Background
Chronic venous insufficiency (CVI) is a disorder in which veins fail to pump blood back to the heart adequately. As a result, it can cause varicose veins, skin ulcers, and superficial or deep vein thrombosis in the legs, and symptoms such as pain, fatigue, heaviness, warmth and swelling of the leg. The ambulatory conservative hemodynamic correction of venous insufficiency (CHIVA) method is a minimally invasive surgical technique to treat varicose veins. The CHIVA treatment aims to eliminate venous-venous shunts (abnormal connections between veins) by disconnecting the escape points, preserving the saphenous vein (a vein from the top of the foot to the upper thigh area) and normal venous drainage of the limb's superficial tissues.
How did we identify and evaluate the evidence?
First, we searched the medical literature for randomized controlled trials (RCTs), clinical studies where people are randomly put into one or more treatment groups. This type of study provides the most robust evidence about the effects of treatment. We compared the results and summarized the evidence from all the studies. Finally, we assessed how certain the evidence was. To do this, we considered factors such as the way studies were conducted, study sizes and consistency of findings across studies. Based on our assessments, we categorized the evidence as very low, low, moderate or high certainty.
What did we find?
We found six RCTs that included 1160 participants who had CVI. Three RCTs compared the CHIVA method with vein stripping, one RCT compared the CHIVA method with compression dressings in people with venous ulcers. The newly included studies included three comparisons, one compared CHIVA with vein stripping (where a vein is removed or tied off) and radiofrequency ablation (RFA; which destroys the nerve fibres carrying pain signals to the brain), and one compared CHIVA with vein stripping and endovenous laser therapy (where veins are heated by a laser). The results showed that the CHIVA method may make little or no difference to the recurrence of varicose veins and may reduce slightly nerve injury and bruising in the lower limb compared to stripping. The CHIVA method showed similar numbers of limb infection and superficial vein thrombosis (inflammation and clotting in a vein) as vein stripping. Compared to RFA, CHIVA may make little or no difference to rates of limb infection, superficial vein thrombosis, nerve injury or hematoma (a severe bruise within the soft tissues), but may cause more bruising. Compared to endovenous laser, CHIVA may make little or no difference to recurrence and numbers of side effects.
How reliable is the evidence?
Further studies are needed to confirm these conclusions since they are based on a small number of clinical trials with methodological limitations such as a high risk of bias. In addition, participants and outcome assessors were not blinded to what treatments groups were given, and the results were imprecise due to the low number of events.
How up to date is this review?
The evidence in this Cochrane Review is current to 19 October 2020.
There may be little or no difference in the recurrence of varicose veins when comparing CHIVA to stripping (low-certainty evidence), but CHIVA may slightly reduce nerve injury and hematoma in the lower limb (low-certainty evidence). Very limited evidence means we are uncertain of any differences in recurrence when comparing CHIVA with compression (very low-certainty evidence). CHIVA may make little or no difference to recurrence compared to RFA (low-certainty evidence), but may result in more bruising (low-certainty evidence). CHIVA may make little or no difference to recurrence and side effects compared to endovenous laser therapy (low-certainty evidence). However, we based these conclusions on a small number of trials with a high risk of bias as the effects of surgery could not be concealed, and the results were imprecise due to the low number of events. New RCTs are needed to confirm these results and to compare CHIVA with approaches other than open surgery.
Many surgical approaches are available to treat varicose veins secondary to chronic venous insufficiency. One of the least invasive techniques is the ambulatory conservative hemodynamic correction of venous insufficiency method (in French 'cure conservatrice et hémodynamique de l'insuffisance veineuse en ambulatoire' (CHIVA)), an approach based on venous hemodynamics with deliberate preservation of the superficial venous system. This is the second update of the review first published in 2013.
To compare the efficacy and safety of the CHIVA method with alternative therapeutic techniques to treat varicose veins.
The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, and the World Health Organisation International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries to 19 October 2020. We also searched PUBMED to 19 October 2020 and checked the references of relevant articles to identify additional studies.
We included randomized controlled trials (RCTs) that compared CHIVA to other therapeutic techniques to treat varicose veins.
Two review authors independently assessed and selected studies, extracted data, and performed quantitative analysis from the selected papers. A third author solved any disagreements. We assessed the risk of bias in included trials with the Cochrane risk of bias tool. We calculated the risk ratio (RR), mean difference (MD), number of people needed to treat for an additional beneficial outcome (NNTB), and the number of people needed to treat for an additional harmful outcome (NNTH), with 95% confidence intervals (CI). We evaluated the certainty of the evidence using GRADE. The main outcomes of interest were the recurrence of varicose veins and side effects.
For this update, we identified two new additional studies. In total, we included six RCTs with 1160 participants (62% women) and collected from them eight comparisons. Three RCTs compared CHIVA with vein stripping. One RCT compared CHIVA with compression dressings in people with venous ulcers. The new studies included three comparisons, one compared CHIVA with vein stripping and radiofrequency ablation (RFA), and one compared CHIVA with vein stripping and endovenous laser therapy. We judged the certainty of the evidence for our outcomes as low to very low due to inconsistency, imprecision caused by the low number of events and risk of bias. The overall risk of bias across studies was high because neither participants nor personnel were blinded to the interventions. Two studies attempted to blind outcome assessors, but the characteristics of the surgery limited concealment.
Five studies reported the outcome clinical recurrence of varicose veins with a follow-up of 18 months to 10 years. CHIVA may make little or no difference to the recurrence of varicose veins in the lower limb compared to stripping (RR 0.74, 95% CI 0.46 to 1.20; 5 studies, 966 participants; low-certainty evidence). We are uncertain whether CHIVA reduced recurrence compared to compression dressing (RR 0.23, 95% CI 0.06 to 0.96; 1 study, 47 participants; very low-certainty evidence). CHIVA may make little or no difference to clinical recurrence compared to RFA (RR 2.02, 95% CI 0.74 to 5.53; 1 study, 146 participants; low-certainty evidence) and endovenous laser (RR 0.20, 95% CI 0.01 to 4.06; 1 study, 100 participants; low-certainty evidence).
We found no clear difference between CHIVA and stripping for the side effects of limb infection (RR 0.83, 95% CI 0.33 to 2.10; 3 studies, 746 participants; low-certainty evidence), and superficial vein thrombosis (RR 1.05, 95% CI 0.51 to 2.17; 4 studies, 846 participants; low-certainty evidence). CHIVA may reduce slightly nerve injury (RR 0.14, 95% CI 0.02 to 0.98; NNTH 9, 95% CI 5 to 100; 4 studies, 846 participants; low-certainty evidence) and hematoma compared to stripping (RR 0.59, 95% CI 0.37 to 0.97; NNTH 11, 95% CI 5 to 100; 2 studies, 245 participants; low-certainty evidence). For bruising, one study found no differences between groups while another study found reduced rates of bruising in the CHIVA group compared to the stripping group. Compared to RFA, CHIVA may make little or no difference to rates of limb infection, superficial vein thrombosis, nerve injury or hematoma, but may cause more bruising (RR 1.15, 95% CI 1.04 to 1.28; NNTH 8, CI 95% 5 to 25; 1 study, 144 participants; low-certainty evidence). Compared to endovenous laser, CHIVA may make little or no difference to rates of limb infection, superficial vein thrombosis, nerve injury or hematoma. The study comparing CHIVA versus compression did not report side effects.