Search

Preoperative selective cerebral arteriography is carried out in order to determine if the circle of Willis is intact in the cases of the thoracic aortic aneurysms. As regard to the bilateral vertebrobasilar communications, 26 of 30 patients (86.7%) have good condition, 4 of 30 patients (13.3%) have poor, and in 2 cases the left vertebral artery supplied broad area of posterior cranial fossa. We believe that in the cases in whom the left vertebral artery is dominant, and cross collateral circulation is absent, perfusion of the left subclavian artery is necessary to prevent vertebrobasilar ischemia during aortic aneurysms operation under normothermia.

Para-esophageal anastomosis of left atrium was examined in orthotopic heart transplantation as a new surgical technique for transesophageal electrophysiologic study of the transplanted heart. Seven orthotopic heart transplantations were performed in mongrel dogs. Left atrial appendage of the donor heart was trimmed as a flap and the sinus venosus of right atrium was incised posteriorly. An upper midline incision was made in the posterior wall of left atrium of the recipient after native ventricles were resected. Left atrial appendage flap of the donor heart was anastomosed to the posterior incision of native left atrium, and the remains of left atrium were sutured continuously. Sinus venosus incision of the donor heart was anastomosed to the right atrium of recipient. Ascending aorta and pulmonary trunk were reconstructed in the standard fashion. Transesophageal atrial pacing was possible during and after weaning from cardiopulmonary bypass in all seven cases. The appendage flap was found to occupy one third of the posterior wall of left atrium at the time of sacrifice. It was suggested that para-esophageal anastomosis of left atrium would be an useful technique for transesophageal electrophysiologic study of the transplanted heart.

We reported a 29-year-old man with active endocarditis complicating aortic and mitral valve regurgitation. The echocardiogram showed a mycotic aneurysm at aortic valvular annulus and a aneurysm of mitral valve. Heart failure was progressive and caused anuria. Prior to emergent double valve replacement, 2,500 ml of water was removed. Then hemodynamics became stationary. Urination was good during and after operation. In this case, complicating acute renal failure, dehydration with extracorporeal ultrafiltration method was very effective for improvement of hemodynamics.

Five patients (pts) with life-threatening ventricular tachyarrhythmias (idiopathic VF; 2 pts, Torsade de pointest; 1 pt, VT/VF after valve replacement; 2 pts) underwent surgical treatment of the automatic implantable cardioverter defibrillator (AICD). Implantation of an AICD was indicated for patients who survived circulatory arrest due to documented VT and/or VF. The patient should be medically refractory or medical treatment precluded by hemodynamic instability; other surgical treatment should not be possible. We selected myocardial electrode for sensing and small and large patch electrodes for defibrillating. VF/VT was induced 1 to 6 times for the measurement of defibrillation threshold (DFT). In all of our pts, the AICD appropriately discharged at postoperative EPS. In three of pts, the AICD discharged within the postoperative hospital phase, in two because of sinus tachycardia during treadmill test and restored sinus rhythm after non-sustained VT. As for complications, in one pt. with severe LV dysfunction, incessant form of VT/VF occurred after DFT testing and LV assist circulation and IABP were needed. In two pts, inappropriate discharge and in two, pericarditis were recognized postoperatively. It was considered that this system was effective for the treatment of life-threatening ventricular tachyarrhythmias but strict indication was necessary because of unsolved problems.

The difficulty in obtaining suitable organs for the transplantation is a major problem in Japan. In this study, we assessed the suitable procedure for multiple organ preservation and evaluated organ viabilities after preservation with an unique technique. The heart and lung were preserved with UCLA Formula alone and the liver was preserved with Euro-Collins' solution. The mean ischemic times of the heart, lung and liver were 4.3 hours, 7.5 hours, and 6 hours, respectively. The viability of the heart graft following orthotopic transplantation was evaluated with cardiac output and Left Ventricular End-Diastolic Pressure (LVEDP) under the constant pre-load (CVP 7 mmHg). Cardiac outputs (ml/min.) were 4.01 +/- 1.36 before operation, 3.26 +/- 0.26 at 1 hour after transplantation, 3.24 +/- 0.26 at 4 hours after transplantation (NS). LVEDP (mmHg) was 7.1 +/- 0.8 before operation, 6.5 +/- 0.86 at 1 hour, and 7.4 +/- 1.2 at 4 hours after transplantation (NS). The viability of transplanted lung was evaluated with pressure-tidal volume curve and arterial oxygen tension (PO2) when right pulmonary artery and bronchus were occluded. There was no statistical difference in pressure-volume curve and PO2 tension between the phases of pre- and post-transplantation. After liver transplantation, ICG test (15 min.) showed a sufficient value of 35-40%. In conclusion, the procedures of multiorgan preservation using UCLA Formula and Euro-Collins' solution were successfully performed and its viability of grafts after transplantation remained sufficient.

Orthotopic heart transplantation with sinus venosus incision of right atrium was aimed to preserve the sinus node, terminal crista, sinus node artery and whole right atrial muscle of the transplanted heart. This transplant procedure was performed in eight mongrel dogs and electrocardiogram was followed up to five postoperative months. Direct cross circulation technique was employed as an alternative of cardiopulmonary bypass. Donors and recipients were 6 to 8 kg mongrel puppies, and 19 to 25 kg adult dogs supported the cross circulation. Myocardial protection of the donor heart was carried out by low-flow continuous potassium cardioplegia and topical cooling. Right atrial incision of the donor heart was made longitudinally in the posterior wall of sinus venosus. After a median sternotomy, ascending aorta and superior and inferior venae cavae of the recipient were cannulated and connected respectively with carotid artery and jugular vein of the cardiopulmonary support dog. Electrocardiogram, arterial pressure and central venous pressure of the recipient were monitored, and an electro-magnetic flow meter was employed for measuring the blood flow of direct cross circulation. The native heart was resected after aortic cross-clamping, and left atrium and atrial septum were sutured continuously. Sinus venosus incision of the donor heart was anastomosed to the recipient's right atrium. Ascending aorta and pulmonary trunk were reconstructed in the standard fashion. Aortic cross-clamp time was less than one hour and sinus rhythm of the transplanted heart was continued in all cases. Five of the eight dogs were alive postoperatively for one week to five months.(ABSTRACT TRUNCATED AT 250 WORDS)

A 39-year-old man suffered from acute myocardial infarction. Echo cardiography showed the presence of intra-pericardial fluid. We had emergent operation. We successfully salvaged cardiac rupture with fibrin glue and oxy-cellulose without cardiopulmonary bypass. His post-operative course was uneventful. The patient was discharged on the seventh week after the operation. The problems of acute cardiac rupture were discussed.

This study is to describe the pathophysiological change in the alveolar space due to reperfusion injury in the lung. Six pigs, weighing 20-22 kg, were used. Through the left lateral thoracotomy, both sides of pulmonary artery (PA) and bronchus (Br) were exposed and occluded the left side of PA and Br. Left lung was perfused with 200 ml of UCLA Formula and preserved in room temperature (27 degrees C) for 3 hours. After the clamps were released, right side of PA and Br were clamped and pulmonary artery pressure (PAP) and static lung compliance were measured in ischemic lung. Then, animals were sacrificed and alveolar wash was performed. With the fluid taken from the alveolar wash, the surfactant and protein content in the alveolar space were measured using Malate's method and Lowry's method, respectively. As the results, PAP (mmHg) was significantly increased after the reperfusion, from 34.0 +/- 8.1, to 85.4 +/- 8.7 (p less than 0.001). Lung Compliance (ml/cmH2O) was decreased, from 0.52 +/- 0.07 to 0.31 +/- 0.1 after the reperfusion (p less than 0.001). The content of surfactant in the left lung described as a ratio (left/right) was 252.5 +/- 87.8% of that in right side. The content of protein in the left lung was 289.5 +/- 137% of that in right side. We concluded that both contents of surfactant and protein were increased in alveolar space after the reperfusion.

The authors developed two different methods to immobilize heparin on polymer surfaces. One method involves in situ heparin immobilization on a segmented polyurethane urea (Biomer) surface via hydrophilic poly(ethylene oxide) (PEO, Mn = 4,000) spacers. The other method uses PEO/poly(dimethylsiloxane) (PDMS) block co-polymer and heparin covalently linked in a block co-polymer system (PEO-PDMS-Hep). These surfaces have demonstrated high heparin bioactivity in vitro and excellent blood compatibility in in vitro-ex vivo experiments. This report evaluates the long-term in vivo blood compatibility of these heparin immobilized surfaces. Vascular grafts (6 mm ID, 7 cm in length) were fabricated with Biomer, and heparin was immobilized in situ with PEO spacers (B-PEO4K) and coated on their luminal surfaces with PEO-PDMS-Hep. Biomer and PEO (Mn = 4,000) grafted Biomer (B-PEO4K) were used as controls. The grafts were implanted in the abdominal aorta of dogs and retrieved at 3 months or when graft occlusion was suspected. Retrieved grafts were evaluated with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM measured the thickness of the adsorbed protein layer on the surface and the protein distribution (albumin, fibrinogen, and IgG) visualized by an immunogold method. All heparin immobilized grafts were patent at 3 months, whereas Biomer and B-PEO4K grafts occluded within 1 month. SEM pictures of heparin immobilized surfaces after 3 months demonstrated minimal platelet adhesion and activation without detectable fibrin formation. Heparin immobilized surfaces showed a thin protein layer (300-600 A) even after 3 months, with high concentrations of albumin and IgG and less fibrinogen.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors previously showed that a small caliber xenograft using our crosslinking technique was applicable to aortocoronary bypass grafting. In this study of the graft, the antithrombogenicity and healing process was evaluated at an early stage after implantation. Fresh sheep carotid artery (3mm ID) was obtained and cross-linked with polyepoxy compounds, and then used as a small caliber vascular graft. The graft was white and soft. Six cm segments of the graft were implanted into the carotid arteries bilaterally in nine dogs. Sodium heparin was given during the surgery, but no anticoagulant was used postoperatively. Fifteen grafts from eight dogs were removed from 1 hr to 30 days after implantation, and 13 of 15 grafts were found to be patent. Two grafts, one at 3 days, and the other at 14 days, were occluded. The anastomotic area of the occluded grafts felt hard when touched from the outside. In one dog, the grafts were shown angiographically to be patent at 14 days after implantation, and this dog was kept for long-term observation. Macroscopically, no thrombus was observed on any of the patent grafts. Microscopically, the inner surface near the anastomotic lines was covered with endothelial cells, and infiltration of fibroblasts was observed from the outside 7 days after implantation. No foreign body reactions were seen around the graft. After 30 days of implantation, a thin layer of plasma protein at the middle of the graft was observed by scanning electron microscopy (SEM). From these observations, it was concluded that the grafts exhibited satisfactory early antithrombogenicity and healing after implantation.

A total of 61 VASs developed in Tokyo University were evaluated at 21 institutions in the period 1985-1989 for determination of its reliability and effectiveness. The system is comprised of a pneumatic sack-type pump (Nippon Zeon Co.), and its driving console (Aishin Seiki Co.). The stroke volume of the pump is 40 ml and blood contacting surfaces are coated with Cardiothane. Ages of the patients (pts) ranged from 12-82 yrs (mean 58 yrs). VASs were used in the assist mode of LVAD (54 pts), RVAD (5 pts) and BVAD (2 pts). Most of the cases (58 pts) included postocardiotomy cardiogenic shock after surgery for ischemic (28 pts), valvular (22 pts), both ischemic and valvular (7 pts) and congenital (1 pt) heart diseases. Average duration of the assist ranged from 1 hr-20 days (mean 5.6 dys). The VADs could be weaned in 34 cases (56%) and among these, 13 cases (21%) survived to discharge from the hospital. Causes of death in cases which could be weaned from the VAD included multiple organ failure/due to delayed institution of adequate circulatory support, renal failure and systemic infection. Small and minute thrombus formations were noted in 7 cases however, no pump originated thromboembolism were complicated. No troubles of the pump including leakage nor breakage, no mechanical failures of the driving consoles were experienced in any of the cases. Thus, it is concluded that the system was proved to be clinically effective and reliable.

The authors previously reported on a new cardiac wall substitute (collagen-coated ultrafine polyester mesh, CUFP), which in an animal study showed satisfactory antithrombogenicity due to its hydrophilicity and excellent neointimal formation because it induced cell migration and proliferation. Both the ultrafine polyester mesh, and the collagen cross-linked with a hydrophilic reagent, have a special affinity for host cells. In the current study, the focus was on neointima formation on the CUFP, compared with that on glutaraldehyde-treated equine pericardium (GA graft), over longer time periods. Twenty-one CUFPs, and 19 GA grafts as controls, were implanted as patches in the right ventricular outflow tract in 40 dogs. In the CUFP at 28 days, a thin neointima, which was almost endothelialized, had been formed. Fibroblasts and vasa vasorum were seen inside both the neointima and the graft wall. The CUFP showed a white, shiny, smooth, thin, and uniform neointima with endothilialization at 486 days, and the neointima was firmly anchored by day 699. In the GA graft at 484 days, however, the neointima was partly detached from the GA graft and almost no fibroblasts had infiltrated the graft wall. Therefore, neointimal formation on the CUFP is almost completed within 1 month and maintained over the long term.

Two cases of iatrogenic left main coronary artery stenosis (ICOS) following aortic valve replacement (AVR) are documented. The first patient began to have chest pain due to myocardial ischemia 7 months after AVR. Angiographically, the ostium of her left coronary artery was severely stenotic. She refused coronary bypass grafting. She died of myocardial infarction due to ICOS, 23 months after AVR. Histologically, a loose cellular connective tissue was found around the stenotic coronary arterial lumen. The other patient had chest pain 4 months after aortic and mitral valve replacement. The ICOS was diagnosed angiographically. After she had coronary bypass grafting, she was free from myocardial ischemic symptoms. The onset of myocardial ischemic symptoms in the first six months after AVR is highly suggestive of ICOS, and urgent coronary angiography is recommended and, if proximal stenosis of the coronary arteries is diagnosed, coronary bypass grafting should be performed.

A 63-year-old man with anterior chest oppression was diagnosed as an acute myocardial infarction. The two-dimensional echocardiogram revealed a mass which bulged into the left ventricular cavity. Subsequently, the computed tomographic findings of the mass lesion demonstrated the attenuation values of -49 Hounsfield units, which corresponded to that of fatty tissues. From these findings the left ventricular lipoma was highly suspected. The tumor existed at the base of the anterior papillary muscle. It was successfully resected and mitral valve replacement was performed concomitantly. The tumor was yellowish and sized by 25 X 20 mm. On histological examination of the specimen, the tumor was composed of mature fatty cells. CT scanning was very useful for the preoperative evaluation of lipoma.

Femoral artery pseudoaneurysm is one of multiple vascular complications with intra aortic balloon pumping (IABP). In a series of 815 cases, the incidence of pseudoaneurysm formation was 0.61 percent. Six patients with this complication who underwent successful surgical repair were reviewed. Three cases in our series were obviously due to the unsuitable technique of balloon removal. Especially a patient who underwent IABP insertion after exposure of the femoral artery should undergo open removal of the balloon with reconstruction of the femoral artery. In conclusion, femoral artery pseudoaneurysms are expected to diminish by the appropriate technique of balloon removal.

Daily and intermittent continuous intravenous infusions [by gravity drip, (IVG) or infusion pump, (IVP)] and intermittent short-time intravenous drip infusion of 5-FU were carried out on advanced cancer patients. The MTD and dose-limiting toxicity were investigated in relation to the plasma concentrations of 5-FU determined by HPLC. Responses in eleven patients receiving IVG administration daily at 8-21 mg/kg/day were NC, but those given 5-FU alone showed no adverse reactions. Plasma concentrations were too low to be determined. In 9 patients receiving IVG or IVP administration weekly at 60 mg/kg for 24 hr, 1 of the 5 evaluable patients showed reduced hepatic metastatic lesions. One of 4 patients receiving IVP administration weekly at 120 mg/kg for 48 hr showed a disappearance of metastatic lesions in the skeletal muscle, but bone marrow suppression was observed as dose-limiting toxicity. Pharmacokinetics were more stable in IVP than in IVG with less individual difference in the plasma concentrations. Among the outpatients receiving short-time iv, IVG administration once or twice a week, 2 patients given weekly administrations at 20 mg/kg for 60 min showed slight adverse reactions. In 6 patients given high-dose administrations, bone marrow suppression was observed. When pharmacokinetics in the patients given 5-FU for 60 min were compared between the IVG and IVP groups, there were individual differences in plasma concentrations, but the differences were not significant. It was concluded from above results that the following practical dose schedules would be recommendable: 60 mg/kg for 24hr/week by IVP for inpatients and 20 mg/kg for 60 min/week by IVG for outpatients.

Epicardial approach consists of meticulous dissection of the annular fat pad of the Kent bundle site and subsequent cryocoagulation from the epicardial side. This technique obviates the need of atriotomy and makes ablation without cardiopulmonary bypass possible. In performing this approach for patients with the left parietal or posteroseptal pathway through median sternotomy, special technical strategies are necessary to keep hemodynamic status stable during dissection and cryoablation procedures, because in these cases apex of the heart has to be retracted upward to approach the Kent bundle site. For this purpose, the use of an ultrasonic surgical aspirator for dissection of the annular fat pad is required. With this instrument fat tissue is emulsified and aspirated by stroking the fat pad gently, easy dissection is possible without injury to major coronary vessels, even through a narrow operative field. Another point is to dissect the annulus fat below the coronary sinus (i.e., at the space between the coronary sinus and circumflex coronary artery), not above it. By doing this extensive retraction of the apex is no longer necessary. In performing cryocoagulation care has to be taken not to involve the coronary artery into the lesion. However, too tight retraction of the coronary artery may cause another risk of thrombosis. Sometimes moderate systemic heparinization should be performed during coronary retraction and cryocoagulation procedure.

I. Experimental Studies We examined if laser ablation could make the same characteristic lesion as cryolesion to canine myocardium. Nine mongrel dogs were used in this experiment. Right lateral thoracotomy was performed and Nd:YAG laser was delivered onto the epicardial surface of both ventricles. Laser power of between 10 and 50 W was used with the various duration of 3 and 20 s, keeping the lasing distance 5 mm above the cardiac surface. Histologically, the lesion showed a well-demarcated area consisted of coagulation necrosis and contraction band necrosis in the acute phase, which changed to a fibrous scar in the chronic phase. There was a good correlation (r = 0.79; n = 52, p less than 0.01) between the lasing energy and the depth of the denaturation zone. II. A Case Report A 45-year-old male with ventricular tachycardia (VT) after aortic valve replacement was operated upon with Nd; YAG laser delivery. An antero-lateral thoracotomy through 4th and 6th inter-costal space was performed. The intraoperative mapping showed the three origins of VTs to be near the apex of left ventricle. With cardiopulmonary bypass, Nd; YAG laser was delivered onto the endocardial surface adjacent to arrhythmogenic foci. The lasing power was 10-30 W with the duration of 5.0-9.9 s. One hundred twenty seven trials were done with the total lasing energy to be 12490 J. Subsequently cryoablation was added on this area. Though VT remained in acute phase, 2 weeks later, all of tachyarrhythmia was abolished spontaneously.

During the past 15 years, we followed 21 patients with prosthetic heart valves who experienced a total of 24 pregnancies at mean age of 31.3 +/- 3.6 years. The course of these patients and their pregnancies were reviewed to evaluate the problems associated with prosthetic heart valves and anticoagulation. Among the 21 patients, the aortic valve (AV) had been replaced in 10 (12 pregnancies), the mitral valve (MV) in nine (10 pregnancies), AV + MV in one (one pregnancy), and the tricuspid valve (TV) in one (one pregnancy). The implanted prosthetic valves were mechanical type in 16 cases (Björk-Shiley 15, Starr-Edwards 1) and bioprosthetic type in six (Hancock 5, Ionescu-Shiley 1). With the exception of one case of intra-uterine fetal death probably related with warfarin therapy, all the patients with bioprosthetic valves underwent successful deliveries. Anticoagulant therapy was employed for 11 pregnancies; warfarin for 10 and subcutaneous heparin for one. No anticoagulant therapy was performed for 13 pregnancies. Ten of the 21 mothers had atrial fibrillation. Eighteen pregnancies (67%) culminated in uneventful deliveries for both mothers and infants. Three mothers (13%) died of thromboembolic complications; two of cerebrovascular accidents and one of acute heart failure caused by thrombus on the replaced valve. All of them had Björk-Shiley valves. Oral warfarin was administered in one of the three, heparin in one and no anticoagulant in the remaining one. Massive maternal bleeding occurred in two cases (8%). There were three cases (12%) of intra-uterine fetal death which were caused by intracranial hemorrhages.(ABSTRACT TRUNCATED AT 250 WORDS)

A computer simulation method to study a laser‐induced transient temperature profile of a multilayered phase‐change optical recording disk (PCORD) has been developed. The simulation program consists of two parts. One part is an optical analysis program based on the optical characteristic matrix method, and the other is a thermal analysis program based on the finite‐element method. A new estimation method for thermal conductivity of recording films was proposed. The estimated thermal conductivity of the thin‐film recording media was found to be 50% lower than that of the bulk. Reflectivity, absorbance, and temperature values obtained with this simulation method were compared with those measured by a spectrophotometer and an infrared radiation thermometer when the samples were irradiated in an Ar+ laser beam. The accuracy using this simulator was within 8% for reflectivity and absorbance and within 10% for temperature. A method of optimizing the laser‐absorbing layer was studied. With this method simulations...

From 1978 through 1989, 1200 patients underwent attempted coronary surgery. Seventy-six CABG-patients were recognized aorto-vascular disease. Thirty-one CABG-patients were operated with vascular surgery. Operative mortality of CABG was 0% (0/76). Operative mortality of vascular surgery was 3.2% (1/31). Total operative mortality was 1.1% (1/91).

This study was undertaken to evaluate the optimal myocardial temperature during a 4-hour ischemia induced by blood potassium cardioplegia (PC). Heart-lung preparations with work load circuit were used as experimental model. 24 mongrel dogs were divided into four groups and two myocardial temperatures (moderate hypothermia, deep hypothermia) and two perfusates (PC with blood, PC without blood) were tested. Parameters used to evaluate the myocardial protection include the coronary sinus blood pH of the initial reperfusion and left ventricular stroke work after resuscitation. In blood PC at moderate hypothermia, deleterious acid metabolites were minimally produced as evidenced by the coronary sinus blood pH (7.221 +/- 0.122) at initial reperfusion, and cardiac function was best recovered in this group. Blood PC at moderate hypothermia allows the heart to tolerate 4 h ischemia without an excessively elevated coronary perfusion pressure during cardioplegic infusion.

At present, only the autogenous saphenous vein is acceptable in aorta-coronary bypass grafting. We developed a small-caliber vascular graft and evaluated the potential application for aorta-coronary bypass grafting. Canine carotid arteries were cross-linked with polyepoxy compounds, such as polyglycerol polyglycidyl ether, which is a new cross-linking reagent, and then heparinized by our own method. The polyepoxy compound-cross-linked graft can keep the natural vessel compliance and is stronger than the glutaraldehyde-cross-linked graft; thus, it provides excellent suturability and compliance match. Heparin was gradually released from the graft wall, and thrombus formation was completely prevented during the period before development of the endothelial lining. As a pilot study, the grafts, 2 to 3 mm in internal diameter and 5 to 7 cm in length, were evaluated as bilateral carotid replacements in five dogs. All grafts were patent at intervals of 14 to 177 days. Histologic examinations showed excellent antithrombogenic and healing characteristics, although the endothelialization was delayed by heparin, which inhibits cell adhesion and fibrin deposition. The 3 mm internal diameter graft was evaluated as an aorta-coronary bypass grafting model in eight dogs. Flow within grafts to the right coronary artery ranged from 25 to 35 ml/min, and flow in the circumflex or left anterior descending grafts ranged from 75 to 100 ml/min. Cineangiography was performed to confirm graft patency. Three dogs died of viral infection and one was killed. At necropsy, the grafts remained patent without thrombi along the graft length. Four dogs were allowed to survive for long-term evaluation. All grafts were patent at time intervals to 21 to 113 days with 100% patency. These results led us to conclude that our newly developed small-caliber vascular graft shows great promise in application for aorta-coronary bypass grafting.