Chronic abdominal pain secondary to portosystemic collateral vessels: A case report and review of etiologies

Abstract

Introduction

Portosystemic collateral veins (PSCVs) are rare venous anomalies that arise due to portal hypertension and can closely resemble primary sclerosing cholangitis (PSC) or cholangiocarcinoma (CCA) on imaging studies. Their presence around the common bile duct (CBD) may lead to diagnostic confusion and inappropriate management.

Case presentation

We report the case of a 52-year-old woman with a history of cholecystectomy and post-ERCP pancreatitis who presented with chronic right upper quadrant abdominal pain. MRCP revealed beading and wall thickening of the CBD, raising suspicion for PSC or periductal CCA. Three-phase CT imaging demonstrated dilated paracholedochal collateral veins encasing the CBD. Laboratory investigations showed elevated AST, ALT, ALP, and CA 19–9, with declining hemoglobin and platelets during her latest admission.

Clinical discussion

PSCVs can produce external compression and irregularity of the bile duct, mimicking the imaging features of malignant or inflammatory biliary conditions. Recognizing this vascular anomaly requires correlation of imaging findings with clinical and laboratory data to prevent misdiagnosis.

Conclusion

In patients with persistent abdominal symptoms and a history of biliary procedures or portal vein thrombosis, PSCVs should be included in the differential diagnosis. Accurate and timely identification via CT and MRCP can guide appropriate clinical management and avoid unnecessary interventions.

Highlights

• •Portosystemic collateral veins (PSCVs) represent a critical compensatory response to portal hypertension.
• •Accurate differentiation between PSCVs, cholangiocarcinoma, and primary sclerosing cholangitis (PSC) remains diagnostically challenging.
• •This case highlights the potential for PSCVs to compress the common bile duct, leading to radiologic features similar to PSC and cholangiocarcinoma.
• •Three-phase CT plays a pivotal role in identifying PSCVs and evaluating their impact on the biliary system.

1. Introduction

Portosystemic collateral veins (PSCVs) are abnormal connections between the portal venous system and the systemic venous circulation. They develop in response to portal hypertension, which may result from various conditions such as cirrhosis, liver fibrosis, or portal vein thrombosis. With the development of portal hypertension, transmission of backpressure leads to increased flow in these patent normal portosystemic anastomoses [1,2]. Portosystemic collateral vessels are a sign of portal hypertension in liver cirrhosis [3]. These collateral veins act as shunts, allowing blood to bypass the liver and flow directly into the systemic circulation. As a consequence, gastroesophageal varices may form—dilated veins in the esophagus and stomach that carry a significant risk of life-threatening bleeding [1].

The simplest classification of PSCVs groups esophagogastric varices together while categorizing all other varices as ectopic. Ectopic varices are defined as large PSCVs that occur in parts of the gastrointestinal tract other than the esophagogastric region. They are commonly identified in the duodenum, jejunum, ileum, colon, rectum, omentum, gallbladder, bile duct, uterus, vagina, diaphragm, urinary bladder, as well as at enterostomy stoma sites and anastomotic junctions. Some authors also classify PSCVs based on their drainage pattern into either the superior vena cava (SVC) or the inferior vena cava (IVC) [2].

Various imaging modalities, including computed tomography (CT) and ultrasound, can detect the presence of PSCVs. CT, in particular, is effective for identifying and characterizing the size and location of these veins, as well as for assessing the severity of portal hypertension. Several studies have explored the role of portosystemic collaterals in predicting the presence of gastroesophageal varices in patients with cirrhosis, with some indicating a strong correlation between the two [1].

The aim of this study is to underscore the diagnostic value of specific findings on three-phase CT imaging, which may show both similarities to and differences from MRCP studies. We seek to evaluate the diagnostic accuracy of CT scans in distinguishing between PSCVs, cholangiocarcinoma (CCA), and primary sclerosing cholangitis (PSC)—three distinct medical conditions.

2. Case presentation

2.1. Patient history

A 52-year-old female presented to the emergency department with complaints of persistent right upper quadrant (RUQ) abdominal pain lasting for one month. The pain was described as constant, cramping, and dull. Three months earlier, she had visited the emergency department with RUQ pain radiating to her back and worsening with meals. Based on her clinical presentation and diagnostic evaluations, she underwent a cholecystectomy and was diagnosed with acute cholecystitis.

One month following surgery, the patient returned with upper abdominal pain. During this second admission, physical examination findings and laboratory data were consistent with acute cholangitis caused by a common bile duct (CBD) stone. Magnetic resonance cholangiopancreatography (MRCP) confirmed the presence of the CBD stone, and the patient subsequently underwent endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy for stone removal. Post-ERCP, she developed pancreatitis. In this admission, the patient had no jaundice and no evidence of increased bilirubin levels, and only experienced mild discomfort.

One month later, during the most recent admission, the patient presented again with persistent RUQ abdominal pain, leading to the diagnosis of a portosystemic collateral vein (PSCV). However, the primary cause of admission was portal vein thrombosis (PVT), not PSCVs alone. The patient was treated with anticoagulant therapy and discharged without the need for interventional procedures such as thrombolysis, which was deemed inappropriate one week after diagnosis.

Follow-up imaging, including ultrasonography and repeated endoscopy, confirmed spontaneous portosystemic shunts and esophageal varices (GOV1 based on Sarin-Norton classification). The patient continued long-term anticoagulant therapy and did not require invasive procedures.

2.2. Clinical examination

On physical examination, the patient's vital signs were within normal limits. There was no abdominal tenderness, hepatomegaly, or signs of sepsis. However, mild splenomegaly was noted. Splenomegaly was confirmed on the fourth admission ultrasonography. Although platelet count decreased, there was no strong evidence of sequestration. Importantly, there were no signs of jaundice, a positive Murphy's sign, or rebound tenderness.

2.3. Laboratory findings

Laboratory evaluations revealed elevated liver enzymes (AST, ALT, ALP) and bilirubin levels, which peaked during the second admission and after ERCP. Amylase and lipase levels were significantly elevated post-ERCP. Hemoglobin, white blood cell (WBC) count, and platelet counts progressively declined, with notable decreases during the most recent admission. Despite thrombocytopenia, bone marrow MRI signal remained normal and there was no evidence supporting disseminated intravascular coagulation (DIC). Inflammatory markers such as erythrocyte sedimentation rate (ESR) were elevated during the second admission. Additionally, CA 19–9 was mildly elevated in the last admission (Table 1).

Table 1.

Serial laboratory parameters over multiple admissions.

Parameter	Reference range	First admission	Second admission	Second admission post ERCP	Fourth admission
WBC (×103/μL)	4.0–11.0	8.1	6.7	5.2	3.1
Hb (g/dL)	12.0–16.0 (Female)	11.7	11.7	12.1	9.5
MCV (fL)	80–100	91	91.16	89	86
Plt (×103/μL)	150–400	173	176	165	75
AST (U/L)	0–40	11	604	108	59
ALT (U/L)	0–40	10	835	330	32
ALP (U/L)	44–147	126	543	400	109
Total bilirubin (mg/dL)	0.1–1.2	1.7	8.3	7.9	1.8
Direct bilirubin (mg/dL)	0.0–0.3	0.4	3.8	4.2	0.4
Albumin (g/dL)	3.5–5.0	3.7	3.9	3.5	3.9
GGT (U/L)	9–48 (Female)	–	–	–	50
Amylase (U/L)	30–110	80	89	894	198
Lipase (U/L)	10–140	29	31	525	51
ESR (mm/h)	0–20 (Female)	–	62	–	–
INR	0.8–1.2	1.04	1.06	1	1.09
CA 19–9 (U/mL)	0–37	–	–	–	20
CEA (ng/mL)	0–5	–	–	–	3.2

In subsequent monthly follow-ups, platelet counts recovered to over 150,000, suggesting transient hepatic dysfunction or splenomegaly as possible etiologies.

2.4. Imaging findings

2.4.1. Magnetic resonance cholangiopancreatography (MRCP)

During the second admission, MRCP revealed dilation of both intrahepatic and extrahepatic biliary ducts, with a filling defect noted in the distal common bile duct (CBD), suggestive of a CBD stone. Additionally, dilation of the cystic duct stump was observed, measuring up to 9.5 mm (Fig. 1).

Fig. 1.

(A and B) abdominal T2W coronal magnetic resonance imageing revealed intra and extra hepatic biliary ducts dilation. There is also CBD signal loss in keeping with wall thickening and evidence of thrombosis portal vein.

A follow-up MRCP revealed a persistent suspected stone. However, the presence of CBD wall thickening and beading raised differential considerations, including primary sclerosing cholangitis (PSC), cholangitis, or periductal cholangiocarcinoma (Fig. 2).

Fig. 2.

(A and B) Abdominopelvic CT scan in portal phase in coronal reformats showed enhancement of CBD wall exactly the same as mesenteric veins which is suggesting collateral formation along with CBD.

2.4.2. Endoscopic findings

Endoscopic evaluation identified F1-grade esophageal varices and antral gastritis. During a retrograde exploration via ERCP performed one month prior, signs of pancreatitis were evident—possibly secondary to portal vein thrombosis and subsequent portal hypertension.

2.4.3. Computed tomography (CT)

A three-phase CT imaging study confirmed the presence of portosystemic collateral veins, supporting the diagnosis of portal hypertension. Persistent portal vein thrombosis and cavernous transformation of the portal vein were visualized at the hepatic hilum on follow-up imaging.

Endoscopic evaluation three months later showed persistent F1-grade esophageal varices.

2.5. Patient perspective

“The pain I experienced after my gallbladder surgery was difficult to comprehend. Each hospital visit resulted in a different diagnosis—ranging from cholangitis to pancreatitis. What I did not anticipate was the involvement of abnormal veins around the bile duct (PSCVs) as the underlying cause of my symptoms. Discovering that veins I had never even heard of could be responsible for such persistent discomfort and confusion was both surprising and enlightening.”

2.6. Clinical discussion

PSCVs arise as compensatory mechanisms in response to underlying liver pathology. These collateral channels provide alternative pathways for blood flow between the portal venous and systemic circulations. Multiple etiologies contribute to their development, including portal hypertension, liver cirrhosis, Budd-Chiari syndrome, and portal vein thrombosis (PVT) [1].

Although PVT is frequently associated with cirrhosis and malignancies, less common causes include external compression and tumors. For example, isolated splenic vein thrombosis secondary to a perirenal abscess has been documented as a cause of left-sided portal hypertension and resultant gastrointestinal bleeding [2]. Additionally, tumors such as hepatocellular carcinoma (HCC) can induce PVT either by direct compression or vascular invasion of the portal vein [4]. HCC is a well-documented and prevalent cause of PVT, with reported association rates ranging between 25 % and 50 % [5].

Extrahepatic portal vein obstruction (EHPVO) results in the formation of efferent vessels originating from dilated veins (DVs) in the duodenal bulb, which transport blood hepatopetally via portoportal collaterals into the liver. These portoportal collaterals arise from pre-existing venous plexuses near the common bile duct (CBD) or from patent tributaries of the portal vein located proximal to the site of portal vein occlusion. [2]

The paracholedochal plexus, composed of larger veins running alongside the common bile duct (CBD), can cause external ductal indentations when dilated. In contrast, the epicholedochal plexus consists of smaller veins within the duct wall and leads to wall thickening upon dilation. These para- and pericholedochal collaterals help redirect blood flow around the biliary system and often communicate with vessels such as the gastrocolic trunk and pancreaticoduodenal veins, contributing to complex collateral vascular anatomy [6,7].

In the present case, the patient's PSCVs likely developed secondarily due to portal vein thrombosis. Although imaging raised concerns for cholangiocarcinoma or PSC, lack of jaundice, absence of marked bilirubin elevation, and only mild discomfort reduced the likelihood of obstructive or malignant etiologies.

Turning to the present case, our patient—a 52-year-old female—presented with chronic abdominal pain attributed to PSCVs involving the CBD. Her clinical history includes a cholecystectomy and an episode of pancreatitis following a CBD stone. The recent ERCP procedure for stone removal, which involved stent placement and subsequent retrieval, may have contributed to the development of PSCVs in this region [8,9].

A reliable diagnosis requires integrating clinical, laboratory, and imaging findings, sometimes supported by histopathology. On triple-phase CT, hypoattenuating liver or bile duct masses with arterial enhancement and portal venous washout often suggest malignancy. PSCVs may compress the bile ducts via varices, causing irregularity or dilation. However, typical imaging features like CBD thickening and beading are more consistent with PSC or cholangiocarcinoma. In PSC, these result from chronic inflammation and fibrosis, while cholangiocarcinoma reflects tumoral mass effect. Imaging alone is insufficient to definitively differentiate among these conditions. [10]

Findings in this case are consistent with the existing literature on portal biliopathy, a condition characterized by biliary abnormalities resulting from vascular compression and ischemic injury. These changes often manifest as bile duct irregularities and complications such as recurrent cholangitis [11]. In a similar vein, Condat et al. describe bile duct obstruction due to cavernous transformation of the portal vein, emphasizing the role of extraluminal compression by collateral veins in impairing biliary drainage. These studies underscore the clinical significance of recognizing portal venous abnormalities to avoid misdiagnosis and inform appropriate therapeutic strategies [12]. This case report has been reported in line with the SCARE checklist [13].

3. Conclusion

This case underscores the importance of considering PSCVs as a potential cause of chronic abdominal pain, particularly in patients with a history of biliary interventions and portal vein thrombosis. Although imaging findings can resemble other pathologies such as primary sclerosing cholangitis (PSC) and cholangiocarcinoma, accurate differentiation requires a comprehensive diagnostic approach that integrates clinical history, laboratory investigations, and multimodal imaging. Further research is essential to deepen our understanding of the pathophysiological mechanisms underlying PSCV and to refine diagnostic algorithms for improved patient outcomes.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

We obtained written permission from the patient to present this case report and to include images in the article, a written copy of which is available for submission to the journal, if necessary.

Funding

None.

Author contribution

Zahra Mohammadimanesh - conception and design, acquisition of data, image acquisition writing the paper, final approval of the version to be published.

Soheil mirzaei - writing the paper, final approval of the version to be published.

Reza Naseri - conception and design, acquisition of data, image acquisition writing the paper, final approval of the version to be published.

Maryam Haghighi-Morad - final approval of the version to be published.

Afsaneh safarian – final approval of the version to be published.

Declaration of competing interest

None.