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Objective To examine the relationship between enoxaparin dose adequacy, quantified with anti-Factor Xa (aFXa) levels, and 90-day symptomatic venous thromboembolism (VTE) and post-operative 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 four 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 & 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.

OBJECTIVES To assess the biochemical and clinical outcomes of hospitalized children who received prophylactic enoxaparin. METHODS We conducted a retrospective observational study of hospitalized children aged RESULTS We analyzed 194 children with 13 (6.7%) infants aged .99). CONCLUSIONS Our findings suggest the effectiveness and safety of an anti-Xa level directed strategy of prophylactic enoxaparin. However, this strategy should be investigated in prospective controlled studies.

SUMMARY The Plastic Surgeries Registry Network supported by the American Society of Plastic Surgeons (ASPS) and the Plastic Surgery Foundation offers a variety of options for procedural data and outcomes assessment and research. The Tracking Operations and Outcomes for Plastic Surgeons (TOPS) database is a registry created for and used by active members of ASPS to monitor all types of procedural outcomes. It functions as a way for individual or group practices to follow surgical outcomes and constitutes a huge research registry available to ASPS members to access for registry-based projects. The TOPS registry was launched in 2002 and has undergone several iterations and improvements over the years and now includes more than 1 million procedure records. Although ASPS member surgeons have proven valuable assets in contributing their data to the TOPS registry, fewer have leveraged the database for registry-based research. This article overviews the authors' experience using the TOPS registry for a database research project to demonstrate the process, usefulness, and accessibility of TOPS data for ASPS member surgeons to conduct registry-based research. This article pairs with the report of the authors' TOPS registry investigation related to 30-day adverse events associated with incision location for augmentation mammaplasty.

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 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.

BACKGROUND Venous thromboembolism is a dreaded complication following microsurgical breast reconstruction. Although the high-risk nature of the procedure is well known, a thorough analysis of modifiable risk factors has not been performed. The purpose of this study was to analyze the association of such factors with the postoperative occurrence of venous thromboembolism longitudinally. METHODS Using the Truven MarketScan Database, a retrospective cohort study of women who underwent microsurgical breast reconstruction from 2007 to 2015 and who developed postoperative venous thromboembolism within 90 days of reconstruction was performed. Predictor variables included age, timing of reconstruction, body mass index, history of radiation therapy, history of venous thromboembolism, Elixhauser Comorbidity Index, and length of stay. Univariate analyses were performed, in addition to logistic and zero-inflated Poisson regressions, to evaluate predictors of venous thromboembolism and changes in venous thromboembolism over the study period, respectively. RESULTS Twelve thousand seven hundred seventy-eight women were identified, of which 167 (1.3 percent) developed venous thromboembolism. The majority of venous thromboembolisms (67.1 percent) occurred following discharge, with no significant change from 2007 to 2015. Significant predictors of venous thromboembolism included Elixhauser score (p < 0.01), history of venous thromboembolism (p < 0.03), and length of stay (p < 0.001). Compared to patients who developed a venous thromboembolism during the inpatient stay, patients who developed a postdischarge venous thromboembolism had a lower mean Elixhauser score (p < 0.001). CONCLUSIONS Postoperative venous thromboembolism continues to be an inadequately addressed problem, as evidenced by a stable incidence over the study period. Identification of modifiable risk factors, such as length of stay, provides potential avenues for intervention. As the majority of venous thromboembolisms occur following discharge, future studies are warranted to investigate the role for an intervention in this period. CLINICAL QUESTION/LEVEL OF EVIDENCE Risk, III.

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. Level of Evidence: 4

BACKGROUND Enhanced understanding of early postoperative adverse events will improve patient counseling and preoperative risk modification to decrease complications in implant-based breast augmentation. This study seeks to evaluate the early major adverse events following cosmetic breast augmentation. METHODS A retrospective cohort analysis of the Tracking Outcomes and Operations for Plastic Surgeons database was performed to identify any women undergoing augmentation mammaplasty with an implant between 2008 and 2016. RESULTS A total of 84,296 patients were studied. Major adverse events were identified in 0.37 percent. Seroma requiring drainage was observed in 0.08 percent, hematoma requiring drainage was observed in 0.15 percent, deep wound disruption was observed in 0.09 percent, and implant loss was observed in 0.11 percent. The authors identified multiple independent predictors of major adverse events, including body mass index greater than 30 kg/m2 (relative risk, 2.05; p < 0.001), tobacco use (relative risk, 2.25; p < 0.001), and diabetes mellitus (relative risk, 1.8; p < 0.05). Use of a periareolar incision significantly increased the risk of developing an early postoperative complication (relative risk, 1.77; p < 0.001). CONCLUSIONS The findings of this study indicate an early major adverse event rate following cosmetic breast augmentation with implants of 0.37 percent. The authors identified multiple independent predictors of major adverse events, including body mass index greater than 30 kg/m2, tobacco use, and diabetes mellitus. In addition, when controlling for other factors, periareolar incision significantly increased the risk for major adverse events, when compared to an inframammary incision. CLINICAL QUESTION/LEVEL OF EVIDENCE Therapeutic, III.

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.

Background As posterior component separation techniques continue to gain popularity there is uncertainty regarding the degree of fascial advancement afforded by the various techniques. Our study seeks to compare the degree anterior rectus sheath translation seen in full transversus abdominus release compared to simple release of the posterior lamella of the rectus sheath. Methods Ten hemi-abdomens in five fresh cadavers were dissected. One hemi-abdomen underwent external oblique release. The contralateral hemi-abdomen underwent retrorectus dissection and initial release of the internal lamella of the internal oblique, followed by full transversus abdominus release. A 4 kg weight was suspended from the fascia and excursion was measured after 1) external oblique separation, 2) posterior lamella of the internal oblique separation, and 3) transversus abdominis separation. Results Average unilateral hemifascial translation after release of the external oblique provided an average unilateral hemi-fascial translation of 3.38 cm (+/- 0.69). Release of the posterior lamella of the internal oblique provided 3.98 cm (+/- 0.94). After transversus release the average translation increased to 4.31 cm (+/- 0.89). Conclusions In this cadaveric study, the majority (92%) of fascial advancement afforded by posterior component separation was achieved by an intermediate step in the transversus abdominus release operation: division of the posterior lamella of the internal oblique.

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.

The accepted "one-size-fits-all" dose strategy for prophylactic enoxaparin may not optimize the medication's risks and benefits after surgical procedures. The authors hypothesized that weight-based administration might improve the pharmacokinetics of prophylactic enoxaparin when compared to fixed-dose administration.The FIxed or Variable Enoxaparin (FIVE) trial was a randomized, double-blind trial that compared the pharmacokinetic and clinical outcomes of patients assigned randomly to postoperative venous thromboembolism prophylaxis using enoxaparin 40 mg twice daily or enoxaparin 0.5 mg/kg twice daily. Patients were randomized after surgery and received the first enoxaparin dose at 8 hours after surgery. Primary hypotheses were (1) weight-based administration is noninferior to a fixed dose for avoiding underanticoagulation (anti-factor Xa0.2 IU/ml) and (2) weight-based administration is superior to fixed-dose administration for avoiding overanticoagulation (anti-factor Xa0.4 IU/ml). Secondary endpoints were 90-day venous thromboembolism and bleeding.In total, 295 patients were randomized, with 151 assigned to fixed-dose and 144 to weight-based administration of enoxaparin. For avoidance of under anticoagulation, weight-based administration had a greater effectiveness (79.9 percent versus 76.6 percent); the 3.3 percent (95 percent CI, -7.5 to 12.5 percent) greater effectiveness achieved statistically significant noninferiority relative to the a priori specified -12 percent noninferiority margin (p = 0.004). For avoidance of overanticoagulation, weight-based enoxaparin administration was superior to fixed-dose administration (90.6 percent versus 82.2 percent); the 8.4 percent (95 percent CI, 0.1 to 16.6 percent) greater effectiveness showed significant safety superiority (p = 0.046). Ninety-day venous thromboembolism and major bleeding were not different between fixed-dose and weight-based cohorts (0.66 percent versus 0.69 percent, p = 0.98; 3.3 percent versus 4.2 percent, p = 0.72, respectively).Weight-based administration showed superior pharmacokinetics for avoidance of underanticoagulation and overanticoagulation in postoperative patients receiving prophylactic enoxaparin.Therapeutic, I.

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.

The purpose of this study was to determine if fixed dose enoxaparin prophylaxis provided effective anticoagulation for acute care surgery patients and to examine whether a real-time enoxaparin dose adjustment algorithm optimized anticoagulation.Acute care surgical patients placed on enoxaparin prophylaxis 30 mg twice daily were recruited prospectively. Peak steady state aFXa levels were drawn with a goal peak aFXa range of 0.2-0.4 IU/ml. A real time dose adjustment algorithm was implemented for patients with out-of-range levels.Fifty five patients were included. 56.4% of patients had low aFXa levels (0.2 IU/mL). Real-time enoxaparin dose adjustment significantly increased the proportion of patients who achieved in-range peak aFXa levels, compared to standard dosing (74.5% vs 41.8%, p 0.001). Patients with initial inadequate peak aFXa levels had a higher rate of 90-day post-operative VTE, although not statistically significant (16.1% vs. 8.3%, p = 0.50).The majority of acute care surgery patients receive inadequate VTE prophylaxis with fixed enoxaparin dosing.

Background Venous thromboembolism is a life- or limb-threatening complication that occurs in plastic surgery patients. At present, the optimal dose of enoxaparin that balances the risk of venous thromboembolism and the risk of medication-related adverse drug events-specifically, bleeding-remains unknown. Methods This study compared pharmacodynamic and clinical outcomes, including 90-day venous thromboembolism and 90-day clinically relevant bleeding, between two prospectively performed clinical trials whose sole difference was postoperative anticoagulation strategy. Patients in trial 1 received enoxaparin 40 mg once daily for the duration of inpatient stay, and patients in trial 2 received enoxaparin 40 mg twice daily for the duration of inpatient stay. The study also examined the potential impact of a weight-based twice-daily prophylaxis strategy to achieve in-range anti-factor Xa levels. Results The study compared 94 patients who received once-daily enoxaparin to 118 patients who received twice-daily enoxaparin. Twice-daily enoxaparin was associated with a significant decrease in 90-day acute venous thromboembolism (0 percent versus 5.3 percent; p = 0.012) and a nonsignificant increase in 90-day clinically relevant bleeding (6.8 percent versus 3.2 percent; p = 0.25). Twice-daily enoxaparin at 0.4 to 0.5 mg/kg may allow an increased proportion of patients to avoid both inadequate anticoagulation and overanticoagulation, based on anti-factor Xa levels. Conclusions Twice-daily enoxaparin is superior to once-daily enoxaparin for 90-day acute venous thromboembolism risk reduction. Twice-daily enoxaparin may increase clinically relevant bleeding, although observed differences in this study were not significant. Weight-based twice-daily enoxaparin dosing may optimize the risks and benefits of prophylactic anticoagulation after plastic and reconstructive surgery. Clinical question/level of evidence Therapeutic, II.

To determine the feasibility and impact of real-time anti-factor Xa (aFXa) level monitoring and enoxaparin dose adjustment in orthopaedic trauma. To examine the adequacy of standard fixed-dose enoxaparin chemoprophylaxis and to examine whether patient-specific factors influence enoxaparin metabolism.Prospective cohort.Academic Level-I trauma center.Postoperative adult orthopaedic trauma patients undergoing acute fracture or nonunion surgery of the pelvis, acetabulum, or lower extremity placed on 30 mg of enoxaparin twice daily.Peak steady-state aFXa levels were drawn with a goal range of 0.2-0.4 IU/mL. Patients with out-of-range levels underwent a 10-mg dose adjustment followed by repeat aFXa draws.Peak and trough aFXa levels, 90-day venous thromboembolism, and bleed events.Of 109 enrolled patients, 43% had inadequate initial peak aFXa levels (aFXa0.2 IU/mL) with standard dosing. Higher gross weight, acetabular surgery, and operation length predicted low aFXa levels (P0.001, 0.006, 0.004, respectively). Dose adjustment increased the proportion of patients with in-range aFXa levels from 53.2% to 87.8% (P0.001). Patients with low aFXa levels during hospitalization or at discharge had significantly higher 90-day deep vein thrombosis and pulmonary embolism rates compared to those with adequate aFXa levels (deep vein thrombosis 12% vs. 1.36%; P = 0.023, pulmonary embolism 8% vs. 0%; P = 0.027). There were no major bleed events.Patients receiving inadequate enoxaparin chemoprophylaxis were at significantly increased risk of 90-day venous thromboembolism. Standard fixed-dose enoxaparin provided inadequate chemoprophylaxis in 43% of postoperative orthopaedic trauma patients, which significantly improved with dose adjustment. Weight, acetabular surgery, and operation length predicted inadequate enoxaparin prophylaxis.Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

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.

Perioperative venous thromboembolism (VTE) risk can be quantified with the 2005 Caprini score. The Caprini score has previously been validated by review of the electronic medical record (EMR) in3000 plastic surgery patients. However, the accuracy of Caprini-based risk stratification using the EMR, as opposed to face-to-face contact with the patient, remains unknown.Plastic and reconstructive surgery patients who had surgery under general anesthesia, required postoperative admission, and were started on enoxaparin prophylaxis were identified. The 2005 Caprini scores were calculated retrospectively using EMR review only (no direct contact with the patients) to establish cohort 1. The 2005 Caprini scores were calculated prospectively using face-to-face interaction with the patients, followed by EMR review, to establish cohort 2. For all included patients, EMR review or face-to-face screening was personally performed by the authors. We compared the proportions of patients with identified Caprini risk factors and the aggregate risk scores of patients between cohorts.Complete data were available for 536 unique patients in the EMR review cohort and 207 unique patients in the face-to-face cohort. Patients whose risk scores were calculated face to face had higher Caprini scores than those calculated by EMR review alone. The face-to-face cohort had a higher proportion of patients risk stratified as Caprini 7-8 (29.5% vs 24.8%) and Caprini8 (26.6% vs 10.5%) compared with the EMR review cohort. Patients risk stratified by face-to-face discussion were significantly more likely to be stratified into a higher risk Caprini stratum. Face-to-face discussion identified a 2-fold increase in patients with personal history of deep venous thrombosis (12.6% vs 6.3%; P = .005), a 3-fold increase in patients with family history of VTE (16.9% vs 5.2%; P .001), and a 20-fold increase in patients with personal history of multiple lost pregnancies (13.6% vs 0.6%; P .001) compared with EMR review. Observed differences for family history of VTE and history of pregnancy loss persisted after propensity score analysis, created using component variables in the 2005 Caprini score plus gender; this supports the conclusion that observed differences were not due to site variation or case mix.When it is used in isolation, the EMR may provide inaccurate estimation of patient-level VTE risk using the 2005 Caprini score. This study demonstrates that EMR review may miss key VTE risk factors, such as personal or family history of VTE, history of pregnancy loss, and others; this omission results in lower estimates of perioperative VTE risk. The importance of provider-patient interaction for accurate VTE risk stratification cannot be overstated.

Background Surgeons commonly provide enoxaparin prophylaxis to high-risk patients to decrease venous thromboembolism risk. The authors' prior work demonstrated that most patients receive inadequate venous thromboembolism prophylaxis, based on anti-factor Xa level, when enoxaparin 40 mg/day is provided and that peak anti-factor Xa level correlates with weight. This study models a weight-based strategy for daily enoxaparin prophylaxis and its impact on anti-factor Xa levels. Methods The authors enrolled plastic surgery patients who received enoxaparin 40 mg/day and had anti-factor Xa levels drawn. The enoxaparin dose of 40 mg was converted to a milligram-per-kilogram dose for each patient. Stratified analysis examined the milligram-per-kilogram dose that produced low, in-range, and high anti-factor Xa levels to identify the appropriate milligram-per-kilogram dose to optimize venous thromboembolism prevention and bleeding events. Results Among 94 patients, weight-based dosing ranged from 0.28 to 0.94 mg/kg once daily. For peak and trough anti-factor Xa levels, there was nearly complete overlap for milligram-per-kilogram dosing that produced low versus in-range anti-factor Xa levels. For peak anti-factor Xa, there was nearly complete overlap for milligram-per-kilogram dosing that produced in-range versus high anti-factor Xa levels. Mean milligram-per-kilogram dose was not significantly different between patients who did or did not have postoperative venous thromboembolism (0.41 mg/kg versus 0.52 mg/kg; p = 0.085) or clinically relevant bleeding (0.48 mg/kg versus 0.51 mg/kg; p = 0.73). Conclusions Alterations in enoxaparin dose magnitude based on patient weight cannot allow a high proportion of patients to achieve appropriate anti-factor Xa levels when once-daily enoxaparin prophylaxis is provided. Future research should examine the impact of increased enoxaparin dose frequency on anti-factor Xa levels, venous thromboembolism events, and bleeding. Clinical question/level of evidence Therapeutic, IV.

Background Despite guideline-compliant prophylaxis, an increased rate of deep venous thrombosis (DVT) formation has been reported following autologous versus implant-based breast reconstruction. We hypothesized that tight abdominal fascia closure might decrease lower extremity venous return and promote venous stasis. Methods An observational crossover study of patients who underwent autologous breast reconstruction using transverse rectus abdominis musculocutaneous/deep inferior epigastric artery perforator flaps was conducted. Ultrasonographic measurements of the left common femoral vein (CFV) and right internal jugular vein (IJV) were performed preoperatively, in the postanesthesia care unit, and on postoperative day (POD) 1. Parameters of interest included vessel diameter, circumference, area, and maximum flow velocity. Results Eighteen patients with a mean age and body mass index of 52.7 years (range, 29–76 years) and 31.3 kg/m2 (range, 21.9–43.4 kg/m2) were included, respectively. A 29.8% increase in CFV diameter was observed on POD 1 (p Conclusion Postoperative changes observed in the CFV reflect increased lower extremity venous stasis after microsurgical breast reconstruction and may contribute to postoperative DVT formation.

Background Venous thromboembolism is an important patient safety issue in thoracic surgery patients. The optimal enoxaparin dose remains unclear. This multicenter pre/post clinical trial compared the pharmacokinetics of fixed versus weight-tiered enoxaparin, and their impact on 90-day venous thromboembolism and bleeding. Methods Thoracic surgery patients were prospectively enrolled using a pre/post study design. Cohort 1 received enoxaparin 40 mg daily, and cohort 2 received a weight-tiered regimen: less than 70 kg received 30 mg daily; 70 kg to 89.9 kg received 40 mg once daily; and 90 kg or more received 50 mg daily. The primary study outcome was peak anti-factor Xa levels in response to fixed or weight-tiered enoxaparin. Secondary outcomes included trough anti-factor Xa, 90-day symptomatic venous thromboembolism, and 90-day clinically relevant bleeding. Results One hundred thirty-one patients were prospectively enrolled, including 65 in the fixed-dose cohort and 66 in the weight-tiered cohort. No patient was lost to follow-up. Weight-tiered enoxaparin was not significantly more likely to produce adequate anticoagulation (peak anti-factor Xa 0.3 IU/mL or greater) when compared with fixed-dose enoxaparin (44.3% vs 48.2%, P = .67). Weight-tiered enoxaparin was not more likely to avoid over-anticoagulation (peak anti-factor Xa 0.5 IU/mL or greater) when compared with fixed-dose enoxaparin (3.3% vs 3.6%, P = 1.00). The groups had no significant difference in trough anti-factor Xa. Observed rates of 90-day symptomatic venous thromboembolism and clinically relevant bleeding were low (0% and 3.1%, respectively) and were not significantly different between groups. Conclusions This multicenter pre/post clinical trial did not show a pharmacokinetic advantage to weight-tiered enoxaparin, when compared with fixed-dose enoxaparin, in thoracic surgery patients. ( Clinicaltrials.gov identifier: NCT03251963 .)

Supplemental Digital Content is available in the text., Background: We examined the ability of plastic surgery patients to perform their own venous thromboembolism (VTE) risk stratification using a previously validated patient-completed Caprini risk scoring sheet. Methods: Patients’ Caprini scores were obtained by an attending physician at an office visit through interview and chart review. Subsequently, patients independently completed a previously validated patient reported scoring sheet. We compared patient and physician reported Caprini scores by each Caprini subquestion and by the overall score. We described discordance of scores using frequencies and proportions, quantified the level of agreement using Cohen’s Kappa coefficient, Spearman’s correlation coefficient, and the Wilcoxon rank-sum test, and visualize scoring differences using Bland–Altman plots, where appropriate. Results: We prospectively enrolled 50 patients. Only 24% (n = 12) of patients had exact matches in physician-completed and patient-completed Caprini scores. Among the 76% (n = 38) with discrepancies, 26 received a higher patient-reported score (median = 2 points, range 1–8 points) and 12 received a lower patient-reported score (median = −1.5 points, range −1 to −6 points). Existing venous thromboembolism prophylaxis guidelines support chemical prophylaxis for inpatients with Caprini scores ≥7. Among 38 patients with score discrepancies, 8 (21.1%) would have been incorrectly prescribed chemical prophylaxis and 4 (10.5%) would have been incorrectly denied chemical prophylaxis. Conclusions: Plastic surgery patients cannot reliably calculate their own 2005 Caprini scores. Reliance on patient completed scores alone would promote ~25% of patients receiving inappropriate prophylaxis strategies.

Previous work has demonstrated the occurrence of lower extremity venous stasis in the early postoperative period after breast reconstruction with free abdominal flaps. The authors investigated whether venous stasis persisted through the day of discharge, thus potentially exposing patients to an elevated risk of venous thromboembolism following discharge.Patients who underwent breast reconstruction with free abdominal flaps were enrolled prospectively and underwent duplex ultrasound of the common femoral vein at the following time points: preoperatively, postoperative day 1, and day of discharge. Parameters of interest included common femoral vein diameter, area, and maximum flow velocity.Thirty patients with a mean age of 50.3 years (range, 29 to 70 years) underwent breast reconstruction with 52 free abdominal flaps. A significant increase in common femoral vein diameter (19.1 percent; p0.01) and area (46.8 percent; p0.01) correlated with a significant reduction in maximum flow velocity (-10.9 percent; p = 0.03) between baseline and postoperative day 1. These changes persisted through the day of discharge [common femoral vein diameter, 17.8 percent (p0.01); area, 46 percent (p0.01); and maximum flow velocity, -11.3 percent (p = 0.01)]. Venous parameters were not influenced by unilateral versus bilateral flap harvest (p = 0.48).Postoperative lower extremity venous stasis following autologous breast reconstruction with free abdominal flaps seems to persist through the day of discharge. This finding may explain why patients remain at risk for venous thromboembolism after discharge. Although the authors' findings are at odds with current venous thromboembolism prophylaxis recommendations, additional studies are indicated to examine whether these findings translate into venous thromboembolism events.Therapeutic, IV.

Breast implants are typically placed for cosmetic or reconstructive purposes, and are recognized to have a substantial impact on aesthetics and quality of life. In addition, the presence of a breast implant on the chest wall has a potential benefit of force diffusion or force absorption in traumatic injury. This article reports a series of three patients with preexisting breast implants who suffered penetrating chest trauma. In each case, the presence of a breast implant was potentially lifesaving. We describe the cases in detail, provide a conceptual discussion, and discuss directions for future research. Level of Evidence: 5

Background We used the database of the American College of Surgeons National Surgical Quality Improvement Program to (1) identify risk factors for 30-day venous thromboembolism (VTE) after ventral hernia repair (VHR) and (2) to create and validate a condition-specific assessment tool for the risk of VTE. Methods Open and laparoscopic VHR patients in the American College of Surgeons National Surgical Quality Improvement Program were identified using Current Procedural Terminology code. The occurrence of VTE, including deep-venous thrombosis (DVT) or pulmonary embolus, within 30 days postoperatively was the primary outcome. Regression-based analysis and subsequent bootstrap analysis created a weighted VTE risk assessment model (RAM) for ventral hernia repair. The weighted RAM was used to risk-stratify patients for both 30-day VTE risk and 30-day risk for medical and surgical complications. Results Data for 113,873 hernia repair patients were obtained; 30-day deep-venous thrombosis, pulmonary embolus, and VTE rates were 0.59%, 0.43%, and 0.92%, respectively. The average time to VTE was 10.8 days. A 14-factor, weighted RAM was created. The weighted risk score identified a 25-fold variability (from 0.20 to 4.97%) in VTE risk among the overall VHR population. Although created to risk-stratify for VTE, the risk score also risk-stratified for 30-day medical and surgical complications, inpatient duration of stay, and 30-day mortality. Conclusion The 30-day VTE risk after VHR is 0.92%, but a 25-fold variability in VTE risk exists among the overall hernia population. We demonstrate that a weighted VTE RAM quantifies VTE risk among the population undergoing ventral hernia repair, and that VTE risk score can also be used to risk-stratify for 30-day medical and surgical complications as well as mortality.

Hypercoagulability can pose a significant problem in microsurgical reconstruction. Here, the authors provide a comprehensive review of macrovascular and microvascular clotting phenomena from the unique viewpoint of two microsurgeons and a hematologist. The authors review the literature surrounding prevention of microvascular clots and provide an extensive discussion of hereditary thrombophilia. The authors also make explicit recommendations regarding the utility of thrombophilia testing and preoperative and perioperative management strategies for patients with hypercoagulability.

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.

Low anti-factor Xa level, indicative of inadequate enoxaparin dosing, has a significant association with 90-day venous thromboembolism events. The authors examined the pharmacodynamics of enoxaparin 40 mg twice daily and its correlation with anti-factor Xa level, postoperative venous thromboembolism, and bleeding.Adult patients were admitted after plastic and reconstructive surgery and received enoxaparin 40 mg twice daily. Peak anti-factor Xa levels, which quantify enoxaparin's antithrombotic effect, were drawn, with a goal level of 0.2 to 0.4 IU/ml. Ninety-day symptomatic venous thromboembolism and clinically relevant bleeding were identified.The authors enrolled 118 patients who received enoxaparin 40 mg twice daily. Of these patients, 9.6 percent had low peak anti-factor Xa levels (0.2 IU/ml), 62.6 percent had in-range peak anti-factor Xa levels (0.2 to 0.4 IU/ml), and 27.8 percent had high anti-factor Xa levels (0.4 IU/ml). With enoxaparin 40 mg twice daily, 90.4 percent of patients received at least adequate prophylaxis. Patient weight predicted the rapidity of enoxaparin metabolism. Zero acute 90-day venous thromboembolism occurred. Eight patients (6.8 percent) had clinically relevant 90-day bleeding: clinical consequences ranged from cessation of enoxaparin prophylaxis to transfusion to operative hematoma evacuation.When enoxaparin 40 mg twice daily is provided, 90 percent of patients receive at least adequate venous thromboembolism prophylaxis (anti-factor Xa level0.2 IU/ml). However, 27 percent of the overall population is overtreated (anti-factor Xa level0.4 IU/ml). These pharmacodynamics data likely explain the low rate of 90-day acute venous thromboembolism (0 percent) and the high rate of clinically relevant bleeding (6.8 percent) observed. Future studies are needed to better optimize the risks and benefits of enoxaparin prophylaxis in plastic and reconstructive surgery patients.Therapeutic, IV.

Many patients undergoing thoracic surgical procedures have venous thromboembolism (VTE) events despite the receipt of chemical prophylaxis. Enoxaparin's pharmacologic impact can be quantified by using anti-Factor Xa (aFXa) levels. We hypothesized that enoxaparin 40 mg once daily would be inadequate for most inpatients undergoing thoracic surgical procedures and that a real-time dose adjustment algorithm would be effective.This prospective clinical trial enrolled inpatients who were to undergo a thoracic surgical procedure and placed on enoxaparin 40 mg once daily for VTE prophylaxis after surgical procedures. aFXa levels were used to measure the anticoagulant effect of enoxaparin once steady state had been reached. Patients whose aFXa levels were out of range received real-time enoxaparin dose adjustment and had repeat aFXa levels drawn.Ninety-three inpatients undergoing thoracic surgical procedures were prospectively enrolled. The majority of patients (67.4%) had low peak aFXa levels (0.3 IU/mL), indicative of inadequate enoxaparin prophylaxis, and 30.3% of patients had in-range aFXa levels (0.3 to 0.5 IU/mL). Patient weight had a moderate correlation (rEnoxaparin 40 mg once daily is inadequate for most inpatients undergoing thoracic surgical procedures, based on a pharmacodynamic study of aFXa levels. Future research should examine the impact of weight-based once daily enoxaparin dosing versus twice daily enoxaparin dosing on prophylaxis adequacy.

We appreciate the opportunity to review this article by Dr Hunstad and his colleagues.1 The authors report on observed rates of venous thromboembolism (VTE) and reoperative hematoma in a case series of 132 abdominoplasty patients who received chemoprophylaxis with rivaroxaban 10 mg daily beginning 12 hours after surgery and continuing for ≥7 days. The oral direct inhibitors of factor Xa (FXa) are the newest class of anticoagulant drugs and have ever-expanding indications. Factor X can be activated (to FXa) via either the intrinsic or extrinsic clotting pathways. FXa promotes conversion of prothrombin to thrombin, resulting in clot formation. Enoxaparin accelerates the activity of antithrombin, which accelerates the rate of inactivation of FXa. Inactivation of FXa subsequently decreases thrombin generation. Fondaparinux, the effect of which is largely mediated through FXa inhibition (with some inhibition of Factor IXa), is also an effective anticoagulant. Clinical utility of fondaparinux identified FXa as an appealing target for anticoagulants because it represents a unifying pathway of the extrinsic and intrinsic clotting pathways.2 Rivaroxaban is an oral direct inhibitor of FXa. Rivaroxaban is approved by the United States Food and Drug Administration for prevention of stroke and systemic embolism for patients with nonvalvular atrial fibrillation, treatment of acute VTE, long-term prevention of recurrent VTE after an initial 6 months of therapy, and prevention of VTE after total knee or hip arthroplasty. Approval was based on large phase III trials showing noninferior or superior efficacy and similar or reduced rates of major, intracranial, and fatal bleeding compared with conventional anticoagulants (ie, enoxaparin and/or warfarin).3-7 For patients undergoing total knee arthroplasty, rivaroxaban 10 mg daily reduced the primary outcome of VTE and death compared with enoxaparin 40 mg daily (9.6% vs 18.9%, P < .001) without increased bleeding.6 Similar findings were observed after …

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.

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.

Venous thromboembolism (VTE) can be a life-threatening or limb-threatening complication of thermal injury. The severity of burn injury can be used to predict VTE risk among patients with thermal injury, and a weighted risk-stratification tool has been developed. This article reviews the incidence, diagnosis, and management of thromboembolic events in patients with burns. The article particularly focuses on identifying those patients who are at highest risk for VTE and provides recommendations on mechanical and chemical prophylaxis.

This ballistics study examines whether saline breast implants can decrease tissue penetration in firearm injuries. We hypothesize that the fluid column within a saline breast implant can alter bullet velocity and/or bullet pattern of mushrooming. The two experimental groups included saline implants with 7.4 cm projection and a no implant group. The experimental design allowed the bullet to pass-through an implant and into ballistics gel (n = 10) or into ballistics gel without passage through an implant (n = 11). Shots that passed through an implant had 20.6% decreased penetration distance when compared to shots that did not pass-through an implant; this difference was statistically significant (31.9 cm vs. 40.2 cm, p < 0.001). Implant group bullets mushroomed prior to gel entry, but the no implant group mushroomed within the gel. Bullet passage through a saline breast implant results in direct bullet velocity reduction and earlier bullet mushrooming; this causes significantly decreased ballistics gel penetration.

Background Evidence-based plastic surgery guidelines support the effectiveness of once-daily enoxaparin prophylaxis. Despite prophylaxis, one in 25 highest risk patients has a venous thromboembolism event. The authors examined the pharmacodynamics of standard enoxaparin doses in plastic surgery patients to examine whether patient-level factors predict enoxaparin metabolism, whether inadequate enoxaparin dose predicts downstream venous thromboembolism events, and whether a pharmacist-driven dose-adjustment protocol was effective. Methods The authors recruited adult plastic surgery patients who received postoperative enoxaparin at 40 mg/day. Steady-state peak anti-factor Xa levels, a marker of enoxaparin effectiveness and safety, were determined. Patients with out-of-range anti-factor Xa levels had real-time dose adjustment based on a written protocol. Patients were followed for 90-day venous thromboembolism events. Results Ninety-four patients were recruited, and 44 percent had in-range peak anti-factor Xa levels in response to standard enoxaparin dosing. Patient-level factors including extent of surgical injury and gross weight were independent predictors of enoxaparin metabolism. Patients with low anti-factor Xa levels were significantly more likely to have 90-day venous thromboembolism (10.2 percent versus 0 percent; p = 0.041). Real-time dose adjustment allowed a significantly increased proportion of patients to have in-range levels (67.1 percent versus 44.3 percent; p = 0.002). Conclusions Based on pharmacodynamic data, the majority of plastic surgery patients receive inadequate enoxaparin prophylaxis using fixed dosing. Patient-level factors can predict how patients will metabolize enoxaparin, and patients who receive inadequate enoxaparin prophylaxis are significantly more likely to have downstream venous thromboembolism events. Individualization of enoxaparin prophylaxis may minimize perioperative venous thromboembolism risk and further improve patient safety after plastic and reconstructive surgery procedures. Clinical question/level of evidence Therapeutic, II.

Importance Health care professionals do not adequately stratify risk or provide prophylaxis for venous thromboembolism (VTE) among surgical patients. Computerized clinical decision support systems (CCDSSs) have been implemented to assist clinicians and improve prophylaxis for VTE. Objective To evaluate the effect of implementing CCDSSs on the ordering of VTE prophylaxis and the rates of VTE. Data Sources PubMed, MEDLINE via OVID, EMBASE via OVID, Scopus, Cochrane CENTRAL Register of Controlled Trials, and clinicaltrials.gov were searched in June 2016 for articles published in English from October 15, 1991, to February 16, 2016. A manual search of references from relevant articles was also performed. Study Selection Clinical trials and observational studies among surgical patients comparing CCDSSs with VTE risk stratification and assistance in ordering prophylaxis vs routine care without decision support were included. Of the 188 articles screened, 11 (5.9%) were eligible for meta-analysis. Data Extraction and Synthesis Meta-analysis of Observational Studies in Epidemiology guidelines were followed. Two reviewers extracted data and assessed quality independently. Main Outcomes and Measures Rates of prophylaxis for VTE and VTE events. Random- and fixed-effects models were used to summarize odds ratios and risk ratios. Results Eleven articles (9 prospective cohort trials and 2 retrospective cohort trials) comprising 156 366 individuals (104 241 in the intervention group and 52 125 in the control group) were included. The use of CCDSSs was associated with a significant increase in the rate of appropriate ordering of prophylaxis for VTE (odds ratio, 2.35; 95% CI, 1.78-3.10; P P Conclusions and Relevance Use of CCDSSs increases the proportion of surgical patients who were prescribed adequate prophylaxis for VTE and correlates with a reduction in VTE events.

Venous thromboembolism (VTE) is one of the most common and feared complications in surgical patients, and its prevention has been the subject of a Call to Action from the Surgeon General of the United States. Here, we review the literature on the use of risk assessment models for the stratification of surgical patients into risk groups to guide the administration of pharmacoprophylaxis. Despite some disagreement in the literature and among various guidelines, there is good evidence that risk stratification identifies a 7- to 20-fold variation in postoperative VTE risk among the overall surgical population, including patients at both low and high risk. This information is useful to providers who are making decisions about mechanical prophylaxis and pharmacoprophylaxis.