Anterior Portal Vein Research Articles

Analysis of intrahepatic venovenous shunt by hepatic venography

The necessity of preserving hepatic venous drainage in hepatectomy and liver transplantation has recently been accepted; however, the hepatic vein (HV) can be removed when an effective intrahepatic venovenous shunt (VV shunt) exists. Occlusion venography of the right HV (RHV) was performed in 51 patients to investigate the VV shunt characteristics. Twenty patients had a shunt between the RHV and large HVs whose root diameters were >3 mm, such as the superficial or inferior RHV, or the middle HV. Twenty patients had a shunt between the RHV and small HVs with root diameters < or =3 mm. Eleven patients had no shunt. The change in anterior portal vein blood flow after RHV occlusion, evaluated by Doppler ultrasonography, was minimal (5 +/- 3%) in patients with a shunt between the RHV and large HVs, and less than in patients with a shunt between the RHV and small HVs (38% +/- 18%) or without a shunt (50% +/- 17%; P < .0001). A shunt between the RHV and large HV was less frequently seen in those patients with cirrhosis (3/20) than in those without cirrhosis (17/31; P = .0044). The existence of the shunt between the RHV and large HVs was unpredictable, however, from computed tomographic findings or laboratory data. A hemodynamically significant VV shunt between the RHV and large HV was observed in fewer than half of the patients and less frequently in cirrhotic patients. Preservation of hepatic venous drainage should be considered in patients without a hemodynamically significant VV shunt in liver surgery.

Interventional percutaneous trans-splenic approach in the management of portal venous occlusion after living donor liver transplantation

Interventional percutaneous trans-splenic approach in the management of portal venous occlusion after living donor liver transplantation

Portal vein branching pattern in anomalous right-sided round ligament

To study the relationship of anomalous right-sided round ligament with respect to branches of the portal vein. We studied four patients of right-sided round ligament diagnosed radiologically in the last 5 years. 3-D volume rendered CECT abdominal images were analyzed for attachment of the round ligament in the liver in relation to portal venous anatomy and position of gallbladder. In all cases, a trifurcate pattern of portal venous branching was observed. Right-sided round ligament was attached at the point of divergence of the right anterior portal vein. The region to the left of the point of its attachment drained into the middle hepatic vein while the region to the right of the point of attachment drained into the right hepatic vein. The left portal vein branched into posterior and paramedian branches. Right, middle, and left hepatic veins were visualized having normal course in all cases. In all, the gallbladder was present to the left of the round ligament. Trifurcate pattern of portal vein branching in all four cases. Right-sided round ligament was attached to the bifurcation of the right anterior portal vein in all the cases. The left portal vein branched into posterior and paramedian branches.

First description of the surgical anatomy of the cynomolgus monkey liver

No detailed description of nonhuman primate liver anatomy has been reported and little is known about the similarity between such livers and human liver. The cynomolgus monkey (Macaca fascicularis) was used to establish a preclinical model of genetically modified hepatocytes auto transplantation. Here, we report information gleaned from careful observation and notes obtained from 59 female cynomolgus monkeys undergoing 44 anatomical hepatic resections, 12 main portal vein division dissections and selective branch ligations, and 46 portographies. Additionally, three anatomical liver dissections after total resection at autopsy were performed and served to confirm peroperative observations and for photography to provide illustrations. Our results indicate that the cynomolgus monkey liver has four lobes: the median (the largest), the right and left lateral, and the caudate lobes. In 60% (N=20) of individuals the portal bifurcates into right and left portal veins, in the remaining 40% (N=14) the portal vein trifurcates into right anterior, right posterior, and left portal veins. The anatomy and branching pattern of the hepatic artery and bile ducts closely follow those of the portal branches. Functionally, the cynomolgus monkey liver can be divided into eight independent segments. Thus, we report the first detailed description of the hepatic and portal surgical anatomy of the cynomolgus monkey. The cynomolgus monkey liver is more similar to the human liver than are livers of any small or large nonprimate mammals that have been described.

Left-sided gallbladder with right-sided ligamentum teres hepatis: rare associated anomaly of exomphalos

Purpose The aim of this investigation was to establish the association of left-sided gallbladder and right-sided ligamentum teres hepatis with exomphalos and to clarify the portal venous anomaly associated with right-sided ligamentum teres. Methods Three male infants with exomphalos major associated with left-sided gallbladder and right-sided ligamentum teres hepatis were identified during a retrospective study of exomphalos cases (n = 35) in which exomphalos major comprised 18 cases over 19 years. Results Three infants with exomphalos major (8.6%) had a left-sided gallbladder and right-sided ligamentum teres hepatis. One male infant survived. Computed tomography showed that there is anomalous intrahepatic portal venous branching associated with right-sided ligamentum teres hepatis. The first branch of the portal vein ran to the right posterior segment, and then the portal vein formed a trunk of the left portal vein and right anterior portal veins. The latter vein formed the umbilical segment of the portal vein and finally joined the ligamentum teres hepatis. The inferior vena cava was on the left side below the kidney and crossed to the right side at the level of the kidney. Conclusions Left-sided gallbladder with right-sided ligamentum teres hepatis may not be such a rare associated anomaly in infants with exomphalos. However, there are no reports describing this anomaly with exomphalos in the English medical literature. We believe this is the first report. As long-term survival after repair of exomphalos is increasing, perhaps some of the survivors may develop liver disease which requires liver resection later in life. Recognition of this anomalous relationship with exomphalos is clinically important because it is associated with abnormal intrahepatic portal venous branching and intraabdominal vascular anomalies.

Anomalous intrahepatic portal system in a patient with hilar bile duct cancer

We report a case of anomaly of the intrahepatic portal system in a 65-year-old man with hilar bile duct cancer. Preoperatively, percutaneous transhepatic portography demonstrated that there was a right posterior portal vein arising from the main portal vein. In addition, a large portal branch originated from the left portal vein and coursed toward the right hepatic lobe. Following portal embolization of the right posterior branch, the patient underwent an extended right hepatectomy with a caudate lobectomy. Intraoperatively, to the left at the porta hepatis and then it first gave off the right anterior portal vein originated from the left portal vein and coursed toward the right hepatic lobe horizontally behind the gallbladder and then separated into superior and inferior segmental branches to supply the right anterior segment of the liver. The ramification of some major branches without malposition of the gallbladder or round ligament was the important clinical feature of this anomaly.

U-graft anastomosis for anomalous portal venous branching reconstruction in right lobe living donor liver transplantation

U-graft anastomosis for anomalous portal venous branching reconstruction in right lobe living donor liver transplantation

Left-sided gallbladder: Its clinical significance and imaging presentations

To assess the importance of preoperative diagnosis and presentation of left-sided gallbladder using ultrasound (US), CT and angiography. Retrospective review of 1482 patients who underwent enhanced CT scanning was performed. Left-sided gallbladder was diagnosed if a right-sided ligamentum teres was present. The image presentations on US, CT and angiography were also reviewed. Left-sided gallbladder was diagnosed in nine patients. The associated abnormalities on CT imaging included portal vein anomalies, absence of umbilical portion of the portal vein in the left lobe of the liver, club-shaped portal vein in the right lobe of the liver, and difficulty in identifying segment IV. Angiography in six of nine patients demonstrated abnormal portal venous system (trifurcation type in four of six patients). The main hepatic arteries followed the portal veins in all six patients. The segment IV artery was identified in four of six patients using angiography, although segment IV was difficult to define on CT imaging. Hepatectomy was performed in three patients with concomitant liver tumor and the diagnosis of left-sided gallbladder was confirmed intraoperatively. Left-sided gallbladder is an important clinical entity in hepatectomy due to its associated portal venous and biliary anomalies. It should be considered in US, CT and angiography images that demonstrate no definite segment IV, absence of umbilical portion of the portal vein in the left lobe, and club-shaped right anterior portal vein.

Prevalence and Types of Main and Right Portal Vein Branching Variations on MDCT

Our objective was to investigate the prevalence of variant main and right portal vein ramification in a large group of patients. The study group consisted of 200 patients who underwent consecutive contrast-enhanced abdominal CT examinations performed with an 8-MDCT scanner. Two observers evaluated both thin axial sections and 3D maximum-intensity-projection and volume-rendered images for branching patterns of the main and right portal veins. Conventional main portal vein anatomy was present in 64.5% of the patients. In 9.5% of the patients, the main portal vein trifurcated into the left portal and right anterior and posterior portal veins. In 23.5% of the patients, the main portal vein divided into a common left portal vein-right anterior portal vein trunk and the right posterior portal vein. Three patients (1.5%) had miscellaneous variations. Twenty-two (16.8%) of 131 patients with conventional main portal vein branching had variant right portal vein branching, most of which was a trifurcation, followed by an abnormally proximal origin of the segment VII vein from the right portal vein. Variant main portal vein branching seems to be very frequent. Common right anterior portal vein-left portal vein trunk is far more common than trifurcation. Although less frequent, variations also occur in right portal vein branching.

Types and Frequencies of Biliary Tract Variations Associated with a Major Portal Venous Anomaly: Analysis with Multi–Detector Row CT Cholangiography

To retrospectively determine whether major portal venous variation was more frequently associated with biliary variants, with consideration of the types and frequencies of biliary tract variations in the right and left liver lobes. Before undergoing computed tomographic (CT) cholangiography, patients gave informed consent. The retrospective research protocol was approved, and informed consent was waived by the ethics committee. Forty-four patients aged 29-80 years who underwent multi-detector row CT cholangiography had a major portal vein variation in which the main portal vein diverged into the common trunk of the left portal vein and right anterior sectorial portal vein. One hundred fifty-eight consecutive patients aged 26-89 years who did not have this variation served as the control group. Three radiologists retrospectively evaluated the confluence pattern of the bile duct, the relationship between this pattern and the portal vein, and the major branching pattern of the portal vein. Pearson chi2 and Fisher exact tests were performed to identify significant differences between the two patient groups. The classic hilar confluence pattern, where the right posterior sectorial duct connects supraportally with the right anterior sectorial duct, was less frequent in the patients with the portal vein variation than in the control subjects (32% vs 73%, P < .05). The following biliary tract variations were identified more frequently in the variation group than in the control group (P < .05): right posterior sectorial duct joining left hepatic duct with a supraportal course (34% vs 12%), right posterior sectorial duct joining right anterior sectorial duct with an infraportal course (13% vs 4%), right posterior sectorial duct following an infraportal course (23% vs 8%), and left lateral segmental ducts caudal to the umbilical portion of the portal vein (14% vs 3%). The right hepatic duct, which receives all biliary ducts from the right lobe, was significantly less frequently developed in the variation group (46% vs 79%, P < .05). In addition, retroportal bile ducts were seen in four patients with the portal vein variation (P < .05). Bile duct configurations in patients with portal vein variation were significantly different from those in control subjects.

Proposal for a reclassification of liver based anatomy on portal ramifications

Background Portal branching patterns that differ from those previously described are occasionally encountered during liver surgery. Methods A total of 60 patients with normal intrahepatic venous anatomy underwent helical computed tomography during arterial portography (CTAP). Next, 3 dimensional portograms were reconstructed to verify the locations of the portal veins. Portal branching patterns in the right hemiliver were assessed. Results In all 60 patients examined, the right anterior portal vein bifurcated into the ventral and dorsal branches. In 42 (70 %) of 60 patients, some branches arose from the right posterior portal trunk. Between 1 and 3 branches (mean 2.3 branches per patient) coursed cranially, between 2 and 5 branches (mean 3.2 branches per patient) coursed caudally, and between 1 and 2 branches (mean 1.3 branches per patient) coursed laterally. Conclusions We propose that the right liver should be divided into 3 segments, which are designated as the right anterior, middle, and posterior segments.

Anterior fissure of the right liver ? the third door of the liver

Although the anterior segment of the liver has been divided into segments 8 and 5, we have, during surgical or interventional procedures, occasionally encountered patients in whom the right anterior portal vein does not bifurcate into the superior and inferior branches. Thus, the in vivo anatomy of the right liver was reevaluated to clarify the segmental anatomy. We evaluated the hepatic venous and portal ramification patterns, using three-dimensional images reconstructed from computed tomography. In addition, liver volumetry was performed. All branches arising from the anterior trunk were divided into two groups: the right ventral portal branches (RVP) and the right dorsal portal branches (RDP), and the anterior fissure vein crossed between the RVP and RDP. The ventral and dorsal regions of the anterior segment were approximately equal from a volumetric point of view. The anterior segment seems to be divided into the ventral and dorsal segments by the anterior fissure, and we propose a reclassification of the right liver that divides the right liver into three segments. Dissection of the parenchyma along the anterior fissure makes the third door of the liver open, resulting in the exposing of all Glissonian pedicles of the right liver. The introduction of our segmental anatomy and surgical procedure will allow more systematic and limited liver resections.

Right anterior sector drainage in right-lobe live-donor liver transplantation.

The necessity of providing venous drainage for the right anterior sector of a right-lobe graft in adult-to-adult right-lobe live-donor liver transplantation has been controversial. Inclusion of the middle hepatic vein in the right-lobe graft to ensure better early graft function is also under debate. This report summarizes the views of five Asian centers on the necessity of providing venous drainage to the right anterior sector in a right-lobe graft as presented at the Asian Living Donor Transplantation Symposium 2002. All five centers recognize the importance of adequate drainage of the right anterior sector, but they adopt different approaches in including the middle hepatic vein in the graft. Tokyo University uses an occlusion test of the right hepatic artery and middle hepatic vein to define whether the right anterior sector is dusky or regurgitation of blood flow is present in the right anterior portal vein before the decision is made for middle hepatic vein reconstruction. The Asan Medical Center uses hydrostatically dilated saphenous venous graft to anastomose prominent segment V and VIII hepatic vein branches to the inferior vena cava. The University of Hong Kong Medical Centre includes the middle hepatic vein in every graft and anastomoses it to the recipient's middle or left hepatic vein. Kyoto University uses venous jump graft for anastomosing prominent middle hepatic vein branches to the inferior vena cava for recipients receiving a small-for-size graft or graft with dominant middle hepatic vein drainage. The Chang Gung Memorial Hospital adopts a flexible approach in inclusion of the middle hepatic vein in the graft depending on the donor size and the hepatic venous configuration of the right-lobe graft. In summary, the criteria for inclusion and reconstruction of the middle hepatic vein vary. Further analysis is needed to confirm the importance of adequate drainage of the right anterior sector in right-lobe live-donor liver transplantation.

Portal vein aneurysm of the umbilical portion: imaging features and the relationship with portal vein anomalies.

We evaluated the imaging features of portal vein aneurysm occurring at the umbilical portion and the relation between portal vein aneurysm of the umbilical portion and portal vein anomaly. Retrograde analysis was performed in 18 patients with portal vein aneurysm of the umbilical portion of the portal vein. We analyzed the size, shape, and imaging findings of portal vein aneurysm. In addition, we evaluated associated portal vein anomalies, specifically, the branching pattern of the intrahepatic portal vein and the position of the umbilical portion of the left portal vein. The diameter of the portal vein aneurysm ranged from 1.5 to 2.2 cm and the shape of the portal vein aneurysm was saccular (n = 14) or fusiform (n = 4). Imaging findings of the portal vein aneurysm of the umbilical portion were typical for its vascular nature. Portal vein anomalies were seen in eight of 18 patients (44%): the right anterior segmental portal vein (n = 7) or the right anterior and posterior segmental portal veins (n = 1) originating from the umbilical portion of the left portal vein and a rightward deviation of the umbilical portion of the left portal vein (n = 4). Due to its vascular nature, noninvasive diagnostic modalities can enable the detection of portal vein aneurysm of the umbilical portion, and there is a close relation between portal vein aneurysm of the umbilical portion and portal vein anomaly.

Anatomical variations and surgical strategies in right lobe living donor liver transplantation: lessons from 120 cases.

Anatomical variations in right liver lobe are common. However, clinical implications and surgical management of these variations in living donor liver transplantation have not been analyzed systematically. Surgical anatomy of vascular and biliary structures in 120 right lobe grafts were reevaluated by reviewing the results of preoperative (computerized tomography and Doppler ultrasonography) and intraoperative (cholangiography) imaging as well as surgical findings. The data were analyzed in relation to surgical management of anatomical variations. The incidence of variants leading to multiple portal vein anastomoses was 7.5%. The incidence of dual right hepatic veins was 0.8%; 30% of the grafts had significant accessory hepatic veins (>5 mm) and 13.9% of these were multiple. All of them were successfully reconstructed with technical modifications including venoplasty and venous grafts, except for two cases with multiple intraparenchymal portal vein branches to the anterior segment. The incidence of dual hepatic arteries was 1.7%, but only one of them was reconstructed without negative sequelae. The incidence of variants potentially leading to multiple bile duct anastomoses was 35.0%, and eventually 39.2% of the grafts had multiple orifices. With a variety of techniques including ductoplasty, hepaticohepaticostomy, and biliary stent, total incidence of leakage and stenosis was 10.8% and 9.2%, respectively. Although ductoplasty, internal stent or no stenting, seemed to be associated with increased risk of complications, anatomical variants, multiple bile ducts, and duct-to-duct reconstruction did not bear a significant risk. Anatomical variations of vascular and biliary structures in right lobe grafts are common. However, most can be managed safely with technical modifications. Only cases with intraparenchymal origin of the anterior portal vein(s) may form a relative contraindication, especially when combined with similar biliary variants. Otherwise, intraoperative assessment of biliary anatomy was enough for successful management. Detailed and precise assessment of vascular and biliary anatomy is vital for appropriate surgical management.

Are left-sided gallbladders really located on the left side?

The aim of this investigation was to establish the association between left-sided gallbladders and right-sided round ligaments. The left-sided gallbladder is a rare anomaly and has been classified into two types: 1) gallbladder migration to the left side and 2) development of a second gallbladder with atrophy of the original one. Recently, left-sided gallbladders were reported to be associated with right-sided round ligaments. The authors reviewed 3 patients treated in their departments and 15 patients reported in the literature diagnosed as having left-sided gallbladders accompanied by right-sided round ligaments. Although the gallbladders of all 18 patients were located at the normal site, they were diagnosed as being left sided because of the right-sided round ligaments. This anomaly was accompanied by abnormal intrahepatic portal venous branching, which could be classified into two types. In eight patients, the first branch of the portal vein ran to the posterior segment and then the portal vein formed a trunk of the left and right anterior portal veins. The latter portal vein formed the umbilical portion and finally joined the right-sided round ligament (trifurcation type). In five, the portal vein diverged normally to form the left and right portal veins, then the latter branched to form the anterior and posterior segments, and finally the anterior branch joined the round ligament (bifurcation type). In the other five, the branching type could not be determined. A right-sided round ligament causes a gallbladder at the normal site to be located on the left side. This anomaly should not be diagnosed as a left-sided gallbladder but as a right-sided round ligament. Recognition of this anomaly clinically is important when performing hepatectomy, because it is always associated with abnormal intrahepatic portal venous branching.

Afferent portal venous system in the mesonephros and metanephros of chick embryos: development and degeneration.

In the chick embryo, both mesonephros and metanephros have a renal portal system. The classical literature gives uncertain answers about the development and degeneration of the meso- and metanephric portal venous system. Some mesonephric vessels present angiogenic processes to colonize the metanephros, while others show signs of degeneration and disappear together with the mesonephros. The adult avian kidney has a conspicuously placed valve, the renal portal valve. The development of this functionally important renal portal valve has not yet been studied in detail. Scanning electron microscopy of vascular corrosion casts has been used in this study. Strong mesonephric degeneration as well as metanephric growth and maturation occur in the developmental stages selected for this investigation (7.5, 9, 11, 14, and 21 days of incubation). The mesonephric afferent venous system in the chick embryo is supplied by two vessels, the posterior and the anterior mesonephric portal veins. The posterior mesonephric portal veins show a similar pattern to the anuran (amphibian) kidney. The anterior mesonephric portal vein has not previously been described. Constrictions were found in this vessel, a probable sign of subsequent degeneration. The metanephric afferent venous system is also supplied by two vessels: the caudal and cranial metanephric portal veins. The caudal metanephric portal vein is derived from the postcardinal vein. The cranial metanephric portal vein grows independently throughout the development of the mesonephric vascular system. It is connected to the vertebral venous sinus already at the beginning of its development. The renal portal valve first appears as a capillary network that communicates with the developing afferent and efferent metanephric venous systems. This capillary network later develops to a venous valve. The metanephric afferent venous system shows typical angiogenic signs in corrosion cast, such as nodular protrusions, holes, and enlarged vessels. The postcardinal vein first supplies only the mesonephric tissue as a portal vessel. Then it becomes a common source for both kidney generations. Finally it supplies only the metanephric tissue with venous blood. However, two independent vessels were found to supply the cranial renal regions: the anterior mesonephric portal vein and the cranial metanephric portal vein.

An unusual cause of congenital ascites

A newborn premature male with hydrops fetalis and massive congenital ascites is presented. The ascites recurred despite repeated paracenteses. The ascites was possibly due to a portal vein obstruction caused by malposition of the portal vein and malrotation of the small intestine. This is the first case report of congenital ascites associated with malposition of the portal vein.

Duodenal atresia and stenosis: reassessment of treatment and outcome based on antenatal diagnosis, pathologic variance, and long-term follow-up.

Duodenal atresia and stenosis was observed in 103 infants and children from 1972 to 1991. There were 59 girls and 44 boys. Atresia was noted in 79 instances and stenosis in 24. Maternal hydramnios was detected in 33 cases, 46 babies were premature, and 31 had Down's syndrome. Fifty-four infants had significant associated anomalies including 35 with cardiac defects. Diagnosis was achieved by prenatal ultrasound examination in 14 cases, observation of a double-bubble sign on abdominal radiograph in 73, and contrast studies in 30 infants including 24 with stenosis. At operation annular pancreas was noted in 37 cases, malrotation in 37 cases, anterior portal vein in 4, and a second web in 3. Surgical treatment included duodenoduodenostomy in 85, duodenotomy and web excision in 8, and duodenojejunostomy in 10. Operative survival was 95%. Deaths were related to complex cardiac defects. Despite antenatal diagnosis, prompt intervention, and apparent early surgical success (95% survival), late deaths (5%) and late complications including motility disorders, megaduodenum, gastroesophageal reflux, duodenal-gastric reflux, gastritis, peptic ulcer disease, blind loop syndrome, and biliary-pancreatic conditions may be observed months to years after management during the neonatal period. Modifications in surgical technique including early tapering duodenoplasty may be useful, and close long-term follow-up is an essential component of patient care.

The effect of forage and forage-concentrate diets on rumen fermentation and metabolism of nutrients by the mesenteric- and portal-drained viscera in growing steers.

Growing Friesian steers chronically catheterized in the anterior mesenteric and portal veins were used to study the influence of feeding with either a forage or forage-concentrate diet on nutrient utilization by mucosal tissue. When animals were consuming the forage-concentrate diet the molar proportion of propionate in rumen fluid was significantly increased, although production rate as measured by isotope dilution was not altered. Net rates of absorption of VFA into portal blood when compared with rumen production rates underlined the extent to which metabolism within mucosal tissue modifies the propionate supply to the liver. Net glucose utilization by splanchnic tissue was shown to be significantly lower on the forage-concentrate diet. There were no effects of diet on whole-body glucose turnover or on the proportion of glucose derived from propionate. Animals fed on the forage-concentrate diet had significantly lower concentrations of circulating essential amino acids, due mainly to a reduction in branched-chain amino acid levels. There was net absorption of all amino acids by animals on both diets except for glutamate, glutamine and taurine in forage-fed animals.