Comparative Evaluation of Biomechanical Characteristics of Acellular Dermal Matrix for Hernioplasty

Background. With the introduction of synthetic mesh implants into clinical practice, the recurrence rate of postoperative ventral hernias was signifi cantly reduced. The extensive use of synthetic implants led to the development of specifi c complications. The development of biological implants, based on extensively purifi ed decellularized collagen matrix of xenogeneic origin is highly relevant due to the fact that, unlike synthetic analogues, they have a biological origin and biodegrade in a natural way, gradually being replaced with newly formed connective tissue. The use of bioprostheses reduces the risk of complications.

Objectives. To conduct a comparative evaluation of the biomechanical characteristics of acellular dermal matrix, obtained by detergent-enzymatic decellularization, and commercially distributed Permacol™ matrix.

Methods. Acellular dermal matrix (ADM) was created by using samples of native skin of pig of Landras breed aged 4 months. The dermis was processed by means of detergent-enzymatic method. In order to evaluate and compare the mechanical properties of acellular dermal matrix, the biological samples were divided into 2 groups of 15 samples each. The fi rst group included acellular dermal matrix samples, the second group — native samples of pigs unprocessed dermis. The control group consisted of samples of PermacolTM Surgical Implant, xenotransplant for hernioplasty approved for use in the Russian Federation (Covidien, France). All samples were tested wet using universal testing instrument Instron 1122. MedCalc Statistical Software (Belgium) was used for statistical processing of the study results.

Results. In the present study, pig dermis was processed using a detergent-enzymatic method to produce ADM. Routine histological examination confi rmed the removal of all cellular elements, and at the same time it was proven that the native structure of the dermis remained intact during its processing. The mechanical characteristics of xenogenic ADM were further determined. Its tensile strength was 9.1 ± 0.6 MPa (910 N/cm2 ), elongation to break was 21.1 ± 2.3%, and elastic modulus was 50.0 ± 1.6 MPa. These characteristics largely corresponded to the strength characteristics of native pig dermis and far exceeded the necessary physiological parameters. PermacolTM control was tested in two directions (longitudinal and transverse). In the longitudinal direction, the sample had higher mechanical characteristics: strength — 12.0 ± 1.7 MPa, elongation to break — 29.7 ± 2.4%, stiffness modulus — 47.2 ± 6.5 MPa. In the transverse direction, all indicators were 1.5–2 times lower.

Conclusion. The developed xenogeneic biological implant in the form of ADM demonstrates rather good characteristics of plasticity, tensile strength and elasticity, to be used as a biological endoprosthesis for plasty of hernia defects of the abdominal wall of any size and shape.