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Background Pulmonary complications are the most common adverse event after lung resection, yet few large-scale studies have examined pertinent risk factors after video-assisted thoracoscopic surgery (VATS) lobectomy. Veterans, older and less healthy compared with nonveterans, represent a cohort that requires further investigation. Our objective is to determine predictors of pulmonary complications after VATS lobectomy in veterans. Methods A retrospective review was conducted on patients who underwent VATS lobectomy from 2008 to 2018 using the Veterans Affairs Surgical Quality Improvement Program database. Patients were divided into two cohorts based on development of a pulmonary complication within 30 days. Patient characteristics were compared via multivariable analysis to determine clinical predictors associated with pulmonary complication and reported as adjusted odds ratios (aORs) with 95% confidence intervals. Patients with preoperative pneumonia, ventilator dependence, and emergent cases were excluded. Results In 4,216 VATS lobectomy cases, 480 (11.3%) cases had ≥1 pulmonary complication. Preoperative factors independently associated with pulmonary complication included chronic obstructive pulmonary disease (COPD) (aOR = 1.37 [1.12–1.69]; p = 0.003), hyponatremia (aOR = 1.50 [1.06–2.11]; p = 0.021), and dyspnea (aOR = 1.33 [1.06–1.66]; p = 0.013). Unhealthy alcohol consumption was associated with pulmonary complication via univariable analysis (17.1 vs. 13.0%; p = 0.016). Cases with pulmonary complication were associated with increased mortality (12.1 vs. 0.8%; p Conclusion This analysis revealed several preoperative factors associated with development of pulmonary complications. It is imperative to optimize pulmonary-specific comorbidities such as COPD or dyspnea prior to VATS lobectomy. However, unhealthy alcohol consumption and hyponatremia were linked with development of pulmonary complication in our analysis and should be addressed prior to VATS lobectomy. Future studies should explore long-term consequences of pulmonary complications.

Historically, robotic surgery incurs longer operative times, higher costs, and nonsuperior outcomes compared with laparoscopic surgery. However, in areas of limited visibility and decreased accessibility such as the gastroesophageal junction, robotic platforms may improve visualization and facilitate dissection. This study compares 30-day outcomes between robotic-assisted foregut surgery (RAF) and laparoscopic-assisted foregut surgery in the Veterans Health Administration.This is a retrospective review of the Veterans Affairs Quality Improvement Program database. Patients undergoing laparoscopic-assisted foregut surgery and RAF were identified using CPT codes 43280, 43281, 43282, and robotic modifier S2900. Multivariable logistic regression and multivariable generalized linear models were used to analyze the independent association between surgical approach and outcomes of interest.A total of 9,355 veterans underwent minimally invasive fundoplication from 2008 to 2019. RAF was used in 5,392 cases (57.6%): 1.63% of cases in 2008 to 83.41% of cases in 2019. After adjusting for confounding covariates, relative to laparoscopic-assisted foregut surgery, RAF was significantly associated with decreased adjusted odds of pulmonary complications (adjusted odds ratio [aOR] 0.44, p0.001), acute renal failure (aOR 0.14, p = 0.046), venous thromboembolism (aOR 0.44, p = 0.009) and increased odds of infectious complications (aOR 1.60, p = 0.017). RAF was associated with an adjusted mean ± SD of 29 ± 2-minute shorter operative time (332 minutes vs 361 minutes; p0.001).Veterans undergoing RAF ascertained shorter operative times and reduced complications vs laparoscopy. As surgeons use the robotic platform, clinical outcomes and operative times continue to improve, particularly in operations where extra articulation in confined spaces is required.

Background Preoperative biliary drainage (PBD) has been advocated to address the plethora of physiologic derangements associated with cholestasis. However, available literature reports mixed outcomes and is based on largely outdated and/or single-institution studies. Methods Patients undergoing PBD prior to pancreaticoduodenectomy (PD) for periampullary malignancy between 2014-2018 were identified in the ACS-NSQIP pancreatectomy dataset. Patients with PBD were propensity-score-matched to those without PBD and 30-day outcomes compared. Results 8,970 patients met our inclusion criteria. 4,473 with obstruction and PBD were matched to 829 with no preoperative drainage procedure. In the non-jaundiced cohort, 711 stented patients were matched to 2,957 without prior intervention. PBD did not influence 30-day mortality (2.2% versus 2.4%) or major morbidity (19.8% versus 20%) in patients with obstructive jaundice. Superficial surgical site infections (SSIs) were more common with PBD (6.8% versus 9.2%), however, no differences in deep or organ-space SSIs were found. Patients without obstruction prior to PBD exhibited a 3-fold increase in wound dehiscence (0.5% versus 1.5%) additionally to increased superficial SSIs. Conclusion PBD was not associated with an increase in 30-day mortality or major morbidity but increased superficial SSIs. PBD should be limited to symptomatic, profoundly jaundiced patients or those with a delay prior to PD.

Genetic engineering and implantable bioelectronics have transformed investigations of cardiovascular physiology and disease. However, the two approaches have been difficult to combine in the same species: genetic engineering is applied primarily in rodents, and implantable devices generally require larger animal models. We recently developed several miniature cardiac bioelectronic devices suitable for mice and rats to enable the advantages of molecular tools and implantable devices to be combined. Successful implementation of these device-enabled studies requires microsurgery approaches that reliably interface bioelectronics to the beating heart with minimal disruption to native physiology. Here we describe how to perform an open thoracic surgical technique for epicardial implantation of wireless cardiac pacemakers in adult rats that has lower mortality than transvenous implantation approaches. In addition, we provide the methodology for a full biocompatibility assessment of the physiological response to the implanted device. The surgical implantation procedure takes ~40 min for operators experienced in microsurgery to complete, and six to eight surgeries can be completed in 1 d. Implanted pacemakers provide programmed electrical stimulation for over 1 month. This protocol has broad applications to harness implantable bioelectronics to enable fully conscious in vivo studies of cardiovascular physiology in transgenic rodent disease models.

Racial disparities in colorectal surgery outcomes have been studied extensively in the USA, and access to healthcare resources may contribute to these differences. The Veterans Health Administration (VHA) is the largest integrated healthcare network in the USA with the potential for equal access care to veterans. The objective of this study is to evaluate the VHA for the presence of racial disparities in 30-day outcomes of patients that underwent colorectal resection. Colon and rectal resections from 2008 to 2019 were reviewed retrospectively using the Veterans Affairs Surgical Quality Improvement Program database. Patients were categorized by race and ethnicity. Multivariable analysis was used to compare 30-day outcomes. Cases with “unknown/other/declined to answer” race/ethnicity were excluded. Thirty-six-thousand-nine-hundred-sixty-nine cases met inclusion criteria: 27,907 (75.5%) Caucasian, 6718 (18.2%) African American, 2047 (5.5%) Hispanic, and 290 (0.8%) Native American patients. There were no statistically significant differences in overall complication incidence or mortality between all cohorts. Compared to Caucasian race, African American patients had longer mean length of stay (10.7 days vs. 9.7 days; p

OBJECTIVES Despite society guideline recommendations, intraoperative high-frequency ultrasound (HFUS) and transit-time flow measurement (TTFM) use in coronary artery bypass grafting (CABG) has not been widely adopted worldwide. This retrospective review of the REQUEST (REgistry for QUality assESsmenT with Ultrasound Imaging and TTFM in Cardiac Bypass Surgery) study assesses the impact of protocolled high-frequency ultrasound/TTFM use in specific technical circumstances of CABG. METHODS Three REQUEST study sub-analyses were examined: (i) For off-pump (OPCAB) versus on-pump (ONCAB) procedures: strategy changes from preoperative plans for the aorta, conduits, coronary targets and graft revisions; and for all REQUEST patients, revision rates in: (ii) arterial versus venous grafts; and (iii) grafts to different cardiac territories. RESULTS Four hundred and two (39.6%) of 1016 patients undergoing elective isolated CABG for multivessel disease underwent OPCAB procedures. Compared to ONCAB, OPCAB patients experienced more strategy changes regarding the aorta [14.7% vs 3.4%; odds ratios (OR) = 4.03; confidence interval (CI) = 2.32–7.20], less regarding conduits (0.2% vs 2.8%; OR = 0.09; CI = 0.01–0.56), with no differences in coronary target changes or graft revisions (4.1% vs 3.5%; OR = 1.19; CI = 0.78–1.81). In all REQUEST patients, revisions were more common for arterial versus venous grafts (4.7% vs 2.4%; OR = 2.05; CI = 1.29–3.37), and inferior versus anterior (5.1% vs 2.9%; OR = 1.77; CI = 1.08–2.89) and lateral (5.1% vs 2.8%; OR = 1.83; CI = 1.04–3.27) territory grafts. CONCLUSIONS High-frequency ultrasound/TTFM use differentially impacts strategy changes and graft revision rates in different technical circumstances of CABG. Notably, patients undergoing OPCAB experienced 4 times more changes related to the ascending aorta than ONCAB patients. These findings may indicate where intraoperative assessment is most usefully applied. Clinical trial registration number ClinicalTrials.gov: NCT02385344

Treatment for diverticular disease has evolved over time. In the United States, there has been a trend towards minimally invasive surgical approaches and fewer postoperative complications, but no study has investigated this subject in the Veterans Health Administration.This retrospective review identified patients undergoing elective surgery for diverticular disease from 2004 to 2018. Demographics, comorbidities, operative approach, rates of ostomy creation, and 30-day outcomes were compared. The 15-year time period was divided into 3-year increments to assess changes over time.4198 patients were identified. Complication rate decreased significantly over time (28.1%-15.7%, p 0.001), as did infectious complications (21.5-6.3%, p 0.001). Median hospital length-of-stay decreased from 7 to 5 days (p 0.001). Rates of laparoscopic surgery increased over time (17.7%-48.1%, p 0.001).Increased utilization of laparoscopy in veterans undergoing elective surgery for diverticular disease coincided with fewer complications and a shorter length-of-stay. These trends mirror outcomes reported in non-veterans.

This study aims to compare veterans and non-veterans undergoing transcatheter aortic valve replacement (TAVR) using data from the Society for Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVT) registry.Patients undergoing TAVR at George Washington University (GWU) and veterans treated at Washington DC Veterans Affairs Medical Center (VAMC) who underwent TAVR at GWU from 2014-2020 were included. All patients were reported in the TVT registry. Emergency and valve-in-valve TAVR were excluded. Cohorts were divided based on veteran status. Operators were the same for both groups. Outcomes were compared at 30 days and 1 year. The primary outcome was mortality and secondary outcomes were morbidity metrics.A total of 299 patients (91 veterans, 208 non-veterans) were included. Veterans had higher rates of hypertension (87.9% vs 77.9%; P=.04), diabetes (46.7% vs 28.9%; P.01), and lung disease (2.4% vs 11.0%; P.001). Outcomes were not significantly different between veterans and non-veterans, including 30-day mortality (0% vs 2.9%, respectively; P=.18), 1-year mortality (9.8% vs 10.7%, respectively; P=.61), stroke incidence (0% vs 2.5%, respectively; P=.73), median intensive care unit stay (24 hours in both groups), and overall hospital stay (2 days in both groups).The affiliation between a VAMC and an academic medical center allowed for direct comparison between veterans and non-veterans undergoing TAVR by the same operators using the TVT registry. Despite significantly higher rates of comorbidities, veterans had equivalent outcomes compared with non-veterans. This may be in part due to the comprehensive care that veterans receive in the VAMC and this institution's integrated heart center team.

Temporary postoperative cardiac pacing requires devices with percutaneous leads and external wired power and control systems. This hardware introduces risks for infection, limitations on patient mobility, and requirements for surgical extraction procedures. Bioresorbable pacemakers mitigate some of these disadvantages, but they demand pairing with external, wired systems and secondary mechanisms for control. We present a transient closed-loop system that combines a time-synchronized, wireless network of skin-integrated devices with an advanced bioresorbable pacemaker to control cardiac rhythms, track cardiopulmonary status, provide multihaptic feedback, and enable transient operation with minimal patient burden. The result provides a range of autonomous, rate-adaptive cardiac pacing capabilities, as demonstrated in rat, canine, and human heart studies. This work establishes an engineering framework for closed-loop temporary electrotherapy using wirelessly linked, body-integrated bioelectronic devices.

Cerebrovascular accident (CVA) after coronary artery bypass grafting (CABG) is a devastating complication. Patient comorbidities and intraoperative elements contribute to the risk of CVA. The aim of this study is to identify risk factors for CVA in Veterans undergoing CABG.Veterans undergoing isolated CABG from 2008 to 2019 were retrospectively identified using the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. Thirty-day postoperative outcomes were observed. Univariate analysis followed by multivariable logistic regression identified independent risk factors for postoperative CVA. Receiver operating characteristic diagnostics identified optimal inflection points between continuous risk factors and odds of CVA.Twenty-eight thousand seven hundred fifty-seven patients met inclusion criteria. Incidence of CVA was 1.1% (310 cases). In multivariate analysis, preoperative cerebrovascular disease had the strongest association with postoperative CVA (adjusted odds ratio = 2.29; p .001). There was an inverse relationship between CVA incidence and ejection fraction (EF), with EF of 35%-39% conferring a 2.11 times higher risk compared to EF 55% (p .001). CVA incidence was not different in on-pump versus off-pump cases; however, after 104 min or more on bypass patients had a 55% greater adjusted odds of CVA (p .001). Other risk factors included poor kidney function, prior myocardial infarction, and intra-aortic balloon pump use.The risk of CVA after CABG is multifactorial and involves multiple organ systems, including cardiac disease, poor renal function, and cerebrovascular disease, which was the strongest contributing risk factor. Optimization of these comorbidities and time on bypass may help improve clinical outcomes and lower the risk of this devastating complication.

The adverse effects of tobacco use on postoperative outcomes are well documented. While smoking cessation is associated with overall improvement in long-term survival for lung cancer patients, the effects of cessation shortly before lung surgery are unclear. This study compares thirty-day outcomes after lobectomy between active smokers, recent quitters, and non-smokers. Patients who underwent lobectomy for cancer at national Veterans Affairs medical centers from 2012-2018 were retrospectively identified in the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. The sample was stratified into three groups: smokers within two weeks of surgery ("active smokers"), those who quit between two weeks and three months prior to surgery ("recent quitters"), and "non-smokers". Propensity score matching was performed to compare groups. Of 5,715 patients who met inclusion criteria, 2,696 were non-smokers, 774 were recent quitters, and 2,245 were active smokers. After propensity matching, 572 patients comprised each group. Compared to recent quitters, active smokers had 48% higher odds of suffering a pulmonary complication (95% confidence interval (CI): 1.03-2.14; p=0.035) and 72% higher odds of suffering multiple complications (CI: 1.07-2.76; p=0.026). Relative to non-smokers, active smokers had 81% higher odds of pulmonary complications (CI: 1.34-2.65; p=0.003). No differences were detected in outcomes comparing recent quitters to non-smokers. Veterans undergoing lobectomy for cancer who quit 2 weeks before surgery had less pulmonary complications than active smokers. Recent quitters have similar outcomes to non-smokers. Surgeons should therefore encourage patients to quit smoking, including just prior to lung surgery.

Endovascular treatment in thoracic aortic diseases has increased in use exponentially since Dake and colleagues first described the use of a home-made transluminal endovascular graft on 13 patients with descending thoracic aortic aneurysm at Stanford University in the early 1990s. Thoracic endovascular aneurysm repair (TEVAR) was initially developed for therapy in patients deemed unfit for open surgery. Innovations in endograft engineering design and popularization of endovascular techniques have transformed TEVAR to the predominant treatment choice in elective thoracic aortic repair. The number of TEVARs performed in the United States increased by 600% from 1998 to 2007, while the total number of thoracic aortic repairs increased by 60%. As larger multicenter trials and meta-analysis studies in the 2000s demonstrate the significant decrease in perioperative morbidity and mortality of TEVAR over open repair, TEVAR became incorporated into standard guidelines. The 2010 American consensus guidelines recommend TEVAR to be “strongly considered” when feasible for patients with degenerative or traumatic aneurysms of the descending thoracic aorta exceeding 5.5 cm, saccular aneurysms, or postoperative pseudoaneurysms. Nowadays, TEVAR is the predominant treatment for degenerative and traumatic descending thoracic aortic aneurysm repair. Although TEVAR has been shown to have decreased early morbidity and mortality compared with open surgical repair, endovascular manipulation of a diseased aorta with endovascular devices continues to have significant risks. Despite continued advancement in endovascular technique and devices since the first prospective trial examined the complications associated with TEVAR, common complications, two decades later, still include stroke, spinal cord ischemia, device failure, unintentional great vessel coverage, access site complications, and renal injury. In this article, we review common TEVAR complications with some corresponding radiographic imaging and their management.

Thousands of per- and polyfluoroalkyl substances (PFAS) exist in the environment and pose a potential health hazard. Suspect and nontarget screening with liquid chromatography (LC)–high-resolution tandem mass spectrometry (HRMS/MS) can be used for comprehensive characterization of PFAS. To date, no automated open source PFAS data analysis software exists to mine these extensive data sets. We introduce FluoroMatch, which automates file conversion, chromatographic peak picking, blank feature filtering, PFAS annotation based on precursor and fragment masses, and annotation ranking. The software library currently contains ∼7 000 PFAS fragmentation patterns based on rules derived from standards and literature, and the software automates a process for users to add additional compounds. The use of intelligent data-acquisition methods (iterative exclusion) nearly doubled the number of annotations. The software application is demonstrated by characterizing PFAS in landfill leachate as well as in leachate foam generated to concentrate the compounds for remediation purposes. FluoroMatch had wide coverage, returning 27 PFAS annotations for landfill leachate samples, explaining 71% of the all-ion fragmentation (CF2)n related fragments. By improving the throughput and coverage of PFAS annotation, FluoroMatch will accelerate the discovery of PFAS posing significant human risk.

Background A lateral pancreaticojejunostomy, or a Puestow procedure, is used in chronic pancreatitis with ductal dilation and pain. The current literature on the Puestow is sparse. This study examines outcomes of Puestow procedures nationwide. Methods Using ACS-NSQIP database, patients who underwent a Puestow procedure from 2010 to 2016 were identified. Univariate analysis and multivariable regression models were used to identify predictors of mortality and morbidities. Covariates included in the regression models were chosen based on clinical significance. Results The cohort included 524 patients. The 30-day mortality rate was 1.2%(n = 6). At least one major complication occurred in 19.1% of patients including death (1.2%), major organ dysfunction (8.2%), pulmonary embolism (1.3%), and surgical site infections (13.0%). Diabetes, COPD, and transfusions were the strongest predictors of complications. Conclusions The Puestow procedure is an acceptable treatment modality with low rates of morbidity and mortality. Minimizing transfusions and optimizing pulmonary status may improve 30-day outcomes.

OBJECTIVE Surgery for early stage non-small cell lung cancer can be curative. A delay from diagnosis to surgery can lead to increased mortality. Our objective was to determine if referring patients to specialists before a thoracic surgeon caused a delay in definitive treatment. MATERIALS AND METHODS A retrospective review was conducted of patients who had surgery for non-small cell lung cancer by a single surgeon at our institution from 2013 to 2016. Patients were divided into 2 groups: those who saw a specialist before a thoracic surgeon and patients who were referred directly to a surgeon once the pulmonary nodule was identified on computed tomography (CT). The time from initial CT to resection was compared. Secondary analysis compared private insurance versus Medicare/Medicaid. Percentage of patients upstaged was compared. RESULTS There was no significant difference between groups when comparing time from CT to surgery (79.88 vs. 79.90 d; P=0.58). There was a significant decrease in time from CT to surgery for patients with private insurance compared with Medicare/Medicaid patients (66.05 vs. 86.99 d; P=0.03) and fewer private insurance patients were upstaged (22.9% vs. 31.8%; P=0.32). More patients who saw a different specialist first were upstaged compared with patients sent directly to thoracic surgery (32.6% vs. 22.2%; P=0.22). CONCLUSIONS When comparing time from CT detection of a lung nodule to surgery, no significant difference was found between patients sent to nonthoracic specialists first and those referred directly to a thoracic surgeon. There was a significant decrease in time from CT to surgery for patients with private insurance compared with Medicare/Medicaid.

Background Prior studies suggest similar efficacy between large-bore chest tube (CT) placement and small-bore pigtail catheter (PC) placement for the treatment of pleural space processes. This study examined reintervention rates of CT and PC in patients with pneumothorax, hemothorax, and pleural effusion. Methods This retrospective study examined patients from September 2015 through December 2020. Patients were identified using ICD codes for pneumothorax, hemothorax, or pleural effusion. Use of a pigtail catheter (≤14Fr) or surgical chest tube (≥20Fr) was noted. The primary outcome was overall reintervention rate within 30 days of tube insertion. Patients who died with a pleural drainage catheter in place, unrelated to complications from chest tube placement, were excluded. Results There were 1032 total patients in the study: 706 CT patients and 326 PC patients. The PC group was older with more comorbidities and more likely to have effusion as the indication for pleural drainage. Patients with PC were 2.35 times more likely to have the tube replaced or repositioned ( P < .0001), 1.77 times more likely to require any reintervention ( P = .001) and 2.09 times more likely to remain in the hospital >14 days ( P < .0001) compared to patients with CT. Conclusion PCs have a significantly higher reintervention rate compared to CT for the treatment of pneumothorax, hemothorax, and pleural effusion. Although PC are believed to cause less pain and tissue trauma, they do not necessarily drain the pleural space as well as CT. Decisions on which method of draining the chest should be made on a case-by-case basis.

Genetic engineering and implantable bioelectronics have transformed investigations of cardiovascular physiology and disease. However, the two approaches have been difficult to combine in the same species: genetic engineering is applied primarily in rodents, and implantable devices generally require large animal models. We recently developed several miniature cardiac bioelectronic devices suitable for mice and rats to combine the advantages of molecular tools and implantable devices. Successful implementation of these device-enabled studies requires microsurgery approaches that reliably interface bioelectronics to the beating heart with minimal disruption to native physiology. This protocol describes how to perform an open thoracic surgical technique for epicardial implantation of novel wireless cardiac bioelectronic devices in adult rats and has significantly lower mortality than transvenous implantation approaches. In addition, we provide the methodology for a full biocompatibility assessment of the physiological response to the implanted device. The surgical implantation procedure takes about 40 minutes to complete for an experienced operator, and up to 8 surgeries can be completed in one day. Implanted pacemakers provide programmed electrical stimulation for over 1 month. This protocol has broad applications to enable fully conscious in vivo studies of cardiovascular physiology in transgenic rodent disease models.

Previous studies reported that increased hospital case volume improves outcomes after esophagectomy. Yet, the standard for high and low-volume hospitals varies in the literature. This study attempts to define the relationship between hospital operative volume and 30-day post-operative outcomes of esophagectomy in the Veterans Affairs (VA) system.This is a retrospective review of patients that underwent esophagectomy from 2008 to 2019 utilizing the Veterans Affairs Surgical Quality Improvement Program Database. Receiver operating characteristic (ROC) analysis quantified an inflection point of optimal association between 30-day morbidity and mortality by facility volume. This point was used to separate cohorts for comparison of outcomes using 1:1 propensity score matching (PSM) to account for confounding covariates.Two thousand two hundred and twelve esophagectomies were performed from 2008 to 2019 and ROC analysis identified an inflection point at 43 cases (4 cases/y) where bidirectional operative volume significantly affected outcomes. Subsequent PSM resulted in 1718 cases utilized for analysis (n = 859 per cohort). Facility volume ≥4 cases/y was significantly associated with decreased odds of 30-day mortality (odds ratio(OR) = 0.57; P = 0.03), shorter length of stay (median 13 versus 14 d; P = 0.04) and longer operative times (6.5 versus 6.0 h; P 0.001).VA hospitals that averaged ≥4 esophagectomies/y had significantly lower rates of mortality and length of stay. This volume threshold may serve as a benchmark to determine the optimal setting for esophageal resection. However, our findings also may reflect the benefits of cumulative operating room and multidisciplinary team experience at VA centers in conjunction with dedicated surgeons. Future studies should focus on long-term outcomes after esophagectomy in relation to hospital operative volume.

Background Veterans undergoing elective surgery for diverticular disease have an ostomy creation rate of 18%. The purpose of this study was to analyze the outcomes and timing of ostomy reversal surgery, perioperative complications, and differences between colostomy and ileostomy reversal outcomes. Methods A retrospective review of the Veterans Affairs Surgical Quality Improvement Project (VASQIP) database was performed. Patients undergoing elective colectomy for diverticular disease between 2004 and 2018 were identified. Demographics, comorbidities, ostomy type, time to reversal, and postoperative complications were analyzed. Results 4,198 patients underwent elective colectomy for diverticular disease, with 751 patients (17.9%) receiving an ostomy. Of patients who received an ostomy, 407 had ostomy reversal surgery within the Veterans Health Administration system (54.2%), with 243 colostomies, 149 ileostomies, and 15 unspecified. Median time to ostomy reversal was 5.0 months (interquartile range 3.2, 7.8). Complication rate after reversal was 23.1%; surgical site infection was most common (9.1%). Patients with American Society of Anesthesiologists classification >3 (adjusted odds ratio (aOR) = .40[.22-.72]), increasing age (aOR = .98[.97-.99]), laparoscopic index procedure (aOR = .42[.27-.63]), and hypertension (aOR = .63[.46-.87]) were less likely to have their ostomy reversed. There were no differences in postoperative complication rates after ostomy vs ileostomy reversals. Reversals after 4.6 months were associated with 3.4-times higher odds of complications. Conclusion Ostomy creation and reversal rates are similar between the veteran and non-veteran populations in the United States. Delays in reversal surgery were associated with worse postoperative outcomes, which underscore the importance of close follow-up for patients with an ostomy after elective colectomy for diverticular disease.

The pigment lead white ((PbCO3)2·Pb(OH)2) was analyzed by LDI-MS/MS and LDI-Orbitrap-MS/MS for the first time. The elucidation of formulae from a suite of isotopically complex cluster ions was obtained from low- and high-resolution full- and tandem-mass spectra in concert with both deductive and inductive reasoning. The unique isotopic pattern of lead was used both to delineate the full-scan spectrum into superclusters and to identify the monoisotopic mass of each cluster, from which a lead-limited, accurate formula could be derived. Chemical formulae for the clusters of lead white followed the form PbxOyHz. Also, the in situ detection of lead white by LDI-MS was achieved for cross sections of painted works of art.

Dysfunction of the right ventricle (RV) is common in patients with advanced left-sided valve disease and the significant impact of RV dysfunction on both short and long-term outcome is well established. However, considerations of RV function are largely absent in current management guidelines for valve disease and cardiac procedural risk models. As the indications and use of trans-catheter therapies rapidly expand for patients with acquired valvular disease, it is critical for clinicians to understand and consider RV function when making decisions for these patients. This review summarizes contemporary data on the assessment of RV function, the prognostic importance of baseline RV dysfunction on surgical and transcatheter procedures for acquired left-sided valvular disease, and the relative impact of these interventions on RV function. Baseline RV dysfunction is a powerful predictor of poor short- and long-term outcome after any therapeutic intervention for acquired left-sided cardiac valve disease. Surgical intervention for aortic or mitral valve disease is associated with a significant but transient decline in RV function, whereas trans-catheter procedures generally do not appear to have detrimental effects on either longitudinal or global RV function. Guidelines for therapy in patents with acquired left-sided valvular disease should account for RV dysfunction. Whereas surgical intervention in these patients leads to a predictable decline in RV function, trans-catheter therapies largely do not appear to have this effect. Further study is needed to determine the impact of these findings on current practice.

Understanding the evolutionary stability and possible context-dependence of biological containment techniques is critical as engineered microbes are increasingly under consideration for applications beyond biomanufacturing. While batch cultures of synthetic auxotrophic Escherichia coli previously exhibited undetectable escape throughout 14 days of monitoring, the long-term effectiveness of synthetic auxotrophy is unknown. Here, we report automated continuous evolution of a synthetic auxotroph using custom chemostats that supply a decreasing concentration of essential biphenylalanine (BipA). After 100 days of evolution in three separate trials, populations exhibit no observable escape and are capable of normal growth rates at 10-fold lower BipA concentration than the ancestral synthetic auxotroph. Allelic reconstruction of three proteins implicated in small molecule transport reveals their contribution to increased fitness at low BipA concentrations. Mutations do not appear in orthogonal translation machinery nor in synthetic auxotrophic markers. Based on its evolutionary stability, we introduce the progenitor synthetic auxotroph directly to mammalian cell culture. We observe containment of bacteria without detrimental effects on HEK293T cells. Overall, our findings reveal that synthetic auxotrophy is effective on timescales and in contexts that enable diverse applications.One Sentence SummaryTo ascertain whether life inevitably finds a way, we continuously evolve an Escherichia coli strain that was not able to escape from engineered biocontainment before, and we find that it does not escape even after 100 days of evolution, nor does it escape when added to mammalian cell culture.

Racial disparities in colorectal surgery outcomes have been studied extensively in the USA, and access to healthcare resources may contribute to these differences. The Veterans Health Administration (VHA) is the largest integrated healthcare network in the USA with the potential for equal access care to veterans. The objective of this study is to evaluate the VHA for the presence of racial disparities in 30-day outcomes of patients that underwent colorectal resection.Colon and rectal resections from 2008 to 2019 were reviewed retrospectively using the Veterans Affairs Surgical Quality Improvement Program database. Patients were categorized by race and ethnicity. Multivariable analysis was used to compare 30-day outcomes. Cases with "unknown/other/declined to answer" race/ethnicity were excluded.Thirty-six-thousand-nine-hundred-sixty-nine cases met inclusion criteria: 27,907 (75.5%) Caucasian, 6718 (18.2%) African American, 2047 (5.5%) Hispanic, and 290 (0.8%) Native American patients. There were no statistically significant differences in overall complication incidence or mortality between all cohorts. Compared to Caucasian race, African American patients had longer mean length of stay (10.7 days vs. 9.7 days; p 0.001). Compared to Caucasian race, Hispanic patients had higher odds of pulmonary-specific complications (adjusted odds ratio with 95% confidence interval = 1.39 [1.17-1.64]; p 0.001).The VHA provides the benefits of integrated healthcare and access, which may explain the improvements in racial disparities compared to existing literature. However, some racial disparities in clinical outcomes still persisted in this analysis. Further efforts beyond healthcare access are needed to mitigate disparities in colorectal surgery. CLASSIFICATIONS: [Outcomes]; [Database]; [Veterans]; [Colorectal Surgery]; [Morbidity]; [Mortality].

Background Video-assisted thoracoscopic surgery (VATS) offers reduced morbidity compared with open thoracotomy (OT) for pulmonary surgery. The use of VATS over time has increased, but at a modest rate in civilian populations. This study examines temporal trends in VATS use and compares outcomes between VATS and OT in the Veterans Health Administration (VHA). Methods Patients who underwent pulmonary surgery (wedge or segmental resection, lobectomy, or pneumonectomy) at Veterans Affairs centers from 2008 to 2018 were retrospectively identified using the Veterans Affairs Surgical Quality Improvement Project database. The cohort was divided into OT and VATS and propensity score matched, taking into account the type of pulmonary resection, preoperative diagnosis, and comorbidities. Thirty-day postoperative outcomes were compared. The prevalence of VATS use and respective complications over time was also analyzed. Results A total of 16,895 patients were identified, with 5,748 per group after propensity matching. VATS had significantly lower rates of morbidity and a 2-day reduction in hospital stay. Whereas 76% of lung resections were performed open in 2008, nearly 70% of procedures were performed using VATS in 2018. While VATS was associated with an 8% lower rate of major complications compared with thoracotomy in 2008, patients undergoing VATS lung resection in 2018 had a 58% lower rate of complications (p Conclusions VATS utilization at VHA centers has become the predominant technique used for pulmonary surgeries over time. OT patients had more complications and longer hospital stays compared with VATS. Over the study period, VATS patients had increasingly lower complication rates compared with open surgery.

Cold stress syndrome (CSS) in the Florida manatee (Trichechus manatus latirostris) results in perturbations to many physiological pathways, often leading to further illness or death. In this study, we applied a non-targeted lipidomics approach with ultra-high performance liquid chromatography and high-resolution tandem mass spectrometry to characterize changes related to CSS in the lipidomic profiles of manatee plasma. Lipidomic analyses were conducted on healthy manatee (control) and cold-exposed manatee plasma samples with varying concentrations of Serum Amyloid A (SAA), an acute-phase protein that is associated with inflammatory disease. Control manatees (n = 10) were compared to all manatees exposed to cold temperatures (n = 17), and a subset of those manatees with SAA values > 120 μg/mL (n = 9). Increased SAA values were associated with higher levels of various acylcarnitine lipids, while several triacylglycerols and oxidized triacylglycerols were significantly lower in manatees with cold exposure. These identified lipids are critical molecules involved in the maintenance of energy homeostasis and could potentially be examined in conjunction with current physical parameters to characterize cold stress. The ability to detect such differences highlights the addition of lipidomics as a valuable tool in understanding cold stress and potentially other illnesses in manatees. Further investigation into the function of the altered lipids could greatly increase our understanding of lipid metabolism in physiologically stressed manatees as well as other marine mammals and inform future management recovery strategies.

Objectives Low-dose computed tomography (LDCT) screening is an important tool for reducing lung cancer mortality. This study describes a single center's experience with LDCT and attempts to identify any barriers to compliance with standard guidelines. Materials and methods This is a retrospective review of a single university-based hospital system from 2015 to 2019. All individuals who met eligibility for lung cancer screening were entered into a database. The definition of adherence with the screening program was determined by the recommended timeline for the follow-up LDCT. Cohorts were split by adherence and demographics were compared. Results A total of 203 LDCTs were performed in 121 patients who met eligibility for LDCT and had appropriate surveillance from 2015 to 2019. The average age was 64 years old. The overall adherence rate for prescribed LDCTs was 59.1%. Patients with Lung-RADS score 2 had 2.43 times higher odds of adherence relative to patients with Lung-RADS score 1 (odds ratio [OR]=2.43; 95% confidence interval [CI]: 1.23-4.83; P=0.011). African American patients had 42% lower odds of adherence relative to white patients (OR=0.58; 95% CI: 0.32-1.06; P=0.076). Patients with non-District of Columbia zip codes had 57% higher odds of adherence relative to those with District of Columbia zip codes, although this did not reach statistical significance (OR=1.57; 95% CI: 0.87-2.82; P=0.136). Conclusions Despite the implementation of a multidisciplinary, academic LDCT screening program, overall adherence rate to prescribed follow-up scans was suboptimal. Socioeconomic disparities and African American race may negatively affect adherence to lung cancer screening LDCT guidelines. Patients with concerning findings on initial LDCT had a higher association of adherence to guidelines.

Background Traumatic duodenal injury is a rare, potentially devastating condition with challenging management decisions. Contemporary literature on operative management of duodenal injury is lacking. The purpose of this study is to assess optimal management strategies based on outcomes of patients with traumatic duodenal injury at a single trauma center. Methods A retrospective study of patients with traumatic duodenal injury from 2013-2020 at a level 1 trauma center was performed. Patient demographics, grade of injury as noted on CT scan or intraoperatively, surgical procedure(s) performed, and resultant outcomes were extracted. Results After excluding one patient due to death on arrival, 23 patients met inclusion criteria. Injuries consisted of grade 1 (n = 7), grade 2 (n = 2), grade 3 (n = 12), and grade 5 (n = 2); there were no grade 4 injuries. Patients were predominantly male (83%) with a median age of 30 years old. Nineteen patients (82%) underwent surgery. Four of nine patients (44%) with grade 1/2 injuries had hematomas and were managed non-operatively. The remaining five patients (56%) with grade 1/2 injuries underwent operation, which included primary repair (n = 3), duodenal exclusion (n = 1), and periduodenal drainage (n = 1). Of 12 patients with grade 3 injury, 6 underwent primary repair and 6 underwent resection. Three patients who underwent primary repair and one who underwent resection developed a duodenal leak. All patients with grade 5 injury (n = 2) underwent pancreaticoduodenectomy. Conclusion Grade 1 and 2 duodenal hematomas can be managed non-operatively, while lacerations require operative repair. Outcomes may be better following resection in patients with grade 3 injury.

OBJECTIVES Factors such as more diffuse atherosclerosis, plaque instability and accelerated vascular calcification in patients with chronic and end-stage renal disease (ESRD) can potentially present intraoperative challenges in coronary artery bypass grafting (CABG) procedures. We evaluated whether patients with chronic and ESRD experienced more surgical strategy changes and/or graft revisions than patients with normal renal function when undergoing CABG procedures according to a protocol for intraoperative high-frequency ultrasound and transit-time flow measurement (TTFM). METHODS Outcomes of CABG for patients with chronic and ESRD and patients with normal renal function enrolled in the multicentre prospective REQUEST (REgistry for QUality assESsmenT with Ultrasound Imaging and TTFM in Cardiac Bypass Surgery) study were compared retrospectively. The primary end point was frequency of intraoperative surgical strategy changes. The secondary end point was post-protamine TTFM parameters. RESULTS There were 95 patients with chronic and ESRD and 921 patients with normal renal function. Patients with chronic and ESRD undergoing CABG according to a protocol for intraoperative high-frequency ultrasound and TTFM had a higher rate of strategy changes overall [33.7% vs 24.3%; odds ratio (OR) = 1.58; 95% confidence interval (CI) = 1.01–2.48; P = 0.047] and greater revisions per graft (7.0% vs 3.4%; odds ratio = 2.14; 95% CI = 1.17–3.71; P = 0.008) compared to patients with normal renal function. Final post-protamine graft TTFM parameters were comparable between cohorts. CONCLUSIONS Patients with chronic and ESRD undergoing CABG procedures with high-frequency ultrasound and TTFM experience more surgical strategy changes than patients with normal renal function while achieving comparable graft flow. Clinical trial registration number ClinicalTrials.gov NCT02385344

A 9-week feeding trial was conducted with juvenile red drum, Sciaenops ocellatus, to evaluate the use of soy oil as a fish oil replacement. Three primary protein sources (fishmeal - FM, soybean meal - SBM, and soy protein concentrate - SPC) were utilized with 100% fish oil (FM, SBM, SPC), 75% fish oil (SBM, SPC), or 50% fish oil (FM, SBM, SPC) as the lipid source. Traditional growth and performance metrics (specific growth rate, feed consumption, feed conversion ratio) were tracked and tissue samples (liver, muscle, plasma, adipose, and brain) were collected for gas chromatography-based fatty acid profiling. Ten lipid metabolism related genes were analyzed for potential expression differences between dietary treatments in liver and muscle tissues and whole body and fillet tissues were sampled for proximate composition analyses. Forty- four fatty acids were measured by gas chromatography-flame ionization detector (GC-FID) and evaluated with principle component analysis and ANOVA to understand the dietary influence on lipid metabolism and health. Significant differences in growth rate were observed with the SBM 50% fish oil diet outperforming the FM 100% fish oil reference diet. All other soy protein-based diets performed statistically equivalent to both FM reference diets (100% and 50% fish oil) in regard to growth, however all soy protein-based formulations had significantly lower feed conversion ratios than the fishmeal-based references (p < .001). Gene expression differences were not significant in most cases, however often trended similarly as the observed performance. Fatty acid profiles differed as a function of oil source, with no apparent influence by protein source, with C18:2n-6 (linoleic acid) being-the primary differentiator. Overall, the six soy protein, fishmeal-free formulations performed equivalently or better than the fishmeal references with up to 50% of fish oil replaced by soybean oil.

Background: Studies of the civilian population with left main coronary artery disease (LMCAD) who underwent coronary artery bypass grafting (CABG) have shown 2% to 4.2% 30-day mortality. However, there is a lack of reporting from the veteran population. Here we analyze the outcomes of veterans with LMCAD who underwent CABG by a single surgeon at a single Veterans Affairs Medical Center (VAMC). Methods: Veterans who underwent isolated CABG between 1998 to 2018 at a VAMC were further divided into a group with significant left main coronary artery disease (LMCAD) of stenosis greater than or equal to 50% and a group without left main coronary artery stenosis (non-LMCAD). The primary outcome was mortality. Secondary outcomes included postoperative complications. Multivariable regression analysis and Kaplan-Meier survival analysis were used to compare the two cohorts. Results: The demographics and comorbidities are similar between the two cohorts except for higher average age and percentage of stroke in the LMCAD group (n = 509) compared to non-LMCAD (n = 927). Perioperative complications are comparable between the two groups except for increased length of stay (LOS) in the LMCAD group (12.9 ± 15.9 days versus 10.9 ± 9.0 days in non-LMCAD, P < .001). 30-day mortality in the LMCAD group is 4.1% versus 1.4% in non-LMCAD. However, Kaplan-Meier curves show no significant difference in adjusted overall survival throughout 15 years between the groups (P = .560). Conclusion: Veterans with LMCAD who underwent CABG have similar postoperative complications compared to non-LMCAD group. The 30-day mortality is higher in the LMCAD group; however, there is no difference in long-term survival.

Understanding the interaction between organisms and the environment is important for predicting and mitigating the effects of global phenomena such as climate change, and the fate, transport, and health effects of anthropogenic pollutants. By understanding organism and ecosystem responses to environmental stressors at the molecular level, mechanisms of toxicity and adaptation can be determined. This information has important implications in human and environmental health, engineering biotechnologies, and understanding the interaction between anthropogenic induced changes and the biosphere. One class of molecules with unique promise for environmental science are lipids; lipids are highly abundant and ubiquitous across nearly all organisms, and lipid profiles often change drastically in response to external stimuli. These changes allow organisms to maintain essential biological functions, for example, membrane fluidity, as they adapt to a changing climate and chemical environment. Lipidomics can help scientists understand the historical and present biofeedback processes in climate change and the biogeochemical processes affecting nutrient cycles. Lipids can also be used to understand how ecosystems respond to historical environmental changes with lipid signatures dating back to hundreds of millions of years, which can help predict similar changes in the future. In addition, lipids are direct targets of environmental stressors, for example, lipids are easily prone to oxidative damage, which occurs during exposure to most toxins. This is the first review to summarize the current efforts to comprehensively measure lipids to better understand the interaction between organisms and their environment. This review focuses on lipidomic applications in the arenas of environmental toxicology and exposure assessment, xenobiotic exposures and health (e.g., obesity), global climate change, and nutrient cycles. Moreover, this review summarizes the use of and the potential for lipidomics in engineering biotechnologies for the remediation of persistent compounds and biofuel production. With the preservation of certain lipids across millions of years and our ever-increasing understanding of their diverse biological roles, lipidomic-based approaches provide a unique utility to increase our understanding of the contemporary and historical interactions between organisms, ecosystems, and anthropogenically-induced environmental changes.

Objective: Heart disease is still the leading cause of death for both men and women in the United States, and the rate of cardiovascular disease in veterans is even higher than in civilians. This study examines age-related outcomes for veterans undergoing cardiac surgeries at a single institution. Methods: We included all veterans undergoing coronary artery bypass grafting (CABG) and/or valve surgery between 1997 to 2017 at a single Veterans Affairs (VA) medical center. We stratified this cohort into 4 age groups: ≤59 years old, 60–69 years old, 70–79 years old, and ≥80 years old. Outcomes in age groups were compared using standard statistical methods with the ≤59 years old group as reference. Results: A total of 2,301 patients underwent open cardiac procedures at our institution. The frequency of simultaneous CABG and valve operations increased with age. Usage of cardiopulmonary bypass versus off-pump CABG and operative time was not associated with age. Increased pulmonary and renal complications as well as rates of postoperative arrhythmias all were associated with increasing age. There was no statistically significant difference in 30-day mortality. However, multivariable analysis adjusted for covariates showed all-cause mortality significantly was increased with older age groups (aHR ≥80 years old: 2.94 [2.07-4.17], P < .01; aHR 70-79 years old: 2.15 [1.63-2.83], P < 0.01, with ≤59 years old as reference). Conclusions: Older patients may have comparable perioperative mortality as their younger counterparts. However, age still is a significant predictor of all-cause mortality, pulmonary and renal complications, and postoperative arrhythmia, and should be considered as a major factor in preoperative risk assessment.

Background: The Surgical Treatment for Ischemic Heart Failure (STICH) trial showed that surgical revascularization in ischemic cardiomyopathy (ICM) patients improves long-term mortality compared with medical treatment alone. This study examines how veterans with ICM undergoing revascularization fare against patients without ICM; it also examines the outcomes in the veteran population. Methods: This is a retrospective review of a single-center database. From 2000 to 2018, 1,461 patients underwent isolated coronary artery bypass grafting (CABG). Two-hundred-one patients with an ejection fraction less than 35% were classified as the ICM cohort. The primary outcome was mortality. Secondary outcomes included postoperative complications. Subgroup analysis was performed within the ICM cohort comparing off-pump CABG (OPCAB) versus on-pump CABG (ONCAB). Results: ICM patients had a higher incidence of myocardial infarction (MI), diabetes, chronic kidney disease (CKD), and preoperative intra-aortic balloon pump (IABP) use. The non-ICM cohort was more functionally independent. OPCAB was performed in 80.1% of ICM and 66.3% of non-ICM cohorts. There was no statistical difference between ICM and non-ICM cohorts in 30-day mortality (OR 1.94[0.79 – 4.75], P = .15). The ICM cohort had an increased 5-year mortality (OR 1.75[1.14 – 2.69], P = .01) and 10-year mortality (OR 1.71[1.09 - 2.67], P = .02). The ICM cohort showed improved, although not statistically significant, short-term mortality with OPCAB compared with ONCAB (3.1% versus 12.5%, OR 0.31[0.05 – 1.82], P = .20). Conclusion: Veterans with ICM undergoing CABG demonstrated similar short-term survival compared with non-ICM veterans. The long-term survival in the ICM cohort still is inferior to patients without ICM. There is a trend toward improved short-term survival in patients with ICM undergoing OPCAB.

The peculiar ionization of anthraquinones, including the artistic dyes alizarin and purpurin, is examined. When alizarin (MW = 240) is ionized by either LDI or MALDI it exhibits a dominant ion of m / z 242 [M + 2H] + with a far greater abundance than expected from the 13 C isotopic contribution from the [M + H] + ion at m / z 241. For the first time, MS/MS analysis of these anomalous [M + 2H] + ions is presented, which indicates that they arise from a laser-induced photoreduction of one of the anthraquinone’s carbonyl groups. MS/MS daughter ions produced from neutral losses of either water or ammonia from the [M + 2H] + ions exhibit different relative abundances, depending upon their respective functional groups’ proximity to the reduced carbonyl. LDI-MS/MS was used for the in situ detection of alizarin in a painting cross section and a swatch of dyed silk.

Recoding and repurposing genetic codons By recoding bacterial genomes, it is possible to create organisms that can potentially synthesize products not commonly found in nature. By systematic replacement of seven codons with synonymous alternatives for all protein-coding genes, Ostrov et al. recoded the Escherichia coli genome. The number of codons in the E. coli genetic code was reduced from 64 to 57 by removing instances of the UAG stop codon and excising two arginine codons, two leucine codons, and two serine codons. Over 90% functionality was successfully retained. In 10 cases, reconstructed bacteria were not viable, but these few failures offered interesting insights into genome-design challenges and what is needed for a viable genome. Science , this issue p. 819

A 9-week feeding trial was conducted with juvenile red drum, Sciaenops ocellatus, to evaluate the use of soy oil as a fish oil replacement. Three primary protein sources (fishmeal - FM, soybean meal - SBM, and soy protein concentrate - SPC) were utilized with 100% fish oil (FM, SBM, SPC), 75% fish oil (SBM, SPC), or 50% fish oil (FM, SBM, SPC) as the lipid source. Traditional growth and performance metrics (specific growth rate, feed consumption, feed conversion ratio) were tracked and tissue samples (liver, muscle, plasma, adipose, and brain) were collected for gas chromatography-based fatty acid profiling. Ten lipid metabolism related genes were analyzed for potential expression differences between dietary treatments in liver and muscle tissues and whole body and fillet tissues were sampled for proximate composition analyses. Forty- four fatty acids were measured by gas chromatography-flame ionization detector (GC-FID) and evaluated with principle component analysis and ANOVA to understand the dietary influence on lipid metabolism and health. Significant differences in growth rate were observed with the SBM 50% fish oil diet outperforming the FM 100% fish oil reference diet. All other soy protein-based diets performed statistically equivalent to both FM reference diets (100% and 50% fish oil) in regard to growth, however all soy protein-based formulations had significantly lower feed conversion ratios than the fishmeal-based references (p < .001). Gene expression differences were not significant in most cases, however often trended similarly as the observed performance. Fatty acid profiles differed as a function of oil source, with no apparent influence by protein source, with C18:2n-6 (linoleic acid) being-the primary differentiator. Overall, the six soy protein, fishmeal-free formulations performed equivalently or better than the fishmeal references with up to 50% of fish oil replaced by soybean oil.

Inexpensive DNA sequencing and advances in genome editing have made computational analysis a major rate-limiting step in adaptive laboratory evolution and microbial genome engineering. We describe Millstone, a web-based platform that automates genotype comparison and visualization for projects with up to hundreds of genomic samples. To enable iterative genome engineering, Millstone allows users to design oligonucleotide libraries and create successive versions of reference genomes. Millstone is open source and easily deployable to a cloud platform, local cluster, or desktop, making it a scalable solution for any lab. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1223-1) contains supplementary material, which is available to authorized users.

Indiscriminate use of synthetic pesticides can be hazardous to both humans and the environment, but the use of natural products as a source of bio-based products, such as Melia azedarach extracts, is an interesting approach to overcome these hazards. Unfortunately, the limonoids found in M. azedarach with desired insecticidal properties (e.g. azadirachtin) may also be present with limonoids toxic to mammals. The goal of this report was to develop a fast and reliable MS-based experiment to characterize meliatoxins in crude extracts of M. azedarach, in order to provide unequivocal assessment of the safety for extracts for application in the field. MS and MS/MS experiments using MALDI ionization were evaluated as tools for the assignment of characteristic ions produced by each meliatoxin in crude extracts. The use of different experiments in combination, such as the analysis of fragment m/z 557 and [M + Na]+ (adducts ions m/z 681 and m/z 667), MALDI-MS can be used for detection of meliatoxins A1/B1 or A2/B2 in a crude extract and may be used to discriminate meliatoxins A from B, respectively. Subsequent MS/MS experiments can distinguish between the presence of group 1 and/or 2 in each class of meliatoxins classifying the proposed approach as a quick and efficient quality control method of meliatoxins in real M. azedarach samples.