Hiroshi Ohuchi

Aprotinin and recombinant human erythropoietin reduce the need for homologous blood transfusion in cardiac surgery

The effects of low dose aprotinin (Trasylol) and preoperative administration of recombinant human erythropoietin (EPO) were evaluated in 144 patients undergoing cardiopulmonary bypass divided into four groups. Group I (n = 43) received a subcutaneous administration of EPO (18,000 U) one week before operation and intraoperative administration of low-dose aprotinin (mean; 1.38 +/- 0.26 x 10(6) kallikrein inactivator units; KIU) from extracorporeal circulation, group II (n = 39) received only preoperative administration of EPO, group III (n = 28) received only intraoperative administration of low-dose aprotinin (mean; 1.46 +/- 0.25 x 10(6) KIU), and group IV (n = 34) were not administered either drug. Compared with group IV, the intraoperative blood loss was significantly lower in group I (p < 0.01), and in group II or III (p < 0.05). The postoperative drainage in 24 hours was significantly lower in groups I and III receiving aprotinin than in the other groups. The mean volume of total homologous blood transfusion and the percentage of cases not requiring a homologous blood transfusion in each group was, respectively, 74 +/- 235 ml and 88.4% in group I, 282 +/- 1289 ml and 87.2% in group II, 414 +/- 584 ml and 60.7% in group III, and 976 +/- 1931 ml and 44.1% in group IV. Significant differences were recognized between group I and group IV (p < 0.05). These findings indicate that when used in combination, both drugs reduce blood loss and the need for a homologous blood transfusion more effectively than either drug alone.

Paraplegia due to acute spinal epidural hematoma after routine cardiac surgery

Sirs: Paraplegia is one of the most devastating complications of cardiovascular surgery. However, its incidence after routine cardiac surgery is presumed to be extremely low, especially in the absence of severe cardiac dysfunction or hypotension [1]. Paraplegia occurred due to acute spinal epidural hematoma in a patient whose clinical course was otherwise quite uneventful after mitral valve replacement, and resulted in a permanent motor function deficit of both lower limbs despite an emergent laminectomy and a rigorous medical treatment. A 52-year-old man who had recurrent mitral regurgitation after mitral valvuloplasty underwent mitral valve replacement through median resternotomy and under a moderately hypothermic cardiopulmonary bypass. This operation was carried out uneventfully within 5 h without blood transfusion. The cardiopulmonary bypass time was 150 min, and activated coagulation time was maintained at around 500 s. As usual, an epidural catheter was not inserted. He regained consciousness soon after he was transferred to the intensive care unit and was extubated 5 h later. His hemodynamic condition was stable, and neurological symptoms were absent. On the following day, however, he felt mild weakness in both lower limbs in the morning and paraplegia developed around noon. The posterior column sensation was also disturbed. Data, including platelet count, prothrombin time, thrombo test, and fibrinogen level were compatible for a patient who had undergone cardiac surgery on the preceding day. Transverse myelopathy at L1 cord level was diagnosed. Magnetic resonance imaging revealed an epidural hematoma of the spine (Fig.1a). Emergent laminectomy was performed, and a fresh thrombus of 30 g weight (Fig.1b) was removed about 14 h after the development of limb weakness, 10 h after paraplegia developed. Despite this emergent laminectomy and the rigorous medical treatment his motor functions did not recover. Two years later he is now independent in a wheelchair, but he needs much help in his daily life. He is otherwise doing well. Hemorrhagic events are not rare among patients who undergo cardiac surgery because of the heavy use of anticoagulants. The etiology of spinal epidural hematoma is often idiopathic, and its occurrence is low, but we should be aware of this uncommon sequelae because urgent treatment is warranted whenever it occurs. Posterior column sensation often recovers, at least partially, but the probability of motor function recovery declines progressively after the development of paraplegia. Fair or occasional complete recovery can be expected if the operation is performed within 8 h, but after 24 h recovery is considered to be usually impossible [2]. The prognosis is much worse in patients with rapidly progressive spinal symptoms, and paralysis is often irreversible even if decompression is performed much earlier than described above [2, 3]. Therefore immediate action of physicians is very important. The early and even subtle symptoms should never be missed even in the absence of cardiac dysfunction, which require high indices of suspicion for this complication [2]. Better established systems for emergency situations and closer cooperation of medical staff are also essential.

Lay-open pulmonary arterioplasty for postoperative hilar pulmonary artery stenosis

OBJECTIVE Lay-open pulmonary arterioplasty, a novel surgical technique to enlarge postoperative stenosis at the hilar pulmonary artery, was evaluated. METHODS Lay-open arterioplasty, in which the enlarged hilar stenotic pulmonary artery is partially made up of previous surgical scar tissue instead of being covered by a patch, was performed on 10 patients whose ages ranged from 2.2 to 15.7 years. Surgical results were assessed by angiography. RESULTS All patients tolerated the procedure without bleeding or embolic complications associated with pulmonary arterioplasty. Nine patients underwent concomitant procedures including total repair (n = 5), central interposing shunt (n = 3), and right ventricular outflow tract reconstruction (n = 1). No deaths or life-threatening events occurred during the total follow-up period of 18 patient-years. The stenotic segment was significantly enlarged from the preoperative diameter of 0.9 +/- 1.1 mm (mean +/- standard deviation) to the postoperative diameter of 8.0 +/- 1.3 mm, values which correspond to 7.0% +/- 8.8% and 68.4% +/- 11.5% of the normative values, respectively. A follow-up angiogram (n = 5) revealed an increase in the pulmonary artery diameter balanced with somatic growth (initial value, 65.2% +/- 9.0% of normal; second value, 69.1% +/- 7.7% of normal). No aneurysms or clinically significant restenoses were seen on the angiograms. CONCLUSIONS Our initial midterm results with this method were promising. The pulmonary arteries subjected to this procedure grew in proportion to somatic growth.

Development and clinical application of minimally invasive cardiac surgery using percutaneous cardiopulmonary support

OBJECTIVES Optimal cardiopulmonary support during minimally invasive cardiac surgery remains controversial. We developed cardiopulmonary bypass for minimally invasive cardiac surgery using percutaneous peripheral cannulation. METHODS Subjects were 34 patients (age: 58 +/- 13 years; range: 17-73) undergoing minimally invasive cardiac surgery using percutaneous cardiopulmonary support between June 1997 and March 1999. Procedures included atrial septal defect closure (n = 14), partial atrioventricular septal defect closure (n = 1), mitral valve replacement (n = 8), mitral valve repair (n = 3), aortic valve replacement (n = 6), coronary artery bypass grafting (n = 1), and right atrial myxoma extirpation (n = 1). Bicaval venous drainage from the right internal jugular vein and the femoral vein and arterial return to the femoral artery were instituted by percutaneous cannulation. Venous drainage was implemented by negative pressure (-20 to -40 mmHg) and arterial return was by conventional roller pump. All procedures were conducted through a skin incision 8 +/- 1 cm, from 6 to 10 cm and partial sternotomy. Aortic cross clamping and cardioplegic solution were administered in the surgical field. RESULTS The operation lasted 224 +/- 45 min., cardiopulmonary bypass 104 +/- 32 min., and aortic clamping 77 +/- 23 min.. No deaths occurred. One patient with residual atrial septal defect required reoperation through the same skin incision. Only 1 patient required homologous blood transfusion. The average postoperative hospital stay was 15 +/- 5 days. CONCLUSIONS Minimally invasive cardiac surgery using percutaneous cardiopulmonary support is safe and an excellent option for selected patients affected by single valve lesion, simple cardiac anomalies, and coronary artery bypass grafting.

Clinical effects of ventricular assist system in end-stage cardiac failure. Advantages of left ventricular blood drainage for recovery from cardiac dysfunction.

OBJECTIVES Heart transplantation is extremely limited currently in Japan. As a consequence ventricular assist system implantation is employed the patient falls into end-stage cardiogenic shock. This preliminary report describes our initial clinical experience with use of 2 kinds of ventricular assist system for 13 Japanese patients. METHODS 7 patients were supported by a left ventricular assist system with blood drainage from the left atrium (LA drainage Group) using a Toyobo ventricular assist system, while another 6 patients were supported by a left ventricular assist system with blood drainage from the left ventricle (LV drainage Group) using the Toyobo ventricular assist system (1 patient) or TCI-LVAS (5 patients). RESULTS The average duration of ventricular assist system support in the LV drainage Group was 112 days including two on-going patients (now at 39 days and 241 days) and in the LA drainage Group was 49 days. The average left ventricular ejection fraction at 3 weeks after ventricular assist system implantation was improved from 12.3 to 54% using the TCI-LVAS and from 14 to 33% using the Toyobo ventricular assist system with drainage from the left ventricle. However, this was decreased from 20 to 10% using the Toyobo ventricular assist system with drainage from the left atrium. The ventricular assist system was explanted in 4 patients (31%) with recovery of cardiac dysfunction and 3 were long survivors. The 2 on-going patients are awaiting heart transplantation. Thus the current survival rate overall is 38%. The survival rate (67%) is excellent in the LV drainage Group including 2 long survivors after explantation. CONCLUSION Ventricular assist system support with drainage from the left ventricle seems to be more advantageous for cardiac functional recovery than from the left atrium for end-stage heart failure.

Successful treatment of ascending aortic graft infection after operation for acute aortic dissection with peripheral malperfusion

Mediastinitis with infection of an ascending aortic graft is hard to heal and is a highly fatal complication. We had a patient in whom mediastinitis with infection of such a graft as well as an ascending aorta-femoral artery bypass graft developed after the initial operation for type A aortic dissection accompanied by peripheral malperfusion. We treated it successfully by inserting a stent into the true lumen of the thoracoabdominal aorta and using a cryopreserved homograft to replace the infected ascending aortic fabric graft.

Combined coronary artery bypass grafting and abdominal aortic aneurysm repair.

The purpose of this paper was to assess the results and feasibility of simultaneous coronary artery bypass grafting and abdominal aortic aneurysm repair. Twenty nine patients with a mean age of 65 years underwent simultaneous coronary artery bypass grafting and abdominal aortic aneurysm repair between June 1990 and March 2002. All patients had significant coronary artery disease and were considered as indicated for coronary artery bypass grafting. This was performed first in 28 patients and simultaneously with abdominal aortic aneurysm repair in one, with a mean number of grafts of 2.5, a mean aortic cross-clamp time of 40 minutes, and a mean bypass time of 115 minutes. Eight straight and 21 bifurcated grafts were employed. The total operating time averaged 400 minutes. The median postoperative hospital stay was 18 days. One patient died of stroke and mediastinitis, for a mortality rate of 3.5%. This experience suggests that combined coronary artery bypass grafting and abdominal aortic aneurysm repair is both safe and effective.

Global Myocardial Ischemia as a Complication of an Acute Type A Aortic Dissection

A 36-year-old female was admitted for severe chest pain followed by profound shock. Electrocardiography showed severe ST segment depression (0.5-0.7 mV) in all leads except aVR and aVL. Echocardiography revealed an intimal flap in the ascending aorta and coexisting grade 3 aortic regurgitation. She was immediately intubated and transferred to the intensive care unit. Transesophageal echocardiography (TEE) demonstrated an intimal tear at 2 cm above the sinotubular junction, and the ostium of the left main trunk was oppressed by the intimal flap during diastole. Emergency graft replacement of the ascending aorta and aortic hemiarch concomitant with aortic valve resuspension was performed successfully. The ECG changes reversed to normal immediately after the operation. The patient was extubated 2 days postoperatively and discharged from the hospital 14 days postoperatively. TEE is useful for the rapid evaluation of coronary malperfusion as a complication of acute aortic dissection, especially in patients with hemodynamic instability.

Allograft pulmonary artery root replacement for refractory isolated pulmonic valve endocarditis.

Abstract A 45-year-old diabetic woman was subjected to percutaneous cardiopulmonary support for a life-threatening pulmonary embolism. One month later, she developed isolated pulmonic valve endocarditis. The causative organism was methicillin-resistant Staphylococcus aureus. Because of the uncontrollable infection and residual pulmonary hypertension, she underwent pulmonary artery root replacement with a cryopreserved pulmonary allograft. The postoperative course was very good. In this case, allograft implantation with a full root played a very important role because this method permitted thorough resection of the infected tissues and reconstruction which is highly resistant to infection.

Aortic regurgitation causd by the proximal dissecting flap invagintion to the left ventricle

A 68-year-old male with sudden back pain and cardiogenic shock status transferred to our ward. Transthoracic echocardiography revealed that the abnormal rond shape string was in the left ventricular outflow tract. The continuity from the string to the aortic valve was unclear. Intimal flap could not be detected at the level of the ascending aorta. Color Doppler flow imaging showed that the severe AR jet extended into the round string. TEE showed that the intimal tear and flap was seen just above the left subclavian artery. Preoperative diagnosis was acute Stanford type A dissection and acute severe AR due to the inversion of the proximal intimal flap to the left ventricular outflow tract through the aortic valve. At operation, the proximal intimal flap was dissected circumferentially and was cut all the way around 8 cm above the aortic valve ring and was inverted to the left ventricular outflow tract. The aortic valve was preserved because of its normal character after exclusion of the proximal intimal flap. Ascending and arch replacement was carried out. Postoperative TEE and TTE showed no findings of AR. The patient’s postoperative course was uneventful. To our knowledge, this is the first reported case that severe AR caused by the proximal intimal invagination to the left ventricle.