Microdialysis as a method for biochemical and physiological studies of the porcine and human disc

Abstract

At present, no minimally invasive technique exists for the continuous evaluation of the biochemistry of animal and human intervertebral discs, but for research purposes microdialysis may be such a new technique. Thus, the aims of this study were to (1) evaluate if microdialysis can be used successfully in lumbar porcine disc and (2) develop a suitable procedure for the application of microdialysis in the human disc. Conventional specific pathogen-free pigs were used to evaluate cannulation (n ¼ 2) and then insertion of a 10 mm microdialysis membrane, including recovery of a dialysate from the nucleus pulposus (n ¼ 6). The procedure was performed immediately after euthanasia and aided by fluoroscopy to guide the needle and confirm catheter placement. Access to lumbar porcine disc was obtained with an 18 G 2 in. needle applied at a 35-458 angle from the sagittal plane, and took less than 8 min to perform. At a 0.5 mL/min flush rate, dialysates could be recovered and analysable amounts of glucose, lactate and pyruvate were obtained. In one human cadaver, the L4-L5 disc was accessed by a 19 G 3 in. needle inserted at a 35-408 angle. It was possible to apply 10 mm as well as 30 mm microdialysis membranes in the nucleus. In both species the position of the membranes was verified by direct fluoroscopy and with contrast fluid. The results obtained from porcine and human cadavers are promising, and encourage further in vivo studies using microdialysis technique on intervertebral discs.

Microdialysis for the Assessment of Intervertebral Disc and Vertebral Cancellous Bone Metabolism in a Large Porcine Model

“…Microdialysis as a method is, among others, advantaged by dynamic and simultaneous in vivo sampling from multiple compartments of the unbound water-soluble molecules from the interstitial space of the investigated tissue (9,10). For the particular cases of bone tissue and the intervertebral disc, microdialysis has only been applied for the assessment of metabolism in the femoral head of humans and pigs, and in a cadaver study, respectively (11)(12)(13)(14). To date, microdialysis sampling from vertebral cancellous bone and the intervertebral disc has been limited to antimicrobials in a porcine model (15,16).…”

Cytokine and Chemokine Recovery Is Increased by Colloid Perfusates during Dermal Microdialysis

“…To assess ex vivo recovery from a tissue environment that more closely represents the in vivo situation when performing DM and to study the possible influence of any tissue adherent effects on recovery, we used the retrodialysis method, which is basically inverse microdialysis, on excised human and porcine cadaver skin. Cadaver tissue has been previously used to study dermopharmacy, tissue physiology, and biochemistry [ 40 , 41 , 42 , 43 ]. For this study, full skin samples (3 × 2 cm 2 ) from human volunteers (harvested after receiving informed consent and collected according to recommendations from the German Medical Council and local review board as well as from the Declaration of Helsinki) and domestic pigs (10 × 20 cm 2 ) containing the epidermis, dermis, and subcutis were collected.…”