Socioeconomic disadvantage is a leading variable in risk score for major amputation following emergent infrainguinal arterial bypass surgery.

OBJECTIVE: The purpose of this study was to identify patients at particularly high risk for major amputation after emergent infrainguinal bypass to help tailor postoperative and long-term patient management. METHODS: In the Vascular Quality Initiative, we identified 2126 patients who underwent emergent infrainguinal artery bypass. Two primary outcomes were investigated: major ipsilateral amputation above the ankle level during the index hospitalization and major amputation above the ankle at any time after emergent infrainguinal bypass surgery (perioperative and postdischarge combined). Binary logistic regression analysis was performed for each outcome using variables that achieved a univariable P value of ≤.10. We then determined which variables have a multivariable association for the outcomes as defined by a regression P value of ≤.05. A risk score was then created for the outcome of amputation after emergent infrainguinal bypass using weighted beta-coefficient. Variables with a multivariable P value of ≤.05 were included in the risk score and weighted based on their respective regression beta-coefficient in a point scale. RESULTS: Overall, 17.1% of patients (368/2126) underwent major amputation at some point in follow-up after emergent infrainguinal artery bypass. The mean follow-up duration on the amputation variable was 261 days with the end point being time of amputation or time of last follow-up data on the amputation variable. Variables with a significant multivariable association (P < .05) with major amputation at any point after emergent infrainguinal arterial bypass were home status in top 10% (most deprived) of Area Deprivation Index, prior infrainguinal ipsilateral arterial bypass, prior ipsilateral endovascular arterial intervention, prosthetic bypass conduit, postoperative skin/soft tissue infection, and postoperative need to revise or thrombectomize bypass. Pertinent negatives on multivariable analysis included all baseline comorbidities, insurance status, race, and gender. There is steep progression in amputation rate ranging from 5% at scores of 0 and 1 to >60% for scores in of >10. Area under the curve analysis revealed a value of 0.706. CONCLUSIONS: Patients living in the most disadvantaged socioeconomic neighborhoods have an increased risk of amputation after emergent infrainguinal arterial bypass independent of baseline comorbidities and perioperative events. Baseline comorbidities are not impactful regarding amputation rates after emergent infrainguinal bypass surgery. The need for bypass revision or thrombectomy during the index hospitalization is the most impactful factor toward amputation after emergency bypass. A risk score with quality accuracy has been developed to help identify patients at particularly high likelihood of limb loss, which may aid in counseling regarding heightened vigilance in postoperative and long-term follow-up care.

Risk score for one-year mortality following emergent infra-inguinal bypass.

OBJECTIVE: The purpose of this study is to identify variables that place patients at higher risk for mortality following emergent infra-inguinal bypass. Further, this study will create a risk score for mortality following emergent infra-inguinal bypass to help tailor postoperative and long-term patient management. METHODS: In the Vascular Quality Initiative, we identified 2126 patients who underwent emergent infra-inguinal artery bypass. Two primary outcomes were investigated: 30 day mortality following emergent infra-inguinal bypass; and 1-year mortality following emergent infra-inguinal bypass. The first step in analysis was univariable analysis for each outcome with χ2 analysis for categorical variables and Student t-test for comparison of means of ordinal variables. Next, binary logistic regression analysis was performed for each outcome utilizing variables that achieved a univariable P value ≤ .10. Factors with a multivariable P value ≤ .05 were included in the risk score, and points were weighted and assigned based on the respective regression beta-coefficient in the multivariable regression. RESULTS: Variables with a significant multivariable association (P < .05) with 1-year mortality were: increasing age; body mass index less than 20 kg/m2; coronary artery disease; active hemodialysis at time of presentation; anemia at admission; prosthetic conduit for emergent bypass; postoperative myocardial infarction; postoperative acute renal insufficiency; perioperative stroke; baseline non-ambulatory status; new onset hemodialysis requirement perioperatively; need for bypass revision or thrombectomy during index admission; lack of statin prescription at discharge; lack of antiplatelet medication at discharge; and, lack of anticoagulation at time of hospital discharge. Pertinent negatives included all sociodemographic variables including rural living status, insurance status, and Area Deprivation Index home area. The risk score achieved an area under the curve of 0.820, and regression analysis of the risk score achieved an overall accuracy of 87.9% with 97.7% accuracy in predicting survival, indicating the model performs better in determining which patients will survive rather than precisely determining 1-year mortality. CONCLUSIONS: Discharge medications are the primary modifiable variable impacting survival after emergent infra-inguinal bypass surgery. In the absence of contraindication, all these patients should be discharged on antiplatelet, statin, and anticoagulant medications after emergent infra-inguinal bypass as they significantly enhance survival. Social determinants of health do not impact survival among patients treated with emergent infra-inguinal bypass at Vascular Quality Initiative centers. A risk score for mortality at 1 year after emergent infra-inguinal bypass has been created that has excellent accuracy.

Predictive Modeling for One-Year Lower Extremity Endovascular Revascularization Failure in Black Persons.

INTRODUCTION: Black persons bear a disproportionate burden of peripheral artery disease (PAD) and experience higher rates of endovascular revascularization failure (ERF) when compared with non-Hispanic White persons. We aimed to identify predictors of ERF in Black persons using predictive modeling. METHODS: This retrospective study included all persons identifying as Black who underwent an initial endovascular revascularization procedure for PAD between 2011 and 2018 at a midwestern tertiary care center. Three predictive models were developed using (1) logistic regression, (2) penalized logistic regression (least absolute shrinkage and selection operator [LASSO]), and (3) random forest (RF). Predictive performance was evaluated under repeated cross-validation. RESULTS: Of the 163 individuals included in the study, 113 (63.1%) experienced ERF at 1 y. Those with ERF had significant differences in symptom status (P < 0.001), lesion location (P < 0.001), diabetes status (P = 0.037), and annual procedural volume of the attending surgeon (P < 0.001). Logistic regression and LASSO models identified tissue loss, smoking, femoro-popliteal lesion location, and diabetes control as risk factors for ERF. The RF model identified annual procedural volume, age, PAD symptoms, number of comorbidities, and lesion location as most predictive variables. LASSO and RF models were more sensitive than logistic regression but less specific, although all three methods had an overall accuracy of ≥75%. CONCLUSIONS: Black persons undergoing endovascular revascularization for PAD are at high risk of ERF, necessitating need for targeted intervention. Predictive models may be clinically useful for identifying high-risk patients, although individual predictors of ERF varied by model. Further exploration into these models may improve limb salvage for this population.

Investigation of center-specific saphenous vein utilization rates in femoral popliteal artery bypass and associated impact of conduit on outcomes.

OBJECTIVE: The purpose of this study is to investigate variation in great saphenous vein (GSV) use among the various centers participating in the Vascular Quality Initiative infrainguinal bypass modules. Further, differences in outcomes in femoral-popliteal artery bypass with single segment GSV conduit vs prosthetic conduit will be documented. Center GSV use rate impact on outcomes will be investigated. METHODS: Primary exclusions were patients undergoing redo bypass, urgent or emergent bypass, and those in whom prosthetic graft was used while having undergone prior coronary artery bypass grafting. The distribution of GSV use across the 260 centers participating in Vascular Quality Initiative infrainguinal bypass module was placed into histogram and variance in mean GSV use evaluated with analysis of variance analysis. Centers that used GSV in >50% of bypasses were categorized as high use centers and centers that used the GSV in <30% of cases were categorized as low use centers. Baseline differences in patient characteristics and comorbidities in those undergoing bypass with GSV vs prosthetic conduit were analyzed with χ2 testing and the Student t test, as were those undergoing treatment in high vs low use centers. Multivariable time-dependent Cox regression analyses were then performed for the primary outcomes of major amputation ipsilateral to the operative side and mortality in long-term follow-up. High vs low use center was a dichotomous variable in these regressions. Secondary outcomes of freedom from graft infection and freedom from loss of primary patency were performed with Kaplan-Meier analysis. RESULTS: Among centers with >50 patients meeting inclusion criteria for this study, GSV use ranged from 15% to 93% (analysis of variance P < .001). When considering all centers irrespective of number of patients, the range was 0% to 100%. On Kaplan-Meier analysis, GSV conduit use was associated with improved freedom from loss of primary or primary assisted patency, improved freedom from major amputation after index hospitalization, improved freedom from graft infection after the index hospitalization, and improved freedom from mortality in long-term follow-up (log-rank P < .001 for all four outcomes). Both low use center (hazard ratio, 1.35; P < .001) and prosthetic graft use (hazard ratio, 1.24; P < .001) achieved multivariable significance as risks for mortality in long-term follow-up. Other variables with a multivariable mortality association are presented in the manuscript. Low use center and prosthetic bypass were significant univariable but not multivariable risks for major amputation after index hospitalization. CONCLUSIONS: There is remarkably wide variation in GSV use for femoral popliteal artery bypass among various medical centers. GSV use is associated with enhanced long-term survival as well as freedom from loss of bypass patency and graft infection. The data herein indicate institutional patterns of prosthetic conduit choice, which has the potential to be altered to enhance outcomes.

Objective assessment of physician work in infrainguinal arterial bypass surgery.

OBJECTIVE: The purpose of this study is obtain robust objective data from the Vascular Quality Initiative on physician work in infrainguinal artery bypass surgery. Operative time, patient comorbidities, anatomical complexity, consequences of adverse outcomes, and postoperative length of stay all factor into procedure relative value unit assignment and physician reimbursement. METHODS: Baseline demographics and comorbidities were identified among 74,920 infrainguinal bypass surgeries in Vascular Quality Initiative between 2003 and 2022. Investigation into areas of progressive complexity over time was conducted. Bypasses were divided into 10 cohorts based on inflow and target arteries and conduit type. Mean operative times, lengths of stay, major morbidity rates, and 90-day mortality rates were identified across the various bypasses. Comparison of relative value unit per minute service time during the acute inpatient hospital admission was performed between the most 4 common bypasses and 14 commonly performed highly invasive major surgeries across several subdisciplines. RESULTS: Patients undergoing infrainguinal arterial bypass have an advanced combination of medical complexities highlighted by diabetes mellitus in 40%, hypertension in 88%, body mass index >30 in 30%, coronary artery disease that has clinically manifested in 31%, renal insufficiency in 19%, chronic obstructive pulmonary disease in 27%, and prior lower extremity arterial intervention (endovascular and open combined) in >50%. The need for concomitant endarterectomy at the proximal anastomosis site of infrainguinal bypasses has increased over time (P < .001). The indication for bypass being limb-threatening ischemia as defined by ischemic rest pain, pedal tissue loss, or acute ischemia has also increased over time (P < .001), indicating more advanced extent of arterial occlusion in patients undergoing infrainguinal bypass. Finally, there has been a significant (P < .001) progression in the percentage of patients who have undergone a prior ipsilateral lower extremity endovascular intervention at the time of their bypass (increasing from 9.9% in 2003-2010 to 31.9% in the 2018-2022 eras). Among the 18 procedures investigated, the 4 most commonly performed infrainguinal bypasses were included in the analysis. These ranked 14th, 16th, 17th and 18th as the most poorly compensated per minute service time during the acute operative inpatient stay. CONCLUSIONS: Infrainguinal arterial bypass surgery has an objectively undervalued physician work relative value unit compared with other highly invasive major surgeries across several subdisciplines. There are elements of progressive complexity in infrainguinal bypass patients over the past 20 years among a patient cohort with a very high comorbidity rate, indicating escalating intensity for infrainguinal bypass.

Endovascular aortic repair with EndoAnchors demonstrate good mid-term outcomes in physician-initiated multicenter analysis-The PERU registry.

OBJECTIVES: We aim to describe real-world outcomes from multicenter data about the efficacy of adjunct Heli-FX EndoAnchor usage in preventing or repairing failures during infrarenal endovascular aneurysm repair (EVAR), so-called EndoSutured-aneurysm-repair (ESAR). METHODS: The current study has been assigned an identifier (NCT04100499) at the US National Library of Medicine (https://ClinicalTrials.gov). It is an observational retrospective study of prospectively collected data from seven vascular surgery departments between June 2010 and December 2019. Patients included in the ANCHOR registry were excluded from this analysis. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. Follow-up imaging was scheduled according to each center's protocol, which necessarily included either abdominal ultrasound or radiography or computed tomographic scan imaging. The main outcomes analyzed were technical success, freedom from type Ia endoleaks (IaEL), all-cause and aneurysm-related mortality, and sac variation and trends evaluated for those with at least six months imaging follow-up. RESULTS: Two hundred and seventy-five patients underwent ESAR in participating centers during the study period. After exclusions, 221 patients (184 males, 37 females, mean age 75 ± 8.3 years) were finally included for analysis. Median follow-up for the cohort was 27 (interquartile range 12-48) months. A median 6 (interquartile range 3) EndoAnchors were deployed at ESAR, 175 (79%) procedures were primary and 46 (21%) revision cases, 40 associated with type IaEL. Technical success at operation (initial), 30-day, and overall success were 89, 95.5, and 96.8%, respectively; the 30-day success was higher due to those with subsequent spontaneous proximal endoleak seal. At two years, freedom from type IaEL was 94% for the whole series; 96% and 86% for the primary and revision groups, respectively; whereas freedom from all-cause mortality, aneurysm-related mortality, and reintervention was 89%, 98%, and 87%, respectively. Sac evolution pre-ESAR was 66 ± 15.1 vs. post ESAR 61 ± 17.5 (p < 0.001) and for 180 patients with at least six-month follow-up, 92.2% of them being in a stable (51%) or regression (41%) situation. CONCLUSIONS: This real-world registry demonstrates that adjunct EndoAnchor usage at EVAR achieves high rates of freedom from type IaEL at mid-term including in a high number of patients with hostile neck anatomy, with positive trends in sac-size evolution. Further data with longer follow-up may help to establish EndoAnchor usage as a routine adjunct to EVAR, especially in hostile necks.

Right-sided Upper Extremity Access for Patients Undergoing Parallel Graft Placement during Endovascular Aortic Repair is Not Associated with Increased Neurologic Events When Compared with Left Upper Extremity Access.

BACKGROUND: The safety and efficacy of right axillary cannulation during complex aortic aneurysm repair for the deployment of chimney grafts is controversial; however, there are few studies that compare right and left upper extremity access. We favor the right axillary approach because of the relative ease of access to the visceral branches and the ability of surgeons and nursing staff to work on the same side of the patient, while avoiding the left sided image intensifier. We aim to demonstrate that right-sided access is equivalent or safer than left-sided access in terms of technical success and complication rates, with a focus on neurologic outcomes. METHODS: This is a single-institution retrospective study with a review of patients who underwent aortic intervention from January 2012 through December 2018. A total of 398 aortic interventions were performed, and 97 of these required brachial, axillary, or subclavian arterial access for attempted ChEVAR or thoracic endovascular aortic repair with parallel chimney grafts. Primary end points that were analyzed were site or sites of upper extremity access, technical success, 30-day mortality, cerebrovascular events, and subclavian/axillary artery injury. The number of parallel grafts, age, mean hospital length of stay, prior aortic intervention, emergent or elective status were also analyzed. RESULTS: Ninety-seven endovascular aortic operations required upper extremity access, with 67 using access from the right upper extremity, 26 using access from the left upper extremity, and 4 using bilateral upper extremity access. A total of 68.0% of patients had undergone prior aortic surgery. Technical success was achieved in 85 cases (87.6%). Five total patients suffered cerebrovascular accidents, with 2 occurring in left-sided access (7.7%), 2 in right-sided access (3.0%), and 1 in bilateral access (25%). CONCLUSIONS: Right upper extremity access for patients undergoing parallel graft placement during endovascular aortic aneurysm repair is a safe and feasible approach that is not associated with an increased risk of stroke or neurological events as compared with left upper extremity access.

Gaussian Surface Curvature Mapping Indicating High Risk Type B Thoracic Aortic Dissections.

BACKGROUND: Identifying fragile aortas that are more likely to lead to adverse clinical outcomes would provide surgeons with a better sense of how to balance the risks of surgical versus medical management in patients with type B dissections. We examine the progression of a type B dissection into a type A dissection in a patient and analyze changes in the Gaussian surface curvature distribution, as well as the response of the stress distribution at the lesser curve in response to pressurization. We hypothesize that examining the Gaussian curvature will provide us with a link between aortic surface geometry and the stress distribution, which is crucial to understanding the process driving aortic dissection. METHODS: Computed tomography scans of a patient before and after the type A dissection are obtained. These are segmented in Simpleware ScanIP. Centerline curvatures are calculated on segmented models in ScanIP. Models are then pressurized in the finite element analysis software Abaqus. The Gaussian curvature is calculated by exporting segmentations into the computational program Matlab and applying a modified previously published algorithm. RESULTS: The centerlines generated in ScanIP fail to capture the change in the acuity of the lesser curve before and after the type A dissection. Instead, Gaussian curvature analysis shows that the curvature distribution before the type A dissection is much wider compared with the distribution after the type A dissection. In addition, analyzing the stress distribution in response to pressurization reveals that before the type A dissection there is a large divergence in the principal stress vectors at the lesser curve but this transitions to a more uniform hoop stress after the type A dissection. CONCLUSIONS: Our analysis demonstrates that Gaussian surface curvature analysis captures changes in aortic geometry that are otherwise silent in centerline curvature analysis. Here, we show that as the aorta develops a type A dissection it is able to more smoothly handle the hoop stress at the lesser curve compared with the stress focusing seen in the before type A geometry. We propose that the geometric focusing before type A creates a higher energy stress state, which is relaxed on retrograde dissection. Thus, Gaussian curvature analysis may provide a window to capture underlying geometric instability in type B dissections.

Successful endovascular repair of aortic rupture caused by axillary intra-aortic balloon insertion for a Jehovah's Witness patient with situs inversus anomaly.

We report the successful endovascular repair of a rare case of aortic rupture caused by axillary intra-aortic balloon pump (IABP) insertion failure. A 38-year-old Jehovah's Witness female with situs inversus totalis was referred to our hospital for acute decompensated heart failure. We placed an axillary IABP for circulatory support. However, an exchange was required due to balloon malfunction (kinked driveline). Unfortunately, the exchange was complicated by an iatrogenic aortic rupture along with a large hematoma compressing the trachea. Emergent endovascular repair was performed successfully without any blood transfusion. Postoperative computed tomography showed a successfully repaired aorta and resolving hematoma.

Anatomic and clinical characterization of the narrow distal aorta and implications after endovascular aneurysm repair.

OBJECTIVE: The purpose of this analysis was to compare 1-year clinical outcomes after endovascular repair of abdominal aortic aneurysms with the EXCLUDER device in patients with standard and narrow aortic bifurcations (AOBs). METHODS: Data were prospectively collected from a 1055-participant subset of the multicenter Global Registry for Endovascular Aortic Treatment (GREAT) treated for abdominal aortic aneurysm repair between August 2010 and September 2015. There were 117 patients with a narrow AOB (NB; defined as <16 mm) and 938 patients with a standard bifurcation (SB). The 30-day and 1-year morbidity, mortality, and reintervention outcomes were analyzed, with Kaplan-Meier survival curve analysis conducted on freedom from mortality and freedom from reintervention. RESULTS: The mean distal aortic neck diameter was 12.4 mm in the NB cohort and 25.3 mm in the SB cohort (P < .001), with NB patients also exhibiting significantly smaller diameter proximal aortic necks (P < .001). Patients in the NB cohort were more often female (25.6% vs 15.1%; P = .004) and with more severe comorbidity burden. There was a significantly higher rate of surgical cutdown access in the NB cohort (P < .001). Procedural survival was 100% in both groups. The 30-day mortality and safety outcomes were similar; however, all-cause mortality was significantly higher in the SB cohort through 1 year (P = .02). The 1-year freedom from mortality was estimated as 92.1% in the SB cohort and 99.1% in the NB cohort. Freedom from reintervention was estimated as 95.1% in the SB cohort and 92.8% in the NB cohort at 1 year. Through 1-year follow-up, 24 SB patients (2.6%) and 4 NB patients (3.4%) exhibited an endoleak requiring reintervention (P > .99). Type II endoleaks represented 72% and 60% of treated endoleaks, respectively. Through 1 year, 10 SB patients (1.0%) and 2 NB patients (1.7%) exhibited occlusive/thrombotic events (P = .54). There were no reported instances of kinking, migration, fracture, compression, or dissection through 1 year in either cohort. One SB patient experienced thoracic aortic aneurysm rupture. CONCLUSIONS: The 1-year outcomes after endovascular aneurysm repair with the EXCLUDER device were comparable in the NB and SB cohorts. A narrow AOB was not found to be associated with a higher incidence of later limb occlusions or endoleaks. Female patients were disproportionately more likely to have a narrow AOB, which correlated with narrowed proximal necks and access vessels, and a more severe comorbidity burden.

Pseudomonas aeruginosa virulence expression is directly activated by morphine and is capable of causing lethal gut-derived sepsis in mice during chronic morphine administration.

OBJECTIVE: This study was designed to examine the effect of morphine administration on the intestinal mucus barrier and determine its direct effect on the virulence and lethality of Pseudomonas aeruginosa, one of the most frequent pathogens to colonize the gut of critically ill patients. BACKGROUND DATA: Surgical injury is associated with significant exposure of host tissues to morphine from both endogenous release and its use as a potent analgesic agent. Morphine use in surgical patients exposed to extreme physiologic stress is well established to result in increased infection risk. Although morphine is a known immunosuppressant, whether it directly induces virulence expression and lethality in microbes that colonize the human gut remains unknown. METHODS: Mice were implanted with a slow release morphine or placebo pellet with and without intestinal inoculation of P. aeruginosa created by direct cecal injection. Mucus production and epithelial integrity was assessed in cecal tissue via Alcian blue staining and histologic analysis. In vivo and in vitro P. aeruginosa virulence expression was examined using reporter strains tagged to the epithelial barrier disrupting protein PA-I lectin. P. aeruginosa chemotaxis toward morphine was also assayed in vitro. Finally, the direct effect of morphine to induce PA-I lectin expression was determined in the absence and presence of methylnaltrexone, a µ opioid receptor antagonist. RESULTS: Mice intestinally inoculated with P. aeruginosa and implanted with a morphine pellet demonstrated significant suppression of intestinal mucus, disrupted intestinal epithelium, and enhanced mortality; whereas exposure of mice to either systemic morphine or intestinal P. aeruginosa alone enhanced intestinal mucus without mortality, suggesting a shift in P. aeruginosa during morphine exposure to a mucus suppressing, barrier disrupting, and lethal phenotype. Direct exposure of P. aeruginosa to morphine in vitro confirmed that morphine can transform P. aeruginosa to a more virulent phenotype that is attenuated in part by methylnaltrexone. CONCLUSIONS: Morphine administration shifts intestinal P. aeruginosa to express a virulent phenotype and may play a role in its ability to causes lethal gut-derived sepsis in a susceptible host.

Resection of intracaval leiomyomatosis using abdominal approach and venovenous bypass.

BACKGROUND: Intravenous leiomyomatosis is the venous involvement of a histologically benign uterine tumor. This uncommon tumor can present contemporaneously with the primary uterine tumor or in a delayed fashion. Tumor extends up the venous system, via the iliac or ovarian veins, and can involve portions or all of the inferior vena cava and can extend into the heart as well. Complete resection of this tumor is the therapeutic goal. Previous reports have described the use of combined thoracic and abdominal approaches, cardiopulmonary bypass, circulatory arrest, and a single report of an entirely abdominal approach to resection without bypass. METHODS AND RESULTS: We present a review of the existing literature describing surgical intervention for intravenous leiomyomatosis and describe two cases of tumor extending up the intra-abdominal vena cava. Using venovenous bypass without need for thoracotomy, we were able to resect both tumors with minimal blood loss and no hemodynamic instability. CONCLUSIONS: We suggest that venovenous bypass is an excellent tool in resection of these tumors and should be considered for many cases in lieu of full cardiopulmonary bypass or circulatory arrest.

Red death in Caenorhabditis elegans caused by Pseudomonas aeruginosa PAO1.

During host injury, Pseudomonas aeruginosa can be cued to express a lethal phenotype within the intestinal tract reservoir-a hostile, nutrient scarce environment depleted of inorganic phosphate. Here we determined if phosphate depletion activates a lethal phenotype in P. aeruginosa during intestinal colonization. To test this, we allowed Caenorhabditis elegans to feed on lawns of P. aeruginosa PAO1 grown on high and low phosphate media. Phosphate depletion caused PAO1 to kill 60% of nematodes whereas no worms died on high phosphate media. Unexpectedly, intense redness was observed in digestive tubes of worms before death. Using a combination of transcriptome analyses, mutants, and reporter constructs, we identified 3 global virulence systems that were involved in the "red death" response of P. aeruginosa during phosphate depletion; they included phosphate signaling (PhoB), the MvfR-PQS pathway of quorum sensing, and the pyoverdin iron acquisition system. Activation of all 3 systems was required to form a red colored PQS+Fe(3+) complex which conferred a lethal phenotype in this model. When pyoverdin production was inhibited in P. aeruginosa by providing excess iron, red death was attenuated in C. elegans and mortality was decreased in mice intestinally inoculated with P. aeruginosa. Introduction of the red colored PQS+Fe(3+) complex into the digestive tube of C. elegans or mouse intestine caused mortality associated with epithelial disruption and apoptosis. In summary, red death in C. elegans reveals a triangulated response between PhoB, MvfR-PQS, and pyoverdin in response to phosphate depletion that activates a lethal phenotype in P. aeruginosa.

Fenestrated Endovascular Aortic Repair With Chimney Graft for Thoracoabdominal Aneurysm.

Thoracoabdominal aneurysms pose technical challenges for endovascular repair due to involvement of visceral and renal vessels. We report a case series of four patients diagnosed with thoracoabdominal aneurysm who underwent complex endovascular repair with Fenestrated Device and chimney grafts (FEVARCh). FEVARCh is a technically feasible approach for repair of thoracoabdominal aneurysms that involve renal, superior mesenteric, and celiac arteries for patients not appropriate for open surgical repair. Further studies are needed to understand the implications of resultant Type 1a endoleaks and strategies to minimize the displacement of the main body graft with adjunct chimneys.

The shifting care and outcomes for patients with endangered limbs - Critical limb ischemia (SCOPE-CLI) registry overview of study design and rationale.

BACKGROUND: Critical limb ischemia (CLI), the most severe form of peripheral artery disease, is associated with pain, poor wound healing, high rates of amputation, and mortality (>20% at 1 year). Little is known about the processes of care, patients' preferences, or outcomes, as seen from patients' perspectives. The SCOPE-CLI study was co-designed with patients to holistically document patient characteristics, treatment preferences, patterns of care, and patient-centered outcomes for CLI. METHODS: This 11-center prospective observational registry will enroll and interview 816 patients from multispecialty, interdisciplinary vascular centers in the United States and Australia. Patients will be followed up at 1, 2, 6, and 12 months regarding their psychosocial factors and health status. Hospitalizations, interventions, and outcomes will be captured for 12 months with vital status extending to 5 years. Pilot data were collected between January and July of 2021 from 3 centers. RESULTS: A total of 70 patients have been enrolled. The mean age was 68.4 ± 11.3 years, 31.4% were female, and 20.0% were African American. CONCLUSIONS: SCOPE-CLI is uniquely co-designed with patients who have CLI to capture the care experiences, treatment preferences, and health status outcomes of this vulnerable population and will provide much needed information to understand and address gaps in the quality of CLI care and outcomes.ClinicalTrials.gov identifier (NCT Number): NCT04710563 https://clinicaltrials.gov/ct2/show/NCT04710563.

The human microbiome and surgical disease.

OBJECTIVE: The purpose of this review article is to summarize what is currently known about microbes associated with the human body and to provide examples of how this knowledge impacts the care of surgical patients. BACKGROUND: Pioneering research over the past decade has demonstrated that human beings live in close, constant contact with dynamic communities of microbial organisms. This new reality has wide-ranging implications for the care of surgical patients. METHODS AND RESULTS: Recent advances in the culture-independent study of the human microbiome are reviewed. To illustrate the translational relevance of these studies to surgical disease, we discuss in detail what is known about the role of microbes in the pathogenesis of obesity, gastrointestinal malignancies, Crohn disease, and perioperative complications including surgical site infections and sepsis. The topics of mechanical bowel preparation and perioperative antibiotics are also discussed. CONCLUSIONS: Heightened understanding of the microbiome in coming years will likely offer opportunities to refine the prevention and treatment of a wide variety of surgical conditions.

Pseudomonas aeruginosa potentiates the lethal effect of intestinal ischemia-reperfusion injury: the role of in vivo virulence activation.

BACKGROUND: Experimental models of intestinal ischemia-reperfusion (IIR) injury are invariably performed in mice harboring their normal commensal flora, even though multiple IIR events occur in humans during prolonged intensive care confinement when they are colonized by a highly pathogenic hospital flora. The aims of this study were to determine whether the presence of the human pathogen Pseudomonas aeruginosa in the distal intestine potentiates the lethality of mice exposed to IIR and to determine what role any in vivo virulence activation plays in the observed mortality. METHODS: Seven- to 9-week-old C57/BL6 mice were exposed to 15 minutes of superior mesenteric artery occlusion (SMAO) followed by direct intestinal inoculation of 1.0 × 10(6) colony-forming unit of P. aeruginosa PAO1 into the ileum and observed for mortality. Reiterative studies were performed in separate groups of mice to evaluate both the migration/dissemination pattern and in vivo virulence activation of intestinally inoculated strains using live photon camera imaging of both a constitutive bioluminescent P. aeruginosa PAO1 derivative XEN41 and an inducible reporter derivative of PAO1, the PAO1/lecA:luxCDABE that conditionally expresses the quorum sensing-dependent epithelial disrupting virulence protein PA 1 Lectin (PA-IL). RESULTS: Mice exposed to 15 minutes of SMAO and reperfusion with intestinal inoculation of P. aeruginosa had a significantly increased mortality rate (p < 0.001) of 100% compared with <10% for sham-operated mice intestinally inoculated with P. aeruginosa without SMAO and IIR alone (<50%). Migration/dissemination patterns of P. aeruginosa in mice subjected to IIR demonstrated proximal migration of distally injected strains and translocation to mesenteric lymph nodes, liver, spleen, lung, and kidney. A key role for in vivo virulence expression of the barrier disrupting adhesin PA-IL during IIR was established since its expression was enhanced during IR and mutant strains lacking PA-IL displayed attenuated mortality. CONCLUSIONS: The presence of intestinal P. aeruginosa potentiates the lethal effect of IIR in mice in part due to in vivo virulence activation of its epithelial barrier disrupting protein PA-IL.

Outcomes of chimney and fenestrated endografting using Viabahn VBX and atrium iCAST stents.

BACKGROUND: The Atrium iCAST balloon expandable stent is the traditional choice of stent for chimney and fenestrated endovascular aneurysm repair (ChEVAR and FEVAR respectively). Due to the iCAST's lack of flexibility, the Gore Viabahn balloon-expandable stent (VBX; W. L. Gore & Associates, Inc., Newark, DE, USA) has arisen as a flexible alternative for parallel or branch graft placement during complex EVAR. Our purpose was to analyze patients' outcomes after undergoing ChEVAR or FEVAR using VBX or iCAST stents with the major outcome of assessing stent graft patency. The secondary outcome was residual aneurysm sac behavior. METHODS: We retrospectively reviewed patients who were treated by ChEVAR or FEVAR with placement of iCAST or VBX stents from July 2012 to August 2018. Patients received follow-up CT scan and/or aortic duplex imaging. RESULTS: We examined 53 cases (70% ChEVAR and 30% FEVAR) with 15.6 months (0-76.5 months) mean follow-up period. Placement of stents included renal (65 iCAST and 38 VBX), superior mesenteric (12 iCAST and 13 VBX), celiac (4 iCAST and 5 VBX), and iliac arteries (1 iCAST and 5 VBX). A total of 143 stents (57% iCAST and 43% VBX) were successfully deployed with 100% initial patency. Follow-up patency was similar for both stent types (100% VBX vs 98.7% iCAST). VBX and iCAST had the same follow-up Type 1a endoleak occurrence (9%). Average aneurysm sac sizes for iCAST decreased more than VBX (9% iCAST and 4% VBX, P=0.21), however, the iCAST group had longer follow-up. CONCLUSIONS: Our experience demonstrates that the use of VBX stents for ChEVAR and FEVAR is a safe and effective alternative to iCAST stents with excellent mid-term patency without a negative impact on endoleak frequency.

Computational analysis of endovascular aortic repair proximal seal zone preservation with endoanchors: A case study in cylindrical neck anatomy.

BACKGROUND: Endovascular aortic repair is the common approach for abdominal aortic aneurysms, but endoleaks remain a significant problem with long-term success. Endoanchors have been found to reduce the incidence of type 1A endoleaks and can treat intraoperative type 1a endoleaks. However, little is known about the optimal number and position of endoanchors to achieve the best outcome. METHODS: Using image segmentation and a computational model derived from a reconstructed native patient abdominal aortic aneurysm geometry, the stability of the proximal seal zone was examined through finite element analysis in Abaqus (Dassault Systèmes, Providence, RI). The biomechanical parameter of contact area was compared for varying numbers (0, 2, 4, 8) and positions (proximal, medial, distal) of endoanchors under different adhesion strengths and physiologic pressure conditions. RESULTS: In every simulation, an increase in adhesion strength is associated with maintenance of proximal seal. For biologically plausible adhesion strengths, under conditions of normal blood pressure (120 mm Hg), the addition of any number of endoanchors increases the stability of the endograft-wall interface at the proximal seal zone by approximately 10% compared with no endoanchors. At hypertensive pressures (200 mm Hg), endoanchors increase the stability of the interface by 20% to 60% compared with no endoanchors. The positioning of endoanchors within the proximal seal zone has a greater effect at hypertensive pressures, with proximal positioning increasing stability by 15% compared with medial and distal positioning and 30% compared with no endoanchors. CONCLUSIONS: Endoanchors improve fixation within the proximal seal zone particularly under conditions of high peak systolic pressure. Seal zone stabilization provides a mechanism through which endoanchor addition may translate into lower rates of type 1a endoleaks for patients.