Association of plasma free-3-methoxy-4-hydroxyphenyl (ethylene)glycol, natural killer cell activity and delirium in postoperative patients

We measured and compared levels of plasma free 3-methoxy-4-hydroxyphenyl (ethylene)glycol (pMHPG), a major metabolite of noradrenaline, and natural killer (NK) cell activity in 26 patients prior to their undergoing an operation for cardiovascular diseases; 11 of whom expressed delirium and 15 who did not. In conclusion, we found that pMHPG levels before an operation were higher in patients with postoperative delirium than in the patients without, while NK cell activity showed no difference between the two groups. It is possible that hyperactivity of noradrenargic neurons is connected with the development of postoperative delirium. Furthermore, we considered that measurement of pMHPG level before operation might be a useful tool to predict the occurrence of postoperative delirium.

Inferior vena cava injury after catheterization: report of a case

We present a patient with retroperitoneal hematoma suspicious of inferior vena cava injury after catheterization for hemodialysis. Emergency computed tomography revealed extensive retroperitoneal hematoma and inferior vena cava angiography revealed extravasation. Emergent laparotomy was performed and repaired the perforation of inferior vena cava. His postoperative courses were uneventful and he remains well after the operation.

Feasibility of cryopreserved tracheal xenotransplants with the use of short-course immunosuppression

OBJECTIVE

We evaluated the feasibility of discordant xenotransplantation of the cryopreserved trachea with intermittent immunosuppression to help solve the shortage of donor tracheas.

METHODS

Two experiments were performed with heterotopic transplantation models in 14 guinea pigs and 85 rats. So that the minimal dose of FK506 for viable fresh xenografts could be determined, FK506 was given in escalating doses (0, 1.5, 2.5, and 3.5 mg/kg) for recipient animals after xenogeneic transplantation. With the goal of obtaining a long-term survival of the xenografts, the effect of cryopreservation on xenografts was assessed and thereafter different cycles of immunosuppression every third week were evaluated in fresh or cryopreserved xenografts in the second experiment.

RESULTS

An FK506 dosage of more than 2.5 mg/kg per day was much more effective than smaller dosages, as demonstrated by morphologic assessment. A higher dosage of FK506 potentially delayed the rejection of xenografts and can thus maintain tracheal xenograft viability for less than 4 weeks in rat recipients. In experiment 2, the cryopreserved xenografts showed less histologic viability than fresh xenografts but greater patency of the lumen. The patency of cryopreserved xenografts was favorably maintained for a longer period than that of fresh xenografts with either the same number or more cycles of immunosuppression.

CONCLUSIONS

We conclude that the synergistic effect of cryopreservation and adequate intermittent immunosuppression may enable tracheal xenografts to remain viable over longer periods.

Limit of warm ischemia time before cryopreservation in rat tracheal isografts

BACKGROUND

The viability of cadaveric tracheal grafts undergoing cryopreservation is still unclear. We evaluated the limit of warm ischemia time before cryopreservation in rat tracheal isografts.

METHODS

Each isograft was harvested from donor rats 0 to 48 hours (0, 6, 12, 18, 24, and 48 hours) after circulatory arrest, immersed in the preservative solution, and stored in a deep freezer until reaching -80 degrees C and then was kept in liquid nitrogen for 3 months. Heterotopic transplantation into the omentum was performed after the isografts were thawed. Graft morphology 3 months after transplantation was assessed.

RESULTS

The stepwise increase of warm ischemia time significantly reduced graft survival. A prolonged period of warm ischemia had a degenerative effect on both the epithelium and cartilage. The morphology of the epithelium and cartilage in isografts undergoing warm ischemia for less than 18 hours was better preserved, whereas it deteriorated in isografts undergoing warm ischemia for more than 24 hours.

CONCLUSIONS

We thus conclude that the permissible period of warm ischemia before 3-month cryopreservation to maintain tracheal isograft viability is 18 hours in rats.

Mid-term follow up results of Japanese heart transplant patients operated in UCLA Medical Center

Japanese candidates have been accepted for heart transplantation by the UCLA Medical Center in the US since 1993 due to the lack of donors available from brain-dead patients.

OBJECTIVES AND METHODS

We monitored to patients who underwent such heart transplantation and have been seen at the out-patient clinic at Tokyo Women's Medical University following transplantation. Pre-operative diagnosis was dilated cardiomyopathy in all patients. One patient underwent Novacor implantation as a bridge to heart transplant. All patients underwent cardiac echocardiography and cardiac catheterization including intraluminal echography.

RESULTS

All patients survived with an actuarial survival curve of 100% at 1 year, 100% at 3 years and 87% at 5 years in 4.15 years of average follow-up. Two patients died due to liver dysfunction and cerebral emboli. The postoperative functional status of patients was New York Heart Association classification I in 8 (100%). Immunosuppressive therapies included triple drug therapy using either cyclosporin or tacrolimus. The incidence of acute rejection (/pt) exceeding grade 3 was 4% within three months, 3.5% in 3-6 months, and no significant rejection episode more than 6 months after transplantation. Posttransplantation coronary artery disease was seen in 2 patients, but no progression was seen after diltiazem therapy.

CONCLUSION

Our postoperative follow-up after cardiac transplantation appears to be satisfactory.

St. Jude Medical prosthetic aortic valve malfunction due to pannus formation

According to the literature, the incidence of pannus formation with the St. Jude Medical prosthetic aortic valve has been reported at 0.03% and 0.14% (per patient-year), with no case report of St. Jude Medical prosthetic aortic valve malfunction due to pannus formation. Between 1980 and 1999, 1,186 patients underwent aortic valve replacement at our institute. We encountered 2 aortic valve malfunctions due to pannus formation, including the case of a 53-year-old woman who suffered a St. Jude medical aortic valve malfunction 13 years after the initial operation. A second aortic valve replacement was successful and the postoperative course was uneventful. The possibility of pannus formation on St. Jude Medical aortic valves must thus be considered and its mechanism clarified.

Regional cardiac sympathetic reinnervation in transplanted human hearts detected by 123I-MIBG SPECT imaging

The purpose of this study was to assess the regional cardiac sympathetic reinnervation late (> or = 1 year) after heart transplantation (HTX) by means of 123I-MIBG (MIBG) scintigraphy. Eight patients with a pretransplantation diagnosis of idiopathic dilated cardiomyopathy underwent MIBG scintigraphy more than one year after HTX. The presence or absence of regional MIBG uptake was evaluated in each SPECT image, and global MIBG uptake was semi-quantitatively assessed by the heart to mediastinum ratio (H/M). Five of 8 patients had visible MIBG uptake in both planar and SPECT images (PU group), whereas 3 of 8 patients had no uptake, 2 of them after a period of 2 years, and one of them as long as 5 years after HTX, respectively (NU group). Positive regional MIBG uptake involved the basal anterior region in all 5 patients, the basal septal region in 4 patients, the basal lateral region in 3 patients and the basal posterior region in 1 patient. The H/M value was 1.24+/-0.10 in the PU group and 1.09+/-0.03 in the NU group. In conclusion, MIBG SPECT can detect regional sympathetic reinnervation, indicating that basal septal and lateral regions next to the basal anterior are more likely to be reinnervated, but reinnervation is much less likely to occur in the midventricular and apical regions.

Effect of ATP-potassium channel opener nicorandil on long-term cardiac preservation

BACKGROUND

ATP-sensitive potassium channels have been shown to be one of the important protective mechanisms for the ischemic myocardium. The purpose of this study was to evaluate the protective effect of nicorandil, an ATP-sensitive potassium channel opener, on myocardium during 6 hours hypothermic preservation.

METHODS

Preserved rat hearts were randomly divided into 4 groups according to cardioplegia and preservation protocols as follows: (1) histidine-tryptophan-ketoglutarate solution (HTK) for both cardioplegic and immersing solutions (group A); (2) nicorandil-added HTK for cardioplegic solution and nicorandil-free HTK for immersing solution (group B); (3) nicorandil-free HTK for cardioplegic solution and nicorandil-added HTK for immersing solution (group C); and (4) nicorandil-added HTK for both cardioplegic and immersing solutions (group D).

RESULTS

The recovery of postischemic cardiac function, including left ventricular developed pressure and end-diastolic pressure, was significantly improved in group B and group C as compared with the other groups (p<0.05). Postischemic intracellular calcium concentration was significantly lower in group B and group C than in group A (p<0.05).

CONCLUSIONS

We concluded that nicorandil-induced hyperpolarizing arrest could reduce ischemia-derived myocyte injury and inhibit the influx of calcium into the myocytes in long-term cardiac preservation.

[Late results of SJM and CM valves in bentall procedure]

Recently, Bentall procedure is commonly performed for annuloaortic ectasia with aortic regurgitation or dissecting aneurysm. And the operative results are improving. In this study, we evaluated results of the St. Jude Medical (SJM) and Carbomedics (CM) valves which were used in this procedure. From 1979 to 1994, 87 SJM valves and 22 CM valves were implanted in the aortic position of Bentall procedure. Total follow-up was 528.6 years in the SJM group and 56.5 years in the CM group. According to the Kaplan-Meier actuarial method and the Cox-Mantel statistical analysis, actuarial survival, thromboembolism free rate, reoperation free rate, event free rate were not different between the SJM and CM groups. These results suggest that, current selection of the SJM and CM valves would be acceptable in Bentall procedure.

[A case report of total aortic reconstruction and choice of staged operation in Marfan syndrome]

A 37-year-old man with Marfan syndrome underwent four operations for extensive cardiovascular disease. He was diagnosed as having AAE, AR and DeBakey type I aortic dissection. First, Bentall operation using Piehler procedure and total aortic arch replacement using retrograde cerebral perfusion and profound hypothermia at 18 degrees C were performed on May 11, 1994. Second, repair of leakage of the right coronary artery anastomosis and grafting for the descending thoracic aortic aneurysm were performed on December 3, 1994. Y-type grafting for the AAA was performed on December 21, 1996. Last, grafting for TAAA was performed under hypothermia at a rectal temperature of 20 degrees C on November 17, 1997. This surgical strategy of staged operation for extensive cardiovascular disease in Marfan syndrome is an effective method. Regular follow-up by CT is necessary for deciding the time and method of reoperation.

[Efficacy of terminal warm blood cardioplegia in combination with Bretschneider-HTK solution for myocardial protection]

Many reports indicated that terminal warm blood cardioplegia (TWBC) was useful for reduction of the reperfusion injury in cardiac operations. We introduced Bretschneider-HTK solution (B-HTK) from April 1992, and combined use of the TWBC and the B-HTK was performed from May 1996. The purpose of this study was to evaluate clinical efficacy of the TWBC in combination with B-HTK for myocardial protection. In patient with valve operations from May 1995 to May 1997, clinical results were compared between the B-HTK with TWBC group (34 patients) and the B-HTK alone group (37 patients). Between two groups, there was no significant difference in patient characteristics, preoperative NYHA class, cardiopulmonary bypass time, aortic cross clamp time, minimum rectal temperature, rewarming and circulatory support time, incidence of IABP and blood concentration of max CPK, max GOT. Furthermore, the cardiac index in 1 postoperative day showed some trend to be higher in the combined TWBC group than that in the B-HTK alone group. But there was no significant difference between two groups in the LV shortening fraction at 14 postoperative day. Incidence of DC defibrillation was significantly lower in the combined TWBC group than that in the B-HTK alone group. These results suggested that combination of the TWBC might be useful for reduction of the reperfusion injury following myocardial protection with B-HTK solution.

Current strategy of temporary circulatory support for severe cardiac failure after operation

BACKGROUND

After open heart operations about 1% of patients still need temporary circulatory support for severe cardiac failure, and over half of those patients die during or after the support. This study assessed the efficacy of the current strategy of circulatory support.

METHODS

We assessed clinical outcome of 64 consecutive patients (1.5% of pump cases) who had temporary circulatory support associated with perioperative variables. The results were analyzed by logistic regression analysis.

RESULTS

The weaning and discharge rates were 50.0% and 26.7% with venoarterial bypass, 76.2% and 57.1% with biventricular bypass, 87.5% and 37.5% with isolated left ventricular bypass, and 60.0% and 40.0% with pulsatile left ventricular assistance, respectively. Logistic regression analysis identified presupport cardiogenic shock (odds ratio, 9.922) and support type (14.684) as factors significantly associated with nonweaning from the temporary support, and cardiogenic shock (28.268), support duration (2.948), and support type (14.184) as factors significantly associated with mortality during or after the circulatory support.

CONCLUSIONS

The current strategy of temporary circulatory support improved clinical outcome of patients with severe cardiac failure. Early application of circulatory support before profound cardiogenic shock and proper selection of the support type might be key factors for successful circulatory support postoperatively after operation.

Protective effect of JTV519, a new 1,4-benzothiazepine derivative, on prolonged myocardial preservation

BACKGROUND

JTV519 is know to protect cardiomyocytes from calcium overloading-induced damage. The aim of this study was to investigate the potential protective effect of JTV519 on myocardium subjected to prolonged ischemia and the underlying mechanism of such protection. The effect of JTV519 was also compared with that of diltiazem, a 1,5-benzothiazepine derivative.

METHODS

Isolated rat hearts were randomly divided into three groups. Control hearts were arrested with histidine-tryptophan-ketoglutarat (HTK) cardioplegic solution alone. In the JTV519 group of hearts, cardiac arrest was achieved with JTV519 (10(-3) mmol/L) in the HTK solution. Hearts in the diltiazem group were arrested with diltiazem (0.5 mmol/L) in the HTK solution. All the hearts were then subjected to 6-hour storage in HTK solution at 4 degrees C.

RESULTS

After a 30-minute reperfusion, the left ventricular developed pressure in the JTV519 and diltiazem groups were improved significantly compared with the control group. There was a significantly lower left ventricular end-diastolic pressure level and higher recovery of coronary flow in the JTV519 group than in the control group. The postischemic intracellular calcium concentration was attenuated by adding JTV519 or diltiazem to HTK cardioplegia.

CONCLUSION

As an adjunct to cardioplegia, JTV519 showed a significant protective effect on myocardium undergoing 6 hours of ischemia. The beneficial protective effects of JTV519 are correlated with its ability to inhibit the postischemic rise in intracellular calcium.

Effects of immunosuppressants on platelet-derived growth factor-A chain mRNA expression and coronary arteriosclerosis in rat cardiac allografts

Graft coronary arteriosclerosis (GCA) that results in proliferative and obstructive lesions limits the long-term success of cardiac transplantation. Despite extensive study, the pathogenic mechanisms underlying GCA are still unclear and therapeutic strategies for this condition have been inadequate. In this study, we compared the therapeutic effectiveness of cyclosporine A (CsA), 15-deoxyspergualin (DSG), and Multiglycosidorum tripterygii (MT) on GCA. In addition, we studied the correlation between the extent of GCA and the degree of platelet-derived growth facter (PDGF)-A chain mRNA expression in cardiac grafts. Lewis rats receiving heterotropic heart transplants from Wistar King donors were treated with 10 mg kg(-1) day(-1) of CsA (n=7), 5 mg kg(-1) day(-1) of DSG (n=7) or 30 mg kg(-1) day(-1) of MT (n=7) respectively. Histological evaluation of coronary arteriosclerosis and Northern blot analysis of cardiac allograft PDGF-A chain mRNA expression were conducted on day 60 after transplantation. Varying levels of GCA were observed in the 21 transplanted hearts. Significant differences in both the degree of PDGF-A mRNA expression and the extent of GCA were found among the 3 groups. GCA was significantly reduced in allografts treated with MT or DSG in comparison with the level seen in CsA-treated grafts. A significant correlation was found between PDGF-A chain mRNA expression and the grade of arterial intimal thickening (r=0.76, p<0.05) as well as with the incidence of diseased vessels (r=0.82, p<0.01). Our results indicate that both MT and DSG are more effective in the treatment of GCA than CsA. In our cardiac allografts, the degree of PDGF-A chain mRNA expression correlated well with the extent of GCA, suggesting that PDGF-A may play an important role in the development of transplant-related GCA.

Multiglycosidorum tripterygii, a new immunosuppressant, supresses coronary arteriosclerosis after heart transplantation

BACKGROUND

Graft coronary arteriosclerosis is the major limiting factor for long-term survival after heart transplantation. In this study, we investigate the effect of multiglycosidorum tripterygii on graft coronary arteriosclerosis and platelet-derived growth factor A mRNA expression of transplanted hearts.

METHODS

Three groups of Lewis rats (n = 7/Group) underwent heterotopic heart transplantation from Wistar-King donors and were treated with cyclosporine A (10 mg/ kg/day) for 60 days (Group A) or with multiglycosidorum tripterygii (30 mg/kg/day) for 60 days (Group B) or with cyclosporine A for the first 30 days and followed by multiglycosidorum tripterygii for another 30 days (Group C). Histological evaluations of rejection and coronary arteriosclerosis, as well as Northern blot analysis on graft platelet-derived growth factor A mRNA expression were made 60 days after transplantation.

RESULTS

Morphometric results indicated no significant difference in rejection among three groups. However, the extent of graft coronary arteriosclerosis in Group B (1.12 +/- 0.21) and Group C (1.41 +/- 0.19) was significantly less than that seen in Group A (1.72 +/- 0.18) (p < 0.01 andp < 0.05, respectively). Furthermore, the incidence of diseased vessels was significantly less in Group B (29.5% +/- 7.8%) and Group C (42% +/- 9.1%) compared with Group A (69.1% +/- 11%) (p < 0.01 and p < 0.05, respectively). The expression of platelet-derived growth factor A mRNA of cardiac allograft was also significantly suppressed in Group B (25.4 +/- 6.2) and Group C (39.8 +/- 9.4), when compared with Group A (62.2 +/- 12.9) (p < 0.01 and p < 0.05, respectively).

CONCLUSION

Multiglycosidorum tripterygii is superior to cyclosporine in prevention and attenuation of graft coronary arteriosclerosis and this efficacy is probably associated with the depressed expression of graft platelet-derived growth factor A mRNA in the multiglycosidorum tripterygii-treated groups.

Clinical experience of left ventricular assist systems at the Heart Institute of Japan

The main indications for left ventricular assist system (LVAS) support are postcardiotomy ventricular failure as temporary circulatory support and end-stage cardiomyopathy as chronic circulatory support. To clarify the efficacy of LVAS support, we assessed the clinical outcome of a pneumatic LVAS and an electromagnetic LVAS for patients with severe ventricular failure. As of March 1998, 5 patients with postcardiotomy ventricular failure had received the pneumatic LVAS support, and 2 other patients with end-stage idiopathic cardiomyopathy had undergone implantation of the electromagnetic LVAS. The drive control of the LVAS was mainly counterpulsation in the diastole of the native heart. In the 5 postcardiotomy patients, the duration of pneumatic LVAS support ranged from 30 to 312 h (mean, 109.2). All 3 patients with more than 72 h support were successfully weaned, and 2 of them survived. The other 2 patients with cardiogenic shock and less than 36 h support could not be weaned from the LVAS. In the 2 cardiomyopathy patients, 1 patient was well maintained by the electromagnetic LVAS support and underwent successful heart transplantation 7 months later. The other patient has been chronically supported by the LVAS for 2 months and is doing well so far. These results suggest that selective application of the pneumatic LVAS as a temporary support and the electromagnetic LVAS as a chronic support might be appropriate for maximizing the effectiveness of LVAS treatment for profound cardiac failure.

[Postoperative therapy using human atrial natriuretic peptide in cases of valve replacement]

The effect of hANP (atrial natriuretic peptide) was investigated clinically in 40 patients who underwent isolated valve replacement. Patients were divided into four groups: aortic regurgitation (AR), aortic stenosis (AS), mitral regurgitation (MR) and mitral stenosis (MS). Each group was divided into two subgroups: one was administered hANP after the operation until leaving ICU, and the other was not administered hANP. We measured the levels of hANP and c-GMP and blood pressure, pulmonary artery pressure, central venous pressure and levels of Na, K of urine and blood prcoperatively, immediately postoperatively and 1, 2, 4, 6 hours after operation. First, to examine the relationship between preoperative level of hANP and cardiac function, the relationship between preoperative level of hANP and history of cardiac failure and pulmonary artery wedge pressure (PAWP) were evaluated. Also, we evaluated the relationship between preoperative level of hANP and each dimension on echocardiography. There was a weak statistical relationship between hANP and PAWP (row = 0.39 (p = 0.04) Pearson correlation method) and there was no statistical relationship between hANP and duration of cardiac failure (row = 0.00445 (p = 0.98) Pearson correlation method). Preoperatively Left atrial diameter (LAD) showed a statistical relationship with level of hANP in every group using Spearman correlation method. Other dimensions such as left ventricular diastolic diameter (LVDd) and left ventricular systolic diameter (LVDs) and also fractional shortening (FS) did not show a strong correlation with preoperative level of hANP. Especially, in AS group there was a strong relationship between every dimension and preoperative level of hANP. Only in MS group LAD and the level of hANP were negatively related. This finding suggests that atrial dilatation results in reduction of secretion of hANP in cases of MS on long term follow up. Finally, hNAP therapy was shown to have a continuous diuretic effect, with stable hemodynamics.

Inhibitory effect of Multiglycosidorum tripterygii on coronary arteriosclerosis after heart transplantation

BACKGROUND

Graft coronary arteriosclerosis (GCA) is the major limiting factor for long-term survival after heart transplantation. In this study, we investigated the effect of Multiglycosidorum tripterygii (MT) on GCA and platelet-derived growth factor A (PDGF-A) mRNA expression of transplanted hearts.

METHODS

Two groups of Lewis rats (n=7/group) underwent heterotopic heart transplantation from Wistar-King donors and were treated with either cyclosporine (CsA;10 mg/kg/day) or MT (30 mg/kg/ day). Histological evaluations of rejection and coronary arteriosclerosis, as well as Northern blot analysis on graft PDGF-A mRNA expression were made 60 days after transplantation.

RESULTS

Morphometric results indicated no significant difference in rejection between the CsA- and MT-treated groups. However, the extent of GCA in the MT-treated group was significantly less than that seen in the CsA-treated group (P<0.01). The expression of PDGF-A mRNA of cardiac allograft was also significantly suppressed in the MT-treated group when compared with the CsA-treated group (P<0.01).

CONCLUSION

MT is superior to CsA in preventing graft coronary arteriosclerosis, and this efficacy is probably associated with the depressed expression of graft PDGF-A mRNA in the MT-treated group.

Effectiveness of ischemic preconditioning on long-term myocardial preservation

BACKGROUND

This study was designed to assess whether the protective effect of ischemic preconditioning can be adapted for myocardium undergoing 6 hr of ischemia.

METHODS

Eighteen isolated rat hearts were perfused with oxygen-bicarbonated Krebs-Henseleit buffer in the Langendorff mode for 35 min (group A, controls) or perfused in the Langendorff apparatus for 20 min, followed by 5 min of global normothermic ischemia and 10 min of buffer perfusion (group B, preconditioning) or followed by two cycles of 2.5 min of global normothermic ischemia plus 5 min of buffer perfusion (group C, preconditioning). The hearts were then arrested and preserved for 6 hr with Bretschneider's histidine-tryptophan-potassium cardioplegic solution at 4 degrees C, followed by 30 min of reperfusion. Recovery of cardiac function, postischemic enzyme leakage, and intracellular calcium concentration were compared.

RESULTS

After 6 hr of ischemia, the hearts that underwent preconditioning in groups B and C showed better recovery of left ventricular developed pressure (P<0.05), a lower end-diastolic pressure level (P<0.05), less leakage of creatine kinase, and a lower intracellular calcium concentration than those in group A. There were no statistical differences in the rate of recovery of coronary flow.

CONCLUSIONS

Our study demonstrated that ischemic preconditioning improves myocardial functional recovery after 6 hr of hypothermic preservation in the isolated rat heart. Preconditioning might be useful for preserving the heart against long-term ischemia/reperfusion injury.

Should the aortic valve homograft be recryopreserved?

BACKGROUND

The number of homograft donors is limited and the once-thawed homograft may be unsuitable for the recipient and obliged to be wasted. The purpose of this study was to investigate the possibility of recryopreserving and using the once-thawed homograft for another patient.

METHODS

Canine aortic valve leaflets were frozen to -80 degrees C by a programmed freezer, stored in liquid nitrogen, and thawed after 1 week. A subgroup of leaflets was left at 4 degrees C for 15 minutes, re-cryopreserved, and thawed after 1 week. Pathologic and flow cytometric evaluations were performed.

RESULTS

After thawing, by pathology, alignment of the fibers was acceptably maintained but the membrane and cytoplasm of the fibroblast were damaged. These findings were not significantly aggravated even after rethawing. By flow cytometry, fibroblast viability was 90.7%+/-1.7% immediately after thawing, 87.6%+/-1.0% after thawing for 15 minutes at 4 degrees C, 63.7%+/-2.7% during refreezing at 0 degrees C, and 39.4%+/-4.3% after rethawing.

CONCLUSIONS

From the standpoint of fibroblast viability, it is not possible to recryopreserve the once-cryopreserved and thawed aortic valve homograft.

Experience of patients with end-stage heart failure who underwent heart transplant at UCLA

From 1993 to 1997, nine Japanese heart transplant candidates were accepted by the University of California at Los Angeles (UCLA) Medical Center, because no donor heart was available in Japan from a brain-dead patient. In all nine heart transplant patients described in this investigation, the preoperative diagnosis was dilated cardiomyopathy. One patient underwent implantation with a Novacor left ventricular assist device (Baxter Japan, Tokyo, Japan) as a bridge to heart transplant. All patients survived surgery and for a long-term period. The actuarial 1-year and 3-year survival curves of these patients were both 100%. The postoperative functional status was New York Heart Association Class 1 in all patients (100%). Immunosuppressive triple drug therapy (azathioprine, steroids, and cyclosporine) was given in seven patients; in two patients, cyclosporine was withdrawn and replaced by FK506 due to refractory rejection. The incidence of acute rejection per patient of more than grade 3 according to the International Society for Heart and Lung Transplantation was 6% within 3 months and 4.5% in 3-6 months; there was no rejection episode more than 6 months after transplantation. Post-transplant coronary artery disease was seen in two patients. However, no disease progression was seen after diltiazem therapy. These results may encourage heart transplantation in Japan.

Mechanical circulatory support for severe heart failure after operation

To evaluate the clinical results of circulatory support for severe heart failure after operation, we examined 62 patients (39 males and 23 females) who underwent circulatory support for postoperative heart failure from 1984 to 1996. Their ages ranged from 22 to 78 (mean 52) years. In 62 patients, 35 had valvular, 25 had ischemic, and 2 had congenital heart disease. Postoperation, 29 patients underwent venoarterial bypass (VAB), 20 had biventricular bypass (BVB), and 8 had left ventricular bypass (LVB). The remaining 5 patients received a pulsatile left ventricular assist device (LVAD). The weaning and discharge rates of the patients by type of support were 51.7% and 31.0% with VAB, 75.0% and 55.0% with BVB, 87.5% and 37.5% with LVB, and 60.0% and 40.0% with LVAD, respectively. The complete results of this series (64.5% weaning rate and 40.3% discharge rate) were acceptable.

Association between the degree of platelet-derived growth factor-A chain mRNA expression and coronary arteriosclerosis in the transplanted heart

Although intimal and medial proliferation of smooth muscle cells is recognized as one of the key mechanisms in the development of graft coronary arteriosclerosis, the role of platelet-derived growth factor (PDGF) in this process is still uncertain, because of the undetermined pathogenesis of graft coronary arteriosclerosis (GCA). In the present study, the correlation between the extent of GCA and the degree of PDGF-A chain expression in cardiac grafts was investigated in 21 rats with GCA of varying extent. Lewis rats underwent heterotopic heart transplantation from Wistar King donors and were treated with cyclosporine A (10 mg/kg/day) (n = 7), 15-deoxyspergualin (5 mg/kg/day) (n = 7), or Multiglycosidorum tripterygii (MT) (30 mg/kg/day) (n = 7). Histological evaluations of coronary arteriosclerosis, as well as Northern blot analysis of graft PDGF-A chain expression were made, 60 days after transplantation. Graft coronary arteriosclerosis of varying extent was observed among the 21 transplanted hearts. Significant correlations were found between the PDGF-A chain mRNA expression of cardiac allograft and the grade of arterial intimal thickening (Spearman's r = 0.76, P < 0.005) as well as the incidence of diseased vessels (r = 0.82, P < 0.001). The PDGF-A chain mRNA expression of the cardiac allograft is associated with the extent of GCA, indicating that PDGF-A plays an important role in the development of GCA.

Cardioprotective efficacy of ischemic preconditioning on long-term myocardial ischemia

This study was designed to assess whether the protective effect of ischemic preconditioning can be adapted for myocardium undergoing 6 h of no-flow ischemia. Twelve isolated rat hearts were either perfused with oxygen-bicarbonated Krebs-Henseleit buffer in the Langendorff mode for 35 min (n=6), or perfused in the same way for 20 min, following 5 min of global normothermic ischemia and 100 min of buffer-perfusion (n=6). The 12 hearts were then preserved for 6 h in HTK solution at 4 degrees C, followed by 30 min of reperfusion. Recovery of cardiac function, metabolic activity and intracellular free calcium concentration were compared between the two groups. After 6 h ischemia, the hearts that underwent preconditioning showed better recovery of left ventricular developed pressure (P<0.01), a lower end-diastolic pressure level (P<0.05), less creatine kinase leakage and a lower calcium concentration. There was no statistical difference in the recovery rate of coronary flow and leakage rate of LDH between the two groups. In conclusion, this experiment demonstrates that ischemic preconditioning improved myocardial functional recovery after 6 h of hypothermic ischemic preservation in the isolated rat heart. Preconditioning might be a potential mechanism for preserving the heart against long-term ischemia/reperfusion injury.

[Implantation of the Novacor left ventricular assist device in a patient with dilated cardiomyopathy]

The Novacor left ventricular assist device has been widely applied as a bridge to heart transplantation. The patient, a 29-year-old, male had severe left ventricular failure due to dilated cardiomyopathy. The heart failure had progressively worsened and showed severely reduced wall motion of the left ventricle with fraction shortening of 0.03. His cardiac catheterization data with 7 r of dopamine infusion was as follows; RA(12), RV46/9EDP(12), PA(w)(31), cardiac Index 1.73 l/min/cm2. Novacor implantation was performed on March 11th, 1996. After the implantation the patient was extubated on day 3 and recovered rapidly. No complications, such as bleeding or thromboembolic episodes were seen. The patient was flown to the USA for cardiac transplantation on 24th, September, 1996. During the 11-hour flight from Narita to Los Angeles, he experienced no adverse effects. The patient underwent a successful cardiac transplant at UCLA Medical Center. His post-operative course was uneventful. We believe that either chronic circulatory support or the bridge to transplant using Novacor LVAS will be a significant breakthrough for the treatment of Japanese patients with severely deteriorated cardiomyopathy.

Clinical assessment of prolonged myocardial preservation for patients with a severely dilated heart

BACKGROUND

The purpose of this study was to compare the myocardial protective effect of histidine-tryptophan-potassium and glucose-insulin-potassium cardioplegic solutions in patients with a dilated heart (left ventricular diastolic diameter > 55 mm, left ventricular systolic diameter > 45 mm) associated with prolonged cross-clamp time (longer than 200 minutes).

METHODS

We selected 20 patients with dilated hearts due to severe aortic regurgitation. Glucose-insulin-potassium cardioplegia was used in 11 patients and histidine-tryptophan-potassium cardioplegia was used in 9 patients.

RESULTS

After operation, the cardiac index was significantly increased in the histidine-tryptophan-potassium group (p < 0.05). Postoperative percent fractional shortening was 13.4% +/- 3.1% in the glucose-insulin-potassium group and 23.6% +/- 2.6% in the histidine-tryptophan-potassium group (p < 0.05). Creatine kinase levels were significantly lower in the histidine-tryptophan-potassium group than that in the glucose-insulin-potassium group (p < 0.05). The incidence of ventricular arrhythmia (higher than Lown's grade 2) was lower in the histidine-tryptophan-potassium group.

CONCLUSIONS

These data support the superiority of the histidine-tryptophan-potassium method over the glucose-insulin-potassium method for protection of the dilated heart during prolonged ischemia in open heart operations.

[Aortic valve replacement with the Toronto stentless porcine valve in a patient with clipping for cerebral arterial aneurysm]

A 48-year-old man, who had a cerebral arterial aneurysm, was admitted in our institution for operation of aortic valve stenosis. At first, he underwent clipping for cerebral arterial aneurysm under precise management of his hemodynamic condition. After the clipping operation, we performed aortic valve replacement with the Toronto stentless porcine valve because no anticoagulant therapy was ideal for patient with cerebrovascular disease and larger effective orifice area was preferable for stenotic aortic annulus. By means of echocardiography, mean pressure gradient of the aoric valve decreased from 42 mmHg to 22 mmHg after the valve operation. He was discharged from the hospital on the 23rd postoperative day, and he has been doing well without thromboembolic events and bleeding complications for five postoperative months. This experience suggest that the Toronto stentless porcine valve might be one of the valve of choice for patients with aortic valve disease and cerebrovascular disease.

[Simultaneous tricuspid valve operation in patients undergoing aortic and mitral double valve replacement]

In triple valvular surgery, AVR+MVR+TVR or TVP, there are some problems around operation, because patients impaired cardiac function after a long history of the disease and some of them are reoperation cases. The sixty-five patients operated from May in 1980 to June in 1993 were examined. They were divided into two groups, group P and group R, depending upon procedure of tricuspid position. Group P consisted of 51 patients and group R of 14 patients. There were 22 (34%) reoperations. In group P, organic changes in tricuspid valve were mild, however in group R, there were commissural fusion in 8 patients, destruction of leaflet due to infectious endocarditis in one patient, and marked tricuspid annular dilatation in five patients. There was one early death in group R, no early death in group P. Actuarial survival rate at the 10th postoperative year was good as 81.6% in group P and 85.7% in group R. There were no significant differences in operative mortality and actuarial survival between group P and R.

[Transesophageal echocardiographic findings in patients after heart transplantation]

The diagnostic value of transesophageal echocardiography was investigated in heart transplant recipients, i.e., four patients who received orthotopic heart transplantation and one patient who received total heart transplantation. Donor-recipient atrial anastomosis was identified in the four patients with orthotopic heart transplantation, but not in the patient with total heart transplantation. Transthoracic and transesophageal echocardiography detected no thrombus or spontaneous echo contrast in any of the patients. Color Doppler transesophageal echocardiography showed trivial mitral regurgitation in all patients. Total heart transplantation resulted in no protruding suture line and normal atrial cavity size. The patient with total heart transplantation showed some difference in the peak flow velocity of the right and left pulmonary veins (left superior pulmonary vein: 48 cm/sec; right superior pulmonary vein: 86 cm/sec), possibly due to stenosis at the suture line between the left atrium and right superior pulmonary vein, or compression of the right superior pulmonary vein by the anastomosis between the superior vena cava and right atrium. Transesophageal echocardiography was helpful for detecting thrombus in the left atrium and left atrial appendage after heart transplantation, and allowed evaluation of the flow pattern in the pulmonary veins and left atrial appendage as well as abnormal flow in the atrium. In conclusion, transesophageal echocardiography is useful in the follow-up of heart transplant recipients.

[A case of DVR with Nicks's procedure for active infective endocarditis with periannular abscess]

We successfully performed DVR with aortic annular reconstruction by Nick's procedure for a case of active infective endocarditis (IE) with perianular abscess. The patient was 26-year-old woman, who suffered from acute AR and MR due to active IE. At operation, a bicuspid aortic valve was noted with scattered vegetations. The periannular abscess extended from the aortic annulus to the anterior mitral leaflet on which there was a leaflet aneurysm. The complete debridement of infected lesions resulted in the defect of aortic annulus at the area of the aorto-mitral fibrous continuity. We reconstructed the aortic annulus by the equine pericardial patch and performed DVR, followed by the reconstruction of the aortic root by Nicks's procedure. After the operation the antibiotics had been administrated to the patient until CRP became completely negative. The patient was discharged from our hospital at 59 POD with no evidence of recurrence of IE. In such cases, we acknowledge the importance of as much complete debridement of infected lesions as possible and regard Nicks's procedure useful as one of the options for reconstruction of aortic root after debridement.

Hypertrophic obstructive cardiomyopathy with abnormalities of the mitral valve complex

The mechanism of obstruction of the left ventricular outflow tract (LVOT) in hypertrophic obstructive cardiomyopathy (HOCM) is mainly due to dynamic systolic anterior motion (SAM) of the mitral valve. We report a case of HOCM with mitral regurgitation (MR) associated with complicated abnormalities of the mitral apparatus which contributed to a high pressure gradient through the LVOT. A small, 53-year-old woman was admitted for chest pain and palpitation. Examinations revealed asymmetric septal hypertrophy of the left ventricle, MR, SAM of the mitral valve and a high pressure gradient (108 mmHg) through the LVOT. Operative findings revealed an abnormally hypertrophied interventricular septum, an extensively thickened and enlarged anterior mitral leaflet (AML), malposition of the origin of the anterior papillary muscle arising closer to the aortic annulus than normal, and its direct insertion into the AML without any distinguishable chordae tendineae. The hypertrophied septum and the large and protruding AML appeared to obstruct the LVOT, resulting in a loss of subaortic clearance that was recovered after mitral valve replacement and myectomy. Pathology of the papillary muscle was characteristic of HOCM, showing disorganization and disarray of myocardial fibers, bizarre-shaped nuclei, and intercellular fibrosis, while those of the mitral leaflets negated both rheumatic changes and endocarditis.

[Long-term results of cardiac valve replacement with a Delrin-disk model of the Björk-Shiley valve prosthesis--comparative analysis with the Spherical-disk model]

Records from 99 patients who received the Delrin-disk model (Group D) of the Björk-Shiley (BS) prosthesis between December, 1971 and November, 1974 were reviewed and compared to those from 248 patients who received the Spherical-disk model BS between January, 1975 and June, 1981 (Group S). Complete follow-up was obtained in 98.8% of the patients. The follow-up was over 1302.3 patient-years (mean 13.2 years per patient) in Group D and 2967.5 patient-years (mean 12.0 years per patient) in Group S. Early mortality was not significantly different (Group D: 18.2%, Group S: 10.5%). Of 15 late deaths in Group D, 12 (60%) were valve related and of 58 late deaths in Group S, 34 (58.6%) were valve related. The survival proportion based on Kaplan-Meier analysis, and which included early deaths, was equivalent in both groups (Group D: 65.7% at 21 years, Group S: 64.8% at 18 years). The freedom from reoperation was 74.3% at 21 years for Group D and 95% at 18 years for Group S (p < 0.005). The incidence of prosthetic valve dysfunction in Group D was significantly higher than that in Group S during 15 years after insertion of the valve. The freedoms from thromboembolism and valve-related events were not significant in both groups. Gross examination of the explanted Delrin disk found wear indentations and excessive clearance between the disk and the prosthetic ring. Therefore, disk wear was the primary cause of prosthetic valve dysfunction for the Delrin model. These results suggest that patients with the Delrin-disk model of the Björk-Shiley prosthesis should receive close follow-up for structural integrity of the valve. Further, reoperation might be needed due to significant valve dysfunction in this group of patients.

Aortic valve replacement in small aortic annulus with or without annular enlargement

BACKGROUND AND AIMS OF THE STUDY

Surgical treatments for aortic valve disease in the presence of a small aortic annulus need appropriate indications for operative procedures and precise selection of valve prostheses. The objective of this study was to compare long term results after aortic annular enlargement with those after operation using a small valve prosthesis.

MATERIALS AND METHODS

Since 1980, 45 patients with small aortic annulus underwent operation at our institution. There were six men and 39 women, and their ages ranged from 16 to 69 with a mean of 45.6 years. Of these patients, 28 underwent aortic annular enlargements (Nicks' procedure in 13, Manouguian's in 12 and apico-aortic bypass in three patients) and 17 patients received standard aortic valve replacement with a small valve prosthesis (19 mm Standard St. Jude Medical). Mean follow up was 8.6 years in the enlargement group and 4.9 years in the standard group.

RESULTS

Early mortality was 3.6% (1/28) in the enlargement group and 5.9% (1/17) in the standard group (NS). The 10-year actuarial survival including all deaths was 85.7% in the enlargement group and 62.7% in the standard group (p < 0.10). The rate of freedom from reoperation at 10 years was 90.7% in the enlargement group and 93.8% in the standard group (NS). The 10-year freedom from all valve-related events was 81.0% in the enlargement group and 58.8% in the standard group (p < 0.05).

CONCLUSIONS

The above results suggest that long term mortality and morbidity after aortic annular enlargement might be superior to those after standard AVR with a small valve prosthesis.

[Cardiac surgery in patients on chronic hemodialysis]

From March 1993 to February 1993, 36 patients with chronic renal failure underwent cardiac surgery with intraoperative hemodialysis (HD). We examined and compared the medium term results of those patients cased upon the time periods of operation and types of heart disease. With respect to the time periods of operation, the 1st term (n = 12) was between March 1985 and February 1989, and the 2nd term (n = 24) was between March 1989 and February 1993. Concerning types of disease, Group A was comprised of 24 patients with ischemic heart disease, and Group B was comprised of 12 patients with valvular or congenital heart disease. Only one early death was observed in the 1st term (8.3%: LOS). As for late death, 5 cases were observed in the 1st term (45.3%), and 2 cases were observed in the 2nd term (8.3%). The actuarial survival rate (post 3 years) was 72.7% in the 1st term and 91.3% in the 2nd term. In each case, the survival rate of the 2nd term was significantly better than the that of the 1st term (p < 0.025). When compared cased upon the types of disease, the actuarial survival rate (post 6 years) was 84.6% in Group A, and 45.5% in Group B, respectively. This difference was statistically significant (p < 0.05). Causes of late death were cerebral hemorrhage in 5 cases, sudden and unknown in one and DIC in the remaining one patient. There were many postoperative complications in this series in addition to the above stated fatal ones. The majority of them, however, were successfully treated, if early diagnosis of them was obtained. During the perioperative period through the long-term period, incidents of fatal hemorrhage among patients on chronic dialysis were reduced by 1) strict management of hypertension; 2) HD without use of Heparin; and 3) with respect to patients who required Warfarin after valve replacement, through the careful anti-coagulant therapy which maintained the thrombo-test (TT) value at precise levels.

Determinants of clinical results of mechanical circulatory support for ventricular failure after cardiotomy

To clarify determinants of clinical results of circulatory support for ventricular failure after cardiotomy, we examined 53 patients (33 men and 20 women) who underwent circulatory support for post operative heart failure from 1984 to October 1995. Their ages ranged from 22 to 74 years (mean, 51 years). In 53 patients, 32 had valvular, 19 had ischemic, and 2 had congenital heart disease. After operation, 21 patients underwent venoarterial bypass, 20 underwent biventricular bypass, and 8 underwent left ventricular bypass. The remaining 4 patients received a pulsatile left ventricular assist device. Weaning and discharge rates of the patients by type of support were 52.4% and 28.6% with venoarterial bypass, 75.0% and 55.0% with biventricular bypass, 87.5% and 37.5% with left ventricular bypass, and 75.0% and 50.0% with left ventricular assist device, respectively. The results of this series (67.9% weaning rate and 41.5% discharge rate) were acceptable. Peri-operative variables before and during circulatory support were analyzed multivariately by logistic regression analysis. Selected independent determinants (odds ratio) of significant difference (p < .05) were type of support (7.547) for non weaning and pre support cardiogenic shock (17.246), and type of support (8.780) and support duration (1.487) for mortality. These results suggest that early application before profound shock and appropriate selection of type of support might be key factors in successful circulatory support for ventricular failure occurring after cardiotomy.