Mechanochemical Ablation: Current Status in the Management of Varicose Veins: A Comprehensive Review
Correspondence Address :
Dr. Venkata Bharath Kumar Reddy Lakkireddy,
B6/17, 2nd Floor, B6 Extension, Safdarjang Enclave, New Delhi-110029, India.
E-mail: lakkibharathreddy@gmail.com
Varicose veins, a common venous disorder, often lead to significant discomfort and a reduced quality of life. Over the years, numerous treatment approaches have been explored to alleviate the associated symptoms. Surgical interventions such as saphenofemoral junction ligation and Great Saphenous Vein (GSV) stripping were transformative in their time, but the emergence of endovenous techniques like Endovenous Laser Therapy (EVLT) and Radiofrequency Ablation (RFA) marked a significant shift. While these endovenous techniques have shown exceptional clinical outcomes and cost-effectiveness, they do come with the drawback of pain due to the application of heat for ablation and the necessity of infiltrating tumescent anaesthesia around the vein. In recent years, non thermal, non tumescent methods have arisen as effective alternatives that reduce patient discomfort. These methods encompass procedures such as Mechanochemical Ablation (MOCA) and endovenous cyanoacrylate glue, which minimise heat generation and eliminate the need for tumescent anaesthesia. This article provides a comprehensive overview of the current status of MOCA. It covers its mechanism of action, clinical outcomes, cost-effectiveness, and safety profiles in managing varicose veins.
Great saphenous vein stripping, Non thermal, Tumescent endovenous techniques
Varicose veins are a prevalent issue, affecting nearly one-third of the population. This has resulted in substantial healthcare expenditures, with venous disease accounting for approximately 1-2% of the healthcare budget (1). This condition encompasses a spectrum of lesions, ranging from telangiectasias and reticular veins to more severe manifestations such as varicose veins, trophic ulcerations, and thrombotic complications. A significant proportion of these cases can be attributed to venous hypertension secondary to reflux in one or more GSVs (2).
The treatment of Chronic Venous Disease (CVD) has been shown to significantly enhance the quality of life for affected individuals. Historically, the management of axial reflux of the GSV and Small Saphenous Vein (SSV) involved surgical ligation and stripping through substantial incisions. While effective, these open procedures are associated with considerable morbidity (3). In contrast, endovenous ablation techniques have become the standard of care for GSV ablation. They offer advantages such as reduced postoperative pain, a lower incidence of surgical site infections, quicker return to normal activities, and work resumption. However, it is worth noting that these benefits come with the drawback of high equipment costs (4). Additionally, the use of thermal energy in procedures like EVLT and RFA has been associated with procedural pain, necessitating the use of tumescent anaesthesia. These techniques have also been linked to complications, including thermal burns and skin rashes (5).
A study by Puggioni A et al., conducted between 2001 and 2004, revealed an overall complication rate of 15.4% in limbs treated with EVLT (20.8% in the EVLT group and 7.6% in the RFA group). These complications included superficial thrombophlebitis, excessive pain, haematoma, oedema, and cellulitis. Notably, few of these adverse effects required hospitalisation (6). To mitigate the complications associated with thermal energy, innovative methods such as sclerotherapy, cyanoacrylate glue, and MOCA have emerged.
Non thermal, non tumescent methods for varicose vein treatment have gained rapid popularity due to their clinical efficacy, combined with a superior safety and tolerability profile. Cyanoacrylate glue treatment, which initiates vein fibrosis through rapid polymerisation, has shown promise but is associated with rare complications (7),(8),(9). MOCA involves mechanical injury to the endothelium combined with infusion of liquid sclerosants without the use of tumescent anaesthesia (10). This review article aims to provide a comprehensive understanding of MOCA and its role in the management of varicose veins.
MOCA ingeniously combines mechanical endothelial damage, achieved through a rotating wire or radial cutting hooks, with concurrent catheter-guided infusion of a liquid sclerosant. This dual approach irreversibly disrupts the cellular membranes of the endothelium, triggering vein fibrosis (1),(10). The mechanical and chemical damage to the endothelium not only aids the sclerosant’s penetration into the vessel wall but also induces vasoconstriction, as substantiated by ex-vivo and animal models (2),(11). This dual mechanism implies that MOCA may yield lower recanalisation rates compared to methods relying solely on mechanical or chemical ablation (1). There are two established systems of MOCA: one is the ClariVein system (4), and the other is the Flebogriff system, a more recent system.
a) The ClariVein System
The ClariVein system represents a notable form of MOCA. It utilises a rotating catheter tip spinning at 3500 rpm to mechanically agitate the vessel wall. Simultaneously, it releases a 1.5-2% sodium tetradecyl sulphate solution through the tip of the catheter for chemical sclerosis. This procedure can be performed using local anaesthesia at the insertion site, and through a 4 or 5 Fr sheath. The technique involves percutaneous introduction of the ClariVein sheath and wire into the vessel, followed by controlled withdrawal of the catheter and wire down the vein while ultrasound guidance ensures proper sclerosant administration. Postprocedure care entails a 24-hour compression bandage from the foot to the groin, followed by thigh-high compression stockings at 15 to 20 mm Hg for 48 hours, with daytime use for the subsequent 10 days (Table/Fig 1) (4).
b) The Flebogriff System
The Flebogriff system, a newer MOCA method, comprises five retractable elements with sharp tips that induce mechanical endothelial damage. This innovative approach facilitates stronger vessel contraction and deeper penetration of the sclerosant into the vein wall (Table/Fig 2) (1).
Comparison of Efficacy
In a clinical trial conducted in 2012 by Elias S and Raines JK, where 30 GSVs in 29 patients were mechanochemically ablated and followed for safety and efficacy, no major postoperative complications were reported, and the occlusion rate was an impressive 96.7% (12).
In a randomised controlled trial by Mohamed AH et al., where 150 patients were equally randomised between Endovenous Laser Ablation (EVLA) and MOCA, both groups reported low intraprocedural pain scores. Pain levels during axial EVLA were 22 (9-44) compared to 15 (9-29) during MOCA. At the one-year mark, duplex-derived anatomical occlusion rates after EVLA were 91%, while MOCA achieved 77%. Notably, both groups experienced significant improvements in the Venous Clinical Severity Score (VCSS) and the Aberdeen Varicose Vein Questionnaire (AVVQ), with no significant differences between them (13).
A randomised controlled study by Belramman A et al., comparing postprocedural pain using visual analog scales, revealed that MOCA and Cyanoacrylate Adhesive Embolisation (CAE) techniques produced similar periprocedural pain scores (14).
A multicentre prospective randomised controlled trial conducted by Holewijn S et al., involved 213 patients, with 105 in the MOCA group and 104 in the RFA group. The study showed that MOCA resulted in lower median pain scores during the first 14 days compared to RFA. At 30 days, similar complication numbers and Health-Related Quality of Life (HRQoL) scores were observed. While MOCA exhibited a lower anatomic success rate at one and two years compared to RFA, clinical success rates and HRQoL scores were similar (15).
In a prospective observational study involving 68 patients with unilateral GSV incompetence, MOCA-treated patients reported significantly less postoperative pain during the first 14 days compared to RFA-treated patients. This lower pain score was associated with an earlier return to normal activities and work resumption (16).
In a systematic review conducted by Alozai T et al., (17) over the Flebogriff system of MOCA, the three month anatomic success rate was 95.6%, and the 12-month anatomic success rate was 93.2% (Table/Fig 3) (12),(13),(14),(15),(16),(17).
Complications Associated with MOCA
MOCA is generally considered a safe procedure with a low-risk of complications. Some patients may experience temporary side-effects such as mild discomfort, bruising, or swelling at the treatment site. Phlebitis, inflammation of the vein, is a potential complication, but it often resolves without significant issues. Haematoma, or localised bleeding, may occur, and in rare cases, allergic reactions to the sclerosing agent are possible.
In the MARADONA trial conducted by Holewijn S et al., in 2018, hyperpigmentation was seen in seven patients in the MOCA group and two patients in the RFA group. There were two serious cardiac adverse events, one in the MOCA group (ventricular fibrillation at one year) and one in the RFA group (unstable angina at two years). One patient developed deep venous thrombosis in the RFA group at the 1-year mark, without clinical sequelae (15).
An early clinical trial by Elias S and Raines JK, involving 30 GSVs in 29 patients, reported no adverse events beyond minor local ecchymosis (12). A later trial by Whiteley MS et al., treated 85 patients (104 limbs) over one year and noted a technical success rate of 99%. No major complications were observed, with minor complications such as hyperpigmentation, haematoma/bruising, induration, superficial thrombophlebitis, and prolonged pain occurring in less than 14.3% of patients (11).
Lane TR et al., reported a rare complication of MOCA using ClariVein, known as retrograde inversion stripping of the GSV. However, the patient remained asymptomatic and pain-free, with no abnormal neurology or cutaneous numbness during follow-up appointments (Table/Fig 4) (11),(12),(16),(17),(18).
The systematic review of the Flebogriff system has shown no major complications except for deep vein thrombosis in 0.3% of patients and minor complications like thrombophlebitis and hyperpigmentation in 13-14.5% and 3.3-10.0% of patients, respectively, within three months (16).
Cost-effectiveness
A review article by Epstein D et al., compared the cost-effectiveness of various varicose vein treatments. It considered factors like the cost of staff, kit, consumables, anaesthesia, and more. The analysis revealed that conservative management emerged as the most cost-effective option. Ultrasound-Guided Foam Sclerotherapy (UGFS) was the least expensive treatment over five years but had a higher likelihood of requiring reintervention or retreatment, indicating lower effectiveness. MOCA, EVLA, and High Ligation and Stripping (HL/S) exhibited similar costs and outcomes, suggesting comparable value for money. However, high ligation and surgery required more time in the operating theatre and longer patient recovery, which led to its replacement by endothermal procedures. MOCA, while effective, had a relatively high acquisition cost compared to established methods. CAE had a substantially higher acquisition cost but lacked evidence regarding reinterventions (19).
The studies comparing MOCA with traditional methods have shown promising results, including reduced postoperative pain and comparable improvements in patient-reported outcomes. While MOCA presents a compelling alternative, it is essential to consider factors such as cost-effectiveness, complications, and long-term efficacy. Ultimately, the choice of treatment should be tailored to the individual patient’s needs and preferences, considering factors like cost, pain tolerance, and clinical outcomes. Continued research and clinical evaluation will further refine our understanding of MOCA’s role in the management of varicose veins, offering patients a more comfortable and effective treatment option.
DOI: 10.7860/JCDR/2024/67934.19173
Date of Submission: Oct 15, 2023
Date of Peer Review: Nov 23, 2023
Date of Acceptance: Feb 07, 2024
Date of Publishing: Mar 01, 2024
AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was informed consent obtained from the subjects involved in the study? No
• For any images presented appropriate consent has been obtained from the subjects. No
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ETYMOLOGY: Author Origin
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