Search

This article, titled "Pulmonary Complications in Patients undergoing Sternum-sparing Coronary Artery Bypass Grafting (TCRAT)," compares the occurrence of pulmonary complications in patients undergoing sternum-sparing coronary artery bypass grafting (TCRAT) versus standard coronary artery bypass grafting (CABG) via full median sternotomy (FS). The study analyzed the records of 151 TCRAT patients and 229 FS patients who underwent elective or urgent CABG. The results showed that TCRAT patients had a higher incidence of pleural effusions compared to FS patients, but this did not significantly impact clinical outcomes. The study also found that longer operation times were associated with longer ICU stays in TCRAT patients. [Extracted from the article]

Copyright of Anaesthesist is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: In the presented retrospective study, we report on our results with partial resection of infected prosthetic grafts after aorto-bifemoral graft placement in eight male and three female patients. Methods: In all 11 patients clinical signs of infection were observed and bacteriological cultures were positive. Three patients underwent immediate surgery for perforation of an aneurysm at the distal anastomosis, eight patients underwent elective surgery. In all cases silver-coated Dacron prostheses were implanted. Assessment of outcome was based on survival, limb salvage, persistent or recurrent infection, and prosthetic graft patency. Results: In two cases, a partial wound dehiscence occurred which was treated with ambulant Vacuseal dressings for 16 and 21 days until secondary wound healing was achieved. In eight patients systemic markers of inflammation completed normalised within nine days. Follow-up CT-scans failed to demonstrate any signs of recurrent infection or peri-graft fluid collections. Patients were treated with specific antibiotic therapy for no more than three months. Post-operative bacteriological cultures were negative in all patients. The mean follow-up was 2.5±0.5 yrs. During follow-up, none of the patients died and there were no amputations. Conclusion: Despite only partial resection of the infected prostheses, the reported surgical procedure offers good results. This approach maybe particularly suitable for the treatment of elderly patients with prosthesis infections. [Copyright &y& Elsevier]

Objective: The objective of this study was to describe the diastolic pressure-flow relationship and to assess critical occlusion pressure in arterial coronary bypass grafts in human beings. Methods and results: Fifteen patients were studied following elective surgical coronary artery bypass grafting. Flow in the left internal mammary artery bypass to the left anterior descending artery was measured and simultaneously, aortic pressure, coronary sinus pressure and left ventricular end-diastolic pressure were recorded. The zero-flow pressure intercept as a measure of critical occlusion pressure was extrapolated from the linear regression analysis of the instantaneous diastolic pressure-flow relationship. Mean diastolic flow was 46 ± 17 mL min-1, mean diastolic aortic pressure was 60.5 ± 10.0 mmHg. Diastolic blood flow was linearly related to the respective aortic pressure in all patients (R-values 0.7-0.99). The regression lines had a mean slope of 2.1 ± 1.2 mL min-1 mmHg-1. Mean critical occlusion pressure was 32.3 ± 9.9 mmHg and exceeded mean coronary sinus pressure and mean left ventricular end-diastolic pressure by factors of 3.1 and 2.6, respectively. Conclusions: Our data demonstrate the presence of a vascular waterfall phenomenon in the coronary circulation after internal mammary artery bypass grafting. Critical occlusion pressure in arterial grafts considerably exceeds coronary sinus pressure as well as left ventricular end-diastolic pressure and should thus be used as the effective downstream pressure when calculating coronary perfusion pressure. Our data further suggest that the slope of diastolic pressure-flow relationships provides a more rational approach to assess regional coronary vascular resistance than conventional calculations of coronary vascular resistance. [ABSTRACT FROM AUTHOR]

The effect of AT1 receptor blockade on myocardial stunning is still somewhat ambiguous. In some prior studies, coronary occlusion was of too long duration such that the effects of infarction and stunning on the recovery of contractile function could not be distinguished. In others, blood pressure was decreased such that the improved wall excursion could be the consequence of reduced afterload and/or of attenuated stunning. The present study, therefore, investigated the effect of the AT1 receptor antagonist candesartan in a pure model of myocardial stunning with controlled systemic hemodynamics. Fourteen anesthetized open-chest dogs were subjected to 15 minutes occlusion of the left circumflex coronary artery (LCx) and 4 hours subsequent reperfusion. Systemic hemodynamics (micromanometer), regional myocardial blood flow (colored microspheres), and posterior wall thickening (PWT, sonomicrometry) were measured, and data were compared between 7 placebo controls (group 1) and 7 dogs receiving 1 mg/kg candesartan i.v. before LCx occlusion (group 2). Left ventricular peak pressure was kept constant by an intra-aortic balloon, and heart rate did not change throughout the protocol. Regional myocardial blood flow was not different between the groups under control conditions, increased in response to candesartan in group 2 (posterior subendocardial blood flow from 0.99 ± 0.18 to 1.57 ± 0.45; p < 0.05 vs. control conditions), but was not different during myocardial ischemia and at 4 hours of reperfusion between the groups. Under control conditions and during myocardial ischemia, PWT was also not different between the groups. At 4 hours of reperfusion, PWT was still depressed in group 1 (−1.5 ± 3.4 % vs. 17.7 ± 5.6 % during control conditions, p < 0.05), whereas PWT had recovered in group 2 (11.4 ± 3.7 % at 4 hours reperfusion vs. 18.3 ± 2.7 during control conditions, NS, p < 0.05 vs. group 1). In conclusion, pretreatment with the AT1 receptor antagonist candesartan improved the functional recovery of reperfused myocardium. This attenuation of myocardial stunning was not based on more favorable systemic hemodynamics or regional myocardial blood flow. [ABSTRACT FROM AUTHOR]

We report a case of large paradoxical embolisms through a patent foramen ovale in a patient with acquired heparin-induced thrombocytopenia type II (HIT). One large ventricular thrombus embolizing through the aortic valve was documented on videotape for the first time while performing transesophageal echocardiography. A 56-year-old man was admitted with acute respiratory failure initially believed to have an exacerbated chronic obstructive pulmonary disease. Arterial oxygen saturation was only 33%. He received antibiotic and anti-obstructive treatments and was mechanically ventilated for 7 days. Few hours after extubation, he developed recurrent severe dyspnea accompanied by acute pain and pulselessness in his left leg. Transthoracic echocardiography revealed an enlarged right ventricle and suggested the presence of free-floating thrombi both in the right and in the left-heart cavities. During transesophageal echocardiography, a large serpentine left-heart thrombus embolized through the aortic valve and disappeared. The patient developed ventricular fibrillation and underwent successful cardiopulmonary resuscitation including emergency thrombolysis with alteplase. Four hours later, the surgeon retrieved a 20-cm long thrombus from the left femoral artery. [ABSTRACT FROM AUTHOR]

Abstract Background More than 50% of aortocoronary saphenous vein grafts are occluded 10 years after surgery. Intimal hyperplasia is the initial critical step in the progression toward occlusion. Internal mammary veins, which are physiologically prone to less hydrostatic pressure, may undergo an accelerated progression to intimal hyperplasia and thus be suitable for investigation of the mechanisms of aortocoronary vein graft disease. Methods Six minipigs underwent aortocoronary bypass grafting using standard cardiopulmonary bypass and cardioplegic arrest. Mammary vein were grafted in a reversed manner from ascending aorta to left anterior descending coronary artery (LAD). The proximal LAD was ligated, rendering the anterior left ventricle vein graft-dependent. Minipigs were killed after 4 weeks, and vein grafts were harvested. Histological and immunohistological investigation were performed with respect to morphometric analysis, endothelial damage/dysfunction (v-Willebrand-factor (vWF)), smooth muscle cells (α-smooth actin) and proliferation rate (proliferation marker Ki 67). Results Mean intimal area of vein grafts was increased compared to ungrafted mammary veins. Intimal hyperplasia in vein grafts was characterized by massive accumulation of smooth muscle cells with a high proliferation rate and endothelial perturbation. Significant (p = 0.001) intimal hyperplasia of the grafted mammary vein compared to the ungrafted mammary vein was found. These changes were absent in ungrafted mammary veins. Conclusion The present study demonstrates a pig model of aortocoronary vein graft intimal hyperplasia which is characterized by an accelerated progression within internal mammary veins. The model is suitable to investigate the pathophysiology of aortocoronary vein graft intimal hyperplasia as well as therapeutic approaches.