No abstract

The clinical experience with 11 patients undergoing ex situ operation of the liver (nine operations) or surgery on an in situ hypothermic perfused liver after vascular isolation (three operations) is described. These methods have been confined to situations and tumour stages otherwise deemed untreatable, or to situations where resection would not have been sufficiently radical. In one patient the ex situ approach avoided the need to undertake liver grafting for a benign tumour. To date, hepatocellular tumours and metastases not compromising global hepatic function or causing cholestasis are considered to be suitable conditions; cholestasis appears to be highly detrimental for the postoperative course after an ex situ procedure. Elaboration of methods for better grading of pre-existing liver damage and of its prognostic significance is essential. The assessment of the final therapeutic value of the described procedure requires further experience.

Over a 30-month period, 60 patients (30 in each group) suffering from end-stage liver disease or primary hepatic malignancy and scheduled for liver transplantation were enrolled in a prospective, randomized study to compare two methods of liver preservation: histidine-tryptophan-ketoglutarate (HTK) solution versus University of Wisconsin (UW) solution. Entry criteria for both groups were: age (18-65 years), elective surgery (transplantable or urgent category of the recipients), first transplantations and harvesting procedure performed by the same team. The parameters under investigation were the clinical and laboratory data pre- and post-transplantation, as well as follow-up data such as complications and survival. There were no significant differences in the two groups as far as the evaluation criteria were concerned, even when cold ischemia time was more than 15 h (n = 7). A slight, yet not significant, increase in late complications of the biliary anastomoses could be seen in the UW group. Hepatocellular injury (SGOT, SGPT, GLDH, lactate) appeared to be more marked in the HTK group. These results suggest that both HTK and UW solutions are appropriate for clinical use in liver transplantation, even if cold ischemia time is more than 15 h.

SummaryMyocardial oxygen consumption indices that are frequently applied to man such as tension-time index (TTI), pressure-rate product (P 9 HR) and triple product (TP) have not been fully validated so far. These easily obtainable indices and a modified TTI (P -x/H--R), therefore, were examined in I0 closed-chest dogs with very broad variations of hernodynarnics and oxygen consumption (3-36 rnl/rnin -100 g) analyzing 162 steady states. Myocardial blood flow was directly measured by a differential pressure coronary sinus catheter. I~O 2 was varied by administration of catecholamines and other inotropic drugs, atropine, beta-blocking agents and hypoand hypervolernia. Over a wide range of hernodynarnic states, correlations with directly measured MVO 2 of TTI (r = 0.63), P 9 HR (r = 0.87), TP (r = 0.65) and P 9 %/HR (r = 0.80) are not satisfactory due to neglect of contractility and cardiac volumes by these terms. Better correlations are obtained when relating these indices to IV[Vo2 under different inotropic states. At normal and moderately increased contractility, correlations with M~O2 rose as follows: TTI (r = 0.96), P 9 HR (r = 0.91), TP (r = 0.96) and P 9 ~ (r = 0.94). Significant rises in correlation are due to the close relationship between peak pressure and dP/dtma x at only moderately increased contraction velocity. Correlation differences within this inotropic range must be related to incorporation or neglect of ejection time as a partial determinant of MVO 2. At markedly increased contractility, results for these indices, however, are in part very poor: TTI (r = 0.40), P -HR (r = 0.81), TP (r = 0.38) and P 9 ~/HR (r = 0.76). Within this inotropic state neglect of dP/dtma x as a rna]or determinant of MVO 2 and the inverse relationship between ejection time and dP/dtma x mainly account for these correlation shifts. It is concluded that non-invasively obtainable indices, currently in use, are no reliable predictors of actual overall MVO2 of the left ventricle if the contractile state of the rnyocardium is not checked invasively before. The broad variability of the relation of the energy demand of velocity of tension development to rnaintenance of systolic wall tension is not sufficiently considered by these terms. Appropriate caution, therefore, is necessary when applying those indirect indices of M'~rO2 to humans.

The cardioplegic HTK-solution (Bretschneider) has not been used in human liver transplantation as yet. Herein the first results obtained from 14 patients with HTK-preserved liver grafts are presented. The suitability of HTK-solution could be shown. All grafts functioned primarily except one, where initial non-function was obviously due to donor reasons. The early postoperative peak values of transaminases as a sign of ischemic damage were average and similar to the values of other flushout solutions. Using HTK primary function could be achieved even in livers prospectively assessed as only of fair quality, and livers with poor donor function tests (MegX) functioned from the beginning. HTK-solution therefore seems to allow widening of the acceptance criteria for donor livers. It was not the aim of this trial to extend cold ischemic time, but 3 livers with 11 h and 12 h 25 showed immediate function. How far cold ischemic time can be extended is a still open question. All livers were rapidly cooled and homogeneously flushed out due to the low viscosity of HTK-solution. All livers had a soft consistency after perfusion indicating a low degree of cell edema. HTK therefore is an effective solution for liver preservation.