Yoshihisa Morimoto

Extended replacement of aortic arch aneurysms through left posterolateral thoracotomy

OBJECTIVE To present our experience of total aortic arch replacement through a left posterolateral thoracotomy. METHODS Sixteen patients (13 males; mean age 62.1+/-11.3 years) with extended thoracic aortic aneurysms, including those in the thoracoabdominal aorta, underwent replacement through a left posterolateral thoracotomy. The pathology of the diseased aorta was non-dissecting aneurysm due to aortitis in 1 patient and aortic dissection in 15 patients (acute type A: 1, chronic type A: 12, chronic type B: 2). In a prior operation, the patient with aortitis had undergone the Bentall procedure with endovascular stenting of the brachiocephalic artery, and among the other 15 patients, one previously had endovascular stenting for the aortic arch and 12 had hemi-arch replacement for acute type A dissection. Extension of arch replacement was the aortic arch and descending aorta in eight patients, the ascending arch and descending aorta in five patients and the descending arch, and thoracoabdominal aorta in three patients. Additional retroperitoneal dissection was required for the repair of a thoracoabdominal aortic aneurysm. RESULTS One patient died of traumatic cerebral hemorrhage on day 145 (hospital mortality 6.3%). Average duration of ventilation support was 19.4+/-17.0h and length of ICU stay was 3.6+/-1.6 days. Actuarial survival at 2 years after the operations was 67.7%. However, no aortic-related mortality was observed during follow-up. CONCLUSIONS Early results of extended aortic arch replacement through a left posterolateral thoracotomy were satisfactory in selected patients.

Sivelestat attenuates postoperative pulmonary dysfunction after total arch replacement under deep hypothermia

BACKGROUND Total arch replacement necessitating deep hypothermia with circulatory arrest has a greater effect on pulmonary function than other cardiac surgery using cardiopulmonary bypass (CPB). Since April 2004, 100mg of sivelestat sodium hydrate was administrated by bolus injection into pulp circuit at the initiation of CPB in every case performed total arch replacement. We investigated the hypothesis that prophylactic use of the drug attenuates post-pump pulmonary dysfunction. METHODS A retrospective analysis of 120 consecutive patients who underwent total arch replacement from August 2001 to December 2006 was conducted. Patients were divided into two groups according to the date of surgery, April 2004, when we started sivelestat administration. Group A (n=60), operated after April 2004, was administrated sivelestat at the initiation of CPB. Group B (n=60), before April 2004, was not administrated. Time courses of hemodynamic variables were evaluated until 24h after surgery and those of respiratory variables and inflammatory markers until 48 h after surgery. RESULTS There were no significant differences in patient age, sex, prevalence of chronic obstructive lung disease, preoperative lung function, time of operation and CPB, minimum temperature, and aprotinin usage. Hospital mortality occurred in two patients in the group B (3.3%) and no patient in group A (0%). Postoperative hemodynamic variables were not different between the two groups. Respiratory index, oxygenation index were significantly better in patients pretreated with sivelestat (respiratory index; p<0.001, oxygenation index; p<0.001, respectively). CRP was significantly lower in patients pretreated with sivelestat (p=0.022). Except for patients who required tracheostomy or re-exploration for bleeding, patients pretreated with sivelestat were extubated significantly shorter (group A: 12.6+/-10.8h, group B: 25.5+/-12.9h, p=0.033). No patient with postoperative respiratory failure requiring tracheostomy was noted in sivelestat group. CONCLUSION Prophylactic administration of sivelestat at the initiation of CPB results in better postoperative pulmonary function, leading to earlier extubation time. Our study suggests that sivelestat was effective in facilitating postoperative respiratory management in total arch replacement.

Endovascular treatment of aortoureteric fistula.

Purpose: To report successful endovascular treatment of massive hemorrhage from an aortoureteric fistula. Case Report: An 82-year-old man who had undergone total cystectomy and bilateral ureterostomy for bladder cancer was transferred with massive hemorrhage from the ureterostomy. Angiography demonstrated an aortoureteric fistula between the terminal aorta and the left ureter. The patient had pancytopenia from unknown causes on admission, so a stent-graft made from a Gianturco Z-stent covered with Dacron graft was implanted; complete hemostasis was obtained immediately. He died of coexistent plasma cell leukemia 42 days after the operation; however, complete hemostasis had been maintained, and infection around the stent-graft was not recognized at autopsy. Conclusions: Stent-graft implantation can be a useful therapy for control of massive bleeding from an aortoureteric fistula.

Successful Management of Threatened Aortic Rupture Late After Rib Fracture Caused by Blunt Chest Trauma

A 62-year-old man was crushed in a car accident and diagnosed with a fractured left ninth rib, pulmonary and heart contusion, hemopneumothorax, and descending aortic injury based on a computed tomography scan. He underwent chest tube drainage and was intubated for mechanical ventilation because a bone fragment of the ninth rib threatened to penetrate the descending aorta. On the second posttrauma day, computed tomography showed the bone fragment of the ninth rib approaching the descending aorta. He underwent graft replacement of the injured portion of the descending thoracic aorta, and we removed the fractured left ninth rib.

Platelet Scintigraphy in the Diagnosis of Arteriosclerosis Obliterans

Abstract.Purpose: We evaluated the efficacy of platelet scintigraphy using autologous platelets labeled with 111In-oxine, to assess the degree of arteriosclerotic activity in arteriosclerosis obliterans (ASO). Methods: Thirty-three patients with clinical signs of ASO, seen between January 1996 and August 1999, were enrolled in this study. Scintigraphic imaging results were compared with the findings of contrast angiography in 26 patients, 17 of whom were taking antiplatelet and/or anticoagulant drugs during the platelet imaging study. Results: Angiography demonstrated atherosclerotic lesions at 38 sites from the abdominal aorta to the popliteal arteries in 23 patients. There was an accumulation of platelets at 17 of these sites (45%) and at 6 other sites without definite angiographic abnormalities. Lesions that resulted in less than 50% stenosis were detected slightly, but not significantly, less often than lesions with higher degrees of stenosis and occlusion (50% vs 30%, P = 0.73). The frequency of true-positive scintigraphic results was statistically higher in patients not taking antithrombotic agents than in those taking antithrombotic agents (70% vs 32%, P = 0.02). Conclusions: Our results suggest that imaging with 111In-oxine-labeled platelets may be useful for evaluating the pathophysiologic characteristics of atherosclerotic lesions in patients with ASO.

Gender-linked impact of epicardial adipose tissue volume in patients who underwent coronary artery bypass graft surgery or non-coronary valve surgery

Background Traditional and non-traditional risk factors for atherosclerotic cardiovascular disease (ASCVD) are different between men and women. Gender-linked impact of epicardial adipose tissue volume (EATV) in patients undergoing coronary artery bypass grafting (CABG) remains unknown. Methods Gender-linked impact of EATV, abdominal fat distribution and other traditional ASCVD risk factors were compared in 172 patients (men: 115; women: 57) who underwent CABG or non-coronary valvular surgery (non-CABG). Results In men, EATV, EATV index (EATV/body surface area) and the markers of adiposity such as body mass index, waist circumference and visceral fat area were higher in the CABG group than in the non-CABG group. Traditional ASCVD risk factors were also prevalent in the CABG group. In women, EATV and EATV index were higher in the CABG group, but other adiposity markers were comparable between CABG and non-CABG groups. Multivariate logistic regression analysis showed that in men, CABG was determined by EATV Index and other ASCVD risk factors including hypertension, dyslipidemia, adiponectin, high sensitive C-reactive protein (hsCRP) and type 2 diabetes mellitus (Corrected R2 = 0.262, p < 0.0001), while in women, type 2 diabetes mellitus is a single strong predictor for CABG, excluding EATV Index (Corrected R2 = 0.266, p = 0.005). Conclusions Our study found that multiple risk factors, including epicardial adipose tissue volume and traditional ASCVD factors are determinants for CABG in men, but type 2 diabetes mellitus was the sole determinant in women. Gender-specific disparities in risk factors of CABG prompt us to evaluate new diagnostic and treatment strategies and to seek underlying mechanisms.

Spontaneous Esophageal Rupture Treated by Conservative Therapy

The prognosis of spontaneous esophageal rupture of the esophagus worsens over time from disease onset to treatment and, in severe cases, may require surgery to save the patients life. Patients appearing at the hospital considerably after esophageal perforation have no appropriate surgical alternatives and face poor prospects. We conservatively treated a severe case following 2-day lapse of after disease onset, managing a favorable outcome. A 58-year-old man who developed upper abdominal and back pain after vomiting from drinking was transferred to our institute in an emergency due to pain intensifying 2 days after the symptom onset. Chest X-ray revealed a large quantity of bilateral pleural effusion similar to gastrointestinal content, which we withdrew through intrathoracic drainage. Esophagography showed perforation of the esophagus. The patients poor general condition, including septic shock and adult respiratory distress syndrome, contraindicated radical surgery, so we instituted conservative therapy such as continuous thoracic drainage hyperalimentation. Oral intake was started in month 4 after admission. The patient was discharged in good general condition 7 months after onset.

Reverse diastolic flow in the common carotid artery in severe aortic regurgitation, causing brain ischemia

Diastolic reverse flow in the common carotid artery (CCA) at duplex sonography can be seen in patients with severe aortic regurgitation (AR). We report a patient with severe AR whose diastolic reverse flow in the right CCA caused transient brain ischemia. To our knowledge, there are no descriptions of diastolic steal volume by AR causing cerebral ischemia. This is the first description of this rare pathophysiologic form of cerebral ischemia.

Indium-111-oxine-labeled platelet scintigraphic images in the assessment of thrombogenicity in small-caliber prosthetic vascular grafts.

Antithrombogenicity is one of the essential factors for successful development of small-caliber prosthetic vascular grafts, and its accurate evaluation is important. The purpose of this study was to investigate the efficacy of indium-111-oxine-labeled (111In) platelet scintigraphic images in the assessment of graft thrombogenicity. Fibrin-coated knitted polyester vascular prostheses, 2 mm in diameter and 2 cm in length, were implanted in the bilateral common carotid arteries of 18 Japanese white rabbits. The grafts were explanted on postoperative days 1, 3, 7, 10, 14, and 30 (six grafts on each of the days), and 111In platelet scintigraphy was performed with visual, semiquantitative, and quantitative analysis. The relationships among the three analyses were evaluated. Platelet depositions on the luminal surface were clearly visualized with 111In-platelet scintigraphy if the number of 111In platelets was more than 4.8 × 104 counts per minute, even if a macroscopic thrombus formation was not observed. There was a highly significant correlation between the graft region of interest on the images and the total platelet deposition (p < .0001). The images in the thrombotic grafts have shown a very strong 111In-platelet accumulation, but there were some limitations in the 111In-platelet scintigraphic images. 111In-platelet scintigraphic images are useful for evaluating platelet deposition in small-caliber vascular prostheses if they are performed with a proper understanding of their limitations.

A True Aneurysm of Posterior Tibial Artery

True aneurysms of tibial artery are uncommon. We report a case of a 47-year-old woman who suffered from a distal embolism in the left toes. The surgical intervention involved an aneurysmectomy and the interposition of the posterior tibial artery using the saphenous vein graft. She has been doing well 22 months after the operation.