Bioprosthetic Valve Deterioration: Accumulation of Circulating Proteins and Macrophages in the Valve Interstitium

Histologic evaluations revealed excessive accumulations of macrophages and absence of fibroblastic interstitial cells in explanted bioprosthetic valves. Comprehensive gene and protein expression analysis and histology unveiled an accumulation of fibrinogen and plasminogen, an activator of infiltrated macrophages, from degenerated valve surfaces in the interstitial spaces. These pathologies were completely reproduced in a goat model replaced with an autologous pericardium-derived aortic valve. Further preclinical animal experiments using goats demonstrated that preventing infiltration of macrophages and circulating proteins by increasing collagen density and leaflet strength is an effective treatment option.

Contemporary patterns of the management of truncus arteriosus (primary versus staged repair): outcomes from the Japanese National Cardiovascular Database

OBJECTIVES

Although primary repair in early infancy has for decades been the prevalent strategy for management of truncus arteriosus (TA), recent concerns about the levels of morbidity and mortality have led to consideration of a staged surgical approach. Our goal was to describe recent patterns of management, to characterize patients who underwent primary or staged repair and to evaluate risk factors associated with operative mortality in a contemporary multicentre cohort.

METHODS

In the Japanese Cardiovascular Surgery Database, we identified all cases of TA undergoing an initial surgical procedure from 2008 to 2018. Operative mortality was defined as death within 30 days of an operation or in-hospital death regardless of the length of hospital stay. The hospital volume was defined by the average volume of TA repairs per year.

RESULTS

The total number of patients undergoing initial surgery for TA was 286. Sixty-eight (24%, 68/286) underwent primary repair (primary repair group). The remaining 218 (76%, 218/286) underwent initial bilateral pulmonary artery banding as part of a planned staged approach (staged repair group). One hundred sixty-two patients out of 218 initially banded patients underwent the repair of TA during this study period. Concomitant diagnoses in the entire cohort included interrupted aortic arch repair in 36 patients and truncal valve regurgitation in 32. No centres handling an average of ≥2 truncus cases/year of the repair of TA were identified in this cohort. A total of 30% (85/286) of the cases were performed at centres that handled an average of ≥1 and <2 cases/year. The remaining 70% were at centres with <1 case/year. Overall, 37 patients (12.9%; 37/286) died. The operative mortality rates in the primary and staged repair groups were similar: that for the primary repair group was 16.2% (11/68) versus 11.9% for the staged repair group (26/218; P = 0.41). With multivariable logistic regression analysis, the factors most strongly associated with operative mortality were preoperative heart failure requiring catecholamine support (odds ratio, 4.18; 95% confidence interval 1.96-8.96) and the repeat bilateral pulmonary artery banding (odds ratio, 3.89; 95% confidence interval 1.08-14.07).

CONCLUSIONS

The staged repair of TA has emerged as the preferred option for surgical timing at most of the centres participating in the Japanese Cardiovascular Surgery Database. The management outcomes of the patients with TA were favourable, even for the patients at low-volume centres.

[Minimally Invasive Cardiac Surgery Following Anesthesia Induction under Percutaneous Cardiopulmonary Support for Prosthetic Valve Dysfunction and Severe Pulmonary Hypertension in a Patient with Previous Mitral Valve Replacement]

A 47-year-old woman with a history of mitral valve replacement (MVR) through a median sternotomy was admitted to our hospital due to dyspnea on exertion. Echocardiography showed bioprosthetic valve dysfunction with mitral stenosis. Right heart catheter examination revealed severe pulmonary hypertension and right ventricular dysfunction. We considered that she could not tolerate the hemodynamic changes during induction of general anesthesia without any cardiopulmonary support. Therefore, the percutaneous cardiopulmonary support was started before induction of anesthesia. To avoid the risk of injury to cardiac structures, we performed redo mitral valve replacement via right mini-horacotomy in the 4th intercostal space. Severe calcification was found in the leaflets of the prosthetic valve. She was discharged home on postoperative day 42.

A simple mouse model of pericardial adhesions

Background

Postoperative pericardial adhesions are considered a risk factor for redo cardiac surgery. Several large- and medium-size animal models of pericardial adhesions have been reported, but small animal models for investigating the development of anti-adhesion materials and molecular mechanisms of this condition are lacking. In this study, we aimed to establish a simple mouse model of pericardial adhesions to address this gap.

Methods

We administered blood, minocycline, picibanil, and talc into the murine pericardial cavity via one-shot injection. Micro-computed tomography analyses of contrast agent-injected mice were carried out for methodological evaluation. We investigated various dosages and treatment durations for molecules identified to be inducers of pericardial adhesion. The adhesive grade was quantified by scoring the strength and volume of adhesion tissues at sacrificed time points. Histological staining with hematoxylin and eosin and Masson’s trichrome, and immunostaining for F4/80 or αSMA was performed to investigate the structural features of pericardial adhesions, and pathological features of the pericardial adhesion tissue were compared with human clinical specimens.

Results

Administration of talc resulted in the most extensive pericardial adhesions. Micro-computed tomography imaging data confirmed that accurate injection into the pericardial cavity was achieved. We found the optimal condition for the formation of strong pericardial adhesions to be injection of 2.5 mg/g talc for 2 weeks. Furthermore, histological analysis showed that talc administration led to an invasion of myofibroblasts and macrophages in the pericardial cavity and epicardium, consistent with pathological findings in patients with left ventricular assistive devices.

Conclusions

We successfully established a simple mouse model of talc-induced pericardial adhesions, which mimics human pathology and could contribute to solving the clinical issues related to pericardial adhesions.

Biochemical and histological evidence of deteriorated bioprosthetic valve leaflets: the accumulation of fibrinogen and plasminogen

Calcification of bioprosthetic valves (BVs) implanted in aortic position can result in gradual deterioration and necessitate aortic valve replacement. The molecular mechanism of calcium deposition on BV leaflets has been investigated, but remains to be fully elucidated. The present study aimed to identify explanted bioprosthetic valve (eBV)-specific proteins using a proteomics approach and to unveil their biochemical and histological involvements in calcium deposition on BV leaflets. Calcification, fibrosis, and glycosylation of the valves were histologically assessed using Von Kossa, Masson's Trichrome and Alcian Blue staining, as well as immunostaining. Protein expression in the explanted biological valves was analysed using proteomics and western blotting. In a histological evaluation, αSMA-positive myofibroblasts were not observed in eBV, whereas severe fibrosis occurred around calcified areas. SDS-PAGE revealed three major bands with considerably increased intensity in BV leaflets that were identified as plasminogen and fibrinogen gamma chain (100 kDa), and fibrinogen beta chain (50 and 37 kDa) by mass analysis. Immunohistochemistry showed that fibrinogen β-chain was distributed throughout the valve tissue. On the contrary, plasminogen was strongly stained in CD68-positive macrophages, as evidenced by immunofluorescence. The results suggest that two important blood coagulation-related proteins, plasminogen and fibrinogen, might affect the progression of BV degeneration.

Summary: Fibrinogen was specifically deposited on whole deteriorated tissue valve leaflets, and plasminogen-positive macrophages strongly invaded the areas around calcified bioprosthetic and native tissues.

Refractory ventricular fibrillations after surgical repair of atrial septal defects in a patient with CACNA1C gene mutation - case report

BACKGROUND

Congenital long QT syndrome (LQTS) can cause ventricular arrhythmic events with syncope and sudden death resulting from malignant torsades de pointes (TdP) followed by ventricular fibrillations (VFs). However, the syndrome is often overlooked prior to the development of arrhythmic events in patients with congenital heart diseases demonstrating right bundle branch block on electrocardiogram (ECG). We present a case of an adult patient with congenital heart disease who developed VFs postoperatively, potentially due to his mutation in a LQTS related gene, which was not identified on preoperative assessment due to incomplete evaluation of his family history.

CASE PRESENTATION

A 64-year-old man was diagnosed as having multiple atrial septal defects. He presented with no symptoms of heart failure. His preoperative ECG showed complete right bundle branch block (CRBBB) with a corrected QT interval time of 478 ms. He underwent open-heart surgery to close the defects through median sternotomy access. Three hours after the operation, he developed multiple events of TdP and VFs in the intensive care unit. Cardiopulmonary resuscitation and multiple cardioversions were attempted for his repetitive TdP and VFs. He eventually reverted to sinus rhythm, and intravenous beta-blocker was administered to maintain the sinus rhythm. After this event, his family history was reviewed, and it was confirmed that his daughter and grandson had a medical history of arrhythmia. A genetic test confirmed that he had a missense mutation in CACNA1C, p.K1580 T, which is the cause for type 8.

CONCLUSIONS

This case highlights the importance of paying attention to other ECG findings in patients with CRBBB, which can mask prolonged QT intervals.

Aortic Coarctation 28 Days after an Arterial Switch Operation in a Neonate

Aortic coarctation rarely occurs after an arterial switch operation for D-transposition of the great arteries with intact ventricular septum. We report the case of a neonate patient in whom aortic coarctation developed 28 days after an uncomplicated arterial switch operation. Preoperatively, the aorta was noted to have an irregular shape, but there was no pressure gradient across the lesion. The patient underwent successful reoperation to correct the coarctation. We hope that our report raises awareness of a rare early complication after arterial switch operation with intact ventricular septum, and the need to carefully monitor the aortic isthmus in patients who have aortic irregularities, even in the absence of a pressure gradient.

Aortopulmonary collateral arteries: a rare complication after arterial switch operation for transposition of the great arteries

Collateral vascular arteries from the descending aorta to the pulmonary arteries are uncommon after arterial switch operation. Here, we report the case of a baby girl treated with coil embolization for abnormal blood flow from the descending aorta to the pulmonary arteries after arterial switch operation. A baby girl weighing 1324 g was delivered at 32 weeks 4 days of gestation, and she had D-transposition of the great arteries and a ventricular septal defect. She underwent nitrogen inhalation to reduce pulmonary blood flow before arterial switch operation. After the operation, she presented with left heart failure due to the presence of abnormal blood flow from the descending aorta to the pulmonary arteries, and she was successfully treated with coil embolization. After the treatment, her condition improved dramatically, and she was discharged without any complications.

Left ventricular ball-like thrombus after acute myocardial infarction with essential thrombocythemia

Left ventricular (LV) thrombus after acute myocardial infarction (AMI) is a frequent complication that is associated with a risk of systemic embolism. Essential thrombocythemia (ET) has opposing tendencies towards hemorrhage and thrombogenesis and it can cause AMI via thrombogenesis. Ball-like LV thrombus is associated with a high risk of systemic embolism. We describe surgical resection of LV ball-like thrombus from a patient with ET. A 60-year-old woman presented at our hospital with transient ischemic attack accompanied by transient hemiplegia. Ultrasonic cardiography revealed a mobile ball-like thrombus in the LV after transmural AMI of the anterior wall. We performed emergency LV thrombectomy because of the mobile LV thrombus with embolism. Platelet aberrations and pathological bone marrow findings were consistent with a diagnosis of ET. We administered the patient with anti-coagulation drugs and the DNA replication inhibitor hydroxycarbamide to decrease the platelet count. She continues to survive and is doing well without major postoperative complications. .

[Outcomes after total arch replacement using antegrade selective cerebral perfusion under right axillary artery perfusion]

Although the outcomes of total arch replacement have been improving, the prevention of cerebral infarction is still an important consideration in aortic arch surgery. Herein, we reviewed our experience with total arch replacement using antegrade selective cerebral perfusion under right axillary artery perfusion. Between January 2002 and March 2013, total arch replacement was performed for 125 patients including 31 patients with acute aortic dissection. An 8 mm polyester grafts was sutured to the axillary artery through the right subclavicular incision and was connected to cardiopulmonary bypass circuit. Antegrade selective cerebral perfusion under hypothermic circulatory arrest was initiated using right axillary artery perfusion. Postoperative cerebral infarction occurred in 5.6% of patients. Hospital mortality rate was 3.2%. The 5-year rate of freedom from aortic event was 83%. The 5-year survival rate was 75%. We consider that right axillary artery perfusion is advantageous for preventing cerebral infarction in total arch replacement.

Successful staged repair for a rare type of truncus arteriosus with interruption of the aortic arch and abnormal origin of the left coronary artery

We report a successful staged repair for a quite rare combination of truncus arteriosus (TA), Van Praagh type A4, and abnormal origin of the left coronary artery (CA). Furthermore, the case was complicated by a variant of the chromosomal anomaly in cat-cry syndrome. The presence of interruption of the aortic arch (IAA) and abnormal CA origin has been previously reported to increase mortality. To decrease the risk of bronchomalacia in infants, bilateral pulmonary artery banding (PAB) was performed as the first stage procedure for adjusting the pulmonary flow. Staged repair is a useful strategy for infants with complex TA.

Usefulness of the Guglielmi detachable coil for embolization of a systemic venous collateral after Fontan operation: A case report

Embolization of collateral veins is often treated with rigid coils (Gianturco and interlocking detachable coils type). However, when dealing with tortuous and dilated collateral veins, there is a high risk for technical failure and coil migration due to inflexibility of the coils. To safely and successfully solve this problem, Guglielmi detachable coils (GDC) can be used for embolization. Their flexibility allows for easy navigation in tortuous veins, low risk of unintended coil release or coil migration, and safe deployment. A 12-year-old girl with a single ventricle had severe cyanosis and a low exercise tolerance 5 years after Fontan procedure. The symptoms were caused by a tortuous and dilated collateral from the left phrenic vein into the left pulmonary vein, forming a right-to-left shunt. The collateral, which had a large diameter and high flow, and therefore a high risk of coil migration, was successfully embolized with 8 GDC. There were no complications such as coil migration or cerebral infarction. Transcatheter embolization increased her systemic oxygen saturation from 81%-84% to 94%-95%, and increased her ability to exercise. The embolization procedure using flexible GDC was low risk compared with other rigid coil embolization techniques when performing embolization of tortuous and dilated collateral veins.

Twenty-six-year durability of an Ionescu-Shiley standard profile pericardial aortic valve

The Ionescu-Shiley pericardial valve (Shiley, Inc, Irvine, CA, USA) is a first generation bioprosthesis made from bovine pericardium. Despite its excellent hemodynamic performance, use of this prosthesis ceased because it had an unacceptably high rate of early structural deteriorations, especially in the era of the standard profile valve. We experienced a rare case of very long durability of an Ionescu-Shiley standard profile (ISSP) bioprosthesis.

[The perioperative management of congenital heart surgery in newborn and infants]

The feature of perioperative care for congenital heart surgery in newborn and infant is that the change of environment surrounding the baby should be considered. Especially the baby with anomaly of pulmonary artery, pulmonary vein, relation of the great vessels or patent ductus arteriosus (PDA) dependent heart defects is in a stable condition in the womb. Cardiopulmonary system changes immediately after birth, and symptoms of congenital heart disease will appear. In this part, we describe the pre- and post-operative care in newborn and infant with congenital heart defects.

Fontan operation through a right lateral thoracotomy to treat Cantrell syndrome with severe ectopia cordis

A median sternotomy would be very difficult for Cantrell syndrome with severe ectopia cordis. For Cantrell syndrome and tricuspid atresia after left modified Blalock-Taussig shunt with severe ectopia cordis, defect in the middle and inferior portion of the sternum, and the closing of ventriculo-peritoneal shunt, we performed extracardiac total cavopulmonary connection through a right lateral thoracotomy after establishing right modified Blalock-Taussig shunt and performing coil embolization of left modified Blalock-Taussig shunt by cardiologists.

Successful repair of transposition of the great arteries with right aortic arch and coarctation of the aorta

A one-month-old girl with a diagnosis of situs solitus, d-transposition of the great arteries, coarctation of the aorta, and right aortic arch underwent a successful rapid two-stage repair. The combined anatomy of coarctation and right aortic arch is relatively rare, and even rarer in combination with transposition of the great arteries. We report the first successful surgical intervention to correct these anomalies.

[Staged surgical palliations for hypoplastic left heart syndrome with poor preoperative conditions]

A 2.8 kg-female newborn diagnosed as hypoplastic left heart syndrome was transferred to our hospital after resuscitation against systemic circulatory failure due to closure of the ductus arteriosus. Her systemic circulation was stabilized after alprostadil (lipo-PGE1) and inotorpic agent infusion along with mechanical ventilation support. On admission, signs of a pulmonary high-flow and low systemic perfusion were evident. Impaired coagulation aspect was gradually noted. Because a surgical palliation with cardiopulmonary bypass was considered to be at high-risk, a bilateral pulmonary artery banding was indicated. Through a median sternotomy, the right and left pulmonary arteries were individually banded. The patient was continued on the same ventilation strategy. Cardiac, hepatic and renal dysfunctions were improved over next few days and the patient weaned from ventilatory support. She underwent combined Norwood stage I and II repair at 4 months of age with weight of 4.8 kg. Postoperative course has been uneventful and the patient is now followed up in preparation for Fontan operation.

Mean xenograft survival of 14.6 days in a small group of hDAF-transgenic pig hearts transplanted orthotopically into baboons

INTRODUCTION

In a discordant orthotopic xenotransplantation model (pig-to-baboon) donor pigs expressing human decay accelerating factor (hDAF) as a regulator of complement activity were used to prevent hyperacute xenograft rejection (HXR). We investigated a modified immunosuppressive therapy consisting of ERL080 (Novartis Pharma AG, Base, Switzerland), cyclosporin A (Neoral), steroids, and a cyclophosphamide (CyP) induction protocol with several reduced doses to prevent acute vascular rejection (AVR).

METHODS

Donor hearts were harvested from hDAF-transgenic pigs (18.8 +/- 2.6 kg, Imutran Ltd., a Novartis Pharma AG Company). Four adult baboons (25.6 +/- 2.7 kg) with high titers of xenoreactive antibodies (XAb) served as recipients. Serological and hemodynamic parameters were measured. Finally, myocardial tissue was sampled for histological and immunohistochemical examinations.

RESULTS

In the first baboon, an acute graft failure occurred after 1 hour due to preservation injury. The second succumbed after 11.1 day due to an acute renal failure. The third died after 13.1 days of an ileus. The fourth baboon had continuously excellent cardiac function (mean echocardiographic ejection fraction, 69.2%), but succumbed on day 20 due to anemia. Corrected mean xenograft survival (excluding the first baboon because of a technical failure) was 14.6 +/- 2.6 days. XAb decreased after day 3 to constantly low levels (<1:64 titer) after CyP induction. White blood cell count decreased from 10.3 +/- 0.8 to 0.9 +/- 0.3 G/L after day 3. Macroscopically and histologically no typical signs of HXR or severe AVR could be detected.

CONCLUSIONS

These results confirm that hDAF transgen blocks HXR in this life-supporting model. AVR was prevented by using a modified quadruple immunosuppressive drug combination (Neoral, ERL080, steroids, and several small single doses of CyP). An optimum "fine-tuning" of immunosuppression is required to achieve the best risk-benefit ratio.

Combination of hDAF-transgenic pig hearts and immunoadsorption in heterotopic xenotransplantation of immunosuppressed baboons

INTRODUCTION

Hyperacute xenograft rejection (HXR) and acute vascular rejection (AVR) after xenotransplantation are triggered by xenoreactive antibodies (XAb) and an activated complement cascade. In a heterotopic (abdominal) xenotransplantation model we combined immunoadsorption (IA, Ig-Therasorb column) and a quadruple immunosuppressive drug therapy in recipient baboons with donor pig hearts transgenic for human decay accelerating factor (hDAF).

METHODS

According to XAb titers between 6 and 14 cycles of IA were performed preoperatively in 4 recipient baboons (18.6 +/- 2.5 kg). Hearts of hDAF-transgenic donor pigs (6.1 +/- 1.1 kg, Imutran Ltd., a Novartis Pharma AG Company, Basel, Switzerland) were heterotopically transplanted using the abdominal technique in baboons. Immunosuppression consisted of cyclophosphamide (CyP) induction therapy, ERL080 (Novartis Pharma AG), cyclosporin A (CyA, Neoral), and steroids. Blood levels of mycophenolate, CyA, immunoglobulins (Ig), anti-pig-antibodies, complement factors, and cardiac enzymes were determined. Abdominal electrocardiography (ECG), echocardiography, and palpation were used for monitoring of the pig hearts. Myocardial tissue specimens were examined using immunohistochemistry, light microscope (LM), and electron microscope (EM).

RESULTS

Ten cycles of IA alone removed 78% of XAb and accordingly IgM, IgG, IgA, complement C3, and C4. None of the xenografts was hyperacutely rejected, but xenograft failure occurred after 5.0 +/- 1.3 days (range, 2.4-8.0 days) because of an AVR associated with a rapid XAb increase within 24 hours. White blood cell count (10.3 +/- 2.2 G/L) showed a maximum of 13.1 +/- 2.1 (day 1) and constant levels (1.4 +/- 0.3-2.1 +/- 1.3 G/L) between day 3 and 6. Histology (LM/EM) showed massive hemorrhage, necrosis, and vascular thrombi as signs of AVR.

CONCLUSION

Although HXR was prevented by using IA and hDAF-transgenic donor hearts, AVR was not avoided due to insufficient immunosuppressive regimen used and a missed postoperative IA treatment as a result of an inefficient control of XAb production.

When should pulmonary artery angioplasty be performed for fontan candidates with pulmonary coarctation?

We performed concomitant pulmonary artery angioplasty and the Blalock-Taussig shunt under median sternotomy and cardiopulmonary bypass at the neonatal stage in Fontan candidates with pulmonary coarctation to obtain optimum pulmonary circulation. This surgical strategy realized appropriate early growth of the pulmonary artery necessary for the Fontan operation.

[Total cavopulmonary connection for grown diminutive pulmonary artery after staged Blalock-Taussig shunt]

We report a two-year-old girl with asplenia, [A, L, L] DORV, pulmonary atresia, common AV valve, PDA, and TAPVC, who successfully underwent total cavo pulmonary connection (TCPC). Deep cyanosis was pointed out since birth. Cardiac catheterization performed on the sixth day after birth revealed a diminutive pulmonary artery tree of which PA index was 41 mm2/m2. Left modified Blalock-Taussig shunt was created at 27 days of age. The PA index increased to 282 mm2/mm2, but disparity in diameter between the left and the right pulmonary artery was yielded by PDA subsidence. Therefore additional contralateral B-T shunt was made at one year of age. Follow-up cardiac catheterization at 28 months of age showed well developed pulmonary artery; PA index of 460 mm2/m2, right pulmonary resistance (Rp) of 3.49 units, left Rp of 2.33 units, and estimated total Rp was 1.39. According to study, bidirectional Glenn procedure or TCPC was indicated. Considering necessity of urgent repair of common pulmonary vein obstruction, regurgitation of the common atrio-ventricular valve and pulmonary artery stenosis, TCPC was performed with concomitant repair of the associated lesions. Severe butterfly-figure stenosis of the central PA was augmented by anastomosing both the left SVC and the left-sided atrium. In conclusion, diminutive pulmonary artery could be adequately grown by phase-in Blalock-Taussig shunts. Pulmonary blood flow scintigraphy was thought to be useful for estimation of pulmonary resistance in such cases with different pulmonary resistance between right and left PA.

[Surgical management of patent ductus arteriosus in low body weight infants]

Between January 1980 and December 1994, seventeen premature infants weighing less than 2500 g underwent surgical management for the isolated patent ductus arteriosus (PDA). Indometacine therapy for closure of PDA was not effective for all these patients. In terms of the body weight at birth, they were divided into two groups; Group I (G-I) consisted of ten patients with birth weight less than 1000 g and Group II (G-II) of seven patients weighing more than 1000 g. The age at operation was 22.1 +/- 15.4 days in the G-I and 14.3 +/- 11.4 days in the G-II. The ductus was ligated in all patients but one of the G-II, in whom it was divided. There were five (50%) hospital deaths in the G-I and none in the G-II. The causes of death in the G-I were related to necrotizing enterocolitis (NEC) in two and infant respiratory distress syndrome (IRDS), acute renal failure, and broncho-esophagial fistula in each. The age at operation tended to be older in nonsurvivors rather than in survivors in the G-I (28.0 +/- 16.8 days vs. 16.2 +/- 14.0 days, respectively, but the difference did not reach significance). Before surgery, all patients in the G-I required mechanical ventilator support and nine of them were associated with IRDS. In contrast, only two patients in the G-II needed mechanical ventilation preoperatively. The postoperative period of intubation was also significantly longer in the G-I than in the G-II (51.6 +/- 35.2 days vs. 2.2 +/- 1.5 days, respectively, p < 0.05). In conclusions, the surgery for PDA can be safely performed even in small premature babies weighing less than 1000 g. When medical therapy for PDA is not effective in the premature patients, the surgical management should be considered as early as possible before their conditions become worse due to such critical complications as NEC, IRDS, and renal failure.

Primary cardiac angiosarcoma with superior vena caval syndrome: review of surgical resection and interventional management of venous inflow obstruction

Primary cardiac angiosarcoma occurs rarely, and surgical resection is often required to relieve symptoms. A 66-year-old man whose presenting symptoms were palpitations and general fatigue is presented. Echocardiography revealed a large tumour occupying most of the right atrium. When superior vena caval (SVC) syndrome developed, surgical resection of the tumour was attempted. The tumour was found to have invaded the inflow of SVC, left atrium, right ventricle and ascending aorta. The bulk of the tumour was resected, requiring reconstruction of the right atrium and caval inflows. Histopathological diagnosis of the tumour was primary angiosarcoma. In the postoperative period, symptoms of SVC syndrome recurred, which were relieved temporarily by balloon angioplasty. After one month, recurrence of symptoms was again managed by catheter dilation. On this occasion a metallic stent was deployed, which prevented further symptoms of SVC syndrome during the eight months before the patient died with generalized metastases.

[A surgical case of supravalvular aortic stenosis with severe hypoplastic ascending aorta (diffuse type) in Williams-Beuren syndrome]

We report a six-year-old boy who underwent ascending aortic reconstruction for supravalvular aortic stenosis of diffuse type associated with Williams-Beuren syndrome. The diagnosis was first made at the age of six months. Because of progressive left ventricular hypertrophy, cardiac catheterization was performed at the age of five years and showed left ventricular pressure of 200 mmHg, the ascending aortic pressure of 202 mmHg, the descending aortic pressure of 115 mmHg, and left ventricular end-diastolic volume of 33.5 ml (90% of normal). Whole ascending aorta except sinus Valsalva was severely hypoplastic, so called diffuse type of supravalvular aortic stenosis. The ascending aorta was only 6.3 mm in diameter, whereas the diameter of the aortic annulus was 20.6 mm. The ascending aortic reconstruction of Doty's type was performed from the aortic root to the distal aortic arch with a equine pericardium reinforced by Dacron velour using selective perfusion to the right bracheocepharic artery, the left common carotid artery and the right femoral artery to avoid circulatory arrest. Postoperative course was uneventful and post operative catheterization revealed left ventricular pressure of 128 mmHg, the ascending aortic pressure of 126 mmHg and the descending aortic pressure of 90 mmHg. Mild residual pressure gradient was probably due to hypoplastic descending aorta. In conclusion, patch aortic reconstruction for ascending aorta under selective cerebral perfusion for a six-year old boy can be performed without postoperative neurological complication.

[Color M-mode Doppler analysis of left ventricular inflow in pediatric patients]

This study evaluated the clinical usefulness of analyzing left ventricular (LV) filling by color M-mode Doppler echocardiography in pediatric patients. The LV-filling patterns of color M-mode Doppler echocardiography were obtained by LV inflow in the apical 4-chamber or long-axis view, and the time difference between the occurrence of peak velocity at the mitral tip and in the apical region (M-AP) was calculated. The peak velocity at each depth was determined by adequate selection of the Nyquist limit by shifting the zero point after freezing the color M-mode. LV volume and posterior wall motion velocity were obtained simultaneously. The catheter-derived data were compared with echo-derived data in 7 patients (mean age 12.0 years). The M-AP correlated positively with the time constant of LV relaxation (tau; r = 0.83, p < 0.05), pulmonary capillary wedge pressure (r = 0.83, p < 0.05), and negatively with peak diastolic posterior wall motion velocity (r = -0.78, p < 0.05). The M-AP was compared with other echo-derived data between Group N (35 children with normal cardiac function, mean age 4.3 years) and Group F (12 children with LV ejection fraction less than 40%, mean age 9.5 years). The M-AP was significantly longer in Group F (53.3 +/- 14.0 vs 116.5 +/- 30.5 msec; p < 0.001), but there was no significant difference in the E/A or deceleration time of E between the 2 groups. In Group N, the E/A correlated to LV end-diastolic volume and heart rate, but the M-AP showed no correlation. In Group F, the M-AP correlated with the percentages of normal LV end-diastolic volume (r = 0.76, p < 0.01) and LV ejection fraction (r = -0.58, p < 0.05). The M-AP was not influenced by LV size or heart rate and could easily differentiate normal heart from failing heart, and thus this is a useful parameter for evaluating diastolic function in pediatric patients.

[A case of modified Fontan operation with reconstruction of the nonconfluent pulmonary artery]

A three-year-old girl with complex cardiac anomalies and right isomerism successfully underwent a modified Fontan procedure and reconstruction of the nonconfluent pulmonary artery using autologous tissues. These cardiac anomalies included single right ventricle, atresia of the pulmonary trunk with nonconfluent pulmonary artery, atrial septal defect, common atrioventricular valve, bilateral PDAs, and bilateral SVCs. Preoperative cardiac catheterization showed elevated pulmonary artery pressure (mean pressure of 24 mmHg) and a small orifice of common pulmonary vein chamber. Pulmonary arteriographies showed balanced development of the branches. Indication for Fontan procedure was finally determined by measurement of the pulmonary artery and vein pressures and pulmonary vascular resistance before the cardiopulmonary bypass in the operation. Nonconfluent pulmonary artery was reconstructed by direct anastomosis of the right and left branches in the posterior aspect and enlarged with autologous pericardium patch. Intracardiac anomalies were repaired by enlargement of common pulmonary vein orifice (from 5 mm to 15 mm in diameter) and right atrial oblique partition. Furthermore, Fontan circulation was established by pulmonary artery angioplasty, direct anastomosis of left SVC to left pulmonary artery and direct anastomosis of right atrial appendage to pulmonary artery. Postoperative clinical course was uneventful, and cardiac catheterization showed mean right atrial pressure of 14 mmHg, cardiac index of 3.5 l/min/m2, and no pressure gradient at the site of reconstruction of the pulmonary artery.

An automatic flow controller for a centrifugal blood pump

To regulate the perfusion flow rate of a centrifugal blood pump, a microcomputer controller was developed. The computer monitored the flow rate of the pump with an electromagnetic flowmeter or an ultrasonic pulse Doppler flowmeter, rotational speed of the pump, aortic pressure, and the amount of blood in a reservoir. A discrete integral controller with a control interval of 1 s was adopted for the controller. For the safety of the control system, we added functions for detecting a clamp on the tubing, a dislocation of the flow sensor, or an inverse direction of the flow sensor. During a standby period, the computer calculated the rotational speed from aortic pressure to minimize the forward or the backward flow at the start of the pump perfusion. The automatic flow controller was used on 5 patients during cardiac operations and maintained the flow rate within +/-6% of the set point.

[A surgical case of total anterior papillary muscle rupture after acute myocardial infarction]

Mitral regurgitation (MR) due to rupture of the papillary muscle is one of the most serious complications of acute myocardial infarction (AMI) as well as ventricular septal perforation and ventricular free wall rupture. We experienced a case of complete rupture of the anterior papillary muscle. A 68-year-old man experienced an episode of dyspnea. Electrocardiographic findings were consistent with postero-lateral infarction. Massive MR is present on color Doppler imaging. He was transferred to our hospital for urgent operative indication because of papillary muscle rupture due to AMI. Six hours after the onset, the operation was performed with intra-aortic balloon pump in place. The anterior papillary muscle was ruptured completely in the mid portion. He underwent a mitral valve replacement with a SJM prosthetic valve. There is a few cases with successful urgent surgery for a complete rupture of anterior papillary muscle.

[Right atrial flap method for repair of partial anomalous pulmonary venous drainage into the high superior vena cava--case report]

We report an alternative method of repairing partial anomalous pulmonary venous return (PAPVR) wherein anomalous veins drain into the high portion of superior vena cava (SVC). A six year old girl, weighing 19 kg underwent cardiac catheterization for cardiomegaly. The study showed sinus venous defect and pulmonary veins anomalously drained from the right upper and middle lobe into the high SVC. Under cardiopulmonary bypass with aortic and bicaval direct cannulation, a 2-cm-wide pedicled flap made from the middle part of the right atrium (RA), was pulled into the SVC. The atrial flap divided the SVC from the ostium of the uppermost pulmonary vein (PV) to the ASD. This posterior tunnel drained anomalous PV blood into the left atrium. Postoperative echocardiogram and magnetic resonance imaging showed adequate space in the SVC and the PV channel. The patient maintained normal sinus rhythm after surgery. The advantage of this method is to minimize the risk of injuring the sinus node or sinus node artery, and to easily reconstruct both the SVC and PV channel without using prosthetic materials, even in patients with small RA.

[Surgical treatment of infective endocarditis : an analysis of the risk factor for operative mortality]

From January 1980, through December 1995, 60 patients underwent surgical treatment of infective endocarditis (IE) at Sakakibara Hospital. Of 60 patients, 40 showed active endocarditis and 20 healed endocarditis at the time of operation. The over-all hospital mortality was 10% (6/60). The complication of cerebral accident (embolism and bleeding) was related to a higher incidence of operative mortality. The reconstructions of destruction and disruption of ventricular-aortic or mitral-aortic continity in the presence of acute infection of the annular tissue were in need of radical and complex surgical techniques. It is recommended to follow up these patients thoughtfully and to perform reoperation or re-reoperation before a patient develops severe heart failure or multiple organ failure.

[Myocardial infarction caused by spontaneous coronary artery dissection associated with significant mitral regurgitation--a successful surgical case]

We experienced a case of 34-year-old male with old myocardial infarction, which seemed to be caused by spontaneous dissection of the left circumflex coronary artery, and associated papillary muscle disfunction with resultant significant mitral regurgitation. He was treated surgically by coronary artery bypass grafting and mitral valvuloplasty. Ungraftable circumflex was abandoned; instead, pediculated graft of the right gastroepiploic artery was anastomosed to the mid-portion of the right coronary artery, which also had been spontaneously dissected. Mitral regurgitation was treated with Reed's plasty of the posterior commissure and the ring annuloplasty using Carpentier-Edwards Ring. His postoperative course has been smooth and uneventful. According to the English literature of the Western hemisphere, spontaneous coronary arterial dissection usually occurs in relatively young people with a striking predilection for women, and nearly all report deal only with the coronary abnormality. To our knowledge, this is the first report of a surgical case of the spontaneous coronary dissection associated with significant mitral regurgitation.

[A case report of aortic valve replacement after 16 years from repair of ruptured sinus Valsalva aneurysm]

A case of aortic valve replacement after 16 years from the repair of ruptured sinus valsalva aneurysm (RSVA) was reported. The patient has undergone direct closure of RSVA with VSD type I at 34 years old. At the operation, no attempt was made as to aortic valve regurgitation because of small regurgitation, Selloers 1 on aortography. At 50 years old, he developed dyspnea on exertion, to-and-fro murmur due to aortic valve regurgitation, Selloers 3. Aortic valve replacement, we confirmed the completely closure of right coronary sinus valsalva, and histopathologically observed the degenerative change of only right coronary cusp.