Hepatic Artery Peak Systolic Velocity Research Articles

Hepatic arterial buffer response in monochorionic twins with selective fetal growth restriction.

Monochorionic twins (MC) have higher risk ofperinatal morbi-mortality compared to singletons and dichorionic twins (DC). Selective fetal growth restriction (sFGR) increases the chances of adverse outcome. Hepatic arterial buffer response (HABR) is an important mechanism for maintaining liver perfusion. We hypothesised that HABR is active in monochorionic diamniotic twins (MCDA) with sFGR where restricted fetus may have liver hypoperfusion. The objective of this study is to test whether the HAV-ratio is diminished in pregnancies affected by selective fetal growth restriction pointing to activation of HABR in the growth-restricted fetus. sFGR was defined according to a consensus definition. Hepatic artery (HA) peak systolic velocity (PSV) was measured and its correlation with fetal Dopplers and pregnancy characteristics were determined. A ratio using HA-PSV (HAV-ratio) was calculated and its association with sFGR was established. Further analysis of HA-PSV was performed comparing z-scores between normal and growth restricted fetuses. We included 202 MCDA pregnancies, 160 (79 %) normal and 42 (21 %) with sFGR. HAV-ratio was significant different between groups. The mean HAV-ratio was 1.01 (±0.20) for normal twins and 0.77 (±0.25) for sFGR. Furthermore, HA-PSV z-scores was significant increased in in growth-restricted fetus (0.94±1.45), while in normal fetuses was-0.16 (±0.97). Our findings demonstrate that, in pregnancies with sFGR, HAV-ratio is significantly lower than in normal MCDA pregnancies. The lower HAV-ratio is due to an increase in HA PSV in the growth restricted fetus. This observation indicates an activation of HABR in the small fetus.

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.

Hepatic arterial buffer response: activation in donor fetuses and the effect of laser ablation of intertwin anastomosis.

Hepatic arterial buffer response (HABR) is an important defence mechanism for maintaining liver blood flow. It is suspected that HABR is active in monochorionic diamniotic twins (MCDA) with twin-to-twin transfusion syndrome (TTTS) where donor compensates a setting of volume depletion and the recipient an overload. The present study investigates whether in TTTS, HABR is active in donor and/or recipient individually and try to determine if the activation of HABR is a direct response to TTTS. Hepatic artery (HA) peak systolic velocity (PSV) was measured in normal MCDA fetuses and TTTS. Correlation with relevant fetal Dopplers and characteristics were determined. Z-scores for HA-PSV (HAV-Z) were calculated and its association with TTTS in donors and recipients were determined as well as changes in HAV-Z after laser treatment. In this study 118 MCDA were included, 61.9 % normal and 38.1 % TTTS. Of the TTTS 22 required laser treatment. A total of 382 scans were performed in normal group and 155 in TTTS. Our data demonstrates that in donors HAV-Z was 2.4 Z-scores higher compared to normal fetuses (β=2.429 95 % CI 1.887, 2.971; p<0.001) and after laser treatment HAV-Z reduced (β=-1.829 95 % CI-2.593,-1.064; p<0.001). There was no significant difference between recipients and normal (β=-0.092 95 % CI-0.633, 0.449; p=0.738). HABR is active in TTTS, promoting an increased hepatic blood flow in donors. The activation is direct response to TTTS as shown by the reduction in HAV-Z after laser. This finding provides important insights into the pathophysiology of TTTS.

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.

Sonographic Assessment of Acute Versus Chronic Cholecystitis: An Ultrasound Probability Stratification Model.

What sonographic variables are most predictive for acute cholecystitis? What variables differentiate acute and chronic cholecystitis? The surgical pathology database was reviewed to identify adult patients who underwent cholecystectomy for cholecystitis and had a preceding ultrasound of the right upper quadrant within 7 days. A total of 236 patients were included in the study. A comprehensive imaging review was performed to assess for gallstones, gallbladder wall thickening, gallbladder distension, pericholecystic fluid, gallstone mobility, the sonographic Murphy's sign, mural hyperemia, and the common hepatic artery peak systolic velocity. Of 236 patients with a cholecystectomy, 119 had acute cholecystitis and 117 had chronic cholecystitis on surgical pathology. Statistical models were created for prediction. The simple model consists of three sonographic variables and has a sensitivity of 60% and specificity of 83% in predicting acute versus chronic cholecystitis. The most predictive variables for acute cholecystitis were elevated common hepatic artery peak systolic velocity, gallbladder distension, and gallbladder mural abnormalities. If a patient had all three of these findings on their preoperative ultrasound, the patient had a 96% chance of having acute cholecystitis. Two of these variables gave a 73-93% chance of having acute cholecystitis. One of the three variables gave a 40-76% chance of having acute cholecystitis. If the patient had 0 of 3 of the predictor variables, there was a 29% chance of having acute cholecystitis. Gallbladder distension, gallbladder mural abnormalities, and elevated common hepatic artery peak systolic velocity are the most important sonographic variables in predicting acute versus chronic cholecystitis.

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.

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.

Assessment of hepatic function, perfusion and parenchyma attenuation with indocyanine green, ultrasound and computed tomography in a healthy rat model: Preliminary determination of baseline parameters in a healthy liver.

Defining reference intervals in experimental animal models plays a crucial role in pre-clinical studies. The hepatic parameters in healthy animals provide useful information about type and extension of hepatic damage. However, in the majority of the cases, to obtain them require an invasive techniques. Our study combines these determinations with dynamic functional test and imaging techniques to implement a non-invasive protocol for liver evaluation. The aim of the study was to determine reference intervals for hepatic function, perfusion and parenchyma attenuation with analytical and biochemical blood parameters, indocyanine green, ultrasound and computed tomography in six healthy SD rats. Six males healthy SD rats were followed for 4 weeks. To determine hepatic function, perfusion and parenchyma attenuation analytical and biochemical blood parameters, indocyanine green, ultrasound and computed tomography were studied. Results were expressed as Means ± standard error of mean (SEM). The significance of differences was calculated by using student t-test, p < 0.05 was considered statistically significant. 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. 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, help to characterize liver parenchyma, and could be a potential tool for early detection of liver parenchymal alterations and linear follow-up of patients. Further studies in rats with liver disease are necessary to verify the usefulness of these parameters.

Strategies for a successful hepatic artery anastomosis in liver transplantation: A review of 51 cases

Hepatic artery reconstruction is a critical aspect of liver transplantation. The microsurgeon faces several challenges when reconstructing the hepatic artery-the donor hepatic artery stalk is short and often a poor match for the usually hypertrophic recipient vessels. Previous inflammation impedes vessel dissection, and recipient vessels have a tendency to delaminate with manipulation. We review 51 consecutive liver transplantations to highlight these problems and propose strategies for a successful reconstruction of the hepatic artery. A prospective study involving all adult patients undergoing liver transplantation at the Singapore General Hospital from January 2015 to December 2018 was undertaken. All hepatic artery anastomoses were performed by 2 microsurgeons at 10x magnification. Patients were started on a standard immunosuppressive regimen. Postoperative ultrasound scans on days 1, 3, 5, 7, 9 and 14 were used to confirm arterial patency. There were 51 patients who underwent liver transplantation during the study period. Of this number, 31 patients received deceased donor grafts and 20 received living donor grafts. A total of 61 anastomoses were performed (5 dual anastomosis, 4 radial artery interposition grafts) with 1 case of hepatic artery thrombosis that was successfully salvaged. The mean (range) postoperative resistive index and hepatic artery peak systolic velocity were 0.69 (0.68-0.69) and 1.0m/s (0.88-1.10m/s), respectively. Hepatic artery thrombosis after liver transplantation is poorly tolerated. The challenges of hepatic artery reconstruction in liver transplantation are related to vessel quality and length. The use of microsurgical technique, appropriate recipient vessel selection, minimisation of vessel manipulation with modified instruments, variation in anastomosis techniques, and use of radial artery interpositional grafts are useful strategies to maximise the chances of success.

Middle hepatic vein incorporation in live donor liver graft transplantation; implication and safety

Background: In this study, we have used the middle hepatic vein with the right lobe, and we studied the venous outflow dynamics immediately after transplant retrospectively meanwhile we studied the impact of the graft function on donor functionality and overall donor safety. &#x0D; Method: Between October 2017 to October 2020, we performed 40 adult to adult live donor liver transplants at Zheen International Hospital (Erbil, Kurdistan Region). Postoperative Doppler ultrasound was performed for recipients and donors immediately after surgery and then daily until discharge. &#x0D; Results: The donor age (28.5 ± 6.9) year, male/ female 19/ 21, intensive care unit stay (1.2 ± 0.43), floor stay (5.2 ± 1.4) days, their portal vein velocity (43.5 ± 18.4 ml/sec), hepatic artery resistive index (0.6 ± 0.09) and triphasic/ continuous venous outflow 30/10, their postoperative day one and at the discharge total serum bilirubin were (2.8 ± 1.8) and (2 ± 1.4), their postoperative day one and at the discharge international normalization ratio were (1.7 ± 0.5) and (1.2 ± 0.2) respectively. The recipient age (48.5 ± 11.3), male/female 27/13, intensive care unit stay (4.75 ± 3.9), floor stay (7.7 ± 3.7) days, portal vein velocity (63.96 ± 24.65 ml/sec), hepatic artery peak systolic velocity (74.76 ± 32.85) hepatic artery resistive index (0.7 ± 0.15), and triphasic/continuous venous outflow 27/13. &#x0D; Conclusions: Middle hepatic vein incorporation in live donor liver graft is safe with a favorable outcome for recipient and donor, doppler US is one the important tool for evaluation and follow up of donor and recipient for detection of vascular complications and assessment of venous outflow and graft function. In addition, early discharge of the donor is a reasonable option. &#x0D;

Study of Early Postoperative Doppler Changes Post Living Donor Liver Transplantation and Their Impact on Early Mortality and Small-for-Size Syndrome: A Retrospective Study.

BackgroundAdult-to-adult living donor liver transplantation (LDLT) has been a common practice because of the deficiency of deceased donor liver transplants. Liver hemodynamics differ substantially between cases with end-stage liver disease undergoing LT because of various degrees of hepatic affection, nature of implicated causative factors, and pathogenesis of the hepatic disorder. The present retrospective study primarily aimed to study the early postoperative doppler changes after adult to adult LDLT. The secondary aim was to assess these hemodynamics’ impact on early in-hospital deaths and small for size syndrome (SFSS) development.MethodsThis retrospective work was done on 123 adult cases with end-stage liver disease for whom adult LDLT was performed after exclusion of pediatric patients and those with vascular complications.ResultsPostoperative (PO) mean portal vein velocity (PVV), hepatic artery (HA) peak systolic velocity (PSV), and HA resistivity index (RI) declined gradually but significantly post adult LDLT. Phasicity of hepatic veins changes towards the triphasic waveform gradually in the early PO period. There is a notable negative relationship between PO mean PVV with PO mean HA PSV. Higher PO HA RI affected PO mortality, while higher PO PVV and lower HA PSV increased the incidence of SFSS.ConclusionEarly postoperative Doppler changes post-LDLT (PO PVV, HA RI, and HA PSV) can affect both mortality and SFSS development.

The effect of water intake on ultrasound tissue characteristics and hemodynamics of adult livers.

Aim of the studyTo assess the effect of water intake on ultrasound tissue characteristics and hemodynamics of adult livers.Material and methodsIn February 2020, we prospectively performed ultrasound shear wave elastography and attenuation imaging (ATI) of the liver parenchyma, and spectral Doppler sonography of the portal vein and hepatic artery in 19 adult healthy volunteers (10 men and 9 women, mean age 27 years, mean body mass index 24.65 kg/m2). We measured liver shear wave velocity (SWV, m/s), shear wave dispersion (SWD, m/s/kHz), attenuation coefficient (dB/cm/MHz), main portal vein velocity (PVV, cm/s), hepatic artery peak systolic velocity (PSV, cm/s), and end diastolic velocity (EDV, cm/s) immediately before and at different time points (15, 30, 45, and 60 minutes) after water intake (1.0 l water and 1.5 l water for body weight < 150 lbs. and ≥ 150 lbs., respectively).ResultsThe differences in SWV, PVV, hepatic artery PSV and EDV before and after water intake were significant (p < 0.01) whereas the differences in SWD and ATI were not (p > 0.05) based on repeated measures ANOVA tests. The values of SWV, PVV, PSV, and EDV reached a peak at 30-45 minutes and returned to baseline 60 minutes after water intake. We observed positive correlations of SWV with PVV, PSV, and EDV in linear regression analyses (r2 > 0.73).ConclusionsWater intake affects the liver stiffness and hemodynamics. No water intake at least one hour prior to liver ultrasound elastography and Doppler sonography is recommended.

Spectral Doppler Ultrasound Can Help Diagnose Children With Hepatic Sinusoidal Obstructive Syndrome After Hematopoietic Stem Cell Transplantation.

Hepatic sinusoidal obstruction syndrome (SOS) is a potentially fatal complication after hematopoietic stem cell transplantation (HSCT). Current clinical guidelines state that spectral Doppler changes occur late in the disease, and imaging is only useful for confirming SOS diagnosis. Our primary objective was to examine abdominal ultrasound variables as predictors of development of SOS in pediatric HSCT patients. A single-center cohort retrospective study was conducted on patients aged 0 to 21 years who underwent HSCT between September 2001 and May 2017 at our institution. Patients were excluded if they did not have abdominal ultrasounds after HSCT. Clinical, demographic, grayscale, and spectral Doppler liver ultrasound findings were evaluated. We modeled the odds of SOS diagnosis within 100 days after HSCT as a function of each of the 15 ultrasound variables. A total of 333 patients received an HSCT. One hundred forty subjects had ultrasound data available. Thirty-two patients developed SOS, and 9 of these patients died. Sinusoidal obstruction syndrome odds more than double per 1-SD increase in peak systolic velocity in common hepatic artery or left hepatic artery and more than triple per 1-SD decrease in main portal vein velocity or change in ascites severity. Several ultrasound variables were statistically significant predictors in the Cox models for time to SOS diagnosis. Several ultrasound variables can be used as predictors for a patient's risk of developing SOS. The strongest predictors are ascites severity, main portal vein velocity, common hepatic artery peak systolic velocity, and left hepatic artery peak systolic velocity.

Role of hepatic colour duplex ultrasound in assessment of non alcoholic fatty liver disease-nafld

Abstract Background Gray-scale ultrasonography (US) is an initial, easy to use and widely available imaging modality for NAFLD, the presence of fat infiltration in the liver in the absence of excessive alcohol consumption and other causes of liver disease, is the most common cause of fatty liver, with a prevalence as high as 15-25% in many populations. Objective to determine the effect of obesity and NAFLD on the Doppler waveform pattern of the liver vascularity. Methods A case control study, conducted at Ain Shams University in the period between july and December 2018 . In both groups, liver span &amp; subcutaneous fat was measured by ultrasonographic examination. Hepatic vein waveform pattern &amp; portal vein mean flow velocity were assessed &amp; hepatic artery resistance index was measured by duplex Doppler ultrasonography examination. Results Our study included 50 patients , 20 were control &amp; 30 were cases.. The mean age of cases was 45.30 ± 10.15 SD &amp; the mean age of control was 32.70 ± 10.95 SD rendering the mean age of cases &amp; control of high statistical significance (p value=0.000). The Subcutaneous fat showed high significant statistical difference between cases &amp; control groups with mean subcutaneous fat in control =0.75 ± 0.14 SD &amp; mean subcutaneous fat in cases= 1.23 ± 0.42 SD with p –value = 0.000. The liver span showed high significant statistical difference between cases &amp; control groups with mean in control =15.11 ± 0.85 SD &amp; mean liver span in cases= 17.46 ± 1.67SD ( p value = 0.000). Hepatic vein wave pattern was normal in all 20 control (100%). In the 30 cases,the Hepatic vein wave pattern was triphasic in 12 patients (40%) &amp; biphasic or monophasic In 18 patients (60%) with high statistical significance (p-value =0.000). There was negative correlation between the hepatic vein velocity &amp; BMI with ( p value=0.0032). There was no statistically significant difference between cases &amp; control as regards all Doppler indices including the Hepatic artery RI(resistive index), Hepatic artery PSV(peak systolic velocity), Portal vein velocity(maximum &amp; minimum)&amp; hepatic vein velocity (maximum velocity) where the p value was more than 0.05. Conclusion Patients with NAFLD have a high rate of abnormal hepatic vein Doppler waveform patterns ,which can be biphasic or monophasic rather than alterations in hepatic artery resistance index values by duplex Doppler ultrasonography. Also the fatty infiltration of hepatocytes can increase liver span &amp; the subcutaneous fat.

Liver Doppler Findings in Pediatric Patients After Total Pancreatectomy and Islet Autotransplantation.

This study was intended to establish normal values for velocities in the hepatic artery and portal veins in pediatric patients after total pancreatectomy and islet autotransplantation (TPIAT). A retrospective review was performed of liver Doppler studies in pediatric patients after TPIAT over 6 years at an academic children's hospital. Doppler velocities in the liver vasculature and the hepatic artery resistive index were recorded. Sixty-five pediatric patients were evaluated. There were no cases of portal vein thrombosis or other hepatic vascular complications. The mean hepatic artery peak systolic velocity was 157.6 cm/s (SE, 60.9 cm/s), with a mean resistive index of 0.57 (SE, 0.09). The mean main portal vein velocity was 31.9 cm/s (SE, 12.9 cm/s). Portal vein thrombosis is rare in pediatric patients after TPIAT. A wide range of hepatic artery and portal vein velocities are encountered in children immediately after TPIAT without hepatic vascular complications and can be considered normal.

Role of Doppler Ultrasonography in Defining Normal and Abnormal Graft Hemodynamics After Living-Donor Liver Transplant.

Our aim was to investigate the early changes that occur after graft perfusion in living-donor liver transplant by Doppler ultrasonography. We prospectively evaluated liver grafts of 30 patients who underwent living-donor liver transplant during an 18-month period and who were followed for 1 year postoperatively. The hepatic artery peak systolic velocity, resistivity index, portal vein velocity, portal vein anastomotic velocity ratio, and hepatic vein pattern were compared after excluding patients who developed vascular complications and acute rejection episodes. We observed intraoperative increases in the mean hepatic artery peak systolic velocity (96.3 ± 65 cm/s), the resistivity index (0.78 ± 0.091), and the portal vein velocity (99.6 ± 48 cm/s), which started to normalize after 2 weeks. In comparing the mean portal vein velocity, portal vein anastomotic velocity ratio, hepatic artery peak systolic velocity, and resistivity index after excluding 5 patients who developed vascular complications, we observed overall significance levels of P < .001, P = .039, P < .001, and P = .040. After we excluded 9 patients who developed acute rejection, our comparison of the portal vein velocity, hepatic artery peak systolic velocity, and resistivity index showed overall significance (P < .001, P < .001, and P = .043). Early and transient increases in portal vein velocity, anastomotic velocity ratio, hepatic artery peak systolic velocity, and resistivity index are common after living-donor liver transplant, with significant declines in the first 2 weeks posttransplant.

The risk factors of splenic arterial steal syndrome after orthotopic liver transplantation

To discuss the risk factors of splenic arterial steal syndrome (SASS) after orthotopic liver transplantation. Twenty-four cases who confirmed SASS after liver transplantation in Tianjin First Central Hospital between June 2005 and June 2013 were analyzed retrospectively. Another 96 cases were selected randomly from those patients of the same time with no complication of SASS patients postoperatively as control group. Clinical data of two groups including diameter of splenic artery and hepatic artery preoperatively, weight of graft, weight of recipients, cold/warm ischemia time, an hepatic period and operation time and so on were collected. Others including hepatic artery peak systolic velocity (PSV), end diastolic velocity (EDV), blood flow resistance index and portal vein average velocity (PVF) on the first day after liver transplantation, the day before diagnosis, the day when diagnosed, the 1, 3, 7 days after treatment in SASS group and on 1, 3, 7, 9, 11, 14 days after liver transplantation in control group. Statistical analysis were made between two groups. The splenic artery/hepatic artery ratio preoperatively and weight of donor liver,and the GRWR in SASS group and control group were 1.26 and 1.00, 1 032 g and 1 075 g, (1.40±0.30)% and (1.82±0.21)% respectively, with significantly statistical differences (Z=-6.40, Z=-2.22, t=-6.50; all P<0.05). The warm ischemia time, the cold ischemia time, the anhepatic period and operation time in SASS group and control group were 3.5 minutes and 4.0 minutes, 10.25 hours and 10.10 hours, 43 minutes and 45 minutes, 8.7 hours and 8.7 hours, with no significantly statistical differences (all P>0.05). RI of hepatic went up gradually in the early time after transplantation while dropped obviously when spleen artery spring coils embolization was received (P<0.01) and trended to stable two weeks later. Splenic artery/hepatic artery ratio and GRWR are the positive and negative risk factors respectively for SASS. The gradual rising of hepatic RI in the early time after transplantation may be the warning signal SASS and spleen artery spring coils embolization is the effective strategy for SASS after liver transplantation.

Effects of fat accumulation in the liver on hemodynamic variables assessed by Doppler ultrasonography.

To investigate the effect of various degrees of fatty liver infiltration on hepatic hemodynamics using Doppler ultrasonography. We included 40 patients with hepatic steatosis and 20 healthy volunteers. Hepatic steatosis was quantified by a chemical shift MRI. Hepatic artery peak systolic and end-diastolic velocity, resistance index (RI) and pulsatility index (PI), hepatic vein RI and PI, portal vein RI, PI, congestion index, and peak maximum velocity were evaluated by Doppler ultrasonography. The hepatic vein waveforms were classified as triphasic, biphasic, or monophasic. Kruskal-Wallis test was performed for comparing more than two groups. If significant differences were found, Mann-Whitney U test with Bonferroni correction was performed for pair-wise comparisons. Pearson &gch;(2) and Fisher's exact tests were used to compare categorical variables. According to MRI, 15 patients had mild, 14 patients had moderate, and 11 patients had severe fatty infiltration. Portal vein peak maximum velocity was median: 19.8 (range 12-33.3), 21.1 (8-41.8), 16.6 (10.6-24.9), and 29.2 (14.1-40.4) cm/s. Congestion index was 0.05 (0.02-0.16), 0.07 (0.01-0.17), 0.11 (0.06-0.24), and 0.05 (0.02-0.16). Hepatic artery RI was 0.75 (0.56-1.00), 0.66 (0.52-0.87), 0.83 (0.38-1.00), and 0.76 (0.48-2.76), and PI was 1.83 (0.90-3.13), 1.38 (1.04-2.63), 1.97 (0.86-2.90), and 1.82 (0.70-2.90) (p = .046 and p = .036) in the mild, moderate, severe steatosis, and control groups, respectively. The rate of triphasic hepatic vein waveforms was higher in controls than in patients with severe steatosis. Portal vein flow velocity decreases in severe hepatic steatosis when compared with controls.

Endovascular treatment of hepatic artery stenosis after liver transplantation

Hepatic artery stenosis (HAS) after orthotopic liver transplantation is a significant risk factor for subsequent hepatic artery thrombosis (HAT). HAT is associated with a 30%-50% risk of liver failure culminating in retransplantation or death. Traditional treatment of hepatic artery complications has been surgical, with hepatic artery revision or retransplantation. Endovascular therapy of HAS, described primarily in the interventional radiology literature, may provide a less-invasive treatment option. This was a retrospective review of all endovascular interventions performed for HAS after orthotopic liver transplantation over a 31-month period (August 2009 to January 2012). Patients with duplex ultrasound imaging evidence of severe main HAS (peak systolic velocity of >400 cm/s, resistive index of <.5) underwent endovascular treatment with either primary stent placement or percutaneous transluminal angioplasty (PTA) alone. Patients were followed with serial ultrasound imaging to assess for treatment success and late restenosis. Reintervention was performed if significant restenosis occurred. Thirty-five hepatic artery interventions were performed in 23 patients. Over the 31-month study period, 318 orthotopic liver transplantations were performed, yielding a 7.4% (23/318) rate of hepatic artery intervention. Primary technical success was achieved in 97% (34/35) of cases. Initial treatment was with PTA alone (n = 10) or primary stent placement (n = 13). The initial postintervention ultrasound images revealed improvements in hepatic artery peak systolic velocity (267 ± 118 [posttreatment] vs 489.9 ± 155 cm/s [pretreatment]; P < .0001) and main hepatic artery resistive index (0.61 ± 0.08 [posttreatment] vs 0.41 ± 0.07 [pretreatment]; P < .0001). At a mean follow-up of 8.2 ± 1.8 months (range, 0-29), there were 12 reinterventions in 10 patients for recurrent HAS. Thirty-one percent (n = 4/13) of patients undergoing initial stent placement required reintervention (at 236 ± 124 days of follow-up) compared with 60% (n = 6/10) of patients undergoing initial PTA (at 62.5 ± 44 days of follow-up). Primary patency rates (Kaplan-Meier) after primary stent placement were 92%, 85%, and 69% at 1, 3, and 6 months, respectively, compared with 70%, 60%, and 50% after PTA (P = .17). Primary-assisted patency for the entire cohort was 97% at 6 and 12 months. Major complications were one arterial rupture managed endovascularly and one artery dissection that precipitated HAT and required retransplantation. The overall rate of HAT in the entire cohort was 4.3% (1/23). Endovascular treatment of HAS can be performed with high technical success, excellent primary-assisted patency, and acceptable morbidity. Initial use of a stent may improve primary patency when compared with PTA. The need for reintervention is common, placing particular importance on aggressive surveillance. Longer follow-up and a larger cohort are needed to confirm these encouraging early results.

Prediction of early hepatic artery thrombosis by intraoperative color Doppler ultrasound in pediatric segmental liver transplantation

Early hepatic artery thrombosis (eHAT) after transplantation is associated with a high incidence of graft failure and mortality in pediatric segmental liver transplantation (LT). The evaluation of intraoperative color Doppler ultrasound (CD-US) parameters and their sensitivity and specificity for the prediction of eHAT were important. Pediatric segmental LTs were performed in 49 consecutive patients from October 2006 to December 2010 in our hospital. A total of seven patients (14.3%) experienced eHAT (within one month) after LT. The intraoperative hepatic artery (HA) diameter (p = 0.026), hepatic arterial peak systolic velocity (HAPSV) (p = 0.006), and hepatic artery resistance index (HARI) (p = 0.000) had significant difference between eHAT group and non-eHAT group. Taking a HA diameter <2 mm, a HAPSV of <40 cm/s and a HARI of <0.6 as threshold to predict eHAT, the sensitivity and specificity were 85.7%, 85.7%, 85.7%, and 61.9%, 76.2%, 88.1%, respectively. A HARI of <0.6 was shown to be the most sensitive and specific single parameter for predicting eHAT.