Can an aneurysm (abnormal dilation of a blood vessel) occur from the splenic vein to the left renal vein?

Splenic Vein Aneurysms with Communication to the Left Renal Vein

Yes, a splenic vein aneurysm can develop with communication between the splenic vein and left renal vein, though this is a rare vascular anomaly. 1, 2

Anatomy and Classification of Visceral Aneurysms

• Splenic artery aneurysms are the most common visceral aneurysms (60% of all visceral aneurysms), while splenic vein aneurysms are much rarer 1
• Visceral aneurysms are defined as localized arterial dilatations ≥50% of the normal vessel diameter 3
• Venous aneurysms can develop along the splenic vein and may communicate with other venous structures, including the left renal vein 2
• Arteriovenous fistulas between splenic artery and splenic vein can lead to venous aneurysmal dilatation that may extend to adjacent venous structures 4, 5

Pathophysiology and Presentation

• Splenic vein aneurysms can occur in isolation or in conjunction with arteriovenous fistulas 4
• Portal hypertension is a common cause of splenic vein aneurysms, but they can occur without portal hypertension 2
• Splenic arteriovenous fistulas with venous aneurysmal dilatation can cause:
  • Left-sided (sinistral) portal hypertension 6
  • Splenomegaly and hypersplenism 6, 5
  • Pancytopenia due to hypersplenism 6, 5
  • Gastric varices 6
• Most patients with splenic vascular aneurysms are asymptomatic at discovery, with aneurysms typically found incidentally during abdominal imaging 1
• Approximately 20% of patients present with either chronic upper abdominal pain or acute rupture 1

Diagnostic Approach

• Cross-sectional imaging is essential for diagnosis and treatment planning:
  • CT angiography (CTA) is the optimal imaging choice for detailed vascular anatomy 3
  • MR angiography (MRA) may be substituted if CT cannot be performed 3
  • Ultrasound can be useful for initial detection and surveillance 3, 1
• Imaging should evaluate:
  • Size and location of the aneurysm
  • Involvement of adjacent vascular structures (including renal vein)
  • Presence of arteriovenous fistulas
  • Evidence of portal hypertension or splenomegaly 3, 6

Management Considerations

• Treatment options depend on symptoms, size, and risk factors:
  • Asymptomatic small aneurysms may be observed with periodic imaging surveillance 3
  • Symptomatic aneurysms (pain, evidence of expansion) generally warrant intervention 2
  • Aneurysms with arteriovenous fistulas typically require treatment due to hemodynamic effects 4, 5
• Treatment approaches include:
  • Endovascular techniques: coil embolization or stent placement with technical success rates of 67-100% 1
  • Surgical options: aneurysmectomy, splenectomy, or combined procedures 7, 2
  • For splenic vein aneurysms communicating with the left renal vein, treatment may require addressing both vessels 2

Special Considerations and Pitfalls

• Female gender is a risk factor for splenic artery aneurysms, with higher incidence in women 1
• Pregnancy significantly increases rupture risk, with maternal mortality rates up to 70% and fetal mortality exceeding 90% 1
• Patients undergoing catheter-based interventions should be monitored closely for development of abdominal pain, which may indicate complications 1
• Correction of hypersplenism-related pancytopenia may require splenectomy in cases with significant splenic involvement 6, 5