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C J Imber

Publications and source records attributed to C J Imber.

6 recordsLinked to original sources

Hepatic control of perfusate homeostasis during normothermic extrocorporeal preservation.

BACKGROUND: We investigated the ability of the isolated porcine liver to maintain acid-base homeostasis in the perfusate and the impact of ischemia-reperfusion injury without or with extracorporeal perfusion. METHODS: Harvested livers were either stored for 24 hours in cold University of Wisconsin solution or preserved by continuous, normothermic, oxygenated sanguineous perfusion with supplemental nutrition, prostacyclin, and bile salts. After a further 24-hour period of reperfusion of both groups on an extracorporeal circuit, the perfusate was assessed for both biochemical indices of synthetic and metabolic liver function as well as hepatocellular injury and blood gas analysis. RESULTS: Livers injured by cold ischemia during preservation displayed inferior synthetic and metabolic functions. Perfused livers, which displayed minimal ischemic injury, produced more bicarbonate than the cold-stored organs, suggesting autoregulation of pH homeostasis in perfused livers in contrast to progressively worsening acidosis in cold-stored organs. CONCLUSIONS: Given proper physiologic substrate the porcine liver has the ability to maintain acid-base homeostasis, provided there is not a significant ischemia-reperfusion injury.

Adenosine↗

Extended preservation of non-heart-beating donor livers with normothermic machine perfusion.

BACKGROUND: Non-heart-beating donor (NHBD) livers represent an important organ pool, but are seldom utilized clinically and require rapid retrieval and implantation. Experimental work with oxygenated perfusion during preservation has shown promising results by recovering function in these livers. This study compared sanguinous perfusion with cold storage for extended preservation of the NHBD liver in a porcine model. METHODS: Porcine livers were subjected to 60 min of in vivo total warm ischaemia before flushing, after which they were preserved by one of two methods: group 1 (n = 4), University of Wisconsin (UW) solution by standard cold storage for 24 h; group 2 (n = 4), oxygenated autologous blood perfusion on an extracorporeal circuit for 24 h. All livers were subsequently tested on the circuit during a 24-h reperfusion phase. RESULTS: Livers in group 1 showed no evidence of viability during the reperfusion phase with no bile production or glucose utilization; they also displayed massive necrosis. Livers in group 2 demonstrated recovery of function by synthetic function, substrate utilization and perfusion haemodynamics; these livers displayed less cellular injury by hepatocellular enzymes. All differences in parameters between the two groups were statistically significant (P < 0.05). These findings were supported by histological examination. CONCLUSION: Warm ischaemia for 1 h and simple cold storage (UW solution) for 24 h renders the liver non-viable. Oxygenated, sanguinous perfusion as a method of preservation recovers liver function to a viable level after 24 h of preservation.

Animals↗

Cost implications of mitral valve replacement versus repair in mitral regurgitation.

BACKGROUND: Mitral valve repair and replacement (MVR) with preservation of the tendinous chordae [MVR(p)], may have better results than MVR with valve excision [MVR(e)]. It is not known whether the type of surgery affects in-hospital stay and cost. METHODS AND RESULTS: We reviewed all patients who had mitral valve surgery for regurgitation over 5 years from January 1991. Patients were considered in three groups; MVR(e), MVR(p), and Repair. Cost was calculated using operating room, intensive care unit, and ward expenses, not hospital charges. There were a total of 253 patients; 84 MVR(e), 42 MVR(p), and 127 Repair. Mean ages and preoperative New York Heart Association (NYHA) classes were similar in the three groups. There were more male patients in the Repair (62%) and MVR(p) (67%) groups than in the MVR(e) (44%) group (P<.05), and more patients with degenerative etiology in the Repair group (P<.01). A majority of MVR(e) were in atrial fibrillation (63%), while 59% of Repair were in sinus rhythm (P<.01). Of 9 patients who died in the hospital; four had MVR(e), 3 had MVR(p), and 2 had Repair. In univariate analyses, in-hospital stay increased with patient age >70 years (P<.01), preoperative atrial fibrillation (P<.05), and NYHA class III or IV (P<.01). The median and interquartile ranges for postoperative stay was 10 (8 to 13) days for MVR(e), 8 (7 to 11) days for MVR(p), and 8 (7 to 10) days for Repair (P<.01 versus MVR(e); multivariate analysis adjusting for age, rhythm, and NYHA class). Cost per patient was US $14469 for MVR(e), $13151 for MVR(p), and $11606 for Repair. CONCLUSIONS: Repair and MVR(p) may predict shorter in-hospital stay and reduced cost, although there are important differences in the group of patients who have MVR(e).

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