In Vivo Biocompatibility Assessment of a Novel Cyanoacrylate-Polylactic Acid Hemostatic Patch.

Abstract

<b>Background and Objectives:</b> Although cyanoacrylate-polylactic acid (CA + PLA) patches shorten the time to hemostasis after partial hepatectomy, their long-term biocompatibility remains uncertain. We compared the 5-month histopathological footprint of a novel CA + PLA patch (Study group) with a licensed fibrinogen/thrombin matrix (TachoSil^® group) and electrocautery (Control group). <b>Methods:</b> Thirty-three male Wistar rats underwent a 3 × 1.5 cm hepatic segment resection and were randomized to the Control (<i>n</i> = 5), Study (<i>n</i> = 14), or TachoSil^® (<i>n</i> = 14) group. The animals were sacrificed on postoperative day (POD) 50, 100, or 150. Blinded semiquantitative scoring (0-3) was used to capture inflammation intensity, and the number of neutrophils (PMNs), lymphocytes (Ly's), isolated histiocytes, and foreign-body giant cells (FBGCs). <b>Results:</b> The proportions of animals in each group across the different sacrifice time points were homogeneous (χ² = 4.34, <i>p</i> = 0.36). The median inflammation remained mild (2 [IQR 1-2]) in the Control and Study groups but lower in the TachoSil^® group (1 [1-2], <i>p</i> = 0.47). The FBGC scores differed markedly (score ≥ 2: 64% in Study, 0% in Control, 14% in TachoSil^®; <i>p</i> < 0.001). Fibrosis occurred almost exclusively in the Study group (79% vs. 0%; χ² = 22.4, <i>p</i> < 0.001). Mature vessels were most frequently observed in the TachoSil^® group (50%, aOR = 5.1 vs. Study, <i>p</i> = 0.04). Abscesses only developed in the Study group (29%, <i>p</i> = 0.046). Within the TachoSil^® group, inflammation (ρ = -0.62, <i>p</i> = 0.019) and Ly infiltration (ρ = -0.76, <i>p</i> = 0.002) declined with time; no significant temporal trends emerged in the Study group. <b>Conclusions:</b> At the five-month follow-up, there was an exuberant foreign-body reaction, dense collagen deposition, and a higher abscess rate around the CA + PLA patch compared with both TachoSil^® and cautery. Conversely, TachoSil^® evolved toward a mature, well-vascularized scar with waning inflammation. These findings underscore the importance of chronic-phase evaluation before clinical adoption of new hemostatic biomaterials.