Reoperation in Two Patients with SJM Toronto SPV and Medtronic Freestyle Stentless Bioprosthetic Valves / 日本心臓血管外科学会雑誌

Stentless bioprosthetic valves have been implanted for treatment of aortic valve disease, especially in elderly patients ; these valves have the advantage of durability and excellent hemodynamics compared with stented bioprosthetic valves. Although good long-term results in patients with stentless bioprosthetic valves have been reported recently, reoperation has been gradually increasing. We performed reoperation for the SJM Toronto SPV and Medtronic Freestyle valves in one patient each. The SJM Toronto SPV was used in a 30-year-old woman ; however, 8 years later, the valve showed severe calcification and adhesions, and could not be completely removed (Case 1). The other reoperation case, wherein a 69-year-old man underwent aortic valve replacement with the Medtronic Freestyle 4 years previously, showed no adhesion around the implanted valve, which could be easily removed from the autologous aortic annulus. Consequently, the first patient required reimplantation of a small mechanical valve (SJM #19). In contrast, we were able to use a stentless bioprosthetic valve (Prima Plus #23) for the second patient. Further observations on stentless bioprosthetic valves are required.

Risk Assessment for a Learning Curve in Endovascular Abdominal Aortic Aneurysm Repair with the Zenith Stent-Graft: The First Year in Japan / 日本心臓血管外科学会雑誌

In Japan, doctors inexperienced stent-graft new devices are required to secure agreement on criteria and choice of the device size in endovascular aneurysm repair (EVAR) from experienced doctors. It was hoped that strict patient selection might reduce the learning curve for initial successes in given procedures. In a leading center in Japan, a number of cases which were scheduled for operation at other institutes were evaluated anatomically. We surveyed the initial success of Zenith AAA system implantation in the remaining cases by inexperienced doctors and evaluated the results. This study aimed to verify the validity of strict patient selection in improving the success rate of inexperienced doctors. We enrolled 112 consecutive patients from 19 institutes, who were scheduled for repair between January and October in 2007. All patients were evaluated on the basis of a less-than-3mm reconstructed CT image. Mean patient age was 76±5.7 years. All cases satisfied the Zenith's anatomic prerequisites. Fifteen cases were excluded for various reasons, the major reason being insufficiency of the proximal landing zone (LZ) length, angle and contour. The second reason was difficulty to approach via the iliac artery. Ninety seven cases were included, of which 17 cases were low-risk candidates for EVAR. Medium-risk seventy two cases requiring some advice to avoid problems with device size, technique of implantation and choice of main-body side. Eight cases were high-risk, requiring the presence of an experienced surgeon. Excluded cases had significantly shorter proximal LZ, larger aortic diameters 15mm below the renal artery and tortuous access routes on preliminary measurement by inexperienced doctor. Perioperative mortality was 0%, while the major complications were injury to the iliac artery in one high-risk case and thromboembolism of the superficial femoral artery in another. Perioperative proximal type I endoleak occurred in 5 cases. In 3 of these cases, the endoleak was eliminated by implantation of a Palmatz stent. In the other 2 cases, it disappeared within a month without additional procedures. These cases had a significantly greater angle between the proximal LZ and the suprarenal aorta and significant amount of mural thromboses in the proximal LZ. Perioperative type III endoleak occurred in 3 cases. In all cases the endoleak was eliminated by additional procedure. Perioperative type II endoleak occurred 8 cases. In 3 of these cases, the endoleak disappeared within a month. In the 5 other cases, the endoleak did not disappear. Mid-term results showed iliac leg thromboembolism in one case and new type II endoleaks in 3 cases. Type II endoleak occurred in cases which had significantly greater angles between the proximal LZ and the aneurysm. The results which were evaluated in our center had excellent perioperative and mid-term outcomes. We think this evaluation system is effective for risk assessment and reduces the learning curve in EVAR. In anatomically marginal cases, it is possible for proximal type I endoleak and injury of the iliac artery to occur. It is impossible to exclude these marginal cases if treatment need for EVAR is a priority. In these cases, lessexperienced operators should be trained in troubleshooting techniques in advance.

Reoperation for Valvular Surgery and Thoracic Aortic Aneurysm Repair with Functioning IMA Grafts after Previous CABG / 日本心臓血管外科学会雑誌

The use of the internal mammary artery (IMA) is now routine in most coronary artery bypass grafting (CABG) because of its improved long-term patency and survival. A small but important percentage of these patients will require valve surgery and thoracic aortic aneurysm repair following CABG. These operations present a challenging problem for the cardiac surgeon because of difficulties regarding approach, dissection around the IMA and optimal myocardial protection. We investigated surgical results and the effectiveness of various methods of myocardial protection in 8 patients who underwent reoperations between December 1983 and June 2005. The mortality was 13%. There were 2 perioperative myocardial infarctions (25%), 6 cases of prolonged ventilation (75%), 3 cases of low output syndrome (38%), 1 case of acute renal failure (13%) and 1 case of sepsis (13%). We carried out resternotomy for 6 patients without any hospital death or perioperative myocardial infarction. Our reoperation approach had acceptable risk control with resternotomy, avoidance of dissecting the IMA and hypothermic perfusion.

A Case of Aortic Replacement for a Patient with Bilateral Internal Carotid Stenoses / 日本心臓血管外科学会雑誌

A 71-year-old man was given a diagnosis of saccular aneurysm of the aortic arch (maximum 48mm in diameter) at the age of 68. When he was 69 years old, he began to take steroids for autoimmune hepatitis (AIH). The following year, the aneurysm was enlarged to 52mm. Further examinations showed the aneurysm to extend to the ostium of the left subclavian artery. Since he had transient ischemic attacks, ultrasonography of the carotid arteries was performed. Bilateral internal carotid stenoses were detected, however, cold Xe CT showed an almost normal pattern of cerebral blood flow. We decided that operation was feasible using retrograde cerebral perfusion (RCP). Liver dysfunction due to AIH improved, and his steroid dosage was tapered. Using RCP, the no-touch technique and the elephant trunk procedure, he underwent the replacement of ascending aorta and aortic arch and was discharged without major complications. RCP and the no-touch technique might enable safer operations on patients with carotid stenoses.

Surgical Strategy for Thoracic Aortic Aneurysm with Abdominal Aortic Aneurysm / 日本心臓血管外科学会雑誌

We evaluated the surgical strategy for thoracic aortic aneurysm associated with abdominal aortic aneurysm. From January 1982 to March 1999, 24 consecutive patients underwent surgical treatment for thoracic aortic aneurysm with abdominal aortic aneurysm. Staged operation was performed if one was only slightly dilated, but extensive operation was needed if the size of both aneurysms was greater than 6cm. In cases of thoracic aortic aneurysm with abdominal aortic aneurysm up to 4cm in size, surgical treatment was performed only for the thoracic aortic aneurysm. Circulatory support during operation was established from the ascending aorta, and circulatory arrest with deep hypothermia and retrograde cerebral perfusion were used for brain protection during surgery for thoracic aortic arch aneurysm. Hospital mortality was 12.5% (3/24 cases). The causes of death were cerebral infarction and respiratory failure. Antegrade systemic perfusion and aortic no-touch technique were an effective method of surgery for thoracic aortic aneurysm with abdominal aortic aneurysm to avoid perioperative embolism and major complications. We successfully performed staged operation, but regular radiographic follow-up was needed.

A Case of Papillary Fibroelastoma of the Left Ventricular Septum Complicated with a Rheumatic Valve / 日本心臓血管外科学会雑誌

A 50-year-old man was referred to our hospital with a tumor in the left ventricle. He had suffered from rheumatic fever when 14 years old. He had shown signs of chronic heart failure due to atrial fibrillation and rheumatic valves (ASr, MSr) for 10 years. There was a history of unaccountable fever and rash, so infective endocarditis was suspected and echocardiography was performed. It showed a homogeneous mass with a diameter of approximately 10mm, fixed directly to the left ventricular septum 20mm below the aortic valvular ring. At operation, the tumor was excised together with endocardium and a part of the muscular coat. The rheumatic aortic and mitral valves were replaced with a 21mm SJM AHP and a 27mm SJM MTK mitral valve, respectively. Tricuspid annuloplasty (TAP) (De Vega 29mm) was also performed. Histopathological examination of the tumor revealed benign papillary fibroelastoma. It suggested that the tumors were secondary to mechanical wear and tear, and represent a degenerative process due to rheumatic valve disease.