BIOMECHANICALALTERATIONS AND FLOW DYNAMICS OF THEINTERATRIAL SEPTUM FOLLOWING DEVICE AND PATCH CLOSURES:AN ADVANCED MATHEMATICAL, PHYSICAL, AND CLINICALINVESTIGATION

DOI : 10.36106/ijar

Volume - 16 | Issue - 07 | July - 2026 | PRINT ISSN No. 2249 - 555X

https://www.worldwidejournals.com/indian-journal-of-applied-research-(IJAR)/fileview/biomechanical-alterations-and-flow-dynamics-of-the-interatrial-septum-following-device-and-patch-closures-an-advanced-mathematical-physical-and-clinical-investigation_July_2026_0889412017_8703934.pdf

Objective: The interatrial septum (IAS) is a highly specialized, compliant cardiac structure that modulates interatrial mechanical energy transfer during the cardiac cycle. Transcatheter device deployment or rigid surgical patch closure disrupts native IAS compliance. This study evaluates the biophysical, hydrodynamic, and structural sequelae of altering IAS material properties through advanced physics, continuum mechanics, and mathematical probability models. Methods: We constructed a multi-layered continuum mechanics model using an isotropic, hyperelastic strain energy function to represent native IAS compliance. We simulated structural shifts under four conditions: direct suture closure of defects >8 mm, implantation of rigid occluders, rigid synthetic patch closure (Dacron/GORETEX), and flexible biological patches (autologous vs. chemically fixed pericardium). Fluid-Structure Interaction (FSI) simulations captured boundary shear stresses, micro-motions ("aortic snuggle"), and valvular strain.Results: Native IAS compliance ranges from1.2 x10^-2 to 2.5 x10^-2 mL/mmHg. Direct closure of defects >8 mm shifts the local stress tensor into pathological margins, yielding a suture-line tension exceeding approx. 1.8 N/cm. Implanting a rigid patch or Nitinol device drops local compliance toward zero, triggering high localized shear stress > 4.5 Pa and cyclical micro-motion against the aortic root. This mechanical mismatch generates a long-term mathematical probability of structural erosion or Right Sinus of Valsalva (RSOV) perforation (P_erosion approx. 0.1% - 0.3%). Highly compliant right atrial (RA) chambers act as mechanical buffers, dampening systemic energy transformations by up to 35%. Eliminating local IAS compliance induces significant upstream and downstream fluid-structure stresses. These alterations contribute to micro-erosion, valvular strain, and rare but catastrophic structural erosions. Future paradigms must leverage custom bio-resorbable or auxetic materials combined with machine-learning-driven modelling to match patient-specific native tissue compliance.