Animal models of fulminant hepatic failure: need to test liver support devices

Fulminant hepatic failure is one of the most dramatic entities in clinical medicine, but experimental studies of its pathogenesis, evolution and treatment have, so far been limited by the lack of satisfactory animal models for testing new supportive treatment options. The variable aetiology, complex pathogenetic mechanisms and inconstant clinical evolution of human fulminant hepatic failure make it particularly difficult to establish an "ideal fulminant hepatic failure animal model" suitable for all studies: it is no longer mandatory to develop one single model serving all possible scientific needs, but the use of a specific model for a specific issue is more advisable. The currently available animal models of fulminant hepatic failure are the hepatotoxic, surgical and combined hepatotoxic and surgical models. From a general point of view, surgical models may be particularly appropriate for studying the consequences of hepatic necrosis on cerebral oedema. The anhepatic model is very useful for validating new supportive measures to bridge the period between the onset of fulminant hepatic failure and the time at which a suitable organ becomes available and, despite the many difficulties involved in their development, hepatotoxic models may still be useful for mimicking an acetaminophen overdose. The efficacy and reproducibility of a liver support system can be demonstrated by means of preclinical experimental models that mimic the specific application required in humans as closely as possible.

Detection of biliary complications after orthotopic liver transplantation with MR cholangiography

To assess the diagnostic value of magnetic resonance cholangiography (MRC) when evaluating biliary complications in the follow-up of liver transplant patients. One hundred and thirteen patients prospectively underwent MR imaging and MR cholangiography at 1.5-T unit after orthotopic liver transplantation (OLT). After the acquisition of axial T1- and T2-weighted sequences, MRC involved a coronal, non breath-hold, respiratory-triggered, fat-suppressed, two-dimensional, thin-slab, heavily T2-weighted fast spin-echo sequence, and coronal breath-hold, thick-slab, single-shot T2-weighted sequences. The images and maximum intensity projections were evaluated by two readers in order to determine biliary anatomy and the presence of complications, whose final diagnosis was based on endoscopic retrograde cholangiography (ERC) in 50 patients, percutaneous trans-hepatic cholangiography (PTC) in five, and by integrating clinical follow-up with ultrasound and MR findings in 58 cases. MRC had a sensitivity of 93%, a specificity of 92%, a positive predictive value of 86%, a negative predictive value of 96%, and a global diagnostic accuracy of 93% in detecting all types of biliary complications in OLT patients. MRC is a reliable technique for detecting post-OLT biliary complications. We now restrict the use of ERC to patients for whom therapeutic procedures are advocated or whose MRC results are equivocal.

Very early tracheal extubation without predetermined criteria in a liver transplant recipient population

This study of all patients undergoing orthotopic liver transplantation (OLT) at our center between January 1997 and December 1999 evaluated the feasibility and safety of very early tracheal extubation without previous selection. Anesthetic management was the same in all cases, and tracheal extubation was performed on the basis of standardized criteria routinely adopted in operating rooms throughout the world, i.e., no residual curarization or anesthetic action, ability to swallow efficiently, and stable hemodynamics. One hundred sixty-nine patients underwent 181 OLTs during the study period. Tracheal extubation was performed within 3 hours of surgery in 115 cases, 8 hours in 19 cases, and 8 to 24 hours in 10 cases. In 36 cases, artificial ventilation was required for more than 24 hours or weaning was not possible. One patient died of primary graft nonfunction within 24 hours and was excluded from the analysis. The feasibility of early extubation was influenced by the amount of intraoperative transfused blood; efficacy of kidney, cardiac, and pulmonary function; and presence of encephalopathy (P <.001). No correlation was found with age or pre-OLT severity of hepatic disease, and the postoperative period was not compromised by early weaning. Very early extubation was feasible and safe in a large number of unselected transplant recipients, thus suggesting that the definition of early tracheal extubation should be changed from 8 to 3 hours after surgery.

Molecular monitoring of Candida albicans infections in liver transplant recipients

This report describes the use of the 27A probe for the molecular monitoring of Candida albicans infections in liver transplant recipients. Nosocomial candidiasis is the major fungal infection in liver transplant recipients, with Candida albicans being the species most frequently isolated. The molecular epidemiology of Candida albicans infections has been widely investigated, but scant attention has been focused on monitoring the identity of infecting strains in individual patients over the entire course of their hospitalization. In the study presented here, a total of 179 Candida albicans isolates were collected from 10 liver transplant recipients during multiple surveillance cultures performed before and after liver transplantation and from three healthcare workers at the Transplant Unit of Ospedale di Cisanello, Pisa (Italy). Computer-aided analysis of the 27A-probed DNA fingerprints, used to compare the genetic relatedness of all the Candida albicans isolates, showed that most of the patients colonized with Candida albicans before transplantation harbored a unique Candida albicans genotype. This genotype persisted over the entire course of hospitalization and caused multiorgan failure in two patients, both of whom died from endogenously borne Candida albicans infections. Nosocomial acquisition of Candida albicans strains could be monitored in a timely manner in the other patients; for some of them, subsequent strain replacement was registered at different body sites during the post-transplant period. Neither cross-infection between patients nor transmission from healthcare workers to patients occurred in this hospital setting. These results indicate that the molecular monitoring of Candida albicans strains isolated from liver transplant recipients during their hospitalization may provide timely information about the identity of individual Candida albicans strains causing infections.

[Prevention of mycotic infections in liver transplant recipients: comparison of two chemoprophylactic protocols]

BACKGROUND

The aim of the study was to compare and evaluate the efficacy of two chemoprophylactic protocols against mycotic infections in a liver transplant recipients population.

DESIGN

single-blind, randomized.

SETTING

Liver transplant Center of a National Health System teaching hospital.

METHODS

Eighty-eight consecutive patients submitted to liver transplantation were enrolled in the study. Immediately before surgery they were randomized to receive sequential treatment with intravenous liposomal amphotericine B + oral itraconazole or intravenous fluconazole + oral itraconazole. Intravenous drugs were administered in the first postoperative week, and oral treatments for the following three weeks. In addition to analyzing the frequency and incidence of colonization, local and disseminated infection of mycotic origin, the causes of death and the possible risk factors for mycotic disease have been examined.

RESULTS

Eighty-five patients completed the study. No significative difference was evident in the two groups as regards to single organ and systemic fungal infection rate. Two out of a total of 5 deaths were related to mycotic disease. Pre-transplant fungal colonization, more severe liver disease indicating the transplant procedure and the rejection of the graft were all risk factors for the development of mycotic infection.

CONCLUSIONS

The two protocols used in the study showed and equal efficacy in preventing fungal infections in liver transplant recipients.

Personality change as defensive responses of patients evaluated for liver transplant

Patients affected by endstage liver disease and awaiting liver transplant suffer very stressful conditions. The aim of this study was to evaluate the person ality and behavioral responses of a group of liver transplant candidates, 95 men (M age 50 yr.) and of a group of 18 normal men (M age 49 yr.). The 16 Personality Factor Questionnaire of Cattell, and the PSY Inventory for Behavioral Assessment were administered to assess personality and behavior. On the 16PF Questionnaire, patients had significantly different mean scores from normal subjects on Scale B- (low mental capacity), G (conformity), N (shrewdness), and Q1- (conservatism). They also showed a somewhat lower but not a statistically significant mean on Scale E (submissiveness). In addition, on the four second-order factors of the 16PF (Anxiety, Control, Pathemia, and Extraversion) patients had a significantly higher mean on Control. With respect to PSY Inventors factors, patients showed impairment in energy, sleep, sexual disturbances, and obsessive behaviors. It appears these patients with endstage liver disease, who were evaluated for liver transplant, showed psychological regressive functioning, i.e., high control and dependency on medical staff, submissiveness, which are interpretable as defensive responses to upcoming transplant.

Report of a life-threatening arrhythmia after hospital discharge in a liver transplant recipient with previously unknown congenital long QT syndrome

The long QT syndrome affects heart rhythm by prolonging ventricular repolarisation; it is potentially life-threatening since it can evolve into torsades de pointes (a polymorphic ventricular tachycardia) and/or ventricular fibrillation. The case is presented of a 55-year-old liver transplant recipient with a genetically determined long QT syndrome not detected by the standard preoperative cardiological evaluation. It was mild in the immediate post-operative period but developed into torsades de pointes after discharge, probably as a result of therapy. This case was particularly challenging because the first arrhythmic episodes were short and electocardiographically silent, and thus the related faints were thought to have a neurological basis. When the true cause emerged during a monitored episode of torsades de pointes, electric defibrillation was used to restore sinus rhythm and isoproterenol administered to increase heart rate and thus shorten the prolonged QT interval Long-term control was obtained by means of an implantable intracardiac defibrillator. In orthotopic liver transplant recipients with long QT syndrome, particular attention should be given to post-operative therapy as some routinely used drugs can trigger life-threatening ventricular arrhythmias.

Oxidative stress in fulminant hepatic failure: comparison of two pig models with and without liver necrosis

BACKGROUND/AIMS

No experimental study has clearly demonstrated how liver necrosis worsens the evolution of fulminant hepatic failure. Considering that several types of liver injury are associated with oxidative stress, we decided to measure plasma oxidative markers in two pig models of fulminant hepatic failure without and with liver necrosis.

METHODOLOGY

Fulminant hepatic failure was produced in two groups of six pigs each by either total hepatectomy or complete hepatic devascularization. The following parameters were recorded before and during the course of hepatic failure: electrocerebral activity, plasma vitamin E, malondialdehyde and fluorescent protein-aldehyde adducts, total cholesterol, lactate-dehydrogenase, creatine phosphokinase, and ammonium.

RESULTS

Despite comparable survival periods, hepatic necrosis was associated with earlier electrocerebral deterioration. Plasma concentration of malondialdehyde and fluorescent protein-aldehyde adducts rose and vitamin E content decreased in both groups. However, while in the group without liver necrosis the rates of cholesterol and vitamin E decay were identical, in the group with liver necrosis cholesterol concentration decreased less than vitamin E concentration, strongly indicating a true intravascular oxidation of vitamin E. Interestingly, in both models the rise of oxidative parameters preceded the development of cell injury.

CONCLUSIONS

Oxidative stress, although present in both models, was significantly higher in the group with liver necrosis.

[Blood coagulation monitoring during liver transplantation: Sonoclot analysis and laboratory tests]

BACKGROUND

Aim of this paper is to validate blood coagulation data obtained using the Sonoclot thromboelastographic analyser (Sienco Inc., Morrison, USA) by means of standard laboratory tests during orthotopic liver transplantation (OLT).

METHODS

DESIGN

comparative study between laboratory data and Sonoclot analysis on simultaneously collected blood samples.

SETTING

National Health System Liver Transplantation Center.

PATIENTS

fifty-one patients, both males and females, affected by terminal hepatic disease submitted to OLT were enrolled in the study.

DATA COLLECTION

simultaneous blood samples were collected during the pre-anhepatic, anhepatic and post-reperfusion phases of OLT; coagulation status was assessed by means of either standard Laboratory tests (INR, aPTT, Fibrinogen, PLT, D-Dimer) and Sonoclot analyser data (SonACT, Rate, Time to Peak, Downward Deflection); a statistical analysis was performed (Pearson s chi(2) test).

RESULTS

A statistically significative correlation between the analysed data was found. The Sonoclot analyser was useful in identifying platelets dysfunction and was more sensitive to detect fibrinolysis.

CONCLUSIONS

The Sonoclot thromboelastographic analyser is a reliable device for monitoring coagulation during OLT.

Inhibited differentiation of Langerhans cells in the rat epidermis upon systemic treatment with cyclosporin A

The immunosuppressant drug cyclosporin A (CsA) is known to cause reduction in number, DNA synthesis and function of Langerhans cells (LC). Since also the differentiation of LC is known to be hampered in conditions of acquired immunodeficiency not due to drugs, we investigated whether this occurs with CsA. Rats were injected subcutaneously with CsA (5, 10 and 50 mgxkg(-1) x d(-1)) for three weeks; the skin was analyzed by Ia immunohistochemistry and by electron microscopy. Epidermal immunolabeled cells were 15+/-3.5 (mean +/- SEM) per 100 basal keratinocytes in untreated controls and 8.75+/-1.3, 4.75+/-1.0 and 1.7+/-1.2 upon increasing doses of CsA (p<0.01). By electron microscopy, monocytoid cells with deep invaginations of the plasma membrane and roundish LC poor in Birbeck granules appeared in the epidermis upon treatment. The results suggest that CsA inhibits the differentiation of LC precursors in the epidermis and that this can in part explain the selective increase in the risk of skin viral disease and cancer in chronically treated patients.

The dorsal sector of human liver: embryological, anatomical and clinical relevance

The dorsal liver sector has been recognized as the parenchyma surrounding the vena cava and is quite independent of the remaining liver. It is that part of the organ in which the hepatic portion of the vena cava develops and its venous outflow remains strictly connected with the vena cava by means of multiple, not dissectable effluents as well as with the main hepatic veins. Therefore, this sector is a major shunt between the main hepatic veins and the inferior vena cava, which enlarges and ensures venous drainage for survival in cases of Budd-Chiari syndrome. The dorsal sector consists of two segments: a left one (segment I) corresponding roughly to the caudate lobe and a right one (segment IX) in front and on the right of the vena cava, including the so-called caudate process. The identification of a dorsal liver sector and its detailed anatomy is of primary importance for surgical practice, since cholangiocarcinoma of bile duct hilar confluence extends to the dorsal sector and makes resection of this sector necessary for efficient therapy and due consideration of the pedicles of segment I and IX is required to perform successful hemihepatectomy as well as liver partition for split liver grafting.

A new technique for total hepatectomy in the pig for testing liver support devices

BACKGROUND

A large animal model of total hepatectomy is suitable to test the efficacy of any system designed to support patients in hepatic coma. The models previously described in the pig entail a significant degree of surgical trauma, which might alter the evolution of the ensuring hepatic failure and compromise the reproducibility of the model.

METHODS

Twenty-eight pigs underwent a total hepatectomy according to a new technique. A model was considered satisfactory when it required no blood transfusions and when hematologic and hemodynamic parameters determined before, during, and until 4 hours after hepatectomy showed no significant variations. Moreover, to revive the pattern of hepatic coma produced in the anhepatic model, 7 pigs were monitored until brain death occurred.

RESULTS

Twenty-five pigs (89%) underwent a smooth total hepatectomy with minimal variations of the selected parameters. They constituted a highly homogeneous group. Survival of the 7 pigs, followed up until brain death occurred, ranged from 625 to 1595 minutes (mean 1013.57 minutes). The animals remained stable until a few hours before brain death, an event heralded by a final sharp increase of the serum ammonia level and by a well-evident decline of both arterial pressure and liver-dependent clotting factors.

CONCLUSIONS

This technique of total hepatectomy allows the construction of a reproducible model of anhepaty suitable to test the efficacy of any system conceived to temporarily replace hepatic functions.

[Early tracheal extubation ofter orthotopic liver transplantation]

BACKGROUND

To evaluate an early tracheal extubation feasibility in previously unselected orthotopic liver transplantation (OLT) patients.

METHODS

DESIGN

retrospective analysis.

SETTING

National Health System Intensive Care Unit.

PATIENTS

all the patients who underwent OLT during 1997 at our institution were evaluated. The anesthestic management was the same for all of them and a veno-venous bypass was always used during the anhepatic phase. Tracheal extubation was performed when metabolic and haemodynamic parameters were stable; the following extubation criteria were also considered: no residual curarization, normocarbia, ability to keep the airway patent, good respiratory drive, ability to carry out simple orders. No pre- or intraoperative criteria, as previously reported in the literature for OLT patients, were followed to perform tracheal extubation in the postoperative period.

RESULTS

During 1997 forty OLTs were performed in 38 patients. Twenty-eight patients were successfully extubated within 3 hours from the end of the surgical procedure; three patients were extubated within 6 hours and three within 24 hours from the end of surgery; four patients needed more then 24 hours of ventilation or were impossible to wean. No patient was re-intubated. A correlation appeared evident between early extubation and the amount of the transfused red cell units, kidneys and lungs function, cardiovascular efficiency; no correlation emerged with patients age or the pre-transplant severity of the hepatic disease.

CONCLUSIONS

To perform a safe early tracheal extubation in previously unselected OLT patients is feasible and it can be carried out in a wide number of them. The previously reported timing characterizing as "early" a tracheal extubation should be moved from 8 to 3 hours.

Percutaneous cholecystostomy for acute cholecystitis in critically ill patients

BACKGROUND/AIMS

The aim of this study was to ascertain the therapeutic efficacy of percutaneous cholecystostomy in a selected group of high-risk patients who were physiologically unable to tolerate an open procedure.

METHODOLOGY

We reviewed the hospital records of 11 critically ill patients who underwent percutaneous cholecystostomy for acute cholecystitis during the intensive care unit course of major underlying diseases.

RESULTS

Percutaneous cholecystostomy was easily performed in all cases (feasibility rate: 100%). No procedure-related death was recorded and minor complications occurred in 2 patients (18%). Percutaneous cholecystostomy led to resolution of the sepsis in all but 1 patient with gangrenous calcolous cholecystitis who required emergent cholecystectomy (success rate: 91%). Percutaneous cholecystostomy was the permanent treatment in all patients with acalcolous cholecystitis. Among patients with calcolous cholecystitis, 4 underwent delayed elective cholecystectomy, 1 required no further treatment, and 2 eventually died from the evolution of their underlying diseases. After a mean follow-up of 25 months (range: 12-32 months), none of the patients managed non-operatively required surgery or re-hospitalization.

CONCLUSIONS

Ease of performance, low complication rate, and high success rate make percutaneous cholecystostomy the procedure of choice for critically ill patients with acute cholecystitis. Whenever possible, percutaneous cholecystostomy should be followed by elective cholecystectomy. However, especially in acalcolous cholecystitis, it may constitute the definitive treatment.

[Orthotopic liver transplant. Analysis of costs related to anesthesiologic and intensive care phases]

BACKGROUND

To evaluate anesthesia and Intensive Care Unit (ICU) costs for Orthotopic Liver Transplantation (OLT) through a point by point analysis of the entire process from anesthesia induction to ICU discharge.

DESIGN

Retrospective analysis.

SETTING

Regional Transplantation Centre participating to the Italian National Health Care System.

METHODS

Anesthesia and ICU costs for each OLT performed during 1997 were estimated through the analysis of costs of the following categories: drugs, medical and nurse staff, blood bank, radiology, laboratory, haemoderivates.

RESULTS

Forty OLTs were performed in 38 recipients during the study period. The total charges for the anesthesia and ICU management of these patients calculated in US dollars were 583.433,23 (considering the exchange rates valid in January 1998). ICU costs resulted approximately 2.5 times higher than those for anesthesia. Blood bank and drugs were the categories that had the greatest impact on the final expense whereas laboratory had the lowest. The charges referred to medical and nurse staff resulted higher in the ICU than for anesthesia.

CONCLUSIONS

The Italian National Health Care System has to deal with limited resources; costs analysis of high-tech procedures as OLT is of basic importance to optimise resources allocation and to enforce money-saving actions.

Human preformed IgG combining with membrane-bound porcine serotransferrin lyse porcine endothelial cells through antibody-dependent cellular cytotoxicity

Preformed antibodies are involved in xenograft rejection. The purpose of this work was to characterize porcine xenoantigens recognized by human preformed IgG (hpIgG), and to investigate the role of hpIgG in xenogeneic rejection. IgG eluted from porcine livers perfused with human plasma, human sera and total human IgG were immunoblotted on porcine aortic endothelial cell extracts. The amino acid sequence of a 76-kDa antigen constantly revealed was 100% homologous with porcine serotransferrin (psTf). hpIgG from human sera, human IgG1 and IgG2 and F(ab')2gamma specifically bound to psTf. Neutralization by psTf abolished that binding. Although alpha1,3-linked galactose residues (Gal(alpha)1,3Gal) is the dominant epitope recognized by preformed antibodies in the swine-to-human combination, the analysis of carbohydrate composition of psTf showed that the molecule was devoid of Gal(alpha)1,3Gal moieties and that preformed anti-psTf IgG bound to epitopes localized on the peptide core of the molecule. Purified human anti-psTf IgG antibodies were able to bind to psTf linked to its receptor on porcine endothelial cells, and to kill those cells through antibody-dependent cellular cytotoxicity.

Water-glove balloon system: a useful option to salvage liver grafts with postreperfusion suprahepatic vena caval kinking

BACKGROUND

Although exceedingly rare, kinking of suprahepatic vena cava after liver transplantation can lead to both graft failure and patient demise. The features of a case of suprahepatic vena caval kinking are herein reported along with the description of an original solution adopted to rescue the graft.

METHODS

In order to correct vascular kinking, two surgical gloves filled with sterile saline solution were placed in appropriate positions in the subdiaphragmatic space.

RESULTS

Caval obstruction was immediately relieved. Over a period of 7 days, gloves were progressively deflated and eventually removed without need for laparotomy. Vena caval kinking did not recur.

CONCLUSIONS

The "water-glove balloon system" described in this report seems to be an efficient and inexpensive method to rescue liver grafts in the presence of kinking or torsion of the suprahepatic vena cava. Surgeons dedicated to the transplantation of the liver should therefore retain this option in their cultural background.

Need and supply of liver grafts in Tuscany

BACKGROUND

Epidemiological data are fundamental to adequately plan the activity of a liver transplantation centre.

AIM

To evaluate the ratio between need and supply of liver grafts in Tuscany and to develop a regional strategy aimed at increasing donor recruitment.

METHODS

The need for liver grafts was estimated on the basis of an epidemiological study: 19 Medical Units were requested to fill in a questionnaire inquiring into all Tuscan patients evaluated for liver disease during three different periods of one month each in 1996. The information collected was matched with the selection criteria currently employed at our centre and the patients were classified into the following four categories: 1. current transplantation candidates; 2. future transplantation candidates; 3. candidates not suitable on account of age; 4. candidates not suitable on account of exclusion criteria. The number of liver donors was obtained from the donor registry.

RESULTS

Questionnaires were returned for a total of 452 patients: 27 (5.97%) were classified as current transplantation candidates, 62 (13.72%) as future transplantation candidates and 19 (4.20%) as candidates not suitable on account of age. The annual incidence and prevalence of transplantation candidates were 14.7 and 30.6 cases per million inhabitants, respectively. If age (> or = 61 years) was not considered in the exclusion criteria, the annual prevalence of transplantation candidates reached 52.1 cases per million inhabitants. During the same period there were 44 organ donors (12.2 donors per million inhabitants) of whom 33 were suitable for liver donation (9.3 liver donors per million inhabitants). To reduce this discrepancy a new programme for organ recruitment, based upon the Spanish model, has been recently employed.

CONCLUSIONS

The annual need for liver grafts in Tuscany largely exceeds the number of donors currently available. It is hoped that the new regional programme for organ recruitment will improve these figures.

Effect of cilastatin on cyclosporine-induced acute nephrotoxicity in kidney transplant recipients

BACKGROUND

Cyclosporine (CsA)-induced acute nephrotoxicity could be reduced by prevention of parenchymal accumulation of the drug itself. The objective of this prospective study was to evaluate whether cilastatin, an inhibitor of active tubular resorption of CsA, reduces CsA-induced acute nephrotoxicity in kidney graft recipients.

METHODS

Sixty-nine kidney recipients with immediate graft functional recovery were randomly assigned to either the treatment group (imipenem/cilastatin, n=33) or the control group (ceftazidime, n=36). All patients followed a standard immunosuppressive regimen based on CsA and low-dose prednisone. Graft function and CsA levels were evaluated 3, 5, 10, 15, and 30 days after transplantation.

RESULTS

Compared with the control group, imipenem/cilastatin administration reduced the serum creatinine level in the first 2 weeks after transplantation, reaching a significant effect on postoperative day 10 (P<0.05). No significant differences were demonstrated between the two groups for CsA levels, patient and graft survival, and all the other examined parameters.

CONCLUSIONS

Our findings support the hypothesis that cilastatin administration can reduce CsA-induced acute nephrotoxicity after kidney transplantation.

Surgical research in orthotopic liver transplantation: experiences in the pig model

Since the very beginning of liver transplantation in humans, research in animals has had close relationship with clinical practice. Results obtained in animals have been transferred to the clinics and problems borne in the clinics have been addressed again in animals for to be answered clearly. In this review the authors report their experience of transplantation in the pig model and discuss the significance of a team cooperation in the laboratory as a preparatory step for clinical practice.

Exclusively aortic cold flushing for liver procurement from hemodynamically stable donors. An experimental study in the pig

Liver cooling before grafting is usually achieved by aortic plus portal flushing; exclusively aortic flushing is reserved to hemodynamically unstable or non heart-beating donors. We have compared the effects of "aortic plus portal" (8 cases) and "aortic" (8 cases) cold flushing on the early function of pig liver grafts from hemodynamically stable donors. The time for liver removal (mean +/- standard deviation) was 30.4 +/- 7.1 min. in the "aortic plus portal" and 19.7 +/- 3.3 min. in the "aortic" group (p < 0.01). All the recipients survived for at least 72 hrs; only those of the "aortic plus portal" group showed some degree of primary liver dysfunction; recipient serum aspartate transaminase (AST) was significantly higher in the "aortic plus portal" than the "aortic" group. Since aortic flushing allowed for shorter operation times and was better tolerated than and at least as effective as aortic plus portal flushing, it can be proposed for routine liver procurement even from hemodynamically stable donors.

Segmental organization of the pig liver: anatomical basis of controlled partition for experimental grafting

Segmental anatomy has been investigated on 54 pig livers by bench-top radiology and ultrasonography of hepatic and portal vessels and bile ducts and dissection of suprahepatic veins. Eight segments were recognized, homologous to those of the human liver. Major variations were found only of arterial distribution. The inferior vena cava invariably ran within the parenchyma of the right lobe and close to the liver hilum; suprahepatic veins were also entirely intraparenchymal. Therefore, the pig liver can easily be divided into two halves, but only the right one can be used for reduced-size grafting into a recipient.

Partial hepatic resection for ischemic graft damage after liver transplantation: a graft-saving option?

BACKGROUND

Intrahepatic biliary strictures or parenchymal infarcts may occur after liver transplantation as a complication of ischemic damage to the graft. In some selected cases the lesions appear to be confined to a part of the liver. We report our experience with partial graft resection in this setting.

METHODS

From January 1984 to December 1991, 286 liver transplantations were performed in 257 recipients. Seven patients, three children and four adults, underwent partial hepatectomy 3 to 218 weeks after liver transplantation of a full-size graft. The clinical presentation included septic parenchymal infarcts (n = 4) and nonanastomotic biliary strictures (n = 3) complicating (n = 5) artery thrombosis or not (n = 2). There were four left hepatectomies, two left lobectomies, and one right hepatectomy. In four instances partial hepatectomy was performed after failed attempt at biliary reconstruction (n = 2) or arterial revascularization (n = 2). Partial graft resection was performed extrafascially without Pringle's maneuver and mobilization of the remnant liver to preserve its vascularization.

RESULTS

No surgical complications occurred, and none of the patients experienced acute hepatic failure during the postoperative period. All patients were discharged home 10 to 96 days (median, 23 days) after liver resection. Two patients had recurrent ischemic cholangitis. One patient underwent successful regrafting for recurrent Budd-Chiari syndrome; one patient died of tumor recurrence. Six patients were alive with a follow-up ranging from 12 to 45 months.

CONCLUSIONS

These results suggest that partial graft resection is a safe and graft-saving option after liver transplantation in selected patients with localized ischemic damage of the graft.

Liver transplantation for end-stage liver disease associated with alpha-1-antitrypsin deficiency in children: pretransplant natural history, timing and results of transplantation

Alpha-1-antitrypsin deficiency is an inborn metabolism error which can cause emphysema and liver disease. As regards the pathophysiology of liver disease, this deficiency is poorly understood, and it is also not known why only a small proportion of Pi ZZ individuals progress towards cirrhosis and liver failure. Since there is no specific therapy for end-stage liver disease associated with alpha-1-antitrypsin deficiency, patients are considered candidates for liver transplantation. In this paper, the natural history of 16 children who underwent liver transplantation is reviewed. Fourteen patients had neonatal cholestasis as a first symptom of the disease and hepatosplenomegaly was present in all children by the age of 12 months. In 11 children, jaundice recurred, always with liver function deterioration. Two patients had a histological paucity of interlobular bile ducts and required early transplantation due to rapid progression of liver failure. At the time of pretransplant assessment, all the patients in this study had portal hypertension and seven of them had experienced at least one episode of gastrointestinal bleeding. One child had moderate intrapulmonary shunts with hypoxemia, but the others had normal spirometry and blood gases. There was no other extrahepatic complication of alpha-1-antitrypsin deficiency. Eighteen orthotopic liver transplantations were performed in 16 patients. One patient died 8 days after retransplantation due to graft necrosis. Fifteen patients (94%) were alive after a median follow-up of 22 months with an excellent quality of life, normal serum alpha-1-antitrypsin levels and without evidence of liver disease recurrence or pulmonary complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Normothermic liver perfusion ex situ: a resuscitation tool for hepatic grafts damaged by warm ischemia

Ex situ perfusion of the liver has been proposed as a preservation tool for organs to be grafted; in this study, we have investigated whether this procedure could help to reverse damage caused by prolonged ischaemia. The liver was explanted from 6 pigs under general anaesthesia. The organs were subject to warm ischaemia (37 degrees C) for 30 min., cooled in situ by portal infusion of Euro Collins, excised and maintained ischaemic at 4 degrees C for 30 min. more. Afterwards, normothermic perfusion was achieved through the portal vein and hepatic artery for 6 hrs. The parameters measured allowed to follow up the hemodynamic, metabolic and structural response of the liver to the experimental procedure. By electron microscopy, generalized hepatocyte damage was observed after ischaemia, but appeared to be reversed in most cells after ex situ perfusion. Wide areas of sinusoidal walls were devoid of endothelial lining; where this was present, however, it was normal in structure. Kupffer and Ito cells had normal structure whenever observed. Four livers were implanted orthotopically into recipient animals, which were monitored for hemodynamic and biochemical parameters during surgery and followed up to one week. Post mortem examination was performed on the animals which died before this end point. Two of them were alive after one week. Two animals died, one for a perforation of the right hepatic vein and the other for massive necrosis of the left lobe with sepsis and hemorrhage. These results indicate that normothermic ex situ perfusion of the liver has the potential to become a valuable tool to reverse ischaemic injury and monitor organ function before grafting.

Orthotopic liver transplantation in the pig: a surgical experience with 124 liver transplants

From January 1988 to June 1990 one-hundred-twenty-four orthotopic liver transplantation (OLT) were performed in pigs, using a surgical procedure already described in the literature but with two major modifications. One of these modifications was the end-to-end microsurgical anastomosis of the proper hepatic arteries of the donor and recipient; the second one was the reduction in length of the donor suprahepatic vena cava to 1-2 mm before anastomosing it with the recipient suprahepatic vena cava at the level of the diaphragm. The first 24 transplants were used to develop the surgical technique. The latter was then applied to all subsequent 100 transplants, and results are herein presented. Good outcome of surgery appeared to depend on the modifications adopted in surgical technique, use of a pump-driven veno-venous bypass during the anhepatic phase of surgery, administration of cyclosporin A postoperatively, and training of the operator.

A new surgical model of acute liver failure in the pig: experimental procedure and analysis of liver injury

In this research, the effects of portocaval shunt plus 70% partial hepatectomy were evaluated in 11 pigs. Hepatic coma and death from progressive liver failure occurred in 5 pigs between 14 and 64 h from surgery, whereas 3 pigs, which also showed symptoms of progressive liver failure, died of presumed gastric hemorrhage between 17 and 19 h after surgery. In 3 pigs, transient liver failure was followed by complete recovery, as judged by clinical, electroencephalographic and biochemical parameters. No case of death occurred among the pigs treated with portocaval shunt alone or 70% partial hepatectomy alone as controls. This new model for acute liver failure is reproducible, seems to be potentially reversible, causes death due to hepatic failure after a time period sufficiently long to allow for the institution of support procedures, is applied to a large animal and lacks relevant biohazard. Therefore, this model may be used to evaluate possible support procedures during acute liver failure.

Morphological changes in rat pancreatic acinar cells induced by long-term treatment with cyclosporine and their reversal after withdrawal

Cyclosporine (CsA), administered to rats at daily doses of 10 and 50 mg/kg body weight, for 21 days, influenced negatively the structures involved in the synthesis, storage and secretion of digestive enzymes in pancreatic acinar cells. A dose-related, significant reduction in basophilic cell regions, secretion granule content, and overall size of acinar cells was appreciable by light microscopy and morphometry. By electron microscopy, the acinar cells of the rats given 10 mg/kg/day CsA were similar to the controls, whereas with the higher dose most cells showed reduction in the size of nucleoli, increase in the number of lysosomes, and evidence of autophagy. In only a few cells was autophagy particularly severe and involved almost the entire cytoplasm. Nine weeks after withdrawal from CsA treatment, the structural recovery of acinal cells was complete, and features indicating enhanced protein synthesis and mitochondrial multiplication were observed by electron microscopy. In conclusion, prolonged administration of CsA to rats induces changes in the acinar cells indicating a depression of their activity, without substantial impairment in the viability of the most of them, even at high doses. This accounts for complete restoration of the acinar tissue upon withdrawal.

Immunocytochemical and ultrastructural changes of islet cells in rats treated long-term with cyclosporine at immunotherapeutic doses

Daily cyclosporine doses of 10 mg/kg body weight for 21 days in Wistar rats cause impairment in glucose homeostasis and changes in the amount of immunostainable hormones and in the ultrastructure of the cells of the pancreatic islets. CsA induces hyperglycemia and reduced glucose tolerance, and causes a decrease in immunoreactive insulin and an increase of somatostatin and pancreatic polypeptide (PP) immunoreactivities, leaving glucagon immunoreactivity unaffected. Ultrastructurally, different degrees of dilation of rough endoplasmic reticulum cisternae and enlargement of Golgi apparatus can be observed in B cells, together with a pronounced reduction in the number of secretory granules. Nevertheless, there were no apparent morphological changes of the other cytoplasmic organelles, suggesting that the drug, besides a depression of protein synthesis, as previously stated, also induces a substantial defect in granulogenesis, probably due to impairment in the intracellular transport of the hormone from the sites of synthesis to the secretory granules. The B cell alterations are not accompanied by any sign of B cell degeneration or death. Non-B cells did not show any of the ultrastructural changes found in B cells and were similar to those of the control rats. The above findings indicate that CsA at immunotherapeutic doses causes impairment in the secretory processes of B cells specifically. An hypothesis on the mode of action of CsA on B cells is drawn.

Veno-venous bypass in experimental liver transplantation: portal-jugular versus caval-portal-jugular

This study was undertaken to compare the changes in physiologic variables caused by the use of two different types of pump-assisted veno-venous bypass during experimental liver transplantation. The experiments, performed on female pigs weighing 30 +/- 2 kg, were divided into two groups depending on the bypass used. During the anhepatic phase a pump-assisted portal-jugular (PJ) bypass was used in Group 1 (n = 8) at a flow rate of 15 ml kg-1-min-1, while a pump-assisted caval-portal-jugular (CPJ) bypass was used in Group 2 (n = 8) at a flow rate of 20 ml kg-1-min-1. Intraoperative haemodynamics, pulmonary gas exchange, haematological and serum biochemical parameters were evaluated. Postoperative animal survival rate and complications associated with the bypass used were evaluated. Mean pulmonary artery pressure (Ppa) and pulmonary vascular resistance (Pvr) showed significantly different behaviour in the two groups, whereas the remaining parameters all showed the same trend. Thus an earlier and more substantial increase in Ppa and Pvr values was found in Group 1 when compared to Group 2 during the anhepatic phase. The different behaviour shown by Group 1 may depend on the release of circulating vasoactive substances generated following pelvic venous congestion caused by the temporary clamping of the inferior vena cava. In conclusion, this study indicates that the pump-assisted CPJ bypass is more suitable than the pump-assisted PJ bypass. Furthermore, in order to obtain better results it should be used routinely in porcine liver transplantation.

Alterations in the fine structure of the pig liver upon cold ischemia

The fine structure of the pig liver was examined after 30 min of warm ischemia at 37 degrees C, after 2 h of cold ischemia at 4 degrees C and after 30 min of warm ischemia followed by a further 30 min of cold ischemia. After warm ischemia, limited mitochondrial swelling was observed in hepatocytes. After cold ischemia, alone or following warm ischemia, vesiculation and vacuolation of the hepatocyte cytoplasm and appearance of intrasinusoidal blebs deriving from hepatocytes were observed with different intensity among the animals. These findings suggest that cooling and storing the liver at 4 degrees C may lead to injury, which could negatively influence the viability of the organ, with different intensity from case to case.

Bioavailability of intramuscular ciclosporin in the pig

We conducted a cross-over single-dose pharmacokinetic study in 4 pigs to measure the bioavailability of ciclosporin (CS) after intravenous and intramuscular administration. Each animal was given 5 mg/kg i.v. followed by 20 mg/kg i.m. after 1 week. Serial blood samples were taken over 36 h after each dose, and the concentration of CS was assayed by radioimmunologic methods. The pharmacokinetic parameters after intravenous administration were (mean +/- SD; n = 4): clearance = 327 +/- 21 ml/h/kg; volume of distribution = 7.2 +/- 2.8 liters/kg. The same parameters after intramuscular dosing were: clearance = 326 +/- 59 ml/h/kg; volume of distribution = 6.9 +/- 2.1 liters/kg. The percent bioavailability of intramuscular CS was 101.9 +/- 13.3 with a mean absorption time of 10.6 +/- 2.7 h. Our results indicate that following a single dose, the percent bioavailability of intramuscular CS in pigs is considerably greater than that reported in previous studies.

[Orthotopic liver transplant in pigs: several variations of the surgical technic]

A technique of orthotopic liver transplantation in the pig is presented. The use of a veno-venous cava-portal-jugular shunt during the anhepatic phase helped by a roller pump with moderate systemic heparinization is described. Technical modifications of arterious and biliary anastomosis are described as well. This technique is not only similar to the procedure applied to man, but it also provides a safe and reproducible experimental model. It has produced good results according to a survival rate equal to 95% at 48 hour and 87.5% at one week in the orthotopic liver transplantation in the pig.

One liver for two: an experimental study in primates

The need for liver grafts is critical in countries where brain death is not accepted as a legal criterion for organ retrieval. This experimental study was conducted with nonhuman primates in order to evaluate the feasibility of liver transplantation using a living donor. An original technique was employed to remove the left part of the liver from the donor: transection of the parenchyma was done while the blood flow was kept to the left part of the liver. In the recipients, the graft was placed heterotopically. No blood transfusions were administered to donors or recipients. In spite of a few failures, due to consequences of intraoperative bleeding, several donor operations using this original technique were successful, in the immediate postoperative period as well as several months later. Among the recipients, the large number of early failures suggests that the heterotopic position is probably not the appropriate one and that orthotopic transplantation should be preferred.

Discordant heart xenografts in the rat. Additional effect of plasma exchange and cyclosporine, cyclophosphamide, or splenectomy in delaying hyperacute rejection

Natural antidonor antibodies are known to play a prominent role in hyperacute xenograft rejection. The aim of this work was to devise an experimental protocol to prolong the survival time of guinea pig heart xenografts transplanted into rats. A technique of continuous plasma exchange adapted to small animals was used to remove the natural cytotoxic antibodies from the recipient prior to the transplantation. In some experiments, cyclosporine (CsA), cyclophosphamide (CY), or splenectomy were associated with the plasma exchange. In this highly discordant xenogenic donor-recipient combination, the mean graft survival time in nontreated rats was 16 min. When an exchange of 1.5 plasma volume was performed 24 hr before the transplantation, no prolongation of the graft survival time was observed. When CsA, CY, or splenectomy were associated with the plasma exchange, the graft survival time was significantly increased by more than 2500% (up to 418 min with CsA). When used isolately, none of these 3 immunosuppressive methods was able to prolong the graft survival time. Natural cytotoxic antibodies were monitored by a complement-mediated cytotoxicity assay. After a plasma exchange, the titers decreased from 1:16-1:32 to 1:1-1:2. When no immunosuppressive method was associated with the plasma exchange, the antibodies returned to their initial level within the 24 hr that preceded the transplantation, and the graft was rejected as in nontreated animals. When an immunosuppressive method was associated with the plasma exchange, and particularly in the case of CsA, the titers remained low, and the hyperacute rejection was delayed. Therefore, it can be concluded that plasma exchanges, associated with CsA, are an efficient experimental protocol in the rat to increase the survival time of guinea pig heart xenografts. The effect of the treatment is correlated with the decrease in natural cytotoxic antidonor antibodies.