Which modality for which vein? A narrative review of strategic modality selection for chronic venous disease treatment

A non-systematic narrative search of MEDLINE/PubMed was performed to identify comparative trials, long-term series, meta-analyses, and key reviews addressing HL/S, endovenous TT, CAC, MOCA, and UGFS. The search covered publications from 2000 to 2025 using combinations of keywords such as “chronic venous disease,” “varicose veins,” “great saphenous vein,” “endovenous laser ablation,” “radiofrequency ablation,” “cyanoacrylate closure,” “mechanochemical ablation,” and “foam sclerotherapy.” Current guidelines from the European Society for Vascular Surgery and the Society for Vascular Surgery/American Venous Forum/American Vein and Lymphatic Society were also reviewed. Evidence was synthesized descriptively rather than quantitatively, with attention to anatomical indications, efficacy, complications, and practical considerations for modality selection. Because this was a narrative review, the author did not aim to capture all available studies exhaustively and did not perform a formal risk-of-bias assessment.

Advantages

HL/S is the most traditional and longest-established operative method for CVD treatment. One of its advantages is the sense of certainty it provides, because the surgeon directly visualizes the target veins throughout the procedure.

HL/S can also be applied when puncture or endovenous access to the target vein is difficult. In some patients, the saphenous vein is difficult to puncture, has poor straightness with pronounced tortuosity, or thrombophlebitic event, such that endovenous catheters or fibers cannot be advanced smoothly or would require multiple puncture sites. In such situations, HL/S remains a reliable option independent of endovenous access.

Another advantage of HL/S is in cases where thrombus is present within the saphenous trunk, particularly near the junction of the deep venous system. Advancing wires, catheters, or fibers in this setting may theoretically dislodge and propagate thrombus locally or systemically. Therefore, when thrombus is located within the segment that needs to be treated, surgical interventions such as partial stripping or local resection may be the most appropriate and safest strategy.

In patients with dilated or aneurysmal change near the junction, unfavorable junctional anatomy was associated with an increased risk of endovenous heat-induced thrombosis (EHIT) after endovenous thermal ablation (ETA).^8,9 In contrast, surgical high ligation is not affected by the presence of a junctional aneurysm in the same way, and is essentially free from TT-related EHIT concerns in this clinical scenario.

Since the widespread adoption of endovenous modalities, baseline vein diameter has been identified as one of the strongest predictive factors for recurrence, particularly recanalization, after treatment. This has been demonstrated in TT and NTNT alike.^10,11 When the vein diameter is large, the volume and surface area of the venous wall increases, and the intraluminal blood volume also increases. To achieve effective thermal or chemical damage to the endothelium in such large-caliber veins, more intensive intervention is inevitably required. For TT, this means delivering higher total energy or higher linear endovenous energy density (LEED); for NTNT techniques, it may require injecting a larger amount of cyanoacrylate glue and/or increasing the degree of mechanical or chemical abrasion. However, intensifying these parameters naturally tends to increase procedure-related pain and may adversely affect postprocedural recovery.

Even if the author considers CAC alone, when the vein diameter doubles, the luminal volume increases by a factor of approximately four-fold and not double. Thus, simply adding one or two extra glue injections may be insufficient to achieve complete occlusion of this markedly increased volume. In contrast, with HL/S, an increase in vein diameter does not by itself lead to a higher revascularization rate, because the diseased trunk segment is physically removed. Although TT can achieve good occlusion rates even in relatively large-diameter veins, no long-term data exists on stable anatomic closure in extremely aneurysmal veins or in trunks approaching 15–20 mm in diameter. In the author’s opinion, one of the greatest advantages of HL/S is that it allows the operator to treat very large-diameter veins without the same degree of concern about revascularization or recurrence that exists with endovenous modalities.

Recently published SVS/AVF/AVLS guidelines explicitly note that, in patients with an epifascial or very superficial saphenous vein, mini-phlebectomy or limited stripping has advantages over TT or NTNT in preventing skin burns, hyperpigmentation, and induration.^6,7 Similarly, CAC was associated with phlebitis-like abnormal reactions (PLAR) or irritation and hypersensitivity phenomena that are particularly likely to occur when the treated saphenous segment lies close to the skin or is epifascial.^12,13 These observations further support the role of surgical removal (or limited stripping) in managing epifascial or superficial trunks.

Finally, although cost-effectiveness varies widely between healthcare systems and countries, HL/S can be performed at substantially lower cost in some countries. In this context, HL/S is often feasible at approximately one-half to one-third of the cost of other endovenous modalities, representing a significant economic advantage for patients in the author’s country.

Limitations and drawbacks

The limitations and drawbacks of HL/S are, straightforward. Since the procedure is performed through surgical incisions, it inevitably leaves scars, and the physical act of avulsing or stripping the vein tends to produce more extensive ecchymosis and postoperative pain than that with endovenous modalities, with a correspondingly longer recovery period and slower return to normal activities.^2,14,15 However, some randomized trials have reported broadly comparable levels of postoperative pain between HL/S and endovenous laser ablation, suggesting that adequate perivenous tumescent infiltration can at least partially offset this traditional disadvantage.^16,17

Nerve injury can also be more pronounced after HL/S, particularly when the below-the-knee (BTK) segment of the saphenous vein is stripped. Clinically relevant rates of saphenous nerve injury have been documented after saphenous vein stripping, and more extensive and distal stripping was associated with higher rates or greater severity of sensory disturbance along the saphenous nerve distribution.^18,19 Thus, when BTK disease is treated with stripping rather than endovenous techniques, the risk of nerve-related morbidity becomes a major practical limitation.

Recurrence following HL/S is a challenge and the mechanisms of recurrence differ fundamentally between HL/S and endovenous modalities. Recurrence after endovenous treatment is related to recanalization of a previously treated truncal vein, leading to persistent/recurrent reflux. In contrast, recurrence after stripping is more often associated with neovascularization at the high ligation site and other changes that are captured within the framework of recurrent varices after surgery (REVAS).^14,20,21 In theory, if high ligation is performed accurately and the saphenous trunk is completely stripped, REVAS should be minimal aside from a subset of cases driven by neovascularization. In everyday practice, however, recurrent varicose veins after HL/S are strongly influenced by anatomic variables that are difficult to predict pre-operatively, such as previously unrecognized or newly developed perforating veins, communicating veins, and other complex patterns of reflux.^20,21

In addition, when the patient is markedly obese, HL/S becomes even less favorable. To expose and control the saphenofemoral junction (SFJ) or saphenopopliteal junction (SPJ), larger skin incisions and more extensive dissection may be required, which can increase tissue trauma, bleeding, wound-related problems, and the risk of nerve injury.^2,22 In such patients, HL/S is clearly at a disadvantage compared with endovenous techniques, which allow junctional treatment through percutaneous access with minimal disruption of overlying soft tissues.

Advantages

From a historical standpoint, TT has been compared directly with HL/S and has become firmly established as an alternative treatment modality with multiple advantages over conventional surgery. In randomized trials, Cochrane reviews, and meta-analyses, TT has consistently shown lower rates of procedure-related bleeding, hematoma, wound infection, and other incision-related problems than that observed with HL/S, along with reduced postoperative pain and faster recovery, including an earlier return to normal daily activities and work.^2,3,14,15,23 These benefits are closely related to the minimally invasive, percutaneous nature of TT, which avoids groin incisions and long stripping tracks.

As mentioned earlier in regard to HL/S, the relative advantage of TT becomes even more pronounced in obese patients. In such patients, surgical exposure of SFJ or SPJ typically requires larger incisions and more extensive soft-tissue dissection, which can increase bleeding, wound complications, and postoperative discomfort. By contrast, TT enables treatment of SFJ or SPJ reflux through ultrasound-guided percutaneous access, with minimal disruption of the overlying adipose tissue and skin. This makes junctional treatment substantially easier and less morbid in obese individuals than that with HL/S.

Similarly, when BTK segments of the great saphenous vein require treatment, the risk of saphenous nerve injury is an important practical concern. Extensive BTK stripping has been associated with clinically relevant saphenous nerve injury and long-lasting sensory disturbance,^18,19 whereas TT offers the possibility of treating BTK reflux with a more controlled thermal profile and limited dissection. Although nerve injury can still occur with TT, especially if tumescent anesthesia is inadequate, the overall risk of nerve-related morbidity is generally considered to be lower than that with long-segment BTK stripping.^29–31

Finally, because TT has effectively become the standard endovenous approach in current practice and guidelines,^1,6,7,23 it has the practical advantage of being applicable to the great majority of typical CVD cases encountered in daily clinical work. With appropriate selection of energy parameters and tumescent anesthesia, TT can be adapted to a wide range of truncal vein diameters and anatomic variations, providing a versatile and broadly applicable “workhorse” modality for the endovenous treatment of saphenous reflux.

Limitations and drawbacks

The limitations of TT are quite restricted, which is precisely why most contemporary guidelines recommend TT as a first-line option over other modalities in the treatment of CVD.^1,6,7 Nevertheless, because TT relies on intraluminal heat to destroy endothelial cells, induce damage to the vein wall, and trigger inflammation and subsequent fibrosis, it inevitably carries its own specific drawbacks.

First, when the target saphenous vein runs in an epifascial or very superficial plane, there is a real risk of skin burns and hyperpigmentation. As noted earlier, the recent SVS/AVF/AVLS guidelines explicitly state that if the saphenous vein is close to the skin (e.g. <0.5 cm from the skin surface), thermal ablation may result in skin burns, hyperpigmentation, or induration. Therefore, in this clinical setting, the guidelines suggest that mini-phlebectomy or limited stripping may be more effective option than TT to reduce skin-related adverse events.^6,7 Even with meticulous and generous tumescent infiltration to protect the skin and subcutaneous tissues—which can substantially reduce the risk of true skin burns—it remains difficult in practice to prevent hyperpigmentation completely in such cases.

Second, TT can be technically challenging when the course of the vein is not straight and endovenous access or device advancement is not easily achieved in a single pass. Examples include marked tortuosity, focal aneurysmal changes, segments with fibrotic transformation after previous phlebitis, or the presence of intraluminal thrombus. In these scenarios, advancing a catheter or laser fiber can be difficult or unsafe, and in some patients a limited stripping, segmental phlebectomy or UGFS may be easier and more straightforward than attempting TT.

Even in large diameter veins, TT could achieve good occlusion rates and favorable clinical outcomes.^10,26 However, as the vein diameter increases, it often becomes necessary to use higher levels of thermal energy than would be needed for a smaller caliber trunk. In practice, increasing vein diameter often prompts operators to deliver higher total thermal energy—by applying higher LEED in EVLA or by modifying segmental treatment patterns in RFA—although specific strategies vary between systems and are not well-standardized.^26,32,33

Once higher thermal doses are used for large vein, it is almost inevitable that peri-procedural pain and perivenous tissue injury will increase compared with TT protocols that employ lower energy. Several studies evaluating “higher-energy” EVLA of the great saphenous vein have indeed reported greater postoperative pain, bruising, and induration when elevated LEEDs are applied, illustrating the trade-off between energy delivery and local morbidity.^34–38

In contrast, because HL/S physically removes the diseased trunk, its technical success is less directly dependent on vein diameter once the vein has been properly ligated and stripped. Thus, while many operators can expect TT to provide lower pain scores and at least comparable recurrence rates to HL/S in veins of more typical caliber—for instance, in great saphenous veins up to around 8–10 mm in diameter—this advantage becomes less certain in the setting of markedly enlarged trunk. In such extreme cases, it is difficult to conclude that TT is consistently less painful and less prone to recurrence than that with HL/S.

Finally, compared with HL/S, TT inevitably requires dedicated capital equipment (laser generator or RF console) and single-use consumables such as catheters or fibers. Multiple economic evaluations have shown that these device-related costs generally make TT more expensive than HL/S at the procedure level. ³⁹ This cost differential remains an important limitation of TT in healthcare systems where reimbursement is constrained or where patients bear a substantial proportion of treatment expenses out of their pocket.

Advantages

The greatest advantage of CAC is that intra- and early post-procedural pain are significantly lower than that with HL/S or TT.^5,42 Because CAC does not require tumescent injections, patients are spared the discomfort associated with multiple tumescent needle passes. In clinical trials in which concomitant phlebectomy was either not performed or carefully standardized, CAC has shown closure rates and postoperative pain scores that are comparable or even superior to that of TT, despite not requiring compression stockings in the CAC arm, whereas stockings were routinely used after TT.^1,6,7,42,43 These findings are most clearly illustrated in the VeClose randomized trial and its long-term extensions, in which CAC demonstrated non-inferior anatomic success, similar or better early pain scores, and faster return to normal activities when compared with that of RFA.^5,42,44,45

As per the recent guidelines, when treating BTK disease—particularly reflux in the lower calf segment—NTNT modalities are attractive options because they avoid thermal energy and thereby eliminate the risk of thermal nerve injury in this vulnerable zone.^6,7 In this specific anatomic context, CAC can be considered to be a safer alternative to TT from the standpoint of nerve preservation.

From the perspective of anatomic efficacy, CAC could achieve closure rates that are broadly equivalent to those of TT, at least in the short-to mid-term, and patient-reported satisfaction was also high.^5,23,42–44 A recent systematic review and meta-analysis of CAC reported 12-months closure rates of approximately 95%–97%, with no significant differences in anatomic success compared with EVLA or RFA, and with fewer mild adverse events and better periprocedural pain and recovery profiles. ⁴³

When CAC is compared with MOCA within the broader NTNT group, several analyses have suggested that CAC may offer somewhat higher anatomic closure rates, although both techniques typically achieve favorable occlusion in appropriately selected cases.^45,46 Taken together, these data support the view that CAC occupies a strong position within the NTNT spectrum with high anatomic success. ¹

Limitations and drawbacks

The most obvious drawback of CAC is its higher cost compared with more established modalities. Although CAC does not require capital equipment such as a laser generator or RF console, the single-use adhesive kit is substantially more expensive than the fibers or catheters used for TT in most healthcare systems. In cost analyses and health technology assessments, these device-related costs consistently make CAC more expensive at the procedure level than those of HL/S or TT, even when the absence of tumescent anesthesia and compression stockings is taken into account.^39,43 The magnitude of this cost difference, however, varies considerably between countries and reimbursement environments. Anyway, no current evidence demonstrates that CAC is more cost-effective than established modalities such as TT or HL/S.

Several studies and guideline discussions have also raised concerns regarding CAC efficacy in very large-diameter veins. Some data indicate that larger baseline saphenous diameter is an important predictor of recanalization after CAC, with failure risk increasing as the trunk diameter approaches or exceeds 6.6 mm or 12 mm.^11,47

Although some authors have proposed that “additional injections” of glue could compensate for the larger luminal volume in these veins, the basic geometric relationship between radius and volume (volume increasing with the cube of the radius) implies that there are inherent limitations to what can be achieved simply by adding a small number of extra glue deliveries.^{11,43,46,48,49}

In practical terms, currently the most widely used VenaSeal^TM closure system (Medtronic, Minneapolis, Minn) contains 5 mL of glue in a single kit. In routine practice, this volume may be insufficient to cover multiple saphenous veins in one session—for instance, bilateral GSV reflux in tall patients, or combined treatment of GSV, SSV, and accessory saphenous veins—so that, unlike HL/S or TT, CAC cannot treat extensive length or multiple saphenous veins with a single disposable unit. In such situations, either multiple CAC kits or a staged strategy may be required, which further amplifies the cost disadvantage compared with those of HL/S or TT.

The most widely discussed complications of CAC are PLAR and related irritation or hypersensitivity phenomena. Although the underlying mechanisms have not yet been fully elucidated, clinical and histopathologic data suggest that these reactions span a spectrum from transient, “irritation-like” phlebitic changes that resolve spontaneously, to true type IV hypersensitivity with characteristic histologic patterns on excised vein segments.^12,13,50,51 In the many published series, PLAR often presents with localized pain, erythema, and pruritus several days after the procedure.^12,13,50 Most reactions improve with conservative, symptomatic management using nonsteroidal anti-inflammatory drugs, antihistamines, and short courses of corticosteroids. However, when a persistent, biopsy-proven type IV hypersensitivity pattern recurs despite medical therapy, several reports have described surgical excision of the affected vein segments as a definitive management strategy.^50,51 In addition, although rare, there is a report of recurrent generalized urticaria following CAC. ⁵²

PLAR is particularly prone to develop when the treated GSV segment is epifascial or very superficial, close to the skin.^12,13,53,54 In such cases, the inflammatory reaction is not only more likely to occur but can also be more symptomatic, with substantial pain and pruritus in the early postoperative period. Clinically, this means that some patients may experience a less favorable recovery profile after CAC than they would after TT or HL/S, despite the inherent advantages of a NTNT.

For these reasons, before recommending CAC, the physician should carefully review the patient’s allergy history and provide detailed pre-procedural counseling about the possibility of PLAR and hypersensitivity reactions, including their usual benign course and the small but real risk of persistent symptoms requiring more intensive management. Adequate informed consent and realistic expectation-setting are essential components of safe CAC practice.

Advantages

Like CAC, MOCA has repeatedly been shown to result in less peri-procedural pain and faster recovery than that observed with TT in many series, while providing comparable early occlusion rates and improvements in clinical severity and quality-of-life scores.^4,32,46,56 In many respects, MOCA has been grouped together with CAC under the NTNT umbrella in recent guidelines and reviews, although its mechanism of action differs substantially from that of cyanoacrylate-based systems.^1,6,7,32,46

As with CAC, current guidelines also emphasize the potential advantages of MOCA when treating reflux in lower calf segments of the saphenous vein, particularly in BTK disease, where avoiding thermal nerve injury is a key priority.^1,6,7,29,30 In short-term and early mid-term studies, MOCA has shown anatomic success and clinical outcomes that are broadly comparable to that of TT with low peri-procedural pain scores and rapid return to normal activities.^4,32,46

Unlike CAC, the sclerosant used in MOCA does not remain as a solid foreign material within the treated vein. From a biochemical perspective, the sclerosant is metabolized and cleared, leaving no persistent polymerized cast in situ. Consequently, MOCA does not carry the same potential for foreign-body–driven reactions that are uniquely associated with cyanoacrylate glue. For patients who desire NTNT treatment but have a history suggestive of hypersensitivity to cyanoacrylate or are reluctant to accept an intravascular glue implant, MOCA can therefore serve as a valuable alternative.^{12,13,46,50,51}

Limitations and drawbacks

Recently, one of the limitations highlighted for MOCA has been its relatively lower long-term closure rate compared with that of TT and, in some analyses, with CAC. Several clinical studies and systematic reviews have suggested that, although early anatomical success is great, mid-to long-term occlusion tends to decline more rapidly with MOCA than those with TT or CAC, especially in large-diameter veins.^4,32,46,56 In particular, follow-up data over 1–3 years indicate that when the treated truncal diameter is > 7 mm, the risk of recanalization or recurrent reflux increases, and closure rates become less robust than that in smaller-caliber veins.^58,59

It is also important to recognize that most of the medium- and long-term MOCA data currently available are derived from ClariVein system-based series, whereas published Flebogrif system-based data remain relatively limited. The two systems, although grouped together as MOCA, differ substantially in device design and sclerosant formulation: ClariVein system uses a rotating wire with liquid sclerosant, whereas Flebogrif system uses multiple sharp ‘cutting element’ hooks with foam sclerosant. From a practical standpoint, the mechanical injury created by Flebogrif system appears stronger than that produced by the ClariVein system tip, and the foam formulation may interact differently with the vein wall. However, whether these differences translate into different closure rates or different long-term patterns of efficacy remains to be fully clarified and will require further dedicated studies.^26,46,57

Reflecting these uncertainties, the latest ESVS guideline assign MOCA a slightly lower level of evidence or strength of recommendation compared with those of TT or CAC. ¹ Therefore, when MOCA is being considered—especially in cases where the target vein diameter is relatively large—the operator should carefully reflect on these issues and the alternative options before deciding on the final treatment strategy.

Because MOCA is fundamentally a sclerosant-based therapy, it shares many of the potential adverse effects associated with liquid or foam sclerosants. In most MOCA protocols, approximately 0.2 mL of sclerosant is injected per centimeter of target vein; in liquid-based systems, the recommended limitation total volume per session is typically around 10 mL, corresponding to roughly 50 cm of truncal vein. Although dilution can extend the length of vein treated, this necessarily increases the total sclerosant dose, which in turn raises the theoretical risk of dose-related adverse events. Therefore, caution is required when treating long segments or multiple truncal veins during the same session.^60–62

For foam-based systems such as Flebogrif system, current European recommendations generally advise not exceeding a total foam volume of approximately 16 mL per session. ¹ In practice, this recommendation may limit the number of veins that can be treated in a single sitting. Nevertheless, in one study using Flebogrif system, multiple great saphenous veins were treated safely with a mean foam volume of 17.7 mL and a maximum of 31 mL, suggesting that higher total doses can be used under careful monitoring and in experienced hands. ⁵⁷

As with other sclerosant-based treatments, MOCA is associated with a relatively high likelihood of post-procedural thrombophlebitis in the treated trunk, and studies have reported that thrombophlebitis and hyperpigmentation can occur more frequently when the treated segment is suprafascial or very close to the skin. ⁶³ In these circumstances, current SVS/AVF/AVLS guidelines echo prior recommendations for TT and NTNT, stating that “while nonthermal techniques may cause hyperpigmentation or induration, mini phlebectomy or limited stripping is safe and effective if the saphenous vein is close to the skin (<0.5 cm).”^6,7 Thus, in suprafascial disease, the operator should consider whether MOCA or limited surgical removal would best balance efficacy with the risk of skin-related adverse events.

Finally, as with CAC, MOCA relies on dedicated single-use devices that are more expensive than the disposables used for TT or HL/S. Although MOCA does not require capital equipment, these higher device-related costs mean that MOCA is generally more expensive than conventional surgery and not clearly more cost-effective than TT; thus, robust evidence of superior cost-effectiveness is still lacking.