Thrombosis in the setting of obesity or inflammatory bowel disease

Effectiveness, safety, and costs of thromboprophylaxis with enoxaparin or unfractionated heparin in inpatients with obesity

Background

Obesity is a frequent and significant risk factor for venous thromboembolism (VTE) among hospitalized adults. Pharmacologic thromboprophylaxis can help prevent VTE, but real-world effectiveness, safety, and costs among inpatients with obesity are unknown.

Objective

This study aims to compare clinical and economic outcomes among adult medical inpatients with obesity who received thromboprophylaxis with enoxaparin or unfractionated heparin (UFH).

Methods

A retrospective cohort study was performed using the PINC AI™ Healthcare Database, which covers more than 850 hospitals in the United States. Patients included were ≥18 years old, had a primary or secondary discharge diagnosis of obesity [International Classification of Diseases (ICD)-9 diagnosis codes 278.01, 278.02, and 278.03; ICD-10 diagnosis codes E66.0x, E66.1, E66.2, E66.8, and E66.9], received ≥1 thromboprophylactic dose of enoxaparin (≤40 mg/day) or UFH (≤15,000 IU/day) during the index hospitalization, stayed ≥6 days in the hospital, and were discharged between 01 January 2010, and 30 September 2016. We excluded surgical patients, patients with pre-existing VTE, and those who received higher (treatment-level) doses or multiple types of anticoagulants. Multivariable regression models were constructed to compare enoxaparin with UFH based on the incidence of VTE, pulmonary embolism (PE)---------related mortality, overall in-hospital mortality, major bleeding, treatment costs, and total hospitalization costs during the index hospitalization and the 90 days after index discharge (readmission period).

Results

Among 67,193 inpatients who met the selection criteria, 44,367 (66%) and 22,826 (34%) received enoxaparin and UFH, respectively, during their index hospitalization. Demographic, visit-related, clinical, and hospital characteristics differed significantly between groups. Enoxaparin during index hospitalization was associated with 29%, 73%, 30%, and 39% decreases in the adjusted odds of VTE, PE-related mortality, in-hospital mortality, and major bleeding, respectively, compared with UFH (all p < 0.002). Compared with UFH, enoxaparin was associated with significantly lower total hospitalization costs during the index hospitalization and readmission periods.

Conclusions

Among adult inpatients with obesity, primary thromboprophylaxis with enoxaparin compared with UFH was associated with significantly lower risks of in-hospital VTE, major bleeding, PE-related mortality, overall in-hospital mortality, and hospitalization costs.

Early Administration of Vancomycin Inhibits Pulmonary Embolism by Remodeling Gut Microbiota

Pulmonary embolism (PE) is a common and potentially fatal condition in the emergency department, and early identification of modifiable risk factors for prevention and management is highly desirable. Although gut dysbiosis is associated with a high incidence of venous thromboembolism, the role and mechanisms of the gut microbiome in the pathogenesis of venous thromboembolism, especially PE, remain unexplored. Here, we attempted to elucidate the benefits of the gut microbiome in the pathogenesis of PE using multiple antibiotics and fecal microbiota transplantation (FMT) for early intervention in a classical mouse model of PE. The results showed that early administration of various antibiotics (except ampicillin) could inhibit pulmonary thrombosis to a certain extent and reduced mortality in young and old mice with PE. Among them, vancomycin has the best inhibitory effect on PE. With the help of gut microbiota sequencing analysis, we found that antibiotic treatment can reshape the gut microbiota; especially vancomycin can significantly improve the gut microbiota structure in PE mice. Furthermore, FMT could transfer vancomycin-modified gut microbes into mice and inhibit the pathogenesis of PE, possibly due to increased intestinal colonization by Parasutterella. These data elucidate the underlying molecular mechanism by which early administration of vancomycin can remodel the gut microbiota to suppress PE, providing new clues for clinical optimization and development of PE prevention strategies.

Operative management of acute abdomen after bariatric surgery in the emergency setting: the OBA guidelines

BACKGROUND

Patients presenting with acute abdominal pain that occurs after months or years following bariatric surgery may present for assessment and management in the local emergency units. Due to the large variety of surgical bariatric techniques, emergency surgeons have to be aware of the main functional outcomes and long-term surgical complications following the most performed bariatric surgical procedures. The purpose of these evidence-based guidelines is to present a consensus position from members of the WSES in collaboration with IFSO bariatric experienced surgeons, on the management of acute abdomen after bariatric surgery focusing on long-term complications in patients who have undergone laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass.

METHOD

A working group of experienced general, acute care, and bariatric surgeons was created to carry out a systematic review of the literature following the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) and to answer the PICO questions formulated after the Operative management in bariatric acute abdomen survey. The literature search was limited to late/long-term complications following laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass.

CONCLUSIONS

The acute abdomen after bariatric surgery is a common cause of admission in emergency departments. Knowledge of the most common late/long-term complications (&gt; 4 weeks after surgical procedure) following sleeve gastrectomy and Roux-en-Y gastric bypass and their anatomy leads to a focused management in the emergency setting with good outcomes and decreased morbidity and mortality rates. A close collaboration between emergency surgeons, radiologists, endoscopists, and anesthesiologists is mandatory in the management of this group of patients in the emergency setting.

Incidence and Predictors of Recurrence and Mortality Following First Venous Thromboembolism Among the Saudi Population: Single-Center Cohort Study

Background

Little is written about recurrence and mortality rates after a first episode of venous thromboembolism (VTE) among Saudi population.

Aim

Determine incidence rates and assess predictors of recurrence and mortality following the first VTE event.

Patients and Methods

A total of 1124 patients aged ≥18 years with symptomatic VTE confirmed by imaging tests were evaluated. The incidence of VTE recurrence and mortality were assessed. The association between patient characteristics, and VTE recurrence and mortality was explored by estimating the hazard ratio (HR) and 95% confidence interval (CI). The difference between cancer-related, provoked and unprovoked VTE in terms of recurrence and mortality was explored using Kaplan–Meier curves.

Results

The annual incidence rate of the first VTE was 1.7 per 1000 patients. Of 1124 patients with first VTE, 214 (19%) developed recurrent VTE, and 192 (17%) died with overall incidence rates of 15.8 per 100 person-years (95% CI, 13.8–18.0) and 10.0 per 100 person-years (95% CI, 8.7–11.5). Intensive care unit (ICU) admission (HR, 2.15; 95% CI, 1.67–3.10), presence of active cancer (HR, 2.97; 95% CI, 1.87–3.95), immobilization (HR, 2.52; 95% CI, 1.79–3.67), infection (HR, 2.32; 95% CI, 1.94–3.45), and pulmonary embolism ± deep venous thrombosis (HR, 2.22; 95% CI, 1.56–3.16) were found to be independent predictors of recurrent VTE. Recurrence carries a high hazard of mortality (HR, 5.21; 95% CI, 3.61–7.51). The estimated median time to VTE recurrence was lower in cancer-related VTE (18.7 months) compared with provoked (29.0 months) and unprovoked VTE (28.4 months). The estimated survival median time was lower in cancer-related VTE (21.8 months) compared with provoked (30.5 months) and unprovoked VTE (29.8 months).

Conclusion

Immobilization and presence of active cancer, infection, and PE ± DVT were significant predictors of recurrent VTE. Patients who developed recurrent VTE had a 5.2-fold higher hazard of mortality compared with patients with no VTE recurrence.

Thromboembolism is associated with poor prognosis and high mortality in patients with inflammatory bowel disease: A case-control study

BACKGROUND

The information on the risk of thromboembolism (TE) in inflammatory bowel disease (IBD) and its predictors are lacking, especially from developing countries. The present study evaluated the prevalence, predictors, and prognosis of TE in IBD.

METHODS

This case-control study included 35 patients with IBD (ulcerative colitis [UC, n = 25]; Crohn's disease [CD], n = 10) and history of TE, from a cohort of 3597 patients (UC n = 2752, CD n = 845) under follow-up from 2005 to 2018. Details on demographics, extraintestinal manifestations (EIMs), patient status, type and outcomes of TE, treatment details, and disease course were compared with IBD patients without TE (age, gender, and duration of follow-up matched) in the ratio of 1:4.

RESULTS

Prevalence of TE in IBD was 0.9% (UC-0.89%, CD-1.2%). Among TE patients (mean age: 34.9 ± 13.1 years, 48.6% males), median duration from diagnosis to TE was 12 (inter-quartile range [IQR]: 3-36) months, 37% had other EIMs, 94.1% had moderate/severe disease at time of TE, 62.8% had steroid-dependent/refractory disease, and 5 patients (14.2%) died because of disease-related complications. Lower limb was the commonest site (57.1%), 14.3% had pulmonary TE, and 31.4% had involvement of multiple sites. Phenotypically, more patients with TE (among UC) had steroid-dependent disease (60% vs. 25%, p = 0.001), pancolitis (76% vs. 36%, p = 0.002), chronic continuous disease course (44% vs. 19%, p = 0.009), and acute severe colitis (48% vs. 18%, p = 0.002), of which the latter three were also independent predictors of TE.

CONCLUSION

Approximately 1% of patients with IBD develop thromboembolism relatively early during their disease course, and TE is associated with severe disease and higher disease-related complications including mortality.

Translating MSC Therapy in the Age of Obesity

Mesenchymal stromal cell (MSC) therapy has seen increased attention as a possible option to treat a number of inflammatory conditions including COVID-19 acute respiratory distress syndrome (ARDS). As rates of obesity and metabolic disease continue to rise worldwide, increasing proportions of patients treated with MSC therapy will be living with obesity. The obese environment poses critical challenges for immunomodulatory therapies that should be accounted for during development and testing of MSCs. In this review, we look to cancer immunotherapy as a model for the challenges MSCs may face in obese environments. We then outline current evidence that obesity alters MSC immunomodulatory function, drastically modifies the host immune system, and therefore reshapes interactions between MSCs and immune cells. Finally, we argue that obese environments may alter essential features of allogeneic MSCs and offer potential strategies for licensing of MSCs to enhance their efficacy in the obese microenvironment. Our aim is to combine insights from basic research in MSC biology and clinical trials to inform new strategies to ensure MSC therapy is effective for a broad range of patients.

Management of Venous Thromboembolism in Morbid Obesity With Rivaroxaban or Warfarin

BACKGROUND

Rivaroxaban is a first-line option for the management of venous thromboembolism (VTE). However, limited data are available regarding its effectiveness in morbidly obese patients.

OBJECTIVE

To evaluate rates of thrombosis and bleeding in morbidly obese patients receiving rivaroxaban or warfarin for VTE.

METHODS

A multicenter, retrospective cohort study was conducted to compare rates of bleeding and thrombosis in patients receiving rivaroxaban versus warfarin for acute VTE. Patients were included if they were older than 18 years and had a body mass index (BMI) greater than 40 kg/m² or weight greater than 120 kg. The primary effectiveness outcome was hazard of VTE recurrence; the primary safety outcome was hazard of major bleeding. Patients were followed for up to 12 months.

RESULTS

A total of 1281 patients were identified for acute VTE and were included in this study with 487 patients receiving rivaroxaban and 785 receiving warfarin. The average cohort age was 57.6 ± 14.6 years, and the average weight was 136.4 ± 27.2 kg. After controlling for confounding factors, the use of rivaroxaban was not associated with an increased hazard of VTE events when compared with warfarin (hazard ratio [HR] = 0.69, 95% confidence interval [CI]: 0.42-1.08, P = 0.12) or major bleeding (HR = 1.29, 95% CI: 0.66-2.30, P = 0.52).

CONCLUSION AND RELEVANCE

No difference was observed in obese patients with weight >120 kg or BMI >40 kg/m² receiving rivaroxaban or warfarin for VTE treatment in hazard of VTE or major bleeding. Either agent may be considered an appropriate treatment option in this population.

The Metabolic Profiles of Metabolically Healthy Obese and Metabolically Unhealthy Obese South African Adults over 10 Years

Obesity is associated with an increased cardiometabolic risk, but some individuals maintain metabolically healthy obesity (MHO). The aims were to follow a cohort of black South African adults over a period of 10 years to determine the proportion of the group that maintained MHO over 10 years, and to compare the metabolic profiles of the metabolically healthy and metabolically unhealthy groups after the follow-up period. The participants were South African men (n = 275) and women (n = 642) from the North West province. The prevalence of obesity and the metabolic syndrome increased significantly. About half of the metabolically healthy obese (MHO) adults maintained MHO over 10 years, while 46% of the women and 43% of men became metabolically unhealthy overweight/obese (MUO) at the end of the study. The metabolic profiles of these MHO adults were similar to those of the metabolically healthy normal weight (MHNW) group in terms of most metabolic syndrome criteria, but they were more insulin resistant; their CRP, fibrinogen, and PAI-1act were higher and HDL-cholesterol was lower than the MHNW group. Although the metabolic profiles of the MUO group were less favourable than those of their counterparts, MHO is a transient state and is associated with increased cardiometabolic risk.

Inflammatory bowel disease causing retroperitoneal varicosity mimicking a renal artery aneurysm: A novel case report and literature review

A 17-year-old female presented to our hospital complaining of bloody diarrhea 4-6 times per day for the past month. She was a known case of inflammatory bowel disease noncompliant to her medications. Abdominal computed tomography revealed an unusually dilated mass in the retroperitoneum at L2 vertebral level connecting the lumbar and left renal veins. The renal artery was visualized separately, and a diagnosis of communicating vein varicosity was made. This lesion can be misleading on imaging, hence our aim to disseminate our findings to practicing radiologists. The differential diagnosis of these lesions include retroperitoneal lymphadenopathy, renal artery aneurysms, and testicular cancers causing retroperitoneal lymphadenopathy. To our knowledge, this is the first case to be reported in association with inflammatory bowel disease, perhaps providing a novel insight into the pathogenesis of this lesion that has not been considered in the contemporary literature.

Reveals of candidate active ingredients in Justicia and its anti-thrombotic action of mechanism based on network pharmacology approach and experimental validation

Thrombotic diseases seriously threaten human life. Justicia, as a common Chinese medicine, is usually used for anti-inflammatory treatment, and further studies have found that it has an inhibitory effect on platelet aggregation. Therefore, it can be inferred that Justicia can be used as a therapeutic drug for thrombosis. This work aims to reveal the pharmacological mechanism of the anti-thrombotic effect of Justicia through network pharmacology combined with wet experimental verification. During the analysis, 461 compound targets were predicted from various databases and 881 thrombus-related targets were collected. Then, herb-compound-target network and protein-protein interaction network of disease and prediction targets were constructed and cluster analysis was applied to further explore the connection between the targets. In addition, Gene Ontology (GO) and pathway (KEGG) enrichment were used to further determine the association between target proteins and diseases. Finally, the expression of hub target proteins of the core component and the anti-thrombotic effect of Justicia's core compounds were verified by experiments. In conclusion, the core bioactive components, especially justicidin D, can reduce thrombosis by regulating F2, MMP9, CXCL12, MET, RAC1, PDE5A, and ABCB1. The combination of network pharmacology and the experimental research strategies proposed in this paper provides a comprehensive method for systematically exploring the therapeutic mechanism of multi-component medicine.

Cerebral venous sinus thrombosis in patients with inflammatory bowel disease: a retrospective study

Cerebral venous sinus thrombosis (CVST) is a rare and devastating complication of inflammatory bowel disease (IBD). Early diagnosis and prompt treatment could improve prognosis. The aim of our study was to investigate the clinical data and predictive factors of inflammatory bowel disease in patients with a diagnosis of CVST. All IBD patient data were collected from July 2013 and September 2020. Clinical data, predictive factors and prognosis were compared between IBD patients with CVST and the IBD control group. The incidence of CVST in our study was 0.48%. The mean age of IBD patients with CVST was 34.9 years. The average duration of IBD was 4 years when cerebrovascular events occurred. The clinical presentation of CVST included headache (73.1%), vomiting (30.8%), limb dysmetria (26.9%), speech impairment (11.5%), blurred vision (7.7%), epileptic seizures (7.7%) and drowsiness (3.8%). The most common location for CVST was the transverse sinus (61.5%) followed by the superior sagittal sinus (30.8%). Anaemia, low albumin and elevated D-dimer were independent predictors of CVST in patients with IBD. Anticoagulation therapy was effective. The prognosis of IBD patients with CVST was worse than that of IBD patients without CVST. Early identification of the risk and clinical features of CVST in IBD patients is important. Prompt antithrombotic therapy is a safe and effective treatment.

Lifestyle Influences Changes in Fibrin Clot Properties Over a 10-Year Period on a Population Level

Case-control and observational studies have provided a plausible mechanistic link between clot structure and thrombosis. We aimed to identify lifestyle, demographic, biochemical, and genetic factors that influence changes in total fibrinogen concentration and clot properties over a 10-year period in 2,010 black South Africans. Clot properties were assessed with turbidimetry and included lag time, slope, maximum absorbance, and clot lysis time. Linear mixed models with restricted maximum likelihood were used to determine whether (1) outcome variables changed over the 10-year period; (2) demographic and lifestyle variables, biochemical variables, and fibrinogen single-nucleotide polymorphisms influenced the change in outcome variables over the 10-year period; and (3) there was an interaction between the exposures and time in predicting the outcomes. A procoagulant risk score was furthermore created, and multinomial logistic regression was used to determine the exposures that were associated with the different risk score categories. In this population setting, female gender, obesity, poor glycemic control, increased low-density lipoprotein cholesterol, and decreased high-density lipoprotein cholesterol contributed to the enhanced progression to prothrombotic clot properties with increasing age. Alcohol consumption on the other hand, offered a protective effect. The above evidence suggest that the appropriate lifestyle changes can improve fibrin clot properties on a population level, decreasing cardiovascular disease risk and thus alleviate the strain on the medical health care system.

Interacting hepatic PAI-1/tPA gene regulatory pathways influence impaired fibrinolysis severity in obesity

Fibrinolysis is initiated by tissue-type plasminogen activator (tPA) and inhibited by plasminogen activator inhibitor 1 (PAI-1). In obese humans, plasma PAI-1 and tPA proteins are increased, but PAI-1 dominates, leading to reduced fibrinolysis and thrombosis. To understand tPA–PAI-1 regulation in obesity, we focused on hepatocytes, a functionally important source of tPA and PAI-1 that sense obesity-induced metabolic stress. We showed that obese mice, like humans, had reduced fibrinolysis and increased plasma PAI-1 and tPA, due largely to their increased hepatocyte expression. A decrease in the PAI-1 (SERPINE1) gene corepressor Rev-Erbα increased PAI-1, which then increased the tPA gene PLAT via a PAI-1/LRP1/PKA/p-CREB1 pathway. This pathway was partially counterbalanced by increased DACH1, a PLAT-negative regulator. We focused on the PAI-1/PLAT pathway, which mitigates the reduction in fibrinolysis in obesity. Thus, silencing hepatocyte PAI-1, CREB1, or tPA in obese mice lowered plasma tPA and further impaired fibrinolysis. The PAI-1/PLAT pathway was present in primary human hepatocytes, and associations among PAI-1, tPA, and PLAT in livers from obese and lean humans were consistent with these findings. Knowledge of PAI-1 and tPA regulation in hepatocytes in obesity may suggest therapeutic strategies for improving fibrinolysis and lowering the risk of thrombosis in this setting.

Effectiveness and Safety of Apixaban vs. Warfarin in Venous Thromboembolism Patients with Obesity and Morbid Obesity

This study integrated 5 United States healthcare claims databases to evaluate the risk of recurrent venous thromboembolism (VTE) and major bleeding (MB) among VTE patients who initiated apixaban vs. warfarin, stratified by obesity. Obese and morbidly obese patients were identified based on diagnosis codes. Stabilized inverse probability treatment weighting (IPTW) was conducted to balance observed patient characteristics between treatment cohorts. An interaction analysis was conducted to evaluate treatment effects of apixaban vs. warfarin according to obesity status. Cox proportional hazard models were used to evaluate the risk of recurrent VTE and MB among IPTW weighted obese and morbidly obese patients. A total of 112,024 non-obese patients and 43,095 obese patients were identified, of whom 19,751 were morbidly obese. When stratified by obesity status post-IPTW, no significant interactions were observed for effects of apixaban vs. warfarin on recurrent VTE or MB (interaction p > 0.10). Among IPTW obese and morbidly obese patients, apixaban was associated with a significantly lower risk of recurrent VTE (obese: 0.73 [0.64–0.84]; morbidly obese: 0.65 [0.53–0.80]) and MB (obese: 0.73 [0.62–0.85]; morbidly obese: 0.68 [0.54–0.86]) as compared with warfarin. In this large sample of obese and morbidly obese VTE patients, apixaban had a significantly lower risk of recurrent VTE and MB vs. warfarin.

The hematologic consequences of obesity

The prevalence of obesity is increasing and progressively influencing physician-patient interactions. While there is a sizable amount of data demonstrating that obesity is a state of low-grade inflammation, to our knowledge, there is no single review summarizing its effects on hematologic parameters and thrombotic risk. We performed a literature search which largely surfaced observational studies, with a few systematic reviews and meta-analyses of these studies. We took care to review the mechanisms driving an inflammatory state and obesity's effect on white blood cells, red blood cells, platelets, and thrombotic risk. There is an observed relative, and sometimes absolute leukocytosis driven by this inflammatory state. Obesity is also associated with increased platelet counts and an increased risk for venous thromboembolism (VTE). Lastly, the association between obesity, iron deficiency (ID), and red blood cell counts may be present but remains uncertain. Recognizing the above associations may provide clinicians with reassurance regarding otherwise unexplained hematologic abnormalities in obese individuals. We hope this review will prompt future studies to further understand the underlying mechanisms driving these abnormalities and identify modifiable risk factors and potential therapeutic targets to prevent the development of probable obesity-associated conditions with significant morbidity and mortality, such as ID and VTE.

Prothrombotic effects of high uric acid in mice via activation of MEF2C-dependent NF-κB pathway by upregulating let-7c

Serum uric acid is reportedly associated with thrombosis development. However, still unclear is the mechanism of high uric acid in thrombosis with the involvement of let-7c. In an aim to fill this void, we conducted this study by treating mice and human umbilical vein endothelial cells with high uric acid. Analysis indicated that let-7c was upregulated in hyperuricemia patients as well as in mice and human umbilical vein endothelial cells treated with high uric acid. Furthermore, high uric acid inhibited myocyte enhancer factor-2C, but activated nuclear factor-kappa B pathway in human umbilical vein endothelial cells. Then the targeting relationship between let-7c and myocyte enhancer factor-2C was verified. On the one hand, high uric acid shortened activated partial thromboplastin time and prothrombin time of mice and declined tissue plasminogen activator level. Additionally, the treatment prolonged thrombin time and elevated the levels of thrombosis related molecules or proteins such as Fibrinogen and D-dimer. Nevertheless, these alternations could be reversed by inhibition of let-7c and nuclear factor-kappa B pathway or overexpressing myocyte enhancer factor-2C. To sum up, our results uncovered the pro-thrombotic effect of high uric acid in mice by activating myocyte enhancer factor-2C-dependent nuclear factor-kappa B pathway via let-7c upregulation.

Surgical venous thromboembolism prophylaxis: clinical practice update

BACKGROUND

Perioperative medicine continues to evolve as new literature emerges. This article provides an update on prevention of venous thromboembolism (VTE) in surgical patients.

METHODS

We reviewed articles on VTE prevention in surgical patients published in peer-reviewed journals since the publication of 2012 ACCP guidelines on VTE prevention in surgical patients.

RESULTS

Methods of VTE prophylaxis include aggressive ambulation, mechanical prophylaxis, and pharmacological prophylaxis. In non-orthopedic surgery, the overall approach remains assessment of thrombosis risk with the recommendation to use a risk assessment tool such as the modified Caprini score. Low molecular weight heparin (LMWH) appears to be more effective than unfractionated heparin (UFH) for VTE prophylaxis in non-orthopedic surgery. For orthopedic surgery, recent studies now recognize aspirin as an option for VTE prophylaxis after total hip arthroplasty, total knee arthroplasty, and hip fracture surgery. Extended prophylaxis with LMWH reduces the risk of symptomatic VTE in high risk abdominal and pelvic cancer surgery without an appreciable increase in risk of bleeding and decreased symptomatic VTE in major orthopedic surgery but with more minor but not major bleeding. Prophylactic Inferior vena cava (IVC) filter placement or surveillance compression ultrasonography is not recommended in management or detection of VTE in surgical patients.

CONCLUSIONS

This article aims to provide insight into data from last several years which has potential to change clinical practices in perioperative setting.

Association of Preoperative Body Weight and Weight Loss With Risk of Death After Bariatric Surgery

IMPORTANCE

Perception of weight loss requirements before bariatric surgery varies among patients, physicians, and health insurance payers. Current clinical guidelines do not require preoperative weight loss because of a lack of scientific support regarding its benefits.

OBJECTIVE

To examine the association of preoperative body mass index (BMI) and weight loss with 30-day mortality after bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from 480 075 patients who underwent bariatric surgery from 2015 to 2017 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, which covers more than 90% of all bariatric surgery programs in the United States and Canada. Clinical and demographic data were collected at all participating institutions using a standardized protocol. Data analysis was performed from December 2018 to November 2019.

EXPOSURES

Preoperative BMI and weight loss.

MAIN OUTCOMES AND MEASURES

30-day mortality after bariatric surgery.

RESULTS

Of the 480 075 patients (mean [SD] age 45.1 [12.0] years; 383 265 [79.8%] women), 511 deaths (0.1%) occurred within 30 days of bariatric surgery. Compared with patients with a preoperative BMI of 35.0 to 39.9, the multivariable-adjusted odds ratios for 30-day mortality for patients with preoperative BMI of 40.0 to 44.9, 45.0 to 49.9, 50.0 to 54.9, and 55.0 and greater were 1.37 (95% CI, 1.02-1.83), 2.19 (95% CI, 1.64-2.92), 2.61 (95% CI, 1.90-3.58), and 5.03 (95% CI, 3.78-6.68), respectively (P for trend < .001). Moreover, compared with no preoperative weight loss, the multivariable-adjusted odds ratios for 30-day mortality for patients with weight loss of more than 0% to less than 5.0%, 5.0% to 9.9%, and 10.0% and greater were 0.76 (95% CI, 0.60-0.96), 0.69 (95% CI, 0.53-0.90), and 0.58 (95% CI, 0.41-0.82), respectively (P for trend = .003).

CONCLUSIONS AND RELEVANCE

In this study, even moderate weight loss (ie, >0% to <5%) before bariatric surgery was associated with a lower risk of 30-day mortality. These findings may help inform future updates of clinical guidelines regarding bariatric surgery.

Association between obesity and venous thromboembolism

Background and aims

Obesity is associated with numerous pathological conditions, including venous thromboembolism (VTE). VTE is a multifactorial disease; more than half of the hospitalized patients are at risk for VTE.

We aimed to assess the risk of VTE associated with obesity, taking into account the class of obesity (according to the body mass index), gender, age and the intervention of other acquired risk factors.

Methods

A case-control study including 732 patients was designed. Collected data included: age, gender, body mass index, pregnancy/postpartum state, use of hormonal therapy, personal and family history of VTE, smoking, prolonged immobilization and the presence of comorbidities - acquired risk factors for VTE. The risk of VTE was expressed as odds ratio (OR) with 95% confidence interval. Multiple logistic regression analysis was used to detect the independent risk factors. P value <0.05 was considered significant statistic.

Results

Obesity was associated with a 6.2-fold increased risk for VTE. The risk of VTE associated with obesity was highest in patients aged >50 years and in cases included in classes II and III of obesity. The interaction between obesity and another acquired risk factor has almost doubled the risk of VTE. Multivariate logistic regression analysis showed obesity as an independent risk factor for VTE for both female and male patients.

Conclusions

Obesity is an independent and moderate risk factor for VTE. The risk increases with body mass index, age and the presence of other acquired risk factors.

[Diagnostic and therapeutic management of venous thromboembolic disease in obese patients]

Despite the high proportion of obese patients this population remains understudied in the field of venous thromboembolic disease (VTE). Obesity is a risk factor for pulmonary embolism and/or deep vein thrombosis, especially when it is associated with other risk factors for VTE. Currently there is no validated diagnostic algorithm for VTE in the population of obese patients. Moreover, imaging examinations can be of poor quality and inconclusive. In the prevention of VTE, data concerning obese patients are mainly based on low-level studies. Apart from the context of bariatric surgery, an adjustment of heparin doses according to the weight of the patient is proposed only on a case-by-case basis. According to the current guidelines, therapeutic fixed dose oral anticoagulants should not be prescribed for patients with weights exceeding 120kg or a body mass index>40kg/m². Heparin doses should be weight adjusted and monitored with anti-Xa activity. Anti vitamin K can be prescribed but require INR monitoring. Therefore, new studies specifically dedicated to obese patients are required in the field of VTE for better diagnostic and therapeutic management.

Presentation and Management of Arterial Thromboembolisms during Active Inflammatory Bowel Disease: Case Series and Literature Review

BACKGROUND

Active inflammatory bowel disease (IBD) is associated with considerable risk for thromboembolism; however, arterial thromboembolism is rare and associated with considerable morbidity and mortality. Their management requires careful coordination between multiple providers, and as a consequence, much of the published literature is limited to case reports published across specialties.

METHODS

We examined our recent institutional experience with aortoiliac, mesenteric, and peripheral arterial thromboembolisms in patients with either Crohn's disease or ulcerative colitis. To supplement our experience, a comprehensive literature review was performed using MEDLINE and EMBASE databases from 1966 to 2019. Patient demographics, flare/thromboembolism management, and outcomes were abstracted from the selected articles and our case series.

RESULTS

Fifty-two patients with IBD, who developed an arterial thromboembolism, were identified (49 from published literature and 3 from our institution). More than 82% of patients presented during an active IBD flare. Surgical intervention was attempted in 77% of patients, which included open thromboembolectomy, catheter-directed thrombolysis, or bowel resection. Thromboembolism resolution was achieved in 76% of patients with comparable outcomes with either catheter-directed thrombolysis or open thrombectomy (83.3% vs. 68.2%). Nearly one-third of patients underwent small bowel resection or colectomy. In 2 patients, thromboembolism resolution was achieved only after total abdominal colectomy for severe pancolitis. Multiple thromboembolectomies were associated with higher risk for amputation. Overall mortality was 11.5% but was greatest for occlusive aortoiliac and mesenteric thromboembolism (14.3% and 57%, respectively). All survivors of occlusive superior mesenteric artery thromboembolism suffered short gut syndrome requiring small bowel transplant.

CONCLUSIONS

Patients with IBD, who develop an arterial thromboembolism, can expect overall poor outcomes. Catheter-directed thrombolysis achieved comparable outcomes with open thromboembolectomy without undue bleeding risk. Total abdominal colectomy for moderate-to-severe pancolitis is an emerging strategy in the management of refractory arterial thromboembolism. Successful surgical management may include open thromboembolectomy, catheter-directed thrombolysis, and bowel resection when indicated.

A Case of Bilateral Acute Inferior Limb Ischemia in a Patient With Ulcerative Colitis

A patient was diagnosed with ulcerative colitis (UC) in 2010. In March 2015, she had abdominal pain, diarrhea, bloody stool, and UC has relapsed. In June 2015, pain and sensory disturbance of both lower limbs appeared. Blood flow at the distal femoral artery was not confirmed with magnetic resonance angiography, and it was diagnosed as bilateral acute inferior limb ischemia. Arterial thrombolectomy with Fogarty’s balloon catheter was performed and blood flow was improved. The severity of UC was moderate with Mayo score 8. Thrombosis is considered to be a complication with a high incidence in inflammatory bowel disease. Reports of arterial thrombosis are very rare. It is important to evaluate the risk of bleeding and thrombosis in active or severe cases in UC and need to do thrombotic prophylactic treatment simultaneously with UC treatment.

The gut microbiome and thromboembolism

The gut microbiome plays a critical role in various inflammatory conditions, and its modulation is a potential treatment option for these conditions. The role of the gut microbiome in the pathogenesis of thromboembolism has not been fully elucidated. In this review, we summarize the evidence linking the gut microbiome to the pathogenesis of arterial and venous thrombosis. In a human host, potentially pathogenic bacteria are normal residents of the human gut microbiome, but significantly outnumbered by commensal anaerobic bacteria. Several disease states with an increased risk of venous thromboembolism (VTE) are associated with an imbalance in the gut microbiome characterized by a decrease in commensal anaerobic bacteria and an increase in the abundance of pathogenic bacteria of which the most common is the gram-negative Enterobacteriaceae (ENTERO) family. Bacterial lipopolysaccharides (LPS), the glycolipids found on the outer membrane of gram-negative bacteria, is one of the links between the microbiome and hypercoagulability. LPS binds to toll-like receptors to activate endothelial cells and platelets, leading to activation of the coagulation cascade. Bacteria in the microbiome can also metabolite compounds in the diet to produce important metabolites like trimethylamine-N-oxide (TMAO). TMAO causes platelet hyperreactivity, promotes thrombus formation and is associated with cardiovascular disease. Modulating the gut microbiome to target LPS and TMAO levels may be an innovative approach for decreasing the risk of thrombosis.

Cutaneous manifestations in inflammatory bowel disease (Review)

Inflammatory bowel disease (IBD) is defined as a chronic condition characterized by unpredictable relapsing episodes of gastrointestinal inflammation. IBD is not limited to the gastrointestinal tract and should be considered a systemic disease which can involve any organ. Cutaneous manifestations in IBD are frequent and comprise a broad spectrum of diseases, ranging from mild to severe and sometimes debilitating lesions. Some of the cutaneous manifestations can present signs of an underlying intestinal disease, leading to the screening for non-detected IBD even in the absence of symptoms. Cutaneous EIMs are divided into 4 categories: i) Disease-specific lesions that show the same histopathologic findings as the underlying gastrointestinal disease, ii) reactive lesions which are inflammatory lesions that share a common pathogenetic mechanism but do not share the same pathology with the gastrointestinal disease, iii) associated conditions are more frequently observed in the context of IBD, without sharing the pathogenetic mechanism or the histopathological findings with the underlying disease and iv) drug-related skin reactions.

By word of mouse: using animal models in venous thrombosis research

Deep vein thrombosis (DVT) is a disease with high prevalence and morbidity. It can lead to pulmonary embolism with severe respiratory insufficiency and risk of death. Mechanisms behind all stages of DVT, such as thrombosis commencement, propagation, and resolution, remain incompletely understood. Animal models represent an invaluable tool to explore these problems and identify new targets for DVT prevention and treatment. In this review, we discuss existing models of venous thrombosis, their advantages and disadvantages, and applicability to studying different aspects of DVT pathophysiology. We also speculate about requirements for an "ideal model" that would best recapitulate features of human DVT and discuss readouts of various models.

Current knowledge in pathophysiology and management of Budd-Chiari syndrome and non-cirrhotic non-tumoral splanchnic vein thrombosis

Budd-Chiari syndrome and non-cirrhotic non-tumoral portal vein thrombosis are 2 rare disorders, with several similarities that are categorized under the term splanchnic vein thrombosis. Both disorders are frequently associated with an underlying prothrombotic disorder. They can cause severe portal hypertension and usually affect young patients, negatively influencing life expectancy when the diagnosis and treatment are not performed at an early stage. Yet, they have specific features that require individual consideration. The current review will focus on the available knowledge on pathophysiology, diagnosis and management of both entities.

Obesity Is Independently Associated With Higher Annual Burden and Costs of Hospitalization in Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Approximately 15%-40% patients with inflammatory bowel diseases (IBD) are obese. There is an inconsistent association between obesity and IBD phenotype and course. We conducted a nationally representative cohort study to estimate and compare the burden, costs, and causes for hospitalization in obese vs non-obese patients with IBD.

METHODS

Using the Nationwide Readmissions Database 2013, we identified obese (based on administrative claims code) and non-obese patients who had been hospitalized at least once, from January through June 2013, and followed them for re-hospitalization until December 2013. We compared annual burden (total days spent in hospital), costs, causes, and outcomes of hospitalization between obese and non-obese patients after 1:1 propensity score matching.

RESULTS

We identified 42,285 patients with IBD, of which 12.4% were obese. After propensity score matching, we included 5128 obese and 5128 non-obese IBD patients in our analysis. Compared to non-obese patients, obese patients spent more days in hospital annually (median, 8 vs 5 days) (P < .01), with higher hospitalization-related costs (median, $17,277 vs $11,847) (P < .01); this pattern persisted in subsets of high-need and high-cost patients. Compared to non-obese patients, obese patients were more likely to be hospitalized with preventable admissions (19% vs 15%) or cardiopulmonary complications (16% vs 12%).

CONCLUSIONS

In an analysis of data on patients with IBD from the Nationwide Readmissions Database 2013, we found obesity to be independently associated with higher burden and costs of hospitalizations. Strategies should be considered to target obesity as adjunctive therapy for patients with IBD.

In silico thrombin generation: Plasma composition imbalance and mortality in human immunodeficiency virus

Background

Effective HIV treatment with antiretroviral therapy has prolonged survival and shifted causes of death to non-AIDS illnesses such as cardiovascular disease. We have shown that inflammation and HIV viral load associate with pro- and anticoagulant factor imbalances resulting in increased thrombin generation when mathematically modeled. We explore the hypothesis that factor compositional imbalance, corresponding to increased in silico thrombin generation, predicts mortality among HIV+ persons.

Methods

In a nested case-control study of HIV+ individuals on continuous antiretroviral therapy in two large trials, we evaluated cases (any non-violent mortality, n = 114) and matched controls (n = 318). Thrombin generation in response to a tissue-factor initiator for each individual was calculated by a mathematical model incorporating levels of factors (F)II, V, VII, VIII, IX, X, antithrombin, tissue factor pathway inhibitor, and protein C (PC) measured at study entry to the trials. In silico thrombin generation metrics included clot time, maximum rate (MaxR), maximum level (MaxL), and area under the curve (AUC).

Results

Levels of antithrombin and PC decreased, while FV and FVIII were higher in cases vs controls. This resulted in a more procoagulant phenotype with increased MaxR, MaxL, and AUC in cases compared to controls (P < 0.05 for all).

Conclusions

Antithrombin, FV, FVIII, and PC were the major contributors to the increased thrombin generation associated with mortality risk. Our results suggest that mortality in HIV is associated with an increase in in silico thrombin generation via altered balance of pro- and anticoagulant factors, likely due to an inflammatory response signal, and resulting coagulopathy.

Catheter-Related Venous Thrombosis in Hospitalized Pediatric Patients with Inflammatory Bowel Disease: Incidence, Characteristics, and Role of Anticoagulant Thromboprophylaxis with Enoxaparin

OBJECTIVE

To describe the incidence and characteristics of central venous catheter (CVC)-related thrombosis in hospitalized pediatric patients with active inflammatory bowel disease (IBD) and report the potential usefulness of anticoagulant thromboprophylaxis (AT).

STUDY DESIGN

We conducted a retrospective study of patients who were admitted to our children's hospital in the last 2 years with active IBD and required a CVC and identified all patients with an objectively confirmed symptomatic CVC-related thrombosis. To assess the usefulness of a recently implemented institutional AT protocol, we compared the frequency of CVC-related thrombosis, nadir hemoglobin, and red blood cell transfusion requirements in patients who received AT with those who did not during the study period.

RESULTS

A total of 40 patients with IBD who required 47 consecutive hospitalizations were included. AT was administered during 24 of 47 hospitalizations (51%). Patients who received AT were similar to those who did not receive AT with regard to demographics, IBD phenotypes, extent of colonic involvement, and thrombotic risk factors. CVC-related thrombosis occurred in 5 of 23 hospitalizations (22%) in which AT was withheld compared with 0 of 24 hospitalizations (0%) in which patients received AT (P = .02). The red blood cell transfusion requirements and nadir hemoglobin were not significantly different between the 2 groups.

CONCLUSIONS

We observed a high incidence of CVC-related thrombosis in hospitalized children with IBD. Administration of AT in our population was associated with significant reduction in CVC-related thrombosis without evidence of increased bleeding.

The Role of Inflammation in Venous Thromboembolism

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT), and pulmonary embolism (PE), is becoming increasingly recognized as a cause of morbidity and mortality in pediatrics, particularly among hospitalized children. Furthermore, evidence is accumulating that suggests the inflammatory response may be a cause, as well as consequence, of VTE, but current anticoagulation treatment regimens are not designed to inhibit inflammation. In fact, many established clinical VTE risk factors such as surgery, obesity, cystic fibrosis, sepsis, systemic infection, cancer, inflammatory bowel disease, and lupus likely modulate thrombosis through inflammatory mediators. Unlike other traumatic mechanisms of thrombosis involving vascular transection and subsequent exposure of subendothelial collagen and other procoagulant extracellular matrix materials, inflammation of the vessel wall may initiate thrombosis on an intact vein. Activation of endothelial cells, platelets, and leukocytes with subsequent formation of microparticles can trigger the coagulation system through the induction of tissue factor (TF). Identification of biomarkers to evaluate VTE risk could be of great use to the clinician caring for a patient with inflammatory disease to guide decisions regarding the risk:benefit ratio of various types of potential thromboprophylaxis strategies, or suggest a role for anti-inflammatory therapy. Unfortunately, no such validated inflammatory scoring system yet exists, though research in this area is ongoing. Elevation of C-reactive protein, IL-6, IL-8, and TNF-alpha during a response to systemic inflammation have been associated with increased VTE risk. Consequent platelet activation enhances the prothrombotic state, leading to VTE development, particularly in patients with other risk factors, most notably central venous catheters.

Involvement of inflammatory markers in pathogenesis of venous thromboembolism

Inflammation of the venous wall is involved in thrombogenesis, thrombus resolution, wall remodeling and the post-thrombotic syndrome. Different mechanisms are involved in both arterial and venous thrombosis and patients with atherothrombosis hold a higher risk of venous thrombosis. Although inflammation may represent the connection between arterial and venous thrombosis, it is not yet sure if it is the cause or consequence of venous thrombosis. Consequently, the relationships between inflammation markers as indicators of the inflammatory process and clinical venous thromboembolism need to be investigatd. For example, inflammation mediators such as the pro-inflammatory cytokines interleukin 8 (IL-8), IL-6, monocyte chemotactic protein 1 (MCP-1), C Reactive Protein (CRP), vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), matrix metalloproteinases and tumor necrosis factor alpha (TNF alpha) are all involved in thrombogenesis. Studies of venous thromboembolism on animal models proved that there are specific phases of the inflammatory process in venous thromboembolism and thrombus resolution. Knowing the molecular and immunologic mechanisms, identifying and understanding the inflammation markers which are relevant for venous thrombosis, can help to target specific pathways and to develop future therapies of this disease

D-Dimer levels are correlated with disease activity in Crohn's patients

Various indices have been used to assess Crohn's disease (CD). However, the question of whether the Crohn's Disease Activity Index (CDAI) is associated with coagulation function has not been fully confirmed. In this study, we examined the association between CDAI and the coagulation and fibrinolysis parameters. In a retrospective and observational cohort study, the CDAI of 108 patients from two hospital centers was calculated, and its correlations with the prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), international normalization ratio (INR), fibrinogen (Fg) and plasma D-Dimer were investigated. Significant differences were found for PT, APTT, TT, INR, Fg and D-Dimer between the healthy controls and CD patients. However, no significant difference was found between the CDAI-High and CDAI-Low groups of CD patients. Moreover, the CDAI was positively correlated with the level of D-Dimer in CD patients of two hospitals, regardless of the detection method (hospital 1: r=0.3268, p= 0.0042; hospital 2: r=0.5553, p=0.0008). Among the blood coagulation and fibrinolysis parameters, the D-Dimer level was highly correlated with CDAI in CD patients. Thus, the level of D-Dimer expression may be a promising new marker for assessing CD disease activity.

Fatal pulmonary embolism following splenectomy in a patient with Evan's syndrome: case report and review of the literature

Background

Evans syndrome (ES) is a rare disease characterized by simultaneous or sequential development of autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP) with or without immune neutropenia. Splenectomy is one of the treatment options for disease refractory to medical therapy. Venous thromboembolism (VTE) following splenectomy for hematological diseases has an incidence of 10%.

Case presentation

Here we describe a case report of a young patient hospitalized with severe hemolytic anemia with Hgb 4.8 g/dl. He developed thrombocytopenia with platelet nadir of 52,000/mm³, thus formally diagnosed with ES. He failed standard medical therapy. He underwent splenectomy and had a fatal outcome. Autopsy confirmed the cause of death as pulmonary embolism (PE).

Conclusions

This case report and review of the literature highlight important aspects of the association between VTE, splenectomy, and hemolytic syndromes including the presence of thrombocytopenia. The burden of the disease is reviewed as well as various pathophysiologic mechanisms contributing to thromboembolic events in these patients and current perioperative prophylactic anticoagulation strategies. Despite an advancing body of literature increasing awareness of VTE following splenectomy, morbidity and mortality remains high. Identifying high risk individuals for thromboembolic complications from splenectomy remains a challenge. There are no consensus guidelines for proper perioperative and post-operative anti-coagulation. We encourage future research to determine which factors might be playing a role in increasing the risk for VTE in real time with hope of forming a consensus to guide management.

ADAMTS13 Deficiency Worsens Colitis and Exogenous ADAMTS13 Administration Decreases Colitis Severity in Mice

Background  Inflammatory bowel disease (IBD) affects 1.6 million people in the United States. IBD is associated with an increased risk of thrombosis, which rises with disease activity. The pathogenesis of IBD and its increased thrombotic risk is not completely understood. Ultra large von Willebrand factor (ULVWF) multimers are secreted from activated endothelium, leading to recruitment of platelets and leukocytes. A disintegrin and metalloproteinase with thrombospondin type I repeats motif 13 (ADAMTS13) cleaves highly adhesive ULVWF into smaller, less bioactive, multimers, releasing them into circulation. Mice deficient in ADAMTS13 (ADAMTS13 ^−/− ) have heightened inflammatory and thrombotic responses.

Objectives  We hypothesized that upon colitis induction, ADAMTS13 ^−/− mice would have more severe symptoms compared with wild-type (WT) mice, and rhADAMTS13 administration to mice with colitis would improve their condition.

Results  Dextran sodium sulfate–induced colitis was worse in ADAMTS13 ^−/− mice than WT. ADAMTS13 ^−/− showed increased weight loss, worse anemia, and increased clinical and histologic colitis severity, compared with WT mice. ADAMTS13 ^−/− mice had increased VWF release, with accumulation at inflamed colonic sites. Also, the majority of mice showed one or more submucosal colonic thrombi. ADAMTS13 deficiency worsened colitis and propagated intestinal inflammation, most likely through increased platelet–leukocyte recruitment by VWF. Treatment of WT mice with rhADAMTS13 decreased colitis severity without worsening anemia. Additionally, several immune-mediated chronic murine colitis models, and inflamed colon tissue specimens from IBD patients, showed increased VWF release at inflamed sites, suggesting a generalizability of our findings.

Conclusion  Measuring VWF/ADAMTS13 levels could have clinical utility. When applicable, the administration of ADAMTS13, in addition to primary treatment, may improve outcomes for IBD patients.