A Case of Hydrophilic Polymer Embolism after TEVAR / 日本心臓血管外科学会雑誌

Hydrophilic polymer embolism (HPE) associated with endovascular therapy has steadily gained attention. We report a case of a 70-year-old man who had undergone one-debranched TEVAR. He had a history of distal arch replacement for dissecting aortic aneurysm 14 years earlier. Pseudoaneurysm at the proximal site of graft anastomosis was found on computed tomography (CT) angiogram during the follow-up. 1 debranching TEVAR was performed using the pull-through technique. Fourth days after the procedure, a skin rash appeared in the right lower extremity around the access site. Skin biopsy with pathological examination revealed HPE. We decided to observe a patient because there was no symptom of limb ischemia. Skin lesions improved and he was discharged on the 27th postoperative day. Hydrophilic polymers are widely used in the endovascular devices and there is an urgent need to better understand the complication of HPE.

The Efficacy of Conventional Aortic Valve Replacement for Severe Aortic Valve Stenosis Divided by Risk Classification Using the Japanese Scoring System / 日本心臓血管外科学会雑誌

<b>Objective</b> : Transarterial or transapical aortic valve replacement (TAVR) procedures have been performed for high-risk patients with severe aortic valve stenosis (AS) in western countries. A high-risk patient is defined as having an STS score greater than 10%. In Japan, aortic valve replacement (AVR) with cardiopulmonary bypass (CPB) is standard care for AS, even if the patient is at high risk of developing complications. We calculated an expected operative risk of patients using a JAPAN score established by Japanese Adult Cardiovascular Surgery Database (JACVSD). <b>Patients and Methods</b> : Patients were divided into three groups : score less than 5%, low risk (LR) ; score 5-10%, moderate risk (MR) ; score more than 10%, high risk (HR). We also evaluated the efficacy of conventional AVR in each group. Between January 2002 and May 2011, we performed conventional AVR in our hospital and 116 patients who underwent AVR for symptomatic AS were enrolled in this study. <b>Results</b> : There were 79 patients in the LR group, 30 patients in the MR group and 7 patients in the HR group. The mean score was 2.6±1.1% in the LR group, 6.8±1.4% in the MR group and 23.3±16.8% in the HR group respectively. The mean follow-up period was 7.6±0.3 years. Preoperative co-morbidity was not statistically significant among three groups, however more octogenarians were found in the HR group. The aortic valve area and left ventricular ejection fraction (LVEF) were significantly smaller in the HR group. There were 4 cancer patients. The HR group had significantly longer operation and CPB times than the LR group. The operative mortality in all cases was 1.6%. Overall survival at 5 years was 78%. Actual survival at 5 years was 77% in the LR group, 82% in the MR group and 71% in the HR group. The major adverse cardiac and cerebrovascular event (MACCE)-free ratio at 5 years was 85%. Absence of death caused by MACCE at 5 years was 93%. All cancer patients died after AVR due to advancement in cancer. <b>Conclusion</b> : The results of conventional AVR with CPB were satisfactory in each group. Cancer patients may be good candidates for TAVR in the future.

Aortic Dissection Caused by the Right Axillary Artery Perfusion / 日本心臓血管外科学会雑誌

Aortic dissection during cardiac operation is a rare but serious complication. Early detection and adequate repair is essential in this situation. A 69-year-old man in whom an aortic valve sparing operation for aortic root dilatation with aortic regurgitation had been begun, had an intraoperative aortic dissection 10min after the start of right axillary artery perfusion. Intraoperative transesophageal echocardiography and direct epi-aortic echo revealed acute aortic dissection extending from the aortic root to at least the descending aorta. The dissection was successfully repaired by a Bentall operation and hemiarch replacement using hypothermic circulatory arrest, selective cerebral perfusion, and antegrade perfusion from an anastomosed graft.

Two Cases of Stent-Grafting for Ruptured Aneurysms / 日本心臓血管外科学会雑誌

In cases of stent-grafting for ruptured aneurysm, endoleak is a serious problem. We report 2 cases of ruptured aneurysms that were treated with endovascular stent-graft placement. Case 1: A 79-year-old woman had a ruptured thoracic aortic aneurysm that was treated with endovascular stent-grafting from the distal arch to the descending aorta. Although her infra-operative course was uneventful, she died suddenly the day after operation. Autopsy revealed re-rupture of the aneurysm due to endoleak from the proximal site. Case 2: An 84-year-old woman was treated with endovascular stent-grafting for ruptured abdominal aortic aneurysm. The stent-graft was inserted from the infra-renal abdominal aorta to the right common iliac artery with femoro-femoral crossover bypass placement. There was evidence of type II endoleak that occurred via the left internal iliac artery (IIA) and inferior mesenteric artery (IMA) 16 days after surgery. A CT scan performed 6 months after surgery revealed an increase in aneurysm size and persistent type II endoleak. Both embolization of the aneurysmal sac through the IMA and surgical ligation of the IMA failed, and endoleak from the IMA persisted. Re-rupture of the aneurysm occurred 10 months after initial surgery and emergency open surgery was performed. In stent-grafting for ruptured aneurysms, only the thrombus outside the graft resists the pressure caused by the endoleak. We conclude that endoleak after stent-grafting for ruptured aneurysm should be treated completely as soon as possible because of the risk of re-rupture.

Surgical Treatment of Patent Ductus Arteriosus and Aortic Stenosis in a Patient with a Porcelain Aorta / 日本心臓血管外科学会雑誌

This paper reports on a case in which a heavily-calcified so-called “porcelain aorta” (including the ductus arteriosus) was observed, together with a patent ductus arteriosus and aortic stenosis associated with a bicuspid aortic valve. A 76-year-old man had been referred to our hospital on a diagnosis of aortic stenosis. Since angiography revealed slight contrast in an area on the right side of the heart, echocardiography was performed and revealed patent ductus arteriosus. Severe circumferential calcification of the ascending aorta and aortic arch was observed on CT scans. Almost no calcification was observed in other areas. Aortic valve replacement and closure of the ductus arteriosus (transpulmonary approach) were performed by means of a balloon to temporarily occlude the aorta, as surgical clamping was impossible due to calcification. Hypothermic systemic perfusion and antegrade selective cerebral perfusion were used. The postoperative progress of the patient was good. Bicuspid aortic valve and patent ductus arteriosus are highly likely to be present in combination in cases of congenital cardiac anomaly, and it is therefore necessary to be particularly attentive when diagnosing such cases. It was considered that our patient, an adult suffering patent ductus arteriosus, was a rare case in which the calcified ductus arteriosus was observed and the calcification had spread to the ascending aorta.

Early and Mid-Term Results of Endovascular Stent-Graft Placement for the Treatment of Abdominal Aortic Aneurysms / 日本心臓血管外科学会雑誌

We performed endovascular stent-graft placement on 39 patients with abdominal aortic aneurysms between 1996 and March 2002-a period of approximately 5 years (first half: until the end of June 1998, second half: July 1998 onward). Three patients in the first half of the period and 8 patients in the second half were 80 years or older. Two cases of mycotic aneurysm were observed. During the second half, we encountered high-risk cases in which the patients had complications such as coronary artery disease (5 patients), COPD (1 patient) and thoracic aortic aneurysm (4 patients). Although we had to switch to surgery in 3 patients during the first half of the period, we successfully placed stent-grafts in the other 36 cases (92%). Endoleaks were observed in 6 patients, and dissection of the iliac artery was observed in 5 patients (stents had been placed in all patients). In 50% of all cases in the first half of the period and 89% of all cases in the second half, stent-graft placement was successful and no endoleak was observed. During the follow-up period, 3 cases required additional treatment, and another 4 cases required surgery. Four patients died in hospital during the first half of the period, and 3 patients died during the following 3 years. The 3-year survival rate was 82%. It was considered that stent-graft placement for abdominal aortic aneurysms is particularly effective for high-risk patients, and that the results of this type of therapy will improve in the future.

A Case Report of Double Aortic Arch, Vascular Ring Associated with Tracheal Stenosis / 日本心臓血管外科学会雑誌

We report a case of vascular ring with tracheal stenosis, which might be related to a prolonged endotracheal intubation. A symptomatic 2-month-old boy was admitted to our institution after prolonged intubation without a definite diagnosis. His symptoms were stridor and dyspnea, but not dysphagia. Echocardiography detected a vascular ring and this was confirmed by computed tomography and magnetic resonance imaging (MRI) (Edwards IA type). The left anterior aortic arch was divided distal to the left subclavian artery through left thoracotomy and the ligamentum arteriosus was not identified. On postoperative day (POD) 2, endotracheal extubation was unsuccessfully attempted. Further examination such as MRI and bronchoscopy revealed intimal hyperplasia of the trachea with mild compression of the trachea from the outside. We performed aortopexy and division of the small long ductus which might not be a mechanism of the tracheal compression through right thoracotomy in the second operation with successful extubation on POD 3. The patient has been discharged from the hospital and followed up at the outpatient clinic without any symptom. Tracheomalacia was a common associated anomaly in vascular ring. However, other mechanisms such as inflammatory reaction associated with prolonged intubation should be considered and be avoided in the pediatric population.

Effect of Continuous Intravenous Administration of Diltiazem Hydrochloride on Supraventricular Tachyarrhythmia after Open Heart Surgery / 日本心臓血管外科学会雑誌

Because supraventricular tachyarrhythmias after open heart surgery are often resistant to DC cardioversion and treatment with antiarrhythmic agents, we sometimes have difficulty in the postoperative management of these arrhythmias. We attempted to use intravenous infusion of diltiazem hydrochloride (3-5mcg/kg/min) for 6 patients with supraventricular tachyarrhythmias, 5 of whom had atrial fibrillation and 1 with sinus tachycardia after open heart surgery. The ventricular rate was remarkably reduced from the pretreatment value by this infusion therapy. Diltiazem infusion during atrial fibrillation in 5 patients regularized the ventricular rate (normalization of R-R intervals). These results indicate that diltiazem was effective in obtaining almost constant preload with each cardiac cycle for the postoperative deteriorated cardiac muscle. The hemodynamic parameters obtained with the Swan-Ganz catheter showed that both right and left ventricular functions improved after the infusion of diltiazem. There was no adverse effect due to the administration of diltiazem. We concluded that the intravenous infusion of diltiazem is an effective method to manage supraventricular tachyarrhythmias after open heart sugery without deterioration of the cardiac function or side effects.

Relationship between Arterial Keton Body Ratio(AKBR) and Hepatic Blood Flow after Extracorporeal Circulation / 日本心臓血管外科学会雑誌

Recently, arterial keton body ratio (AKBR) has attracted attention as a new indicator of liver function which is in equibilium with the ratio between oxidized and reduced forms of free nicotinamide-adenine dinucleotides (free NAD⁺/NADH ration) in the mitochondria. There are few reports on whether AKBR contributes to the hepatic energy charge in the open heart surgery with extra corporeal circulation (ECC) or not. This study was undertaken to clarify the contribution of AKBR to the hepatic energy charge during ECC and the relationship between AKBR and hepatic blood flow. AKBR was determined before, during and after ECC in the open heart surgery for 14 patients. Furthermore, the blood flow in hepatic artery, portal vein and liver microcirculation was measured before, during and after ECC in canine models. Finally, the pulsatile perfusion was performed in canine models and compared with the conventional non-pulsatile perfusion for the blood flow and AKBR. In clinical cases, AKBR was decreased in all cases during the ECC. AKBR which was measured at 2 or 3hr after weaning from the ECC was negatively correlated to the total perfusion time with -0.57 as the correlation coefficient. Six patients who were on the ECC over 180min did not show a good recovery of the AKBR after weaning from the ECC. Especially, three patients presented a clinical picture of acute hepatic failure with jaundice, elevation of the serum levels of transaminase and direct hyperbililubinemia, but only one showed hypoglycemia. These patients showed no improvement in clinical data and AKBR. The patient with improved AKBR recovered clinically. In our experiment, the blood flow in the hepatic artery, portal vein was measured by electromagnetic blood flow meter and the liver microcirculation was measured by laserdoppler flowmeter. The blood flow was decreased remakably in the non-pulsatile group at all sites of measurement: it recovered after ECC in hepatic artery and portal vein, but liver microcirculation did not improve well. AKBR was decreased during ECC and did not recover after ECC in the non-pulsatile perfusion. When the pulsatile perfusion was performed, liver circulation was maintained well, and AKBR recovered well after ECC. The above results suggest that AKBR reflects the liver microcirculation and pulsatile perfusion is beneficial to the liver microcirculation. Pulsatile circulation, however, involves several problems, hemolysis, the decrease of platelets, and so on, but these problems have been improved gradually. We think that the pulsatile perfusion will be used in clinical operations to maintain the good hepatic circulation.

Experimental Study on the Evaluation of the Right Ventricular Function Using a Modified Swan-Ganz Catheter / 日本心臓血管外科学会雑誌

We tried to evaluate the right ventricular function using a modified Swan-Ganz catheter with a rapid responsive thermistor. Twenty-four dogs comprised this series. Twelve were the model of left heart failure (Group A), and the other twelve were the model of right heart failure (Group B) produced by multiple ligation of coronary arteries. Dogs were studied for some of the circulatory indices before and after ligation with left atrial pressure at 10, 15 and 20mmHg in group A, and right atrial pressure at 10, 15 and 20mmHg in group B by volume loading. In group A, when the left atrial pressure was kept constant, right ventricular ejection fraction (RVEF) and right ventricular stroke work index (RVSWI) were decreased significantly after the ligation of coronary arteries. But there was no significant change in the peak right ventricular pressure-right ventricular endsystolic volume index ratio (peak RVP/RVESVI) associated with ligation. In group B, significant changes were observed in RVEF, RVSWI and peak RVP/RVESVI. Thus, it was found that right ventricular contractility in selective left heart failure was not reduced. <i>E</i>_max was considered to be a valuable index of ventricular contractility not affected by preload and afterload of ventricle, but this index is not easily measured clinically. The index peak RVP/RVESVI which is nearly equivalent to <i>E</i>_max, has an advantage in that it can be determined by the thermodilution method widely used in general. We conclude that this index is very useful to us for post-operative care in cardiac surgery.