In the Five Trials Underpinning the Cochrane Conclusion, More Than 200 Patients in the “CHIVA Arms” Received Treatment That Did Not Follow CHIVA Principles

Key Takeaways

In 2023, Massimo Cappelli, Raffaele Molino Lova, Mauro Pinelli, and Claude Franceschi published a critical review in Veins and Lymphatics, examining the randomized controlled trials, systematic reviews, and clinical guidelines on CHIVA indexed in Medline and the Cochrane Central database up to June 2023.

The authors raise a question that merits serious discussion: among the 419 patients allocated to the CHIVA arms of the five randomized controlled trials underpinning the most recent Cochrane systematic review, more than 200 received treatment that did not follow CHIVA principles. In the authors’ view, this bias at the level of treatment delivery may have affected how these studies evaluated the efficacy of CHIVA.

It should be noted that this is a view put forward by the review’s authors after returning to the original RCTs and analyzing the treatment process item by item; it is not a conclusion of the Cochrane systematic review itself. But the challenge points to a foundational question in evidence-based medicine: before evaluating whether a treatment is effective, one must first confirm that what was delivered in the study was indeed that treatment.

Why do the authors argue that these treatments were not truly CHIVA?

The most recent Cochrane systematic review holds that the current evidence is insufficient to establish CHIVA as superior to other treatments for varicose veins, drawing chiefly on five randomized controlled trials.

Cappelli and colleagues re-analyzed these studies. In their assessment, of the 419 patients allocated to the CHIVA arms, more than 200 in fact received treatment that did not follow CHIVA’s core principles.

This is not to say that Cochrane’s statistical analysis was in error. What the authors question is whether a substantial proportion of the patients entering the analysis as the “CHIVA arm” in fact received treatment delivered according to CHIVA’s principles.

CHIVA is not a fixed set of operative maneuvers, but a method of devising an individualized treatment strategy on the basis of hemodynamic assessment. Before surgery, the patient’s reflux pathways and shunt types must be identified, and the decisions on which veins to preserve, where to interrupt flow, and in what order to proceed follow from that analysis.

Consequently, even where a treatment is labeled “CHIVA” in the case records or in the study’s group allocation, if the operator did not carry out the hemodynamic analysis and strategic planning that CHIVA requires — using instead a fixed operative technique or a different treatment rationale — whether it can represent CHIVA itself is open to question.

If the authors’ assessment holds, then the question these studies leave behind is not only how effective CHIVA is, but: what exactly was being evaluated?

“Low certainty of evidence” may not be a purely statistical matter

Systematic reviews generally rate the certainty of the current CHIVA evidence as low. Conventionally, this has been attributed to limited sample sizes, differences in study design, and the difficulty of blinding.

This review raises another possibility: if the treatment delivered in a study did not accurately represent CHIVA, then the factors affecting certainty of evidence may lie not only in sample size and study design, but further upstream — in whether the intervention was correctly delivered.

Put differently, only once the object of study is confirmed to be accurate can the subsequent statistical comparison answer the clinical question it was meant to address.

On the guidelines, what different views do the authors offer?

The relevant American and European vascular surgery guidelines both state that CHIVA should be performed by vascular surgeons familiar with the technique.

The review’s authors take a different view. In their assessment, command of the various treatments within one’s specialty is part of a specialist’s professional responsibility; on that basis, invoking an operator’s unfamiliarity with CHIVA as grounds for limiting its use remains open to discussion.

The authors also raise a longer-term consideration from the standpoint of vein preservation: if a destructive treatment is chosen simply because the operator cannot perform CHIVA, the patient may permanently lose the great saphenous vein — and for some patients with severe peripheral arterial disease, where angioplasty or stenting is not feasible, the great saphenous vein may still be an important autologous conduit for infra-inguinal arterial bypass.

It should be noted that this represents the view of the review’s authors and does not reflect the official position of the current guidelines.

What this review really reminds us of

The value of this review may lie less in supporting or opposing CHIVA than in reminding clinicians and researchers of a way of reading evidence: when a study concludes that “a given treatment showed no advantage,” it is worth confirming whether what the study actually evaluated was that treatment itself.

This matters particularly for CHIVA. CHIVA depends on preoperative hemodynamic assessment and individualized strategic planning; it is not a procedure that can be reproduced by following a fixed sequence of steps. If the treatment was not delivered according to CHIVA’s principles, then even where the study’s allocation still reads “CHIVA,” the results may not be directly usable in evaluating CHIVA itself.

The core question Cappelli and colleagues raise, therefore, is not a simple repudiation of the past randomized trials, but a call to re-examine: were those studies, cited repeatedly over many years, evaluating CHIVA — or other treatments performed under CHIVA’s name?

This is a question that any medical technique dependent on operator judgment, diagnostic process, and individualized strategy must face when it comes to be evaluated by the standards of evidence-based medicine.

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References: Cappelli M, Molino Lova R, Pinelli M, Franceschi C. The troubled course of the CHIVA Cure through clinical studies: a critical review. Veins and Lymphatics. 2023;12(1):11886. doi:10.4081/vl.2023.11886.

About the authors: This review was written by Massimo Cappelli, Raffaele Molino Lova, Mauro Pinelli, and Claude Franceschi, and published in Veins and Lymphatics.

Disclaimer: This article is compiled from publicly available literature for the purpose of professional information exchange and content research. It does not constitute specific diagnostic or treatment advice.

About CHIVA News: This column is produced by GCM (Global CHIVA Management). We are dedicated to tracking and sharing the latest academic developments, literature analyses, and clinical-practice discussions in the field of hemodynamic treatment of lower-limb venous disease worldwide, providing rigorous and objective medical information for clinical professionals.