A Novel Knitted Polytetrafluoroethylene Patch for Cardiovascular Surgery.

Polytetrafluoroethylene (PTFE) is widely used in cardiovascular surgeries; however, postoperative complications such as thrombosis, calcification, and neointimal hyperplasia are yet to be resolved in patients. We developed two types of novel knitted PTFE patches and evaluated them using a swine model. Both patches were composed of knitted PTFE impregnated with micro-PTFE particles, and one of them was pressed after PTFE impregnation. Twenty micromini pigs were used in this study. After left lateral thoracotomy, the new patches (n = 8 for each type of patch) were implanted into the descending aorta and left atrium for the high- and low-pressure models, respectively. Clinically used expanded PTFE (ePTFE) patches were used as the control material (n = 4). The patches were explanted and histopathologically examined at 4, 12, and 24 weeks after implantation. A tensile test was also applied to the high-pressure model at 12 and 24 weeks. As a result, there was no significant difference noted in the tensile test, intimal hyperplasia thickness, or endothelialization among the three patches. In contrast, the degree of macrophage infiltration into the patches and the degree of macrophage, lymphocyte, and granulocyte infiltration outside the patches were lower in the new patches than in the control ePTFE. The degree of cellular infiltration outside new patches decreased over time. There were no significant differences between the two new patch types in these results. In conclusion, our novel knitted PTFE patch showed noninferiority in durability and intensity and less inflammatory responses than a clinically used ePTFE patch.

Adult ALCAPA: from histological picture to clinical features.

BACKGROUND: Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary anomaly that results in high mortality if left untreated. Our aim was to extend our knowledge of the histological, angiographic, and clinical characteristics of ALCAPA in order to deepen our understanding of this rare entity. CASE PRESENTATION: We were involved in the assessment, treatment, and pathological evaluation of two adult ALCAPA patients who were rescued from ventricular fibrillation and then surgically treated to establish a dual coronary artery system. Histological studies indicated various chronic ischemic changes in the myocardium, patchy fibrosis, and severely thickened arteriolar walls in both ventricles. The first patient is alive and well 11.5 years after surgical correction without any implantable cardioverter defibrillator (ICD) activations. The second patient required re-do surgery 9 months after the initial operation but subsequently died. Histologically, chronic ischemic alteration of the myocardium and thickened arteriolar walls persisted even after surgical correction, and coronary angiography (CAG) showed an extremely slow flow phenomenon even after surgical correction in both patients. The average postoperative opacification rate in the first case was 7.36 + 1.12 (n = 2) in the RCA, 3.81 + 0.51 (n = 3) in the left anterior descending (LAD) artery, and 4.08 + 0.27 (n = 4) in the left circumflex (LCx) artery. The slow flow phenomenon may represent persistent high arteriolar resistance in both ventricles. CONCLUSIONS: Seldom reported or new findings in adult ALCAPA were identified in two cases. More frequent diagnosis of adult ALCAPA can be expected because of the widespread availability of resuscitation and more advanced diagnostic modalities. Accumulation of pathological and clinical findings and confirmation of the long-term follow-up results after treatment may contribute to expanding our knowledge of this rare entity and establishing optimal treatment.

Epicardial infrared ablation to create a linear conduction block on a beating right atrium.

BACKGROUND: It is still difficult to create a secure linear conduction block on a beating heart from the epicardial side. To overcome this drawback we developed an infrared coagulator equipped with a cuboid light-guiding quartz rod. This study was designed to electrophysiologically confirm the efficacy of a new ablation probe using infrared energy in a clinical case. METHODS: The infrared light from a lamp is focused into the newly developed cuboid quartz rod, which has a rectangular distal exit-plane that allows 30 mm × 10 mm linear photocoagulation. Two pairs of electrodes were attached to the right atrium of a patient who was undergoing surgery. Each pair of electrodes was placed 10 mm from an ablation line. The change in conduction time between the two pairs of electrodes was measured during ablation. The predicted conduction time delay ratio was 1.54. RESULTS: The actual conduction time after ablation was 1.38-1.43 times longer than the pre-ablation conduction time. CONCLUSIONS: The infrared ablation using a newly developed cuboid probe made it possible to create a linear conduction block on the beating right atrial free wall clinically.

Off-pump hemostasis for left ventricular rupture after myocardial infarction with Hydrofit® and Surgicel®.

Left ventricular free wall rupture (LVFWR) is a catastrophic complication of myocardial infarction. In these cases, cardiopulmonary bypass (CPB) should be performed for left ventricular repair, but can impact hemodynamic stability. An 87-year-old man presented with acute shock. He was diagnosed with LVFWR after myocardial infarction. We describe a simple, effective, and reproducible technique to achieve hemostasis at the LVFWR site during emergency operation using Hydrofit® and Surgicel® surgical hemostatic agents. We simply placed and manually pressed the Hydrofit® and Surgicel® composite on the bleeding site. This technique provides complete hemostasis without CPB establishment.

[Reconstruction of Unilateral Absent Pulmonary Artery Using Ringed Prosthetic Graft;Report of a Case].

We have repaired a unilateral absent pulmonary artery(UAPA) using a prosthetic graft with a ring. Case 1 was a 1-month old girl. The right pulmonary artery(RPA) was anti-anatomically reconstructed with a 4 mm ePTFE graft. In postoperative year 1, however, the graft became stenosed due to compression by the ascending aorta. We reversed the stenosis with a 6 mm stent by percutaneous transluminal angioplasty. Case 2 was 6-year old boy. His RPA was anatomically reconstructed with a ringed 5 mm ePTFE graft when he was 5-months old. In postoperative year 6, he needed the graft exchanged because of the relatively decreased pulmonary flow due to body growth. Therefore, we exchanged the graft with an anti-anatomically ringed 12 mm ePTFE graft. No graft stenosis was observed during the perioperative course. Using a prosthetic graft with a ring may be a good solution to avoid compression from the ascending aorta.

[Surgical Treatment of Large Muscular Ventricular Septal Defect nearby the Moderator Band Using the Sandwich Method;Report of a Case].

We describe the rare case of a 1-year-old girl who had large muscular ventricular defect (VSD) nearby the moderator band. We experienced the patch closure using sandwich method. A 1-month-old girl was referred to our institution for treatment of muscular VSD. At the age of 2 month, she underwent the pulmonary artery banding to control the pulmonary high flow. After follow up, the patient have reached 70 cm tall and weighed 7 kg. One year after the "sandwich operation", cardiac catheterization revealed the tiny residual shunt. Nevertheless, the cardiac function was good and the growth was in fine fettle. Sandwich method is a useful surgical technique to close the muscular VSD without resect the right ventricular trabeculation.