clamps time (ACCT). Group 1; 23 patients, ACCT within 120 minutes, and Group 2; 21 patients, ACCT exceeding 120 minutes. After the operation blood was taken periodically to check creatine phosphokinase (CPK) and its iso-enzyme creatine-kinase (CK-MB) and GOT etc. Then their levels were compared between the two groups. Although there seemed to be a tendency that the highest levels of these enzymes increase according to the ACCT, there was no significant difference in CK-MB level between the two groups. Judging from the operative results and the postoperative study of enzymatic level, RCCBC is safe and useful for aortic valve surgery, especially when long ACCT is necessary for correcting complicated lesions or when the coronary orifice is not suitable for coronary perfusion in aortic dissection.     

Dealing with dilated ascending aorta during aortic valve replacement: advantages of conservative surgical approach

Five to fifteen percent of patients undergoing aortic valve replacement (AVR) will have an ascending aortic aneurysm requiring a concomitant surgical procedure. On the other hand, a dilated ascending aorta is known to be a potential source of complications after AVR. From 1972 to 1988, 2278 AVR, either isolated or combined with a second cardiac procedure, were performed in our institution. In the same time interval, a dilated ascending aorta was treated in additional 291 consecutive patients during AVR. Three different surgical options were employed: aortic remodelling and external wall support in 164 patients (56.4%), composite graft replacement in 81 patients (27.8%) and a supracoronary graft in 46 patients (15.8%). Early mortality was 4.8%. Aortic remodelling plus external wall support had the lowest early mortality (1.8%) and the best 8-year survival (89.6%). Supracoronary grafting had a higher early mortality (6.4%) and lower 8-year survival (73.2%). The results of the composite graft were least favourable: early mortality was 9.8% and 8-year survival 76.5%. The results point out the necessity for instituting the appropriate surgical procedure for a dilated ascending aorta during AVR. They show that conservative aortic surgery with preservation of endothelial lining gives excellent early and late results.     

Does Functional Mitral Regurgitation Improve with Isolated Aortic Valve Replacement?

BACKGROUND: The surgical treatment of mitral valve regurgitation (MR) at the time of aortic valve replacement (AVR) remains controversial. The purpose of this study was to evaluate the change in severity of MR following isolated AVR, and to determine survival benefit. METHODS: Between 1991 and 2001, 250 patients underwent isolated AVR; 196 patients had concomitant functional MR. Follow-up transthoracic echocardiography (TTE) was available on 107 patients, with a median of 818 +/- 752 days. Aortic valve was stenotic in 77 and regurgitant in 30 patients. RESULTS: Mean age was 67 +/- 15 years and 57 (53%) were male. Preoperative MR was trivial (1+) in 27 (25%), mild (2+) in 44 (41%), moderate (3+) in 29 (27%), and severe (4+) in 7 (7%). At follow-up TTE, MR improved by 1 or 2 grades in 48 patients (45%). Of patients with preoperative 2+ MR, 19 (43%) improved, 16 (36%) remained unchanged, and 9 (21%) worsened. Although some patients with preoperative 3+ MR exhibited improvement, 11 (38%) remained with moderate-to-severe MR. Of those with a preoperative MR of 4+, 3 (71%) improved, and 4 remained with 3-4+ MR. For patients with preoperative 1 to 2+ MR, survival at 3 years was 98% compared to 78% for those with 3 to 4+ MR (p = 0.038). CONCLUSION: Functional MR does not always improve after isolated AVR. Survival is lower for patients with preoperative 3 to 4+ MR. Moderate-to-severe MR should be repaired at the time of aortic valve surgery.     

Surgical management of esophageal cancer. A decade of change.

OBJECTIVE: To examine trends for use of transhiatal esophagectomy (THE) and to relate outcome variables to changes in use, controlling for preoperative risk. BACKGROUND: High operative morbidity and mortality rates are reported with conventional transthoracic esophagectomy (TTE). Transhiatal esophagectomy has been proposed as an alternative but is controversial. METHODS: In this retrospective study divided into early and late time periods, outcome variables were subjected to univariate and multivariate analyses. RESULTS: Use of THE increased significantly in the late period (p < 0.0001). Patients who had THE had significantly higher American Society of Anesthesiologists (ASA) risk scores (p < 0.001). By the late period, 92% of patients with ASA III/IV scores were resected by THE. Postoperative morbidity decreased significantly and operative mortality decreased from 15% to 0% (p < 0.01) between the early and late time periods. By multivariate analysis, ASA > or = III and TTE were associated with adverse surgical outcome. Pathologic stage determined disease-free survival, which was 37% at 3 years for all survivors. CONCLUSIONS: Increased use of THE results in better operative outcome and does not adversely affect disease-free survival.     

Mechanical Aortic Valve Replacement in Children and Adolescents After Previous Repair of Congenital Heart Disease

Due to improved outcome after surgery for congenital heart defects, children, adolescents, and grown‐ups with congenital heart defects become an increasing population. In order to evaluate operative risk and early outcome after mechanical aortic valve replacement (AVR) in this population, we reviewed patients who underwent previous repair of congenital heart defects. Between July 2002 and November 2008, 15 (10 male and 5 female) consecutive patients (mean age 14.5 ± 10.5 years) underwent mechanical AVR. Hemodynamic indications for AVR were aortic stenosis in four (27%), aortic insufficiency in eight (53%), and mixed disease in three (20%) after previous repair of congenital heart defects. All patients had undergone one or more previous cardiovascular operations due to any congenital heart disease. Concomitant cardiac procedures were performed in all of them. In addition to AVR, in two patients, a mitral valve exchange was performed. One patient received a right ventricle‐pulmonary artery conduit replacement as concomitant procedure. The mean size of implanted valves was 23 mm (range 17–29 mm). There were neither early deaths nor late mortality until December 2008. Reoperations were necessary in five (33%) and included implantation of a permanent pacemaker due to complete atrioventricular block in two (15%), mitral valve replacement with a mechanical prosthesis due to moderate to severe mitral regurgitation in one (7%), aortocoronary bypass grafting due to stenosis of a coronary artery in one (7%), and in one (7%), a redo subaortic stenosis resection was performed because of a secondary subaortic stenosis. At the latest clinical evaluation, all patients were in good clinical condition without a pathological increased gradient across the aortic valve prosthesis or paravalvular leakage in echocardiography. Mechanical AVR has excellent results in patients after previous repair of congenital heart defects in childhood, even in combination with complex concomitant procedures. Previous operations do not significantly affect postoperative outcome.     

Ten-year experience with aortic valve replacement in 482 patients 70 years of age or older: operative risk and long-term results

A retrospective analysis of an institutional experience with aortic valve replacement (AVR) in patients 70 years of age or older during 1976 to 1987 was performed. The study was prompted in part by the current interest in palliative aortic valvoplasty, an interest based to a certain extent on the impression that AVR in the elderly has a high mortality. The mean age of the patients was 75.0 +/- 4.0 years (+/- the standard deviation) (range, 70 to 89 years). Eighty-three percent of patients received porcine valves and 17%, mechanical valves. Preoperatively 32% were in New York Heart Association class III, and 59% were in class IV. Operative mortality was 5.6% for elective isolated AVR for aortic stenosis (19% of all patients), 8.2% for all isolated AVR (38%), and 12.4% overall. Concomitant operative procedures were done in 62.0%; AVR with coronary artery bypass grafting (42%) had an operative mortality of 14.3%. Multivariate analysis showed significant predictors of operative mortality to be emergency operation (p less than 0.01), isolated aortic regurgitation (p = 0.01), and previous cardiac operation (p = 0.02). Follow-up (34 +/- 27 months) was 94% complete. Five-year survival from late cardiac-related death was 81.0%. The constant yearly hazard rate for late death for patients 70 years of age or older who underwent AVR was 5.42% per year, which is similar to the 5.77% per year rate calculated for age-matched and sex-matched controls. Five-year freedom from reoperation was 99%; from late thromboembolic complications, 91%; and from late anticoagulant-related complications, 94%. Freedom from all valve-related morbidity and mortality was 61% at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stentless and stented aortic valve replacement in elderly patients: Factors affecting midterm clinical and hemodynamical outcome.

OBJECTIVE: To report on the midterm results of aortic valve replacement (AVR) with stented and stentless bioprosthesis in an elderly population by analyzing the factors affecting survival and hemodynamical performance. METHODS: In a retrospective study, 145 patients with a Toronto stentless prosthesis are compared with 110 patients with a stented Carpentier-Edwards valve. The 5- to 10-year clinical outcome, transprosthetic gradients, and early and late left ventricular mass (LVM) regression are analyzed in view of specific prosthesis- and patient-related factors. RESULTS: Actuarial survival at 5 years is 82% after stentless AVR versus 68% after stented AVR (p < 0.001) in elderly patients. However, there was no difference in survival at 8 years, being 55.9% and 59.5%, respectively. Univariate analysis revealed that advanced age at the time of operation, NYHA class IV, use of a stented xenograft, presence of patient-prosthesis mismatch (PPM) (IEOA < or = 0.85 cm2/m2), and severe preoperative left ventricular (LV) hypertrophy (LVMI > 180 g/m2) affected survival adversely. But multivariate analysis determined only age, NYHA class IV and excessive LV hypertrophy as independent predictors of late mortality. Stented and stentless xenografts were equally effective in terms of transprosthetic gradients and LVMI regression. The use of a stentless valve significantly reduced the occurrence of PPM (18% vs 41%, p < 0.01). Early LVMI regression at 1 year was optimized by the avoidance of PPM, indicated by a higher absolute (43.7+/-28.3 g/m2 vs 58.6+/-33.8 g/m2, p = 0.003) and relative (25.0+/-12.7% vs 31.4+/-14.9%, p=0.004) mass regression. However, late LV remodeling was predominantly affected by systemic hypertension and severe preoperative LV hypertrophy, resulting in the incomplete LVMI resolution in 61.3% and 66.7% of these patients, respectively. Conclusion: In elderly patients, aortic valve replacement appears to be equally effective with a stentless or stented bioprosthesis. Midterm clinical outcome is mainly determined by patient-related factors such as age, advanced NYHA class, and severity of preoperative LV hypertrophy. Regarding post-AVR left ventricular remodeling, patient-prosthesis mismatch influences the early phase, whereas arterial hypertension affects the late regression more. However, the left ventricular remodeling is continuously compromised by the preoperative presence of excessive hypertrophy, despite the efficacy of the aortic valve replacement.     

Unoperated severe aortic stenosis: decision making in an adult UK-based population

INTRODUCTION

Severe symptomatic aortic stenosis is associated with a poor prognosis, with most patients dying 2–3 years after diagnosis. We analysed the proportion of patients with severe aortic stenosis not referred for aortic valve replacement (AVR) in a UK-based population and the clinical factors contributing to this.

METHODS

Retrospective analysis of patients with echocardiographic evidence of severe aortic stenosis was performed at a university teaching hospital.

RESULTS

A total of 178 consecutive patients with severe aortic stenosis (AVA: <1cm², mean pressure gradient: ≥40mmHg, or visually severe on echocardiography) were included in the study. Eighty-three patients did not have AVR (95% confidence interval: 39–54%). The cohort included 146 symptomatic patients (82%) and 32 (18%) who were asymptomatic. The most common reason for non-referral in symptomatic patients was ‘high operative risk’ and in asymptomatic patients ‘no symptoms’. Of the patients who did not have AVR, only 19% (n=16) were referred for a surgical opinion. None of the patients in the asymptomatic group underwent echocardiographic stress imaging. The thirty-day operative mortality rate in the AVR group was 2.3%. Symptomatic patients who underwent AVR had superior survival, even after adjusting for co-morbidities (p<0.001).

CONCLUSIONS

A considerable proportion of patients with severe aortic stenosis are not referred for surgery although they have a clear indication for AVR. Patients are often estimated as being too high risk or having prohibitive co-morbidities. Among asymptomatic patients, stress imaging was rarely used despite its useful role prognostically and in deciding the best time for intervention.     

Does moderate mitral regurgitation impact early or mid-term clinical outcome in patients undergoing isolated aortic valve replacement for aortic stenosis?

OBJECTIVE: The early and mid-term impact of functional mitral regurgitation (MR) in patients undergoing isolated aortic valve replacement (AVR) for aortic stenosis remains unresolved. METHOD: Through our institutional databank, using a case-match study, we identified 58 patients with MR grades 0-1 and 58 patients with MR grades 2-3 (patients matched for sex, age, ejection fraction (EF), NYHA, diabetes, and CVA). Data were collected prospectively (mean duration of follow-up: 3.2 +/- 2.4 years). RESULTS: Perioperative morbidity (re-operation for bleeding, low cardiac output, CVA, renal failure) was comparable among groups. Difference in mortality between the two groups was non-significant (7.0 vs. 3.5%, P = 0.67 in groups MR 2-3 vs. 0-1, respectively). At early echocardiographic follow-up, 7/58 patients (12.1%) within group MR grades 0-1 increased their MR to grades 2-3; among which only two remained with MR grades 2-3 at mid-term follow-up. Within MR group 2-3, 18/58 (31.0%) remained with MR grades 2-3 among which 7/18 (38.9%) decreased of at least one grade at follow-up. Eight year actuarial survival was comparable in both groups: MR grades 0-1 = 60.9% vs. MR grades 2-3 = 55.0%; P = 0.1. Actuarial survival of patients with MR grades 2-3 postoperatively was similar to patients with MR grades 0-1 (MR grades 0-1 = 59.0%, MR grades 2-3 = 58.9%, P = NS). CONCLUSIONS: Presence of preoperative moderate functional MR (grades 2-3) in patients undergoing isolated AVR for aortic stenosis regresses in the majority of patients postoperatively and has no significant impact on perioperative morbidity or mortality, nor mid-term survival. Thus, moderate functional MR should be treated conservatively in the majority of patients especially in the elderly subjected to isolated AVR for aortic stenosis.     

Aortic valve replacement in the elderly. Risk factors and long-term results.

OBJECTIVE: The current study was undertaken to determine long-term results of aortic valve replacement (AVR) in the elderly, to ascertain predictors of poor outcome, and to assess quality of life. SUMMARY BACKGROUND DATA: Aortic valve replacement is the procedure of choice for elderly patients with aortic valve disease. The number of patients aged 70 and older requiring AVR continues to increase. However, controversy exists as to whether surgery devoted to this subset reflect a cost-effective approach to attaining a meaningful quality of life. METHODS: This study reviews data on 247 patients aged 70 to 89 years who underwent isolated AVR between 1980 and 1995; there were 126 men (51%) and 121 women (49%). Follow-up was 97% complete (239/247 patients) for a total of 974.9 patient-years. Mean age was 76.2 +/- 4.8 years. Operative mortality and actuarial survival were determined. Patient age, gender, symptoms, associated diseases, prior conditions, New York Health Association class congestive heart failure, native valve disease, prosthetic valve type, preoperative catheterization data, and early postoperative conditions were analyzed as possible predictors of outcome. Functional recovery was evaluated using the SF-36 quality assessment tool. RESULTS: Operative mortality was 6.1% (15/247). Multivariate logistic regression showed that poor left ventricular function and preoperative pacemaker insertion were independent predictors of early mortality. After surgery, infection was predictive of early mortality. Overall actuarial survival at 1, 5, and 10 years was 89.5 +/- 2% (198 patients at risk), 69.3 +/- 3.4% (89 patients at risk), and 41.2 +/- 6% (13 patients at risk), respectively. Cox proportional hazards model showed that chronic obstructive pulmonary disease and urgency of operation were independent predictors of poor long-term survival. Postoperative renal failure also was predictive of poor outcome. Using the SF-36 quality assessment tool, elderly patients who underwent AVR scored comparably to their age-matched population norms in seven of eight dimensions of overall health. The exception is mental health. CONCLUSIONS: Aortic valve replacement in the elderly can be performed with acceptable mortality. Significant preoperative risk factors for early mortality include poor left ventricular function and preoperative pacemaker insertion. Predictors of late mortality include chronic obstructive pulmonary disease and urgency of operation. These results stress the importance of operating on the elderly with aortic valve disease; both long-term survival and functional recovery are excellent.     

Management of mild to moderate aortic valve disease during coronary artery bypass grafting.

OBJECTIVE: The long term survival of patients with mild to moderate aortic valve disease who do not have valve replacement at the time of coronary artery bypass grafting (CABG) is unknown. Therefore we have reviewed our experience with such patients. METHODS: We reviewed the medical records of consecutive patients between June 1978 and December 1996, and identified 40 patients with mild to moderate aortic valve disease, who underwent CABG, without valve replacement (study group). Mean preoperative aortic gradient was 34 mmHg and mean intraoperative gradient 20 mmHg. Eleven patients underwent valve inspection, and an equal number, underwent valve repair. The records of 61 other patients with severe aortic valve disease, who underwent concomitant aortic valve replacement (AVR) and CABG (control group), were also reviewed. RESULTS: Survival was significantly better in the control group. Eleven patients (27.5%) in the study group underwent reoperation for AVR, with no operative mortality. Multivariate analysis confirmed valve replacement at initial CABG to be the only predictor of survival (beta=0.586,P=0.038) Preoperative gradient <40 mmHg, intraoperative gradient <20 mmHg, age over 70, sex, aortic stenosis and valve pathology did not predict survival in the study group. CONCLUSION: Patients with mild to moderate aortic valve disease undergoing coronary artery bypass grafting may be best served by valve replacement, rather than repair, inspection or no procedure.     

Realistic expectations of surgical treatment of aortic dissections: The stanford experience

Over a 16-year span, 125 unselected patients with acute and chronic aortic dissections underwent uniform surgical treatment. Fifty-three had acute type A(Ac-A), 29 had chronic type A(Ch-A), 20 had acute type B(Ac-B), and 23 had chronic type B(Ch-B) dissections. Major preoperative complications were encountered frequently; 14% of dissections had ruptured. All patients underwent aortic replacement with tubular grafts; concomitant aortic valve replacement (AVR) was performed in 11% of the Ac-A patients and 38% of Ch-A patients. The primary intimal tear was resected in 78% of operations. Follow-up averaged 4.5 years and extended beyond 13 years. Overall operative mortality rate was 34% for Ac-A, 14% for Ch-A, 45% for Ac-B, and 22% for Ch-B patients. Between January, 1974 and October, 1979 these mortality rates (63 patients Ac-A, 17 Ch-A, 7 Ac-B, 12 Ch-B) declined to 22%, 18%, 14%, and 17%, respectively. Actuarial survival rates (± SEM) for the entire series were 54±5% at 5 years and 26±7% at 10 years. Excluding operative deaths, these were 76±5% and 37±10% at similar intervals. Multiple preoperative variables correlated with both operative risk and long-term survival, but the survival rate appeared not to be influenced by whether AVR was performed (type A patients) or by whether the primary intimal tear was resected (all patients). No differences in long-term survival were evident between the 4 subgroups of patients. Survivors generally sustained satisfactory functional results and experienced good rehabilitation. The results of this investigation argue for immediate operative treatment of acute type A dissections and, possibly, of acute type B dissections as well. Furthermore, surgical resection of symptomatic and/or expanding chronic type A and chronic type B dissections ameliorates symptoms and provides satisfactory long-term survival. Surgical treatment does not “cure” the disease. However, as evidenced by the declining operative risk, acceptable durability of repair, and improved long-term survival, surgical therapy can result in salvage of a substantial majority of patients with life threatening dissection of the aorta.     

The importance of aortic compliance as a prognostic factor after aortic valve replacement

A variety of clinical variables and physiological parameters have been discussed in relation to postoperative survival and symptoms in aortic regurgitation (AR). Many of them have been derived from left ventricular morphology and functions, but there has been no parameter from aortic functions. As the heart is united with the aortic tree to form a circulatory system and both heart and aorta affect each other, aortic functions also have an important prognostic value after aortic valve replacement (AVR). This study was performed to clarify the participation of aortic functions in determining the prognosis after AVR. Fifteen consecutive patients undergoing isolated AVR for AR were evaluated. Twenty-one preoperative hemodynamic and dimensional variables of both heart and aorta were analyzed to determine the risk factors for early postoperative morbidity. These variables were obtained from chest X-ray film, electrocardiogram, echocardiogram, cine-aorto-ventriculogram and pressure manometries. All patients were divided in two groups according to the postoperative course. Group I composed of 10 patients took relatively smooth postoperative course, except two patients suffering from cardiac tamponade. Group II composed of 5 patients suffered from low cardiac output syndrome (LOS) and/or dangerous arrhythmias postoperatively. Two out of them died of uncontrollable ventricular arrhythmias. There were no statistic differences between two groups in the factors derived from preoperative examinations, i.e. CTR, LVDsI, PWT, R/Th, %FS, EDVI, EF, CI, LVEDP, etc. Mean aortic compliance of group II, (3.8 +/- 2.1) X 10(-4) mmHg-1, was, however, significantly lower than that of group I, (21.7 +/- 4.8) X 10(-4) mmHg-1, (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Changing strategy for aortic stenosis with coronary artery disease by transcatheter aortic valve implantation

Coronary artery disease (CAD) is combined with aortic stenosis (AS) in 40–50 % of patients with typical angina. Recently, transcatheter aortic valve implantation (TAVI) has changed the guideline for AS in patients with high comorbidity. At the same time more than 60 % of isolated CABG has been performed without cardiopulmonary bypass in Japan. CABG is recommended and should be considered in patients with primary indication for AVR and luminal stenosis >70 % in major coronary arteries and the left internal thoracic artery (LITA) by guidelines. AVR is indicated for severe AS undergoing CABG. It is generally accepted to perform AVR for moderate AS at the time of CABG by valve guidelines. However, prophylactic AVR for moderate AS associated with CABG may increase the early operative risk and expose the patients to postoperative long-term valve related complications. AVR after previous CABG poses potential risk for mortality and morbidity. The presence of patent ITA is a significant risk of its injury and difficulty of myocardial protection during aortic cross-clamping. Therefore, at present, for severe AS previous CABG with patent ITA should be one of the definite indications of TAVI. Rationale of TAVI in patients with severe AS and CAD has not been clearly delineated. The safety of TAVI irrespective of the extent and anatomy of CAD is still controversial. PCI is not appropriate before TAVI in high-risk patients with CAD. In the near future hybrid TAVI will be realistic considering least operative mortality and morbidity in high-risk patients.     

Long-term experience with porcine aortic valve xenografts

Between 1971 and 1975, glutaraldehyde-preserved porcine aortic valve xenografts were employed for isolated replacement of the mitral valve (MVR) in 243 patients, replacement of the aortic valve (AVR) in 167 patients, and double valve replacement (AVR and MVR) in 51 patients. Postoperatively, long-term anticoagulation was not routinely given. Operative mortality rates for AVR, MVR, and double valve groups were 7.8, 6.0, and 11.8 per cent, respectively; the majority of early postoperative deaths were associated with concomitant coronary artery disease. No death was attributable to xenograft dysfunction. Follow-up of all patients was obtained. The total duration of follow-up for the MVR group was 347 patient-years, for the AVR GROUP 148 148 patient-years, and for double valve replacement 37 patient-years; maximum follow-up for these three groups was 4.4, 4.0, and 2.4 years, respectively. Actuarial analysis of postoperative survival rates at a common interval of 3 years showed 78 per cent for MVR patients, 91 per cent for AVR patients, and 80 per cent (projected) for patients with double valve replacement (85, 96, and 91 per cent for operative survivors, respectively. At this same interval 92 per cent of MVR patients, 99 per cent of AVR patients, and 93 per cent (projected) of patients with double valve replacement were free of thromboembolic episodes. Altogether, 12 of the total 512 valves implanted exhibited some evidence of dysfunction during the entire period of follow-up evaluation, but in only 2 instances (both mitral) was intrinsic pathological involvement of the xenograft tissue documented. Actuarial analysis of xenograft dysfunction at a common interval of 3 years after operation showed 95 per cent of MVR patients, 98 per cent of AVR patients, and 97 per cent (projected) of patients with double valve replacement to be free of this complication. These data support the use of glutaraldehyde-preserved porcine xenografts as superior bioprostheses that pose a low risk of thromboembolism without anticoagulation. The over-all durability of such valves, within the restriction of a maximum current follow-up interval of 4.4 years, appears comparable to that of currently available mechanical prostheses and justifies continued clinical use.     

Clinical outcome of aortic valve replacement in the elderly

Since elderly patients are being referred for surgery in increasing numbers, we reviewed the clinical outcome of 459 consecutive patients aged 70 to 89 years, who had aortic valve replacement between 1993 and 2000. We subdivided the study population into three groups: in Group 1 we included patients aged 70-74 years old; in Group 2 patients aged 75-79 years old; and in Group 3 patients aged 80 years old or older. An isolated AVR was performed in 289 patients (63%), concomitant coronary artery bypass graft (CABG) in 168 patients (36.6%), an isolated ventricular septal defect (VSD) closure in one patient (0.2%) and an isolated atrial septal defect (ASD) closure in one patient (0.2%). The overall perioperative mortality rate was 7% (32 patients), without significant differences among the three groups (P=0.88). Our study confirms the good outcome of aortic valve replacement in elderly patients even in octagenarians and only concomitant CABG procedures increase the operative risk, reducing long-term survival (P<0.05).