Kiyotoshi Akita

Respiratory and Hemodynamic Changes in Patients with Chronic Thromboembolic Pulmonary Hypertension 1 Year after Pulmonary Endarterectomy

We reviewed the results of thromboembolectomy, which was performed for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), 1 year after the operation. We obtained hemodynamic and respiratory data of 60 patients from the 112 patients who were operated at our institute. The hemodynamic parameters such as mean pulmonary arterial pressure (PAP), pulmonary vascular resistance (PVR), and cardiac index (CI) were significantly improved after the operation, and this improvement of pulmonary hemodynamics persisted even a year after the operation. A significant improvement in gas exchange was observed immediately after the operation and a further elevation in the partial pressure of oxygen in arterial blood (PaO2) was observed 1 year after the operation. (English Translation of J Jpn Coll Angiol 2012; 52: 53-58).

Accuracy of 64-Slice Multidetector Computed Tomography for Diseased Coronary Artery Graft Detection

BACKGROUND Sixty-four-slice multidetector computed tomography (64-MDCT) has been shown to be a feasible modality for diagnosing coronary artery disease. We studied the accuracy of 64-MDCT in the detection of diseased grafts and also evaluated its limitations. METHODS This study comprised 19 patients who underwent coronary artery bypass grafting and both invasive coronary angiography (ICA) and 64-MDCT. The 64-MDCT images were analyzed for bypass graft occlusion and significant stenosis (>50%) of the anastomosis, and the results were compared with those of ICA. RESULTS A total of 90 anastomoses, including 25 proximal anastomoses, were evaluated. Of 65 distal anastomoses, including 5 previously occluded grafts in redo cases, 12 distal anastomoses were identified by 64-MDCT as occluded. In comparison, only 10 grafts were identified as occluded by ICA. The sensitivity, specificity, positive predictive value, and negative predictive value for patency were 100% (10 of 10), 96.5% (55 of 57), 83.3% (10 of 12), and 100% (55 of 55), respectively. The ICA patent grafts were evaluated with respect to stenosis. Invasive coronary angiography identified significant stenosis at only 1 site, whereas 64-MDCT showed significant stenosis at 6 sites. The sensitivity, specificity, positive predictive value, and negative predictive value for stenoses were 100% (1 of 1), 93.1% (67 of 72), 16.7% (1 of 6), and 100% (67 of 67), respectively. CONCLUSIONS Although 64-MDCT demonstrated diagnostic accuracy in evaluating bypass grafts, limitations of this method include false positive results in cases of competitive flow between the graft and the native coronary artery.

Total arch replacement for a distal arch aneurysm with aberrant right subclavian artery

Aberrant right subclavian artery is a rare condition with a prevalence of 0.5%–2.0% of the population. We report a case of distal aortic arch aneurysm with right subclavian artery. A 75-year-old man who was asymptomatic was referred to our hospital for a thoracic aortic aneurysm. Computed tomography showed a 55-mm fusiform aneurysm of the distal arch and an aberrant right subclavian artery. Total arch replacement was performed via median sternotomy with antegrade selective cerebral perfusion and hypothermic circulatory arrest. We reconstructed the aberrant right subclavian artery in the normal position to avoid compression of the esophagus and trachea caused by future aneurysmal dilatation of the orifice of the aberrant right subclavian artery and potential high risk for rupture.

The importance of preoperative magnetic resonance imaging in valve surgery for active infective endocarditis

PurposeValve surgery for active infective endocarditis (IE) can cause fatal brain hemorrhage. Our current study aimed to evaluate the incidence of septic cerebral lesions in active IE patients by performing preoperative magnetic resonance imaging (MRI) including T2*- weighted sequences and magnetic resonance angiography (MRA) before urgent valve surgery, and to investigate whether such preoperative evaluation affects postoperative outcomes.MethodsEighteen patients were referred to our department for native valve IE during 2006–2010. Urgent surgery was indicated in cases of hemodynamic failure resulting from valve destruction, refractory sepsis, and mobile vegetations measuring >10 mm. For these patients, we performed preoperative MRI and MRA.ResultsMales comprised 67% of the subjects, with average age 53 ± 15 years. No clinical evidence of acute stroke was noted. Of the 18 patients, urgent surgery was indicated in 15; of these, 10 (67%) showed a brain lesion related to IE: 6 patients had acute or subacute brain infarctions, 2 patients had brain infarction with brain abscess, and 2 patients had hemorrhagic brain infarction and so did not undergo urgent surgery. Thus, 13 patients underwent urgent valve surgery. Among the 5 patients who did not undergo urgent surgery, 4 patients later underwent valve surgery for healed IE. No hospital deaths or neurological complications occurred.ConclusionMRI of patients with active IE revealed a high incidence of cerebral lesions caused by IE. The use of MRI to detect septic embolism and intracerebral hemorrhage may provide important information for better surgical outcomes.

Recent Outcomes of Surgery for Chronic Type B Aortic Dissection

OBJECTIVE Chronic type B dissection though optimal is still considered to be a controversial procedure, even in the advent of stent grafts. Recently, we used a novel surgical technique involving left axillary perfusion to analyze the results of our surgical strategy and compare them with those reported in the literature. MATERIALS AND METHODS Between August 2004 and July 2009, 39 patients underwent graft replacement for chronic type B aortic dissection. The left axillary artery was used for perfusion inflow. Perfusion was maintained at approximately 23˚C during open proximal anastomosis. The graft was anastomosed to the distal true lumen whenever possible. RESULTS Open proximal anastomosis was performed in 22 patients (56%). In 24 cases (62%), grafts were anastomosed to the true lumen of the peripheral aorta. The early overall mortality rate was 3% (1 patient). Permanent cerebral infarction occurred in 2 patients (5%); and paraparesis, in 1 patient (3%). The Kaplan-Meier survival estimates were 91% at 2 years and 88% at 5 years. CONCLUSION Our surgical strategy is associated with excellent short-term and midterm outcomes. Although further investigation is needed, this strategy may be useful for patients with chronic type B dissection.

Saccular True Aneurysm of the Ascending Aorta 19 Years After Aortic Cannulation: Report of a Case

A 61-year-old woman who had undergone surgery for a right ventricular myxoma 19 years earlier was admitted to our hospital for treatment of a saccular aneurysm of the ascending aorta at the site of the previous aortic cannulation. We resected the aneurysm completely and closed it with a polyester patch. Pathologic examination revealed an aortic wall saccular aneurysm, without atherosclerotic changes or bacterial cultures, consisting of elastic fibrous tissue and artificial material. There were inflammatory changes at the top of the aneurysm, with continuity of medial elastic fibrous tissue inside. These pathological findings strongly suggested a true aneurysm with continuity of medial elastic fibrous tissue. We report this extremely unusual case of a saccular true aneurysm at a previous aortic cannulation site.

Left axillary arterial perfusion for cerebrospinal protection in proximal descending aortic aneurysm

A 73-year-old man presented with DeBakey type IIIa chronic aortic dissection. The aneurysm of the descending aorta was replaced using an open proximal technique with hypothermic circulatory arrest. For cerebrospinal protection, the left axillary artery was cannulated, which perfuses the vertebral artery and affects the Willis arterial circle, the anterior spinal artery, and the collateral blood supply to the spinal cord. Cannulation of the left axillary artery was a safe and effective surgical option for antegrade cerebral perfusion and spinal protection.

Arch replacement using antegrade selective cerebral perfusion for shaggy aorta

Background: Embolic stroke during arch replacement is a serious concern in patients with shaggy aorta. Objective: To evaluate shaggy aorta in patients who received total aortic arch replacement with antegrade selective cerebral perfusion utilizing axillary perfusion. Method: Between January 2005 and December 2010, 63 patients underwent preoperative contrast-enhanced computed tomography scanning of the aorta to evaluate atheromatous plaque. We analyzed operative data to investigate which factors were associated with outcomes and survival. Results: Shaggy aorta was found in 34 (54%) patients. There were 3 (5%) cases in the ascending aorta, 26 (41%) in the aortic arch, and 19 (30%) in the descending aorta. Operative mortality occurred in 1 (2%) patient. Although stroke occurred in 2 (3%) shaggy aorta patients, shaggy aorta was not associated with an increased likelihood of stroke (p = 0.4951). Survival was significantly lower in patients with shaggy descending aorta (p = 0.0411) and in patients >75-years old (p = 0.0200); these traits were identified as independent risk factors for late death (p = 0.0368 and p = 0.0100, respectively). Conclusion: We concluded that our perfusion technique protects patients with shaggy aorta against embolism, and that the survival is lower in patients with shaggy descending aorta.

Paraplegia following the emergency surgical repair of a nonruptured symptomatic abdominal aortic aneurysm: Report of a case

This report presents an extremely rare case of paraplegia following emergency surgery for a nonruptured symptomatic abdominal aortic aneurysm. A 62-year-old man underwent an emergency surgical repair for a symptomatic nonruptured infrarenal abdominal aortic aneurysm. On postoperative day 2 paraplegia following spinal cord ischemia occurred at the T8 level. The site of the ischemia was situated too high for clamping to have caused this condition, unless the patient had a congenital anomaly in the blood supply to the spinal cord or it had been caused by the previously occluded great radicular artery, which was maintained by the collateral blood supply from the iliac circulation.

Circulatory assistance and surgery for residual pulmonary hypertension following thromboendarterectomy.

Chronic thromboembolic pulmonary hypertension (CTEPH) complicated by pulmonary hypertension is resistant to medical therapy and has a poor prognosis. The only therapy effective for CETPH is thromboendarterectomy (TEA). CTEPH is divided into four types, depending on the presence of thrombus in the pulmonary arteries. In Japan, CTEPH is generally divided into central and peripheral types. The results of surgery for the central type have recently become more favorable. However, the results of surgery for the peripheral type are not favorable due to inadequate surgical indications, surgical procedures, and perioperative care. To improve the results of surgery for peripheral CTEPH, the most important issue is treating residual pulmonary hypertension. For patients with residual pulmonary hypertension, it is impossible to perform removal from extracorporeal circulation during surgery. In addition, it is difficult to save lives unless percutaneous cardiopulmonary support (PCPS) is introduced in all cases. However, with circulatory assistance with PCPS alone, several deaths have occurred due to left ventricular failure during the procedure. Therefore, the authors began to use circulatory assistance with intraaortic balloon pumping (IABP). The authors compared circulatory assistance with PCPS alone with concomitant use of PCPS and IABP for postoperative residual pulmonary hypertension in patients with CTEPH. Although there have been few surgeries for this disease in Japan, we discuss the results of 30 recent surgical cases.