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Introduction: We describe a case of pulmonary gas embolism caused by portal vein gas (PVG) observed using echocardiography. Echography revealed gas flowing through the hepatic vein, inferior vena cava, right atrium, and right ventricle, as well as pulmonary hypertension. The patient was diagnosed as having pulmonary gas embolism caused by PVG. Objective: We consider PVG routes to pulmonary circulation, diagnosis of gas embolism caused by PVG, and treatment of gas embolism caused by PVG.Methods: We reviewed reports of eight cases of gas embolism caused by PVG and compared these cases to cases of gas embolism without PVG. Results: Mortality of gas embolism caused by PVG was 67%, positive blood culture was observed in six cases, and pulmonary edema was seen in three cases. PVG initially excites microbubble formation, which causes tissue damage in the liver and liver abscess. A large volume of PVG causes portal obstruction. As a result, portal hypertension, a portosystemic shunt or gastrointestinal congestion can occur. PVG can travel to the systemic vein through the liver or portosystemic shunt without anomaly and cause pulmonary gas embolism, followed by arterial embolism. In this environment, sepsis easily occurs. Echocardiography is useful for diagnosis of gas embolism caused by PVG, but the gas can be seen intermittently. The view of pulmonary edema is important for pulmonary gas embolism caused by PVG. Conclusion: It is important to treat the underlying disease, but PVG must be considered and treated as the gas embolism’s source.

Ligamentum teres joining to the right branch of the portal vein in a 79-year-old Japanese male cadaver was noted during student dissection at Kumamoto University in 2004. The ligamentum teres entered the liver along the left side of the gallbladder fossa. The quadrate lobe was not distinguished from the left lobe in the visceral surface. When the liver parenchyma was removed by tearing off to expose the branches of the portal and hepatic veins, it was clarified that the ligamentum teres unusually joined to the bifurcation of the upper anterior and lower anterior branches of the right branch of the portal vein. The ligamentum teres is the remnant of the umbilical vein working throughout fetal life. Initially a pair of the umbilical veins entered the sinus venosus. During the fourth and fifth weeks they connect to the hepatic sinusoids, which become the portal and hepatic veins, and the parts entering the sinus venosus of both umbilical veins disappear. By the eighth week, as all remainder of the right umbilical vein disappears, the left umbilical vein is the only one to carry blood from the placenta to the liver. It results in the ligamentum teres joining to the left branch of the portal vein. However, in the present case it is thought that the right umbilical vein remained instead of the left one for some reason, and it then became the right ligamentum teres joining to the right branch of the portal vein.

Three cases of persistent right umbilical vein associated with left-sided gallbladder are presented. This poorly understood, rare variant is due to obliteration of the left umbilical vein during embryonic development. The left-sided gallbladder, associated with persistent right umbilical vein, is not anomalous positioning of the gallbladder but an embryologic abnormality of the umbilical vein that causes the gallbladder to migrate to the left of the ligament teres. Findings and clinical relevance are discussed.

The liver is supplied by the common hepatic artery from the celiac trunk and by the portal vein from the gastrointestine. This double blood supply to the liver by the hepatic artery and the portal vein produced a complicated structure in the liver. For the blood outflow, we can see right, intermediate and left hepatic veins, and irregular veins: the accessory hepatic veins. These veins drain the blood in the liver into the inferior vena cava. In this study, we studied the layout of the accessory hepatic vein draining segments 6 and 7 in the human livers and attempted to reconsider the structure of the liver by the layout of the accessory hepatic vein. Sixty livers were subjected in this study. They were prepared by using forceps to trace the layout of the blood vessels inside the livers. We carefully examined the relation between the layouts of the accessory vein to the segments 6 and 7 and of the portal vein. The confluence patterns of the accessory hepatic vein into the inferior vena cava were also examined to find the character of the vein. The relation between the accessory hepatic vein and standard hepatic veins was also studied. We found 2.2 accessory hepatic veins in one liver on average in our study. The vein was always within the area of segments 6 and 7, and did not surpass the boundary. We found at most five accessory hepatic veins in a liver in two cases. The accessory hepatic vein to the segments 6 and 7 always had its stem on the dorsal side to the portal vein. Different from the stem, the periphery of the accessory hepatic vein freely distributed with the peripheral branches of the portal vein. The area distributed by the accessory vein was also always dorsal part within the segments 6 and 7. The vein was small usually, but was big in few cases. When the vein was big, the area became solely drained by the accessory vein, because the standard hepatic veins (right and intermediate hepatic veins) did not reach the area, and we did not find any communication between the accessory vein and the standard veins. As the remaining region in the segments 6 and 7 became smaller, the draining right standard hepatic vein became shorter and smaller. The region drained by the accessory hepatic vein excluded the standard hepatic veins. Therefore, there are two different draining venous networks in the area of segments 6 and 7 classified by Couinaud. The accessory hepatic vein draining segments 6 and 7 distributed somewhere dorsal side in the segments 6 and 7. The area where the accessory vein distributed was the region where standard hepatic veins did not reach. This would suggest that the region drained by the accessory hepatic vein makes an isolated segment in the liver in the segments 6 and 7 by the Couinaud’s Classification. The area might have a unique blood circulation system.

This study was conducted to find the boundary vein indicating the intersegmental plane between the caudate lobe and the adjacent liver segments.Major hepatic veins of the human liver commonly run through the intersegmental plane and are widely used for the landmarks to define the boundary of both sides of liver segments. As the caudate lobe is a small independent unit of the liver separate from the right and left livers, the existence of the boundary hepatic vein to the adjacent liver segments has been expected.Fifty-four adult cadaveric livers were minutely dissected to elucidate the correlation between the portal vein branches and the hepatic veins on both the caudate lobe and the adjacent liver segments.Among the hepatic veins of the caudate lobe, the caudate processus hepatic vein entering the inferior vena cava at hepatic hilum runs in the segmental plane between the caudate processus and the right liver. Three types of the caudate processus hepatic vein directly entering the inferior vena cava and 1 type of the exceptional hepatic vein that was the tributary of the right hepatic vein were observed. They drained the blood of the caudate processus and a part of the right liver, respectively.The caudate processus hepatic vein is one of the candidates of the hepatic vein indicating the boundary between the caudate lobe and the adjacent liver segments. New procedures will be developed on the liver surgeries by acquiring the anatomic features of this vein.

The vascular architecture of the human liver is established at the end of a complex embryological history. The hepatic primordium emerges at the 4th week and is in contact with two major venous systems of the fetal circulation: the vitelline veins and the umbilical veins. The fetal architecture of the afferent venous circulation of the liver is acquired between the 4th and the 6th week. At the end of this process, the portal vein is formed from several distinct segments of the vitelline veins; the portal sinus, deriving from the subhepatic intervitelline anastomosis, connects the umbilical vein, which is the predominant vessel of the fetal liver, to the portal system; the ductus venosus connects the portal sinus to the vena cava inferior. At birth, the umbilical vein and the ductus venosus collapse; the portal vein becomes the only afferent vein of the liver. The efferent venous vessels of the liver derive from the vitelline veins and are formed between the 4th and the 6th week. The hepatic artery forms at the 8th week; intrahepatic arterial branches progressively extend from the central to the peripheral areas of the liver between the 10th and the 15th week. Hepatic sinusoids appear very early, as soon as hepatic cords invade the septum transversum at the 4th week. They then progressively acquire their distinctive structural and functional characters, through a multistage process. Vascular development and differentiation during liver organogenesis is, therefore, a unique process; many of the cellular and molecular mechanisms involved remain poorly understood.

To achieve a safer living related liver transplantation (LRLT) using the right lateral sector, anatomical variations of the portal vein, hepatic artery and bile duct for the right lateral sector and their three dimentional (3D) relationship were assessed by integrated 3D-CT images. 52 patients who underwent contrast enhanced multi-detector row CT (MD-CT) and MD-CT cholangiography were enrolled. Data from contrast enhanced MD-CT were used to reconstruct the 3D images of the hepatic artery and portal vein. 3D images reconstructed from MD-CT data of the hepatic artery, portal vein and bile duct were integrated into a single image. The dual branching of the right lateral portal vein was observed in 22 (42.3%) patients. Three (5.8%) had dual right lateral ducts and 14 (26.9%) had dual right lateral arteries. Among them, "south-turning" artery and "north-turning" bile duct was observed in 22 (42.3%). "South-turning" artery and "south-turning" bile duct were 3 (5.8%). "North-turning" artery and "north-turning" bile duct were 2 (7.4%). Only 27 (51.9%) had single portal vein, bile duct and artery for the right lateral sector, those were preferable as candidates for right lateral sector graft transplantation. 3D anatomical variations of portal vein, artery and bile duct for the right lateral sector were complexed, and only half of the donor candidates had preferable hepatic structures for right lateral sector graft transplantation. Understanding of the 3D hepatic structures by 3D-CT may contribute to a better definition of anatomical contraindications for LRLT which may further results in more safe and widely applied right lateral sector graft LRLT.

Portal vein thrombosis is observed in up to 10% of liver transplant candidates, hindering execution of the procedure. A dilated gastric vein is an alternative to portal vein reconstruction and decompression of splanchnic bed. We present two cases of patients with portal cavernoma and dilated left gastric vein draining splanchnic bed who underwent liver transplantation. The vein was dissected and sectioned near the cardia; the proximal segment was ligated with suture and the distal segment was anastomosed to the donor portal vein. Gastroportal anastomosis is an excellent option for portal reconstruction in the presence of thrombosis or hypoplasia. It allows an adequate splanchnic drainage and direction of hepatotrophic factors to the graft.

The meso-Rex bypass procedure has been used to treat patients with portal hypertension from extrahepatic portal vein obstruction. This report describes modifications of this procedure in 5 patients. Either the splenic or coronary vein was used as the venous inflow point, and the bypass was performed either directly through transposition of the vein or with the use of a venous conduit.

To assess haemodynamic changes in the liver under temporary occlusion of an intrahepatic portal vein.Between February 2000 and October 2004, 16 patients with hepatobiliary disease underwent single-level dynamic computed tomography during hepatic arteriography (SLD-CTHA) under temporary balloon occlusion of an intrahepatic portal vein. All patients needed percutaneous transhepatic portography for therapy of their disease. SLD-CTHA was undertaken to clarify the time-attenuation curve influenced by portal vein occlusion, and it was performed continuously over a period of 30s. The difference in absolute attenuation of the liver parenchyma in segments with occluded and non-occluded portal vein branches was determined by means of the CT number, and the difference in absolute attenuation of the occluded and non-occluded portal veins themselves was also evaluated.SLD-CTHA demonstrated a demarcated hyperattenuation area in the corresponding distribution of the occluded portal vein branch. The attenuation of the liver parenchyma supplied by the occluded portal vein was significantly higher than that in the non-occluded area (p0.01). The balloon-occluded portal branch enhancement in 15 of 16 cases (94%) appears due to arterio-portal communications. Failure to evaluate a remaining case for portal branch enhancement was due to absence of a visualized portal branch in the section.Under temporary occlusion of an intrahepatic portal vein, hepatic angiography produced enhancement of the occluded portal branches and their corresponding parenchymal distribution; this finding is considered consistent with the presence of arterio-portal communications.

The authors describe a case of extrahepatic portal vein (EHPV) thrombosis and portal hypertension treated with a variant of mesenterico-left portal vein bypass (MLPVB) or Rex shunt. In this case, a segment of autogenous greater saphenous vein was used to bridge the distance between the left gastric vein inflow and the left portal vein. Use of such nontraditional conduit in similar circumstances may expand the application of portal revascularization/decompression procedures in treating these patients.

The anatomical variations of the portal vein and the hepatic artery ramifications were analysed on liver corrosion casts in 20 dogs as a possible aid in the surgical management of the organ. The portal vein ramified similarly in all dogs. It divided into the smaller right portal branch from which vessels for the caudate process and both right lobes arose and the substantial left portal branch, which supplied the remaining liver portions and in 12 cases also the dorsal part of the right lateral lobe. Right lateral, right medial and left branches are the major arteries originating from the hepatic artery; however, their origin and course varied among individual animals. In 10 livers, the right lateral and the left branches originated from the hepatic artery, while the right medial branch arose from the left branch and usually supplied the right medial lobe solely. In nine livers, the right medial branch arose directly from the hepatic artery and supplied quadrate lobe and gallbladder as well, while in one liver the common artery, which subsequently divided into lobar branches, branched away from the hepatic artery. An additional branch for the caudate process, originating directly from the hepatic artery, was observed in 10 livers. Certain liver portions received the arterial blood from two major branches, which was particularly characteristic for the right medial lobe (six livers) and caudate process (10 livers). The course of the major arterial branches was also variable, although they proceeded in close anatomical relationship with the portal vein branches. The left arterial branch accompanied the left portal branch on its dorsal aspect (15 cases) or crossed it from the caudal aspect (five cases). The right lateral branch crossed the initial parts of the left and right portal branches either from cranial (12 cases) or caudal aspects (eight cases), while the right medial branch always crossed the left portal branch from its caudal aspect.

膵頭十二指腸切除術後の総肝動脈の破綻による出血に対して肝動脈結紮と門脈部分動脈化により救命できた症例を経験した. 症例は54歳, 男性で, 下部胆管癌の診断で亜全胃温存膵頭十二指腸切除を施行した. 術後36時間後よりドレーンより膵液の排出を認め, その2時間後腹腔内出血によるショック状態となり, 緊急開腹手術を施行した. 出血点は総肝動脈にあいた約8mmの孔, 血管壁は脆弱であった. 縫合修復は不可能で, 総肝動脈を結紮し止血した. 肝動脈血の欠如を補うため, 回結腸動静脈吻合を行った. 術後は黄疸・肝機能障害, 膵胃吻合部の縫合不全を認め, 集中治療を必要としたが, 徐々に軽快し, 第60病日に軽快退院した. 膵頭十二指腸切除術後の総肝動脈出血は致命的な合併症で, 再手術により救命できたことは外科治療上意義があると考え報告した.

Gas in portal veins is a rare phenomenon observed secondary to bowel ischaemia and necrosis. A young girl with history of pica ingestion presented with acute abdomen with huge distension. Investigation revealed air in hepatic portal veins, air within stomach wall, and massive distension of stomach secondary to acute pancreatitis. Successful conservative treatment confirmed the current concept that all cases of hepatic portal venous gas do not warrant immediate surgical intervention.

We encountered a case with a gastric varix that drained into the gastro-renal shunt, left pericardiacophrenic vein, and several other dilated collateral veins. This patient had a circumaortic venous ring. For this case we successfully performed balloon-occluded retrograde transvenous obliteration in which sclerotic agents were infused from the balloon catheter advanced to the left pre-aortic renal vein and the tip was wedged into the end of the gastro-renal shunt. Before injection of sclerotic agents, collateral veins other than the left pericardiacophrenic vein were embolized with micro-coils. During the injection, the left pericardiacophrenic vein was occluded temporarily with a micro-balloon catheter coaxially advanced from the catheter inserted from the femoral vein to the left pericardiacophrenic vein through the left brachiocephalic vein.

We report a case of intraperitoneal hemorrhage from the extrahepatic portal vein after pancreaticoduodenectomy for distal bile duct carcinoma. A stent-graft was deployed from the superior mesenteric vein to the main portal vein using a transhepatic approach. After the procedure, the patient remained free of intraperitoneal hemorrhage and was discharged 2 months later.

Varices located outside the esophagogastric junction (ectopic varices) can be located in several sites. Rectal varices occur in 44 % to 78 % of patients with portal hypertension and are significantly more common in patients with noncirrhotic portal hypertension compared to patients with cirrhosis (89 % vs. 56 %) [1]. Although they are potentially a serious cause of lower gastrointestinal (GI) bleeding, massive bleeding is rare. These varices represent dilated portosystemic shunting between the superior rectal veins (inferior mesenteric system) and the middle/inferior rectal veins (internal iliac system). It is important to differentiate them from hemorrhoids; a misdiagnosis may have disastrous consequences in management. Unlike hemorrhoids, rectal varices extend beyond 4 cm from the anal verge, collapse with digital pressure, and do not prolapse into the proctoscope. Transjugular intrahepatic portosystemic shunt (TIPS) placement, endoscopic band ligation, endoscopic injection sclerotherapy, and underrunning the varix with suture are the main treatment options available [2]. The accompanying image is from a patient with extrahepatic portal vein obstruction, who had undergone a proximal splenorenal shunt 12 years ago and presented now with lower GI bleeding due to shunt occlusion. The rectal varices (Fig. 1) were successfully treated with endoscopic injection of cyanoacrylate glue. References

Liver resections that require ex vivo techniques occur rarely, but when done are generally performed on veno-veno bypass to maintain venous return and decompress the portal circulation during the anhepatic phase of the procedure. We describe an ex vivo extended left hepatectomy that was performed with preservation of the inferior vena cava and the use of a temporary portacaval shunt to eliminate the need for veno-venous bypass. Ex vivo resection allowed reconstruction of right hepatic vein branches, using the patient's reversed portal vein bifurcation as a graft to provide venous outflow.

Background/Purpose Portosystemic shunt operations are indicated in patients with extrahepatic portal hypertension owing to portal vein thrombosis (EPH-PVT) suffering from recurrent variceal bleeding despite endoscopic sclerotherapy. Mesenterico left portal bypass procedure (MLPB) is an alternative procedure to the portosystemic shunt operations in patients with EPH-PVT. MLPB operation reestablishes hepatopetal portal blood flow. We herein present our experience with MLPB in children with EPH-PVT. Methods Six patients were treated for EPH-PVT with recurrent bleeding despite endoscopic sclerotherapy (2 boys and 4 girls) in our unit. All patients were evaluated preoperatively with complete blood count, portal duplex system Doppler ultrasonography, magnetic resonance angiography, and upper gastrointestinal (GI) endoscopy. MLPB operation was performed as described by de Ville de Goyet. During the postoperative period, patients were evaluated with complete blood count, portal duplex system Doppler ultrasonography, upper GI endoscopy, and magnetic resonance angiography. Results Six patients were assessed to be candidates for MLPB procedure and were operated to perform the MLPB procedure. Left portal veins were found to be patent during the operation in 4 patients, and the MLPB procedure was performed. Internal jugular vein was used in 3 patients and enlarged inferior mesenteric vein in 1 patient. Left portal veins of the remaining 2 patients were found to be obliterated; therefore, mesocaval shunt was performed. The postoperative course of the patients was uneventful except for 1 patient. During the following period, the leukocyte and the platelet counts were significantly increased in 3 of the 4 patients after the MLPB procedure. Upper GI bleeding occurred in the early postoperative period in 1 patient with MLPB procedure because of prepyloric ulcer that was successfully treated by endoscopic sclerotherapy. Internal jugular vein graft thrombosis was detected on the 10th postoperative day. This patient underwent a second laparotomy, the distal half of the graft was found to be sclerosed and narrowed that the graft was revised with a synthetic allograft. Conclusions Based on a review of the literature, the MLPB functions well in patients with portal hypertension caused by portal vein thrombosis and appears to have a physiologic advance over shunts that decompress but do not return blood directly to the liver. Because intra-abdominal veins appear to function well as a conduit in this operation, it may be favored by eliminating additional incision and increased risk in such patients.

We report the case of a 67-year-old woman with portal tumor thrombus (PTT) associated with gastric carcinoma. Abdominal ultrasound (US) revealed a marked thickening of the gastric wall and a mass lesion in the splenic vein. Color Doppler US showed the intraportal mass to be blood flow-poor and revealed a gastroepiploic vein extending from the splenic hilum to the portal confluence, passing behind the peritoneum. These findings corresponded well with gastric carcinoma with PTT. Endoscopy confirmed the presence of an advanced type II carcinoma predominantly located in the upper body, which yielded histological results consistent with a well-differentiated adenocarcinoma. The patient's general condition deteriorated rapidly, and she died 2 months later. To the best of our knowledge, this is the first report describing the presence of a large gastroepiploic vein secondary to gastric carcinoma-associated PTT.

Endothelin-1 is a potent vasoconstrictor formed by vascular endothelium. This study was designed to investigate the hepatic effect of endothelin-1 produced by portal vascular endothelium.Portal venous pressure, portal venous flow, hepatic arterial flow, tissue blood flow, and tissue oxygen pressure were measured during portal vein endothelin-1 infusion in dogs at rates of 1.0 to 5.0 ng/kg per minute. Sinusoidal width during maximal infusion was determined morphometrically. Serum concentrations of mitochondrial glutamic oxaloacetic transaminase and endothelin-1 in portal and hepatic venous blood were also measured.Intraportal endothelin-1 infusion dose-dependently increased portal venous pressure and reduced portal venous and hepatic arterial blood flow. Tissue blood flow and oxygen pressure also decreased. Endothelin-1 also significantly increased serum mitochondrial glutamic oxaloacetic transaminase and constricted hepatic sinusoids. These changes reversed after completion of infusion.Intraportal endothelin-1 caused circulatory and histological changes in hepatic sinusoids that may suggest the role of endothelin-1 formed by portal venous bed epithelium.

Three main hepatic veins: right, middle and left are constant, but there is a variable number of retrohepatic vessels called accessory or minor hepatic veins. The most important of them are veins reffered to as middle right hepatic vein (MRHV) draining segment VII and inferior right hepatic vein (IRHV) draining segment VI. The incidence of large MRHV and IRHV reaching or exceeding a caliber of 5mm, their arrangement in the liver and drainage territories were investigated in our collection of 142 injection-corrosion specimens of the liver. In 1/5 of the cases with large IRHV this vein drains small part of segment VI, sometimes its insignificant marginal part so it couldn?t be used for segment VI preservation when it is necessary. A precise knowledge of the vein anatomy of right posterior sector of the liver and its vein drainage territories is very important during complex dissections of the retrohepatic areas, resections and preservation liver parenchima.

An infant presented with clinical signs and symptoms suggestive of a pyloric stenosis. On abdominal ultrasound, pyloric stenosis was excluded, and other causes for proximal duodenal obstruction, such as a duodenal web or annular pancreas, were suspected. At surgery, the cause was found to be due to an anterior portal vein or preduodenal portal vein, compressing the duodenum. There were no associated findings such as midgut malrotation, duodenal web and congenital anomalies. The treatment was a diamond-shaped duodeno-duodenostomy anterior to the portal vein. The patient improved after surgery.

Middle hepatic vein reconstruction during the right-lobe living donor liver transplant procedure has been recognized to be a significant factor. We initially reconstructed only a single middle hepatic vein orifice draining into segment 8. In cases where the right-lobe liver graft has several major middle hepatic vein tributaries, including veins draining segment 5 that are remote from the right hepatic vein orifice, a long and thick interposition conduit is necessary for reconstruction. Among 11 consecutive adult patients who received a right-lobe liver graft without a middle hepatic vein at our institution, 8 underwent reconstruction of all major middle hepatic vein tributaries using a vein graft from the recipient's superficial femoral vein. The remaining 3 patients had no major middle hepatic vein tributaries. Posttransplant-computed tomography imagings showed increased liver mass with a patent superficial femoral vein graft in 8 patients. In the absence of a venous system from a deceased donor, a recipient superficial femoral vein offers an excellent size match to maintain the venous outflow of middle hepatic vein tributaries. Reconstruction with recipient superficial femoral vein plays an important role in maximizing liver function and minimizing morbidity in the early posttransplant period.

This paper is a case report describing a boy with Down syndrome and a novel combination of multiple vascular anomalies: extrahepatic portal hypertension, an arterio-venous malformation (AVM) at the ileo-caecal junction, and caval/iliac vein anomalies and developing anal bleeding. We considered that the ileo-caecal AVM would be one of the causes of the repeated hematochezia. The patient underwent ileo-caecal resection with the AVM, and anastomosis of the left external iliac vein and the jejunal branch vein because of the stenosis of the superior mesenteric vein (Clatworthy mesocaval shunt). Intraoperative portal pressure measurement at the site of the right colic vein showed a moderate pressure reduction (42.5-31.5 cm H2O). On the fourth month after operation, gastrointestinal fiberscopy showed no existence of esophageal varices. One year after operation, the patient was doing well without bleeding.

In this study veins that constituted the portal vein were investigated in eight adult Van cats. The portal vein of the Van cat was composed of five peripheral branches which supplied the abdominal organs and two intrahepatic branches at the hepatic porta. The peripheral branches were cranial mesenteric, splenic, gastroduo- denal, right gastric and cystic veins. The cranial mesenteric vein was the largest vessel that joined to the portal vein, and was constituted by the caudal pancreaticoduodenal, ileal, ileocolic and jejunal veins. The splenic vein was formed by the left gastric, left gastroepiploic, pancreatic and short gastric veins. The gastroduodenal vein was formed by the cranial pancreaticoduodenal and right gastroepiploic veins. The right gastric vein separately joined to the portal vein. The caudal mesenteric vein joined to the portal vein either alone or by a common trunk receiving either the caudal pancreaticoduodenal vein or ileocolic vein. The caudal mesenteric vein also opened rarely into the splenic vein. Intrahepatic branches were the right branch which gave off the ramus caudatus and ramus dexter lateralis, and the left branch which gave off the ramus dexter medialis, ramus quadratus, ramus sinister lateralis and ramus sinister medialis.

Portal vein embolization can be performed safely, and so far no major complications have been reported. We report an extremely rare complication of portal vein embolization, a case of portal and mesenteric thrombosis in a 65-year-old patient with protein S deficiency. Right portal vein embolization was carried out prior to extended right hepatectomy for advanced gallbladder carcinoma involving the hepatic hilus. Computed tomography 14 days after embolization revealed massive thrombosis of the portal and the superior mesenteric veins. A protein S deficiency was found by means of an extensive workup for hypercoagulable state. Portal vein embolization may have triggered a cascade of events that was expressed as portal and mesenteric vein thrombosis resulting from deficiency of protein S. It may be better to determine the concentrations of such coagulation regulators prior to portal vein embolization.

Liver surgeons favor using the entity called the 'dorsal liver' (i.e. the caudate lobe and other paracavally located liver parenchyme of segments 7 and 8). According to minute dissection of 48 livers, we describe the territories of the left/right portal veins, hepatic ducts and hepatic arteries in the dorsal liver. In the caudate lobe, the right hepatic artery, rather than the left hepatic artery (23/48 vs 19/48 for right vs left, respectively), tended to supply the 'left' portal vein territory. Similarly, paradoxical drainage patterns, such as the right hepatic duct draining the left portal vein territory, were found in seven of 48 livers. In the territory of the hilar bifurcation, right hepatic artery dominance was also evident and various bile drainage patterns were found. These included double drainage by the bilateral hepatic ducts (3/48) and drainage into the confluence of bilateral ducts (6/48). In contrast, the arterial supply and biliary drainage of the paracavally located parenchyme of segments 7 and 8 usually depended on the proper segmental arteries and ducts and their variations were within the range of those found in other parts of the right lobe. Therefore, the dorsal liver concept may not be anatomical but, rather, simply aimed at usefulness in surgery. Nevertheless, clear subdivision of the caudate lobe according to biliary drainage and/or arterial supply seemed difficult because of the paradoxical relatioships among the portal vein, hepatic artery and bile duct. Consequently, the present results support extended surgery based on the dorsal liver concept for carcinomas involving the caudate lobe.

The patient was a 30-year-old male from Guinea, who had been living in Japan for 10 years. He was diagnosed as having chronic active schistosomiasis mansoni with portal hypertension. Ultrasonography of the liver showed wide high-echo bands in the hilus of the portal vein, and its central and peripheral branches. Selective splenic arteriography demonstrated enlargement of the portal vein trunk and amputation of large peripheral branches of portal vein. On peritoneoscopy, the liver surface showed medium-sized block-like formations separated by irregular linear septa with mild to moderate depression, and many tiny white structures were observed on the liver surface. On magnifying peritoneoscopy, some irregular abnormal veins were observed, and normal peripheral branches of the portal vein were almost diminished on the liver surface. Wide white structures assumed to be thickened medium-sized branches of the portal vein were also observed on the deeper part of the liver surface. Histological examination of the liver biopsy specimens revealed broad collagenous fibrosis of the portal area with slight infiltration of eosinophils, a few schistosomal ova, diminishing of the peripheral branches of the portal vein and dilatation of abnormal vessels in some portal tracts.

We report an autopsy on a 46-year-old man, a case that presented the concurrence of two rare vascular variations of the lesser omentum: aberrant right gastric vein draining directly into the liver, and multiple hepatic arteries. Although the left gastric vein emptied into the left aspect of the portal vein, the right one was found to ascend from the gastric lesser curvature along the right aspect of the common bile duct and to reach directly the porta hepatis. A left hepatic artery originating from the left gastric artery entered the porta hepatis in conjunction with the left ramus of the portal vein. A predominant right hepatic artery arose from the superior mesenteric artery and entered the porta hepatis in conjunction with the right ramus of the portal vein. The proper hepatic artery originating from the celiac artery entered the porta hepatis in conjunction with the aberrant right gastric vein. The possibility of a common underlying mechanism for these rare vascular variations is discussed.

Congenital absence of the portal vein (CAPV) is a rare malformation that is often accompanied by other anomalies such as cardiac and skeletal malformations and/or hepatic tumors. We describe here a case of CAPV complicating hepatic tumors in a 16-year-old Japanese girl. Abdominal ultrasonography revealed a hyperechoic tumor in the liver and dilatation of the portal vein that appeared to be connected directly with the inferior vena cava. Subsequent abdominal computed tomography (CT) revealed tumors and magnetic resonance angiography confirmed that the portal vein entered directly into the inferior vena cava just above the liver. In addition, there was absence of the right portal vein and the left intrahepatic branch except for the presence of left portal vein only within the porta hepatis. These findings led to a diagnosis of CAPV complicated hepatic tumors. Careful monitoring of these hepatic tumors is ongoing due to the possibility of malignant transformation.

Objective— To determine the feasibility of indirect suture passage around the right portal vein for attenuation of right-sided intrahepatic portosystemic shunts (IHPSS). Study Design— Anatomic study of cadavers and prospective evaluation of clinical cases. Animals— Nine canine cadavers (median weight, 20.5 kg) and 6 client-owned dogs suspected of having right-sided IHPSS. Methods— Silicone casts of the caudal vena cava and pre- and intrahepatic portal veins were made in fresh canine cadavers. A suture was passed dorsal to the portal vein above and below its bifurcation and pulled laterally so that it surrounded the right portal vein. The number and size of portal and caudal vena cava branches that interfered with the suture passage were recorded. Intra- and postoperative complications were evaluated in 3 dogs with right-sided IHPSS and 3 dogs suspected of having right-sided IHPSS that had right portal vein dissection and occlusion using this technique. Results— Suture passage and placement around the right portal vein were easily accomplished in all 9 specimens. A 1 mm branch from the dorsal surface of the right portal vein was included in the encircling ligature in 4 specimens. The dissection technique was used successfully in 3 dogs with right-sided IHPSS and 2 other clinical cases. The portal branch to the papillary process of the caudate lobe interfered with suture placement in 1 dog with a central IHPSS. Conclusions— Indirect suture passage for ligation of the right portal vein can be successfully performed in normal dogs and dogs with congenital portosystemic shunts. Clinical Relevance— Hemorrhage, vascular trauma, and surgery time may be reduced using this technique for attenuation of right-sided IHPSS.

The purpose of our investigation was to examine changes in the hemodynamics of the liver after artificial occlusion of a gastrorenal shunt.Nine patients with portal hypertension underwent splenic arteriography and CT arterial portography during infusion of contrast material via the splenic artery. Images were obtained with the balloon catheter both inflated and deflated in the gastrorenal shunt, and results were compared.During the portal phase of splenic arteriography, the intrahepatic portal vein was more clearly seen when the balloon occluded the gastrorenal shunt. Mean CT attenuation values of branches of the intrahepatic portal vein on CT arterial portograms acquired when the balloon catheter was inflated were higher than values acquired when the balloon was deflated; however, results for the inferior vena cava were the opposite. Differences in CT attenuation values were statistically significant for the right branch of the portal vein, main portal vein, right lobe of the liver parenchyma, and inferior vena cava.Closure of large gastrorenal shunts (hepatofugal portasystemic shunts) causes the portal blood flow to switch from hepatofugal to hepatopetal, which increases the effective intrahepatic portal blood flow.

The presence of portal venous gas within the hepatic parenchyma is usually associated with a guarded prognosis and a mortality rate approaching 75%. However, there are infrequent causes of portal venous gas not associated with dire clinical outcomes. We describe three patients who made uneventful clinical recoveries after presenting with clinical and imaging manifestations of ischaemic bowel and hepatic portal venous gas, two of which had distended but non-necrotic bowel at laparotomy.

Purpose: The relationship of the portal vein bifurcation to the liver capsule in Asians, which is an important landmark for transjugular intrahepatic portosystemic shunt, has not previously been described. Methods: The anatomy of the portal vein bifurcation was studied in 70 adult Chinese cadavers; it was characterized as intrahepatic or extrahepatic. The length of the exposed portion of the right and left portal veins was measured when the bifurcation was extrahepatic. Results: The portal vein bifurcation was intrahepatic in 37 cadavers (53%) and extrahepatic in 33 cadavers (47%). The mean length of the right and left extrahepatic portal veins was 0.96 cm and 0.85 cm respectively. Both were less than or equal to 2 cm in 94% of the cadavers with extrahepatic bifurcation. There was no correlation between the presence of cirrhosis and the location of the portal vein bifurcation (p = 1.0). There was no statistically significant difference in liver mass in cadavers with either extrahepatic or intrahepatic bifurcation (p = 0.40). Conclusions: These findings suggest that for transjugular intrahepatic portosystemic shunt placement, a portal vein puncture 2 cm from the bifurcation will be safe in most cases.

Summary Aberrant gastric veins draining directly into the liver are rare variations of the portal vein system. We report on an autopsy in which both right and left gastric veins drained directly into the liver without joining the portal vein. Although the left gastric artery adopted a standard disposition, the left gastric vein was indeed found to ascend from the lesser curvature through the upper part of the lesser omentum. After receiving branches from the gastroesophageal junction, it directly entered the left part of the porta hepatis . The right gastric vein ascended from the lesser gastric curvature along and in front of the right aspect of the common bile duct without ending in the portal vein. It crossed in front of the common hepatic duct and directly entered the porta hepatis . Careful dissection within the liver parenchyma showed that both gastric veins ended in the intra-hepatic part of the left branch of the portal vein. Although aberrant gastric veins are known variations of the portal vein system, the conjunction of both right and left gastric vein has never been reported. It highlights the possibility that the venous drainage of the gastric lesser curvature may be totally independent of the main portal vein.

This study investigates the relevant anatomy for applying the hanging maneuver to hepatectomy by an anterior approach, where liver mobilization is not possible. Using 176 cadaveric livers, we morphometrically investigated the distribution of venous openings within the retrohepatic portion of the inferior vena cava (IVC); next, we conducted a series of experiments to identify which course for insertion of a pair of forceps preserved the thickest of these veins. After anterior dissection of the liver, we carried out an anterior incision along a plane within an area free of venous openings in the IVC. The area free of venous openings was between the thickest caudate vein and the inferior right hepatic vein (IRHV), and averaged 16.2 mm in width. When forceps were inserted along the rightward course connecting the right inferior angle of the right lobe and the same pocket-like space between the terminals of the middle and right hepatic veins, the caudate vein was very likely to be preserved, whereas the IRHV was not. In contrast, the leftward course connecting the gallbladder fossa and the pocket-like space provided an almost opposite incidence of damage. The portal territory of the hilar bifurcation was most likely to be damaged during a virtual incision along an avascular plane; however, the caudate branch of left portal origin was rarely damaged. The rightward course may be the best method for forceps insertion in cases where there is no IRHV. To preserve the caudate vein and the IRHV, taping on the right side of the IRHV and retracting to the right, or changing the direction of the forceps from leftward to rightward when the tip of the forceps is anterior to the IVC is recommended. The hanging maneuver by an anterior approach without mobilization is convenient for right or left hepatectomy for large tumors or hardened liver.

Background: 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. Methods: 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. Results: 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). Conclusion: 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.

症例は67歳,女性.精神分裂病で入院中であった.平成11年12月7日より腹満・腹痛と嘔吐がみられた.腸閉塞が疑われ当科を受診した.腹部単純X線で著明な胃拡張を認めた.腹部超音波で肝内に遠肝性に移動するhigh echoic lesionを認めた.腹部CTで肝外側区域に門脈内ガス(HPVG)を認めた.上部消化管内視鏡検査で胃に多発するびらんを認めた.精神疾患に起因した摂食障害により,胃が急激に過伸展し,拡張とびらんを生じ,びらん部からガスが移行し, HPVGを形成したものと考えた.胃内容を吸引し,絶飲絶食とした.翌日の腹部超音波ではHPVGは消失していた.症状も消失したため退院した.HPVGは比較的稀な病態で,開腹術を要する予後不良の徴候と考えられてきた.しかしながら,腸管壊死を伴わない場合には必ずしも予後不良ではなく,治療方針の決定には常にHPVGの成因を推測し,不必要な開腹術を回避する必要があると思われた.

Leiomyosarcomas are smooth muscle-derived tumors generally found intra-abdominally in the retoperitoneum, mesentery, or omentum. Only approximately 5% of these tumors originate from vessel wall smooth muscle. Those derived from the splenic vein are exceedingly rare, with only one previously published case in the literature. We present a second case of leiomyosarcoma of the splenic vein in a 58-year-old woman with 2 months of epigastric pain. A distal pancreatectomy was performed to include the tumor found centered in the splenic vein at the splenic and portal vein confluence and growing into the pancreas in the body on the posterior aspect. A saphenous vein patch was used for reconstruction.

This 59-year-old woman underwent living donor liver transplantation using a left lobe graft as an aid for autoimmune hepatitis in 2003. Splenectomy was also performed because of blood type incompatibility. Follow-up endoscopic and computed tomography examinations showed gastroesophageal varices with extra hepatic portal vein thrombosis in 2007 that increased (esophageal varices [EV]: locus superior [Ls], moderately enlarged, beady varices [F2], Blue varices [Cb], presence of small in number and localized red color sign [RC1] and telangiectasia [TE+], gastric varices [GV]: extension from the cardiac orifice to the fornix [Lg-cf], moderately enlarged, beady varices [F2], white varices [Cw], absence of red color sign [RC-]). Portal venous flow to the gastroesophageal varices was also confirmed from a large right gastric vein. The splenic vein was thrombosed. Blood flow to the liver graft was totally supplied from the hepatic artery. The graft was functioning well. Because these gastroesophageal varices had a high risk of variceal bleeding, we decided to proceed with a portal reconstruction of a surgical portosystemic shunt in 2008. Severe adhesions were observed around the portal vein. It was impossible to perform portal reconstruction. There were relatively fewes adhesious in the left lower side of the abdominal cavity. We decided to create an inferior mesenteric vein to left gonadal vein shunt. The portal vein pressure decreased from 31.0 to 21.5 cm H2O thereafter. The postoperative course was smooth without any complication. This patient was discharged on the postoperative day 15. Follow-up endoscopic study showed the improvement in the gastroesophageal varices (EV: Ls, F2, Cb, RC(-), GV: Lg-c, F2, Cw, RC-) at 3 months after the operation. We also comfirmed the patency of the shunt by serial computed tomography examinations.