title: Ex vivo proof-of-concept of end-to-end scaffold-enhanced laser-assisted vascular anastomosis of porcine arteries.
abstract: OBJECTIVE
  The low welding strength of laser-assisted vascular anastomosis (LAVA) has hampered the clinical application of LAVA as an alternative to suture anastomosis. To improve welding strength, LAVA in combination with solder and polymeric scaffolds (ssLAVA) has been optimized in vitro. Currently, ssLAVA requires proof-of-concept in a physiologically representative ex vivo model before advancing to in vivo studies. This study therefore investigated the feasibility of ex vivo ssLAVA in medium-sized porcine arteries.
  
  
  METHODS
  Scaffolds composed of poly(ε-caprolactone) (PCL) or poly(lactic-co-glycolic acid) (PLGA) were impregnated with semisolid solder and placed over coapted aortic segments. ssLAVA was performed with a 670-nm diode laser. In the first substudy, the optimum number of laser spots was determined by bursting pressure analysis. The second substudy investigated the resilience of the welds in a Langendorf-type pulsatile pressure setup, monitoring the number of failed vessels. The type of failure (cohesive vs adhesive) was confirmed by electron microscopy, and thermal damage was assessed histologically. The third substudy compared breaking strength of aortic repairs made with PLGA and semisolid genipin solder (ssLAVR) to repairs made with BioGlue.
  
  
  RESULTS
  ssLAVA with 11 lasing spots and PLGA scaffold yielded the highest bursting pressure (923 ± 56 mm Hg vs 703 ± 96 mm Hg with PCL ssLAVA; P = .0002) and exhibited the fewest failures (20% vs 70% for PCL ssLAVA; P = .0218). The two failed PLGA ssLAVA arteries leaked at 19 and 22 hours, whereas the seven failed PCL ssLAVA arteries burst between 12 and 23 hours. PLGA anastomoses broke adhesively, whereas PCL welds failed cohesively. Both modalities exhibited full-thickness thermal damage. Repairs with PLGA scaffold yielded higher breaking strength than BioGlue repairs (323 ± 28 N/cm(2) vs 25 ± 4 N/cm(2), respectively; P = .0003).
  
  
  CONCLUSIONS
  PLGA ssLAVA yields greater anastomotic strength and fewer anastomotic failures than PCL ssLAVA. Aortic repairs with BioGlue were inferior to those produced with PLGA ssLAVR. The results demonstrate the feasibility of ssLAVA/R as an alternative method to suture anastomosis or tissue sealant. Further studies should focus on reducing thermal damage.
authors.affiliation: Department of Cardiothoracic Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Dara R
authors.initials: DR
authors.lastname: Pabittei
authors.affiliation: Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Electronic address: m.heger@amc.uva.nl.
authors.forename: Michal
authors.initials: M
authors.lastname: Heger
authors.affiliation: LifeTec Group, Eindhoven, The Netherlands.
authors.forename: Sjoerd
authors.initials: S
authors.lastname: van Tuijl
authors.affiliation: Department of Biomedical Engineering, Material Technology, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Simonet
authors.affiliation: Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Wadim
authors.initials: W
authors.lastname: de Boon
authors.affiliation: Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Allard C
authors.initials: AC
authors.lastname: van der Wal
authors.affiliation: Department of Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Ron
authors.initials: R
authors.lastname: Balm
authors.affiliation: Department of Cardiothoracic Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; LifeTec Group, Eindhoven, The Netherlands; Department of Biomedical Engineering, Material Technology, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Bas A
authors.initials: BA
authors.lastname: de Mol
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology / Q000601:surgery*; D062186:Arterial Pressure; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D002339:Carotid Arteries / Q000502:physiology / Q000601:surgery*; D005240:Feasibility Studies; D006801:Humans; D066298:In Vitro Techniques; D019344:Lactic Acid; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods*; D054023:Lasers, Semiconductor; D023421:Models, Animal; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D013314:Stress, Mechanical; D013552:Swine; D013997:Time Factors; D054457:Tissue Scaffolds
chemical_list: D011091:Polyesters; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C016240:polycaprolactone; D011100:Polyglycolic Acid; D019344:Lactic Acid