The PassTrue® technique for evaluating the needle/tissue mechanical interaction in a medicolegal simulation setting

Background. The increasing availability of body donations and the expansion of reference centers provide forensic clinical anatomy with the opportunity to experimentally reproduce, in ex vivo settings, the effects of specific interactions on the human body, such as needle-tissue interaction in medical procedures. Objectives. The primary objective of this study was to develop a reproducible, standardized benchtop methodology that enables the identification of the trajectory traveled by the needle when piercing soft tissue, causing detectable iatrogenic tissue damage. Materials and methods. Skeletal muscle tissue samples were harvested from a fresh-frozen 78-year-old male body housed at our Reference Center, Center for Body Donation. Needle transfixions were then tested using a novel technique designed for this purpose (PassTrue (R) methodology): full-thickness tissue transfixion by a needle, insertion into the needle of a coaxial thread, grasping the thread with forceps, and needle withdrawal, so that the in-place thread indicates the route of transfixion. This procedure was tested against the control procedure without a thread. Results. Microscopic analysis revealed a pattern consistent with the needle's course during transfixion in all cases with the PassTrue (R) technique (10/10), but not in controls (0/10). Conclusions. Our novel methodology improves the efficiency of assessing needle-tissue interactions, enabling identification of the needle's trajectory within biological tissues.