An Experimental Study of Intraluminal Hyperpressure Reproducing a Gastric Leak Following a Sleeve Gastrectomy

A gastric leak (GL) represents the main post-operative complication following a sleeve gastrectomy (SG) and occurs most commonly at the top of the stapling, without any clear explanation.

This experimental study evaluates the biomechanical behavior of post-SG gastric specimens using both insufflation and tensile tests.

A total gastrectomy followed by an ex vivo SG was performed in 15 pigs. The "sleeved" stomachs were subjected to intraluminal hyperpressure until failure. Uniaxial circumferential and longitudinal tensile tests were performed using gastric strips obtained from the "resected" stomachs. All the deformations and burst pressures were recorded and analyzed.

A GL appeared in the upper third of the stapling in 73% of cases. The mean burst pressure was 26.3 ± 5.3 mmHg and was significantly correlated with the volume of the "sleeved" stomachs (p = 0.02). The overall deformation of the "sleeved" stomachs was comparable in the frontal (38.3%) and profile (40.5%) planes. The greatest displacement was observed at the failure zone (11 mm on average). The biomechanical behavior of the stomach wall differed according to the strip orientation. The circumferential strips presented a higher strain-to-failure rate (97%) and a lower Young's modulus (0.99 MPa) when compared to the longitudinal strips (45% and 2.58 MPa, respectively).

This preliminary study reproduced a GL in the same location as observed during clinical practice. The volume of the SG influenced the burst pressure. Further experimental studies and numerical simulations should evaluate the impact of shape modifications on an SG.