Quality of life after open repair wins in the long term, sub-analysis of DREAM shows

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According to a quality of life sub-analysis from the DREAM trial, endovascular aneurysm repair (EVAR) shows a moderate benefit of quality of life up to six weeks after the procedure but open repair wins in the long run. The results were presented by Jan D Blankensteijn, associate professor of surgery, VU Medical Center, Amsterdam, The Netherlands, at the VEITHsymposium (14–18 November,  New York, USA).

The DREAM (Dutch randomised endovascular aneurysm management) trial was a multicentre, randomised controlled trial set to compare endovascular and open aneurysm repair of aortic abdominal aneurysms. The trial enrolled, between November 2000 and December 2003, 351 eligible patients who were randomly assigned to undergo open or endovascular repair, the patients were considered on the basis that they had to be suitable for both techniques.  


Blankensteijn said that, in order to measure health-related quality of life, SF36 and EQ5D questionnaires were sent pre-operatively and at 13 time points over five years after aneurysm repair. “We achieved a respectable 78% response rate throughout the entire trial,” he said.


He explained that in the SF36 score, 36 questions are converted into subscores scales describing quality of life in various domains such as physical function, general health, bodily pain, vitality, among others. “These subscores were summarised in a physical and mental component, and EQ5D score measures were also calculated,” he added.


The results of the physical component summary, Blankensteijn continued, have shown that “clearly the operation has an initial impact on quality of life, lesser for endovascular as reported previously, but you need to revise these findings”. He commented: “The difference is there and is statistically significant. As the difference is almost three points [2.65], this represents a moderate size effect. After six weeks, the tables are turned and the average difference is only two points [1.95] for a small to moderate size effect. It is statistically significant but because it is two points over almost five years, it is a far more relevant difference than the three-point benefit of endovascular which only lasted the first six weeks.”


Blankensteijn added that a similar pattern was seen in the mental component summary, “although the differences between open and endovascular repair were not significant and the effect size was small.” The EuroQol-5-domains scores, he said, had a similar pattern but a long-term advantage of open repair, “confirming this finding to be consistent over different quality of life measures”.


Blankensteijn told delegates: “In the long run, open repair wins. The question now is, why is that?” He went on to talk about different theories.


“Are the summary scores maybe hiding effects in the subscores? While not all of the subscores show statistical significant differences, the pattern is similar. There is an early advantage for endovascular repair and an advantage for open repair beyond six weeks,” he said.  


He continued: “How about the subjectiveness of self-report quality of life questionnaires? Patients expect ‘big’ operations to kill them; and if they survive, they feel better. In contrast, ‘small’ operations are expected to have no impact at all so any harm decreases their quality of life. Although this may be true, it is more likely to be an early closed-up effect and therefore an unlikely and incomplete catch up connection.”


Blankensteijn then questioned whether the more intense EVAR follow-up protocol could be responsible for the difference. “Follow-up protocols in the DREAM trial were similar for EVAR and open repair, at least for the first 24 months. So the difference in quality of life, as a result, was already there at three months. So again, this is an unlike explanation.”

Was there any covariate shift over time due to skewed mortality risk in the long run? “DREAM is a randomised trial with no long-term differences in survival and the multivariate analysis showed no significant effect on the endpoints,” he noted.


How about the higher reintervention rates after EVAR? “This is certainly a logical explanation as there were more reinterventions after endovascular repair, particularly beyond four years. But after adjusting for reinterventions,open repair still wins in the long run with similar digits,” he said.


“So finally, is quality of life better after EVAR or open repair? It is more of a philosophical question. In the physical component summary graph, you can notice a gradual loss of physical quality of life as the population ages for both open repair and EVAR. The endovascular repair scores were better in the first few weeks, but they never seem to catch up the open scores.”    


In conclusion, Blankensteijn said, there is a short-lived marked benefit of quality of life in EVAR, in the first three months after the procedure. Beyond six months postoperatively, the quality of life scores after open repair sustain a small to moderate benefit up to five years postoperatively. “The higher reintervention rates after EVAR do not seem to be responsible for this difference,” he stated.


Blankensteijn told Vascular News: “Health-related quality of life instruments may not be entirely suited for head-to-head comparisons of two surgical techniques but it is currently the best we have got as no validated aneurysm repair-specific quality of life questionnaires exist. The reported results should be considered as an indication that if patient reported outcomes of less-invasive procedures are better in the short-term it does not automatically mean this effect will persist in the long run. Despite the slight prevalence of long-term health-related quality of life after open repair, which may be of interest for healthcare payers, the perioperative mortality and morbidity advantage of EVAR will be far more relevant for the patients when the decision is on them.”

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