Postoperative Thromboembolism Research Articles

Thrombotic and Bleeding Outcomes Following Perioperative Interruption of Direct Oral Anticoagulants and Vitamin K Antagonists in Patients with Non-Valvular Atrial Fibrillation - a Comparative Analysis

Background: Atrial fibrillation (AF) is a common disorder that will affect up to 5.6 million patients in the U.S. by 2050. Both direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs), typically warfarin, are used for stroke prevention in AF and such patients frequently undergo invasive procedures requiring anticoagulant interruption. Temporary interruption of anticoagulants can be associated with significant morbidity and mortality in the form of thromboembolic and bleeding complications. DOACs have a short half-life and fast onset of action, thereby facilitating their perioperative management as compared to VKAs. Despite important differences in perioperative management and pharmacokinetics between DOACs and VKAs, there is a paucity of data comparing perioperative outcomes in DOAC and VKA-treated patients.Methods: We undertook a single-center, retrospective chart review that compared consecutive DOAC- or warfarin-treated patients with AF who underwent perioperative anticoagulant interruption for invasive procedures between January 2017 and March 2018. Perioperative warfarin interruption was done as per CHEST guidelines (Douketis et al. Chest 141,2 Suppl). Perioperative bridging with low-molecular-weight heparin was only used for patients with CHADS2 scores of 5-6 or in patients with stroke within the past 6 months. Perioperative interruption of DOACs was done as per Thrombosis Canada guidelines, with anticoagulation held for 3 half-lives prior to low bleeding risk procedures and 5 half-lives for high bleeding risk procedures. Primary outcomes included the 30-day post-operative thromboembolic and major bleeding rates. Secondary outcomes included the 30-day clinically relevant non-major bleeding (CRNMB) andl mortality rates. Major bleeding and CRNMB were defined according to ISTH definitions. Procedural bleeding risk was defined as per Schulman et al (Circulation 2015; 132(3)). Outcome events were independently adjudicated by two investigators. Outcomes from patients on DOACs and VKAs were compared. Demographic data was analyzed on a per-patient basis, p-values were calculated using independent T-Test, Chi-Square/Fisher's Exact Test where appropriate. Outcome data was analyzed on a per-interruption basis. P-values for unadjusted and adjusted comparisons were calculated using generalized estimating equations (GEE) to account for correlation between multiple procedures on the same patients.Results: 325 DOAC patients and 199 warfarin patients underwent 351 and 221 periprocedural interruptions, respectively. Warfarin patients had a significantly higher mean age, CHADS2 score, and proportion with renal dysfunction (Table 1). There was no statistically significant difference in 30-day post-operative rates of thromboembolism, CRNMB, and overall mortality, but warfarin patients had a significantly higher rate of major bleeding (Table 2). This latter result remained statistically significant following multivariate logistic regression correction for age, CHADS2 score and level of renal dysfunction. All bleeding events occurred post-procedure, with major bleeding events occurring from post-operative day 1 to post-operative day 25. None of the warfarin patients with major bleeding received perioperative bridging; the mean international normalized ratio (INR) at the time of major bleeding was 3.3. Most major bleeding events (7/8) in the VKA arm were surgical, with a single non-surgical major-bleed (spontaneous ICH on post-operative day 15 following urological surgery).Conclusions: The perioperative interruption of warfarin was associated with a higher 30-day rate of major bleeding as compared with DOAC interruption. Re-initiation of warfarin should be done judiciously following high bleeding risk procedures, and close INR monitoring may be warranted. [Display omitted] DisclosuresShaw:Portola Pharmaceuticals: Research Funding. Douketis:Janssen: Consultancy; Pfizer: Other: Advisory Board; Boehringer-Ingelheim: Consultancy, Other: Advisory Board, Research Funding; Portola: Other: Advisory Board; The Medicines Company: Other: Advisory Board; Daiichi-Sankyo: Other: Advisory Board; Biotie: Other: Advisory Board; Bayer: Other: Advisory Board; Sanofi: Consultancy, Other: Advisory Board; BMS: Other: Advisory Board; Astra-Zeneca: Other: Advisory Board. Carrier:Bayer: Honoraria; Pfizer: Honoraria; BMS: Honoraria, Research Funding; Leo Pharma: Research Funding.

Complications Arising From Perioperative Anticoagulant/Antiplatelet Therapy in Major Colorectal and Abdominal Wall Surgery.

Postoperative hemorrhage and thromboembolism are recognized complications following colorectal and abdominal wall surgery, but accurate documentation of their incidence, trends, and outcomes is scant. This is relevant given the increasing number of surgical patients with cardiovascular comorbidity on anticoagulant/antiplatelet therapy. This study aims to characterize trends in the use of anticoagulant/antiplatelet therapy among patients undergoing major colorectal and abdominal wall surgery within the past decade, and to assess rates of, outcomes following, and risk factors for hemorrhagic and thromboembolic complications. This is a retrospective cross-sectional study conducted at a single quaternary referral center. Patients who underwent major colorectal and abdominal wall surgery during three 12-month intervals (2005, 2010, and 2015) were included. The primary outcomes measured was the rate of complications relating to postoperative hemorrhage or thromboembolism. One thousand one hundred twenty-six patients underwent major colorectal and abdominal wall surgery (mean age, 61.4 years (SD 16.3); 575 (51.1%) male). Overall, 229 (21.7%) patients were on anticoagulant/antiplatelet agents; there was an increase in the proportion of patients on clopidogrel, dual antiplatelet therapy, and novel oral anticoagulants over the decade. One hundred seven (9.5%) cases were complicated by hemorrhage/thromboembolism. Aspirin (OR, 2.22; 95% CI, 1.38-3.57), warfarin/enoxaparin (OR, 3.10; 95% CI, 1.67-5.77), and dual antiplatelet therapy (OR, 2.99; 95% CI, 1.37-6.53) were most implicated with complications on univariate analysis. Patients with atrial fibrillation (adjusted OR 2.67; 95% CI, 1.47-4.85), ischemic heart disease (adjusted OR, 2.14; 95% CI, 1.04-4.40), and mechanical valves (adjusted OR, 7.40; 95% CI 1.11-49.29) were at increased risk of complications on multivariate analysis. The severity of these events was mainly limited to Clavien-Dindo 1 (n = 37) and 2 (n = 46) complications. This is a retrospective study with incomplete documentation of blood loss and operative time in the early study period. One in ten patients incurs hemorrhagic/thromboembolic complications following colorectal and abdominal wall surgery. "High-risk" patients are identifiable, and individualized management of these patients concerning multidisciplinary discussion and critical-care monitoring may help improve outcomes. Prospective studies are required to formalize protocols in these "high-risk" patients. See Video Abstract at http://links.lww.com/DCR/A747.

Longer Operative Time in Elderly Patients Undergoing Posterior Lumbar Fusion Is Independently Associated With Increased Complication Rate.

Study Design:Retrospective cohort study.Objective:To determine the effects of operative time on postoperative complications in patients age 65 and older undergoing posterior lumbar fusion.Methods:All patients age 65 and older undergoing posterior lumbar fusion were identified in the 2012 to 2015 American College of Surgeons National Surgical Quality Improvement Program database. The primary outcome measures were complications occurring up to 30 days postoperatively, including death, any complication, and complication subtypes. The primary independent variable was operative duration. Both bivariate and multivariate analyses utilized logistic regression and analyzed operative duration as a continuous variable. Statistical significance was considered P < .05.Results:A total of 4947 patients age 65 and older undergoing posterior lumbar fusion were identified. The mean operative time was 3.3 hours (SD 1.7). The overall complication rate was 13.4% (n = 665). In multivariate analysis, each incremental hour of operative time was associated with increased risk of postoperative thromboembolism (odds ratio [OR] = 1.23; 95% confidence interval [CI] = 1.10-1.37), transfusion (OR= 1.25; 95% CI = 1.18-1.32), urinary tract infection (OR = 1.21; 95% CI = 1.10-1.32), and total postoperative complications (OR = 1.22; 95% CI = 1.16-1.27).Conclusion:For patients age 65 and older undergoing posterior lumbar fusion, longer operative time is associated with greater risk for thromboembolism, transfusion, intubation, kidney injury, urinary tract infection, surgical site infection, and overall postoperative complications. This data highlights several specific complications that are influenced by operative time in older patients, and further supports the need for future protocols that seek to safely minimize operative time for posterior lumbar fusion.

Post-operative thromboembolism prophylaxis after urgent general surgery

Post-operative thromboembolism prophylaxis after urgent general surgery

Elevated Venous Thromboembolism Risk Following Colectomy for IBD Is Equal to Those for Colorectal Cancer for Ninety Days After Surgery.

The risk of postoperative venous thromboembolism is high in patients with colon cancer and IBD. Although The American Society of Colon and Rectal Surgeons suggests posthospital prophylaxis after surgery in patients with colon cancer, there are no such recommendations for patients with IBD. This study aims to analyze the incidence and risk factors for postoperative venous thromboembolism. This was a retrospective review using the Explorys platform. Aggregated electronic medical records from 26 major health care systems across the United States from 1999 to 2017 were used for this study. Patients who underwent colon surgery were included. Patients were followed up to 90 days postoperatively for deep vein thrombosis and pulmonary embolism. A total of 75,620 patients underwent colon resections, including 32,020 patients with colon cancer, 9850 patients with IBD, and 33,750 patients with diverticulitis. The 30-day incidence of venous thromboembolism was higher in patients with cancer and IBD than in patients with diverticulitis (2.9%, 3.1%, and 2.4%, p < 0.001 for both comparisons). The 30-day incidence of venous thromboembolism in patients with ulcerative colitis is greater than in patients with Crohn's disease (4.1% vs 2.1%, p < 0.001). The cumulative incidence of venous thromboembolism increased from 1.2% at 7 days after surgery to 4.3% at 90 days after surgery in patients with cancer, and from 1.3% to 4.3% in patients with IBD. In multivariable analysis, increase in the risk of venous thromboembolism was associated with cancer diagnosis, IBD diagnosis, age ≥60, smoking, and obesity. This study was limited by its retrospective nature and by the use of the aggregated electronic database, which is based on charted codes and contains only limited collateral clinical data. Because of the elevated and sustained risk of postoperative thromboembolism, patients with IBD, especially ulcerative colitis, might benefit from extended thromboembolism prophylaxis similar to that of patients with colon cancer. See Video Abstract at http://links.lww.com/DCR/A544.

Adequate timing of thromboembolic prophylaxis in colorectal cancer surgery

Background: It has been found that patients with colorectal cancer are at increased risk for postoperative venous thromboembolism. The aim of this prospective study is to evaluate the incidence of venous thromboembolism and major bleeding complications in patients undergoing colorectal cancer who are treated with preoperative or postoperative venous thromboprophylaxis.Methods: This prospective study included 30 patients from September 2013 to November 2017. There were 22 males and 8 females; mean age was 66.7±5.5 years (range 44-78). Author divided the patients randomly into two groups (group A=15 cases with preoperative and group B = 15 cases with postoperative venous thromboprophylaxis).Results: There was no significant difference in preoperative versus postoperative thromboembolic prophylaxis regarding postoperative DVT 0/15(0%) vs 1/15 (6.6%), P=0.69, no bleeding complications and no pulmonary embolism.Conclusions: Preoperative and postoperative thromboembolic prophylaxis are equally safe in venous thromboembolism protection.

Safety of Outpatient Shoulder Surgery at a Freestanding Ambulatory Surgery Center in Patients Aged 65 Years and Older: A Review of 640 Cases

Introduction:With increasing utilization of surgery centers, it is important to demonstrate the safety of outpatient shoulder surgery in freestanding ambulatory surgery centers. No studies have specifically looked at the Medicare-age population and the rate of outpatient shoulder procedure complications in these patients at an ambulatory surgery center.Methods:Six hundred forty patients were included in our study between 2000 and 2015. The incidence of major complications was identified, including acute infection requiring intravenous antibiotics or irrigation and débridement, postoperative transfer to a hospital, wrong-site surgical procedures, retention of a foreign object, postoperative symptomatic thromboembolism, medication errors, and bleeding/wound complications.Results:There was a total of seven occurrence reports in seven patients, for a reported adverse event rate of 1.01%.Conclusions:Our findings are consistent with currently reported outpatient hospital-based data and illustrate the safety of outpatient shoulder procedures at a freestanding ambulatory surgery center in Medicare-age patients.

Deep venous thrombosis after major abdominal surgeries: a tertiary level centre study

Background: Deep venous thrombo-embolism is a proven major complication in the postoperative setup among the western population. Hence specific guidelines exist on thrombo-prophylaxis for surgical patients. The limited number of studies available on the Indian patients do not provide conclusive data regarding the incidence of postoperative thrombo-embolism. Also, Indian patients are not routinely given prophylactic anticoagulants in many settings still now. In this research, we studied the incidence of deep venous thrombosis among patients who underwent major abdominal surgeries, over a period of 2 years.Methods: This retrospective descriptive study was done on patients who underwent any sort of major abdominal surgery from the surgical wards of Government Medical College, Thiruvananthapuram, for 2 years. This data was used to analyses the incidence of and factors related to postoperative deep venous thrombo-embolism.Results: We studied a total of 334 patients who fulfilled the inclusion criteria. Among these patients, only 1.19% developed deep venous thrombosis during the post-operative period. Since no guidelines existed regarding the usage of thrombo-prophylaxis during that period, very few patients were found to have used any of the prophylactic measures.Conclusions: The incidence of postoperative deep venous thrombosis is not very high in the Indian population after major abdominal surgeries. This might be due to the relatively low prevalence of hyper-coagulable states in the community itself. As a corollary, routine chemical prophylaxis might be administered only in high risk patients. Other measures like early ambulation and mechanical prophylaxis might be used in patients with lesser risk.

Novel venous thromboembolic disease (VTED) prophylaxis for total knee arthroplasty-aspirin and fish oil.

Despite the demonstrated success of multiple anticoagulation therapies for post-operative prophylaxis of thromboembolic disease in lower extremity arthroplasties, each modality comes with a unique set of limitations. Thus, the ideal anticoagulation medication which provides adequate therapy with minimal cost, complications, or added patient work is yet to be defined. One promising novel thrombophylactic supplement is fish oil, as many preliminary clinical trials have demonstrated a protective effect of fish oil against thrombosis in multiple clinical settings. In addition, others have demonstrated synergistic effect when combined with aspirin. However, there are paucity of studies that compared combined aspirin and fish oil therapy for venous thromboembolism prophylaxis with other pharmacological agents, especially in the field of orthopaedics. Therefore, this study evaluated: (I) risk of post-operative deep vein thrombosis (DVT) and pulmonary embolism (PE), and (II) bleeding complications; among patients who had primary total knee arthroplasty (TKA) and received one of the following regimens: (i) 325 mg aspirin and mechanical pulsatile stocking; (ii) rivaroxaban; or (iii) 325 mg aspirin and 1,000 mg fish oil. This was a 6-year prospective study analyzing the postoperative thromboembolic prophylaxis received by patients who underwent primary TKA. Patients who had a previous history of thromboembolic disease were excluded from the study due to an increased risk of recurrent clot formation. A total of 850 patients were enrolled. A total of 300 patients enrolled between October 2011 and June 2013 received 325 mg aspirin and mechanical pulsatile stocking, while 250 patients enrolled between June 2013 and December 2014 received rivaroxaban. A total of 300 patients enrolled between January 2015 and July 2017 received 325 mg aspirin and 1,000 mg fish oil. Major venous thromboembolic events (VTEs) and bleeding complications within the first 90 days post-operatively were recorded in each cohort. The odds ratios (ORs) and 95% confidence intervals (CIs), for thromboembolic and bleeding events were calculated and compared between the aspirin and fish oil cohort vs. aspirin and pulsatile stocking cohort, and aspirin and fish oil cohort vs. rivaroxaban cohort. A P value of <0.05 was used to determine statistical significance. A total of 25 DVT events were recorded including 1 of 300 (0.33%) in the aspirin and fish oil cohort, 22 of 300 (7.33%) in the aspirin and pulsatile stocking cohort and 2 of 250 (0.8%) in the rivaroxaban cohort. When comparing ORs, patients who received aspirin and fish oil demonstrated significantly lower risk for thromboembolic events when compared to the aspirin and pulsatile stocking group (OR: 0.045; 95% CI: 0.0061-0.3394; P<0.05). When compared to the rivaroxaban cohort the ORs did not differ significantly (OR: 0.416; 95% CI: 0.0376-4.6223; P>0.05). In addition, no PE events were recorded in any of the cohorts. When compared to rivaroxaban, the fish oil and aspirin cohort demonstrated significantly lower incidence of bleeding episodes (1 of 300, 0.33% vs. 30 of 250 patients, 12%; OR: 0.0278; 95% CI: 0.0038-0.2051; P<0.05). No bleeding events were recorded in the aspirin and pulsatile stocking cohort. This study demonstrated the potentially synergistic anti-thromboembolic effect of aspirin and fish oil in the prevention of post-operative venous thromboembolism in primary TKA patients. Based on the results from this study, the authors conclude that the combination of aspirin and fish oil maybe an excellent thromboprophylactic modality for patients to use after TKA. These results warrant further, larger prospective studies analyzing the use of fish oil supplements in VTE prophylaxis.

Portal Vein Thrombosis in the Setting of Newly Diagnosed Cushing's Syndrome.

The hallmark manifestations of Cushing’s syndrome (CS) are well known, but hypercoagulability is perhaps least recognized. Patients with CS are at increased risk of both spontaneous and postoperative thromboembolism, with the significant majority of events occurring in the lower extremity and pulmonary venous circulations. We present a case of portal vein thrombosis (PVT) occurring in the setting of newly diagnosed CS due to a left adrenal adenoma. Factor VIII activity was approximately 2.5-fold elevated, a known mechanism by which hypercortisolemia predisposes to venous thrombosis. Acute abdominal pain and fever responded well to unfractionated heparin and parenteral antibiotics, and CS was eventually cured by left adrenalectomy. No thromboembolic events have occurred since surgery. PVT is uncommon and usually occurs as a complication of primary or secondary hepatobiliary malignancies and cirrhosis. To the best of our knowledge, this is just the second reported case of PVT due to CS and the first published in the English language literature.

The diagnostic value of plasma fibrin related markers in perioperation of femoral fracture

Objective: To investigate potential value of fibrin related markers in patients with femoral fracture during perioperative period. Methods: Ninety-five patients were enrolled, including 39 males with (53±24) years old and 56 females with (73±13) years old, of which 44 fracture on caput femoris, 34 collum femoris and 17 shaft of femur. Sampling on the day before operation and 1(st,) 3(rd,) 5(th) days after operation, fibrin monomer (FM), D-dimer(DD), fibrinogen degradation product (FDP) and other coagulation assays were detected by reagents from Stago. Difference in day-to-day and between surgical sites were analyzed with general linear model (repeated measures). Results: FDP level on pre-operation, 1(st,) 3(rd,) 5(th) day after operation were 7.88(5.19, 12.12), 15.68(9.84, 29.48), 8.44 (6.27, 12.49) and 10.28 (7.56, 14.00) mg/L, the value of fibrin monomer were 5.00 (5.00, 6.03), 9.89(5.04, 30.12), 5.00 (5.00, 6.04) and 5.02(5.00, 5.76) mg/L. The value of D-Dimer were 2.24(1.41, 3.60), 4.78(2.74, 9.18), 2.60(1.79, 3.88) and 2.91(2.20, 3.85) mg/L, respectively, each parameter changs statistically during observation (Z=4.758, 6.027, 3.238 respectively, P<0.05). On the 5th day after surgery, fibrin monomer in patients with venous thrombus embolism (VTE) were higher than that in patients without VTE, 10.18(7.24, 28.11) mg/L vs 5.10(5.00, 6.73) mg/L (Z=-1.580, P<0.05), which showed potential value evaluating of post-operative VTE. No statistical changes were found in prothrombin time or thrombin time (TT) (P>0.05), but activated partial thromboplastin time (APTT) varied from day to day in (38.1±4.9), (40.8±5.2), (45.1±6.2) and (41.9±6.3)s with statistically difference (F=7.127, P<0.05). Similarly, fibrinogen changed statistically in (5.01±0.94), (4.99±1.35), (6.00±1.75), (5.81±1.38)g/L (F=8.927, P<0.05). Conclusion: Fibrin monomer, additional to markers as D-dimer, shows its value on activated coagulation associated to post-operative thromboembolism for patients receiving femoral surgery.

Інтраопераційний гіперкоагулятивний синдром як фактор післяопераційного тромбозу у венозній системі

Гіперкоагулятивний синдром раннього післяопераційного періоду формується в основному за рахунок підвищення вмісту в плазмі тромбін-фібринової фракції гемокоагулятивного каскаду згортальної системи крові. Для попередження розвитку післяопераційного тромбоемболізму слід відразу після закінчення хірургічного втручання розпочати введення нефракціонованих гепаринів (НФГ), які, проявляють переважаючий вплив на тромбін-фібриновий комплекс (ІІа фактор), з подальшим призначенням низькомолекулярних гепаринів (НМГ) (згідно з галузевими стандартами), які проявляють переважаючий вплив на Ха фактор.

Postoperative Thromboembolism in Gynecologic Oncology Patients. Still a Lethal but Preventable Complication

Background: Gynecologic oncology patients are considered high risk for venous thromboembolic events (VTE), which, despite advances in prevention and management, remain a common cause of morbidity and mortality. Methods and findings: Several clinical trials in gynecologic and general surgery, both for benign and malignant conditions, have addressed the issue of risk assessment and appropriate thromboprophylaxis. This review focuses on epidemiology, risk stratification and preventive measures in patients undergoing surgery for genital tract malignancies. A literature search using PubMed, MEDLINE, and Cochrane search engines was performed using predefined data fields. Conclusion: Thromboprophylaxis is of utmost importance in this group of patients. Patients’ compliance and optimal implementation of the existing available measures could further reduce VTE events in patients with gynecologic malignancies.

Prevalence of deep venous thrombosis detected by ultrasonography before surgery in patients with gastric cancer: a retrospective study of 1140 consecutive patients.

The prevalence of deep venous thrombosis (DVT) in patients with gastric cancer before surgery is unknown. This study aimed to clarify the risk factors for DVT of the lower extremities in patients with gastric cancer before surgery and to evaluate the usefulness of ultrasonographic screening for prevention of postoperative pulmonary thromboembolism (PTE). Patients who had undergone lower-extremity venous ultrasonography before surgery for gastric cancer were retrospectively analyzed. Univariate and multivariate logistic regression analyses were performed to identify the predictors of DVT before surgery. Perioperative management of patients with DVTs and the incidence of postoperative PTE were investigated. Of the total 1140 patients, 86 had DVT preoperatively. On univariate analysis, the incidence of DVT was significantly higher with: female sex; age ≥80years; PS≥1 (vs. PS=0); stage IV (vs. stages I-III); history of preoperative chemotherapy; and the presence of a central venous catheter (CVC). Multivariate logistic regression analysis demonstrated that sex, age ≥80years, PS≥1, history of preoperative chemotherapy, and the presence of CVC were significantly correlated with DVT before surgery. Postoperative PTE occurred in 2 patients with proximal DVT. No patients in whom DVT was not detected developed PTE. Female sex, older age, worse PS, the presence of CVC, and a history of preoperative chemotherapy were the independent risk factors for DVT. Routine lower-extremity venous ultrasonographic screening is useful for prevention of PTE because it can identify patients at high or low risk for PTE.

The Safety of Hand and Upper-Extremity Surgical Procedures at a Freestanding Ambulatory Surgery Center: A Review of 28,737 Cases.

More procedures are being completed on an outpatient basis at freestanding ambulatory surgery centers. The purpose of our study was to determine the safety and rate of adverse events in outpatient hand and upper-extremity surgical procedures. A retrospective review of cases at a single, freestanding ambulatory surgery center over an eleven-year period was performed. In our analysis, 28,737 cases were performed and were included. Adverse events were defined as serious complications causing harm to a patient or leading to additional treatment. Using state-reportable adverse events criteria as a guideline, we divided the adverse events into seven categories: infection requiring intravenous antibiotics or return to the operating room, postoperative transfer to a hospital, wrong-site surgical procedure, retention of a foreign object, postoperative symptomatic thromboembolism, medication error, and bleeding complications. These adverse events were then analyzed to determine if they led to additional laboratory testing, hospital admission, return to the operating room, emergency department visits, or physical or mental permanent disability. There were fifty-eight reported adverse events, for an overall rate of 0.20%. There were no deaths. There were fourteen infections, eighteen postoperative transfers to a hospital, twenty-one hospital admissions after discharge, one medication error, and four postoperative hematomas. There were no cases of wrong-site surgical procedures or retained foreign bodies. Our study shows that, with a selected patient population, a very low adverse event rate (0.20%) can be achieved. Our review showing few adverse events, no deaths, and no wrong-site surgical procedures supports our view that hand and upper-extremity surgical procedures can be completed safely in the outpatient setting at a freestanding ambulatory surgery center. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Sustained-release synthetic biomarkers for monitoring thrombosis and inflammation using point-of-care compatible readouts.

Postoperative infection and thromboembolism represent significant sources of morbidity and mortality but cannot be easily tracked after hospital discharge. Therefore, a molecular test that could be performed at home would significantly impact disease management. Our lab has previously developed intravenously delivered 'synthetic biomarkers' that respond to dysregulated proteases to produce a urinary signal. These assays, however, have been limited to chronic diseases or acute diseases initiated at the time of diagnostic administration. Here, we formulate a subcutaneously administered sustained release system by using small PEG scaffolds (<10 nm) to promote diffusion into the bloodstream over a day. We demonstrate the utility of a thrombin sensor to identify thrombosis and an MMP sensor to measure inflammation. Finally, we developed a companion paper ELISA using printed wax barriers with nanomolar sensitivity for urinary reporters for point-of-care detection. Our approach for subcutaneous delivery of nanosensors combined with urinary paper analysis may enable facile monitoring of at-risk patients.

Legal issues related to postoperative pulmonary thromboembolism in Korea.

PurposeCurrently, development of pulmonary thromboembolism (PTE) after surgery is frequently being followed by legal action in Korea, as consequences may be fatal. In the current study, we assessed possible countermeasures that medical teams can take when faced with conflicting opinions on responsibility for PTE.MethodsA retrospective analysis of claims handled by the Supreme Court and subordinate courts, from 1999 to 2015, was performed. We analyzed the type of procedure, associated complications, and critical legal points from the recorded judgments along with any liability limitations on surgeons.ResultsAfter reviewing cases between 1999 and 2015, a total of 18 cases were analyzed. There were no cases in which the surgeon was held accountable between 1999 and 2002. From 2003, there were instances of the surgeon being held accountable, with a peak of cases in 2013. Legal standards applied in judicial decision-making related to appropriate use of preventive measures, operation characteristics, doctor's reaction towards symptom occurrence, obligation of postoperative medical care, and duty of explanation.ConclusionThe courts in Korea have changed their position from one of denying doctors' liability to one of enforcing responsibility for PTE. Surgeons are therefore being held responsible with greater frequency, depending on the details of the case. Lessons can be learnt from precedents that can be incorporated into medical education and training programs with the aim of reducing both major PTE complication rates and litigation costs.

The best modern practices to reduce surgical complications after total hip and knee replacement

Although there is the use of pharmacological prophylaxis to prevent venous thromboembolic diseases after total hip or knee replacement, venous thromboembolism is considered one of the main and serious complications. Moreover, the incidence of deep venous thrombosis among the patients who have total hip or total knee replacements is still high. The use of regional anaesthesia in arthroplasty has been increasing recently. In addition to its effects in elimination pain, regional anaesthesia may help to reduce the incidence of postoperative thromboembolism. Given this, this paper aims to highlight the role of regional anaesthesia to improve outcomes of hip and knee arthroplasty.

A structured look at the problem of patients’ safety in surgery

To study surgeons' awareness about safety of patients in surgery and to determine necessary educational measures in this area. 110 surgeons were interviewed. Mean length of work was 16.1±0.97 years. 88.2% of surgeons worked at hospitals. 47.3% of surgeons were engaged elective surgery. Previously 55.5% of respondents were involved into conflict with patients. A half of respondents are familiar with WHO program «About patient' safety» and key issues of patient' safety during prevention of postoperative thromboembolic and infectious complications. 76% of respondents have the possibility to use videoendoscopic technologies, but only 36% of them realize these techniques. Up to 33% of respondents consider to be studied at certification cycles only. Many surgeons use the Internet as the main source of information. Current tendencies of surgical development require to focus on perioperative safety and the need for intensive research of the technologies of surgical patients' safety.

Are Korean Patients Different from Other Ethnic Groups in Total Knee Arthroplasty?

Most of the implants used for total knee arthroplasty (TKA) in Asian patients have been produced based on anthropometry of Western people. Since anatomic features and life styles are different between Western and Eastern people, there would be ethnic differences in terms of conformity of implants to the patient's anatomy or clinical results after TKA. Therefore, surgeons in Asia are particularly interested in related surgical techniques and implant designs used in TKA for improved clinical results and patient satisfaction. In this review, we investigated the anthropometric differences of Koreans from Westerners. Koreans are of shorter stature, less weight, and smaller skeletal structure and have a higher incidence of constitutional varus alignment of the lower extremity. Moreover, compared to Westerner TKA populations, the proportion of female patients was large and primary osteoarthritis was prevalent in preoperative diagnosis in Korean TKA patients. Culturally, Koreans have life styles that demand high flexion positions of the knee such as squatting, kneeling, and cross-legged sitting. Although there were no notable differences in the complication and revision rates following TKA between Westerners and Koreans, the incidence of postoperative deep vein thrombosis and pulmonary thromboembolism was lower in Koreans than Westerners. We hope that further research on implant designs and more interest in TKA will improve outcomes in Korean patients.