Triplex Sonographic Evaluation of Portal Vein Indices Among Adults in Port Harcourt, Nigeria.

Background: Chronic liver disease is characterized by progressive hepatic fibrosis and changes in hepatic vascular hemodynamics. Sonography is a readily available tool in the assessment of the hepatic hemodynamic alterations that occur in chronic liver diseases. Aim: This study was aimed at sonographically determining the portal vein indices in apparently healthy adults by estimating the portal vein diameter, cross-sectional area, and portal vein velocity. Methods: This was a prospective, cross-sectional study carried out among 62 apparently healthy individuals. The participants underwent gray scale and Doppler ultrasonographic examinations of the portal vein. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) IBM Corp. version 23.0 (Armonk, NY: USA). The comparison of means of two groups was with the unpaired t-test, and level of significance was set at 5% (P < 0.05). Results: Forty-six (74.2%) of the 62 participants recruited were male and 16 (25.8%) were female. Participants were aged 18-65 years with a mean age of 39.90 ± 10.34 years. The means of portal vein diameter, cross-sectional area, and portal vein velocity are 1.15 ± 0.12 cm, 0.88 ± 0.18 cm2, and 18.37 ± 2.04 cm/s, respectively. There was no statistically significant difference of all portal vein ultrasound parameters between males and females, except portal vein flow velocity which was higher in males, t-test = 2.273 and P = 0.027 (>0.05). There was no significant correlation between age and ultrasound parameters P > 0.05. Conclusion: The normal values of portal vein diameter, cross-sectional area, and portal vein velocity were established.

Sufficient hepatic artery flow compensates for poor portal vein flow after liver transplantation in patients with portal vein thrombosis.

OBJECTIVE: Portal vein thrombosis (PVT) does not preclude liver transplantation (LT), but poor portal vein (PV) flow after LT remains a predictor of poor outcomes. Given the physiologic tendency of the hepatic artery (HA) to compensate for low PV flow via vasodilation, we investigated whether adequate HA flow would have a favorable prognostic impact among patients with low PV flow following LT. METHODS: This study included 163 patients with PVT who underwent LT between 2004 and 2015. PV and HA flow were categorized into quartiles, and their association with 1-year graft survival (GS) and biliary complication rates was assessed. For both the HA and the PV, patients at the lowest two quartiles were categorized as having low flow and the remainder as having high flow. RESULTS: The median MELD score was 22 and 1-year GS was 87.3%. As expected, GS paralleled PV flow with patients at the lowest flow quartile faring the worst. In combination of PV and HA flows, high HA flow was associated with improved 1-year GS among patients with low PV flow (P = .03). Similar findings were observed with respect to biliary complication rates. CONCLUSIONS: Sufficient HA flow may compensate for poor PV flow. Consequently, meticulous HA reconstruction may be central to achieving optimal outcomes in PVT cases.

Retrograde portal vein flow and transarterial chemoembolization in patients with hepatocellular carcinoma - a case-control study.

BACKGROUND AND AIMS: Transarterial chemoembolization (TACE) is the most common treatment for hepatocellular carcinoma (HCC). In case of portal vein (PV) flow diversion, outcome may be compromised due to a decompensation of hepatic perfusion following arterial embolization. The aim of this study was to determine whether TACE in patients with retrograde PV flow results in a stronger deterioration of liver function and a poorer survival compared to patients with orthograde PV flow. METHODS: A database of 606 patients treated with TACE between 2000 and 2015 at Hannover Medical School was screened for Doppler ultrasound (US) findings on PV flow prior to TACE. A total of 407 patients were identified, among which 32 patients had retrograde PV flow. RESULTS: Patients with retrograde PV flow had significantly more often liver cirrhosis with advanced hepatic dysfunction (93.5% vs. 72.7%, p < .05). Median overall survival (OS) was 12 and 19 months in patients with retro- and orthograde PV flow, respectively (HR 1.27, p > .05). Patients with retrograde PV flow showed a trend for a shorter OS when matched for cirrhosis (12 vs. 21months, HR 1.51), Child-Pugh score/albumin-bilirubin grade (12 vs. 15 months). There was no difference in the deterioration of liver function after repeated treatments between both groups as assessed by increase of CP points and ALBI grade. CONCLUSIONS: Retrograde PV flow alone was not a significant prognostic marker, but patients with retrograde PV flow and advanced liver cirrhosis treated with TACE had a very short survival. Assessment of PV flow prior TACE may be helpful in borderline cases considered for TACE.

Ultrasonographic evaluation of abdominal organs after cardiac surgery.

BACKGROUND: Disturbances of the hepatosplanchnic region may occur after cardiac operations. Experimental studies have implicated impairment of splanchnic blood supply in major abdominal organ dysfunction after cardiopulmonary bypass (CPB). We investigated the impact of the cardiac operation and CPB on liver, kidney, and renal perfusion and function by means of ultrasonography and biochemical indices in a selected group of cardiac surgery patients. MATERIALS AND METHODS: Seventy five patients scheduled for a major cardiac operation were prospectively included in the study. Criteria for selection were moderate or good left ventricular ejection fraction and absence of previous hepatic or renal impairment. Ultrasound examination of the hepatic and renal vasculature and examination of biochemical parameters were performed on the day preceding the operation (T0), on the first postoperative day (T1), and on the seventh postoperative day (T2). RESULTS: Portal vein velocity and flow volume increased significantly, whereas hepatic artery velocity and flow volume decreased at T1 in comparison with T0. Hepatic vein indices remained unaffected throughout the observation period. Renal artery velocity and flow decreased, whereas renal pulsatility index and renal resistive index increased at T1 as compared with T0. Aspartate aminotransferase and alanine aminotransferase values were increased as compared with baseline values 24 h postoperatively. All parameters displayed a trend to approach preoperative levels at T2. Strong negative correlations between alanine aminotransferase values at T1 and hepatic artery velocity and flow volume at the same time point were also demonstrated (R = 0.638, P < 0.001 and r = 0.662, P < 0.001, respectively). CONCLUSIONS: The increase in portal vein flow and velocity and the decrease in hepatic artery flow and velocity in the period after CPB might be attributed to the hypothermic bypass technique and the hepatic arterial buffer response, respectively. The decrease in renal blood flow and velocity and the parallel increase in Doppler renal pulsatility index and renal resistive index could be considered as markers of kidney hypoperfusion and intrarenal vasoconstriction. Maintaining a high index of suspicion for the early diagnosis of noncardiac complications in the period after CPB and institution of supportive care in case of compromised splanchnic perfusion are warranted.

Quantification of hepatic blood flow using a high-resolution phase-contrast MRI sequence with compressed sensing acceleration.

OBJECTIVE. The objective of our study was to evaluate the performance of a high-spatial-resolution 2D phase-contrast (PC) MRI technique accelerated with compressed sensing for portal vein (PV) and hepatic artery (HA) flow quantification in comparison with a standard PC MRI sequence. SUBJECTS AND METHODS. In this prospective study, two PC MRI sequences were compared, one with parallel imaging acceleration and low spatial resolution (generalized autocalibrating partial parallel acquisition [GRAPPA]) and one with compressed sensing acceleration and high spatial resolution (sparse). Seventy-six patients were assessed, including 37 patients with cirrhosis. Two observers evaluated PC image quality. Quantitative analyses yielded a mean velocity, flow, and vessel area for the PV and HA and an arterial fraction. The PC techniques were compared using the paired Wilcoxon test and Bland-Altman statistics. The sensitivity of the flow parameters to the severity of cirrhosis was also assessed. RESULTS. Vessel delineation was significantly improved using the PC sparse sequence (p < 0.034). For both in vitro and in vivo measurements, PC sparse yielded lower estimates for vessel area and flow, and larger differences between PC GRAPPA and PC sparse were observed in the HA. PV velocity and flow were significantly lower in patients with cirrhosis on both PC sparse (p < 0.001 and p = 0.042, respectively) and PC GRAPPA (p < 0.001 and p = 0.005, respectively). PV velocity correlated negatively with Child-Pugh class (r = -0.50, p < 0.001), whereas the arterial fraction measured with PC sparse was higher in patients with Child-Pugh class B or C disease than in those with Child-Pugh class A disease, with a trend toward significance (p = 0.055). CONCLUSION. A high-spatial-resolution highly accelerated compressed sensing technique (PC sparse) allows total hepatic blood flow measurements obtained in 1 breath-hold, provides improved delineation of the hepatic vessels compared with a standard PC MRI sequence (GRAPPA), and can potentially be used for the noninvasive assessment of liver cirrhosis.

A central approach to splenorenal shunt in pediatric living donor liver transplantation.

The management of LSRS is a crucial problem to ensure a sufficient PV flow during pediatric LT. Although several techniques have been indicated to solve this problem, a more appropriate approach to LSRS is still needed in pediatric LT. We herein present a modified surgical approach to the ligation of LSRS via the left side of the IVC for a nine-month-old boy with severe portal hypertension and a history of Kasai portoenterostomy. LSRS was identified and exposed through the left side of the IVC and the dorsal surface of the pancreas from the superior side of the body of the pancreas. The post-operative course was uneventful with an excellent PV flow. The central approach for the ligation of LSRS is worth considering as an alternative procedure for a patient with collateral vessels and a history of multiple laparotomies.

Somatostatin therapy protects porcine livers in small-for-size liver transplantation.

Small-for-size (SFS) injury occurs in partial liver transplantation due to several factors, including excessive portal inflow and insufficient intragraft responses. We aim to determine the role somatostatin plays in reducing portal hyperperfusion and preventing the cascade of deleterious events produced in small grafts. A porcine model of 20% liver transplantation is performed. Perioperatively treated recipients receive somatostatin and untreated controls standard intravenous fluids. Recipients are followed for up to 5 days. In vitro studies are also performed to determine direct protective effects of somatostatin on hepatic stellate cells (HSC) and sinusoidal endothelial cells (SEC). At reperfusion, portal vein flow (PVF) per gram of tissue increased fourfold in untreated animals versus approximately threefold among treated recipients (p = 0.033). Postoperatively, markers of hepatocellular, SEC and HSC injury were improved among treated animals. Hepatic regeneration occurred in a slower but more orderly fashion among treated grafts; functional recovery was also significantly better. In vitro studies revealed that somatostatin directly reduces HSC activation, though no direct effect on SEC was found. In SFS transplantation, somatostatin reduces PVF and protects SEC in the critical postreperfusion period. Somatostatin also exerts a direct cytoprotective effect on HSC, independent of changes in PVF.

Diagnostic Accuracy of Portal Vein Flow Velocity for Esophageal Varices in Cirrhotic Patients.

Background Variceal bleeding is a life-threatening complication of cirrhosis. Traditionally, endoscopy has been utilized as a preferred modality for the detection and grading of esophageal varices. However, endoscopy is an invasive procedure and may not be readily available in resource-limited settings. To overcome this limitation, various non-invasive tests, including Doppler ultrasonography (DUS) with portal vein (PV) velocity measurement, have been investigated to predict the presence of esophageal varices (EV). This study aimed to evaluate the potential utility of portal vein flow velocity (PVFV) as a non-invasive alternative to endoscopic screening for predicting the presence of esophageal varices among cirrhotic patients. Methodology This validation cross-sectional study was carried out at the Department of Gastroenterology and Hepatology, Pakistan Kidney and Liver Institute & Research Centre (PKLI&RC), Lahore, Pakistan from June 8, 2022, to March 8, 2023. Cirrhotic patients were enrolled based on clinical, laboratory, and radiological assessments. Doppler ultrasonography was performed to measure portal vein flow velocity along other relevant indices. Subsequently, all patients underwent endoscopic evaluation to screen and grade the esophageal varices. Univariate and multivariate logistic regression analyses were performed to identify significant clinical predictors of EV based on the results of the independent sample t-tests or Mann-Whitney U tests. Receiver operating characteristic (ROC) curves were employed to determine the optimal cut-off value for portal vein flow velocity (PVFV). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated based on the identified cut-off value. A p-value ≤ 0.05 was considered statistically significant. Results A cohort of 137 cirrhotic patients was enrolled. The study population consisted of 92 males (67.2%) and 45 females (32.8%). Endoscopic screening confirmed the presence of esophageal varices in 81 patients (59.91%). A multivariate analysis revealed that aspartate aminotransferase to platelet ratio index (APRI) (p=0.008) and portal vein flow velocity (p=0.001) were significant factors associated with esophageal varices and were used for receiver operating characteristic (ROC) analysis. The area under the curve (AUC) for PVFV was 0.981, and for APRI, it was 0.711. At a cut-off value of 18 cm/sec for PVFV, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy for esophageal varices were found to be 93.83%, 92.86%, 95%, 91.23%, and 93.43%, respectively. Conclusion Measurement of portal vein flow velocity using Doppler ultrasonography (DUS) is a reliable screening method for predicting the presence of esophageal varices (EV) in patients with liver cirrhosis. DUS offers several advantages, including its non-invasive nature, cost-effectiveness, and widespread availability, making it a recommended approach due to its high diagnostic accuracy.

Proximal Splenic Artery Embolization for Refractory Ascites and Hydrothorax Post-Liver Transplant.

PURPOSE: Proximal splenic artery embolization (pSAE) has been advocated as a valuable tool to ameliorate portal hyper-perfusion (PHP). The purpose of this study was to determine the safety and efficacy of pSAE to treat refractory ascites (RA) and/or refractory hydrothorax (RH) in the setting of PHP post-liver transplant. MATERIAL AND METHODS: A total of 30 patients who underwent pSAE for RA and/or RH after liver transplantation (LT) between January 2007 and December 2017 were analyzed retrospectively. The patients were divided into groups according to the time frame from pSAE to clinical resolution in order to identify predictors of RA/RH response to the procedure. RESULTS: Twenty-four (80%) patients responded to pSAE within three months, whereas 6 (20%) still required additional treatments for RA/RH at three months post-pSAE. In all cases clinical symptoms resolved within six months. Complications after pSAE were as follows: 2 cases of splenic infarction (6.6%), one case of post-splenic embolization syndrome (3.3%), one case of hepatic artery thrombosis (3.3%) and one case of portal vein (PV) thrombosis (3.3%). Increased intraoperative PV flow volume and increased pre-pSAE PV velocity, as well as higher estimated glomerular filtration rate were associated with early RA/RH resolution. CONCLUSION: pSAE is safe and effective in treating RA and RH due to PHP after LT. This study suggests that clinical parameters indicating more severe PHP and better kidney function are possible predictors for early response to pSAE.

A Novel Splenic Vein Flow Volume to the Portal Vein Flow Velocity Index as a Predictor for the Degree of Esophageal Varices in Liver Cirrhosis Patients.

Bleeding esophageal varices (EV) have the highest mortality rate from all complications of liver cirrhosis (LC). Several Doppler ultrasound (DUS) studies have been done on the splenic or portal vein (PV) to evaluate the hemodynamic of the esophageal vein. Our study focused on finding a better index using the ratio from two parameters correlated with EV, splenic vein flow volume (SFV), and PV flow velocity. In this study, 28 patients with LC were evaluated using DUS to compare the SFV to PV flow velocity/speed (Sv/Ps) index and other measured DUS parameters with the EV degree. Afterward, the receiver operating characteristic (ROC) curve analysis was performed on statistically significant DUS parameters. Mean Sv/Ps index value in the group of nonvarices was 9.89 ± 3.56; 19.50 ± 5.56 in the small esophageal varices (SEV) and 74.12 ± 29.37 in the large esophageal varices (LEV) group with p < 0.001. ROC curve analysis generated an optimal cutoff point of 16.5 (90% sensitivity and 100% specificity) to predict the presence of EV and the cutoff point of 46.7 (100% sensitivity and specificity) to predict the presence of LEV. In conclusion, the Sv/Ps index measured using DUS can be used as a noninvasive method to predict the presence of EV, especially in predicting LEV.

Factors Raising Serum Ammonia Level During Lenvatinib Treatment of Patients With Hepatocellular Carcinoma.

BACKGROUND/AIM: Hepatic encephalopathy is an adverse event resulting from lenvatinib use in patients with hepatocellular carcinoma (HCC). We analyzed the influence of lenvatinib on portal venous flow velocity (PVV) and serum ammonia concentration. PATIENTS AND METHODS: Eleven patients with unresectable HCC were enrolled, including three with modified albumin-bilirubin (mALBI) grade 1, three with grade 2a, and five with grade 2b. PVV was measured by Doppler ultrasound sonography before and on day 2 of administration. RESULTS: Out of 11 patients, one developed hepatic encephalopathy. PVV was reduced in 10 patients, and the change from baseline was significantly correlated with lenvatinib dosage. The increase in serum ammonia concentration was affected by lenvatinib dose and baseline hepatic function as a threshold between mALBI grade 2a and 2b statistically. There was no correlation between changes in PVV and serum ammonia concentration. CONCLUSION: Lenvatinib might directly disturb hepatocyte metabolism to result in increased serum ammonia concentration.

Living donor liver transplantation in small-for-size setting.

Small-for-Size Syndrome (SFSS) is one of the most feared complication of adult split liver and living donor liver transplantation. SFSS stems from a disproportionate/excessive portal vein flow relative to the volume of the implanted liver graft, and is currently one of the major practical limits to partial liver grafts' transplantation. In the last few decades many graft inflow modulation (GIM) techniques have been proposed to curtail the portal vein flow, allowing for successful transplantation of small partial liver grafts. Graft inflow modulation techniques span from Splenic Artery Ligation (SAL), to Splenectomy, Porto-Systemic Shunts and the lately proposed Splenic Devascularization. A patient tailored approach balancing the risk of SFSS with GIM specific morbidity, is more important than identifying the ideal GIM technique. Here we summarize the most recently published data to provide general indications in the challenging preoperative choice of a GIM techniques.

Correlation Between Sonographic Portal Vein Diameter and Flow Velocity With the Clinical Scoring Systems MELD and CTP in Cirrhotic Patients: Is There a Relationship?

Background: Liver cirrhosis is defined as a chronic disease of the liver with destruction of the hepatic parenchymal cells. The aim of the current study was to investigate the correlation between sonographic portal vein diameter (PVD) as well as portal flow velocity (PFV) with the clinical scoring systems; CTP and MELD in cirrhotic patients. Methods: In this cross sectional study, convenience sampling enrolled 108 patients, diagnosed with liver cirrhosis. Blood samples were taken and all patients subsequently underwent Doppler sonography to determine mean portal vein velocity and diameter. Results: All 108 patients (66 males and 42 females) were enrolled in study. The mean age (± SD) was 50.9 ± 17.6 years (range 13 - 85). The results of the present work revealed weak +ve correlation between MELD and CHILD scores (r = 0.629; P = 0.01). Moreover, the mean PVD showed a little or no +ve correlation with both MELD and CHILD scores (r = 0.216, P = 0.05) and (r = 0.241, P = 0.05) respectively. However, the mean PFV showed no statistical significant relationship with MELD score (P = 0.41). Conclusion: Sonographic portal vein parameters cannot be a substitute for clinical grading and staging of cirrhosis; and we cannot propose it as a single acceptable diagnostic indicator in grading liver cirrhosis with accuracy.

Hepatic perfusion and hemodynamic effects of transjugular intrahepatic portosystemic shunts.

The liver depends on a dual blood supply from the hepatic artery and the portal vein. The normal liver receives 70% portal flow and 30% hepatic arterial flow, with most arterial blood feeding the biliary tree. As cirrhosis robs the liver of its regenerative capacity, the portal flow decreases and intrahepatic portosystemic shunting increases with a variable increase in arterial flow across arterioportal shunts. This compensation mechanism attempts to reperfuse remaining sinusoids. Transjugular intrahepatic portosystemic shunts (TIPS) or surgical portosystemic shunts may acutely diminish portal perfusion further, leading to hepatic failure. Small-diameter TIPS or surgical shunts reduce the incidence of complications by preserving nutritive portal flow. Although the inverse relationship of arterial and portal flow is physiologically valid, there is individual variation in the ability to substitute one blood supply for another. This variability may result from anatomic or functional factors influencing the flow across arterioportal shunts. Hepatic perfusion curves derived from enhanced imaging studies can subtype cirrhotic patients into favorable versus unfavorable perfusion patterns. Patients with high arterial flow to the liver or patients with retained portal-type flow curves have better survival and morbidity compared with those patients with unfavorable flow manifest by diminished arterial-type curves on hepatic perfusion analysis.