Susan Eagle

Preservation solution impacts physiologic function and cellular viability of human saphenous vein graft

INTRODUCTION Recent clinical data suggest intraoperative preservation of human saphenous vein (HSV) in normal saline is associated with vein graft failure. We evaluated the influence of several preservation media on acute physiologic function and cellular viability of HSV conduit. METHODS Unprepared (UP) HSV obtained from coronary artery bypass graft patients was characterized on a muscle bath after 2-hour storage in 6 solutions: Plasma-Lyte A, 0.9% NaCl (normal saline), University of Wisconsin solution, Celsior solution, autologous whole blood, or glutathione-ascorbic acid L-arginine (GALA) solution. Vascular smooth muscle contractility was assessed after exposure to depolarizing KCl and phenylephrine. The relaxation of phenylephrine-precontracted HSV to sodium nitroprusside and carbachol (endothelial-independent and -dependent relaxation, respectively) was also assessed. Cellular viability was determined via the methyl thiazolyl tetrazolium (MTT) assay. Rat aortae were used to assess the effect of pH during graft preservation on endothelial-dependent relaxation. RESULTS Preservation of HSV in normal saline and autologous whole blood impaired contractile responses to KCl relative to UP tissues, whereas preservation in University of Wisconsin solution and Celsior solution enhanced contractile responses (P < .05). Relative to UP tissues, responses to phenylephrine were decreased with preservation in normal saline, whereas preservation in University of Wisconsin solution, Celsior solution, and GALA all potentiated these responses (P < .05). Only preservation in normal saline impaired endothelial-independent relaxation (P = .005). Preservation in Plasma-Lyte A (P = .02), normal saline (P = .002), and University of Wisconsin solution (P = .02) impaired endothelial-dependent relaxation. Normal saline preservation decreased MTT viability index relative to UP tissues (0.02 ± 0.002 mg(-1)0.5 mL(-1) vs 0.033 ± 0.005 mg(-1)0.5 mL(-1); P = .03). Endothelial function was impaired by acidic pH in rat aorta. CONCLUSION Preservation of HSV in normal saline causes graft injury leading to impaired physiologic function and decreased viability of the HSV. This harm is mitigated by the use of buffered salt solutions as preservation media.

Anesthetic management and outcomes for patients with pulmonary hypertension and intracardiac shunts and Eisenmenger syndrome: a review of institutional experience

STUDY OBJECTIVE To propose a set of recommendations for the perioperative management of patients with Eisenmenger syndrome and similar physiology, based on 20 years of experience at a single institution. DESIGN Retrospective study of institutional outcomes of Eisenmenger syndrome patients and patients with balanced or fixed right-to-left intracardiac shunts with pulmonary hypertension undergoing noncardiac surgery. SETTING Single center, university-affiliated hospital. MEASUREMENTS Measurements included data from patients with Eisenmenger syndrome or similar physiology, shunt direction, right ventricular systolic pressure, congestive heart failure classification, noncardiac surgery, type of anesthesia, echocardiographic and catheterization data, mortality within 30 days of surgery, choice of monitoring, and vasopressor use. MAIN RESULTS 33 patients with Eisenmenger syndrome or similar physiology undergoing 53 general, regional and/or monitored anesthetic procedures were identified. Significant systemic arterial hypotension occurred in 14 individuals (26%) and oxygen desaturation in 9 (17%) patients. Administration of an intravenous (IV) vasopressor agent during induction significantly decreased the incidence of hypotension. The type of IV induction agent did not influence hemodynamic alterations, though patients who received propofol experienced a trend towards increased hypotension (83% of pts) when a vasopressor was not used. Inhalational induction, regardless of vasopressor use, was more likely to result in hypotension (60% of pts). The 30-day mortality was 3.8% (two pts). Both patients had minor elective procedures with monitored anesthesia care (MAC). CONCLUSIONS Hypotension is more common in patients with Eisenmenger syndrome and similar physiology when a vasopressor is not used during the peri-induction period, regardless of induction agent. Etomidate tended to have better hemodynamic stability than other induction agents. The use of a vasopressor is recommended. We present general recommendations for anesthesiologists and strongly recommend use of a vasopressor before or during induction to reduce hypotension along with complete avoidance of inhalational induction. Further, MAC anesthesia has been associated with perioperative and 30-day mortality.

Pressure control during preparation of saphenous veins.

IMPORTANCE Long-term patency of human saphenous veins (HSVs) used as autologous conduits for coronary artery bypass grafting (CABG) procedures remains limited because of vein graft failure (VGF). Vein graft failure has been reported to be as high as 45% at 12 to 18 months after surgery and leads to additional surgery, myocardial infarction, recurrent angina, and death. Preparation of HSVs before implantation leads to conduit injury, which may promote VGF. OBJECTIVES To investigate whether pressure distension during vein graft preparation leads to endothelial injury and intimal thickening and whether limiting intraluminal pressure during pressure distension by using a pressure release valve (PRV) preserves endothelial function and prevents neointima thickening. DESIGN, SETTING, AND PARTICIPANTS Segments of HSVs were collected in a university hospital from 13 patients undergoing CABG procedures immediately after harvest (unmanipulated [UM]), after pressure distension (after distension [AD]), and after typical intraoperative surgical graft preparation (after manipulation [AM]). Porcine saphenous veins (PSVs) from 7 healthy research animals were subjected to manual pressure distension with or without an in-line PRV that prevents pressures of 140 mm Hg or greater. Endothelial function of the HSVs and PSVs was determined in a muscle bath, endothelial integrity was assessed, and intimal thickening in PSVs was evaluated after 14 days in organ culture. MAIN OUTCOMES AND MEASURES Endothelial function was measured in force, converted to stress, and defined as the percentage relaxation of maximal phenylephrine-induced contraction. Endothelial integrity was assessed by immunohistologic examination. Neointimal thickness was measured by histomorphometric analysis. RESULTS Pressure distension of HSVs led to decreased mean (SEM) endothelial-dependent relaxation (5.3% [2.3%] for AD patients vs 13.7% [2.5%] for UM patients; P < .05) and denudation. In the AM group, the function of the conduits was further decreased (-3.2% [3.2%]; P < .05). Distension of the PSVs led to reduced endothelial-dependent relaxation (7.6% [4.4%] vs 61.9% [10.2%] in the control group; P < .05), denudation, and enhanced intimal thickening (15.0 [1.4] µm vs 2.2 [0.8] µm in the control group; P < .05). Distension with the PRV preserved endothelial-dependent relaxation (50.3% [9.6%]; P = .32 vs control), prevented denudation, and reduced intimal thickening (3.4 [0.8] µm; P = .56 vs controls) in PSVs. CONCLUSIONS AND RELEVANCE Use of a PRV during graft preparation limits intraluminal pressure generated by manual distension, preserves endothelial integrity, and reduces intimal hyperplasia. Integration of this simple device may contribute to improved long-term vein graft patency.

Takotsubo Cardiomyopathy and Coronary Vasospasm During Orthotopic Liver Transplantation: Separate Entities or 'Common Mechanism?

l AKOTSUBO CARDIOMYOPATHY (idiopathic or transient left ventricular apical ballooning syndrome [ABS]) is reversible condition frequently precipitated by a stressful rigger that clinically mimics an acute ST-elevation myocardial nfarction.1 Characteristically, hypokinesis or akinesis occurs in he mid and apical segments of the left ventricle in the absence f epicardial coronary lesions. Preserved (or hyperdynamic) unction of the basal myocardial segments results in apical allooning, assuming the shape of a Japanese pot used to catch ctopus (a takotsubo). This syndrome has been reported in the perioperative setting fter both minor and major (eg, orthotopic liver transplantation) urgical procedures.2-4 Intraoperatively, ABS manifests as cariogenic shock and is displayed as ST-elevation on an electroardiogram (ECG) without angiographic evidence of coronary cclusion.5 Coronary vasospasm has also been described as a eparate entity during liver transplantation, with similar clinical igns also representative of an acute myocardial infarction.2,6,7 he authors report a patient presenting intraoperatively with imultaneous severe right coronary artery (RCA) vasospasm nd ABS during liver transplant surgery.

Detrimental effects of mechanical stretch on smooth muscle function in saphenous veins

OBJECTIVE This study evaluated the smooth muscle functional response and viability of human saphenous vein (HSV) grafts after harvest and explored the effect of mechanical stretch on contractile responses of porcine saphenous vein (PSV). METHODS The contractile responses (stress, 10(5) N/m(2)) of deidentified, remnant HSV grafts to depolarizing potassium chloride and the agonist norepinephrine were measured in a muscle organ bath. Cellular viability was evaluated using a methyl thiazole tetrazolium (MTT) assay. A PSV model was used to evaluate the effect of radial, longitudinal, and angular stretch on smooth muscle contractile responses. RESULTS Contractile responses varied greatly in HSV harvested for autologous vascular and coronary bypass procedures (0.04198 ± 0.008128 × 10(5) N/m(2) to 0.1192 ± 0.02776 × 10(5) N/m(2)). Contractility of the HSV correlated with the cellular viability of the grafts. In the PSV model, manual radial distension of ≥ 300 mm Hg had no impact on the smooth muscle responses of PSV to potassium chloride. Longitudinal and angular stretch significantly decreased the contractile function of PSV by 33.16% and 15.26%, respectively (P < .03). CONCLUSIONS There is considerable variability in HSV harvested for use as an autologous conduit. Longitudinal and angular stretching during surgical harvest impairs contractile responsiveness of the smooth muscle in saphenous vein. Avoiding stretch-induced injuries to the conduits during harvest and preparation for implantation may reduce adverse biologic responses in the graft (eg, intimal hyperplasia) and improve patency of autologous vein graft bypasses.

Transesophageal Echocardiography During Orthotopic Liver Transplantation: Maximizing Information Without the Distraction

From the Vanderbilt University School of Medicine, Department of Anesthesiology, Nashville, TN. Financial support: Departmental funding. Address reprint requests to Amy C. Robertson, MD, MMHC, Vanderbilt University School of Medicine, Department of Anesthesiology, 1301 Medical Center Drive, 4648 TVC, Nashville, TN 32732-5614. E-mail: amy.robertson@vanderbilt.edu & 2013 Elsevier Inc. All rights reserved. 1053-0770/2601-0001

The Adult With Fontan Physiology: Systematic Approach to Perioperative Management for Noncardiac Surgery

36.00/0 http://dx.doi.org/10.1053/j.jvca.2012.11.016

Extending the use of the pacing pulmonary artery catheter for safe minimally invasive cardiac surgery.

p v c SINCE 1971, Fontan palliation has been the primary surgical approach for complex congenital heart lesions not suitable or biventricular repair.1 Such lesions include hypoplastic leftheart syndrome, tricuspid atresia, unbalanced atrioventricular septal defects, double-inlet left ventricle, double-outlet right ventricle, and some forms of heterotaxy syndrome (Fig 1).1-6 The advancement of surgical techniques and medical management have resulted in greater than 90% survival rate 10 years after Fontan palliation, allowing patients with complex congenital heart lesions to survive into adulthood.7-10 As a result, atients with Fontan palliation increasingly are presenting to he adult perioperative setting for laparoscopic, obstetric, orhopedic, and other noncardiac procedures.11-14 Although it is recommended that adults with Fontan physiology be managed at centers with cardiac anesthesiologists and cardiologists who specialize in the care of the adult with congenital heart disease, emergency situations may preclude safe transport to such centers.15 As such, anesthesiologists utside of referral centers also must be familiar with the anatmy, long-term manifestations, and unique perioperative mangement of patients with Fontan palliation.

Incidental discovery of an ascending aortic thrombus: should this patient undergo surgical intervention?

OBJECTIVE In this study, the therapeutic use of pacing pulmonary artery catheters in association with minimally invasive cardiac surgery was evaluated. DESIGN A retrospective study. SETTINGS A single institutional university hospital. PARTICIPANTS Two hundred twenty-four consecutive patients undergoing minimally invasive cardiac surgery through a small (5-cm) right anterolateral thoracotomy using fibrillatory arrest without aortic cross-clamping. MEASUREMENTS AND MAIN RESULTS Two hundred eighteen patients underwent mitral valve surgery (97%) alone or in combination with other procedures. Six patients underwent other cardiac operations. In all patients, the pacing pulmonary artery catheter was used intraoperatively to induce ventricular fibrillation during the cooling period, and in the postoperative period it also was used in 37 (17%) patients who needed to be paced, mainly for bradyarrhythmias (51%). There were no complications related to the insertion of the catheters. Six (3%) patients experienced a loss of pacing capture, and 2 (1%) experienced another complication requiring the surgical removal of the catheter. Seven (3%) patients needed postoperative implantation of a permanent pacemaker. CONCLUSIONS In combination with minimally invasive cardiac surgery, pacing pulmonary artery catheters were therapeutically useful to induce ventricular fibrillatory arrest intraoperatively and for obtaining pacing capability in the postoperative period. Their use was associated with a low number of complications.

Peripheral Venous Waveform Analysis for Detecting Hemorrhage and Iatrogenic Volume Overload in a Porcine Model.

FIGURE 1. Diagnostic imaging: A, computed tomographic angiogram of the a giogram demonstrating a filling defect; C, transesophageal echocardiogram sho image. From the Department of Cardiac Surgery, the Department of Anesthesiology, and the Division of Cardiovascular Medicine, Vanderbilt Heart & Vascular Institute, Nashville, Tenn. Disclosures: None. Received for publication June 9, 2009; accepted for publication July 5, 2009; available ahead of print Aug 19, 2009. Address for reprints: John G. Byrne, MD, Vanderbilt Heart and Vascular Institute, 1215 21st Ave South, Medical Center East 5th Floor South Tower, Nashville, TN 37232-8802 (E-mail: john.byrne@vanderbilt.edu). J Thorac Cardiovasc Surg 2010;140:e14-6 0022-5223/