Letter to the Editor: reassessing comparative claims in subcostal single-port robotic lobectomy

HIGHLIGHTS Follow-up imbalance limits the validity of oncologic equivalence between subcostal and multi-port approaches. Multi-port heterogeneity obscures configuration-specific differences relevant to technical performance. Secular gains in perioperative care may inflate perceived functional benefits of subcostal access. Absence of anatomical eligibility metrics introduces indication bias that favors single-port cohorts. To the Editor, We read with interest the comparison by Lee and colleagues evaluating subcostal single-port (SP) versus intercostal multi-port (MP) robotic lobectomy, which provides timely evidence on perioperative recovery and functional outcomes across two widely adopted robotic platforms[1]. As minimally invasive thoracic surgery continues to shift toward uniportal and subcostal strategies, rigorous methodological scrutiny is essential to clarify their true clinical value. Several aspects of the present study therefore merit closer examination before firm conclusions can be drawn regarding oncologic equivalence or the functional advantages attributed to subcostal access. This comment adheres to the TITAN 2025 guidelines for transparent and ethical reporting of AI-assisted research[2]. A major methodological limitation lies in the pronounced disparity in follow-up, with a median of 21.5 months in the SP cohort compared with 54.4 months in the MP cohort. Under this imbalance, most SP patients have not traversed the biologically relevant window in which recurrence typically emerges, leading survival curves to be shaped largely by early, low-risk intervals and extensive censoring. Apparent 3-year equivalence therefore reflects restricted observation rather than demonstrated prognostic parity. Without a prespecified non-inferiority construct, wide confidence intervals spanning clinically meaningful differences cannot be interpreted as evidence of comparable oncologic performance. More credible inference requires harmonized follow-up windows or analytic frameworks that incorporate differential exposure to recurrence risk through time-dependent approaches. The consolidation of two-port and three-port Xi procedures into a single MP comparator further complicates causal interpretation. These configurations diverge in port geometry, arm interference patterns, assistant reliance, and the degree of intercostal disruption, each of which directly shapes postoperative pain and functional recovery. Treating them as interchangeable masks configuration-specific strengths and limitations that matter for platform selection, training pathways, and credentialing. From a translational perspective, the key question is whether the advantages attributed to SP persist when compared with the most optimized MP technique rather than with an averaged amalgam of heterogeneous practices. Analyses that respect port-number granularity would therefore yield a firmer foundation for technical recommendations. Temporal confounding presents an additional challenge, as SP procedures were concentrated in recent years while MP procedures occurred earlier, during a period marked by rapid institutional gains in perioperative care. Improvements in enhanced recovery after surgery adherence, multimodal analgesia, respiratory physiotherapy, and chest-tube management are known to enhance pain control and pulmonary recovery independent of the access platform[3]. When calendar time is unaccounted for, these secular improvements risk being misattributed to subcostal SP robotics, producing an inflated perception of functional benefit. Adjustment for year of surgery or modelling care-pathway evolution within mixed-effects frameworks would more accurately distinguish platform-specific effects from institutional maturation. Finally, the subcostal approach is intrinsically indication dependent, yet the study lacks objective anatomical eligibility metrics. Patients with narrow subcostal corridors, elevated body mass index, deep diaphragms, upper-lobe tumors, or bulky upper mediastinal lymphadenopathy are generally considered less suited for subcostal access and more likely to be allocated to MP approaches[4,5]. If such anatomically challenging cases were preferentially allocated to the MP arm, the SP cohort may represent a structurally more favorable subset, skewing comparisons of operative complexity, pain, and recovery. Prospective studies should prespecify anatomical thresholds and incorporate quantitative measures such as subcostal angle or thoracic depth into adjustment models to ensure that differences attributed to access route reflect true technical performance rather than case selection. In summary, the study contributes valuable early experience with subcostal SP robotics, yet the interpretability of its comparative claims is constrained by methodological, temporal and anatomical considerations. Clarifying these issues is not merely academic; it directly informs platform selection, credentialing pathways and resource allocation as centers weigh the clinical and economic implications of adopting next-generation robotic systems. Future investigations grounded in harmonized follow-up, anatomically balanced cohorts and configuration-specific comparators will be essential to determine when subcostal SP access offers a truly meaningful advance in safety, function and long-term oncologic value.