BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder with an incidence of approximately 1 in 5000 in the general population. It is characterized by vasodilation, which affects specific organs, such as the skin, mucous membranes, brain, lungs, gastrointestinal tract, liver, and others. However, HHT rarely involves the portal venous system to cause serious clinical complications.
METHODS: A 68-year-old woman was admitted to the emergency department due to four consecutive days of abdominal pain and bloody stool and was subsequently diagnosed with HHT. Computed tomography angiography confirmed the presence of an arteriovenous fistula (AVFs). Considering this specific manifestation, whole exome sequencing was performed. After a comprehensive evaluation, a selective superior mesenteric artery embolization was prioritized to avoid intestinal ischemia. The postoperative symptoms of the patient were quickly relieved. Unfortunately, two months post-procedure the patient died from intestinal necrosis and abdominal infection related to remaining AVFs.
CONCLUSIONS: For patients with diffuse superior mesenteric AVFs, selective mesenteric arterial embolization may lead to positive short-term outcomes.

Radiologists are familiar with the appearances of a normal portal vein; variations in its anatomy are commonplace and require careful consideration due to the implications for surgery. These alterations in portal vein anatomy have characteristic appearances that are clearly depicted on CT, MR, and US images. Similarly, there are numerous congenital and acquired disorders of the portal vein that are deleterious to its function and can be diagnosed by using imaging alone. Some of these conditions have subtle imaging features, and some are conspicuous at imaging but poorly understood or underrecognized. The authors examine imaging appearances of the portal vein, first by outlining the classic and variant anatomy and then by describing each of the disorders that impact portal vein function. The imaging appearances of portal vein abnormalities discussed in this review include (a) occlusion from and differentiation between bland thrombus and tumor in vein and the changes associated with resultant hepatic artery buffer response changes, cavernous transformation of the portal vein, and portal biliopathy; (b) ascending thrombophlebitis of the portal vein (pylephlebitis); (c) portal hypertension and its causes and sequelae; (d) the newly described disease entity portosinusoidal vascular disorder; and (e) intra- and extrahepatic shunts of the portal system, both congenital and acquired (including Abernethy malformations), and the associated risks. Current understanding of the pathophysiologic processes of each of these disorders is considered to aid the approach to reporting. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

BACKGROUND: The pathogenesis of portal vein thrombosis (PVT) in cirrhosis is multifactorial, with altered hemodynamics being proposed as a possible contributor. The present systematic review was conducted to study the role of assessment of portal hemodynamics for the prediction of PVT in patients with cirrhosis.
METHODS: Three databases (Medline, Embase, and Scopus) were searched from inception to February 2023 for studies comparing portal venous system parameters in patients with cirrhosis developing PVT with those not. Results were presented as mean difference (MD) or odds ratio (OR) with their 95% confidence intervals (CIs).
RESULTS: A total of 31 studies (patients with cirrhosis: 19 studies, patients with cirrhosis undergoing splenectomy: 12 studies) were included. On pooling the data from multivariable analyses of the included studies, a larger portal vein diameter was a significant predictor of PVT in patients with cirrhosis without or with splenectomy with OR 1.74 (1.12-2.69) and OR 1.55 (1.26-1.92), respectively. On the other hand, a lower portal vein velocity (PVV) was a significant predictor of PVT in cirrhotics without or with splenectomy with OR 0.93 (0.91-0.96) and OR 0.71 (0.61-0.83), respectively. A PVV of <15 cm/s was the most commonly used cut-off for the prediction of PVT. Patients developing PVT also had a significantly higher splenic length, thickness, and splenic vein velocity.
CONCLUSIONS: The assessment of portal hemodynamic parameters at baseline evaluation in patients with cirrhosis may predict the development of PVT. Further studies are required to determine the optimal cut-offs for various parameters.

Development of postattenuation neurological signs (PANS) is a potentially severe complication after surgical attenuation of congenital portosystemic shunts in cats. This review summarizes findings of 15 publications that report occurrence of PANS in cats. PANS includes seizures but also milder neurologic signs such as blindness, ataxia, abnormal behavior, tremors, and twitching. Incidence of PANS and specifically postattenuation seizures in studies including a minimum of five cats ranges from 14.3% to 62.0% and 0% to 32.0%, respectively. Etiology of PANS in cats is unknown, however, several hypotheses have been proposed including central nervous system disease/derangement, perioperative hypoglycemia and electrolyte disturbances, and postoperative portal hypertension. A number of possible risk factors have been identified including lower grades of intraoperative postocclusion mesenteric portovenography and osmolality at 24 h postoperatively. Evidence for use of prophylactic antiepileptics such as levetiracetam to prevent or reduce incidence of PANS in cats is limited and does not support their use. Because the cause is unknown, treatment is aimed at controlling neurologic signs, preventing progression to more severe signs, and providing general supportive care. Prospective studies comparing the efficacy of different antiepileptics for treatment of PANS in cats are required. Prognosis for recovery is variable and dependent on severity of neurologic signs. For cats surviving to discharge, long-term survival is possible but persistence or recurrence of neurologic signs in the long-term is not uncommon.

The presence of portal vein thrombosis (PVT) has previously been considered a contraindication to the insertion of transjugular intrahepatic portosystemic shunts (TIPSS). However, patients with PVT may have portal hypertension complications and may thus benefit from TIPSS to reduce portal venous pressure. There is an increasing body of literature that discusses the techniques and outcomes of TIPSS in PVT. This review summarizes the techniques, indications and outcomes of TIPSS in PVT in published case reports, case series and comparative trials, especially regarding the reduction in portal hypertensive complications such as variceal bleeding. A comprehensive literature search was conducted using MEDLINE and PubMed databases. Manuscripts published in English between 1 January 1990 and 1 March 2021 were used. Abstracts were screened and data from potentially relevant articles analyzed. TIPSS in PVT has been reported with high levels of technical success, short-term portal vein recanalization and long-term PV patency and TIPSS patency outcomes. Several comparative studies, including randomized controlled trials, have shown favorable outcomes of TIPSS compared with non-TIPSS treatment of PVT complications. Outcomes of TIPSS with PVT appear similar to those in TIPSS without PVT. However, TIPSS may be more technically difficult in the presence of PVT, and such procedures should be performed in expert high-volume centers to mitigate the risk of procedural complications. The presence of PVT should no longer be considered a contraindication to TIPSS. TIPSS for PVT has been acknowledged as a therapeutic strategy in recent international guidelines, although further studies are needed before recommendations can be strengthened. KEY POINTS: Portal vein thrombosis (PVT) is no longer a contraindication to the insertion of transjugular intrahepatic portosystemic shunts (TIPSS) TIPSS often leads to the spontaneous dissolution of PVT, but can be combined with mechanical or pharmacological thrombectomy TIPSS reduces portal hypertensive complications of PVT, such as variceal bleeding, and can also facilitate liver transplantation where PVT may otherwise interfere with vascular anastomoses Studies have shown favorable long-term outcomes of TIPSS compared with TIPSS without PVT; as well as compared with non-TIPSS treatment of PVT complications TIPSS in PVT should be performed in high-volume specialist centers due to technical difficulties.

In case of mechanical cholestasis, along with stagnation in the veins and bile ducts, lymph production increases, which contributes to the accumulation of ascitic fluid. In the peribiliaryareas, where the extramural biliary glands are located, an accumulation of lymphatic vessels has been observed in all the preparations.In these same areas, a contrast-enhanced microtomography showed transition of the ink-gelatin contrast agents (using gelatin and India ink) from the extramural part of the mucous glands to the lumen of the lymphatic capillaries and blood vessels.Lymphobiliary connections were visualized during the preparation of the sections of the portal triad of the lobar and sectoral portal tracts under a binocular microscope. More reliable evidence of the existence of lymphobiliary connections in the portal triad region was revealed on histological preparations stained with traditional methods.; Thus, anatomically, the area of the portal triad appears to be one of the alternative areas of lymphobiliary communications, which further confirms its high adaptive capacity in case of stagnation of bile.

BACKGROUND: Several options have been proposed for the treatment of congenital extrahepatic portosystemic shunts (cEHPSS) in dogs, but formal comparisons among different treatment options are currently unavailable. A previous evidence-based review (2012) found low quality of evidence for papers assessing the treatment of cEHPSS in dogs.
OBJECTIVE: To assess the quality of evidence available in the treatment of cEHPSS, summarize the current state of knowledge with respect to outcome after cEHPSS management, and compare different treatment techniques.
METHODS: Not used.
METHODS: A bibliographic search was performed without date or language restrictions. Studies were assessed for quality of evidence (study design, study group sizes, subject enrollment quality, and overall risk of bias) and outcome measures reported (perioperative outcome, clinical outcome, and surgical or interventional outcome), all reported with 95% confidence intervals. A network meta-analysis was performed.
RESULTS: Forty-eight studies were included. Six retrospective studies (grade 4b) compared 2 techniques and 7 were abstracts (grade 5). The quality of evidence was low and risk of bias high. Regarding surgical outcome, statistically significant superiority of ameroid constrictor over thin film band was observed (P = .003). No other comparisons were statistically significant.
CONCLUSIONS: The evidence base of choice of treatment of cEHPSS in dogs remains weak despite recent publications on the subject. Ameroid is superior to thin film band in causing EHPSS closure. Blinded randomized studies comparing different treatment modalities, which routinely include postoperative imaging to assess cEHPSS closure and acquired portosystemic shunt development are essential.

BACKGROUND: Hepatic portal venous gas (HPVG) is a rare radiological finding in which gas enters the portal venous system and it is associated in case of necrotizing colitis with a mortality of 75%. We report a case of iatrogenic HPVG with a review of literature.
METHODS: A 41 years old patient underwent total colectomy and ileal pouch- anal anastomosis with derivative ileostomy for a familiar adenomatous polyposis coli in June 2008. A stenosis of the pouch-anal anastomosis developed. The patient underwent several endoscopic dilations. A recurrence of the stenosis was observed. The patient underwent to several endoscopic procedure. After the last colonoscopy the patient showed a fever with abdominal pain. A CT scan showed little peri-anastomotic collections and massive hepatic portal venous gas.
CONCLUSIONS: The management of HPVG varied from surgical intervention to non-operative procedure. The surgical approach it\'s reserved to clinically unstable patients or those with evidence of peritonitis or bowel perforation. Stable patients, like those with an HPVG consequence of an endoscopic procedure, can be treated with non- operative management.
CONCLUSIONS: Our experience confirm that hepatic portal venous gas can be related to endoscopic procedure; thus, it can be managed on the basis of patient\'s general clinical conditions, and in selected cases it will disappear without therapeutic interventions with a good outcome.

Hematochezia is a rare clinical presentation of congenital extrahepatic portosystemic shunt (CEPS). We describe a series of three patients with type II CEPS presenting as hematochezia that were treated by catheter embolization, followed by a brief review of published articles. Hematochezia of the patients was due to the giant inferior mesenteric vein, superior rectal vein and colonic varices. The catheter embolization was successfully accomplished in all of the patients. After a mean follow-up of 27 months, no serious adverse effects were observed. For unexplained massive hematochezia, CEPS needs to be considered as a differential diagnosis. Based on our present results and the review of the literature, transcatheter permanent embolization of the giant inferior mesenteric vein might be an effective and safe treatment for type II CEPS.Level of Evidence Level 4, case series.

The aim of this study was to establish the evidence base for the treatment of intrahepatic congenital portosystemic shunts in dogs through a systematic review of the pertinent literature. Studies were filtered for evidence to answer the question \"Which of the treatment options for intrahepatic CPSS in dogs offers the best short- and long-term outcome?\" Studies were assigned a level of evidence based on a system published by the Oxford Centre for Evidence-Based Medicine. Thirty-two studies were included in the review. Twenty-six provided level 4 evidence and six provided level 5 evidence. There were no level 1, 2 or 3 studies. One study compared surgical treatment with medical management and one study compared suture ligation with ameroid constrictor placement. The remaining studies were case series describing the outcome for one treatment method alone. Methods and timings of assessments of short- and long-term outcomes were highly varied, making direct comparisons challenging. The evidence regarding the treatment of intrahepatic congenital portosystemic shunts in dogs is weak, with only two studies directly comparing treatments. There is a lack of evidence regarding short- and long-term outcomes on which to base clinical decisions.