Laparoscopic Fixation of Biologic Mesh At the Hiatus with Fibrin Or Polyethylene Glycol (PEG) Sealant in a Porcine Model

Eric D Jenkins, MD, Sopon Lerdsirisopon, MD, Kevin P Costello, Lora Melman, MD, Margaret M Frisella, RN, Brent D Matthews, MD, Corey R Deeken, PhD. Dept. of Surgery, Section of Minimally Invasive Surgery, Washington University School of Medicine (St. Louis, Missouri)

OBJECTIVES: Despite evidence that biologic mesh reinforcement improves outcomes for paraesophageal hernia repair, biologic meshes are not commonly utilized due to the technical complexity of fixation at the hiatus. If adequate incorporation at the hiatus could be demonstrated, the potential simplicity of utilizing a tissue sealant for biologic mesh fixation would increase the use of these materials for reinforcement of laparoscopic paraesophageal hernia repairs and ensure the best outcomes for patients. The objective of this study was to determine the acute and chronic fixation strengths achieved by either fibrin or polyethylene glycol (PEG) polymer sealants to secure biologic mesh at the hiatus in a porcine model.

METHODS: Thirty-two (n=32) female, domestic pigs were divided into four groups: acute fibrin sealant (n=8); acute PEG sealant (n=8); chronic fibrin sealant (n=8); and chronic PEG sealant (n=8). Laparoscopically, a 5.5 x 8.5cm piece Surgisis BiodesignTM Hiatal Hernia Graft (porcine small intestine submucosa) was oriented with the U-shaped cut-out around the gastroesophageal junction and the short axis in the craniocaudal direction to simulate hiatal reinforcement with a biologic mesh. The mesh was then secured with 2mL of either fibrin sealant (TISSEEL, 500IU/mL, Baxter BioSurgery) or PEG sealant (COSEAL, Baxter BioSurgery). Pigs in the acute groups were survived for 2 hours to allow for complete polymerization of the sealants, and pigs in the chronic group were survived for 14 days. After euthanasia, specimens of the mesh-tissue interface were harvested and subjected to lap shear testing on an Instron® materials testing system to measure fixation strength. The fixation interface (measuring 3x3cm) was tested, and the fixation strength (N/cm²) was calculated by dividing the maximum load sustained during the test by the area of the fixation interface. Results are reported as mean ± SEM. A one-way ANOVA with Fisher’s post-test was performed with p<0.05 considered significant.

RESULTS: No significant differences were observed between the acute fixation strengths of the two sealants (fibrin: 0.13±0.05N/cm² and PEG: 0.17±0.03N/cm², p>0.05). However, fixation strength increased over time with chronic fixation strength significantly greater than acute fixation strength for both fibrin and PEG sealants (fibrin: 1.59±0.39N/cm² and PEG 1.56±0.35N/cm², p<0.05 for all comparisons). However, no significant differences were observed between the chronic fixation strengths of the two sealants.

CONCLUSIONS: This study has demonstrated the feasibility of utilizing either fibrin or PEG sealants to secure biologic mesh at the hiatus in a porcine model of laparoscopic paraesophageal hernia repair. There does not appear to be an advantage to utilizing PEG sealants over fibrin sealants for this application since both types of sealants achieved similar acute and chronic fixation strengths. Future studies are planned to evaluate laparoscopic fixation of other types of biologic mesh at the hiatus using fibrin and/or PEG sealants.