Efficacy of intraportal infusion of prostaglandin E1 to improve the hepatic blood flow and graft viability in porcine liver transplantation

Effects of Trendelenburg position and increased airway pressure on hepatic regional blood flow of normal and resected liver

High portal venous blood flow (Qpv) may contribute to posthepatectomy liver failure. Both Trendelenburg position (TP) and elevated airway pressure (Paw) increase backpressure to venous return and may thereby reduce Qpv. The aim of this study was to evaluate the effects of TP and increased Paw on hepatosplanchnic hemodynamics before and after major liver resection. Arterial and venous blood pressures, Qpv, extrasplanchnic inferior vena cava (Qivc), superior mesenteric (Qsma), hepatic (Qha), and carotid artery blood flows (Qca) were measured in 14 anesthetized and mechanically ventilated pigs in supine and 30° TP during end-expiratory hold at 5 cmH2O positive end-expiratory pressure (PEEP) and during inspiratory hold with Paw of 15, 20, 25, and 30 cmH2O. After major liver resection, the interventions were repeated in seven randomly selected animals. At baseline, TP increased right atrial pressure (Pra) and Qpv but not Qivc or Qsma. With increased Paw in the supine position, Pra increased and all regional blood flows decreased. TP during increasing Paw attenuated the decrease in Qpv, Qsma, and Qivc but not in Qha or Qca. After liver resection, the effects of TP during increasing Paw remained, albeit at higher portal vein pressures. However, TP alone did not increase IVC venous return. Increasing Paw in supine position reduces Qpv and all other regional flows, while the reduction in Qpv is attenuated in TP, suggesting partly preserved liver waterfall or decreased intrahepatic resistance. Liver resection, despite resulting in major intrahepatic blood flow changes, does not fundamentally influence the interaction of increasing Paw and TP on regional perfusion.

NEW & NOTEWORTHY In Trendelenburg position (TP), liver blood flow is the only contributor to increased venous return measured in the inferior vena cava (IVC), which attenuates the decreased IVC venous return induced by increasing airway pressure. After liver resection, TP similarly attenuated effects of increasing airway pressure.

Portal flow modulation in living donor liver transplantation: review with a focus on splenectomy

Small-for-size graft (SFSG) syndrome after living donor liver transplantation (LDLT) is the dysfunction of a small graft, characterized by coagulopathy, cholestasis, ascites, and encephalopathy. It is a serious complication of LDLT and usually triggered by excessive portal flow transmitted to the allograft in the postperfusion setting, resulting in sinusoidal congestion and hemorrhage. Portal overflow injures the liver directly through nutrient excess, endothelial activation, and sinusoidal shear stress, and indirectly through arterial vasoconstriction. These conditions may be attenuated with portal flow modulation. Attempts have been made to control excessive portal flow to the SFSG, including simultaneous splenectomy, splenic artery ligation, hemi-portocaval shunt, and pharmacological manipulation, with positive outcomes. Currently, a donor liver is considered a SFSG when the graft-to-recipient weight ratio is less than 0.8 or the ratio of the graft volume to the standard liver volume is less than 40%. A strategy for transplanting SFSG safely into recipients and avoiding extensive surgery in the living donor could effectively address the donor shortage. We review the literature and assess our current knowledge of and strategies for portal flow modulation in LDLT.

Porcine model for the study of liver regeneration enhanced by non-invasive 13C-methacetin breath test (LiMAx test) and permanent portal venous access

Introduction

Despite advances in perioperative management and surgical technique, postoperative liver failure remains a feared complication after hepatic resection. Various supportive treatment options are under current discussion, but lack of structured evaluation. We therefore established a porcine model of major liver resection to study regeneration after partial hepatectomy in a reliable and well-defined pre-clinical setting.

Methods

Major hepatectomy was performed on seven minipigs with the intention to set up a non-lethal but relevant transient impairment of liver function. For steady postoperative vascular access (e.g. for blood withdrawal, measurement of venous pressure), permanent catheters were implanted into the internal jugular and portal veins, respectively. Animals were followed up for 30 days; clinical and laboratory results were recorded in detail. Monitoring was enhanced by non-invasive determination of the maximum liver function capacity (LiMAx test).

Results and conclusions

The established porcine model appeared suitable for evaluation of postoperative liver regeneration. Clinical characteristics and progression of liver function impairment as well as subsequent recovery were comparable to courses known from surgery in humans. Laboratory parameters (e.g. liver enzymes, bilirubin, INR, coagulation factor II) showed relevant derangements during postoperative days (POD) 0 to 3 followed by normalization until POD 7. Application of the LiMAx test was feasible in minipigs, again showing values comparable to humans and kinetics in line with obtained laboratory parameters. The exteriorized portal vein catheters enabled intra- and postoperative monitoring of portal venous pressures as well as easy access for blood withdrawal without relevant risk of postoperative complications.

Impact of Portal Hemodynamic Changes in Partial Liver Grafts on Short-Term Graft Regeneration in Living Donor Liver Transplantation

BACKGROUND

Regeneration of partial liver grafts is critical for successful living donor liver transplantation (LDLT), especially in adult recipients. The purpose of this study was to investigate the intraoperative hemodynamic changes in partial liver grafts and characterize their potential impact on post-transplant liver regeneration in LDLT.

METHODS

We examined the portal venous flow (PVF) and hepatic arterial flow (HAF) to partial liver grafts by means of ultrasonic transit time flowmeter of donors immediately before graft retrieval and of the corresponding recipients after vascular reconstruction in 48 LDLT cases. We evaluated post-transplant liver regeneration according to the changes in graft liver volume between the time of transplantation and the 7th post-transplant day.

RESULTS

There was a significant increase in PVF to the partial liver grafts in recipients (rPVF) compared with that in donors. In contrast, graft HAF in recipients significantly decreased compared with that in donors. The rPVF inversely correlated with graft weight (GW)-recipient body weight ratio (GRWR), whereas HAF volume showed no significant correlation. The rPVF/GW positively correlated with the rate of liver regeneration (GRR), which inversely correlated with GRWR. The rPVF/GW was significantly higher, and GRR tended to be larger in the small graft group than in the non-small graft group.

CONCLUSIONS

Intraoperative portal hemodynamic changes in partial liver grafts strongly affect their post-transplant regeneration. In particular, in small liver grafts, an immediate and remarkable increase in graft PVF may contribute to rapid liver regeneration after LDLT if the increased PVF remains within a safe range.

The optimal immunosuppressive protocol for the portal vein infusion of PGE1 and methylprednisolone in pediatric liver transplantation for fulminant hepatic failure of unknown etiology

The outcome of LTx in pediatric patients with FHF of unknown etiology remains inferior to that of LTx in pediatric patients with cholestatic diseases. A higher incidence of steroid-resistant severe rejection has been increasingly recognized among the responsible factors. We assessed the efficacy of the administration of steroids and PGE1 via PVI in the management of LTx for FHF in pediatric patients. In our early cohort (1995-2007), seven patients who underwent LTx for FHF of unknown etiology were treated with conventional immunosuppressive therapy (calcineurin inhibitor and a steroid). Seven of eight grafts (one patient underwent re-LTx) sustained CV and/or CPV associated with ACR, and four patients died of a graft failure or infectious complications that were associated with the treatment for rejection. Of note, the pathological incidence of CV/CPV was significantly higher in recipients with FHF of unknown etiology than in recipients with biliary cholestatic disease during the same study period (87.5% vs. 13.7%, p < 0.00001). From 2008, three patients underwent LTx for cryptogenic FHF with PVI and conventional IS. PVI was well tolerated, and no relevant severe complications were observed. More strikingly, the patients who received PVI overcame biopsy-proven immunological events and are all currently doing well with excellent graft function after more than five yr. We conclude that PVI is technically safe and effective for preventing severe rejection in pediatric patients who undergo LTx for FHF of unknown etiology and that it does not increase the risk of fatal infectious complications.

Small for size liver remnant following resection: prevention and management

In the latest decades an important change was registered in liver surgery, however the management of liver cirrhosis or small size hepatic remnant still remains a challenge. Currently post-hepatectomy liver failure (PLF) is the major cause of death after liver resection often associated with sepsis and ischemia-reperfusion injury (IRI). ''Small-for-size'' syndrome (SFSS) and PFL have similar mechanism presenting reduction of liver mass and portal hyper flow beyond a certain threshold. Few methods are described to prevent both syndromes, in the preoperative, perioperative and postoperative stages. Additionally to portal vein embolization (PVE), radiological examinations (mainly CT and/or MRI), and more recently 3D computed tomography are fundamental to quantify the liver volume (LV) at a preoperative stage. During surgery, in order to limit parenchymal damage and optimize regenerative capacity, some hepatoprotective measures may be employed, among them: intermittent portal clamping and hypothermic liver preservation. Regarding the treatment, since PLF is a quite complex disease, it is required a multi-disciplinary approach, where it management must be undertaken in conjunction with critical care, hepatology, microbiology and radiology services. The size of the liver cannot be considered the main variable in the development of liver dysfunction after extended hepatectomies. Additional characteristics should be taken into account, such as: the future liver remnant; the portal blood flow and pressure and the exploration of the potential effects of regeneration preconditioning are all promising strategies that could help to expand the indications and increase the safety of liver surgery.

Early Graft Dysfunction in Living Donor Liver Transplantation and the Small for Size Syndrome

LDLT has arisen as a viable means to reduce waitlist mortality. However, its widespread embrace by the liver transplant community has been met with frustration centered on donor morbidity and small-for-size-syndrome. Focusing on the later entity, we describe the initial recognition of this early graft dysfunction, the theorized pathophysiology and solutions to remedy its emergence.

"Small-for-flow" syndrome: shifting the "size" paradigm

The "small-for-size" syndrome and "post-hepatectomy liver failure" refers to the development of liver failure (hyperbilirubinemia, coagulopathy, encephalopathy and refractory ascites) resulting from the reduction of liver mass beyond a certain threshold. This complication is associated with a high mortality and is a major concern in liver transplantation involving reduced liver grafts from deceased and living donors as well as in hepatic surgeries involving extended resections of liver mass. The limiting threshold for liver resection or transplantation is currently predicted based on the mass of the remnant liver (or donor graft) in relation to the body weight of the patient, with a ratio above 0.8 being considered safe. This approach, however, has proved inaccurate, because some patients develop the "small-for-size" syndrome despite complying with the "safe" threshold while other patients who surpass the threshold do not develop it. We hypothesize that the development of the "small-for-size" syndrome is not exclusively determined by the ratio of the mass of the liver remnant (or graft) to the body weight, but it is instead strictly determined by the hemodynamic parameters of the hepatic circulation. This hypothesis is based in recent clinical and experimental reports showing that relative portal hyperperfusion is a critical factor in the development of the "small-for-size" syndrome and that maneuvers that manipulate the hepatic vascular inflow are able to prevent the development of the syndrome despite liver-to-body weight ratios well below the "limiting" threshold. Measurements of hepatic blood flow and pressure, however, are not routinely performed in hepatic surgeries. Focusing on the "flow" rather than in the "size" may improve our understanding of the pathophysiology of the "small-for-size" syndrome and "post-hepatectomy liver failure" and it would have important implications for the clinical management of patients at risk. First, hepatic hemodynamic parameters would have to be measured in hepatic surgeries. Second, these parameters (in addition to liver mass) would be the principal basis for deciding the "safe" threshold of viable liver parenchyma. Third, the hepatic hemodynamic parameters are amenable to manipulation and, consequently, the "safe" threshold may also be manipulated. Shifting the paradigm from "small-for-size" to "small-for-flow" syndrome would thus represent a major step for optimizing the use of donor livers, for expanding the indications of hepatic surgery, and for increasing the safety of these procedures.

Effectiveness of intraportal prostaglandin E1 administration after liver transplantation

PURPOSE

Prostaglandin E1 (PGE1) has been used to improve hepatic blood flow and to reduce ischemia reperfusion injuries of allografts in liver transplantation. However, PGE1 undergoes extensive metabolic clearance in the pulmonary and splanchnic circulation during intravenous administration. We analyzed the effect of intraportally administered PGE1.

METHODS

Sixty living-donor liver transplant recipients received continuous infusions of PGE1 for 10 days immediately after the reperfusion of the allografts. Of them, 40 recipients received PGE1 intravenously (IV group) via the internal jugular vein, and 20 recipients received PGE1 intraportally (IP group) through a catheter in the inferior mesenteric vein. Data were collected for 3 weeks postoperatively.

RESULTS

The IP group exhibited lower initial aspartate aminotransferase and alanine aminotransferase levels compared with the IV group. However, no apparent differences were recognized in the serum albumin, total bilirubin, alkaline phosphatase, r-glutamyl transpeptidase, or prothrombin time levels between the 2 groups. Chylorous ascites were observed more frequently in the IP group. There was no difference in portal venous flow measured by Doppler sonogram between the 2 groups during the first postoperative week.

CONCLUSION

This study demonstrated that intraportal administration of PGE1 had a better cytoprotective effect against hepatocellular damage than intravenous administration, although it did not have additional benefits for perihepatic hemodynamics.

Strategies for improving the outcomes of small-for-size grafts in adult-to-adult living-donor liver transplantation

Living-donor liver transplantation (LDLT) has been refined and accepted as a valuable treatment for patients with end-stage liver disease in order to overcome the shortage of organs and mortality on the waiting list. However, graft size problems, especially small-for-size (SFS) grafts, remain the greatest limiting factor for the expansion of LDLT, especially in adult-to-adult transplantation. Various attempts have been made to overcome the problems regarding SFS grafts, such as increasing the graft liver volume and/or controlling excessive portal inflow to a small graft, with considerable positive outcomes. Recent innovations in basic studies have also contributed to the treatment of SFS syndrome. Herein, we review the literature and assess our current knowledge of the pathogenesis and treatment strategies for the use of SFS grafts in adult-to-adult LDLT.

The effect of intraportal prostaglandin E1 on adhesion molecule expression, inflammatory modulator function, and histology in canine hepatic ischemia/reperfusion injury

BACKGROUND

Prostaglandin E1 (PGE1) is known to protect the liver from I/R, however, the mechanism of cytoprotection is not well understood. This study investigates the effect of intraportal infusion of PGE1 in a warm liver ischemia/reperfusion (I/R) model on cytokines, adhesion molecules and liver structure.

MATERIALS AND METHODS

Twenty dogs underwent laparotomy under general anesthesia. PGE1 (0.02 microg\kg\min) was perfused through the portal vein in the PGE1 group (n = 10), or a similar volume of Ringer's solution in the control group (n = 10) for 15 min. Liver ischemia was induced by hepatic artery and portal vein occlusion and PGE1 was infused via the portal vein for 60 min. The occlusion was released and PGE1 infusion recommenced for 30 min. Blood and liver biopsies were sampled at baseline, 60 min ischemia, and 30 min reperfusion and assessed for transaminases, cytokines, adhesion molecules, and electron microscopy.

RESULTS

PGE1 infusion significantly reduced transaminases TNF-alpha, sICAM-1, sP-selectin, and sE-selectin on ischemia and reperfusion. PGE1 reduced hepatocytic degeneration, portal and central ICAM-1 expression, central and sinusoidal VCAM-1 expression, portal and central P-selectin expression, and portal and sinusoidal E-selectin expression on reperfusion.

CONCLUSION

Intraportal PGE1 infusion reduced I/R injury and was associated with down-regulation of ICAM-1, VCAM-1, P-selectin, and E-selectin on reperfusion.

The Use of Prostaglandins in the Immediate Postsurgical Liver Transplant Period

INTRODUCTION

Experimental evidence has suggested that prostaglandins have positive effects on hepatic perfusion after transplantation. However, randomized clinical trials have failed to show their usefulness to decrease the incidence of primary nonfunction. In order to demonstrate its therapeutic role, we performed a clinical study in which PGE1 was administered only after the appearance of posttransplant liver dysfunction.

MATERIALS AND METHODS

Forty patients with macroscopic signs of hypoperfusion or lacking bile production at the end of the operation (n = 24) or with an increase in transaminases and fall in biliary production in the first 24 hours postsurgery (n = 16) were administered alprostadil (PGE1; 0.01 mug/kg/min to the maximum plateau of 0.06 mug/kg/min). We measured the mean values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), activated thromboplastin time-ratio (aPTT-r), international normalized ratio (INR), bilirubin, creatinine and plasma nitrogen, PaO(2)/FiO(2) at the start of the treatment and every 6 hours for 48 hours, and daily diuresis.

RESULTS

There appeared to be a significant decrease in AST, INR, aPTT-r, and creatinine clearance (P < .05), while there was a significant rise in the blood urea nitrogen (P < .001). ALT and bilirubin did not show significant variations. The PaO(2)/FiO(2) ratio showed a significant decrease (P < .001) in pulmonary vasodilatation.

CONCLUSIONS

Prostaglandins used in the manner in our study showed a significant efficiency to improve liver dysfunction after transplantation.

Left trisegmentectomy and combined resection of the inferior vena cava, without reconstruction, for giant cystadenocarcinoma of the liver

A 54-year-old woman with giant liver cystadenocarcinoma underwent left trisegmentectomy with combined resection of the inferior vena cava (IVC) and the right hepatic vein. As a result, only the right inferior hepatic vein was preserved as a drainage vein. Because the perivertebral plexus and the azygos vein were both well developed, neither veno-venous bypass nor IVC reconstruction was performed. The developed collateral veins acted as the venous drainage pathway to maintain a stable systemic circulation. On the seventh postoperative day, portal vein flow dramatically decreased and the patient tended to liver failure. Prostaglandin E(1) (PGE(1)) was administrated via the superior mesenteric artery. The portal flow then gradually increased and liver failure was avoided. Six months after the operation, she was re-admitted due to obstructive jaundice and presented with complete stenosis of the common bile duct (CBD). The jaundice persisted and liver dysfunction progressed. The patient died seven months after the operation. The confluence of the right inferior vein and the IVC could have been deformed, causing outflow blockade. The intrinsic shunt was not good enough to act as the drainage pathway, and IVC reconstruction may have been needed.

Effect of intraportal infusion to improve small for size graft injury in living donor adult liver transplantation

The most important problem in the living donor adult liver transplantation (LDALT) is a small for size graft. Although a right lobe graft is used in many cases in order to avoid small for size graft, for a donor, the risk has few in left lobe graft. We evaluate the effect of an intraportal infusion treatment to the small for size graft. One hundred and twelve patients who underwent LDALT were studied. The graft weight recipient standard liver volume ratio (GV/SLV) of these patients were 50% or less. We divided the patients into following two groups; infusion group (n = 53) and control group (n = 59). For the infusion group, 16 G double lumen catheter was inserted into portal vein and nafamostat mesilate (protease inhibitor which stabilize coagulofibrinolytic state; 200 mg/day), prostaglandin E(1) (vasodilator and hepatoprotective effect; 500 microg/day) and thromboxane A(2) synthetase inhibitor (vasodilator and anticoagulant effect; 160 mg/day) were administrated continuously for 7 days. Small-for-size graft syndrome was defined as bilirubin >10 mg/dl and ascites >1000 cc on postoperative day (POD) 14. Comparison examination of a background factors and postoperative bilirubin and amount of ascites was carried out. The mean GV/SLV did not have the difference at 39.1% of infusion group, and 38.3% of control group (P = 0.58). By the control group, 15 patients (25.4%) were small-for-size graft syndrome, however, there was only two (3.8%) small-for-size graft syndrome in infusion group (P = 0.04). The bilirubin levels of infusion and control group on 7 and 14 POD were 9.9 and 7.8 vs. 9.5 and 10.5 mg/dl, respectively. The amount of ascites of infusion group on 7 and 14 POD were 870 and 430 cc, respectively. On the contrary, in control group, the amount of ascites on 7 and 14 POD were 1290 and 1070 cc, respectively. Bilirubin levels and the amount of ascites on 7 and 14 POD were lower in the patients with infusion group then those with control group. There were no differences between infusion group and control group in age, sex and Child's classification. The intraportal infusion had an effect in prevention of hyperbilirubinemia and loss in quality of excessive ascites in the patients with small for size graft. This was suggested to be what is depended on the improvement of the microcirculation insufficiency considered one of the causes of small-for-size graft syndrome.

Initial hepatic microcirculation correlates with early graft function in human orthotopic liver transplantation

Microcirculatory disturbances are an initial causative determinant in hepatic ischemia/reperfusion injury. The aim of this study was to assess sinusoidal perfusion during human liver transplantation using orthogonal polarization spectral imaging and to evaluate the significance of intraoperative microcirculation for early postoperative graft function. Hepatic microcirculation was measured in 27 recipients undergoing full-size liver transplantation and compared to a group of 32 healthy living-related liver donors. The microvascular parameters were correlated with postoperative aspartate aminotransferase and bilirubin levels. Hepatic perfusion following liver transplantation was found to be significantly decreased when compared with the control group. Volumetric blood flow within the individual sinusoids increased due to sinusoidal dilatation and enhanced flow velocity. Regression analysis of postoperative aspartate aminotransferase and bilirubin with microvascular parameters revealed significant correlations. The extent of volumetric blood flow increased within the first 30 minutes after reperfusion and showed a significant correlation with postoperative aspartate aminotransferase release and bilirubin elimination. In conclusion, postischemic hepatic microvascular perfusion was analyzed in vivo, demonstrating significant microvascular impairment during liver transplantation. Sinusoidal hyperperfusion appears to confer protection against postischemic liver injury, as given by the correlation with aspartate aminotransferase and bilirubin levels. Thus, these findings may have therapeutic importance with respect to mechanisms mediating postischemic reactive hyperemia.

Prevention of primary nonfunction after canine liver allotransplantation: the effect of gadolinium chloride

PURPOSE

Effective suppression of Kupffer cell function is believed to contribute to the prevention of preservation/reperfusion injury. In this study, effect of gadolinium, a synthetic Kupffer cell suppressant, on the reperfusion injury was examined using a canine partial liver transplantation model.

METHODS

About a 70% partial liver segment was harvested and reimplanted in a mongrel recipient dog weighing 20 to 25 kg. Gadolinium chloride (10 mg/kg) was infused via the cephalic vein 24 hours before harvest of the partial liver (gadolinium group, n = 5). Serum aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and morphologic grading of graft were compared with those of a control group (n = 5). Statistical analysis was done with an independent t-test.

RESULTS

Average total ischemic time was 4 hours and 27 minutes. At 1 hour after reperfusion, there were no significant differences in AST, ALP, or LDH levels, or pathologic scores. At 48 hours after reperfusion, AST (P = .03) and LDH (P = .05) levels were significantly lower in the gadolinium group.

CONCLUSION

Kupffer cell blockade using gadolinium chloride may be effective to reduce ischemia reperfusion injury, but the effect is not evident at an early stage of reperfusion.

Living-donor liver transplantation: present status and future perspective

About 15 years have passed since the first liver transplant from a living donor (living donor liver transplantation: LDLT), and the status of the procedure has since been established as a standard cure for end-stage liver disease in Japan where liver transplantation (LTx) from deceased donors has not yet been accepted. However, the following problems are surfacing with the increase in the number of LDLTs between adults: graft size mismatching, an ABO blood-type incompatible transplantation, the expansion of LDLT indication to hepatocellular carcinoma (HCC), the relapse of hepatitis C after LDLT, marginal donors, and the freedom from immunosuppressive treatment. In this article we outline the present conditions of these problems and the future view of the LDLT.

Living donor liver transplantation with special reference to ABO-incompatible grafts and small-for-size grafts

Living donor liver transplantation (LDLT) has developed on the basis of increased safety of conventional liver surgery and the need for expanding donor sources, especially in children. Indications for LDLT were soon extended to adult patients in Japan, where cadaveric donation was limited. The right liver is now routinely transplanted to adults to avoid small-for-size graft syndrome, even though the right liver graft has the disadvantages of less remaining donor liver and the question of donor safety. Assessing the suitable size or quality of the graft, as well as of the remnant donor liver, is one of the most important problems in adult LDLT. Although several tactics have been proposed to manage the small-for-size syndrome, their efficacy remains a question. We suggest that small-for-size syndrome is preventable by engaging in careful donor selection or using effective agents for hepatic microcirculatory disturbance control. Sometimes for LDLT only ABO-incompatible grafts are available from relatives, but they must be transplanted despite the expected poor outcome in adults and older children. To overcome the problems in this situation, we developed a novel protocol including intraportal infusion therapy with methylprednisolone, prostaglandin E1, and gabexate mesylate. Two adult patients undergoing ABO-incompatible LDLT have now survived 53 and 35 months after transplantation with good liver function. However, the other two patients suffered thrombotic microangiopathy postoperatively and died owing to cerebral hemorrhage or multiple organ failure, respectively. Further investigation is needed to improve the outcome of liver transplantation across the ABO blood group barrier.

Effect of short-term administration of prostaglandin E1 on viability after ischemia/reperfusion injury with extended hepatectomy in cirrhotic rat liver

The cytoprotective effect of prostaglandin E(1) (PGE(1)) has been demonstrated experimentally and clinically against hepatic ischemia and reperfusion injury and against the effects of partial hepatectomy in both individual and combined models of noncirrhotic livers. Cirrhotic livers are more vulnerable to ischemia/reperfusion injury during hepatectomy than are noncirrhotic livers, and postoperative malfunctioning complicates life with multiple organ failure. Cirrhotic livers with tumors have mostly been treated conservatively because extended hepatectomy with induced ischemia during surgery is impossible. The purpose of our study was to document postoperative surgical adaptation in inoperable cases with improved survival after extended hepatectomy in a rat model of cirrhosis treated by PGE(1). Cirrhosis was induced by intraperitoneal injections of 1% dimethylnitrosamine. The liver was subjected to 15 minutes of total ischemia by occluding the hepatoduodenal ligament. Hepatectomy was performed during ischemia. Pretreatment with PGE(1) (0.4 microg/kg/min) (or without it in the controls) was given for 15 minutes by intravenous infusion prior to inducing ischemia and during reperfusion. Portal venous flow (PVF) and liver tissue blood flow (LTBF) were measured during reperfusion. At the end of 60 minutes of reperfusion, venous blood was collected for liver function tests. The animals were followed up regarding survival for 48 hours. The PVF and LTBF were significantly improved in the PGE(1) group. The blood chemical analysis indicated that PGE(1) significantly suppressed posthepatectomy liver dysfunction. Most importantly, PGE(1) treatment markedly improved the survival rate, from 42% in the controls to 75% in the test animals at 24 hours after hepatectomy and from 17% in the controls to 58% in the test animals at 48 hours. We concluded that short-term administration of PGE(1) makes extensive hepatectomy possible under ischemic conditions in cirrhotic livers.

A chromatographic method for the quantification of prostaglandin E(1) and prostaglandin A(1) encapsulated in an intravenous lipid formulation

Peripheral vascular disease is a common ailment of the aged and diabetic communities. As the numbers of these individuals increase, the need for therapeutic interventions will continue to grow. One of the possible therapies is the use of prostaglandins (PGE(1), prostacyclin and Iloprost) to decrease the vascular tone and increase vascular blood flow. Due to the hydrophobicity of the prostaglandins and prostaglandin analogues, various vehicles have been utilized to maintain the active pharmaceutical ingredient in a stable solution, e.g. alpha-cyclodextrin (Alprostadil, Edex) or emulsified lipid vehicles. In our laboratory, we designed a method for separating and assaying lipid-encapsulated PGE(1). Utilizing organic extraction, automated solid-phase extraction and precipitation techniques, we validated the measurement of the PGE(1) and PGA(1) content of the clinical drug formulation in the microgram per milliliter concentration range with an high performance liquid chromatography (HPLC) assay.

Appraisal of intra-arterial infusion of prostaglandin E1 in patients undergoing major hepatic resection report of four cases

In order to reduce risk for postoperative acute liver failure, prostaglandin E1 (PGE1) was administered either from the hepatic artery (HA) or the superior mesenteric artery (SMA) in four high-risk cases undergoing major hepatic resection. Two cases were subjected to HA PGE1 infusion for 3 or 4 days after surgery at a rate of 0.01 microg/kg/min. Both patients had hepatocellular carcinoma (HCC) associated with chronic hepatitis, and ICG R15 was 17.6% and 14.5%, respectively. Right hemihepatectomy and extended right hemihepatectomy were performed. Serum total bilirubin (T. Bil.) peak value was 2.2 mg/100 ml in Case 1 and 2.1 mg/100 ml in Case 2. In Case 1, decreased bile flow was observed immediately after cessation of PGE1. The other two cases were subjected to SMA PGE1 infusion for 5 or 6 days after surgery at the same rate. In Case 3, right hemihepatectomy was performed for HCC on a cirrhotic liver four weeks after right portal vein embolization, in which preoperative ICG R15 was 19.0%. Peak T. Bil level was 3.7 mg/100 ml with uneventful postoperative course. In Case 4 with a huge cholangioma, right trisegmentectomy was performed. Peak serum T. Bil level was 1.7 mg/100 ml in this uneventful postoperative course. In Case 3 and Case 4, portal blood flow, measured by Doppler ultrasonography, was markedly increased by PGE1 infusion. From these results, intra-arterial PGE1 infusion might be useful in prevention of postoperative liver failure after major hepatic resection.

The influence of pulsatile preservation on renal transplantation in the 1990s

BACKGROUND

Unlike simple cold storage (CS), pulsatile machine preservation (MP) of kidneys for transplantation permits pharmacologic manipulation of the perfusate and aids in the pretransplant assessment of the kidney graft. These characteristics of MP may have importance in the era of increasing use of extended criteria donor kidneys. The overall aim of this article is to critically assess practices at our preservation unit with respect to graft function. Specific aims are to (1) compare the influence of MP versus CS on graft function, (2) determine which pretransplant variables have significance in pretransplant assessment, and (3) determine whether pharmacologic manipulation during MP is advantageous.

METHODS

There were 650 consecutive kidneys preserved in our laboratory between January 1, 1993 and March 1, 999, by either MP or CS. All MP kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer-MPS or Belzer II solution. Perfusion parameters and electrolytes were measured serially during pulsatile perfusion. All CS kidneys were stored in University of Wisconsin solution. All kidneys obtained from donors exhibiting extended criteria features underwent pretransplant frozen section biopsies. Transmission electron microscopy (EM) was performed on a subset of kidneys undergoing pharmacologic manipulation. Four agents were assessed prospectively for their ability to influence MP characteristics when added to perfusate: PGE1, trifluoperazine, verapamil, and papaverine.

RESULTS

MP was associated with improved immediate, 1-, and 2-year graft function and reduced length of initial hospital stay when compared with CS grafts. Changes in the machine perfusion variables flow and resistance, and the [Ca++] in perfusate, were significantly associated with delayed graft function (DGF) after the transplant. Biopsy information was not predictive of DGF. The addition of PGE1 to perfusate improved MP characteristics, reduced the release of [Ca++] into perfusate, and ameliorated mitochondrial ischemic injury in transmission EM images. Early graft function was improved in the presence of PGE1+MP, compared with function in the presence of other pharmacologic agents or CS alone.

CONCLUSIONS

MP is associated with improved early and long term renal function. Moreover, PGE1 augments MP in improving graft function. The combination of MP+PGE1 may be important in optimizing the ability to use extended donor criteria kidneys and, thereby, improve the overall efficiency of cadaveric renal transplantation.

Intraportal perfusion of prostaglandin E1 attenuates hepatic postischaemic microcirculatory impairments in rats

BACKGROUND

The efficacy of intraportal perfusion with prostaglandin E1(PGE1) in decreasing postischaemic hepatic microcirculatory damage was studied in rats.

METHODS

An extrahepatic portosystemic shunt was created by attaching the spleen to a subcutaneous site on the left lateral wall of the abdomen in male Wistar rats weighing between 200 and 350 g. Four weeks later, when the shunt was mature, the portal vein and hepatic artery were occluded for 60 min. The animals were divided into the following three groups according to the type of intraportal perfusion during the ischaemic phase: group 1 consisted of untreated animals; group 2, animals perfused with lactated Ringer's solution; and group 3, animals perfused with PGE1 (0.1 microg/kg per min). The hepatic microcirculation was observed under an inverted intravital microscope after the injection of fluorescent dyes to label leucocytes and damaged cells 30 and 60 min after reperfusion. The liver was removed 60 min after reperfusion and stained immunohistochemically using 1A29, an anti-rat intercellular adhesion molecule-1 (ICAM-1) antibody.

RESULTS

The leucocyte velocity during reperfusion was lowest in group 1 and highest in group 3. Of the three groups, group 3 showed the least leucocyte adhesion to the sinusoidal walls and terminal venules, the lowest damaged cell count and the lowest ICAM-1 expression on the sinusoidal walls.

CONCLUSION

The results of this study suggest that hepatic perfusion with PGE1 markedly alleviates microcirculatory damage associated with ischaemia and reperfusion through the inhibition of leucocyte-endothelium interactions.

Experimental study of the effect of intraportal prostaglandin E1 on hepatic blood flow during reperfusion after ischaemia and hepatectomy

BACKGROUND

Prostaglandin E1 (PGE1) has protective effects experimentally and clinically in individual models of hepatic ischaemia-reperfusion injury and of partial hepatectomy. The present study investigated the effects of intraportal administration of PGE1 on hepatic blood flow, systemic arterial pressure and long-term animal survival after 60 min of total liver ischaemia followed by 70 per cent partial hepatectomy in rats.

METHODS

Total liver ischaemia was induced by occluding the hepatoduodenal ligament for 60 min. PGE1 0.5 microg per kg per min was infused intraportally for 15 min before inducing ischaemia and for 120 min after ischaemia in the treatment group. Normal saline was infused in the control group. During ischaemia 70 per cent partial hepatectomy was performed. Portal venous flow (PVF), peripheral tissue blood flow (PTBF) and hepatic artery flow were measured before and after ischaemia. Serum biochemical analysis was carried out at 1, 3 and 24 h, and 7 and 14 days; and liver histology at 1 and 24 h, and 7 days after reperfusion. Survival was followed for 1 year.

RESULTS

Intraportal infusion of PGE1 significantly improved PVF and PTBF without affecting the systemic arterial pressure. Long-term survival was significantly higher in the PGE1 group. Serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels decreased significantly, and 2-h bile flow was significantly improved, in the PGE1 group. Histological examination revealed significant portal venous congestion, sinusoidal congestion, fatty degeneration and tissue necrosis 24 h and 7 days after reperfusion in the control group.

CONCLUSION

PGE1 has a protective effect against liver damage when the liver is injured by warm ischaemia and reperfusion followed by partial resection.

Protective effect of prostaglandin E1 against ischemia/reperfusion-induced liver injury: results of a prospective, randomized study in cirrhotic patients undergoing subsegmentectomy

BACKGROUND/AIMS

The cytoprotective effects of prostaglandin E1 on livers suffering from ischemia/reperfusion injury in the clinical setting are unproved. These effects were examined, focusing on inflammatory cytokine and nitric oxide metabolism.

METHODS

Twenty-four cirrhotic patients with hepatocellular carcinoma undergoing subsegmentectomy under ischemia induced only by Pringle's maneuver were divided into two groups (patients given prostaglandin E1 by injection and untreated controls) and postoperative results were compared. Peripheral blood was taken perioperatively and the plasma aminotransferase, cytokines and nitrate/nitrite levels of the two groups were compared. Two liver specimens were taken from each patient, one before ischemia and the other after hepatectomy, and the levels of inducible nitric oxide synthase and cytokine mRNAs and proteins were analyzed.

RESULTS

Although no apparent differences were recognized in postoperative complications or duration of postoperative hospital stay between the groups, the perioperative plasma aminotransferase level was significantly lower in the prostaglandin E1 group. Significant differences were also seen in interleukin-6 and nitrate plasma levels during the observation period and the interleukin-6 protein levels in the liver supernatants after hepatectomy in the two groups. In contrast, no significant differences were apparent between the interleukin-1 beta and tumor necrosis factor-alpha plasma levels of the two groups. The corrected fluorescence activities of interleukin-6 and inducible nitric oxide synthase mRNAs in the liver after hepatectomy correlated significantly. No interleukin-1 beta or tumor necrosis factor-alpha mRNAs or proteins were detected.

CONCLUSIONS

Prostaglandin E1 exerted hepatoprotective effects on livers suffering from ischemia/reperfusion injury, and interleukin-6 might play an important role in these effects.

Hepatic stellate cell contraction is inhibited by lipo-prostaglandin E1 in vitro

Prostaglandin E₁ (PGE₁ ) has been reported to have, experimentally and clinically, a protective effect against liver damage. This effect may result from the relaxation of hepatic stellate cells, whose contraction induces vasoconstriction of hepatic sinusoids. However, prostaglandins are unstable and a new drug delivery system is necessary to administer a sufficient amount of prostaglandin to achieve a protective effect in the liver. The aim of the study is to investigate the effects of lipo-prostaglandin E₁ (lipo-PGE₁ ) which has a novel drug delivery system on the stellate cell contraction induced by endothelin-1 in vitro. Lipo-PGE₁ inhibited endothelin-1-induced stellate cell contraction in concentrations of 10, 30 and 50 ng/mL. Therefore, lipo-PGE₁ may show a cytoprotective effect in the liver through the relaxation of stellate cells and an increase in the hepatic sinusoidal blood flow.