Predictors and In-Hospital Outcomes Among Patients Using a Single Versus Bilateral Mammary Arteries in Coronary Artery Bypass Grafting.

The benefit of bilateral mammary artery (BIMA) use during coronary artery bypass grafting (CABG) continues to be debated. This study examined nationwide trends in BIMA use and factors influencing its utilization. Using the National Inpatient Sample, adults undergoing isolated multivessel CABG between 2005 and 2015 were identified and stratified based on the use of a single mammary artery or BIMA. Regression models were fit to identify patient and hospital level predictors of BIMA use and characterize the association of BIMA on outcomes including sternal infection, mortality, and resource utilization. An estimated 4.5% (n = 60,698) of patients underwent CABG with BIMA, with a steady increase from 3.8% to 5.0% over time (p<0.001). Younger age, male gender, and elective admission, were significant predictors of BIMA use. Moreover, private insurance was associated with higher odds of BIMA use (adjusted odds ratio 1.24) compared with Medicare. BIMA use was not a predictor of postoperative sternal infection, in-hospital mortality, or hospitalization costs. Overall, BIMA use remains uncommon in the United States despite no significant differences in acute postoperative outcomes. Several patient, hospital, and socioeconomic factors appear to be associated with BIMA utilization.

Understanding lung transplant listing practices: Survival in lung transplant candidates who improve clinically to delisting.

BACKGROUND: Occasionally, lung transplant candidates improve to the point where they are removed from the transplant list. We sought to determine the characteristics and outcomes of lung transplant candidates who improved to delisting both before and after implementation of the lung allocation score. METHODS: Using the United Network for Organ Sharing database, we reviewed all adult patients listed for lung transplant between 1987 and 2012. The last permanent status change was classified into transplanted, improved to delisting (improved), or deteriorated to delisting (deteriorated). Survival time was calculated using the linked date of death from the Social Security Administration. Survival analysis was performed via the Kaplan-Meier method, and adjusted multivariable logistic regressions identified characteristics predicting improvement to delisting. RESULTS: Of 13,688 candidates, 12,188 (89.0%) were transplanted, 454 (3.3%) improved, and 1,046 (7.6%) deteriorated. The 5-year mortality was greater in improved (hazard ratio = 1.21 [1.07-1.38], P = .002) and deteriorated (hazard ratio = 3.36 [3.11-3.64], P < .001) candidates relative to those transplanted; however, 1-year survival was greater in improved versus transplanted candidates (75.9% vs 67.2%, log rank P < .001). Older, female patients listed for primary pulmonary hypertension and retransplantation were more likely to improve to delisting. The proportion of improved patients varied by hospital quartile volume (P < .001) and the United Network for Organ Sharing geographic region (P < .001). The number of patients improving to delisting decreased after implementation of the lung allocation score. CONCLUSION: Lung transplant candidates improving to delisting faced less short-term but greater long-term mortality relative to transplanted candidates. Given that the improved population decreased dramatically after implementation of the lung allocation score, redefining patient listing criteria appears to have improved patient appropriateness for transplant.

Prospective, open-label investigation of the pharmacokinetics of daptomycin during cardiopulmonary bypass surgery.

As methicillin-resistant Staphylococcus aureus (MRSA) becomes more prevalent, vancomycin is becoming increasingly used as a prophylaxis against surgical-site infections for cardiothoracic surgeries. However, vancomycin administration can be challenging, and the pharmacokinetics of alternative antibiotics in this setting are poorly understood. The primary objective of this investigation was to describe the pharmacokinetics of daptomycin in patients undergoing coronary artery bypass graft surgery. We enrolled 15 patients undergoing coronary artery bypass surgery requiring cardiopulmonary bypass. Each subject was administered a single open-label dose of daptomycin (8 mg/kg of body weight) for surgical prophylaxis. Fourteen daptomycin plasma samples were collected. Safety outcomes between subjects who received daptomycin and 15 control subjects who received the standard-of-care antibiotic were compared. The mean maximal concentration of daptomycin (C(max)) was 84.4 ± 27.1 µg/ml; the mean daptomycin concentration during the cardiopulmonary bypass procedure was 33.2 ± 11.4 µg/ml and was 30.9 ± 12.7 µg/ml at sternum closure. Mean daptomycin concentrations at 12, 18, 24, and 48 h were 22.7 ± 9.7, 16.2 ± 8.2, 12.0 ± 4.7, and 3.5 ± 2.3 µg/ml, respectively. Mean daptomycin concentrations were consistently above the MIC at which 90% of the tested isolates are inhibited (MIC90) for S. aureus and S. epidermidis during the cardiopulmonary bypass procedure. Daptomycin was not associated with surgical-site infections or differences in adverse events compared to findings for control subjects. We found that a single dose of daptomycin at 8 mg/kg was well tolerated and achieved adequate plasma concentrations against common pathogens associated with surgical-site infections after cardiothoracic surgery. Daptomycin may be considered an alternative surgical prophylaxis antibiotic for patients undergoing cardiothoracic bypass surgery who are unable to receive vancomycin.

Midterm results of endovascular treatment of complicated acute type B aortic dissection.

OBJECTIVES: The operative mortality and morbidity of patients with complicated acute type B aortic dissection remain high. The endovascular approach has been proposed as a potential alternative. The purpose of this study is to review the contemporary outcome of patients undergoing endovascular treatment for complicated acute type B aortic dissection. METHODS: A retrospective analysis of 28 patients undergoing endovascular interventions for acute type B aortic dissection was performed. Kaplan-Meier survival analysis was used for statistical computation. RESULTS: Indications for emergency endografting were rupture in 4 (14%) patients, severe lower body malperfusion in 8 (29%) patients, visceral/renal malperfusion in 7 (25%) patients, persistent chest pain despite proper anti-impulsive therapy in 5 (18%) patients, uncontrollable hypertension in 1 (4%) patient, and acute dilatation of false lumen with impending rupture in 3 (11%) patients. Three (11%) patients died early. Three patients died during follow-up of non-aorta-related causes. Overall survival was 82% and 78% at 1 and 5 years' follow-up, respectively. The aorta-related mortality was 10% for the entire follow-up period. Complete thrombosis of the false lumen in the thoracic aorta was achieved in 22 (85%) members of the surviving cohort, and partial thrombosis was achieved in the remainder. The rate of treatment failure according to Stanford criteria was 18% at 5 years. Mean follow-up was 36 months, and follow-up was complete in 28 (100%) patients. CONCLUSIONS: Thoracic aortic endografting for complicated acute type B aortic dissection can be performed with a relatively low postoperative morbidity and mortality in experienced hands. The endovascular approach to life-threatening complications of acute type B aortic dissection appears to have a favorable outcome in midterm follow-up.

Benign esophagobronchial fistula with and without esophageal obstruction: two ends of the surgical spectrum.

Acquired esophagobronchial fistula (EBF) is uncommon and its surgical remediation is challenging. Management depends on the cause, degree of pulmonary involvement, and existence of esophageal obstruction. We report management of two EBF cases representing extremes of the surgical spectrum. One patient with EBF secondary to mediastinal fungal infection underwent pulmonary resection and esophageal repair. Another, who was positive for human immunodeficiency virus, required esophageal resection and fistula closure, but no pulmonary resection. Successful outcome was achieved in both patients.

The correlation of near-infrared spectroscopy with changes in oxygen delivery in a controlled model of altered perfusion.

Alterations in regional tissue perfusion may precede global indications of shock. This study compared regional tissue oxygenation saturation (StO2) using near-infrared spectroscopy with standard hemodynamic and biochemical variables in 40 patients undergoing cardiopulmonary bypass (CPB). Mean arterial pressure, cardiac output, oxygen delivery, arterial blood gases, and lactate were recorded at specific intervals during surgery. Data were organized by stage of procedure, and the relationship of StO2 to established parameters was investigated. With initiation of CPB, StO2 declined by 12.9 per cent (standard deviation +/- 14.75%) with a delayed increase in lactate from 0.9 (interquartile range [IQR], 0.6-1.5) mmol/L to 2.3 (IQR, 1.8-2.5) mmol/L. The minimum StO2 value preceded the maximum lactate level by an average time of 93.9 (standard deviation +/- 86.3) minutes. Additionally, a decrease in StO2 corresponded with an increase in base deficit of 4.84 (standard deviation +/- 2.37) mEq/L over the same period. Calculated oxygen delivery decreased from a baseline value of 754 (IQR, 560-950) mL/min to 472 (IQR, 396-600) mL/min with initiation and maintenance of CPB. For patients undergoing CPB, StO2 is a reliable, noninvasive monitor of perfusion, which correlates well with oxygen delivery and identifies perfusion deficits earlier than lactate or base deficit.

Clinical patterns of surgical endocarditis.

BACKGROUND: This study was aimed at defining clinical and anatomic patterns in cases of surgical endocarditis (SE). METHODS: SE cases done between 1981 and 1997 at our metropolitan county hospital were retrospectively analyzed. RESULTS: A total of 106 consecutive episodes of SE involving 125 valves in 100 patients were studied. SE included 71 aortic, 42 mitral, and 12 tricuspid valves. The etiologies included intravenous drug abuse (IVDA) in 48 (45%) and dental source in 30 (28%). A congenitally deformed valve was present in 19 (18%). Compared to non-IVDA, IVDA episodes of SE were more often superimposed on previously normal valves (38/48 [79%] vs. 30/58 [52%])**, S. aureus infections (17/43 [40%] vs. 9/54 [17%])*, active endocarditis (38/48 [79%] vs. 32/58 [55%])*, and surgically treated on an urgent basis (10/48 [21%] vs. 4/58 [7%])*. Overall, macroemboli occurred in 53 (50%) of SE and was associated with pseudoaneurysm*, preoperative neurologic dysfunction,** and operative death.** The operative mortality (defined by Society of Thoracic Surgeons) for SE was 5/106 (4.7%). Macroembolism,** aortoventricular discontinuity,** abscesses,* pseudoaneurysm,** and preoperative renal failure* were associated with mortality. Prosthetic valve endocarditis was present in 10 of 106 episodes of SE (9.4%). *p < or = 0.05; **p < or = 0.01. CONCLUSION: (1) The aortic valve is most commonly associated with SE, (2) SE of a previously normal valve is more likely to occur with IVDA than other etiologies, (3) macroemboli occur in half of SE and is associated with an increased operative mortality.

Endograft exclusion of acute and chronic descending thoracic aortic dissections.

OBJECTIVES: To analyze the results of endograft exclusion of acute and chronic descending thoracic aortic dissections (Stanford type B) with the AneuRx (n = 5) and Talent (n = 37) thoracic devices and to compare postoperative outcomes of endograft placement acutely (<2 weeks) and for chronic interventions. METHODS: Patients treated for acute or chronic thoracic aortic dissections (Stanford type B) with endografts were included in this study. All patients (n = 42) were enrolled in investigational device exemption protocols from August 1999 to March 2005. Three-dimensional computed tomography reconstructions were analyzed for quantitative volume regression of the false lumen and changes in the true lumen over time (complete >95%, partial >30%). RESULTS: Forty-two patients, all of whom had American Society of Anesthesiologists (ASA) risk stratification > or =III and 71% with ASA > or = IV, were treated for Stanford type B dissections (acute = 25, chronic = 17), with 42 primary and 18 secondary procedures. All proximal entry sites were identified intraoperatively by intravascular ultrasound (IVUS). The procedural stroke rate was 6.7% (4/60), with three posterior circulation strokes. Procedural mortality was 6.7% (4/60). The left subclavian artery was occluded in 11 patients (26%) with no complaints of arm ischemia, but there was an association with posterior circulation strokes (2/11) (18%). No postoperative paraplegia was observed after primary or secondary intervention. Complete thrombosis of the false lumen at the level of endograft coverage occurred in 25 (61%) of 41 patients < or =1 month and 15 (88%) of 17 patients at 12 months. Volume regression of the false lumen was 66.4% (acute) and 91.9% (chronic) at 6 months. Lack of true lumen volume (contrast) increase and increasing false lumen volume (contrast) suggests continued false lumen pressurization and the need for secondary reintervention. Thirteen patients (31%) required 18 secondary interventions for proximal endoleaks in 6, junctional leaks in 3, continued perfusion of the false lumen from distal re-entry sites in 3, and surgical conversion in 4 for retrograde dissection. CONCLUSIONS: Preliminary experience with endografts to treat acute and chronic dissections is associated with a reduced risk of paraplegia and lower mortality compared with open surgical treatment, the results of medical treatment alone, or a combination.

Pulmonary embolectomy for acute massive pulmonary embolism.

BACKGROUND: Acute massive pulmonary embolism usually results in death if not diagnosed early and treated aggressively. Thrombolytic therapy and catheter embolectomy are increasingly used as definitive management. Emergent open embolectomy is often reserved as a last resort when less invasive methods have failed or the patient is in cardiopulmonary arrest. METHODS: We reviewed our experience with early open pulmonary embolectomy in patients with acute massive pulmonary embolism from January 1998 to February 2004. RESULTS: Eleven patients underwent early pulmonary embolectomy. Five (45%) patients were men, and the average age was 48 years. In 4 (36%) patients, a massive pulmonary embolism occurred after a surgical procedure or trauma. The remaining 7 patients had chronic medical diseases. The diagnosis was established primarily by clinical findings along with spiral computerized tomography or transesophageal echocardiography. Eight (73%) patients survived and were discharged from the hospital. The 3 patients who died suffered cardiac arrest preoperatively and were taken to the operating room with cardiopulmonary resuscitation in progress. Only 1 patient survived after preoperative cardiac arrest. CONCLUSIONS: Early open pulmonary embolectomy using cardiopulmonary bypass is an effective form of treatment for acute massive pulmonary embolism with excellent long-term results. Preoperative cardiac arrest is associated with a high mortality. Spiral computerized tomography and transesophageal echocardiography are important diagnostic tools.

Selective use of cardiopulmonary bypass in trauma patients.

The need for cardiopulmonary bypass (CPB) in the treatment of trauma patients is controversial, and not all level I trauma centers have CPB readily available. Our purpose was to review the selective use of CPB in the management of trauma victims at a level I trauma center in Los Angeles County. We reviewed the records of all patients for whom the CPB team was called in from 1994 to 2002. Perfusionists were present for the initial operative management of 24 patients, 22 (92%) of which were male. Twelve patients had penetrating and nine had blunt injuries, two were severely hypothermic, and the last suffered embolization of a bullet to the pulmonary artery. Overall survival was 75 per cent. Sixteen (67%) patients required CPB due to the life-threatening nature of their injuries and/or hemodynamic instability; 11 (69%) survived. The remaining 8 patients were operated on with the CPB team present but on standby; 7 (88%) survived. Cardiopulmonary bypass could be life-saving in select trauma patients with major chest injuries. Hypothermia, acidemia, and shock can be reversed earlier while allowing increased time to gain adequate exposure and perform quality repairs. Level I trauma centers should have CPB capabilities immediately available.

Administration of nesiritide in patients after coronary artery bypass surgery induces brisk diuresis.

Recombinant human brain natriuretic peptide, nesiritide, has recently been used in limited studies to enhance postoperative diuresis. A retrospective chart review was conducted at a university hospital to assess the efficacy of nesiritide in cardiac surgery patients with fluid overload refractory to diuretics and dopamine. Nine out of 137 patients who underwent coronary artery bypass grafting at the institution from May 2003 to July 2004 exhibited fluid overload despite diuretics and dopamine. Those who did not respond to the therapy, as manifested by oliguria and heart failure, were started on nesiritide. Urine output, weight change, central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), and serum creatinine were the main outcome measures. Within 6 hours after initiation of nesiritide, the average urine output increased from 28 to 130 mL/h. Serum creatinine levels were not significantly different after 24 hours. The mean CVP decreased from 14 to 10 within 12 hours while the PAWP decreased from 24 to 17 mm Hg. Systemic pressures did not change. One patient had to eventually undergo hemodialysis for complications of renal failure. Our experience demonstrates that infusion of nesiritide in patients with heart failure and fluid overload improves diuresis and hemodynamics without major side effects.

The presenting chest roentgenogram in acute type A aortic dissection: a multidisciplinary study.

Acute type A aortic dissection requires early diagnosis and prompt surgical intervention. It is not entirely clear whether patients with this form of dissection have clear-cut chest roentgenogram (CXR) patterns or whether the CXR can guide the physician in directing further workup for acute aortic dissection. The purpose of this study is to evaluate the impact of the initial CXR in arousing suspicion for acute type A aortic dissection. Twelve physicians from four specialties (emergency medicine, radiology, cardiology, and cardiothoracic surgery) evaluated the presenting CXR of ten patients with acute type A aortic dissection and the CXRs of ten normal individuals in a blinded manner. They were asked whether the CXRs were normal or abnormal (part A) and what the findings were and then were asked whether the CXRs were suspicious for acute aortic dissection (part B) and what the findings were. In part A, of the normal CXRs 81 of 120 (68%) readings were recorded as normal. Of the dissection CXRs 112 of 120 (93%) readings were recorded as abnormal (P < 0.001). In part B, the physicians were asked specifically about suspicion for aortic dissection. Of the normal CXRs 101 of 120 (84%) readings were listed as not suspicious for dissection (i.e., 16% of the normal CXRs were listed as supsicious for dissection). Of the dissection CXRs 88 of 120 (73%) readings were recorded as suspicious for dissection (p < 0.001). The most frequent findings on a dissection CXR when physicians were specifically asked about dissection included widened mediastinum in 46 of 120 (38%) followed by not suspicious for dissection in 32 of 120 (27%). Among the physician specialties the only statistically significant finding was that the cardiology group was the most likely group to find an abnormality in a "normal" CXR. This data indicates that the presenting CXR is neither sensitive nor specific for acute type A dissection. In a patient with a suspicious history or physical examination, however, a CXR showing mediastinal widening or other aortic abnormalities should increase the suspicion for dissection and warrant further workup. Furthermore in a patient with a clinical suspicion a normal CXR reading should not delay echocardiography to rule out type A dissection.