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Biomedical subjects

T Shinoka

Publications and source records attributed to T Shinoka.

At least 19 recordsLinked to original sources

[Current status of tissue engineering for therapeutic use].

During the past three decades, significant advances have been made in the field of transplantation. However, clinical obstacles such as donor scarcity, cost, infection and life-long immunosuppression(especially within the pediatric age group) have become the major limitations for organ transplantation. This article discusses the recent progresses as well as the remaining challenges in tissue engineering that may enable such technology to replace organ transplantation. Additionally, we describe a practical method for tissue engineering in the field of cardiovascular surgery.

Absorbable Implants↗

Tissue engineering of autologous aorta using a new biodegradable polymer.

BACKGROUND: Ovine pulmonary valve leaflets and pulmonary arteries have been tissue-engineered (TE) from autologous cells and biodegradable polyglycolic acid (PGA)-polyglactin copolymers. Use of this cell-polymer construct in the systemic circulation resulted in aneurysm formation. This study evaluates a TE vascular graft in the systemic circulation which is based on a new copolymer of PGA and polyhydroxyalkanoate (PHA). METHODS: Ovine carotid arteries were harvested, expanded in vitro, and seeded onto 7-mm diameter PHA-PGA tubular scaffolds. The autologous cell-polymer vascular constructs were used to replace 3-4 cm abdominal aortic segments in lambs (group TE, n = 7). In a control group (n = 4), aortic segments were replaced with acellular polymer tubes. Vascular patency was evaluated with echography. All control animals were sacrificed when the grafts became occluded. Animals in TE group were sacrificed at 10 days (n = 1), 3 (n = 3), and 5 months (n = 3). Explanted TE conduits were evaluated for collagen content, deoxyribonucleic acid (DNA) content, structural and ultrastructural examination, mechanical strength, and matrix metalloproteinase (MMP) activity. RESULTS: The 4 control conduits became occluded at 1, 2, 55, and 101 days. All TE grafts remained patent, and no aneurysms developed by the time of sacrifice. There was one mild stenosis at the anastomotic site after 5 months postoperatively. The percent collagen and DNA contents approached the native aorta over time (% collagen = 25.7%+/-3.4 [3 months] vs 99.6%+/-11.7 [5 months], p < 0.05; and % DNA = 30.8%+/-6.0 [3 months] vs 150.5%+/-16.9 [5 months], p < 0.05). Histology demonstrated elastic fibers in the medial layer and endothelial specific von Willebrand factor on the luminal surface. The mechanical strain-stress curve of the TE aorta approached that of the native vessel. A 66 kDa MMP-2 was found in the TE and native aorta but not in control group. CONCLUSIONS: Autologous aortic grafts with biological characteristics resembling the native aorta can be created using TE approach. This may allow the development of "live" vascular grafts.

Animals↗

Postischemic hyperthermia exacerbates neurologic injury after deep hypothermic circulatory arrest.

BACKGROUND: Aggressive surface warming is a common practice in the pediatric intensive care unit. However, recent rodent data emphasize the protective effect of mild (2 degrees - 3 degrees C) hypothermia after cerebral ischemia. This study evaluates different temperature regulation strategies after deep hypothermic circulatory arrest with a survival piglet model. METHODS: Fifteen piglets were randomly assigned to 3 groups. All groups underwent 100 minutes of deep hypothermic circulatory arrest at 15 degrees C. Brain temperature was maintained at 34 degrees C for 24 hours after cardiopulmonary bypass in group I, 37 degrees C in group II, and 40 degrees C in group III. Neurobehavioral recovery was evaluated daily for 3 days after extubation by neurologic deficit score (0, normal; 500, brain death) and overall performance category (1, normal; 5, brain death). Histologic examination was assessed for hypoxic-ischemic injury (0, normal; 5, necrosis) in a blinded fashion. RESULTS: All results are expressed as mean +/- standard deviation. Recovery of neurologic deficit score (12.0 +/- 17.8, 47.0 +/- 49.95, 191.0 +/- 179.83; P = .05 for group I vs III), overall performance category (1.0 +/- 0.0, 1.4 +/- 0.6, 2.8 +/- 1.3; P < .05 for group I vs III), and histologic scores (0.0 +/- 0.0, 1.0 +/- 1.2, 2.8 +/- 1.8; P < .05 for group I vs III cortex) were significantly worse in hyperthermic group III. These findings were associated with a significantly lower cytochrome aa3 recovery determined by near-infrared spectroscopy in group III animals (P = .0041 for group I vs III). No animal recovered to baseline electroencephalographic value by 48 hours after deep hypothermic circulatory arrest. Recovery was significantly delayed in the hyperthermic group III animals, with a lower amplitude 14 hours after the operation, which gradually increased with time (P < .05 for group III vs groups I and II). CONCLUSIONS: Mild postischemic hyperthermia significantly exacerbates functional and structural neurologic injury after deep hypothermic circulatory arrest and should therefore be avoided.

Animals↗

Creation of viable pulmonary artery autografts through tissue engineering.

BACKGROUND: "Repair" of many congenital cardiac defects requires the use of conduits to establish right ventricle to pulmonary artery continuity. At present, available homografts or prosthetic conduits lack growth potential and can become obstructed by tissue ingrowth or calcification leading to the need for multiple conduit replacements. Tissue engineering is an approach by which cells are grown in vitro onto biodegradable polymers to construct "tissues" for implantation. A tissue engineering approach has recently been used to construct living cardiac valve leaflets from autologous cells in our laboratory. This study assesses the feasibility of a tissue engineering approach to constructing tissue-engineered "living" pulmonary artery conduits. MATERIALS AND METHODS: Ovine artery (group A, n = 4) or vein (group V, n = 3) segments were harvested, separated into individual cells, expanded in tissue culture, and seeded onto synthetic biodegradable (polyglactin/polyglycolic acid) tubular scaffolds (20 mm long x 15 mm diameter). After 7 days of in vitro culture, the autologous cell/polymer vascular constructs were used to replace a 2 cm segment of pulmonary artery in lambs (age 68.4 +/- 15.5 days, weight 18.7 +/- 2.0 kg). One other control animal received an acellular polymer tube sealed with fibrin glue without autologous cells. Animals were sacrificed at intervals of 11 to 24 weeks (mean follow-up 130.3 +/- 30.8 days, mean weight 38.9 +/- 13.0 kg) after echocardiographic and angiographic studies. Explanted tissue-engineered conduits were assayed for collagen (4-hydroxyproline) and calcium content, and a tissue deoxyribonucleic acid assay (bis-benzimide dye) was used to estimate number of cell nuclei as an index of tissue maturity. RESULTS: The acellular control graft developed progressive obstruction and thrombosis. All seven tissue-engineered grafts were patent and demonstrated a nonaneurysmal increase in diameter (group A = 18.3 +/- 1.3 mm = 95.3% of native pulmonary artery; group V = 17.1 +/- 1.2 mm = 86.8% of native pulmonary artery). Histologically, none of the biodegradable polymer scaffold remained in any tissue-engineered graft by 11 weeks. Collagen content in tissue-engineered grafts was 73.9% +/- 8.0% of adjacent native pulmonary artery. Histologically, elastic fibers were present in the media layer of tissue-engineered vessel wall and endothelial specific factor VIII was identified on the luminal surface. Deoxyribonucleic acid assay showed a progressive decrease in numbers of cell nuclei over 11 and 24 weeks, suggesting an ongoing tissue remodeling. Calcium content of tissue-engineered grafts was elevated (group A = 7.95 +/- 5.09; group V = 13.2 +/- 5.48; native pulmonary artery = 1.2 +/- 0.8 mg/gm dry weight), but no macroscopic calcification was found. CONCLUSIONS: Living vascular grafts engineered from autologous cells and biodegradable polymers functioned well in the pulmonary circulation as a pulmonary artery replacement. They demonstrated an increase in diameter suggesting growth and development of endothelial lining and extracellular matrix, including collagen and elastic fibers. This tissue-engineering approach may ultimately allow the development of viable autologous vascular grafts for clinical use.

Animals↗

Tissue-engineered heart valve leaflets: does cell origin affect outcome?

BACKGROUND: We previously reported the successful creation of tissue-engineered valve leaflet constructs and the implantation of these autologous tissue leaflets in the pulmonary valve position in a lamb model. The optimal cell origin for creating these valve leaflets remains unclear. This study was designed to compare dermal with arterial wall myofibroblasts as the cells of origin for the leaflet constructs. METHODS AND RESULTS: Mixed cell populations of endothelial cells and fibroblasts were isolated from ovine femoral arteries or subdermis and then expanded in vitro. A synthetic biodegradable polymer scaffold was then seeded with the cultured cells. The tissue scaffold was composed of a polyglactin woven mesh sandwiched between two nonwoven polyglycolic acid mesh sheets, which measured 3x3 cm in size and 3.2 mm in thickness. The cell-seeded polymer construct was implanted to replace one pulmonary valve leaflet in the same juvenile animal from which the cells had originally been obtained. Using cardiopulmonary bypass, the right posterior leaflet of the pulmonary valve was completely resected and replaced with an autologous engineered valve leaflet. In group D (n=5), the cells were obtained from subdermis, and in group A (n=4), they were obtained from the arterial wall. Eight to 10 weeks after leaflet implantation, the animals were killed, and the implanted valve leaflets were examined histologically, biochemically, and biomechanically. The dimensions of each tissue-engineered leaflet (TEL) were compared with those of the two remaining native valve leaflets to obtain a growth index. A 4-hydroxyproline assay was performed to evaluate collagen content. Leaflet tensile strength was evaluated in vitro by using a Vitrodyne V-1000 mechanical tester. Factor VIII and elastin stains were performed to histologically assess the presence of endothelial cells and elastin, respectively. In all animals, the TEL persisted in the pulmonary valve position after 8 to 10 weeks, and all polyglycolic acid polymer had been degraded. Group A leaflets had a higher growth index (0.86+/-0.11) than group D (0.41+/-0.08) (P<.05). Macroscopically, the group D leaflets appeared thicker and contracted. Histologically, elastic fibers were more abundant in group A than in group D. Total collagen content and biomechanical testing showed no differences between groups. Leaflets from both groups had positive staining for factor VIII on the surface, confirming growth of endothelial cells to cover the TEL. CONCLUSIONS: Autologous TEL derived from vascular fibroblasts seem to develop functionally and morphologically like the native valve leaflets in the pulmonary circulation. Use of arterial myofibroblasts for the creation of TEL seems preferable to dermal fibroblasts with current tissue culture conditions.

Animals↗

The in vitro construction of a tissue engineered bioprosthetic heart valve.

PROBLEM: Heart valve replacement with either a nonliving xenograft or a mechanical prosthesis is an effective therapy for valvular heart disease. Both of these approaches have limitations, including their inability to grow, repair, and remodel. In addition, a mechanical prosthesis requires long-term anticoagulation therapy. METHODS: This study demonstrates the in vitro creation of tissue engineered heart valve tissue using cardiovascular cells on degradable polymer matrices, 40 heart valve leaflets were created using this technique from two sources. Xenograft leaflets were created using human dermal fibroblasts and bovine aortic endothelial cells (n = 20) or allograft valve leaflets were created using sheep myofibroblasts and sheep endothelial cells (n = 20). A mixed sheep cell population was obtained consisting of endothelial cells and myofibroblasts. Endothelial cells were labelled with acethylated low density lipoprotein (Ac-Dil-LDL) and cells were separated into two groups using an activated cell sorter: LDL positive cells comprised of a pure endothelial cell population and LDL negative cells comprised of mixed cell population containing myofibroblasts and smooth muscle cells. The LDL negative cells were seeded on a synthetic polyglycolic acid (PGA) mesh and grown in vitro to form a tissue-like fibroblast-mesh core. Endothelial cells were then seeded onto the surface of the fibroblast-mesh core, forming a single monolayer. RESULTS: Histological evaluation of these constructs revealed an inner core of LDL negative cells and outer endothelial-like cells which were factor VIII positive. There was no evidence of capillary formation from endothelial cells invading the myofibroblasts and smooth muscle matrix and the endothelial lining appeared complete. CONCLUSIONS: It is feasible to construct allogenic heart valve tissue which could be used to make a valve.

Animals↗

Tissue-engineered heart valves. Autologous valve leaflet replacement study in a lamb model.

BACKGROUND: We have previously reported the successful creation of tissue-engineered valve leaflets and the implantation of these autologous tissue leaflets in the pulmonary valve position. This study was designed to trace cultured cells that were seeded onto a biodegradable polymer with the use of a 1,1'-dioctadecyl-3,3,3' 3'-tetramethylindo-carbocyanine perchlorate (Di-1) cell-labeling method. We also examined the time-related biochemical, biomechanical, and histological characteristics and evolution of these tissue constructs. METHODS AND RESULTS: Mixed cell populations of endothelial cells and fibroblasts were isolated from explanted ovine arteries. Endothelial cells were selectively labeled with an acetylated low density lipoprotein marker and separated from fibroblasts with the use of a fluorescence-activated cell sorter. A synthetic biodegradable scaffold consisting of polyglycolic acid fibers was seeded first with fibroblasts, then coated with endothelial cells. Using these methods, we implanted autologous cell/polymer constructs in six animals. In two additional control animals, a leaflet of polymer was implanted without prior cell seeding. In each animal, cardiopulmonary bypass was used to completely resect the right posterior leaflet of the pulmonary valve and replace it with an engineered valve leaflet with (n = 6) or without (n = 2) prior cultured cell seeding. The animals were killed either after 6 hours or after 1, 6, 7, 9, or 11 weeks, and the implanted valve leaflets were examined histologically, biochemically, and biomechanically. 4-Hydroxyproline assays were performed to determine collagen content. Leaflet strength was evaluated in vitro with a mechanical tester Factor VIII and elastin stains were done to verify histologically that endothelial cells and elastin, respectively, were present. Animals receiving leaflets made from polymers without cell seeding were killed and examined in a similar fashion after 8 weeks. In the control animals, the acellular polymer leaflets were completely degraded, with no residual leaflet tissue at 8 weeks. The tissue-engineered valve leaflet persisted in each animal in the experimental group. 4-Hydroxyproline analysis of the constructs showed a progressive increase in collagen content. Immunohistochemical staining demonstrated elastin fibers in the matrix and factor VIII on the surface of the leaflet. The cell-labeling experiments demonstrated that the cells on the leaflets had persisted from the in vitro seeding of the leaflets. CONCLUSIONS: In the tissue-engineered heart valve leaflet, transplanted autologous cells generated a proper matrix on the polymer scaffold in a physiological environment at a period of 8 weeks after implantation.

Animals↗

Hypoxic stress alone does not modulate endothelial surface expression of bovine E-selectin and intercellular adhesion molecule-1 (ICAM-1).

UNLABELLED: Hypoxemia is a common event in many vascular diseases, especially vascular ischemia. Since endothelial cells of blood vessels are exposed to conditions within the vascular space and leucocytes play a key role in ischemia/reperfusion injury, we hypothesized that endothelial exposure to hypoxia may regulate expression of surface proteins important in leucocyte-endothelial interactions, such as E-selectin and intercellular adhesion molecule (ICAM-1). In this study, we used isolated bovine aortic endothelial monolayers to examine endothelial surface alterations of E-selectin and ICAM-1 induced by tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS) and hypoxia using a whole cell enzyme-linked immunosorbent assay (ELISA). Bovine endothelial exposure to TNF-alpha (50 ng/mL) induced a time dependent increase (range 0-24h) in specific E-selection surface expression. Endothelial exposure to hypoxia alone (pO2 approximately 3 mmHg, range 0-24 h), however, failed to elicit endothelial E-selectin expression. Endothelial exposure to LPS brought about a dose- and time-dependent (range 0.5 ng/mL and 2-8 h) increase in specific ICAM-1 surface expression (max. 3.5 +/- 0.15-fold increase over no cytokine control at 10 ng/mL, 4 h). Hypoxia (pO2 approximately 3 mmHg, 8h), however, did not induce ICAM-1 surface expression over normoxia levels. IN CONCLUSION: i) bovine endothelial E-selectin and ICAM-1 surface expression are regulated molecules, ii) hypoxia, per se, does not regulate surface expression of either E-selectin or ICAM-1. These results suggest that hypoxic endothelia may require additional external signals for generation of adaptive inflammatory responses.

Animals↗

Tissue engineering heart valves: valve leaflet replacement study in a lamb model.

BACKGROUND: Valve replacements using either bioprosthetic or mechanical valves have the disadvantage that these structures are unable to grow, repair, or remodel and are both thrombogenic and susceptible to infection. These characteristics have significantly limited their durability and longevity. In an attempt to begin to overcome these shortcomings, we have tested the feasibility of constructing heart valve leaflets in lambs by seeding a synthetic polyglycolic acid fiber matrix in vitro with fibroblasts and endothelial cells. METHODS: Mixed cell populations of endothelial cells and fibroblasts were isolated from explanted ovine arteries. Endothelial cells were selectively labeled with an acetylated low-density lipoprotein marker and separated from the fibroblasts using a fluorescent activated cell sorter. A synthetic biodegradable scaffold constructed from polyglycolic acid fibers was seeded with fibroblasts, which grew to form a tissue-like sheet. This tissue was subsequently seeded with endothelial cells, which formed a cellular monolayer coating around the leaflet. Using these constructs, autologous (n = 3) and allogenic (n = 4) tissue engineered leaflets were implanted in 7 animals. In each animal the right posterior leaflet of the pulmonary valve was resected and replaced with an engineered valve leaflet. RESULTS: All animals survived the procedure. Postoperative echocardiography demonstrated no evidence of stenosis and trivial pulmonary regurgitation in the autografts and moderate regurgitation in the allogenic valves. Collagen analysis of the constructs showed development of an extracellular matrix. Histologic evaluation of the constructs demonstrated appropriate cellular architecture. CONCLUSIONS: This preliminary experiment showed that a tissue engineered valve leaflet constructed from its cellular components can function in the pulmonary valve position. Tissue engineering of a heart valve leaflet is feasible, and these preliminary studies suggest that autograft tissue will probably be superior to allogenic tissue.

Animals↗

[A successful circulatory assist in acute left heart failure after a rapid two-stage arterial switch operation].

A 6-month-old female with transposition of the great arteries with intact ventricular septum successfully survived with the aid of a circulatory assist device for acute left heart failure after rapid two stage-arterial switch operation (ASO). The interval between pulmonary artery banding and ASO was 9 days. Left heart failure appeared immediately after ASO, so we started the circulatory assist with a centrifugal pump. The left ventricular function gradually recovered. After 43 hours assisted circulation, she was successfully weaned from the pump. Subsequent recovery was uneventful and the patient was discharged from the hospital on the 40th postoperative day. In case of acute left heart failure after ASO due to sudden changes in the left ventricular afterload, adaptation of the left ventricle can be expected by a relatively short period of circulatory assist with centrifugal pump.

Acute Disease↗

[Two cases of successful arterial switch operation for double outlet right ventricle associated with straddling and cleft mitral valve].

We successfully performed an anatomical repair for double outlet right ventricle associated with straddling and cleft mitral valve in two patients. In both patients position of the anterior and posterior papillary muscles was found to be normal. Therefore, all staddled mitral component was detached. The mitral valve competency was achieved by suture-closure of the cleft and annuloplasty. This procedure facilitated intraventricular re-routing from the left ventricle to the pulmonary artery. Then arterial switch was performed. Postoperative course was uneventful and no significant mitral valve regurgitation was found in either patient postoperatively. This procedure can be a good option in patients with double outlet right ventricle associated with straddling mitral valve.

Child, Preschool↗

[A successful repair of ventricular septal defect and patient ductus arteriosus associated with pulmonary hypertension in an infant with left lung agenesis].

We report the first case of successful repair of ventricular septal defect (VSD) and patent ductus arteriosus (PDA) associated with pulmonary hypertension in an infant with left lung agenesis. A 70-days-old infant was referred to our hospital with the diagnosis of congenital heart disease and abnormalities of the left lung. Two-dimensional echocardiogram showed ventricular septal defect and patent ductus arteriosus associated with pulmonary hypertension. Computed tomogram of the chest and bronchogram confirmed agenesis of the left lung. The operation was performed at age 114 days with the body weight 4333 g. VSD was closed with the patch and PDA was ligated under cardiopulmonary bypass. Postoperative course was uneventful. Cardiac catheterization, 50 days after operation, revealed normal pulmonary arterial pressure and good cardiac function. Agenesis of the lung is a rare condition and often associated with congenital abnormalities of the skeletal, gastrointestinal, genitourinary and cardiovascular system. As the prognosis is poor especially in those with congenital heart disease, the cardiac surgery is mandatory for the patient to survive.

Abnormalities, Multiple↗

[Late results and problems after atrial switch operation].

Between 1970 and June 1992, 137 consecutive patients with transposition of the great arteries and double outlet right ventricle underwent an atrial switch operation at the Heart Institute of Japan. They included 74 patients with a Senning operation (Group I) and 63 patients with a Mustard operation (Group II). Ages at operation ranged from 1 month to 15 years (average 25.7 months) and follow-up period in 114 operative survivors ranged from 1 month to 22 years (average 6.8 years in the Senning group, 10.9 years in the Mustard group). Twelve-year actuarial survival rate was 90.1% in Group I and 64.1% in Group II, and 22-year actuarial survival rate was 64.1% in Group II. There were 6 and 13 late deaths in group I and group II, respectively. Sudden Death occurred in 7 patients in the late postoperative period presumably due to arrhythmias, although there were no symptoms and signs of arrhythmias in 4 of the 7 patients. Five other patients died from cardiac failure in the late postoperative period. Ninety-two percent of group I and seventy-one percent of group II maintained normal sinus rhythm evaluated by the electrocardiogram and Holter's electrocardiogram in the late postoperative period. Mean PQ interval in the late postoperative period was 0.14 +/- 0.03 seconds in group I and 0.17 +/- 0.03 seconds in group II; Group II had a higher incidence of arrhythmias than group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Anatomic correction of atrioventricular discordance.

Between June 1989 and September 1991, 11 patients underwent anatomic correction of atrioventricular discordance. Their ages at operation ranged from 1 to 11 years (mean 6.7 years) and their weights ranged from 7.1 to 31.8 kg (mean 19.1 kg). Atrial situs was solitus in nine and inversus in two patients. Ventriculoarterial connection was discordant in five and was double-outlet right ventricle in six patients. Associated congenital heart defects were seen in all patients, including 10 with ventricular septal defect, eight with atrial septal defect, nine with pulmonary stenosis or pulmonary atresia, seven with tricuspid regurgitation, and four with mitral regurgitation. Five patients had prior Blalock-Taussig shunts. One patient with an intact ventricular septum had repeated pulmonary banding. Anatomic correction consisted of the Senning and Rastelli procedures in three, the Mustard and Rastelli procedures in five, the Senning and arterial switch operations in two, and the Mustard and arterial switch operations in one patient. In addition, mitral valvuloplasty or valvular annuloplasty was performed in three patients. We did not encounter kinking or torsion of the translocated coronary arteries in our three patients with the arterial switch operation. There was one surgical death. The other patients pursued satisfactory postoperative courses (mean follow-up period of 12.6 months). We recommend that anatomic correction for atrioventricular discordance should be indicated, especially in patients with any sign of systemic right ventricular dysfunction.

Cardiac Surgical Procedures↗

Konno procedure for congenital aortic stenosis with a single coronary artery from the left coronary sinus.

A right coronary artery originating from the left coronary sinus and traversing anteriorly is thought to be one of the contraindications for a Konno aortoventriculoplasty in congenital aortic stenosis because this procedure necessitates incision of the right ventricular outflow tract. The case of a 5-year-old girl with congenital aortic stenosis associated with a single coronary artery, successfully treated surgically by the Konno procedure and right coronary artery reimplantation, is reported. Preoperatively there was a pressure gradient between the left ventricle and the ascending aorta of 109 mmHg, which disappeared postoperatively. A postoperative angiography showed a patent right coronary artery.

Abnormalities, Multiple↗

[Surgical correction of atrioventricular discordance--results and follow-up].

Between January 1977 and October 1991, 47 consecutive patients with atrioventricular discordance, ventriculoarterial discordance, and two ventricles underwent intracardiac repair at the Heart Institute of Japan. Their ages at operation ranged from 2 months to 21 years (average 9.2 years) and period of follow-up ranged from 1 month to 168 months (average 65.1 months). There were five basic anatomic types according to the associated anomalies, grouped into (1) situs solitus, ventriculoarterial (V-A) discordance or double-outlet right ventricle (DORV), ventricular septal defect (VSD) and pulmonary outflow tract obstruction (POTO) (31 patients); (2) situs solitus, V-A discordance and VSD (6 patients); (3) situs solitus, V-A discordance and tricuspid regurgitation (TR) (2 patients); (4) situs inversus, V-A discordance or DORV, VSA and POTO (7 patients); (5) situs inversus, V-A discordance and VSD (1 patient). TR was evident preoperatively in 13 patients (28% of 47 patients), one of whom had Ebstein's anomaly. The conventional operation, which consisted of closure of VSD (34 patients), posterolateral pulmonary outflow enlargement (2 patients), tricuspid valvuloplasty (2 patients), and tricuspid replacement (1 patient) using the anatomical right ventricle as the systemic ventricle, was performed in 35 patients (RV group). The anatomic correction (so-called "double switch operation"), the new alternative operation using the anatomical left ventricle as the systemic ventricle, was achieved in 12 patients (LV group). Anatomic correction consisted of Senning and RV-PA ECR in 3, Mustard and RV-PA ECR in 4, Senning and arterial switch in 2, and Mustard and arterial switch in 1 patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Two-stage Jatene procedure after Mustard or Senning operation].

We have successfully performed a two-stage Jatene procedure in four patients who showed severe anatomical right ventricular dysfunction after atrial switch (Mustard or Senning) operation for transposition of the great arteries. All four patients developed an adequate left ventricular pressure for the arterial switch operation by one or two-stage pulmonary artery banding. Left ventricular posterior wall thickness increased sufficiently enough after the banding although left ventricular ejection fraction showed significant decrease. After Jatene procedure left ventricular ejection fraction recovered, and RV end-diastolic volume which had been prominently enlarged preoperatively was dramatically normalized. Cardiac index increased from 3.6 +/- 1.6 l/min/m2 preoperatively to 5.3 +/- 6.1 l/min/m2 postoperatively with the decrease in left atrial pressure. Postoperative electrophysiological study revealed the recovery of sinus node function and atrial conduction by means of the take-down of atrial switch operation previously performed. We conclude that the Jatene procedure should be an ideal alternative in patients with right ventricular dysfunction after atrial switch operation. The left ventricle could be prepared by an effective pulmonary artery banding in most instances.

Cardiac Surgical Procedures↗

[A case of mitral valve replacement for Libman-Sacks endocarditis].

A 38-year-old female was admitted to our hospital because she was suffered from severe dyspnea on effort. She had a history of nasal bleeding, endocarditis, fever, proteinuria, and alopecia at the age of 16, and was diagnosed as SLE. She was suffered from recurrent cerebral infarctions at the age of 35 and 38, and then mitral regurgitation was pointed out. Preoperative examination revealed non-active phase of SLE and UCG showed massive mitral regurgitation. Operative findings showed thrombosed verrucca circumferentially on the mitral valve. Mitral valve replacement (B-S #27) was done with using a felt strip in order to reinforce the mitral annular tissues. Histological findings of the verrucca showed Libman-Sacks endocarditis. Postoperative course was uneventful. Surgical treatment for Libman-Sacks endocarditis is extremely rare.

Adult↗