Majority of the highly variable NLRs in maize share genomic location and contain additional target-binding domains.

Nucleotide-binding, Leucine Rich Repeat proteins (NLRs) are a major class of immune receptors in plants. NLRs include both conserved and rapidly evolving members, however their evolutionary trajectory in crops remains understudied. Availability of crop pan-genomes enables analysis of the recent events in the evolution of this highly complex gene family within domesticated species. Here, we investigated the NLR complement of 26 nested association mapping (NAM) founder lines of maize. We found that maize has just four main subfamilies containing rapidly evolving highly variable NLR (hvNLR) receptors. Curiously, three of these phylogenetically distinct hvNLR lineages are located in adjacent clusters on chromosome 10. Members of the same hvNLR clade show variable expression and methylation across lines and tissues, consistent with their rapid evolution. By combining sequence diversity analysis and AlphaFold2 computational structure prediction we predicted ligand binding sites in the hvNLRs. We also observed novel insertion domains in the LRR regions of two hvNLR subfamilies that likely contribute to target recogniton. To make this analysis accessible, we created NLRCladeFinder, a Google Colaboratory notebook, that accepts any newly identified NLR sequence, places it in the evolutionary context of the maize pan-NLRome, and provides an updated clade alignment, phylogenetic tree, and sequence diversity information for the gene of interest.

Inadequate Performance of ChatGPT on Orthopedic Board-Style Written Exams.

BACKGROUND: Chat Generative Pre-Trained Transformer (ChatGPT) is an artificial intelligence (AI) chatbot capable of delivering human-like responses to a seemingly infinite number of inquiries. For the technology to perform certain healthcare-related tasks or act as a study aid, the technology should have up-to-date knowledge and the ability to reason through medical information. The purpose of this study was to assess the orthopedic knowledge and reasoning ability of ChatGPT by querying it with orthopedic board-style questions. METHODOLOGY: We queried ChatGPT (GPT-3.5) with a total of 472 questions from the Orthobullets dataset (n = 239), the 2022 Orthopaedic In-Training Examination (OITE) (n = 124), and the 2021 OITE (n = 109). The importance, difficulty, and category were recorded for questions from the Orthobullets question bank. Responses were assessed for answer choice correctness if the explanation given matched that of the dataset, answer integrity, and reason for incorrectness. RESULTS: ChatGPT correctly answered 55.9% (264/472) of questions and, of those answered correctly, gave an explanation that matched that of the dataset for 92.8% (245/264) of the questions. The chatbot used information internal to the question in all responses (100%) and used information external to the question (98.3%) as well as logical reasoning (96.4%) in most responses. There was no significant difference in the proportion of questions answered correctly between the datasets (P = 0.62). There was no significant difference in the proportion of questions answered correctly by question category (P = 0.67), importance (P = 0.95), or difficulty (P = 0.87) within the Orthobullets dataset questions. ChatGPT mostly got questions incorrect due to information error (i.e., failure to identify the information required to answer the question) (81.7% of incorrect responses). CONCLUSIONS: ChatGPT performs below a threshold likely to pass the American Board of Orthopedic Surgery (ABOS) Part I written exam. The chatbot's performance on the 2022 and 2021 OITEs was between the average performance of an intern and to second-year resident. A major limitation of the current model is the failure to identify the information required to correctly answer the questions.

ChatGPT Is Moderately Accurate in Providing a General Overview of Orthopaedic Conditions.

Background: ChatGPT is an artificial intelligence chatbot capable of providing human-like responses for virtually every possible inquiry. This advancement has provoked public interest regarding the use of ChatGPT, including in health care. The purpose of the present study was to investigate the quantity and accuracy of ChatGPT outputs for general patient-focused inquiries regarding 40 orthopaedic conditions. Methods: For each of the 40 conditions, ChatGPT (GPT-3.5) was prompted with the text "I have been diagnosed with [condition]. Can you tell me more about it?" The numbers of treatment options, risk factors, and symptoms given for each condition were compared with the number in the corresponding American Academy of Orthopaedic Surgeons (AAOS) OrthoInfo website article for information quantity assessment. For accuracy assessment, an attending orthopaedic surgeon ranked the outputs in the categories of <50%, 50% to 74%, 75% to 99%, and 100% accurate. An orthopaedics sports medicine fellow also independently ranked output accuracy. Results: Compared with the AAOS OrthoInfo website, ChatGPT provided significantly fewer treatment options (mean difference, -2.5; p < 0.001) and risk factors (mean difference, -1.1; p = 0.02) but did not differ in the number of symptoms given (mean difference, -0.5; p = 0.31). The surgical treatment options given by ChatGPT were often nondescript (n = 20 outputs), such as "surgery" as the only operative treatment option. Regarding accuracy, most conditions (26 of 40; 65%) were ranked as mostly (75% to 99%) accurate, with the others (14 of 40; 35%) ranked as moderately (50% to 74%) accurate, by an attending surgeon. Neither surgeon ranked any condition as mostly inaccurate (<50% accurate). Interobserver agreement between accuracy ratings was poor (κ = 0.03; p = 0.30). Conclusions: ChatGPT provides at least moderately accurate outputs for general inquiries of orthopaedic conditions but is lacking in the quantity of information it provides for risk factors and treatment options. Professional organizations, such as the AAOS, are the preferred source of musculoskeletal information when compared with ChatGPT. Clinical Relevance: ChatGPT is an emerging technology with potential roles and limitations in patient education that are still being explored.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia). METHODS: A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate. STRUCTURE: Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia). METHODS: A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate. STRUCTURE: Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

The Diversity of Surgical Trainees Index identifies racial and ethnic disparities among surgical specialties.

OBJECTIVE: Racial and ethnic disparities have been well-described among surgical specialties; however, variations in underrepresented in medicine (URiM) representation between these specialties have not previously been quantified. METHODS: Data collected from Accreditation Council for Graduate Medical Education (ACGME) annual reports were used to derive the Diversity of Surgical Trainee Index (DoSTI), which was calculated as the proportion of URiM residents and fellow physicians within a given surgical specialty, relative to the overall proportion of URiM trainees within all surgical and non-surgical ACGME-accredited programs in the same academic year. RESULTS: From 2013 to 2022, a total of 108,193 ACGME-accredited residency programs trained 1,296,204 residents and fellows in the United States. Of these, 14.1% (n = 182,680) of trainees self-identified as URiM over the study period. The mean DoSTI among all surgical specialties was 0.80 (standard error, 0.01) compared with all ACGME-accredited programs. High DoSTI specialties incorporated significantly higher proportions of trainees who identify as Hispanic (8.7% vs 6.3%) and Black or African American (5.2% vs 2.5%) when compared with low DoSTI specialties (P < .0001 each). General surgery (1.06 ± 0.01), plastic surgery (traditional) (1.12 ± 0.06), vascular surgery (integrated) (0.96 ± 0.03), and vascular surgery (traditional) (0.94 ± 0.06) had the highest DoSTI (P < .05 each vs composite). On linear regression analysis, only ophthalmology (+0.01/year; R2 = 0.41; P = .019), orthopedic surgery (+0.01/year; R2 = 0.33; P = .047), otolaryngology (+0.02/year; R2 = 0.86; P < .001), and pediatric surgery (+0.06/year; R2 = 0.33; P = .048) demonstrated an annual increase in DoSTI. CONCLUSIONS: The DoSTI is a novel metric used to quantify the degree of URiM representation among surgical specialties. DoSTI has revealed specialty-specific variations in racial/ethnic minority representation among surgical training programs. This metric may be used to improve provider awareness and identify high performing DoSTI specialties to highlight best practices to ultimately recruit a more diverse surgical workforce.

High allelic diversity in Arabidopsis NLRs is associated with distinct genomic features.

Plants rely on Nucleotide-binding, Leucine-rich repeat Receptors (NLRs) for pathogen recognition. Highly variable NLRs (hvNLRs) show remarkable intraspecies diversity, while their low-variability paralogs (non-hvNLRs) are conserved between ecotypes. At a population level, hvNLRs provide new pathogen-recognition specificities, but the association between allelic diversity and genomic and epigenomic features has not been established. Our investigation of NLRs in Arabidopsis Col-0 has revealed that hvNLRs show higher expression, less gene body cytosine methylation, and closer proximity to transposable elements than non-hvNLRs. hvNLRs show elevated synonymous and nonsynonymous nucleotide diversity and are in chromatin states associated with an increased probability of mutation. Diversifying selection maintains variability at a subset of codons of hvNLRs, while purifying selection maintains conservation at non-hvNLRs. How these features are established and maintained, and whether they contribute to the observed diversity of hvNLRs is key to understanding the evolution of plant innate immune receptors.

Endovascular Management of Aortic Stump Blowout by Parallel Grafting and Coil Embolization of Visceral Aorta.

Aortic graft and endograft infections remain a significant source of morbidity and mortality after abdominal aortic aneurysm repair. With graft excision and extra-anatomic bypass, an infrarenal aortic stump remains which can have suture line dehiscence and catastrophic stump blowout. Treatment of this is extremely challenging, especially for severely co-morbid patients who cannot undergo major surgery, or in patients with a hostile abdomen. We present a case study of a 74-year-old male found to have an aortoenteric fistula (AEF). This case broadens operative options for this type of patient population by demonstrating an endovascular technique for addressing aortic stump blowout by parallel grafting and coil embolization of the visceral aorta.

Limited English Proficiency and Graves' Disease at an Urban Safety Net Hospital.

INTRODUCTION: Decision-making regarding definitive therapy for Graves' disease requires effective patient-provider communication. We investigated whether patients with limited English proficiency have differences in thyroidectomy outcomes or perioperative management when compared to English proficient (EP) patients at a safety net hospital with high-volume endocrine surgery practice. METHODS: Retrospective study of patients who underwent thyroidectomy (2012-2021) for Graves' disease within a tertiary referral system. Demographics, preoperative factors, and postoperative outcomes were abstracted via chart review and compared between EP and limited English proficient (LEP) patients in univariate analyses. Odds of postoperative complications were assessed via multivariable logistic regression. Time metrics such as time from endocrinology consultation to surgery were compared via Kaplan-Meier analysis and adjusted Cox proportional regression models. RESULTS: Of 236 patients, 85 (36%) had LEP. Low and equivalent complication rates occurred across language groups (<1% permanent). LEP patients had similar odds of thyroidectomy-specific complications (odds ratio = 1.2; 95% confidence interval 0.6-2.4). Adjusted Cox proportional hazards ratios showed that LEP patients experienced significantly shorter time from endocrinology consultation to surgery compared to EP patients [hazard ratio = 0.7; 95% confidence interval 0.5-0.9]. CONCLUSIONS: Thyroidectomy-specific complication rate for patients with Graves' disease was low, and we detected no independent association between complications and English language proficiency. Non-English primary language was independently associated with reduced time from endocrinology consultation to surgery. This finding must be interpreted with nuance and is likely multifactorial. It may reflect a well-organized, efficient system for under-resourced patients, or it may derive from communication barriers that limit robust shared decision-making, thus accelerating time to surgery.

Risk factors and consequences of wound complications following sartorius flap reconstruction.

OBJECTIVE: Groin wound complications are common following vascular surgery and can lead to significant patient morbidity. Sartorius muscle flap coverage may help to prevent vascular graft infection in the setting of wound dehiscence or infection. However, risk factors and consequences of wound complications following sartorius flap reconstruction remain incompletely investigated. METHODS: We retrospectively queried all patients who underwent sartorius flap reconstruction at a tertiary academic medical center. Data collected included patient demographics, medical comorbidities, surgical indication, index vascular procedure, and postoperative outcomes. The primary outcome was wound complication following sartorius flap procedure, which was defined as groin wound infection, dehiscence, or lymphocutaneous fistula. RESULTS: From 2012 to 2022, a total of 113 patients underwent sartorius flap reconstruction. Of these, 66 (58.4%) were performed after the development of a prior groin complication, and 47 (41.6%) were prophylactic. A total of 88 patients (77.9%) had a prosthetic bypass graft adjacent to the flap. Twenty-nine patients (25.7%) suffered a wound complication following sartorius flap reconstruction, including 14 (12.4%) with wound dehiscence, 13 (11.5%) with wound infection, and two (1.8%) with lymphocutaneous fistula. Patients with wound complications had a higher body mass index (28.8 vs 26.4 kg/m2; P =.03) and more frequently active smokers (86.2% vs 66.7%; P = .04). Additionally, patients with wound complications had a higher unplanned 30-day hospital readmission rates (72.4% vs 15.5%; P < .001), reintervention rates (75.9% vs 8.3%; P < .001), and re-do flap reconstruction rates (13.8% vs 2.4%; P = .02). On multivariable analysis, higher body mass index was independently associated with post-flap wound complications (adjusted odds ratio [aOR], 1.01; 95% confidence interval [CI], 1.001-1.03; P = .037). Consequently, wound complications were associated with both surgical reintervention (aOR, 35.4; 95% CI, 9.9-126.3; P < .001) and unplanned hospital readmission (aOR, 17.8; 95% CI, 5.9-54.1; P < .001). CONCLUSIONS: Sartorius flap reconstruction is an effective adjunct in facilitating wound healing of groin wounds. However, wound complications are common following sartorius flap reconstruction and may be associated with reintervention and unplanned hospital readmission. These data support the judicious and thoughtful utilization of sartorius flap procedures among high-risk patients.

Long-term outcomes for hybrid aortic arch repair.

OBJECTIVE: Since its inception in the early 2000s, hybrid arch repair (HAR) has evolved from novel approach to well-established treatment modality for aortic arch pathology in appropriately selected patients. Despite this nearly 20-year history of use, long-term results of HAR remain to be determined. As such, objectives of this study are to detail the long-term outcomes for HAR within an expanded classification scheme. METHODS: From August 2005 to August 2022, 163 consecutive patients underwent HAR at a single referral institution. Operative approach was selected according to an institutional algorithm and included zone 0/1 HAR in 25% (n = 40), type I HAR in 34% (n = 56), and type II/III HAR in 41% (n = 67). Specific zone 0/1 technique was zone 1 HAR in 31 (78%), zone 0 with innominate snorkel (zone 0S HAR) in 7 (18%), and zone 0 with single side-branch endograft (zone 0B HAR) in 2 (5%). The 30-day and long-term outcomes, including overall and aortic-specific survival, as well as freedom from reintervention, were assessed. RESULTS: The mean age was 63 ± 13 years and almost one-half of patients (47% [n = 77]) had prior sternotomy. Presenting pathology included degenerative aneurysm in 44% (n = 71), residual dissection after prior type A repair in 38% (n = 62), chronic type B dissection in 12% (n = 20), and other indications in 6% (n = 10). Operative outcomes included 9% mortality (n = 14) at 30 days, 5% mortality (n = 8) in hospital, 4% stroke (n = 7), 2% new dialysis (n = 3), and 2% permanent paraparesis/plegia (n = 3). The median follow-up was 44 month (interquartile range, 12-84 months). Overall survival was 59% and 47% at 5 and 10 years, respectively, whereas aorta-specific survival was 86% and 84% at the same time points. At 5 and 10 years, freedom from major reintervention was 92% and 91%, respectively. Institutional experience had a significant impact on both early and late outcomes: comparing the first (2005-2012) and second (2013-2022) halves of the series, 30-day mortality decreased from 14% to 1% (P = .01) and stroke from 6% to 3% (P = .62). Improved operative outcomes were accompanied by improved late survival, with 78% of patients in the later era vs 45% in the earlier era surviving to 5 years. CONCLUSIONS: HAR is associated with excellent operative outcomes, as well as sustained protection from adverse aortic events as evidenced by high long-term aorta-specific survival and freedom from reintervention. However, surgeon and institutional experience appear to play a major role in achieving these superior outcomes, with a five-fold decrease in operative mortality and a two-fold decrease in stroke rate in the latter half of the series. These long-term results expand on prior midterm data and continue to support use of HAR for properly selected patients with arch disease.

Impact of Integrated Vascular Surgery Residency on General Surgery Resident and Vascular Fellow Operative Volume: A National Analysis.

BACKGROUND: The impact of integrated vascular surgery (VS) residency (0 + 5) programs on general surgery (GS) resident and VS fellow (5 + 2) operative volume has not been investigated on a national scale. METHODS: Accreditation Council for Graduate Medical Education (ACGME) case logs were reviewed for GS resident, VS resident, and VS fellow operative volume from 2001-2021. Integrated VS resident data was available from 2012-2021, corresponding with the introduction of the 0 + 5 paradigm. Trends in operative volume were evaluated via linear regression analysis. RESULTS: The national cohort of chief GS resident graduates increased from 1005 to 1357 per year. Total operative volume also increased from 932 to 1039 cases (+7.4 cases/yr, R2 = .80, P < .0001) among GS residents. Major vascular cases decreased among GS residents from 138 to 101 cases (-2.4 cases/yr, R2 = .58, P < .0001) with a decrease in proportion of chief-level vascular cases from 30.4% to 11.9% (-1.0%/yr, R2 = .92, P < .0001). Palliative procedures (amputations and hemodialysis access) comprised a significant proportion of GS cases (median 44.7%). Concurrently, integrated VS graduates increased from 11 to 37 per year, with an increase in major vascular case volume from 506 to 658 cases (+18.4 cases/yr, R2 = .63, P = .01). Total VS fellow major case volume also increased from 369 to 444 cases (+3.5 cases/yr, R2 = .73, P < .0001). CONCLUSIONS: The introduction of the 0 + 5 intgrated VS residency paradigm has correlated with a significant decrease in GS operative experience in major vascular procedures on a national level. Traditional VS fellow case volume does not appear to be impacted by 0 + 5 integrated residents. Further analysis with program-level data may help to explain the causative relationship of these findings.

Surgical Specialty Impacts Quality of Operative Training in Carotid Endarterectomy.

BACKGROUND: Carotid endarterectomy (CEA) is currently performed by multiple surgical specialties. The impact of surgical specialty and operative volume on post-CEA outcomes has been well described. However, it is unclear whether trainees of different surgical specialties have similar quality of operative training. METHODS: Data from Accreditation Council for Graduate Medical Education annual reports were collected and compared between graduating vascular surgery (VS) residents, VS fellows, and neurological surgery (NS) residents. Only cases reported as chief/senior/lead resident, surgeon junior, or surgeon fellow were included in analysis. Linear regression analysis was utilized to evaluate trends in case-mix and volume. RESULTS: From 2013 to 2022, total CEA case volume was higher among VS residents and fellows, compared to NS residents (52.8 ± 0.8 vs. 44.3 ± 1.4 vs. 12.9 ± 0.6, P < 0.0001). Additionally, VS residents and fellows performed other carotid operations including transfemoral or transcarotid artery stenting (11.1 ± 0.9 vs. 11.2 ± 0.8 vs. 0), carotid body tumor resection (0.7 ± 0.1 vs. 0.7 ± 0.0 vs. 0), and extracranial cervical bypass (6.7 ± 0.3 vs. 6.3 ± 0.3 vs. 0) that were not reported by the NS resident cohort (P < 0.0001 each). On linear regression analysis, total CEA procedures did not change for VS residents (R2 = 0.03, P = 0.62), decreased for VS fellows (-1.29 cases/yr, R2 = 0.75, P < 0.0001), and decreased among NS residents (-0.41 cases/yr, R2 = 0.44, P = 0.01) over the study period. CONCLUSIONS: Although residents of multiple surgical specialties are trained in CEA, vascular training offers significantly greater numbers and diversity of extracranial carotid cases. It also appears that CEA volume is decreasing among neurosurgical trainees. In light of recent reports on the volume-outcome effect in carotid surgery, these data may have implications for future practice patterns in the domain of extracranial carotid artery disease.

Concerning Trends in Vascular Surgery Trainee Operative Experience in Venous Disease.

BACKGROUND: Comprehensive vascular care includes both arterial and venous disease management. However, operative training in venous disease is often significantly overshadowed by arterial procedures, despite the public health burden of acute and chronic venous disease. The purpose of this study is to evaluate the case-mix and volume of venous procedures performed by graduating integrated vascular surgery residents and fellows in the United States. METHODS: Accreditation Council for Graduate Medical Education national operative log reports were compiled for graduating integrated VSR (vascular surgery residency) and traditional vascular surgery fellowship (VSF) trainees from academic years 2013 to 2022. Only cases categorized as "surgeon fellow", "surgeon chief", or "surgeon junior" were included. Linear regression analysis was utilized to evaluate trends in case-mix and volume. RESULTS: Over the 10-year study period, total vascular cases increased for both VSR (mean 870.5 ± 9.3 cases, annual change +9.5 cases/year, R2 = 0.77, P < 0.001) and VSF (mean 682.1 ± 6.9 cases, annual change +6.7 cases/year, R2 = 0.85, P < 0.001) trainees. Concurrently, the proportion of venous cases in the VSR group decreased from 12.5% to 7.3% (annual change -3.7 cases/year, R2 = 0.72, P < 0.001). VSR trainees experienced an annual decrease in 4 of the top 5 venous case types performed, including venous angioplasty/stenting (-1.6 cases/year, P = 0.002), vena cava filter placement (-0.9 cases/year, P = 0.002), endoluminal ablation (-0.2 cases/year, P = 0.47), diagnostic venography (-1.7 cases/year, P < 0.001), and varicose vein treatment (-1.0 cases/year, P < 0.001). Venous cases proportions also decreased in the VSF group from 8.4% to 6.2% (annual change -2.2 cases/year, R2 = 0.54, P = 0.002). VSF trainees experienced an annual decrease in 4 of the top 5 venous case types, including venous angioplasty/stenting (-1.5 cases/year, P = 0.003), diagnostic venography (-1.2 cases/year, P < 0.001), vena cava filter placement (-0.2 cases/year, P = 0.44), endoluminal ablation (-0.6 cases/year, P < 0.001), and varicose vein treatment (-0.1 cases/year, P = 0.04). Both VSR and VSF trainee groups graduated with fewer than 5 cases for each of the following venous procedures-percutaneous mechanical thrombectomy, venous thrombolysis, open venous reconstruction, sclerotherapy, venous embolectomy, portal-systemic shunting, venous ulceration treatment, and arteriovenous malformation treatment. CONCLUSIONS: Current vascular residents and fellows have limited exposure to venous procedures, in part due to a proportional decline in venous cases. More robust venous operative experience is needed during surgical training. Further studies are needed to understand whether this discrepancy in venous and arterial training impacts career progression and patient outcomes.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms.

BACKGROUND: Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAAs), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear. METHODS: A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency. RESULTS: From 1999 to 2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and 2 (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs. 66 years, P = 0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs. 23.2%, P < 0.001). Conduit type did not impact postoperative complication rates (P = NS each). MALE rates were low overall (19.2% at 2 years), and similar when stratified by conduit type (log rank P = 0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, P < 0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, P = 0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, P = 0.97) were not associated with MALE. CONCLUSIONS: Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

Mouse Lumbar Vertebra Uniaxial Compression Testing with Embedding of the Loading Surface.

There is increasing awareness that cortical and cancellous bone differ in regulating and responding to pharmaceutical therapies, hormone therapies, and other treatments for age-related bone loss. Three-point bending is a common method used to assess the influence of a treatment on the mid-diaphysis region of long bones, which is rich in cortical bone. Uniaxial compression testing of mouse vertebrae, though capable of assessing bones rich in cancellous bone, is less commonly performed due to technical challenges. Even less commonly performed is the pairing of three-point bending and compression testing to determine how a treatment may influence a long bone's mid-diaphysis region and a vertebral centrum similarly or differently. Here, we describe two procedures to make compression testing of mouse lumbar vertebrae a less challenging method to perform in parallel with three-point bending: first, a procedure to convert a three-point bending machine into a compression testing machine, and second, an embedding method for preparing a mouse lumbar vertebra loading surface.

A national analysis of vascular surgery resident operative experience in peripheral artery disease.

BACKGROUND: Endovascular and hybrid interventions have played an increasingly prominent role in the treatment of peripheral arterial disease (PAD) in the past decade. This shift has prompted concerns about the adequacy of open surgical training for current surgical residents. Moreover, the recent Best Surgical Therapy in Patients With Critical Limb Ischemia trial has further emphasized the importance of open surgical techniques in the treatment of peripheral arterial disease. The purpose of this study was to examine national temporal trends in peripheral operative volume among integrated vascular surgery residents. METHODS: Data was obtained from the Accreditation Council for Graduate Medical Education national data reports for integrated vascular surgery residents. Case volumes for surgeon chief or surgeon junior cases were collected from academic years 2012 to 2013 and 2021 to 2022. Trends in case-mix and volume were evaluated using linear regression analysis. RESULTS: The mean total vascular operative volume increased from 851.2 to 914.3 cases among graduating chief residents, with an annual growth of 8.5 ± 1.7 cases/year (R2 = 0.77; P < .0001). Major vascular case volume also increased at a rate of 5.7 ± 1.2 cases/year (R2 = 0.74; P < .001). Among operative categories, peripheral cases were the most frequent (n = 232.2 [26.6%]) and demonstrated the greatest annual growth (+8.0 ± 0.8 cases/year, R2 = 0.93; P < .001). No changes were seen in volume of open peripheral cases, including suprainguinal bypass (+0.1 ± 0.2 cases/year; R2 = 0.08; P = .40) or femoropopliteal bypass procedures (-0.1 ± 0.2 cases/year; R2 = 0.17; P = .20). Infrapopliteal bypass (+0.4 ± 0.1 cases/year; R2 = 0.48; P = .006), iliac/femoral endarterectomy (+1.3 ± 0.2 cases/year; R2 = 0.82; P < .001), and leg thromboembolectomy (+0.4 ± 0.1 cases/year; R2 = 0.64; P < .001) all demonstrated annual growth. For endovascular peripheral cases, aortoiliac revascularization (+3.4 ± 0.3 cases/year; R2 = 0.94; P < .001), femoropopliteal revascularization (+5.4 ± 0.2 cases/year; R2 = 0.98; P < .001), and tibioperoneal revascularization (+2.0 ± 0.2 cases/year; R2 = 0.92; P < .001) all increased in volume. Lower extremity amputations, including above-knee amputation (+0.6 ± 0.2 cases/year; R2 = 0.65; P < .001) and below-knee amputation (+0.9 ± 0.2 cases/year; R2 = 0.72; P < .001) also demonstrated an increase in volume. CONCLUSIONS: Current graduating residents have higher open and endovascular case volumes for peripheral artery disease on a national level, despite the increasing popularity of endovascular techniques. Further studies are needed to identify how these trends may impact current vascular surgery milestones. These trends may also influence the rising interest in competency-based training programs.

Sex-based differences in outcomes after lower extremity bypass for chronic limb-threatening ischemia.

BACKGROUND AND AIMS: Lower extremity bypass surgery is an effective treatment option for patients with chronic limb-threatening ischemia (CLTI). Recent studies have suggested that sex-based differences may impact patient outcomes following lower extremity revascularization, however, results have been inconsistent. METHODS: In this multicenter analysis, we retrospectively identified all infrainguinal bypass procedures performed for CLTI from 2002 to 2021. Patients were separated into two groups based on sex. Primary outcomes were major limb amputation and reintervention for graft patency. RESULTS: Of 843 bypasses performed over the study period, 347 (41.2%) patients were female. Racial/ethnic distribution and medical comorbidities were similar across sex groups. Surgical indications and operative details were also similar between groups, including conduit type (49.9% autogenous), bypass target (65.4% infrageniculate), and concurrent endarterectomy (38.9%). Female and male patients had similar hospital length of stay (6 days [4-9] vs 6 days [4-9]), hospital readmission (25.6% vs 25.0%), and postoperative complications (p=NS each). Female patients had higher major amputation rates (10.1% vs 6.3%, p=0.04) after one year, whereas reintervention rates were similar between groups (26.2% vs 24.6%, p=NS). After accounting for patient factors, female sex (odds ratio [OR] 1.02 [1.00-1.04]), infrageniculate target (OR 1.02 [1.00-1.04]), and bypass for tissue loss (OR 1.02 [1.00-1.04]) were associated with major amputation after bypass (p<0.05 each). CONCLUSIONS: Female sex is associated with a small but significant increase major amputation after lower extremity bypass surgery for CLTI, despite similar clinical presentation, medical comorbidities, and operative details. These data support the increasingly recognized sex disparities in peripheral arterial disease.

High intraspecies allelic diversity in Arabidopsis NLR immune receptors is associated with distinct genomic and epigenomic features.

Plants rely on Nucleotide-binding, Leucine-rich repeat Receptors (NLRs) for pathogen recognition. Highly variable NLRs (hvNLRs) show remarkable intraspecies diversity, while their low variability paralogs (non-hvNLRs) are conserved between ecotypes. At a population level, hvNLRs provide new pathogen recognition specificities, but the association between allelic diversity and genomic and epigenomic features has not been established. Our investigation of NLRs in Arabidopsis Col-0 has revealed that hvNLRs show higher expression, less gene body cytosine methylation, and closer proximity to transposable elements than non-hvNLRs. hvNLRs show elevated synonymous and nonsynonymous nucleotide diversity and are in chromatin states associated with an increased probability of mutation. Diversifying selection maintains variability at a subset of codons of hvNLRs, while purifying selection maintains conservation at non-hvNLRs. How these features are established and maintained, and whether they contribute to the observed diversity of hvNLRs is key to understanding the evolution of plant innate immune receptors.

Preoperative Anemia is Associated with Poorer Postoperative Outcomes in Patients Undergoing Infrainguinal Bypass Surgery.

BACKGROUND: Preoperative anemia is an important, modifiable risk factor among surgical patients. However, data are scarce on the impact of preoperative anemia on postoperative outcomes after infrainguinal bypass. METHODS: In this multi-institutional analysis, data were retrospectively collected on all infrainguinal bypass procedures performed between 2010 and 2020. Patients were grouped by preoperative hemoglobin as per the National Cancer Institute anemia scale (mild, 10 g/dL-lower limit of normal; moderate, 8.0-9.9 g/dL; severe, 6.5-7.9 g/dL). Multivariable comparisons were performed using logistic regression analysis. RESULTS: A total of 492 patients underwent bypass for peripheral artery disease over the 10-year study period. Median preoperative hemoglobin was 11.0 g/dL (interquartile range 9.5-12.7) and median follow-up was 1.7 years. Preoperative anemia was prevalent among bypass patients (mild 52.4% [n = 258], moderate 26.4% [n = 130], and severe 5.1% [n = 25]). Women were more likely to have moderate (49.2% [women] vs. 50.8% [men]) or severe anemia (52.0% [women] vs. 48.0% [men]) compared with normal hemoglobin (17.7% [women] vs. 82.3% [men]) (P < 0.001). Patients with preoperative anemia were more likely to present with tissue loss (22.8% [normal] vs. 47.7% [moderate] vs. 52.0% [severe], P = 0.01). Bypass target and conduit types were similar between groups. Anemic patients had longer median hospital length of stay compared with nonanemic patients (4 days [normal] vs. 5 days [mild] vs. 6 days [moderate] vs. 7 days [severe], P < 0.001). Postoperative mortality at 30 days was similar across anemia groups (2.5% [normal] vs. 4.6% [moderate] vs. 8.0% [severe], P = 0.23). On multivariable analysis, however, postoperative mortality was independently associated with severe anemia (odds ratio 7.5 [1.2-48.8], P = 0.04) and male gender (odds ratio 7.5 [1.2-26.4], P = 0.03). CONCLUSIONS: Preoperative anemia is common among patients undergoing infrainguinal bypass surgery and is an independent risk factor for postoperative mortality. Future investigation is needed to determine whether correction of anemia improves postoperative outcomes in these high-risk patients.