Efficacy of robotic versus open transversus abdominis release in a porcine model

Transversus abdominis muscle release (TAR) combines retromuscular mesh placement with posterior component separation and muscle release. TAR is usually an open technique for abdominal wall reconstruction; however, several centers have performed this operation robotically and claim better clinical outcomes when compared to open surgery. We sought to compare robotic versus open TAR utilizing a porcine model.

Animals were randomized to open versus robotic TAR with mesh placement, survived for 4 weeks, then underwent diagnostic laparoscopy to assess adhesive burden and adhesion tenacity. T-peel testing was utilized to assess mesh ingrowth. The primary outcome was adhesive burden; secondary outcomes included mesh incorporation, contraction, and operative time.

Nine robotic and eight open TARs were performed. Mean operative time was significantly shorter for the open cases compared to robotic cases (88.6 ± 12.9 min versus 228.3 ± 46.2, p < 0.01). Operative time in the robotic arm of the study decreased over time, from 300 to 165 min. No difference was seen in the mean adhesion area between the two groups. Adhesion tenacity and mesh flatness were similar. The work required to peel the mesh off surrounding tissue was significantly higher in the open TAR than in the robotic TAR group: 52.6 ± 15.5 and 32.9 ± 10.6 mJ/cm², respectively (p < 0.01).

There were no differences in adhesions between the robotic and open approaches, but greater mesh contraction and ingrowth was observed in the open TAR group. Though operative time was longer in the robotic group, time dropped by about 40% from the first case to the last.