Is LMWH Sufficient for Anticoagulant Prophylaxis in Bariatric Surgery? Prospective Study

Five-Year Analysis of the MBSAQIP Database: Are We Getting Better?

BACKGROUND

The MBSAQIP has been used to evaluate risk and create risk models. Previous studies have determined what complications matter most.

STUDY DESIGN

This study was a registry-based analysis of patients who underwent laparoscopic Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) between January 1, 2015, and December 31, 2019, at centers participating in MBSAQIP. Cases were identified using Current Procedural Terminology. Patients less than 18 years old were excluded. A chi-square test was used to assess differences in the prevalence of complications and effects across years. Using a multivariable Poisson regression model with a link log and robust estimation, prevalence ratio estimates and 95% CI were obtained.

RESULTS

A total of 690,770 observations met the inclusion criteria. Mean (SD) age was 44.5 (±12.0) years, and mean (SD) BMI was 45.2 kg/m2 (±7.9). SG cases accounted for 73.45% of all observations. There was a significant relative reduction in readmissions, end-organ dysfunction, and all-cause mortality from 2015 to 2019 in the SG subgroup. There were also noticeable reductions in 30-day readmission, ICU admission, and end-organ dysfunction in the RYGB subgroup. For complications, bleeding, postoperative pneumonia, and stroke were significantly decreased in the RYGB subgroup, but only bleeding was significantly decreased in the SG subgroup during the 5-year study period.

CONCLUSIONS

There has been a continuous improvement in several (but not all) outcomes through the years that the MBSAQIP has been collecting data. Different outcomes were reduced between the SG and RYGB subgroups, and the decrease in all-cause mortality was only noted in the SG subgroup.

Thromboelastography-Based Profiling of Coagulation Status in Patients Undergoing Bariatric Surgery: Analysis of 422 Patients

INTRODUCTION/PURPOSE

Some clinical indicators suggest hypercoagulability/hyperaggregability in patients with morbid obesity. Thromboelastography (TEG®) has been used to profile coagulation status in surgical patients. We aimed to assess coagulation profiles in patients with morbid obesity undergoing bariatric surgery by correlating demographic and patient characteristics to pre-operative TEG® values.

MATERIALS AND METHODS

Pre-operative TEG® values from 422 patients undergoing bariatric surgery were evaluated. TEG® results were analyzed by gender, use of medications known to alter the coagulation profile, and body mass index (BMI).

RESULTS

Patients have a mean of 45.03 ± 11.8 years, female (76.3%), and with a mean BMI of 42 kg/m ¹. The overall coagulation profile of female patients was significantly different from males, even in the sub-cohort without use of medications known to alter coagulation. The majority of patients (94%) with a G value > 15 dynes/cm ¹ (clot strength) were female. In females, there was no association between BMI and TEG® values; however, in men, there was a statistically significant difference in TEG® values for those with BMI < 40 kg/m ¹ compared to those with BMI > 50 kg/m².

CONCLUSIONS

TEG®-based analysis of coagulation profiles offers unique insights. Compared to laboratory normal values (R time, angle, maximal amplitude, and G values), patients with morbid obesity may have a tendency for hypercoagulability/hyperaggregability, with mean values at the higher limit. A significant hypercoagulable difference in TEG® values was identified in female as compared to male patients. Male patients with a BMI greater than 50 kg/m² were also found to be increasingly hypercoagulable.

The Obese Patient: Facts, Fables, and Best Practices

The prevalence of obesity continues to rise worldwide, and anesthesiologists must be aware of current best practices in the perioperative management of the patient with obesity. Obesity alters anatomy and physiology, which complicates the evaluation and management of obese patients in the perioperative setting. Gastric point-of-care ultrasound (PoCUS) is a noninvasive tool that can be used to assess aspiration risk in the obese patient by evaluating the quantity and quality of gastric contents. An important perioperative goal is adequate end-organ perfusion. Standard noninvasive blood pressure (NIBP) is our best available routine surrogate measurement, but is vulnerable to greater inaccuracy in patients with obesity compared to the nonobese population. Current NIBP methodologies are discussed. Obese patients are at risk for wound and surgical site infections, but few studies conclusively guide the exact dosing of intraoperative prophylactic antibiotics for them. We review evidence for low-molecular-weight heparins and weight-based versus nonweight-based administration of vasoactive medications. Finally, intubation and extubation of the patient with obesity can be complicated, and evidence-based strategies are discussed to mitigate danger during intubation and extubation.

Missing something? A scoping review of venous thromboembolic events and their associations with bariatric surgery. Refining the evidence base

Background

Venous thromboembolic events (VTE) post-bariatric surgery (BS) lead to morbidity and mortality.

Methods

This scoping review assessed whether reported VTE post-BS could be under/over-estimated; suggested a possible number of VTE post-BS; appraised whether VTE are likely to decrease/increase; examined BS as risk/protective factor for VTE; and mapped the gaps, proposing potential solutions.

Results

VTE appears under-estimated due to: identification/coding of BS and VTE; reporting of exposure (BS); and reporting of outcomes (VTE). The review proposes a hypothetical calculation of VTE post-BS. VTE are unlikely to decrease soon. BS represents risk and protection for VTE. Better appreciation of VTE-BS relationships requires longer-term strategies.

Conclusion

VTE are underestimated. Actions are required for understanding the VTE-BS relationships to in order to crease VTE by better-informed prevention strategy/ies.

The role of bariatric surgery in normalization of the coagulation profiles

BACKGROUND

Bariatric surgery achieves appropriate excess weight loss, controlling related co-morbidities, including coagulation abnormalities.

OBJECTIVE

We investigated the change in the coagulation profile after postoperative weight stabilization, correlating between EWL ratio and change in the coagulation profile.

SETTING

This study took place in our teaching institution (university setting).

METHODS

Between the years 2012 and 2014, 67 patients underwent surgery; 47 patients underwent laparoscopic sleeve gastrectomy (SG) and 20 patients underwent Roux-en-Y gastric bypass (RYGB). Average follow-up of postoperative thromboelastography (TEG) parameters was 30 ± 10.8 months (12-77). Average body mass index (BMI) before surgery was 41.7 ± 4.6kg/m², average percentage of EWL at the time of data collection was 79%. Patients were divided into 3 groups, 6 patients had EWL < 50%, 13 had an EWL > 100%, and 48 had EWL between 50% and 100%.

EXCLUSION CRITERIA

use of anticoagulation, antiplatelet, or contraceptive medications; known thrombophilic, renal, hepatic, and hematologic diseases/disorders. Two follow-up groups: 1-2 years and over 2 years. Patients underwent pre and postoperative TEG coagulation studies, including maximal amplitude (MA), and clot strength (G).

RESULTS

Coagulation profile improved after bariatric surgery. Most prominent change seen in MA and G. There was a linear correlation between the EWL ratio and improvement of MA values starting at 50% EWL peaking at 60%-70%. There was no difference in the coagulation profile after surgery in the two surgery groups (SG and RYGB).

CONCLUSIONS

Achieving appropriate weight loss after bariatric surgery improves the coagulation profile as measured by TEG, probably decreasing thromboembolic risk in those patients. We recommend expanding the current indication for bariatric surgery to include patients with altered coagulation profile measured by TEG.

Venous thromboembolic events after bariatric surgery: Protocol for a systematic review and meta-analysis

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Venous Thromboembolic Events after Bariatric Surgery.

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This protocol undertakes a systematic review and metanalysis of venous thromboembolic events after bariatric surgery.

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Methodology, searches, eligibility, and data extraction for analysis are described.

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Following the PRISMA guidelines, it describes the approach for pooled estimates.

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Findings will have key clinical consequences for patient care.

Introduction

Considerably large numbers of bariatric surgery (BS) procedures are undertaken globally, and are projected to increase with the obesity epidemic. Venous thromboembolic events (VTE) comprise an important cause of postoperative morbidity and mortality after BS and an important issue with wide clinical and financial repercussions. Yet, a precise extent of the prevalence of VTE after BS for obesity and its mortality remains uncertain.

Methods and analysis

In order to respond to this knowledge gap, we will conduct a systematic review and meta-analysis of the prevalence of and mortality associated with VTE after BS. This protocol outlines the methodology that will be used and the search strategies and eligibility criteria that will be utilized to identify and select studies, as well as the method by which data from the selected studies will be extracted for analysis. PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), WHO International Clinical Trials Registry Platform, Cochrane Library, MEDLINE, Scopus, clinicaltrials.gov and Google scholar will be searched from 01 January 1990 through 10th April 2020, for original studies written in English that provided prevalence estimates of VTE after BS. Articles will also be searched for mortality estimates of VTE after BS. STROCSS (Strengthening the Reporting of Cohort Studies in Surgery) criteria will evaluate the methodological quality of the selected studies. The use of fixed effect or random effects model will be subject to the findings of the statistical tests for heterogeneity. Publication bias will be visually estimated by inspecting the funnel plots. Pooled estimates will be computed. Th current protocol conforms to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines and has been submitted to the PROSPERO International Prospective Register of systematic reviews. No ethical clearance is required for this study. This systematic review and meta-analysis will be published in a peer-reviewed journal and presented at national and international conferences.

Four-Year Evolution of a Thrombophylaxis Protocol in an Enhanced Recovery After Surgery (ERAS) Program: Recent Results in 485 Patients

“Enhanced recovery after surgery” (ERAS) protocols may reduce morbidity, length of hospital stay (LOS), and costs. During the 4-year evolution of a bariatric ERAS protocol, we found that administration of thrombophylaxis selectively to high-risk morbidly obese patients (assessed postoperatively by Caprini score ≥ 3) undergoing omega loop gastric bypass (“mini” gastric bypass) or sleeve gastrectomy resulted in safe outcomes. Both procedures proved equally effective with this protocol. The vast majority of rapidly mobilized, low-risk patients did not appear to require antithrombotic heparin. Similar to other reported ERAS outcomes, our recent year’s results in 485 patients included a mean LOS of 1.08 ± 0.64 days (range 1–14), with 460 (95.0%) discharged on day 1 and 99.6% by day 2. There were 13 30-day complications (2.7%), two reinterventions (0.4%), and no hemorrhages.