Recent Advances in Clinical Trials
Open AccessDual-Chamber Physiologic-Cost Modeling for Minimally Invasive Thoracolumbar Reconstruction in Hematologic-Fragility Hosts: A Conceptual Framework with an Illustrative Myelodysplastic Syndrome Case
Authors: Chi-Ming Chiang.
Abstract
Background: Myelodysplastic syndromes (MDS) couple marrow failure with skeletal fragility, creating a narrow physiological margin for complex spine reconstruction. Conventional evaluations of minimally invasive surgery focus on aggregate blood loss, complications, and costs, but rarely partition the physiologic burden across organ-system domains that are critical in hematologic-fragility hosts.
Objective: To introduce a dual-chamber physiologic-cost model (DPCM) that decomposes total physiologic cost into chest-wall/lung and paraspinal-muscle domains, illustrate its application in a minimally invasive thoracolumbar reconstruction for MDS, and outline its extension toward decision-analytic modeling and multicenter evaluation.
Methods: We treated total physiologic cost (TPC) as the sum of chest-wall/lung burden (C_chest) and paraspinal-muscle burden (C_paraspinal). C_chest was proxied by chest-tube duration and 30-day pulmonary complications, whereas C_paraspinal was proxied by estimated blood loss, red-cell and platelet transfusions, 30-day surgical-site infection, and length of stay. These proxies were quantified in a late-elderly woman with transfusion-dependent MDS who underwent video-assisted thoracoscopic anterior decompression with autologous fibular strut reconstruction followed by percutaneous posterior fixation under restrictive transfusion thresholds. DPCM indices were compared qualitatively against published medians for open thoracotomy and open posterior exposures, as well as minimally invasive benchmarks.
Results: The hybrid thoracoscopic–percutaneous strategy achieved stable anterior column support and restored alignment with an estimated blood loss of 320 mL, 1 unit of red cells and 2 units of platelets transfused, 2 chest-tube days, and a 9-day hospital stay. No pulmonary or wound complications occurred within 30 days. Relative to historical open benchmarks, the DPCM indicated marked reductions in both C_chest and C_paraspinal, reflected by lower blood loss, transfusion exposure, chest-tube duration, and length of stay. The DPCM structure proved readily amenable to conceptual extension into a state-transition (Markov) decision model for long-term cost-effectiveness analysis.
Conclusions: In hematologic-fragility hosts such as MDS, a dual-chamber physiologic-cost framework makes explicit the organ-system trade-offs of access and fixation choices. The illustrative case suggests that thoracoscopic anterior reconstruction with autologous fibular strut and percutaneous posterior fixation can minimize physiologic cost while satisfying restrictive transfusion strategies. Embedding DPCM within a state-transition model provides a pathway for multicenter, model-based comparisons of minimally invasive versus open strategies in high-risk spine populations.
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