E‑vita open plus for treating complex aneurysms and dissections of the thoracic aorta

Full details of all clinical outcomes considered by the committee are available in the assessment report overview.

The key clinical outcomes for the E‑vita open plus presented in the decision problem were:

• completion and success of technical procedure(s)

• mortality

• major complications, for example stroke, paraplegia, renal failure, myocardial infarction and other events that may delay discharge

• length of intensive care unit stay

• total length of hospital stay

• freedom from further interventions

• long-term survival rates

• incidence of junctional endoleak

• device-related adverse events.

The sponsor identified 13 papers relevant to the E‑vita open plus. Most of these were derived from the International E‑vita Open Registry, which is reported to contain data on 70% to 80% of patients in 11 European centres who have received the E‑vita open or open plus devices to treat their complex aortic disease. The sponsor excluded 10 (of the 13) papers from further consideration, either because the data were already included in a more recent report on the entire register dataset at the time of publication (Jakob et al. 2011), or because they reported on small numbers of patients or on animal studies. The external assessment centre excluded a further 2 papers from its evaluation: a small study with limited follow-up, and a study using the same data as the paper by Jakob et al. (2011). The external assessment centre judged that the principal clinical evidence for the E‑vita open plus was presented in the observational study on the International E‑vita Open Registry by Jakob et al. (2011).

Jakob et al. (2011) reported observational data, gathered between January 2005 and December 2010, for 274 patients with complex aortic disease enrolled in the International E‑vita Open Registry from, at the time, 8 European centres. This comprised the entire dataset at the time of publication. Details of the 274 patients treated, in terms of condition and interventions, are shown in tables 1 and 2. Outcomes were presented as proportions and survival analysis was carried out using the Kaplan–Meier technique. Stent-graft deployment and arch replacement were carried out under selective antegrade cerebral perfusion during a mean time of 75 minutes. Median length of hospital stay was 19 days (range 12 to 29). Adverse events are shown in table 3. For patients with dissections the false lumen was assessed postoperatively and at a median time of 59 months (range 28 to 99) after surgery. The false lumen thrombosed fully in 83% (62 of 75) of patients with acute aortic dissection, and 72% (68 of 94) of patients with chronic aortic dissection. After follow-up these figures rose to 93% and 92% respectively. For patients with aneurysms, complete exclusion of the aneurysm was achieved in 77% of cases (61 of 79). The overall 5‑year survival rate was 74%. Of the 233 patients surviving the procedure initially, secondary endovascular intervention was needed in 13% (29) and surgery downstream was needed in 3% (6) of cases.

The sponsor presented limited evidence on clinical outcomes for 2-stage procedures to allow comparison with those for the E‑vita open plus. The external assessment centre therefore carried out a systematic review and meta-analysis of available data for the comparator procedures. The review identified 10 papers and the meta‑analysis provided pooled estimates of outcome rates with 95% confidence intervals for in-hospital and 30 day mortality, stroke, bleeding, paraplegia and renal failure, which were the main complications reported in the literature. The external assessment centre was unable to calculate single outcome estimates for the combined 2-stage procedures because of a lack of data. It judged that direct comparisons between the E‑vita open plus and the comparators would therefore be complex and that the figures did not take into account factors such as survival from stage 1 to 2 or the impact of the combined outcomes for each procedure. Long-term survival rates could not be included in the meta-analysis because no confidence intervals were reported and individual patient data were not available. The pooled estimate data for the comparators are shown in table 3.

During consultation, an additional clinical report was identified that presented more recent data from the International E‑vita Open Registry (Jakob and Tsagakis, 2013). The paper reported outcomes for in-hospital mortality, stroke, paraplegia and 5-year survival rates for a total of 416 patients from 11 international centres. No outcomes were reported for 30-day mortality, bleeding or renal failure. Figures for 5-year survival rates were reported for 3 subgroups but no overall figure was reported or could be calculated from the data presented. The external assessment centre determined that, overall, there was insufficient information available, in terms of completeness or long-term follow-up, to provide additional reliable estimates of outcome rates beyond those derived from the Jakob et al. (2011) study (see section 3.4).