Hiromichi Sonoda

The novel EuroSCORE II algorithm predicts the hospital mortality of thoracic aortic surgery in 461 consecutive Japanese patients better than both the original additive and logistic EuroSCORE algorithms

OBJECTIVES The European System for Cardiac Operative Risk Evaluation (EuroSCORE) II was developed to improve the overestimation of surgical risk associated with the original (additive and logistic) EuroSCOREs. The purpose of this study was to evaluate the significance of the EuroSCORE II by comparing its performance with that of the original EuroSCOREs in Japanese patients undergoing surgery on the thoracic aorta. METHODS We have calculated the predicted mortalities according to the additive EuroSCORE, logistic EuroSCORE and EuroSCORE II algorithms in 461 patients who underwent surgery on the thoracic aorta during a period of 20 years (1993-2013). RESULTS The actual in-hospital mortality rates in the low- (additive EuroSCORE of 3-6), moderate- (7-11) and high-risk (≥11) groups (followed by overall mortality) were 1.3, 6.2 and 14.4% (7.2% overall), respectively. Among the three different risk groups, the expected mortality rates were 5.5 ± 0.6, 9.1 ± 0.7 and 13.5 ± 0.2% (9.5 ± 0.1% overall) by the additive EuroSCORE algorithm, 5.3 ± 0.1, 16 ± 0.4 and 42.4 ± 1.3% (19.9 ± 0.7% overall) by the logistic EuroSCORE algorithm and 1.6 ± 0.1, 5.2 ± 0.2 and 18.5 ± 1.3% (7.4 ± 0.4% overall) by the EuroSCORE II algorithm, indicating poor prediction (P < 0.0001) of the mortality in the high-risk group, especially by the logistic EuroSCORE. The areas under the receiver operating characteristic curves of the additive EuroSCORE, logistic EuroSCORE and EuroSCORE II algorithms were 0.6937, 0.7169 and 0.7697, respectively. Thus, the mortality expected by the EuroSCORE II more closely matched the actual mortality in all three risk groups. In contrast, the mortality expected by the logistic EuroSCORE overestimated the risks in the moderate- (P = 0.0002) and high-risk (P < 0.0001) patient groups. CONCLUSIONS Although all of the original EuroSCOREs and EuroSCORE II appreciably predicted the surgical mortality for thoracic aortic surgery in Japanese patients, the EuroSCORE II best predicted the mortalities in all risk groups.

Mechanical Prosthesis Is Reasonable for Mitral Valve Replacement in Patients Approximately 65 Years of Age

BACKGROUND The long-term results of mitral valve replacement (MVR; n = 631) with a bileaflet mechanical prosthesis or a Carpentier-Edwards Perimount bioprosthesis were evaluated in Japanese patients of different age groups. METHODS A total of 507 bileaflet mechanical prostheses and 124 bioprostheses have been implanted since 1982 at our institution. Follow-up was completed for 6,598 patient-years in 98.4% of the cases. RESULTS Among the patients 70 years of age and older, the rate of freedom from valve-related death and valve-related morbidity at 10 years after surgery were significantly better in the bioprostheses group (93.3% ± 6.4% and 83.7% ± 8.7%, respectively; n = 35) than in the mechanical prostheses group (71.1% ± 8.0% and 60.9% ± 8.9%, respectively; n = 82), and neither structural valve deterioration (SVD) nor resulting re-MVR were observed for bioprostheses. In contrast, among the patients 64 years and younger, no significant differences were observed in long-term survival between the mechanical prostheses group (n = 347) and the bioprostheses group (n = 76), while significantly lower rates of freedom from SVD and re-MVR were observed in the bioprostheses group compared with those obtained in the mechanical prostheses group. As for the controversial intermediate-age group of 65 to 69 years, the general tendencies were similar to those observed in the group 64 years and younger. CONCLUSIONS Based on our comparative evaluation, bioprostheses should be chosen for MVR in patients 70 years of age and older, whereas mechanical prostheses were better in the patients 64 years of age and younger. The use of bioprostheses in Japanese patients 65 to 69 years of age is not preferable for preventing SVD and subsequent re-MVR.

Transcranial Doppler Study to Assess Intracranial Arterial Communication Before Aortic Arch Operation

BACKGROUND The assessment of intracranial arterial communication is important to prevent a stroke from occurring during an aortic arch operation. Bilateral axillary artery perfusion was used with the left common carotid artery perfusion for selective cerebral perfusion. A preoperative left carotid artery compression test with measurement of the left middle cerebral artery (LMCA) flow was performed to determine how safe it was to interrupt the perfusion to the left common carotid artery. METHODS Eighteen patients who were scheduled for an aortic arch operation underwent the test. Before surgery, the LMCA flow was detected using transcranial Doppler ultrasonography. During manual compression of the left carotid artery, the flow velocity of the LMCA was measured and expressed as a percent in comparison to the precompression value. RESULTS During carotid artery compression, flow velocity of the LMCA was reduced to 56% +/- 36% (median, 63%; range, 0% to 100%) of the precompression value. The communication to the LMCA assessed with magnetic resonance angiography showed a weak relationship to the functional flow reserve of the LMCA based on a transcranial Doppler study. The results indicated that morphologic observation with magnetic resonance angiography did not reflect the dynamic nature of the intracranial collaterals. CONCLUSIONS A preoperative left carotid artery compression test with a measurement of the flow of the LMCA is useful to assess the feasibility of interrupting perfusion to the left carotid artery during aortic arch surgery with bilateral axillary artery perfusion.

Haemostatic profile of small children during and following cardiopulmonary bypass

OBJECTIVE We evaluated changes of the haemostatic system during pediatric cardiac surgery during and after cardiopulmonary bypass (CPB). METHOD Twenty-five children under 15 kg of body weight undergoing open-heart surgery were divided into three groups; 9 patients (Group A), no bank blood was used throughout the surgery; 8 patients (Group B), packed red cells were used in the priming of CPB circuit; 8 patients (Group C) in cyanotic condition, for whom surgery was performed without bank blood. CPB caused a significant decrease of platelet counts in all three groups, the levels of which remained similar next morning. RESULTS Platelet counts decreased more significantly in Group C (59+/-27 k/mm3) than in Group A (119+/-42 k/mm3) and B (104+/-27 k/mm3). Platelet function-platelet activating factor test (HemoSTATUS) did not significantly decrease throughout the perioperative period in Group A. HemoSTATUS value decreased during CPB and recovered after CPB in Group B and C. Prothrombin time international ratio (PT-INR) and activated partial thromboplastin time were significantly prolonged just after CPB and recovered until next morning in all three groups. PT-INR was more prolonged in Group C (2.92+/-0.62) than in Group A (2.08+/-0.27) and B (2.42+/-0.42). There was no significant difference in postoperative bleeding for the first 12 hours among the three groups. CONCLUSION Although extreme hemodilution during CPB significantly impairs the coagulation and platelet system, these changes are usually transient and tolerable with minimal postoperative hemorrhage. However, a prolonged CPB and preoperative cyanotic condition may induce a critical decrease of platelet counts and increase postoperative bleeding.

Advantages of the L-incision approach comprising a combination of left anterior thoracotomy and upper half-median sternotomy for aortic arch aneurysms

Although surgical outcomes of total arch replacement have improved, the strategy for extended arch aneurysms remains controversial. We have applied the L-incision approach (combination of left anterior thoracotomy and upper half-median sternotomy) for total arch replacement for single-stage repair of extensive arch aneurysms. We retrospectively reviewed the operative outcomes of patients who underwent total arch or extended total arch replacement for degenerative aneurysms from 1999 to 2010. Operations were performed via median sternotomy in 47 patients (M group) and the L-incision approach was used in 38 patients (L group). Through the L-incision approach, we were able to complete distal anastomosis below the pulmonary hilus. The L-incision approach has advantages of reducing selective antegrade cerebral perfusion and lower body circulatory arrest times compared with the M group. Recurrent laryngeal nerve palsy and renal dysfunction were less frequent in the L group than those in the M group. Respiratory dysfunction and wound infection were similar between the groups. Hospital mortalities were 5.3% in the L group and 6.4% in the M group. The L-incision approach has similar or better postoperative outcomes compared with the median sternotomy approach. This approach could be useful for single-stage extended total arch replacement with relatively low risk.

Long-Term Comparison of Three Types of Aortic St. Jude Medical Mechanical Prosthesis in Japanese Patients

BACKGROUND The long-term results achieved with aortic St. Jude Medical (SJM) mechanical prostheses in various age groups of Japanese patients have not been previously compared or reported. METHODSANDRESULTS Since 1981, a total of 240 SJM valves were implanted in 79 patients using the Standard model, in 58 patients with the Hemodynamic Plus model, and in 103 patients with the Regent model for aortic valve replacement (AVR). Follow-up was completed for 2,397 patient-years in 97.5% of the patients, among whom the effect of age was compared, and the subjects were divided into younger (<65 years) and older (≥65 years) groups. Hospital mortality rate was 2.5%. No structural valve deterioration was observed during the follow-up period. In addition, no significant differences were observed in long-term survival between the 3 models. In contrast, significantly better rates of freedom from all-cause death (P<0.0001), valve-related death (P=0.0018) and valve-related morbidity (P=0.0021), including bleeding events (P=0.0007), were observed in the younger group (n=157, 50.6±1.0 years old) than in the older group (n=83, 72.5±0.7 years old). CONCLUSIONS All types of SJM valve used for single AVR achieved satisfactory early and long-term results in each age group even 25 years after surgery. When selecting this prosthesis for elderly patients, however, relatively worse performance may be expected compared with that observed in younger patients.

Acute torrential mitral regurgitation during transcatheter aortic valve replacement: a case report

BackgroundTranscatheter aortic valve replacement (TAVR) is a minimally invasive approach to aortic valve replacement. However, critical cardiovascular collapse can occur during the procedure for various reasons.Case presentationA 90-year-old man with severe aortic stenosis and left circumflex artery stenosis developed acute torrential mitral regurgitation (MR) during TAVR. The valve deployment process induced left ventricular dyssynchrony due to left bundle-branch block and myocardial ischemia in the left circumflex artery region with torrential MR. Transesophageal echocardiography clearly demonstrated the mechanisms of MR, which was successfully bailed out by left ventricular pacing and intra-aortic balloon pumping.ConclusionsMR can be seriously exaggerated by various and complicated mechanisms during TAVR and should be rapidly assessed and appropriately managed depending on its mechanisms.

Comparison of cardiac energetics after transcatheter and surgical aortic valve replacements

OBJECTIVES The effect of transcatheter aortic valve replacement (TAVR) on cardiac energetics has not been described. We compared changes in cardiac energetics after TAVR with those after surgical aortic valve replacement (SAVR). METHODS We retrospectively estimated end-systolic elastance (Ees) and effective arterial elastance (Ea) using blood pressure and left ventricular (LV) volume obtained from echocardiography. LV efficiency [ventriculoarterial coupling (Ea/Ees) and the stroke work to pressure-volume area ratio (SW/PVA)] was calculated. Measurements were taken before, 1 week after and 1 year after bioprosthetic aortic valve replacement (TAVR, n = 56; SAVR, n = 61) in patients with severe aortic stenosis and preserved ejection fraction. RESULTS Patients with TAVR had a lower aortic valve pressure gradient and larger stroke volume 1 week after the procedure than those with SAVR. Ea was more markedly decreased, and LV efficiency was significantly improved 1 week after TAVR (SW/PVA 68.1% ± 8.4% to 72.0% ± 8.5%, P < 0.001), but LV efficiency was unchanged 1 week after SAVR (SW/PVA 70.1% ± 7.4% to 69.1%  ±  8.0%). LV efficiency was improved 1 year after both procedures (SW/PVA 75.5% ± 6.1% in TAVR; 74.7% ± 6.4% in SAVR). CONCLUSIONS TAVR decreases the transvalvular pressure gradient further without deteriorating stroke volume in the early postoperative period, which is accompanied by early improvement in afterload and LV efficiency compared with SAVR. Improvement in LV efficiency at mid-term follow-up is satisfactory after both procedures.

Extended parasternal approach for aortic and tricuspid valve surgery.

We report an extended parasternal approach to aortic and tricuspid valves used in a 31-year-old man. The patient presented with a deformed sternum and severe adhesion between the sternum and right ventricular outflow tract, caused by postoperative mediastinitis, which lasted for 4 years after a radical operation for tetralogy of Fallot during his childhood. The extended parasternal approach provided a safe and excellent exposure of both aortic and tricuspid valves without postoperative chest wall instability.