Portal Vein Flow Research Articles

Factors Affecting Persistent Splenomegaly After Adult-to-Adult Living Donor Liver Transplantation Using a Left Lobe

BackgroundThe aim of the present study was to evaluate spleen volume (SV) and the factors influencing it after adult-to-adult living donor liver transplantation (A2LDLT) using a left lobe. MethodsPretransplant computed tomography (CT) and post-transplant CT 2 years after A2LDLT were examined by volumetric analysis in 24 patients. We divided the recipients into the following 2 groups according to the post-transplant SV: >500 mL (Group A) and ≤500 mL (Group B). The factors affecting the change in post-transplant SV were compared between the 2 groups. ResultsThe mean pretransplant SV decreased significantly after A2LDLT. Platelet counts after living donor liver transplantation increased significantly relative to the pretransplant values. Post-transplant SV was >500 mL in 9 patients (Group A) and ≤500 mL in 15 (Group B). Pretransplant SV, platelet count, anhepatic time, operative time, intraoperative blood loss, post-transplant portal vein pressure >20 mm Hg, and post-transplant portal vein flow >250 mL/min/100 g graft weight showed significant differences between the 2 groups. Actual graft volume (GV) and GV/standard liver volume ratio showed no intergroup differences. Multivariate analysis showed that the only significant factor related to a post-transplant SV of >500 mL was the pretransplant SV. Post-transplant platelet counts were significantly increased from the pretransplant values in both Group A and Group B. ConclusionsPretransplant SV is the only significant factor predicting a SV of >500 mL after A2LDLT. However, even in patients with a SV of >500 mL, the platelet count increased significantly from the pretransplant value.

Insulin resistance and portal heamodynamics changes before and after treatment by new direct antivirals drugs in chronic HCV

Background and study aim: Insulin resistance is typically associated with chronic hepatitis C virus and its improvement after treatment of HCV with new direct antiviral drugs may change portal hemodynamics. This study aimed at assessing changes in HOMA-IR, APRI score and platelet count/spleen diameter ratio as fibrotic markers and changes of portal hemodynamics after treatment with direct- acting antiviral drugs. Patients and Methods: TheStudy included 100 chronic HCV patients who were eligible for treatment with direct-acting antiviral drugs. HOMA-IR, APRI score and platelet count/ spleen diameter ratio and changes of portal hemodynamics were calculated. Results: The noninvasive indices of liver fibrosis were assessed before and after HCV treatment. Insulin resistance improved significantly after treatment from (3.2±0.9) to (2.9±0.7). Doppler parameters of the studied group also showed marked improvement after treatment where the portal vein flow velocity and flow volume increased (15.8 ±1.7 vs 16.1±1.3) and (728.3±128.2 vs 1059.9±29.6) respectively. Hepatic artery resistive index and calculated congestive index of portal vein also, showed improvement (0.6±0.1 vs 0.49±0.1) (0.077 ±0.014 vs 0.051 ± 0.017) respectively. Conclusion: Direct-acting antiviral drugs may reduce inflammatory and fibrotic sequelae of HCV infection. Also, portal hypertensive indices improved and HOMA-IR, APRI score and platelet count/splenic diameter ratio show improvement.

Aberrant left gastric vein is associated with hepatic artery variations.

To investigate the imaging findings and hepatic artery variations encountered in patients with aberrant left gastric vein (ALGV). A retrospective database search between January 2014 and November 2018 was carried for ALGV. The course and types (1-3) of ALGV, the presence of associated liver lesions, and coexistence of hepatic artery variations were reviewed on CT images. A total of 32 patients (22 men, 68.7%) with a mean age of 52.5years (range 22-76years) were found to have ALGV. The prevalence of ALGV was 0.073%. The most frequent type of ALGV was type 1 (n = 22, 68.7%), followed by type 3 (n = 7, 21.8%) and type 2 (n = 3, 9.3%). We noticed mild-to-severe parenchymal hyperdensity at the posterior aspect of segments II and III in patients with type 1 (n = 20/22) and type 2 (n = 2/3) ALGV consistent with fat sparing due to third inflow effect. Two out of seven patients with type 3 ALGV had main portal vein thrombosis; however, the presence of ALGV maintained left portal vein flow in these patients. Twelve (37.5%) patients had accompanying hepatic artery variation. Left hepatic and right hepatic artery variations were detected in 8 (25%) and 2 (6.25%) of the patients, respectively. In 2 patients, Michels type IV variation was detected. Aberrant left gastric vein is associated with hepatic artery variations, which can be important for preoperative and pretransplant planning.

Model Assisted Analysis of the Hepatic Arterial Buffer Response During Ex Vivo Porcine Liver Perfusion.

The hepatic arterial buffer response is a well-known phenomenon in hepatic circulation, describing the response of hepatic arterial resistance to changes in portal vein flow. Several vasoactive metabolites underlying its mechanism have been proposed, however, there is currently no clear consensus. The aim of this study is to investigate the hepatic arterial buffer response of porcine livers preserved in a controlled ex vivo perfusion machine. Porcine livers are perfused on an ex vivo perfusion machine and hemodynamic experiments investigating the hepatic arterial resistance response to portal vein flow and vena cava pressure variations are conducted. A simple hemodynamic model is developed to support the interpretation of the received measurements. Further, a mechanism is proposed that explains hepatic arterial resistance changes in response to vena cava pressure as myogenic and in response to portal vein flow as a combined washout and myogenic effect. A clear correlation between hepatic sinusoidal pressure levels and hepatic arterial resistance is observed where an increase of approximately 4mmHg of hepatic sinusoidal pressure level results in doubling of the hepatic arterial resistance. This relation is considered during the analysis of the portal vein flow variations resulting in a reduced isolated effect of adenosine washout on hepatic arterial resistance. With an average buffer capacity of 27% during our experiments, the hepatic arterial buffer response shows to be unimpaired in the ex vivo scenario. First, washout and myogenic effects both influence the hepatic arterial buffer response; and second, hepatic sinusoidal pressure levels strongly influence the hepatic arterial resistance. These results present new findings in hemodynamics of the liver, which are fundamental for successful ex vivo liver perfusion.

Changes in the Velocity of Blood in the Portal Vein in Mild Acute Pancreatitis-A Preliminary Clinical Study.

Background and objective: Portal vein thrombosis is associated with a decrease in the main blood velocity in this vessel. While most studies examine etiological factors of portal vein thrombosis after its occurrence, we aimed to evaluate portal vessels and assess whether mild acute pancreatitis affects blood flow in the portal vein and increases the risk of thrombosis. Materials and methods: This prospective single centered follow-up study enrolled 66 adult participants. Fifty of them were diagnosed with mild acute pancreatitis based on the Revised Atlanta classification, and 16 healthy participants formed the control group. All participants were examined three times. The first examination was carried out at the beginning of the disease and the next two at three-month intervals. Blood samples were taken and color Doppler ultrasound performed the first time, whereas ultrasound alone was performed during the second and third visits. Mean and maximal blood velocities and resistivity index in the main portal vein and its left and right branches were evaluated. Results: Mean velocity of the blood flow in the main portal vein and its right and left branches was not significantly different from healthy individuals during the acute pancreatitis phase: 23.1 ± 8.5 cm/s vs. 24.5 ± 8.2 cm/s (p = 0.827); 16.4 ± 7.9 cm/s vs. 16.4 ± 8.1 cm/s (p = 1.000); and 8 ± 3.4 cm/s vs. 7.4 ± 2.5 cm/s (p = 0.826), respectively. The same was observed when comparing the maximal blood flow velocity: 67.9 ± 29 cm/s vs. 67.5 ± 21 cm/s (p > 0.05); 45.4 ± 27 cm/s vs. 44 ± 23.8 cm/s (p = 0.853); and 22.2 ± 9.8 cm/s vs. 20 ± 7.3 cm/s (p = 0.926), respectively. Changes in venous blood velocities were not significant during the follow-up period in separate study groups. Conclusions: Portal blood flow velocities do not change during mild acute pancreatitis in the inflammatory and postinflammatory periods. This observation suggests that mild acute pancreatitis does not increase the risk of portal vein thrombosis.

Evaluation of Portal Vein Doppler Findings in Patients with Crimean⁻Congo Hemorrhagic Fever.

Background and objectives: In this study, we compare portal vein Doppler ultrasound (US) findings between patients with Crimean–Congo hemorrhagic fever (CCHF) and healthy persons and investigate the practicability of these findings in the prediction of disease severity. Materials and Methods: In this prospective study, portal vein Doppler US was performed in patients diagnosed with CCHF and healthy persons between March 2016 and May 2018. The patients were grouped according to mild-to-moderate and severe progression of CCHF. Liver size, portal vein diameter, portal vein flow rate, spleen volume, and splenic vein diameter were recorded in the patients and healthy controls. Results: Of the 48 patients diagnosed with CCHF, 25 were male. According to the scoring made, 38 patients were evaluated as having mild-to-moderate disease progression, and 10 were evaluated as having severe disease progression. With respect to the Doppler US findings, liver size, spleen volume, portal vein diameter, splenic vein diameter, and portal vein flow rate were significantly higher in the patient group compared with the controls. However, no significant difference was found in these parameters between the severe and mild-to-moderate progression groups. Conclusions: In the evaluation of and follow-up with patients with CCHF, portal vein Doppler US is a non-invasive and reliable tool for diagnosis.

Predictive Value of Hepatic Venous Pressure Gradient for Graft Hemodynamics in Living Donor Liver Transplantation

The hepatic venous pressure gradient (HVPG) measurement is known to correlate with the severity of portal hypertension in patients with liver cirrhosis. This retrospective study investigated the clinical value of preoperative measurement of HVPG in patients who underwent adult-to-adult living donor liver transplantation (LDLT) and its predictive value for hepatic hemodynamics after graft reperfusion. For this study, 75 patients who underwent adult-to-adult LDLT were divided into 2 groups (HVPG<16mm Hg or HVPG≥16mm Hg) to investigate the correlation between preoperative HVPG and characteristics and surgical outcomes of the patients, including portal vein flow (PVF) and hepatic artery flow (HAF) after graft reperfusion. In total, 35 (46.7%) patients had an HVPG≥16mm Hg. These patients had significantly higher international normalized ratio values, serum creatinine levels, and Model for End-Stage Liver Disease scores compared with the 40 patients with HVPG<16mm Hg. They also had higher rates of variceal bleeding, encephalopathy, and intractable ascites as well as lower serum albumin levels and platelet counts compared with those patients with HVPG<16mm Hg. Portal inflow modulation (PIM) was frequently performed in the patients with HVPG≥16mm Hg compared with those with HVPG<16mm Hg. No significant differences in surgical outcomes after LDLT were found between these 2 groups except for postoperative ascites. Preoperative HVPG showed a positive correlation with PVF and a negative correlation with HAF after graft reperfusion (false discovery rate [FDR] P=0.08 and FDR P=0.08, respectively). In linear regression analyses, preoperative HVPG was independently associated with PVF after graft reperfusion. In conclusion, our findings indicate that preoperative HVPG is associated with hepatic hemodynamics after graft implantation in LDLT. HVPG as a routine preoperative evaluation may be helpful for surgical planning of PIM.

Portal Hypertension Is Associated With Congestive Encephalopathy and Delirium After Cardiac Surgery

BackgroundVenous congestion might lead to congestive encephalopathy after cardiac surgery. However, objective signs of congestion have yet to be associated with delirium. Portal vein flow pulsatility is a congestion marker that may identify a subgroup of patients at risk. MethodsWe performed a retrospective study and a prospective study in patients undergoing cardiac surgery. Adult patients who underwent portal vein Doppler imaging by the attending physician during usual care in the intensive care unit were included in the retrospective cohort. For the prospective cohort, patients had a cognitive and echocardiographic evaluation the day before surgery and daily for 3 days after surgery. Delirium was independently assessed by the nursing staff in the prospective cohort. ResultsA total of 237 patients in the retrospective cohort and 145 patients in the prospective cohort were included, for whom 1074 portal Doppler evaluations were performed. An association was found between delirium and portal vein pulsatility in the retrospective cohort (odds ratio [OR], 2.69; confidence interval [CI], 1.47-4.90; P = 0.001). In the prospective cohort, significant associations were found between the presence of portal vein pulsatility and the development of cognitive dysfunction and asterixis assessed by the investigators (OR, 2.10; CI, 1.25-3.53; P = 0.005 and OR, 2.23; CI, 1.13; 4.41; P = 0.02, and delirium detected by the nursing staff (hazard ratio, 2.63; CI, 1.13-6.11; P = 0.025). Higher N-terminal pro-beta natriuretic peptide measurements (OR, 4.03; CI, 1.78-9.15; P = 0.001) and cerebral desaturations (OR, 2.54; CI, 1.12-5.76; P = 0.03) were associated with cognitive dysfunction. ConclusionThese data present an association among hepatic congestion, delirium, and encephalopathy in patients undergoing cardiac surgery. Further studies should explore whether those neurological complications may have a congestive origin in some patients.

Optimal design and implementation of solar PV-wind-biogas-VRFB storage integrated smart hybrid microgrid for ensuring zero loss of power supply probability

Abstract Uninterrupted access to electric power has become the basic need of today’s world. Rural parts of many countries still do not have access to electricity or have electric power access to weak distribution grids with inadequate transmission and distribution system infrastructure. However, the countries where there is an abundance of solar radiation, a good potential of bio-degradable waste and average availability of wind source, access to electricity for those remote areas can be managed by distributed power generation. Considering the fact that the renewable energy sources (Solar, Wind etc.) are intermittent in nature, battery energy storage systems (BESS) and other reservoirs like biogas energy sources are the potential candidates to be integrated with the renewable sources to ensure continuous access to electricity and energy security. In this paper, a unique combination of Solar PV, Wind, Biomass and Vanadium Redox Flow Battery (VRFB) storage integrated hybrid Microgrid has been modeled and implemented practically for the first time. The capacity selection of different renewable sources for satisfying daily energy demand and their techno-commercial optimization has been performed through HOMER simulation. Further, the peak load shaving that is a limitation of HOMER model, has been established through PSCAD simulation by providing the real life data of different renewable sources, VRFB storage and the load profile as input to the model. The simulation model performances have been validated by a practical 10 kWP solar PV, 1 kW wind and 15 kVA Biogas generator integrated with 1 kW 6 h VRFB storage based Microgrid installed at India Institute of Engineering Science and Technology campus, India. In addition to these, zero loss of power supply probability (LPSP) has been ensured by implementing smart scheduling and controller considering the intermittency of the renewable sources. As a part of the financial analysis, project Investment on Return (IRR) and pay back has been calculated considering initial investment, operation and maintenance cost and revenue of generation.

Pressure gradients, laboratory changes, and outcomes with transjugular intrahepatic portosystemic shunts in pediatric portal hypertension.

Indications for TIPS are well described in adults and involve complications of PHTN. Complications from PHTN are associated with PSG of>12mmHg in adults. It is unclear if these parameters apply to children with PHTN. To assess whether adult criteria for TIPS placement can be utilized in children, describe laboratory changes over time, and report outcomes. We performed a retrospective review of 34 pediatric patients who underwent TIPS, examining indications, radiology, PSG reductions, laboratory changes, and outcomes. Most patients had PHTN due to parenchymal liver disease including congenital hepatic fibrosis (n=5), biliary atresia (n=5), cystic fibrosis-related liver disease (n=3) and cavernous transformation of the portal vein (n=6). Indications for TIPS included variceal bleeding, recurrent ascites, and maintenance of portal vein flow following thrombolysis. Variceal bleeding was observed in six children with PSG<12mmHg. Minor complications occurred in eight subjects. Continued bleeding occurred in one patient. Six patients were successfully bridged to transplantation, and three patients died secondary to end-stage disease. Standard laboratory tests stabilized after TIPS placement and hematocrit increased. TIPS placement in pediatric patients was performed for complications of PHTN. Unlike adult series, a substantial proportion of our cases treated extrahepatic PHTN from cavernous transformation of the portal vein. Children presented with sequelae of PHTN with PSG below 12mmHg, below the adult standard. We found TIPS in pediatrics to be safe and effective with laboratory stabilization and improvement in hematocrit.

Purpose of the measurement of intraoperative hepatic hemodynamics in liver transplant surgery

Liver graft function depends on different biological factors that are related to the donor, the recipient and the potential damage arising from the organ preservation technique. However, adequate hepatic artery flow and portal vein flow rates ensure a sufficient flow of oxygen and nutrients in order to ensure a suitable cellular graft function after the extreme metabolic decrease condition induced by hypothermia and the preservation solution. Liver inflow is a highly complex system due to its double irrigation system. These two systems are connected by the well-known “hepatic arterial buffer response” concept. This mechanism explains changes in hepatic arterial flow (HAF) as a compensation for changes in the portal vein flow (PVF), so that the hepatic artery adjusts total flow in relation to alterations in the portal blood flow. At the moment, the minimum HAF and PVF required for an adequate regeneration and functional recovery of the liver graft have not been yet established.

Portal Vein Flow by Doppler Ultrasonography and Liver Volume by Computed Tomography in Living Donor Candidates: Correlation with Indocyanine Green Test

Our goal was to investigate the correlation between indocyanine green test results and imaging parameters in living liver donor candidates. Our study included 219 healthy donor candidates who were evaluated with Doppler ultrasonography (portal vein time average flow), computed tomography (liver volume), liver biopsy (fat fraction), and indocyanine green retention rate at 15 minutes. Portal vein time average flow (r= -0.375), fat-free liver volume/body weight ratio (r = -0.239), and portal vein time average flow × fat-free liver volume/body weight ratio (r = -0.424) showed significant correlations with indocyanine green retention rate at 15 minutes (all P < .001). Imaging parameters were significantly correlated with indocyanine green retention rate at 15 minutes in living liver donor candidates.

03:27 PM Abstract No. 366 Quantification of the heat-sink effect during microwave ablation with 4D-flow MRI in an in-vivo porcine liver model

Image-guided thermal ablation has become the standard of care for treating early stage liver cancer. However, a significant limitation to a successful ablation procedure is the heat-sink effect, which may lead to suboptimal thermal dose delivery. Currently, there is no reliable method for quantifying the heat-sink effect due to limited information on blood vessel flow and its associated anatomy relative to the ablation zone. The purpose of this study was to use 4D-flow MRI to map out liver flow patterns and correlate flow rates with ablation zone volumes. Female domestic swine (n=3) were anesthetized and prepared as per IACUC guidelines. A subject-specific map of the hepatic vasculature was generated via 4D-flow MRI. Microwave ablation zones were created in individual liver lobes near major vessels by applying 65 W for 5 minutes through a high-powered microwave antenna. For each ablation zone, the pre-ablation and post-ablation flow rates (mL/sec) of the encompassed vessels, as well as their corresponding ablation sizes (mL) were recorded and analyzed via logistic regression modeling and Student t-test. A total of n=9 ablation zones were created that encompassed individual portal and hepatic veins. There were 3/6 (50%) thrombosed portal veins and 0/8 (0%) thrombosed hepatic veins (p=0.21). Hepatic vein flow rate decreased significantly after ablation (2.3±0.7 mL/sec vs 1.5 ±0.4 mL/sec, p=0.01). Portal vein flow rate similarly decreased (2.1±0.9 mL/sec vs 1.8±1.1 mL/sec, p=0.72) after ablation, although not significantly so. Ablation zones that encompassed vessels with flow rates > 2.0 mL/sec were significantly smaller in volume than ablation zones encompassing vessels with flow rates < 2.0 mL/ sec (4.2±3.0 mL vs 9.3±2.5 mL, p=0.03). Microwave ablation zones were found to be significantly smaller in volume when encompassing vessels with flow rates greater than 2.0 mL/sec. Both portal veins and hepatic veins show decreased flow in ablation zones, likely relating to their response to thermal damage. Mapping out blood flow vasculature with 4D-flow MRI prior to ablation zones can assist clinicians in deciding how aggressively to treat liver tumors.

SPLENIC SIZE RELATION TO THE PORTAL VEIN DOPPLER ANALYSIS IN SUDANESE LIVER TRANSPLANTS

The purpose of this study was to identify the specific Doppler criteria for the portal vein as well as the spleen length or volume in liver transplants. A relative study was done after performing venous Doppler sonographic studies in 45 liver transplant cases (4 whole liver, 41 lobar) with no known vascular complications. The ultrasonic Doppler study were targeted to the portal vein flow direction, flow velocity in Doppler level and the caliber in gray scale level. Average gray scale and color flow mapping appearances as well as normal monophasic wave character was found. The following Doppler parameters were evaluated: for the portal veins, venous pulsatility index. There were no cases of portal vein obstruction found in our sample (neither stenosis, nor occlusion). Mean portal vein velocity was (less than 55 cm /s), the splenic length was (13.7±1.5). The relation between the portal venous index, and the splenic length was built. Both are useful parameters for diagnosing liver transplants complications.

Portal Venous Flow Alterations in Hepatic Artery Thrombosis Following Liver Transplant.

The hepatic vasculature is a unique system due to a dual supply that includes the hepatic artery and portal vein, which interact when the liver vascular supply is decreased. Hepatic artery buffer response, an intrinsic regulatory mechanism that compensates for blood supply, maintains increased hepatic artery flow and caliber in response to portal vein failure. Previous studies revealed that portal vein flow showed no alterations to establish adequate blood supply in response to hepatic artery occlusion. Here, we analyzed portal vein flow changes in patients with hepatic artery thrombosis after liver transplant. From December 1988 to October 2017, our center performed 580 liver transplant procedures. Those diagnosed with hepatic artery thrombosis (19 females, 24 males) by Doppler ultrasonography during postoperative week 1 were analyzed. Patients received either surgery or endovascular treatment for hepatic artery thrombosis, with patency confirmed by Doppler ultrasonography. We compared portal vein flow velocity and caliber before and after treatment using Wilcoxon signed rank and Mann Whitney U tests. Mean patient age was 18.9 ± 21.4 years. Portal vein flow velocity pretreatment (median of 70 cm/ s) was significantly higher than posttreatment (median of 52 cm/ s) in all patients (P < .001). Median flow velocity decreased significantly after treatment when subgroups were compared, including age (adult vs child), transplant type (orthotopic transplant vs living donor), and treatment (surgery vs endovascular). However, portal vein flow velocity showed a significantly higher decrease in the surgery subgroup than in the endovascular treatment subgroup (P = .018). There was no significant relationship between portal vein calibers before and after treatment (P = .36). The significant decrease in portal vein flow velocity after successful treatment of hepatic artery thrombosis may represent a compensatory flow change of the portal vein in response to diminished hepatic artery flow.

Intrahepatic Portosystemic Venous Shunt in a Non-Cirrhotic Adult Female with Encephalopathy

Introduction: Intrahepatic portosystemic venous shunts (IPSVS) are rare anomalous vascular connections within the liver that are often asymptomatic. However, significant shunting of blood may present as encephalopathy. Cross sectional imaging and Doppler studies are essential to characterize the shunt and determine portosystemic shunt ratios. High flow shunts may be treated using coil embolization or surgery. Result: We present the case of a 57-year-old previously asymptomatic lady who was admitted for confusion and behavioral change. Work-up revealed deranged liver function and hyperammonemia. Triphasic CT scan showed an aneurysmal connection between the right anterior portal vein and the middle hepatic vein measuring 1.9 cm in widest diameter. The left portal vein was small. The liver had homogenous parenchyma and smooth borders. Aside from small hepatic cysts, there were no other lesions detected. Doppler ultrasound showed turbulent flow across the connection with a portovenous shunt ratio of 73%. The size of the shunt precluded safe coil embolization. Surgical treatment was then opted for and she underwent a hepatotomy from the superior border of the liver until the aneurysmal shunt connection was identified and isolated. The connection was then divided between clamps and the stumps sutured close. Blood flow in the left portal vein then increased immediately. Her postoperative course was unremarkable and she was discharged improved. She remains well 8 months after surgical correction of the shunt. Conclusion: A high index of suspicion should prompt the search for IPSVS in patients presenting with encephalopathy in the absence of liver cirrhosis. Imaging studies are essential in assessing the type and severity of the portovenous shunting and in guiding the management. Symptomatic patients with high shunt ratios should be treated promptly using interventional radiologic procedures or surgery.

Ultrasonic measurements of the liver in Mongolians

Purpose To identify the ultrasonic measurements of the liver in Mongolians. Materials & Methods in this study were involved 10000 participants aged 18-68, 5000 of them are men and 5000 are women. Ultrasonography was performed in accordance with general standards. We used Aloka alfa-10 with 3.5-5.0 MHz convex probes and dopplerography. The dimension of liver is directly dependent on the BMI, age group. Results average age 43.41 ± 0.43, weight 67.46 ± 0.43 kg, height 164.9 ± 0.23 sm, BMI 24.74 ± 0.15. Liver size was measured ultrasonically anterior-posterior size of right and left lobes. This measurement 107.6 ± 0.36 mm of the right lobe, 58.6 ± 0.50 mm of left lobe. Diameter of portal vein is 9.90 ± 0.12 mm, the blood flow of portal vein to the liver, Vp = 26,18 sm/sec. The size of liver directly related with BMI. In patients aged over 68 right lobe size was 94,32 ± 0,57 mm, and left lobe size was 55.6 ± 0.51mm. Conclusion The ultrasound measures of liver in Mongolians are 5 right lobe 107.6 ± 0.36 mm, left lobe 58.6 ± 0.50 mm, portal vein 9.90 ± 0.12 mm. Liver size is directly related with BMI, age and gender.

Big steps in advances of doppler ultrasound

Doppler Ultrasound is clinically important for evaluation of various hepatic vascular disease as well as hepatic vessel evaluation after liver transplantation. However, there are some limitations in conventional Doppler methods as follows: 1) time consuming and labor intensive and 2) limited slow flow sensitivity. There are two recently advanced Doppler signal-processing methods (i.e., UltraFast and superb microvascular imaging), which overcome those limitations. UltraFast Doppler ultrasound, which emerged with the advent of massive parallel computing (or processing) capabilities, transmits several tilted plane waves into the medium and coherently sums the backscattered echoes to reconstruct US images, leading to a marked increase in the frame rate, while conventional ultrasound imaging involves sequential medium insonification via focused beams and successive image reconstruction. A stored UltraFast Doppler clip contains information on both spectral analysis and color-coded flow imaging and could be retrospectively evaluated quantitative analysis, because UltraFast ultrasound has high spatio-temporal resolution. Superb microvascular imaging (SMI, Cannon Medical Systems Corporation, Tochigi, Japan) uses a different kind of adaptive wall filter, which could minimize the flash artifact and increased sensitivity to slow flow and improve the signal detection of flow from small vessels. Therefore, in clinical practice, UltraFast Doppler can be performed by anyone. If the exam protocol such as acquisition of clip by less experienced sonographer and evaluation by retrospective wave reconstruction by specialist can be established, efficient work force management can be possible. Superb Microvascular imaging can distinguish very slow portal flow by portal hyper tension and so forth from thrombus. Thrombus can be evaluated with almost the same resolution as CT. The weak flow of a small hepatic artery hiding by vigorous flow of portal vein after liver transplantation can be also distinguished. In conclusion, smart application of recent advanced Doppler technique will help comprehensive assessment of hepatic vascular abnormalities.

A Tailored Strategy for Recipient Hepatectomy: Left Portal Flow Preserving High Hilar Dissection

Summary: High hilar dissection (HHD) technique was reported as a novel technique for recipient hepatectomy. It allowed performing multiple tension-free duct to duct biliary anastomoses, hence reducing biliary complications. However, longer anhepatic phase is its main drawback. We describe a new modification of HHD technique, called left portal vein flow preserving HHD (LFP-HHD). It involves high intrahepatic division of hilar structures while maintaining the portal venous drainage through the left portal vein. Control of right hemi-liver inflow allows for division of the right hepatic vein, and further dissection of the retro-hepatic inferior vena cava easily and safely. Dissection of the anterior hilar structures can be accomplished. According to the co-ordination with the donor and bench surgery, the liver could be easily explanted. LFP-HHD technique is a novel simple technique for recipient hepatectomy that can be tailored for certain clinical conditions. It overcomes limitations of original HHD technique without compromising its merits.

Intraoperative stent placement for the treatment of acute portal vein complications in pediatric living donor liver transplantation.

Pediatric living donor liver transplantation (LDLT) in low weight recipients remains one of the most complex surgical procedures, with portal vein (PV) complications occurring in up to 19% of cases. When decreased PV flow is diagnosed intra- or perioperatively, intraoperative stent placement is a good substitute for surgical adjustment. Still, at the present moment, little is known about the technical feasibility, safety, efficacy, and long-term outcome of intraoperative stenting in LDLT. Between 2006 and 2017, seven pediatric recipients underwent PV stent placement during the transplant or in the immediate post-operative setting. Preoperative, operative, and post-operative parameters were documented retrospectively. In total, nine stents were placed in seven patients. Procedures were technically successful in all patients. During the mean imaging follow-up period of 1313days, none of the patients showed PV abnormality and PV stent remained patent throughout the post-transplant course. There were no deaths or graft loses during the follow-up period. Intraoperative stenting through the inferior mesenteric vein approach offers both a high feasibility and satisfactory results, with the potential for excellent long-term primary patency despite continued growth in children.