Incidence and Risk Factors for Deep Vein Thrombosis after Radiofrequency and Laser Ablation of the Lower Extremity Veins

Strategies to reduce rates of severe endothermal heat-induced thrombosis following radiofrequency ablation

OBJECTIVE

Endothermal heat-induced thrombosis (EHIT) is a potential complication of radiofrequency ablation (RFA). Data on effective prophylaxis of EHIT are limited. In 2018, a high-volume, single institution implemented strategies to decrease the incidence of EHIT, including a single periprocedural prophylactic dose of low-molecular-weight heparin to patients with a great saphenous vein (GSV) diameter of ≥8 mm or saphenofemoral junction (SFJ) diameter of ≥10 mm and limiting treatment to one vein per procedure. The size threshold was derived from existing literature. The study objective was to evaluate the effects of these institutional changes on thrombotic complication rates after RFA.

METHODS

A retrospective cohort control study was conducted using the Vascular Quality Initiative database. Data were collected for patients who underwent RFA with a GSV diameter of ≥8 mm or SFJ diameter of ≥10 mm from January 2015 to July 2022. The clinical end points were thrombotic complications (ie, thrombophlebitis, EHIT, deep vein thrombosis) and bleeding complications. Patient demographic and procedural variables were included in the analysis, and significant variables after univariable logistic regression were included in a multivariable logistic regression.

RESULTS

After the policy change, the overall vein center EHIT rate decreased from 2.6% to 1.5%, with a trend toward significance (P = .096). The inclusion criterion of a GSV diameter of ≥8 mm or an SFJ diameter of ≥10 mm yielded 845 patients, of whom 298 were treated before the policy change and 547 after. There was a significant reduction in the rate of EHIT classified as class ≥III (2.34 vs 0.366; P = .020) after the institutional changes. Treatment of two or more veins and an increased vein diameter were associated with an increased risk of EHIT (P = .049 and P < .001, respectively). No significant association was found between periprocedural anticoagulation and all-cause thrombotic complications or EHIT (P = .563 and P = .885, respectively).

CONCLUSIONS

The institutional policy changes have led to lower rates of EHIT, with a reduction in severe EHIT rates in patients with an ≥8-mm diameter GSV or a ≥10-mm diameter SFJ treated with RFA. Of the changes implemented, restricting treatment to one vein was associated with a reduction in severe EHIT. No association was found with periprocedural low-molecular-weight heparin, although a type 2 error might have occurred. Alternative strategies to prevent thrombotic complications should be explored, such as increasing the dosage and duration of periprocedural anticoagulation, antiplatelet use, and nonpharmacologic strategies.

The 2023 Society for Vascular Surgery, American Venous Forum, and American Vein and Lymphatic Society clinical practice guidelines for the management of varicose veins of the lower extremities. Part II: Endorsed by the Society of Interventional Radiology and the Society for Vascular Medicine

The Society for Vascular Surgery, the American Venous Forum, and the American Vein and Lymphatic Society recently published Part I of the 2022 clinical practice guidelines on varicose veins. Recommendations were based on the latest scientific evidence researched following an independent systematic review and meta-analysis of five critical issues affecting the management of patients with lower extremity varicose veins, using the patients, interventions, comparators, and outcome system to answer critical questions. Part I discussed the role of duplex ultrasound scanning in the evaluation of varicose veins and treatment of superficial truncal reflux. Part II focuses on evidence supporting the prevention and management of varicose vein patients with compression, on treatment with drugs and nutritional supplements, on evaluation and treatment of varicose tributaries, on superficial venous aneurysms, and on the management of complications of varicose veins and their treatment. All guidelines were based on systematic reviews, and they were graded according to the level of evidence and the strength of recommendations, using the GRADE method. All ungraded Consensus Statements were supported by an extensive literature review and the unanimous agreement of an expert, multidisciplinary panel. Ungraded Good Practice Statements are recommendations that are supported only by indirect evidence. The topic, however, is usually noncontroversial and agreed upon by most stakeholders. The Implementation Remarks contain technical information that supports the implementation of specific recommendations. This comprehensive document includes a list of all recommendations (Parts I-II), ungraded consensus statements, implementation remarks, and best practice statements to aid practitioners with appropriate, up-to-date management of patients with lower extremity varicose veins.

Thromboembolic outcomes are decreased with the use of a standardized venous thromboembolism risk assessment and prophylaxis protocol for patients undergoing superficial venous procedures

OBJECTIVE

Patients with venous insufficiency can be treated with ablation or phlebectomy, or both. Patients undergoing superficial venous procedures have an elevated risk of deep vein thrombosis (DVT) and pulmonary embolism (PE). At our institution, we initiated a standardized protocol in which patients with a Caprini score (2005 version) of ≥8 are treated with 1 week of prophylactic anticoagulation after the procedure. Duplex ultrasound was performed at 1 week and then within 90 days after the procedure. This aim of the present study was to determine the thrombotic and clinical outcomes after superficial vein procedures using a standardized protocol for DVT/PE risk assessment and prophylaxis.

METHODS

We performed a retrospective analysis of prospectively collected data of superficial vein procedures from 2015 to 2021 at a single center. The patient demographics, CEAP (Clinical-Etiology-Anatomy-Pathophysiology) clinical class, venous clinical severity score, patient-reported outcomes, treatment type, Caprini scores, pre- and postoperative anticoagulation use, and outcomes were collected. Descriptive statistics were used for the patient demographics, procedure details, and unadjusted surgical outcomes. Multivariable logistic regression was used to evaluate the relationship between procedure type and DVT and PE after adjusting for patient characteristics, disease severity, periprocedural anticoagulation, and Caprini score.

RESULTS

A total of 1738 limbs were treated with ablation (n = 820), phlebectomy (n = 181), or ablation and phlebectomy (n = 737). More patients were women (67.1%) and White (90.9%). The overall incidence of DVT/PE was 1.4%. Patients undergoing ablation with phlebectomy had higher rates of DVT/PE (2.7%) than those undergoing ablation (0.2%) or phlebectomy alone (1.7%; P < .01). However, only 30% of DVTs were above the knee. On multivariate analysis, only the procedure type predicted for DVT/PE. However, patients undergoing ablation and phlebectomy achieved better patient-reported outcomes (Caprini score, 5.9) compared with those undergoing ablation (Caprini score, 7.2) or phlebectomy (Caprini score, 7.9) alone (P < .01). The best improvement in the venous clinical severity score was seen with phlebectomy alone.

CONCLUSIONS

The expected difference in the DVT/PE rates between high- and low-risk groups did not materialize in our patients, perhaps secondary to the additional chemoprophylaxis prescribed for the high-risk cohort (Caprini score, ≥8). These results call for a randomized trial to assess the efficacy of a standardized protocol in the reduction of DVT/PE after superficial vein procedures.

Systematic Review and Meta-analysis of the Additional Benefit of Pharmacological Thromboprophylaxis for Endovenous Varicose Vein Interventions

OBJECTIVE

The primary objective of this systematic review and meta-analysis was to elucidate the rate of venous thromboembolism (VTE) after endovenous interventions for varicose veins in the presence of pharmacological and mechanical thromboprophylaxis versus mechanical thromboprophylaxis alone.

BACKGROUND

The VTE rate after endovenous procedures for varicose veins is higher than other day-case procedures and could be reduced with pharmacological thromboprophylaxis.

METHODS

The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines with a registered protocol (PROSPERO: CRD42021274963). Studies of endovenous intervention for superficial venous incompetence reporting the predefined outcomes with at least 30 patients were eligible. Data were pooled with a fixed effects model.

RESULTS

There were 221 trials included in the review (47 randomized trial arms, 105 prospective cohort studies, and 69 retrospective studies). In randomized trial arms, the rate of deep venous thrombosis with additional pharmacological thromboprophylaxis was 0.52% (95% CI, 0.23%-1.19%) (9 studies, 1095 patients, 2 events) versus 2.26% (95% CI, 1.81%-2.82%) (38 studies, 6951 patients, 69 events) with mechanical thromboprophylaxis alone. The rate of pulmonary embolism in randomized trial arms with additional pharmacological thromboprophylaxis was 0.45% (95% CI, 0.09-2.35) (5 studies, 460 participants, 1 event) versus 0.23% (95% CI, 0.1%-0.52%) (28 studies, 4834 participants, 3 events) for mechanical measures alone. The rate of EHIT grade III to IV was 0.35% (95% CI, 0.09-1.40) versus 0.88% (95% CI, 0.28%-2.70%). There was 1 VTE-related mortality and 1 instance of major bleeding, with low rates of minor bleeding.

CONCLUSIONS

There is a significant reduction in the rate of DVT with additional pharmacological thromboprophylaxis and routine prescription of anticoagulation after endovenous varicose vein intervention should be considered. VTE risk for individual study participants is heterogeneous and risk stratification in future randomized interventional studies is critical to establish the clinical effectiveness and safety of additional pharmacological thromboprophylaxis.

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.

Comparison of Modified Above-Knee and Conventional Surgery with the Stripping of the Great Saphenous Vein of Varicose Veins of the Lower Extremities: A Retrospective Study

OBJECTIVE

To compare the clinical effects of modified above-knee and conventional surgery with the stripping of the great saphenous vein of varicose veins of the lower extremities.

METHODS

Clinical data of patients with a varicose vein of the lower extremity from May 2016 to May 2018 were collected. A retrospective study was conducted on the patients receiving modified above-knee and conventional surgery with the great saphenous vein stripping. The baseline characteristics and long-term follow-up data were compared between the groups.

RESULTS

There were no significant differences in baseline characteristics between the two groups (P > 0.05). The surgeries were successfully performed by the same group of surgeons under local anesthesia and neuraxial anesthesia. The hospital stay, operation time, intraoperative blood loss, total length, and number of incisions in the above-knee group were comparable to those in the conventional surgery group (P > 0.05). The incidence of saphenous nerve injury and subcutaneous hematoma in the above-knee group was lower than that in the conventional surgery group (P < 0.05). There were no significant differences in recurrent varicose vein incidences (P > 0.05). After surgery, the venous clinical severity score (VCSS) and chronic venous insufficiency questionnaire (CIVIQ-14) scores of both groups were higher than those before operation (P < 0.05). There was no significant difference in VCSS score or CIVIQ-14 scores between the two groups postoperation (P > 0.05). At 24 months after surgery, the above-knee group (71.8%) and conventional surgery group (73.2%) resulted in changes of at least two CEAP-C clinical classes lower than baseline, respectively.

CONCLUSION

The modified above-knee technique can ensure clinical outcomes, reduce intraoperative blood loss and complication incidences, and shorten the operative time. This gives evidence that the modified above-knee technique is worthy of clinical application.

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.

Literature review of distal deep vein thrombosis

OBJECTIVE

Although distal deep vein thrombosis (DDVT) has been more frequently diagnosed with the availability of better ultrasound imaging quality, the data on the best method to manage DDVT have been conflicting. The aim of the present review was to summarize the current and evidence-based recommendations for the diagnosis and management of DDVT and to provide a summary of the most recent societal guideline recommendations.

METHODS

A literature review of DDVT was performed. The PubMed databases were queried for articles on the epidemiology, risk factors, diagnosis, and management of DDVT.

RESULTS

The prevalence of isolated DDVT has been reported in a broad range. The reported risk factors include older age, active malignancy, a low degree of mobility, acute infection, and atrial fibrillation. With more evidence, anticoagulation therapy was found to be associated with a reduced risk of recurrent venous thromboembolism (VTE) and/or thrombus propagation compared with conservative management. However, anticoagulation was associated with an increased risk of bleeding in a number of studies. The rate of VTE recurrence ranged from 7% to 23% during a follow-up period ranging from 3 months to 8 years. The significant risk factors for VTE recurrence included cancer, older age, an unprovoked event, and inpatient status.

CONCLUSIONS

Few studies have addressed the diagnosis and management of DDVT. Further research is needed to standardize the best approach to diagnose and treat DDVT.

Reducing the risk of venous thromboembolism following superficial endovenous treatment: A UK and Republic of Ireland consensus study

Objectives

Venous thromboembolism is a potentially fatal complication of superficial endovenous treatment. Proper risk assessment and thromboprophylaxis could mitigate this hazard; however, there are currently no evidence-based or consensus guidelines. This study surveyed UK and Republic of Ireland vascular consultants to determine areas of consensus.

Methods

A 32-item survey was sent to vascular consultants via the Vascular and Endovascular Research Network (phase 1). These results generated 10 consensus statements which were redistributed (phase 2). ‘Good’ and ‘very good’ consensus were defined as endorsement/rejection of statements by >67% and >85% of respondents, respectively.

Results

Forty-two consultants completed phase 1. This generated seven statements regarding risk factors mandating peri-procedural pharmacoprophylaxis and three statements regarding specific pharmacoprophylaxis regimes. Forty-seven consultants completed phase 2. Regarding venous thromboembolism risk factors mandating pharmacoprophylaxis, ‘good’ and ‘very good’ consensus was achieved for 5/7 and 2/7 statements, respectively. Regarding specific regimens, ‘very good’ consensus was achieved for 3/3 statements.

Conclusions

The main findings from this study were that there was ‘good’ or ‘very good’ consensus that patients with any of the seven surveyed risk factors should be given pharmacoprophylaxis with low-molecular-weight heparin. High-risk patients should receive one to two weeks of pharmacoprophylaxis rather than a single dose.