Duplex Doppler endosonography in the diagnosis of splenic vein, portal vein, and portosystemic shunt thrombosis

A systematic review and meta-analysis of portal vein morphometry in pediatric and adult populations: Drawing the line between normal and abnormal findings

PURPOSE

The morphometry of the hepatic portal vein is of clinical importance, particularly in pre-operative assessments, surgical management, and diagnoses of liver conditions. This systematic review and meta-analysis aimed to characterize the morphometry of the normal portal vein in both pediatric and adult patients.

METHODS

The study, conducted using the PRISMA guidelines and registered with PROSPERO, utilized the MEDLINE, EMBASE, SCOPUS and Web of Science databases up to May 2020, and updated to May 2023. All studies reporting extractable data on diameter, length, and cross-sectional area (CSA) of the main, left, and right portal veins (PV, LPV, RPV, respectively) were included. The AQUA Tool was used to assess the quality of the included studies. Data analysis included subgroup analyses based on geographical location, sex, age, and imaging modality.

RESULTS

A total of 122 studies with 11,637 subjects were eligible for inclusion. Overall, the pooled mean diameter of the PV (PVD) was 10.09 mm (95% CI: 9.56-10.62). Significant differences in diameter were found between pediatric (6.60 mm; 95% CI: 5.38-7.82) and adult (10.72 mm; 95% CI: 10.25-11.19) subjects. Additionally, there was a significantly larger PVD measurement from computed tomography (CT) than other imaging modalities: CT, 13.28 mm (95% CI: 11.71-14.84); magnetic resonance imaging (MRI), 10.50 mm (95% CI: 9.35-11.66) and ultrasound (US), 9.81 mm (95% CI: 9.47-10.16). The mean diameters of the LPV and RPV were 8.27 mm (95% CI: 6.78-9.77) and 8.33 mm (95% CI: 6.70-9.95), respectively. Mean PV length in adults is 48.63 mm (95% CI: 35.63-61.64). Mean CSA of the PV was 1.09 cm2.

CONCLUSIONS

The study obtained aim to improve the understanding of portal vein anatomy, especially with relevance to surgical interventions of the liver in both pediatric and adult patients. Measurements from ultrasound imaging closely approximates the generated pooled PVD mean for pediatric and adult patients. CT imaging, however, significantly exceeded the established 13 mm threshold for adults. For pediatric patients, a threshold of 8 mm is proposed as a diagnostic upper limit for a normal PVD. Although not significant, the PVD decreased from the portal confluence towards its bifurcation.

Pylephlebitis — a rare complication of a fish bone migration mimicking metastatic pancreatic cancer: A case report

BACKGROUND

Pylephlebitis is a rare condition, poorly recognized by clinicians and with few references. In this case, the clinical appearance resembled the clinical course of a pancreatic cancer and was originated by the ingestion of a fish bone, making the case more interesting and rare.

CASE SUMMARY

A 79-year-old female presented to the emergency department with fever, loss of appetite and jaundice. Tenderness in the right upper quadrant was present. Inflammation marker were high. A computed tomography (CT) scan revealed gallstones and aspects compatible with acute pancreatitis. The patient was admitted to surgery ward and has her condition aggravated. A magnetic resonance revealed multifocal liver lesions. Later, a cholangiopancreatography and an endoscopic ultrasound (US) were able to diagnose the condition. Specific treatment was implemented and the patient made a complete recovery.

CONCLUSION

In conclusion, this case report demonstrates for the first time the diagnosis of an unusual case of pylephlebitis complicated by the migration of a fish bone, mimicking metastatic pancreatic cancer. Clinical presentation and traditional imaging studies, such as transabdominal US and CT, remain the standard for diagnosing this condition.

Quantitative investigation of vascular response to mesenteric venous thrombosis using large-field-of-view photoacoustic microscopy

Mesenteric venous thrombosis (MVT) is one of major causes leading to severe mesenteric ischemia. Vascular network plays an important role during the occurrence and development of MVT. However, there lacks an appropriate imaging method, which features advanced volumetric resolving capability, superior sensitivity to hemoglobin, and ultra-large field-of-view (FOV), to investigate vascular response of MVT. In this study, we developed and applied a large-FOV optical resolution photoacoustic microscopy to quantify the vascular response during the entire course of two different MVT models in which we ligated the superior mesenteric vein and inferior mesenteric vein, respectively. Furthermore, we developed a quantitative algorithm to derive total vascular length, relative concentration of total hemoglobin and vascular density over the FOV to reveal different vascular responses in different MVT models.

Isolated Gastric Varices due to Essential Thrombocytosis Related to Splenic Vein Thrombosis: A Challenge to Uncover the Concealed Diagnosis

Essential thrombocytosis is associated with gastrointestinal (GI) vascular thrombosis. Sinistral portal hypertension (left-sided portal hypertension) due to splenic vein thrombosis can lead to isolated gastric varices and should be suspected in a patient with obscure GI bleeding with normal liver function. This case reviews the challenges presented in diagnosing isolated gastric varices due to splenic vein thrombosis through radiologic or endoscopic studies. Unrevealing radiologic or endoscopic studies does not rule out splenic vein thrombosis, which should be suspected in a patient with essential thrombocytosis and obscure GI bleeding.

What should be known prior to performing EUS exams? (Part II)

In “What should be known prior to performing EUS exams, Part I,” the authors discussed the need for clinical information and whether other imaging modalities are required before embarking EUS examinations. Herewith, we present part II which addresses some (technical) controversies how EUS is performed and discuss from different points of view providing the relevant evidence as available. (1) Does equipment design influence the complication rate? (2) Should we have a standardized screen orientation? (3) Radial EUS versus longitudinal (linear) EUS. (4) Should we search for incidental findings using EUS?

Mesenteric venous thrombosis presenting as gastrointestinal bleeding, a challenging diagnosis

Acute mesenteric venous thrombosis (MVT) is an uncommon cause of intestinal ischemia and is associated with high morbidity and mortality. Patients with acute MVT often present with gastrointestinal (GI) bleeding and other unspecific findings making the diagnosis challenging. This condition requires emergent treatment. The high rates of misdiagnosis of these patients and subsequently the delay in proper and quick management put patients at increased risk of having a negative outcome. Physicians should suspect acute MVT in patients with GI bleed while also considering other factors such as, a past medical history of pro-thrombotic conditions, past surgical history of splenectomy, symptoms of nausea, vomiting, abdominal pain, physical exam findings of abdominal tenderness and abdominal distention and a laboratory workup indicating leukocytosis and an increased plasma lactic acid level. An increase in the yield of accurate diagnosis of acute MVT is possible if physicians in the ED accurately interpret all these findings. The authors herein present a case of acute MVT in a patient whose initial complaint was GI bleeding and provide a thorough review of the literature of cases of acute MVT presenting with GI bleed.

Imaging and minimally invasive endovascular therapy in the management of portal vein thrombosis

Thrombosis of the portal venous system, although rare in the general population, is commonly diagnosed in patients with specific underlying conditions including prothrombotic diseases, cirrhosis, hepatobiliary malignancy, and intraabdominal inflammation. Recent improvements in imaging have played a fundamental role in increased detection of portal vein thrombosis (PVT), frequently reported in asymptomatic patients as an incidental finding. Minimally invasive, endovascular therapy is a medically rational option to achieve recanalization of the portal vein as an adjunct to conservative medical management. This review focuses on the advances in imaging modalities to diagnose, stage and follow-up PVT, and gives a short overview of the available endovascular techniques in this field.

Utility of endoscopic ultrasound in the diagnosis and management of esophagogastric varices

Endoscopic ultrasound (EUS) has significantly improved our understanding of the complex vascular structural changes in patients with portal hypertension. At present, EUS is a useful diagnostic tool for the evaluation of esophagogastric varices (EGVs) and guidance of endoscopic therapy. Several studies have employed this new technique for the diagnosis and management of esophageal and gastric varices, respectively. In the present review, we have summarized the current status of EUS for the diagnosis and management of EGVs and clarified the clinical feasibility of this procedure. New indications for EUS can be developed in the future after adequate validation.

Ultrasonography in gastroenterology

Ultrasonography (US) is a safe and available real-time, high-resolution imaging method, which during the last decades has been increasingly integrated as a clinical tool in gastroenterology. New US applications have emerged with enforced data software and new technical solutions, including strain evaluation, three-dimensional imaging and use of ultrasound contrast agents. Specific gastroenterologic applications have been developed by combining US with other diagnostic or therapeutic methods, such as endoscopy, manometry, puncture needles, diathermy and stents. US provides detailed structural information about visceral organs without hazard to the patients and can play an important clinical role by reducing the need for invasive procedures. This paper presents different aspects of US in gastroenterology, with a special emphasis on the contribution from Nordic scientists in developing clinical applications.

Splanchnic venous thrombosis and pancreatitis

Pancreatitis is an inflammatory process with local and systemic manifestations. One such local manifestation is thrombosis in splanchnic venous circulation, predominantly of the splenic vein. The literature on this important complication is very sparse. This review offers an overview of mechanism of thrombosis, its pathophysiology, diagnosis, and management in the setting of acute as well as chronic pancreatitis.

Endoscopic ultrasound: contrast enhancement

The development of ultrasound contrast agents has allowed for the evaluation of vascularity in digestive organs by contrast-enhanced endoscopic ultrasonography (EUS). Contrast-enhanced Doppler EUS and contrast-enhanced harmonic EUS (CH-EUS) have improved characterization of pancreatic tumors, lymph nodes, and gastrointestinal submucosal tumors and compliment EUS fine-needle aspiration (FNA) in identifying malignant tumors. Moreover, CH-EUS can be used to identify the target for EUS-guided FNA by clearly depicting the outline of the lesions.

Usefulness of endoscopic ultrasonography in hepatology

Endoscopic ultrasonography (EUS) is used to evaluate patients with hepatobiliary diseases. The technique is useful for the diagnosis of esogastric varices in selected cases of portal hypertension, and to evaluate the pathogenic role and prognostic value of the collateral circulation in patients with this condition. When coupled with the Doppler technique, EUS can be used to guide injection sclerotherapy and to verify the obliteration of varices (particularly fundal varices) after endoscopic treatment. Hemodynamic changes induced in the collateral circulation by vasoactive drugs can also be measured with Doppler-EUS. Fine-needle aspiration under EUS guidance is useful in the diagnosis of focal liver lesions and perihepatic adenopathy, and in the evaluation of biliary tract diseases. New indications can be developed in the future after adequate experimental validation.

Endoscopic ultrasonography and portal hypertension: where are we in 2009?

Endoscopic ultrasonography is currently a sensitive diagnostic and therapeutic tool with established indications, but its role in the management of portal hypertension is not well defined. This article briefly reviews indications, technologic improvements, diagnostic and interventional applications of endoscopic ultrasonography in portal hypertension.

[Bleeding from gastric varices as the initial manifestation of primary pancreatic lymphoma]

In patients with pancreatic cancer, the most frequent symptoms are abdominal pain, weight loss and jaundice. Upper gastrointestinal bleeding produced by gastric varices is a rare entity in these patients and requires the presence of splenic vein thrombosis (SVT) to be excluded. We describe the case of a young man who presented to the emergency department with hematemesis. Diagnostic tests revealed primary pancreatic lymphoma (PPL), which provoked splenic vein thrombosis, collateral circulation and the formation of isolated bleeding gastric varices. To date, we have found no reports in the literature of PPL with this form of presentation. Finally, we review the literature, with emphasis on the importance of excluding splenic vein thrombosis in patients with isolated gastric varices, and discuss certain features of the diagnosis and treatment of PPL.

Vascular disorders of the liver

This guideline has been approved by the American Association for the Study of Liver Diseases (AASLD) and represents the position of the association.

Endoscopic ultrasonography in the diagnosis and management of portal hypertension. Where are we next?

Endoscopic ultrasonography has recently emerged as an accurate, non-invasive and reproducible alternative means of providing data for patients with portal hypertension. It is well established that endoscopic ultrasonography is more sensitive than endoscopy in the diagnosis of gastric varices. Dilated venous abnormalities outside the gastrooesophageal lumen, which cannot be diagnosed by endoscopy, are readily visible with endoscopic ultrasonography or miniature probes. Endoscopic ultrasonography is also useful to predict the risk of variceal recurrence and thus the risk of rebleeding after endotherapy which cannot be reliably predicted using endoscopy alone. The introduction of echo endoscopes equipped with Doppler facilities has allowed the sonographic visualisation of the vessels and the evaluation of vascular blood flow along with possible morphologic and haemodynamic changes after endoscopic or pharmacological therapy. However, despite its theoretical advantages, relative evidence suggests that in the clinical setting of portal hypertension, endoscopic ultrasonography remains an investigational tool with limited clinical applications.

Endoscopic ultrasonography: equipment and technique

By definition, endoscopic ultrasonography (EUS) combines endoscopy and high-frequency ultrasound, incorporating a small ultrasonic transducer into the tip of endoscopes. For the upper gastrointestinal tract, mostly oblique-viewing endoscopes are used, although recently, forward viewing instruments have become available. For colorectal EUS, rigid probes for the rectum and a flexible forward-viewing echocolonoscope are available. EUS generates ultrasound either mechanically or electronically, depending on the type of instrument used. The electronic technique potentially allows the incorporation of (color) Doppler ultrasound, which allows for additional processing and postprocessing functions. This generally is considered the EUS technique of the future.

EUS-guided portal vein catheterization and pressure measurement in an animal model: a pilot study of feasibility

BACKGROUND

The extrahepatic portal vein is inaccessible to direct catheterization.

METHODS

Because EUS can readily image the portal vein, the feasibility of EUS-guided portal vein catheterization by using a 22-gauge needle was studied in 7 normal pigs and 14 pigs in which portal hypertension was induced (7/14 anticoagulated).

RESULTS

Catheterization was not possible by EUS or transhepatic methods in, respectively, 3 and 5 animals. One anticoagulated animal had a small amount of periduodenal bleeding as a result of EUS catheterization. The mean normal portal vein pressure (1 standard deviation) as determined by EUS and transhepatic methods was, respectively, 20.3 (4) mm Hg and 20.4 (2) mm Hg. Injection of polyvinyl alcohol particles increased the portal vein pressure by 10.2 (11.59) mm Hg. There was a close correlation under all conditions between the mean portal vein pressures obtained by EUS and transhepatic catheterization (r=0.91).

CONCLUSIONS

EUS-guided portal vein catheterization appears to be feasible in an animal model and provides accurate pressure measurements.

Endoscopic ultrasound is a sensitive and specific test to diagnose portal venous system thrombosis (PVST)

OBJECTIVES

Thrombosis of the portal venous system (PVS) may complicate cirrhosis, pancreatitis, malignancies, and hypercoagulable states. Computed tomography (CT) scanning can diagnose thrombi present in the lumen of the PVS, but is probably insensitive. Endoscopic ultrasound (EUS) may be a more sensitive test for diagnosing PVS thrombosis (PVST). We sought to determine the accuracy of EUS for the diagnosis of PVST.

METHODS

Using a retrospective analysis of patients' studies retrieved from a database at Massachusetts General Hospital, we determined the sensitivity and specificity of EUS in 16 patients with PVST and 29 without PVST as proven by surgery and/or CT scanning. All patients underwent a linear EUS exam of the PVS and the results of the EUS report were used as the basis of the study.

RESULTS

The sensitivity of EUS for the finding of PVST was 81% in 13 of 16 patients and the specificity was 93% in 27 of 29 patients with an overall accuracy of 89% (40/45). In an additional group of 11 patients, EUS demonstrated the presence of a PVST that was not detected by CT scanning.

CONCLUSION

Linear EUS is a highly sensitive and specific test for PVST.

A linear-array freehand 3-D endoscopic ultrasound

Recognition of the clinical importance of linear-array endoscopic ultrasound (EUS) has increased. In this study, we developed a linear-array 3-D EUS, a miniature position sensor attached to the tip of the echoendoscope used in freehand scanning. To evaluate the geometrical accuracy of the 3-D reconstruction of the system, the diameter of a sphere-shaped phantom (38 mm) was determined by five examiners and five measurers. Measured size of the sphere was 39.03 +/- 1.29 mm, with variance between examiners and measurers, and interaction of examiners with measurers was not significant. In animal and clinical studies, the system facilitated anatomical interpretation of the EUS images, especially in the pancreatobiliary area and vascular images. We concluded that this system is both accurate and reproducible, and may resolve difficulties in linear-array EUS.

Pancreatic cancer presenting as bleeding gastric varices

Given the extremely poor prognosis of pancreatic adenocarcinoma, early diagnosis is crucial; however, clinical signs and symptoms of the disease are neither sensitive nor specific. In the two cases described, previously undiagnosed pancreatic cancers initially presented with upper gastrointestinal tract hemorrhage. Endoscopic surveys to identify the origin of the bleeding revealed gastric varices secondarily attributed to splenic vein thrombosis. Upon further investigation, the splenic vein occlusions were found to be caused by pancreatic tumors. A review of the incidence, pathogenesis, diagnostic modalities, and implications of splenic vein occlusion is included.

Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

BACKGROUND

Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated.

METHODS

Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug administration.

RESULTS

Portal venous flow measured by EUS flowmetry and TTU flowmetry correlated significantly (R = 0.92, P < 0.001, n = 18). The limits of agreement in a Bland-Altman plot were from -0.262 l/min to +0.164 l/min. The change in portal venous flow after terlipressin measured by EUS and TTU correlated significantly (R = 0.88, P < 0.05, n = 6). All values used for analyses were the means of five repeated measurements.

CONCLUSIONS

EUS measures portal venous flow with an acceptable correlation and agreement with TTU in anaesthetized pigs. The method is capable of monitoring the effects of pharmacologic intervention on the portal system.

Splenic vein thrombosis secondary to focal pancreatitis diagnosed by endoscopic ultrasonography

We report splenic vein thrombosis diagnosed by endoscopic ultrasonography (EUS) after the failure of extracorporeal ultrasound and contrast enhanced computed tomography to establish the diagnosis in a patient with gastrointestinal bleeding and anemia. Subsequent preoperative magnetic resonance imaging revealed findings of retroperitoneal fibrosis and confirmed the EUS findings. Splenic vein thrombosis is a well-known cause of gastrointestinal bleeding and splenomegaly; pancreatitis and pancreatic tumors are its most common underlying causes. Abdominal ultrasound and computed tomography are frequently used to diagnose splenic vein thrombosis. We discuss the use of EUS for diagnosis of vascular anomalies in the gastrointestinal tract and the association of splenic vein thrombosis, retroperitoneal fibrosis, and pancreatitis.

Dieulafoy's vascular malformation: role of endoscopic ultrasonography in therapeutic decision-making

BACKGROUND

Dieulafoy's vascular malformation may cause severe, potentially life-threatening gastrointestinal bleeding. Endoscopic diagnosis may be difficult because of minute mucosal lesions, and additional intramural abnormalities are usually not encountered. Endoluminal high-frequency ultrasonography is a new modality for imaging intramural and perivisceral structures.

METHODS

We report two cases of recurrent severe gastric bleeding in which different endosonographic modalities were used in the diagnosis of Dieulafoy's malformation, and the impact of endosonography on therapeutic strategy is discussed. In the first case a radial-scanning 7.5/12-MHz echoendoscope and a linear 20-MHz miniature probe were applied for B-mode imaging in a stable-state patient who had undergone previous endoscopic sclerotherapy, and arterial flow signals from the small intramural lesion were recorded using a 10-MHz transendoscopic pulsed Doppler probe. In the other case urgent endosonography was performed shortly after a bleeding episode, disclosing an aberrant large-calibre artery entering the gastric wall with a long submucosal branch.

RESULTS

Both patients were successfully operated on with a transabdominal approach.

CONCLUSION

Endosonography is a quick and safe diagnostic method and should be considered when vascular malformations are suspected as the cause of gastric bleeding.

Endosonography-guided celiac plexus neurolysis

BACKGROUND

We have evaluated the safety and efficacy of performing endosonography-guided celiac plexus neurolysis (EUS CPN) in patients with pain due to intra-abdominal malignancies.

METHODS

Thirty patients with upper abdominal pain requiring narcotic analgesia and suspected or known intra-abdominal malignancy were selected for EUS CPN. This group included 25 patients with pancreas carcinoma and 5 patients with intra-abdominal metastases. Using the linear array ultrasound endoscope and a prototype needle catheter, transgastric injection of the celiac plexus with bupivacaine and 98% dehydrated absolute alcohol was accomplished.

RESULTS

Pain scores were significantly lower compared with baseline at 2, 4, 8, and 12 weeks after EUS CPN (median follow-up: 10 weeks). At these follow-up intervals, 82% to 91% of patients required the same or less pain medication and 79% to 88% of patients had persistent improvement in their pain score. Comparison of patients with TXNXM1 versus TXNXMO pancreatic carcinoma revealed higher initial pain scores (7.9 +/- 1.92 versus 5.8 +/- 2.0, p = .02) and a greater decline in pain scores (decrease of 6.1 +/- 3.1 versus 4.8 +/- 2.0, p = .004). Complications were minor and consisted of transient diarrhea in four patients.

CONCLUSION

EUS CPN is a safe and effective means for improving pain control in patients with intra-abdominal malignancy. The technique may be performed as an outpatient at the same setting as the EUS staging examination.

Management of upper gastrointestinal bleeding in the patient with chronic liver disease

This article reviews the management of severe upper gastrointestinal bleeding in the patient with chronic liver diseases. The initial assessment, diagnostic work-up, and treatment options for variceal and nonvariceal bleeding are discussed. The role of diagnostic and therapeutic endoscopy for esophagogastric varices is reviewed with special emphasis on new endoscopic techniques including variceal band ligation and cyanoacrylate injection. Various pharmacologic, surgical, and radiologic treatment options for variceal bleeding also are discussed. In addition, nonvariceal causes of severe upper gastrointestinal bleeding are reviewed including peptic ulcer diseases, Mallory-Weiss tear, portal hypertensive gastropathy, and gastric antral vascular ectasia.