A study of laparoscopic incisional hernia repair with patient reported outcome measures and circulating biomarkers

Background: Research priorities have been established in hernia surgery that include patient-reported outcome measures (PROMs) and the long-term monitoring of intraperitoneal onlay mesh products (IPOM). In addition to this, incisional hernia recurrence has been hypothesised as a manifestation of individual physiological differences in the processes of abdominal wall healing. Methods: The TACKoMesh randomised controlled trial was performed to compare post-operative pain and other key outcomes following elective laparoscopic incisional hernia repair with Symbotex™ IPOM placement using one of two spiral-tack mesh-fixation devices - Protack™ vs Reliatack™. Clinical data, including PROMs, collected at five designated time points during one year of follow up were described and compared between the treatment groups. In addition to clinical follow up, a sub-cohort of patients underwent blood sampling within the trial. Biomarkers for inflammation and collagen turnover were identified and circulating concentrations quantified for all collected samples. Biomarker data, in the context of clinical outcomes, was described and compared to test the emerging hypotheses on pain, mesh implantation and abdominal wall healing following laparoscopic incisional hernia repair with IPOM. Results: There was no difference in reported pain 'on activity' and a suggestion of less pain 'at rest when choosing Reliatack™ vs Protack™. Significantly more knots and tacks were used in the Reliatack™ group, and operative time and mesh-fixation time were significantly longer. There was no significant difference in PROMs between treatment groups. An early worsening in pain and reported quality of life (Day 30) was improved at Day 365. Inflammatory profiling displayed set patterns in the temporal evolution of assay biomarkers following incisional hernia repair. The pro-inflammatory signal (IL-6 and CRP) was significantly elevated from baseline at post-operative Day 6 and 30, with a trend towards an increase in counterregulatory IL-10. Markers of inflammation, onward signalling (Cortisol and TNF-alpha) and tissue repair (PDGF-AA and VEGF) showed a trend towards increased elevation at these timepoints but were not significantly different from baseline. There were no observed correlations between the inflammatory signal and reported pain, size of mesh prosthesis, and number of tacks deployed. A panel of biomarkers for abdominal wall hernia was identified by way of a systematic review of the literature. Specific patterns in the temporal evolution of these biomarkers following incisional hernia repair were displayed. When comparing patients that developed and remained free from hernia recurrence, there was significantly lower circulating concentrations of Procollagen I and higher Procollagen III in the hernia recurrence group at multiple timepoints, including pre-operatively. There was no detected difference in any of the assayed biomarkers when comparing treatment groups, Protack™ vs Reliatack™. Conclusion: There is no benefit in post-operative pain when choosing Reliatack™ or Protack™. PROMs measures did not differ significantly between the groups but patterns for the entire cohort were displayed. The inflammatory signal following spiral-tack IPOM-fixation is raised from baseline on post-operative Days 1, 6 and 30. The finding with greatest potential impact is the significantly altered levels of Procollagen I and III detected between patients that developed and remained free from incisional hernia recurrence. Study of collagen turnover and the inflammatory signal following abdominal wall hernia repair holds future utility by enhancing risk prediction models and developing more acute comparators for surgical products and methods of repair.