Postoperative Low Molecular Weight Heparin Research Articles

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

BackgroundMetabolic and bariatric surgery (MBS) venous thromboembolism (VTE) prescribing practices vary widely. Our institutional VTE prophylaxis protocol has historically been unstandardized. ObjectivesTo 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. SettingSingle Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program-accredited academic hospital. MethodsWe 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. ResultsA 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. ConclusionsDeveloping 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.

Preoperative Venous Thromboembolism Screening and Postoperative Selective Anticoagulant Therapy Effectively Prevents Postoperative Symptomatic Venous Thromboembolism in Gynecological Malignancies: A 15-Year, Single-Center Study.

The aim of this study was to determine which type of prophylaxis was effective for postoperative symptomatic venous thromboembolism (VTE) in patients with gynecological malignancies. A total of 1756 consecutive patients undergoing laparotomy as first-line treatment were included. In Period 1 (2004-2009), low-molecular weight heparin (LMWH) was not available for postoperative VTE prophylaxis, but available in after Period 2 (2009-2013). In Period 3 (2013-2020), patients with pretreatment VTE could switch from LMWH to direct oral anticoagulant (DOAC) as of 2015. Preoperative VTE was screened by measuring D-dimer, followed by venous ultrasound imaging, and computed tomography and/or perfusion lung scintigraphy. Postoperative symptomatic VTE occurred with an incidence of 2.8% by the measures without prophylactic LMWH administration in Period 1. The incidence of postoperative symptomatic VTE was 0.6% in Period 2 and 0.3% in Period 3, being significantly reduced compared with Period 1 (P < .01 and < .0001). The incidences were not significantly different between Periods 2 and 3, but no patient switching to DOAC in Period 3 (n = 79) developed symptomatic VTE. Our preoperative VTE screening and postoperative selective LMWH administration were significantly preventive against postoperative symptomatic VTE.

Intraoperative Heparin Bolus and Postoperative Anticoagulation with Low Molecular Weight Heparin Increase Reliability of Microsurgical Free Flaps for Upper Extremity Reconstruction.

Microsurgery is an indispensable tool of upper extremity reconstruction addressing defect coverage and the restoration of function. Perioperative anticoagulation and antiplatelet therapy are controversially discussed with impact on microsurgical outcome, but without clear evidence. This study aims to evaluate the impact of perioperative anticoagulation and antiplatelet therapy in microsurgical upper extremity reconstruction. All eligible patients treated with microsurgical upper extremity reconstruction between January 2000 and July 2014 were included in a comparative analysis to define a superior anticoagulation and antiplatelet regime in a retrospective study. Endpoints were all major complications (e.g., total flap loss, arterial and venous thrombosis) as well as minor complication. A total of 183 eligible free flaps to the upper extremity were transferred in 169 patients. Altogether, 11 arterial (6.0%) and 9 venous (4.9%) thromboses, 11 total flap losses (6.0%), and 16 cases with hematoma (8.7%) were detected. In the subgroup analysis, patients who did not receive any heparin intraoperatively (n = 21; 11.5%) had a higher rate of major complications (p = 0.001), with total flap loss being the most frequent event (p = 0.004). A trend was shown for intraoperative bolus administration of 501 to 1,000 units unfractionated heparin (UFH) intravenously to have the lowest rate of major complications (p = 0.058). Intraoperative administration of acetylsalicylic acid (n = 13; 8.1%) did not have any influence on the rate of major complications. Postoperative anticoagulation with continuous UFH intravenously (n = 68; 37.2%) resulted in more frequent complications (p = 0.012), for example, an increased rate of total flap loss (p = 0.02) and arterial thrombosis (p = 0.02). The results of the present study favor administration of 501 to 1,000 units UFH intravenously as an intraoperative bolus (e.g., 750 units UFH intravenously). Postoperative low molecular weight heparin subcutaneous application in a prophylactic dose given once or twice a day was associated with less complications compared with continuous infusion of UFH, although continuously applied UFH may reflect an increased risk profile.

A Prospective Study Assessing Wound Complications in a Series of Foot and Ankle Patients Treated With Enoxaparin: A Baseline for Future Studies.

Background and objectiveLow-molecular-weight heparin (LMWH) prophylaxis has now become the gold-standard practice in patients requiring lower limb immobilization. We had noticed an increase in the incidence of wound-healing problems at our center, and the severity of the problems was found to be worse in patients undergoing foot and ankle surgery since we had adopted this practice. In this study, we aimed to describe the incidence and severity of wound-healing problems in this group of patients.MethodsThis was a prospective study and we collected data on the frequency and severity of wound problems occurring in patients undergoing a variety of foot and ankle operations. All patients underwent a standard agreed-on method of wound closure and dressings. Wounds were reviewed after two weeks and wound characteristics were noted using a rigid proforma. The primary outcome measure was to determine the incidence of delayed wound healing (DWH) and wound infections requiring antibiotics. Secondary outcomes were the characteristics of each delayed-healing wound.ResultsA total of 158 patients met the inclusion criteria of the study. One patient was not given postoperative LMWH and was excluded from the final analysis. Seven patients (4.5%) were noted to have DWH and four patients (2.6%) had a wound infection at the two-week postoperative follow-up. None of the patients required a second operation. Among patients with wound-healing problems, wound contour irregularities were noted in 51% and margin separation was noted in 65%.ConclusionThe overall incidence of wound-healing problems such as DWH and wound infections was low in patients receiving prophylactic LMWH for foot and ankle surgery. Where postoperative wound problems did occur, these were associated with poor wound characteristics such as margin separation or contour irregularity. Further studies should be conducted to ascertain if the use of LMWH leads to problems with wound appearance.

Extended thromboprophylaxis following major abdominal/pelvic cancer-related surgery: A systematic review and meta-analysis of the literature

BackgroundPostoperative venous thromboembolism (VTE) is a significant source of morbidity and mortality in cancer patients undergoing major abdominopelvic surgery. Many guidelines recommend the use of extended duration postoperative low molecular weight heparin (LMWH) thromboprophylaxis, although the evidence for its overall safety and efficacy is unclear. AimsWe sought to assess the 30-day postoperative rates of VTE and bleeding complications following major abdominopelvic cancer surgery and to explore the potential risks and benefits of extended duration thromboprophylaxis with LMWH in such setting. MethodsA systematic search of the literature was conducted. Observational studies and RCTs of adult patients that underwent abdominopelvic cancer surgery were included. Pooled proportions for the outcome measures and pooled relative risks for the extended duration thromboprophylaxis analyses were generated. ResultsA total of 68 studies (1,631,118 patients) were included in the analysis. The 30-day postoperative rate of VTE was 1.7% (95%CI: 1.5 to 1.9, I2 = 98%). The postoperative rate of clinically-relevant bleeding complications was 3.5% (95%CI: 1.6 to 6.1, I2 = 99%). Extended duration thromboprophylaxis was associated with a significant reduction in the incidence of clinical VTE (1.0% vs 2.1%; Risk ratio (RR) 0.48, 95%CI: 0.31 to 0.74; I2 = 0), without a significant increase in clinically-relevant bleeding (4.0% vs. 4.9%; RR 1.0, 95%CI: 0.66 to 1.5, I2 = 0). ConclusionsThe overall risk of symptomatic VTE within 30 days of surgery was relatively low. Extended LMWH thromboprophylaxis following major abdominopelvic cancer surgery was associated with a reduced incidence of clinical VTE without an increase in clinically-relevant bleeding.

Postoperative low molecular weight heparin bridging treatment for patients at high risk of arterial thromboembolism (PERIOP2): double blind randomised controlled trial

ObjectiveTo determine the efficacy and safety of dalteparin postoperative bridging treatment versus placebo for patients with atrial fibrillation or mechanical heart valves when warfarin is temporarily interrupted for a planned...

Posterior Fossa Hemorrhage Following the Use of Low-Molecular-Weight Heparin: Lessons Learned and Recommendations for the Treatment and Prophylaxis of Postoperative Venous Thromboembolism.

IntroductionVenous thromboembolism (VTE) is the most common preventable cause of morbidity and mortality among neurosurgery patients. Several studies have concluded that the use of chemical prophylaxis among patients undergoing a craniotomy reduces the incidence of VTE, and it is presumed to be safe. However, these studies do not differentiate between a supratentorial and posterior fossa craniotomy. Furthermore, the prophylactic or therapeutic use of low-molecular-weight heparin (LMWH) has been reported to increase the risk of intracranial hemorrhage. In this study, we describe the clinical details and outcomes for all patients who underwent posterior fossa craniotomy and developed posterior fossa hemorrhage secondary to postoperative use of LMWH during the study period. We also propose recommendations pertaining to postoperative heparin use after posterior fossa surgeries.MethodsData were retrospectively collected for patients presenting with posterior fossa hemorrhage following anticoagulant use among those who previously underwent posterior fossa craniotomy by the senior author (R.W.P.) from January 1, 2011, through December 31, 2018.ResultsWe identified five patients who experienced postoperative hemorrhage while receiving LMWH in the initial setting of posterior fossa craniotomy. After hemorrhaging, four patients had low Glasgow Outcome Scale (GOS) scores (≤3) and failed to return to their baseline neurological status. These four patients had a Glasgow Coma Scale (GCS) score of 15/15 in the immediate postoperative period and received heparin within 72 hours of surgery.ConclusionsBased on our findings, there is a possible association between the increased risk of hemorrhage and the early postoperative use of LMWH. The debilitating outcomes among the majority of these patients warrant the cautious use and further investigation of postoperative LMWH to appropriately quantify the risk. Further comparative studies with a larger sample size are required to provide insight into the pathophysiology of our findings.

Adding a Preoperative Dose of LMWH may Decrease VTE Following Bariatric Surgery.

Bariatric procedures are the most effective management for obesity. There is no standard venous thromboembolism (VTE) prophylaxis for both dosing and duration of anticoagulation following laparoscopic sleeve gastrectomy. Our purpose was to assess the optimum regimen for VTE prophylaxis in bariatric procedures and to reduce the incidence of perioperative bleeding. This is a prospective randomized study which involved 100 morbidly obese patients, subdivided into two groups; group A received postoperative low molecular weight heparin (LMWH) prophylaxis alone starting from day 1 to day 15 in dose 1mg/kg/day in a maximum dose 120mg/day, and group B received both pre- and postoperative LMWH; at night of surgery 12h preoperatively and postoperative starting from day 1 to day 15 with the same dose. All patients underwent mesenteric and bilateral lower limbs duplex 15days postoperative using Philips iU machine and linear (L9-3), convex (C5-1) and sector (S5-1) probes. Regarding postoperative VTE, we found statistically significant increase in postoperative VTE in patients of group A (four cases) without any case complicated with VTE in patients of group B (P value = 0.041). Regarding postoperative bleeding, we found statistically insignificant percent of cases complicated with postoperative bleeding in group B compared to group A (P value 0.315). Preoperative as well as a postoperative prophylactic anticoagulant as LMWH is recommended to prevent perioperative VTE. There was an insignificant increase in postoperative bleeding in patients who received preoperative prophylactic anticoagulants.

Efficacy and Safety of Low-Molecular-Weight Heparin on Prevention of Venous Thromboembolism after Laparoscopic Operation for Gastrointestinal Malignancy in Japanese Patients: A Multicenter, Open-Label, Prospective, Randomized Controlled Trial

The risk of venous thromboembolism (VTE) after surgery for malignancy in Japanese patients is unclear; therefore, standard prevention protocols have not been established, especially for minimally invasive procedures. We aimed to investigate the additional effect of low molecular weight heparin (LMWH) on prevention of VTE after laparoscopic surgery for gastrointestinal malignancy. From February 2013 to January 2017, 400 patients scheduled for laparoscopic surgery were included. Cases were randomly allocated to the physical therapy group (Control group; 201 patients) or to the combination-therapy group (LMWH group; 199 patients), in which enoxaparin sodium (20 mg [= 2000 IU] twice a day) was administered for 1 week postoperatively in addition to the physical therapy. A diagnosis of VTE was made by contrast-enhanced CT or ultrasonography when symptomatic or D-dimer was ≥10 μg/mL. VTE was observed in 1.2% and 4.0% of patients in the LMWH and Control groups, respectively (odds ratio [OR] 0.3, 95% confidence interval [CI] 0.03-1.53). Pulmonary embolism was confirmed only in the Control group (1.7%). No major bleeding occurred in either group. Logistic multiple regression analysis revealed that surgical time extension (OR 1.02, 95% CI 1.00-1.04) was a risk factor of VTE, while administration of LMWH (OR 0.21, 95% CI 0.03-0.99), male sex (OR 0.12, 95% CI 0.01-0.60), and early cancer (OR 0.17, 95% CI 0.02-0.82) reduced the risk of VTE. Postoperative LMWH administration is safe. The additional effect of LMWH administration on the physical therapy was not statistically proven in this study. However, it could be useful for the patients with risk factors such as female sex, long operation time, and higher cancer stage.

Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer: ASCO Clinical Practice Guideline Update.

To provide updated recommendations about prophylaxis and treatment of venous thromboembolism (VTE) in patients with cancer. PubMed and the Cochrane Library were searched for randomized controlled trials (RCTs) and meta-analyses of RCTs published from August 1, 2014, through December 4, 2018. ASCO convened an Expert Panel to review the evidence and revise previous recommendations as needed. The systematic review included 35 publications on VTE prophylaxis and treatment and 18 publications on VTE risk assessment. Two RCTs of direct oral anticoagulants (DOACs) for the treatment of VTE in patients with cancer reported that edoxaban and rivaroxaban are effective but are linked with a higher risk of bleeding compared with low-molecular-weight heparin (LMWH) in patients with GI and potentially genitourinary cancers. Two additional RCTs reported on DOACs for thromboprophylaxis in ambulatory patients with cancer at increased risk of VTE. Changes to previous recommendations: Clinicians may offer thromboprophylaxis with apixaban, rivaroxaban, or LMWH to selected high-risk outpatients with cancer; rivaroxaban and edoxaban have been added as options for VTE treatment; patients with brain metastases are now addressed in the VTE treatment section; and the recommendation regarding long-term postoperative LMWH has been expanded. Re-affirmed recommendations: Most hospitalized patients with cancer and an acute medical condition require thromboprophylaxis throughout hospitalization. Thromboprophylaxis is not routinely recommended for all outpatients with cancer. Patients undergoing major cancer surgery should receive prophylaxis starting before surgery and continuing for at least 7 to 10 days. Patients with cancer should be periodically assessed for VTE risk, and oncology professionals should provide patient education about the signs and symptoms of VTE.Additional information is available at www.asco.org/supportive-care-guidelines.

Double Blind Randomized Control Trial of Postoperative Low Molecular Weight Heparin Bridging Therapy for Patients Who Are at High Risk for Arterial Thromboembolism (PERIOP 2)

▪BackgroundIt remains uncertain if patients with atrial fibrillation or mechanical heart valves requiring interruption of warfarin for procedures benefit from post-procedure anticoagulant bridging therapy.MethodsIn order to determine the efficacy and safety of postoperative LMWH bridging, we conducted a multicenter randomized double-blind controlled trial of patients with atrial fibrillation or a mechanical heart valve who require interruption of warfarin for a planned procedure. We excluded patients with active bleeding within 30 days, platelet count <100 x10⁹/L, spinal, cardiac or neurosurgery, life expectancy <3months, creatinine clearance <30ml/min, multiple mechanical valves or a Starr-Edwards valve, mechanical valve with history of stroke or TIA, or a history of heparin induced thrombocytopenia. The last dose of warfarin was given 6 days prior to the procedure. All patients received pre-procedure bridging therapy with dalteparin 200 IU per kilogram (max 18,000 IU) subcutaneously in the morning day-3 and day-2 then dalteparin 100 IU per kilogram (max 18,000 IU) subcutaneously 24 hours pre-procedure. Warfarin was resumed in the evening of the procedure at twice the usual dose for the first two days and then titrated according to INR. After the procedure (same day or next day), when hemostasis had been achieved, patients were randomized to receive dalteparin or placebo for at least 4 days and until the INR was greater than 1.9. Randomization was stratified by presence of a mechanical valve, by the post-procedure risk for major bleeding, and by centre. For patients at high risk for post-procedure major bleeding, dalteparin or placebo was administered at a fixed daily dose of 5000 IU. For patients at low risk for post-procedure major bleeding, dalteparin or placebo was administered at a daily dose of 200 IU per kilogram (max 18,000 IU). The primary analysis was a comparison of the proportion of patients who had major thromboembolism (stroke, proximal DVT, PE, MI, peripheral embolism) over 90 days by Chi-squared test according to the intention to treat principle. Secondary outcomes were major bleeding, all cause mortality and a composite outcome of major thromboembolism and major bleeding.ResultsStarting in October 2006 we randomized a total of 1471 patients of whom 1167 had atrial fibrillation (without mechanical heart valves) and 304 had mechanical valves (99 also had atrial fibrillation). Last follow up was completed in May 2016. Baseline characteristics were similar between the LMWH and the placebo groups (see Table 1). Due to a randomization program system error at two centres more atrial fibrillation patients were randomized to dalteparin rather than to placebo. Major thromboembolism occurred in 6/820 (0.71%) dalteparin patients and 7/650 (1.11%) placebo patients. Major post-procedure bleeding occurred in 12 (1.46%) dalteparin patients and 16 (2.46%) placebo patients. Findings were similar in patients with atrial fibrillation alone and in patients with mechanical heart valves (with or without atrial fibrillation) (Table 2).ConclusionsIn patients with atrial fibrillation and/or mechanical heart valves who had warfarin interrupted for a procedure there was no benefit from post-procedure LMWH bridging. [Display omitted] DisclosuresKovacs:Bayer: Research Funding; Daiichi Sankyo Pharma Development: Research Funding. Wells:Janssen: Honoraria; Sanofi: Honoraria; BMS: Honoraria, Research Funding; Bayer: Honoraria. Schulman:Boehringer-Ingelheim: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria; Sanofi: Honoraria; Bayer: Honoraria.

Postoperative Thromboembolic Prophylaxis with Low-Molecular-Weight Heparin and Risk of Rebleeding in Patients with Chronic Subdural Hematomas: A Comparative Retrospective Cohort Study.

Early postoperative administration of low-molecular-weight heparin (LMWH) to prevent thromboembolic events in patients with chronic subdural hematoma (CSDH) is controversial. Our goal was to investigate impact of early postoperative LMWH administration on recurrence rate of CSDHs. Retrospective review was performed of 136 patients with CSDHs who were operated on during an 18-month period. Early postoperative administration of LMWH was at the discretion of the treating surgeon. This resulted in patients treated (heparin [H] group) or not treated with LMWH (no heparin [NH] group). All patients underwent imaging 4 weeks after surgery or earlier in cases of deterioration. The primary outcome variable was reoperation. Secondary outcomes were reoperation, important residual hematoma (defined as hematoma depth of more than one third of original size), and incidence of thromboembolic complications. Relative risk and absolute risk reduction were calculated. We included 105 patients, 50 (47.6%) in the NH group and 55 (52.4%) in the H group. Nine patients (18%) in the NH group and 6 patients (10.9%) in the H group required secondary surgery (relative risk 0.61, 95% confidence interval 0.23-1.58, P= 0.404, absolute risk reduction 0.07). Eleven patients (22%) in the NH group and 15 patients (27.3%) in the H group presented with important residual hematoma or underwent surgery for hematoma recurrence (relative risk 1.24, 95% confidence interval 0.63-2.44, P=0.532, absolute risk reduction-0.05). Our data provide preliminary evidence that early postoperative administration of LWMH does not increase risk of clinically relevant recurrence of CSDHs.

Oral anticoagulants for primary prevention, treatment and secondary prevention of venous thromboembolic disease, and for prevention of stroke in atrial fibrillation: systematic review, network meta-analysis and cost-effectiveness analysis.

Warfarin is effective for stroke prevention in atrial fibrillation (AF), but anticoagulation is underused in clinical care. The risk of venous thromboembolic disease during hospitalisation can be reduced by low-molecular-weight heparin (LMWH): warfarin is the most frequently prescribed anticoagulant for treatment and secondary prevention of venous thromboembolism (VTE). Warfarin-related bleeding is a major reason for hospitalisation for adverse drug effects. Warfarin is cheap but therapeutic monitoring increases treatment costs. Novel oral anticoagulants (NOACs) have more rapid onset and offset of action than warfarin, and more predictable dosing requirements. To determine the best oral anticoagulant/s for prevention of stroke in AF and for primary prevention, treatment and secondary prevention of VTE. Four systematic reviews, network meta-analyses (NMAs) and cost-effectiveness analyses (CEAs) of randomised controlled trials. Hospital (VTE primary prevention and acute treatment) and primary care/anticoagulation clinics (AF and VTE secondary prevention). Patients eligible for anticoagulation with warfarin (stroke prevention in AF, acute treatment or secondary prevention of VTE) or LMWH (primary prevention of VTE). NOACs, warfarin and LMWH, together with other interventions (antiplatelet therapy, placebo) evaluated in the evidence network. Efficacy Stroke, symptomatic VTE, symptomatic deep-vein thrombosis and symptomatic pulmonary embolism. Safety Major bleeding, clinically relevant bleeding and intracranial haemorrhage. We also considered myocardial infarction and all-cause mortality and evaluated cost-effectiveness. MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library, reference lists of published NMAs and trial registries. We searched MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library. The stroke prevention in AF review search was run on the 12 March 2014 and updated on 15 September 2014, and covered the period 2010 to September 2014. The search for the three reviews in VTE was run on the 19 March 2014, updated on 15 September 2014, and covered the period 2008 to September 2014. Two reviewers screened search results, extracted and checked data, and assessed risk of bias. For each outcome we conducted standard meta-analysis and NMA. We evaluated cost-effectiveness using discrete-time Markov models. Apixaban (Eliquis®, Bristol-Myers Squibb, USA; Pfizer, USA) [5 mg bd (twice daily)] was ranked as among the best interventions for stroke prevention in AF, and had the highest expected net benefit. Edoxaban (Lixiana®, Daiichi Sankyo, Japan) [60 mg od (once daily)] was ranked second for major bleeding and all-cause mortality. Neither the clinical effectiveness analysis nor the CEA provided strong evidence that NOACs should replace postoperative LMWH in primary prevention of VTE. For acute treatment and secondary prevention of VTE, we found little evidence that NOACs offer an efficacy advantage over warfarin, but the risk of bleeding complications was lower for some NOACs than for warfarin. For a willingness-to-pay threshold of > £5000, apixaban (5 mg bd) had the highest expected net benefit for acute treatment of VTE. Aspirin or no pharmacotherapy were likely to be the most cost-effective interventions for secondary prevention of VTE: our results suggest that it is not cost-effective to prescribe NOACs or warfarin for this indication. NOACs have advantages over warfarin in patients with AF, but we found no strong evidence that they should replace warfarin or LMWH in primary prevention, treatment or secondary prevention of VTE. These relate mainly to shortfalls in the primary data: in particular, there were no head-to-head comparisons between different NOAC drugs. Calculating the expected value of sample information to clarify whether or not it would be justifiable to fund one or more head-to-head trials. This study is registered as PROSPERO CRD42013005324, CRD42013005331 and CRD42013005330. The National Institute for Health Research Health Technology Assessment programme.

Patient Adherence and Experience with Extended Use of Prophylactic Low-Molecular-Weight Heparin Following Pancreas and Liver Resection

BackgroundGuidelines recommend 28 days venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) following major abdominal surgery for cancer. Overall adherence with these recommendations is poor, but little is known about feasibility and tolerability from a patient perspective. MethodsAn institution-wide policy for routine administration of 28 days of post-operative LMWH following major hepatic or pancreatic resection for cancer was implemented in April 2013. Patients having surgery from July 2013 to June 2015 were approached to participate in an interview examining adherence and experience with extended duration LMWH. ResultsThere were 100 patients included, with 81.4 % reporting perfect adherence with the regimen. The most frequent reasons for non-adherence were that a healthcare provider stopped the regimen or because of poor experience with injections. Most patients were able to correctly recall the reason for being prescribed LMWH (82.6 %), and 78.4 % of patients performed all injections themselves. Over half the patients (55.7 %) did not find the injections bothersome. ConclusionPatients reported high adherence and a manageable experience with post-operative extended-duration LMWH in an ambulatory setting following liver or pancreas resection. These findings suggest that patient adherence is not a major contributor to poor compliance with VTE prophylaxis guidelines.

Experimental Thromboprophylaxis with Low Molecular Weight Heparin After Microsurgical Revascularization.

There is great variability among microsurgeons as regards the use of prophylactic anticoagulant after revascularization and this is probably due to lack of comparative data. Also, there has been much debate regarding the benefit of anti-thrombotic therapies versus the risk of complications such as systemic bleeding and hematoma formation. To evaluate the effectiveness of postoperative low molecular weight heparin (LMWH) as a prophylactic anticoagulant therapy after microsurgical repair of the femoral artery and vein in rats. Randomized, blinded study. The femoral artery and vein of 40 Sprague Dawley rats were sectioned and repaired with microsurgical sutures under general anesthesia. They were randomly divided into 2 groups: Group (A) in which the 20 rats were injected with Enoxaparin subcutaneously at a dose 1.5mg/kg once daily for 3 successive days; Group (B), the control group, in which 20 rats were injected with isotonic sodium chloride 0.9% subcutaneously in a blinded fashion. After 7days, the femoral vessels were re-explored and patency of the femoral vessels was assessed with empty-and-refill test. There were a total of 12 vascular thrombosis among 74 microsurgical repair in both groups with percentage of 16.22% including, 5 arterial anastomosis and 7 venous anastomosis. The incidence of thrombosis in the treatment group (A) was 18.4% while the incidence of thrombosis in the control group (B) was 13.8%. This difference was not statistically significant using Fisher exact test. Postoperative administration of LMWH did not provide the desired protection against thrombosis after microsurgical vascular repair.

Incidence of venous thromboembolism and hemorrhage related safety studies of preoperative anticoagulation therapy in hip fracture patients undergoing surgical treatment: a case-control study.

BackgroundVenous thromboembolism is a common postoperative complication following orthopedic surgeries, with morbid and potentially fatal consequences. Perioperative low-molecular-weight heparin (LMWH) therapy can reduce the incidence of venous thromboembolism, but may also increase the risk of bleeding complications. Current literature reflects the need to balance the improved efficacy of early initiating prophylaxis with increased risk of perioperative bleeding. The purpose of this study was to compare the effectiveness and hemorrhage related safety of preoperative versus postoperative LMWH therapy for prevention of deep venous thrombosis (DVT) and pulmonary embolism (PE) in hip fracture patients.MethodsWe retrospectively evaluated 222 patients who underwent surgical treatment at Peking University People's Hospital between January 2009 and December 2010. Patients were allocated to two groups, receiving either preoperative or postoperative initiation of LMWH therapy for venous thromboembolism prophylaxis. Preoperative anticoagulation therapy was initiated 1–12 days prior to surgery (133 patients), and postoperative anticoagulation therapy was initiated 12 h after completion of surgery (89 patients). The preoperative group was further subdivided into four subgroups according to the time of initiation of therapy: 1–3 days before surgery (group A, 54 patients), 4–6 days before surgery (group B, 57 patients), 7–9 days before surgery (group C, 15 patients), and 10–12 days before surgery (group D, 7 patients). Occurrences of DVT, PE, adverse drug effects, intraoperative and postoperative bleeding were recorded, along with concentrations of preoperative and postoperative hemoglobin and length of hospital stay. The above parameters were compared between groups.ResultsAmong recipients of preoperative anticoagulation therapy, two patients developed postoperative PE (1.5 %), one patient developed DVT (0.75 %). In the group receiving postoperative initiation of anticoagulation therapy, one patient each developed PE and DVT (1.1 %, 1.1 %). There was no difference in the occurrence of PE and DVT between the two groups (P>0.05, Chi-square tests). We identified the incidences of major bleeding, minor bleeding, and intraspinal hematoma after spinal anesthesia, which were 0 %/0 %, 3.76 %/3.37 %, and 0 %/0 %, respectively in preoperative and postoperative anticoagulation groups. There was no significant difference in the incidence of bleeding complications between patients receiving preoperatively initiated LMWH with patients receiving postoperatively initiated LMWH. Spinal anesthesia was administered to 168 patients, with no cases of postoperative intraspinal hematoma.ConclusionsPreoperative anticoagulation therapy with LMWH may not increase intraoperative or postoperative blood loss, or the rate of intraspinal hematoma after spinal anesthesia, but also does not significantly reduce the risk of postoperative DVT or PE, compared to postoperative initiation.

Post-operative use of Low Molecular Weight Heparin: Are patients doing their bit?

Introduction: Current National Institute for Health and Care Excellence (NICE) guidelines recommend the use of Low Molecular Weight Heparin (LMWH) for one month post-operatively in abdominal and pelvic cancer surgery to reduce risk of venous thromboembolism. We audited the prescription of LMWH at discharge and the compliance of patients with LMWH post-operatively and instigated measures to improve compliance. Materials and Methods: All patients undergoing major urological surgery from November 2011 to April 2012 were audited, with data collected on evidence of post-operative prescription (from discharge summaries). Patients within this 3-month period were questioned regarding compliance following discharge. Following this, changes were instigated to improve compliance (earlier discussion of post-operative LMWH administration in clinic, improved patient and junior doctor education). All patients undergoing surgery from November 2012 to June 2013 were identified and a re-audit completed. Results: Post-operative prescription of LMWH improved overall from 73% to 88%. Patient compliance to complete LMWH course improved from 23% to 88%. At re-audit, 97% of patients felt that training was adequate, and 94% of patients understood the rationale for taking LMWH at re-audit. Conclusion: Education of junior doctors improved prescription of LMWH at discharge. Improved patient education improves community LMWH use compliance post-discharge.

Incidence Of Symptomatic Venous Thromboembolism In Patients With Hemophilia Undergoing Joint Replacement Surgery: A Retrospective Study

BackgroundHip and knee arthroplasty (THA and TKA), in general, pose a high risk for venous thromboembolism (VTE), and pharmacologic VTE prophylaxis is often strongly recommended. In patients (pt) with hemophilia undergoing THA/TKA, given the underlying bleeding diathesis, the routine use of pharmacologic VTE prophylaxis is controversial. In this study, we report THA/TKA outcomes in pt with hemophilia in our institution. MethodsRetrospective chart review of Mayo Comprehensive hemophilia center pt undergoing THA and TKA. Medical records were reviewed for objectively documented VTE for up to 3 months after surgery. Results42 consecutive pt with hemophilia A (n=38) or B (n=4) underwent 71 operations: THA (n=32) and TKA (n=39) over a period of 39 years. All pt received compression stockings up to 6 weeks after surgery; 6/71 (8.4%) received sequential intermittent compression and 2/71 (2.8%) received postoperative low molecular weight heparin (LMWH). Symptomatic femoral vein DVT occurred in 1/42 pt (2%); (1/71, 1.4% of operations (1.4%)), 10 days after THA for traumatic hip fracture and after the LMWH was discontinued. The patient was subsequently found to be heterozygous for the factor V Leiden gene mutation. For up to 3 months after surgery, there were no additional cases of symptomatic DVT. There was no unexpected bleeding in the 2 patients receiving LMWH. ConclusionIn this this study, routine use of compression stockings without the use of pharmacologic prophylaxis resulted in a low rate of symptomatic VTE in patients with hemophilia. This may be similar to the incidence in the general population receiving LMWH (Heit, JA et al Annals of Internal Medicine 2000) A limited sample size precludes definitive recommendations for practice. For appropriate high risk patients, limited use of pharmacologic prophylaxis may still be important. Disclosures:No relevant conflicts of interest to declare.

Exclusive Low-Molecular-Weight Heparin as Bridging Anticoagulant After Mechanical Valve Replacement

Unfractionated heparin has been the standard anticoagulant used immediately after mechanical heart valve replacement (MHVR). The purpose of this study was to assess a postoperative anticoagulation protocol with low-molecular-weight heparin (LMWH) immediately after MHVR without the use of unfractionated heparin or anti-factor Xa monitoring. We performed a prospective, single-center, observational study of 1,063 consecutive patients undergoing elective MHVR with postoperative LMWH anticoagulation treatment. The exclusion criteria were as follows: renal failure, intraaortic balloon counterpulsation, critical perioperative state, or a recent neurologic event. The postoperative anticoagulation protocol used subcutaneous enoxaparin as a bridging anticoagulant treatment beginning on the first postoperative day and continuing until vitamin K antagonist treatment was fully effective. Patients were followed for 6 weeks. The primary endpoints were the incidence of thromboembolic or major bleeding events. Eleven (1%) thromboembolic events occurred. Ten of these events were transient or permanent strokes. Major bleeding events occurred in 44 patients (4.1%), 7 of which were observed before the enoxaparin treatment period. At the time of discharge, 570 patients (53.6%) were no longer receiving LMWH treatment due to achieving the target international normalized ratio. The mean length of hospital stay was 8.5 ± 2.9 days. There were no deaths during the 6-week follow-up period. In our highly selected population, after MHVR, postoperative anticoagulation using LMWH is associated with a low rate of thromboembolic and major bleeding events. This large observational study demonstrates that the use of LMWH as an anticoagulant is effective and safe after MHVR.

Incidence of Venous Thromboembolism After Minimally Invasive Surgery in Patients With Newly Diagnosed Endometrial Cancer

To estimate the incidence of postoperative venous thromboembolism among patients undergoing minimally invasive surgery for endometrial cancer, and to characterize risk factors associated with the development of venous thromboembolism. Patients with newly diagnosed endometrial cancer who were scheduled to undergo a planned minimally invasive surgery procedure from May 1, 2007 to December 31, 2010 were identified. The incidence of symptomatic postoperative venous thromboembolism was estimated in the patients who did not require conversion to laparotomy. Various clinicopathologic variables were tested for an association with the development of a postoperative venous thromboembolism using standard statistical tests. A total of 573 cases were identified. Postoperative low molecular weight heparin was administered to 125 (22%) patients during their immediate postoperative hospital stay. All patients had sequential compression devices placed intraoperatively. Seven (1.2%) patients had development of a symptomatic venous thromboembolism. The factors associated with development of a postoperative venous thromboembolism were: body mass index (BMI) (P=.005); estimated blood loss (P=.03); and operative time (P=.01). A high-risk group was determined to be patients with BMIs of 40 or higher and an operative time of 180 minutes or more. In this group, the incidence of venous thromboembolism was 9.5% (4 of 42) compared with 0.6% (3 of 531) in all others (P=.001). The incidence of venous thromboembolism in patients with newly diagnosed endometrial cancer undergoing minimally invasive surgery is very low. There appears to be no clear justification for the routine use of a heparin for perioperative thromboprophylaxis in the majority of these patients. Thromboprophylaxis with heparin, however, may be a consideration in morbidly obese patients (BMI of 40 or higher) after a procedure that lasts 3 hours or more. II.