A systematic review and meta-analysis for the association between duration of anticoagulation therapy and the risk of venous thromboembolism in patients with lower limb superficial venous thrombosis.

OBJECTIVE: The aim of this study was to determine the association between the duration of systemic anticoagulation therapy (ACT) and the risk of further venous thromboembolism (VTE) in patients with superficial venous thrombosis (SVT). METHODS: A systematic review and meta-analysis were performed using searches of Medline and Cochrane Library databases in September 2023. Papers that provided VTE incidence within mid-term follow-up of ≥45 days in patients who received any ACT were included. Patients were categorized into subgroups according to the course of treatment: (1) no ACT (0 days); (2) ACT of ≤14 days; (3) ACT of 15 to 30 days; (4) ACT of 31 to 45 days; and (5) ACT of >45 days. Reported events were transformed to events per 100 patient-years, and a random-effects model was used to calculate pooled rates for proportions. The primary outcome (VTE) was a combination of SVT progression or recurrence with the occurrence of deep vein thrombosis (DVT) and pulmonary embolism (PE). Secondary outcomes included major and clinically relevant non-major or minor bleeding. RESULTS: Twenty-four studies (10 randomized controlled trials and 14 cohort studies) combining outcomes in 12,341 patients were included in the quantitative synthesis. Minimum VTE and SVT recurrence or progression rates were observed with the ACT duration of 31 to 45 days of 16.2 (95% confidence interval [CI], 10.4-23.3) and 8.2 (95% CI, 3.1-15.8) events per 100 patient-years, respectively. Minimum DVT and PE rates observed with the treatment duration of 15 to 30 days were 5.5 (95% CI, 2.8-9.1) and 0.9 (95% CI, 0.5-1.3) events per 100 patient-years, respectively. Short-term treatment of ≤14 days was associated with the highest rates of VTE of 59.7 (95% CI, 37.7-86.4), DVT of 13.7 (95% CI, 9.6-18.4), and PE of 3.1 (95% CI, 1.4-5.6) events per 100 patient-years. Major bleeding rates were unrelated to the duration of ACT and did not exceed 0.5 events per 100 patient-years. The highest rate of clinically relevant non-major or minor bleeding was observed with ACT duration of 31 to 45 days of 14.2 (95% CI, 5.5-26.8) events per 100 patient-years. The most common risk factors for VTE included male sex, cancer, personal history of DVT, PE, or SVT, and thrombosis of non-varicose veins. CONCLUSIONS: Prolonged systemic anticoagulation is associated with the tendency to decrease VTE rates in patients with lower limb SVT.

Intermittent Pneumatic Compression in Addition to Standard Prophylaxis of Postoperative Venous Thromboembolism in Extremely High-risk Patients (IPC SUPER): A Randomized Controlled Trial.

OBJECTIVE: To assess the efficacy of adjunctive IPC to standard prophylaxis of postoperative VTE in patients at extremely high-risk. SUMMARY OF BACKGROUND DATA: The standard prophylaxis for postoperative VTE is insufficient in extremely high-risk patients. It is unclear whether an adjunctive use of IPC would result in a lower incidence of postoperative venous thrombosis. METHODS: We randomly assigned patients who underwent major surgery and had a Caprini score of ≥11 to receive either IPC in addition to standard prophylaxis with anti-embolic stockings (pressure of 18-21 mm Hg at the ankle) and low-molecular-weight heparin (IPC group) or standard prophylaxis alone (control group). The primary outcome was an asymptomatic venous thrombosis of the lower limbs, as detected by duplex ultrasound scan performed before inclusion and every 3-5 days after surgery. RESULTS: A total of 407 patients underwent randomization, of which 204 were assigned to the IPC group and 203 to the control group. The primary outcome occurred in 1 (0.5%) patient in the IPC group and 34 (16.7%) patients in the control group [relative risk, 0.03, 95% confidential interval (CI): 0.01-0.21]. Pulmonary embolism occurred in none of the 204 patients in the IPC group and in 5 (2.5%) patients in the control group (relative risk, 0.09; 95% CI, 0.01-1.63), and postoperative death occurred in 6 (2.9%) patients in the IPC group and 10 (4.9%) in the control group (relative risk, 0.50; 95% CI, 0.50-1.60). CONCLUSIONS: Among patients with a Caprini score of ≥11 who received standard prophylaxis for VTE, adjunctive IPC resulted in a significantly lower incidence of asymptomatic venous thrombosis.

The frequency and clinical significance of nontarget superficial and deep vein occlusion after physician compounded foam sclerotherapy of varicose tributaries.

OBJECTIVE: To evaluate the incidence and clinical relevance of silent nontarget occlusion (NTO) of superficial and deep veins occurring after ultrasound-guided foam sclerotherapy (UGFS) that can be detected by serial duplex ultrasound scan (DUS). METHODS: This retrospective analysis evaluated the medical records of patients treated with UGFS at a private clinic in Moscow, Russia from 2015 to 2017. All patients underwent serial DUS at 1 to 2 weeks and 1, 3, 6, and 12 months after UGFS. RESULTS: During the observation period, 268 patients were treated with UGFS, using physician compounded polidocanol foam 257 lower limbs of 196 patients (73%) with varicose veins who underwent DUS at 1 to 2 weeks after the last session of UGFS (inclusion time-point): 139 women and 57 men (mean age: 44.2 ± 12.2 years) with the following CEAP clinical class distribution: C2, 74.0%; C3, 20.0%; C4, 4.5%; and C5, 1.5%. NTO at the inclusion time-point occurred in 60 limbs (23.3%) of 57 patients (28.5%) and was symptomatic only in three limbs (1.2%). Most occlusions were localized in the untreated great saphenous vein trunk (n = 28) and the calf muscle veins (n = 23). Overall, 72%, 44%, 29%, and 10% of all limbs and 77%, 45%, 28%, and 12% of limbs with NTO were followed up by DUS at 1, 3, 6, and 12 months, respectively. There were no cases of thrombus progression or symptomatic venous thromboembolism (VTE). At six months, no deep vein occlusions persisted. CONCLUSIONS: The frequency of nontarget vein occlusion after UGFS revealed by serial DUS may be as high as 23.3%. These occlusions tend to resolve within six months and are not associated with symptomatic VTE.

Utilization of the Caprini score in conjunction with thrombodynamic testing reduces the number of unpredicted postoperative venous thromboembolism events in patients with colorectal cancer.

BACKGROUND: The thrombodynamic test (TD) is a novel global test of hemostasis that allows to study the spatial-temporal characteristics of a clot formation in real time under conditions close to natural ones and demonstrates high sensitivity to detect the state of hypercoagulation. The main paraments of the test are the velocity of clot growth, clot's size, and clot density. The objective of this study was to compare the classic Caprini 2005 score and its modified version in association with the results of TD. The goal is to predict postoperative venous thromboembolism (VTE) in surgical patients undergoing surgery for colorectal cancer. METHODS: This was a prospective observational clinical study involving 80 patients (33 men and 47 women; mean age, 73.9 ± 7.2 years) who underwent major (79 cases) or minor (1 case) surgery for colorectal cancer. Patients were at high risk for postoperative VTE (ie, a mean Caprini score of 9.9 ± 2.0) and received combined prophylaxis (ie, antiembolic compression stockings and enoxaparin 40 mg once daily) until discharge. Enoxaparin was administered at a fixed time of blood sampling for the TD test. Duplex ultrasound scan was performed to detect postoperative vein thrombosis before and 5 to 7 days after surgery. RESULTS: Postoperative vein thrombosis was found in 21 of 80 patients (26.3%; 95% confidence interval, 17.9%-36.8%). Regression analysis and receiver operating characteristic (ROC) curve showed that Caprini scores significantly predicted VTE (P < .0001; area under the curve [AUC] = 0.839 ± 0.045). Analysis of ROC curve coordinates showed that a cutoff point of 11 scores had a sensitivity of 76.2% and a specificity of 74.6%. The results of the TD test showed significant hypercoagulation despite enoxaparin administration in patients with VTE. Regression analysis and ROC curves demonstrated that the following TD parameters had the greatest predictability for postoperative DVT: initial velocity of clot growth (Vin) and clot size (CS) measured at 12 hours after enoxaparin administration (AUC, 0.697 ± 0.063 and AUC, 0.790 ± 0.059, respectively), as well as Vin and CS measured 24 hours after the enoxaparin injection (S = 0.847 ± 0.059 and S = 0.803 ± 0.069, respectively). The cutoff points for VTE prediction at 12 and 24 hours seemed to be a Vin of greater than 62.5 and greater than 64.5 µm/minute (normal range, 35-56 µm/minute) as well as a CS of greater than 1351.5 and greater than 1333.5 µm (normal range, 800-1200 µm), respectively. Identified thresholds for TD parameters have been integrated into Caprini scores under the item "other congenital or acquired thrombophilia." The total Caprini scores were recalculated in patients where one or all TD parameters had exceeded the cutoff followed by reanalysis of the ROC curves. The best predictability was found for Caprini scores considering the elevation of all four TD parameters (AUC, 0.924 ± 0.029) with increased cutoff to a score of 12 with a sensitivity of 85.7% and a specificity of 81.4%. The use of cutoffs for the original and modified scores could be used to calculate the number of patients that were under cutoff but developed with VTE: 10.2% and 5.9%, respectively. CONCLUSIONS: Integrating TD parameters into the Caprini score increases the ability to predict postoperative VTE.