Altered Fibrinolysis during and after Surgery

Protracted fibrinolysis resistance following cardiac surgery with cardiopulmonary bypass: A prospective observational study of clinical associations and patient outcomes

BACKGROUND

Surgery on cardiopulmonary bypass (CPB) elicits a pleiomorphic systemic host response which, when severe, requires prolonged intensive care support. Given the substantial cross-talk between inflammation, coagulation, and fibrinolysis, the aim of this hypothesis-generating observational study was to document the kinetics of fibrinolysis recovery post-CPB using ClotPro® point-of-care viscoelastometry. Tissue plasminogen activator-induced clot lysis time (TPA LT, s) was correlated with surgical risk, disease severity, organ dysfunction and intensive care length of stay (ICU LOS).

RESULTS

In 52 patients following CPB, TPA LT measured on the first post-operative day (D1) correlated with surgical risk (EuroScore II, Spearman's rho .39, p < .01), time on CPB (rho = .35, p = .04), disease severity (APACHE II, rho = .52, p < .001) and organ dysfunction (SOFA, rho = .51, p < .001) scores, duration of invasive ventilation (rho = .46, p < .01), and renal function (eGFR, rho = -.65, p < .001). In a generalized linear regression model containing TPA LT, CPB run time and markers of organ function, only TPA LT was independently associated with the ICU LOS (odds ratio 1.03 [95% CI 1.01-1.05], p = .01). In a latent variables analysis, the association between TPA LT and the ICU LOS was not mediated by renal function and thus, by inference, variation in the clearance of intraoperative tranexamic acid.

CONCLUSIONS

This observational hypothesis-generating study in patients undergoing cardiac surgery with cardiopulmonary bypass demonstrated an association between the severity of fibrinolysis resistance, measured on the first post-operative day, and the need for extended postoperative ICU level support. Further examination of the role of persistent fibrinolysis resistance on the clinical outcomes in this patient cohort is warranted through large-scale, well-designed clinical studies.

Abnormal bleeding after lumbar vertebrae surgery because of acquired factor XIII deficiency: A case report and literature review

RATIONALE

Abnormal bleeding due to low fibrinogen (Fib) and coagulation factor XIII (FXIII) levels after lumbar vertebral surgery is exceedingly rare. Excessive bleeding is also associated with secondary hyperfibrinolysis. This report presents a case of abnormal incision bleeding caused by coagulation factor XIII deficiency (FXIIID) and secondary hyperfibrinolysis in a state of low fibrinogen after lumbar vertebral surgery.

PATIENT CONCERNS

A middle-aged woman experienced prolonged incision and excessive bleeding after lumbar vertebral surgery.

DIAGNOSIS

Combined with coagulation factors, coagulation function tests, and thromboelastography, the patient clinical presentation supported the diagnosis of FXIIID and secondary hyperfibrinolysis in a hypofibrinogenemic state.

INTERVENTIONS

Cryoprecipitat, Fresh Frozen Plasma, Fibrinogen Concentrate, Leukocyte-depleted Red Blood Cells, Hemostatic (Carbazochrome Sodium Sulfonate; Hemocoagulase Bothrops Atrox for Injection; Tranexamic Acid).

OUTCOMES

After approximately a month of replacement therapy and symptom treatment, the patient coagulation function significantly improved, and the incision healed without any hemorrhage during follow-up.

LESSONS

Abnormal postoperative bleeding may indicate coagulation and fibrinolysis disorders that require a full set of coagulation tests, particularly coagulation factors. Given the current lack of a comprehensive approach to detect coagulation and fibrinolysis functions, a more comprehensive understanding of hematology is imperative. The current treatment for FXIIID involves replacement therapy, which requires supplementation with both Fib and FXIII to achieve effective hemostasis.

The influence of lower-leg injury and knee arthroscopy on natural anticoagulants and fibrinolysis

BACKGROUND

Patients with lower-leg injuries and those undergoing knee arthroscopy are at increased risk of developing venous thromboembolism. The mechanism is unknown, including the influence of lower-leg injury and knee arthroscopy on natural anticoagulant factors and fibrinolysis.

OBJECTIVES

To study the effect of lower-leg injury and knee arthroscopy on plasma levels of anticoagulant and fibrinolytic factors.

METHODS

We applied the following 2 designs to investigate this effect: a cross-sectional study for lower-leg trauma and a before-and-after study for knee arthroscopy. Plasma samples of POT-CAST- and POT-KAST-randomized clinical trial participants (collected shortly after lower-leg trauma or before or after arthroscopy) were analyzed for clot lysis time and levels of antithrombin, tissue factor pathway inhibitor, protein C, free protein S, plasminogen, tissue plasminogen activator, plasminogen activator inhibitor 1, antiplasmin, thrombin activatable fibrinolysis inhibitor, plasmin-antiplasmin, and D-dimer. For the effect of lower-leg injury, samples of 289 patients were compared with preoperative samples of 293 arthroscopy patients, acting as controls using linear regression and adjusting for age, sex, body mass index, comorbidities, and diurnal variation. For the effect of knee arthroscopy, mean changes were calculated for 277 patients using linear mixed models adjusted for diurnal variation. Parameters other than CLT and D-dimer were measured in smaller subsets.

RESULTS

In lower-leg injury patients, most parameters were stable, whereas D-dimer increased. After arthroscopy, most parameters decreased (especially clot lysis time, D-dimer, plasminogen, and anticoagulant factors), whereas tissue plasminogen activator and thrombin activatable fibrinolysis inhibitor slightly increased.

CONCLUSION

In contrast to lower-leg injury, knee arthroscopy was associated with decreased natural anticoagulant factor levels. Neither lower-leg injury nor knee arthroscopy affected in vivo fibrinolysis.

Genomic Analysis of Thrombophilia Variants in the General Population for the Creation of an Effective Preoperative Screening Tool

BACKGROUND

 The loss of a free flap in reconstructive microsurgery is a devastating complication in both the intraoperative and postoperative setting. Previous research has identified a variety of genetic polymorphisms that induce a hypercoagulable state and predispose patients to clot formation and subsequent free flap loss. We aim to review the risks of performing microsurgery on patients who are genetically predisposed to hypercoagulability, as well as identify options, for preoperative screening of inherited thrombophilia.

METHODS

 A thorough literature review was conducted with an online database. A total of 30 studies were reviewed to identify genetic polymorphisms that cause inherited thrombophilia. Through manual review of the literature, a table was created that included thrombotic risk factors and their associated genetic polymorphisms. If the information was available, prevalence for each thrombotic risk was also reported.

RESULTS

 Overall, 18 thrombotic risk factors that contribute to hereditary thrombophilia were identified and linked with specific genes and/or genetic polymorphisms. In studies that did not look at particular ethnic groups, 13 unique thrombotic risk factors were identified. In studies that examined specific ethnic groups exclusively, 12 thrombotic risk factors were identified and related to their respective gene or group of genes. Five of the 18 thrombotic risk factors identified were associated with increased risks of both venous and arterial thrombosis. The remainder of the thrombotic risk factors was associated with increased risk of venous thrombosis exclusively.

CONCLUSION

 The use of genetic screening tests for hereditary thrombophilia in the preoperative setting can serve as an effective preventative measure against postoperative thrombosis. Further exploration of thrombotic risk factors and their related genetic polymorphisms are important steps in reducing postoperative free flap loss.