Kenji Minatoya

Prospective comparative study of brain protection in total aortic arch replacement: deep hypothermic circulatory arrest with retrograde cerebral perfusion or selective antegrade cerebral perfusion

BACKGROUND The purpose of this study was to compare the results of total aortic arch replacement using two different methods of brain protection, particularly with respect to neurologic outcome. METHODS From June 1997, 60 consecutive patients who underwent total arch replacement through a midsternotomy were alternately allocated to one of two methods of brain protection: deep hypothermic circulatory arrest with retrograde cerebral perfusion (RCP: 30 patients) or with selective antegrade cerebral perfusion (SCP: 30 patients). Preoperative and postoperative (3 weeks) brain CT scan, neurological examination, and cognitive function tests were performed. Serum 100b protein was assayed before and after the cardiopulmonary bypass, as well as 24 hours and 48 hours after the operation. RESULTS Hospital mortality occurred in 2 patients in the RCP group (6.6%) and 2 in the SCP group (6.6%). New strokes occurred in 1 (3.3%) of the RCP group and in 2 (6.6%) of the SCP group (p = 0.6). The incidence of transient brain dysfunction was significantly higher in the RCP group than in the SCP group (10, 33.3% vs 4, 13.3%, p = 0.05). Except in patients with strokes, S-100b values showed no significant differences in the two groups (RCP: SCP, prebypass 0.01+/-0.04: 0.05+/-0.16, postbypass 2.17+/-0.94: 1.97+/-1.00, 24 hours 0.61+/-0.36: 0.60+/-0.37, 48 hours 0.36+/-0.45: 0.46+/-0.40 microg/L, p = 0.7). There were no intergroup differences in the scores of memory decline (RCP 0.74+/-0.99; SCP 0.55+/-1.19, p = 0.6), orientation (RCP 1.11+/-1.29; SCP 0.50+/-0.76, p = 0.08), or intellectual function (RCP 1.21+/-1.27; SCP 1.05+/-1.15, p = 0.7). CONCLUSIONS Both methods of brain protection for patients undergoing total arch replacement resulted in acceptable levels of mortality and morbidity. However, the prevalence of transient brain dysfunction was significantly higher in patients with the RCP.

Overview of Late Outcome of Medical and Surgical Treatment for Takayasu Arteritis

Takayasu arteritis (TA), which is a nonspecific inflammatory disease of unknown origin, causes various types of aortoarterial stenosis/occlusion or dilatation (Figure). Historically, Mikito Takayasu, a Japanese ophthalmologist, described a peculiar wreathlike arteriovenous anastomosis around the papillae of the retina (Takayasu disease) in 1908.1 In the first necropsy case reported in 1940, this ophthalmologic finding was related to cervical vessel occlusion.2,3 Subsequently, this nonspecific panarteritis that affects the intima and the adventitia of the aorta and its main branches was called Takayasu arteritis . Its clinical manifestations are varied and related to the vessel that presents the stenotic or occlusive lesions, such as the aortic arch (pulseless disease),4 descending thoracic or abdominal aorta (atypical coarctation),5 renal arteries,6 coronary arteries,7 and pulmonary arteries. Aortic aneurysm8 and aortic valve regurgitation with ascending aortic dilatation9 may also develop in some instances. Pharmacological treatment with corticosteroids is usually the initial treatment. Some patients require surgical treatment such as bypass grafting and graft replacement or endovascular repair including percutaneous transluminal angioplasty (PTA) and stent grafting, even in the active phase or in the inactive chronic phase with adequate control of the inflammation. Since the 1960s, acceptable early and midterm outcomes of medical and/or surgical treatment have been published. However, the long-term outcome, including that of recently developed endovascular treatment, has not been discussed. In this article, we describe an overview, particularly focusing on the late outcome of treatment for TA. Figure. Three-dimensional computed tomographic findings of an active phase of Takayasu arteritis (21 years, female). Three-dimensional computed tomographic findings include multiple stenotic lesions on the carotid and subclavian arteries (A), aneurysmal dilatation of the ascending aorta to the aortic arch and of the main pulmonary artery (B), aneurysmal dilatation of the descending aorta, stenosis of the right renal …

Predictive Factors for Mortality and Cerebral Complications in Arteriosclerotic Aneurysm of the Aortic Arch

BACKGROUND The incidence of cerebral complications is high in patients with aortic arch aneurysm. METHODS Between December 1977 and December 1995, 246 patients with arteriosclerotic arch aneurysm underwent operation. Thirty-nine patients had an aneurysm involving the entire arch, 193 had only distal arch aneurysm, and 14 had arch aneurysm extending to the descending aorta. Eighty-seven patients underwent replacement of the total arch, 85 had replacement of only the distal arch, 14 had simultaneous replacement of the descending aorta, 45 had patch repair, and 15 had thromboexclusion. Selective cerebral perfusion was used in 112 patients and partial bypass in 58 in the earlier series of patients, but deep hypothermic circulatory arrest with retrograde cerebral perfusion technique was exclusively applied in the most recent 76 patients. RESULTS There were 50 (20%) early deaths and 37 (19%) late deaths. Postoperative stroke was found in 26 (11%) patients of which 13 (50%) died. Mutual predictive factors for postoperative mortality and stroke were earlier series, preoperative chronic renal failure, ruptured aneurysm, arch clamping during procedure, and using partial cardiopulmonary bypass. Among 129 patients operated on during the most recent 5 years, early mortality and incidence of stroke decreased to 14.7% and 6.9%, respectively. CONCLUSIONS Results of operations for arteriosclerotic aneurysms of the transverse aortic arch in 246 patients during a period of 17 years have been improving but are still not satisfactory.

MRA of the Adamkiewicz artery: a preoperative study for thoracic aortic aneurysm.

PURPOSE The purpose of this work was to investigate the ability of MR angiography (MRA) to visualize the Adamkiewicz artery (AKA) as a preoperative study of thoracic aortic aneurysm to prevent ischemic injury of the spinal cord. METHOD Twenty-six patients scheduled for surgical or endovascular stent-graft repair of thoracic aortic aneurysm were studied with a three-dimensional contrast MRA. Data acquisition was repeated two times following injection of Gd-DTPA. Source images were processed with multiplanar reconstruction and maximum intensity projection. RESULTS The AKA was identified in 69% (18/26). In three patients, selective angiography of the intercostal artery confirmed the AKA at the same level and side predicted by MRA. The anterior spinal artery and the anterior medullary vein were observed in 50% (13/26) and 65% (17/26), respectively. CONCLUSION Contrast MRA is a promising technique to visualize the AKA noninvasively as a preoperative evaluation of thoracic aortic aneurysms.

Preoperative demonstration of the Adamkiewicz artery by magnetic resonance angiography in patients with descending or thoracoabdominal aortic aneurysms

OBJECTIVE Investigating the possibility of magnetic resonance angiography (MRA) to visualize the Adamkiewicz artery of as a preoperative study of thoracic aortic aneurysms. METHODS From February 1998 to March 1999, 26 consecutive patients who had aneurysms of the thoracoabdominal or descending aorta underwent preoperative MRA to visualize the Adamkiewicz artery. Mean age was 60.5+/-11.5 years. Fifteen patients had non-dissecting aneurysm and 11 had aortic dissections. Nineteen patients underwent replacement of the aneurysms, four patients underwent endovascular stent-graft repair, and three patients were discharged without treatment of aneurysm. MRA was performed on a 1.5-T system (Magnetom, Siemens) and data acquisition was repeated two times following injection of gadolinium-DTPA. Source images were reconstructed with multiplanar reconstruction and maximum intensity projection. Criteria for the Adamkiewicz artery of were that the artery ascends from the dorsal branch of the intercostal or lumbar artery to the anterior mid-sagital surface of the spinal cord in the early phase. RESULTS The Adamkiewicz arteries were demonstrated in 18 patients (69%). These arteries were originated from the left intercostal or lumbar arteries in 13 (72.2%) patients and from the right in 5 (27.8%) and from the Th8 branch in three, Th9 in seven, Th10 in two, Th11 in four, and L1 in two. All patients had graft replacement of the aorta using a partial bypass. All intercostal or lumber arteries, which were visualized as the origin of the Adamkiewicz artery, were reattached to the grafts. No spinal cord injury occurred. CONCLUSION Preoperative detection the Adamkiewicz artery was possible by MRA and was very useful to reduce the incidence of ischemic injury of the spinal cord during surgery of the thoracoabdominal or descending aorta.

Evolving arch surgery using integrated antegrade selective cerebral perfusion: impact of axillary artery perfusion.

OBJECTIVE The study objective was to determine the impact of integrated antegrade selective cerebral perfusion with right axillary artery perfusion during arch surgery. METHODS All surgeries were performed through a median sternotomy. Direct cannulation of the right axillary artery in the axilla was used for cardiopulmonary bypass and antegrade selective cerebral perfusion under hypothermia. In addition, ascending aortic or femoral artery perfusion was used. The clinical records of 531 patients (median age, 72 years) between 1999 and 2006 were reviewed, of whom 137 patients (25.8%) underwent emergency surgery. There were 164 dissecting and 367 nondissecting aortic lesions. The surgeries included total arch replacement in 431 patients, partial arch replacement in 9 patients, and hemiarch replacement in 91 patients. RESULTS The early mortality rate was 4.0% (2.3% of 30-day mortality and 1.7% of in-hospital mortality). The incidence of permanent neurologic dysfunction was 2.9% in all (3.3% in total arch replacement and 1.0% in hemiarch or partial arch replacement). The incidence of temporary dysfunction was 9.9% in all (10.6% in total arch replacement and 7.0% in hemiarch or partial arch replacement). Multivariate analysis demonstrated that the risk factors for early mortality were chronic renal failure, ruptured nondissecting aneurysm, and prolonged surgery. The midterm survival was 87.2% +/- 1.7% at 3 years and 80.5% +/- 2.6% at 5 years. CONCLUSION Right axillary artery perfusion is an advantageous adjunct to cardiopulmonary bypass and antegrade selective cerebral perfusion in arch surgery.

Early and long-term results of surgery for aneurysms of the thoracic aorta in septuagenarians and octogenarians

OBJECTIVE The purpose of this study was to demonstrate early and long-term results of surgery for thoracic aortic aneurysm in patients over 70 years of age compared with those of patients under 70 years and to clarify the clinical problems peculiar to this subset of patients. PATIENTS AND METHODS Of 1157 patients who underwent surgery for thoracic aortic aneurysm from 1978 to December 1997, 261 who were 70 years or older were selected for analysis. Mean age at the time of surgery was 74.4 +/- 3.5 years. Aneurysms were atherosclerotic in 177 patients and aortic dissection in 84. Acute aortic dissection was found in 25 patients and ruptured aneurysm in 44. The control group consisted of 896 patients under 70 years. Preoperative complications such as AAA, peripheral arterial disease, emphysema, and old cerebral infraction were more common in the older group. Operative procedures consisted of replacement of the ascending aorta or hemiarch in 51 patients, total arch replacement in 75, distal arch replacement in 35, descending aorta replacement in 75, replacement of the thoracoabdominal aorta in 28, and extra-anatomical repair and others in 15. The technique of extracorporeal circulation was selective cerebral perfusion in 69 patients, deep hypothermic circulatory arrest in 90, femoro-femoral bypass in 39, left heart bypass in 12, and temporary aorto-arterial bypass in 30, and others in 21. RESULT Early mortality was 21% (54 patients), which was greater than that of the control group (113 patients, 13%, P < 0.01). The incidence of postoperative stroke, transient brain dysfunction, and respiratory problems was higher in the study group (P < 0.01 in all). Mean duration in ICU among survivors was 9.3 +/- 20.2 days and that of the control group was 5.9 +/- 2.8 days (P < 0.01). In a recent series (from 1991 to 1997) postoperative mortality improved to 15.6% (30/192 patients) in the study group however this result was still inferior to that of the control group (8.6%, 39/452, P = 0.03) however mortality of emergency surgery during the same periods was still high (31%, 11/35 patients). Logistic regression analysis revealed that significant risk factors for postoperative hospital death were surgery before 1991, age over 70 years, preoperative cardiac problems, aneurysm rupture, postoperative stroke, low output syndrome, bleeding, and acute renal failure. Postoperative follow-up was obtained in 408 patients/year and the longest period was 10.2 years. Late deaths were documented in 31 patients. Five-year and 10-year survival were 61.2 +/- 5.7% and 31.3 +/- 16.4%, respectively. In the control group the 5-year and 10-year survival were 78.0 +/- 2.1% and 62.5 +/- 4.0%, respectively (P = 0.03). However, survival of the early survivors in the study group was similar with that of the age-matched normal population. Aortic reoperation was performed in 13 patients. Freedom from aortic reoperation was 86.7 +/- 4.2% at 5 years and 80.5 +/- 7.1% at 10 years in the study group and 83.4 +/- 1.8% at 5 years and 64.1 +/- 13.3% at 10 years in the control group (P = 0.27). CONCLUSION Although recent advances have been achieved, early and long-term results of surgery for thoracic aortic aneurysm in patients older than 70 years were less satisfactory compared with those of patients under 70 years of age, especially in patients who required emergency surgery. Preoperative disorder of the vital organ systems was considered to be the main causative factor for high mortality, however, pertinent surgical strategies are necessary to improve the outcome of elderly patients.

Evolving Selective Cerebral Perfusion for Aortic Arch Replacement: High Flow Rate With Moderate Hypothermic Circulatory Arrest

BACKGROUND Although hypothermic circulatory arrest (HCA) combined with selective cerebral perfusion (SCP) is a safe strategy for aortic arch surgery, neither the optimal temperature of hypothermia nor the optimal SCP flow rate has been clearly determined. We have since 2002 gradually elevated the temperature of HCA from 20 degrees C to 28 degrees C for aortic arch surgery. This study explored the impact of different temperatures during HCA with SCP on neurologic complications. METHODS Since January 2002, 229 patients have undergone aortic arch replacement (mean age, 70.8 +/- 9.7 years; 156 male) with HCA and SCP through median sternotomy in our institution. Eighty-one patients were cooled to 20 degrees C (group A), 81 were cooled to 25 degrees C (group B), and 67 were cooled to 28 degrees C (group C). The brachiocephalic and left common carotid arteries were perfused separately during SCP in all cases. The left subclavian artery was additionally perfused in group C. Twenty-two operations in group A, 17 in group B, and 6 in group C were performed emergently (p = 0.58). The SCP flow rate was maintained at approximately 10 mL.kg(-1).min(-1) in groups A and B and approximately 15 mL.kg(-1).min(-1) in group C to keep blood pressure in the temporal artery at approximately 60 mm Hg. RESULTS The early mortality rate was 3.7% (3 of 81) in group A, 0% in group B, and 1.5% (1 of 67) in group C (p = 0.19). Postoperative stroke occurred in 2 patients (2.5%) in group A, in 3 (3.7%) in group B, and in 4 (6.0%) in group C (p = 0.55). Postoperative transient neurologic dysfunction occurred in 7 patients (8.6%) in group A, in 9 patients (11.1%) in group B, and in 4 patients (6.0%) in group C (p = 0.54). No patients in any group had postoperative paraplegia. The mean durations of circulatory arrest were 64 +/- 21 minutes in group A, 49 +/- 14 minutes in group B, and 46 +/- 13 minutes in group C (p < 0.0001). The mean durations of SCP were 145 +/- 67 minutes in group A, 116 +/- 48 minutes in group B, and 111 +/- 61 minutes in group C (p = 0.0007). Mean SCP flow rates were 8.8 +/- 1.9 mL.kg(-1).min(-1) in group A, 10.5 +/- 3.1 mL.kg(-1).min(-1) in group B, and 19.0 +/- 4.2 mL.kg(-1).min(-1) in group C (p < 0.0001). CONCLUSIONS The rate of postoperative neurologic events did not increase with use of higher temperature. The temperature during HCA could be safely increased to 28 degrees C with high SCP flow rate. Use of moderate HCA with SCP during aortic arch replacement permits radical reconstruction of the aortic arch and can avoid the need for deep hypothermia.

Surgical Treatment of Aortic Regurgitation due to Takayasu Arteritis Long-Term Morbidity and Mortality

BACKGROUND The goal of this retrospective study was to determine the late outcome of surgical treatment for aortic valve regurgitation due to Takayasu arteritis and correlate it with evidence of inflammation on pathological examination. METHODS AND RESULTS Ninety consecutive patients who underwent surgery for aortic valve regurgitation due to Takayasu arteritis between 1979 and 2003 were studied. Intraoperative pathological specimens of the aortic wall from 69 patients were retrospectively examined for inflammation. Aortic valve replacement was performed in 63 patients (group A) and composite graft repair in 27 patients (group B). The aortic root diameter was 39.9+/-9.5 mm in group A and 54.4+/-13.6 mm in group B (P<0.0001). Preoperative steroid therapy was performed in 40 patients (44.4%). Hospital mortality was 4.8% (3/63) in group A and 7.4% (2/27) in group B. The overall 15-year survival rate was 76.1%. Detachment of the valve or graft occurred in 11.1% (7/63) of group A and in 3.7% (1/27) of group B patients (P=0.43). Late dilatation (>50 mm) of the residual ascending aorta occurred in 11.1% (7/63) of group A and in 3.7% (1/27) of group B patients (P=0.43). Active inflammation was confirmed in intraoperative pathological specimens of 10 patients, and detachment of the valve or graft occurred in 4 of these patients. Univariate analysis of background variables revealed active inflammation to be a risk factor for detachment (P=0.0001; risk ratio 55). CONCLUSIONS Late dilatation of the ascending aorta after aortic valve replacement is a clinically important finding. Active inflammation could be related to valve or graft detachment.

Mutation of ACTA2 gene as an important cause of familial and nonfamilial nonsyndromatic thoracic aortic aneurysm and/or dissection (TAAD)

Approximately 20% of aortic aneurysm and/or dissection (AAD) cases result from inherited disorders, including several systemic and syndromatic connective‐tissue disorders, such as Marfan syndrome, Ehlers‐Danlos syndrome, and Loeys‐Dietz syndrome, which are caused by mutations in the FBN1, COL3A1, and TGFBR1 and TGFBR2 genes, respectively. Nonsyndromatic AAD also has a familial background, and mutations of the ACTA2 gene were recently shown to cause familial AAD. In the present study, we conducted sequence analyses of the ACTA2 gene in 14 unrelated Japanese patients with familial thoracic AAD (TAAD), and in 26 with sporadic and young‐onset TAAD. Our results identified three mutations of ACTA2, two novel [p.G152_T205del (c.616+1G>T), p.R212Q] and one reported (p.R149C), in the 14 patients with familial TAAD, and a novel mutation (p.Y145C) of ACTA2 in the 26 sporadic and young‐onset TAAD patients, each of which are considered to be causative for TAAD. Some of the clinical features of these patients were the same as previously reported, whereas others were different. These findings confirm that ACTA2 mutations are important in familial TAAD, while the first sporadic and young‐onset TAAD case with an ACTA2 mutation was also identified. Hum Mutat 30:1–6, 2009.