Faiz Y Bhora1, Erik E Lewis2, Sadiq S Rehmani2, Adil Ayub2, Wissam Raad2, Adnan M Al-Ayoubi2, Robert S Lebovics3. 1. Department of Thoracic Surgery, Icahn School of Medicine at Mount Sinai, New York, New York. Electronic address: faiz.bhora@mountsinai.org. 2. Department of Thoracic Surgery, Icahn School of Medicine at Mount Sinai, New York, New York. 3. Department of Otolaryngology, Mount Sinai West, Mount Sinai Health System, New York, New York.
Abstract
BACKGROUND: Methods for tracheal graft research have presented persistent challenges to investigators, and three-dimensional (3D)-printed biosynthetic grafts offer one potential development platform. We aimed to develop an efficient research platform for customizable circumferential 3D-printed tracheal grafts and evaluate feasibility and early structural integrity with a large-animal model. METHODS: Virtual 3D models of porcine subject tracheas were generated using preoperative computed tomography scans. Two designs were used to test graft customizability and the limits of the construction process. Designs I and II used 270-degree and 360-degree external polycaprolactone scaffolds, respectively, both encompassing a circumferential extracellular matrix collagen layer. The polycaprolactone scaffolds were made in a fused-deposition modeling 3D printer and customized to the recipient's anatomy. Design I was implanted in 3 pigs and design II in 2 pigs, replacing 4-ring tracheal segments. Data collected included details of graft construction, clinical outcomes, bronchoscopy, and gross and histologic examination. RESULTS: The 3D-printed biosynthetic grafts were produced with high fidelity to the native organ. The fabrication process took 36 hours. Grafts were implanted without immediate complication. Bronchoscopy immediately postoperatively and at 1 week demonstrated patent grafts and appropriate healing. All animals lived beyond a predetermined 1-week survival period. Bronchoscopy at 2 weeks showed significant paraanastomotic granulation tissue, which, along with partial paraanastomotic epithelialization, was confirmed on pathology. Overall survival was 17 to 34 days. CONCLUSIONS: We propose a rapid, reproducible, resource efficient method to develop various anatomically precise grafts. Further graft refinement and strategies for granulation tissue management are needed to improve outcomes.
BACKGROUND: Methods for tracheal graft research have presented persistent challenges to investigators, and three-dimensional (3D)-printed biosynthetic grafts offer one potential development platform. We aimed to develop an efficient research platform for customizable circumferential 3D-printed tracheal grafts and evaluate feasibility and early structural integrity with a large-animal model. METHODS: Virtual 3D models of porcine subject tracheas were generated using preoperative computed tomography scans. Two designs were used to test graft customizability and the limits of the construction process. Designs I and II used 270-degree and 360-degree external polycaprolactone scaffolds, respectively, both encompassing a circumferential extracellular matrix collagen layer. The polycaprolactone scaffolds were made in a fused-deposition modeling 3D printer and customized to the recipient's anatomy. Design I was implanted in 3 pigs and design II in 2 pigs, replacing 4-ring tracheal segments. Data collected included details of graft construction, clinical outcomes, bronchoscopy, and gross and histologic examination. RESULTS: The 3D-printed biosynthetic grafts were produced with high fidelity to the native organ. The fabrication process took 36 hours. Grafts were implanted without immediate complication. Bronchoscopy immediately postoperatively and at 1 week demonstrated patent grafts and appropriate healing. All animals lived beyond a predetermined 1-week survival period. Bronchoscopy at 2 weeks showed significant paraanastomotic granulation tissue, which, along with partial paraanastomotic epithelialization, was confirmed on pathology. Overall survival was 17 to 34 days. CONCLUSIONS: We propose a rapid, reproducible, resource efficient method to develop various anatomically precise grafts. Further graft refinement and strategies for granulation tissue management are needed to improve outcomes.
Authors: Joanna F Weber; Sadiq S Rehmani; Mirza Zain Baig; Robert Lebovics; Wissam Raad; Cliff Connery; Faiz Y Bhora Journal: JTCVS Open Date: 2020-11-18
Authors: Dewy C van der Valk; Casper F T van der Ven; Mark C Blaser; Joshua M Grolman; Pin-Jou Wu; Owen S Fenton; Lang H Lee; Mark W Tibbitt; Jason L Andresen; Jennifer R Wen; Anna H Ha; Fabrizio Buffolo; Alain van Mil; Carlijn V C Bouten; Simon C Body; David J Mooney; Joost P G Sluijter; Masanori Aikawa; Jesper Hjortnaes; Robert Langer; Elena Aikawa Journal: Nanomaterials (Basel) Date: 2018-05-03 Impact factor: 5.076