RESUMEN
Case report is devoted to successful pancreatectomy for cancer of terminal part of common bile duct in a patient with heterotaxy syndrome. The main difficulties during dissection of pancreaticoduodenal complex arose due to anatomical disorientation and the lack of standard topographic and anatomical landmarks. Preoperative computed tomography with assessment of visceral vessel anatomy is essential in all patients with biliopancreaticoduodenal tumors. If heterotaxy syndrome is suspected, additional examination is required to detect other potential abnormalities and prepare for unusual situation.
Asunto(s)
Neoplasias del Conducto Colédoco , Síndrome de Heterotaxia , Pancreaticoduodenectomía , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/diagnóstico por imagen , Conducto Colédoco/cirugía , Neoplasias del Conducto Colédoco/complicaciones , Neoplasias del Conducto Colédoco/diagnóstico por imagen , Neoplasias del Conducto Colédoco/cirugía , Disección , Duodeno/irrigación sanguínea , Duodeno/diagnóstico por imagen , Duodeno/cirugía , Síndrome de Heterotaxia/complicaciones , Síndrome de Heterotaxia/diagnóstico , Síndrome de Heterotaxia/diagnóstico por imagen , Humanos , Páncreas/irrigación sanguínea , Páncreas/diagnóstico por imagen , Páncreas/cirugía , Cuidados Preoperatorios , Circulación Esplácnica , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Pancreaticobiliary maljunction (PBM) arises from a developmental abnormality during the embryonic period; thus, these patients may have anatomical variations of the liver blood supply, including aberrant vessels and unusual locations. METHODS: We reviewed retrospectively the vascular anatomy of 52 patients with PBM, who were seen between 1998 and 2013. RESULTS: There were 11 male patients and 41 female patients. Sixteen patients had bile duct type (C-P type) PBM, 35 had pancreatic duct type (P-C type) PBM, and one had complex type PBM. Thirty-three patients had biliary dilatation. Nine (17.3 %) patients had an aberrant (replaced or accessory) hepatic artery and 2 (3.8 %) had an aberrant portal vein. Among 39 patients evaluated by contrast-enhanced computed tomography, 8 (20.5 %) had their right hepatic artery positioned on the ventral side of the common bile duct. The presence of aberrant hepatic vessels was not related to the type of confluence, biliary dilatation, type of Todani classification, or associated biliary malignancies. CONCLUSIONS: The incidence of the right hepatic artery being located on the ventral side of the common bile duct may be higher in patients with PBM than the naturally occurring incidence of about 10 % in the general Japanese population.
Asunto(s)
Conductos Biliares/patología , Arteria Hepática/patología , Hígado/irrigación sanguínea , Conductos Pancreáticos/patología , Vena Porta/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Conducto Colédoco/irrigación sanguínea , Dilatación Patológica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenRESUMEN
Results of surgical treatment of 120 patients, suffering complicated forms of chronic pancreatitis, were analyzed. In 5 patients pancreaticoduodenal resection in accordance to Whipple method have constituted the operation of choice. The indications for operation were: impossibility to exclude completely the malignant process inside pancreatic head; enhancement of the pancreatic head, causing duodenal, common biliary duct and the pancreatoduodenal zone vessels compression; cystic changes of pancreatic head with several episodes of hemorrhage inside the cyst and duodenum. The immediate, short-term and intermediate results of the operation were estimated as good and satisfactory.
Asunto(s)
Conducto Colédoco/cirugía , Duodeno/cirugía , Páncreas/cirugía , Pancreatectomía/métodos , Pancreaticoduodenectomía/métodos , Pancreatitis Crónica/cirugía , Adulto , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/patología , Duodeno/irrigación sanguínea , Duodeno/patología , Femenino , Hemorragia/patología , Hemorragia/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Páncreas/irrigación sanguínea , Páncreas/patología , Pancreatectomía/instrumentación , Pancreaticoduodenectomía/instrumentación , Pancreatitis Crónica/patologíaRESUMEN
Modern classifications of lymph nodes of the hepatopancreatobiliary zone organs, applied by domestic and leading foreign surgeons were analyzed. A modified classification of lymph nodes was proposed, basing on recommendations of Japanese society of pancreatologists (V edition). Basing on own experience, the results of studying of the lymph nodes groups and extent of lymphadenectomy in patients while presence of malignant tumors of pancreas and distal portion of common biliary duct were analyzed.
Asunto(s)
Adenocarcinoma/cirugía , Neoplasias del Conducto Colédoco/cirugía , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía , Neoplasias Pancreáticas/cirugía , Adenocarcinoma/irrigación sanguínea , Adenocarcinoma/patología , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/patología , Conducto Colédoco/cirugía , Neoplasias del Conducto Colédoco/irrigación sanguínea , Neoplasias del Conducto Colédoco/patología , Humanos , Escisión del Ganglio Linfático/métodos , Ganglios Linfáticos/irrigación sanguínea , Metástasis Linfática , Páncreas/irrigación sanguínea , Páncreas/patología , Páncreas/cirugía , Neoplasias Pancreáticas/irrigación sanguínea , Neoplasias Pancreáticas/patologíaRESUMEN
OBJECTIVE: The aim of this study was to determine the contribution of the hepatic artery, gastroduodenal artery, and portal vein to the microvascular blood flow in the common bile duct (CBD). BACKGROUND: Biliary complications are a common cause of graft loss after liver transplantation. The occurrence is, partly, attributed to hepatic artery thrombosis, which is considered to be the sole provider of blood flow to the bile ducts. However, the contribution of the portal vein and the gastroduodenal artery to the bile ducts is unknown. METHODS: Microvascular blood flow in the CBD was determined in 15 patients who underwent a pancreaticoduodenectomy with a combination of laser Doppler flowmetry and reflectance spectrophotometry. Microvascular blood flow was measured at baseline, during clamping the portal vein, during clamping the hepatic artery, and during clamping both. After transection of the CBD, these 4 measurements were repeated. RESULTS: Compared with baseline measurements, the microvascular blood flow through the CBD decreased to 62% after clamping the portal vein, 51% after clamping the hepatic artery, and 31% after clamping both. After the CBD was transected, these 3 measurements were 60%, 31%, and 20%, respectively. CONCLUSIONS: : Historically, the hepatic artery has been considered mainly responsible for biliary blood flow. We show that after transection of the CBD, mimicking the situation after liver transplantation, the contribution of the portal vein to the microvascular blood flow through the CBD is 40%. This study emphasizes the importance of the portal vein, and disturbances in portal venous blood flow could contribute to the formation of biliary complications after liver transplantation.
Asunto(s)
Conducto Colédoco/irrigación sanguínea , Vena Porta/fisiología , Flujo Sanguíneo Regional , Arterias/fisiología , Duodeno/irrigación sanguínea , Arteria Hepática/fisiología , Humanos , Microvasos , Estómago/irrigación sanguíneaRESUMEN
BACKGROUND AND AIMS: Current methods to diagnose malignant biliary strictures are of low sensitivity. Confocal endomicroscopy is a new approach that may improve the diagnosis of indeterminate biliary strictures. The purpose of this study was to evaluate indeterminate biliary strictures using probe-based confocal laser endomicroscopy and to understand the histologic basis for the confocal images. METHODS: Fourteen patients with indeterminate biliary strictures underwent endoscopic retrograde cholangiopancreatography with examination of their common bile duct with fluorescein-aided probe-based confocal laser endomicroscopy. Standard brushings and biopsies were performed. In parallel, rat bile ducts were examined either with conventional staining and light microscopy or with multiphoton microscopy. RESULTS: Earlier published criteria were used to evaluate possible malignancy in the confocal images obtained in the 14 patients. None of the individual criteria were found to be specific enough for malignancy, but a normal-appearing reticular pattern without other putative markers of malignancy was observed in all normal patients. Multiphoton reconstructions of intact rat bile ducts revealed that the reticular pattern seen in normal tissue was in the same focal plane but was smaller than blood vessels. Special stains identified the smaller structures in this network as lymphatics. CONCLUSIONS: Our limited series suggests that a negative confocal imaging study of the biliary tree can be used to rule out carcinoma, but there are frequent false positives using individual earlier published criteria. An abnormal reticular network, which may reflect changes in lymphatics, was never seen in benign strictures. Better correlation with known histologic structures may lead to improved accuracy of diagnoses.
Asunto(s)
Neoplasias de los Conductos Biliares/patología , Colangiopancreatografia Retrógrada Endoscópica/métodos , Enfermedades del Conducto Colédoco/patología , Conducto Colédoco/patología , Microscopía Confocal/métodos , Animales , Neoplasias de los Conductos Biliares/diagnóstico , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/ultraestructura , Enfermedades del Conducto Colédoco/diagnóstico , Constricción Patológica/diagnóstico , Constricción Patológica/patología , Humanos , Microscopía Confocal/instrumentación , RatasRESUMEN
The common bile duct may present a number of anatomical peculiarities regarding its size, course and relations, which should be taken into consideration by the anatomists and by the surgeons as well, during the surgery of the gallbladder, pancreas and duodenum. In the present study, we have analyzed the anatomical peculiarities of the common bile duct in 150 adult corpses of both sexes from the Anatomy Department and 22 human fetuses from the Pathology Department, University of Medicine and Pharmacy Cluj-Napoca.
Asunto(s)
Conducto Colédoco/embriología , Conducto Colédoco/patología , Adulto , Ampolla Hepatopancreática/irrigación sanguínea , Ampolla Hepatopancreática/embriología , Ampolla Hepatopancreática/patología , Cadáver , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/fisiología , Duodeno/irrigación sanguínea , Duodeno/embriología , Duodeno/patología , Femenino , Feto/patología , Humanos , Masculino , Modelos Biológicos , Tamaño de los ÓrganosAsunto(s)
Conducto Colédoco/irrigación sanguínea , Hemobilia/terapia , Hemostasis Endoscópica/instrumentación , Stents , Várices/complicaciones , Colangiopancreatografia Retrógrada Endoscópica , Hemobilia/etiología , Hemostasis Endoscópica/métodos , Humanos , Masculino , Metales , Várices/cirugía , Adulto JovenRESUMEN
Obstructive jaundice by vascular compression is rare. The causative arteries were identified as the right hepatic artery, gastroduodenal artery, cystic artery, proper hepatic artery, and an unspecified branch of the common hepatic artery. Also the venous system, such as enlarging collateral veins in cases of portal hypertension was a causative vessel. Herein, we describe a case of a proximal choledocholithiasis due to compression of the common bile duct by right hepatic artery originated from gastroduodenal artery. Final diagnosis and treatment were achieved through an operation.
Asunto(s)
Conducto Colédoco/patología , Arteria Hepática , Ictericia Obstructiva/diagnóstico , Colangiografía , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/cirugía , Diagnóstico Diferencial , Humanos , Ictericia Obstructiva/diagnóstico por imagen , Ictericia Obstructiva/etiología , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: Celiac axis stenosis due to compression by the median arcuate ligament has been reported in patients undergoing pancreaticoduodenectomy; it leads to the development of major collateral pathways that feed the hepatic artery. Dividing these important collaterals during pancreaticoduodenectomy can cause ischemic complications which may lead to a high mortality rate. To prevent these complications, it is necessary to assess intrahepatic arterial flow. CASE PRESENTATION: A 71-year-old Japanese man with anorexia was referred to us for the treatment of alcoholic chronic pancreatitis. Computed tomography revealed a pancreatic head tumor with a calculus, associated with the dilatation of the main pancreatic duct and intrahepatic bile duct. Three-dimensional imaging demonstrated focal narrowing in the proximal celiac axis due to median arcuate ligament compression and a prominent gastroduodenal artery that fed the common hepatic artery. The preoperative diagnosis was alcoholic chronic pancreatitis with common bile duct obstruction and celiac axis stenosis due to median arcuate ligament compression. Pancreaticoduodenectomy with median arcuate ligament release was scheduled. Before the division of the median arcuate ligament, the peak flow velocity and resistive index of his intrahepatic artery measured with Doppler ultrasonography decreased from 37.7 cm/second and 0.510, respectively, to 20.6 cm/second and 0.508 respectively, when his gastroduodenal artery was clamped. However, these values returned to baseline levels after the division of the median arcuate ligament. These findings suggested that pancreaticoduodenectomy could be performed safely. Our patient was discharged on postoperative day 17 without significant complications. CONCLUSION: The intraoperative quantitative evaluation of intrahepatic arterial blood flow using Doppler ultrasonography was useful in a patient who underwent pancreaticoduodenectomy, who had celiac axis stenosis due to compression by the median arcuate ligament.
Asunto(s)
Arteriopatías Oclusivas/cirugía , Arteria Celíaca/diagnóstico por imagen , Arteria Hepática/diagnóstico por imagen , Síndrome del Ligamento Arcuato Medio/etiología , Pancreaticoduodenectomía/efectos adversos , Anciano , Arteriopatías Oclusivas/complicaciones , Arteriopatías Oclusivas/diagnóstico , Arteriopatías Oclusivas/fisiopatología , Arteria Celíaca/patología , Conducto Colédoco/irrigación sanguínea , Constricción Patológica/diagnóstico por imagen , Constricción Patológica/etiología , Arteria Hepática/patología , Humanos , Imagenología Tridimensional , Circulación Hepática , Masculino , Síndrome del Ligamento Arcuato Medio/diagnóstico por imagen , Síndrome del Ligamento Arcuato Medio/cirugía , Pancreatitis Alcohólica/complicaciones , Ultrasonografía DopplerRESUMEN
BACKGROUND: Biliary complications are important during liver transplantation because of their effect on recipient and graft survival, incidence, and the long treatment period. These complications are associated with 50% morbidity and 30% mortality rates in recent studies. One of the most important reasons for biliary anastomosis complications is arterial ischemia. We present the results of our telescopic biliary anastomosis technique performed on the mucosa of the main biliary duct. PATIENTS AND METHODS: Fifty-six cases of telescopic biliary reconstruction were performed in 203 patients during 2015. Fifty cases and 52 patients who underwent standard reconstruction were chosen and compared. All patients had been scanned retrospectively. Statistical analyses were conducted with χ2 and Mann-Whitney U tests for the complications that occurred during the first 3 months. A P value <.05 was considered significant. RESULTS: No clinical or demographic differences were detected between the groups. About 90% of both groups were living donor liver transplantation cases. Five (10%) anastomotic leaks occurred in telescopic reconstruction group (n = 50), and 13 (25%) occurred in the standard reconstruction group (n = 52; P < .05). CONCLUSION: The arterial blood supply is better if the biliary anastomosis is made on the mucosal side of the main biliary duct. Early period anastomotic leaks may decrease significantly.
Asunto(s)
Conducto Colédoco/cirugía , Trasplante de Hígado/métodos , Anastomosis Quirúrgica/métodos , Fuga Anastomótica/etiología , Procedimientos Quirúrgicos del Sistema Biliar/métodos , Estudios de Casos y Controles , Conducto Colédoco/irrigación sanguínea , Femenino , Estudios de Seguimiento , Vesícula Biliar/cirugía , Supervivencia de Injerto/fisiología , Arteria Hepática/cirugía , Humanos , Isquemia/etiología , Donadores Vivos , Masculino , Persona de Mediana Edad , Membrana Mucosa/cirugía , Estudios RetrospectivosAsunto(s)
Neoplasias de los Conductos Biliares/diagnóstico , Enfermedades del Conducto Colédoco/diagnóstico , Endoscopía Gastrointestinal/estadística & datos numéricos , Enfermedades Inflamatorias del Intestino/diagnóstico , Microscopía Confocal/estadística & datos numéricos , Animales , Neoplasias de los Conductos Biliares/patología , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/patología , Conducto Colédoco/ultraestructura , Enfermedades del Conducto Colédoco/patología , Constricción Patológica/patología , Medios de Contraste , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/patología , Endoscopía Gastrointestinal/métodos , Gastroenterología/métodos , Humanos , Aumento de la Imagen/métodos , Enfermedades Inflamatorias del Intestino/patología , Mucosa Intestinal/patología , Mucosa Intestinal/ultraestructura , Ratones , Microscopía Confocal/métodos , RatasRESUMEN
The incidence of severe bile duct injuries has significantly increased since the introduction of laparoscopic cholecystectomy. The ideal reconstruction procedure for traumatic defects of the bile duct should be technically simple and should preserve both the physiological passage of bile and the sphincter of Oddi. In this article we describe a new technique for bile duct reconstruction in a pig model by means of an autologous vein graft that is splinted by a endoluminal biodegradable polylactate acid stent. In 12 pigs the external jugular vein was removed and used as an autologous vein graft. After performing a median laparotomy a 2-cm segment was resected from the bile duct. The common bile duct was reconstructed by a venous interponate that had been endoluminally stented by a biodegradable polylactate acid stent. For the examination of stent degradation, 2 pigs were sacrificed at 3, 4, and 5 months (stent degradation group) and the remaining 6 pigs at 6 months (survival group). All the pigs in the survival group survived for 6 months before being sacrificed. After 4 months the stent material had been completely broken down and the vein graft had been relined with bile duct epithelium. Thus, this new technique for bile duct reconstruction using an autologous vein graft with an endoluminal stent is simple to perform and reliable, and constitutes an interesting alternative to bilodigestive anastomosis due to the preservation of the papilla of Vateri.
Asunto(s)
Implantación de Prótesis Vascular/métodos , Conducto Colédoco/cirugía , Animales , Materiales Biocompatibles , Biodegradación Ambiental , Prótesis Vascular , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/lesiones , Conducto Colédoco/patología , Femenino , Stents , Sus scrofa , Factores de Tiempo , Trasplante Autólogo , Venas/trasplanteRESUMEN
There were examined 120 patients, using the method of the integral rheography of the body (according to method of M. I. Tyshchenko), and than operated on for the acute cholecystitis. In 60 patients, constituting the main group, cholecystectomy using minimal approach (CHMA) was done and in 60 (control group)--open cholecystectomy (OCH) using wide laparotomy. After performance of OCH the significant reduction of volumetric indices of blood flow was established. Extremely significant changes of the hemodynamics indices was observed on 1-3 days and than they had slowly improved and on 7-9 day restored, but not completely up to primary data in majority of cases. After performance of CHMA the indices changes were less significant and had restored earlier.
Asunto(s)
Colecistectomía/métodos , Colecistitis/cirugía , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/cirugía , Pletismografía de Impedancia/métodos , Enfermedad Aguda , Femenino , Humanos , MasculinoRESUMEN
PURPOSE: To investigate (1) diagnostic performance of transabdominal color doppler ultrasound (US) and endoscopic ultrasound (EUS) for detection and sub-classification of common bile duct varices (CBDV) in patients with portal vein thrombosis (PVT), and (2) clinical significance and natural history of CBDV subtypes. PATIENTS AND METHODS: During a 4-year period, 56 patients with PVT underwent US and EUS for the presence and subtypes of CBDV. Natural history was analyzed for patients who attended control visits. RESULTS: CBDV were diagnosed in 57 and 59 % of patients with US and EUS, respectively. In 19 % of patients, EUS revealed different CBDV subtypes than previously seen by US. The most common were paracholedochal (PCV), while the least common were epicholedochal (ECV) and Submucosal varices (SMV). Nine patients had obstructive jaundice and underwent ERCP which was complicated by hemobilia in two patients with SMV. Among eight patients who underwent control EUS (median follow-up 60 months), the form of CBDV remained unchanged. Two patients bled from esophageal varices, both with ECV. CONCLUSION: While abdominal US and EUS are equally sensitive for detection of CBDV, EUS allows more precise determination of CBDV subtype. Patients with SMV might be at increased risk of bleeding upon ERCP.
Asunto(s)
Conducto Colédoco/irrigación sanguínea , Endosonografía , Vena Porta/patología , Ultrasonografía Doppler en Color , Várices/diagnóstico por imagen , Trombosis de la Vena/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Conducto Colédoco/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Várices/complicaciones , Adulto JovenAsunto(s)
Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Conducto Colédoco/irrigación sanguínea , Cálculos Biliares/cirugía , Hemobilia/terapia , Hipertensión Portal/complicaciones , Hipotensión Controlada , Complicaciones Intraoperatorias/terapia , Esfinterotomía Endoscópica/efectos adversos , Várices/complicaciones , Adulto , Colangiografía , Endosonografía , Humanos , Masculino , Nitroglicerina/administración & dosificación , Vasodilatadores/administración & dosificaciónAsunto(s)
Cateterismo , Colangiopancreatografia Retrógrada Endoscópica , Colestasis Extrahepática/complicaciones , Colestasis Extrahepática/terapia , Conducto Colédoco/irrigación sanguínea , Cálculos Biliares/complicaciones , Cálculos Biliares/terapia , Hemobilia/complicaciones , Hemobilia/terapia , Hipertensión Portal/complicaciones , Hipertensión Portal/terapia , Várices/complicaciones , Adulto , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Resultado del Tratamiento , Adulto JovenAsunto(s)
Colecistectomía Laparoscópica/métodos , Conducto Colédoco/irrigación sanguínea , Hipertensión Portal/complicaciones , Vena Porta/anomalías , Várices/etiología , Anciano , Colecistectomía Laparoscópica/efectos adversos , Coledocolitiasis/diagnóstico por imagen , Coledocolitiasis/cirugía , Conducto Colédoco/patología , Conducto Cístico/irrigación sanguínea , Conducto Cístico/cirugía , Femenino , Hemorragia/terapia , Humanos , Resultado del Tratamiento , Ultrasonografía/métodos , Várices/diagnósticoRESUMEN
The perivascular epithelioid clear cell tumor (PEComa) has been described in a number of locations, including the pancreas, uterus, bladder, prostate, and gastrointestinal tract. We report the existence of a similar tumor occurring in the distal common bile duct of a 51-year-old man admitted for obstructive jaundice. The tumor had characteristic histologic features of a PEComa, including a richly vascular organoid architecture, tumor cells with clear to lightly eosinophilic cytoplasm, and variably prominent nucleoli. Immunohistochemically, the tumor cells were positive for HMB-45 and neuron specific enolase but negative for epithelial markers, smooth muscle markers, other neuroendocrine markers, vimentin, melan-A, and S-100 protein. PEComas appear to be ubiquitous tumors with characteristic histology and immunophenotype. Although most of these tumors have behaved in a benign fashion, they should be considered tumors of uncertain malignant potential given previous reports of recurrence and metastases. During a short follow-up period following a conservative local excision, our patient remains free of disease.
Asunto(s)
Adenocarcinoma de Células Claras/patología , Neoplasias de los Conductos Biliares/patología , Vasos Sanguíneos/patología , Conducto Colédoco/patología , Células Epitelioides/patología , Adenocarcinoma de Células Claras/química , Adenocarcinoma de Células Claras/cirugía , Neoplasias de los Conductos Biliares/química , Neoplasias de los Conductos Biliares/cirugía , Biomarcadores de Tumor/análisis , Conducto Colédoco/irrigación sanguínea , Conducto Colédoco/cirugía , Supervivencia sin Enfermedad , Células Epitelioides/química , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Juego de Reactivos para DiagnósticoRESUMEN
The diagnosis of biliary duct varices and portal vein occlusion should be considered when nodular or notched defects in the wall of the biliary duct system are shown by cholangiography or when pedunculated vascular structures in the bile ducts are seen at surgery. We present two cases of common hepatic and common bile duct varices due to portal vein occlusion.