The safety and usefulness of cool head-warm body perfusion in aortic surgery.

OBJECTIVE: To determine the safety and usefulness of antegrade hypothermic cerebral perfusion in conjunction with mild hypothermic (tepid) visceral perfusion (so-called cool head-warm body perfusion; CHWB) in aortic surgery; the clinical outcomes and perioperative data on this new technique were retrospectively analyzed. METHODS: From January 1990 to March 1999, 59 patients underwent ascending aorta or aortic arch surgery using antegrade selective cerebral perfusion (SCP). Three perfusion techniques, differentiated by perfusion temperature, were used, those being deep hypothermia (DH; nasopharyngeal temperature of 20 degrees C, n=14), moderate hypothermia (MH; nasopharyngeal temperature of 28 degrees C, n=17) and CHWB (nasopharyngeal temperature of 25 degrees C and bladder temperature of 32 degrees C, n=28). Selection of the technique largely followed a chronological pattern, in this order: DH, MH and, more recently, CHWB. The three groups were retrospectively compared in terms of operative outcome, duration of cardiopulmonary bypass (CPB) and operation, and intraoperative blood loss. RESULTS: The early (within 30 days after surgery) mortality/hospital mortality (including operative mortality) was 7.1/21.4, 5.9/11.8 and 3.6/7.1% in the DH, MH and CHWB groups, respectively. The rate of stroke was 7.1, 6.3 and 3.6% in the DH, MH and CHWB groups, respectively. No statistical difference was found in early or hospital mortality, or in the rate of stroke among the three groups. The CPB time, especially the time for rewarming, was significantly shorter in the CHWB than in the DH group. Likewise, the operation time, especially the time after CPB, was significantly shorter in the CHWB than in the DH and MH groups. Blood loss was significantly less in the CHWB than in the DH group. CONCLUSION: Our data suggest that CHWB perfusion in aortic surgery is a safe and useful technique in shortening the operation time and reducing blood loss, but further prospective study is necessary.

Clinical application of power Doppler imaging to visualize coronary arteries in human beings.

Supplementation of angiographic information during bypass procedures is an attractive goal for the echocardiographic researcher. Compared with color flow mapping, power Doppler imaging is superior in terms of identifying small vessels and noise suppression because of the use of Doppler signal strength for imaging. Although power Doppler imaging does not provide information about flow velocity or its direction, it does show detailed vessel flow in a static organ. Our study was designed to obtain angiographic images of the coronary artery by the use of power Doppler imaging in 31 patients during open heart surgery. During cold cardioplegic infusion, the epicardial coronary artery and the coronary artery within myocardium, such as the septal perforator, could be well visualized by power Doppler imaging. There was good correlation between the diameters of coronary arteries measured from power Doppler imaging and those from quantitative coronary angiography (r = 0.964, p < 0.0001). We obtained clear and accurate images of the coronary artery by using power Doppler imaging during cardiac standstill. These images might provide meaningful supplemental information to the operator, such as confirming the target coronary artery during the cardioplegia and choosing the appropriate arterial portion for a bypass operation.

Initial experience with cool head, warm body perfusion in aortic arch surgery.

BACKGROUND: Hypothermia has been an essential technique in aortic arch surgery for protecting the brain. To reduce the adverse effect caused by hypothermia, we modified the perfusion technique in aortic arch surgery. Initial results using this modified technique are reviewed. METHODS: Nineteen patients were operated on for aortic aneurysm involving the aortic arch. Fifteen patients had nondissecting aneurysm and four patients had type A dissecting aneurysm including three with acute dissection. While on the hypothermic (25 degrees C to 28 degrees C of nasopharyngeal temperature) antegrade selective cerebral perfusion (SCP) was performed by direct cannulation to the brachiocephalic and left common carotid arteries, visceral perfusion via the femoral artery or graft was performed with tepid or normothermia (34 degrees C to 36 degrees C). RESULTS: Hospital mortality rate was 5.3% (1/19 patients). None of the 19 patients suffered from stroke postoperatively. Duration of total cardiopulmonary bypass and SCP was 144 +/- 36 minutes and 90 +/- 34 minutes, respectively. Eighteen surviving patients were extubated at 9.4 +/- 13.2 hours and stayed in the intensive care unit (ICU) for 3.0 +/- 1.8 days after the surgery. CONCLUSIONS: Our initial experience revealed that the modified technique using simultaneous hypothermic cerebral perfusion and tepid or normothermic visceral perfusion can be a useful adjunct during aortic arch surgery providing quick recovery.

[Emergency percutaneous cardiopulmonary support for patients with cardiac arrest or severe cardiogenic shock].

A total of 20 patients who developed cardiac arrest or severe cardiogenic shock were resuscitated with percutaneous cardiopulmonary support system (PCPS). The etiology of shock was acute myocardial infarction (n = 8), post-infarction left ventricular (LV) free wall rupture (n = 9) and others (n = 3). After successful resuscitation with PCPS, 17 patients underwent therapeutic interventions: either closure of an LV rupture (n = 9), coronary artery bypass grafting (n = 4), percutaneous transluminal angioplasty (n = 1) and percutaneous transluminal coronary recanalization (n = 1). Of the 20 patients, 17 were weaned from PCPS or standard cardiopulmonary bypass. Nine patients survived longer than 30 days and 6 patients were discharged from the hospital. In nine patients with LV free wall rupture, one could be discharged from the hospital. Even though our experience is still small in number, it can be concluded that cardiopulmonary resuscitation using PCPS improves survival in fatally ill patients.

Improved management of selective cerebral perfusion in aortic arch surgery.

To establish a safe and reliable method for cerebral protection in aortic arch surgery, the authors attempted antegrade selective cerebral perfusion (SCP) based on the characteristics of jugular venous oxygen saturation (SjO2). Twenty patients were divided into two groups: a control group and SCP group. In the control group, in 13 adult patients undergoing cardiac surgery using standard hypothermic cardiopulmonary bypass, the relationship between SjO2 and nasopharyngeal temperature (NPT) during rewarming showed an inverse linear correlation:SjO2 = -2.3 NPT + 133 (r = 0.616). In the SCP group, seven patients with aortic arch aneurysm underwent surgery using SCP performed through direct cannulation of the innominate and left carotid arteries. While on SCP (83 +/- 24 min), the blood was warmed from 28 to 36 degrees C. Cerebral perfusion pressure of 40-60 mm Hg was necessary to maintain the SjO2 equal to the value in the control group at each NPT during SCP in all seven patients. None of the patients had any post operative complications. Our experience suggests that SCP can be safely performed at both mild hypothermia and normothermia under monitoring of perfusion pressure and SjO2 in aortic arch surgery.

Emergency cardiopulmonary bypass support in patients with severe cardiogenic shock after acute myocardial infarction.

A total of 16 patients who developed severe cardiogenic shock were resuscitated with a percutaneous cardiopulmonary support system (PCPS). The etiology of shock was acute myocardial infarction (n = 7), or post-infarction left-ventricular (LV) free wall rupture (n = 9). After successful resuscitation with the PCPS, 15 patients underwent therapeutic interventions: closure of an LV rupture (n = 9), coronary artery bypass grafting (n = 4), percutaneous transluminal angioplasty (n = 1), and percutaneous transluminal coronary recanalization (n = 1). Of the 16 patients, 14 were weaned from PCPS or standard cardiopulmonary bypass. Six patients survived longer than 30 days, 3 (19 percent) of whom were discharged from the hospital. The long-term survival rate in the 6 patients who underwent coronary revascularization was 33 percent (2/6). Of the 9 patients with LV free wall rupture, 1 was discharged from the hospital. Even though it cannot be concluded, from this small number of patients, that cardiopulmonary resuscitation using PCPS improves survival, it appears that PCPS is a powerful resuscitative modality for seriously ill patients with acute myocardial infarction or LV rupture.

Separation of the natural atria in experimental implantation of total artificial heart.

Atrial connections in a single-unit total artificial heart (TAH) may be difficult to make because of the rigidity of the device and the fixed position of the atrial inlets. We developed a technique to separate the natural atrial borders in an experimental implantation of a unitary TAH. In this technique, the interatrial groove was dissected to separate the posterior wall of the right atrium from the roof of the left atrium before cardiopulmonary bypass (CPB) was initiated. After initiation of CPB and cardiectomy, the atrial septum was separated completely, and the right atrial wall was reconstructed with glutaraldehyde-treated autopericardium. We believe that this simple adjunctive technique provides increased mobility of the atrial cuffs and allows for an easier connection of the unitary TAH.

Overseas transport of a patient with an extracorporeal left ventricular assist device.

An 18-year-old boy with end-stage cardiomyopathy who was undergoing support with an extracorporeal pneumatic left ventricular assist device was transported from Japan to the United States. During the 17-hour flight, the patient's condition was stable, and the pneumatic assist device worked well under low atmospheric pressure in the cabin. Subsequently, he had a successful heart transplantation after 119 days of left ventricular assist device support.

[A successful use of VAS for bridge to heart transplantation after oversea transportation in a 18-year-old patient with dilated cardiomyopathy].

An 18-year-old boy with dilated cardiomyopathy developed a relatively rapid deterioration and went into severe congestive heart failure. After short-while use of percutaneous cardiopulmonary support system (PCPS) and IABP, LVAS was indicated because of persisting low cardiac output syndrome and deterioration of organ functions. An LVAS (TOYOBO) was implanted on June 26, 1992 in a fashion of left atrium to ascending aorta bypass. Satisfactory circulatory support (flow rates of 4-5 L/min) was achieved resulting in complete recovery of the organ functions. After two months of LVAS support, the patient was transported to U.S.A.. The LVAS system was working well without any problems during 17 hrs flight under low atmospheric pressure (0.8 atm) in the plane. The patient successfully underwent heart transplantation (HTx) at Texas Heart Institute after 119 days support of LVAS. The patient is doing well enjoying active life after HTx. This is the first case of successful bridge use of extracorporeal LVAS to HTx in Japan.

Changes in left ventricular performance after global ischemia: assessing LV pressure-volume relationship.

To determine the effect of ischemia and reperfusion on left ventricular systolic function, we studied the ischemia-induced rightward shift of the ventricular pressure-volume relationship. Eight mongrel dogs were intubated, and their hearts were exposed through a thoracotomy. A conductance catheter and micromanometer were used to obtain instantaneous left ventricular pressure-volume data. The dogs were subjected to 20 minutes of normothermic global myocardial ischemia, followed by 80 minutes of reperfusion under total cardiopulmonary bypass. Data were acquired during transient (10- to 12-second) periods of acute volume loading before ischemia and at 20-minute intervals during reperfusion as bypass was continued. The relationship between stroke work and end-diastolic volume (ie, preload recruitable stroke work [PRSW]) and the end-systolic pressure-volume relationship were highly linear throughout the study (mean r = 0.954 to 0.983 for PRSW; mean r = 0.954 to 0.984 for end-systolic pressure-volume relationship). Ischemia produced changes in the PRSW: (1) the slope decreased significantly at 20 minutes and 40 minutes of reperfusion then returned to preischemic levels at 60 minutes and 80 minutes, and (2) the x-intercept increased significantly up to 60 minutes. The preload recruitable work area (the area under the linear regression line of PRSW) reflected changes in both slope and x-intercept of PRSW and was significantly decreased throughout the 80 minutes of reperfusion despite gradual recovery. The slope and the x-intercept of the end-systolic pressure-volume relationship did not change after ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

[Experimental study on heparin-free cardiopulmonary bypass using nafamostat mesilate (FUT-175) and heparin-coated circuit].

We investigated whether the combination of a new synthetic protease inhibitor, nafamostat mesilate (FUT-175), and heparin-coated cardiopulmonary bypass (CPB) circuit can achieve heparin-free CPB in rabbits. Nine rabbits underwent 2 hours of CPB with heparin-coated circuits. In 4 rabbits (FUT-Group), FUT was administered before (2 mg/kg in bolus) and during (5 mg/kg/hr continuously) CPB. In 5 rabbits (Heparin-Group), heparin was given before (4 mg/kg) and at 1 hour (2 mg/kg) of CPB. Activated clotting time, activated partial thromboplastin time and fibrin degradation products showed no significant differences between the two groups during CPB. However, prothrombin time was significantly (p < 0.05) shorter in FUT-Group than in Heparin-Group. Platelet counts in FUT-Group was significantly lower than Heparin-Group. Massive clots were observed in all of the venous reservoirs of FUT-Group after CPB, whereas there were no major clots in Heparin-Group. The occlusion rate of hollow fibers of the oxygenators was significantly higher in FUT-Group (55 +/- 25%, mean +/- SD) than in Heparin-Group (14 +/- 12%). We concluded that heparin-free CPB with FUT and heparin-coated circuit is difficult in rabbits because activation of the extrinsic coagulation cascade cannot be sufficiently suppressed by FUT.

Peripheral organ perfusion augmentation during left ventricular failure. A controlled bovine comparison between the intraaortic balloon pump and the Hemopump.

Despite the use of inotropic therapy and the intraaortic balloon pump (IABP), inadequate peripheral organ perfusion and subsequent multiorgan failure from left ventricular dysfunction is a major cause of death following cardiac surgery. To compare the end-organ perfusion provided by the IABP with that of the recently developed Hemopump Cardiac Assist System, blood flow from visceral organs was measured by ultrasonic flow probes during separate periods of support with each of these pumps. Ten calves underwent coronary artery ligations with beta-receptor blockade; hemodynamic parameters were recorded before the induction of failure, during unsupported cardiac failure, and during Hemopump and IABP support. Improvement in mean cardiac output, mixed venous oxygen saturation, and pulmonary artery wedge pressure was significantly greater (p < 0.05) during Hemopump support than during IABP support. Renal artery flow was significantly greater during Hemopump support (276 +/- 74.2 cc/min) than during IABP support (164 +/- 79.6 cc/min). Hepatic artery flow was significantly greater during Hemopump support (34.7 +/- 25.7 cc/min) than during IABP support (24.4 +/- 18.9 cc/min), and portal vein flow was significantly greater during Hemopump support (1588 +/- 315 cc/min) than IABP support (1259 +/- 310 cc/min). There were no significant differences, however, between carotid artery flow during Hemopump support (292 +/- 171 cc/min) and that during IABP support (317 +/- 204 cc/min). We conclude that renal, hepatic, and mesenteric perfusion provided by the nonpulsatile Hemopump is superior to that of the IABP in this bovine model of left ventricular failure. Therefore, the Hemopump may be more effective in preventing multiorgan failure during recovery of ventricular function.

Long-term results of entry closure and aneurysmal wall plication with axillofemoral bypass: a new procedure for repair of DeBakey type 3 dissecting aneurysm.

To prevent aneurysm rupture, avoid pseudoaneurysm formation, and preserve intercostal arteries, a new procedure for repair of DeBakey type 3 dissecting aneurysm was developed. Since January 1977, 28 patients have undergone repair of type 3 dissecting aneurysm. Fifteen patients with type 3b underwent this new procedure (group 1) and 13 patients with type 3a dissecting aneurysm underwent segmental graft replacement (group 2). In group 1 a permanent axillofemoral bypass was placed on the right side. Next the intrathoracic false lumen was opened longitudinally, the entry was closed, and the aneurysmal wall was sutured around the true lumen as tightly as possible. The operative mortality rate was 20% in group 1 and 31% in group 2. One of 15 patients in group 1 died of operation-related causes, whereas three patients in group 2 died. There were six late deaths: three in group 1 and three in group 2. Paraplegia occurred in neither group 1 nor group 2. The mean diameter of the plicated descending aorta was 24.0 +/- 2.7 mm 3 months after surgery. No recurrence was detected in group 1. These results suggested that this new surgical technique for repair of type 3 dissection reduces the incidence of paraplegia and pseudoaneurysm formation.

Assessment of regional and transmural myocardial perfusion by means of intraoperative myocardial contrast echocardiography during coronary artery bypass grafting.

By using intraoperative myocardial contrast echocardiography, we assessed regional myocardial perfusion and transmural blood flow distribution immediately after myocardial revascularization. A total of 62 revascularized myocardial areas were studied in 31 patients undergoing coronary artery bypass grafting. The revascularized areas were divided into three different areas: S area, supplied by significantly stenosed coronary arteries (43 areas); C area, supplied by coronary collateral situation associated with totally occluded coronary arteries (12 areas); MI area, preexisting transmural myocardial infarction (7 areas). Myocardial contrast echocardiography was obtained by direct injection of 2 ml of sonicated 5% human albumin into the saphenous vein grafts at rest and during atrial pacing. Each area was divided into two layers of endocardial and epicardial halves, and myocardial enhancement of peak intensity was measured for each half and endocardial/epicardial gray level ratio was calculated: (1) The peak intensity of myocardial enhancement in S area and C area was significantly higher than that in MI area at rest as well as during pacing after myocardial revascularization. There was no significant difference in the peak intensity between S area and C area both at rest and during pacing. In S area the peak intensity significantly increased during pacing (p < 0.01), whereas it did not change in C area and MI area. (2) S area demonstrated no significant change in endocardial/epicardial intensity ratio during pacing. In contrast, the ratio in C area significantly decreased during pacing. (3) In S area with preoperative percent increase of segmental wall thickening lower than 25%, there was a significant correlation (r = 0.84, p < 0.001) between the peak intensity of myocardial enhancement and the postoperative changes of percent increase of segmental wall thickening in the revascularized areas. Thus, immediately after myocardial revascularization, intraoperative myocardial contrast echocardiography could provide a quantitative assessment of regional myocardial perfusion as well as blood flow distribution in the areas with myocardial infarction and with coronary collateral situation and in the areas supplied by stenosed coronary arteries.

Effects of terminal cardioplegia with leukocyte-depleted blood on heart grafts preserved for 24 hours.

Canine hearts immersed in modified Collins solution were transplanted heterotopically (n = 23) and orthotopically (n = 15) to evaluate the effect of terminal warm-blood cardioplegia with or without leukocyte depletion. As the index for graft function, preload recruitable stroke work was measured in both series before harvesting (control) and after transplantation (percentage). The heterotopic hearts were divided into four groups (group 1 to 4) according to the preservation method; hearts were preserved for 3 hours in group 1 and for 24 hours in groups 2, 3, and 4. Simple terminal warm-blood cardioplegia was applied in group 3, and terminal warm-blood cardioplegia with leukocyte depletion was used in group 4. In the orthotopic series, five hearts were transplanted soon after harvesting (group 5) to simulate on-site transplantation, and the remaining ten hearts were transplanted after 24 hours of hypothermic preservation without and with terminal warm-blood cardioplegia with leukocyte depletion (groups 6 and 7, respectively). Among the heterotopic transplants, the percentage of preload recruitable stroke work was highest in group 4 (91% +/- 6%, 51% +/- 4%, 83% +/- 10%, 140% +/- 11% in groups 1, 2, 3 and 4, respectively). All orthotopic transplants in groups 5 and 7 were weaned from cardiopulmonary bypass without inotropic support and without significant differences in cardiac function between groups 5 and 7 (percentage of preload recruitable stroke work, 99% +/- 10% versus 102% +/- 2%; cardiac output, 122 +/- 10 versus 140 +/- 22 ml/kg/min). No orthotopic transplants in group 6 could be weaned from cardiopulmonary bypass, even with inotropic support.(ABSTRACT TRUNCATED AT 250 WORDS)

[A surgical case of thoracic aortic aneurysm due to Takayasu's aortitis associated with ulcerative colitis].

We experienced a case of thoracic aortic aneurysm due to Takayasu's aortitis associated with ulcerative colitis. Steroid was medicated to control inflammation and operation was performed. The ascending aorta, aortic arch, brachiocephalic artery, and left carotid artery were replaced by artificial graft. We made elephant trunk type anastomosis at the distal side of the graft to provide for growth of the aneurysm after operation. This was a rare case considered autoimmune overlapping syndrome, and its background was complicated by HLA-Bw52 and parasitic Metagonimus Yokogawai. Relationship between steroid medication and progression of the disease is not certain yet. Postoperative course is uneventful, no recurrence of inflammation is seen and the aneurysm is not enlarged until now.