Systematic Review and Meta-Analysis of Ex-Situ and In-Situ Fenestrated Stent-Grafts for Endovascular Repair of Aortic Arch Pathologies.

Purpose: To gain insight into safety and efficacy of in situ and ex-situ fenestration techniques for total endovascular arch repair. The term ex-situ fenestration is referring to physician-modified stent-graft technique where fenestration is performed on a back table.

Methods: Electronic search was conducted according to PRISMA (Preferred Reporting Items for Systematic review and Meta-analyses) guidelines from 2000 to 2020. The main outcomes measured were 30-day mortality, stroke, aortic-related mortality, and reintervention rates.

Results: Fifteen studies were eligible: 7 ex-situ fenestration (189 patients) and 8 in-situ fenestration (149 patients). In ex-situ group, dissection was the main pathology treated and proximal sealing zones were Z0 or 1 in 53.5% of patients. In in-situ group, dissection and aneurysm were equally represented in around 40% of cases and proximal sealing zones were Z0 or 1 in 46.5% of patients. Cumulative 30-day all-cause mortality was similar in both groups: 3.8% (95% confidence interval [CI]: 1.7%-8.2%) and 3.8% (95% CI: 1.6%-8.9%), respectively, in ex-situ and in-situ groups and stroke rate of 2.8% (95% CI: 1.1%-7%) and 5.3% (95% CI: 2.6%-10.5%). After a 11.1 ± 2.6 months mean follow-up for ex-situ and 16.7 ± 2.3 months for in-situ group, there were 5.2 and 1.4 reinterventions per 100 patients-years, respectively, for ex-situ and in situ groups. Aortic-related mortality rates of, respectively, 3.2% (95% CI: 1.3%-7.4%) and 2.6% (95% CI: 0.9%-7.3%) were noted in ex-situ and in situ groups.

Conclusion: The reported data show favorable short-term results of both ex-situ and in-situ fenestration techniques with low mortality and strokes rates. However, durability is still questionable given the lack of long-term data. Both options may have their place in arch repair beyond the spectrum of emergent and urgent cases, on condition that results stand the test of time.

Clinical impact: In situ and ex-situ fenestration techniques have been initially developed to overcome emergency or as a bail out techniques however giving the promessing favorable short term results indications of these techniques may be extended to elective patients ineligible to customized stent-grafts and possibly in the futur to more elective cases as an option for total endovascular arch repair.