[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%.

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.

Extended repair of thoracic aorta through left thoracotomy after aortic root replacement.

A patent distal false lumen after repair of type A aortic dissection often poses serious late complications. We present a successful repair of dissecting aortic aneurysm through left thoracotomy, extending from the ascending to descending thoracic aorta after composite graft replacement of the aortic root. Although staged operations, including the elephant trunk procedure, are usually chosen for remaining extensive aortic disease after replacement of the aortic root or the ascending aorta, a single-stage repair from the ascending to the descending thoracic aortas through left thoracotomy can be a favorable option to treat a patient with this type of aortic disease.

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.

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.

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.

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.

Right heart bypass for left circumflex coronary artery bypass grafting.

Displacement of the heart to expose the left circumflex artery (LCX) causes hemodynamic disturbance during off-pump coronary artery bypass grafting (CABG). We applied right heart bypass (RHB) using a heparin-coated centrifugal pump without an oxygenator in an attempt to stabilize the hemodynamics. Five mongrel dogs (15.5-20 kg) were used. Hemodynamic parameters were continuously monitored at a fixed rate of 80 beats/min. The LCX was exposed with the use of an Octopus Tissue Stabilizer. After baseline data were obtained, each dog was placed in the Trendelenburg position. Finally, RHB was established with different pump flows. LCX exposure caused a significant decrease in aortic flow (to 33.1% +/- 13.1% of the baseline value) and arterial mean pressure (to 68.3% +/- 8.5%) (P < 0.001). Trendelenburg positioning caused these values to recover to 57.1% +/- 6.7% and 72.5% +/- 7.7%, respectively. RHB with 50% flow significantly improved the hemodynamic values, although 100% flow significantly increased LAP by 134.8% +/- 19.7% (P < 0.01). Tilting of the canine heart to expose the LCX caused significant deterioration of the hemodynamic values. Trendelenburg positioning was moderately effective, and RHB very effective, in improving the hemodynamics. In a limited number of cases, an appropriate flow of RHB may provide safe hemodynamic assistance during off-pump CABG of the LCX.

The effect of thorough preoperative disinfection on the incidence of postoperative mediastinitis.

This study was conducted to evaluate the effectiveness of scrubbing the skin of patients scheduled to undergo elective cardiac surgery with disinfectant solutions in an attempt to reduce the incidence of the potentially fatal postoperative complication of mediastinitis. Since April 1991, we have routinely disinfected the skin of all such patients three times preoperatively. A retrospective comparison of the incidence of mediastinitis before and after April 1991 was carried out. Microbiological examinations of the anterior chest were conducted in ten patients admitted for elective operations, and in four patients admitted for emergency surgery. Specimens were obtained before each scrubbing, before the operation, and just after skin closure. There was a significant decrease in the general incidence of mediastinitis after April 1991 (P < 0.01). Microbiologically, significant decreases in colony counts were also observed after the first (P < 0.05) and second scrubbing (P < 0.05) in the ten patients specifically studied before elective surgery. No colonies grew in the postoperative specimens from any of these patients, but colony formations were observed in two of the four patients who underwent emergency surgery (P = 0.066). Thus, we conclude that our thorough disinfection method effectively achieves adequate, prolonged suppression of the skin flora, which explains the marked decrease in the incidence of mediastinitis in our hospital since its institution.

Dissecting aortic aneurysm presenting as pyrexia of unknown origin: report of a case.

We describe herein the case of a 51-year-old woman with a dissecting aneurysm of the aorta who presented with pain in the chest followed by prolonged pyrexia of unknown origin (PUO) lasting 6 weeks. Because of the fever associated with a murmur of aortic regurgitation, she was initially misdiagnosed as having infective endocarditis. This unusual case serves to remind us that clinicians should bear in mind the possibility of aortic dissection in patients presenting with PUO.

Oxygen utilization and hemodynamic response during exercise in children after Fontan procedure.

Eight patients, 9.1 to 16.5 years of age, were studied 2.8 to 8.5 years after Fontan operation. Oxygen utilization was determined during upright bicycle exercise. The cardiac index and stroke index were measured by echocardiography and the anaerobic threshold was determined. The results were compared with 10 patients after surgical closure of the atrial septal defect. Anaerobic threshold (AT) in Fontan patients was lower than in the control subjects. Oxygen consumption at each stage of exercise was significantly lower in the Fontan group compared with the control subjects. From the beginning of exercise until AT, the increase in stroke index was lower in the Fontan patients than in the control subjects. After that point, the stroke index decreased significantly in the Fontan patients while it remained almost at the same level in the control subjects. Significant correlations were observed between the oxygen pulses and the stroke index at AT both in the control and Fontan groups. These results suggest that impaired exercise capacity in Fontan patients is mainly due to a subnormal response of the stroke index at AT and to the decreased response of the stroke index and the heart rate at the maximal workload.

[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.

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.

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.