Intrahepatic Portal Vessels Research Articles

Hypoattenuating periportal halo on CT in a patient population can occur in presence of a variety of diseases.

Many pathologies can occur in the periportal space and manifest as fluid accumulation, visible in Computed tomography (CT) images as a circumferential region of low attenuation around the intrahepatic portal vessels, called periportal halo (PPH). This finding is associated with different types of hepatic and extra-hepatic disease in humans and remains a non-specific sign of unknown significance in veterinary literature. The aim of this study was to investigate the prevalence of PPH in a population of patients undergoing CT examination and to assess the presence of lesions related to hepatic and extra-hepatic disease in presence of PPH. CT studies including the cranial abdomen of dogs and cats performed over a 5-year period were retrospectively reviewed. The prevalence of PPH was 15% in dogs and 1% in cats. 143 animals were included and the halo was classified as mild, moderate and severe, respectively in 51%, 34% and 15% of animals. The halo distribution was generalized in 79 cases, localized along the second generation of portal branches in 63, and along the first generation only in one. Hepatic disease was present in 58/143 and extra-hepatic disease in 110/143 of the cases. Main cause of hepatic (36%) and extra-hepatic disease (68%) was neoplasia. Associations between halo grades and neoplasia revealed to be not statistically significant (p = 0.057). In 7% of animals the CT examination was otherwise unremarkable. PPH is a non-specific finding, occurring in presence of a variety of diseases in the examined patient population.

Intrahepatic venous collaterals in dogs with congenital intrahepatic portosystemic shunts are associated with focal shunt or hepatic vein narrowing

Dogs with congenital intrahepatic portosystemic shunts (IHPSS) occasionally have multiple smaller intrahepatic, tortuous blood vessels surrounding the primary shunt. This study was a retrospective, observational design that was also descriptive and anatomic in nature. Objectives were to characterize vascular morphology in IHPSS dogs presenting with intrahepatic venous collaterals (IVCs) relative to IHPSS dogs without IVCs, and to propose reasons for IVC development. The authors hypothesized that (a) IVCs develop secondary to flow resistance around a focal area of a shunt or draining hepatic vein narrowing and (b) the presence of IVC is associated with portal vessel development before intervention. Anonymized CT angiograms (CTA) and fluoroscopic portovenograms (FPV) of dogs with IHPSS were evaluated for the presence of IVCs, focal narrowing within the IHPSS, and intrahepatic portal vessels>5mm long. Eleven of 47 (23%) dogs had IVCs identified. IVCs were significantly associated with focal narrowing in the shunt or draining hepatic vein on CTA (P=0.039) and FPV (P=0.021). IVCs were not associated with the presence of intrahepatic portal branches>5mm long on portovenography (P=0.42) or CTA (P=0.49). Focal narrowing in the shunt (circumferential soft tissue narrowing>20% of the shunt diameter) was significantly associated with intrahepatic portal branches>5mm long on both modalities (P<0.001). IVCs are associated with focal narrowing of the shunt or draining hepatic vein in dogs with IHPSS. IVC should be distinguished from other conditions when evaluating a CTA for canine IHPSS.

Use of clinician-performed ultrasound in the assessment of safe umbilical venous catheter tip placement.

Safe tip placement of umbilical venous catheters (UVCs) in sick neonates is critical in minimising risk. We aimed to demonstrate the utility of clinician-performed ultrasound (CPU) in identifying UVCs that are placed within small intrahepatic portal vessels or within the heart despite the appearance of being well placed on X-ray. This was a retrospective observational study of preterm and term neonates who had a UVC placed and the position assessed by X-ray and/or CPU according to the Royal Prince Alfred Hospital level 3 neonatal intensive care unit (NICU) guideline. Cases were identified by exporting the records of all admissions between 1 April 2015 and 30 June 2016 from the NICU's data collection database. Paper-based medical records, NICU's data collection database records and the ultrasound reporting system were reviewed to determine X-ray and CPU findings. A total of 157 neonates had 169 UVCs placed. CPU was performed in 77% (111). In 15 cases (14%), UVC placement on X-ray appeared appropriate based on estimated vertebral level; however, CPU demonstrated the line to be in an unsafe position (small intrahepatic portal vessel (3); right atrium (9); left atrium (3)). Assessment of safe UVC placement by estimations according to vertebral level on X-ray alone is inadequate. CPU offers confident localisation of the UVC tip and enables corrective manipulation of intracardiac or intrahepatic UVCs in real time. We recommend CPU as an adjunct to X-ray to ensure safe UVC placement.

The role and significance of digital reconstruction technique in liver segments based on portal vein structure

Objective: To study the segment of liver according to the large amount of three-dimensional(3D) reconstructive images of normal human livers and the vascular system, and to recognize the basic functional liver unit based on the anatomic features of the intrahepatic portal veins. Methods: The enhanced CT primitive DICOM files of 1 260 normal human livers from different age groups who treated from October 2013 to February 2017 provided by 16 hospitals were analyzed using the computer-aided surgery system.The 3D liver and liver vascular system were reconstructed, and the digital liver 3D model was established.The vascular morphology, anatomical features, and anatomical distributions of intrahepatic portal veins were statistically analyzed. Results: The digital liver model obtained from the 3D reconstruction of CAS displayed clear intrahepatic portal vein vessels of level four.Perform a digital liver segments study based on the analysis of level four vascular distribution areas.As the less anatomical variation of left hepatic portal vein, the liver was classified into four types of liver segmentation mainly based on right hepatic portal vein.Type A was similar to Couinaud or Cho's segmentation, containing 8 segments(537 cases, 42.62%). Type B contained 9 segments as there are three ramifications of right-anterior portal vein(464 cases, 36.82%). The main difference for Type C was the variation of right-posterior portal vein which was sector shape(102 cases, 8.10%). Type D contained the cases with special portal vein variations, which needs three-dimensional simulation to design individualized liver resection plan(157 cases, 12.46%). These results showed that there was no significant difference in liver segmental typing between genders(χ(2)=2.179, P=0.536) and did not reveal any significant difference in liver segmental typing among the different age groups(χ(2)=0.357, P=0.949). Conclusions: The 3D digital liver model can demonstrate the true 3D anatomical structures, and its spatial vascular variations.The observation of anatomic features, distribution areas of intrahepatic portal veins and individualized liver segmentation achieved via digital medical 3D visualization technology is of great value for understand the complexity of liver anatomy and to guide the precise hepatectomy.

Reproducibility study of four‐dimensional flow MRI of arterial and portal venous liver hemodynamics: Influence of spatio‐temporal resolution

To evaluate influence of variation in spatio-temporal resolution and scan-rescan reproducibility on three-dimensional (3D) visualization and quantification of arterial and portal venous (PV) liver hemodynamics at four-dimensional (4D) flow MRI. Scan-rescan reproducibility of 3D hemodynamic analysis of the liver was evaluated in 10 healthy volunteers using 4D flow MRI at 3T with three different spatio-temporal resolutions (2.4 × 2.0 × 2.4 mm(3), 61.2 ms; 2.5 × 2.0 × 2.4 mm(3), 81.6 ms; 2.6 × 2.5 × 2.6 mm(3), 80 ms) and thus different total scan times. Qualitative flow analysis used 3D streamlines and time-resolved particle traces. Quantitative evaluation was based on maximum and mean velocities, flow volume, and vessel lumen area in the hepatic arterial and PV systems. 4D flow MRI showed good interobserver variability for assessment of arterial and PV liver hemodynamics. 3D flow visualization revealed limitations for the left intrahepatic PV branch. Lower spatio-temporal resolution resulted in underestimation of arterial velocities (mean 15%, P < 0.05). For the PV system, hemodynamic analyses showed significant differences in the velocities for intrahepatic portal vein vessels (P < 0.05). Scan-rescan reproducibility was good except for flow volumes in the arterial system. 4D flow MRI for assessment of liver hemodynamics can be performed with low interobserver variability and good reproducibility. Higher spatio-temporal resolution is necessary for complete assessment of the hepatic blood flow required for clinical applications.

Association between hepatic histopathologic lesions and clinical findings in dogs undergoing surgical attenuation of a congenital portosystemic shunt: 38 cases (2000–2004)

To review hepatic histopathologic lesions in dogs undergoing surgical attenuation of a congenital portosystemic shunt (CPSS) in relation to clinical findings and tolerance of complete surgical attenuation. Retrospective case series. 38 dogs that underwent surgical attenuation of a CPSS. Hepatic histologic examination findings and medical records of dogs undergoing surgical attenuation of a single CPSS between August 2000 and July 2004 were reviewed. Liver biopsy specimens were obtained from 38 dogs during surgery prior to complete (n = 16) or partial (22) attenuation of a CPSS and from 13 of the same dogs a median of 3 months following surgical attenuation. Portal tracts were inadequate for interpretation in 2 liver biopsy specimens. Liver biopsy specimens obtained prior to surgical attenuation of a CPSS had a lack of identifiable portal veins (13/36 dogs), hepatic arteriolar proliferation (25/36), ductular reaction (5/36), steatosis (16/38), and iron accumulation (32/38). Lack of identifiable portal veins on histologic examination was associated with increased hepatic arteriolar proliferation, decreased tolerance to complete surgical CPSS attenuation, and decreased opacification of intrahepatic portal vessels on portovenography. Ductular reaction was always associated with failure to tolerate complete surgical attenuation of a CPSS. Surgical CPSS attenuation resulted in significant clinical, serum biochemical, and portovenographic changes indicative of improved liver function, but only subtle changes in hepatic histologic examination findings. Dogs without identifiable intrahepatic portal veins that had a ductular reaction on hepatic histologic examination were less likely to tolerate complete attenuation of a CPSS.

Association of mesenteric portovenographic findings with outcome in cats receiving surgical treatment for single congenital portosystemic shunts

To determine whether hepatic portal vascularity assessed via intraoperative mesenteric portovenography (IMP) is related to outcome in cats undergoing surgical attenuation of a congenital portosystemic shunt (CPSS). Retrospective case series. 25 cats, each with 1 CPSS, in which IMP was performed before and after temporary complete occlusion of the shunting vessel to provide complete (n=9) or partial (16) shunt attenuation. Medical records were reviewed for signalment, clinical history, postoperative complications, clinical outcome, and results of bile acids stimulation testing. Portovenograms obtained before and after shunt occlusion were graded to determine whether degree of intrahepatic portal branching was correlated with degree of shunt attenuation, clinical or biochemical factors, postoperative complications, or outcome. In 12 of the 16 cats that had partial CPSS attenuation, procedures were later repeated to achieve complete (n=9) and additional partial (1) CPSS attenuation. Degree of opacification of the intrahepatic portal vessels increased significantly (higher portovenogram grade) after CPSS attenuation. The median portovenogram grade assigned after temporary shunt occlusion at the first surgery was significantly higher in cats that did not have postattenuation neurologic complications or neurologic signs at follow-up than in cats that did. It was also higher in cats that had a better clinical response to surgery versus those that had a poor response and in cats with reduced preprandial and postprandial serum bile acids concentrations at follow-up versus those that did not. IMP may be used to help predict complications and outcome following surgical treatment of CPSS in cats.

Cortocircuitos venosos portosistémicos intrahepáticos: diagnóstico mediante ecografía Doppler

Intrahepatic portasystemic venous shunts are venous vascular lesions that allow intrahepatic portal vessels to communicate with hepatic veins. They may present in patients with portal hypertension or be discovered incidentally; it is considered that the latter may be congenital or acquired.A noninvasive method, Doppler ultrasound aids in the diagnosis of these anomalous communications by providing images of the vessels and the direction, velocity and volume of the blood flow through the shunt.We present four cases of intrahepatic portasystemic venous shunt.

Hemodinamic changes in intrahepatic portal vessels after percutaneous ethanol injection of hepatocellular carcinoma under general anesthesia

Hemodinamic changes in intrahepatic portal vessels after percutaneous ethanol injection of hepatocellular carcinoma under general anesthesia

Reverse flow in intrahepatic portal vessels and liver function impairment in cirrhosis

Objectives: Our aim was to describe the hemodynamic patterns and assess the prevalence of reversal of flow (RF) in intrahepatic portal vessels (IPV) in patients with chronic active hepatitis (CAH) and patients with cirrhosis. Patients : 100 consecutive patients with CAH, and 178 consecutive cirrhotic patients (48 Child A, 114 Child B and 38 Child C class) underwent Echo-Color-Doppler for evaluation of flow direction in segmental IPV, right and left portal vein (RPV, LPV), in main portal vein (MPV), splenic vein (SV), superior mesenteric vein (SMV) and porto-systemic shunts (paraumbilical, spleno-renal, left gastric vein). The patients were followed-up clinically for 3–15 months. Results: Patients with CAH showed RF in SV in 1/100 and hepatopetal flow in MPV, SMV, SV, IPV in 99/100 patients. Eleven of 178 (6.2%) cirrhotic patients showed RF only in the SV, 3/178 (1.7%) showed alternating (`back and forth') flow only in IPV, RPV and LPV with continuous hepatopetal flow in PV and 10/178 (5.6%) showed completely RF in IPV. Four of ten patients of this last group showed hepatopetal flow in MPV. The other six patients showed RF in MPV associated with hepatofugal flow through a large left gastric vein in three cases and through the SV in three cases. The other cirrhotic patients (154/178=86.5%) showed hepatopetal flow in IPV, MPV, SMV and SV. In no case RF in SMV was observed. Prevalence of RF in IPV was significantly higher in Child C patients (8/31=25.8%) than Child B patients (5/104=4.7%) and than in Child A patients (0%) (p<0.01). Prevalence of Child C class was significantly higher in patients with RF in IPV (8/13=61.5%) than in patients with RF only in extraepatic portal vessels (2/11=18.2%) and patients without RF (21/154=13.6%) (p<0.001). No patient with RF in IPV was in Child A class. Incidence of death was significantly higher in patients with RF in IPV than in patients without RF and patients with RF only in SV. Conclusions: RF in IPV is not a rare event (9% in our series) that mainly occurs in cirrhosis with advanced liver function impairment.

IMO 1412 Hemodinamic changes in intrahepatic portal vessels after percutaneous ethanol injection of hepatocellular carcinoma under general anesthesia

IMO 1412 Hemodinamic changes in intrahepatic portal vessels after percutaneous ethanol injection of hepatocellular carcinoma under general anesthesia

ULTRASONOGRAPHIC DIAGNOSIS OF CONGENITAL PORTOSYSTEMIC SHUNTS IN DOGS: RESULTS OF A PROSPECTIVE STUDY

The aims of this study were to determine if accurate diagnosis of congenital portosystemic shunt was possible using two dimensional, grey‐scale ultrasonography, duplex‐Doppler, and color‐flow Doppler ultrasonography in combination, and to determine if dogs with congenital portosystemic shunts have increased or variable mean portal blood flow velocity. Eighty‐two dogs with clinical and/or clinicopathologic signs compatible with portosystemic shunting were examined prospectively. Diagnosis of congenital portosystemic shunt was subsequently confirmed in 38 of these dogs using operative mesenteric portography: 14(37%) dogs had an intrahepatic shunt and 24(63%) had an extrahepatic shunt. Ultrasonography had a sensitivity of 95%, specificity of 98%, and accuracy of 94%. Ultrasonographic signs in dogs with congenital portosystemic shunts included small liver, reduced visibility of intrahepatic portal vessels, and anomalous blood vessel draining into the caudal vena cava. Correct determination of intra ‐ versus extrahepatic shunt was made ultrasonographically in 35/38 (92%) dogs. Increased and/or variable portal blood flow velocity was present in 21/30 (70%) dogs with congenital portosystemic shunts. In one dog with an intrahepatic shunt the ultrasonographic diagnosis was based partly on finding increased mean portal blood flow velocity because the shunting vessel was not visible. Detection of the shunting vessel and placement of duplex‐Doppler sample volumes were facilitated by use of color‐flow Doppler. Two‐dimensional, grey‐scale ultrasonography alone is sufficient to detect most intrahepatic and extrahepatic shunts; sensitivity is increased by additional use of duplex‐Doppler and color‐flow Doppler. Increased and/or variable portal blood flow velocity occurs in the majority of dogs with congenital portosystemic shunts.

Ultrasonographic diagnosis of congenital portosystemic shunt in 14 cats.

Twenty-four cats with clinical and, or, clinicopathological signs compatible with portosystemic shunting were examined prospectively using two-dimensional grey-scale, duplex and colour-flow Doppler ultrasonography. Diagnosis of congenital portosystemic shunt was subsequently confirmed in 14 cats using operative mesenteric portography and surgery. Of the 14 affected cats, nine were purebred; eight were male and six female. The mean age at the time of diagnosis was nine months (range four to 27 months). Ultrasonographic evidence of a small liver was present in seven cats (50 per cent); visibility of intrahepatic portal vessels was reduced in three (21 per cent). An anomalous blood vessel was identified ultrasonographically in each cat; in 10 cats (71 per cent) the vessel was observed to originate from the portal vein and drain into the caudal vena cava. Abnormally variable portal blood flow was present in eight of the 10 cats in which it was measured. At surgery, six shunts were intrahepatic and eight extrahepatic; the ultrasonographic diagnosis of intra- versus extrahepatic shunt was correct in 13 cats (93 per cent). No anomalous blood vessels or abnormalities affecting the portal vein were detected ultrasonographically in any of the 10 cats that did not have congenital portosystemic shunting. Hence, the accuracy of ultrasonography for diagnosis of congenital portosystemic shunting in this series was 100 per cent.

The effect of hepatic portal dissection on the portal vein structure in biliary atresia.

Superior mesenteric portograms were performed on 30 patients with biliary atresia (BA) at the time of initial portoenterostomy in 20, and at the stoma closure operation in 10. A withered-branch-shaped irregularity of the intrahepatic portal vein (PV) and collateral vessels were seen in 2 of 11 patients with portal pressures (PP) of 200 to 300 mmH2O; in 1 of 2 patients with PPs of over 300 mmH2O at the initial operation; and in 3 jaundice-free patients with PPs of 285, 320, and 305 mmH2O, respectively, at the stoma closure operation. Collaterals were the only abnormalities seen in two additional jaundice-free patients with PPs of 370 and 183 mmH2O, respectively. No anatomic changes in the extrahepatic PV at the porta hepatis were found on the portograms of either group of patients. Thus, we conclude that portal dissection itself does not affect the PV structure anatomically, a finding which has important implications in determining whether or not portoenterostomy adversely affects potential liver transplantation.

Vascular complications after liver transplantation: a 5-year experience.

During the past 5 years, 104 angiographic studies were performed in 87 patients (45 children and 42 adults) with 92 transplanted livers for evaluation of possible vascular complications. Seventy percent of the studies were abnormal. Hepatic artery thrombosis was the most common complication (seen in 42% of children studied, compared with only 12% of adults) and was a major complication that frequently resulted in graft failure, usually necessitating retransplantation. In six children, reconstitution of the intrahepatic arteries by collaterals was seen. Three survived without retransplant. Arterial stenosis at the anastomosis or in the donor hepatic artery was observed in 11% of patients. Portal vein thrombosis or stenosis occurred in 13% of patients. Two children and one adult with portal vein thrombosis demonstrated hepatopetal collaterals that reconstituted the intrahepatic portal vessels. Uncommon complications included anastomotic and donor hepatic artery pseudoaneurysms, a hepatic artery-dissecting aneurysm, pancreaticoduodenal mycotic aneurysms, hepatic artery-portal vein fistula, biliary-portal vein fistula, hepatic vein occlusion, and inferior vena cava thrombosis.

Adenosine modulation of hepatic arterial but not portal venous constriction induced by sympathetic nerves, norepinephrine, angiotensin, and vasopressin in the cat.

Intrinsic regulation of hepatic arterial blood flow depends upon local concentrations of adenosine. The present data show that i.a. infusions of adenosine cause dilation of the hepatic artery and inhibition of arterial vasoconstriction induced by norepinephrine, vasopressin, angiotensin, and hepatic nerve stimulation. Vasoconstriction induced by submaximal nerve stimulation (2 Hz) and norepinephrine infusions (0.25 and 0.5 micrograms X kg-1 X min-1, i.p.v.) were equally inhibited by adenosine. Supramaximal nerve stimulation (8 Hz) was inhibited to a lesser extent. The data are consistent with the hypotheses that (a) adenosine causes nonselective inhibition of vasoconstrictor influences on the hepatic artery; and (b) adenosine antagonizes neurally induced vasoconstriction by a purely postsynaptic effect and does not decrease norepinephrine release. In contrast with the hepatic artery, the intrahepatic portal resistance vessels are not affected by even large doses of adenosine; neither responses in basal tone nor antagonism of vasoconstrictor effects of nerve stimulation, norepinephrine, or angiotensin could be demonstrated. The data are consistent with the hypothesis that the smooth muscle of the portal resistance vessels does not contain adenosine receptors, whereas adenosine receptors on the smooth muscle of the hepatic arterial resistance vessels are of major regulatory importance. Whether endogenous levels of adenosine can reach sufficient concentration to modulate endogenous constrictors remains to be determined.

Sonographic differentiation of extra- and intrahepatic masses.

The sonographic features in the evaluation and differentiation of extra- and intrahepatic masses were assessed in two groups of patients. These signs included discontinuity of the liver capsule, internal invagination or external bulging of the liver capsule, formation of a retroperitoneal fat wedge, displacement of the intrahepatic portal vessels or hepatic veins, shift of the inferior vena cava, and displacement of the right kidney. Evaluation of the results in 25 patients in whom the mass was intrahepatic and in 33 with an extrahepatic mass indicates that internal invagination of liver capsule (81.8%), its discontinuity (33.3%), formation of triangular fat wedge (75.7%), shift of the inferior vena cava anteromedially (36.3%), and anterior displacement of right kidney (28.1%) are the signs most frequently observed in extrahepatic masses. The characteristic features of the intrahepatic masses were displacement of hepatic vascular radicles (84%), external bulging of the liver capsule (56%), and posterior shift of the inferior vena cava (32%). The evaluation of masses in the right upper abdomen according to these criteria gives an accurate definition of their anatomic origin. However, masses exceeding 10 cm in diameter may present diagnostic problems.

Angiographic studies of the totally arterialized rat liver.

Twenty-three angiographies were performed in 20 rats with a totally arterialized liver. The arterialization was obtained by the construction of an end-to-side portacaval shunt (PCS) and an arteriovenous (AV) fistula between the left gastric artery and the portal stump. Microsurgical technique was necessary because of the small diameter of the AV fistula (0.5 mm). The angiographic examinations showed an AV fistula patency rate of 70% and a PCS rate of 100%. A successively increasing diameter of the fistula with dilation of the intrahepatic portal vessels was demonstrated in the rats with a patent arterioportal fistula. Tortuous and irregular vessels were also observed. All these signs suggest an overarterialization which developed despite the use of a very small AV fistula. None of the three rats examined histologically had cirrhosis of the liver. Further research is needed to attempt to avoid or minimize the deleterious effects of overarterialization of the portal tree, while utilizing the advantages of a dual liver blood supply in patients with decompressive PCS.

Computer tomographic findings in portal hypertension caused by liver cirrhosis. 1. Morphologic changes--qualitative and quantifiable parameters

The CT findings in 80 patients with confirmed portal hypertension due to intrahepatic block were analysed retrospectively. The findings included ascites, hypo-dense areas in the liver, nodular or irregular liver contour, the inability to define intrahepatic portal vessels with narrow window settings, the so-called "kissing" sign and evidence of hepato-fugal collaterals and thickening of the wall of the oesophagus. Electronic measurements of various organs (liver, spleen) and vessel diameters (portal vein, superior mesenteric vein) provide parameters which permit classification of patients into the cirrhotic group, as compared with a control group. The statistical significance of this classification was checked by the Kolmogoroff-Smirnoff test.

Portographic liver changes in idiopathic noncirrhotic portal hypertension.

Intraoperative and transhepatic portograms in patients with noncirrhotic portal hypertension, or idiopathic portal hypertension, were compared with portograms of patients with liver cirrhosis. Although the portograms in idiopathic portal hypertension varied from case to case, they were distinctly different from those in cirrhosis. The most common features of the former included a paucity of medium-sized portal branches, irregular and often obtuse-angled division of the peripheral branches, occasional abrupt interruptions of them, an avascular area beneath the liver surface, nonopacification of some of the large intrahepatic portal branches and of their periphery, and increase of very fine vasculature around large intrahepatic portal branches. These findings are compatible with occlusion of intrahepatic portal vessels at various levels.