Thalassemia intermedia and cavernous transformation of portal vein thrombosis in pregnancy

We report a rare case of a cavernous transformation of portal vein (CTPV) thrombosis accompanied by Thalassemia and thrombophilia during pregnancy that was successfully treated by low molecular weight heparin. The clinical presentation, diagnosis and the treatment are discussed.     

An anatomic investigation of radical resection of tumor in the hepatic duct confluence

The fetal umbilical vein in the ligamentum teres can be reopened to provide a 10 centimeter long vein, as wide as the left portal vein or the central splenic vein, that gives access to the left portal vein in the umbilical fissure of the liver. By cutting the ligamentum teres, this potential autologous venous graft is lost and, therefore, the ligamentum teres should never be sacrificed without reason. The umbilical side of the reopened umbilical vein can be anastomosed with the splenic vein to form a portal vein bypassing conduit that enters the liver in the umbilical fissure and take over function of the portal vein. From the results of this postmortem investigation, it can be concluded that radical block resection of the area consisting of the hepatic duct confluence, classic right hepatic lobe and complete hepatoduodenal ligament, preceded by construction of a complete separate afferent blood supply of the classic left hepatic lobe, is possible both anatomically and technically. There is no indication denying the supposition that the result of such a procedure is functionally analogous to standard extended right lobectomy with bilioenteric reconstruction.     

In vivo use of human umbilical vessels and the ductus venosus arantii.

Clinical use of umbilical vessels in the neonate is commonplace. In the adult, surgical reopening of the umbilical vein is feasible in the majority of patients, providing direct access to the portal circulation. Umbilical vein catheterization allows for portal manometry in the intact, unanesthetized state. Prolonged catheterization has served to facilitate physiologic and pharmacologic studies hitherto unavailable. Selective splanchnic catheterization with hepatoportography permits roentgenographic studies, important in the evaluation of patients with hepatobiliary diseases. Clinically, the umbilical vein has been used in the study of portal hemodynamics, portal decompression and hemofiltration, portal arterialization and in evaluating hepatic trauma. This method of access to the portal circulation has provided a route for study of the effects of drugs, hormones and other biologic materials on the portal circulation and for administration of antibiotics and other chemotherapeutic agents into the portal system. The procedure of umbilical vein catheterization is simple and repeated catheterization is possible. The ductus venosus, on the other hand, is not clinically usable and pertinent information has been reviewed. The ex vivo use of neonatal umbilical veins as vascular conduits is not included in this review.     

Management of portal venous thrombosis in hepatic transplant recipients

Portal venous thrombosis in hepatic transplant candidates is considered a relative contraindication to transplantation. In addition to thrombectomy, which is often technically impossible, donor portal venous arterialization or extra-anatomic venous bypass have been described. Two patients who underwent portal venous resection and subsequent anatomic reconstruction are presented herein. In the first patient, a graft with donor common iliac vein was interposed, and in the second, the donor portal vein was long enough to be anastomosed to the mesentericosplenic venous confluens. One patient is well 12 months after transplantation with patent portal vein and the other died of fungal sepsis after rejection treatment (the portal vein being open and unobstructed at autopsy).     

Behavior of the portal vein system in man after laparotomy.

At the end of an abdominal operation, a Teflon catheter was inserted into the portal vein, where it remained for nine days. Thus, blood samples could be withdrawn for analyses, and pressures could be recorded. The investigations were carried out in 41 patients who had a gastric or intestinal operation and had an uncomplicated postoperative course. The pressures in the portal vein and the arterioportal oxygen content difference were constant with 7 to 8 millimeters of mercury and by 2 volume per cent, respectively, during the period of all nine postoperative days. The pressure gradient between portal and central veins was about 6 millimeters of mercury. By infusing 350 to 500 milliliters of dextran 60 on day one or two postoperatively, the cardiac output was elevated about one-third, the central venous pressure increased from 0.9 to 4.9 millimeters of mercury and the portal venous pressure increased from 7.8 to 9.7 millimeters of mercury. This means that the pressure difference between the portal and central veins diminished. Simultaneously, the oxygen content difference between the systemic and pulmonary artery decreased from 4.7 to 3.3 volume per cent and between the systemic artery and portal vein, from 1.8 to 1.3 volume per cent. By assuming a constancy of the oxygen consumption in the region of the mesenteric circulation during infusion, it can be calculated from the behavior of the arterioportal oxygen content difference that the flow increase in the portal vein nearly equals that of cardiac output. The physical transhepatic resistance decreased about 50 per cent.     

The successful management of portal vein thrombosis after hepatic transplantation with a splenorenal shunt

Portal vein thrombosis is an infrequent complication after hepatic transplantation, but is quite dramatic when it occurs. It is usually managed by retransplantation with a significant mortality rate. We present a patient in whom portal vein thrombosis after hepatic transplantation was ultimately managed by a splenorenal shunt. The portal vein thrombosis was manifested by bleeding esophageal varices and, yet, normal hepatic function obviated the need for a new graft (one was not readily available). To the best of our knowledge, this is the first presentation of a patient with a transplant of the liver with acute portal vein occlusion and maintained hepatic function who has been successfully managed by a portosystemic shunt.     

Isolated gastric varices due to focal splenic vein stenosis.

Left-sided portal hypertension due to splenic vein stenosis is a very rare disease. We report a case of this condition in a 21-year-old woman who suffered from a first episode of tarry stool passage with fresh blood vomiting. Panendoscopy showed isolated gastric varices while sonography showed a normal liver but the presence of splenomegaly with prominent collateral circulations. Further imaging studies, including abdominal computed tomography, splenoportography and percutaneous transhepatic portography, revealed a focal stenotic proximal splenic vein resulting in left-sided portal hypertension. The collateral circulation ran from the short gastric veins via the left gastric veins into the main portal vein. The intraportal venous pressure was within normal limits. Splenectomy was performed and near normal wedge liver biopsy pathology confirmed non-cirrhotic extrahepatic portal hypertension. The patient had no further variceal bleeding after surgery.     

Computer simulation of hemodynamic changes after right lobectomy in a liver with intrahepatic portal vein aneurysm.

BACKGROUND/PURPOSE: Intrahepatic portal vein aneurysm is rare and its natural history is unknown. A 22-year-old healthy man, who wished to donate part of his liver to his diseased father, was incidentally diagnosed to have an intrahepatic portal vein aneurysm. The surgical decision of performing live donor hepatectomy for such a patient is normally difficult. We combined modern imaging reconstruction technologies with scientific computing as a new modality to foresee the risks of surgical complications. METHODS: Cross-sectional computed tomography images were used to reconstruct the three-dimensional image of portal vein distribution using the 3D-Doctor v3.5 software. The reconstructed images were further employed to generate surface and interior meshes with CFX software. Simulated hemodynamic changes in velocity, pressure, and wall stress were determined for the right lobectomy case pre- and postoperatively. RESULTS: The simulation results indicated that aneurismal pressure would be elevated significantly to 12.03 mmHg after operation. The left segmental portal venous blood flow would increase from 2.95- to 4.25-fold. The area near the branch point of one left segmental portal vein, which supplies blood to liver segment 4, and the portal vein aneurysm would endure high shear stress gradient. The resulting elevated aneurismal pressure may cause the thin wall to enlarge and rupture, while the high shear stress gradient would lead to vascular endothelial cell injury. Living donor surgery was not recommended hemodynamically based on the simulated results. CONCLUSION: Scientific computing and modern imaging technologies can be applied together to aid surgeons to make the best decision in difficult clinical situations.     

Successful pregnancy in a patient with portal hypertension secondary to portal vein thrombosis due to essential thrombocythaemia: a rare case

Essential thrombocythaemia (ET) is a disease characterized by an increased platelet count, megakaryocytic hyperplasia and a hemorrhagic or thrombotic tendency. Pregnancy in patients with ET can have a favorable outcome. However, ET has also been reported to complicate pregnancy by recurrent abortions, intrauterine death, and fetal growth retardation due to placental infarctions. ET has an unusual prevalence of intraabdominal (hepatic, portal and mesenteric) vein thrombosis, especially in young patients, which can lead to portal hypertension. There are ample cases in the literature of both essential thrombocytosis complicating pregnancy and portal hypertension complicating pregnancy, but the coincidence of both conditions appears to be unique. In this case report, we report a successful pregnancy in a patient with a prior diagnosis of essential thrombocytosis with remote secondary portal vein thrombosis and portal hypertension (PH).     

Atypical abdominal pain in the first trimester of pregnancy

We report the case of a 22-year-old woman who presented a violent epigastric pain at eight-weeks gestation. Superior mesenteric vein thrombosis was detected, with an extension to portal vein and remaining blood flow. Screening for thrombophilia revealed a heterozygote prothrombin gene mutation. Portal vein thrombosis is uncommon and difficult to diagnose. Diagnosis is made by Doppler ultrasound, a second intention test to be done in case of unusual upper abdominal pain during pregnancy.     

Insulin, glucagon and glucose in the regeneration response of the liver

The effects of intraduodenal glucose load on the hepatic uptake of insulin, glucagon and glucose after a 70 per cent hepatectomy were studies in anesthetized dogs. Dogs without a hepatectomy served as the control study. Data were derived from plasma concentrations in the portal vein, aorta and hepatic vein with simultaneous portal vein and hepatic artery plasma flow measurements. The concentrations of glucose in the arterial blood of dogs after a hepatectomy were less than those for the controls throughout the study, while insulin and glucagon concentrations showed no differences between the groups. Hepatic uptakes of insulin, glucagon and glucose per gram of liver perfused were significantly greater in the hepatectomy group and occurred because the amounts of these substances reaching the liver remnant were the same as those for the controls. The increased uptake of insulin and glucagon after partial hepatectomy may reflect increased binding of these hormones to the liver cell receptors, by which hepatic regeneration is induced. Increased glucose uptake could serve as the substrate for the accelerated anabolic processes.     

Internal jugular venous autograft in extrahepatic portal hypertension.

A 26 year old female with repeated episodes of upper gastrointestinal bleeding, secondary to extensive extrahepatic portal and superior mesenteric venous obstruction, was surgically treated by interposing an internal jugular vein autograft between a collateral channel and the inferior vena cava. The follow-up observation during a seven and one-half year period has shown no recurrence of bleeding, disappearance of esophageal varices and a widely patent graft with normal portal vascular pressures. The internal jugular vein is a readily accessible autogenous graft of adequate caliber that can maintain patency under rigorous conditions. Its use is recommended in constructing portal-systemic venous shunts in those instances of extrahepatic portal hypertension in which conventional shunts cannot be established or, if they can be established, are liable to closure.     

Simultaneous measurement of hepatic arterial and portal venous flows by transit time ultrasonic volume flowmetry

Simultaneous measurement of the hepatic artery and the portal vein was performed successfully upon 15 anesthetized patients during abdominal operations with the use of transit time ultrasonic volume flowmeter. The hepatic arterial flow, portal venous flow and total hepatic flow were 267.3 +/- 21.2, 746.4 +/- 41.3 and 1,010.7 +/- 52.7 milliliters per minute, respectively. The ratio of hepatic arterial flow to portal venous flow was 0.36 +/- 0.03. Temporary occlusion of the portal vein resulted in a significant increase in hepatic arterial flow (23.6 +/- 4.3 per cent, p less than 0.01), whereas temporary occlusion of the hepatic artery did not alter portal venous flow significantly. Occlusion of the common hepatic artery induced a significant decrease in hepatic arterial flow (p less than 0.05), but did not alter portal venous flow significantly. The results of this approach had useful clinical meanings in one patient in whom the Appleby's operation was performed in which sufficient hepatic arterial flow was needed after the common hepatic artery was ligated. Data are presented for hepatic circulation measured by transit time ultrasonic volume flowmeter, which is a good device to use to assess portal venous flow as well as hepatic arterial flow with reproducibility and stability.     

The jugular vein as an interposition graft in the distal splenorenal shunt

The selective distal splenorenal shunt is the preferred portal decompression procedure for patients with refractory bleeding esophageal varices. An autogenous jugular vein interposition graft in the distal splenorenal position obviates the tedious struggle associated with mobilizing the splenic vein from the pancreatic substance, thereby lessening blood loss, avoiding postoperative pancreatitis and shortening operative time. An autogenous jugular vein interposition distal splenorenal shunt can, therefore, be performed with less morbidity while affording the same physiologic benefits as the standard distal splenorenal shunt.     

Quantification of the capacity of the liver to remove ammonia from the circulation of dogs with portacaval transposition.

To quantitate the ammonia that the liver removes from the circulation and to investigate the distribution of this substance during and after an exogenous ammonia load, ten dogs with portacaval transposition were studied by placing catheters in the hepatic and portal veins through the external jugular vein, in the portal vein going to the liver and in the infrarenal vena cava through the femoral vein. A catheter also was inserted into the femoral artery. Blood ammonia levels were measured in each catheter, then an infusion of ammonium sulfate, 0.7 milligram per minute per kilogram for 45 minutes through the infrarenal vena cava, was given continuously. All other catheters were simultaneously sampled at 15 minute intervals during the infusion and for a 45 minute period after it was stopped. By using a continuous infusion of indocyanine green and Fick's formula, the total hepatic blood flow was estimated in five of the ten dogs. Thus, knowing the amounts of ammonia in the hepatic inflow and outflow tracts and relating them to the estimated hepatic blood flow, the hepatic extraction ratios of ammonia were calculated. The estimated hepatic blood flow changed minimally before and after portacaval transposition. The blood ammonia levels in all sites where samples were obtained, except for the hepatic vein, followed uniform patterns. In the femoral artery, the portal vein and liver-portal vein now anastomosed to the infrahepatic infrarenal vana cava-the blood ammonia levels during the period of infusion increased by at least 90 per cent. When the infusion was discontinued, the blood ammonia levels decreased but remained elevated, from 30 to 60 per cent of the preinfusion blood ammonia levels. Blood ammonia levels in the hepatic veins increased some but never exceeded 56 micrograms per 100 milliliters. It also was found that the liver removes 80 to 87 per cent of the ammonia reaching it by means of the urea cycle; the other 13 to 19 per cent of the ammonia returns to the circulation through the hepatic veins and is distributed into the circulation, causing the blood ammonia levels to remain higher for at least 45 minutes after the ammonia infusion load was discontinued than the preinfusion control levels in all the sites where samples were obtained.     

A simple and direct approach to the portal triad structures for a left lobectomy or a left lateral segmentectomy

The hilar isolation and dissection of portal pedicle is usually performed prior to hepatectomy in order to minimize blood loss intraoperatively. In some instances, it is difficult to visualize and encircle the bifurcation of the portal triad structures. We recommend the use of a simple and safe method of direct approach to the transverse portion of the portal vein in the left lobectomy or lateral segmentectomy, by incision and dissection of the ligament teres hepatis and continuing fatty tissue.     

Three-dimensional color power imaging of the fetal hepatic circulation

OBJECTIVE: The purpose of this study was to describe the use of three-dimensional power Doppler ultrasonography to identify vascular congenital anomalies of fetal portosystemic and umbilical venous systems. STUDY DESIGN: In a prospective study, the hepatic and umbilical venous systems were examined in 390 fetuses with two-dimensional ultrasonography, color, and spectral Doppler imaging. Fetuses suspected to have anomalies of the portal system and ductus venosus were additionally examined with three-dimensional power Doppler ultrasonography. RESULTS: Vascular anomalies were identified in 8 fetuses (absent ductus venosus, n=4; direct connection between the umbilical vein and the right atrium, n=2; and direct connection between the umbilical vein and the inferior vena cava, n=2) out of the 310 in which the venous system could be adequately imaged (prevalence=2.6%). Three-dimensional power Doppler imaging showed the course of the umbilical vein, its relationship to the portosystemic circulation, and whether a ductus venosus was present. CONCLUSION: Three-dimensional power Doppler ultrasonography can be used to image normal fetal hepatic and portal circulation, as well as identify anomalies of the fetal portosystemic and umbilical venous systems.     

Absent ductus venosus in the fetus: review of the literature and first report of direct umbilical venous drainage to the coronary sinus

The ductus venosus connects the portal and umbilical veins with the inferior vena cava and acts as a sphincter to protect the fetus from placental overcirculation. Its absence usually causes hydrops fetalis and is associated with high mortality rate, chromosomal anomalies and congenital malformations. In this condition, the umbilical vein almost always drains directly into right-sided structures such as inferior vena cava or right atrium. We reviewed the literature and describe the first case of a fetus with absent ductus venosus and direct connection of the umbilical vein to the coronary sinus.     

Manifestations of carcinoma of the uncinate process by means of superior mesenteric arteriography

Identification of carcinoma arising in the uncinate region of the pancreas is difficult because of the peculiar topographic relationship of this lesion with adjacent structures. Among the various diagnostic procedures performed upon ten patients with this malignant lesion, superior mesenteric arteriography provided the most helpful information, including signs of invasion in the main trunk of the superior mesenteric artery and vein and in the proximal portion of the jejunal arteries. A clearer visualization of these vascular involvements was attained in the right posterior oblique projection rather than in the anteroposterior projection. On the contrary, the arterial and portal vessels belonging to the celiac territory, such as superior pancreaticoduodenal arteries, dorsal pancreatic artery, gastroduodenal artery, splenic vein and portal vein, were almost free of involvement. At laparotomy, almost all of the patients had direct extension of the tumor to the superior mesenteric vessels, forming a cancerous core in the root of mesentery. All died of cachexia within six months after a palliative surgical procedure. Serial roentgenograms of superior mesenteric artery, especially taken in the oblique projection, are the best means of confirming carcinoma of the uncinate process, for which only a few available methods have been established to evaluate the clinical aspects.     

Application of rat in situ single-pass intestinal perfusion in the evaluation of presystemic extraction of indinavir under different perfusion rates

BACKGROUND/PURPOSE: First-pass effect has been an important concern for oral pharmaceuticals. An in vivo system was developed for measuring different concentrations of pharmaceuticals in the portal vein and hepatic vein (via the inferior vena cava) for delineating presystemic metabolism under different perfusion rates by using indinavir as an exemplary agent. METHODS: An in situ single-pass intestinal perfusion technique was modified from previous studies to concomitantly obtain portal and hepatic venous bloods. Portal and hepatic venous samples were simultaneously taken from rats at appropriate time points using the perfusion model of 1 mg/mL indinavir at flow rates of 0.05, 0.1, 0.5 and 1.0 mL/min. The indinavir concentrations were assayed by binary-gradient high-pressure liquid chromatography with UV detection. RESULTS: The mean indinavir concentrations in portal vein concentration-time profiles at different perfusion times under various flow rates were all higher than those obtained for hepatic veins. At flow rates of 0.5 and 1.0 mL/min, in particular, the area under the curve (AUC) and maximal concentration (Cmax) of indinavir absorption were significantly different between portal veins and hepatic veins (p < 0.05), indicating considerable hepatic involvement in the presystemic extraction of indinavir. The system also has potential for use when estimating the hepatic extraction ratio (E(H)) and hepatic clearance (Cl(H)). CONCLUSION: This in vivo approach could provide another useful tool for improving our basic understanding of the absorption kinetics and hepatic metabolism of pharmaceuticals under development and facilitating the clinical application of such.