Intrahepatic Left Portal Vein Research Articles

Pediatric liver cirrhosis interventional procedures: from biopsy to transjugular intrahepatic portosystemic shunt

Cirrhosis is a complex diffuse process whereby the architecture of the liver is replaced by abnormal nodules because of the presence of fibrosis. Several pediatric diseases such as extrahepatic portal vein obstruction, biliary atresia, alpha-1-antitrypsin deficit and autoimmune hepatitis can lead to cirrhosis and portal hypertension in children. In this article the authors describe interventional radiology procedures that can facilitate the diagnosis and treatment of diseases associated with liver cirrhosis and portal hypertension in the pediatric population. These procedures include image-guided liver biopsy, mesenteric–intrahepatic left portal vein shunts, balloon-occluded retrograde transvenous obliteration, transjugular intrahepatic portosystemic shunts and splenic embolization.

Value of preoperative computed tomography for meso-Rex bypass in children with extrahepatic portal vein obstruction

BackgroundExtrahepatic portal vein obstruction (EHPVO) is the most important cause of hematemesis in children. Intrahepatic left portal vein and superior mesenteric vein anastomosis, also known as meso-Rex bypass (MRB), is becoming the gold standard treatment for EHPVO. We analyzed the value of preoperative computed tomography (CT) in determining whether MRB is feasible in children with EHPVO.ResultsWe retrieved data on 76 children with EHPVO (50 male, 26 female; median age, 5.9 years) who underwent MRB (n = 68) or the Warren procedure (n = 8) from 2013 to 2019 and retrospectively analyzed their clinical and CT characteristics. The Rex recess was categorized into four subtypes (types 1–4) depending on its diameter in CT images. Of all 76 children, 7.9% had a history of umbilical catheterization and 1.3% had leukemia. Sixteen patients (20 lesions) had associated malformations. A total of 72.4% of Rex recesses could be measured by CT, and their mean diameter was 3.5 ± 1.8 mm (range 0.6–10.5 mm). A type 1, 2, 3, and 4 Rex recess was present in 9.2%, 53.9%, 11.8%, and 25.0% of patients, respectively. MRB could be performed in patients with types 1, 2, and 3, but those with type 4 required further evaluation. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of CT were 100%, 83.8%, 42.1%, 100%, and 85.5%, respectively.ConclusionsAmong the four types of Rex recesses on CT angiography, types 1–3 allow for the performance of MRB.

Description of the Vascular Anatomy of Livers with Absence of the Portal Bifurcation.

The absence of the portal bifurcation (APB) is a rare anatomic variation, in which the horizontal part of the left portal vein (PV) is missing. The aim of this study was to identify the vascular architecture in livers with APB. Computed tomography data for 17,651 patients were reviewed; five patients (0.03%) were found to present with APB. The liver volume and anatomy of APB patients were compared with those of 30 patients with normal livers. All the APB patients exhibited an independent posterior branch of the PV. The intrahepatic left PV (LPV) ran through either the ventral (n = 2, 40%) or dorsal side (n = 3, 60%) of the middle hepatic vein. The frequency of medial branches diverging from the LPV was higher in patients with APB than in normal patients (p < 0.001). The left hepatic duct (LHD) ran through the inside of the left lobe along the left PV in 40% of the patients with APB, whereas in the remaining 60% of the patients with APB, the LHD ran on the outside of the liver separately from the left PV and joined the right hepatic duct. The liver volume of the left lateral section was significantly smaller (p = 0.014), and the posterior section was significantly larger (p = 0.014) in patients with APB than in patients with normal livers. The unique anatomical characteristics and the positional relation of the vessels should be considered preoperatively in patients with APB.

Meso - Rex shunt using the inferior mesenteric vein in a paediatric patient

Abstract Extrahepatic portal vein obstruction primarily results from congenital vascular malformations or acquired portal venous thrombosis. Portal hypertension can lead to various complications such as recurrent upper gastrointestinal hemorrhage secondary to varices, ascites, hypersplenism, or encephalopathy. Meso-rex shunt is a curative surgical procedure that uses autologous vein graft as a bypass to redirect blood from the superior mesenteric vein (SMV) to the patent intrahepatic left portal vein in patients. The most common vein graft used is internal jugular vein (IJV) harvested from the patient's neck. Meso-Rex shunt using the inferior mesenteric vein (IMV) has been rarely described in the literature. It avoids neck dissection and its associated complications. It also reduces the number of anastomoses down to one. We report a 14-year-old girl who underwent a successful meso-Rex shunt using the IMV and summarize the literature.

Splenectomy with proximal spleno-left portal shunt for extrahepatic portal vein obstruction in children

PurposeTo report our initial experience with splenectomy and proximal spleno-left portal shunt as an alternative to the standard Rex shunt, when not applicable, in children with Extrahepatic Portal Vein Obstruction (EHPVO). MethodsPatients from March 2015 till September 2018, with EHPVO not suitable for Rex shunt or whose caregivers refused to consent for Internal Jugular Vein (IJV) dissection were assessed and prepared for splenectomy with proximal spleno-left portal shunt. The operative technique includes splenectomy, freeing of the splenic vein from the pancreatic bed till its junction with the inferior mesenteric vein, and then anastomosis with the intrahepatic left portal vein at the Rex recess. A distal lieno-renal shunt was performed in one patient and was excluded from the study. ResultsA total of 14 patients (mean age: 4.6 years) underwent splenectomy with proximal spleno-left portal shunt during the study period. The mean operative time was 246 min, while the mean postoperative hospital stay was 4.1 days. The patients' follow up period ranged from 6 to 42 months (median: 19.6 months). Only two patients had a single attack of variceal bleeding, 2 and 2.5 months postoperative respectively, and required endoscopic management with no further bleeding episodes. While the rest of patients showed an improvement of their variceal grades after the surgery. ConclusionSplenectomy with proximal spleno-left portal shunt seems to be a valuable alternative to the standard Rex shunt in treatment of children with EHPVO unsuitable for or following unsuccessful Rex shunt. Level of evidenceIV

The value of multi-slice spiral computed tomography portography in assessing severity of liver cirrhosis and predicting episode risks of hepatic encephalopathy

To explore the clinical value of multi-slice spiral computed tomography portography (MSCTP) in assessing severity of liver cirrhosis and predicting episode risks of hepatic encephalopathy (HE). Eighty-six patients with liver cirrhosis who were hospitalized in the Department of Gastroenterology at the Affiliated Hospital of Yan'an University were included in the study.All patients underwent 64-slice MSCTP to grade the portal vein anatomy.The West Haven criteria were used for semi-quantitative assessment of each patient's mental state.The Child-Pugh grading system was used to assess the extent of cirrhosis.Comparison of measurement data between multiple groups was made by one-way ANOVA analysis, and comparison of such between two groups was made by the Mann-Whitney U test, Ranked data were compared with the rank-sum test, and count data were compared by the Chi-Square test.Correlation analysis was performed with Spearman's correlation test. Comparison of the HE grade III group and the HE grade I group showed significant differences between the two in the diameters of left gastric vein, the splenic vein, the intrahepatic left portal vein and the intrahepatic right portal vein (P less than 0.05).Comparison of the Child-Pugh grade C group and the Child-Pugh grade A group showed significant differences between the two in diameters of the left gastric vein, the splenic vein, the intrahepatic left portal vein and the intrahepatic right portal vein (P less than 0.05).The diameters of the main portal vein were not significantly different between the ChildPugh grades and HE classifications (P more than 0.05).The results of MSCTP did show significant differences between different HE classifications in patients with liver cirrhosis and the rate of formation of portal vein thrombosis and fistulas of the hepatic artery-portal vein (P less than 0.05), .but no significant differences with the esophageal and gastric varices, varicose veins around the esophagus, and periumbilical varicose veins (P more than 0.05).HE classification was significantly correlated with formation of portal vein thrombosis and fistula of the hepatic artery-portal vein (r=0.687, P less than 0.05 and r=0.565, P less than 0.05, respectively).MSCTP grading (grade 1:n=35, grade 2:n=36, grade 3:n=15) was not correlated with the Child-Pugh grade (grade A:n=36, grade B:n=32, grade C:n=18) (Z=-0.135, P more than 0.05).Incidence of HE was significantly different among the different MSCTP grades (grade 1:0%(0), grade 2:33.3% (12/36), grade 3:66.7% (10/15); x2=26.468, P less than 0.05).The MSCTP grade was significantly correlated with the episode risks of HE (r=0.552, P less than 0.05). MSCTP may be valuable for assessing severity of liver cirrhosis and for predicting episode risks of HE; however, future studies with larger sample numbers is required for validation of our findings.

Meso-Rex bypass for extrahepatic portal vein obstruction in children

Meso-Rex bypass (MRB) and portosystemic surgical shunt (PSS) are both used to treat extrahepatic portal vein obstruction (EHPVO) in children. The aim of this study was to analyse the outcome of MRB and PSS to select patients who could benefit from a prophylactic MRB. This single-centre retrospective study of children who underwent either MRB or PSS for EHPVO was conducted between 1996 and 2010. Details of patient demographics and preoperative evaluation were collected. Success rates, defined as shunt patency after a minimum of 6 months and clearance of varices or symptoms, were compared. Determinants of outcomes were explored. Sixty-nine patients underwent a MRB or PSS. Median (interquartile range, i.q.r.) age at surgery was 6.6 (4.0-10.6) years. Twenty-four patients (35 per cent) had had a neonatal umbilical catheter (NUC) placed previously and 47 (68 per cent) had experienced an upper gastrointestinal bleed. Imaging assessment of the intrahepatic left portal vein was considered favourable in 40 patients. Of 43 MRBs attempted, 11 failed during surgery and four patients had persistent thrombosis after a median of 55 (i.q.r. 18-107) months. The success rate of MRB was 60 per cent (26 of 43) compared with 100 per cent (26 of 26) for PSS (P < 0.001). It was lower among patients in whom a NUC had been used (2 of 10 versus 24 of 33; P = 0.004), for procedures undertaken early in the series (6 of 16 versus 20 of 27; P = 0.020) and when the imaging pattern was unfavourable (0 of 5 versus 26 of 38; P = 0.006). On multivariable analysis, only a previous history of NUC predicted failure (P = 0.016). Prophylactic MRB seems a good treatment option for EHPVO in children, but should be done only by an experienced team in patients with favourable imaging and without a previous history of NUC.

Transplantation of an allogeneic vein bioengineered with autologous stem cells: a proof-of-concept study

Extrahepatic portal vein obstruction can have severe health consequences. Variceal bleeding associated with this disorder causes upper gastrointestinal bleeding, leading to substantial morbidity and mortality. We report the clinical transplantation of a deceased donor iliac vein graft repopulated with recipient autologous stem cells in a patient with extrahepatic portal vein obstruction. A 10 year old girl with extrahepatic portal vein obstruction was admitted to the Sahlgrenska University Hospital in Gothenburg, Sweden, for a bypass procedure between the superior mesenteric vein and the intrahepatic left portal vein (meso Rex bypass). A 9 cm segment of allogeneic donor iliac vein was decellularised and subsequently recellularised with endothelial and smooth muscle cells differentiated from stem cells obtained from the bone marrow of the recipient. This graft was used because the patient's umbilical vein was not suitable and other strategies (eg, liver transplantation) require lifelong immunosuppression. The graft immediately provided the recipient with a functional blood supply (25-30 cm/s in the portal vein and 40 mL/s in the artery was measured intraoperatively and confirmed with ultrasound). The patient had normal laboratory values for 9 months. However, at 1 year the blood flow was low and, on exploration, the shunt was patent but too narrow due to mechanical obstruction of tissue in the mesocolon. Once the tissue causing the compression was removed the graft dilated. We therefore used a second stem-cell populated vein graft to lengthen the previous graft. After this second operation, the portal pressure was reduced from 20 mm Hg to 13 mm Hg and blood flow was 25-40 cm/s in the portal vein. With restored portal circulation the patient has substantially improved physical and mental function and growth. The patient has no anti-endothelial cell antibodies and is receiving no immunosuppressive drugs. An acellularised deceased donor vein graft recellularised with autologous stem cells can be considered for patients in need of vascular vein shunts without the need for immunosuppression. Swedish Government.

Pre- and postoperative imaging and interventions for the meso-Rex bypass in children and young adults

The meso-Rex bypass is a physiological and anatomical bypass procedure for relief of extrahepatic portal vein obstruction and restoration of mesenteric venous return to the liver. Most patients who are candidates for the bypass are children or young adults with portal hypertension and hypersplenism secondary to cavernous transformation of the portal vein. Most frequently, the bypass utilizes an autologous venous graft to connect the intrahepatic left portal vein to the infrapancreatic superior mesenteric vein (SMV) re-establishing first-pass portal perfusion. We describe the preoperative imaging of the 92 bypass candidates, the surgical anatomy as reflected in postoperative imaging, and the imaging of bypass complications at our institution.Preoperative imaging with US, CT and MR is directed to demonstrate patency and size of the left portal vein and SMV, to define the extent of cavernous transformation and splanchnic collaterals, and to assess for any associated abdominal vascular or solid organ abnormalities. Postoperative imaging is aimed at diagnosing meso-Rex bypass stenosis or occlusion and the interventional management of these complications.

Carbon dioxide‐based portography: An alternative to conventional imaging with the use of iodinated contrast medium

To clarify the efficacy of carbon dioxide (CO(2)) as a contrast material to evaluate portal vein images by percutaneous transhepatic portography (PTP). Twenty patients (38-76 years; male 13, female 7) with chronic liver diseases were the subjects of this prospective study. Portal venous opacification by PTP was compared between CO(2)-based images and iodinated contrast medium (ICM)-based images by two independent reviewers, according to the three-grade scoring; 0 for none, 1 for weak and 2 for sufficient. Total scores of extrahepatic portal veins (137 for CO(2), 93 for ICM), collateral vessels (64 for CO(2), 60 for ICM) and intrahepatic portal veins (69 for CO(2), 76 for ICM) were not statistically significant between CO(2)-based and ICM-based images (P = 0.0623). Sufficient opacification of superior mesenteric vein was more frequent on CO(2)-based images (none 0, weak 4, sufficient 16) than ICM-based images (none 19, weak 0, sufficient 1; P < 0.0001). The score was not statistically significant between CO(2)-based and ICM-based images in portal trunk, splenic vein, inferior mesenteric vein and other collateral vessels. Although opacification grade in the intrahepatic left portal vein was not statistically significant between CO(2)-based and ICM-based images (P = 0.1515), weak opacification was significantly frequent on CO(2)-based images (weak 10, sufficient 10) compared to ICM-based images (weak 0, sufficient 20; P = 0.0003) in the intrahepatic right portal vein. Inter-reviewer agreement was excellent between the two reviewers for CO(2)-based images (kappa = 0.913) and ICM-based images (kappa = 0.924). Carbon dioxide may be a first-line contrast material for evaluating portal vein images by PTP.

Rapid Intrahepatic Tumor Seeding after Percutaneous Ethanol Injection Therapy for Hepatocellular Carcinoma

A 73-year-old man with hepatocellular carcinoma (HCC) had been treated repeatedly with transcatheter arterial embolization (TAE) and percutaneous ethanol injection therapy (PEIT) since 2000. HCC recurrence near the intrahepatic left portal vein was treated by PEIT in 2004. The patient complained of fatigue and upper abdominal pain 28 days later. Abdominocentesis and abdominal computed tomography demonstrated rupture of the recurrent HCC and multiple intrahepatic recurrences. We successfully performed emergency TAE, but the patient died of liver failure. Rapid seeding of multiple intrahepatic tumors after PEIT is a rare event, but such a possibility must be kept in mind.

Congenital hepatic shunts.

Abnormal vascular connections within the hepatic parenchyma are occasionally seen at ultrasonography (US) and require further evaluation. The radiologic findings in 42 children with infantile hepatic hemangioma (n = 28), vascular malformations (n = 10), or infradiaphragmatic total anomalous pulmonary venous return (TAPVR) (n = 4) associated with congenital vascular shunting were retrospectively reviewed. Arteriovenous connections are seen in infantile hepatic hemangiomas and arteriovenous malformations and manifest with aortic tapering at the level of the celiac trunk, hepatic artery enlargement with a low resistivity index (RI), and increased flow velocities in the hepatic veins that may assume an arterialized spectral pattern in late-stage disease. Congenital arterioportal shunts demonstrate a low RI in the hepatic artery, hepatofugal arterialized flow in the portal vein, and rapid development of signs of portal hypertension. Portosystemic shunting may be intra- or extrahepatic. A pulsatile triphasic spectral pattern is seen in the portomesenteric venous system in children with portosystemic shunting, and macroscopic connections between the portal system and the hepatic veins are evident. Infradiaphragmatic TAPVR is associated with a tortuous vessel that parallels the aorta, ends at the intrahepatic left portal vein or the ductus venosus, and has hepatopetal flow. Familiarity with the US features of various congenital abnormal hepatic vascular connections will aid in diagnosis and treatment.

Experience with the Rex shunt (mesenterico-left portal bypass) in children with extrahepatic portal hypertension

Extrahepatic portal vein thrombosis (EPVT) in children can lead to severe bleeding from gastrointestinal varices, ascites, thrombocytopenia from hypersplenism, and other coagulation disorders. The authors have used the superior mesenteric vein to intrahepatic left portal vein (Rex) shunt in 5 children with symptomatic EPVT and report their results with this novel technique. Children with symptomatic portal hypertension were screened for the underlying cause. All children with essentially normal livers and obstruction of the extrahepatic portal vein were considered for the Rex shunt. Evaluation included liver function tests, liver biopsy, and radiological evaluation of the intrahepatic vascular anatomy. Five patients between the ages of 2.8 and 10.5 years underwent evaluation for portal hypertension secondary to extrahepatic portal vein obstruction. Three patients had idiopathic extra hepatic portal vein thrombosis with cavernous transformation, 1 had thrombosis after a living-related liver transplant, and 1 had compression and obstruction of the main portal vein from enlarged lymph nodes after treatment of systemic histoplasmosis. All patients were symptomatic. Three patients had intermittent bleeding from esophageal and gastric varices, and all 5 had relative degrees of hypersplenism with enlarged spleens and thrombocytopenia (11,000 to 77,000). Three patients had significant leukopenia. Results of imaging studies suggested that 3 patients had inadequate intrahepatic portal veins for shunting, but all patients at exploration underwent successful shunting. There were no serious intraoperative complications. Postoperative complications included ascites in 2 patients that resolved within 1 month. There were no early shunt thromboses. The median postoperative length of stay was 7 days. Clinical follow-up ranged from 7 to 21 months. Gastrointestinal bleeding did not recur in any patient, and ascites resolved in all. Spleen size decreased significantly (P < .01) from 9.4 +/- 4.0 cm to 5.0 +/- 3.7 cm below the left costal margin. Mean platelet count and white blood cell count rose after shunting from 79 +/- 42 to 176 +/- 73 (P < .02) and 5.4 +/- 2.3 to 7.5 +/- 3.9 (P = .06), respectively. All shunts were studied at 1 and 7 days, and 3 and 6 months after the procedure. Shunt patency was documented in all cases. Subsequently, shunt blockage occurred in 2 patients. The Rex shunt has proven to be an effective method of resolving portal hypertension caused by EPVT including thrombosis after living donor transplantation. This shunt is preferable to other surgical procedures because it eliminates portal hypertension and its sequelae by restoring normal portal flow to the liver.