Acute portal hypertension due to delayed post-splenectomy arteriovenous fistula: A case report

Abstract

BACKGROUND

Portal hypertension is typically associated with cirrhosis, but acute etiologies must be considered in atypical cases. Post-splenectomy arteriovenous fistula (AVF) is a rare vascular complication that can lead to acute portal hypertension with nonspecific symptoms.

CASE SUMMARY

A 43-year-old man presented with acute abdominal pain, hematemesis, and melena, eight years after open splenectomy. Computed tomography angiography revealed a splenic AVF. Emergency laparotomy with splenic artery ligation was performed. The patient recovered uneventfully and remained asymptomatic at five-year follow-up.

CONCLUSION

Splenic AVF should be considered in patients with new-onset portal hypertension, a history of splenectomy, and no liver disease. Prompt diagnosis and surgical intervention yield excellent outcomes.

Key Words: Portal hypertension; Post-splenectomy; Arteriovenous fistula; Acute abdominal pain; Delayed complication; Case report

Core Tip: A delayed splenic arteriovenous fistula can cause acute portal hypertension years after splenectomy. Computed tomography angiography confirms the diagnosis, and prompt surgical or endovascular intervention leads to full recovery.

INTRODUCTION

Portal hypertension is generally considered a chronic, progressive disease associated with cirrhosis[1]. However, acute forms can also occur due to atypical causes, which may present with non-classical symptoms such as unexplained abdominal pain, early satiety, or insidious thrombocytopenia, potentially delaying diagnosis[2].

CASE PRESENTATION

Chief complaints

A 43-year-old man presented in 2014 with a 3-day history of acute abdominal pain, vomiting and diarrhea, followed by hematemesis and melena.

History of present illness

A 43-year-old man presented in 2014 with a 3-day history of acute right upper quadrant abdominal pain that progressively worsened, accompanied by nausea and vomiting. The vomitus consisted of gastric contents mixed with dark red blood. He also developed melena. Since onset, he experienced lethargy and poor appetite, while sleep and urine output remained normal. He was referred to our hospital for further management. Throughout the illness, he remained afebrile, without chills, fever, or jaundice.

History of past illness

His past medical history was significant for an open splenectomy performed in 2006 following a motor vehicle accident. Initial assessment and management for suspected acute cholecystitis at an outside institution had provided no symptomatic relief.

Personal and family history

No family history of similar diseases.

Physical examination

The abdomen was mildly distended on inspection. Palpation revealed tenderness in the right upper quadrant, but no rebound tenderness or guarding.

Laboratory examinations

Laboratory findings revealed a positive fecal occult blood test and mildly elevated liver enzymes.

Imaging examinations

Abdominal ultrasound demonstrated ascites, marked dilation of the portal vein (16 mm) and splenic vein (18 mm), and increased Doppler flow velocities, consistent with acute portal hypertension.

Urgent contrast-enhanced abdominal computed tomography (CT) angiography was performed. The arterial phase revealed premature and intense opacification with dilation of the splenic and portal veins (Figure 1A). Three-dimensional reconstruction clearly delineated an abnormal vascular communication between the splenic artery and the residual splenic vein near the pancreatic tail, confirming the diagnosis of a splenic arteriovenous fistula (AVF) (Figure 1B).

Figure 1 Abdominal computed tomography angiography findings in splenic arteriovenous fistula. A: Abdominal computed tomography (CT) angiography shows dilation and early filling of splenic vein (yellow arrow) and portal vein (blue arrow) in arterial phase; B: Three-dimensional reconstruction CT showed a fistula between the splenic artery (orange arrow) and the dilated splenic vein (yellow arrow); C: Abdominal CT angiography shows no early filling of portal vein (blue arrow) in arterial phase 8 months later.

FINAL DIAGNOSIS

Caused by a splenic AVF.

TREATMENT

The patient underwent an emergency laparotomy. The distal splenic artery was identified, ligated, and divided to occlude the fistula.

OUTCOME AND FOLLOW-UP

The postoperative course was uneventful. Follow-up ultrasonography performed one week later revealed a significant reduction in the splenic vein diameter (12 mm) and a decrease in its maximum flow velocity to 22 cm/second. The patient was discharged on postoperative day 11, asymptomatic.

At the 8-month follow-up, repeat CT angiography confirmed the absence of early venous filling during the arterial phase, confirming successful fistula closure (Figure 1C). The patient has remained asymptomatic for five years since the intervention (Table 1).

Table 1 Timeline of clinical course and management.

Year	Phase	Clinical event
2006	Initial etiology	Underwent open splenectomy after trauma
2014	Portal hypertension	Presenting with acute abdominal pain, hematemesis, and melena
2015-present[1]	Follow-up	Symptom resolution was followed by long-term asymptomatic survival

DISCUSSION

Portal hypertension is generally considered a chronic, progressive disease associated with cirrhosis[1]. However, acute forms can also occur due to atypical causes[2]. In this case, the fistula creates a high-flow, low-resistance shunt from the splenic artery into the portal system, leading to acute portal hypertension[2]. The rapid increase in portal pressure can lead to the abdominal pain, variceal bleeding, ascites, and even high-output cardiac failure[3-5]. In contrast to cirrhotic portal hypertension, which usually features signs of chronic liver disease, acute postsurgical portal hypertension often presents with nonspecific symptoms such as abdominal pain or heart failure, delaying recognition. A history of splenectomy in the absence of liver disease serves as a critical clue for pursuing vascular imaging. Particularly after ruling out various acute abdominal conditions, such as cholecystitis, cholangitis, appendicitis, and intestinal obstruction.

In most cases, the portal hypertension develops in the postoperative period or within 3 years after surgery. However, symptoms could also develop after more than 3 years in very few cases[6]. The variability in onset time may be attributed to gradual dilation of the fistula tract or changes in collateral circulation. If left untreated, persistent shunting may lead to irreversible liver damage. CT angiography serves as a sensitive and specific method of diagnosing splenic AVF[7]. In most cases, early treatment by ligation or embolization of splenic artery is indicated to reverse acute portal hypertension, high-output cardiac failure, and other related complications[8,9]. Therefore, clinicians should be aware of this condition especially for those with new onset portal hypertension, history of splenectomy and absence of liver disease.

CONCLUSION

Therefore, clinicians should be aware of post-splenectomy AVF especially for those with new onset portal hypertension, history of splenectomy and absence of liver disease.