Low Anti-Factor Xa Level Predicts 90-Day Symptomatic Venous Thromboembolism in Surgical Patients Receiving Enoxaparin Prophylaxis: A Pooled Analysis of Eight Clinical Trials.

OBJECTIVE: To examine the relationship between enoxaparin dose adequacy, quantified with anti-Factor Xa (aFXa) levels, and 90-day symptomatic venous thromboembolism (VTE) and postoperative bleeding. SUMMARY BACKGROUND DATA: Surgical patients often develop "breakthrough" VTE events-those which occur despite receiving chemical anticoagulation. We hypothesize that surgical patients with low aFXa levels will be more likely to develop 90-day VTE, and those with high aFXa will be more likely to bleed. METHODS: Pooled analysis of eight clinical trials (N = 985) from a single institution over a 4 year period. Patients had peak steady state aFXa levels in response to a known initial enoxaparin dose, and were followed for 90 days. Survival analysis log-rank test examined associations between aFXa level category and 90-day symptomatic VTE and bleeding. RESULTS: Among 985 patients, 2.3% (n = 23) had symptomatic 90-day VTE, 4.2% (n = 41) had 90-day clinically relevant bleeding, and 2.1% (n = 21) had major bleeding. Patients with initial low aFXa were significantly more likely to have 90-day VTE than patients with adequate or high aFXa (4.2% vs 1.3%, P = 0.007). In a stratified analysis, this relationship was significant for patients who received twice daily (6.2% vs 1.5%, P = 0.003), but not once daily (3.0% vs 0.7%, P = 0.10) enoxaparin. No association was seen between high aFXa and 90-day clinically relevant bleeding (4.8% vs 2.9%, P = 0.34) or major bleeding (3.6% vs 1.6%, P = 0.18). CONCLUSIONS: This manuscript establishes inadequate enoxaparin dosing as a plausible mechanism for breakthrough VTE in surgical patients, and identifies anticoagulant dose adequacy as a novel target for process improvement measures.

Prevention of Venous Thromboembolism in Microvascular Surgery Patients Using Weight-Based Unfractionated Heparin Infusions.

BACKGROUND: Unfractionated heparin infusions are commonly used in microvascular surgery to prevent microvascular thrombosis. Previously, fixed-dose heparin infusions were believed to provide sufficient venous thromboembolism (VTE) prophylaxis; however, we now know that this practice is inadequate for the majority of patients. Anti-factor Xa (aFXa) level is a measure of unfractionated heparin efficacy and safety. This study evaluated the pharmacodynamics of weight-based dose heparin infusions and the impacts of real-time aFXa-guided heparin dose adjustments. METHODS: This prospective clinical trial enrolled adult microvascular surgery patients who received a weight-based heparin dose following a microsurgical procedure. Steady-state aFXa levels were monitored, and patients with out-of-range levels received dose adjustments. The study outcomes assessed were aFXa levels at a dose of heparin 10 units/kg/hour, time to adequate aFXa level, number of dose adjustments required to reach in-range aFXa levels, and clinically relevant bleeding and VTE at 90 days. RESULTS: Twenty-one patients were prospectively recruited, and usable data were available for twenty patients. Four of twenty patients (20%) had adequate prophylaxis at a heparin dose of 10 units/kg/hour. Among patients who received dose adjustments and achieved in-range aFXa levels, the median number of dose adjustments was 2 and the median weight-based dose was 11 units/kg/hour. The percentage of patients with in-range levels was significantly increased (65 vs. 15%, p = 0.0002) as a result of real-time dose adjustments. The rate of VTE at 90 days was 0%, and clinically relevant bleeding rate at 90 days was 15%. CONCLUSION: Weight-based heparin infusions at a rate of 10 units/kg/hour provide a detectable level of anticoagulation for some patients following microsurgical procedures, but most patients require dose adjustment to ensure adequate VTE prophylaxis.

Call to Action to Prevent Venous Thromboembolism in Hospitalized Patients: A Policy Statement From the American Heart Association.

Venous thromboembolism (VTE) is a major preventable disease that affects hospitalized inpatients. Risk stratification and prophylactic measures have good evidence supporting their use, but multiple reasons exist that prevent full adoption, compliance, and efficacy that may underlie the persistence of VTE over the past several decades. This policy statement provides a focused review of VTE, risk scoring systems, prophylaxis, and tracking methods. From this summary, 5 major areas of policy guidance are presented that the American Heart Association believes will lead to better implementation, tracking, and prevention of VTE events. They include performing VTE risk assessment and reporting the level of VTE risk in all hospitalized patients, integrating preventable VTE as a benchmark for hospital comparison and pay-for-performance programs, supporting appropriations to improve public awareness of VTE, tracking VTE nationwide with the use of standardized definitions, and developing a centralized data steward for data tracking on VTE risk assessment, prophylaxis, and rates.

Estrogen Continuation and Venous Thromboembolism in Penile Inversion Vaginoplasty.

BACKGROUND: Estrogen therapy and penile inversion vaginoplasty (PIV) are necessary, life-saving interventions for many transfeminine patients. Patients undergoing PIV are generally at low baseline risk for venous thromboembolism (VTE) based on Caprini Score. Estrogen therapy may increase VTE risk in surgical patients, but its cessation may be psychiatrically dysphoric for transfeminine patients. AIM: This study examines whether perioperative estrogen cessation impacts VTE risk in patients undergoing PIV. METHODS: This was a pre-post study of patients undergoing PIV. From 2014 through 2018, all patients stopped estrogen therapy for 2 weeks before surgery and resumed 1 week postoperatively (group 1). Starting in 2019, all patients continued estrogen therapy perioperatively, with dose reductions for those whose dose was >6 mg/day (group 2). OUTCOMES: The primary outcome was 90-day VTE rate. RESULTS: 178 patients were included in the study, with 117 in group 1 and 61 in group 2. Median Caprini Score was 4 in group 1 (interquartile range: 3-6) and 3 in group 2 (interquartile range: 3-4) (P = .011). Complications per patient were higher in group 1 (2.2 vs 0.9, P < .001), with a longer follow-up (14.1 vs 10.2 months, P < .001). Rates of 90-day VTE were not different between groups (0.0% vs 1.6%, P = .166). CLINICAL IMPLICATIONS: Patients undergoing PIV are generally at low risk for VTE, based on 2005 Caprini Scores. This study provides preliminary evidence that perioperative estrogen therapy continuation does not appear to substantially increase VTE risk in transfeminine patients undergoing PIV with low Caprini Scores, although more investigation is needed to establish true safety. STRENGTHS & LIMITATIONS: Strengths include the pre-post design and single-surgeon experience, high proportion of patients with 90-day follow-up, and relatively large series to understand baseline VTE risk by Caprini Score in a PIV population. The main weakness of this study is its limited power to measure true differences in VTE risk based on estrogen continuation. CONCLUSIONS: This study suggests that perioperative estrogen continuation may be safe for patients undergoing PIV, the overwhelming majority of whom are at low baseline VTE risk. However, clinicians should weigh the magnitude of the risks and benefits of estrogen cessation on a case-by-case basis. Nolan IT, Haley C, Morrison SD, et al. Estrogen Continuation and Venous Thromboembolism in Penile Inversion Vaginoplasty. J Sex Med 2021;18:193-200.

Postoperative Venous Thromboembolism Prophylaxis Utilizing Enoxaparin Does Not Increase Bleeding Complications After Abdominal Body Contouring Surgery.

BACKGROUND: Venous thromboembolism (VTE) chemoprophylaxis warrants an individualized, risk-stratified approach, and constitutes a relatively controversial topic in plastic surgery. OBJECTIVES: The aim of this study was to determine the safety of a 7-day postoperative enoxaparin regimen for VTE prophylaxis compared with a single preoperative dose of heparin in abdominal body contouring surgery. METHODS: This single-institution pre-post study investigated the safety of a 7-day enoxaparin postoperative regimen in abdominal body contouring procedures performed by a single surgeon from 2007 to 2018. Four procedures were included: traditional panniculectomy, abdominoplasty, fleur-de-lis panniculectomy, and body contouring liposuction. Group I patients received a single dose of 5000 U subcutaneous heparin in the preoperative period, and no postoperative chemical prophylaxis was administered. Group II patients received 40 mg subcutaneous enoxaparin in the immediate preoperative period, then once daily for 7 days postoperatively. RESULTS: A total of 195 patients were included in the study, 66 in Group I and 129 in Group II. The groups demonstrated statistically similar VTE risk profiles, based on the 2005 Caprini risk-assessment model. There were no statistically significant differences in the 2 primary outcomes: postoperative bleeding and VTE events. Group I patients had higher reoperation rates (22.7% vs 10.1%, P = 0.029), which was secondary to higher rates of revision procedures. CONCLUSIONS: A 7-day postoperative course of once-daily enoxaparin for VTE risk reduction in abdominal body contouring surgery does not significantly increase the risk of bleeding. Implementation of this regimen for postdischarge chemoprophylaxis, when indicated following individualized risk stratification, is appropriate.

Cross-Leg Flaps for Lower Extremity Salvage: A Scoping Review.

BACKGROUND: Lower extremity trauma with soft tissue loss presents a challenge to the reconstructive surgeon. Cross-leg flaps, first described by Hamilton in 1854, are still used to salvage traumatized lower extremities in patients not suitable for free tissue transfer, or those who are receiving care in locations with limited resources. METHODS: A scoping review methodology was used to examine the evidence supporting the use of cross-leg flaps in modern healthcare. RESULTS: There have been 409 cases of cross-leg flaps reported in the modern literature, with the majority of flap cases occurring outside the United States in Turkey, India, and Japan. The most common indication was trauma, mentioned in 93.2% of patients (n = 353 of 379), and anatomic limitation, including inadequate vasculature, was the main reason for not performing free tissue transfer (52.8% of patients; n = 170 of 322). The majority are cross-leg fasciocutaneous flaps (85.8%, n = 273 of 318), based off the posterior tibial artery (27.5%, n = 50 of 182) and peroneal artery (26.9%, n = 49 of 182) and, covering defects of the distal third of the leg (55.5%, n = 151 of 272), or the foot (27.9%, n = 76 of 272). The pedicles are typically divided at 3 weeks (mean 20.9 days) after external fixation is used as the immobilization method (57.7%, n = 184 of 319). Flap survival was 100% across all publications except one (n = 349 of 350 patients), making cross-leg flaps a robust and reliable reconstructive option. CONCLUSION: In resource-limited environments or in patients who are unsuitable for microvascular free tissue transfer, the cross-leg flap remains an impactful and reliable option for limb salvage.

Venous Thromboembolism in Aesthetic Surgery: Risk Optimization in the Preoperative, Intraoperative, and Postoperative Settings.

The purpose of this Continuing Medical Education (CME) article is to provide a framework for practicing surgeons to conceptualize and quantify venous thromboembolism risk among the aesthetic and ambulatory surgery population. The article provides a practical approach to identify and minimize venous thromboembolism risk in the preoperative, intraoperative, and postoperative settings.

Adequacy of Fixed-Dose Heparin Infusions for Venous Thromboembolism Prevention after Microsurgical Procedures.

BACKGROUND: In microvascular surgery, patients often receive unfractionated heparin infusions to minimize risk for microvascular thrombosis. Patients who receive intravenous (IV) heparin are believed to have adequate prophylaxis against venous thromboembolism (VTE). Whether a fixed dose of IV heparin provides detectable levels of anticoagulation, or whether the "one size fits all" approach provides adequate prophylaxis against VTE remains unknown. This study examined the pharmacodynamics of fixed-dose heparin infusions and the effects of real-time, anti-factor Xa (aFXa) level driven heparin dose adjustments. METHODS: This prospective clinical trial recruited adult microvascular surgery patients placed on a fixed-dose (500 units/h) unfractionated heparin infusion during their initial microsurgical procedure. Steady-state aFXa levels, a marker of unfractionated heparin efficacy and safety, were monitored. Patients with out-of-range aFXa levels received protocol-driven real-time dose adjustments. Outcomes of interest included aFXa levels in response to heparin 500 units/h, number of dose adjustments required to achieve goal aFXa levels, time to reach goal aFXa level, and 90-day clinically relevant bleeding and VTE. RESULTS: Twenty patients were recruited prospectively. None of 20 patients had any detectable level of anticoagulation in response to heparin infusions at 500 units/h. The median number of dose adjustments required to reach goal level was five, and median weight-based dose to reach goal level was 11.8 units/kg/h. Real-time dose adjustments significantly increased the proportion of patients with in-range levels (60 vs. 0%, p = 0.0001). The 90-day VTE rate was 5% and 90-day clinically relevant bleeding rate was 5%. CONCLUSIONS: Fixed-dose heparin infusions at a rate of 500 units/h do not provide a detectable level of anticoagulation after microsurgical procedures and are insufficient for the majority of patients who require VTE prophylaxis. Weight-based heparin infusions at 10 to 12 units/kg/h deserve future study in patients undergoing microsurgical procedures to increase the proportion of patients receiving adequate VTE prophylaxis.

Individualized Venous Thromboembolism Risk Stratification Using the 2005 Caprini Score to Identify the Benefits and Harms of Chemoprophylaxis in Surgical Patients: A Meta-analysis.

OBJECTIVE: We performed a meta-analysis to investigate benefits and harms of chemoprophylaxis among surgical patients individually risk stratified for venous thromboembolism (VTE) using Caprini scores. SUMMARY OF BACKGROUND DATA: Individualized VTE risk stratification may identify high risk surgical patients who benefit from peri-operative chemoprophylaxis. METHODS: MEDLINE, EMBASE, and the Cochrane Library (CENTRAL) databases were queried. Eligible studies contained data on postoperative VTE and/or bleeding events with and without chemoprophylaxis. Primary outcomes included rates of VTE and clinically relevant bleeding after surgical procedures, stratified by Caprini score. A meta-analysis was conducted using a random-effects model. RESULTS: Among 13 included studies, 11 (n = 14,776) contained data for VTE events and 8 (n = 7590) contained data for clinically relevant bleeding with and without chemoprophylaxis. The majority of patients received mechanical prophylaxis. A 14-fold variation in VTE risk (from 0.7% to 10.7%) was identified among surgical patients who did not receive chemoprophylaxis, and patients at increased levels of Caprini risk were significantly more likely to have VTE. Patients with Caprini scores of 7 to 8 [odds ratio (OR) 0.60, 95% confidence interval (95% CI) 0.37-0.97] and >8 (OR 0.41, 95% CI 0.26-0.65) had significant VTE risk reduction after surgery with chemoprophylaxis. Patients with Caprini scores ≤6 comprised 75% of the overall population, and these patients did not have a significant VTE risk reduction with chemoprophylaxis. No association between postoperative bleeding risk and Caprini score was identified. CONCLUSIONS: The benefit of peri-operative VTE chemoprophylaxis was only found among surgical patients with Caprini scores ≥7. Precision medicine using individualized VTE risk stratification helps ensure that chemoprophylaxis is used only in appropriate surgical patients and may minimize bleeding complications.

Feasibility of the internal mammary lymph node flap as a vascularized lymph node transfer: A cadaveric dissection study.

BACKGROUND: We performed cadaveric dissections to examine the feasibility of an internal mammary-based lymph node flap as a donor site for vascularized lymph node transfer. METHODS: Internal mammary vessels and adjacent nodes were dissected in ten fresh cadaver specimens. Surgeon inspection and palpation identified the number of nodes in the specimen. Specimens were examined macro- and microscopically by a pathologist for correlation of lymph node counts. Kappa statistic correlated surgeon- and pathologist-reported node counts. RESULTS: Surgeon- and pathologist-reported node counts were moderately correlated (kappa 0.57). Inspection and palpation correctly predicted node presence or absence in 80% of specimens. Sixty percent of flaps contained between 1 and 3 nodes, with a mean of 2.0 nodes when nodes were present. CONCLUSIONS: Inspection and palpation predicts the presence or absence of nodes in 80% of flaps. Nodes were present in 60% of internal mammary-based flaps, and one to three nodes can be transferred. © 2015 Wiley Periodicals, Inc. Microsurgery 36:485-490, 2016.

Complications after sternal reconstruction: a 16-y experience.

BACKGROUND: Unlike risk factors associated with sternotomy complications, those associated with sternal reconstruction have not been well elucidated. We sought to examine complication rates after sternal wound reconstruction and to identify perioperative risk factors associated with these complications. METHODS: We evaluated the records of 230 consecutive patients who underwent sternal reconstruction with muscle flaps after cardiac surgery. Patient demographics, clinical comorbidities, and operative procedure types were evaluated against two outcome variables-major complications and reconstructive failure. RESULTS: The mean age of our cohort was 62 y. Major complications (readmission, reoperation, or death) occurred in 76 patients (33%), including mortality rate of 3.5%. Obesity, chronic obstructive pulmonary disease, and type of reconstructive procedure correlated with an increased risk of major complications. Reconstructive failure occurred in 39 patients (17%) and was associated with female gender, obesity, previous coronary artery bypass graft procedure, and prior left internal mammary artery usage. Regression analyses demonstrated that obesity is independently associated with an increased risk of major complications and that women are at an increased risk of reconstructive failure. Reconstructions involving the rectus abdominis were correlated with an increased risk of major complications, but this difference was not significant in multiple regression analysis. CONCLUSIONS: Usual risk factors for sternal wound development after cardiac surgery include diabetes, age, obesity, tobacco use, history of stroke, bilateral left internal mammary artery harvest, and significant blood transfusion. In distinction, this study found that the risks independently associated with major complications and reconstructive failures after reconstruction of sternal wounds are limited to obesity and female gender.

Loupes-Only Microsurgery is a Safe Alternative to the Operating Microscope: An Analysis of 1,649 Consecutive Free Flap Breast Reconstructions.

BACKGROUND: Loupes-only microsurgery challenges the paradigm that free flap surgery requires an operating microscope. We describe our loupes-only microsurgery experience with an emphasis on rates of intraoperative anastomotic revision and total flap loss. METHODS: We identified all patients having breast reconstruction with muscle-sparing transverse rectus abdominis myocutaneous (ms-TRAM) or deep inferior epigastric perforator (DIEP) flaps over 7 years. We examined rates of intraoperative anastomotic revision and total flap loss as markers of technical quality. For one high-volume surgeon who started loupes-only microsurgery while at our institution, we examined rates of intraoperative anastomotic revision and total flap loss rates over time to evaluate for a learning curve. RESULTS: We performed 1,649 ms-TRAM or DIEP flaps in 1,063 patients. For 1,649 flaps, the rate of artery anastomotic revision was 2.2% (36 arteries) and venous anastomotic revision was 2.2% (37 veins). Any microvascular revision was performed in 3.5% (58 flaps). Total flap loss rate was 1.2% (20 flaps).For the "learning curve" analysis, there were no clinically relevant differences in rates of any intraoperative anastomotic revision or total flap loss during the first 60 months after loupes-only microsurgery was adopted. Total flap loss during this surgeon's first 60 months of loupes-only microsurgery was 1.6% (10 of 638 flaps). CONCLUSIONS: Loupes-only microsurgery is a safe alternative to the operating microscope for free flap breast reconstruction using the deep inferior epigastric system. Our total flap loss rate of 1.2% in 1,649 flaps is at the low end of published flap loss rates.

Building surgical capacity in low-resource countries: a qualitative analysis of task shifting from surgeon volunteers' perspectives.

INTRODUCTION: Surgical volunteer organizations (SVOs) focus considerable resources on addressing the backlog of cases in low-resource countries. This model of service may perpetuate dependency. Efforts should focus on models that establish independence in providing surgical care. Independence could be achieved through surgical capacity building. However, there has been scant discussion in literature on SVO involvement in surgical capacity building. METHODS: Using qualitative methods, we evaluated the perspectives of surgeons with extensive volunteer experience in low-resource countries. We collected data through in-depth interviews that centered on SVOs using task shifting as a tool for surgical capacity building. RESULTS: Some of the key themes from our analysis include the ethical ramifications of task shifting, the challenges of addressing technical and clinical education in capacity building for low-resource settings, and the allocation of limited volunteer resources toward surgical capacity building. CONCLUSION: These themes will be the foundation of subsequent studies that will focus on other stakeholders in surgical capacity building including host communities and SVO administrators.

Medicinal leeches for surgically uncorrectable venous congestion after free flap breast reconstruction.

BACKGROUND: Free tissue transfer is an accepted method for breast reconstruction. Surgically uncorrectable venous congestion is a rare but real occurrence after these procedures. Here, we report our experience with the management of surgically uncorrectable venous congestion after free flap breast reconstruction using medicinal leech therapy. METHODS: We queried our prospectively maintained institutional database for all patients with venous congestion after free flap breast reconstruction since 2005. Chart review was performed for all patients having post-operative venous congestion. We compared patients with surgically correctable venous congestion and surgically uncorrectable venous congestion requiring medicinal leech therapy. RESULTS: Twenty-three patients had post-operative venous congestion, and four of these patients were surgically uncorrectable requiring medicinal leech therapy. Patients who required leech therapy had lower hemoglobin nadirs, received more blood transfusions, and received a higher number of total units of red blood cells than patients who did not require leech therapy. Among four patients who required leech therapy, one flap was partially salvaged and three flaps were completely lost. Leech therapy was associated with higher total flap loss rates (75.0% vs. 42.1%) and longer length of stay (8.0 ± 3.6 days vs. 6.5 ± 2.1 days) when compared to non-leeched flaps. These differences were not statistically significant (P = 0.32 and P = 0.43, respectively). CONCLUSIONS: In patients with surgically uncorrectable venous congestion after free flap breast reconstruction, total flap loss is common despite leech therapy. When venous congestion cannot be corrected, total flap removal may be a better option than attempted salvage with leech therapy.

Patient selection for day case-eligible surgery: identifying those at high risk for major complications.

BACKGROUND: Due to economic pressures and improvements in perioperative care, outpatient surgical procedures have become commonplace. However, risk factors for outpatient surgical morbidity and mortality remain unclear. There are no multicenter clinical data guiding patient selection for outpatient surgery. The authors hypothesize that specific risk factors increase the likelihood of day case-eligible surgical morbidity or mortality. METHODS: The authors analyzed adults undergoing common day case-eligible surgical procedures by using the American College of Surgeons' National Surgical Quality Improvement Program database from 2005 to 2010. Common day case-eligible surgical procedures were identified as the most common outpatient surgical Current Procedural Terminology codes provided by Blue Cross Blue Shield of Michigan and Medicare publications. Study variables included anthropometric data and relevant medical comorbidities. The primary outcome was morbidity or mortality within 72 h. Intraoperative complications included adverse cardiovascular events; postoperative complications included surgical, anesthetic, and medical adverse events. RESULTS: Of 244,397 surgeries studied, 232 (0.1%) experienced early perioperative morbidity or mortality. Seven independent risk factors were identified while controlling for surgical complexity: overweight body mass index, obese body mass index, chronic obstructive pulmonary disease, history of transient ischemic attack/stroke, hypertension, previous cardiac surgical intervention, and prolonged operative time. CONCLUSIONS: The demonstrated low rate of perioperative morbidity and mortality confirms the safety of current day case-eligible surgeries. The authors obtained the first prospectively collected data identifying risk factors for morbidity and mortality with day case-eligible surgery. The results of the study provide new data to advance patient-selection processes for outpatient surgery.

Qualitative analysis of the perspectives of volunteer reconstructive surgeons on participation in task-shifting programs for surgical-capacity building in low-resource countries.

BACKGROUND: Experts agree that the global burden of untreated surgical disease is disproportionately borne by the world's poorest. This is partly because of a severe shortage of surgical care providers. Several experts have emphasized the need to research solutions for surgical-capacity building in developing countries. Volunteer surgeons already contribute significantly to directly tackling surgical disease burden in developing countries. We qualitatively evaluated their interest in participating in task-shifting programs as a surgical capacity-building strategy. METHODS: We conducted semi-structured interviews with surgeons familiar with delivery of surgical care in developing countries through their extensive volunteer experiences. The interviews followed a structured guide that centered on task shifting as a model for surgical capacity-building in developing countries. We analyzed the interview transcripts using established qualitative methods to identify themes relevant to the interest of volunteer surgeons to participate in task-shifting programs. RESULTS: Most participants were open to involvement in task-shifting programs as a feasible way for surgical capacity-building in low-resource communities. However, they thought that surgical task shifting would need to be implemented with some important requisites. The most strongly emphasized condition was direct supervision of lower-skilled providers by fully trained surgeons. CONCLUSIONS: There is a favorable view regarding the involvement of surgeon volunteers in capacity-building efforts. Additionally, volunteer surgeons view task shifting as a feasible way to accomplish surgical capacity building in developing countries-provided that surgical tasks are assigned appropriately, and lower level providers are adequately supervised.

Unfractionated Heparins, Low-Molecular-Weight Heparins, and Indirect Factor Xa Inhibitors in Plastic and Reconstructive Surgery: An Evidence-Based Review.

SUMMARY: Venous thromboembolism can present with devastating complications and sequalae, particularly in the surgical patient. Current data supports prophylactic anticoagulant use in the high-risk inpatient, defined as those with a 2005 Caprini Risk Assessment Model score of ≥7. The most utilized chemoprophylaxis agents include unfractionated heparin, low-molecular-weight heparins, and indirect factor Xa inhibitors. The authors review their mechanisms of action, metabolism, reversal agents, indications, contraindications, advantages, and disadvantages in plastic and reconstructive surgery.