An Experimental Study of the Effects of IABP on Coronary Artery Bypass Graft Flow Waveform.

PURPOSE: Graft evaluation after coronary artery bypass grafting (CABG) is still not sufficient. This study analyzed the flow waveform of coronary arteries and grafts during intra-aortic balloon pumping (IABP) assist. METHODS: Subjects were eight pigs that underwent off-pump CABG. Using transit-time flow measurement (TTFM) and occluder, blood flow waveforms were recorded while changing the degree of stenosis of Seg.6 and the left internal thoracic artery (LITA) and analyzed by percentage of reverse flow component to the total blood flow (R/T) and the ratio of diastolic blood flow of IABP operative and IABP inoperative (D1/D0). RESULT: Reverse flow of the LITA was reduced when stenosis of Seg.6 increased and R/T decreased. The average diastolic blood flow of Seg.8 and the LITA increased with IABP on showing a D1/D0 of 1 or more. R/T of the LITA increased when stenosis of Seg.6 was fixed and increasing the degree of LITA stenosis. D1/D0 increased up to a 75% LITA stenosis and is decreased in more severe stenosis. CONCLUSION: R/T is significantly higher in the antagonist or stenosis during IABP assist and was able to confirm the effectiveness of the graft as a functional assessment of graft. D1/D0 is useful as an indicator of the effectiveness of IABP on coronary blood flow.

Efficacy of modified less invasive quick replacement using mild hypothermic arrest and partial retrograde cerebral perfusion for type A acute aortic dissection.

OBJECTIVE: We previously reported a unique technique called "less invasive quick replacement (LIQR)" for treating type A acute aortic dissection with moderate hypothermic arrest (28 °C). This study examines the modified LIQR using mild hypothermic arrest (30 °C) with partial retrograde cerebral perfusion (RCP). METHODS: 187 patients were divided into 2 groups: group L consisted of 130 patients underwent LIQR without any cerebral perfusion; group M consisted of 57 patients who were treated with modified LIQR. In modified LIQR, circulatory arrest was commenced under the 30 °C for open distal aortic stamp fixation. RCP was used during final half anastomosis of the prosthesis and then rapid re-warming was initiated. RESULTS: The incidence of additional valve or coronary surgeries was significantly higher in group M (28.1%) than in group L (9.2%). The average rectal temperature was significantly higher in group M (29.5 °C) than in group L (27.4 °C). The durations of brain ischemia (M 7.7 min; L 18.6 min), cardiopulmonary bypass (M 82.0 min; L 93.3 min), and overall operation (M 145.2 min; L 154.2 min) were significantly shorter in group M. The incidence of postoperative brain damage was 6 patients (4.6%) in group L, but none in group M. The hospital mortality rate was 3 patients in group L (2.3%). All group M patients were discharged from the hospital without any complications. CONCLUSION: Modified LIQR is safe and effective. It makes the surgery much quicker and is a less invasive procedure. The surgical outcome was also favorable.

Efficacy of a newly modified technique for distal limited open stenting in octogenarians with aortic arch aneurysm.

OBJECTIVE: We assessed the efficacy of distal limited open stenting procedure in octogenarians with distal aortic arch aneurysm. METHODS: During the last 5 years, 24 patients underwent distal limited open stenting. Mean patient age was 81.6 ± 2.5 years, ranging from 80 to 90 years. The hemicircumference of the anterior surface of the arch around the left common carotid artery was obliquely incised, and a J-Graft Open Stent (Japan Lifeline Co, Ltd, Tokyo, Japan) was inserted into the descending aorta. During open stenting, circulatory arrest was induced at a rectal temperature of 28°C without any cerebral perfusion. As soon as the proximal side of the stent graft and aortic incision were concomitantly sutured, rapid rewarming was initiated through heated blood perfusion. RESULTS: The durations of circulatory arrest, aortic crossclamping, cardiopulmonary bypass, the overall operation, postoperative mechanical ventilation, and hospital stay were 17.0 minutes, 27.8 minutes, 106.1 minutes, 167.6 minutes, 11.0 hours, and 13.9 days, respectively. The in-hospital mortality was 0%. There were no incidences of brain damage, renal failure, or respiratory failure. At the time of this study, 21 patients were doing well and visiting the outpatient clinic, and 19 scored more than 20 points on the Mini-Mental State Examination, indicating no development of dementia. The actuarial survival at 5 years was 82.4%. CONCLUSIONS: This unique technique is safe and effective. It is a very attractive procedure that can contribute to maintaining a good long-term quality of life for octogenarians with distal aortic arch aneurysm.

Limited Distal Arch Open Stenting for Type B Aortic Dissection with an Enlarged Ulcer-Like Projection, Complicated by Abdominal Aortic Occlusion.

A 79-year-old man underwent bifurcated graft replacement for abdominal aortic aneurysm, but the graft was totally occluded owing to an acute type B aortic dissection. We could not have access to the root for performing endovascular stenting for dissecting aneurysm. Furthermore, it was difficult to remove the aneurysm via a left thoracotomy because it was impossible to perfuse the lower body with blood from the femoral artery and also a left axillary arterial cannulation was unusable. Herein, we report a patient who was successfully treated with open surgical aortic stenting for an enlarged ulcer-like projection complicated by a type B aortic dissection.

Efficacy of limited proximal arch replacement for type A acute aortic dissection with critical complications.

OBJECTIVE: We assessed the efficacy of limited proximal arch replacement for type A acute aortic dissection (AAD) with critical complications. METHODS: Sixty-four patients with average age of 64.5 ± 13.0 years, who were intubated prior to arriving at hospital due to cardiopulmonary arrest, cardiac tamponade, or vital organ mal-perfusion, were divided into two groups: group PA consisted of 52 patients undergoing proximal arch repair with mild hypothermic circulatory arrest; group TA consisted of 12 patients who underwent total arch replacement with moderate hypothermia and selective cerebral perfusion. RESULTS: The intimal tear on the distal side of the left subclavian artery was not excised in 11 patients (21.2 %) of group PA. The intimal tear was excised in all patients in group TA. The durations of cerebral protection (PA, 18.7; TA, 70.3 min), cardiopulmonary bypass (PA, 121.5; TA, 206 min), and overall operation (PA, 181.8; TA, 403.8 min) were significantly shorter in group PA. The incidence of postoperative brain damage was significantly lower in group PA (9.6 %) than in group TA (33.3 %). The mortality rate was significantly lower in group PA (5.8 %) than in group TA (58.3 %). Distal arch to descending aortic replacement was required in four patients of group PA during follow-up period. There were no complications or mortality during the reoperation. The actuarial survival rate at 10 years was significantly better in group PA (66.5 %) than in group TA (25 %). CONCLUSION: Limited proximal arch repair is suitable for high-risk patients with AAD, despite no excision of the intimal tear.

Less Invasive Quick Open Stenting using a J Graft Open Stent for Distal Arch Aneurysms.

A new device of aortic stent graft made in Japan has been available since July 2014. Here, we describe a novel, unique surgical technique named "less invasive quick open stenting" at a rectal temperature of 28°C without any cerebral perfusion for treating distal arch aneurysms. All 12 patients were discharged from the intensive care unit within 24 hours after surgery without any complications. This technique aids in the exclusion of atherosclerotic plaques on the aortic wall and shortens the duration of circulatory arrest; moreover, it represents a very attractive option to prevent recurrent nerve injury.

Outcomes of Open Surgical Repair for Type B Dissecting Aortic Aneurysm With Alternative Methods in the Endovascular Stent Era.

We assessed the midterm outcomes of 2 types of open surgical repair for type B dissecting aortic aneurysm (BDA). During the last 4 years, 86 patients with BDA (mean age, 68.5 ± 9.8 years; range: 41-87 years) underwent open repair. The average duration between the dissection onset and surgery was 51.5 ± 31.3 months. If the BDA was of open type with patent false lumen or the aneurysm extended for a long segment, descending or thoracoabdominal aortic repair was performed with left thoracotomy. If the BDA was of the closed type with thrombosed false lumen and the aneurysm was located around the distal arch, open stent implantation was performed with our unique technique using circulatory arrest with a rectal temperature of 28 °C without any cerebral perfusion. Left thoracotomy was performed in 68 patients. The durations of aortic clamping and cardiopulmonary bypass were 65.2 ± 16.9 and 78.5 ± 34.6 minutes, respectively. Open stent implantation was performed in 18 patients. The durations of circulatory arrest and cardiopulmonary bypass were 19.1 ± 5.1 and 86.2 ± 17.8 minutes, respectively. In the present study, 4 patients (4.7%) required reexploration for bleeding and 1 patient (1.2%) had a stroke, but none suffered paraplegia. The hospital mortality rate was 1.2% (1 patient), resulting from retrograde type A dissection. The actuarial aortic event-free survival rate, including operative death, was 96.4% at 3 years. Both open surgical procedures for BDA were relatively safe, with favorable early and midterm outcomes, and may be superior for avoiding neurologic complications.

Emergency coronary artery bypass grafting after substernal gastric tube interposition for esophageal cancer.

A 67-year-old man who had undergone substernal gastric tube interposition due to esophageal cancer showed ST changes on electrocardiography. Diagnosis was severe stenosis of the left anterior descending branch that required emergency coronary artery bypass grafting. Preoperative computed tomography (CT) showed the feeding arteries of the gastric tube were in contact with the left internal mammary artery. Therefore, we felt harvesting this artery could be dangerous and decided to perform a median sternotomy, approaching from the right side of the gastric tube. The pericardium was easily and safely reached. We undertook on-pump cardiac arrest single coronary artery bypass grafting of the left anterior descending artery with a saphenous vein graft. The postoperative course was uneventful without mediastinitis. Cardiac surgery after esophageal cancer is often performed from a left thoracotomy. But, we recommend a median sternotomy be performed as an option. Preoperative contrast-enhanced CT should be considered as it may indicate the need for a significant revision such as a median sternotomy.

Case of sudden death from retrograde type A dissection two days after surgery for a type B dissecting aneurysm.

A 64-year-old man underwent a descending aortic replacement for a chronic type B dissecting aneurysm with left thoracotomy. The patient was weaned from the mechanical ventilator immediately after surgery without any neurological complications. However, on the second post-operative day, he suddenly suffered from cardiopulmonary arrest when talking with his family. Despite 6 hours of cardiopulmonary resuscitation, the patient died. The postmortem examination revealed a 1000 mL blood volume and huge hematoma in the pericardium owing to a retrograde type A dissection, which descended from an intimal laceration between the common carotid and left subclavian arteries that corresponded with aortic cross clamping. We here report a rare case of iatrogenic retrograde type A dissection caused by surgical clamping on the aortic arch 2 days post-surgery.

Screening and management for ischemic heart disease in patients undergoing emergency surgery for a type A acute aortic dissection.

PURPOSE: We assessed the incidence of coronary artery disease (CAD) during hospitalization after emergency surgery for a type A acute aortic dissection. METHODS: A total of 123 patients underwent multi-slice computed tomography (MSCT) scans during an early stage after surgery. The patients were divided into two groups: group I consisted of 14 patients (11.4%) who had coronary artery stenosis of more than 75% on MSCT, and group II consisted of 109 patients (88.6%) who had no coronary lesions. RESULTS: The prevalence of diabetes, dyslipidemia and a smoking history was significantly higher in group I. Although the serum low-density lipoprotein cholesterol levels were similar, the high-density lipoprotein cholesterol (HDL) level was significantly lower in group I (36.4 ± 7.9 mg/dl) than in group II (49.6 ± 13.5 mg/dl, P = 0.0005). The maximum carotid intima-media thickness (IMT) was significantly thicker in group I (1.17 ± 0.37 mm) compared to group II (0.96 ± 0.33 mm, P = 0.0297). The logistic regression analysis detected that a carotid IMT over 1.1 mm (odds ratio 4.35, P = 0.0371) and HDL less than 40 mg/dl (odds ratio 3.90, P = 0.0482) were predictors for CAD. CONCLUSIONS: CAD screening should be recommended for patients with aortic dissection who have several atherosclerosis risk factors, even after emergency surgery.

Emergency repair of acute aortic dissection in a patient with relapsing polychondritis.

Relapsing polychondritis (RP) is a rare, inflammatory, multiorgan disorder affecting cartilaginous structure and other connective tissue. Cardiovascular complications occur in 10%-52% of patients. We report a case of emergency surgery for an acute aortic dissection in a patient with RP. A 45-year-old female who had been taking corticosteroids (10 mg/day) for 2 years for RP presented at another hospital with dyspnea and severe chest and back pain. Acute aortic dissection was diagnosed, and we performed emergency replacement of the ascending aorta. We could not control the bleeding from suture holes of the native aorta because the vessel was so fragile. Thus, we performed a delayed sternal closure. The day after surgery, bleeding had decreased, and we could close the chest wall. Infection was well controlled, and the patient suffered minimal additional complications. She was discharged to home by herself 29 days after surgery and returned to normal life.

Novel device accurately measures graft resistance and compliance to ensure quality of coronary artery bypass.

INTRODUCTION: The purpose of this study is to know the influence of coronary artery bypass grafting (CABG) on coronary circulation. In the present study, we evaluated CABG by using a novel flow analyzer that can calculate bypass graft resistance (Ra), resistance of the peripheral bed to which graft connects (Rp), the inertia of blood flow through the graft (L) and vascular wall compliance (C). METHODS: We performed off-pump CABG surgery on fifteen pigs assigned to the following groups (n = 5 each): normal CABG, competitive flow grafts and constrictive grafts. RESULTS: The wave pattern of 3 groups showed a clearly different form. In normal CABG and competitive flow group, we accepted a statistical difference in Rp and flow. In normal CABG and constrictive grafts. We accepted a statistical difference in Ra and flow. CONCLUSION: We can know the relationship between CABG and coronary circulation by this device in detail. This device will be useful for evaluating graft performance during CABG.

Evaluation of a new device for the intraoperative assessment of coronary artery bypasses grafting.

PURPOSE: The aim of this study was to evaluate a new flow analyze device that can intraoperatively measure compliance and resistance of coronary artery bypass grafting (CABG) by the parameter identification method. METHODS: Subjects were 95 patients who underwent CABG. Angiography soon after surgery confirmed patency in 90 grafts and graft failure in 5 grafts. Variables of aortic pressure and the graft flow were entered into this new device that includes a mathematical coronary circulation model to extrapolate other information the data; thus, we can estimate intraoperative flow rate, resistance, and compliance. Flow rate, resistance, and compliance were compared between patent and failed graft groups and among three different type grafts. RESULTS: There were no differences in flow rate, resistance, and compliance among the three grafts types. Between the patent and failed graft groups, there were statistically significant differences in flow rate and resistance, and compliance tended to be lower for the failed graft group. CONCLUSIONS: By measuring graft resistance and compliance, this new device is useful for evaluating graft performance during CABG.

Right atrial free-floating thrombus in a patient with massive pulmonary embolism: a case of 'emboli in transit'.

A 78-year-old man was admitted with sudden onset of dyspnea followed by syncope. Contrast-enhanced computed tomography showed embolism in the right main pulmonary artery and left upper pulmonary artery. Echocardiography revealed a large, free-floating thrombus and cine magnetic resonance imaging showed highly mobile, low-signal intensity mass in the right atrium, which protruded into the right ventricle during diastole. During surgery the thrombus migrated into the pulmonary artery trunk, but it was successfully removed.

Estimation of cardiac function with rotary blood pump.

BACKGROUND: A rotary blood pump may be implanted as a bridge to cardiac transplantation. Also, mechanical, histological, and biochemical improvements have been described in cardiac function after the implantation of a left ventricular assists device (LVAD). Thus there is considerable enthusiasm that LVAD might be used as a bridge to the recovery of myocardial function. Unlike a pulsatile pump, however, we cannot stop the rotary blood pump to estimate cardiac function. If the rotary blood pump stops, back flow will occur. In this study, a new method was examined that can estimate cardiac function without stopping the pump. MATERIALS AND METHODS: Twelve pigs were subjected to this acute study. The pump was implanted as an LVAD with an inlet cannula inserted into the left ventricle and the outlet cannula into the ascending aorta. The assist ratio was changed to 75%, from 25%. The relationship between the dp/dt of the left ventricle pressure and the differentiated pump flow rate was examined. Also, cardiac function was changed by epinephrine loading to estimate this method under hyperdynamic heart conditions. RESULTS: There was high positive correlation between the dp/dt of left ventricle pressure and differentiated the pump flow rate to 75% assisted ratio, from 25%. This relationship was established under hyperdynamic conditions. CONCLUSION: This method is simple and useful for estimating the cardiac function without pump stoppage.

Coronary artery surgery results 2005 in Japan.

This report is focused on the status and outcome of coronary artery surgery performed in Japan, from January 1 to December 31, 2005. A total of 12,207 cases underwent coronary artery bypass grafting (CABG), as an isolated or concomitant procedure. Isolated CABG was performed in 9,827 patients. The operative mortality for patients who underwent isolated CABG was 1.91% in 2005. The mortality for initial elective CABG was 0.89%. These are the most improved results obtained since annual surveys started over 30 years ago. Since 1996 the number of off-pump CABG (OPCAB) cases increased year after year. This less-invasive procedure was performed on 4,936 patients in 2005, which is 61.0% the of total number of CABG cases. Mortality improved after complete OPCAB to 0.60%, which is the lowest rate since this procedure has been introduced. More than half (50.6%) of 4 and/or more grafting patients underwent OPCAB, which is higher rate than that (49.7%) in 2004. The percentage of elderly patients undergoing coronary artery bypass surgery is rising every year. In 2005, 46.5% of patients were aged 70 years or older and 7.8% were aged 80 years or older. The utilization rate of arterial grafts was 70%.

Multiple papillary fibroelastomas of the aortic valve: case report.

Papillary fibroelastoma is the third most common primary tumor of the heart and most commonly involve the cardiac valves. Most papillary fibroelastomas do not cause symptoms and they are usually incidental findings by routine echocardiography or at autopsy. However, multiple papillary fibroelastomas are extremely rare. We report a case with papillary fibroelastoma which was incidentally found on echocardiography. Upon surgery, a tumor was found on each aortic cusp. Pathological findings of these tumors were consistent with those of papillary fibroelastoma.

A case of aortic valve replacement with St. Jude Medical Regent valve (first implant in Japan).

The St. Jude Medical (SJM) Regent valve was developed as a new mechanical valve by improving the conventional SJM valve. The effective orifice area is wider than that of Hemodynamic Plus (HP) series. The efficacy of the new valve has been reported in Europe and the United States. On October 26, 2004, we first performed aortic valve replacement (AVR) with the SJM Regent valve for aortic valve stenosis in Japan. A 64-year-old female was admitted to our hospital with dyspnea on exertion. She was diagnosed with aortic valve stenosis. She underwent AVR with a 17 mm SJM Regent valve. According to the results of echocardiography conducted two months postoperatively, the peak pressure gradient of the prosthetic valve was 32.0 mmHg, the mean pressure gradient was 13.2 mmHg, and the effective orifice area index (EOAI) was 0.92 cm2/m2. Cinefluoroscopy showed the valve opening angle of 85 degrees indicating full opening. She was discharged 15 days after surgery without complications. As demonstrated by the present case, implantation of a 17 mm SJM Regent valve produced a satisfactory result reflected by lower pressure gradient and absence of patient-prosthetic mismatch. In the future, the new valve is expected to be the optimum mechanical valve for a narrow annulus.

Successful surgical treatment of rupture of coronary arteriovenous fistula with unconsciousness after chest and back pain.

A 65 year-old woman was admitted to our hospital, because of unconsciousness after chest and back pain. Echocardiography showed pericardial effusion. She suffered from pre-shock due to cardiac tamponade. Although a cause of cardiac tamponade was unclear, we performed emergency surgical treatment without coronary angiography. In operation, we found a rupture of coronary arteriovenous fistula and repaired it. The patient recovered from the surgery uneventfully. Coronary artery fistula is an abnormal communication between a coronary artery and a cardiac chamber or major vessel. It is the most common congenital anomalies of the coronary arteries. Many patients with these anomalies remain asymptomatic, but some patients develop symptoms of congestive heart failure, infective endocarditis, myocardial ischemia, arrhythmia, or rupture of an aneurismal fistula. Usually, the dilatation of fistula is common, and although 19% of this may become aneurysmal, the rupture of the aneurysm is very rare. We report a case of ruptured coronary arteriovenous fistula who underwent successful emergent surgery.