[Aortic valve replacement through right anterolateral thoracotomy for aortic stenosis after mediastinal radiation therapy].

A 76-year-old woman had severe aortic stenosis on transthoracic echocardiography [aortic valve area (AVA): 0.7 cm2, max pressure gradient (PG): 108 mmHg]. Since she was on radiation therapy for breast cancer, we considered that median sternotomy was a risk factor for mediastinitis, and right thoracotomy was chosen for aortic valve replacement. The operation was performed through a right anterolateral thoracotomy. Cardiopulmonary bypass was established with right femoral artery cannulation, right atrial cannulation, and right superior pulmonary vein cannulation for venting. The patient's postoperative course was uneventful. This method appears to be an alternative approach for aortic valve replacement in patients that are not suitable candidates for median sternotomy.

Cardiac sarcoma showing bone formation and neurogenic markers: report of a case.

A 54 year-old Japanese female with cardiac insufficiency was found to have a left atrial mass and smaller masses on the mitral valve. Excisional surgery of the masses and mitral valve replacement were carried out. In spite of intensive post-operative radiation therapy, the patient died of intra-atrial recurrence and brain metastases after 8 months. Tumour cells were spindled to oval, were positive for vimentin, S100 protein and neurone specific enolase. Laminin and fibronectin were also demonstrated. Bone formation and myxoid areas were present. An ultrastructurally identifiable stromal component, possibly responsible for laminin and fibronectin staining, was also present. The merits of the two main diagnostic possibilities - a mesenchymal/fibroblastic sarcoma showing bone and aberrant S100 protein, and a malignant peripheral nerve sheath tumour with bone - were discussed. In practical terms, the tumour was given the diagnosis of unclassifiable sarcoma of the left atrium. Atrial sarcomas showing neural markers and bone formation are exceedingly rare, and this report adds a further exceptionally uncommon case to the literature.

An evaluation of the intraoperative transit time measurements of coronary bypass flow.

OBJECTIVE: The intraoperative measurement of the coronary bypass flow enables the identification of technical errors while the sternum is still open. The transit-time flow method is able to effectively measure the internal thoracic artery graft flow. The aim of the present study was to analyze the factors which affected the bypass flow rate. METHODS: We measured the blood flow of 291 in situ internal thoracic artery (ITA) and 190 saphenous vein (SV) grafts constructed in 171 patients undergoing coronary artery bypass grafting from December 1996 to March 2000 using this method during the surgery. All patients underwent postoperative coronary angiography before the patients were discharged. The blood flow rate of all bypass grafts constructed was assessed after the patients were weaned from cardiopulmonary bypass. RESULTS: The mean flow rate of all ITA grafts was 65.1+/-36.7 ml/min and that of all SV grafts was 56.4+/-29.9 ml/min. According to analyses using correlation tests, the graft flow was found to significantly correlate with the grafted perfusion areas and the diameter of the bypassed coronary arteries. However, no significant difference was observed between the flow rates of the ITA grafts with and without stenosis or string phenomenon, but significant (P<0.0001) correlation was observed between the occurrence of a string sign and the degree of proximal stenosis of the recipient coronary artery. Regarding SV grafts, the mean flow rate of occluded grafts (29.2+/-20.5 ml/min) was significantly (P<0.0001) less than non-occluded grafts (56.4+/-29.9 ml/min). CONCLUSIONS: The bypass flow was affected by such a large number of factors that only measuring the bypass flow rate could not sufficiently predict either stenosed or narrowed grafts. However, ITA grafts bypassed to the coronary arteries with less stenosis were shown to more easily become narrowed.

Coronary artery bypass grafting within 30 days of an acute myocardial infarction.

UNLABELLED: Early surgical intervention is now often considered for symptomatic patients after an acute myocardial infarction. Conversely coronary artery bypass grafting soon after an acute myocardial infarction poses substantial risks. The present study was performed to evaluate the results of Coronary artery bypass grafting soon after an acute myocardial infarction. METHODS: From November 1991 to November 1999, 478 consecutive patients underwent coronary artery bypass grafting and 68 of these underwent an operation within 30 days of AMI. The data of these patients were analyzed retrospectively. Univariate and multivariate analyses of many variables were performed regarding operative mortality. RESULTS: Operative mortality (7.4%) was significantly higher in the patients with an acute myocardial infarction than in the patients without it (0.8%) during the same period as the subjects of this study. Coronary artery bypass grafting without arterial grafts was solely determined to be the predictor of survival. The survival curve demonstrated better long-term results in patients undergoing bypass grafting with arterial grafts than in patients undergoing bypass grafting with venous grafts alone. CONCLUSIONS: If hemodynamic conditions can not be stabilized, then coronary artery bypass grafting using arterial grafts, when indicated, should be performed even early after AMI.

Stroke after coronary artery bypass grafting in patients with cerebrovascular disease.

BACKGROUND: Stroke has been associated with a significantly increased mortality from coronary artery bypass grafting (CABG). To determine the predictors of stroke in patients undergoing CABG, we collected data on 472 consecutive patients. METHODS: From March 1991 to March 1999, all patients undergoing CABG at our institution underwent routine duplex scanning of the extracranial carotid and vertebral arteries. Seven patients with symptomatic carotid stenosis were treated by carotid endarterectomy (CEA) before CABG. RESULTS: There was a 10-fold increase in mortality (12.5%) associated with postoperative stroke. Many variables were analyzed by a multivariate technique and the severity of extracranial carotid artery stenosis was determined to be the only independent predictor of postoperative stroke (p < 0.01). None of the patients with carotid artery occlusion and none of the patients who underwent CEA before CABG experienced a stroke. CONCLUSIONS: To reduce the stroke rate, the indications for prophylactic CEA may be extended for asymptomatic patients with carotid artery stenosis greater than 75%.

Aortic arch repair using hypothermic circulatory arrest technique associated with pharmacological brain protection.

OBJECTIVE: Hypothermic circulatory arrest is a standard procedure for the treatment of aortic arch. However, there is a time limit for this procedure. There is now an urgent need to develop prophylactic measures to extend the time limit. We have used a pharmacological mixture of thiopental, nicardipine and mannitol for all patients undergoing circulatory arrest since 1991 to extend the safe limit. The purpose of this study was to analyze the neurological complications demonstrated by these patients and to evaluate the brain-protective effects of our measure. METHODS: The clinical records of 75 consecutive patients undergoing an aortic arch repair using a hypothermic circulatory arrest technique during the past 8 years were retrospectively reviewed. Systemic cooling was continued until a total disappearance of EEG activity. Prior to circulatory arrest, 15 or 30 mg/kg of thiopental, 20 mg of nicardipine and 300 ml of mannitol were infused into the venous reservoir of a cardiopulmonary bypass circuit. Graft replacement was performed in all patients and the extent of replacement was a total aortic arch in 43 patients, a distal aortic arch in 17, a hemiarch in 13 and a distal aortic arch and a total descending aorta in two. RESULTS: The duration of circulatory arrest ranged from 16 to 80 min (mean 41.5 min), and it exceeded 45 min in 37 patients. Operative mortality was 10.7% and two patients died of stroke. Three patients had permanent and three other patients had transient neural deficits. The incidence of stroke was 8.0% as a whole, and no correlation between the incidence of neurological complications and the duration of circulatory arrest was found. A multivariate analysis showed that the duration of circulatory arrest was determined as a predictor of neither operative mortality nor postoperative stroke. CONCLUSIONS: The findings of the present study suggest that our pharmacological brain protection appears to be effective for safely extending hypothermic circulatory arrest.

Results of a total aortic arch replacement for an acute aortic arch dissection.

OBJECTIVES: Recently, the immediate results of a surgical repair for an acute aortic arch dissection have dramatically improved. However, a total aortic arch replacement is recommended in a limited number of patients with an intimal tear located in the aortic arch. We have performed a total aortic arch replacement for all such patients with an acute aortic arch dissection since September 1995. METHODS: During the past 4 years, 27 consecutive patients who had an aortic arch dissection underwent a total aortic arch replacement. Twenty-five patients underwent an emergency operation. In 5 patients the intimal tear was located in the aortic arch, but in the rest of the patients, it was located in the ascending aorta or the proximal descending aorta. To obliterate any false channels, gelatin-resorcin-formol glue was used. RESULTS: The hospital mortality was 11%, and no cerebral complications were observed. Postoperative aortography and computed tomography showed no evidence of any persisting false channels in 15 patients (65%). During the follow-up period (ranging from 5 months to 4 years), two patients underwent a reoperation because of the recurrence of a dissection at the sinus of Valsalva. All patients, except for one who died after a reoperation, are still alive and free from any serious events at this writing. CONCLUSIONS: Resecting both the ascending and transverse aorta, irrespective of whether the intimal tear is located in the aortic arch, may be an acceptable alternative at experienced centers because of its low mortality and good midterm results.

Posterior ventricular septal perforation in an 80-year-old man.

Ventricular septal perforation is a complication of acute myocardial infarction that is fatal unless treated surgically. Posterior ventricular septal perforation remains particularly difficult to repair successfully. We report an 80-year-old man with postinfarction posterior ventricular septal perforation who successfully underwent surgical repair using a technique similar to that described by Daggett et al. and was discharged in good health without postoperative septal shunt.

[Should arterial grafts be used for urgent coronary artery bypass surgery?].

It is not clear whether arterial grafts should be used for emergency or urgent coronary artery bypass grafting (CABG) because harvest of internal thoracic arteries (ITAs) is not easy under urgent conditions and the blood flow through the ITAs may be inadequate immediately after CABG. The purpose of this study was to assess whether the use of arterial grafts in urgent CABG affects the outcome adversely or not. Twenty consecutive patients who underwent urgent CABG within 48 hours following coronary angiography at our institute between July 1991 and October 1998 were reviewed. The patients who underwent CABG with associated procedures were excluded. Among these subjects, 11 patients received at least one arterial graft. Only 1 patient died of subarachnoidal hemorrhage, and the hospital mortality rate was 5.0%. According to the overall survival rate, cardiac-death-free rate, and cardiac-event-free rate, the long-term outcome was much better in the patients with arterial grafts than those with saphenous vein grafts alone. We suggest that arterial grafts should be used even for urgent CABGs since the use of arterial grafts may not affect operative results adversely and will confer better long-term benefits.

Protective effect of thiopental against cerebral ischemia during circulatory arrest.

BACKGROUND: One of the most important disadvantages of the hypothermic circulatory arrest technique is the limited time allowable for circulatory arrest. Thiopental is usually used to protect the brain against ischemic injuries. However, it remains uncertain how well thiopental reduces cerebral metabolism. We investigated its effectiveness by comparing outcomes after different doses. METHODS: Fifty patients who underwent aortic arch repair with hypothermic circulatory arrest had their records reviewed. Electroencephalograms (EEG) and partial pressures of oxygen in the internal jugular vein (PjO2) were monitored. Following confirmation of total disappearance of EEG activity, 15 or 30 mg/kg thiopental was administered before circulatory arrest Th duration of circulatory arrest ranged from 16 to 77 min. RESULTS: Hospital mortality rate was 10% and 4 (8%) patients developed neu-rologic complications, but 3 of them were transient. After thiopental infusion, PjO2 increased significantly from 430 to 499mmHg (p <0.01), indicating that thiopental reduces cerebral oxygen consumption. The rate of the decrease in PjO2 during circulatory arrest was slower with the higher thiopental dose, suggesting that thiopental lowered the cerebral metabolic rate of oxygen during circulatory arrest. CONCLUSION: It appears that thiopental has protective effects against cerebral ischemia under profound hypothermia.

Effects of coronary artery bypass grafting using internal mammary arteries for diabetic patients.

OBJECTIVES: In our institute, internal mammary arteries (IMAs) have been preferred for coronary artery bypass grafting (CABG) in diabetic patients. The purpose of this study was to evaluate the influence of diabetes and IMA grafting on survival after CABG. BACKGROUND: The influence of diabetes on the results of CABG is not well documented, and there is controversy about whether the use of IMAs conveys greater survival benefits to diabetic patients. METHODS: A total of 420 consecutive patients who underwent CABG from April 1990 to July 1998 were reviewed; 211 of these patients had diabetes mellitus at the time of surgery. Internal mammary artery grafts have been used with increasing frequency, and bilateral IMAs have been used when possible since 1993. Internal mammary artery grafts were used in 164 nondiabetic patients (78%) and in 155 diabetic patients (73%). Seventy-eight nondiabetic patients and 74 diabetic patients received bilateral IMA grafts. RESULTS: The postoperative mortality was 2.4% in the nondiabetic and 2.8% in the diabetic group. With regard to postoperative complications, diabetic patients had a significantly higher rate of chest wound infection (p < 0.05), irrespective of whether IMAs were used or not. The use of bilateral IMAs did not increase the risk of chest wound infection in nondiabetic or diabetic patients. Overall survival curve, cardiac death-free curve and cardiac event-free curve were not affected adversely by diabetes, and in diabetic patients, CABG with saphenous veins alone conveyed significantly (p < 0.01) less long-term benefit than did CABG with at least one IMA graft. CONCLUSIONS: It was suggested that IMA grafts should be preferred in diabetic patients.

[A case report of coronary artery bypass grafting using hypothermic circulatory arrest technique for the severely calcified ascending aorta].

Severe calcification of the ascending aorta makes coronary artery bypass grafting (CABG) complicated since aortic cross-clamping may induce cerebral embolization of aortic debris or aortic dissection. Furthermore, there are problems that the distal aortic occlusion becomes incomplete and proximal anastomosis between the ascending aorta and saphenous veins becomes impossible. CABG for a 56 year-old male with severely calcified ascending aorta was successfully conducted using hypothermic circulatory arrest technique. His right internal thoracic artery was bypassed to LAD under fibrillatory arrest and then his right gastroepiploic artery was bypassed to the distal portion of RCA under hypothermic circulatory arrest. There was no complication and left ventricular ejection fraction improved from 16% to 38% postoperatively.

Coronary-coronary bypass using the internal thoracic artery: a sparing procedure of the arterial conduit.

BACKGROUND: The internal thoracic artery (ITA) is well known to be the best conduit for coronary artery bypass grafting. However, the bilateral use of ITAs remains limited because in situ right ITAs (RITAs) do not possess an adequate length to be directed to the posterolateral myocardium. We thus considered using free ITAs for conduits between the two segments of the same coronary artery. METHODS: From March 1997 to May 1999, 17 patients underwent coronary-coronary bypass grafting (C-CBG) using free ITAs. Early operative results were analyzed. C-CBG was indicated when the right ITA had an inadequate length or when a distal part of the ITA was left unused. RESULTS: No patient died after C-CBG and none have experienced angina since C-CBG (mean follow-up period 27.3 +/- 19.8 months). Postoperative angiography was performed in all subjects at discharge. Only one coronary-coronary bypass graft was occluded, the other grafts were patent, and there were no stenotic changes. Bilateral ITAs were used in 75% of the patients undergoing CABG during the period of this study. CONCLUSIONS: C-CBG can expand the use of bilateral ITAs and can provide an alternative method for revascularization of the posterolateral myocardium.

[Repair of mitral regurgitation caused by prolapse of the anterior mitral leaflet].

Mitral regurgitation caused by prolapse of the anterior mitral leafleft has been considered to be difficult for reconstruction. In Japan, these cases have been repaired mainly by replacement of chordae with artificial sutures. We have repaired them by Carpentier's technique. We report a series of 9 patients with pure mitral regurgitation caused by ruptured or elongated chordae of the anterior mitral leaflet. Two of them had lesions at both anterior and posterior leaflet. All patients underwent mitral valve repair by segmental transposition of the posterior leaflet. As for associated procedures, there were ring annuloplasty with Carpenter rings (9 cases), sliding technique (8 cases) reported by Carpentier, reinforcement by transposition of secondary chordae of the posterior leaflet (6 cases), commissuroplasty (1 case), and closure of leaflet perforation. All patients survived operations and all patients except one underwent left ventriculography postoperatively. In only 2 patients, residual mitral regurgitation classed as I/IV was observed. All patients returned home in New York Heart Association class I. Follow-up ranged from 7 to 45 months (mean follow-up 20 months). All patients were free from reoperation or thromboembolism. Although longer follow-up is necessary, this technique appears to be adequate for the repair of patients with anterior leaflet prolapse.

New left main trunk reconstruction technique using a flap of the main pulmonary arterial wall.

A new technique is described for ostiumplasty of the left main coronary artery using a flap of the main pulmonary arterial wall. Venous or pericardial patches are conventionally used to enlarge coronary ostial lesions, we used a flap of the pulmonary arterial wall with expectation that it is viable over the long term. This technique seems to surpass conventional coronary artery bypass grafting.

[Surgical treatment of type A acute aortic dissection--experience of hypothermic circulatory arrest associated with the cerebroplegia].

From 1992 to July 1996, 19 patients (aged 39 to 78 years) were operated on for type A acute aortic dissection. Our operative strategy is that all patients in whom aortic dissection involves the segment of transverse aortic arch should undergo simultaneous replacement or repair of the aortic arch and ascending aorta. Among these 19 patients, 17 were operated on within 24 hours after onset. In 13 patients, graft replacement extended from the ascending aorta to the transverse portion of the arch. The aortic stumps were prepared with the Teflon left both inside and outside of the aortic wall. Recently these were reconstructed with the aid of the Gelatin-Resorcin-Formaling glue, instilled into the false lumen. Cerebral protection was achieved by hypothermic circulatory arrest associated with the cerebroplegia (thiopental, nicradipine and mannitol). In one patient associated with severe aortic regurgitation, a valved conduit was implanted and the coronary arteries were reimplanted. CABG was performed concomitantly in two patients for involvement of the proximal coronary arteries by the dissection process. The hospital mortality rate was 26% (5/19). However, in two of them, death was not directly related to the operative procedure. One patient died of graft versus host disease (GVHD), another patient died of acute epidural hemorrhage which was undetected until the repair was completed. During the postoperative course, in all but two patients, the false lumens of the aortic arch and/or descending thoracic aorta were confirmed to be totally thrombosed by the examination of CT scan and/or aortography. It is concluded that the surgical treatment of type A acute aortic dissection can be successfully performed, even if the graft replacement extended to the transverse aortic arch.

[The treatment of patients with distal arch aneurysms--hypothermic circulatory arrest and left posterolateral exposure].

In ten patients we treated with distal arch aneurysms exposed through left posterolateral incisions, we induced profound hypothermia and circulatory arrest. Before circulatory arrest, thiopental, nicardipine and glycerol were used to protect the brain. The brain function was objectively evaluated through continuous recording of EEG and PO2 tension of the internal jugular vein. A cardiopulmonary bypass was introduced via the left atrium, pulmonary artery and left femoral artery cannulation. After proximal anastomosis between the graft and transverse aorta, graft cannulation was added. The distal aortic arch was replaced in all patients, with the entire descending thoracic aorta additionally replaced in two. No patients died in hospital. Two suffered neurological deficit, i.e., one having slight memory impairment and the other having a left-sided stroke due to right cerebral infarction, but recovering completely within a week. Our results indicate that profound hypothermia and circulatory arrest can be implemented safely when treating patients with distal arch aneurysm.

[An adult case of anomalous origin of the left coronary artery from the pulmonary artery].

An adult case of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) was presented. A 37-year-old male was admitted for ventricular arrhythmia and chest pain. The catheterization, left ventriculography and coronary arteriography revealed ALCAPA with anterolateral ventricular aneurysm and mild mitral regurgitation. An operation using Takeuchi procedure was performed. The postoperative course was uneventful and the results of the catheterization, left ventriculography and coronary arteriography performed immediately and five years after the operation were excellent except mild supravalvular pulmonary stenosis. Six years later, the patient is asymptomatic and well.