C4D as a diagnostic adjunct in lung allograft biopsies

Abstract

Background: While University of Wisconsin (UW) solution is the current gold standard for donor heart preservation, it has limitations in terms of both duration and adequacy of protection. Our laboratory has been interested in a more physiologic approach to heart preservation by maintaining the heart at its’ resting membrane potential (hyperpolarized arrest) using the KATP channel agonist Pinacidil (PIN). The purpose of this study was to compare our PIN solution with UW, a depolarizing solution, and to quantify the protective effect of PIN in both solutions. Methods: 32 rabbit hearts received 1 of 4 solutions in a crystalloidperfused Langendorff apparatus: 1) UW Solution, 2) a solution containing 0.5 mmol/L of PIN, 3) UW solution with PIN, and 4) solution #2 without PIN. 30 minutes of perfusion was followed by data acquisition. Left ventricular pressure-volume curves were generated by inflating an intraventricular balloon. All hearts were placed in cold storage for 8 hours, followed by 1 hour of reperfusion before data acquisition. Results: Postischemic developed pressure (DP) was better preserved by PIN (76.8% 3.8%) than by UW (48.3% 2.5%). (p 0.001) When PIN was removed from our solution, the DP dropped significantly (46.6% 3.2%). (p 0.001) This recovery was not different from that observed in UW. When PIN was added to UW, the DP increased but not significantly. (54.9% 3.3%) Diastolic compliance was better preserved by PIN (239.9% 77.2%) when compared with UW (711.1% 193.1%). (p 0.027 vs. UW) When PIN was removed from our solution, diastolic compliance fell. (688.8% 158.2%)(p 0.027 vs. no PIN) Compliance was not effected by the addition of PIN to UW. (841.2% 252.5%) Conclusions: Our results support the superiority of our hyperpolarizing solution for heart preservation over UW and indicate that PIN is beneficial in maintaining cardiac function and compliance. This benefit is not observed when PIN is placed into a depolarizing solution such as UW.