Over recent decades, surgical aortic valve replacement has increasingly faced competition from TAVI, which has evolved from a therapy reserved for high-risk patients to an option offered to progressively younger and lower-risk populations. In response, surgical techniques have undergone a parallel transformation toward less invasive strategies. Alternative approaches have been developed, including MT (right anterolateral, right transverse, or right parasternal longitudinal thoracotomy), partial sternotomy (MS), and, more recently, totally endoscopic surgery (TT) in highly specialized centers.

Multiple investigations have compared full sternotomy with MS or MT, and some have directly contrasted MS and MT. However, the study published in Interdisciplinary CardioVascular and Thoracic Surgery is the first to compare all three minimally invasive strategies, including TT, while excluding patients treated via full sternotomy.

The authors conducted a comprehensive systematic search across 8 databases, followed by a network meta-analysis (MA) of the selected studies. Among 785 screened publications, 25 studies (3 prospective and 22 retrospective), encompassing nearly 35000 patients, met the inclusion criteria and underwent rigorous quality assessment. Surgical outcomes were analyzed using a propensity score–matched MA, enabling both direct and indirect comparisons of MT and TT versus MS. Heterogeneity testing, publication bias assessment, and sensitivity analyses were performed. Additionally, 2 subgroup analyses were conducted according to the number of centers (single-center vs multicenter) and the number of surgeons (single surgeon vs multiple surgeons). Given that not all studies included comparisons among the three techniques and that reported outcomes differed across intraoperative variables, length of stay, mortality, and complications, multiple MAs were ultimately generated using different combinations of studies and patient cohorts.

Regarding overall findings, CPB time, myocardial ischemic time, and total operative time were longer with TT compared with MS and MT, which showed broadly comparable durations. In contrast, TT was associated with shorter intensive care unit (ICU) stay compared with MS and MT, which again demonstrated similar results. Mortality did not differ significantly among the 3 techniques, although the MA assessing mortality exhibited the greatest heterogeneity. Postoperative complications were generally comparable across groups, except for neurologic events, which were less frequent in the TT group compared with MS.

COMMENTARY:

Minimally invasive aortic valve replacement has become one of the most compelling surgical alternatives to TAVI, which continues to expand its indications despite the limited availability of long-term follow-up data. In this context, critically evaluating the performance of different minimally invasive strategies is essential. Nonetheless, comparing distinct techniques across heterogeneous institutions while minimizing bias remains inherently challenging.

This study presents a meticulous and well-structured systematic review with appropriate quality appraisal. However, among the studies included in the network MA, only 3 incorporated patients undergoing TT. Of these, only 1 directly compared all three minimally invasive techniques, and another compared TT with MT. The remaining studies focused on MS versus MT. Although propensity score matching was applied, the authors acknowledge potential bias related to limited data availability. It is reasonable to assume that differences across observational studies (such as institutional setting, perioperative protocols, surgical expertise, geographic region, and type of implanted prosthesis) may influence outcomes and warrant cautious interpretation.

The longer operative, CPB, and ischemic times observed with TT are not unexpected, whereas the similarity between MS and MT may appear more surprising. Notably, subgroup analyses revealed that comparable operative times between MT and MS were primarily observed in single-center or single-surgeon studies, likely reflecting highly specialized environments. In contrast, in multicenter or multisurgeon studies, MT was associated with longer operative durations than MS. A similar pattern was observed for ICU and total hospital length of stay: in multicenter or multisurgeon analyses, MS and MT yielded comparable hospitalization times, whereas in specialized settings, MT was associated with shorter ICU and overall hospital stay.

As previously mentioned, mortality was similar across all three techniques. However, the authors were unable to exclude the possibility of publication bias or the disproportionate influence of individual studies in sensitivity analyses. Overall postoperative complications were comparable, but subgroup analyses again identified differences. Postoperative bleeding rates between MS and MT varied depending on whether studies were single-center or multicenter, and mechanical ventilation times also differed, underscoring the role of institutional expertise and perioperative management protocols.

In summary, this high-quality systematic review and network MA provides valuable insight into the distinctions among the three currently available minimally invasive approaches for aortic valve replacement. Although results must be interpreted cautiously given inherent interstudy variability and methodological constraints, the findings suggest that TT offers potential advantages. Faster postoperative recovery and a lower incidence of neurologic and bleeding complications may offset the longer operative, CPB, and ischemic times. Further prospective, multicenter studies directly comparing all three techniques are needed to validate these observations and refine patient selection.

REFERENCE:

Husen TF, Vidya AP, Heuts S, Prasetyo A, Nugroho AKZ, Lorusso R et al. Comparative Study of Different Minimally Invasive Aortic Valve Replacement Techniques: A Systematic Review and Network Meta-Analysis. Interdiscip CardioVasc Thorac Surg 2025; doi:10.1093/icvts/ivaf244.

Yilmaz A, Van Genechten S, Claessens J, Packlé L, Maessen J, Kaya A. A totally endoscopic approach for aortic valve surgery. Eur J Cardiothorac Surg. 2022 Nov 3;62(6):ezac467. doi: 10.1093/ejcts/ezac467. PMID: 36165709.