A direct comparison of prophylactic low-molecular-weight heparin versus unfractionated heparin in neurosurgery: A meta-analysis

Enhanced Recovery After Surgery Protocols and Spinal Deformity

The authors outline a review of preoperative, intraoperative, and postoperative considerations surrounding adult spinal deformity. Preoperative management topics include imaging, hemoglobin A1c levels before spine surgery, osteoporotic management, and prehabilitation. Topics surrounding intraoperative management include the use of antibiotics, liposomal bupivacaine, and Foley catheters. The authors also discuss postoperative questions surrounding analgesia, nausea and vomiting, thromboembolic prophylaxis, and early mobilization. Throughout their discussion, the authors incorporate enhanced recovery after surgery protocols to hopefully lead to future discussions regarding optimizing complex spinal patients.

Thromboprophylaxis with argatroban in critically ill patients with sepsis: a review

During sepsis, an initial prothrombotic shift takes place, in which coagulatory acute-phase proteins are increased, while anticoagulatory factors and platelet count decrease. Further on, the fibrinolytic system becomes impaired, which contributes to disease severity. At a later stage in sepsis, coagulation factors may become depleted, and sepsis patients may shift into a hypo-coagulable state with an increased bleeding risk. During the pro-coagulatory shift, critically ill patients have an increased thrombosis risk that ranges from developing micro-thromboses that impair organ function to life-threatening thromboembolic events. Here, thrombin plays a key role in coagulation as well as in inflammation. For thromboprophylaxis, low molecular weight heparins (LMWH) and unfractionated heparins (UFHs) are recommended. Nevertheless, there are conditions such as heparin resistance or heparin-induced thrombocytopenia (HIT), wherein heparin becomes ineffective or even puts the patient at an increased prothrombotic risk. In these cases, argatroban, a direct thrombin inhibitor (DTI), might be a potential alternative anticoagulatory strategy. Yet, caution is advised with regard to dosing of argatroban especially in sepsis. Therefore, the starting dose of argatroban is recommended to be low and should be titrated to the targeted anticoagulation level and be closely monitored in the further course of treatment. The authors of this review recommend using DTIs such as argatroban as an alternative anticoagulant in critically ill patients suffering from sepsis or COVID-19 with suspected or confirmed HIT, HIT-like conditions, impaired fibrinolysis, in patients on extracorporeal circuits and patients with heparin resistance, when closely monitored.

Safety and Efficacy of Low Molecular Weight Heparin for Thromboprophylaxis in the Elderly: A Network Meta-Analysis of Randomized Clinical Trials

Background: Given their changing pathophysiology, elderly patients carry a high risk of embolism and bleeding events; hence, use of appropriate anticoagulants is very important. Low molecular weight heparin (LMWH) is one of the most widely used anticoagulants although LMWHs differ in their anti-Xa, antithrombin, and anticoagulant activities. To date, no study has directly compared the safety and efficacy of different LMWHs in the elderly. We aimed to compare such differences by conducting a network meta-analysis.

Methods: We searched the Pubmed, Embase, and Cochrane databases for randomized controlled trials (RCTs) of LMWHs that included patients ≥60 years old up to July 22, 2020. Safety outcomes included venous thromboembolism (VTE) or VTE-related death, deep thrombus embolism, and pulmonary embolism. Safety outcomes were clinically relevant bleeding, major bleeding, minor bleeding, and all-cause death. We calculated relative ratios (RR) and 95% confidence intervals (CI) for all outcomes. The cumulative ranking probabilities (SUCRA) were conducted to rank the comparative effects and safety of all LMWHs.

Results: We included 27 RCTs (30,441 elderly), comprising five LMWHs. LMWH was more effective than placebo in preventing VTE or VTE-related death (RR 0.36, 95% CI 0.25–0.53) but less effective than a novel oral anticoagulant (RR 1.59, 95% CI 1.33–1.91) and safer than acenocoumarol regarding risk of clinically relevant bleeding (RR 0.67, 95% CI 0.49–0.90). However, indirect comparison of efficacy and safety of the five LMWHs showed no significant difference in our network analysis, and the subgroup analyses (such as in patients with deep venous thrombosis, cardiac disease, or age >65 years old) supported the results. The SUCRA showed that tinzaparin performed best in preventing VTE or VTE-related death (SUCRA 68.8%, cumulative probability 42.3%) and all-cause death (SUCRA 84.2%, cumulative probability 40.7%), whereas nadroparin was predominant in decreasing the risk of clinically relevant bleeding (SUCRA 84.8%, cumulative probability 77.0%).

Conclusions: On present evidence, there are no significant differences in the efficacy and safety of different LMWHs for the elderly. According to the rank probability analysis, nadroparin seems to be safer for the elderly with a high risk of bleeding, whereas tinzaparin is more effective for those with low bleeding risk.

Prophylactic Low-Molecular-Weight Heparin Versus Unfractionated Heparin in Spine Surgery (PLUSS): A Pilot Matched Cohort Study

BACKGROUND

Despite a proven superior efficacy of prophylactic low-molecular-weight heparin (LMWH) over unfractionated heparin (UFH) in the majority of surgical specialties, chemoprophylactic techniques after spine surgery have not been established because of the fear of epidural hematomas with LMWH.

OBJECTIVE

To determine the efficacy of LMWH vs UFH in the prevention of venous thromboembolism (VTE) events, balanced against the risk of epidural hematoma.

METHODS

This is the first matched cohort design that directly compares prophylactic LMWH to UFH after spine surgery for degenerative/deformity pathologies at a tertiary academic center. Prospectively collected patients receiving prophylactic LMWH and a historical cohort of patients receiving prophylactic UFH (prior to 2017) were matched in 1:1 ratio based on age ±5 yr, American Society of Anesthesiologists classification, location in the spinal column, and type of surgery.

RESULTS

Of 562 patients, VTE events equaled 1.4% (n = 8): 1.4% (n = 4) with LMWH was exactly equal to 1.4% (n = 4) with UFH. Epidural hematomas reached 0.8% (n = 5): 1.4% (n = 4) with UFH vs 0.3% (n = 1) with the LMWH (P = .178). Utilizing adjusted odds ratio (ORadj), the type of chemoprophylaxis after spine surgery failed to predict VTE events. Similarly, the chemoprophylactic technique failed to predict epidural hematoma in the multivariable regression analysis, although UFH trended toward a higher complication rate (ORadj = 3.15 [0.48-20.35], P = .227).

CONCLUSION

Chemoprophylactic patterns failed to predict VTE. Although no differences in epidural hematoma rates were detected, our analysis does highlight a trend toward a safer profile with LMWH vs UFH. LMWH may be a safe alternative to UFH in spine surgery.

Comparison of the Safety of Prophylactic Anticoagulants After Intracranial Surgery

BACKGROUND

Venous thromboembolism (VTE) represents a rare but preventable postoperative complication. Unfractionated heparin (UH) and low-molecular-weight heparin (LMWH) are used to prevent VTE, but comparative studies of their safety and efficacy in the neurosurgical context are limited.

OBJECTIVE

To determine the relative safety and efficacy of UH and LMWH for prophylaxis after cranial surgery.

METHODS

We performed a retrospective analysis of 3204 elective intracranial surgical admissions in 2901 patients over the period 2013 to 2018. From chart review, we extracted demographic and clinical features, including diagnosis and procedure, drugs administered, and the occurrence of VTE events. To compare postoperative outcomes, we performed propensity score matching of patients receiving different drugs, and reviewed postoperative cranial imaging. To contextualize our results, we selected 14 prior neurosurgical studies of VTE prophylaxis to compare our outcomes to the existing literature.

RESULTS

In our sample of 3204 admissions, the overall rate of VTE was 0.8% (n = 27). Rates of VTE were not statistically different in matched cohorts receiving UH and LMWH (1.7% vs 1.0%, respectively); however, LMWH was associated with a higher rate of clinically significant intracranial hemorrhage (ICH) (3.4% vs 0.5%, P = .008). Literature review and meta-analysis supported these findings. Across studies, UH and LMWH were associated with similar rates of VTE. Studies in which patients received LMWH reported significantly higher rates of ICH (4.9% higher, P = .005).

CONCLUSION

We find that LMWH and UH show similar efficacy in preventing VTE; however, LMWH is associated with higher rates of ICH.

Risk Factors Associated with Symptomatic Deep Vein Thrombosis Following Elective Spine Surgery: A Case-Control Study

BACKGROUND

Few studies provide insight into risk factors (RFs) associated with postoperative deep vein thrombosis (DVT) following elective spinal surgery. DVTs are detrimental in this population because of the risk of pulmonary embolization or surgical site hemorrhage with treatment.

OBJECTIVE

Elective spine surgery patients have a low incidence of DVT, thus a case-control study was selected to investigate RFs associated with postoperative, symptomatic DVT.

METHODS

Cases were matched to controls in a 1:2 ratio based on surgery type. Risk of having a prior DVT and choice of subcutaneous heparin dosing following surgery was analyzed in a multivariate regression model with other potentially confounding variables.

RESULTS

A total of 195 patients were included in this study. Independent of patient age, history of DVT was associated with postoperative symptomatic DVT (odds ratio [OR], 4.09; 95% confidence interval [CI], 1.22-13.78). Two versus 3 times daily postoperative heparin dosing (OR, 1.56; 95% CI, 0.32-7.56), surgery length (OR, 1.32; 95% CI, 0.98-1.79), and patient age (OR, 1.04; 95% CI, 1.0-1.08) were not statistically significant, independent RFs. Older age and longer length of surgery trended toward association with DVT without reaching significance. Length of stay was increased from 3-5 days (P < 0.001) in DVT patients compared with controls.

CONCLUSIONS

These results suggest that patients with a history of DVT undergoing elective spinal surgery are at higher risk of developing symptomatic DVT postoperatively resulting in significantly increased length of stay. Further studies on additional preoperative screening and medical optimization in elective spine surgery patients may help reduce the rate of symptomatic, postoperative DVT.