Surgical as Opposed to Transcatheter Aortic Valve Replacement Improves Basal Interventricular Septal Hypertrophy.

BACKGROUND: Basal interventricular septum (IVS) hypertrophy (BSH) with reduced basal IVS contraction and IVS-aorta angle is frequently associated with aortic stenosis (AS). BSH shape suggests compression by the longitudinally elongated ascending aorta, causing basal IVS thickening and contractile dysfunction, further suggesting the possibility of aortic wall shortening to improve the BSH. Surgical aortic valve replacement (SAVR), as opposed to transcatheter AVR (TAVR), includes aortic wall shortening by incision and stitching on the wall and may potentially improve BSH. We hypothesized that BSH configuration and its contraction improves after SAVR in patients with AS. Methods and Results: In 32 patients with SAVR and 36 with TAVR for AS, regional wall thickness and systolic contraction (longitudinal strain) of 18 left ventricular (LV) segments, and IVS-aorta angle were measured on echocardiography. After SAVR, basal IVS/average LV wall thickness ratio, basal IVS strain, and IVS-aorta angle significantly improved (1.11±0.24 to 1.06±0.17; -6.2±5.7 to -9.1±5.2%; 115±22 to 123±14°, P<0.001, respectively). Contractile improvement in basal IVS was correlated with pre-SAVR BSH (basal IVS/average LV wall thickness ratio or IVS-aorta angle: r=0.47 and 0.49, P<0.01, respectively). In contrast, BSH indices did not improve after TAVR. CONCLUSIONS: In patients with AS, SAVR as opposed to TAVR improves associated BSH and its functional impairment.

Left Atrial Remodeling in Segmental vs. Global Mitral Valve Prolapse　- Three-Dimensional Echocardiography.

BACKGROUND: Segmental and global mitral valve prolapse (MVP) comprise 2 representative phenotypes in this syndrome. While mitral regurgitation (MR) severity is a major factor causing left atrial (LA) remodeling in MVP, prominent mitral valve (MV) annulus dilatation in global MVP may specifically cause inferiorly predominant LA remodeling. We compared MV annulus and LA geometry in patients with segmental and global MVP.Methods and Results:LA volume as well as inferior, middle, and superior LA cross-sectional areas (CSA) were measured on 3-D echocardiography in 20 controls, in 40 patients with segmental MVP, and in 18 with global MVP. On multivariate analysis, MR severity was primarily associated with LA dilatation in segmental MVP (P<0.001), while MV annular dilatation was primarily associated with LA dilatation in global MVP (P<0.001). Although there was no regional predominance in LA dilatation in segmental MVP, inferior predominance of LA dilatation was significant in global MVP (increase in inferior, middle, and superior LA-CSA relative to mean of the controls: +220±70% vs. +171±55% vs. +137±37%, P<0.001). CONCLUSIONS: LA remodeling in segmental and global MVP is considerably different regarding its association with MR volume or MV annular dilatation and its regional predominance. While MR volume may mainly contribute to LA remodeling in segmental MVP, MV annular dilatation seems to have an important role in LA remodeling in global MVP. (Circ J 2016; 80: 2533-2540).

Basal Left Ventricular Dilatation and Reduced Contraction in Patients With Mitral Valve Prolapse Can Be Secondary to Annular Dilatation: Preoperative and Postoperative Speckle-Tracking Echocardiographic Study on Left Ventricle and Mitral Valve Annulus Interaction.

BACKGROUND: Prominent mitral valve (MV) annular dilatation with only modest left ventricular (LV) dilatation in patients with MV prolapse (MVP) suggests predominant dilatation in adjacent basal LV, which may augment regional wall tension and attenuate contraction by Laplace's law. We hypothesized that MV annular dilatation in patients with MVP is associated with the basal predominance of LV dilatation and attenuated contraction, which can be altered by surgical MV plasty with annulus reduction. METHODS AND RESULTS: Echocardiography with speckle-tracking analysis to assess regional cross-sectional short-axis area and longitudinal contraction (strain) of basal, middle, and apical LV was performed in 30 controls and 130 patients with MVP. The basal value/averaged middle and apical values (B/M·A ratio) of LV cross-sectional area and strain were obtained. Patients with MVP showed significantly greater MV annular area (6.4±1.6 versus 3.7±0.6 cm2/m2), increased B/M·A LV area ratio (2.4±0.5 versus 1.8±0.2), and reduced B/M·A LV strain ratio (0.83±0.14 versus 0.96±0.09) than controls (P<0.001). Multivariable analyses identified that MV annular dilatation was independently associated with increased B/M·A LV area ratio (ß=0.60, P<0.001), which was associated with reduced B/M·A LV strain ratio (ß=-0.32, P<0.001). In 35 patients with MVP, B/M·A LV area and strain ratio significantly altered after surgical MV plasty with annulus reduction (2.5±0.5-1.8±0.3 and 0.73±0.10-0.89±0.17, P<0.001, respectively). CONCLUSIONS: In patients with MVP, MV annular dilatation was associated with the basal predominance of LV dilatation and reduced contraction, which can be altered by surgical MV plasty with annulus reduction, suggesting unfavorable influence from MV annular dilatation on basal LV.

Morphometric study of the human mitral annulus: guide for mitral valve surgery.

BACKGROUND: during mitral valve surgery, it is important for surgeons to understand the anatomy of the mitral valve annulus to prevent surgical complications. This study aimed to perform morphometry of the mitral annulus to facilitate secure suturing during ring annuloplasty or replacement of the mitral valve. METHODS: an anatomical study was carried out on 7 human hearts. We divided the mitral valve annulus into sections containing 8 different points. It was noted that the annulus was a complex structure which has fibrous continuity with the mitral leaflets, and with or without the aortic annulus. RESULTS: there was always a segment of the annular fibrous structure which was facing directly toward the left ventricular cavity. The length of the segment ranged from 1.0 to 3.4 mm. In terms of the size of the annulus, there were large variations within the subject and among the subjects. The shortest distance between the mitral annulus and left circumflex coronary artery was at the anterolateral commissure, and the length was 3.3 mm. CONCLUSION: this study has improved understanding of the anatomy of the mitral annulus, which could help surgeons to avoid operative complications. Based on this study, several suggestions are made for placing sutures for mitral valve replacement and mitral ring annuloplasty.

Mitral stenosis reversed by medical treatment for heart failure.

It is reported that functional mitral stenosis frequently develops after ring annuloplasty for ischemic mitral regurgitation. The mechanism is a combination of annular size reduction by surgery and diastolic mitral valve tethering, restricting the anterior leaflet opening due to posteriorly displaced papillary muscles with left ventricular dilatation. We report the case of a 57-year-old man who had a history of successful mitral valve plasty for degenerative mitral regurgitation. Four years later he developed heart failure, severe hypertension, mild mitral regurgitation, and significant mitral stenosis, which were reversed by aggressive medical treatment for heart failure.

[Development of hemostatic sealant for arterial anastomosis; clinical application].

For the purpose of examining the clinical applicability of a newly developed surgical sealant, animal experiments were performed, and clinical trial was followed. In animal experiments, several animal models, including carotid artery anastomosis model and coronary artery bypass grafting model were undertaken. In each model, complete hemostasis of the anastomoses using four simple interrupted sutures, was obtained. In addition, elastomeric property of the sealant prevented thinning of the arterial wall. The clinical trial performed in patients with thoracic aortic surgery showed significantly better hemostasis even under heparinized condition. Based on these excellent results, clinical usage of the sealant was approved.

Evidence of a vicious cycle in mitral regurgitation with prolapse: secondary tethering attributed to primary prolapse demonstrated by three-dimensional echocardiography exacerbates regurgitation.

BACKGROUND: In patients with mitral valve prolapse, nonprolapsed leaflets are often apically tented. We hypothesized that secondary left ventricular dilatation attributed to primary mitral regurgitation (MR) causes papillary muscle (PM) displacement, resulting in this leaflet tenting/tethering, and that secondary tethering further exacerbates malcoaptation and contributes to MR severity. METHODS AND RESULTS: Three-dimensional transesophageal echocardiography was performed in 25 patients with posterior mitral leaflet prolapse with an intact anterior mitral leaflet (AML) and 20 controls. From 3D zoom data sets, 11 equidistant antero-posterior cut planes of the mitral valve at midsystole were obtained. In each plane, tenting area of nonprolapsed leaflet and prolapse area of prolapsed leaflet were measured. Prolapse/tenting volume of each region was obtained as the product of interslice distance and the prolapse/tenting area. AML tenting volume and whole leaflet prolapse/tenting volume were then obtained. The PM tethering distance between PM tips and anterior mitral annulus was measured from 3D full-volume data sets. The severity of MR was quantified by vena contracta area extracted from color 3D transesophageal echocardiography data sets. AML tenting volume was significantly larger in patients with posterior mitral leaflet prolapse compared with that in controls (1.2 ± 0.5 versus 0.6 ± 0.2 mL/m(2); P<0.001). Multivariate regression analysis identified independent contribution to AML tenting volume from an increase in PM tethering distance. Multivariate regression analysis identified independent contributions to MR severity (vena contracta area) from both whole leaflet tenting volume (r=0.44; P<0.05) and prolapse volume (r=0.44; P<0.05). AML tenting volume decreased along with left ventricular volume and PM tethering distance postrepair (n=8; P<0.01). CONCLUSIONS: These results suggest that primary mitral valve prolapse with MR causes secondary mitral leaflet tethering with PM displacement by left ventricular dilatation, which further exacerbates valve leakage, constituting a vicious cycle that would suggest a pathophysiologic rationale for early surgical repair.

A novel electron paramagnetic resonance spin-probe technique demonstrates the relation between the production of hydroxyl radicals and ischemia-reperfusion injury.

OBJECTIVE: Many previous studies have suggested an increase in hydroxyl radical (OH) production after myocardial ischemia-reperfusion; however, traditional techniques have not been able to conclusively prove this phenomenon. We investigated whether the production of OH was increased during myocardial reperfusion using a novel electron paramagnetic resonance (EPR) technique using an OH-specific spin probe. An OH scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), was used to examine the relationship between OH production and post-ischemic functional recovery or the degree of myocardial injury. METHODS: We used an isolated rabbit-heart preparation perfused with support-rabbit blood, and the heart was reperfused after normothermic global ischemia. Heart samples were reacted with the OH-specific spin probe, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (hydroxyl-TEMPO). The rate of decay of the EPR signal showed OH production. We investigated the rate of EPR signal decay and cardiac function. RESULTS: The rate of signal decay was significantly increased just after reperfusion compared with that of pre-ischemia (2.00×10(-2)±0.77×10(-2)min(-1) vs 0.11×10(-2)±0.02×10(-2)min(-1), p<0.01). Administration of MCI-186 reduced the rate of decay to 0.86×10(-2)±0.14×10(-2)min(-1) just after reperfusion (p<0.01). Cardiac function was significantly improved 60 min after reperfusion using MCI-186 compared without MCI-186 (left ventricular developed pressure was 95±9 mm Hg vs 60±6 mm Hg and the first derivative of the left ventricular pressure (dP/dt) was 1843±200 mm Hg s(-1) vs 1182±127 mm Hg s(-1)). CONCLUSIONS: A novel EPR spin-probe technique demonstrated the relation between the production of OH and ischemia-reperfusion injury. We confirmed that OH production influenced cardiac function and myocardial ischemia-reperfusion injury.

Experimental use of an elastomeric surgical sealant for arterial hemostasis and its long-term tissue response.

OBJECTIVES: Reliable suture line hemostasis should improve the outcome of aortic surgery. We examined the hemostatic effect and the tissue response of a novel elastomeric surgical sealant. METHODS: Using porcine internal carotid arteries, we performed 16 end-to-end anastomoses with four stitches of simple interrupted sutures under full heparinization. The anastomoses were divided into two groups (eight anastomoses per group). Either novel sealant or fibrin glue was applied. The amount of bleeding was measured during the 30 s period after removing the vascular clamp. In a separate experiment, we applied the novel sealant around the abdominal aorta of rabbits (n=6) to assess the effect of the elastomeric property of the sealant on arterial wall histology. For comparison, we applied cyanoacrylate, which has no elastomeric property (n=6). A histological study was performed three months after the operation. RESULTS: The novel sealant prevented arterial bleeding. The amount of bleeding from the anastomoses applied with novel sealant and fibrin glue was 0.12+/-0.03 g vs. 91.8+/-16.5 g, respectively (P<0.001). Thinning of the rabbit aortic wall was observed in the cyanoacrylate-treated abdominal aorta, whereas no thinning was observed in the novel sealant group. Histological examination revealed neither cell death nor necrosis in the novel sealant group. CONCLUSIONS: The novel sealant effectively prevented arterial bleeding from the anastomosis under full heparinization. In addition, the elastomeric property of the sealant prevented thinning of the aortic wall. The novel sealant may be a promising hemostatic agent for arterial anastomosis.

A Rho-kinase inhibitor improves cardiac function after 24-hour heart preservation.

OBJECTIVE: The Rho-kinase signaling pathway is associated with coronary vasculopathy and myocardial dysfunction after cardiac transplantation. This study evaluated whether using a Rho-kinase inhibitor during allograft storage could limit early endothelial dysfunction and improve myocardial performance after reperfusion. METHODS: This experiment was performed with an isolated working rabbit heart model and a support rabbit. Donor hearts (control group, n = 8) were arrested with an extracellular type of cardioplegia, preserved with University of Wisconsin solution, and then immersed in University of Wisconsin solution for 24 hours (1 degrees C). The Rho-kinase inhibitor (Rho-kinase inhibitor group, n = 8) was administrated in the cardioplegic solution, the preservation University of Wisconsin solution, and the storage University of Wisconsin solution. Left ventricular performance was evaluated from the modified Frank-Starling curve in the working mode. Coronary blood flow and donor heart rate were measured in Langendorff mode. Effective evaluation of the Rho-kinase inhibitor was inferred from phosphorylated myosin light chain. The expression of endothelial nitric oxide synthase mRNA was analyzed to assess endothelial function. RESULTS: The Frank-Starling curve showed a significant left and upward shift in the Rho-kinase inhibitor group compared with the control group (P < .05). The coronary blood flow and heart rate in the Rho-kinase inhibitor group at 120 minutes was significantly higher than in the control group (P < .05). Phosphorylated myosin light chain was significantly suppressed in the Rho-kinase inhibitor group (P < .05). Endothelial nitric oxide synthase mRNA levels in the Rho-kinase inhibitor group increased 4-fold relative to those seen in the control group. CONCLUSIONS: Treatment with Rho-kinase inhibitor during allograft harvest and storage enhanced coronary blood flow and ventricular recovery through nitric oxide-dependent endothelial protection after reperfusion. Rho-kinase inhibitor could help prevent early myocardial dysfunction after transplantation.

Patent ductus arteriosus with hemiazygos communication to left superior vena cava.

We experienced the ligation of patent ductus arteriosus (PDA) via the left thoracotomy in a 24-day-old infant with inferior vena cava defect and hemiazygos communication to a persistent left superior vena cava (LSVC). Although the large hemiazygos vein (HAzV) crossed just in front of PDA, its mobilization enabled the smooth ligation of PDA without hemodynamic instability. The postoperative course was uneventful.

Elastomeric surgical sealant for hemostasis of cardiovascular anastomosis under full heparinization.

PURPOSE: We developed a novel surgical sealant, a viscous diisocyanated prepolymer, applicable to arterial hemostasis. The purpose of this study is to evaluate hemostatic effect of this surgical sealant under heparinized conditions. METHODS: The effectiveness of this sealant was verified by applying it to the end-to-end anastomosis of canine carotid arteries. Five mongrel dogs were used. After a complete heparinization, the carotid arteries were clamped, divided, and end-to-end anastomoses were performed with four simple interrupted sutures. The sealant was coated on the anastomosis. After 5 min the clamps were removed and the hemostatic effect was evaluated. Three dogs were immediately subjected to macroscopic evaluation. Two dogs were subjected to angiography after 3 months and 16 months, respectively. RESULTS: No bleeding occurred in any of the anastomoses immediately after the removal of the clamp. Macroscopic finding revealed no leakage of the sealant into the lumen. Carotid angiography revealed patent anastomoses without stenosis. CONCLUSION: A novel surgical sealant exhibited rapid and potent hemostatic effect on a moisturized tissue under full heparinization.

Risk evaluation and midterm outcome of cardiac surgery in patients on dialysis.

The medical charts of 54 patients on maintenance dialysis who underwent cardiovascular surgery (37 elective and 17 urgent/emergency) from 1994 to 2004 were retrospectively analyzed. Thirty patients had coronary artery bypass grafting (17 elective and 13 urgent/emergency), 18 had valve replacement (16 elective and 2 urgent/emergency), and 6 underwent aortic surgery (4 elective and 2 urgent/emergency). The overall early mortality rate was 11.1%, comprising 2 patients (5.4%) who had elective operations and 4 (23.5%) who had urgent or emergency operations ( p = 0.049). The overall 5-year survival rate was 48.4%. The 5-year survival rate was 67.2% for elective surgery and 10.5% for urgent/emergency surgery ( p = 0.0001). The midterm clinical results after elective cardiovascular surgery were acceptable, whereas the results after urgent/emergency surgery were poor. For elective surgery, sufficient and detailed preoperative examinations might have contributed to the better operative outcome. Early diagnosis and consultation to avoid urgent/emergency operations in dialysis patients is recommended.

Surgical experience of cardiac tumors: early and late results.

PURPOSE: Cardiac tumors include benign and malignant neoplasms that arise within the cardiac chambers or myocardium. This study summarizes our surgical experiences with cardiac tumors. METHODS: Between 1975 and 2003, 51 patients with cardiac tumors were surgically treated. RESULTS: Myxomas. Forty-seven cardiac myxomas were excised in 46 patients with an average age of 51.7 +/- 18 years. The preoperative symptoms included congestive heart failure (37%) and embolism (30%). The incidence of preoperative embolization was significantly higher in the gelatinous and lobated myxomas than in the solid and smooth form (P = 0.017). The early mortality rate was 2.2%. Although the late mortality rate was 9.7%, no patients died from cardiological causes (mean follow-up, 11.2 years). Only 1 patient required surgery for recurrence. Benign nonmyxomatous tumors. Three patients with a mean age of 26.3 +/- 19.0 years showed benign nonmyxomatous tumors. There were no perioperative or late deaths. Malignant tumors. Two patients were diagnosed to have malignant tumors and although there was no perioperative death, both died postoperatively within 6 months. CONCLUSIONS: Cardiac myxomas and nonmyxomatous benign cardiac tumors show excellent results after a surgical excision, with a low morbidity and mortality. A surgical resection should thus be considered as a treatment option for patients with malignant tumors.

The UW solution has greater potential for longer preservation periods than the Celsior solution: comparative study for ventricular and coronary endothelial function after 24-h heart preservation.

OBJECTIVE: Improvement of long-term heart preservation methods would potentially increase the donor pool and improve survival. We compared the efficacies of the University of Wisconsin (UW) and Celsior solutions on ventricular and endothelial functions after 24-h preservation. METHODS: We used an isolated heart preparation perfused with blood. The heart was excised from a rabbit, stored for 24 h in the UW or Celsior solution, and then perfused with blood from a support-rabbit. We evaluated cardiac output and coronary endothelial function. RESULTS: The Frank-Starling curve showed a significant left and upward shift in the UW group compared with that in the Celsior group (p<0.01). There were no significant differences between the groups for the coronary blood flow in response to sodium nitroprusside or acetylcholine. The serum creatine kinase MB level after reperfusion was significantly lower in the UW group than in the Celsior group (10.7+/-1.4 ng/mL vs 30.4+/-5.4 ng/mL, p<0.01), whereas lipid peroxide levels did not differ significantly between the two groups. CONCLUSIONS: The UW group showed better left ventricular function than the Celsior group, indicating that the UW solution has greater potential for long-term preservation than Celsior solution.

A comparative study of cardiac preservation with Celsior or University of Wisconsin solution with or without prior administration of cardioplegia.

BACKGROUND: We have previously reported the cardiac functional and metabolic benefits of administration of extracellular-type cardioplegia before preservation with University of Wisconsin solution. Celsior solution was designed to be used both as an arresting solution and a storage solution for heart transplantation. The objective of the present study is to compare cardiac function of hearts arrested and preserved with Celsior solution to hearts arrested with cardioplegia followed by preservation with UW solution. METHODS: Rabbit hearts were divided into 4 groups: in the Celsior group, hearts were arrested and preserved with Celsior solution; in the C-Celsior group, hearts were arrested by an extracellular-type cardioplegia and preserved with Celsior solution; in the UW group, hearts were arrested and stored in University of Wisconsin solution; and, in the C-UW group, hearts were arrested with extracellular-type cardioplegia and stored in University of Wisconsin solution. After 6 hours of preservation, cardiac function was measured using modified Frank-Starling curves in the isolated blood-perfused working heart. RESULTS: Cardiac function in the Celsior group was inferior to that in both the C-UW group and UW group. The C-Celsior group demonstrated inferior cardiac function compared with the Celsior group (p < 0.01), whereas no significant difference was observed between the C-UW and UW groups. CONCLUSIONS: Celsior solution did not surpass UW solution regardless of the use of cardioplegia. Further studies are required to develop optimal solution for use as both an arresting solution and a storage solution.

Venous cannulation for extracorporeal circulation after total cavopulmonary connection with extracardiac conduit.

We report two cases of venous cannulation after a total cavopulmonary connection (TCPC) with extracardiac conduit. Venous cannulation was performed via side graft sutured to the extracardiac conduit in an end-to-side fashion. The first case was a 3-year-old girl, who suffered from an atypical inferior vena cava obstruction after TCPC. The obstruction region was distal to the anastomosis site of extracardiac conduit and inferior vena cava. She underwent a surgical release of obstruction under cardiopulmonary bypass without circulatory arrest. The second case was a 2-year-old girl, who needed an extracorporeal membrane oxygenation support after TCPC due to severe low cardiac output syndrome. She was decannulated successfully after thirty-nine-hour support.

Angiotensin II type 1 receptor antagonist protects ventricular and coronary endothelial function after 24-hour heart preservation.

BACKGROUND: Angiotensin II type 1 (AT1) receptor antagonists may enhance the cyclic guanosine monophosphate-nitric oxide system and thereby attenuate ventricular and coronary endothelial dysfunction after heart preservation. METHODS: We used an isolated rabbit heart preparation perfused with blood from a support rabbit. The rabbit heart was excised, stored for 24 hours, and then perfused with blood from a support rabbit that was treated with an AT1 receptor antagonist (telmisartan; 5 mg/kg) or solvent. We evaluated the cardiac output with the working preparation, and coronary blood flow and coronary endothelial function with the Langendorff preparation. In addition, we measured the serum nitric oxide level in the coronary effluent. RESULTS: The Telmisartan Group showed higher plasma angiotensin II levels (928.6 +/- 136.2 vs 271.6 +/- 81.6 pg/ml, p < 0.01), better cardiac output (116.2 +/- 5.4 vs 88.8 +/- 7.1 ml/min, p < 0.05), and higher coronary blood flow (25.0 +/- 2.2 vs 14.9 +/- 1.3 ml/min, p < 0.01). The coronary blood flow in response to acetylcholine was higher in the Telmisartan Group (47.8 +/- 3.9 vs 28.0 +/- 2.1 ml/min, p < 0.01), but there was no difference in response to sodium nitroprusside. The Telmisartan Group showed higher serum nitric oxide levels in the coronary effluent (33.9 +/- 4.6 vs 20.6 +/- 3.3 mumol/liter, p < 0.05). CONCLUSIONS: Treatment with the AT1 receptor antagonist improved ventricular and endothelial function after 24-hour heart preservation. These data imply that AT1 activation plays a critical role in reperfusion injury. AT1 receptor blockade may be a promising strategy for long-term heart preservation.

Three-layered synthetic pericardial substitutes reduce postoperative pericardial adhesions.

BACKGROUND: The development of postoperative pericardial adhesions increases the risk of cardiac reoperations. The purpose of this study was to test a new pericardial substitute (UBE sheet; UBE Industries, Ltd, Tokyo, Japan) that consists of 3 layers, namely, a middle layer of polyester inserted between 2 layers of silicone-urethane copolymer. METHODS: Before implantation into the animals, platelet adhesion to the UBE sheet was evaluated in vitro. In the canine model, the UBE sheet (group I; n = 6) was implanted for 3 months. The development of adhesions, epicardial reactions, the shrink ratio of the patch, and macrophage infiltration to the epicardium with histologic examination were evaluated. As a control, an expanded polytetrafluoroethylene sheet (group II; n = 5) was implanted in the same manner. RESULTS: Scanning electron microscopy of the platelets adhered to the sheet showed that the UBE sheet was superior in biocompatibility compared with the expanded polytetrafluoroethylene sheet. In the canine study, group I showed fewer adhesions than group II (median [25th percentile, 75th percentile]: 0.0 [0.0, 0.0] vs 1.0 [1.0, 2.3]; P = .003; Mann-Whitney U test), fewer epicardial reactions (1.75 [1.0, 3.0] vs 3.0 [3.0, 3.0]; P = .034), and a smaller shrink ratio (8.0% [5.5%, 12.4%] vs 31.7% [30.0%, 44.8%]; P = .006). Immunohistologic studies showed fewer macrophage infiltrations (86 [56.8, 139.3] vs 201 [161.0, 276.5] in 3 fields; P = .045) into the epicardium of group I. CONCLUSIONS: The new 3-layered pericardial substitute clearly reduced adhesion formation. We concluded that this sheet may cause fewer adhesions and a less severe inflammatory reaction after cardiac surgery, thereby facilitating safe adhesiolysis reoperation.

Extracorporeal cardiac shock wave therapy markedly ameliorates ischemia-induced myocardial dysfunction in pigs in vivo.

BACKGROUND: Prognosis of ischemic cardiomyopathy still remains poor because of the lack of effective treatments. To develop a noninvasive therapy for the disorder, we examined the in vitro and vivo effects of extracorporeal shock wave (SW) that could enhance angiogenesis. METHODS AND RESULTS: SW treatment applied to cultured human umbilical vein endothelial cells significantly upregulated mRNA expression of vascular endothelial growth factor and its receptor Flt-1 in vitro. A porcine model of chronic myocardial ischemia was made by placing an ameroid constrictor at the proximal segment of the left circumflex coronary artery, which gradually induced a total occlusion of the artery with sustained myocardial dysfunction but without myocardial infarction in 4 weeks. Thereafter, extracorporeal SW therapy to the ischemic myocardial region (200 shots/spot for 9 spots at 0.09 mJ/mm2) was performed (n=8), which induced a complete recovery of left ventricular ejection fraction (51+/-2% to 62+/-2%), wall thickening fraction (13+/-3% to 30+/-3%), and regional myocardial blood flow (1.0+/-0.2 to 1.4+/-0.3 mL x min(-1) x g(-1)) of the ischemic region in 4 weeks (all P<0.01). By contrast, animals that did not receive the therapy (n=8) had sustained myocardial dysfunction (left ventricular ejection fraction, 48+/-3% to 48+/-1%; wall thickening fraction, 13+/-2% to 9+/-2%) and regional myocardial blood flow (1.0+/-0.3 to 0.6+/-0.1 mL x min(-1) x g(-1)). Neither arrhythmias nor other complications were observed during or after the treatment. SW treatment of the ischemic myocardium significantly upregulated vascular endothelial growth factor expression in vivo. CONCLUSIONS: These results suggest that extracorporeal cardiac SW therapy is an effective and noninvasive therapeutic strategy for ischemic heart disease.