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A 54-year-old male with liver cirrhosis (Child-Pugh score 5) presented with severe hepatogenous diabetes (HbA1c 12.6%). Contrast-enhanced CT showed a large portosystemic shunt from the inferior mesenteric vein to the left internal iliac vein. Glucose monitoring showed postprandial hyperglycemia and reactive hypoglycemia. After balloon-occluded retrograde transvenous obliteration (BRTO) and partial splenic transarterial embolization, postprandial hyperglycemia was diminished. Seven months later, HbA1c had improved from 12.6% to 6.7%. In this case, postprandial hyperglycemia occurred by direct delivery of glucose into the systemic circulation via the shunt, and fasting hypoglycemia occurred during treatment with oral antidiabetic agents and insufficient gluconeogenesis. BRTO of the portosystemic shunt resulted in improvement in hepatogenous diabetes.

This case report describes a 13-year 10-month-old girl who underwent a deceased-donor split LT for primary diagnosis of biliary atresia at the age of 12 months, who presented with a lower GI bleed. Ultrasound and CT revealed a venous vascular anomaly involving the cecum and ascending colon, with communication of the SMV and pelvic veins consistent with a CEPS. Associated varices were noted in the pelvis along the uterus and urinary bladder. These findings were confirmed by trans-hepatic porto-venography, which was diagnostic and therapeutic as a successful embolization of the CEPS was performed using micro-coils. There were no complications following the procedure and no further GI bleeding occurred, illustrating the efficacy of this treatment option for CEPS. We discuss the literature regarding the presenting complaint of GI bleeding post-LT, CEPS as a rare cause of GI bleeding and its association with PV, and the classification and treatment of CEPS., (© 2020 Wiley Periodicals LLC.)

Abernethy malformation is a rare congenital anomaly in which there is direct communication between the portal and systemic venous circulation. The clinical presentation ranges from asymptomatic with incidental detection on imaging to secondary complications of disease or related to associate anomalies. This is a retrospective analysis of data from nine patients with Abernethy malformation at a single center. This is a referral center for Pediatric Cardiology and for Hepatobiliary and Pancreatic Surgery. The patients presented to the Pulmonary Hypertension Clinic/the Hepatobiliary Surgery Clinic. Out of nine patients, four were male. Type II Abernethy malformation was present in five patients whereas three patients had type I malformation. One of the patients had communication between inferior mesenteric vein and internal iliac vein. Five out of nine patients were erroneously diagnosed as idiopathic primary pulmonary hypertension and were treated with vasodilators. One patient required living donor liver transplant. One patient was managed with surgical shunt closure whereas two patients required transcatheter shunt closure. The rest of the patients were managed conservatively. Abernethy malformation is more common than previously thought and the diagnosis is often missed. There are various management options for Abernethy malformation, which includes surgical or transcatheter shunt closure and liver transplant. Management of Abernethy malformation depends upon type, presentation, and size of shunt.

Acute mesenteric venous thrombosis (MVT) is the rarest cause of acute mesenteric ischaemia, so thrombosis of a variant inferior mesenteric vein (IMV) is especially uncommon in the setting of antiphospholipid syndrome (APS). Here, we present such a case of seronegative APS initially manifesting as an anomalous IMV thrombosis in a 76-year-old woman. Although guidelines support anticoagulation with vitamin K antagonists in these patients, we anticoagulated with rivaroxaban (a direct oral anticoagulant (DOAC)) due to patient preference, which resulted in complete clinical and endoscopic resolution. IMV thrombosis is a rare form of MVT, only two case reports describe successful anticoagulation with DOACs in the setting of MVT and none report APS as an underlying aetiology. Therefore, this case provides the opportunity to review the pathophysiology of MVT, APS and their medical management including current trends in anticoagulation., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Purpose: The gold standard for the diagnosis of malrotation is barium contrast study of the upper gastrointestinal system (UGCS), while color Doppler ultrasonography (CDUS) is another method used in the diagnosis. We investigated the value of CDUS for the diagnosis of malrotation in this study., Methods: UGCS images, CDUS images, plain abdominal images, demographic data, and symptoms of 82 patients who were investigated for presumed malrotation during a 7-year period were evaluated, retrospectively., Results: All patients underwent CDUS, and 18% of these patients were diagnosed with malrotation as the superior mesenteric vein was seen to be on the left of the superior mesenteric artery. We found that 16% of the 75 patients who underwent UGCS were diagnosed with malrotation. The sensitivity and specificity of CDUS in the diagnosis of malrotation was found to be 93.8 and 100%, respectively. The respective values for UGCS were 91.7 and 98.4%., Conclusion: Current data in the literature and our results underline that UGCS may yield false-positive and false-negative results. Although CDUS was found to be a reliable method for the diagnosis of malrotation in our study, the limitations of UGCS are also recognized for CDUS. Prospective studies are needed to determine the more valuable method.

Hepatic encephalopathy is suspected in non-cirrhotic cases of encephalopathy because the symptoms are accompanied by hyperammonaemia. Some cases have been misdiagnosed as psychiatric diseases and consequently patients hospitalized in psychiatric institutions or geriatric facilities. Therefore, the importance of accurate diagnosis of this disease should be strongly emphasized. A 68-year-old female patient presented to the Emergency Room with confusion, lethargy, nausea and vomiting. Examination disclosed normal vital signs. Neurological examination revealed a minimally responsive woman without apparent focal deficits and normal reflexes. She had no history of hematologic disorders or alcohol abuse. Her brain TC did not demonstrate any intracranial abnormalities and electroencephalography did not reveal any subclinical epileptiform discharges. Her ammonia level was > 400 mg/dL (reference range < 75 mg/dL) while hepatitis viral markers were negative. The patient was started on lactulose, rifaximin and low-protein diet. On the basis of the doppler ultrasound and abdomen computed tomography angiography findings, the decision was made to attempt portal venography which confirmed the presence of a giant portal-systemic venous shunt. Therefore, mechanic obliteration of shunt by interventional radiology was performed. As a consequence, mesenteric venous blood returned to hepatopetally flow into the liver, metabolic detoxification of ammonia increased and hepatic encephalopathy subsided. It is crucial that physicians immediately recognize the presence of non-cirrhotic encephalopathy, in view of the potential therapeutic resolution after accurate diagnosis and appropriate treatments., Competing Interests: Conflict-of-interest statement: All authors have no conflicts of interests to declare.

CASE DESCRIPTION Two Pembroke Welsh Corgis with gastrointestinal signs including inappetence, diarrhea, lethargy, and hypersalivation were referred for evaluation. CLINICAL FINDINGS Diagnostic testing included abdominal ultrasonography and CT angiography. One patient had a cranial mesenteric artery-to-mesenteric vein fistula with multiple acquired extrahepatic portosystemic shunts. The second patient had both cranial and caudal mesenteric artery-to-mesenteric vein fistulas and multiple acquired extrahepatic portosystemic shunts. TREATMENT AND OUTCOME Both patients underwent minimally invasive coil embolization of the mesenteric arterioportal fistulas, with complete occlusion confirmed by means of angiography at procedure completion. Clinical outcome approximately 1 year after treatment was assessed as fair to good because of recurrence of clinical signs that required medical management in 1 dog and some persistent serum biochemical abnormalities. CLINICAL RELEVANCE Outcome for the 2 patients described suggested that coil embolization may be a feasible and effective minimally invasive technique for the treatment of mesenteric arterioportal fistulas in dogs. However, further investigation of the potential for chronic hepatic disease in patients with a history of acquired portosystemic shunts is warranted.

Visceral artery pseudoaneurysm and arteriovenous fistula following penetrating abdominal injuries is a rarely observed complication. Presently described is the case of a 44-year-old male admitted to the hospital after having previously experienced penetrating abdominal trauma. The patient had developed a pseudoaneurysm in the superior mesenteric artery and an arteriovenous fistula between the superior mesenteric artery and vein following surgery. The patient underwent successful coil embolization procedure and he was discharged 1 day after intervention.

During our dissection classes, we saw a venous collar formed around the superior mesenteric artery (SMA) by the jejunal tributaries of superior mesenteric vein in an adult male cadaver. The jejunal tributaries united themselves to form two common jejunal veins. Upper common jejunal vein crossed superficial to SMA and opened into the SMV in front of the uncinate process of pancreas. The inferior common jejunal vein crossed behind the SMA from left to right and opened into the SMV, 4 cm below this level. A communicating vein connected the two common jejunal veins with each other.

The Abernethy malformation is a rare congenital malformation defined by the presence of an extrahepatic portosystemic shunt. Although most patients are asymptomatic, clinical encephalopathy is present in 15% of cases. We present a patient with type 2 Abernethy malformation, hyperammonemia, and encephalopathy. Shunt closure was performed successfully using interventional angiography; however, hyperammonemia recurred 3 months later. The diagnosis of Abernethy malformation can be made easily, but the ideal patient management strategy has not yet been established. This is the first reported patient with recurrence of hyperammonemia after interventional treatment; we discuss the therapeutic options for Abernethy malformation.

A 2-year-old boy presented with pneumonia and an abdominal mass was noted incidentally. A right lobe hepatic mass classified as PRETEXT III and congenital absence of the portal vein with drainage of the superior mesenteric vein to the inferior vena cava (Abernethy malformation type I) were confirmed by computed tomography and angiography. After a clinical diagnosis of hepatoblastoma had been made, he was treated with 4 cycles of doxorubicin and cisplatin and hepatic arterial chemoembolization with doxorubicin, after which the tumor was classified as POSTEXT III. He underwent a right extended hepatic lobectomy with resection of the caudate lobe but died on postoperative day 4 due to hepatic failure. The Abernethy malformation type I is associated with the development of hepatic tumors, and the abnormal blood flow might predispose to hepatic failure after liver resection. Extensive study of the hepatic vasculature is warranted in patients with suspected malformations. Liver transplant could be considered in patients with congenital portosystemic shunt and malignant liver tumors.

Background: Malrotation with midgut volvulus is a common surgical emergency in children. A diagnostic tool for malrotation with characteristics ideal in emergency settings such as non-invasiveness and rapidity remains a keenly debated issue among surgeons and radiologists alike., Methods: Fifty-two pediatric patients of suspected malrotation with midgut volvulus were studied between 1998 and 2016. All patients underwent plain abdominal X-ray and Color Doppler; contrast upper gastrointestinal (GI) studywas done in some patients. All cases were operated and diagnosis was confirmed. A subset of 60 pediatric patients with nonspecific GI complaints were also examined to see relative position of superior mesenteric vein (SMV)/superior mesenteric artery (SMA) in control population., Result: A total of 52 suspected cases of malrotation were admitted from May 1998 to November 2015, 43 had inversion of SMA/SMV and nine had SMV anterior of SMA in Color Doppler. All 43 cases of inversion of SMA/SMV were cases of malrotation after surgical confirmation; while five out of nine cases of SMV anterior to SMA had malrotation., Conclusion: In appropriate clinical settings, Color Doppler documenting the reversal or aberrant SMV/SMA axis is not only predictive but also diagnostic of malrotation of gut.

Purpose: To assess the usefulness of the relative position of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing intestinal malrotation in situs anomaly., Materials and Methods: From January 2004 to April 2015, 33 patients with situs anomalies were enrolled in this study who underwent abdominal USG, CT or MRI as well as upper gastrointestinal series (UGIS) or surgery: situs inversus (n=16), left isomerism (n=10), and right isomerism (n=7); age 21.2±23.2years (mean±standard deviation), range 0-72 years. The intestinal malrotation was confirmed with UGIS and/or operation in 16 patients. Relative positions of the SMV to the SMA were classified into four groups by reviewing abdominal USG, CT, or MRI: right sided, left sided, ventral sided, and dorsal sided. The incidence of malrotation was analyzed for each group., Results: In 16 patients with situs inversus, there was reversed SMA-SMV relationship: left sided (n=11) or ventral sided (n=5). One situs inversus patient with ventral sided SMV had intestinal malrotation (6.25%). 17 patients with situs ambiguus showed various SMA-SMV relationships (ventral sided, n=7; left sided, n=5; right sided, n=4; dorsal sided, n=1). Among them, 15 patients (88.2%) had intestinal malrotation. Two patients with normal rotation had either right sided or dorsal sided SMV., Conclusion: Situs ambiguus was commonly associated with intestinal malrotation with a variable SMA-SMV relationship. Reversal of the mesenteric vascular relationship was observed in situs inversus with normal rotation, not excluding the possibility of intestinal malrotation., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Superior mesenteric arteriovenous fistula (SMAVF) is a rare vascular disorder usually following penetrating abdominal trauma or gastrointestinal surgery. Percutaneous endovascular treatment such as embolization, has been widely used to treat this disease. We report a patient, who was presented with melena at the onset of his symptoms, then an acute hematemesis in shock. A SMAVF was diagnosed on an angiogram after a large mesenteric vein was seen on CT. The patient had a successful emergency endoscopic variceal ligation (EVL) to stop bleeding. Then the patient received fistula embolization with covered stent.

Objective: To describe the anatomy of congenital portosystemic shunts involving the left colic vein in dogs and cats., Methods: Retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. For inclusion a shunt involving the left colic vein with recorded intraoperative mesenteric portovenography or computed tomography angiography along with direct gross surgical observations at the time of surgery was required., Results: Six dogs and three cats met the inclusion criteria. All cases had a shunt which involved a distended left colic vein. The final communication with a systemic vein was variable; in seven cases (five dogs, two cats) it was via the caudal vena cava, in one cat it was via the common iliac vein and in the remaining dog it was via the internal iliac vein. In addition, two cats showed caudal vena cava duplication., Clinical Significance: The morphology of this shunt type appeared to be a result of an abnormal communication between either the left colic vein or the cranial rectal vein and a pelvic systemic vein (caudal vena cava, common iliac vein or internal iliac vein). This information may help with surgical planning in cases undergoing shunt closure surgery., (© 2016 British Small Animal Veterinary Association.)

Ischemic colitis is a rare, life-threatening, consequence of mesenteric arteriovenous malformations. Ischemia ensues from a steal phenomenon through shunting, and may be compounded by the resulting portal hypertension. Computed tomographic angiography is the most common first-line test because it is quick, non-invasive, and allows for accurate anatomic characterization. Also, high-resolution three-dimensional images can be created for treatment planning. Magnetic resonance angiography is similarly sensitive for vascular mapping. Conventional angiography remains the gold standard for diagnosis and also allows for therapeutic endovascular embolization. Our patient underwent testing using all three of these modalities. We present the first reported case of this entity in a patient with a vascular connective tissue disorder.

Purpose: To observe a case of congenital extrahepatic portosystemic shunt and discuss it from the embryological and clinical viewpoints., Methods: An 85-year-old female cadaver was employed for a dissection course at Aichi Medical University in 2009., Results: There was no evidence of liver cirrhosis macroscopically or microscopically. A portosystemic shunt was observed that involved communication between the inferior mesenteric vein, inferior vena cava (IVC), and left ovarian vein by a single Y-shaped shunt vessel., Conclusions: To the best of our knowledge, this is the first reported case of the above-mentioned three veins being connected by a single Y-shaped shunt vessel. Considering the other venous diameters, the shunt appeared to flow into the splenic vein and IVC. It cannot be denied that this shunt may have led to hepatic encephalopathy, although the shunt effect may have been minimal. Embryological development of IVC appears to occur close to the plexus of anastomosing vitelline veins, forming the portal vein.

Circumportal pancreas is a congenital fusion anomaly of the pancreas where the pancreatic tissue from the uncinate process, anomalously encases the portal vein and/or the superior mesenteric vein. Depending upon the level of the pancreatic annulus the variant can be classified into three subtypes-suprasplenic, infrasplenic or mixed; and each subtype exhibits either an anteportal or retroportal main pancreatic duct. Limited literature is available on this intriguing anomaly primarily because of its relatively low prevalence in humans (published prevalence rates vary from 0.2 to 2.5 %), probable lack of awareness among medical professionals and its generally symptomless course. In an attempt to appraise the embryological basis, clinicoradiological manifestations and potential surgical implications of circumportal pancreas, literature published in English was searched using PubMed and information collated so as to provide up-to-date information on this relatively understudied entity. The anomaly by itself remains innocuous but its preoperative recognition in those undergoing pancreatic resection bears decisive influence on planning and selecting apposite surgical resection planes as inadvertent duct injury can lead to pancreatic fistula.

Porto-mesenteric venous thrombosis following a trans-arterial occlusion of a superior mesenteric arteriovenous fistula is a rare occurrence. We present a case of endovascular management of one such case treated pharmacomechanically with catheter-directed mesenteric thrombolysis and transjugular intrahepatic portosystemic shunt creation without long-term successful outcome.

Portal annular pancreas (PAP) is a rare anatomical anomaly in which the pancreatic parenchyma surrounds the superior mesenteric vein and portal vein (PV) annularly. This anomaly requires careful consideration in pancreatic resection. A case is presented and the technical issues are discussed. A 61-year-old female was referred to the hospital for suspected papilla Vater adenocarcinoma. Preoperative computed tomography showed that the PV was annularly surrounded by pancreatic parenchyma. Surgery revealed the uncinate process extended extensively behind the PV and fused with the pancreatic body. The pancreas was first divided above the PV, and it was divided again in the body after liberating the PV from pancreatic annulation. The postoperative course was uneventful without pancreatic fistula. It is safer to divide the pancreatic body on the left of the fusion between the uncinate process and the pancreatic body to reduce the risk of pancreatic fistula in pancreaticoduodenectomy for PAP.

Superior mesenteric arteriovenous fistulas are rare, especially when iatrogenic in origin. Management of these fistulas can be surgical or endovascular. Endovascular embolisation is the preferred modality with a low rate of complications. Among the reported complications, bowel ischaemia is considered an unlikely occurrence. We report a case of a complex iatrogenic arterioportal fistula that was managed by endovascular embolisation and controlled through both its inflow and outflow, and was later complicated by bowel ischaemia.

Context: Pancreatic arteriovenous malformations are a rare entity that can be incidentally discovered during MDCT examinations., Case Report: We describe a rare case of asymptomatic arteriovenous malformation presenting at MDCT as a hypervascular mass in the pancreatic head., Conclusion: Pancreatic arteriovenous malformations are a rare entity, often asymptomatic, that can be correctly diagnosed by MDCT, especially with the use of specific electronic reconstructions.

Background: The D3 right colectomy for cancer requires dissection in the vicinity of the superior mesenteric vessels, which requires preoperative 3D imaging in these patients., Case Report: We present a patient with a caecum adenocarcinoma cancer which underwent D3 resection of the right colon, preceded by pre-operative MDCT with 2D multiplanar reconstruction and 3D volume rendering., Results: The dataset analysis revealed a rare congenital aneurysm of the superior mesenteric vein below the spleno-mesenteric confluence and a co-existing anomalous irrigation in the form of an ileo-mesenteric trunk. The surgical procedure was carried out as planned and the patient presents no signs of recurrence of the disease one year after the intervention., Conclusions: The case presented - with a rare and complicated vascular situs - illustrates particularly well that multimodal post-processing of the CT dataset for volume rendering allows proper assessment of the arrangement of pertinent blood vessels, and, consequently in the planning, setup and accomplishing the delicate operation, avoiding the surgical pitfalls and iatrogenic injuries., (Celsius.)

Background: Demonstration of the third duodenal segment (D3) in retroperitoneal location has been recently proposed as a method for excluding malrotation., Objective: This study was performed to determine whether a retroperitoneal third duodenal segment can reliably exclude malrotation., Materials and Methods: CTs of 38 patients with proven malrotation and 100 patients without malrotation were evaluated for the location of the duodenum/proximal small bowel, and the relationship of the superior mesenteric vein (SMV) to superior mesenteric artery (SMA)., Results: The D3 segment was in normal retroperitoneal location in 100% of control patients, compared to 2.5% or (1 of 38) of patients with malrotation. Nine of 11 patients (91%) with malrotation imaged prior to surgery had the proximal bowel in an abnormal location, while all 100 control patients had it in a normal location. The SMV was in normal relationship to the SMA in 11/38 patients (29%) with malrotation, compared to 79% of normal controls. In 10 controls, a branch of the SMV was partially wrapped around the SMA, potentially mimicking partial mesenteric volvulus., Conclusion: A retroperitoneal location of the D3 segment makes the diagnosis of malrotation unlikely but not impossible. Additional imaging of the duodenojejunal junction or cecum may be necessary to reliably exclude intestinal malrotation.

This case presents a complication of attempted separation of parapagus conjoined twins, related to loss of an intact mesenteric-portal venous axis. Despite known lack of a superior mesenteric artery in the right twin, initial evaluation in the operating room suggested that separation was possible. After hepatic division, however, it became apparent that the mesenteric drainage was not separable; and the operation was aborted. Subsequently, significant growth failure and hypoglycemia were noted in the right twin. The situation was corrected by creating a shunt to reinstitute mesenteric flow to the right twin's liver and separating the twin's mesenteric drainage. One year postoperatively, both twins are independently nourishing themselves and have been free from hospitalization with stable glucoses., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A large shunt between the inferior mesenteric vein (IMV) and the inferior vena cava (IVC) is a rare type of portosystemic shunt in patients with hepatic encephalopathy. We report a patient with hepatic encephalopathy due to a large IMV-IVC shunt who was successfully treated by balloon-occluded retrograde transvenous obliteration. The procedure involved a combination of 11 metallic coils and 5 ml of 5% ethanolamine oleate with iopamidol as the sclerosing agent. After complete obliteration of the shunt, his symptoms disappeared. At 2-years follow-up he was free of clinical symptoms, the size of his liver had slightly increased, and his liver function was preserved.

Background: Congenital portosystemic shunts (PSS) with preserved intrahepatic portal flow (type II) present with a range of clinical signs. The indications for and benefits of repair of PSS remain incompletely understood. A more comprehensive classification may also benefit comparative analyses from different institutions., Methods: All children treated at our institution for type II congenital PSS from 1999 through 2009 were reviewed for presentation, treatment, and outcome., Results: Ten children (7 boys) with type II PSS were identified at a median age of 5.5 years. Hyperammonemia with varying degrees of neurocognitive dysfunction occurred in 80%. The shunt arose from a branch of the portal vein (type IIa; n = 2), from the main portal vein (type IIb; n = 7), or from a splenic or mesenteric vein (type IIc; n = 1). Management included operative ligation (n = 6), endovascular occlusion (n = 3), or a combined approach (n = 1). Shunt occlusion was successful in all cases. Serum ammonia decreased from 130 ± 115 μmol/L preoperatively to 31 ± 15 μmol/L postoperatively (P = .03). Additional benefits included resolution of neurocognitive dysfunction (n = 3), liver nodules (n = 1), and vaginal bleeding (n = 1)., Conclusion: Correction of type II PSS relieves a wide array of symptoms. Surgery is indicated for patients with clinically significant shunting. A refined classification system will permit future comparison of patients with similar physiology., (Copyright © 2011 Elsevier Inc. All rights reserved.)

We report a patient of lower esophageal carcinoma with reversed intestinal rotation and major vascular anomalies including pre-duodenal pre-pancreatic portal vein, absence of the confluence of the splenic vein with the superior mesenteric vein, and deficiency of the common hepatic artery. We performed subtotal esophagectomy with three-field lymphadenectomy following reconstruction with the stomach. The postoperative course was uneventful. This might be the first case that had such complicated anatomical anomalies and radical esophagectomy was performed. As we had preoperatively recognized these anatomical anomalies on radiographic examinations, we could successfully perform esophagectomy and reconstruction without any complications.

Post-transplant children are regularly followed by colour Doppler US exam. Liver parenchyma, biliary tract and portal, subhepatic and arterial vascularisation are checked. We observed a post-transplant child with spontaneous meso-portal bypass after portal vein thrombosis (PVT). After orthotopic liver transplantation (OLT), PVT is frequently observed. When it occurs early (before 3 weeks), it has been identified as a cause of graft failure. On the other hand, late PVT (after 3 weeks) can be extremely well-tolerated, with cavernous transformation of the portal vein and formation of hepatopetal collaterals that deliver blood to the liver. However, extrahepatic portal hypertension (EHPH) and its related complications can develop. Cavernoma transformation is usually seen, but spontaneous shunt is not yet described in transplant patients. Distinction from the classic cavernoma can be achieved by the depiction of a single transcapsular vessel. This bypass partially corrects the EHPH. However it was decided to completely prevent shunt development by performing a surgical mesenterico-left portal vein bypass.

Hepatic encephalopathy most commonly occurs in patients with cirrhosis and end-stage liver disease, however, the disorder can also occur in the presence of intrahepatic or extrahepatic shunts when the intrahepatic circulation is effectively bypassed. The majority of extrahepatic shunts described to date develop between a mesenteric vein and inferior vena cava. Herein we report a novel case of a superior mesenteric vein to left internal iliac vein shunt that led to hepatic encephalopathy in a 57-year-old woman with no apparent underlying liver disorder. The patient presented with confusion, disorientation, and hyperammonemia. Workup for parenchymal liver disease was negative and liver biopsy findings did not show significant liver disease. Magnetic resonance imaging revealed a serpiginous 1-cm-wide shunt that diverted superior mesenteric vein blood from the portal confluence to the left internal iliac vein. Surgical closure of the shunt led to marked improvement of the patient with the resolution of hepatic encephalopathy. This report is the first description of a portosystemic shunt, likely congenital, linking these 2 vessels resulting in clinically significant hepatic encephalopathy. The findings emphasize that abdominal and pelvic imaging should be considered in patients with signs of hepatic encephalopathy that have none to minimal hepatic disease.