Successful 18‐h acellular extracorporeal perfusion and replantation of porcine limbs ‐ Histology versus nerve stimulation

Abstract

Summary The current standard for composite tissue preservation is static cold storage (SCS) and is limited to 6 h until irreversible muscle damage occurs. Extracorporeal perfusion (ECP) is a promising technique for prolonged preservation, however, functional results have been scarcely researched. This article assessed neuromuscular function and compared results to histological alterations to predict muscle damage after ECP. Forelimbs of twelve Dutch landrace pigs were amputated and preserved by 4 h SCS at 4–6 °C (n = 6) or 18 h mid‐thermic ECP with University of Wisconsin solution (n = 6). Limbs were replanted and observed for 12 h. Sham surgery was performed on contralateral forelimbs (n = 12). Histology analysis scored four subgroups representing different alterations (higher score equals more damage). Muscle contraction after median nerve stimulation was comparable between ECP, SCS, and sham limbs (P = 0.193). Histology scores were higher in ECP limbs compared to SCS limbs (4.8 vs. 1.5, P = 0.013). This was mainly based on more oedema in these limbs. In‐vivo muscle contraction was well preserved after 18 h ECP compared to short SCS, although histology seemed inferior in this group. Histology, therefore, did not correlate to muscle function at 12 h after replantation. This leads to the question whether histology or neuromuscular function is the best predictor for transplant success.

24-hour Perfusion of Porcine Myocutaneous Flaps Mitigates Reperfusion Injury: A 7-day Follow-up Study

“…To provide oxygenated, continuous, and nonpulsatile flow, a custom-made semiclosed extracorporeal circuit was set up according to previous studies performed by the same research group. 16,26,27 ( See document, Supplemental Digital Content 1, which provides details of the ex-vivo perfusion system and perfusion settings. http://links.lww.com/PRSGO/B933).…”

“…Ten randomly selected high-power fields from each biopsy specimen were assessed for damage of muscle fibers by a pathologist (DM), blinded to the intervention groups. A modified "histologic injury severity score" (HISS) (range 0-12, Table 2) was used to assess for ischemia-reperfusion injury-induced alterations, according to methods previously described by Muller et al 14 and Kruit et al 27 Signs for damaged muscle fibers were defined by four subgroups: interstitial edema, inflammation, variation in shape and size of myocytes, and damaged muscle fibers (necrotic + hypoxic + regenerating myocytes).…”

Superior preservation of capillaries, myofibrils and mitochondria after long-term extracorporeal perfusion of free muscle flaps – A descriptive electron microscopy study

“…A promising technique for prolonged skeletal muscle preservation is continuous extracorporeal perfusion (ECP) or machine perfusion. Preservation by ECP has multiple benefits over static cold storage (SCS), such as the washout of toxic metabolites, buffering and cell-protecting characteristics of the preservation solutions and the ability to oxygenate or cool the tissue [7][8][9]. The overall effect is a reduction of ischemia-reperfusion injury to the tissue resulting in improved (functional) outcomes after tissue replantation [9,10].…”

“…Preservation by ECP has multiple benefits over static cold storage (SCS), such as the washout of toxic metabolites, buffering and cell-protecting characteristics of the preservation solutions and the ability to oxygenate or cool the tissue [7][8][9]. The overall effect is a reduction of ischemia-reperfusion injury to the tissue resulting in improved (functional) outcomes after tissue replantation [9,10]. ECP of muscle tissue will predominantly be applicable in the clinical setting of preservation of composite tissues that contain a large degree of skeletal muscle.…”

Ex Vivo Thrombolysis to Salvage Free Flaps Using Machine Perfusion: A Pilot Study in a Porcine Model

“…Utilizing machine perfusion systems for ex vivo thrombolysis technique allows for controlled oxygenated flow, with adjustable temperatures and inline pressures. [16][17][18] These well-controllable circumstances enable the administration of high doses of thrombolytic agents over a longer period which would otherwise be hazardous for the patient. 19 It is hypothesized that thrombosed flaps could be salvaged using machine perfusion and adding thrombolytic agent to the preservation solution improves lytic efficacy by increasing their bioavailability at the site of the thrombus.…”