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1.  Retroperitoneal Hematoma With Abdominal Compartment Syndrome During Minimally Invasive Mitral Valve Replacement 
The Annals of thoracic surgery  2010;89(4):e17-e18.
Although retroperitoneal hematomas most often occur secondary to trauma, they are a reported complication of ruptured aneurysms, anticoagulation therapy, and femoral vascular access. In the cardiovascular literature, retroperitoneal hematomas have occurred after percutaneous coronary interventions; however, these hematomas rarely bleed to the extent that they cause abdominal compartment syndrome. The present report describes the case of an adult patient who had a retroperitoneal hematoma develop during minimally invasive mitral valve replacement with intraoperative abdominal compartment syndrome requiring emergent surgical decompression.
PMCID: PMC4336645  PMID: 20338294
2.  Pseudoaneurysm Formation After Medtronic Freestyle Porcine Aortic Bioprosthesis Implantation: A Word of Caution 
The Annals of thoracic surgery  2014;98(6):2061-2067.
A growing literature describes aneurysmal deterioration after implantation of the stentless porcine aortic Medtronic Freestyle bioprosthesis (MFB; Medtronic Inc, Minneapolis, MN), with some suggesting inadequate tissue fixation with immune response as a cause. However, disjointed reports make the significance of these findings difficult to interpret. We address this concern by aggregating available data.
We reviewed institutional data, the Food and Drug Administration’s Manufacturer and User Facility Device Experience registry, and the medical literature for mention of aneurysm or pseudoaneurysm after MFB. Case details were aggregated, and the rate of aneurysmal deterioration was estimated. Immunohistopathologic examination of institutional explanted specimens was performed to elucidate a cause.
We found 42 cases of aneurysmal deterioration with adequate detail for analysis; all occurred with full root replacement and valve sizes ranging from 23 to 29 mm. The rate of aneurysmal deterioration considering all data sources was 1.1% (9 of 851; 95% confidence interval, 0.5% to 2.0%) vs 4.7% (4 of 86; 95% confidence interval, 1.3% to 11.5%) at our institution, where yearly surveillance imaging is performed. Rate of aneurysmal deterioration appeared constant until 5 years after the operation; however, events are reported out to 10 years. Consistent with previous reports, histopathology demonstrated an immune cell infiltrate in areas of MFB wall breakdown.
Aneurysmal deterioration is an increasingly described complication of MFB implantation as a full root, with an incidence as high as 4.7%. Given the observed immune reaction and lack of occurrence in smaller (19-mm and 21-mm) valve sizes, inadequate pressure fixation of larger valves is a potential etiology. Patients with MFB require annual surveillance imaging, and consideration of this complication should factor into preoperative decision making because treatment mandates redo root replacement, which may not be feasible in high-risk patients.
PMCID: PMC4336162  PMID: 25301369
3.  Assessment of Different Threshold Preoperative Glomerular Filtration Rates as Markers of Outcomes in Lung Transplantation 
The Annals of thoracic surgery  2014;98(1):283-290.
The evidence behind the widely used prelung transplant glomerular filtration rate (GFR) cutoff of 50 mL/min per 1.73 m2 is limited. This study reviews data from a large cohort to assess outcomes associated with this historical cutoff and to estimate other possible cutoffs that might be appropriate in lung transplantation.
We conducted a retrospective cohort analysis of lung recipients at a single center. Recursive partitioning and receiver operating characteristics analysis were used to estimate other potential GFR cutoffs with 1-year mortality as the outcome. Postoperative outcomes around the various cutoffs, including survival, acute kidney injury, and dialysis, were assessed using χ2, Kaplan-Meier, and Cox regression methods.
A total of 794 lung recipients met study inclusion criteria. Compared with 778 patients with GFR 50 mL/min per 1.73 m2 or greater at time of transplant, 16 patients with GFR below this cutoff were older and more likely to have restrictive disease. One-year mortality below the cutoff was 31.3% compared with 15.1% above the cutoff (p = 0.021). Recursive partitioning estimated potential GFR cutoff values between 46 and 61 mL/min per 1.73 m2. Patients with GFR below these cutoffs were at significantly higher risk for adverse outcomes (p < 0.05). Receiver operating characteristics analysis was less successful at identifying meaningful cutoff values with areas under the curve approximately 0.5.
Study results support the practice of requiring candidate GFR 50 mL/min per 1.73 m2 or greater for lung transplantation. Future work should focus on reproducing the analysis in a larger cohort of patients including more individuals with low GFR.
PMCID: PMC4332517  PMID: 24793682
4.  In Parallel Artificial Lung Attachment at High Flows in Normal and Pulmonary Hypertension Models 
The Annals of thoracic surgery  2010;90(1):259-265.
End stage lung disease patients who require a thoracic artificial lung (TAL) must be extubated and rehabilitated prior to lung transplantation. The purpose of this study is to evaluate hemodynamics and TAL function under simulated rest and exercise conditions in normal and pulmonary hypertension sheep models.
The TAL, the MC3 Biolung®, was attached between the pulmonary artery and left atrium in nine normal sheep and eight sheep with chronic pulmonary hypertension. An adjustable band was placed around the distal pulmonary artery to control the percentage of cardiac output (CO) diverted to the TAL. Pulmonary system hemodynamics and TAL function were assessed at baseline (no flow to the TAL) and with approximately 60, 75, and 90% of CO diverted to the TAL. Zero, 2, and 5 mcg/kg/min of intravenous dobutamine were used to simulate rest and exercise conditions.
At 0 and 2 mcg/kg/min, CO did not change significantly with flow diversion to the TAL for both models. At 5 mcg/kg/min, CO decreased with increasing TAL flow up to 28±5% in normal sheep and 23±5% in pulmonary hypertension sheep at 90% flow diversion to the artificial lung. In normal sheep, the pulmonary system zeroth harmonic impedance modulus, Z0, increased with increasing flow diversion. In hypertensive sheep, Z0 decreased at 60% and 75% flow diversion and returned to baseline levels at 90%. TAL outlet blood oxygen saturation was ≥ 95% under all conditions.
Pulmonary artery to Left atrium TAL use will not decrease CO during rest or mild exercise but may not allow more vigorous exercise.
PMCID: PMC4332709  PMID: 20609788
Artificial organs; Pulmonary vascular resistance/hypertension; Transplantation, lung; Bioengineering
5.  Factors Affecting Survival After Mitral Valve Replacement in Patients With Prosthesis–Patient Mismatch 
The Annals of thoracic surgery  2010;90(4):1202-1211.
The purpose of this study was to determine the impact of prosthesis–patient mismatch on long-term survival after mitral valve replacement.
From 1992 to 2008, 765 patients underwent bioprosthetic (325; 42%) or mechanical (440; 58%) mitral valve replacement, including 370 (48%) patients older than 65 years of age. Prosthesis–patient mismatch was defined as severe (prosthetic effective orifice area to body surface area ratio <0.9 cm2/m2), moderate (0.9 to 1.2 cm2/m2), or absent (>1.2 cm2/m2).
Multivariate analysis identified nine risk factors for late death including advanced age, earlier operative year, chronic renal insufficiency, peripheral vascular disease, congestive heart failure, nonrheumatic origin, concomitant coronary artery bypass grafting, lower body surface area, and more severe prosthesis–patient mismatch (lower effective orifice area to body surface area ratio; p < 0.05). For bioprosthetic recipients older than 65 years of age, survival at 5 and 10 years was 30% ± 7% and 0% ± 0% with severe mismatch compared with 43% ± 4% and 21% ± 5% for absent or moderate mismatch, respectively (p = 0.05). For mechanical recipients younger than 65 years of age, survival at 5 and 10 years was 77% ± 4% and 62% ± 6% with moderate or severe mismatch compared with 82% ± 3% and 66% ± 4%, respectively, without mismatch (p = 0.08).
Severe mismatch adversely affected long-term survival for older patients receiving bioprosthetic valves. With mechanical valves, there was a trend toward impaired survival when mismatch was moderate or severe in younger patients. Thus, selection of an appropriate mitral prosthesis warrants careful consideration of age and valve type.
PMCID: PMC4332802  PMID: 20868815
6.  Surgical Experience With Cardiac Papillary Fibroelastoma Over a 15-Year Period 
The Annals of thoracic surgery  2012;94(2):537-541.
Papillary fibroelastomas are rare, benign cardiac tumors. They are predominantly asymptomatic. However, they can lead to serious complications, namely thromboembolic events. Symptomatic lesions can be managed primarily with surgical excision and valvular preservation. Controversy exists as to the management of asymptomatic lesions.
All patients diagnosed with cardiac papillary fibroelastoma between 1996 and 2012 at a single institution were queried for clinical and pathologic characteristics.
Twenty-three patients with 29 lesions were identified. Most lesions were solitary, less than 1.0 cm in diameter, and occurred in patients greater than 60 years of age. The most common presentation was thromboembolic complication. All were managed successfully with surgical excision. One patient developed a recurrence or metachronous lesion within 3 months of initial surgical intervention.
Papillary fibroelastomas are rare, benign, predominantly asymptomatic cardiac tumors that can cause potentially serious complications. The natural history and etiology of papillary fibroelastomas are largely unknown. Controversy exists over the management of asymptomatic lesions. However, there is consensus that symptomatic lesions should undergo surgical excision with valvular preservation when possible. A unique case of a possible papillary fibroelastoma recurrence is also described.
PMCID: PMC4329773  PMID: 22626753
7.  Thoracic Endovascular Aortic Repair for Chronic DeBakey IIIb Aortic Dissection 
The Annals of thoracic surgery  2014;98(6):2092-2098.
Thoracic endovascular aortic repair (TEVAR) for chronic DeBakey IIIb dissection with associated descending aneurysm remains controversial. This study examines long-term results of TEVAR for this disorder including examination of anatomic features associated with TEVAR outcomes.
Between July 2005 and January 2013, 32 patients underwent TEVAR for chronic (>30 days) DeBakey IIIb dissection involving the descending thoracic aorta at a single institution and constituted the study cohort.
The mean interval from dissection to TEVAR was 32 ± 44 months (range, 1 to 146 months). There were no 30-day or in-hospital deaths, strokes, or paraplegia. During a 54-month median follow-up, there were no aortic-related deaths. Significant thoracic aneurysm sac regression (>1 cm) in the intervened segment was observed in 89%. Thoracic remodeling was not correlated with the number of visceral vessels arising from the true lumen or the number or size of residual distal fenestrations; failure of thoracic remodeling was associated with fenestrations distal to the endograft(s) in the descending thoracic aorta, most often stent graft-induced new entry tears. Complete resolution of the thoracic and abdominal false lumen after TEVAR was observed in 15.6% (n = 5). All patients in this group had all visceral vessels arising from the true lumen and fewer than three residual distal fenestrations.
Thoracic endovascular aortic repair is effective for chronic DeBakey IIIb dissection with associated descending aneurysm, with excellent 30-day and long-term outcomes and significant aortic remodeling in the vast majority of patients. Thoracic remodeling does not appear dependent on distal anatomic characteristics of the true and false lumens, although care should be taken to cover all thoracic fenestrations and avoid creation of stent graft-induced new entry tears to ensure clinical success. Complete aortic remodeling was observed only in the setting of all visceral vessels off the true lumen with fewer than three residual distal fenestrations, and this would appear the ideal anatomy for TEVAR in this scenario.
PMCID: PMC4330190  PMID: 25282168
8.  The Expanding Role of Mitral Valve Repair in Triple Valve Operations: Contemporary North American Outcomes in 8,021 Patients 
The Annals of thoracic surgery  2014;97(5):1513-1519.
Although the operative risk of multivalve operations has historically been high, current outcomes are poorly understood. We sought to evaluate factors influencing contemporary results of triple-valve operations using The Society of Thoracic Surgeons Adult Cardiac Surgery Database.
Among patients undergoing combined mitral, aortic, and tricuspid valve (triple- valve) operations between 1993 and 2011, aortic valve repair patients were excluded and those having aortic valve replacement were analyzed according to whether they underwent repair vs replacement of the mitral valve (MV) and tricuspid valve (TV). Temporal trends in operative death and clinical outcomes were examined using unadjusted and adjusted analyses.
A total of 8,021 triple-valve patients were studied. The median (25th percentile, 75th percentile) age was 67 years (59, 77 years), 4,809 (60%) were women, 4,488 (56%) had New York Heart Association class III to IV symptoms, and the mean (25th percentile, 75th percentile) ejection fraction was 50% (40%, 60%). MV repair was performed in 2,728 (34%) patients overall and increased over time from 13% (1993 to 1997) to 41% (2008 to 2011). TV repair was performed in 7,512 (94%) patients overall and increased over time from 86% (1993 to 1997) to 96% (2008 to 2011). Unadjusted operative mortality decreased from 17% in 1993 to 9% in 2011. Adjusted odds ratios (95% confidence intervals) of operative mortality were lower in those having MV repair (0.72 [0.61 to 0.85]), TV repair (0.64 [0.50 to 0.83]), and MV D TV repair (0.46 [0.34 to 0.63]) compared with those having replacements. Unadjusted and adjusted odds of stroke were similar between groups and not significant for all.
This large series demonstrates that surgical results of triple-valve operations have continued to improve during the past 18 years. MV and TV repair were associated with improvements in early survival. Although further study is required to understand late outcomes, these data suggest that broader efforts to perform MV repair instead of replacement in this high-risk patient population appear warranted.
PMCID: PMC4330191  PMID: 24680034
9.  Impact of Extracardiac Vascular Disease on Vein Graft Failure and Outcomes After Coronary Artery Bypass Surgery 
The Annals of thoracic surgery  2013;97(3):824-830.
While extracardiac vascular disease (ECVD), defined as a history of peripheral vascular disease (PVD) or cerebrovascular disease (CBVD), is common in patients undergoing coronary artery bypass graft (CABG) surgery, there are limited data available on the association between ECVD, vein graft failure (VGF), and clinical outcomes.
Using data from the Project of Ex-vivo Vein Graft Engineering via Transfection IV (PREVENTIV) trial (n = 3,014), 1-year angiographic follow-up and 5- year clinical outcomes (death, myocardial infarction, and revascularization) were determined in patients with and without ECVD. Logistic regression was used to assess risk of VGF. Generalized estimating equations methods were used to account for correlations in a graft level analysis. Kaplan-Meier estimates and Cox hazards regression were used to compare clinical outcomes. We similarly explored the association of the individual components CBVD and PVD with both VGF and clinical outcomes in an additive model.
Patients with ECVD (n=634, 21%) were older, more commonly female, and had more comorbidities, lower use of internal thoracic artery grafting, and overall worse graft quality than patients without ECVD. VGF rates tended to be higher (patient-level: odds ratio [OR]: 1.23, 95% confidence interval [CI] 0.96 to 1.58, p = 0.099; graft-level: OR: 1.23, 95% CI: 1.00 to 1.53, p = 0.053) in patients with ECVD. VGF rates were significantly higher among CBVD patients (OR: 1.42, 95% CI: 1.03 to 1.97, p = 0.035; graft-level: OR: 1.40, 95% CI: 1.06 to 1.85, p = 0.019). Patients with ECVD had a higher risk of death, myocardial infarction, or revascularization 5 years after CABG surgery (hazard ratio [HR]: 2.96, 95% CI: 2.02 to 4.35, p < 0.001). This relationship was driven by the subset of patients with PVD (HR = 3.32, 95% CI: 2.16 to 5.09, p < 0.001) and not by those with CBVD (HR = 1.10, 95% CI: 0.88 to 1.37, p = 0.40).
ECVD is common among patients undergoing CABG surgery and is associated with similar short-term but increasingly worse long-term clinical outcomes. This higher risk may be partly, but not exclusively, due to higher rates of VGF among these patients.
PMCID: PMC4324323  PMID: 24360877
10.  Influence of Patient Age on Procedural Selection in Mitral Valve Surgery 
The Annals of thoracic surgery  2010;90(5):1479-1486.
Previous studies suggest that mitral valve replacement is comparable to repair in the elderly, and a national trend exists toward tissue valves. However, few direct comparison data are available, and this study evaluated the effects of patient age on risk-adjusted survival after mitral procedures.
From 1986 to 2006, 2,064 patients underwent isolated primary mitral operations (±CABG). Maximal follow-up was 20 years with a median of 5 years. Valve disease etiology was the following: degenerative, 864; ischemic, 450; rheumatic, 416; endocarditis, 98; and “other,” 236. Overall, 58% had repair and 39% had concomitant coronary artery bypass grafting. Survival differences were evaluated with a Cox proportional hazards model that included baseline characteristics, valve disease etiology, and choice of repair versus replacement with tissue or mechanical valves.
Baseline risk profiles generally were better for mechanical valves, and age was the most significant multivariable predictor of late mortality [hazard ratio = 1.4 per 10-year increment, Wald χ2 = 32.7, p < 0.0001]. As compared with repair, risk-adjusted survival was inferior with either tissue valves [1.8, 27.6, <0.0001] or mechanical valves [1.3, 8.1, 0.0044], and no treatment interaction was observed with age (p = 0.18). At no patient age did tissue valves achieve equivalent survival to either repair or mechanical valves.
Mitral repair is associated with better survival than valve replacement across the spectrum of patient age. If replacement is required, mechanical valves achieve better outcomes, even in the elderly. These data suggest that tissue valves should be reserved only for patients with absolute contraindications to anticoagulation who are not amenable to repair.
PMCID: PMC4322678  PMID: 20971244
11.  Comparison of Outcomes Following Heart Replacement Therapy in Patients Over 65 Years Old 
The Annals of thoracic surgery  2014;99(2):582-588.
There are currently no well-defined, evidence-based guidelines for management of end stage heart failure in patients over 65 and decisions to utilize mechanical circulatory support with left ventricular assist device (LVAD), either as a bridge to transplant or destination therapy, or isolated heart transplant (HTx) remain controversial. We aim to compare outcomes following implementation of thee heart replacement strategies in this high-risk population.
We conducted a retrospective, cohort study of all patients between the age of 65–72 receiving a continuous-flow LVAD as bridge to transplant or destination therapy or isolated HTx at our center between 2005–2012. Patients were stratified according to treatment strategy into 3 groups; Group D (destination LVAD, n=23), Group B (bridge to transplant LVAD, n=43), and Group H (HTx alone, n=47). Primary outcomes of interest were survival to discharge and 2-year overall survival.
Patients in Group D were significantly older, had a higher prevalence of ischemic cardiomyopathy, and a higher pulmonary vascular resistance than patients in Groups B or H. There were no significant differences between groups in survival to discharge (87% D vs. 83.7% B vs. 87.2% H, p=0.88) or 2 year overall survival (75.7% D vs. 68.7% B vs. 80.9% H, log-rank p=0.47). Incidence rates of readmission were 1.1 events/patient*year in Group D and 0.5 events/patient*year in Group H.
There was no significant difference in perioperative, short, and medium-term survival between treatment groups. However, LVAD patients had a higher incidence of readmission. Larger trials are needed to refine differences in long-term survival, quality of life, and resource utilization for elderly patients requiring heart replacement therapy.
PMCID: PMC4314340  PMID: 25499474
Circulatory Support; Geriatric; Heart Failure; Heart Transplantation
12.  Does Pneumonectomy Have a Role in the Treatment of Stage IIIA Non-Small Cell Lung Cancer? 
The Annals of thoracic surgery  2013;95(5):1700-1707.
The role of surgical resection for stage IIIA non-small cell lung cancer (NSCLC) is unclear. We sought to examine outcomes after pneumonectomy for patients with stage IIIA disease.
All patients with stage IIIA NSCLC who had pneumonectomy at a single institution between 1999 and 2010 were reviewed. The Kaplan-Meier method was used to estimate long-term survival, and multivariable Cox proportional hazards regression was used to identify clinical characteristics associated with survival.
During the study period, 324 patients had surgical resection of stage IIIA NSCLC. Pneumonectomy was performed in 55 patients, 23 (42%) of whom had N2 disease. Induction treatment was used in 17 patients (31%) overall and in 11 of the patients (48%) with N2 disease. Perioperative mortality was 9% (n=5) overall and 18% (n=3) in patients that had received induction therapy (p=0.17). Complications occurred in 32 patients (58%). Three-year survival was 36% and five-year survival was 29% for all patients. Three-year survival was 40% for N0-1 patients and 29% for N2 patients (p=0.59). In multivariable analysis, age over 60 (HR 3.65, p=0.001), renal insufficiency (HR 5.80, p=0.007), and induction therapy (HR 2.17, p=0.05) predicted worse survival; and adjuvant therapy (HR 0.35, p=0.007) predicted improved survival.
Long-term survival after pneumonectomy for stage IIIA NSCLC is within an acceptable range, but pneumonectomy may not be appropriate after induction therapy or in patients with renal insufficiency. Patient selection and operative technique that limit perioperative morbidity and facilitates the use of adjuvant chemotherapy are critical to optimizing outcomes.
PMCID: PMC4314216  PMID: 23545195
Lung Cancer Surgery; Pneumonectomy; Outcomes
13.  [No title available] 
PMCID: PMC3912465  PMID: 24484804
14.  [No title available] 
PMCID: PMC3914158  PMID: 24484840
15.  [No title available] 
PMCID: PMC3946669  PMID: 24266949
16.  Heartware and Heartmate II Left Ventricular Assist Devices as Bridge to Transplantation: A Comparative Analysis 
The Annals of thoracic surgery  2013;97(2):506-512.
The purpose of this study is to comparatively analyze outcomes of heart transplant patients bridged to transplantation with Heartware (HW-VAD) versus Heartmate II (HMII-VAD) left ventricular assist devices.
Methods and Results
The United Network for Organ Sharing Database was reviewed to identify first-time heart transplant recipients who were bridged-to-transplantation with either HW-VAD (n=141) or HMII-VAD (n=1824) from January 2009 through July 2012. HW-VAD recipients had a higher proportion of female patients (27.0% vs. 18.9%, p=0.019), a lower body surface area (2.01 ± 0.25 vs. 2.06 ± 0.25, p=0.035), and a trend toward a higher peak percentage of panel reactive antibody against Human Leukocyte Class I antigens (40.4% ± 32.8 vs. 33.0% ± 30.4, p=0.070). Pre-transplantation recipient cardiac index (2.33 ± 0.66 vs. 2.33 ± 0.68 L/min/m2), serum creatinine (1.21 ± 0.43 vs. 1.26 ± 0.57 mg/dL), and total bilirubin (1.34 ± 3.45 vs. 1.06 ± 1.84 mg/dL) were comparable between the two groups (p>0.05 for all comparisons). Post-transplantation, there were no significant differences in freedom from rejection or freedom from cardiac allograft vasculopathy. Post-transplant graft survival rates were similar between the HW-VAD group and the HMII-VAD group at one, two and three years (88.4% vs. 87.8%, 79.9% vs. 83.8%, and 77.4% vs. 79.9%, respectively, p=0.843).
These findings suggest similar hemodynamic unloading, pre-transplant end-organ function, and post-transplant outcomes in patients bridged to transplantation with both the Heartware LVAD and Heartmate II LVAD.
PMCID: PMC4311400  PMID: 24140211
Circulatory support devices; Transplantation – heart; Outcomes
17.  Sleeve Lobectomy for Non-Small Cell Lung Cancer with N1 Nodal Disease Does Not Compromise Survival 
The Annals of thoracic surgery  2013;97(1):230-235.
We evaluated if sleeve lobectomy had worse survival compared to pneumonectomy for non-small cell lung cancer (NSCLC) with N1 disease, which may be a risk factor for locoregional recurrence.
Patients who underwent pneumonectomy or sleeve lobectomy without induction treatment for T2-3N1M0 NSCLC at a single institution from 1999-2011 were reviewed. Survival distribution was estimated with the Kaplan-Meier method, and multivariable Cox proportional hazards regression was used to evaluate the impact of resection extent on survival.
During the study period, 87 patients underwent pneumonectomy (n=52, 60%) or sleeve lobectomy (n=35, 40%) for T2-3N1M0 NSCLC. Pneumonectomy and sleeve lobectomy patients had similar mean ages (60.9±10.7 versus 63.5±12.7, p=0.30), gender distribution (69.2% [36 of 52] versus 60.0% [21 of 35] male, p=0.37), mean forced expiratory volume in one second (66.3±15.9 versus 63.5±17.6, p=0.47), stage (61.5% [32 of 52] versus 62.9% [22 of 35] stage II, p=0.90), and tumor grade (51.9% [27 of 52] versus 31.4% [11 of 35] well/moderately differentiated, p=0.17). Postoperative mortality (3.8% [2 of 52] versus 5.7% [2 of 35], p=0.68) and median length of stay (5 [IQR 4-7] versus 5 [4-7] days, p=0.68) were similar between the two groups. Three-year survival after pneumonectomy (46.8% [95% CI: 31.8-60.4%]) and sleeve lobectomy (65.2% [45.5-79.3%]) were not significantly different (p=0.23). In multivariable survival analysis that included resection extent, age, stage, and grade, only increasing age predicted worse survival (HR 1.03/year, p=0.03).
Performing sleeve lobectomy instead of pneumonectomy for NSCLC with N1 nodal disease does not compromise long-term survival.
PMCID: PMC3930644  PMID: 24206972
Lung Cancer Surgery; Lobectomy; Pneumonectomy; Outcomes
18.  Impact of Peri-Operative Acute Kidney Injury as a Severity Index for 30-day Readmission After Cardiac Surgery 
The Annals of thoracic surgery  2013;97(1):111-117.
Of patients undergoing cardiac surgery in the United States, 15–20% are re-hospitalized within 30-days. Current models to predict readmission have not evaluated the association between severity of post-operative acute kidney injury (AKI) and 30-day readmissions.
We collected data from 2,209 consecutive patients who underwent either coronary artery bypass (CABG) or valve surgery at seven member hospitals of the Northern New England Cardiovascular Disease Study Group Cardiac Surgery Registry (NNE) between July 2008 and December 2010. Administrative data at each hospital was searched to identify all patients readmitted to the index hospital within 30 days of discharge. We defined AKI Stages by the AKI Network definition of 0.3 or 50% increase (Stage 1), 2-fold increase (stage 2) and a 3-fold or 0.5 increase if the baseline serum creatinine was at least 4.0 (mg/dL) or new dialysis (stage 3). We evaluate the association between stages of AKI and 30-day readmission using multivariate logistic regression.
There were 260 patients readmitted within 30-days (12.1%). The median time to readmission was 9 (IQR 4–16) days. Patients not developing AKI following cardiac surgery had a 30-day readmission rate of 9.3% compared to patients developing AKI stage 1 (16.1%), AKI stage 2 (21.8%) and AKI stage 3 (28.6%, p <0.001). Adjusted odds ratios for AKI stage 1 (1.81; 1.35, 2.44), stage 2 (2.39; 1.38, 4.14) and stage 3 (3.47; 1.85–6.50). Models to predict readmission were significantly improved with the addition of AKI stage (c-statistic 0.65, p = 0.001) and net reclassification rate of 14.6% (95%CI: 5.05% to 24.14%, p = .003).
In addition to more traditional patient characteristics, the severity of post-operative AKI should be used when assessing a patient’s risk for readmission.
PMCID: PMC4009924  PMID: 24119985
Coronary artery bypass grafts; CABG; Kidney; renal function; failure; dialysis; Outcomes (incl mortality, morbidity, survival, etc.); Surgery; complications; Readmission
19.  Statistical Assessment of Normal Mitral Annular Geometry Using Automated 3D Echocardiographic Analysis 
The Annals of thoracic surgery  2013;97(1):71-77.
The basis of mitral annuloplasty ring design has progressed from qualitative surgical intuition to experimental and theoretical analysis of annular geometry with quantitative imaging techniques. In this work, we present an automated 3D echocardiographic (3DE) image analysis method that can be used to statistically assess variability in normal mitral annular geometry to support advancement in annuloplasty ring design.
3D patient-specific models of the mitral annulus were automatically generated from 3DE images acquired from subjects with normal mitral valve structure and function. Geometric annular measurements including annular circumference (AC), annular height (AH), septolateral diameter (SLD), intercommissural width (ICW), and the AH to ICW ratio (AHCWR) were automatically calculated. A mean 3D annular contour was computed, and principal component analysis (PCA) was used evaluate variability in normal annular shape.
The following mean ± standard deviations were obtained from 3DE image analysis: 107.0 ± 14.6 mm (AC), 7.6 ± 2.8 mm (AH), 28.5 ± 3.7 mm (SLD), 33.0 ± 5.3 mm (ICW), and 22.7 ± 6.9 % (AHCWR). PCA indicated that shape variability was primarily related to overall annular size, with more subtle variation in the skewness and height of the anterior annular peak, independent of annular diameter.
Patient-specific 3DE-based modeling of the human mitral valve enables statistical analysis of physiologically normal mitral annular geometry. The tool can potentially lead to the development of a new generation of annuloplasty rings that restore the diseased mitral valve annulus back to a truly normal geometry.
PMCID: PMC4134944  PMID: 24090576
mitral valve; mitral valve repair; echocardiography
20.  Mitral Stenosis Reversed by Medical Treatment for Heart Failure 
The Annals of thoracic surgery  2013;96(5):e115-e117.
It is reported that functional mitral stenosis frequently develops after ring annuloplasty for ischemic mitral regurgitation. The mechanism is a combination of annular size reduction by surgery and diastolic mitral valve tethering, restricting the anterior leaflet opening due to posteriorly displaced papillary muscles with left ventricular dilatation. We report the case of a 57-year-old man who had a history of successful mitral valve plasty for degenerative mitral regurgitation. Four years later he developed heart failure, severe hypertension, mild mitral regurgitation, and significant mitral stenosis, which were reversed by aggressive medical treatment for heart failure.
PMCID: PMC4281521  PMID: 24182508
21.  Current Spectrum of Surgical Procedures Performed for Ebstein’s Malformation: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database 
The Annals of thoracic surgery  2013;96(5):1703-1710.
Ebstein’s malformation is a rare congenital cardiac anomaly. Available data are limited to individual reports demonstrating highly variable approaches. We sought to understand the spectrum of surgical treatment of Ebstein’s anomaly across institutions.
A retrospective review of surgical procedures performed on patients with primary diagnosis of Ebstein’s malformation (2002 through 2009) in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) was conducted.
A total of 595 operations on 498 patients with Ebstein’s anomaly were included: 116 on neonates (19%), 122 on infants (21%), 264 on children (44%), and 93 on adults (16%). Average annual institutional case volumes were low (median, 1 per year; range, 0 to 8 per year). Neonates had a high rate of palliative procedures: systemic-to-pulmonary artery shunts with or without tricuspid valve closure (43; 37.1%) and tricuspid valve closure (10; 8.6%); Ebstein’s repair or tricuspid valvuloplasty was performed in 32%. The most common procedures among infants were superior cavopulmonary connections (62; 50.8%) and systemic-to-pulmonary shunt (10; 8.2%). Among older patients, procedures were primarily in three categories: tricuspid valve surgery (children, 54.5%; adults, 68.8%), arrhythmia procedures (children, 8.7%; adults, 17.3%), and Fontan (children, 14.8%). In-hospital mortality was high in neonatal patients (23.4%) in comparison with infants (4.1%), children (0.7%), and adults (1.1%).
Surgery for Ebstein’s anomaly consists of a wide range of procedures, with low individual institutional volumes. Mortality is highest among neonates. A prospective multicenter inception cohort study would be valuable to better define indications for specific strategies of surgical management.
PMCID: PMC4276252  PMID: 24067335
23.  Cerebral Blood Flow Autoregulation Is Preserved After Hypothermic Circulatory Arrest 
Patients undergoing aortic surgery with hypothermic circulatory arrest (HCA) may require prolonged rewarming, a maneuver associated with impaired cerebral blood flow (CBF) autoregulation. The purpose of this study was to determine the effects of HCA on CBF autoregulation with validated method based on near-infrared spectroscopy.
Regional cerebral oxygen saturation (rScO2) was monitored in 25 patients undergoing aortic reconstructive surgery. HCA was used in 13 patients. Autoregulation was measured continuously during surgery by calculating the linear correlation coefficient between lowfrequency changes in rScO2 and mean arterial pressure (MAP), generating the variable cerebral oximetry index (COx). When CBF autoregulation is functional, COx is near zero, as CBF and MAP are not correlated, but it approaches 1 when autoregulation is impaired (i.e., CBF is pressure passive). Based on prior studies, impaired autoregulation was defined as COx > 0.3.
COx did not differ between HCA and non-HCA groups before cardiopulmonary bypass or during the cooling phase of surgery, although the lower limit of autoregulation tended to be lower in patients before HCA (p=0.053). During patient rewarming, COx was lower in the HCA group (p=0.045) and abnormal COx was less frequent ( 31% vs 75%, p=0.047) compared with the non-HCA group.
During aortic reconstructive surgery, CBF autoregulation is preserved during the cooling phase of surgery in patients undergoing HCA. Perfusion maneuvers associated with HCA may be protective against impaired autoregulation during rewarming compared with the non-HCA group.
PMCID: PMC3972490  PMID: 24446562
Aorta operations; cerebral autoregulation
24.  Differential Tensile Strength and Collagen Composition in Ascending Aortic Aneurysms by Aortic Valve Phenotype 
The Annals of thoracic surgery  2013;96(6):2147-2154.
Ascending thoracic aortic aneurysm (ATAA) predisposes patients to aortic dissection and has been associated with diminished tensile strength and disruption of collagen. ATAA arising in patients with bicuspid aortic valve (BAV) develop earlier than those with tricuspid aortic valves (TAV) and have a different risk of dissection. The purpose of this study was to compare aortic wall tensile strength between BAV and TAV ATAAs and determine if the collagen content of the ATAA wall is associated with tensile strength and valve phenotype.
Longitudinally and circumferentially oriented strips of ATAA tissue obtained during elective surgery were stretched to failure and collagen content was estimated by hydroxyproline assay. Experimental stress-strain data were analyzed for failure strength and elastic mechanical parameters: α, β and maximum tangential stiffness.
The circumferential and longitudinal tensile strengths were higher for BAV ATAA when compared with TAV ATAA. The α and β were lower for BAV ATAA when compared with TAV ATAA. The maximum tangential stiffness was higher for circumferential when compared with longitudinal orientation in both BAV and TAV ATAA. Amount of hydroxyproline was equivalent in BAV and TAV ATAA specimens. While there was a moderate correlation between the collagen content and tensile strength for TAV, this correlation is not present in BAV.
The increased tensile strength and decreased values of α and β in BAV ATAAs despite uniform collagen content between groups indicate that micro-structural changes in collagen contribute to BAV-associated aortopathy.
PMCID: PMC4016718  PMID: 24021768
Aorta/aortic; Bioengineering; Aneurysm (thoracic ascending); in vitro studies
25.  Disclosure of Physician Specific Behavior Improves Blood Utilization Protocol Adherence in Cardiac Surgery 
The Annals of thoracic surgery  2013;96(6):2168-2174.
Evidence indicates that a transfusion(Tx) trigger hemoglobin(Hgb) value of 8 gm/dL may be safer than a more liberal Tx trigger in cardiac surgery(CS) patients. We hypothesized that weekly physician feedback would improve adherence to such a protocol, but that the public identification of individual physician behavior would have an additive effect.
We concurrently reviewed all adult CS patients at our institution from 12/1/2010-5/27/2011. We matched any cardiac surgery intensive care unit(CSICU) Tx event (red blood cells) with the Hgb value immediately before Tx. Patients requiring massive transfusions (>10 units/24 hours) were excluded. After all providers agreed upon a Hgb of 8 as the Tx trigger, we studied 3 consecutive time periods: no feedback, weekly feedback of group Tx behavior, and weekly feedback with identification of individual surgeon Tx behavior.
Of the 512 patients who underwent cardiac operations, 144 patients underwent 510 Tx events. Compared to period 1, the unadjusted odds of receiving a Tx above 8 gm/dL decreased by 48% in study period 2(OR: 0.52, p<0.01), and 63% in study period 3(OR: 0.37, p <0.001). Single unit transfusion rates increased from 77% to >90%(p<0.001). In hospital mortality also fell from period 1 to period 3(7.0%-1.5%, p=0.02) with the observed to expected mortality ratio decreasing from 2.19 to 0.51.
Blood transfusion protocol adherence improves when weekly feedback is provided. Identifying individual surgeon behavior improves adherence to a greater degree. Routine presentation of quality metrics with identification of individual physician specific behavior may be the most effective way to accomplish performance improvement.
PMCID: PMC4139284  PMID: 24035308
Blood; Outcomes; Postoperative Care; Resuscitation

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