The American Society for Metabolic and Bariatric Surgery (ASMBS) updated position statement on perioperative venous thromboembolism prophylaxis in bariatric surgery

The pharmacist's role in optimizing medication management before, during, and after minimally invasive and bariatric surgery

PURPOSE

Minimally invasive surgery (MIS) with integrated enhanced recovery pathways (ERPs) helps reduce length of stay and improve surgical outcomes. As these procedures have become more prevalent over time, pharmacists are in key positions to manage medications in the perioperative space to help optimize transitions of care and reduce safety events. Here we identify several clinical areas across phases of care for these procedures in which the knowledge and guidance of pharmacists, as members of the interprofessional team, are paramount.

SUMMARY

Perioperative pharmacy expertise is often required for MIS procedures in the areas of acid suppression, antithrombotic management, blood glucose control, drug formulation, immunosuppressant optimization, pain mitigation, and postoperative nausea and vomiting prevention and treatment. For each MIS procedure, pharmacists should identify and consider diet and anatomical changes as well as patient- and surgery-specific risk factors. Pharmacists can then utilize their knowledge of the pharmacokinetics and pharmacodynamics of individual medications along with evidence-based medicine to recommend selection of appropriate agents.

CONCLUSION

Pharmacist contributions to perioperative medication management for MIS procedures can improve care as surgical patients navigate transitions through the perioperative setting. Pharmacists can further incorporate medication expertise through development and implementation of institutional MIS protocols within the context of ERPs. As such, any pharmacist should feel empowered to aid in the care of surgical patients.

County health ranking: untangling social determinants of health and other factors associated with short-term bariatric surgery outcomes

BACKGROUND

The complex interplay of the social determinants of health, race/ethnicity, and traditional surgical risk factors on outcomes following metabolic surgery is poorly understood.

OBJECTIVE

To evaluate the relationship between the social determinants of health as measured by county health ranking (CHR) and short-term metabolic surgery outcomes.

SETTING

Five accredited bariatric program sites at a national academic health system.

METHODS

Data were collected from 5 sites of a single health system from 2010 to 2021. Current procedural terminology codes identified primary and revisional cases. Patient characteristics, procedural data, and 30-day occurrences were collected. CHRs for health factors were determined by ZIP Code and stratified into best, middle, and worst terciles. The primary outcome was 30-day complications, readmissions, or reinterventions/reoperations. Logistic regression assessed the correlation between CHR tercile and morbidity.

RESULTS

We analyzed 4,315 primary and 370 revisional metabolic surgery cases. Overall, 64.0%, 27.4%, and 8.6% of patients lived in the best, middle, and worst CHR terciles, respectively. Patients in the middle and worst CHR terciles were more commonly older; non-Hispanic Black or Hispanic; suffered from preexisting chronic obstructive pulmonary disease or hypertension, were dialysis dependence, were on therapeutic anticoagulation, or had inferior vena cava filters. Middle and worst CHR tercile patients were more likely to undergo index sleeve gastrectomy or robotic-assisted surgery and have surgery performed by a self-designated general surgeon. Thirty-day outcomes were similar across CHR terciles. Racial disparity in multiple short-term outcomes persisted despite adjustment for CHR tercile.

CONCLUSION

Higher-risk patients are more likely to be from counties with lower CHRs, but CHR was not independently associated with 30-day outcomes after metabolic surgery.

American society for metabolic and bariatric surgery: intra-operative care pathway for minimally invasive Roux-en-Y gastric bypass

BACKGROUND

Clinical care pathways help guide and provide structure to clinicians and providers to improve healthcare delivery and quality. The Quality Improvement and Patient Safety Committee (QIPS) of the American Society for Metabolic and Bariatric Surgery (ASMBS) has previously published care pathways for the performance of laparoscopic sleeve gastrectomy (LSG) and pre-operative care of patients undergoing Roux-en-Y gastric bypass (RYGB).

OBJECTIVE

This current RYGB care pathway was created to address intraoperative care, defined as care occurring on the day of surgery from the preoperative holding area, through the operating room, and into the postanesthesia care unit (PACU).

METHODS

PubMed queries were performed from January 2001 to December 2019 and reviewed according to Level of Evidence regarding specific key questions developed by the committee.

RESULTS

Evidence-based recommendations are made for care of patients undergoing RYGB including the pre-operative holding area, intra-operative management and performance of RYGB, and concurrent procedures.

CONCLUSIONS

This document may provide guidance based on recent evidence to bariatric surgeons and providers for the intra-operative care for minimally invasive RYGB.

Bariatric Surgery: Current Trends and Newer Surgeries

Bariatric surgery has evolved and gained in popularity as it has been recognized as the most sustainable and effective treatment for obesity and related diseases. These related diseases are significant causes of obesity related morbidity and mortality. Most bariatric procedures incorporate some component of gastric restriction with or without intestinal bypass, but the full mechanism of these procedures has yet to be elucidated. The most popular surgical procedure remains the sleeve gastrectomy over the last 10 years, while gastric bypass is also still commonly performed. We have also seen growth in revisional bariatric surgery and novel surgical procedures.

Association between bariatric surgery preoperative chemoprophylaxis and postoperative bleeding

BACKGROUND

Use of chemoprophylaxis for prevention of venous thromboembolism (VTE) after bariatric surgery is a generally accepted principle; however, the optimal strategy in terms of medication type and pre- and postoperative dosing is uncertain. In our healthcare system, four hospitals performed bariatric surgery and utilized differing protocols for VTE prophylaxis. The analysis sought to evaluate the association of differing prophylaxis strategies on bleeding and VTE occurrence.

METHODS

Adult patients who underwent laparoscopic sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) from 2018 to 2021 at four hospitals were studied. Patients were grouped by whether or not they received preoperative chemoprophylaxis. The primary outcome was postoperative bleeding, defined as requiring a blood transfusion or reoperation for bleeding within 30 days. Bivariate analyses were performed with Chi-square and Wilcoxon Rank tests where applicable. Multivariate logistic regression was performed for the outcome of postoperative bleeding.

RESULTS

A total of 2145 bariatric surgeries were evaluated (33.6% RYGB, 66.4% SG). Among 1712 patients who underwent surgery at Hospitals A, B, and C, 93.1% received preoperative VTE prophylaxis, compared with 1 patient (0.1%) among 433 patients operated on at Hospital D. Postoperative bleeding occurred more frequently in patients who received preoperative VTE prophylaxis versus those who did not (3.7% vs 1.1%; p < 0.01). After multivariable regression analysis, only RYGB (OR 3.59; p < 0.01) and preoperative VTE prophylaxis (OR 3.54; p = 0.02) were significantly associated with postoperative bleeding. Rates of VTE for patients receiving preoperative VTE prophylaxis or no prophylaxis were not significantly different (0.6% vs. 0.2%; p = 0.26).

DISCUSSION

Preoperative VTE prophylaxis prior to bariatric surgery was associated with postoperative bleeding without differences in VTE occurrence. These results call into question the routine use of VTE chemoprophylaxis for all patients undergoing bariatric surgery and favor selective usage.

Early postoperative COVID infection is associated with significantly increased risk of venous thromboembolism after metabolic and bariatric surgery

BACKGROUND

Patients who undergo metabolic and bariatric surgery (MBS) are at risk for thromboembolism. Patients are susceptible to coronavirus throughout the perioperative period, which also has a well-known association with thrombotic complications.

OBJECTIVES

To identify and define the association between venous thromboembolism (VTE) and postoperative coronavirus diagnosis in bariatric surgery patients.

SETTING

United States.

METHODS

We conducted a retrospective cohort study using the MBS Accreditation and Quality Improvement Program (MBSAQIP) 2021 database to analyze the incidence of VTE within 30 days of surgery. VTE was a composite variable defined as either postoperative pulmonary embolism or postoperative venous thrombus requiring treatment. Cohorts were stratified by whether the patient was diagnosed with postoperative coronavirus. We created a multivariable logistic regression model to determine the adjusted odds of postoperative VTE based on various factors. Additionally, we conducted subset analyses of sleeve gastrectomy and Roux-en-Y bypass cases, the 2 most frequent bariatric operations in the United States.

RESULTS

Patients diagnosed with postoperative coronavirus were significantly more likely to develop postoperative VTE (1.1% versus .3%, P < .001). In our logistic regression model, the adjusted odds of postoperative VTE for patients with postoperative coronavirus was 3.55 (95% CI: 2.15-5.87, P < .001). For patients who underwent Roux-en-Y bypass, the adjusted odds was even greater at 5.69 (95% CI: 2.76-11.70, P < .001).

CONCLUSIONS

Early postoperative coronavirus infection after MBS is associated with higher odds of postoperative VTE. This persisted on subset analyses of the 2 most common procedures and appeared particularly important for Roux-en-Y bypass. COVID infection after MBS may warrant prolonged VTE prophylaxis.

Cardiovascular disease among bariatric surgery candidates: coronary artery screening and the impact of metabolic syndrome

BACKGROUND

Obesity is known as a risk factor for cardiovascular disease (CVD). However, there is an absence of preoperative cardiac risk assessment in bariatric surgery candidates and the incidence of CVD among these high-risk patients is still unknown.

METHODS

A consecutive series of bariatric surgery candidates at two Chinese tertiary hospitals received coronary CT angiography or coronary angiography from 2017 to 2023. Patients were categorized as metabolically unhealthy obesity (MUO) and metabolically healthy obesity (MHO) based on the presence or absence of MetS. CVD was diagnosed based on the maximum intraluminal stenosis > 1% in any of the segments of the major epicardial coronary arteries. Obstructive CVD was defined as coronary stenosis ≥ 50%. Binary multivariable logistic regression was performed to analyze the association between CVD and metabolic status. The number of principal MetS components was categorized into zero (without glycemic, lipid, and BP components), one (with one of the components), two (with any two components), and three (with all components) to explore their association with CVD.

RESULTS

A total of 1446 patients were included in the study. The incidence of CVD and obstructive CVD were 31.7% and 9.6%. Compared with MHO patients, MUO patients had a significantly higher incidence of mild (13.7% vs. 6.1%, P < 0.05), moderate (7.4% vs. 0.8%, P < 0.05), and severe CVD (3.1% vs. 0%, P < 0.05). Following complete adjustment, compared with zero or one component, two principal MetS components was found to be associated with a notable increase in the risk of CVD (OR 2.05, 95% CI 1.18-3.58, P < 0.05); three principal MetS components were observed to have a higher risk of CVD and obstructive CVD (OR 2.68, 95% CI 1.56-4.62, P < 0.001; OR 3.93, 95% CI 1.19-12.93, P < 0.05). Each increase in the number of principal MetS components correlated with a 1.47-fold (95% CI 1.20-1.81, P < 0.001) and 1.78-fold (95% CI 1.24-2.55, P < 0.05) higher risk of CVD and obstructive CVD, respectively.

CONCLUSION

This study reported the incidence of CVD based on multicenter bariatric surgery cohorts. CVD is highly prevalent in patients with obesity, especially in MUO patients. Increased number of principal MetS components will significantly elevate the risk of CVD.

Thromboelastography with Platelet Mapping Identifies High Platelet Reactivity is Associated with Obesity, Diabetes, and Thrombotic Events

BACKGROUND

Metabolic comorbidities such as diabetes and obesity are considered pro-inflammatory states which theoretically increase the risk of perioperative thrombotic events across many surgical disciplines. Currently, there is a paucity of objective metrics to determine such risk and ideal pharmacologic targets. Thromboelastography with Platelet Mapping (TEG-PM) provides a comprehensive profile of coagulation and may provide insight into clot dysregulation.

METHODS

Patients undergoing lower extremity revascularization underwent serial TEG-PM analysis. The relationship between the TEG-PM metrics and thrombosis was evaluated. Preoperative TEG-PM samples of patients with body mass index (BMI)≥25 were compared to those of patients with a normal BMI, and between patients with diabetes mellitus (DM) and those without.

RESULTS

218 TEG-PM samples from 202 patients were analyzed. The BMI≥25 cohort showed significantly greater platelet aggregation [81.9% (±20.9) vs. 68.6% (±27.7), P < 0.01]. Patients with DM were more frequently on full-dose anticoagulation [47.7% vs. 29.7% P = 0.01] yet demonstrated increased clot strength, or adenosine diphosphate (ADP)-Maximum Clot Amplitude (MA) [49.1 (±16.1) vs. 41.5 (±17.1) and 37.7 (±19.6) vs. 31.6 (±17.4) P < 0.01]. 49 patients experienced thrombosis and exhibited greater platelet aggregation [76.6% (±17.8) vs. 66.8% (±30.4) P = 0.03] and greater ADP/arachidonic acid MA [47.1 (±16.6) vs. 41.9 (±18.8) and 38.2 (±17.8) vs. 32.5 (±19.9) both P = 0.05]. Patients who thrombosed were more often diabetic [69.5% versus 51.0% P = 0.03] and on full-dose anticoagulation [75.0% vs. 56.8% P = 0.02].

CONCLUSIONS

Patients with a BMI≥ 25 and those with diabetes demonstrated TEG-PM profiles similar to patients with thrombosis. Diabetes was independently associated with thrombosis, and full-dose anticoagulation was not protective. This suggests the potential utility of TEG-PM for thrombotic risk stratification based on metabolic factors and suggests antiplatelet agents may be effective at prevention of thrombotic events in this population.

Laparoscopic Sleeve Gastrectomy as a First Step Procedure for Oncologic Purposes: An Indication Beyond the Updated Guidelines

BACKGROUND

Obesity is a well-established risk factor for cancer. Laparoscopic sleeve gastrectomy (LSG) is established as a safe procedure providing accelerated weight loss and comorbidity improvement or remission. Additionally, it is approved as a bridging procedure for various non-oncologic surgeries, with very limited data for oncologic procedures. The aim of this study is to present a series of patients with severe obesity and concomitant cancer who underwent LSG prior to definitive oncological procedure.

METHODS

A retrospective review (2008-2023) was conducted in three institutions, identifying 5 patients with cancer and severe obesity who underwent LSG as bridging procedure. Variables analyzed were initial weight, initial body mass index (BMI), type of malignancy, comorbidities, interval between LSG and oncological surgery, weight and BMI before the second intervention, percentage of excess weight loss (%EWL), and postoperative morbidity and mortality.

RESULTS

Malignancies identified were 2 prostate cancers, 1 periampullary neuroendocrine tumor, 1 rectal cancer, and 1 renal clear cell carcinoma. Mean age of patients was 50.2 years, mean initial BMI 47.4 kg/m 2 , and mean BMI before oncological surgery 37 kg/m 2 . Mean time interval between LSG and oncological surgery was 8.3 months. Mean %EWL achieved was 45.2%. Two thromboembolic events were encountered after LSG, while none of the patients developed complications after definitive oncological treatment. The mean follow-up after oncological surgery was 61.6 months.

CONCLUSION

LSG can be proposed as bridging procedure before oncological surgery in meticulously selected patients. Achieved weight loss can render subsequent oncological procedures easier and safer.

The need for standardized perioperative care for patients undergoing bariatric and metabolic surgery in the United Kingdom

Enhanced recovery after surgery (ERAS) protocols are shown to improve patient outcomes and reduce length of hospital stay. However, there is currently limited consensus on the perioperative management of patients undergoing bariatric and metabolic surgery (BMS) in the United Kingdom. This study aims to survey the level of consistency in patient care undergoing BMS. Bariatric nurse specialists from 30 bariatric units completed an anonymised, online survey from 21 December 2022 to 21 February 2023. Most units (77%) have implemented a premade postoperative care bundle protocol including predetermined timing of oral intake (77%) and postoperative day 1 bloods (60%). 63% of units have also established pre-set analgesia and anti-emetic bundles. Date of discharge is variable, ranging from 1 day after surgery (50%) to a 'two night stay' protocol (33%) to within 4 days after surgery (17%). Most follow-up clinics are either led by dietitians (33%) or both bariatric nurse specialists and dietitians collaboratively (57%). Patients are usually established on solid food 6 weeks after surgery in 53% (16/30) units. Chemical venous thromboembolism (VTE) prophylaxis was either given on day of surgery postoperatively (60%), day before (20%) or after (17%) surgery. Our study shows significant variability of care throughout the surgical pathway, in the study population. The results suggest a need for consensus guidelines outlining the best-practice approach to managing patients undergoing BMS; due to the heterogeneity of the patient group, these guidelines should contain overarching generalisable recommendations that can then be tailored to individual patients.

Updates in Bariatric Surgery

Bariatric surgery is currently the most effective long-term treatment for morbid obesity as well as type-2 diabetes mellitus. The field of metabolic and bariatric surgery has seen tremendous growth over the past decade with dramatically reduced risks. This article aims to provide an update on bariatric surgery, highlighting the latest outcomes, improvements, and challenges in the field. Recently, the American Society of Metabolic and Bariatric Surgery (ASMBS) and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) released a major update to the indications for bariatric surgery at BMI ≥35 kg/m2 regardless of co-morbidities and 30-34.9 kg/m2 with obesity-related comorbidities. Sleeve gastrectomy has emerged as the most popular bariatric procedure in the last 10 years with its remarkable efficacy and safety profile. The implementation of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) and Enhanced Recovery After Surgery (ERAS) protocols have significantly improved the quality of care for all bariatric patients. The recent introduction and FDA approval of Glucagon-Like Peptide-1 (GLP-1) agonists for chronic obesity has garnered significant media coverage and popularity, but no guidelines exist regarding its use in relation to bariatric surgery. This update underscores the need for tailored approaches, ongoing research, and the integration of evidence-based medicine and innovations to enhance patient care.

Predicting short-term thromboembolic risk following Roux-en-Y gastric bypass using supervised machine learning

BACKGROUND

Roux-en-Y gastric bypass (RYGB) is a widely recognized bariatric procedure that is particularly beneficial for patients with class III obesity. It aids in significant weight loss and improves obesity-related medical conditions. Despite its effectiveness, postoperative care still has challenges. Clinical evidence shows that venous thromboembolism (VTE) is a leading cause of 30-d morbidity and mortality after RYGB. Therefore, a clear unmet need exists for a tailored risk assessment tool for VTE in RYGB candidates.

AIM

To develop and internally validate a scoring system determining the individualized risk of 30-d VTE in patients undergoing RYGB.

METHODS

Using the 2016-2021 Metabolic and Bariatric Surgery Accreditation Quality Improvement Program, data from 6526 patients (body mass index ≥ 40 kg/m2) who underwent RYGB were analyzed. A backward elimination multivariate analysis identified predictors of VTE characterized by pulmonary embolism and/or deep venous thrombosis within 30 d of RYGB. The resultant risk scores were derived from the coefficients of statistically significant variables. The performance of the model was evaluated using receiver operating curves through 5-fold cross-validation.

RESULTS

Of the 26 initial variables, six predictors were identified. These included a history of chronic obstructive pulmonary disease with a regression coefficient (Coef) of 2.54 (P < 0.001), length of stay (Coef 0.08, P < 0.001), prior deep venous thrombosis (Coef 1.61, P < 0.001), hemoglobin A1c > 7% (Coef 1.19, P < 0.001), venous stasis history (Coef 1.43, P < 0.001), and preoperative anticoagulation use (Coef 1.24, P < 0.001). These variables were weighted according to their regression coefficients in an algorithm that was generated for the model predicting 30-d VTE risk post-RYGB. The risk model's area under the curve (AUC) was 0.79 [95% confidence interval (CI): 0.63-0.81], showing good discriminatory power, achieving a sensitivity of 0.60 and a specificity of 0.91. Without training, the same model performed satisfactorily in patients with laparoscopic sleeve gastrectomy with an AUC of 0.63 (95%CI: 0.62-0.64) and endoscopic sleeve gastroplasty with an AUC of 0.76 (95%CI: 0.75-0.78).

CONCLUSION

This simple risk model uses only six variables to assist clinicians in the preoperative risk stratification of RYGB patients, offering insights into factors that heighten the risk of VTE events.

Extended Post Discharge Prophylaxis for Venous Thromboembolism Prevention After Bariatric Surgery

PURPOSE

The utility of routine post-discharge VTE prophylaxis after bariatric surgery remains a matter of debate. While inpatient chemical prophylaxis decreases the risk of fatal pulmonary embolism, most thromboembolic events occur after discharge and carry high morbidity and mortality. To address this risk, apixaban was introduced as extended prophylaxis for 30 days after surgery.

MATERIALS AND METHODS

The study ranges between 1/2014 and 7/2022. Apixaban was incorporated as routine extended prophylaxis protocol in 05/2017 and is dosed at 2.5 mg BID for 30 days. There were two study groups: those who received apixaban on discharge (n = 1443; 60%) and those who did not (n = 953; 40%). Patients with concern for postoperative bleeding (hypotension, unexplained tachycardia with hematocrit drop > 6%, hematocrit drop > 9%), or on preoperative anticoagulant/antiplatelet therapy (except aspirin), were not discharged on apixaban. Post-discharge VTE, readmission, transfusion, and reoperation rates were compared between groups.

RESULTS

There were 2396 consecutive primary bariatric operations: sleeve gastrectomy (1949; 81%), Roux-en-Y gastric bypass (419; 18%), and duodenal switch (28; 1%). There were no post-discharge VTEs in patients treated with apixaban vs. five (0.5%) VTEs in patients who did not receive treatment; p = 0.02. There was a higher incidence in post-discharge bleeding events in the apixaban group (0.5 vs 0.3%; p = 0.75), mostly requiring readmission for monitoring without intervention or transfusion. In the apixaban group, one patient underwent EGD for bleeding while another required blood transfusion; there were no reoperations for bleeding.

CONCLUSION

There were no post-discharge VTEs in patients who received apixaban. Treatment was associated with a higher risk of self-resolving bleeding events. This study adds to the increasing body of evidence supporting the benefit of routine, extended oral chemoprophylaxis after bariatric surgery.

Risk stratified venous thromboembolism prophylaxis in bariatric patients using a Caprini assessment: practice patterns and opportunities for improvement

BACKGROUND

Venous thromboembolism (VTE) is rare after bariatric surgery but is the most common cause of mortality. The use of VTE risk-stratification tools and compliance with practice guidelines remain unclear.

OBJECTIVES

Our objectives were to determine the utilization of risk-stratified VTE prophylaxis and its impact on VTE and bleeding outcomes.

SETTING

Academic hospital system.

METHODS

Roux-en-Y gastric bypass and sleeve gastrectomy (2016-2021) were identified from our electronic health records. Caprini score and VTE prophylaxis regimen were retrospectively determined. VTE prophylaxis consistent with Caprini guidelines was considered appropriate. Outcomes were compared between VTE prophylaxis cohorts. Variables were compared by Kruskal-Wallis test, Pearson χ2 test, and regression models. A P value of <.05 was considered significant.

RESULTS

A total of 1849 bariatric cases were analyzed, including 64% Roux-en-Y gastric bypass and 36% sleeve gastrectomy cases. Of these, 70% and 3.7% received appropriate risk-stratified VTE prophylaxis during hospitalization and at discharge. The mean Caprini score was higher in those without appropriate prophylaxis (8.45 versus 8.04; P = .0004). Inpatient and 30- and 90-day VTE rates were .22%, .47%, and .64%. All discharge VTE events occurred in those not receiving appropriate Caprini risk-stratified VTE prophylaxis. Inpatient and 30- and 90-day bleeding complications were .22%, .23%, and .35%. The likelihood of receiving appropriate prophylaxis varied by hospital site, and receiving appropriate prophylaxis was not associated with increased bleeding risk.

CONCLUSION

Caprini guideline-indicated VTE prophylaxis can be safely used in bariatric surgery patients and may reduce preventable VTE complications without increasing bleeding risk.

Implementation of the Caprini risk assessment model (RAM) in surgical patients to decrease postsurgical venous thromboembolism and enoxaparin prescription at hospital discharge

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), has been an increasingly common post-surgical complication for surgical patients. In the United States, VTE has become a leading cause of preventable hospital death with more than half occurring after discharge and are directly linked to a recent (within 30 days) hospitalization or surgery [1]. In large, hospital-associated/acquired VTE (HA-VTE) are preventable through measures such as the use of risk stratification tools and chemoprophylaxis. The project institution, a community, academic, medical center, for multiple years has consistently remained a high outlier for postoperative VTE. Also, the choice of VTE chemoprophylaxis in surgical patients at the time of discharge depended on, and varied between, the individual prescribing physician. The goal was to implement and determine the efficacy of a standardized intervention tool, the Caprini risk assessment model (RAM), for reducing postoperative VTE complications and its influence on the physician's prescription of enoxaparin at discharge. Results: Risk assessment scoring pre-operatively increased from 0% baseline to 26.3% at Plan-Do-Study-Act (PDSA) cycle 1 and demonstrated a statistically significant change (p-value = 0.006). Risk assessment scoring pre-operatively was 42.9% by PDSA cycle 2 but was not statistically significantly different from PDSA cycle 1. Risk assessment scoring post-operatively (for eligible patients) remained the same throughout all three cycles at 0%. Appropriate prescription of anticoagulation declined from baseline (12.5%) to PDSA cycle 1 (0%), and improved at PDSA cycle 2 (33.3%), however no differences were significant (p-value 0.302). The National Surgical Quality Improvement Project (NSQIP) database showed a decline in VTE occurrences at the projects institution from baseline (1.02%, 6 occurrences, 2021) to PDSA cycle 2 (0.92%, 4 occurrences, 2022) when compared to the national benchmark (1.0%) for the first time since 2018. Given the significant national problem HA-VTE pose to the public, and the rise in occurrences, this quality improvement (QI) project is clinically relevant.

Intra-operative Tranexamic Acid Administration Significantly Decreases Incidence of Postoperative Bleeding Without Increasing Venous Thromboembolism Risk After Laparoscopic Sleeve Gastrectomy: a Retrospective Cohort Study of Over 400 Patients

BACKGROUND

There is evidence that tranexamic acid (TXA) reduces surgical bleeding and is widely used in trauma, obstetrics and other specialties. This practice is less well-established in laparoscopic sleeve gastrectomy (LSG) due to concerns surrounding venous thromboembolism (VTE); equally postoperative bleeding is a serious complication often requiring re-operation.

METHODS

This retrospective cohort study compared 30-day outcomes following primary LSG in patients receiving intra-operative TXA (March 2020-July 2022) to those who did not (March 2011-March 2020). The primary outcome was postoperative bleeding (Hb < 9 g/dL) requiring transfusion or re-operation. Secondary outcomes were incidence of VTE, serious postoperative complications (Clavien-Dindo > grade 3) and death. Patients underwent standardised-protocol LSG without staple line re-enforcement under a single surgeon within the independent sector (private practice). TXA 1 g intravenous was administered immediately after a methylene blue leak test, prior to extubation.

RESULTS

TXA group had 226 patients and non-TXA group had 192 patients. Mean age was 40.5 ± 10.3 and 39.1 ± 9.8 years, respectively. In the TXA group, no postoperative bleeds [versus 3 (1.6%) in non-TXA group, p = 0.0279] occurred. One staple line leak (0.4%) occurred in the TXA group compared to zero in the non-TXA group (p = ns). There was no VTE or death.

CONCLUSIONS

This is the largest cohort study of intra-operative TXA in primary LSG to date, which demonstrates significant decrease in postoperative bleeding without increasing VTE risk. The authors recommend administration of TXA immediately following leak test, or removal of bougie to maximise efficacy. Data of TXA in LSG is awaited from the randomised controlled PATAS trial.

Achieving durable compliance with venous thromboembolism prophylaxis in bariatric surgery: 3-year data from a major academic medical center

BACKGROUND

Metabolic and bariatric surgery (MBS) venous thromboembolism (VTE) prescribing practices vary widely. Our institutional VTE prophylaxis protocol has historically been unstandardized.

OBJECTIVES

To create a standardized MBS VTE prophylaxis protocol, track protocol compliance, and identify barriers to protocol compliance and address them with Plan-Do-Study-Act (PDSA) cycles.

SETTING

Single Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program-accredited academic hospital.

METHODS

We conducted a retrospective study for all patients undergoing MBS (January 2019 to September 2022). A multidisciplinary group of bariatric clinicians reviewed literature and developed the following standardized VTE prophylaxis protocol: 5000 units preoperative subcutaneous (SC) heparin within 60 minutes of anesthesia induction and postoperative 40 mg SC low molecular weight heparin (LMWH) within 24 hours of surgery. This protocol was distributed to relevant clinical stakeholders. We assessed monthly compliance rates through chart review. Goal compliance was ≥90%. We identified sources of noncompliance and addressed them with PDSA methodology.

RESULTS

A total of 796 patients were included. Preoperative heparin administration increased from a mean of 47% (107/228) preintervention to 96% (545/568) postintervention (P < .0001), and postoperative LMWH administration increased from 71% (47/66) to 96% (573/597, P = .0002). These compliance rates were sustained for 3 years. Barriers to protocol noncompliance included order set timing errors (n = 45), surgeon error (n = 44), surgeon discretion (n = 40), and nursing error (n = 20). No change in bleeding or VTE rates was observed.

CONCLUSIONS

Developing a standardized VTE prophylaxis protocol, monitoring process measures, and engaging relevant stakeholders in PDSA cycles resulted in drastic and durable improvement in VTE prophylaxis compliance rates.

Single-Dose enoxaparin for portomesenteric venous thrombosis prophylaxis after sleeve gastrectomy

Introduction

Portomesenteric venous thrombosis (PMVT) may complicate sleeve gastrectomy. We believe that single dose of enoxaparin postoperatively can reduce the risk of PMVT.

Objective

The objective was to study the outcomes of enoxaparin single dose compared to other perioperative prophylactic doses in preventing PMVT.

Methods

Participants included 590 patients who underwent laparoscopic sleeve gastrectomy (LSG). These retrospective cohort data were collected from patient medical charts after bariatric surgery. Patients were followed up in the close postoperative period and at 1, 3, 6, 12, and 18 months. Descriptive statistical analysis was carried out. The objective was to estimate the incidence of PMVT with postoperative single 40 mg subcutaneous enoxaparin prophylactic regimen.

Results

From January 2017 to December 2021, 590 patients with obesity underwent LSG. Five patients developed PMVT with an estimate incidence of 0.85%. Three patients had unexplained tachycardia and three patients had postoperative bleeding.

Conclusions

Single-dose enoxaparin 40 mg is an effective thrombosis prophylaxis without increasing risk of bleeding.

Just What the Doctor Ordered: Missed Ordering of Venous Thromboembolism Chemoprophylaxis Is Associated With Increased VTE Events in High-risk General Surgery Patients

OBJECTIVE

To define the impact of missed ordering of venous thromboembolism (VTE) chemoprophylaxis in high-risk general surgery populations.

BACKGROUND

The primary cause of preventable death in surgical patients is VTE. Although guidelines and validated risk calculators assist in dosing recommendations, there remains considerable variability in ordering and adherence to recommended dosing.

METHODS

All adult inpatients who underwent a general surgery procedure between 2016 and 2019 and were entered into Atrium Health National Surgical Quality Improvement Program registry were identified. Patients at high risk for VTE (2010 Caprini score ≥5) and without bleeding history and/or acute renal failure were included. Primary outcome was 30-day postoperative VTE. Electronic medical record identified compliance with "perfect" VTE chemoprophylaxis orders (pVTE): no missed orders and no inadequate dose ordering. Multivariable analysis examined association between pVTE and 30-day VTE events.

RESULTS

A total of 19,578 patients were identified of which 4252 were high-risk inpatients. Hospital compliance of pVTE was present in 32.4%. pVTE was associated with shorter postoperative length of stay and lower perioperative red blood cell transfusions. There was 50% reduced odds of 30-day VTE event with pVTE (odds ratio: 0.50; 95% CI, 0.30-0.80) and 55% reduction in VTE event/mortality (odds ratio: 0.45; 95% CI, 0.31-0.63). After controlling for relevant covariates, pVTE remained significantly associated with decreased odds of VTE event and VTE event/mortality.

CONCLUSIONS

pVTE ordering in high-risk general surgery patients was associated with 42% reduction in odds of postoperative 30-day VTE. Comprehending factors contributing to missed or suboptimal ordering and development of quality improvement strategies to reduce them are critical to improving outcomes.

Venous thromboembolism (VTE) prophylaxis after bariatric surgery: a national survey of MBSAQIP director practices

BACKGROUND

Venous thromboembolism (VTE) is the most common cause of death following metabolic/bariatric surgery (MBS), with most events occurring after discharge. The available evidence on ideal prophylaxis type, dosage, and duration after discharge is limited.

OBJECTIVES

Assess metabolic/bariatric surgeon VTE prophylaxis practices and define existing variability.

SETTING

Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP)-accredited centers.

METHODS

The members of the ASMBS Research Committee developed and administered a web-based survey to MBSAQIP medical directors and ASMBS members to examine the differences in clinical practice regarding the administration of VTE prophylaxis after MBS.

RESULTS

Overall, 264 metabolic/bariatric surgeons (136 medical directors and 128 ASMBS members) participated in the survey. Both mechanical and chemical VTE prophylaxis was used by 97.1% of the participants, knee-high compression devices by 84.7%, enoxaparin (32.4% 40 mg every 24 hours, 22.7% 40 mg every 12 hours, 24.4% adjusted the dose based on body mass index) by 56.5%, and heparin (46.1% 5000 units every 8 hours, 22.6% 5000 units every 12 hours, 20.9% 5000 units once preoperatively) by 38.1%. Most surgeons (81.6%) administered the first dose preoperatively, while the first postoperative dose was given on the evening of surgery by 44% or the next morning by 42.2%. Extended VTE prophylaxis was prescribed for 2 weeks by 38.7% and 4 weeks by 28.9%.

CONCLUSIONS

VTE prophylaxis practices vary widely among metabolic/bariatric surgeons. Variability may be related to limited available comparative evidence. Large prospective clinical trials are needed to define optimal practices for VTE risk stratification and prophylaxis in bariatric surgery patients.

Extended postoperative venous thromboembolism prophylaxis after bariatric surgery: a comparison of existing risk-stratification tools and 5-year MBSAQIP analysis

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of 30-day mortality after metabolic and bariatric surgery (MBS). Multiple predictive tools exist for VTE risk assessment and extended VTE chemoprophylaxis determination.

OBJECTIVE

To review existing risk-stratification tools and compare their predictive abilities.

SETTING

MBSAQIP database.

METHODS

Retrospective analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was performed (2015-2019) for primary minimally invasive MBS cases. VTE clinical factors and risk-assessment tools were evaluated: body mass index threshold of 50 kg/m2, Caprini risk-assessment model, and 3 bariatric-specific tools: the Cleveland Clinic VTE risk tool, the Michigan Bariatric Surgery Collaborative tool, and BariClot. MBS patients were deemed high risk based on criteria from each tool and further assessed for sensitivity, specificity, and positive predictive value.

RESULTS

Overall, 709,304 patients were identified with a .37% VTE rate. Bariatric-specific tools included multiple predictors: procedure, age, race, gender, operative time, length of stay, heart failure, and dyspnea at rest; operative time was the only variable common to all. The body mass index cutoff and Caprini risk-assessment model had higher sensitivity but lower specificity when compared with the Michigan Bariatric Surgery Collaborative and BariClot tools. While the sensitivity of the tools varied widely and was overall low, the Cleveland Clinic tool had the highest sensitivity. The bariatric-specific tools would have recommended extended prophylaxis for 1.1%-15.6% of patients.

CONCLUSIONS

Existing MBS VTE risk-assessment tools differ widely for inclusion variables, high-risk definition, and predictive performance. Further research and registry inclusion of all significant risk factors are needed to determine the optimal risk-stratified approach for predicting VTE events and determining the need for extended prophylaxis.

Effectiveness of Body Mass Index-Based Prophylactic Enoxaparin Dosing in Bariatric Surgery Patients

INTRODUCTION

Enoxaparin is administered for venous thromboembolic (VTE) prophylaxis in bariatric surgery patients. There is concern whether body mass index (BMI)-based enoxaparin dosing consistently achieves prophylactic targets in patients with severe obesity.

METHODS

This retrospective study included patients who underwent bariatric surgery at an academic medical center from Jan 2015-May 2021 and had an anti-Xa level drawn 2.5-6 h after ≥3 doses of BMI-based prophylactic enoxaparin. The primary outcome was the percentage of patients who achieved a target anti-Xa level. Secondary outcomes were prevalence of venous thromboembolic and bleeding events within 30 d post-operatively.

RESULTS

Overall, 137 patients were included. Mean BMI was 59.1 ± 10.4 kg/m², mean age was 43.9 ± 13.3 y and 110 patients (80.3%) were female. Target anti-Xa levels were achieved in 116 patients (84.7%); 14 (10.2%) were above target and 7 (5.1%) were below target. Patients with above target anti-Xa levels were significantly shorter in height than those within target range (167.1 versus 159.8 cm, P = 0.003). Five patients (3.6%) had a bleeding event; no thromboembolisms occurred. Anti-Xa levels correlated more strongly with enoxaparin dose per unit estimated blood volume (EBV) than dose per unit BMI (Rho = 0.54 versus Rho = 0.33).

CONCLUSIONS

Target range anti-Xa levels were achieved in 85% of patients using BMI-based enoxaparin dosing. Patients with above target anti-Xa levels were significantly shorter by nearly 3 inches, suggesting an increased risk of overdosing enoxaparin in shorter, obese patients. An EBV-based dosing regimen may better account for patient height and is supported by a greater correlation with anti-Xa levels with dosing based on EBV than BMI.

Factors Associated with Increased Risk for Pulmonary Embolism After Metabolic and Bariatric Surgery: Analysis of Nearly One Million Patients

BACKGROUND

Metabolic and bariatric surgery (MBS) has a low incidence of post-operative morbidity and mortality. Understanding risk factors associated with complications that occur allows surgeons to define at-risk patients and assess the need for preventive and prophylactic measures.

OBJECTIVES

To determine risk factors associated with development of pulmonary embolism (PE) within 30 days of MBS and to predict the increased risk for mortality when PE occurs.

SETTING

USA, MBSAQIP database.

METHODS

Analysis of the MBSAQIP database was undertaken. This included information on 966,646 MBS cases from 2015 to 2019 in the USA.

RESULTS

Twenty-two risk factors for development of PE post-MBS were identified to be statistically significant.

CONCLUSIONS

PE is a relatively uncommon complication after MBS. When it does occur, there is a 50.9-fold increased risk for mortality. Patients with significant risk factors for PE may benefit from higher dose perioperative and/or extended VTE prophylaxis after MBS.