Joshua C. Grimm

Long-term outcomes of aortic root operations for Marfan syndrome: A comparison of Bentall versus aortic valve-sparing procedures

OBJECTIVES Prophylactic aortic root replacement improves survival in patients with Marfan syndrome with aortic root aneurysms, but the optimal procedure remains undefined. METHODS Adult patients with Marfan syndrome who had Bentall or aortic valve-sparing root replacement (VSRR) procedures between 1997 and 2013 were identified. Comprehensive follow-up information was obtained from hospital charts and telephone contact. RESULTS One hundred sixty-five adult patients with Marfan syndrome (aged > 20 years) had either VSRR (n = 98; 69 reimplantation, 29 remodeling) or Bentall (n = 67) procedures. Patients undergoing Bentall procedure were older (median, 37 vs 36 years; P = .03), had larger median preoperative sinus diameter (5.5 cm vs 5.0 cm; P = .003), more aortic dissections (25.4% vs 4.1%; P < .001), higher incidence of moderate or severe aortic insufficiency (49.3% vs 14.4%; P < .001) and more urgent or emergent operations (24.6% vs 3.3%; P < .001). There were no hospital deaths and 9 late deaths in more than 17 years of follow-up (median, 7.8 deaths). Ten-year survival was 90.5% in patients undergoing Bentall procedure and 96.3% in patients undergoing VSRR (P = .10). Multivariable analysis revealed that VSRR was associated with fewer thromboembolic or hemorrhagic events (hazard ratio, 0.16; 95% confidence interval, 0.03-0.85; P = .03). There was no independent difference in long-term survival, freedom from reoperation, or freedom from endocarditis between the 2 procedures. CONCLUSIONS After prophylactic root replacement in patients with Marfan syndrome, patients undergoing Bentall and valve-sparing procedures have similar late survival, freedom from root reoperation, and freedom from endocarditis. However, valve-sparing procedures result in significantly fewer thromboembolic and hemorrhagic events.

Nadir Oxygen Delivery on Bypass and Hypotension Increase Acute Kidney Injury Risk After Cardiac Operations.

BACKGROUND Acute kidney injury (AKI) continues to complicate cardiac operations. We sought to determine whether nadir oxygen delivery (DO2) on cardiopulmonary bypass (CPB) was a risk factor for AKI while also accounting for other postoperative factors. METHODS Using propensity scoring, we matched 85 patients who developed AKI after cardiac operations on CPB with 85 control patients who did not. We analyzed the following variables through midnight on postoperative day 1 (POD1): DO2, antibiotics, blood products and vasopressors (intraoperatively and postoperatively), and hemodynamic variables. RESULTS Univariable analysis revealed AKI patients had lower nadir DO2 on CPB (208 vs 230 mL O2/min/m(2) body surface area, p = 0.03), lower intensive care unit admission blood pressure gradient across the kidney (mean arterial pressure minus central venous pressure; 60 vs 68 mm Hg; p < 0.001), a greater proportion of patients with mean arterial pressure of less than 60 mm Hg for more than 15 minutes in the postoperative period (70% vs 42%, p < 0.001), a greater chance of having a cardiac index of less than 2.2 (74% vs 49%, p = 0.02), and greater total vasopressor use through the end of POD1 (5.2 vs 2.3 mg, p = 0.002). On multivariable analysis, predictors of AKI were a DO2 on CPB of less than 225 mL O2/min/m(2) (odds ratio, 2.46; 95% confidence interval, 1.21 to 5.03; p = 0.01) and postoperative mean arterial pressure of less than 60 mm Hg for more than 15 minutes (odds ratio, 3.96; 95% confidence interval, 1.92 to 8.20; p < 0.001). An average postoperative pressor dose greater than 0.03 μg/kg/min did not reach significance (odds ratio, 1.98; 95% confidence interval, 0.95 to 4.11; p = 0.07). CONCLUSIONS Postoperative hypotension on POD0 or POD1 and low DO2 on CPB both independently increase the AKI risk in cardiac surgical patients.

Association Between Prolonged Graft Ischemia and Primary Graft Failure or Survival Following Lung Transplantation

IMPORTANCE The effect of prolonged graft ischemia (≥6 hours) on outcomes following lung transplantation is controversial. OBJECTIVE To evaluate the effect of prolonged total graft ischemia times on long-term survival rates and the development of primary graft failure (PGF) following lung transplantation. DESIGN, SETTING, AND PARTICIPANTS In this retrospective study, the United Network for Organ Sharing database was queried for adult patients who underwent lung transplantation from May 1, 2005, through December 31, 2011. Primary stratification by the presence of prolonged graft ischemia was performed. Kaplan-Meier estimates at 1 and 5 years were used to compare survival in the 2 cohorts. A multivariable Cox proportional hazards regression model was constructed to identify predictors of 1- and 5-year mortality. A risk-adjusted predictive model for the development of PGF was formulated in a similar fashion. MAIN OUTCOMES AND MEASURES The primary outcome of interest was 1- and 5-year survival. Secondary outcomes included PGF and other postoperative events, such as renal failure, biopsy-proven rejection, and stroke. RESULTS Of the 10,225 patients who underwent lung transplantation, 3127 (30.6%) had allografts exposed to prolonged ischemia. There was no difference in survival at 1 (83.6% [95% CI, 82.3%-84.9%] vs 84.1% [95% CI, 83.3%-85.0%]; P = .41) or 5 (52.5% [95% CI, 51.0%-54.0%] vs 53.5% [95% CI, 51.3%-55.6%]; P = .82) years between patients who received grafts that were or were not exposed to ischemia that lasted 6 hours or more, respectively. Prolonged graft ischemia did not independently predict 1- or 5-year mortality or the development of PGF (odds ratio, 1.11; 95% CI, 0.88-1.39; P = .37). Furthermore, prolonged ischemia did not independently predict 1-year (hazard ratio, 1.09; 95% CI, 0.97-1.22; P =.15) or 5-year (hazard ratio, 1.05; 95% CI, 0.98-1.14; P =.18) mortality or the development of PGF (odds ratio, 1.11; 95% CI, 0.88-1.39; P =.37). CONCLUSIONS AND RELEVANCE No association was found between prolonged total graft ischemia times and primary graft failure or survival following lung transplantation. Given the scarcity of organs and the paucity of suitable recipients, prolonged ischemia time should not preclude transplantation. It is, therefore, reasonable to consider extending the accepted period of ischemia to more than 6 hours in certain patient populations to improve organ use.

Rates and predictors of readmission after minor lower extremity amputations

OBJECTIVE One goal of the Patient Protection and Affordable Care Act is to reduce hospital readmissions, with financial penalties applied for excessive rates of unplanned readmissions within 30 days among Medicare beneficiaries. Recent data indicate that as many as 24% of Medicare patients require readmission after vascular surgery, although the rate of readmission after limited digital amputations has not been specifically examined. The present study was therefore undertaken to define the rate of unplanned readmission among patients after digital amputations and to identify the factors associated with these readmissions to allow the clinician to implement strategies to reduce readmission rates in the future. METHODS The electronic medical and billing records of all patients undergoing minor amputations (defined as toe or transmetatarsal amputations using International Classification of Diseases, Ninth Revision, codes) from January 2000 through July 2012 were retrospectively reviewed. Data were collected for procedure- and hospital-related variables, level of amputation, length of stay, time to readmission, and level of reamputation. Patient demographics included hypertension, diabetes, hyperlipidemia, smoking history, and history of myocardial infarction, congestive heart failure, peripheral arterial disease, chronic obstructive pulmonary disease, and cerebrovascular accident. RESULTS Minor amputations were performed in 717 patients (62.2% male), including toe amputations in 565 (72.8%) and transmetatarsal amputations in 152 (19.5%). Readmission occurred in 100 patients (13.9%), including 28 (3.9%) within 30 days, 28 (3.9%) between 30 and 60 days, and 44 (6.1%) >60 days after the index amputation. Multivariable analysis revealed that elective admission (P < .001), peripheral arterial disease (P < .001), and chronic renal insufficiency (P = .001) were associated with readmission. The reasons for readmission were infection (49%), ischemia (29%), nonhealing wound (19%), and indeterminate (4%). Reamputation occurred in 95 (95%) of the readmitted patients, including limb amputation in 64 (64%) of the patients (below knee in 58, through knee in 2, and above knee in 4). CONCLUSIONS Readmission after minor amputation was associated with limb amputation in the majority of cases. This study identified a number of nonmodifiable patient factors that are associated with an increased risk of readmission. Whereas efforts to reduce unplanned hospital readmissions are laudable, payers and regulators should consider these observations in defining unacceptable rates of readmission. Further, although beyond the scope of this study, it is not unreasonable to assume that pressure to reduce readmission rates in the population of patients with extensive comorbidity may induce practitioners to undertake amputation at a higher level initially to minimize the risk of readmission for reamputation and associated financial penalties and thus deprive the patient the chance for limb salvage.

A Novel Risk Scoring System Reliably Predicts Readmission after Pancreatectomy

BACKGROUND Postoperative readmissions have been proposed by Medicare as a quality metric and can impact provider reimbursement. Because readmission after pancreatectomy is common, we sought to identify factors associated with readmission to establish a predictive risk scoring system. STUDY DESIGN A retrospective analysis of 2,360 pancreatectomies performed at 9 high-volume pancreatic centers between 2005 and 2011 was performed. Forty-five factors strongly associated with readmission were identified. To derive and validate a risk scoring system, the population was randomly divided into 2 cohorts in a 4:1 fashion. A multivariable logistic regression model was constructed and scores were assigned based on the relative odds ratio (OR) of each independent predictor. A composite Readmission after Pancreatectomy (RAP) score was generated and then stratified to create risk groups. RESULTS Overall, 464 (19.7%) patients were readmitted within 90 days. Eight pre- and postoperative factors, including earlier MI (OR = 2.03), American Society of Anesthesiologists class ≥ 3 (OR = 1.34), dementia (OR = 6.22), hemorrhage (OR = 1.81), delayed gastric emptying (OR = 1.78), surgical site infection (OR = 3.31), sepsis (OR = 3.10), and short length of stay (OR = 1.51) were independently predictive of readmission. The 32-point RAP score generated from the derivation cohort was highly predictive of readmission in the validation cohort (area under the receiver operating curve = 0.72). The low-risk (0 to 3), intermediate-risk (4 to 7), and high-risk (>7) groups correlated with 11.7%, 17.5%, and 45.4% observed readmission rates, respectively (p < 0.001). CONCLUSIONS The RAP score is a novel and clinically useful risk scoring system for readmission after pancreatectomy. Identification of patients with increased risk of readmission using the RAP score will allow efficient resource allocation aimed to attenuate readmission rates. It also has potential to serve as a new metric for comparative research and quality assessment.

MELD-XI Score Predicts Early Mortality in Patients After Heart Transplantation

BACKGROUND The aim of this study was to determine the utility of the Model for End-Stage Liver Disease Excluding INR (MELD-XI) in predicting early outcomes (30 days and 1 year) and late outcomes (5 years) in patients after orthotopic heart transplantation (OHT). METHODS The United Network for Organ Sharing database was queried for all adult patients (aged ≥ 18 years) undergoing OHT from 2000 to 2012. A MELD-XI was calculated and the population stratified into score quartiles. Early and late survivals were compared among the MELD-XI cohorts. Multivariable Cox proportional hazards models were constructed to determine the capacity of MELD-XI (when modeled both as a categoric and a continuous variable) to predict 30-day, 1-year, and 5-year mortality. Conditional models were also designed to determine the effect of early mortality on long-term survival. RESULTS A total of 22,597 patients were included for analysis. The MELD-XI cutoff scores were established as follows: low (≤ 10.5), low-intermediate (10.6 to 12.6), intermediate-high (12.7 to 16.4), and high (>16.4). The high MELD-XI cohort experienced statistically worse 30-day, 1-year, and 5-year unconditional survivals when compared with patients with low scores (p < 0.001). Similarly, a high MELD-XI score was also predictive of early and late mortality (p < 0.001) after risk adjustment. There was, however, no difference in 5-year survival between the high score and low score cohorts after accounting for 1-year deaths. Subanalysis of patients bridged to transplant with a continuous-flow left ventricular assist device demonstrated similar findings. CONCLUSIONS This is the first known study to examine the relationship between a high MELD-XI score and outcomes in patients after OHT. Patients with hepatic or renal dysfunction before OHT should be closely monitored and aggressively optimized as early mortality appears to drive long-term outcomes.

Southern surgical association articleA Novel Risk Scoring System Reliably Predicts Readmission after Pancreatectomy

BACKGROUND Postoperative readmissions have been proposed by Medicare as a quality metric and can impact provider reimbursement. Because readmission after pancreatectomy is common, we sought to identify factors associated with readmission to establish a predictive risk scoring system. STUDY DESIGN A retrospective analysis of 2,360 pancreatectomies performed at 9 high-volume pancreatic centers between 2005 and 2011 was performed. Forty-five factors strongly associated with readmission were identified. To derive and validate a risk scoring system, the population was randomly divided into 2 cohorts in a 4:1 fashion. A multivariable logistic regression model was constructed and scores were assigned based on the relative odds ratio (OR) of each independent predictor. A composite Readmission after Pancreatectomy (RAP) score was generated and then stratified to create risk groups. RESULTS Overall, 464 (19.7%) patients were readmitted within 90 days. Eight pre- and postoperative factors, including earlier MI (OR = 2.03), American Society of Anesthesiologists class ≥ 3 (OR = 1.34), dementia (OR = 6.22), hemorrhage (OR = 1.81), delayed gastric emptying (OR = 1.78), surgical site infection (OR = 3.31), sepsis (OR = 3.10), and short length of stay (OR = 1.51) were independently predictive of readmission. The 32-point RAP score generated from the derivation cohort was highly predictive of readmission in the validation cohort (area under the receiver operating curve = 0.72). The low-risk (0 to 3), intermediate-risk (4 to 7), and high-risk (>7) groups correlated with 11.7%, 17.5%, and 45.4% observed readmission rates, respectively (p < 0.001). CONCLUSIONS The RAP score is a novel and clinically useful risk scoring system for readmission after pancreatectomy. Identification of patients with increased risk of readmission using the RAP score will allow efficient resource allocation aimed to attenuate readmission rates. It also has potential to serve as a new metric for comparative research and quality assessment.

Generation-6 hydroxyl PAMAM dendrimers improve CNS penetration from intravenous administration in a large animal brain injury model

&NA; Hypothermic circulatory arrest (HCA) provides neuroprotection during cardiac surgery but entails an ischemic period that can lead to excitotoxicity, neuroinflammation, and subsequent neurologic injury. Hydroxyl polyamidoamine (PAMAM) dendrimers target activated microglia and damaged neurons in the injured brain, and deliver therapeutics in small and large animal models. We investigated the effect of dendrimer size on brain uptake and explored the pharmacokinetics in a clinically‐relevant canine model of HCA‐induced brain injury. Generation 6 (G6, ˜6.7 nm) dendrimers showed extended blood circulation times and increased accumulation in the injured brain compared to generation 4 dendrimers (G4, ˜4.3 nm), which were undetectable in the brain by 48 h after final administration. High levels of G6 dendrimers were found in cerebrospinal fluid (CSF) of injured animals with a CSF/serum ratio of ˜20% at peak, a ratio higher than that of many neurologic pharmacotherapies already in clinical use. Brain penetration (measured by drug CSF/serum level) of G6 dendrimers correlated with the severity of neuroinflammation observed. G6 dendrimers also showed decreased renal clearance rate, slightly increased liver and spleen uptake compared to G4 dendrimers. These results, in a large animal model, may offer insights into the potential clinical translation of dendrimers. Graphical abstract Figure. No caption available.

A Risk Score to Predict Acute Renal Failure in Adult Patients After Lung Transplantation

BACKGROUND Despite the significant morbidity associated with renal failure after lung transplantation (LTx), no predictive models currently exist. Accordingly, the purpose of this study was to develop a preoperative risk score based on recipient-, donor-, and transplant-specific characteristics to predict postoperative acute renal failure in candidates for transplantation. METHODS The United Network of Organ Sharing (UNOS) database was queried for adult patients (≥ 18 years of age) undergoing LTx between 2005 and 2012. The population was randomly divided into derivation (80%) and validation (20%) cohorts. The primary outcome of interest was new-onset renal failure. Variables predictive of acute renal failure (exploratory p value < 0.2) within the derivation cohort were incorporated into a multivariable logistic regression model. Odds ratios were used to assign values to the independent predictors of postoperative renal failure to construct the risk stratification score (RSS). RESULTS During the study period, 10,963 patients underwent lung transplantation, and the incidence of renal failure was 5.5% (598 patients). Baseline recipient-, donor-, and transplant-related factors were similar between the cohorts. Eighteen covariates were included in the multivariable model, and 10 were assigned values based on their relative odds ratios (ORs). Scores were stratified into 3 groups, with an observed rate of acute renal failure of 3.1%, 5.3%, and 15.6% in the low-, moderate-, and high-risk groups, respectively. The incidence of renal failure was found to be significantly increased in the highest risk group (p < 0.001). Furthermore, the risk models predicted rates of renal failure highly correlated with actual rates observed in the population (r = 0.86). CONCLUSIONS We introduce a novel and simple RSS that is highly predictive of renal failure after LTx.

Utilization of AngioVac and Snare for Eradication of a Mobile Right Atrial Thrombus

Although there are multiple etiologies of a right atrial thrombus, the presence of a central venous catheter increases the risk for its development. Once diagnosed, an assessment of patient-specific factors will aid in dictating the appropriate management strategy. In cases of chronic disease or adherent thrombotic masses, thrombolytic therapy might not result in complete resolution of the clot burden and could lead to a devastating embolic event. Accordingly, we present a case of a right atrial thrombus not amenable to medical therapy that was removed only after concomitant utilization of an AngioVac Aspiration System (Vortex Medical, Norwell, MA) and percutaneous snare catheterization.