Sachie Terazawa

Early and Late Outcomes of Aortic Valve Replacement in Dialysis Patients

BACKGROUND Few data are available on the outcomes of aortic valve replacement (AVR) in dialysis patients. Valve selection has been controversial, and systemic calcification in these patients has been an important concern. This study reports our experiences and evaluates whether dialysis patients can be treated in a way that is similar to nondialysis patients. METHODS A retrospective review was performed on 73 AVRs (43 men, 29 women), including one redo operation, for dialysis patients between 1995 and 2007. Mean age was 65.0 +/- 8.3 years. The bioprosthesis was basically selected for elderly patients as for nondialysis patients. RESULTS For a severely calcified ascending aorta, the femoral or subclavian artery was selected for arterial cannulation in 9 patients (12.3%), and aortic cross-clamping under temporary circulatory arrest with moderate hypothermia was applied in 17 (23.3%). Implanted were 51 mechanical and 22 bioprosthetic valves. Four elderly patients in poor general condition received high-performance mechanical valves instead of bioprosthesis to avoid aortic root enlargement. There was no stroke during the perioperative period. Hospital mortality was 6.8%. The overall actuarial survival rate was 74.6% +/- 5.6%, 55.7% +/- 7.6%, and 39.9% +/- 9.7% at 3, 5, and 10 years, respectively. CONCLUSIONS The results for the dialysis patients after AVR were satisfactory. Dialysis patients can be treated in AVR just like nondialysis patients. Valve selection and surgical strategy on a case-by-case basis are important to improve the clinical outcomes in dialysis patients.

Safer aortic crossclamping during short-term moderate hypothermic circulatory arrest for cardiac surgery in patients with a bad ascending aorta

OBJECTIVE Cardiac surgery in patients with severely atherosclerotic or porcelain ascending aorta is technically challenging, with markedly increased risk of atheroembolism. We describe a technique of meticulous crossclamping of a difficult aorta during short-term moderate hypothermic circulatory arrest. METHODS From 1997 to 2007, we found 40 patients (mean age, 70 +/- 8 years), including 14 patients undergoing hemodialysis, whose preoperative computed tomographic and intraoperative epiaortic ultrasonographic scans revealed eggshell calcification (n = 15) or protruding atheromas (n = 25) of the ascending aorta. They underwent cardiac surgery (aortic, 31 patients; mitral, 3 patients; both, 5 patients; and coronary alone, 1 patient) by means of meticulous crossclamping during hypothermic circulatory arrest for 3.4 +/- 1.5 minutes at a rectal temperature of 29.0 degrees C +/- 2.3 degrees C. During hypothermic circulatory arrest, we performed only internal inspection to identify the safe location of crossclamping in 21 patients, whereas we required debridement of calcification or atheroma by using the Cavitron Ultrasonic Surgical Aspirator (Tyco Healthcare, Mansfield, Mass) for safe crossclamping in 19 patients. RESULTS By using this technique, no patients died during the hospital stay. Stroke occurred in 1 (2.5%) patient, and transient agitation occurred in 1 patient. Re-exploration for bleeding was required in 1 patient, and wound infection occurred in 2 patients. During follow-up, with a median time of 5.2 years, the overall survival rates were 100%, 90%, and 76% at 1, 3, and 5 years, respectively. Three patients required reoperations during the follow-up period because of pseudoaneurysm in 2 patients and prosthetic valve infection in 1 patient. CONCLUSION Short-term moderate hypothermic circulatory arrest is quite useful for safe aortic crossclamping after internal inspection or debridement in high-risk patients with a severely atherosclerotic aorta.

Hybrid versus open repair of aortic arch aneurysms: comparison of postoperative and mid-term outcomes with a propensity score-matching analysis

OBJECTIVES Operative strategies for repairing aortic arch aneurysms should be re-evaluated following recent technical advances. METHODS Of 364 patients who underwent aortic arch repair between 2002 and 2014, 58 were high-risk subjects who received isolated hybrid arch repair (HAR) via median sternotomy (type I n = 32, type II n = 1 and type III n = 25). During this period, excluding patients with type A dissection or extensive aneurysms, 124 patients received isolated open arch repair via median sternotomy. The patients in the HAR and open arch repair groups were compared. A propensity score-matching analysis was applied to adjust for baseline risk factors. RESULTS The patients in the HAR group were older (77 years ± 6 vs 69 ± 9, P < 0.0001), exhibited a greater rate of malignancy (21 vs 4.8%, P = 0.0022) and had higher logistic EuroSCORE values (31 ± 18 vs 20 ± 15, P < 0.0001) than those in the open arch repair group. Following propensity score matching creating 38 matched pairs, the differences in preoperative risk diminished. Operative complications, including the mortality rate (2.6 vs 0%), were similar between the groups. Apart from the lower rates of cardiopulmonary bypass (CPB) and circulatory arrest, there was no apparent superiority of HAR with respect to patient recovery. The mean follow-up duration was 52.5 months, during which the rate of freedom from aortic events in the HAR and open arch repair groups was 79 and 99% at 24 months, respectively (P < 0.0001). CONCLUSIONS HAR achieves equivalent short-term results to standard open arch repair, with a decreased need for CPB. However, considering the inferior mid-term outcomes of this procedure, its indications should be limited to high-risk patients.

Transit-time flow characteristics of in situ right gastroepiploic arterial grafts in coronary artery bypass grafting.

OBJECTIVE We investigated flow characteristics of right gastroepiploic arterial grafts, widely used to extend in situ arterial conduits in coronary artery bypass grafting. METHODS Intraoperative transit-time measurements and postoperative angiographic findings were obtained for 111 patients undergoing coronary artery bypass grafting with gastroepiploic artery and bilateral internal thoracic arteries: mean, maximum, and minimum flows; pulsatility index; insufficiency rate; and differentiated index of early diastolic flow. RESULTS Favored target for gastroepiploic artery was posterior descending artery (106 patients, 95%). Patency rates were 91.0% for gastroepiploic artery, 98.2% for left internal thoracic artery, and 97.5% for right internal thoracic artery. There were four flow profiles of gastroepiploic arteries: A (systolic protruded), B (trapezoidal), C (sine waved), and D (diastolic-dominant biphasic). Functional gastroepiploic arteries showed A in 16 cases, B in 6, C in 31, and D in 48, with prevalence according to severity of stenosis in target coronary artery. Two occluded gastroepiploic arteries showed type A, and reverse or competitive flows were types A in 1, B in 1, C in 4, and D in 2. Relative to functional internal thoracic arteries, functional gastroepiploic arteries showed significantly lower minimum flow, higher insufficiency rate, and lower differentiated index of early diastolic flow. CONCLUSION Intraoperative transit-time flow profiles of patent in situ gastroepiploic arterial grafts were classified into four types, closely associated with disease severity of target coronary artery. Patent in situ gastroepiploic arterial grafts show more regurgitant flow and lower differentiated index of early diastolic flow than in situ internal thoracic arterial grafts.

Extended total arch replacement via the L-incision approach: single-stage repair for extensive aneurysms of the aortic arch

OBJECTIVES Total arch replacement via the L-incision approach (a combination of left anterior thoracotomy and upper median sternotomy) can be used to achieve more extensive replacement. METHODS In the period between 2002 and 2014, 279 total arch replacement procedures were performed. After excluding cases of acute aortic dissection and cases involving concomitant, hybrid or frozen elephant trunk procedures, patients who underwent isolated total arch replacement via an L-incision (n = 29) and via median sternotomy (n = 143) were identified and the data pertaining to their cases were analysed. RESULTS Operative mortality was higher in the L-incision group than in the median sternotomy group (6.9 vs 2.1%); however, the difference was not statistically significant. The L-incision group displayed a higher rate of respiratory complications, including pneumonia (28 vs 7.0%, P = 0.0034), the need for tracheostomy (17 vs 2.1%, P = 0.0038) and pulmonary haemorrhage (6.9 vs 0%, P = 0.028). The rate of paraplegia was similar between the groups (0 vs 1.4%, P = 1.00), despite the wider range replaced via the L-incision approach (7.3 ± 1.5 vs 4.7 ± 0.8 anatomical zones, P < 0.001). The rates of other complications and functional recovery were similar. The long-term survival (73 vs 84% at 5 years) and aortic event-free rates (94 vs 96% at 5 years) were similar in both groups. CONCLUSIONS A combination of left anterior thoracotomy and upper median sternotomy can be applied to the single-stage repair of extended aneurysms with acceptable results in appropriately selected patients.

Strategy of Cardiovascular Surgery for Patients With Dementia as Evaluated by Mini-Mental State Examination

BACKGROUND The strategy for cardiovascular surgery in dementia patients is controversial, so we aimed to investigate whether preoperative dementia and its severity might affect the outcomes of cardiovascular surgery by evaluating with the Mini-Mental State Examination (MMSE). Methods and Results: The study group comprised 490 patients undergoing cardiovascular surgery. Their preoperative cognitive status was evaluated using the MMSE, and analysis was performed to compare the patients with MMSE score <24 (dementia group, n=51) or MMSE score 24-30 (non-dementia group, n=439). Furthermore, the effect of the severity of dementia was analyzed with a cut-off MMSE score of 19/20. Risk factors for surgical outcomes were explored using multivariate logistic regression analysis. Hospital mortality was 11.8% in the dementia group and 2.1% in the non-dementia group (P=0.002). Regarding the postoperative morbidities, the incidence of cerebrovascular disorder (P=0.001), pneumonia (P=0.039), delirium (P=0.004), and infection (P=0.006) was more frequent in dementia group. Among the patients with MMSE <20, hospital mortality was as high as 25%, and the rate of delirium was 58%. Multivariate logistic regression analysis revealed that MMSE score <24 (P=0.003), lower serum albumin (P=0.023) and aortic surgery (P=0.036) were independent risk factors for hospital death. CONCLUSIONS Preoperative dementia affects the outcomes of cardiovascular surgery with regard to hospital death and delirium. The surgical indication for patients with MMSE <20 might be difficult, but surgery with an appropriate strategy should be considered for patients with MMSE <24.

Clinical outcomes and quality of life after surgery for dilated ascending aorta at the time of aortic valve replacement; wrapping versus graft replacement

ABSTRACT Wrapping and graft replacement are two optional procedures for the treatment of dilated ascending aorta at the time of aortic valve replacement (AVR). Wrapping is considered less invasive. The aim of this study was to compare the short- and long-term clinical outcomes as well as the long-term quality of life in patients undergoing these two procedures.This study enrolled 40 consecutive patients with dilated ascending aorta who had undergone either wrapping (WAA group, n=20) or replacement (RAA group, n=20) of the ascending aorta at the time of AVR. Short-term outcomes, long-term deaths, and aortic events were evaluated, as was quality of life using the SF-36 Short Form. Long-term maximal proximal aortic diameter was also obtained.There were no early deaths in either group. Pump time was shorter, and transfusion (55% vs. 95%, p=0.035) and postoperative atrial fibrillation (5% vs. 30%, p=0.036) rates were lower, in the WAA than in the RAA group. At a mean follow-up of 4.9 years, the overall 5 year survival rates in the WAA and RAA groups were 78.1% and 87.5%, respectively. There were no significant between group differences in SF-36 scores in any subcategory of this survey. Long-term maximal aortic diameter remained stable in both groups. Both surgical interventions for dilated ascending aorta at the time of AVR yield favorable and comparable results in patients with suitable anatomy. Furthermore, we found no differences in quality of life between these procedures.

The long-term results and changing patterns of biological valves at the mitral position in contemporary practice in Japan

ABSTRACT Mitral valve surgery has changed with the wide acceptance of mitral valve repair. The aim of this study is to obtain the long-term results of patients who underwent mitral valve replacement (MVR) using a biological prosthesis in contemporary practice in Japan. From January 1990 to December 2013, 76 patients underwent MVR using a biological prosthesis with or without concomitant surgery. Data were obtained by means of a questionnaire and a telephone interview. The mean follow-up period was 4.26 years. The etiologies of the patients included dilated cardiomyopathy (DCM) (n=20 [26.3%]), ischemic mitral regurgitation (n=7 [9.2%]). There is a trend towards decreasing number of rheumatic and degenerative disease and increasing number of DCM and ischemic mitral regurgitation. Three patients (3.9%) died in the perioperative period. The 5- and 10-year overall survival rates were 69.6% and 31.7%, respectively. The 5- and 10-year freedom from valve related death were 95.6% and 80.6 %, respectively. The linearized rates of valve-related complications were as follows: thromboembolism (0.63%/patient/year), bleeding (1.25%/patient/year). One patient underwent reoperation for structural degeneration 13 years after the first operation. The present study shows the long-term results of mitral valve replacement with bioproshtesis in a contemporary case series. The practice pattern is changing. The low rate of valve-related complication justify the current patient selection.