Hepatic Artery Resistive Index Research Articles

343.7: The association of hepatic artery resistive index and graft failure; Analysis of various cut-off values.

343.7: The association of hepatic artery resistive index and graft failure; Analysis of various cut-off values.

Doppler ultrasound compared to shear wave elastography for assessment of liver cirrhosis

BackgroundThe progression of liver fibrosis to cirrhosis is a dynamic process necessitating non-invasive evaluation modalities. This study aims to evaluate the ability of Doppler ultrasound studies (DUS) in defining morphological and hemodynamic blood flow changes in the hepatic vasculature coinciding with advanced liver fibrosis.MethodsA prospective study was conducted on 100 patients with liver cirrhosis (F4). All cases underwent liver stiffness (LS) measurement by shear wave elastography (SWE), along with DUS to evaluate the liver texture, splenic size, hepatic artery resistive index (HARI), portal and splenic vein diameters, portal vein velocity (PVV), and hepatic vein waveform (HVV). All measures were assessed concurrently with a highly qualified single operator.ResultsPatients aged 55.5 ± 10.2 years with male predominance (72%). A highly significant correlation was found between LS by SWE and hepatic parenchymal texture, splenic size, portal vein width, and HVV (monophasic and biphasic) (p < 0.001). There were also high significant positive correlations (p < 0.001) between LS and PVV. However, there was no definitive correlation between LS and HARI, as well as splenic vein diameter.ConclusionThe widely available economic Doppler studies including portal vein velocity and hepatic vein waveform changes could be of substantial diagnostic value to liver cirrhosis.Study designProspective cohort study, employing descriptive and analytical statistics.

Hepatic arterial hemodynamics and model for end-stage liver disease (MELD) scores in chronic liver disease: insights from Doppler ultrasonography

BackgroundDoppler ultrasonography is essential to provide insights into hemodynamic alterations and liver function changes in pre-cirrhotic and cirrhotic patients. Utilizing Doppler examinations, this study aims to explore the correlation between hepatic arterial hemodynamics and Model for end-stage liver disease (MELD) scores in chronic liver disease patients.MethodsA study of 50 chronic liver disease patients included sonographic assessments, measuring liver, portal vein size, and flow. Hepatic artery velocity, resistive index (RI), pulsatility index (PI), and acceleration time (AT) were evaluated. Biochemical parameters (serum bilirubin, creatinine, INR) were used to calculate MELD scores, compared with different Doppler sonographic parameters.ResultsThe study found a mean peak systolic velocity (PSV) of 107.42 ± 48.10, with end-diastolic velocity (EDV) of 26.40 ± 14.68, RI of 0.74 ± 0.06, and PI of 1.47 ± 0.24. The mean MELD score was 19.28 ± 6.09. Correlations between MELD scores and PSV, EDV, RI, PI, and AT did not yield statistically significant correlations. 80% of subjects displayed high RI (> 0.7) values in the hepatic artery, and a significant correlation was found between portal vein thrombosis and hepatic artery PSV and RI (p < 0.05).ConclusionsHepatic artery RI and PSV show a significant correlation with portal vein thrombosis. Doppler ultrasonography, while not directly tied to MELD scores, is valuable for non-invasive liver disease monitoring when invasive methods are impractical. Further research is needed to unravel the relationships between hemodynamic changes, MELD scores, and clinical outcomes in a broader patient population.

Liver Elastography in Acute Liver Failure: A Pilot Study.

We aimed to assess the feasibility and reliability of sequential ultrasonographic and elastographic monitoring in acute liver failure (ALF). Observational study. ALF is a rare, life-threatening disease that requires intensive care admission and often liver transplant, where the accurate selection of patients is crucial. Liver elastography is a noninvasive tool that can measure hepatic stiffness, but previous results have been inconclusive in ALF. Patients admitted between October 2021 and March 2023 to the Liver Intensive Therapy Unit at King's College Hospital with ALF were recruited, with healthy control (HC) individuals and acute-on-chronic liver failure (ACLF) used as controls. None. Average shear wave velocity was recorded with ElastPQ on the right and left liver lobes and the spleen. Portal vein flow, hepatic artery resistive index, and peak systolic velocity were also recorded. Physiologic and histologic data were used for comparison. Forty patients with ALF, 22 patients with ACLF, and 9 HC individuals were included in the study. At admission, liver stiffness measurement (LSM) of the right lobe was statistically different between HC individuals (5.6 ± 2 kPa), ALF (31.7 ± 17 kPa), and ACLF (76.3 ± 71 kPa) patients (ALF vs. ACLF, p = 0.0301). Spleen size and stiffness discriminated between ALF (10.4 ± 2 cm and 21.4 ± 16.6 kPa) and ACLF (14 ± 2.3 cm and 42.6 ± 26 kPa). At admission, LSM was not different between ALF patients who spontaneously survived versus patients who died or were transplanted in the following 90 days. However, the trend over the first 10 days of admission was different with a peak of LSM at day 5 in spontaneous survivors followed by reduction during the recovery phase. ALF patients with poor prognosis showed a persistently increased LSM. In ALF stiffness peaks at day 5 of admission with subsequent reduction in patients spontaneously surviving, showing significant difference according to the prognosis at day 7 of admission. LSM might be useful in distinguishing acute from acute-on-chronic liver failure together with spleen volume and stiffness.

Utility of nifedipine use for Doppler ultrasound early after liver transplantation to predict short-term complications and long-term outcomes.

To evaluate the response to nifedipine administration measured by changes in hepatic arterial (HA) flow on post-operative Doppler ultrasound (US) to predict short-term complications and long-term outcomes in liver transplant (LT) patients. Patients who underwent LT with post-operative Doppler US within 3days between 1 January 2005 and 31 December 2015 were included in this retrospective single center study. The patients who received and did not receive nifedipine during the Doppler US comprised the study and control groups, respectively. A positive response to nifedipine was defined as the detection of HA flow when none was present initially or a reduction in HA resistive index (RI) ≥ 0.1 after nifedipine administration. The rates of re-transplantation, re-operation, percutaneous intervention (PCI), and overall survival (OS) were recorded. Cox proportional hazards regression was used to evaluate the association of clinic-demographic variables and Doppler findings with the outcome measures. 444 LT patients (305M/139F, mean age 51.7 ± 17.4years, mean interval between LT-Doppler US 1.12 ± 0.9days) are presented. 220 patients comprised the nifedipine study group [n = 157/220 (71.4%) responder, n = 63/220 (28.6%) nonresponder] and 224 patients comprised the control group. There was no difference in re-transplantation or PCI rates between the groups (all p-values ≥ 0.2 and ≥ 0.08, respectively). The responder group had a lower rate of re-operation vs. the control group (15.9% vs. 24.1%, p = 0.03) and nonresponder group (15.9% vs. 31.8%, p = 0.004). 1-year and 2-year OS were similar between the groups (all p-values > 0.37). Short-term complication rates and long-term outcomes for patients with liver transplant who responded to nifedipine administration on Doppler US are similar to those who did not require nifedipine administration. A lack of response to nifedipine was associated with a higher re-operation rate.

Value of Doppler ultrasonography in predicting clinical outcomes for patients with acute cellular rejection after liver transplantation.

This study investigated the value of Doppler ultrasonography in predicting clinical outcomes after antirejection treatment for patients with acute cellular rejection (ACR) following liver transplantation (LT). This retrospective study included 84 patients who were pathologically diagnosed with ACR and received antirejection treatment within 90 days following LT. Two radiologists searched for abnormal Doppler parameters at ACR diagnosis and within 7 days after antirejection treatment initiation, including portal blood velocity (PBV) <20 cm/s, hepatic artery resistive index <0.5, and a monophasic hepatic vein flow pattern. Interval PBV changes were also evaluated. The frequencies of abnormal Doppler parameters and PBV changes were compared by treatment outcome. The frequency of abnormal PBV in the early post-treatment phase (PBVearly post-treatment) was significantly higher among poor responders (50.0% [10/20]) than among good responders (7.8% [5/64]) (P<0.001). The sensitivity, specificity, and accuracy of abnormal PBVearly post-treatment as a predictor of poor response to antirejection treatment were 50.0% (10/20), 92.2% (59/64), and 82.1% (69/84), respectively. A decrease (>10%) from the PBV at event (PBVevent) to PBVearly post-treatment was significantly more common among poor responders (50.0% [10/20]) than among good responders (20.3% [13/64]) (P=0.019). The sensitivity, specificity, and accuracy of this PBV decrease in predicting poor treatment response were 50.0% (10/20), 79.7% (51/64), and 72.6% (61/84), respectively. Abnormal PBVearly post-treatment and a decrease between PBVevent and PBVearly post-treatment were significantly associated with poor treatment response in patients with ACR after LT. Consequently, Doppler ultrasonography may be useful for predicting clinical outcomes in these patients.

Assessment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome using different scanning approaches for the ultrasonographic evaluation of portal vein blood flow and hepatic artery resistive index in hematopoietic stem cell transplant recipients.

Sinusoidal obstruction syndrome (SOS) is a fatal complication of hematopoietic stem cell transplantation (HSCT). Previously, we established a scoring system (Hokkaido ultrasound-based scoring system-10; HokUS-10) comprising 10 ultrasound parameters for SOS diagnosis. In HokUS-10, the portal vein time-averaged flow velocity (PV TAV) and hepatic artery resistive index (HA RI) are measured using subcostal scanning. However, measurement errors and delineation difficulties occur. Therefore, we aimed to prospectively evaluate PV TAV and HA RI measurements obtained via intercostal scanning as an alternative method to subcostal scanning and determine their cutoff values. HokUS-10 was administered before and after HSCT. PV TAV and HA RI were measured on subcostal and right intercostal scans. We performed 366 scans on 74 patients. The median value (range) of PV TAV in the main and right portal veins was 15.0cm/s (2.2-49.6cm/s) and 10.5cm/s (1.6-22.0cm/s), respectively. A low correlation was observed between the two values (r = 0.39, p < 0.01). The highest diagnostic value of the right portal vein was less than 8.0cm/s. The median value (range) of HA RI in the proper and right hepatic arteries was 0.72 (0.52-1.00) and 0.70 (0.51-1.00), respectively. A strong correlation was observed between the two values (r = 0.65, p < 0.01). The highest diagnostic value of the right HA RI was 0.72 or higher. Quantitative measurement of PV TAV and HA RI using intercostal scanning can be appropriately performed as an alternative method to using subcostal scanning.

Low hepatic artery resistive index on Doppler ultrasound performed on the first post-liver transplant day is associated both with hepatic artery thrombosis and decreased graft survival.

Although liver transplantation (LT) outcomes have improved significantly over the last decades, early vascular complications are still associated with elevated risks of graft failure. Doppler ultrasound (DUS) enables detection of vascular complications, provides hepatic artery Resistive Index (RI). The aim of our study was to evaluate the association of the RI parameters of DUS performed in the first post-transplant week with post-transplant outcomes. All consecutive patients undergoing a first LT between 2001 and 2019 at a single center were included. Patients were divided into two groups: RI < 0.55 and RI ≥ 0.55. Patients were also divided according to the presence or absence of hepatic artery thrombosis (HAT). Graft survival was compared between groups. Overall, 338 patients were included. HAT occurred in 23 patients (6.8%), of which 7 were partial and 16, complete. Biliary complications were more common in patients with HAT (10 [43.5%]) vs. 38 [12.1%] [p < 0.001]). Graft survival was lower for patients with HAT (p = 0.047). Also, RI < 0.55 was associated with increased incidence of HAT (p < 0.001). Additionally, patients with RI < 0.55 on post-operative day 1 had decreased graft survival as compared to patients with RI > 0.55 (p = 0.041). RI on post-operative day 3 and 5 was not predictive of inferior graft outcomes. Intensive use of DUS in the early post-LT period offers the possibility of early diagnosis of vascular complications, guiding medical and surgical management of HAT. Additionally, according to our data, low RI (< 0.55) on the first postoperative day also is a predictor of HAT and decreased graft-survival.

Hepatic Artery and Portal Vein Hemodynamics in Nonalcoholic Fatty Liver Disease in Adult Saudi Patients: A Doppler Ultrasound Study

Background: Nonalcoholic fatty liver disease (NAFLD) is a growing public health problem. With the growing severity of NAFLD, there are considerable alterations in the hemodynamics of the hepatic circulation that might affect the prognosis of the condition, according to numerous reports written to assess the vasculature of the liver in patients affected with fatty liver disease. The aim of the study was to examine hemodynamic alterations in the hepatic artery (HA) and portal vein (PV) in NAFLD patients and determine how they relate to the severity of the condition, and to classify patients into various categories of NAFLD and connect the results to liver size and body mass index (BMI). Methods and Results: One hundred and six diagnosed NAFLD patients who attended the Imaging department at King Fahad Hospital from December 2019 to January 2020 were retrospectively studied. The mean age of the patients was 45.75±15.6 years, with a range of 10-79 years. The patients were examined by a TOSHIBA Xario, SSA-660A ultrasound system utilizing a multifrequency convex transducer (2–5 MHz) for all sonographic exams. B-mode assessed the liver parenchyma, and spectral Doppler estimated the HA and PV. The US appearance of hepatosteatosis, according to the severity of echogenicity, was graded (0-3). Most participants were asymptomatic (76.4%), and diabetes and diabetes with hypertension were diagnosed in 12.3% and 11.3%, respectively. It was observed that grade 1 hepatosteatosis was more prevalent than the other grades: 54 cases versus 41 cases for grade 2 and 11 cases for grade 3. The mean values of liver size and BMI in grade 3 were higher than in grade 1 (P=0.0033 and P=0.0054, respectively). A Spearman test found that the liver size (R=0.19, P=0.05) and BMI (R=0.26, P=0.01) had weak positive, but statistically significant, correlations with the severity of the hepatosteatosis grade. Doppler indices of the HA and PV in NAFLD patients did not differ significantly in hepatosteatosis grades 1-3. Only the PSV and EDV of the main PV showed a significant decrease in the hepatosteatosis grade 2 compared to grade 1 (P=0.0065 and P=0.0234, respectively). Despite the insignificant differences, the Doppler flow parameters of the HA decreased with the severity of hepatic steatosis; for example, the hepatic artery resistive index (HARI) was 0.77±0.16 in grade 1, 0.72±0.16 in grade 2, and 0.75±0.10 in grade 3, respectively. The hepatic artery pulsatility index (HAPI) was 1.62±49 in grade 1, 1.63±.68 in grade 2, and 1.74±0.77 in grade 3. There was also a trend toward a decrease in PSV and end-diastolic velocity (EDV) of HA with the severity of hepatosteatosis. Conclusion: The severity of hepatic steatosis is significantly correlated with liver size and BMI. The blood flow parameters of PV and HA decrease with the severity of hepatic steatosis except for the pulsatility index.

Doppler ultrasonography blood flow changes of the hepatic artery in liver transplants complicated with cholangitis

Cholangitis after liver transplantation may lead to bile duct necrosis. Early diagnosis is essential to prevent graft loss. We aimed to investigate cholangitis related hepatic arterial Doppler ultrasonography findings in liver transplants. Patients complicated with biopsy proven cholangitis in grafts were prospectively evaluated. Vascular complications were excluded. Doppler ultrasonography parameters including hepatic arterial diameter, resistive index, volume flow, and portal vein maximum velocity were measured twice: first during cholangitis and after full recovery. Data of two groups were compared using paired samples t test and Mann-Whitney U test. The mean hepatic arterial volume flow, resistive index, and diameter of 33 patients complicated with cholangitis was observed to decrease after recovery from 0.356 to 0.273 L/min (p = 0.007), from 0.64 to 0.60 (p < 0.001) and from 4.9 to 4.4 mm (p < 0.001), respectively. Portal vein maximum velocity alteration was not statistically significant (p = 0.6). Ultrasound follow-ups after liver transplantation can give us the clue of cholangitis initiation through some altering hepatic arterial Doppler parameters. Even though these are nonspecific findings that can also be observed in vascular complications, baseline Doppler data should be saved for future comparison and considered to prevent biliary associated graft loss.

Value of hepatic artery resistive index in evaluation of liver fibrosis related to non-alcoholic fatty liver diseases

Value of hepatic artery resistive index in evaluation of liver fibrosis related to non-alcoholic fatty liver diseases

Doppler-ultrasound reference values after pediatric liver transplantation: a consecutive cohort study

ObjectivesDoppler ultrasound (DUS) is the main imaging modality to evaluate vascular complications of pediatric liver transplants (LT). The current study aimed to determine reference values and their change over time.MethodsA consecutive cohort of pediatric patients undergoing an LT were retrospectively included between 2015 and 2020. Timepoints for standardized DUS were intra-operative and postoperative (day 0), days 1–7, months 1 and 3, and years 1 and 2. DUS measurements of the hepatic artery (HA), portal vein (PV), and hepatic vein(s) (HV) were included if there were no complications during 2 years follow-up. Measurements consisted of: peak systolic velocity (PSV) and resistive index (RI) for the HA, PSV for the PV, and venous pulsatility index (VPI) for the HV. Generalized estimating equations were used to analyze change over time.ResultsOne hundred twelve pediatric patients with 123 LTs were included (median age 3.3 years, interquartile range 0.7–10.1). Ninety-five HAs, 100 PVs, and 115 HVs without complications were included. Reference values for HA PSV and RI, PV PSV, and HV VPI were obtained for all timepoints (4043 included data points in total) and presented using 5th–95th percentiles and threshold values. All reference values changed significantly over time (p = 0.032 to p < 0.001).ConclusionsDUS reference values of hepatic vessels in children after LT are presented, reference values change over time with specific vessel-dependent patterns. Timepoint–specific reference values improve the interpretation of DUS values and may help to better weigh their clinical significance.Key Points• Doppler ultrasound reference values of pediatric liver transplantations are not static but change over time. Applying the correct reference values for the specific timepoint may further improve the interpretation of the measurements.• The pattern of change over time of Doppler ultrasound measurements differs between the hepatic vessel and measurement; knowledge of these patterns may help radiologists to better understand normal postoperative hemodynamic changes.

Diagnostic Value of Color Doppler Ultrasound and Contrast-Enhanced Ultrasound in the Artery Steal Syndrome After Orthotopic Liver Transplantation.

This study aimed to investigate the application of color Doppler ultrasound (CDU) and contrast-enhanced ultrasound (CEU) in the early diagnosis of arterial steal syndrome (ASS) after orthotopic liver transplantation (OLT). A total of 1827 patients received OLT in our department between January 2007 and December 2021, and CDU and CEU were performed after surgery. Ultrasonographic data were collected and further analyzed. ASS was confirmed by digital subtraction angiography (DSA), and the use of splenic artery embolization was dependent on the DSA findings and clinical conditions. The ultrasonographic data were collected before and after embolization. ASS was found in 23 patients (23/1827; 1.26%). CDU: the portal vein velocity was higher than normal in 17 patients (52.83±21.74 cm/s); the hepatic artery flow signals disappeared in 7 patients; the hepatic artery velocity was 13.57±5.85 cm/s in 16 patients. In 23 patients, the spleen artery velocity was 170.12±32.04 cm/s. CEU: the hepatic artery was observed in 7 patients without hepatic artery flow signals on CDU; in 23 patients, the contrast agent reached the portal vein at the presence of contrast in the hepatic artery or earlier (difference: 2.21±1.09 s). Splenic artery embolization was done in 17 of 23 patients with ASS. The hepatic artery flow velocity, hepatic artery resistance index, splenic artery velocity and time to the presence of contrast were significantly improved after embolization (P<0.05). CDU and CEU are the preferred, effective tools in the diagnosis of ASS. Reduced peak hepatic artery velocity, increased spleen artery velocity and reduced time difference in the contrast reaching the portal vein and hepatic artery are indicative of ASS.

Hepatic perfusion as a new predictor of prognosis and mortality in critical care patients with acute-on-chronic liver failure.

Background and aimsLiver diseases are frequent causes of morbidity and mortality worldwide. Liver diseases can lead to cirrhosis, with the risk of acute-on-chronic liver failure (ACLF). For the detection of changes in hepatic hemodynamics, Doppler ultrasonography is a well-established method. We investigated hepatic hemodynamics via serial Doppler ultrasonography to determine the predictive value of changes in hepatic perfusion for the outcome in patients with severe liver diseases compared to established prognostic models such as the MELD (Model for End-Stage Liver Disease) or CLIF-C (Chronic Liver Failure-Consortium) ACLF score.MethodsIn this prospective cohort study, hepatic perfusion was quantified at baseline before the initiation of treatment and every third day by means of serial measurements of the hepatic artery resistance index (HARI) and the maximum portal vein velocity (PVv) using Doppler ultrasonography in 50 consecutive patients with severe liver diseases admitted to a medical intensive care unit (MICU). The recorded hemodynamic parameters were compared to the MELD score, and the CLIF-C ACLF score to analyze their utility for the prediction of the outcome of patients with severe liver diseases, liver cirrhosis, and ACLF.ResultsThe changes (delta) obtained by serial measurements of the MELD score, HARI, and PVv were analyzed through scatter plots. Bivariate correlation analysis yielded a new positive linear correlation between the delta-HARI and the delta-MELD score (r = 0.469; p < 0.001). In addition, our data revealed a new negative linear correlation between delta-PVv and the delta-MELD score (r = −0.279, p = 0.001). The leading cause of MICU mortality was acute-on-chronic liver failure (ACLF). A subgroup analysis of patients with liver cirrhosis revealed a positive linear correlation between the delta-HARI and the delta-CLIF-C-ACLF score (r = 0.252, p = 0.005). Of clinical relevance, non-survivors of ACLF exhibited a significantly higher mean value for the delta-HARI (0.010 vs. −0.005; p = 0.015) and a lower mean value for the delta-PVv (−0.7 vs. 1.9 cm/s; p = 0.037) in comparison to survivors of ACLF.ConclusionThis study shows the prognostic value of the assessment of hepatic perfusion in critical care patients with severe liver diseases by bedside Doppler ultrasound examination and its utility as an accurate predictor of the outcome in patients with ACLF. Increasing HARI and a decreasing PVv are predictors of an adverse outcome. Delta-HARI and delta-PVv are new biomarkers of prognosis and ACLF-related mortality in patients with liver diseases. Delta-HARI and delta-PVv may be helpful in guiding clinical decision-making, especially in catecholamine and fluid management.

Hepatic artery and portal vein Doppler ultrasound reference values in children aged 0-17 years old.

Doppler ultrasound of the portal vein peak systolic velocity and hepatic artery peak systolic velocity and resistive index in children is often performed during abdominal ultrasound for the assessment of liver and other abdominal pathology. However, evidence-based reference values are not available. We aimed to determine these reference values and to investigate whether they are age-dependent. Children who underwent abdominal ultrasound between 2020 and 2021 were retrospectively identified. Patients without hepatic or cardiac abnormalities at the time of ultrasound or during at least 3 months follow-up were eligible for the study. Ultrasound without hepatic hilum portal vein peak systolic velocity and/or hepatic artery peak systolic velocity and resistive index measurements were excluded. Age-dependent changes were analyzed using linear regression. Normal range reference values were described using percentiles for all ages, and for age subgroups. One-hundred ultrasound examinations performed in 100 healthy children aged 0-17.9 years (median 7.8 years, interquartile range 1.1-14.1 years) were included. Ninety-nine portal vein peak systolic velocity and 80 hepatic artery peak systolic velocity and resistive index measurements were obtained. There was no significant association between portal vein peak systolic velocity and age (β = -0.056, p = 0.68). There were significant associations between age and hepatic artery peak systolic velocity, and between age and hepatic artery resistive index (β = -0.873, p = 0.04 and β = -0.004, p < 0.001, respectively). Detailed reference values were provided for all ages, and for age subgroups. Reference values for the hepatic hilum portal vein peak systolic velocity, hepatic artery peak systolic velocity, and hepatic artery resistive index in children were established. Portal vein peak systolic velocity is not age-dependent, whereas hepatic artery peak systolic velocity and hepatic artery resistive index decrease when children get older.

Intraoperative Doppler Ultrasound for Detection of Early Postoperative Vascular Complications in Orthotopic Liver Transplants.

Liver transplantation is currently the only curative treatment for patients with end-stage liver disease. However, liver transplantation can be associated with catastrophic complications in the early postoperative setting, including hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT). Postoperative complications are associated with hepatic artery resistive index (RI) < 6, systolic acceleration time (SAT) > 0.08 seconds and peak systolic velocity (PSV) > 200 cm/s on doppler ultrasound (DUS). DUS is also used in an intraoperative setting to assess patency and early complications prior to the end of the operative period, allowing for early correction. This literature review evaluates the prevalence of DUS use in intraoperative settings to identify transplant complications. A lack of consistency and minimal knowledge of intraoperative DUS warrants additional research into its usage and standardization.

Effect of meal intake for evaluating hepatic artery by Doppler ultrasonography in liver transplants: Does fasting matter for screening hepatic artery due to hemodynamic changes in splanchnic circulation?

The aim of this study is to assess the utility of fasting on Doppler ultrasonography findings of hepatic artery in liver transplants. Liver transplant patients without vascular abnormalities were prospectively evaluated between December 2017 and January 2020. Doppler sonography was used to describe hemodynamic changes in response to a standard meal. The diameter, peak systolic velocity, blood flow, resistive index (RI) of the main hepatic artery and portal vein peak velocity were measured. The mean hepatic arterial diameter of 44 patients was higher in the fasting group (4.5mm) than in the postprandial group (3.3mm) (p<.05). The mean hepatic arterial blood flow decreased (from .276 to .127 L/min) and hepatic arterial RI increased (from .66 to .71) following meal ingestion (p<.05). Hepatic arterial velocity was significantly lower and portal venous velocity was higher after oral intake. Meal ingestion has an important effect on hepatic artery Doppler features in liver transplants. Therefore, Doppler ultrasound evaluation should be considered after appropriate fasting due to postprandial responses of liver transplant.

Negative dynamics of the hepatic artery resistive index as a predictor of early arterial thrombosis after deceased donor liver transplantation

Aim. The study aim was to assess the negative dynamics of the hepatic artery resistive index as a reliable predictor of early thrombosis in liver transplant recipients from a postmortem donor, to determine risk factors and to identify a group of patients with an increased risk of this complication.Material and methods. From July 2018 to August 2021, 92 orthotopic liver transplants from a deceased donor were performed at the Surgical Clinic of the City Clinical Hospital n.a. S.P. Botkin. All liver grafts were taken from donors with brain death. Control Doppler ultrasound examination of hepatic blood flow in all patients was performed on days 1, 3, 5, 7, if necessary, daily. The hepatic arteries resistive index was considered normal at values from 0.55-0.79, high at 0.8-0.89, extremely high above 0.9. Depending on the resistive index value on the 1st postoperative day and its further dynamics, we divided the patients into 3 groups. In each group, we analyzed the incidence of hepatic artery thrombosis and assessed the impact of various risk factors on the resistive index elevation on the 1st day after surgery and on its growth during dynamic observation in the early postoperative period.Results. Of 92 liver transplants, in three cases, we recorded hepatic artery thrombosis (3.2%), which was not associated with technical difficulties of arterial reconstruction. No mortality was recorded in all three cases. In patients with a normal or high resistive index on the 1st day, without its increase during dynamic observation, the incidence of arterial thrombosis was 0%. In patients with a normal or high resistive index on the 1st day, and its increase during dynamic observation, as well as in patients with an extremely high resistive index on the 1st day, the incidence of arterial thrombosis was 18.1% and 11.1%, respectively. The risk factors of thrombosis were the age of the recipient over 50 years old in an extremely high resistive index on the 1st postoperative day (p=0.024), and the age of the donor over 50 years old in the growth of the resistive index during follow-up (p=0.04).Conclusion. The lack of positive dynamics in the hepatic artery resistive index reduction may be an additional predictor of arterial thrombosis after liver transplantation. This fact makes it possible to identify a high-risk group of arterial thrombosis, to take additional preventive measures in these patients and to improve the immediate results of treatment in this group of patients.

Role of portal color Doppler ultrasonography as noninvasive predictive tool for esophageal varices in cirrhotic patients

BackgroundEsophageal varices (EV) is the most common apprehensive complication of portal hypertension in patients with cirrhotic liver. Guidelines recommend Upper gastro-intestinal endoscopic screening for EV in patients with newly diagnosed chronic cirrhosis (Imperiale et al. in Hepatology 45(4):870–878, 2007). Yet, it is invasive, time consuming and costly. To avoid unnecessary endoscopy, some studies have suggested Doppler ultrasound examination as simple, and noninvasive tool in prediction and assessment of severity of EV (Agha et al. in Dig Dis Sci 54(3):654–660, 2009). Our study was to assess the role of different Doppler indices of portal vein, hepatic and splenic arteries as a noninvasive tool for prediction of esophageal varices in cirrhotic patients.ResultsThis prospective case control study was conducted on 100 cirrhotic liver patients and 100 of healthy volunteers as control group. Patients were subjected to clinical examination, upper gastrointestinal tract endoscopy, abdominal ultrasonography with duplex Doppler evaluation of different portal Doppler hemodynamic indices were done for each patient. The results revealed that portal vein diameter, hepatic artery pulsatility index, portal hypertensive index, portal vein flow velocity, portal congestion index have high sensitivity for prediction of EV. However, Splenic artery resistance index, hepatic artery resistance index HARI, liver vascular index and platelet count/spleen diameter have less sensitivity for prediction of EV.ConclusionMeasuring the portal hemodynamic indices can help physicians as noninvasive predictors of EV in cirrhotic patients to restrict the need for unnecessary endoscopic screening especially when endoscopic facilities are limited.

Assessment of Hepatic Function, Perfusion and Parenchyma Attenuation with Indocyanine Green, Ultrasound and Computed Tomography in a Rat Model: Preliminary Standardization of Baseline Parameters in a Healthy Liver

Introduction: The standardization in experimental animal models plays a crucial role in pre-clinical studies. However, it is necessary to combine these determinations with dynamic functional test and imaging techniques to implement a non-invasive protocol for liver evaluation. Methods: Six healthy SD rats were followed for 4 weeks. The aim of the study was to determine hepatic function, perfusion and parenchyma attenuation with analytical and biochemical blood parameters, indocyanine green, ultrasound and computed tomography. Results: Indocyanine green clearance 5 and 10 minutes after its injection was 80.12% and 96.59%, respectively. Approximate rate of decay during the first 5 minutes after injection was 38% per minute. Hepatic perfusion evaluation with the high-frequency ultrasound was related to cardiovascular hemodynamic and renal perfusion. Portal area, hepatic artery resistance index, hepatic artery and portal peak systolic velocity and average between hepatic artery and porta was 3.41 ± 0.62 mm2, 0.57 ± 0.04 mm2/s, 693.24±102.53 mm2/s, 150.72 ± 17.80 mm2/s and 4.82 ± 0.96 mm2/s, respectively. Heart rate, cardiac output, left renal artery diammetre and renal blood flow were 331.01 ± 22.22 bpm, 75.58 ± 8.72 mL/min, 0.88 ± 0.04 mm2 and 13.65 ± 1.95 mm2/s. CT-scan hepatic average volume for each rat were 21.08±3.32, 17.57±2.76, 14.87±2.83 and 13.67±2.45 cm3 with an average attenuation coefficient of 113.51±18.08, 129,19±7.18, 141,47±1.95 y 151,67±1.2 HU (Figure). Conclusion: Indocyanine green and high-frequency ultrasound could be used in rats as a suitable marker of liver function. Computed tomography, through the study of raw data could help to characterize liver parenchyma.