[Aortic aneurysm].

Thoracic and abdominal aortic aneurysms have potential risk of sudden death, because they have a tendency of rupture. The risk of rupture is high, if they are saccular type or the diameters of them are large enough. Acute aortic dissection has a high risk of sudden death due to cardiac tamponade, if the dissection involves the ascending aorta.

Comparison of neurocognitive results after coronary artery bypass grafting and thoracic aortic surgery using retrograde cerebral perfusion.

OBJECTIVE: Retrograde cerebral perfusion (RCP) is used as an adjunctive method to hypothermic circulatory arrest to enhance cerebral protection in patients undergoing thoracic aortic surgery. It remains unclear whether RCP provides improved neurological and neuropsychological outcome. METHODS: Forty-six patients undergoing thoracic aortic surgery using RCP, and 28 undergoing coronary artery bypass grafting (CABG; n = 28) with CPB, were enrolled in the study. Patients receiving RCP were subdivided into two groups, those with less than 60 min of RCP (S-RCP; n = 27) and with 60 min or more (L-RCP; n = 19). The patients' neurocognitive state was assessed by the revised Wechsler Adult Intelligence Scale a few days before operation, at 2-3 weeks and 4-6 months after operation. RESULTS: There were no stroke, seizure, and hospital mortality in either group. Significant decline between baseline and early scores were seen in three subtests (digit span, arithmetic, and picture completion) for S-RCP and four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP. Significant decline between baseline and late scores were seen in one subtest (arithmetic) for S-RCP, four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP, and one (object assembly) for CABG. The mean change of scores for one late test (digit symbol) was significantly lower in S-RCP than in CABG. The mean change of scores for three early tests (digit span, vocabulary, and picture arrangement) and four late tests (information, digit span, picture completion, and picture arrangement) were significantly lower in L-RCP than in CABG. Stepwise logistic regression analysis disclosed that, after considering the other variables, significant difference in test score changes were observed between CABG and L-RCP for two early tests (picture completion and digit symbol) as well as for three late tests (digit span, similarities, and picture completion). None of test score changes showed significant difference between CABG and S-RCP. CONCLUSIONS: The neurocognitive outcome in patients undergoing RCP less than 60 min were comparable with patients undergoing CABG without circulatory arrest. Prolonged RCP of 60 min or more in patients undergoing surgery of the thoracic aorta was associated with postoperative neurocognitive impairment.

Management of infected grafts and aneurysms of the aorta.

Seventeen patients treated for infected grafts (11/17) or aneurysms (6/17) of the aorta between 1998 and 2003 were reviewed to evaluate our experience with aortic infection. The causative organisms were identified in 12 patients (71%), with 5 (29%) having methicillin-resistant Staphylococcus aureus. A periaortic abscess occurred in eight patients, and all of them were associated with infected grafts. Surgical treatment included cryopreserved allograft replacement in eight patients, prosthetic graft replacement in four patients, and drainage with or without omental wrapping in five patients. One patient was still hospitalized at the end of the study period. Five patients with infected grafts died after the operation during the initial hospitalization. No early mortality occurred in the aneurysm group. The early mortality rate was 31% for all patients, 50% for the graft group, and 63% for patients with a periaortie abscess. Another patient with an infected aneurysm died of arrhythmia after discharge from the initial hospitalization, Ten patients are still alive without evidence of reinfection. The early mortality rate for patients with infected aortic grafts is higher than that for those with infected aneurysms, especially when a periaortic abscess accompanies them. However, the late outcome is favorable, with no reinfection or late treatment-related deaths.

Beneficial effect of acute normovolemic hemodilution in cardiovascular surgery.

OBJECTIVE: The efficacy of acute normovolemic hemodilution (ANH) in avoiding homologous blood transfusion (HBT) during cardiovascular surgery remains controversial. Our objective was to evaluate the impact of ANH on blood transfusion requirements during open cardiovascular surgery using cardiopulmonary bypass (CPB). METHODS: We retrospectively reviewed 243 patients who had undergone open cardiac or thoracic aortic surgery using CPB between September 2001 and July 2003 in our department. ANH was performed when the hematocrit was over 35% and the patient was hemodynamically stable. Risk factors were selected in accordance with the Japanese Adult Cardiovascular Surgery Database and analyzed to determine their effect on perioperative HBT requirement. RESULTS: Of the 243 patients, 64 (26%) underwent preoperative autologous blood donation and 62 (26%) ANH. HBT was required in 62% of patients (150/243) overall, in 32% (20/62) of ANH patients, and in 76% (130/171) of non-ANH patients. Multivariate stepwise logistic regression analysis revealed that preoperative or pre-donation hemoglobin value (p < 0.001), duration of surgery (p = 0.001), intraoperative minimum rectal temperature (p = 0.001), age (p = 0.002), need for emergency surgery (p = 0.003), amount of ANH (p = 0.018), blood loss (p = 0.033) and amount of preoperative autologous blood donation (p = 0.042) were independent predictors of the need for perioperative HBT. CONCLUSIONS: Our data showed that open cardiovascular surgery using CPB continues to pose a high risk of HBT, but that ANH is an effective means of reducing this risk in those patients undergoing these operations.

Neurocognitive outcome after retrograde cerebral perfusion.

BACKGROUND: Neurocognitive outcome in patients undergoing thoracic aortic surgery using retrograde cerebral perfusion (RCP) remains uncertain. METHODS: Forty-two patients undergoing thoracic aortic surgery using RCP were enrolled in the study. The patients' neurocognitive state was assessed by the revised Wechsler Adult Intelligence Scale (WAIS-R) a few days before operation, at 2 to 3 weeks, and at 4 to 6 months after operation. RESULTS: There were no stroke, seizure, and hospital death. Significant performance deterioration was observed in digit span, arithmetic, and picture completion of the WAIS-R subtests. Bivariate comparison showed that older age (late vocabulary, late similarities, and late object assembly), longer RCP time (early picture arrangement, and early block design), later awake time (early and late picture arrangement, and early block design), longer respirator use (early and late digit span, late picture arrangement), longer ICU time (late picture completion, early and late picture arrangement, and early block design), and longer hospital stay (early picture arrangement) were significantly associated with the decline in neurocognitive performance. Stepwise logistic regression analysis disclosed that older age (late similarities and late object assembly), later awake time (late picture arrangement), and longer respirator use (early and late digit span, and late picture arrangement) were most predictive for the decline in neurocognitive performance. CONCLUSIONS: On average, digit span, arithmetic, and picture completion tests were most sensitive in detecting the decline in neurocognitive performance. The relationship between the duration of RCP and neurocognitive test results was not significant.

Successful repair of graft failure and abdominal aortic aneurysm following thoraco-abdominal bypass for atypical aortic coarctation.

A 54-year-old woman, who underwent descendo-abdominal aortic bypass grafting for atypical aortic coarctation complicated with Takayasu's arteritis 37 years previously, was referred to our hospital for treatment of a pseudoaneurysm due to rupture of the graft. Preoperative computed tomography scan also demonstrated an abdominal aortic aneurysm. First, an endovascular stent-graft repair of the pseudoaneurysm was performed, then the abdominal aortic aneurysm was repaired with the aid of cardiopulmonary bypass. Proper surgical planning was important to treat this rare development accompanied by aberrant circulation.

Thrombus originating from frayed distal edge of an aortic stent-graft.

An 87-year-old woman who had undergone a stent-graft repair of a descending aortic aneurysm had additional stent-graft implantation for endoleak. The postoperative course was eventful reflecting her preexisting multiple organ disorder, and despite intensive treatment over a span of 2 months, she died of disseminated intravascular coagulation due to intestinal ischemia. Autopsy revealed a thrombus originating from the frayed distal edge of the graft. Although the relation between intestinal ischemia and the thrombus remains to be proven, this is considered a vital finding.

Multichannel monitoring of cerebral circulatory and oxygenation status using optical topography during deep hypothermic retrograde cerebral perfusion.

In this study, we evaluated changes in the cerebral circulatory and oxygenation status during deep hypothermic total circulatory arrest (TCA) and retrograde cerebral perfusion (RCP) using optical topography, a form of multichannel near-infrared spectrophotometry, to monitor the broad area perfused by the middle cerebral artery. Seven patients underwent thoracic aortic surgery with TCA and RCP via the superior vena cava. Pressure-regulated RCP was performed under pH-stat. No postoperative neurologic complications occurred. Using optical topography, the relative changes in oxy-, deoxy-, and total hemoglobin (oxy-Hb, deoxy-Hb, total Hb) were simultaneously measured from 24 points in both hemispheres. Deoxy-Hb was used for evaluating the regional oxygenation status under RCR The values of deoxy-Hb at the beginning of RCP were regarded as the basal values, and the rate of increase in deoxy-Hb per minute (deoxy-Hb/min) was calculated at each site. Deoxy-Hb/min during TCA was also calculated. In every case, both oxy-Hb and total Hb decreased and deoxy-Hb increased during TCA. When RCP was initiated, the decrease in oxy-Hb and the increase in deoxy-Hb were attenuated. Deoxy-Hb/min was significantly lower under RCP than during TCA in all portions. There was no significant difference of deoxy-Hb/min between any portions during RCP Our results showed that the status of circulation and oxygenation might be uniform in the brain during RCP and better than that under TCA.

Surgical repair of a distal arch aneurysm with a stent-graft.

This study evaluates the effectiveness and potential complications of stent-grafting for the treatment of distal arch aneurysms using profound hypothermia and circulatory arrest with retrograde cerebral perfusion. Between December 1998 and December 2001, 9 consecutive patients with a distal arch aneurysm (6 men and 3 women, mean age 71 years) underwent surgical repair using a stent-graft. Profound hypothermic circulatory arrest and retrograde cerebral perfusion were performed in all patients. Endovascular leakage was screened postoperatively using three-dimensional computerized tomography. The mean follow-up period was 27.4 months. Thirty day mortality was 0%. One patient died 3 months after stent-grafting due to proximal leakage into her aneurysm. The mean postoperative extubation period was 2.1 days. No patients suffered cerebral infarction or paraplegia. Although preliminary outcomes using this technique were good, endovascular leakage is a concern. We suggest that, if major proximal leakage is recognized postoperatively, re-intervention should be performed as soon as possible. Endovascular stent-grafting appears to be a good alternative treatment for distal arch aneurysms, although longer follow-up is necessary to more comprehensively evaluate this procedure.

Early valvular obliteration of cryopreserved aortic valve allograft.

This report describes a 60-year-old male patient who developed early valvular obliteration of a cryopreserved aortic valve allograft with associated severe valvular leakage. The patient had previously undergone two operations for aortic valve insufficiency resulting from infective endocarditis, and prosthetic valve endocarditis: aortic valve replacement with a mechanical prosthesis was done 4 years ago, and two years later aortic root replacement with a cryopreserved allograft was performed. Perforation through the non-coronary cusp of the aortic allograft was found, and valve replacement was achieved using a mechanical prosthesis. The intraoperative findings, histological, immunological, and bacteriological studies of the resected cusps demonstrated negative for infection and rejection, therefore, the valvular perforation might have been caused by an injury or degeneration during management of the homologous graft. The patient showed neither aortic regurgitation on echocardiography nor recurrence of endocarditis 10 months after surgery.

Rupture of a small fusiform thoracic aortic aneurysm.

We report a case of ruptured aortic aneurysm of the distal aortic arch. This aneurysm was fusiform and only 4.0 cm in maximum diameter. Emergency total aortic arch replacement was successful. Rupture of a thoracic aortic aneurysm of this shape and size is possible but extremely rare.

Beating atrial septal defect closure monitored by epicardial real-time three-dimensional echocardiography without cardiopulmonary bypass.

BACKGROUND: We assessed the feasibility of beating atrial septal defect (ASD) closure monitored by real-time 3D echocardiography (RT3DE). METHODS AND RESULTS: RT3DE was developed with prototype ultrasound equipment consisting of a high-speed 3D rendering unit with a frame rate of 5 to 10 frames/s. We also developed a prototype semiautomatic suture device and suture cutting system. In the experiment, 12 mongrel dogs were anesthetized, and after median sternotomy, the echo probe was applied directly to the surface of the right atrium. Three surgical maneuvers (balloon atrial septectomy, enlargement of the ASD, and ASD closure) were performed through the atrial port inserted into the right atrial appendage. The heart was then excised, and the area of the ASD measured by RT3DE was compared with its area measured directly. The ASD was successfully closed in all experimental animals except the first 2. Examination of the excised heart showed that none of the sutures were loose. The mean area of the ASD was 82.5+/-38.6 mm(2) when measured by RT3DE and 81.6+/-38.2 mm(2) when measured directly, and there was a significant correlation between the areas measured by RT3DE and those measured directly (echo measurements=1.007xdirect measurements+0.337; P<0.0001). A Bland-Altman analysis revealed close agreement between the results obtained by the 2 methods (7.807 mm(2) upper and -6.024 mm(2) lower limit of agreement). CONCLUSIONS: Introduction of RT3DE, a semiautomatic suture device, and a suture cutting system made beating ASD closure without cardiopulmonary bypass possible.

Left atrial dissection after double valve replacement.

Left atrial dissection, a rare complication occurring mainly after mitral repair, is reported after double valve replacement in a patient with a connective tissue disease. A 63-year-old woman with systemic sclerosis underwent double valve replacement. Laceration of the tissue between the two mechanical prostheses and dissection of the left atrial wall emerged postoperatively and regurgitation through the dissection caused heart failure, which later improved without surgery. The possible causes of the dissection were thought to be shear forces against the tissue between the two prostheses and tissue fragility due to systemic sclerosis and corticosteroid therapy.

Epicardial pulmonary vein isolation by cryoablation as concomitant cardiac operation to treat nonvalvular atrial fibrillation.

Since Haïssagere and colleagues reported that a rapid firing focus in or close to the pulmonary veins could be the cause of atrial fibrillation, a transcutaneous catheter technique directed at isolating these foci has been developed. How should patients with nonvalvular atrial fibrillation who require cardiac operation be managed? We developed an epicardial technique that uses cryoablation to isolate the left atrial posterior wall and pulmonary veins and used it to treat a patient. Because cryoablation is achieved epicardially, the technique does not require atriotomy and does not prolong aortic cross-clamp time. Isolation of the left atrium was confirmed by electrophyscologic studies, and the patient remains in sinus rhythm 16 months after operation. This concomitant procedure allows treatment of patients with nonvalvular atrial fibrillation.

Surgical treatment of malignant tumors of the right heart.

Seven patients with malignant cardiac tumors were treated surgically in the Department of Cardiothoracic Surgery of the University of Tokyo between 1981 and 2000. Their treatments and outcomes are summarized and discussed. The ages of the patients ranged from 21 to 70 years old (mean: 49.5+/-15) and there were three males and four females. The histopathological diagnoses were hepatocellular carcinoma (HCC), spindle cell sarcoma, round cell sarcoma, osteosarcoma, renal cell carcinoma, and leiomyosarcoma. In four of the cases, the tumor extended or metastasized from other organs, while in the other three cases it originated in the heart. Before the cardiac operation, an above-knee amputation, left nephrectomy, transarterial embolization, or extended right hepatic lobectomy had been performed to treat the primary site of the tumor. Tumor resection using cardiopulmonary bypass was performed in every case. The NYHA classification of heart failure was significantly improved (preop: 3.3+/-0.8, postop: 1.9+/-0.7 [P<0.001]). The mean survival period of the patients who died was 8.8+/-7.0 months. A patient with renal cell carcinoma is still alive after 87 months of follow-up. In summary, surgical treatment of malignant tumors of the right heart can improve the QOL in patients with cardiac failure. However, its effectiveness was temporary in all cases except one case of renal cell carcinoma.

Cerebral metabolism of nitric oxide during retrograde cerebral perfusion.

The aim of this study was to determine whether alpha- or pH-stat protects the brain during deep hypothermic retrograde cerebral perfusion. Fifteen anesthetized dogs on cardiopulmonary bypass were cooled to 18 degrees C under alpha-stat and underwent retrograde cerebral perfusion for 90 minutes under alpha-stat or pH-stat, or underwent antegrade cardiopulmonary bypass under alpha-stat as the control. Cerebral blood flow of the cortex was monitored and serial analyses of blood gases and total nitric oxide oxidation products made. Cerebral blood flow and cerebral metabolic rate for oxygen were significantly higher and plasma levels of nitric oxide oxidation products in the outflow from the brain were significantly lower in retrograde cerebral perfusion under pH-stat than under alpha-stat. This study shows that reduced levels of nitric oxide oxidation products may protect against neuronal damage induced by nitric oxide and that increased cerebral blood flow under pH-stat may lead to a reduction of nitric oxide oxidation products. Under retrograde cerebral perfusion, pH-stat is thus better than alpha-stat for protecting the brain.

Total aortic arch aneurysm repair using a stent graft without cardiac or cerebral ischemia.

A 74-year-old man with an aortic arch aneurysm and a chronic type IIIb aortic dissection underwent total aortic arch repair without cerebral or cardiac ischemia. After confirming no atheromatous change in the ascending aortic wall, a custom-designed 4-limbed graft, prepared for both arterial return of cardiopulmonary bypass and reconstruction of the arch vessels, was anastomosed onto the right side of the ascending aorta. The 3 arch vessels were then bypassed sequentially during systemic cooling and monitoring cerebral perfusion with near-infrared oxymetry. After aortic cross-clamping, a stent graft was inserted into the distal arch from the distal ascending aorta, maintaining cerebral and cardiac perfusion. This procedure is indicated especially in a high-risk patient who has an aortic arch aneurysm without severe atheromatous change in the ascending aorta and the arch vessels.

Surgically repaired delayed mitral regurgitation after radiofrequency catheter ablation for Wolff-Parkinson-White syndrome.

This report describes a male patient with WPW syndrome who underwent surgical repair of sudden, severe mitral valve regurgitation through the posterior leaflet 20 months after successful RF catheter ablation for Kent bundle at the age of 14, and discusses the problem of valvular damage caused by this technique.