[Constrictive pericarditis after minimally invasive coronary artery bypass grafting: report of a case].

Constrictive pericarditis (CP) after off-pump coronary bypass surgery, especially after minimally invasive direct coronary artery bypass (MIDCAB), had rarely been reported. We presened a surgically treated case of CP after MIDCAB via left anterior small thoracotomy. A 57-year-old man underwent MIDCAB with placement of an internal mammary artery to the left anterior descending coronary artery uneventfully. Four years after the operation, he began to experience exertional dyspnea. Computed tomography of the chest showed pericardial thickening. Cardiac catheterization revealed elevation and equalization of the pressures in the 4 chambers, as well as low cardiac output. Pericardiectomy using cardiopulmonary bypass through a median sternotomy was performed successfully without injury to the bypass graft. Postoperative hemodynamic measurements were improved. The patient has resumed normal activity and remained free from heart failure for over 5 years.

[Evaluation of paravalvular leakage occurring after the 3rd mitral valve replacement].

We evaluated the frequency of paravalvular leakage (PVL) in 21 patients who had undergone mitral valve replacement (MVR) 3 times or more in our department between January 1981 and December 2003. Of these 21 patients, 5 underwent MVR 4 times, including the one who underwent the 5th MVR. Seven (38%) of 18 patients who had successfully undergone MVR 3 times and all 2 patients who had successfully undergone MVR 4 times developed PVL. PVL recurred in 6 (67%) of 9 patients who had undergone the 3rd MVR due to the occurrence of PVL. However, PVL recurred in only 1 (11%) of 9 patients who had undergone the 3rd MVR due to some postoperative complications other than PVL. Among 10 patients who developed PVL after the 1st or 2nd MVR, PVL recurred in 7 patients after the 3rd MVR. However, among 8 patients who did not develop PVL after the 1st or 2nd MVR, PVL occurred after the 3rd MVR only in 1 patient. These findings suggest that repeated MVR increases the incidence of PVL, and that patients with a past history of PVL are at a higher risk of developing PVL after repeated MVR.

[Long-term results of conventional aortic valve replacement for small aortic annulus].

We studied cardiac function, clinical outcome and quality of life (QOL) long after aortic valve replacement for pure aortic stenosis. Forty-four patients in small group [St. Jude Medical (SJM) 17 HP, 19 A], and 69 patients in non-small group (19 HP, 21 A, 23 A) operated on from 1984 to 2004 were enrolled in this study. We assessed the clinical data, aortic pressure gradient, left ventricular mass index (LVMI), and ejection fraction (EF) by preoperative and postoperative echocardiography. Moreover to evaluate QOL after the operation, we performed SF-36 used for the evaluation of health and QOL worldwide. Mean follow-up is 7.1 +/- 4.8 years in small group, and 6.8 +/- 4.6 years in non-small group. There were 2 hospital deaths in small group, and 1 in non-small group. The actual survival rate at 10-year were 89.2% in small group, and 85.6% in non-small group. There was no significant difference in hospital mortality, LVMI, long-term survival rate, and the scores of SF-36 between the 2 groups. The use of small sized prosthetic valves in patients with small aortic annulus might be justified when there is no patient-prosthesis mismatch.

[Early and long-term results of valve replacement in patients on chronic hemodialysis].

Cardiac valve replacement carries a high-risk in hemodialysis patients and has been questioned for its results. The purpose of this study is to focus on the early and long-term results in our institution. We retrospectively analyzed the data from 41 hemodialysis patients who underwent valve replacement in our unit from July 1978 to March 2004. Bioprosthetic valves were used in 5 patients (12.2%). The overall operative mortality (30 days) was 17%. The in-hospital death rate was 22%. Late survival rate was 68% at 2 years, 54% at 3 years, 49% at 5 years, and 27% at 10 years for all patients. The incidence of major bleeding and stroke was 41%.

Total cavopulmonary shunt with replacement of common atrioventricular valve for an infant with single atrium and single ventricle.

A 22-month-old male infant with single atrium, single ventricle, regurgitant common atrioventricular valve, pulmonary atresia, patent ductus arteriosus, and inferior vena cava defect with azygos connection was treated successfully with total cavopulmonary shunt and replacement of the common atrioventricular valve. The indications for total cavopulmonary shunt in the management of univentricular heart with azygos continuity are discussed.

Intraoperative assessment of functioning mitral valve.

A technique is presented that allows intraoperative assessment of mitral valve function with the heart filling and actively beating. This technique secures steady coronary perfusion and avoids possible air embolism of the coronary arteries. Repeated assessment and repair during reparative mitral operations are greatly facilitated when this technique is accompanied by warm blood cardioplegia.

Minimally invasive limited pericardiectomy: the hybrid approach.

This communication describes our clinical experience with the hybrid method, a video-assisted anterior minithoracotomy approach developed for minimally invasive limited pericardiectomy to treat 8 patients with massive pericardial effusion. The average operating time was 37.2 minutes, and there was no procedure-related morbidity or mortality. The mean follow-up period was 5.6 months, and there have been no recurrences. The hybrid approach can be accomplished irrespective of pleural adhesions. It eliminates the need for hemipulmonary collapse, making it more advantageous than the totally port-access thoracoscopic approach.

Bridging annuloplasty for common atrioventricular valve regurgitation.

Progressive common atrioventricular valve regurgitation is a serious condition in children with a univentricular heart. We developed a repair procedure that consists of using a Teflon tape bridge and total circular annuloplasty to divide the common atrioventricular valve into two atrioventricular valves. This procedure was performed in 2 infants, and the results were satisfactory. Details of the technique are described.

Mitral valve repair using continuous warm blood cardioplegia.

To achieve satisfactory mitral valve repair, we applied continuous warm blood cardioplegia to seven children with congenital heart disease associated with mitral valve insufficiency. All patients had mild to moderate mitral valve regurgitation before the operation. The competency of the mitral valve was assessed by injecting test solution into the left ventricle through the mitral valve orifice with the heart beating under warm blood perfusion into the aortic root proximal to the cross-clamp. Repair of the mitral valve was performed under normothermic cardiac arrest with continuous antegrade perfusion of warm blood cardioplegia. In all patients, these two procedures could be alternated with ease and safety simply by varying the potassium concentration of cardioplegia. While satisfactory valve repair was obtained with the initial procedure in 4 cases, repair was repeated twice in two and three times in one. There were no operative deaths and no complications directly related to the procedure. Postoperative echocardiography demonstrated good mitral valve function with none to trivial regurgitation in six patients (86%). Continuous warm blood cardioplegia is a useful and safe tool for mitral valve repair.

Arterial blood gas management in retrograde cerebral perfusion: the importance of carbon dioxide.

OBJECTIVES: Many interventional physiological assessments for retrograde cerebral perfusion (RCP) have been explored. However, the appropriate arterial gas management of carbon dioxide (CO2) remains controversial. The aim of this study is to determine whether alpha-stat or pH-stat could be used for effective brain protection under RCP in terms of cortical cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), and distribution of regional cerebral blood flow. METHODS: Fifteen anesthetized dogs (25.1+/-1.1 kg) on cardiopulmonary bypass (CPB) were cooled to 18 degrees C under alpha-stat management and had RCP for 90 min under: (1), alpha-stat; (2), pH-stat; or (3), deep hypothermic (18 degrees C) antegrade CPB (antegrade). RCP flow was regulated for a sagittal sinus pressure of around 25 mmHg. CBF was monitored by a laser tissue flowmeter. Serial analyses of blood gas were made. The regional cerebral blood flow was measured with colored microspheres before discontinuation of RCP. CBF and CMRO2 were evaluated as the percentage of the baseline level (%CBF, %CMRO2). RESULTS: The oxygen content of arterial inflow and oxygen extraction was not significantly different between the RCP groups. The %CBF and %CMRO2 were significantly higher for pH-stat RCP than for alpha-stat RCP. The regional cerebral blood flow, measured with colored microspheres, tended to be higher for pH-stat RCP than for alpha-stat RCP, at every site in the brain. Irrespective of CO2 management, regional differences were not significant among any site in the brain. CONCLUSIONS: CO2 management is crucial for brain protection under deep hypothermic RCP. This study revealed that pH-stat was considered to be better than alpha-stat in terms of CBF and oxygen metabolism in the brain. The regional blood flow distribution was considered to be unchanged irrespective of CO2 management.

Right heart mini-pump bypass for coronary artery bypass grafting: experimental study.

BACKGROUND: Visualization of the left circumflex arteries during off-pump coronary artery bypass grafting (CABG) causes hemodynamic disturbance. We investigated whether right heart mini-pump bypass (RHB), using a centrifugal pump, improved the safety of this procedure by studying the influences of different heart displacement positions, the Trendelenburg maneuver and RHB on hemodynamics. METHOD: Hemodynamic parameters in eight mongrel dogs (15.5-20 kg) were continuously monitored at a fixed heart rate of 80 beats/min through a conventional median sternotomy. The posterior descending artery (PDA) and left circumflex artery (LCX) were exposed using an Octopus tissue stabilizer. After evaluating the influence of the Trendelenburg maneuver on hemodynamics, a heparin-coated centrifugal pump without an oxygenator was introduced and the impact of different pump flow volumes was investigated during RHB. RESULTS: LCX exposure caused significant decreases in aortic flow (to 35. 1+/-12.8%) and arterial mean pressure (to 66.1+/-9.3%) compared with baseline (P<0.001). In contrast to PDA exposure, values remained significantly decreased during the Trendelenburg maneuver. On the contrary, RHB significantly improved the hemodynamic impairments caused by both heart displacement procedures, especially LCX exposure, although 100% pump flow significantly increased left atrial pressure to 131.3+/-19.5% (P<0.01). CONCLUSION: Exposure of the LCX caused severe hemodynamic deterioration, which was not fully reversed by the Trendelenburg maneuver. In contrast, RHB significantly improved hemodynamics, and therefore this technique can be beneficial for CABG of LCX in the limited cases.

Doppler ultrasonographic identification of the critical segmental artery for spinal cord protection.

OBJECTIVE: The purpose of this study is to evaluate the possibility of identifying critical segmental arteries (CSAs) based on Doppler ultrasonographic hemodynamics. METHODS: In 18 mongrel dogs, the descending aorta was scanned directly with a 5-MHz linear probe through left thoracotomies and the flow velocities in segmental arteries were measured by pulsed Doppler. The aorta was cross-clamped between Th13 and L1, and flow velocity changes were recorded. According to flow increases, segmental arteries were divided into three groups: arteries with the largest flow increase (L-arteries), arteries with the smallest increase (S-arteries) and other arteries (O-arteries). Animals were divided into three groups. One aortic segment including an L-artery or an S-artery was perfused via a temporary shunt during 30-min aortic cross-clamping distal to the left subclavian artery (Group L or Group S) and neurological outcomes were compared with those of animals without shunting (Group N) after 24 and 48 h. RESULTS: L-arteries had significantly larger flow increases than S- and O-arteries (74.3+/-33.8, 20.4+/-9.8 and 33.3+/-17.8 cm/s, P<0.01). In Group N, five of the six animals were completely paraplegic (Tarlov Grade 0) and the other was Grade 1. In Group S, four animals were Grade 4 and two were Grade 0 after 24h. However, two animals showed delayed paraplegia. Therefore, four animals were Grade 0 and two were Grade 4 after 48 h. All animals in Group L were neurologically normal (Grade 4) at both after 24h (vs. Group N, P=0.0013) and 48 h (vs. Group N, P=0.0013; vs. Group S, P=0.019). CONCLUSIONS: Flow responses to aortic cross-clamping differed among segmental arteries and selective perfusion of L-arteries completely prevented paraplegia. Therefore, L-arteries were considered to be CSAs. Hemodynamic measurement of segmental arterial flow using Doppler ultrasonography could be clinically useful for spinal cord protection during thoracoabdominal aortic surgery.

Coronary artery bypass grafting in a patient with cryoglobulinemia.

Coronary artery bypass grafting (CABG) was performed in a patient with cryoglobulinemia. In order to decrease the concentration of cryoglobulin, the patient underwent double filtration plasmapheresis (DFPP) pre- and postoperatively as well as during cardiopulmonary bypass. Bypass surgery was performed under total cardiopulmonary bypass, moderate systemic hypothermia, and ventricular fibrillation without aortic crossclamping. No adverse effects of cryoglobulin appeared during the peri- and postoperative course. Technical considerations for open heart surgery in patients with cryoglobulinemia are described.

Midterm results after aortic valve-sparing operation.

OBJECTIVES: We have conducted aortic valve-sparing operation for patients having aortic root dilatation and almost normal aortic valve leaflets since August 1998, and here report midterm results. METHODS: Patients with dilated aortic annulus or Marfan's syndrome were treated with reimplantation, and the remaining patients with remodeling. Either 24 or 26 mm graft was selected based on aortic annular diameter and leaflet size. Aortic valve competence was assessed regularly with echocardiography. RESULTS: Five patients (age: 29 +/- 13 yr), including 4 with Marfan's syndrome, had undergone reimplantation, and 3 (age: 46 +/- 18 yr) remodeling by December 2000. Mean follow-up was 18 (range: 10-32) months, and no postoperative death has occurred and no reintervention has been required thus far. All the patients in the remodeling group showed only a small pressure gradient through the aortic valve and decreased left ventricular diameter. Two in the reimplantation group showed a pressure gradient exceeding 20 mmHg. Two Marfan's syndrome patients in the reimplantation group showed slightly increased diastolic left ventricular diameter and 3 slightly increased systolic left ventricular diameter. Although aortic regurgitation had diminished in all patients by discharge, moderate aortic regurgitation recurred in 1 non-Marfan's syndrome patient in the reimplantation group because of degenerated aortic valve. CONCLUSION: Although postoperative aortic valve function was not perfect in all patients undergoing reimplantation, midterm results after aortic valve-sparing operation were generally satisfactory. Proper selection of patients, procedures, and graft size was thought to be important to ensure a favorable surgical outcome.

[Exercise tolerance after correction of tetralogy of Fallot].

Twenty-six postoperative patients with tetralogy of Fallot (TF) were evaluated by exercise stress test with an upright cycle ergometer. Oxygen uptake was assessed at the anaerobic threshold and the peak achieved work load. Oxygen uptake at the anaerobic threshold (VO2AT) was in the normal range regardless of the existence of residual stenosis (PS) or pulmonary regurgitation (PR). However, oxygen uptake at the peak achieved workload (VO2max) was subnormal in patients with PS or PR. Maximal heart rate in TF patients was lower than normal. Patients with PR showed significantly reduced VO2max as compared with those without PR (p less than 0.05). This is found to be resulted from limitation of the oxygen pulses increase.

[Use of the inferior epigastric artery for coronary artery bypass grafting: preoperative digital subtraction angiography].

Between September 1994 and January 1995, the inferior epigastric artery (IEA) was used as a free graft for direct coronary artery bypass grafting in 4 patients. The IEA is excised from its origin from the external iliac artery as a pedicle with an "oval cuff" of 3 mm in diameter to facilitate the direct anastomosis with the aorta. The 4-week postoperative angiographic study showed that the IEA grafts were patent in all patients. We found that the IEA varies in length, diameter, and the pattern of branching between patients and between the right and left sides in the same patient. The preoperative digital subtraction angiography was useful for evaluating the suitability of IEA.

[Respiratory failure after thymectomy in myasthenia gravis: evaluation of preoperative influencing factors and preventive managements against postoperative respiratory dysfunction].

Postoperative respiratory function was evaluated in 94 patients with myasthenia gravis after thymectomy. Preoperative clinical and pulmonary function data were submitted to statistical analyses. The duration of respiratory support and intratracheal intubation time were significantly correlated to % vital capacity, the clinical stage of myasthenia gravis, and the clinical stage of thymoma. Statistical analyses proved that anticholinesterase drugs taken in immediate postoperative period contributed to the improvement of postoperative respiratory function, and non-depolarizing muscle relaxants, i.e. d-tubocurarine which had been considered to be contraindicated in myasthenia gravis was found to be beneficial immediately after the operation in patients with severely deteriorated respiratory function preoperatively.

[Results and problems of cardiac surgery in the elderly (70 years of age or older)].

Fifty-nine cardiac patients with 70 years of age or older were operated in our Department from 1979 to 1990. The mean age was 73.1 years old, and the male/female ratio was 27/32. The operative procedures performed were CABG in 35 cases, the closure of VSP in 4 cases, the valve surgery in 17 cases and the others in 3 cases. In CABG cases, the operative and late mortalities of the elderly patients were both 2.9% (1 case each), which were comparable to those of the younger patients. The restriction of the bypass grafting only to the key coronary arteries to reduce the operative time was considered to be important. In VSP cases, three of four patients were operated in the acute phase, one being lost because of in-hospital contamination. In the valve group, 24% (4 cases) were lost in the early postoperative period, which was much higher than that of the younger patients (7.2%). The earlier decision of the operation and the use of smaller prosthetic valve avoiding time-consuming aortic root enlargement were considered to be important to reduce the mortality. It is concluded that the results of cardiac surgery in the elderly patients could be satisfactory if one considers its peculiarity well.