Professor Ziv J Haskal MD, Vice Chair and Chief of Vascular and Interventional Radiology at the University of Maryland, Baltimore, US
This early data from this study appear to bolster the already substantial controlled literature comparing TIPS to endoscopic therapy of oesophageal varices. There is undisputed Class I, Level A evidence that proves that TIPS, i.e. portosystemic shunt therapy, yields markedly lower esophageal variceal rebleeding rates compared to endoscopic band ligation or sclerotherapy. Notably, most prior trials, and meta-analyses, were comprised of patients whose shunts were created with bare metal stents. Treated populations varied amongst studies, from ones including Child C patients, to ones specifically excluding them in favour of healthier elective patients. Most, like this one, showed significantly higher crossover from endoscopic therapy to TIPS rescue.
It’s clear that modern TIPS means PTFE stent grafts. The patencies achieved, out-of-the-gate, vastly exceed those of bare stents. For this commentator, a decade of hundreds of bare stent TIPS revisions has essentially disappeared. It stands to reason that the reduced need for TIPS revisions (a need as high as 38% in some controlled trials) will correlate with lower recurrent symptoms, perhaps further magnifying the disparity between endoscopic therapies and TIPS. Several controlled trials comparing stent graft TIPS to medical therapies are underway. This is one such study.
The data in this study is still in early stages, and the details available to us in the abstract and presentation are necessarily thin. While the current conclusion seems eminently plausible, we must wait for more data. Some of the questions to be answered include: why is this a “high risk cirrhotic patient” population per the authors’ title? High risk for mortality – by virtue of their bleeding, amount of transfusion, liver function, metabolic derangement, intubation status, aspiration pneumonia, etc? Indeed, their exclusion of Child-Pugh score patients >13 generally defines the population as ‘healthier’ cirrhotics, but for their bleeding episode. If there is a mixture of oesophageal and gastric varices, then the cohorts will need to be separated, as therapies and endpoints vary in both medical and TIPS groups. Better characterisation of the acuity and metabolic abnormalities that define high risk, i.e. early mortality will be needed, perhaps using APACHE scores and, secondarily, MELD – this is appears to be one of this study’s niches. Indeed, one point that distinguishes most prior randomised trials was time to randomisation. As delays lengthen, from one day to one week, the selection bias toward ‘healthier’ surviving patients grows. Further, details describing graded rates of encephalopathy, the natural downside of TIPS, will be needed. All this data should undoubtedly follow, in the ultimate manuscript.
Finally, we can consider the basic premise: that a PTFE stent graft might provide better outcome than a bare stent when compared to endoscopic therapy. In reality, I would expect the early results of these stents to be relatively similar. In truly acutely bleeding patients, survival is first judged at 30 day intervals, not at one year. The relative upshot of a PTFE stent graft over a bare stent, in this acute window, is likely real, but small. The stent graft, if properly employed, would prevent the acute thromboses attributed to biliary-TIPS fistulae. But again, I’d expect this early effect is small.