Liver transplantation as ultimate tool to treat portal hypertension

The impact of macro- and micro-steatosis on the outcomes of patients who undergo liver transplant: Analysis of the UNOS-STAR database

BACKGROUND AND AIMS

The presence of steatosis in a donor liver and its relation to post-transplantation outcomes are not well defined. This study evaluates the effect of the presence and severity of micro- and macro-steatosis of a donor graft on post-transplantation outcomes.

METHODS

The UNOS-STAR registry (2005-2019) was used to select patients who received a liver transplant graft with hepatic steatosis. The study cohort was stratified by the presence of macro- or micro-vesicular steatosis, and further stratified by histologic grade of steatosis. The primary endpoints of all-cause mortality and graft failure were compared using sequential Cox regression analysis. Analysis of specific causes of mortality was further performed.

RESULTS

There were 9184 with no macro-steatosis (control), 150 with grade 3 macro-steatosis, 822 with grade 2 macro-steatosis and 12 585 with grade 1 macro-steatosis. There were 10 320 without micro-steatosis (control), 478 with grade 3 micro-steatosis, 1539 with grade 2 micro-steatosis and 10 404 with grade 1 micro-steatosis. There was no significant difference in all-cause mortality or graft failure among recipients who received a donor organ with any evidence of macro- or micro-steatosis, compared to those receiving non-steatotic grafts. There was increased mortality due to cardiac arrest among recipients of a grade 2 macro-steatosis donor organ.

CONCLUSION

This study shows no significant difference in all-cause mortality or graft failure among recipients who received a donor liver with any degree of micro- or macro-steatosis. Further analysis identified increased mortality due to specific aetiologies among recipients receiving donor organs with varying grades of macro- and micro-steatosis.

Hemodynamic Evaluation of the Right Heart-Pulmonary Circulation Unit in Patients Candidate to Transjugular Intrahepatic Portosystemic Shunt

In Europe, liver cirrhosis represents the fourth-most common cause of death, being responsible for 170,000 deaths and 5500 liver transplantations per year. The main driver of its decompensation is portal hypertension, whose progression radically changes the prognosis of affected patients. Transjugular intrahepatic portosystemic shunt (TIPS) is one of the main therapeutic strategies for these patients as it reverts portal hypertension, thus improving survival. However, the coexistence of portal hypertension and pulmonary hypertension or heart failure is considered a contraindication to TIPS. Nevertheless, in the latest guidelines, the definition of heart failure has not been specified. It is unclear whether the contraindication concerns the presence of clinical signs and symptoms of heart failure or hemodynamic changes in the right heart-pulmonary circulation. Moreover, data about induced right heart volume overload after TIPS and the potential development of heart failure and pulmonary hypertension is currently scanty and controversial. In this article we revise this issue in finding predictors of cardiac performance after TIPS procedure. Performing a fluid challenge during right heart catheterization might be a promising expedient to test the adaptation of the right ventricle to a sudden increase in preload in the first few months after TIPS. This test may unmask a potential cardiac inability to sustain the hemodynamic load after TIPS, allowing for a clearer definition of heart failure and, consequently, a more robust indication to TIPS.

Effect of liver transplantation on intestinal permeability and correlation with infection episodes

Background

Liver cirrhosis has been known to be associated with increased intestinal permeability (IP); however, little is known about the modification of IP after liver transplantation (LT). The present study was aimed to assess IP after LT and evaluated its association with laboratory tests and clinical parameters, as well as with the development of infections.

Methods

LT recipients were consecutively enrolled and compared with an equal number of patients with liver cirrhosis and healthy subjects. IP was assessed by urinary excretion of chromium-51 ethylenediaminetetraacetic acid (⁵¹Cr-EDTA).

Results

The median ⁵¹Cr-EDTA excretion was found to be higher in 35 LT recipients as compared with that in the healthy controls [4.77% (2.79–6.03) vs. 2.07% (1.57–2.42), p<0.0001], and comparable to that in the cirrhotic patients [3.69% (2.34–6.57), p = 0.445]. ⁵¹Cr-EDTA excretion was not associated with clinical variables, the type of immunosuppressive therapy, donor-related factors, comorbidities and incidence of infections [infection/no infection: 4.97% (3.14–7.03) vs 4.62% (2.79–5.82), p = 0.938].

Conclusion

LT recipients show an increased IP, similar to that in patients with liver cirrhosis. However, it is not associated with a high risk of infections. Further investigations into the pathogenesis of this persistent impairment of the intestinal barrier are warranted.

Pulmonary arterial hypertension populations of special interest: portopulmonary hypertension and pulmonary arterial hypertension associated with congenital heart disease

Guidelines exist for management of pulmonary arterial hypertension (PAH), but information is limited for certain patient subgroups, including adults with portopulmonary hypertension (PoPH) or with PAH associated with congenital heart disease (PAH-CHD). This article discusses screening, clinical management, and prognosis in PoPH and PAH-CHD and, as such, considers the most recent clinical data and expert advice. A multidisciplinary consultation and follow-up by specialists are crucial for management of both PoPH and PAH-CHD, but each condition presents with unique challenges. Development of PoPH most commonly occurs among patients with liver cirrhosis. Initially, patients may be asymptomatic for PoPH and, if untreated, survival with PoPH is generally worse than with idiopathic PAH (IPAH), so early identification with screening is crucial. PoPH can be managed with PAH-specific pharmacological therapy, and resolution is possible in some patients with liver transplantation. With PAH-CHD, survival rates are typically higher than with IPAH but vary across the four subtypes: Eisenmenger syndrome, systemic-to-pulmonary shunts, small cardiac defects, and corrected defects. Screening is also crucial and, in patients who undergo correction of CHD, the presence of PAH should be assessed immediately after repair and throughout their long-term follow-up, with frequency of assessments determined by the patient’s characteristics at the time of correction. Early screening for PAH in patients with portal hypertension or CHD, and multidisciplinary management of PoPH or PAH-CHD are important for the best patient outcomes.

Evaluation of esophagogastric varices after adult-to-adult living donor liver transplantation using a left lobe graft

BACKGROUND

There is little information on whether living donor liver transplantation (LDLT) reduces the supply of blood to esophagogastric varices. The aim of the present study was to assess the effects of LDLT on esophagogastric varices using both endoscopy and transendoscopic microvascular Doppler sonography (EMDS).

PATIENTS AND METHODS

16 LDLT recipients were enrolled in the present study. Esophagogastric varices were assessed by endoscopy before and after LDLT. Direct measurement of variceal blood velocity was performed using EMDS in 12 of the 16 patients, and portal vein pressure before and after graft implantation was measured in 10 of them.

RESULTS

The median interval between LDLT and endoscopic examination was 129 days (range 20-624). Endoscopy demonstrated improvement of esophageal varices in 15 patients and of gastric varices in 4 of 5 patients assessed. The mean blood flow velocity in esophageal varices after LDLT was significantly lower than that before LDLT (8.8 ± 3.6 vs. 0.9 ± 1.2 cm/s, p < 0.001). The mean portal vein pressure did not decrease significantly after LDLT in comparison with that before LDLT (from 25.2 ± 5.2 to 23.1 ± 3.6 mm Hg, p = 0.22).

CONCLUSION

Although portal vein pressure does not decrease immediately after left lobe LDLT, esophagogastric varices are ameliorated after a few months, and variceal blood flow velocity is reduced in almost all patients.

[Portosystemic shunt surgery between TIPS and liver transplantation]

Portosystemic shunt surgery in addition to transjugular intrahepatic portosystemic shunt (TIPS) insertion must still be regarded as a current treatment option for portomesenteric decompression in patients with pharmacological and endoscopic treatment failure, where liver transplantation is not imminent. This applies to secondary prophylaxis of rebleeding from varices in patients with well preserved liver function, e.g. liver cirrhosis CHILD A or extrahepatic portal vein thrombosis. Even if emergency endoscopy represents the treatment of choice in the acute bleeding situation, latest data from San Diego on emergency portacaval shunt surgery are encouraging. Likewise, portacaval shunt procedures can be an attractive alternative to TIPS or liver transplantation for acute Budd-Chiari syndrome or veno-occlusive disease.This article is an update on the systematics and methodology of portacaval shunt surgery, emphasizing the significance of this treatment option based on latest studies.

An assessment of surgery for portal hypertensive patients performed at a single community hospital

PURPOSE

The outcomes of surgery for portal hypertensive patients at a single community hospital in the last two decades were retrospectively examined.

METHODS

From June 1989 to March 2008, 13 of 848 (1.5%) portal hypertensive patients admitted and treated at the community hospital underwent surgery. The types of surgery performed were a distal splenorenal shunt for 2 patients, gastric devascularization and splenectomy for 8, laparoscopic gastric devascularization and splenectomy for 1, distal gastrectomy for 1, and splenectomy alone for 1. This study reviewed the postoperative records of the endoscopic findings and additional treatments, and the perioperative records.

RESULTS

No patient had bleeding from esophagogastric varices during the 75-month mean follow-up period after surgery. Five patients had one or two series of endoscopic treatment for recurrent likely-to-bleed esophageal varices. One patient needed interventional radiology for recurrent gastric varices. No patients died due to upper gastrointestinal bleeding. The survival rates were 87.5% after 5 years and 46.9% after 10 years.

CONCLUSIONS

Surgery for portal hypertensive patients performed at a single community hospital is still safe and effective, and has been adequately incorporated into the late treatment strategy for portal hypertensive patients.

A novel canine model of esophageal varices with a balloon dilatation constrictor

BACKGROUND AND OBJECTIVE

The canine model of esophageal varices with an agar constrictor has been used for studies of the endoscopic treatment of esophageal variceal bleeding, but it has limitations in both stability and successful rate. This study was designed to enhance the model's efficiency and success rate by using a novel approach with a balloon dilatation constrictor.

METHODS

We used 22 adult mongrel dogs to establish the model by progressively compressing and constricting the portal vein through a rechargeable balloon dilatation constrictor in combination with side-to-side portocaval shunt and inferior vena cava (IVC) ligation to increase portal vein pressure (PVP). The rechargeable balloon dilatation constrictor was composed of a hyaline polypropylene (PP) ring, a silica gel tube with a balloon, and an injection pedestal (silica gel) in an implantable vascular access port. The effects were evaluated with pre- and post-shunt PVP measurement, weekly gastroscopy, and portocaval venography.

RESULTS

The mean PVP increased significantly from a preoperative (before side-to-side portocaval shunt and IVC ligation) 12.86 +/- 0.18 cmH(2)O to 26.75 +/- 0.39 cmH(2)O after the model had been established (P < 0.05). After the model was established, gastroscopy performed to assess esophageal varix size demonstrated four varicose veins of grade I, six of grade II, eight of grade III and four of grade IV. The portocaval angiography showed that the IVC and portal vein were completely blocked, that the anastomosis stoma was unobstructed and that the blood flow through esophageal varices via splenetic and gastric veins was blocked.

CONCLUSION

The novel canine model developed with a rechargeable balloon dilatation constrictor is feasible and reliable for modeling esophageal varices.

A modified canine model of portal hypertension with hypersplenism

OBJECTIVE

The aim of this study was to develop and describe an experimental canine model of portal hypertension with hypersplenism.

MATERIAL AND METHODS

Twenty-five dogs were used randomly divided into three groups: group I (control group, n = 5), group II (PVS, n = 10) and group III (PVS + SVS, n = 10). Portal vein stenosis (PVS) was performed in dogs of group II; in group III dogs the model was first prepared by PVS and additional splenic vein stenosis 3 weeks later (PVS + SVS). Portal vein pressure (PVP), length of spleen and fluctuation of hematocyte counts were measured and recorded at the appointed times. Surgery permitted visual verification of portosystemic collateral circulation. Histopathological variation of the spleen and condition of the bone marrow hyperplasia were examined to confirm the development of hypersplenism.

RESULT

Both group II and group III developed prehepatic portal hypertension; group III also presented satisfactory hypersplenism compared to the control group and group II, as documented at surgery and by hematologic and pathologic examination.

CONCLUSIONS

Based on this study, the modified model of portal hypertension (by PVS + SVS) appears appropriate when studying the relationship between hypersplenism and hemodynamics in portal hypertension. It is also likely to be useful in studying the influence of diseased spleen in the treatment of portal hypertension.

Pathophysiologic basis for the medical management of portal hypertension

BACKGROUND

Portal hypertension is a potentially life-threatening complication of cirrhosis, resulting from increased intrahepatic resistance and portal inflow.

OBJECTIVE

Given the complex nature of this disorder, a more complete understanding of the pathophysiology of portal hypertension is necessary to develop new therapies that target specific pathways that regulate portal pressure.

METHODS

This review is based on a literature search of published articles and abstracts on the pathophysiology of portal hypertension, its complications and its treatment.

RESULTS/CONCLUSION

A number of therapies have been developed or are under investigation for the treatment of portal hypertension and its complications. These agents may reduce mortality and improve quality of life for patients with advanced liver disease.

Beneficial effects of living-donor liver transplantation on esophageal varices

BACKGROUND

Liver transplantation (LT) is known to improve bleeding esophageal varices (EVs) and portal hypertension. However, many issues related to EVs after LT remain unresolved, such as whether LT reduces blood supply to EVs, improves the diameter of unruptured EVs, or improves or worsens EVs. The aim of this retrospective study was to determine the effects of living-donor liver transplantation (LDLT) in patients with hepatic failure on EVs and inflow vessels to EVs and the factors associated with deterioration of EVs after LDLT.

METHODS

The study subjects were 35 patients with cirrhosis who underwent LDLT. Endoscopy and multidetector helical computed tomography (MDCT) were performed before and after LDLT. The diameter of the inflow vessel of EVs was measured by MDCT before and after LDLT, together with the LDLT-related reduction rate of the diameter of the gastric vein (RRGV).

RESULTS

Endoscopic examination showed improvement of EVs in 30 of 35 (86%) patients. RRGV improved in 17/35 (49%) patients, did not change in 13/35 (37%), and deteriorated in 5/35 (14%). The cause of RRGV deterioration seemed to be either the complication of portal vein or graft failure. In patients examined endoscopically at >1 year after LDLT, improvement of EVs was associated with significant changes in the rate of reduction of the major inflow vessel diameter and Child-Pugh score, compared with those who showed no improvement.

CONCLUSIONS

LDLT results in improvement of EVs. EVs improved in 86% of the patients. Measurement of RRGV with MDCT is a good tool for prediction of EV improvement after LDLT.

High-definition flow Doppler ultrasonographic technique to assess hepatic vasculature compared with color or power Doppler ultrasonography: preliminary experience

OBJECTIVE

The purpose of this study was to introduce a new high-definition flow (HDF) Doppler technique and to compare its performance with those of color Doppler ultrasonography (CDU) and power Doppler ultrasonography (PDU) for assessment of hepatic vasculature in native and transplanted livers.

METHODS

High-definition flow was invented as a high-resolution bidirectional PDU technique. We obtained CDU, PDU, and HDF images of the hepatic artery (HA), portal vein (PV), and hepatic vein from 60 patients. They were divided into 2 groups: a liver transplantation group (group 1, n = 10) and a native liver group (group 2, n = 50). Two radiologists independently reviewed the cine images and graded them using a 4-point scale in terms of the clarity of the vessel margin and degree of depiction of the HA, flow filling, and flash artifacts. The degree of differentiation between the HA and PV was also evaluated. Flow directionality was recorded, and interobserver agreement was finally analyzed.

RESULTS

Moderate to almost perfect agreement was achieved between radiologists for all parameters of each ultrasonographic technique. High-definition flow was significantly superior to both CDU and PDU with respect to all analyzed items except the degree of flash artifacts (P < .05). With regard to flash artifacts, CDU was significantly better than either PDU or HDF. High-definition flow provided directional information, as did CDU.

CONCLUSIONS

The HDF technique provides better resolution for depicting hepatic vessels as well as their margins with less blooming compared with conventional Doppler ultrasonography in both native and transplanted liver. It also provides solid directional flow information. One point of concern, however, is the frequency of flash artifacts compared with that on CDU.

Current Management of Sinusoidal Portal Hypertension

Portal hypertension resulting from cirrhosis was one of the biggest challenges faced by general surgeons up until the past two decades. The management of portal hypertensive variceal hemorrhage has undergone dramatic changes during this period. Endoscopic variceal ligation and transjugular intrahepatic portosystemic shunts are currently used with great success. The degree of liver dysfunction remains the most important determinant of outcome in these patients. Patients with cirrhosis who have good liver function and recurrent variceal bleed remain candidates for shunt surgery. However, the need for surgical intervention has become a rarity. The success of liver transplantation has ensured that portal hypertension is cured permanently and one does not often see the critically ill and decompensated patient with cirrhosis on the surgical service. A review of the current treatment options in this very ill patient population is the primary focus of this article.

Hemodynamic evaluation before liver transplantation: insights into the portal hypertensive syndrome

The cardiac hemodynamics of patients awaiting liver transplantation is complex. Coronary atherosclerosis, a hyperdynamic circulatory state and cirrhotic cardiomyopathy are present to a variable degree in this population. In this contribution to the Symposium on Portal Hypertension, we expand on our published experience with coronary angiography and cardiac hemodynamics at the time of evaluation of candidacy for liver transplantation in a cohort of 161 patients. Although we confirmed the relation of systemic hemodynamics with the degree of liver failure, we noted a higher prevalence of high output heart failure, defined as an increased left ventricular end-diastolic pressure in the setting of an elevated cardiac output, most notably in patients classified as Child C. Most patients with high pulmonary artery pressure also exhibited evidence of elevated left ventricle filling pressures. A low systemic vascular resistance, a marker of arterial vasodilatation, was similar in the presence of atherosclerosis, a condition where impaired vasorelaxation occurs as a result of endothelial dysfunction. The high prevalence of coronary artery disease in this series supports the observations that atherosclerosis is a major issue in the current population with cirrhosis awaiting liver transplantation. A lower sensitivity of noninvasive screening tools for the detection of coronary atherosclerosis is likely the result of the interaction of the hyperdynamic circulation with the performance of these tests.

[Hepatorenal syndrome]

Hepatorenal syndrome (HRS) is defined as the development of renal insufficiency in chronic liver disease with portal hypertension when other causes of functional renal failure are excluded. Incidence in patients with refractory ascites is 8%, with an overall incidence of renal failure in end stage liver disease being 75%. HRS is predictive for the prognosis of end stage liver failure but its pathogenesis is complex and currently not fully understood.

Improved prognosis for patients hospitalized with esophageal varices in Sweden 1969-2002

Liver cirrhosis may be complicated by the development of esophageal varices. The treatment of esophageal varices has changed radically during the last 30 years. Our aim was to study whether the prognosis for patients with esophageal varices had improved in Sweden between 1969 and 2002. We linked register data from the Hospital Discharge Register and from the Causes of Death Register at The National Board of Health in Sweden between 1969 and 2002 to identify and follow-up all patients with esophageal varices according to International Classification of Diseases-8, -9, and -10. There were 12,281 patients hospitalized with esophageal varices, and for all patients there was an increase in the 5-year survival in the years between 1969 and 1979 as opposed to the years between 1990 and 2002. Better survival occurred for women compared with men, for younger patients compared with older, and for patients hospitalized in the latest decade compared with the earlier decades. We found a significant decrease in the mortality caused by esophageal varices during the years studied but no decrease attributable to other causes. In conclusion, mortality for patients hospitalized with esophageal varices in Sweden decreased between 1969 and 2002. The decrease is seen for both 1- and 5-year mortality, and this suggests that the use of new treatment strategies both for acute variceal hemorrhage and secondary prophylaxis has had an impact on prognosis.