Retrocarotid dissection technique compared to the caudocranial approach for the surgical treatment of carotid body tumors: A 15-year experience.

INTRODUCTION: Carotid body tumors are rare neoplasms with malignant potential. We aim to follow up on our initial experience published in 2015 and compare the occurrence of complications and postoperative outcomes with the use of retrocarotid dissection (RCD) against the standard caudocranial (SCCD) technique. METHODS: This was an observational, case-control study in which we analyzed all of the carotid body tumor resections performed from 1986 to 2022. Parametric and nonparametric tests were used accordingly. Statistical analysis was performed on Stata 17. RESULTS: A total of 181 surgical procedures were included, mean age was 56 years (± 13.63), and 168 (93%) were performed in women. The mean medio-lateral diameter was larger in the RCD group (2.85 ± 1.57 cm vs 1.93 ±1.85 cm; p = 0.002) and presurgical embolization was more frequently performed in the SCCD group (27.5% vs 0.7%; p < 0.001). A total of 40 (22.09%) resections were performed using the SCCD technique. In contrast, in 141 (77.91%) procedures the RCD technique was used. The mean surgical time in the RCD group was lower (197.37 ± 70.56 min vs 232 ± 98.34 min; p = 0.01). No statistically significant difference was found between SCCD and RCD in terms of vascular lesions (n = 20 [11.04%], 15% vs 9%, respectively; p = 0.36), transient or permanent nerve injuries (25% vs 33%, respectively; p = 0.31), or mean intraoperative bleeding (SCCD: 689.95 ± 680.05 mL vs RCD: 619.64 ± 837.94 mL; p > 0.05). CONCLUSIONS: RCD appears to be a safe and equivalent alternative to the standard caudocranial approach in terms of intraoperative bleeding or vascular lesions, with a sustained, significant decrease in surgical time.

Fifteen Years of Experience with Surgical Management of Bilateral Non-familial Carotid Body Tumors.

BACKGROUND: Bilateral carotid body tumors (CBTs) clinical manifestation is infrequent. We conducted this work to describe our experience in the surgical treatment of bilateral CBT and to analyze our results. METHODS: A retrospective, observational study. We analyzed the totality of bilateral CBT resections that had been performed in our institution from January 2008 to September 2023. Data was obtained from medical records and anonymized, ethics approval was obtained from our institution committee. As the number of observations was less than those required by the central limit theorem our sample was considered nonparametric. Statistical analysis was performed on Stata 17. RESULTS: We evaluated 16 patients with a total of 32 CBT; surgical resection was performed in 28 cases (87.50%). Median age of the patients was 60 years (interquartile range [IQR] 46-64). Regarding the Shamblin classification, 9 CBTs (32.14%) were classified as Shamblin I, 11 (39.29%) as Shamblin II, and 8 (28.57%) as Shamblin III. The median Distance to the Base of the Skull (DTBOS) was 3.5 cm (IQR 2.7-5.1), and the median tumor volume was 11.25 cc (IQR 3.4-18.7). The median bleeding volume was 300 ml (IQR 200-500), and the median surgical time was 190 min (IQR 145-240). All surgeries were performed using the Retrocarotid Dissection technique. We documented 9 (32.14%) cases of nerve injuries, all of which were transitory. In the median regression a statistically significant association was found between DTBOS, Shamblin classification and tumor volume with intraoperative bleeding and length of stay. CONCLUSIONS: Surgical treatment remains safe and should be considered the gold standard for accurate histologic diagnosis. DTBOS and tumor volume, in addition to Shamblin classification, must be considered in preoperative planning to predict bleeding and hospital stay.

Multi-perspective ultrasound evaluation of Carotid Intima-Media thickness in hemodialysis access patients and its possible use to predict clinical outcomes.

BACKGROUND: Hemodialysis (HD) patients present an increased carotid intima-media thickness (CIMT) and calcified plaques, and studies have demonstrated that CIMT is predictor for cardiovascular death in this patient population; hence, the importance of identifying early non-invasive markers of atherosclerosis. We aim to propose a new three-perspective CIMT measuring method in HD population, and to further investigate the possible use and value of this method to predict outcomes. METHODS: A cross-sectional study was conducted, the CIMT was measured with duplex ultrasound during the perioperative access planning. Software provided maximum CIMT in a 10 mm (mm) width of the common carotid artery. CIMT was measured in Right (R) and Left (L) carotid arteries, both in anterior (a), lateral (l), and posterior (p) view. The sum of these values (Ra+Rl+Rp+La+Ll+Lp) was completed and termed as Sixth Carotid Intimal (SCI) score. We stratified either in low (summation <4) or high (>=4) SCI score groups. Demographics, patency rates, complications, and mortality were collected; chi-square test was used for our analysis. RESULTS: A total of 30 patients (mean age 49 years and 56% females) that underwent access creation in the upper arm from 2010 to 2016 were selected and studied. A low SCI score was found 19 patients and 11 had high SCI, no significant difference was observed in demographics, history cardiovascular disease, and clinical outcomes as early thrombosis, and primary, primary-assisted patency at 12 months. Interestingly, during the follow up period of 36 months a significant higher difference in late thrombosis rates occurred (63.6% vs 26.3%, p = .044) and a higher all-cause mortality (54.4% vs 15.7%, p = .025) in patients with SCI score group above 4. CONCLUSIONS: The SCI score method, might offer a screening tool for traditional cardiovascular risk factors in HD patients. In this study, we demonstrate an increased rate in late thrombosis and mortality in those with high SCI. Further research is necessary to better define the role of CIMT in vascular surgical procedures.

Mortality and hospitalization trends for aortic aneurysms and dissections in Mexico.

BACKGROUND: In Mexico, there is a paucity of evidence on mortality and hospitalization patterns associated with aortic aneurysms and dissections. OBJECTIVE: To analyze national databases and describe the epidemiological characteristics of different aortic pathologies. MATERIAL AND METHODS: Retrospective, cross-sectional, observational study, in which mortality and hospitalization attributed to aortic aneurysms and dissections were analyzed. Statistical analysis was performed on Stata 16. RESULTS: A total of 6,049 deaths were documented in the general population, which included 2,367 hospitalizations and 476 (20.1%) in-hospital deaths. In addition, a statistically significant age difference was found between mean age at death in the general population (69.5 years) and the in-hospital death group (64.1 years, p < 0.001). As for hospitalizations secondary to ruptured abdominal aortic aneurysms, 149 cases were identified, with a mean age of 65.6 years, out of whom 53 (35.5%) were under 65 years of age, with a mean age of 47.8 years. CONCLUSIONS: Epidemiological reports of aortic pathology in Mexico are scarce; therefore, implementation of screening and detection programs for aortic pathologies is necessary in order to address the disparities identified in this analysis.

ANTECEDENTES: Existe evidencia escasa en México respecto a la mortalidad y patrones del ingreso hospitalario asociados a aneurismas y disecciones aórticos. OBJETIVO: Analizar las bases de datos nacionales y describir las características epidemiológicas de diferentes patologías aórticas agudas. MATERIAL Y MÉTODOS: Estudio transversal y observacional de una base de datos retrospectiva, en el que se analizó la mortalidad y hospitalización atribuidas a aneurismas y disecciones aórticos. El análisis estadístico se realizó en Stata 16. RESULTADOS: Se documentaron 6049 muertes en la población general, 2367 hospitalizaciones y 476 muertes intrahospitalarias. Adicionalmente, se encontró una diferencia estadísticamente significativa entre las medias de edad de fallecimiento de la población general (65.5 años) y de los pacientes que murieron en el hospital (64.1 años), p < 0.001. En cuanto a las hospitalizaciones secundarias a aneurisma de aorta abdominal roto, 149 casos fueron evidenciados con una media de edad de 65.6 años; 53 (35.5 %) de estos tenía menos de 65 años, con una media de edad de 47.8 años. CONCLUSIONES: Los reportes epidemiológicos de patología aórtica en México son escasos, por ello la implementación de programas de tamizaje y la detección de patologías aórticas son necesarias para mejorar las disparidades encontradas en este análisis.

Utility of multimodal molecular imaging in the diagnosis and decision-making in arterial diseases.

Arterial diseases are prevalent in the general population, particularly in the elderly, and they are among the main causes of morbidity and mortality worldwide. Nuclear imaging is a useful tool in diagnosis and follow-up in different areas of medicine, and over the last 2 decades, these study modalities have become more relevant in the field of angiology and vascular surgery due to their potential benefit in the interpretation of pathophysiological mechanisms associated with the natural history and severity of diseases that affect the circulation such as vasculitis, degenerative aortic aneurysms (AA), peripheral arterial disease (PAD), and complications following reconstructive procedures such as graft infections. The literature has shown evidence of an important number of radiotracers for specific molecules involved in the activity of these entities and their utility as predictors during surveillance and possible therapeutic targets. The present narrative review aims to describe the use of nuclear medicine, imaging methods, and radiotracers that have been applied in arterial diseases, as well as the advantages and considerations, their importance in the diagnosis and follow-up of these complex groups of patients, and future perspectives.

Revascularization prevents amputation among patients with diabetic foot during the COVID-19 era.

OBJECTIVE: The COVID-19 pandemic has led to significant changes in healthcare systems that impact the management of chronic diseases such as diabetic foot (DF). We hypothesized that lack of access to healthcare would increase the severity of disease and lead to worse outcomes. METHODS: The medical records of patients with DF were reviewed to determine demographic data and outcomes including wound healing, major amputation (MA), and death. Groups were divided into the pre-COVID-19 era (15 March 2019-15 March 2020) and the COVID-19 era (16 March 2020-16 March 2021); multivariable logistic analysis was performed to identify risk factors for MA. RESULTS: 261 patients with DF were included, 163 in the pre-COVID-19 era and 98 during the COVID-19 era. Patients in the COVID-19 presented with increased cardiovascular disease (19 vs 7%, p = 0.01), increased mean HbA1C (9.1 ± 2.1 vs 8.2 ± 2.1, p = 0.008) and higher WIFI-IV stage (78 vs 53%, p ≤ 0.0001). Patients with DF in the COVID-19 era were more likely to require MA (41 vs 21%, p ≤ 0.0001). Revascularization (OR = 0.12; 95% CI, 0.038-0.38) was a protective factor to reduce MA. CONCLUSIONS: MA among DF patients increased two-fold during the COVID-19 era. Revascularization avoids MA in diabetic patients even during the COVID-19 pandemic, suggesting that revascularization should be performed when possible.

Five-year survival after retroperitoneal oncologic resection with and without vascular surgeon intervention.

OBJECTIVES: Retroperitoneal tumor resection commonly disturbs major vessels; therefore, surgical teams can recruit vascular surgeons to prevent injuries and improve the prognosis of oncologic patients. The objective of the present study is to establish long-term survival after retroperitoneal tumor resection surgery with an emphasis on the potential impact of preventing or repairing major vessel injuries when tumors are adjacent to the aorta or vena cava. METHODS: Retrospective case series including all cases of surgical removal of retroperitoneal tumors between 2007 and 2020 in a highly specialized hospital in Mexico City. Long-term survival was defined as 5 years after surgical intervention. Descriptive statistics, group-comparison tests, and regression analysis were performed using Stata 16. RESULTS: From a total of 70 cases, vascular injury occurred in 30 (42.8%) and the vascular surgeon intervened in 19 (27.1%) of them, 4 (21%) were performed by a vascular surgeon with planned intervention, and in 9 (47.3%) cases the vascular surgeon was called to join the surgery due to emergency. Intraoperative bleeding was 2-fold greater in the group with an emergent participation of vascular surgery in contrast with the planned intervention group (4, 235 mL vs 2, 035 mL, p = 0.04). The regression model revealed a significant association between the intervention of a vascular surgeon and long-term survival (OR 59.3, p = 0.03) after adjusting for sociodemographic and characteristics of oncologic nature. CONCLUSIONS: Planned intervention of vascular surgeons in retroperitoneal tumor resection may have a positive impact not only in trans-operatory period, but also on long-term survival.

The effect of cilostazol on the platelet-derived growth factor-beta/beta isoform reduction on venous hyperplasia in an experimental balloon-induced injury model.

BACKGROUND: Intimal hyperplasia is the response to endothelial injury. Platelet-derived growth factor is released early and favors the formation of intimal hyperplasia. Although multiple treatments, from open surgery to endovascular techniques, have been used they remain controversial. There is currently interest in developing pharmacological strategies to address this pathology. Local vascular inflammation induced by vessel barotrauma generates intimal hyperplasia due to mechanical stress over the venous endothelium. Cilostazol is a selective phosphodiesterase type 3 (PDE3) selective inhibitor with a regulatory effect over intimal hyperplasia. The objective was to investigate cilostazol's role in inhibiting smooth muscle cell proliferation due to changes in the expression and release of PDGF-BB isoform and the effect on developing IH using an experimental model of vascular barotrauma (balloon-induced injury model). METHODS: We included 12 New Zealand rabbits. The balloon-induced injury model (BIIM) and experimental group cilostazol (20 mg/kg/day) included 6 rabbits each. Contralateral veins from 6 rabbits used in BIIM model has been taken as control group. We measured and compared the expression of PDGF-BB and the development of IH. A pathologist board chooses a PDGFRα antibody to localized its expression by immunohistochemistry analysis. Subsequently, using an automated immunohistochemical staining machine, the PDGFR expression was evaluated using a Zeiss Primo Star 4 light microscope. RESULTS: The measurement obtained in the intimal layer was: 126.12 µm2 in the CG, 232 µm2 in the BIIM group, and 178 µm2 in the EG. A statistically significant difference was observed. Baseline serum concentrations of PDGF-BB in the BIIM group were 0.22 pg/mL. At 12 h 0.42 pg/mL, and 0.17 pg/mL at seven days. In the experimental group, the basal levels were 0.33 pg/mL. With the use of cilostazol, a lower peak was obtained at 12 h (0.08 pg/mL). This difference was statistically significant. CONCLUSIONS: Cilostazol induced a significant reduction of IH caused by barotrauma in the venous endothelium, which correlates with decrease in the PDGF-BB in serum. This could be attributed to the pharmacologic effect on PDGFR expression.

Acute pulmonary embolism as a complication in a young male patient with a left popliteal venous aneurysm.

Venous aneurysms are rare and have a prevalence of 0.1 to 0.2% in the reported series. Typically, patients do not present any symptoms, but are prone to develop deep venous thrombosis (DVT) and the most feared complication, pulmonary embolism (PE). We present the case of a previously healthy 36-year-old man who presented at the emergency department with tachycardia, dyspnea, and pleuritic pain. A thoracic computed tomography angiography (CTA) confirmed the diagnosis of acute pulmonary embolism. He was treated with systemic thrombolysis and anticoagulation. In the further workup of the cause of the embolism, computed tomography revealed a fusiform dilation of the left popliteal vein measuring 3 by 3 centimeters (cm) with an incomplete filling defect because of thrombus presence. The patient underwent open surgical repair. At one month follow-up, he was asymptomatic, and an ultrasound revealed complete patency of the popliteal vein without dilatation or thrombus.

Aneurismas venosos são raros, tendo uma prevalência de 0,1 a 0,2% nas séries relatadas. Os pacientes não costumam manifestar sintomas; entretanto, são propensos a desenvolver trombose venosa profunda e a complicação mais temida, embolia pulmonar. Apresentamos o caso de um homem de 36 anos previamente hígido que chegou ao serviço de emergência queixando-se de taquicardia, dispneia e dor pleurítica. Uma angiotomografia computadorizada confirmou o diagnóstico de embolia pulmonar aguda. O paciente foi tratado com trombólise sistêmica e anticoagulantes. Em exames posteriores para investigar a causa da embolia, uma tomografia computadorizada revelou dilatação fusiforme da veia poplítea esquerda medindo 3x3 cm, com enchimento incompleto devido à presença de um trombo. O paciente foi submetido a reparo cirúrgico aberto. No seguimento de 1 mês, ele estava assintomático, e uma ultrassonografia revelou a patência completa da veia poplítea, sem dilatação ou trombo.

Prevalence of abdominal aortic aneurysms in four different metropolitan areas in Mexico.

OBJECTIVE: Epidemiological data on aneurysmal disease affecting the abdominal aorta in Latin American countries are limited. In our institution, the National Institute of Medical Sciences and Nutrition Salvador Zubiran (INCMNSZ), we have reported an Abdominal Aortic Aneurysm (AAA) prevalence of 3.26% in patients at risk from our Ultrasound (US) screening program. We aim to determine and compare the prevalence of undetected AAA in four different Metropolitan areas in Mexico to justify further US screening efforts. METHODS: A cross-sectional multicenter study was conducted in 9 different academic institutions. Abdominal Computed Tomographies (CT) from patients with age equal or greater than 55 years in our center (INCMNSZ), and in 65 year old patients and older in the remainder institutions were systematically reviewed. Abdominal aortic diameters were measured at the level of the superior (SMA) and inferior mesenteric arteries (IMA) in nonaneurysmal aortas and maximum diameters in the found AAA. Categorical data were analyzed by nonparametric statistic test at significance level (P < 0.05), the Pearson test was used to determine the correlation of age and aortic diameters. RESULTS: The cohort included a total of 12, 936 patients paired with respect gender (53% females, with a mean age of 69 years), the AAA prevalence found in the studied Mexican population was 3.08% (399 AAA patients). In centers where more than 200 CTs scans were reviewed, the prevalence was 4.03%, compared to the 4.63% found in centers with less than 200 studies (P = 0.41). In patients between the ages of 55 to 64 from INCMNSZ (3889 total), the prevalence was 0.77%, supporting the need of focused US-screening programs in individuals at the age of 65 and older in our country. CONCLUSIONS: The introduction of a national US Screening Program for the detection of AAA in Mexico represents a challenge in our current health system. This Multicenter initiative demonstrates that our AAA prevalence is not different to other international reports; imaging screening might represent cost-effective strategy for reduction of aneurysm-related mortality.

Physiological and clinical impact in the carotid baroreceptor function following the surgical management of bilateral carotid body tumors.

OBJECTIVE: The bilateral presentation of Carotid Body Tumors (CBT) is rare; the surgical resection of these masses remains the mainstay management due to the malignant potential. We aim to describe, classify, and quantify baroreceptor failure (BRF) after the surgical management of patients with bilateral CBT to better understand the clinical consequences. METHODS: Retrospective review of patients that underwent bilateral CBT resection to assess the changes in baroreceptor function. We describe the clinical events associated to BRF after surgery, baseline patient's demographics, characteristics, comorbidities. Additionally, clinical and a quantitative evaluation of baroreceptor sensitivity were conducted using the Composite Autonomic Severity Score (CASS). RESULTS: From 1986 to 2020, a total 146 CBT resections were performed in 132 patients in our institution. Tumors were removed bilaterally in staged procedures in seven patients with a mean age of 61 years (Standard Deviation 11), six (85%) were females, and there was no family history of paragangliomas. The clinical presentation were palpable masses in 5 (71%), and odynophagia in 2 (29%) cases; malignant histopathology following surgery was found in one case. BRF occurred in one patient after unilateral CBT resection, consisting of bradycardia and a 40 s asystole that was not previously associated to BR sensitivity. Three (43%) patients presented BRF in the immediate postoperative period of the contralateral CBT excision, consisting of volatile hypertensive crisis in two cases, and supraventricular tachycardia in one. All the patients developed (100%) chronic baroreceptor sensitivity symptoms consisting in syncope, vertigo and fatigue in 4 (57%), tachycardia in 2 (28%), and orthostatic headache in one (14%). Autonomic testing showed mixed sympathetic and parasympathetic failure in five (71%), severe sympathetic failure in 1 (14%), and parasympathetic dysfunction in one patient (14%). CONCLUSIONS: Postoperative autonomic assessment confirmed BRF in all studied patients that underwent staged bilateral CBT resection with mixed, sympathetic, and parasympathetic dysfunction. Further studies are necessary to evaluate the incidence and physiological mechanisms of these sequelae to anticipate possible complications and offer the appropriate perioperative management.

A comprehensive approach to complementary and alternative medicine usage among patients from a vascular department.

INTRODUCTION: Use of complementary and alternative medicine (CAM) therapies had been described in patients with disabling, chronic and painful conditions; these characteristics define the majority of vascular surgery (VS) entities. A lack of disclosure about CAM use from patients has been universally cited and may impact effective patient-doctor communication. Our primary objective was to describe CAM use, modalities, perceived benefits, safety, and associated factors among adult patients attending a VS outpatient clinic; we additionally explored patient's attitudes about CAM disclosure with their primary vascular surgeon. METHODS: This cross-sectional study invited 223 consecutive outpatients to an interview where the ICAM-Q (International Complementary and Alternative Medicine Questionnaire) and the PDRQ-9 (Patient-Doctor Relationship Questionnaire-9 items) were applied. In addition, sociodemographics, vascular disease and treatment-related information, comorbidity, and disease severity characteristics were obtained. Appropriated statistics was used; multiple logistic regression analysis identified factors associated to CAM use. All statistical tests were two-sided, and a p value ≤ 0.05 was considered significant. IRB approval was obtained. RESULTS: Patients recruited were primary females (69%) and had a median age of 65 years (54-75). Most frequent vascular diagnoses were chronic venous insufficiency (36.2%) and peripheral artery disease (26%). There were 104 (46.6%) patients who referred CAM use, primarily self-helped practices (96%), and use of herbal, vitamins, or homeopathic medicines (23.7%). Overall, the majority of the patients perceived CAM modalities helpful and 94.6% denied any adverse event. Female sex (OR: 1.768, 95% CI: 0.997-3.135, p = 0.051) and hospitalization during the previous year (OR: 3.173, 95% CI: 1.492-6.748, p = 0.003) were associated to CAM use. The majority of the patients (77%) agreed about CAM disclosure with their primary vascular surgeon; meanwhile, among CAM users, up to 54.9% did not disclose it, and their main reasons were "Doctor didn't ask" (32%) and "I consider it unnecessary" (16%). The patient-doctor relationship was rated by the patients with high scores. CONCLUSIONS: CAM use is frequent and perceived as safe and beneficial among VS outpatients; nonetheless, patients do not disclose CAM use with their primary vascular surgeons, and a wide range of reasons are given by the patients that prevent effective and open communication.

Takayasu's Arteritis from the Patients' Perspectives: Measuring the Pulse to the Patient-Reported Outcomes.

BACKGROUND: Patients with Takayasu's arteritis (TA) experience important changes in lifestyle, quality of life, and functional status due to ischemic symptoms or treatment toxicity. PURPOSE: To describe the clinical characteristics and the patient-reported outcomes (PROs), such as quality of life, disability, fatigue, and perception/impact of the disease in Mexican patients with TA. METHODS: Cross-sectional study including patients with established diagnosis of TA recruited at a tertiary care center. Demographics, comorbidities, clinical characteristics, laboratory, imaging, and treatment were retrieved. Disease activity (the Indian Takayasu Clinical Activity Score (ITAS) 2010), damage (Vasculitis Damage Index (VDI)), quality of life (Short Form 36 (SF-36)), disability (Health Assessment Questionnaire Disability Index (HAQ-DI)), fatigue (Multidimensional Fatigue Inventory-20), and patient's disease perceptions were assessed. RESULTS: Fifteen women were included, with a median age of 41 years (interquartile range (IQR) 30-45) and disease duration of 108 months (IQR 55-197). Median ITAS 2010 and VDI scores were 0 (IQR 0-2) and 3 points (IQR 2-6), respectively. Mean SF-36 score was 71.38 ± 13.39, with mean physical and mental component summaries of 66.52 ± 13.37 and 76.24 ± 14.89, respectively. HAQ-DI mean score was 0.48 ± 0.62, being grip the most affected domain. Among fatigue subscales, the higher scores were present in the physical fatigue (16.3 ± 5.8). Correlations between the HAQ-DI and the VDI score (r = 0.64, P = 0.03); between the general fatigue, score, and disease duration (r = -0.71, P = 0.01); and between the SF-36 total score and the HAQ-DI (r = -0.87, P = 0.0004) were found. CONCLUSIONS: It is important to identify disease-specific outcomes of interest to the patients to develop tools that assess them with a holistic approach.

Systemic lupus erythematosus diagnosis impacts clinical outcomes of arteriovenous fistulas in comparison to other end-stage renal disease etiologies.

OBJECTIVES: Arteriovenous fistulas primary patency at one-year occurs in 43-85% of the patients with end-stage renal disease. The diagnosis attributable to end-stage renal disease has been suggested to impact arteriovenous fistulas outcomes. The objective was to compare primary patency at one week, 1, 3, 6, and 12 months of follow-ups, among systemic lupus erythematosus patients and two control groups; additionally, we evaluated the impact of systemic lupus erythematosus to predict early patency loss. METHODS: A retrospective review of charts from arteriovenous fistulas created between 2008 and 2017 was performed. One-hundred thirty-four patients were identified and classified according to end-stage renal disease attributable diagnosis as: systemic lupus erythematosus cases (N = 14), control-group-1 (91 patients with primarily diabetes and hypertension), and control-group-2 (29 patients with idiopathic end-stage renal disease). A case-control matched design (1:2:1) was proposed. Logistic regression analysis and Kaplan-Meier curves were used. Institutional Review Board approval was obtained. RESULTS: More systemic lupus erythematosus patients lost primary patency at 3 (28.6%) and 12 months (71.4%) than patients from control-groups-1 (vs. 3.6% and 35.7%, respectively) and -2 (vs. 0% and 14.3%, respectively), (p ≤ 0.011 for both). Days of primary patency survival were shorter in systemic lupus erythematosus patients (p = 0.003). Systemic lupus erythematosus diagnosis was the only factor associated with early patency loss, HR: 3.141, 95%CI: 1.161-8.493 (systemic lupus erythematosus diagnosis vs. control-group-1) and HR: 12.582, 95%CI: 1.582-100.035 (systemic lupus erythematosus diagnosis vs. control-group-2). CONCLUSIONS: Diagnosis attributable to end-stage renal disease has a major impact on arteriovenous fistula outcomes in patients. Systemic lupus erythematosus patients have an increased risk of arteriovenous fistulas patency loss within the first six months of follow-up. Patients with idiopathic end-stage renal disease had an excellent one year arteriovenous fistula patency survival.

Managing central venous access during a health care crisis.

OBJECTIVE: During the COVID-19 pandemic, central venous access line teams were implemented at many hospitals throughout the world to provide access for critically ill patients. The objective of this study was to describe the structure, practice patterns, and outcomes of these vascular access teams during the COVID-19 pandemic. METHODS: We conducted a cross-sectional, self-reported study of central venous access line teams in hospitals afflicted with the COVID-19 pandemic. To participate in the study, hospitals were required to meet one of the following criteria: development of a formal plan for a central venous access line team during the pandemic; implementation of a central venous access line team during the pandemic; placement of central venous access by a designated practice group during the pandemic as part of routine clinical practice; or management of an iatrogenic complication related to central venous access in a patient with COVID-19. RESULTS: Participants from 60 hospitals in 13 countries contributed data to the study. Central venous line teams were most commonly composed of vascular surgery and general surgery attending physicians and trainees. Twenty sites had 2657 lines placed by their central venous access line team or designated practice group. During that time, there were 11 (0.4%) iatrogenic complications associated with central venous access procedures performed by the line team or group at those 20 sites. Triple lumen catheters, Cordis (Santa Clara, Calif) catheters, and nontunneled hemodialysis catheters were the most common types of central venous lines placed by the teams. Eight (14%) sites reported experience in placing central venous lines in prone, ventilated patients with COVID-19. A dedicated line cart was used by 35 (59%) of the hospitals. Less than 50% (24 [41%]) of the participating sites reported managing thrombosed central lines in COVID-19 patients. Twenty-three of the sites managed 48 iatrogenic complications in patients with COVID-19 (including complications caused by providers outside of the line team or designated practice group). CONCLUSIONS: Implementation of a dedicated central venous access line team during a pandemic or other health care crisis is a way by which physicians trained in central venous access can contribute their expertise to a stressed health care system. A line team composed of physicians with vascular skill sets provides relief to resource-constrained intensive care unit, ward, and emergency medicine teams with a low rate of iatrogenic complications relative to historical reports. We recommend that a plan for central venous access line team implementation be in place for future health care crises.

Complex Aortic, Visceral and Renal Arteries Reconstruction with a Four-Branch Dacron Graft for Middle Aortic Syndrome Secondary to Takayasu's Arteritis.

The middle aortic syndrome (MAS) is an uncommon clinical expression as a result of isolated stenosis or complete occlusion of the descending thoracic and/or abdominal aorta; Takayasu's arteritis (TA) is a rare vasculitis and a recognized etiology of MAS. We herein present the case of a 52-year-old woman with refractory renovascular hypertension and progressive bilateral lower extremity claudication; she had known history of TA. A computed tomography angiography demonstrated an aortic occlusive lesion compromising the origin of the celiac trunk, superior mesenteric, and bilateral renal arteries. The patient underwent a complex aortic reconstruction with visceral and renal vessels revascularization utilizing a back-table hand-crafted 4-branch Dacron graft through a left thoracoabdominal approach. The patient recovered uneventfully and was discharged on postoperative day 5, and at 36 months from her surgery, she remains symptoms-free and without antihypertensive agents.

Investigation of an Immunogenetic Profile in Patients with Abdominal Aortic Aneurysms and Possible Applications in Screening and Surveillance.

BACKGROUND: The pathogenesis of atherosclerotic abdominal aortic aneurysms (AAAs) remains not fully understood. Histological analyses confirm chronic adventitial and medial inflammatory cell infiltration, and its pathophysiology involves the upregulation of proteolytic pathways; added to this, genetic factors have been suggested to favor the susceptibility for AAA. The aim of the present study was to analyze the association between genetic polymorphism of the class II human leukocyte antigens (HLAs, HLA-DRB1) with the susceptibility to develop AAA in Mexican patients and to initiate a pilot study of single-nucleotide polymorphisms (SNPs) rs1024611 in the monocyte chemoattractant protein-1 (MCP-1/CCL2) gene to investigate a possible role in the AAA pathogenesis. METHODS: In a cohort of patients with AAA, HLA molecular typing was completed for DRB1 loci with LABType SSO-One Lambda kit in 39 patients (69% men with a mean age of 72 years) and compared with 99 without the disease (60% men, mean age 65 years) (control group). Genotyping of rs1024611 in the MCP-1 gene was performed using TaqMan predesigned SNP genotyping assays in 27 patients with AAA (63% men, mean age of 71). Gene frequencies (gfs) and genotype frequencies (Gfs) were determined; categorical data were analyzed by nonparametric statistic test at significance level (P < 0.05), and odds ratios (ORs) were calculated using the STATA v14 software and StatCalc software Epi Info™ 7.2.2.2. RESULTS: Seventy-eight HLA-DRB1 alleles of patients with AAA and 198 from the control group were studied. We observed that the gf of HLA-DRB1*01 was 0.128 in the AAA group compared with 0.05 in the control group (P = 0.03, OR: 2.6, 95% confidence interval [CI]: 1.04-6.5); the gf of HLA-DRB1*16 was 0.115 in the AAA and 0.025 in control group (P = 0.002, OR: 5, 95% CI: 1.6-16.9). The Gf for SNP rs1024611 were 0.51 in the GA genotype, 0.30 in AA, and 0.19 of GG. Four patients with the proinflammatory homozygous genotype GG (80%) were women and younger than patients with other genotypes, and only one had a history of dyslipidemia. CONCLUSIONS: The dissection and interpretation of an immunogenetic profile in patients with AAA is an active and complex field of research that might assist in a more precise identification of those patients at genetic risk. Our study demonstrated increased frequencies of HLA-DRB1*01 and HLA-DRB1*16 alleles in Mexican patients with AAA compared with an ethnically matched control group.

Genetic polymorphism of HLA-DRB1 alleles in Mexican mestizo patients with abdominal aortic aneurysms.

BACKGROUND: Multiple factors are implicated in the etiology and pathogenesis of Abdominal Aortic Aneurysms (AAA). Available literature of genetic studies has previously suggested the possible roles of autoimmunity, genetic predisposition and ethnic susceptibility. Due to the association with autoimmune diseases and proven application in population genetics, we aimed to investigate alleles of the Class II Human Leukocyte Antigens (HLA-DRB1) in the Mexican Mestizo population with aortic aneurysms and determine possible associations with susceptibility. METHODS: We performed a case Control Study; the HLA molecular typing was completed for DRB1 loci by LabType Sequence-Specific Oligonucleotide (SSO) SSO-OneLambda kit (Applied Biosystems; Thermo Fisher Scientific. Inc.) in the studied individuals. Allele frequencies (af) were determined, associations were assessed by chi square or fisher exact tests at significance level (< 0.05), and Odds Ratios (OR) were calculated using the STATA software version 14. RESULTS: The genetic polymorphism of HLA-DRB1 of fifty one patients (70% males with a mean age of 71 years) with atherosclerotic or also known as degenerative AAA were compared with 99 unrelated patients (60% males, mean age 65 years) without the disease [Control group (CG)] from the same ethnic group. We examined a total of 102 Class II HLA-DRB1 alleles of AAA patients and 198 from CG. When comparing af, we observed the HLA-DRB1*01 af of 0.139 in the AAA compared to 0.05 in the CG [p = 0.015, OR 3, 95% confidence interval (CI) 1.29-7.08], the HLA-DRB1*16 af were 0.109 in the AAA and 0.025 in CG (p = 0.006, OR 4.7, 95% CI 1.59-13.98). CONCLUSIONS: Our study confirmed increased frequencies of the alleles HLA-DRB1*01 and HLA-DRB1*16 and their association to the development of AAA in Mexican Mestizo patients. The utility of genetic testing may assist in identifying individuals at genetic risk for the development of this disease in different ethnic groups, who might benefit from earlier ultrasound screening and closer imaging surveillance.

Surgical Management of Bilateral Carotid Body Tumors.

BACKGROUND: Carotid body tumors (CBTs) are rare neoplasms located in the carotid bifurcation. The majority of these tumors are unilateral; bilateral CBTs represent approximately 5% of all affected patients, and the recommended treatment is to surgically remove them in staged-planned surgeries. We describe the experience, outcomes, and the surgical management of bilateral CBTs in our institution. METHODS: A retrospective review of CBTs patients was completed; patient demographics, comorbidities, lesion location, anatomic characteristics, surgical techniques, complications, reinterventions, and other factors that may influence outcomes were evaluated. RESULTS: A total of 109 patients with CBTs were treated surgically; of these, 8 had bilateral CBTs (7%); the mean age was 56 years, and 7 (87%) were females. Thirteen surgical resections were performed, and in 2 of the cases, the pathology report was malignant (15%). Five were classified as Shamblin I (31%), 5 as Shamblin II (31%), and remaining 6 as Shamblin III (38%). The mean time between the first and second procedure was of 10.7 months. Complications included one case of neck hematoma requiring evacuation and postoperative neurologic complications occurred in three patients (one patient with facial and two with vocal cord palsies). None of the studied individuals had a family history of CBT, and all of them lived in altitude areas higher than 2000 meters above mean sea level (mamsl). The mean tumor size was 3.55 cm and 2.75 cm for right and left CBTs, respectively. CONCLUSIONS: A better understanding of the clinical characteristics of patients with bilateral CBTs may lead to a more standardized and optimal management with fewer complications and a better quality of life afterward.

II. THE RESEARCH ETHICS INVOLVING VULNERABLE GROUPS.

Vulnerability in research occurs when the participant is incapable of protecting his or her interests and therefore, has an increased probability of being intentionally or unintentionally harmed. This manuscript aims to discuss the conditions that make a group vulnerable and the tools and requirements that can be used to reduce the ethical breaches when including them in research protocols. The vulnerability can be due either to an inability to understand and give informed consent or to unequal power relationships that hinder basic rights. Excluding subjects from research for the only reason of belonging to a vulnerable group is unethical and will bias the results of the investigation. To consider a subject or group as vulnerable depends on the context, and the investigator should evaluate each case individually.