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.