Keio University Cardiovascular Surgery Phone Number:


Hospital Information

Hospital Information

About us

Message from the Chairman

Embodying a sense of tradition & spirit of innovation

Dr. Ryohei Yozu, MD, PhD

  • Ryohei YOZU MD.,PhD.
  • Chairman & Professor
    Department of Surgery
  • Head of the Division of Cardiovascular Surgery
    Keio University School of Medicine

The Division of Cardiovascular Surgery was founded within the Keio University Cardiovascular Surgery in June 1952. Since then, the Division has remained at the forefront of cardiovascular surgery in Japan for more than half a century by combining constant innovation with surgical tradition; the first institution of its kind in Japan. From its earliest procedures to treat congenital heart disease and rheumatic pericarditis, The Division of Cardiovascular Surgery has maintained an excellent surgical track record. Following on from these early achievements, it became a national leader in surgeries for thoracic and abdominal aortic aneurysms and acute aortic dissection. Today, where coronary artery bypass grafting (CABG) has become a standard of cardiovascular surgery, we are pursuing the same level of surgical excellence in minimally invasive cardiovascular treatment of congenital heart disease, aortic disease, coronary artery disease, and heart valve disease.

In recent years, there have been significant advances in the field of cardiovascular surgery. Expanded indications in the 1990s to include patients with very poor cardiac function and serious noncardiovascular comorbidities proved that conventional prolonged surgeries did not in fact deliver the best outcomes as previously believed. Put simply, this finding highlighted the importance of minimally invasive cardiovascular surgery. At around the same time, remarkable progress was made in catheter-based endovascular procedures, resulting in therapeutic outcomes to rival that of open-heart surgery and providing an indisputable impetus in the shift towards minimally invasive surgery. Developments in medical equipment such as pre-operative diagnostic imaging and a range of surgical instruments including endoscopes coupled with improved techniques based on surgical experience have enabled minimally invasive surgery, with its smaller incisions, to become an established surgical modality in various medical fields. Laparoscopic cholecystectomy, for instance, is now a widely recognized procedure for endoscopic gallbladder removal. Minimally invasive cardiac surgery (MICS) was also introduced and, in the area of coronary artery surgery, off-pump coronary artery bypass grafting (OPCAB) without the use of cardiopulmonary bypass (CPB) has since evolved into a common procedure. MICS has also been adopted in heart procedures that involve intracardiac manipulation requiring use of CPB in the form of small incision techniques and minithoracotomy without complete sternotomy. The Division of Cardiovascular Surgery has developed a procedure known as minithoracotomy MICS by applying minithoracotomy techniques with the aim of further minimizing invasiveness. Minithoracotomy is defined as a procedure that is performed via ports inserted in one or more small incisions. It seeks to further reduce the invasiveness of conventional surgeries by making a smaller incision, and is also referred to as a sternum-sparing procedure because it is done via an intercostal route without any incisions in the sternum. Benefits of minithoracotomy include rapid post-operative recovery, reduced risk of sternal infection and mediastinitis from bacteria, decreased post-operative pain, and a more cosmetically appealing surgical wound.

We employ minithoracotomy as a standard operative technique in mitral valve repair for mitral regurgitation, mitral valve replacement (MVR) for mitral stenosis, and surgical closure of atrial septal defect (ASD). To date, we have performed 328 mitral valve operations and 211 ASD operations (58 and 11 operations, respectively, in 2011). Treatment outcomes have been very good, and patients have come from virtually all over Japan to undergo these surgeries.

This progress can be attributed to our many years of practical experience, at times arduous, and the knowledge of our cardiovascular surgeons. As pioneers of minithoracotomy MICS, we see it as our mission to pass on our accumulated experience in this procedure to patients and the next generation of surgeons as an art based on science. We believe that the widespread application of minithoracotomy MICS in a safe and assured manner as well as expanded training of the surgical techniques involved will lead to safer, totally endoscopic cardiac surgery and, by extension, robotic surgery. Minimal invasiveness is a medical necessity in any field of surgery, and is also a societal requirement from a health economics perspective.

In 2009, we introduced stent graft therapy in the field of thoracic aortic surgery, one of the most invasive procedures in cardiovascular medicine. Over the course of the following year, we performed almost 90 stent graft procedures on abdominal and thoracic aortic aneurysms, and it is currently one of our most important fields.

In 2010, Keio University Hospital became an accredited practitioner of transcatheter atrial septal defect closure using the Amplatzer® septal occluder system. This has enabled the hospital to select from two minimally invasive procedures when treating the congenital heart disease of ASDs, namely minimally invasive small incision surgery (minithoracotomy and axillary incision methods) or catheterization. Thus far, we have performed ASD surgery using the minimally invasive small incision procedure on more than 200 patients who have expressed their satisfaction both in terms of speed of recovery and cosmetic appearance of the surgical scar. We are confident that the recent availability of this innovative catheterization technique will enable Keio University Hospital to adopt a truly comprehensive approach to minimally invasive treatment of ASD.

By offering 'innovative' minimally invasive therapies in addition to our 'traditional' treatments for congenital heart disease, aortic disease, coronary artery disease, and heart valve disease, The Division of Cardiovascular Surgery will continue to provide patient-friendly medical care based on the world's best practice.