Perioperative nutritional optimisation in radical cystectomy: a response to Kapil et al.

Abstract

We sincerely thank Kapil et al. for their thoughtful and constructive commentary on our randomised trial evaluating structured perioperative nutritional optimisation in patients undergoing radical cystectomy (RC) [1]. We appreciate their balanced interpretation and their emphasis on framing nutritional interventions within a biologically and clinically appropriate context [2]. We agree that perioperative nutritional strategies primarily exert their effects through modulation of metabolic resilience, tissue repair, and functional recovery rather than through abrupt reductions in overall complication rates. Accordingly, our study deliberately incorporated recovery-focused endpoints, including gastrointestinal recovery, wound healing, and length of hospital stay, alongside conventional morbidity measures. These outcomes reflect domains that are highly relevant to patients, clinicians, and healthcare systems and align closely with the mechanistic targets of nutritional optimisation. Nevertheless, from a surgical perspective, the overall complication rate remains a critically important outcome in RC [3]. This procedure is among the most morbid operations in urological oncology, with postoperative 90-day complication rates approaching 60% even in high-volume centres incorporating enhanced recovery protocols [4]. Therefore, evaluating whether perioperative nutritional optimisation can mitigate postoperative morbidity represents a clinically meaningful objective that complements, rather than conflicts with, recovery-oriented endpoints. Kapil et al. [2] also appropriately note that the absence of a statistically significant reduction in overall complications should be interpreted in the context of study power. Our trial incorporated an a priori sample size calculation based on anticipated differences in postoperative morbidity. However, as is well recognised in surgical trials, detecting moderate reductions in complication rates following RC typically requires substantially larger cohorts. While statistical significance was not achieved, a consistent numerical trend toward lower complication rates was observed in the intervention arm, supporting the potential clinical relevance of nutritional optimisation. We also appreciate the authors’ discussion of body composition metrics and phase angle as translational markers of nutritional and cellular health. Although each modality has inherent limitations, longitudinal assessment of these parameters provides pragmatic insight into postoperative physiological recovery and reflects real-world clinical feasibility. In conclusion, we concur that structured, dietitian-led perioperative nutritional optimisation should be regarded as an active component of recovery-oriented care rather than an adjunctive measure. Larger multicenter studies will be valuable to further clarify its impact on surgical morbidity and to support standardised implementation. We thank the authors for their insightful contribution, which meaningfully enriches the interpretation and clinical context of our findings. The authors declare no conflicts of interest.