Cirrhosis substantially affects morbidity and mortality in patients who undergo complex surgical ... more Cirrhosis substantially affects morbidity and mortality in patients who undergo complex surgical procedures. However, cirrhosis is not included as a parameter in standardized perioperative cardiac risk assessment models. We sought to identify the impact of cirrhosis on coronary artery bypass grafting (CABG) and off-pump CABG (OPCAB) outcomes. Using the 1998 to 2009 Nationwide Inpatient Sample databases, we identified 3,046,709 patients who underwent CABG procedures, 744,636 (24.4%) of which were OPCAB; 6,448 (0.3%) had cirrhosis. Using hierarchical multivariable regression models, we analyzed the impact of cirrhosis on in-hospital outcomes: mortality, morbidity, length of stay, hospital charges, and disposition. Severity of liver dysfunction was assessed by the Deyo-Charlson comorbidity index. In the overall CABG group, cirrhosis was independently associated with increased mortality (adjusted odds ratio [AOR] 6.9, 95% confidence interval [CI] 2.8 to 17), morbidity (AOR 1.6, 95% CI 1.3 to 2.0), length of stay (+1.2 days; p < 0.001), and hospital charges (+$22,491; p < 0.001). The prevalence of cirrhosis in the OPCAB group was 0.3% (n = 2,246); the OPCAB subgroup analysis revealed that the presence of cirrhosis did not affect mortality or morbidity unless there was severe liver dysfunction (mortality AOR 5.1, 95% CI 3.7 to 6.9; morbidity AOR 2.1, 95% CI 1.6 to 2.4). However, in the on-pump CABG patients, cirrhosis was associated with increased mortality and morbidity regardless of the severity of liver dysfunction. The impact of cirrhosis on perioperative outcomes and health care costs is significant; CABG should be performed on carefully selected cirrhotic patients and, whenever possible, without the use of cardiopulmonary bypass.
We sought to establish the feasibility and efficacy of video-assisted thoracoscopic (VATS) lobect... more We sought to establish the feasibility and efficacy of video-assisted thoracoscopic (VATS) lobectomy in treating lung cancer in a veteran population. We retrospectively analyzed preoperative, intraoperative, and postoperative parameters in 46 VATS versus 45 open lobectomy patients at a single center. The 2 groups were similar in preoperative and intraoperative variables. Although surgical mortality was not significantly different after lobectomy performed with VATS (0 of 46) compared with open lobectomy (2 of 45, 4%; P = .2), there were fewer complications in VATS patients (14 of 46, 30%) than their open counterparts (26 of 45, 58%; P = .009). VATS patients also had a shorter chest tube duration and length of stay. In multivariate analysis, VATS was associated independently with a reduced risk of complications (odds ratio, .359; P = .04). VATS lobectomy in a veteran population is feasible and safe and may lead to better perioperative outcomes than open thoracotomy without compromisi...
ABSTRACT Thoracic endovascular aortic repair (TEVAR) has been gaining popularity for the treatmen... more ABSTRACT Thoracic endovascular aortic repair (TEVAR) has been gaining popularity for the treatment of thoracoabdominal aortic aneurysm (TAAA). We used a nonvoluntary database to examine national trends and regional/hospital variations in the use of TEVAR and open thoracic aortic repair (OTAR) for TAAA. From the 2005-2008 Nationwide Inpatient Sample database, we identified all patients with the diagnosis of TAAA who were treated with TEVAR or OTAR. Rates of these procedures were compared between years, across geographic regions, and between hospitals of various bed sizes. Over the study period, the rate of OTAR remained relatively stable (range, 7.5/100 patients in 2005 to 10.1/100 patients in 2008; P = .26), whereas the rate of TEVAR increased dramatically (range, 1.4/100 patients in 2005 to 6.3/100 patients in 2008; P < .0001). In 2008, 29% (211) of all TEVAR procedures and 11% (130) of all OTAR procedures were performed in western regions of the United States (P = .03). Additionally, 13% (95) of all TEVAR procedures and 3% (35) of all OTAR procedures were performed in smaller hospitals (P < .0001). The use of TEVAR for TAAA repair increased significantly over the study period, whereas OTAR rates remained relatively stable. Our findings suggest that more patients who were otherwise not surgical candidates or did not have traditional surgical indications for OTAR were treated with TEVAR, most commonly in regions or hospitals where OTAR is less often performed. Given the complexity of TAAA cases, these results may have significant implications for patient safety in the current era of heightened health care scrutiny.
Risk models are useful in evaluating and comparing surgical outcomes, but surgeons may not always... more Risk models are useful in evaluating and comparing surgical outcomes, but surgeons may not always agree with the risk estimates derived from these models, particularly in high-risk cases. We examined the concordance between surgeons' and a risk model's predictions of operative mortality in high-risk coronary artery bypass grafting (CABG) patients, and we attempted to identify the reasons for any discrepancies. From the Veterans Affairs Continuous Improvement in Cardiac Surgery Program (CICSP), a prospective database and cardiac surgery risk model, we obtained data regarding 181 high-risk, isolated CABG cases performed at a single institution between April 1998 and April 2008. Cases were considered high risk if the surgeon estimated the patient's operative mortality risk to be ≥ 10%. We compared the mortality predictions made by surgeons and the risk model by using the signed-rank test and investigated cases in which there was a significant discrepancy (at least 2-fold) between the two predictions. The observed 30-d/in-hospital and 180-d mortality rates were 6.1% (11/181) and 11.0% (20/181), respectively. The mean operative mortality prediction made by surgeons (12.0% ± 5.3%) was higher than that made by the risk model (7.5% ± 8.5%) (P < 0.001). There was significant discrepancy between the surgeon and risk model estimates in 62% (113/181) of cases. In 53% (60/113) of these cases, the surgeon reported having considered risk factors not included in the CICSP model, including (most commonly) possible need for an additional procedure (n = 15), compromised mobility (n = 11), liver disease (n = 9), hematologic or immunologic disease (n = 6), and quality of targets (n = 5). In high-risk CABG cases, surgeon and CICSP risk estimates often disagreed markedly, partly because some disease entities of concern to surgeons are not included in the risk model. The higher mortality risk estimated by the surgeons is a better reflection of the considerable mortality risk that extends up to 180 days after surgery.
The Journal of Thoracic and Cardiovascular Surgery, 2016
To evaluate adverse outcomes after elective aortic arch surgery performed at higher or lower temp... more To evaluate adverse outcomes after elective aortic arch surgery performed at higher or lower temperatures (24.0°C-28.0°C vs 20.1°C-23.9°C) within the wide range of moderate hypothermia. Over a 9-year period, a total of 665 patients underwent elective proximal (n = 479) or total (n = 186) arch replacement with moderate hypothermia and antegrade cerebral perfusion. Circulatory arrest was initiated at an actual temperature of 20.1°C to 23.9°C in the lower-temperature group (n = 334; 223 proximal, 111 total) and at 24.0°C to 28.0°C in the higher-temperature group (n = 331; 256 proximal, 75 total). Composite adverse outcome was defined as operative mortality or persistent neurologic event or persistent hemodialysis at discharge. Multivariate logistic regression analysis was used to model adverse outcome. In addition to the actual temperature, a new, balanced variable, "predicted temperature," was analyzed to eliminate surgeon bias. We used this variable in a propensity score-matching analysis to validate the multivariate analysis results. A composite adverse outcome occurred in 7.2% of cases. Operative mortality was 5.1%. The rate of postoperative persistent neurologic deficits was 2.4%. No significant differences were found between the lower- and higher-predicted temperature groups within the moderate hypothermia range in the propensity score-matching analysis. The higher-actual temperature group had a lower rate of ventilator support at >48 hours (P = .036) and less need for tracheostomy (P = .023). Packed red blood cell transfusion and previous coronary artery bypass independently predicted composite adverse outcome (P = .0053 and .0002, respectively), operative mortality (P = .0051 and .0041), and postoperative stroke (P = .045 and .048). Cardiopulmonary bypass time independently predicted composite outcome (P = .0005), operative mortality (P < .0001), ventilatory support for >48 hours (P < .0001), and renal dysfunction (P = .0005). In elective proximal or total arch surgery, higher temperatures (≥24.0°C-28.0°C) within the wide range of moderate hypothermia (20.1°C-28°C) are safe and, compared with colder temperatures, not associated with significantly different rates of composite and adverse outcomes.
Circulation. Cardiovascular genetics, Jan 10, 2015
-ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We so... more -ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We sought to characterize these aortic diseases in a large case series of individuals with ACTA2 mutations. -Aortic disease, management, and outcome associated with the first aortic event (aortic dissection or aneurysm repair) were abstracted from the medical records of 277 individuals with 41 various ACTA2 mutations. Aortic events occurred in 48% of these individuals, with the vast majority presenting with thoracic aortic dissections (88%) associated with 25% mortality. Type A dissections were more common than type B dissections (54% versus 21%), but the median age of onset of type B dissections was significantly younger than type A dissections (27 years, IQR 18-41 versus 36 years, IQR 26-45). Only 12% of aortic events were repair of ascending aortic aneurysms, which variably involved the aortic root, ascending aorta and aortic arch. Overall cumulative risk of an aortic event at age 85 years was 0.76 (95% CI 0.64, 0.86). After adjustment for intra-familial correlation, gender and race, mutations disrupting p.R179 and p.R258 were associated with significantly increased risk for aortic events, whereas p.R185Q and p.R118Q mutations showed significantly lower risk of aortic events compared to other mutations. -ACTA2 mutations are associated with high risk of presentation with an acute aortic dissection. The lifetime risk for an aortic event is only 76%, suggesting that additional environmental or genetic factors play a role in expression of aortic disease in individuals with ACTA2 mutations.
BioGlue-a surgical adhesive composed of bovine albumin and glutaraldehyde-is commonly used in car... more BioGlue-a surgical adhesive composed of bovine albumin and glutaraldehyde-is commonly used in cardiovascular operations. The objectives of this study were to determine whether BioGlue injures nerves and cardiac conduction tissues, and whether a water-soluble gel barrier protects against such injury. In 18 pigs, diaphragmatic excursion during direct phrenic nerve stimulation was measured at baseline and at 3 and 30 min after nerve exposure to albumin (n = 3), glutaraldehyde (n = 3), BioGlue (n = 6), or water-soluble gel followed by BioGlue (n = 6). Additionally, BioGlue was applied to the cavoatrial junction overlying the sinoatrial node (SAN), either alone (n = 12) or after application of gel (n = 6). Mean diaphragmatic excursions in the BioGlue and glutaraldehyde groups were lower at 3 min and 30 min than in the albumin group (P < 0.05). Mean excursions in the gel group were similar to those of the albumin group (P = 0.9). Five BioGlue pigs (83%) and one gel pig (17%) had diaphragmatic paralysis by 30 min (P < 0.05 and P = 0.3 versus albumin, respectively). Coagulation necrosis extended into the myocardium at the cavoatrial junction in all 12 BioGlue pigs but only two gel pigs (33%, P < 0.01). Two BioGlue pigs (17%), but no gel pigs, had focal SAN degeneration and persistent bradycardia (P < 0.01). BioGlue causes acute nerve injury and myocardial necrosis that can lead to SAN damage. A water-soluble gel barrier is protective.
Purpose: The hemodynamic changes induced by infrarenal aortic crossclamping have been well docume... more Purpose: The hemodynamic changes induced by infrarenal aortic crossclamping have been well documented , but the effects of such crossclamping on cere-bral perfusion are unknown. To investigate these effects, we used near-infrared spectroscopy (NIRS) to monitor regional cerebral oxygen saturation (rSO 2) during infra-renal aortic crossclamping in a piglet model. Methods: The study involved 19 piglets, each weighing 7.8 ± 1 kg. The NIRS sensor was placed on each animal's forehead. General anesthesia was induced, and the infrarenal abdominal aorta was mobilized through a laparotomy. After heparin (1 mg/kg) was administered, crossclamps were applied proximally and distally. A 2 mm segment was resected from the proximal aortic stump, and an aorto-aortic anastomosis was performed. Results: Crossclamping lasted for 30.6 ± 6.7 min. Between the time of baseline mea
Cirrhosis substantially affects morbidity and mortality in patients who undergo complex surgical ... more Cirrhosis substantially affects morbidity and mortality in patients who undergo complex surgical procedures. However, cirrhosis is not included as a parameter in standardized perioperative cardiac risk assessment models. We sought to identify the impact of cirrhosis on coronary artery bypass grafting (CABG) and off-pump CABG (OPCAB) outcomes. Using the 1998 to 2009 Nationwide Inpatient Sample databases, we identified 3,046,709 patients who underwent CABG procedures, 744,636 (24.4%) of which were OPCAB; 6,448 (0.3%) had cirrhosis. Using hierarchical multivariable regression models, we analyzed the impact of cirrhosis on in-hospital outcomes: mortality, morbidity, length of stay, hospital charges, and disposition. Severity of liver dysfunction was assessed by the Deyo-Charlson comorbidity index. In the overall CABG group, cirrhosis was independently associated with increased mortality (adjusted odds ratio [AOR] 6.9, 95% confidence interval [CI] 2.8 to 17), morbidity (AOR 1.6, 95% CI 1.3 to 2.0), length of stay (+1.2 days; p < 0.001), and hospital charges (+$22,491; p < 0.001). The prevalence of cirrhosis in the OPCAB group was 0.3% (n = 2,246); the OPCAB subgroup analysis revealed that the presence of cirrhosis did not affect mortality or morbidity unless there was severe liver dysfunction (mortality AOR 5.1, 95% CI 3.7 to 6.9; morbidity AOR 2.1, 95% CI 1.6 to 2.4). However, in the on-pump CABG patients, cirrhosis was associated with increased mortality and morbidity regardless of the severity of liver dysfunction. The impact of cirrhosis on perioperative outcomes and health care costs is significant; CABG should be performed on carefully selected cirrhotic patients and, whenever possible, without the use of cardiopulmonary bypass.
We sought to establish the feasibility and efficacy of video-assisted thoracoscopic (VATS) lobect... more We sought to establish the feasibility and efficacy of video-assisted thoracoscopic (VATS) lobectomy in treating lung cancer in a veteran population. We retrospectively analyzed preoperative, intraoperative, and postoperative parameters in 46 VATS versus 45 open lobectomy patients at a single center. The 2 groups were similar in preoperative and intraoperative variables. Although surgical mortality was not significantly different after lobectomy performed with VATS (0 of 46) compared with open lobectomy (2 of 45, 4%; P = .2), there were fewer complications in VATS patients (14 of 46, 30%) than their open counterparts (26 of 45, 58%; P = .009). VATS patients also had a shorter chest tube duration and length of stay. In multivariate analysis, VATS was associated independently with a reduced risk of complications (odds ratio, .359; P = .04). VATS lobectomy in a veteran population is feasible and safe and may lead to better perioperative outcomes than open thoracotomy without compromisi...
ABSTRACT Thoracic endovascular aortic repair (TEVAR) has been gaining popularity for the treatmen... more ABSTRACT Thoracic endovascular aortic repair (TEVAR) has been gaining popularity for the treatment of thoracoabdominal aortic aneurysm (TAAA). We used a nonvoluntary database to examine national trends and regional/hospital variations in the use of TEVAR and open thoracic aortic repair (OTAR) for TAAA. From the 2005-2008 Nationwide Inpatient Sample database, we identified all patients with the diagnosis of TAAA who were treated with TEVAR or OTAR. Rates of these procedures were compared between years, across geographic regions, and between hospitals of various bed sizes. Over the study period, the rate of OTAR remained relatively stable (range, 7.5/100 patients in 2005 to 10.1/100 patients in 2008; P = .26), whereas the rate of TEVAR increased dramatically (range, 1.4/100 patients in 2005 to 6.3/100 patients in 2008; P < .0001). In 2008, 29% (211) of all TEVAR procedures and 11% (130) of all OTAR procedures were performed in western regions of the United States (P = .03). Additionally, 13% (95) of all TEVAR procedures and 3% (35) of all OTAR procedures were performed in smaller hospitals (P < .0001). The use of TEVAR for TAAA repair increased significantly over the study period, whereas OTAR rates remained relatively stable. Our findings suggest that more patients who were otherwise not surgical candidates or did not have traditional surgical indications for OTAR were treated with TEVAR, most commonly in regions or hospitals where OTAR is less often performed. Given the complexity of TAAA cases, these results may have significant implications for patient safety in the current era of heightened health care scrutiny.
Risk models are useful in evaluating and comparing surgical outcomes, but surgeons may not always... more Risk models are useful in evaluating and comparing surgical outcomes, but surgeons may not always agree with the risk estimates derived from these models, particularly in high-risk cases. We examined the concordance between surgeons' and a risk model's predictions of operative mortality in high-risk coronary artery bypass grafting (CABG) patients, and we attempted to identify the reasons for any discrepancies. From the Veterans Affairs Continuous Improvement in Cardiac Surgery Program (CICSP), a prospective database and cardiac surgery risk model, we obtained data regarding 181 high-risk, isolated CABG cases performed at a single institution between April 1998 and April 2008. Cases were considered high risk if the surgeon estimated the patient's operative mortality risk to be ≥ 10%. We compared the mortality predictions made by surgeons and the risk model by using the signed-rank test and investigated cases in which there was a significant discrepancy (at least 2-fold) between the two predictions. The observed 30-d/in-hospital and 180-d mortality rates were 6.1% (11/181) and 11.0% (20/181), respectively. The mean operative mortality prediction made by surgeons (12.0% ± 5.3%) was higher than that made by the risk model (7.5% ± 8.5%) (P < 0.001). There was significant discrepancy between the surgeon and risk model estimates in 62% (113/181) of cases. In 53% (60/113) of these cases, the surgeon reported having considered risk factors not included in the CICSP model, including (most commonly) possible need for an additional procedure (n = 15), compromised mobility (n = 11), liver disease (n = 9), hematologic or immunologic disease (n = 6), and quality of targets (n = 5). In high-risk CABG cases, surgeon and CICSP risk estimates often disagreed markedly, partly because some disease entities of concern to surgeons are not included in the risk model. The higher mortality risk estimated by the surgeons is a better reflection of the considerable mortality risk that extends up to 180 days after surgery.
The Journal of Thoracic and Cardiovascular Surgery, 2016
To evaluate adverse outcomes after elective aortic arch surgery performed at higher or lower temp... more To evaluate adverse outcomes after elective aortic arch surgery performed at higher or lower temperatures (24.0°C-28.0°C vs 20.1°C-23.9°C) within the wide range of moderate hypothermia. Over a 9-year period, a total of 665 patients underwent elective proximal (n = 479) or total (n = 186) arch replacement with moderate hypothermia and antegrade cerebral perfusion. Circulatory arrest was initiated at an actual temperature of 20.1°C to 23.9°C in the lower-temperature group (n = 334; 223 proximal, 111 total) and at 24.0°C to 28.0°C in the higher-temperature group (n = 331; 256 proximal, 75 total). Composite adverse outcome was defined as operative mortality or persistent neurologic event or persistent hemodialysis at discharge. Multivariate logistic regression analysis was used to model adverse outcome. In addition to the actual temperature, a new, balanced variable, "predicted temperature," was analyzed to eliminate surgeon bias. We used this variable in a propensity score-matching analysis to validate the multivariate analysis results. A composite adverse outcome occurred in 7.2% of cases. Operative mortality was 5.1%. The rate of postoperative persistent neurologic deficits was 2.4%. No significant differences were found between the lower- and higher-predicted temperature groups within the moderate hypothermia range in the propensity score-matching analysis. The higher-actual temperature group had a lower rate of ventilator support at >48 hours (P = .036) and less need for tracheostomy (P = .023). Packed red blood cell transfusion and previous coronary artery bypass independently predicted composite adverse outcome (P = .0053 and .0002, respectively), operative mortality (P = .0051 and .0041), and postoperative stroke (P = .045 and .048). Cardiopulmonary bypass time independently predicted composite outcome (P = .0005), operative mortality (P < .0001), ventilatory support for >48 hours (P < .0001), and renal dysfunction (P = .0005). In elective proximal or total arch surgery, higher temperatures (≥24.0°C-28.0°C) within the wide range of moderate hypothermia (20.1°C-28°C) are safe and, compared with colder temperatures, not associated with significantly different rates of composite and adverse outcomes.
Circulation. Cardiovascular genetics, Jan 10, 2015
-ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We so... more -ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We sought to characterize these aortic diseases in a large case series of individuals with ACTA2 mutations. -Aortic disease, management, and outcome associated with the first aortic event (aortic dissection or aneurysm repair) were abstracted from the medical records of 277 individuals with 41 various ACTA2 mutations. Aortic events occurred in 48% of these individuals, with the vast majority presenting with thoracic aortic dissections (88%) associated with 25% mortality. Type A dissections were more common than type B dissections (54% versus 21%), but the median age of onset of type B dissections was significantly younger than type A dissections (27 years, IQR 18-41 versus 36 years, IQR 26-45). Only 12% of aortic events were repair of ascending aortic aneurysms, which variably involved the aortic root, ascending aorta and aortic arch. Overall cumulative risk of an aortic event at age 85 years was 0.76 (95% CI 0.64, 0.86). After adjustment for intra-familial correlation, gender and race, mutations disrupting p.R179 and p.R258 were associated with significantly increased risk for aortic events, whereas p.R185Q and p.R118Q mutations showed significantly lower risk of aortic events compared to other mutations. -ACTA2 mutations are associated with high risk of presentation with an acute aortic dissection. The lifetime risk for an aortic event is only 76%, suggesting that additional environmental or genetic factors play a role in expression of aortic disease in individuals with ACTA2 mutations.
BioGlue-a surgical adhesive composed of bovine albumin and glutaraldehyde-is commonly used in car... more BioGlue-a surgical adhesive composed of bovine albumin and glutaraldehyde-is commonly used in cardiovascular operations. The objectives of this study were to determine whether BioGlue injures nerves and cardiac conduction tissues, and whether a water-soluble gel barrier protects against such injury. In 18 pigs, diaphragmatic excursion during direct phrenic nerve stimulation was measured at baseline and at 3 and 30 min after nerve exposure to albumin (n = 3), glutaraldehyde (n = 3), BioGlue (n = 6), or water-soluble gel followed by BioGlue (n = 6). Additionally, BioGlue was applied to the cavoatrial junction overlying the sinoatrial node (SAN), either alone (n = 12) or after application of gel (n = 6). Mean diaphragmatic excursions in the BioGlue and glutaraldehyde groups were lower at 3 min and 30 min than in the albumin group (P < 0.05). Mean excursions in the gel group were similar to those of the albumin group (P = 0.9). Five BioGlue pigs (83%) and one gel pig (17%) had diaphragmatic paralysis by 30 min (P < 0.05 and P = 0.3 versus albumin, respectively). Coagulation necrosis extended into the myocardium at the cavoatrial junction in all 12 BioGlue pigs but only two gel pigs (33%, P < 0.01). Two BioGlue pigs (17%), but no gel pigs, had focal SAN degeneration and persistent bradycardia (P < 0.01). BioGlue causes acute nerve injury and myocardial necrosis that can lead to SAN damage. A water-soluble gel barrier is protective.
Purpose: The hemodynamic changes induced by infrarenal aortic crossclamping have been well docume... more Purpose: The hemodynamic changes induced by infrarenal aortic crossclamping have been well documented , but the effects of such crossclamping on cere-bral perfusion are unknown. To investigate these effects, we used near-infrared spectroscopy (NIRS) to monitor regional cerebral oxygen saturation (rSO 2) during infra-renal aortic crossclamping in a piglet model. Methods: The study involved 19 piglets, each weighing 7.8 ± 1 kg. The NIRS sensor was placed on each animal's forehead. General anesthesia was induced, and the infrarenal abdominal aorta was mobilized through a laparotomy. After heparin (1 mg/kg) was administered, crossclamps were applied proximally and distally. A 2 mm segment was resected from the proximal aortic stump, and an aorto-aortic anastomosis was performed. Results: Crossclamping lasted for 30.6 ± 6.7 min. Between the time of baseline mea
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Papers by Scott LeMaire