Long-term results of endovascular repair for distal arch and descending thoracic aortic aneurysms treated by custom-made endografts: usefulness of fenestrated endografts.

OBJECTIVE: We evaluated early and long-term results of atherosclerotic aneurysm repair with custom-made endografts. MATERIALS AND METHODS: Eighty-one consecutive patients underwent thoracic endovascular aortic repair with custom-made endografts. Fenestrated grafts were used in 37 patients (45.7%) to maintain blood flow of the neck and a landing zone for as long as possible for distal arch or proximal descending aneurysms. The rates of perioperative mortality, stroke, paraplegia, and primary endoleaks were assessed to evaluate in-hospital safety. The rates of endoleak development, survival, and freedom from aortic-related death were assessed to evaluate long-term efficiency. RESULTS: Twenty-four patients (29.6%) underwent urgent operations, and 38 (46.9%) underwent distal arch or proximal descending aortic aneurysm repair. There was one case (1.2%) of in-hospital mortality and no cases of stroke. Permanent spinal injury occurred in one patient (1.2%). Early and late endoleaks occurred in one and 16 patients, respectively. The actuarial survival rates were 88.9%, 64.9%, and 51.7% at 1, 5, and 10 years, respectively. The actuarial rates of freedom from endoleaks were 90.1%, 81.3%, and 68.6% at 1, 5, and 10 years, respectively. CONCLUSION: Early results of custom-made endografts were excellent, and fenestrated endografts were safe for distal arch and proximal descending aortic aneurysms.

Factors influencing permanent neurologic dysfunction and mortality after total arch replacement with separate arch vessel grafting using selective cerebral perfusion.

OBJECTIVES: The present study was undertaken to identify risk factors for permanent neurological dysfunction (PND) and in-hospital mortality after total aortic arch replacement (TAR) with separate arch vessel grafting using selective cerebral perfusion (SCP) and hypothermic circulatory arrest. METHODS: Between 1998 and 2008, we preformed a TAR on 143 consecutive patients in two centers by identical methods. Of these, 19 (13.3%) were emergency operations, and 46 (32.2%) were open stent-graft placements. Statistical analysis was performed to determine risk factors for PND and mortality, and furthermore, the survival rate was analyzed. RESULTS: The in-hospital mortality rate was 4.9%, with chronic renal failure (p = 0.0013, odds ratio 10.0) as a significant risk factor. Nine patients (6.3%) had PND, with significant risk factors identified as (1) the presence of an old cerebral or silent lacunar infarction on preoperative imaging methods (p = 0.0458, odds ratio 8.0) and (2) duration of SCP (p = 0.0026, odds ratio 1.036). Long-term survival was the same in patients with or without PND. CONCLUSION: The enhanced vulnerability of the brain in patients with a pre-existing old cerebral infarction or silent lacunar infarction is reflected by a high incidence of PND. Chronic renal failure had an impact on in-hospital mortality.

Outcome after valve surgery in octogenarians and efficacy of early mobilization with early cardiac rehabilitation.

PURPOSE: This study aimed to compare postoperative complications and the surgical outcome in patients aged <80 years versus octogenarian patients. Another aim was to evaluate the safety and efficacy of early mobilization with early cardiac rehabilitation in octogenarians. METHODS: A retrospective analysis was performed in 138 consecutive patients (group Y comprised 118 patients <80 years, and group O comprised 20 octogenarians) who had undergone valve surgery at the authors' institution between July 2007 and December 2009. Furthermore, the efficacy of early mobilization with early cardiac rehabilitation and long-term results were analyzed in 40 consecutive octogenarian patients undergoing valve surgery from 2000. The late survival follow-up was 100% complete. RESULTS: Redo cardiac operations were more frequent (O group 15.0% vs. Y group 3.4%, P = 0.011), and the preoperative EuroSCORE was significantly higher in group O than in group Y (group O 16.4 ± 18.3 vs. group Y 7.5 ± 9.1, P = 0.001). The incidence of delirium/confusion and worsening of renal function after surgery was higher in group O. The hospital mortality was 1.7% in group Y and no hospital death in group O (P > 0.99). Early mobilization with early cardiac rehabilitation significantly reduced the incidence of postoperative delirium/confusion and increased the number of patients who could return directly home. The actuarial 5-year survival rate was 77.7% for octogenarians. CONCLUSION: Although there were more high-risk patients among the octogenarians, valve surgery was a safe, low-risk procedure with excellent long-term results. Early mobilization with early cardiac rehabilitation was significantly effective and safe for postoperative recovery in octogenarians after cardiac valve surgery.

Clinical outcome of aortic valve replacement with 16-mm ATS-advanced performance valve for small aortic annulus.

BACKGROUND: Various surgical techniques have been proposed to treat small aortic annulus. We have used small-diameter mechanical valves for small aortic annulus. The present study examined aortic valve replacement with small diameter mechanical valves to determine their effectiveness. METHODS: The study included 67 patients who underwent elective, isolated aortic valve replacement with ATS-Advanced Performance (AP) valves (ATS Medical, Inc, Minneapolis, MN) within our department. The patients were divided into two groups; patients receiving the 16-mm AP valve (16-mm group) and those receiving valves 18-mm AP or larger (>16-mm group). RESULTS: The mean age of the 16-mm group was significantly higher than that of the >16-mm group. Body surface area was significantly smaller in the 16-mm group than the >16-mm group. We found no significant differences in preoperative conditions between the groups. The effective orifice area index of the mechanical valve was lower in the 16-mm group (0.87+/-0.06 vs 1.12+/-0.13 cm2/m2, p<0.0001). Six patients (40%) in the 16-mm group fell into the category of prosthesis-patient mismatch cases. Although the postoperative pressure gradient was higher in the 16-mm group (33.7+/-12.5 vs 23.16+/-8.78, p<0.01), left ventricular mass index and left ventricular ejection fraction at early and at late follow-up improved from the preoperative period in both groups. We found no significant differences in incidence of postoperative complications, including death. CONCLUSIONS: We believe aortic valve replacement with small-diameter mechanical valves (the ATS-AP valves) in patients with a small annulus provides satisfactory remote prognosis. The use of mechanical valves in elderly patients is considered acceptable with strict clinical monitoring to prevent thromboembolism and anticoagulation therapy-induced complications.

Adventitial mast cells contribute to pathogenesis in the progression of abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is histologically characterized by medial degeneration and various degrees of chronic adventitial inflammation, although the mechanisms for progression of aneurysm are poorly understood. In the present study, we carried out histological study of AAA tissues of patients, and interventional animal and cell culture experiments to investigate a role of mast cells in the pathogenesis of AAA. The number of mast cells was found to increase in the outer media or adventitia of human AAA, showing a positive correlation between the cell number and the AAA diameter. Aneurysmal dilatation of the aorta was seen in the control (+/+) rats following periaortic application of calcium chloride (CaCl2) treatment but not in the mast cell-deficient mutant Ws/Ws rats. The AAA formation was accompanied by accumulation of mast cells, T lymphocytes and by activated matrix metalloproteinase 9, reduced elastin levels and augmented angiogenesis in the aortic tissue, but these changes were much less in the Ws/Ws rats than in the controls. Similarly, mast cells were accumulated and activated at the adventitia of aneurysmal aorta in the apolipoprotein E-deficient mice. The pharmacological intervention with the tranilast, an inhibitor of mast cell degranulation, attenuated AAA development in these rodent models. In the cell culture experiment, a mast cell directly augmented matrix metalloproteinase 9 activity produced by the monocyte/macrophage. Collectively, these data suggest that adventitial mast cells play a critical role in the progression of AAA.

Clinical analysis of acute type A intramural hematoma: comparison between two different pathophysiological types.

BACKGROUND: Type A intramural hematoma (IMH) has two different etiologies, which are rupture of vasa vasorum and penetrating atherosclerotic ulcer (PAU); however, it is difficult to know which is the initiating event. METHODS: Between January 1993 and August 2004, 28 patients of acute type A IMH were treated in our department and were divided into two groups, 20 patients with IMH probably caused by rupture of vasa vasorum (non-PAU group) and 8 patients with IMH probably caused by PAU (PAU group), according to pathologic specimen and atherosclerotic findings on computed tomography. Background factors, radiographic findings, and prognosis were analyzed retrospectively. RESULTS: Surgery was performed in 15 patients (75%) in non-PAU group and 4 patients (50%) in PAU group during the first admission. Late progression was noted in 3 patients, and operation was required. Finally, operation was performed in 22 patients (78.6%). The history of myocardial infarction (p = 0.026) and chronic renal failure (p = 0.026) were more associated with PAU group than with non-PAU group. Ascending aortic diameter at the onset was significantly larger in non-PAU group (50.3 +/- 6.6 mm) than in PAU group (43.9 +/- 9.0 mm; p = 0.046), and there were significantly more ulcer lesions in PAU group (1.9 +/- 0.4) than in non-PAU group (1.1 +/- 0.4; p = 0.0004). There was no significant difference in long-term survival rates between them. CONCLUSIONS: The PAU group patients have more coexisting atherosclerotic diseases and multiple aortic ulcer lesions with significantly mild ascending aortic dilatation compared with non-PAU group patients.

Predictor of neurologic dysfunction after elective thoracic aorta repair using selective cerebral perfusion.

OBJECTIVES: This study was undertaken to determine the factors that influence postoperative neurological dysfunction after selective cerebral perfusion (SCP). DESIGN: From 1995 to August 2004, 60 patients were evaluated for the presence of cerebro-vascular disease (CVD), and then underwent thoracic aortic operations using SCP. Perioperative factors were evaluated by multivariate analyses. RESULTS: Hospital mortality rate was zero. Sixteen patients (26.7%) proved to have CVD. Permanent neurological dysfunction (PND) appeared in three patients (5.0%) and transient neurological dysfunction (TND) in two (3.3%). Univariate analysis revealed superficial temporal artery (STA) pressure during SCP (p = 0.0410) to be a significant risk factor for PND. Variables that achieved values of p < 0.2 (aortic cross-clamp time, presence of CVD, old cerebral infarction, presence of clots or atheroma) were examined with multivariate analysis and the presence of CVD (p = 0.038) and STA pressure during SCP (p = 0.032) were independent risk factors for PND. Multivariate analysis for TND did not show any risk factor. CONCLUSIONS: The presence of CVD was indicated as an independent risk factor for PND after thoracic aortic operations using SCP.

Nitric oxide inhalation prompts weaning from the right ventricular assist device: evaluation under continuous-flow biventricular assistance.

OBJECTIVE: The objective of this study was to investigate the effect of nitric oxide on the recovery of right heart function under global ischemia with a continuous-flow biventricular assist device support. METHODS: Fifteen piglets were divided into three groups: continuous-flow biventricular assist support only (control group), global ischemia with continuous-flow biventricular assist support (ischemia only group), and global ischemia with continuous-flow biventricular assist support plus nitric oxide inhalation (nitric oxide group). Two continuous-flow pumps were used as left and right ventricular assist devices. In the ischemic groups (ischemia only group and nitric oxide group), global ischemia was induced for 30 minutes and followed by a 6-hour reperfusion period; the nonischemic control group underwent a 6-hour perfusion period only. The left ventricular assist device was driven at a flow rate of more than 75 to 80 mL/(min. kg). The right ventricular assist device was driven so as to sustain the left ventricular assist device flow, and the animal was weaned from it in accordance with the objective of cardiac recovery. RESULTS: Mean pulmonary arterial pressure remained low in the nitric oxide group (mean 23 mm Hg), whereas it rose from 19.9 mm Hg to 39.3 mm Hg in the ischemia group and to 26.2 mm Hg in the control group. Mixed venous saturation was maintained at more than 60% in all cases. Although no piglets in the ischemia group were able to survive without continuous-flow biventricular assist support, the right ventricular assist device flow ratio (device flow/total systemic flow) in the nitric oxide group could be reduced in all cases, and it was possible to wean the piglets from right ventricular assist device support in 4 of 5 cases. CONCLUSION: Inhalation of 40-ppm nitric oxide enabled smoother maintenance of the left ventricular assist device flow and prompted the weaning from right ventricular assist device support on continuous-flow biventricular assist.

A safe automatic driving method for a continuous flow ventricular assist device based on motor current pulsatility: in vitro evaluation.

We previously reported that detection of two specific points (the t-point and the s-point) in the relationship between pump speed and Motor Current Amplitude index (ICA) indicates the safe driving range for a continuous-flow ventricular assist device (CFVAD). During the first stage of the present experiment, the characteristic curves relating pump speed and ICA were determined by varying preload (left atrial pressure: -6 to 30 mm Hg), afterload (total circuit resistance: 890 to 3,180 dyne x sec x cm(-5)), and contractility of the left ventricle (total circuit flow: 0.5 to 2.1 L/min). These data showed that an ICA value of 0.18 was always located between the t- and s-points. During the second stage of the experiment, we developed an automatic driving program to control pump speed by maintaining ICA at 0.18. This program was able to drive the CFVAD, without exhibiting regurgitant flow or sucking, under various driving conditions in the mock circulation. Pump speed stabilized within 1 minute after varying the drive conditions. This sensorless method of driving the CFVAD by using a target ICA proved feasible and effective for safe automatic control, within our mock circulation.