Postoperative prophylaxis of venous thromboembolism (VTE) in patients undergoing high ligation and stripping of the great saphenous vein (GSV)

[Varicosis-Current treatment concepts]

Varicosis is a chronic progressive disease characterized by varicose veins of the lower extremities. Pain, swelling and heaviness of the legs are typical symptoms. These symptoms are caused by a pathological venous reflux, arising from a weakness of the vein wall and progressive venous insufficiency. The indications for invasive surgery are the symptomatic clinical, etiological, anatomical, pathophysiological (CEAP) stages C2s-C6. Compression therapy and venoactive drugs can be recommended for conservative therapy. When it comes to surgical treatment conventional open vein surgery is associated with the best long-term results. Endovenous thermal ablation is associated with few postoperative complications and favors earlier mobilization of the patient. Sclerotherapy has become established with good clinical results for the ablation of reticular and telangiectatic veins, for recurrences and complicated vein anatomy.

The risk of venous thromboembolism after minor surgical procedures: A population-based case-control study

BACKGROUND

Surgery is a well-known risk factor for venous thromboembolism (VTE). However, for several minor surgical procedures, thromboprophylaxis is not advised.

OBJECTIVES

These "low-risk" procedures include a wide variation of interventions for which we estimated the VTE risk to verify their "low-risk" status.

PATIENTS/METHODS

We used data from a large population-based case-control study (Multiple Environment and Genetic Assessment study) into causes of VTE, and linked these to the Dutch Hospital Data Registry to identify exposure to surgical procedures. Logistic regression was used to calculate odds ratios for the 90-day and 1-year relative risks of VTE following these procedures, which were adjusted for body mass index (BMI), sex, age, comorbidities, and infection/inflammation.

RESULTS

We included 4247 patients with VTE and 5538 control subjects. Median age and BMI were 48.5 years and 25.5 m²/kg, respectively. Nine unique procedures or groups of procedures were analyzed. One hundred twenty-three participants-90 cases and 33 controls-had undergone a minor procedure within 90 days of the index date, resulting in a 3.5-fold (OR, 3.5; 95% CI, 2.3-5.3) overall increased VTE risk. Furthermore, venous stripping (OR, 7.2; 95% CI, 2.4-21.2), open abdominal/inguinal hernia repair (OR, 3.7; 95% CI, 1.2-11.6), and laparoscopic cholecystectomy (OR, 3.2; 95% CI, 1.0-10.6) were associated with an increased risk. Other minor procedures were less strongly or not associated with an increased risk. In the 1-year period before the index date, all odds ratios were lower.

CONCLUSION

Of the "low-risk" procedures, we found that venous stripping, open abdominal/inguinal hernia repair, and laparoscopic cholecystectomy were associated with a clearly increased risk of VTE within 90 postoperative days.

Current state of the problem of risk assessment and prevention of venous thromboembolic complications after thermal obliteration of superficial veins

Venous thromboembolic complications (VTEO) after modern minimally invasive superficial vein interventions are an infrequent but very dramatic event. This article presents a review of the literature, covering the issues of prevalence, prognosis and pharmacological prevention of VTEO. The performed studies demonstrate that the incidence of symptomatic thrombotic complications after endovenous thermal obliteration does not exceed 0,5%, but taking into account asymptomatic thermally induced thromboses and subclinical occlusions of the muscular veins of the lower leg, this figure can exceed 10%. There is a high heterogeneity of the data, possibly due to differences in the individual risk of VTEO. The most validated tool for assessing the latter is the Caprini Scale, which has not been sufficiently studied in the surgical treatment of varicose veins. The administration of prophylactic doses of anticoagulants after thermal obliteration of saphenous veins is widely used in routine clinical practice, despite the lack of convincing evidence for the appropriateness of this approach. In recent years, the use of direct oral anticoagulants against the official instruction (off-label) has gained great popularity as an alternative to heparin. The largest evidence base has accumulated for the use of rivaroxaban 10 mg, which is associated with high efficacy and safety. Based on completed clinical trials, it is not possible to formulate unequivocal recommendations for prophylactic anticoagulant doses after thermal obliteration of superficial veins at this time. Additional studies are required to identify patients with an individually increased risk of thrombosis in whom prophylactic doses of anticoagulants may be of maximum benefit.

Thrombotic complications after radiofrequency and cyanoacrylate endovenous ablation: Outcomes of a multicenter real-world experience

OBJECTIVE

Chronic venous insufficiency (CVI) affects >40% of the U.S. population; thus, intervention for symptomatic venous disease comprises a large portion of many vascular practices. The treatment of superficial CVI has evolved from open surgical treatment to minimally invasive endovenous closure, including both thermal and nonthermal techniques. Thrombotic complications of thermal ablation have been well reported, with an overall complication rate of <2%. However, a paucity of high-powered, real-world data is available on the thrombotic outcomes of nonthermal techniques. In the present study, we compared the incidence of endovenous heat-induced thrombosis (EHIT) and endovenous glue-induced thrombosis (EGIT) in a large cohort of patients with CVI.

METHODS

A retrospective review was conducted at two tertiary-level institutions of patients who had undergone superficial endovenous ablation from 2018 to 2021. The patient demographics, comorbidities, and periprocedural outcomes were collected through medical record review. A Caprini risk assessment model score was assigned using the information available from the electronic medical records. The patients were categorized by procedure type (ClosureFast [Medtronic Inc, Minneapolis, MN] radiofrequency ablation [RFA] vs VenaSeal [Medtronic Inc] cyanoacrylate glue closure [CAG]). The primary end point was the incidence of EHIT or EGIT. The secondary end point was the incidence of deep vein thrombosis and/or pulmonary embolism.

RESULTS

A total of 803 patients had undergone 1096 procedures during the study period. Their mean age was 62 ± 15 years, and 67% were women. Of the 1096 procedures, 700 were RFA and 396 were CAG procedures, with a combined closure rate of 98% by postprocedure duplex ultrasound at 7 days. The average Caprini score was 5.2 ± 1.8 (RFA, 5.0; vs CAG, 5.4; P < .001). The incidence of EHIT and EGIT was 1.9% and 1.3%, respectively (P = .57). The deep vein thrombosis rate was 0.1% in the RFA cohort and 0.3% in the CAG cohort (P = .81). A comparative analysis of thermal vs nonthermal techniques was performed. A univariate analysis of the risk factors for EHIT and EGIT revealed no significant factors predisposing to thrombotic events.

CONCLUSIONS

The results from the present study have demonstrated the safety of RFA and CAG closure techniques for CVI, with lower thrombotic rates than previously reported. Further work might help to identify how these results can be achieved across all venous ablative techniques for CVI, even for patient populations with advanced venous disease and possibly a greater than average risk of thrombotic events.

Deep Venous Thrombosis and Ulcers of Lower Limbs: Ultrasound Findings in 156 Patients

Venous ulcers (VUs) of lower limbs affect 1% of Western population. In most cases, ultrasounds show only superficial venous insufficiency (SVI), but a deep venous insufficiency (DVI) may also be present without a history of deep vein thrombosis (DVT). To assess SVI and DVI in DVT-positive and DVT-negative patients with VU, a retrospective cohort of 123 patients entered the study (50 male and 73 female, minimum age 29 years and maximum age 90 years, and mean 70.6 years). In 56 patients (45.5%), ulcer was on the right leg, in 52 (42.3%) on the left leg, and in 15 patients (12.2%), ulcer was bilateral, resulting in a total number of 138 limbs in the study. Sixty-six patients suffered DVT, while in 72 anamnesis was negative. Color duplex ultrasound was performed on both limbs, which revealed insufficiencies of superficial and/or deep veins in 18 limbs which had not been affected by an ulcer or a previous DVT. So the study was on 156 limbs. SVI were substantially overlapping in two groups ( p -value = 0.593), while combined SVI and DVI was 72.5% in DVT positive limbs ( p -value = 0.001). In 70% of cases with a femoral vein insufficiency ( p -value = 0.036) or popliteal vein insufficiency (PVI) ( p -value 0,003), a DVT history was present. Of 18 limbs, although not affected by ulcer or previous DVT, eight were positive for DVI (two femoral veins and six popliteal veins). In the patient with VU, the history of DVT is a strong predictor of DVI insufficiency. In DVT-positive patients with ulcer, the number of "combined superficial and deep insufficiencies" appears to be particularly significant and surgical treatment must take this into account. A previous DVT has a low impact on great and small saphenous insufficiencies in ulcer patients; these were substantially overlapping in DVT-positive and DVT-negative patients. The 18 limbs with DVI and SVI without ulcer and DVT history were unexpected result. We think these patients must have a close follow-up to avoid the onset of a VU.

Chemothromboprophylaxis in varicose vein surgery. A systematic review

INTRODUCTION

Venous Thromboembolism (VTE) is a possible complication after varicose vein surgery, reported after both open and endovascular interventions. Nonetheless, there are no internationally accepted recommendations regarding postoperative VTE prevention strategies, with some authors advocating for its use, while others recommend against it. This study aims to systematically review current evidence on the efficacy and safety of chemothromboprophylactic strategies after varicose vein surgery.

EVIDENCE ACQUISITION

A literature search was performed on the MEDLINE, Scopus, SciELO and Web of Science databases, which returned 532 studies. Ten studies were included. Data were extracted using piloted forms.

EVIDENCE SYNTHESIS

A total of 6929 patients were included for analysis, out of which 70.4% were treated by open surgery (n=4878) and 29.6% by endovenous procedures (n=2051; 79.1% EVLA; 20.9% RFA). VTE chemothromboprophylaxis was performed in 76.3% of the patients (n=5284), from which 62.5% were treated by open surgery (n=3301) and 37.5% by endovenous interventions (n=1983). Among those treated by open surgery, reported deep venous thrombosis (DVT) rates ranged between 0-6.25%, while pulmonary embolism (PE) was reported in 0-0.07% of the cases. Regarding endovenous interventions, EHIT and DVT rates ranged between 0-2.5% and 0-0.9%, respectively, with no cases of PE described. The remaining 23.7% of the patients did not underwent VTE chemothromboprophylaxis (n=1645), with DVT and PE rates after open surgery ranging between 0-5.17% and 0-1.48%, respectively. Only one study reported thrombotic complications after endovenous interventions in this subgroup of patients, with post-operative EHIT rates of 7.3%, and no information regarding PE or DVT. Bleeding complications were higher in patients undergoing chemothromboprophylaxis (0-10.2%) when compared to those who did not (0-0.18%), and were more frequent after endovenous interventions (0-10.2% versus 0-0.75% after open surgery).

CONCLUSIONS

VTE is a possible complication after both open and endovascular varicose vein procedures, although overall VTE complications occur less frequently after endovascular interventions. There's a clear heterogeneity regarding peri and postoperative chemoprophylaxis regimens used. Further studies are required to stratify risk factors and indications for chemothromboprophylaxis after varicose vein surgery.

Meta-analysis and systematic review of randomized controlled trials assessing the role of thromboprophylaxis after vascular surgery

BACKGROUND

Venous thromboembolism (VTE) is a well-known complication associated with surgical procedures. The implementation of thromboprophylaxis in this population has become a vital aspect of perioperative care to decrease VTE-associated morbidity and mortality risk. However, data assessing the role of thromboprophylaxis for patients undergoing vascular surgery are sparse. Assessing the role of thromboprophylaxis by low-molecular-weight heparin or unfractionated heparin in vascular surgery.

METHODS

We searched MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception until December 2020, for randomized controlled trials assessing the role of thromboprophylaxis in vascular surgery.

RESULTS

Eight randomized controlled trials met inclusion criteria, including 3130 patients, with a mean age of 55.35 years and 45% were females. Compared with placebo, anticoagulant use was associated with a decrease in deep venous thrombosis (DVT) (risk ratio [RR], 0.34; 95% confidence interval [CI], 0.11-1.05; P = .06; I² = 68%) and pulmonary embolism (PE) (RR, 0.17; 95% CI, 0.02-1.22; P = .08; I² = 41%), but this trend did not attain statistical significance. There was no difference for bleeding outcomes between anticoagulants and placebo (RR, 0.90; 95% CI, 0.05-15.01; P = .94; I² = 76%). There was no significant difference in outcomes when low-molecular-weight heparin was compared directly with unfractionated heparin. In a sensitivity analysis, anticoagulant use was associated with a significant decrease in DVT or PE in patients undergoing venous surgeries, but was not associated with a significant decrease in DVT or PE in patients undergoing arterial surgeries, although this analysis was limited by the small number of studies in each group.

CONCLUSIONS

Among patients undergoing vascular surgery, thromboprophylaxis with anticoagulants showed a trend toward a lesser incidence of VTE when compared with placebo, although this difference was not statistically significant. Bleeding outcomes were comparable between both treatment groups.

Thrombotic complications of superficial endovenous ablation: a contemporary review of thermal and non-thermal techniques

Endovenous ablation has become the preferred means to treat superficial venous insufficiency. Ablative technologies have evolved to include a variety of both thermal and nonthermal techniques. The reported thrombotic complications of endovenous heat induced thrombosis (EHIT) and deep venous thrombosis (DVT) associated with thermal techniques are low (<2% overall). However, the limited data on newer non-thermal technologies suggest these modalities may have thrombotic complication rates upwards of 6%. Additionally, the pathophysiology of thrombotic events related to mechanochemical ablative techniques may differ from EHIT, and thus, may have different implications for management. Described is a case report of a stroke after cyanoacrylate ablation of the great saphenous vein, and a review of the current literature reporting the thrombotic complications associated with current thermal and non-thermal techniques. There exists a need for high volume studies on newer ablative techniques to fully understand their associated thrombotic complications. This review highlights the need for a comprehensive classification system and standard treatment algorithm encompassing of thrombotic complications associated with both thermal and non-thermal ablative techniques.

Venous Thromboembolism Prophylaxis and Thrombotic Risk Stratification in the Varicose Veins Surgery-Prospective Observational Study

Background: An invasive phlebological treatment is still not free from complications such as thrombosis. As in other surgical populations, not only the treatment modality, but also patient condition-related venous thromboembolism (VTE) risk factors matter. The current protocols used in varicose vein surgery centers are based mostly on individual risk assessment as well as on an implementation and extrapolation of general surgery VTE prophylaxis guidelines. In the presented study, the efficacy of routine VTE pharmacological thromboprophylaxis in patients undergoing saphenous varicose vein surgery was prospectively evaluated. In the result assessment, VTE risk factor evaluation and Caprini score results were included; however, due to the limited size of the projected study group, as well as expected limited deep vein thrombosis (DVT) prevalence in this clinical scenario, it was not possible to perform the validation of the Caprini model efficacy in the projected study model. Methods: In the study, 141 patients undergoing saphenous vein stripping and miniphlebectomy in spinal anesthesia were included. In all of the patients, VTE risk factors (including Caprini score evaluation) were assessed, and the routine thromboprophylaxis with enoxaparin 40 mg for 10 days was used. The venous ultrasounds were undertaken before the surgery and on the 10th and 30th day after surgery. The study endpoint was the presence of symptomatic or asymptomatic DVT confirmed in the imaging study. The study safety endpoint was major bleeding occurrence intraoperatively or within 30 days after surgery. Results: The presence of a postoperative DVT was diagnosed in five cases (3.5%) In all of these cases, only distal DVT was confirmed. Despite extensive saphenous varicose vein surgery with stripping and miniphlebectomy performed in nontumescent but spinal anesthesia, no proximal lower leg episode was diagnosed. Three out of five DVT cases were diagnosed on day 10 postoperative control, while a further two were confirmed in the ultrasound examination performed 30 days after procedure. No clinically documented pulmonaly embolism (PE) as well as no bleeding episodes were noticed. Among the factors related to the statistically significant higher DVT occurrence, the results of the Caprini score were identified with odds ratio (OR) = 2.04 (95% CI = (0.998; 4.18)). Another factor that became statistically significant in terms of the higher postoperative DVT prevalence was the reported Venous Clinical Severity Score (VCSS) results (OR = 1.98; 95% CI (1.19; 3.26)). In the multiple logistic regression analysis, the patient age (OR = 0.86; 95% CI (0.75–0.99)), Caprini score evaluation results (OR = 4.04; 95% CI (1.26–12.9)) and VCSS results (OR = 2.4; 95% CI (1.23–4.7)) were of statistical significance as predictors for postoperative DVT occurrence, with a p value of 0.029 for age, and p = 0.017 and p = 0.009 for Caprini score results and VCSS results, respectively. Due to the confirmed limited number of the DVT events in our study cohort, as well as the descriptive and explorative nature of the achieved results, the final clinical potential and significance of the identified parameters, including Caprini score rate and VCSS rate, should be interpreted with caution and studied in the further trials in these clinical settings. Conclusion: All the patients undergoing varicose vein surgery should undergo VTE risk evaluation based on the individual assessment. In VTE risk evaluation, patient and surgical procedure characteristics based on the factors included into the Caprini score but also on specific chronic venous disease-related factors should be taken into consideration. Further studies are needed to propose an objective and validated VTE risk assessment model, as well as a validated antithrombotic prophylaxis protocol in this particular patient group.

A meta-analysis and systematic review of venous thromboembolism prophylaxis in patients undergoing vascular surgery procedures

OBJECTIVE

Perioperative venous thromboembolism (VTE) is generally considered preventable. Whereas the non-vascular surgery literature is rich in providing data about the impact of VTE prophylaxis on VTE outcomes, vascular surgery data are relatively sparse on this topic. This study sought to evaluate the evidence for VTE prophylaxis specifically for the population of vascular surgery patients.

METHODS

A systematic search was conducted in MEDLINE, Cochrane, and Embase databases in December 2018. Included were studies reporting primary and secondary outcomes for common vascular surgery procedures (open aortic operation, endovascular aneurysm repair [EVAR], peripheral artery bypass, amputation, venous reflux operation). A meta-analysis was performed comparing the patients who did not receive VTE prophylaxis and had VTE complications with patients who developed VTE despite receiving prophylaxis.

RESULTS

From 3757 uniquely identified articles, 42 publications met the criteria for inclusion in this review (1 for the category of all vascular operations, 5 for open aortic reconstructions, 2 for EVAR, 1 for open aortic surgery or EVAR, 3 for abdominal or bypass surgery, 2 for peripheral bypass surgery, 2 for amputations, 1 for vascular trauma, and 25 for surgical treatment of superficial venous disease). Five studies met the criteria for inclusion in the meta-analysis. The results demonstrated slightly lower relative risk for development of VTE among patients receiving VTE prophylaxis (relative risk, 0.70; 95% confidence interval, 0.26-1.87). After open aortic reconstruction, the risk of VTE is 13% to 18% and is not reduced by VTE prophylaxis. For EVAR patients, the risk of VTE without prophylaxis is 6%. For patients undergoing peripheral bypass surgery and not receiving therapeutic or prophylactic anticoagulation, the risk of VTE is <2%. For patients undergoing amputations, VTE prophylaxis reduces the risk of VTE. For patients undergoing surgical treatment of superficial venous disease, there is an abundance of literature exploring the utility of VTE prophylaxis, but the evidence is conflicting; some studies demonstrated a benefit, whereas others showed no reduction of VTE with prophylaxis.

CONCLUSIONS

Overall, there is a paucity of literature that addresses the effectiveness of VTE prophylaxis specifically in the population of vascular surgery patients. Our meta-analysis of the literature does not demonstrate a statistically significant benefit of VTE prophylaxis among the vascular surgery patients evaluated; however, it does suggest a low incidence of VTE among patients who receive VTE prophylaxis. Clinicians should identify the patients at high risk for development of postoperative VTE as the risk-benefit ratio may favor VTE prophylaxis in a selected group of patients. Clinicians should use their judgment and established VTE risk prediction models to assess VTE risk for patients. Vascular surgeons should consider reporting VTE incidence as a secondary outcome in publications.

Phlebectomy Techniques for Varicose Veins

Ambulatory phlebectomy is a well-known and widely used procedure for residual symptomatic venous disease. Tumescent anesthesia complements the procedure, providing the ability to perform this intervention in a wide range of practice settings. The procedures are well tolerated by most patients, and complications are rare. They include venous thromboembolism, infection, and hematoma and are generally simple to manage. Alternative and emerging techniques of powered phlebectomy and cyanoacrylate glue are providing alternative forms for treatment and will advance the practice further.

Asymptomatic Isolated Calf Deep Vein Thrombosis: Does It Worsen after Varicose Vein Surgery?

In our varicose vein center, on a trial basis, among the patients with asymptomatic calf deep vein thrombosis (CDVT) we carefully selected the patients for varicose vein surgery using the requirements as follows; 1) the patients had varicose veins with incompetent saphenous veins, 2) sequential examination including DUS confirmed stability and clinical insignificance of asymptomatic CDVT, 3) the patients do not have any risk factors for DVT such as a coagulation profile disorder (antithrombin deficiency, protein C deficiency, protein S deficiency, or antiphospholipid syndrome) or malignancies, 4) surgery is possible under local anesthesia alone, and 5) the patients can understand the concept of asymptomatic CDVT and undergo the surgery on their own will and informed consent. The patients who fulfilled these conditions underwent the varicose vein surgery. Twenty-eight patients with 30 limbs with varicose veins had asymptomatic CDVT, found by preoperative duplex ultrasonography (DUS). Among CDVT, 91% of CDVT existed in the soleal veins. After the diagnosis of the asymptomatic CDVT, serial DUS was performed and showed no changes in the status of the thrombus. Then varicose vein surgery (high ligation of the saphenous junctions either with or without stripping of the saphenous veins) was performed. After the surgery, the CDVT was re-evaluated by DUS. In 27 limbs, CDVT did not show any changes in the status of the thrombus, and in 3 limbs the CDVT was partially resolved. These data suggest that, at least, as far as the patients fulfilled these conditions, varicose vein surgery did not worsen the asymptomatic CDVT. (This is a translation of Jpn J Phlebol 2016; 27: 405–412.)

Haemorheological disturbances in hypertensive type 2 diabetic patients ? influence of antihypertensive therapy

Haemorheological changes have been described in hypertension as well as in diabetes mellitus. Antihypertensive treatment improves rheology in hypertensive patients. The aim of this study was to describe the haemorheological profile and its impact on shear stress in hypertensive type 2 diabetes mellitus patients (HT + DM) and to investigate the effect of antihypertensive therapy on blood rheology using a double-blind randomized protocol, comparing the calcium antagonist amlodipine with the angiotensin-converting enzyme (ACE) inhibitor enalapril. A total of 144 patients with hypertension and type 2 diabetes (64 of transversal study and 80 of randomized clinical trial) were compared with 92 controls belonging to a transversal study. Secondarily, in a separate analysis, therapeutic effects of calcium antagonist amlodipine and ACE inhibitor enalapril were compared in a longitudinal, randomized trial in the patients. We assessed whole-blood viscosity, plasma viscosity, partial and total disaggregation times, haematocrit and fibrinogen. Radial artery systolic flow velocity was measured by pulsed Doppler. Shear stress was calculated as the product of flow velocity x whole-blood viscosity. Compared with controls, patients had significantly higher whole-blood viscosity for all shear rates (P < 0.001) as well as higher arterial diameter and systolic blood flow velocity (2.8 +/- 0.3 vs. 2.6 +/- 0.3 mm, P < 0.001; and 50.8 +/- 11.6 vs. 45.6 +/- 9.8 cm/s, P = 0.01, respectively). Whole-blood viscosity at shear rate gamma = 128/s tended to increase with amlodipine (+1.13%) and decrease with enalapril (-2.47%) (P = 0.028 for inter-group difference). In hypertensive diabetic patients, hyperviscosity contributes to increased shear stress. Haemorheological disturbances in these patients are not significantly influenced by blood pressure lowering with antihypertensive therapy by ACE inhibitor enalapril or calcium antagonist amlodipine. Other factors potentially contributing to rheology and arterial changes may be more critical in HT + DM patients and need further investigation.