Venous Outflow Obstruction: A Rare Cause of Shock in a Recent Kidney Transplant Patient

Introduction: There are four recognized types of shock: distributive, cardiogenic, hypovolemic, and obstructive. Septic shock is the most common among ICU patients, while obstructive shock is rare. We present a case of venous outflow obstruction causing shock in a recent kidney transplant patient. Case Description: A 64-year-old female with end-stage kidney disease (ESKD) secondary to diabetes and hypertension, who had undergone a living-related kidney transplant with immediate graft function, was readmitted one week later with fatigue, lightheadedness, significant right greater than left lower extremity swelling, acute kidney injury, and shock. A full workup for shock revealed no evidence of infectious, cardiologic, or endocrinologic causes. A CT scan of the chest, abdomen, and pelvis without contrast showed no acute chest abnormality but identified a hyperdense area in the right external iliac vein, raising concerns for deep vein thrombosis. Additionally, it showed a narrowed right common iliac vein and inferior vena cava (IVC). A CTA of the pelvis with bilateral lower extremity runoff revealed right greater than left edema and no venous enhancement in the right iliac vein. Interventional radiology performed venography and found an atretic right common iliac vein and IVC with multiple collaterals. Venoplasty and stent placement were performed, extending from the IVC to the right external iliac vein. The patient's hypotension resolved upon relief of the venous obstruction, and she experienced significant improvement in lower extremity swelling. Discussion: This case represents a rare cause of shock. Although the patient was treated with broad-spectrum antibiotics, a thorough infectious workup was negative. Further evaluation for other causes of shock was also unremarkable. The patient's shock resolved with relief of the obstruction, indicating this as the primary etiology. The cause of venous obstruction in this patient was unknown. Risk factors for venous stenosis include thrombotic and non-thrombotic etiologies. Non-thrombotic causes include extrinsic vein compression or obstruction related to an intraluminal device. For ESKD patients, vein stenosis related to the presence of a dialysis catheter is a specific etiology to consider. In summary, this case of venous outflow obstruction highlights the importance of maintaining a broad differential diagnosis in patients presenting with shock.