Early Opioid Use and Postoperative Delirium Following Open Abdominal Aortic Aneurysm Repair.

BACKGROUND: Postoperative delirium is a common complication following open abdominal aortic aneurysm repair (OAR). Opioids have been found to contribute to delirium, especially at higher doses. This study assessed the impact of early postoperative opioid analgesia on postoperative delirium incidence and time to onset. We hypothesized that higher early postoperative opioid utilization would be associated with increased postoperative delirium incidence. METHODS: This was a retrospective analysis of OAR cases at a single quaternary care center from years 2012-2020. The primary exposure was oral morphine equivalents use (OME), calculated for postoperative days 1-7. A cut point analysis using a receiver operator curve for postoperative delirium determined the threshold for high OME (OME>37 mg). The primary outcome was postoperative delirium incidence identified via chart review. Multivariable logistic regression was performed for postoperative delirium and adjusted for covariates meeting P < 0.1 on bivariate analysis. RESULTS: Among 194 OAR cases, 67 (35%) developed postoperative delirium with median time to onset of 3 days (IQR = 2-6). Patients with postoperative delirium were older (74 years vs. 69 years), more frequently presented with symptomatic AAA (47% vs. 27%) and had a higher proportion of comorbidities (all P < 0.05). Cases with high OME utilization on postoperative day 1 (55%) were younger (69 vs. 73 years), less frequently had an epidural (46% vs. 77%), and more frequently developed delirium (42% vs. 25%, all P < 0.05). Epidural use was associated with a significant decrease in OME utilization on postoperative day 1 (33 vs. 83, P < 0.01). Postoperative delirium onset was later in those with high OME use (4 vs. 2 days, P = 0.04). On multivariable analysis, high OME remained associated with postoperative delirium (Table II). CONCLUSIONS: High opioid utilization on postoperative day 1 is associated with increased postoperative delirium and epidural along with acetaminophen use reduced opioid utilization. Future study should examine the impact of opioid reduction strategies on outcomes after major vascular surgery.

Structured discharge documentation reduces sex-based disparities in statin prescription in vascular surgery patients.

OBJECTIVE: Perioperative statin use has been shown to improve survival in vascular surgery patients. In 2018, the Northern California Vascular Study Group implemented a quality initiative focused on the use of a SmartText in the discharge summary. We hypothesized that structured discharge documentation would decrease sex-based disparities in evidence-based medical therapy. METHODS: A retrospective analysis was conducted using Vascular Quality Initiative eligible cases at a single institution. Open or endovascular procedures in the abdominal aorta or lower extremity arteries from 2016 to 2021 were included. Bivariate analysis identified factors associated with statin use and sex. Multivariate logistic regression was performed with the end point of statin prescription at discharge and aspirin prescription at discharge. An interaction term assessed the differential impact of the initiative on both sexes. Analysis was then stratified by prior aspirin or statin prescription. An interrupted time series analysis was used to evaluate the trend in statin prescription over time. RESULTS: Overall, 866 patients were included, including 292 (34%) female and 574 (66%) male patients. Before implementation, statins were prescribed in 77% of male and 62% of female patients (P < .01). After implementation, there was no statistically significant difference in statin prescription (91% in male vs 92% in female patients, P = .68). Female patients saw a larger improvement in the adjusted odds of statin prescription compared with male patients (odds ratio: 3.1, 95% confidence interval: 1.1-8.6, P = .04). For patients not prescribed a statin preoperatively, female patients again saw an even larger improvement in the odds of being prescribed a statin at discharge (odds ratio: 6.4, 95% confidence interval: 1.8-22.7, P < .01). Interrupted time series analysis demonstrated a sustained improvement in the frequency of prescription for both sexes over time. The unadjusted frequency of aspirin prescription also improved by 3.5% in male patients vs 5.5% in female patients. For patients not prescribed an aspirin preoperatively, we found that the frequency of aspirin prescription significantly improved for both male (19% increase, P = .006) and female (31% increase, P = .001) patients. There was no significant difference in the perioperative outcomes between male and female patients before and after standardized discharge documentation. CONCLUSIONS: A simple, low-cost regional quality improvement initiative eliminated sex-based disparities in statin prescription at a single institution. These findings highlight the meaningful impact of regional quality improvement projects. Future studies should examine the potential for structured discharge documentation to improve patient outcomes and reduce disparities.

The natural history of large abdominal aortic aneurysms in patients without timely repair.

OBJECTIVE: Contemporary data on the natural history of large abdominal aortic aneurysms (AAAs) in patients undergoing delayed or no repair are lacking. In this study, we examine the impact of large AAA size on the incidence of rupture and mortality. METHODS: From a prospectively maintained aneurysm surveillance registry, patients with an unrepaired, large AAA (≥5.5 cm in men and ≥5.0 cm in women) at baseline (ie, index imaging) or who progressed to a large size from 2003 to 2017 were included, with follow-up through March 2020. Outcomes of interest obtained by manual chart review included rupture (confirmed by imaging/autopsy), probable rupture (timing/findings consistent with rupture without more likely cause of death), repair, reasons for either no or delayed (>1 year after diagnosis of large AAA) repair and total mortality. Cumulative incidence of rupture was calculated using a nonparametric cumulative incidence function, accounting for the competing events of death and aneurysm repair and was stratified by patient sex. RESULTS: Of the 3248 eligible patients (mean age, 83.6 ± 9.1 years; 71.2% male; 78.1% white; and 32.0% current smokers), 1423 (43.8%) had large AAAs at index imaging, and 1825 progressed to large AAAs during the follow-up period, with a mean time to qualifying size of 4.3 ± 3.4 years. In total, 2215 (68%) patients underwent repair, of which 332 were delayed >1 year; 1033 (32%) did not undergo repair. The most common reasons for delayed repair were discrepancy in AAA measurement between surgeon and radiologist (34%) and comorbidity (20%), whereas the most common reasons for no repair were patient preference (48%) and comorbidity (30%). Among patients with delayed repair (mean time to repair, 2.6 ± 1.8 years), nine (2.7%) developed symptomatic aneurysms, and an additional 11 (3.3%) ruptured. Of patients with no repair, 94 (9.1%) ruptured. The 3-year cumulative incidence of rupture was 3.4% for initial AAA size 5.0 to 5.4 cm (women only), 2.2% for 5.5 to 6.0 cm, 6.0% for 6.1 to 7.0 cm, and 18.4% for >7.0 cm. Women with AAA size 6.1 to 7.0 cm had a 3-year cumulative incidence of rupture of 12.8% (95% confidence interval, 7.5%-19.6%) compared with 4.5% (95% confidence interval, 3.0%-6.5%) in men (P = .002). CONCLUSIONS: In this large cohort of AAA registry patients over 17 years, annual rupture rates for large AAAs were lower than previously reported, with possible increased risk in women. Further analyses are ongoing to identify those at increased risk for aneurysm rupture and may provide targeted surveillance regimens and improve patient counseling.

Capturing the complexity of open abdominal aortic surgery in the endovascular era.

OBJECTIVE: Volume and quality benchmarks for open abdominal aortic surgery and particularly open aortic aneurysm repair (OAR) in the endovascular era are guided by the Society for Vascular Surgery guidelines, but the Vascular Quality Initiative (VQI) OAR module fails to capture the full spectrum of complex OAR. We hypothesized that VQI-ineligible complex OAR would be the dominant form of open repairs performed at a VQI-participating tertiary center. METHODS: All OAR cases performed at a single tertiary care center from 2007 to 2020 were reviewed. The VQI OAR criteria were applied with exclusions (non-VQI) defined as concomitant renal bypass, clamping above the superior mesenteric artery or celiac artery, repairs performed for trauma, anastomotic aneurysm, isolated iliac aneurysm, or infected aneurysms. Linear regression was used to assess temporal trends. RESULTS: Among a total of 481 open abdominal aortic operations, 355 (74%) were OAR. The average annual OAR volume remained stable over 14 years (25 ± 6; P = .46). Non-VQI OAR comprised 54% of all cases and persisted over time (R2 = 0.047, P = .46). Supraceliac clamping (35%) was often necessary. The proportion of endograft explantation cases significantly increased over time from 4% in 2007 to 20% in 2019 (P = .01). Infectious indications represented 20% (n = 70) of cases. Visceral branch grafts were performed in 16% of all cases. OAR for ruptured aneurysm constituted 10% of cases. Thirty-day mortality was significantly higher in non-VQI vs VQI-eligible OAR cases (10% vs 4%; P = .04). CONCLUSIONS: Complex OAR comprises a majority of OAR cases in a contemporary tertiary referral hospital, yet these cases are not accounted for in the VQI. Creation of a "complex OAR" VQI module would capture these cases in a quality-driven national registry and help to better inform benchmarks for volume and outcomes in aortic surgery.

Limb-based patency as a measure of effective revascularization for chronic limb-threatening ischemia.

OBJECTIVE: In 2019, the Global Vascular Guidelines on chronic limb-threatening ischemia (CLTI) introduced the concept of limb-based patency (LBP) defined as maintained patency of a target artery pathway after intervention. The purpose of this study was to investigate the relationship between LBP and major adverse limb events (MALE) after infrainguinal revascularization for CLTI. METHODS: Consecutive patients undergoing revascularization for CLTI between 2016 and 2019 at a single tertiary institution with a dedicated limb preservation team were included. Subjects with aortoiliac disease, prior infrainguinal stents, or existing bypass grafts were excluded. Demographics, Global Limb Anatomic Staging System scores, Wound, Ischemia, foot Infection (WIfI) stages, revascularization details, and limb-specific outcomes were reviewed. LBP was defined by the absence of reintervention, occlusion, critical stenosis (>70%), or hemodynamic compromise with ongoing symptoms of CLTI. MALE included thrombectomy or thrombolysis, new bypass, open surgical graft revision and/or major amputation. RESULTS: We analyzed 184 unique limbs in 163 patients. This cohort was composed of 66.9% male patients with a mean age of 72 years. Baseline characteristics included diabetes (66%), tissue loss (91%), and advanced WIfI stages (30% stage 3, 51% stage 4). Global Limb Anatomic Staging System stage 3 anatomic patterns were common (n = 119 [65%]). Sixty limbs were treated with open bypass (65% involving tibial targets) and 124 underwent endovascular intervention (70% including infrapopliteal targets). The 12-month freedom from MALE and loss of LBP were 74.0% ± 3.7% and 48.6% ± 4.2%, respectively. Diabetes (hazard ratio [HR], 2.56; 95% confidence interval [CI], 1.13-5.83; P = .025) and loss of LBP (HR, 4.12; 95% CI, 1.96-8.64; P < .001) were independent predictors of MALE in a Cox proportional hazard model. Loss of LBP was the sole independent predictor of major limb amputation after revascularization (HR, 4.97; 95% CI, 1.89-13.09; P = .001). Loss of LBP impacted both intermediate-risk limbs (HR, 2.85; 95% CI, 1.02-7.97; P = .047 in WIfI stages 1-3) and high-risk limbs (HR, 3.99; 95% CI, 1.32-12.11; P = .014 in WIfI stage 4). However, the loss of LBP had the greatest impact on patients presenting with WIfI stage 4 disease (31% vs 8% major limb amputation at 12 months in limbs without vs with maintained LBP). CONCLUSIONS: The anatomic durability of revascularization, as measured by LBP, is a key determinant of treatment outcomes in CLTI regardless of the initial mode of intervention undertaken. Loss of LBP is most detrimental in patients presenting with advanced limb threat (WIfI stage 4).

Applicability of the Vascular Quality Initiative mortality prediction model for infrainguinal revascularization in a tertiary limb preservation center population.

OBJECTIVE: Patients undergoing revascularization for chronic limb-threatening ischemia (CLTI) are at elevated risk for both mortality and limb loss. To facilitate therapeutic decision-making, a mortality prediction model derived from the Vascular Quality Initiative (VQI) database has stratified patients into low, medium, and high risk, defined by 30-day mortality estimates of ≤3%, 3%-5%, or >5% and 2-year mortality estimates of ≤30%, 30%-50%, or ≥50%, respectively. The purpose of this study was to compare expected mortality risk derived from this model with observed outcomes in a tertiary center. METHODS: Consecutive patients treated at a single center between 2016 and 2019 were analyzed. Baseline demographics, approach, and mortality events were reviewed. Observed mortality was obtained using life-table methods and compared using a log-rank test with the expected mortality risk that was calculated using the VQI model. RESULTS: This study cohort consisted of 195 revascularization procedures in 169 unique patients stratified into 128 (66%) low-, 50 (26%) medium-, and 17 (8%) high-risk cases based on the VQI model. Ninety percent of revascularizations were performed for tissue loss. Compared with the VQI population, comorbidities were prevalent and included unstable angina or myocardial infarction within 6 months (6% vs 2.4% in VQI; P < .001), congestive heart failure (30% vs 23%; P < .001), and dialysis dependence (14% vs 0.9%; P < .001). Patients were also older (31% vs 21% ≥80 years old; P < .001) and more likely to be frail (45% vs 64% independent; P < .001). High-risk patients were more prevalent in the endovascular group (11% of 132 endovascular interventions vs 3% of 63 bypasses; P = .056). Thirty-day observed mortality exceeded expected VQI prediction model mortality in all groups, although was not statistically significant. The VQI model adequately stratified the studied population into risk groups (P < .001). Low-risk patients with CLTI (65% of the overall cohort) experienced 2-year mortality of 18.9%. However, observed mortality rates for medium- and high-risk VQI strata were similar. After a median follow-up of 28 months, medium-risk patients incurred a significantly higher mortality than predicted (53.5% ± 2.1% vs 36.8% ± 1.1%; P = .016). CONCLUSIONS: The VQI mortality prediction model discriminates mortality risk after limb revascularization in CLTI, accurately identifying a majority subgroup of patients who are suitable for either open or endovascular intervention. However, it may underestimate mortality in a tertiary referral population with high comorbidity burden and was not well calibrated for the medium-risk group. It may be more appropriate to dichotomize patients with CLTI who are candidates for limb salvage into an average-risk and high-risk group.

Validation of natural language processing to determine the presence and size of abdominal aortic aneurysms in a large integrated health system.

OBJECTIVE: Previous studies of the natural history of abdominal aortic aneurysms (AAAs) have been limited by small cohort sizes or heterogeneous analyses of pooled data. By quickly and efficiently extracting imaging data from the health records, natural language processing (NLP) has the potential to substantially improve how we study and care for patients with AAAs. The aim of the present study was to test the ability of an NLP tool to accurately identify the presence or absence of AAAs and detect the maximal abdominal aortic diameter in a large dataset of imaging study reports. METHODS: Relevant imaging study reports (n = 230,660) from 2003 to 2017 were obtained for 32,778 patients followed up in a prospective aneurysm surveillance registry within a large, diverse, integrated healthcare system. A commercially available NLP algorithm was used to assess the presence of AAAs, confirm the absence of AAAs, and extract the maximal diameter of the abdominal aorta, if stated. A blinded expert manual review of 18,000 randomly selected imaging reports was used as the reference standard. The positive predictive value (PPV or precision), sensitivity (recall), and the kappa statistics were calculated. RESULTS: Of the randomly selected 18,000 studies that underwent expert manual review, 48.7% were positive for AAAs. In confirming the presence of an AAA, the interrater reliability of the NLP compared with the expert review showed a kappa value of 0.84 (95% confidence interval [CI], 0.83-0.85), with a PPV of 95% and sensitivity of 88.5%. The NLP algorithm showed similar results for confirming the absence of an AAA, with a kappa of 0.79 (95% CI, 0.799-0.80), PPV of 77.7%, and sensitivity of 91.9%. The kappa, PPV, and sensitivity of the NLP for correctly identifying the maximal aortic diameter was 0.88 (95% CI, 0.87-0.89), 88.8%, and 88.2% respectively. CONCLUSIONS: The use of NLP software can accurately analyze large volumes of radiology report data to detect AAA disease and assemble a contemporary aortic diameter-based cohort of patients for longitudinal analysis to guide surveillance, medical management, and operative decision making. It can also potentially be used to identify from the electronic medical records pre- and postoperative AAA patients "lost to follow-up," leverage human resources engaged in the ongoing surveillance of patients with AAAs, and facilitate the construction and implementation of AAA screening programs.

Establishing a carotid artery stenosis disease cohort for comparative effectiveness research using natural language processing.

OBJECTIVE: Investigation of asymptomatic carotid stenosis treatment is hindered by the lack of a contemporary population-based disease cohort. We describe the use of natural language processing (NLP) to identify stenosis in patients undergoing carotid imaging. METHODS: Adult patients with carotid imaging between 2008 and 2012 in a large integrated health care system were identified and followed through 2017. An NLP process was developed to characterize carotid stenosis according to the Society of Radiologists in Ultrasound (for ultrasounds) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) (for axial imaging) guidelines. The resulting algorithm assessed text descriptors to categorize normal/non-hemodynamically significant stenosis, moderate or severe stenosis as well as occlusion in both carotid ultrasound (US) and axial imaging (computed tomography and magnetic resonance angiography [CTA/MRA]). For US reports, internal carotid artery systolic and diastolic velocities and velocity ratios were assessed and matched for laterality to supplement accuracy. To validate the NLP algorithm, positive predictive value (PPV or precision) and sensitivity (recall) were calculated from simple random samples from the population of all imaging studies. Lastly, all non-normal studies were manually reviewed for confirmation for prevalence estimates and disease cohort assembly. RESULTS: A total of 95,896 qualifying index studies (76,276 US and 19,620 CTA/MRA) were identified among 94,822 patients including 1059 patients who underwent multiple studies on the same day. For studies of normal/non-hemodynamically significant stenosis arteries, the NLP algorithm showed excellent performance with a PPV of 99% for US and 96.5% for CTA/MRA. PPV/sensitivity to identify a non-normal artery with correct laterality in the CTA/MRA and US samples were 76.9% (95% confidence interval [CI], 74.1%-79.5%)/93.1% (95% CI, 91.1%-94.8%) and 74.7% (95% CI, 69.3%-79.5%)/94% (95% CI, 90.2%-96.7%), respectively. Regarding cohort assembly, 15,522 patients were identified with diseased carotid artery, including 2674 exhibiting equal bilateral disease. This resulted in a laterality-specific cohort with 12,828 moderate, 5283 severe, and 1895 occluded arteries and 326 diseased arteries with unknown stenosis. During follow-up, 30.1% of these patients underwent 61,107 additional studies. CONCLUSIONS: Use of NLP to detect carotid stenosis or occlusion can result in accurate exclusion of normal/non-hemodynamically significant stenosis disease states with more moderate precision with lesion identification, which can substantially reduce the need for manual review. The resulting cohort allows for efficient research and holds promise for similar reporting in other vascular diseases.

The Global Limb Anatomic Staging System is associated with outcomes of infrainguinal revascularization in chronic limb threatening ischemia.

OBJECTIVE: The Global Limb Anatomic Staging System (GLASS) has been proposed to facilitate clinical decision-making regarding revascularization for chronic limb threatening ischemia (CLTI). The purpose of the present study was to define its relationship to the treatment outcomes in CLTI. METHODS: Consecutive patients who had undergone peripheral angiography for rest pain or tissue loss from January 2017 to July 2019 at a tertiary referral center with a dedicated limb preservation program were reviewed. Subjects with significant aortoiliac disease, previous infrainguinal stenting or functioning bypass grafts, or GLASS stage 0 were excluded. The GLASS score was assigned from the preintervention angiography findings, and the treating surgeon determined the primary infrapopliteal target artery pathway for the limb at risk. The demographic data, procedural details, and clinical outcomes were analyzed. RESULTS: The study cohort included 167 patients and 194 limbs, of which 175 of 194 limbs (90%) had presented with tissue loss and 149 of 182 limbs (83%) with WIfI (Wound, Ischemia and foot Infection) stage 3 or 4. The GLASS stage was GLASS 1 in 14%, GLASS 2 in 18%, and GLASS 3 in 68%. GLASS 3 anatomy was present in 85% of 52 limbs treated by bypass and 55% of 108 limbs treated by endovascular intervention (EVI; P < .001). Revascularization was not performed in 34 limbs, most of which were GLASS 3 (85%). Immediate technical failure for EVI (ie, failure to establish target artery pathway) occurred exclusively in the setting of GLASS 3 anatomy (n = 13; 22%). After a median follow-up of 10 months, limb-based patency after EVI was significantly lower in GLASS 3 than in GLASS 1 or 2 limbs (42% vs 59%; P = .018). GLASS 3 was associated with reduced major adverse limb events-free survival in both the EVI group (P = .002) and the overall revascularized cohort (P = .001). GLASS 3 was also associated with significantly reduced overall survival, amputation-free survival, and reintervention-free survival. In a Cox proportional hazards model, GLASS 3 (hazard ratio, 2.35; 95% confidence interval, 1.30-4.24; P = .005) and WIfI wound grade 3 (hazard ratio, 2.64; 95% confidence interval, 1.26-5.53; P = .010) were independent predictors of reduced major adverse limb events-free survival after revascularization. CONCLUSIONS: GLASS stage 3 was strongly associated with major adverse clinical outcomes after revascularization in patients with CLTI.

Instilling Resiliency in Surgical Education: The Benefits of Longitudinal Medical Student Learning.

The longitudinal clerkship has been recognized as an innovative, unique model in medical education that demonstrates significantly higher student and preceptor satisfaction with comparable long-term outcomes like performance on standardized examinations. At the center of this model is the student-preceptor relationship, which promotes effective student-directed learning and personal and professional relationships with established faculty mentors. The University of California, San Francisco (UCSF) has two clerkships models: a traditional or "block" model consisting of 2-month sequential clinical rotations in seven core clerkships, and a longitudinal model that integrates parallel out-patient clinical experiences over the entire year with one-on-one faculty preceptors from each core discipline with focused 2-week intensive inpatient rotations. In the setting of the Covid-19 pandemic beginning in Spring of 2020, this arrangement allowed for a natural experiment to evaluate the resiliency of the respective models in the face of unprecedented disruptions in education and healthcare delivery. As described in this perspective, both clerkships required rapid pivots; however, students enrolled in the longitudinal clerkship were more likely to develop stronger relationships with surgical faculty and felt more prepared for making career choices. Medical school curricula may benefit from incorporating longitudinal components, as this model provided flexibility and fostered greater faculty-student mentorship in the setting of disruption to medical education.

Impact of the coronavirus disease 2019 pandemic on an academic vascular practice and a multidisciplinary limb preservation program.

With the aggressive resource conservation necessary to face the coronavirus disease 2019 pandemic, vascular surgeons have faced unique challenges in managing the health of their high-risk patients. An early analysis of patient outcomes after pandemic-related practice changes suggested that patients with chronic limb threatening ischemia have been presenting with more severe foot infections and are more likely to require major limb amputation compared with 6 months previously. As our society and health care system adapt to the new changes required in the post-coronavirus disease 2019 era, it is critical that we pay special attention to the most vulnerable subsets of patients with vascular disease, particularly those with chronic limb threatening ischemia and limited access to care.

Increased Reintervention After Infrainguinal Revascularization for Chronic Limb-Threatening Ischemia in Women.

BACKGROUND: The objective of this study was to determine if there are gender-based differences in major adverse limb events after revascularization for chronic limb-threatening ischemia (CLTI) and to identify potential associated factors. METHODS: This was a single-center retrospective analysis of 151 patients who underwent infrainguinal revascularization for CLTI between April 2013 and December 2015. Only the first revascularized limb was included in patients with bilateral CLTI. Demographic data and clinical outcomes were collected using electronic medical records. RESULTS: The mean age was 68.1 ± 12.1 years, and 55 of 151 (36%) were women. Women were less likely to carry a diagnosis of hyperlipidemia (60% vs. 83%; P = 0.003), less likely to be on a statin medication (58% vs. 81%; P = 0.004), and less likely to undergo an infrapopliteal revascularization (60% vs. 77%; P = 0.04) compared with men. There were no differences between genders with regard to the Society for Vascular Surgery Wound Ischemia and Foot Infection stage at presentation or utilization of open versus endovascular intervention. During the median follow-up time of 678 days (interquartile range, 167-1277 days), 48 of 151 patients (32%) underwent reintervention on the threatened limb and 23 of 151 patients (15%) underwent major amputation. Women were more likely than men to need reintervention (P = 0.02). There was no difference between genders for major amputation (P = 0.48) or overall survival (P = 0.65). In a multivariable Cox proportional hazards model for reintervention that included gender, preoperative body mass index, hyperlipidemia, preoperative anticoagulation, and ischemia score ≥2 (all P < 0.20 in univariate analysis), female gender (hazard ratio [HR], 1.96 [1.10-3.54]; P = 0.02) and hyperlipidemia (HR, 2.32 [1.07-5.03]; P = 0.03) were significantly associated with increased rates of reintervention. CONCLUSIONS: Women undergoing lower extremity revascularization for CLTI were more likely to require reintervention compared with men but had similar rates of limb preservation. Further study is required to understand potential causative factors to improve treatment outcomes in women.

Acetaminophen hepatotoxicity: an updated review.

As the most common cause of acute liver failure (ALF) in the USA and UK, acetaminophen-induced hepatotoxicity remains a significant public health concern and common indication for emergent liver transplantation. This problem is largely attributable to acetaminophen combination products frequently prescribed by physicians and other healthcare professionals, with unintentional and chronic overdose accounting for over 50 % of cases of acetaminophen-related ALF. Treatment with N-acetylcysteine can effectively reduce progression to ALF if given early after an acute overdose; however, liver transplantation is the only routinely used life-saving therapy once ALF has developed. With the rapid course of acetaminophen-related ALF and limited supply of donor livers, early and accurate diagnosis of patients that will require transplantation for survival is crucial. Efforts in developing novel treatments for acetaminophen-induced ALF are directed toward bridging patients to recovery. These include auxiliary, artificial, and bioartificial support systems. This review outlines the most recent developments in diagnosis and management of acetaminophen-induced ALF.

Risk factors for venous thromboembolism after vascular surgery and implications for chemoprophylaxis strategies.

OBJECTIVE: Venous thromboembolism (VTE) is an important cause of postoperative morbidity and mortality. However, the reported incidence after major vascular surgery has ranged from as low as 1% to >10%. Furthermore, little is known about optimal chemoprophylaxis regimens or rates of postdischarge VTE in this population. In the present study, we aimed to better characterize the rates of in-hospital and postdischarge VTE after major vascular surgery, the role of chemoprophylaxis timing, and the association of VTE with mortality. METHODS: A single-center retrospective study of 1449 major vascular operations (2013-2020) was performed and included 189 endovascular abdominal aortic aneurysm repairs (13%), 169 thoracic endovascular aortic aneurysm repairs (12%), 318 open aortic operations (22%), 640 lower extremity bypasses (44%), and 133 femoral endarterectomies (9%). The baseline characteristics, anticoagulant and antiplatelet medications, and outcomes were abstracted from an electronic database with medical record auditing. Postoperative VTE (pulmonary embolism and deep vein thrombosis) within 90 days of surgery was classified by the location, symptoms, and treatment. A cut point analysis using Youden's index identified the most VTE discriminating timing of chemoprophylaxis (including therapeutic vs prophylactic anticoagulant and antiplatelet medications) and Caprini score. Multivariable logistic regression was used to test the association of VTE with chemoprophylaxis timing, Caprini score, and additional risk factors. Cox proportional hazard modeling was used to measure the association between VTE and mortality. RESULTS: The overall VTE incidence was 3.4% (65% deep vein thrombosis; 25% pulmonary embolism; 10% both), and 37% had occurred after discharge. The rate of symptomatic VTE was 2.4%, which was lowest for endovascular abdominal aortic aneurysm repair (0.0%) and highest for open aortic surgery (4.1%; P = .02). Those who had developed VTE had had a longer length of stay, higher rates of end-stage renal disease and prior VTE, and higher Caprini scores (8 vs 5 points; P < .01 for all). Those who had developed VTE were also more likely to have received ≥2 U of blood postoperatively, required an unplanned return to the operating room, had delayed chemoprophylaxis, anticoagulation, and/or antiplatelet initiation of >4 days postoperatively, and had increased 90-day mortality (P < .01 for all). A Caprini score of ≥7 (29% of patients) was associated with postdischarge VTE (2.6% vs 0.7%; P = .01), and chemoprophylaxis, anticoagulation, and antiplatelet timing of >4 days was associated with an increased adjusted odds of VTE (odds ratio, 2.4; 95% confidence interval, 1.1-4.9). Although no fatal VTEs were identified, VTE was an independent predictor of 90-day mortality (adjusted hazard ratio, 2.7; 95% confidence interval, 1.3-5.9). CONCLUSIONS: These data have shown that patients undergoing major vascular surgery are particularly prone to the development of VTE, with frequent hypercoagulable comorbidities. The earlier initiation of chemoprophylaxis was associated with a reduced risk of VTE development. Furthermore, the postdischarge VTE rates might reach thresholds warranting postdischarge chemoprophylaxis, especially for patients with a Caprini score of ≥7.

Patterns and predictors of short-term death after emergency department discharge.

STUDY OBJECTIVE: The emergency department (ED) is an inherently high-risk setting. Early death after an ED evaluation is a rare and devastating outcome; understanding it can potentially help improve patient care and outcomes. Using administrative data from an integrated health system, we describe characteristics and predictors of patients who experienced 7-day death after ED discharge. METHODS: Administrative data from 12 hospitals were used to identify death after discharge in adults aged 18 year or older within 7 days of ED presentation from January 1, 2007, to December 31, 2008. Patients who were nonmembers of the health system, in hospice care, or treated at out-of-network EDs were excluded. Predictors of 7-day postdischarge death were identified with multivariable logistic regression. RESULTS: The study cohort contained a total of 475,829 members, with 728,312 discharges from Kaiser Permanente Southern California EDs in 2007 and 2008. Death within 7 days of discharge occurred in 357 cases (0.05%). Increasing age, male sex, and number of preexisting comorbidities were associated with increased risk of death. The top 3 primary discharge diagnoses predictive of 7-day death after discharge included noninfectious lung disease (odds ratio [OR] 7.1; 95% confidence interval [CI] 2.9 to 17.4), renal disease (OR 5.6; 95% CI 2.2 to 14.2), and ischemic heart disease (OR 3.8; 95% CI 1.0 to 13.6). CONCLUSION: Our study suggests that 50 in 100,000 patients in the United States die within 7 days of discharge from an ED. To our knowledge, our study is the first to identify potentially "high-risk" discharge diagnoses in patients who experience a short-term death after discharge.

The incidence of discordant clinical and genomic risk in patients with invasive lobular or ductal carcinoma of the breast: a National Cancer Database Study.

When molecular testing classifies breast tumors as low risk but clinical risk is high, the optimal management strategy is unknown. One group of patients who may be more likely to have such discordant risk are those with invasive lobular carcinoma of the breast. We sought to examine whether patients with invasive lobular carcinoma are more likely to have clinical high/genomic low-risk tumors compared to those with invasive ductal carcinoma, and to evaluate the impact on receipt of chemotherapy and overall survival. We conducted a cohort study using the National Cancer Database from 2010-2016. Patients with hormone receptor positive, HER2 negative, stage I-III breast cancer who underwent 70-gene signature testing were included. We evaluated the proportion of patients with discordant clinical and genomic risk by histology using Kaplan-Meier plots, log-rank tests, and Cox proportional hazards models with and without propensity score matching. A total of 7399 patients (1497 with invasive lobular carcinoma [20.2%]) were identified. Patients with invasive lobular carcinoma were significantly more likely to fall into a discordant risk category compared to those with invasive ductal carcinoma (46.8% versus 37.1%, p < 0.001), especially in the clinical high/genomic low risk subgroup (35.6% versus 19.2%, p < 0.001). In unadjusted analysis of the clinical high/genomic low-risk cohort who received chemotherapy, invasive ductal carcinoma patients had significantly improved overall survival compared to those with invasive lobular carcinoma (p = 0.02). These findings suggest that current tools for stratifying clinical and genomic risk could be improved for those with invasive lobular carcinoma to better tailor treatment selection.

Applications of Next-Generation Sequencing in Neoantigen Prediction and Cancer Vaccine Development.

Next-generation sequencing has changed the face of cancer immunotherapy research by making tumor-specific cancer vaccines a reality. Whole exome sequencing and RNA sequencing combined with bioinformatic pipelines allow the prediction of neoantigen targets for cancer vaccines. In this review, we discuss the preclinical and early clinical evidence for cancer vaccines; describe methods and challenges in neoantigen prediction; and summarize emerging new technologies that will improve neoantigen cancer vaccine development.

Rapid Response of an Academic Surgical Department to the COVID-19 Pandemic: Implications for Patients, Surgeons, and the Community.

BACKGROUND: As the coronavirus disease 2019 (COVID-19) pandemic continues to spread, swift actions and preparation are critical for ensuring the best outcomes for patients and providers. We aim to describe our hospital and Department of Surgery's experience in preparing for the COVID-19 pandemic and caring for surgical patients during this unprecedented time. STUDY DESIGN: This is a descriptive study outlining the strategy of a single academic health system for addressing the following 4 critical issues facing surgical departments during the COVID-19 pandemic: developing a cohesive leadership team and system for frequent communication throughout the department; ensuring adequate hospital capacity to care for an anticipated influx of COVID-19 patients; safeguarding supplies of blood products and personal protective equipment to protect patients and providers; and preparing for an unstable workforce due to illness and competing personal priorities, such as childcare. RESULTS: Through collaborative efforts within the Department of Surgery and hospital, we provided concise and regular communication, reduced operating room volume by 80%, secured a 4-week supply of personal protective equipment, and created reduced staffing protocols with back-up staffing plans. CONCLUSIONS: By developing an enabling infrastructure, a department can nimbly respond to crises like COVID-19 by promoting trust among colleagues and emphasizing an unwavering commitment to excellent patient care. Sharing principles and practical applications of these changes is important to optimize responses across the country and the world.

Qualitative factors in patients who die shortly after emergency department discharge.

OBJECTIVES: Early death after emergency department (ED) discharge may signal opportunities to improve care. Prior studies are limited by incomplete mortality ascertainment and lack of clinically important information in administrative data. The goal in this hypothesis-generating study was to identify patient and process of care themes that may provide possible explanations for early postdischarge mortality. METHODS: This was a qualitative analysis of medical records of adult patients who visited the ED of any of six hospitals in an integrated health system (Kaiser Permanente Southern California [KPSC]) and died within 7 days of discharge in 2007 and 2008. Nonmembers, visits to non-health plan hospitals, patients receiving or referred to hospice care, and patients with do not attempt resuscitation or do not intubate orders (DNAR/DNI) were excluded. Under the guidance of two qualitative research scientists, a team of three emergency physicians used grounded theory techniques to identify patient clinical presentations and processes of care that serve as potential explanations for poor outcome after discharge. RESULTS: The source population consisted of a total of 290,092 members with 446,120 discharges from six KPSC EDs in 2007 and 2008. A total of 203 deaths occurred within 7 days of ED discharge (0.05%). Sixty-one randomly chosen cases were reviewed. Patient-level themes that emerged included an unexplained persistent acute change in mental status, recent fall, abnormal vital signs, ill-appearing presentation, malfunctioning indwelling device, and presenting symptoms remaining at discharge. Process-of-care factors included a discrepancy in history of present illness, incomplete physical examination, and change of discharge plan by a third party, such as a consulting or admitting physician. CONCLUSIONS: In this hypothesis-generating study, qualitative research techniques were used to identify clinical and process-of-care factors in patients who died within days after discharge from an ED. These potential predictors will be formally tested in a future quantitative study.