[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.

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.

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.

A clinical study of cerebral circulation during extracorporeal circulation.

The objective of this study is to clarify the relationship of cerebral blood flow to extracorporeal circulation flow and mean arterial pressure during nonpulsatile extracorporeal circulation under moderate hypothermia. Cerebral blood flow was determined by an argon saturation and desaturation method after that of Pevsner and colleagues with a mass spectrometer in 21 adult patients undergoing cardiac operations. Cerebral blood flow was 25, 33, 35, and 42 ml/100 gm/min, ranging from 19 to 50 ml/100 gm/min, at extracorporeal circulation flow rates of 40, 50, 60, and 70 ml/kg/min, respectively. Cerebral blood flow increased proportionally to extracorporeal circulation flow. Cerebral blood flow scattered almost transversely to mean arterial pressure and was 31 ml/100 gm/min in a hypotensive group (mean arterial pressure 34 to 50 mm Hg) and 34 ml/100 gm/min in another group (mean arterial pressure 51 to 94 mm Hg). Mean arterial pressure did not significantly influence cerebral blood flow. Cerebral oxygen consumption did not remarkably decrease and remained in the reasonable range when cerebral blood flow was 23 to 40 ml/100 gm/min. Subsequently, we assumed that the average cerebral blood flow value of 25 ml/100 gm/min at an extracorporeal circulation flow rate of 40 ml/kg/min also would be in the safe range. All of the patients are living without cerebral complications. We conclude that (1) cerebral blood flow was extracorporeal circulation flow dependent and (2) cerebral blood flow in the safe range was maintained even in the hypotensive range, provided the extracorporeal circulation flow rate was 40 ml/kg/min or higher.

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%.

Invasive thymoma with intracaval growth into the right atrium.

We report an unusual case of invasive thymoma with intracaval growth into the right atrium. Computed tomography and venacavography demonstrated this manner of extension of thymoma. The tumor was completely removed by means of cardiopulmonary bypass after four courses of chemotherapy. Multidisciplinary treatment for invasive thymoma with this growth pattern is thought to be useful.

Isolation and characterization of horny cell membrane.

The cornified cell membrane and thickened marginal band were obtained from human stratum corneum by a new, faster procedure involving extraction, tripsinization, and density gradient centrifugation. Observations revealed a fine membranous structure with a thickened inner surface of approximately 150 A (marginal band). Each of the membranous samples contained a level of half-cystines markedly higher in amount than that of earlier findings by Matotsy and Matotsy [5]. The samples also contained high amounts of glutamic acid and lysine residues many of which constitute the epsilon-(gamma-glutamyl) lysine cross-linkages of the cell membrane. This study presents the simple isolation procedure and its results highlight the high content of half-cystines in the basic membrane fraction. In addition, the study reveals the importance of S-S cross-linkages during the formation of the cell membrane.

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.

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.

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.

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.

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.

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.

[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.

[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.

[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.

[A case report of ball variance of Smeloff-Cutter prosthetic valve].

A 37-year-old woman had undergone aortic valve replacement with Smeloff-Cutter prosthetic valve in 1967. She visited our hospital because of dyspnea and chest pain about 22 years after the operation. Severe aortic regurgitant murmur was audible and a chest X-ray demonstrated lung edema. A diagnosis was made of acute left heart failure due to prosthetic valve dysfunction, and emergency operation was performed. The Silastic ball was severely deformed and shrunken. Therefore, the ball was easily put off outside the cage. A St. Jude medical prosthetic valve was implanted. The postoperative course was uneventful.

[A case of pulmonary infarction secondary to subacute bacterial endocarditis with subpulmonary VSD].

A case of pulmonary infarction secondary to subacute bacterial endocarditis of pulmonary valve which is associated with subpulmonary VSD is presented. The jet stream of blood through the subpulmonary VSD made damage to the pulmonary valve, which may be one of the reasons why subacute bacterial endocarditis was associated with the subpulmonary VSD. Echocardiography of the right-sided valves will be very useful in order to detect the pulmonary valve endocarditis in congenital heart disease presenting with fever.

[A case of ruptured aortic arch aneurysm into the lung].

Successful surgical treatment of aortic arch aneurysm ruptured into the left lung was reported. The patient was a 74-year-old man suffering from recurrent hemoptysis. Computed tomography and aortic angiography demonstrated a giant aortic arch aneurysm. Emergency operation was performed. Arch reconstruction by a Dacron graft was performed with hypothermic circulatory arrest. The post operative course was uneventful and there was no evidence of cerebral complication. In the emergency operation for ruptured aortic arch aneurysm, hypothermic circulatory is very useful method for cerebral protection.

[Intrathoracic pacemaker implantation in children].

In order to minimize the complications, we introduced the intrathoracic implantation method since 1976. Until 1988, 12 children underwent this method. A pacemaker generator was exchanged in 8 patients, 12 times, because of battery exhaust. Compared with the conventional method (abdominal wall implantation), the complications such as electrode fracture, which was related to the implantation sites, were reduced. Furthermore it was very useful from the cosmetic viewpoint. Although an exchange of generator was very easily done at the first time, it was very difficult at the second time, due to rib fusion accompanying with children's growth.