Zone 2 Versus Zone 3: Thoracic Endovascular Aortic Repair's Tough Choice in Acute Type B Aortic Dissection: Systematic Review and Meta-Analysis.

BACKGROUND: Optimal proximal landing zone selection in thoracic endovascular aortic repair (TEVAR) for acute and subacute Stanford type B aortic dissection remains controversial. This meta-analysis compared zone 2 versus zone 3 deployment with respect to perioperative and mid-term outcomes. METHODS: This study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. PubMed and Scopus were systematically searched up to August 1, 2025. Eligible studies included adult patients with acute or subacute type B aortic dissection undergoing TEVAR with proximal landing in zone 2 or zone 3. Random-effects meta-analyses were performed using odds ratios (ORs) with 95% CIs. Heterogeneity was assessed using I2, and sensitivity analyses included leave-one-out and fixed-effect comparisons. RESULTS: Four studies comprising 907 patients (393 zone 2, 514 zone 3) were included. There was no significant difference in 30-day mortality between groups (OR = 0.94, 95% CI, 0.64-1.39; I2 = 0%). Zone 2 repair was associated with increased spinal cord ischemia in the common-effect model (OR = 2.29, 95% CI, 1.20-4.02), while the random-effects model showed a non-significant but consistent trend (OR = 2.96, 95% CI, 0.61-14.38). The risk of stroke showed a similar trend favoring zone 3 (OR = 2.05, 95% CI, 1.08-3.87). Reintervention rates were higher in zone 2 in the common-effect model (OR = 1.91, 95% CI, 1.24-2.95) but were not robust in sensitivity analysis. Endoleak outcomes showed substantial heterogeneity (I2 = 81.5%), precluding reliable pooling. Other complications and retrograde type A dissection showed no consistent differences between groups. CONCLUSION: Zone 2 TEVAR is associated with a potential increase in neurologic and reintervention-related complications, while mortality remains comparable. The evidence is limited by heterogeneity and small study numbers.Clinical ImpactThese findings support a more individualized approach to proximal landing-zone selection during TEVAR for acute and subacute type B aortic dissection. Zone 3 deployment may be preferable when anatomically feasible, given its potential association with lower rates of spinal cord ischemia and stroke. When zone 2 coverage is necessary, clinicians should carefully weigh the neurologic risks against the anatomical and procedural benefits. The study highlights the importance of incorporating spinal cord protection strategies and meticulous patient selection. Its innovation lies in directly synthesizing comparative evidence on proximal landing zones while testing the robustness of observed differences through sensitivity analyses. These findings may help inform procedural planning while underscoring the need for larger prospective comparative studies.