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Featured researches published by Noritaka Okada.


The Annals of Thoracic Surgery | 2010

Early and Late Outcomes of Aortic Valve Replacement in Dialysis Patients

Keisuke Tanaka; Kazuyoshi Tajima; Yoshiyuki Takami; Noritaka Okada; Sachie Terazawa; Akihiko Usui; Yuichi Ueda

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.


The Journal of Thoracic and Cardiovascular Surgery | 2009

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

Yoshiyuki Takami; Kazuyoshi Tajima; Sachie Terazawa; Noritaka Okada; Kei Fujii; Yoshimasa Sakai

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.


The Annals of Thoracic Surgery | 2009

Simplified Management of Hemodialysis-Dependent Patients Undergoing Cardiac Surgery

Yoshiyuki Takami; Kazuyoshi Tajima; Noritaka Okada; Kei Fujii; Yoshimasa Sakai; Makoto Hibino; Hisaaki Munakata

BACKGROUND The mortality and morbidity rates are high after cardiac surgery in hemodialysis (HD)-dependent patients. To improve their outcomes, optimal perioperative managements should be discussed. METHODS A retrospective analysis of 245 HD patients who underwent cardiac surgery between 1994 and 2007 was conducted. The basic management strategies were (1) low-potassium HD for 2 days before surgery, (2) only hemofiltration during cardiopulmonary bypass, and (3) start of regular intermittent HD on the first postoperative day. Continuous venovenous hemodiafiltration was applied only for patients with hemodynamic instability. RESULTS The causes of renal failure included diabetic (n = 89, 36%), glomerulonephritis (n = 49, 20%), and unknown (n = 75, 31%). The history of HD was 9.7 +/- 7.6 years. The operative procedures included coronary (n = 135), valve (n = 103), and others. The amount of intraoperative ultrafiltration was 6,123 +/- 324 mL during cardiopulmonary bypass for 197 +/- 67 minutes. Two hundred eight patients (85%) were managed with only intermittent HD, whereas 36 patients (15%) needed continuous venovenous hemodiafiltration. The use of continuous venovenous hemodiafiltration significantly declined during the year (26% before 2003 and 3% after 2003; p < 0.001). The amount of fluid removal on the first postoperative day was 1,297 +/- 81 mL. The hospital mortality was 9.7% with the causes including infection (n = 11), cardiac events (n = 6), gastrointestinal events (n = 5), and stroke (n = 2). A multivariate logistic regression analysis revealed that selection of intermittent HD or continuous venovenous hemodiafiltration was not related to the hospital mortality. CONCLUSIONS Simplified management only with intermittent HD can be safely performed in most HD-dependent patients undergoing cardiac surgery.


The Annals of Thoracic Surgery | 2015

Valve Selection for the Aortic Position in Dialysis Patients

Noritaka Okada; Kazuyoshi Tajima; Yoshiyuki Takami; Wataru Kato; Kei Fujii; Makoto Hibino; Hisaaki Munakata; Yoshimasa Sakai; Akihiro Hirakawa; Akihiko Usui

BACKGROUND Prosthetic valve selection in dialysis patients remains controversial because of the limited data available. This study aimed to clarify late clinical outcomes and discuss strategies for optimal valve selection in dialysis patients. METHODS We retrospectively analyzed the data obtained from 406 consecutive patients who underwent aortic valve replacement between 1995 and 2010. We compared valve-related outcomes among 89 dialysis and 317 nondialysis patients. We selected bioprostheses for all patients older than 65 to 70 years, irrespective of the renal function. RESULTS Dialysis was found to be a significant risk factor for bleeding events (hazard ratio, 3.98; 95% confidence interval, 2.51 to 6.30; p < 0.001), however, no significant differences were observed according to the type of prosthesis. The overall survival was significantly worse in the dialysis patients (63% versus 85% at 5 years; p < 0.001), and freedom from structural valve deterioration was also lower in the dialysis patients (82% versus 100% at 5 years; p < 0.001). Among the dialysis patients, an advanced age (≥ 70 years; hazard ratio, 3.53; p = 0.011), diabetes mellitus (hazard ratio, 2.48; p = 0.041), and concomitant coronary artery bypass grafting (hazard ratio, 1.99; p = 0.071) were independent predictors for late death based on a multivariate analysis. CONCLUSIONS Our valve selection criteria in dialysis patients, which are the same as the current practice guidelines for nondialysis patients, are acceptable. Bioprostheses can be considered in all dialysis patients with diabetes or coronary artery disease.


Interactive Cardiovascular and Thoracic Surgery | 2012

A bioresorbable osteosynthesis device can induce an earlier sternal fusion after median sternotomy

Tomohiro Tsunekawa; Akihiko Usui; Hideki Oshima; Shinnichi Mizutani; Yoshimori Araki; Noritaka Okada; Yuichi Ueda

OBJECTIVES We examined the impact of the bioresorbable osteosynthesis sternal pin (Super Fixsorb 30) on sternal healing after median sternotomy. METHODS Sixty-three patients who underwent aortic surgery through median sternotomy between January 2006 and March 2009 were analysed. Sternal pins were utilized in 36 patients in addition to the standard closure of the sternum with Ethibond sutures (Group A), and 27 patients received no pins with the standard Ethibond sternal closure (Group B). The occurrence of transverse sternal dehiscence, anterior-posterior displacement and complete fusion of the sternum were evaluated by a computed tomography scan. The cross-sectional cortical bone density area (CBDA) of the sternum was examined to evaluate the osteoconductivity of the sternal pin over a 12-month period. RESULTS There was no sternal displacement (0%) observed in Group A at discharge. Meanwhile, five displacements (18.5%) were observed in Group B (P = 0.007). The complete sternal fusion rates at 12 months postoperatively were 100% in Group A, and 21.6% in Group B (P < 0.001). A significant increase in the CBDA was observed in Group A (P < 0.001; between CBDA at discharge and 12 months postoperatively). CONCLUSIONS The Super Fixsorb 30 sternal pin reduced an anterior-posterior sternal displacement and facilitated an earlier sternal fusion. The pin may have the potential to promote osteogenesis.


Artificial Organs | 2016

Peripheral Veno‐Arterial Extracorporeal Membrane Oxygenation as a Bridge to Decision for Pediatric Fulminant Myocarditis

Noritaka Okada; Hiroomi Murayama; Hiroki Hasegawa; Satoru Kawai; Hiromitsu Mori; Kazushi Yasuda

It is essential to establish an appropriate initial treatment strategy for pediatric fulminant myocarditis. We reviewed eight cases of pediatric fulminant myocarditis that required extracorporeal membrane oxygenation (ECMO) from 2012 to 2015. The median age was 8 years (range 3 months-13 years), and the median body surface area was 0.89 m(2) (range 0.35-1.34 m(2) ). Peripheral veno-arterial ECMO was initially applied, and we evaluated whether heart decompression was sufficient. If the pump flow was insufficient, central cannulation was performed via median sternotomy (central ECMO). The need for subsequent ventricular assist device (VAD) support was determined 72 h after ECMO initiation. Six patients were bridged to recovery using peripheral ECMO support only (for 3-11 days), whereas two required VAD support. One patient was switched to central ECMO before VAD implantation. Three patients died of multiorgan failure, even though cardiac function recovered in two of those patients. The duration from hospital arrival to ECMO initiation was shorter in the survival (3.3 ± 1.3 h; range 1.6-4.7 h) than in the nonsurvival group (32 ± 28 h; range 0.7-55 h). Peripheral ECMO can be useful as a bridge to decision for pediatric fulminant myocarditis, which is frequently followed by a successful bridge to recovery. It is important to determine whether ECMO support should be initiated before organ dysfunction advances to preserve organ function, which provides a better bridge to subsequent VAD therapy and heart transplant or recovery.


The Journal of Thoracic and Cardiovascular Surgery | 2009

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

Yoshiyuki Takami; Kazuyoshi Tajima; Sachie Terazawa; Noritaka Okada; Kei Fujii; Yoshimasa Sakai

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.


The Journal of Thoracic and Cardiovascular Surgery | 2016

Iatrogenic aortic dissection in an infant with persistent fifth aortic arch and congenital heart defects.

Noritaka Okada; Hiroomi Murayama; Hiroki Hasegawa

From the Department of Cardiovascular Surgery, Aichi Children’s Health andMedical Center, Obu, Aichi, Japan. Disclosures: Authors have nothing to disclose with regard to commercial support. Received for publication Aug 13, 2015; revisions received Oct 1, 2015; accepted for publication Oct 7, 2015; available ahead of print Nov 11, 2015. Address for reprints: Noritaka Okada, MD, PhD, 7-426 Morioka-cho, Obu, Aichi, Japan 474-8710 (E-mail: [email protected]). J Thorac Cardiovasc Surg 2016;151:e55-7 0022-5223/


The Annals of Thoracic Surgery | 2016

Optimal Surgical Management Using a Classic Blalock-Taussig Shunt for an Infected Pseudoaneurysm After a Modified Blalock-Taussig Shunt Procedure

Noritaka Okada; Hiroomi Murayama; Hiroki Hasegawa

36.00 Copyright 2016 by The American Association for Thoracic Surgery http://dx.doi.org/10.1016/j.jtcvs.2015.10.033


European Journal of Cardio-Thoracic Surgery | 2017

Right ventricular centripetal plication: an aggressive right ventricular exclusion technique

Junya Sugiura; Hiroomi Murayama; Noritaka Okada

We present 2 cases of a 3-month-old girl and boy who were diagnosed with an infected pseudoaneurysm 2 months after undergoing left-sided modified Blalock-Taussig shunt (mBTS) operations for pulmonary atresia. Because the shunts in both cases were nearly obstructed, they underwent a 2-stage surgical approach: classic BTS operations through a right thoracotomy to establish sufficient pulmonary flow and infected graft removal through a median sternotomy after close observation of the state of the aneurysms. By utilizing autologous tissue from a different thoracic entry, both patients were successfully managed and recovered without any recurrence of infection.

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