Important progress in the testing of novel interventions is newsworthy, but this story includes premature claims of superiority to standard treatments.
The punctures needed to connect the blood vessels of patients to kidney dialysis machines tend to cause damage that eventually requires grafting blood vessels from other parts of the patient’s body. If a patient runs out of native vessels, artificial grafts can be used, but they are not as good as natural blood vessels. In the Lancet article covered by this story, researchers updated progress with implanting blood vessels grown in a laboratory out of a patient’s own cells. As the story said, there is hope that "one day" such tissue-engineered blood vessels could help people with a variety of circulatory problems.
The story appropriately noted that this study included only 10 patients and the lab-grown vessels worked at least temporarily in just five of them. It also pointed out that the lead researcher is an employee of the company that is developing the technique and funded the study. The reporter interviewed both a researcher who wrote a commentary for the Lancet and the president of the National Kidney Foundation, in order to get independent perspective on the study results. The story also pointed out that even if the lab-grown blood vessels prove to be clinically useful, the technique used in this study would likely be very expensive.
Where the story falls short is the comparisons to standard therapy that go beyond the available evidence. In the lead sentence, the story states that the experimental blood vessels made it "easier and safer" for the study participants to use dialysis machines. The study did not compare the lab-grown blood vessels to conventional approaches, so it is too early to say the new technique is better. Also, the story states that the five patients who successfully received dialysis using the tissue-engineered blood vessels needed "fewer interventions" than regular patients, without making it clear that the claim is based only on the general clinical experience of kidney dialysis patients and not on any direct comparison, Indeed, in the journal article, the study authors stated that "Clearly with only 68 patient-months of graft patency, statistically meaningful comparisons with the standard of care would be premature." This caveat should have been included in the story.
These early clinical trial results show that tissue-engineered blood vessels can function at least temporarily in humans, a newsworthy advance over previously reported animal trials. However, to write that the experimental blood vessels work better than standard approaches is going too far, too soon.
The story included an estimate that tissue-engineered blood vessels could cost more than $15,000, perhaps making them too expensive for wide use.
The story stated that the experimental grafts made it "easier and safer" for patients to use kidney dialysis machines. However, the study did not actually compare the tissue-engineered grafts to standard artifical grafts. The story also stated that when the experimental grafts worked, those patients fared better than regular dialysis patients. But, again, the study did not include any such direct comparisons.
The story stated that the new approach made it "easier and safer" for dialysis. But such a statement can’t be made definitively in a lead sentence of a story on such early research. Indeed, the story presented the picture of harms unevenly, stating that artificial vessels are "prone to infection and inflammation," without explaining how often that happens. We don’t think it helps reader comprehension to paint an existing approach with such a broad negative brush while painting the new and uNPRoven approach with such a broad positive brush.
The story points out that the study reported results from only 10 patients. While it quoted the author of a journal commentary as saying the "technology is very, very promising" and that the study is "a revolutionary milestone," it also quoted the commentator as saying it is "difficult to predict what will happen next."
The story included results from all 10 patients, including three failures, a death that was apparently unrelated to the study, and the withdrawal of one participant.
However, the lead sentence of the story seems to overstate the results by reporting that the tissue-engineered blood vessels made it "easier and safer for them to use dialysis machines." The study did not compare the lab-grown blood vessels to standard artificial grafts, so it is too early to make direct comparisons. The story reported that the five patients whose expermental grafts survived through the study period "needed fewer interventions, including surgeries, to maintain the vessels than regular dialysis patients." However, the study did actually make any directo comparison of the study participants to patients receiving standard therapies. The story did not include the caveat in the journal that "it is too early to conclude that the excellent results seen in the patients who advanced to haemodialysis access will be replicated across a broader range of patients." The authors went on to write that "Clearly with only 68 patient-months of graft patency, statistically meaningful comparisons with the standard of care would be premature."
This story does not address the extent of the diseases which might be treated if this type of tissue-engineered graft is eventually approved for clinical use.
The story explains that if the experimental grafts are shown to work, they would be used as an alternative to existing therapy. However, the story does broaden the potential applications to patient with "circulatory problems." As the story pointed out, the study included only patients with advanced kidney disease whose natural blood vessels had been damaged by repeated access for dialysis therapy.
The story included quotes from a journal commentator and a comment from the president of the National Kidney Foundation, who was not connected with the study. The story noted that the lead researcher is an employee of the company developing the tissue-engineered blood vessel grafts and that the company funded the study.
Although the story makes clear that tissue-engineered blood vessel grafts are still far from clinical use, it says that at least for some patients in this study, the experimental grafts performed better than standard approaches. However, the study did not make any direct comparisons to standard approaches, so there is no evidence to support claims of superiority.
The story makes clear that the tissue-engineered blood vessel grafts are still experimental. It says only that this sort of lab-grown blood might help patients "one day," without predicting success within a specific time period.
The story makes clear that this technology is in the earliest stages of human experimentation and that the purpose of the trials is to eventually develop tissue-engineered grafts to replace the standard artificial grafts used when native grafts are not available.
The story included original quotes from a researcher and journal commentator, as well an independent source.
Systematic, Criteria-Driven
The tale of two “negative” studies. Or, how spin is applied to make research findings look more impressive. A must read. https://johnmandrola.substack.com/p/the-tale-of-two-negative-studies
The @nytimes chose to interview one of the editors of the @AnnalsofIM (publisher of this paper) who "gushed with extraordinary glee: It’s huge! There are very few things that reduce your mortality by 30%."
Turns out coffee is not one of those few things despite all that glee. https://twitter.com/garyschwitzer/status/1533202075928215558
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