High-output Heart Failure Caused by a Tumor-related Arteriovenous Fistula: A Case Report and Literature Review

Renal vein aneurysm secondary to renal cell carcinoma

ABSTRACT

Venous aneurysms are rare entities, especially those involving the visceral veins. Renal venous aneurysms have been documented in isolated case reports and we present one such case. An adult male presented with flank pain and hematuria. The initial ultrasound abdomen was suggestive of a right renal mass with a venous varix of ipsilateral renal vein. Computed tomography (CT) showed a high-complexity mass lesion in the right kidney with tortuous varices in the perinephric space and focal aneurysmal dilatation of the right renal vein. No arteriovenous fistula (AVF) or malformation was identified, but attenuation values suggested arteriovenous shunting. A biopsy of the mass was suggestive of clear cell carcinoma. The patient underwent digital subtraction angiography and embolization, followed by a total nephrectomy. However, the patient presented with brain metastases later and eventually succumbed to the illness. Renal venous aneurysms may develop secondary to venous hypertension, thrombosis, or renal AVFs. CT can help confirm the diagnosis, assess size, estimate graft length if required, and identify possible causes and potential complications. Known complications include rupture, thrombosis, and pulmonary thromboembolism. Treatment options include reconstruction of the renal vein with grafts, endovascular treatments such as embolization if there is an AVF and nephrectomy. Visceral venous aneurysms can cause life-threatening complications that treating physicians must be aware of. Clear-cell renal cell carcinoma is associated with arteriovenous shunting, which can cause venous hypertension, varices, and, as seen in our case, renal vein aneurysms.

Crisis Averted: Clinical T1b Renal Mass with Concurrent Arteriovenous Malformation and Renal Vein Thrombus

Arteriovenous malformations (AVMs) secondary to renal-cell carcinoma (RCC) are well-described in the literature. Independently, renal vein and inferior vena cava tumor thrombi can be detected in locally-advanced RCC. A 67-year-old gentleman presented with a cT1b renal mass detected on workup for elevated creatinine. Multiphase CT imaging obtained for partial nephrectomy surgical-planning revealed an initially-missed renal cortical AVM. This drastically changed the plan for intervention, including use of an open approach with AVM embolization by interventional radiology prior and avoidance of a nephron-sparing approach. Final pathology confirmed the AVM and a subclinical renal vein thrombus masked by arterial flow on CT imaging, making this the first concurrent case described in the literature. Herein, we describe avoidance of catastrophic intraoperative hemorrhage by careful review of preoperative imaging and provide a literature review of imaging modalities for both renal surgical-planning and detection of tumor thrombi in RCC.

Scapular renal cell carcinoma metastasis as a cause of high-output heart failure: a case report

BACKGROUND

High-output heart failure is a rare condition that occurs when the heart is unable to respond to a sustained increase in blood demand. On echocardiography, a cardiac index of > 4 L/min/m² (or 6 L/min) is a clear indicator of this disorder. The causes of high-output heart failure vary, but they all involve peripheral vasodilation or arteriovenous shunting. Renal cell carcinoma is well known for producing high levels of angiogenic growth factors that induce arteriovenous shunts. The decrease in peripheral arterial resistance and the increase in venous return result in a permanent high cardiac output, followed by congestive heart failure. Single bone metastases of renal clear cell carcinoma tumours causing high cardiac output and heart failure symptoms have been reported less than ten times in the medical literature.

CASE PRESENTATION

Before a right-shoulder painful lump with a murmur when auscultated, magnetic resonance imaging revealed a large scapular mass, which was biopsied and found to be a bone metastasis of renal cell carcinoma. Two months later, the patient developed heart failure for the first time. There was no evidence of cardiac disease on echocardiography. The cardiac output was 9.8 L/min and the cardiac index was 5.1 L/min/m². Doppler ultrasound revealed numerous arteriovenous shunts in the large scapular metastasis and a right axillary artery flow of 24% of cardiac output. Sustained lower cardiac output was obtained following lesion-focused radiotherapy and systemic antiangiogenic treatment with axitinib and pembrolizumab.

CONCLUSIONS

Herein, we present a unique case of high-output heart failure in a 70-year-old man diagnosed by echocardiography and upper-limb Doppler ultrasound in the context of metastatic renal cell carcinoma without pre-existing cardiac disease. We stress the potentially life-threatening hemodynamic consequences of hypervascularity associated with arteriovenous shunts within a single metastatic renal cell carcinoma implant, the importance of auscultating any progressing bone mass, and the utility of non-invasive Doppler ultrasound assessment in this setting.