Saphenous vein graft failure after coronary artery bypass surgery: pathophysiology, management, and future directions.

OBJECTIVE: To review our current understanding of the epidemiology and pathogenesis of vein graft failure (VGF), give an overview of current preventive and interventional measures, and explore strategies that may improve vein graft patency. BACKGROUND: VGF and progression of native coronary artery disease limit the long-term efficacy of coronary artery bypass graft surgery. METHODS: We reviewed the published literature on the pathophysiology, prevention, and/or treatment of VGF by searching the MEDLINE (January 1, 1966-January 1, 2012), EMBASE (January 1, 1980-January 1, 2012), and Cochrane (January 1, 1995-January 1, 2012) databases. In addition, we reviewed references from the selected articles for studies not identified in the initial search. Basic science and clinical studies were included; non-English language publications were excluded. RESULTS: Acute thrombosis, neointimal hyperplasia, and accelerated atherosclerosis are the 3 mechanisms that lead to VGF. Preventive measures include matching and quality assessment of conduit and target vessel, lipid-lowering drugs, antithrombotic therapy, and cessation of smoking. Treatment of VGF includes medical therapy, percutaneous intervention, and redo coronary artery bypass graft surgery. In patients undergoing graft intervention, the use of drug-eluting stents, antiplatelet agents, and embolic protection devices may improve clinical outcomes. CONCLUSIONS: Despite advances in management, VGF remains one of the leading causes of poor in-hospital and long-term outcomes after coronary artery bypass graft surgery. New developments in VGF prevention such as gene therapy, external graft support, fully tissue-engineered grafts, hybrid grafts, and synthetic conduits are promising but unproven. Future efforts to reduce VGF require a multidisciplinary approach with a primary focus on prevention.

Interactive financial decision support for clinical research trials.

The purpose of this article is to describe a decision support approach useful for evaluating proposals to conduct clinical research trials. Physicians often do not have the time or background to account for all the expenses of a clinical trial. Their evaluation process may be limited and driven by factors that do not indicate the potential for financial losses that a trial may impose. We analyzed clinical trial budget templates used by hospitals, health science centers, research universities, departments of medicine, and medical schools. We compiled a databank of costs and reviewed recent research trials conducted by the Department of Cardiothoracic Surgery in a major academic health science center. We then developed an interactive spreadsheet-based budgetary decision support approach that accounts for clinical trial income and costs. It can be tailored to provide quick and understandable data entry, accurate cost rates per subject, and clear go/no-go signals for the physician.

Flail chest and pulmonary contusion.

Flail chest is most often accompanied by a significant underlying pulmonary parenchymal injury and can be a life-threatening thoracic injury. Its management is often complicated by the other injuries it is frequently associated with. Similarly, mortality and morbidity are dictated most often by the associated injuries and findings. Its treatment is complex and should first be one of pain management, judicious fluid resuscitation, and excellent pulmonary toilet. In those patients requiring mechanical ventilatory support, or who require ipsilateral thoracocotomy, rib stabilization may be considered depending on a host of potentially conflicting indications and contraindications. At the end of this section are listed the current major recommendations and their levels of evidence.

Penetrating thoracic trauma.

The initial approach to penetrating thoracic trauma is directed towards the pathophysiologic syndrome upon presentation. Most patients are successfully treated with drainage tubes. The unstable patient may necessitate thoracotomy at the emergency room to drain cardiac tamponade, provide cardiac massage and control bleeding. The guidelines for this procedure are reviewed. Need for further work-up of potential injuries to other mediastinal organs is frequently screened by computerized tomography. Surgery might still be needed, on a less emergent basis, in order to repair injuries to the trachea/esophagus, retained hemothorax, or to rule out diaphragmatic injury. Laparoscopic and thoracoscopic procedures may be used in specific situations.

Evolution of a Novel Business Leadership Course for General Surgery Chief Residents.

Background General surgery chief residents are typically well equipped for board examinations but poorly trained to deal with the business challenges of surgical practice. We began a business leadership course to better prepare them for their careers. Methods Chief residents were given one-hour lectures with topics that included: Differences between private/academic practice, personal finances, contracts, practice management, legal issues and health law, and time management. Results Initial evaluations revealed that the topics covered and the presentations were well received. Subsequently, the course was moved to earlier in the academic year to prepare them for contract negotiations and then to Sunday nights to decrease interruptions and allow spouse participation. Conclusions The course evolved into a program that the chief residents feel is an important addition to their education. Moving the meetings to a weekend evening improved attendance, decreased interruptions, and allowed participation by spouses and significant others.

Readmission and mortality in patients discharged the day after off-pump coronary bypass surgery.

BACKGROUND: The fate of patients discharged the day following off-pump coronary bypass (OPCAB) has not previously been reported. We studied the mortality and readmissions of a consecutive series of patients discharged after OPCAB, and compared the outcomes of those discharged the day following surgery to the rest of the group. METHODS: All patients having OPCAB through median sternotomy during the calendar year 2000 by a single surgeon were retrospectively reviewed. Demograghics, intraoperative variables and postoperative complications, readmissions and mortality were recorded. Factors were analyzed to determine associations with time of discharge and readmission. RESULTS: One hundred fifteen patients had isolated OPCAB averaging 3.1 grafts. Two patients (1.8%) died before discharge. Sixty-three of 113 patients (55.8%) were discharged on day 1 and 8 (12.7%) required readmission compared to 13 of 50 (26%) discharged later. Diabetes (p = 0.04) and renal failure (p = 0.01) exhibited univariate association with day 1 discharge while multivariate analysis added infarction. The combination of previous bypass, obesity, acute myocardial infarction, and hypertension was associated with readmission in the entire OPCAB group but not in day 1 discharged patients. CONCLUSIONS: The readmission rate for the entire group (18.6%) was high but lower in day 1 discharge patients (12.7%). Day 1 discharge (55.8%) was unusual in patients with diabetes, renal failure, or recent infarction. Previous bypass, obesity, acute myocardial infarction, and hypertension were associated with readmission for the entire group only. Day 1 discharged patients had no deaths or serious consequences, and there were no readmissions in more than 87%.

Comparison of lipid and non-lipid markers of atherosclerosis in arterial versus venous blood.

BACKGROUND: Early studies have suggested that there may be differences in the concentration of lipoprotein particles and their associated apolipoproteins in arterial and venous blood and that this gradient might explain a proclivity to develop atherosclerotic lesions. The aim of this study was to use current methods of analysis to determine levels of these components, including particle densities and several common inflammatory markers in arterial and venous blood. METHODS: Samples of arterial and venous blood were obtained nearly simultaneously in 26 patients undergoing right and left heart catheterization. Analyses were performed using enzymatic, immunoturbidimetric and ultracentrifugation assays. RESULTS: Data obtained for total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, HDL and LDL particle density, high sensitivity C-reactive protein, serum amyloid-A and apoprotein B-100 concentrations in arterial and venous blood did not demonstrate any significant difference in the means. CONCLUSION: Arterial and venous blood can be used interchangeably to study the effect of blood concentrations of common soluble surrogate markers of atherosclerosis.

Effect of inhaled tacrolimus on ischemia reperfusion injury in rat lung transplant model.

OBJECTIVE: Systemic tacrolimus therapy has been shown to protect against lung ischemia-reperfusion injury in animal models. We sought to investigate on a functional and cellular level if inhaled nanoparticle tacrolimus administered to the donor lung before procurement could similarly attenuate ischemia-reperfusion injury after lung transplant. METHODS: An isogenic orthotopic rat model of single left lung transplant was used. Donor animals were pretreated with inhaled tacrolimus (treatment group) or inhaled lactose (controls) before lung procurement. Lung grafts were subjected to 3 hours of cold ischemia followed by 4 hours of reperfusion after graft implantation. Recipient animal arterial blood gas measurement and isograft wet to dry weight ratios were obtained. Macrophage, neutrophil, and T-cell accumulation and activation in lung isografts, including γδ T-cell, T-helper, and cytotoxic T-cell subtypes were analyzed by flow cytometry. Tacrolimus levels were measured in the lung isograft using liquid chromatography/mass spectrometry. Isograft cytokine levels were measured with commercial enzyme-linked immunosorbent assay and microbead array kits. RESULTS: Oxygenation in treatment group animals was significantly higher than in controls. The presence of macrophages, neutrophils, and all T-cell subtypes in the isografts as well as isograft levels of inflammatory cytokines were all less in the treatment group versus controls, although no single variable achieved statistical significance. CONCLUSIONS: Inhaled nanoparticle tacrolimus treatment of lung donors is associated with an attenuation of ischemia-reperfusion injury on a functional and cellular level in lung transplant.

Feasibility of video-assisted thoracoscopic surgery lobectomy in Veterans Administration patients.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) pulmonary lobectomy has been associated with decreased complication rates and length of stay compared with lobectomy by thoracotomy. No studies have addressed VATS lobectomy in Veterans Administration (VA) patients. METHODS: A retrospective review was undertaken of 50 VATS lobectomies performed between August 2007 and June 2009 by one surgeon in a VA hospital, a university-affiliated county hospital, and a private community hospital. RESULTS: VA patients had more medical comorbidities, poorer lung function, greater current smoker status, and fewer preoperative biopsies. Pleural adhesions or hilar lymphadenopathy were encountered more commonly in VA than nonfederal patients. Surgical times and number of procedures performed were greater in VA patients. There was no statistically significant difference in the risk of postoperative complications or chest tube duration although length of stay was longer for VA patients. CONCLUSIONS: VATS lobectomy is feasible in a VA setting. The evidence strongly suggests that veterans can benefit from VATS lobectomy in terms of improved outcomes and diminished length of stay compared with thoracotomy.

A bovine hemoglobin-based oxygen carrier as pump prime for cardiopulmonary bypass: reduced systemic lactic acidosis and improved cerebral oxygen metabolism during low flow in a porcine model.

OBJECTIVES: Cerebral ischemia can occur during cardiopulmonary bypass, especially during low flow. HBOC-201 (OPK Biotech, Cambridge, Mass) is a hemoglobin-based oxygen-carrying solution that enhances oxygen delivery. This project evaluated the benefits on total body and cerebral oxygen delivery and consumption using HBOC-201 during cardiopulmonary bypass. METHODS: Twelve immature swine were assigned to one of 2 groups. One group used HBOC-201 in pump prime, and the other used donor porcine blood. Cardiopulmonary bypass was initiated and then flow was serially decreased from 100% to 75%, to 50%, and then back to full flow. At each interval, (15)O positron emission tomographic analysis was performed, and blood was collected. Total body and cerebral oxygen delivery and consumption were calculated. Statistical analysis was performed with a Tukey-Kramer adjusted P value based on a repeated measures linear model on log-transformed data. RESULTS: Total and plasma hemoglobin levels were higher in the HBOC-201 group. Oxygen delivery and consumption were not statistically different but did tend to be higher in the HBOC-201 group. Mixed venous saturation was lower in the HBOC-201 group but not significant. Mild metabolic acidosis with increased lactate levels developed in the blood group. Mean cerebral blood flow decreased in both groups when total flow was 50%. In the HBOC-201 group cerebral oxygen metabolism was maintained. CONCLUSIONS: The addition of HBOC-201 for cardiopulmonary bypass appears to improve oxygen use and minimize anaerobic metabolism. Cerebral oxygen use was preserved in the HBOC-201 group, even during decrease in blood flow. These findings support the reported improved oxygen-unloading properties of HBOC-201 and might provide a benefit during cardiopulmonary bypass.

Postoperative internal thoracic artery spasm after coronary artery bypass grafting.

Spasm of the left internal thoracic artery in the perioperative period represents a life-threatening complication after coronary artery bypass grafting. We present a case in which graft spasm was treated with the administration of intra-arterial nitroglycerin and verapamil. Although vasospasm is more often seen in radial artery grafts, this case demonstrates that left internal thoracic artery grafts are also prone to spasm.

Cardiac procedures in lung transplant recipients do not increase mortality in selected patients.

BACKGROUND: Associated comorbidities in potential lung transplant recipients may significantly impact operative morbidity and mortality. We undertook this review to specifically study whether patients who underwent associated cardiac procedures either before (as a prerequisite) or during their lung transplantation had different outcomes when compared with the overall cohort of lung transplant recipients. METHODS: A retrospective chart review was performed of all patients who underwent lung transplantation at the University of Texas Health Science Center at San Antonio from January 1994 to June 2004. The records of these patients were analyzed for patient-days on the ventilator, hospital length of stay, operative morbidity and mortality, and long-term survival. The patients were then divided into two groups and compared: patients who had a cardiac intervention either prerequisite to or concurrent with their transplant (group C, n = 13) and patients who did not (group NC [no cardiac intervention], n = 120). RESULTS: Although the median length of stay was longer in group C when compared with group NC, the number of patient-days on the ventilator and the operative morbidity and mortality were similar for both groups. Likewise, overall long-term survival was not significantly different (Kaplan-Meier method, p = 0.70). CONCLUSIONS: Patients who are otherwise deemed to be good candidates for lung transplantation but are found to have an associated cardiac condition that could adversely affect their candidacy may still be considered for transplantation in selected cases if the cardiac abnormality can be addressed either before or during transplantation.

Novel truncated isoforms of constitutive serum amyloid A detected by MALDI mass spectrometry.

The main focus of the serum amyloid A (SAA) family has been on the acute phase isoforms. However, the constitutive isoform (SAA4) may have a strong effect on the metabolism of human serum lipoproteins. In this study, the SAA4 protein was examined in the high-density lipoprotein fraction of both healthy and diseased individuals. Novel isoforms of SAA4 were detected using ultracentrifugation combined with solid-phase extraction and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Three truncated isoforms were identified as well as two glycosylated isoforms. Patterns of isoform distribution may be significant for assessment of cardiovascular risk as well as direction of patient treatment.