Renal artery thrombosis unveiled: A case report

INTRODUCTION

Renal artery (RA) thrombosis is an uncommon but serious cause of acute kidney injury (AKI) that can result in permanent loss of kidney function.^[1]

The signs and symptoms of this condition are variable and non-specific, making it difficult to diagnose early and easily mistaken for other, more common pathologies.^[2]

This case report presents a case of unilateral RA thrombosis and encourages a high suspicion rate for such a diagnosis, especially if no cause of the patient’s symptoms was evident.

CASE REPORT

A case of a 61-year-old male patient with the medical background of ischemic heart disease, dilated cardiomyopathy with reduced ejection fraction 30%, also known case of atrial fibrillation (AF) on pacemaker cardiac resynchronization therapy (CRT) since July 2023, and had atrioventricular nodal ablation in October 2023. This patient has no medical history of diabetes mellitus, hypertension (HTN), or renal disease. The patient reported no history of cigarette smoking or alcohol consumption.

He presented repeatedly to our emergency department with epigastric and left loin abdominal pain, persistent for around 7 days, radiating to the chest and left iliac fossa, and associated with shortness of breath. No history of fever, vomiting, urinary or bowel complaints, or lower abdominal pain; the patient’s complaint was dismissed before as simple gastritis.

On clinical examination, the patient looked unwell and in pain with a soft abdomen but with tenderness on the left side; bowel sounds were present, and the patient also had palpable peripheral pulses. Pulmonary regurgitation was not done. The patient was anuric on presentation. Vital signs are shown in Table 1. Initial laboratory investigations are shown in Table 2.

An abdominal computerized tomography (CT) scan with intravenous (IV) contrast was done, which revealed acute left RA thrombosis at the level of the hilum. Furthermore, the superior mesenteric vein (SMV) showed a filling defect extending to the proximal part of the portal vein. Still, the complementary Doppler ultrasound showed a patent portal vein, SMV, and the inferior vena cava [Figures 1 and 2]. The full report is shown in Table 3.

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Figure 1:

A 3D representation computerized tomography angiography of the abdomen and pelvis, showing good visualization of the right renal artery and the right kidney, while only a small initial part of the left renal artery is visible; the left kidney is also not visualized.

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Figure 2:

Coronal computerized tomography angiography of the abdomen and pelvis showing contrast filling the right renal artery and visualization of the right kidney, while an absolute cutoff of the left renal artery and poor visualization of the left kidney.

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Patient was transferred to a tertiary hospital as planned for catheter-directed therapy with the intervention of the radiology (IR) department. After a thorough explanation to the patient and his attendant, they accepted and signed written consent. However, the IR team deferred thrombolysis as the left kidney had already infarcted, so the patient was kept on conservative management in the form of anticoagulation and IV hydration.

Transesophageal echocardiography showed a semi-organized thrombus in the left atrial appendage measuring 13 mm × 10 mm, and tiny thread-like masses, mostly thrombi, attached to the CRT with defibrillator leads in the RA [Figures 3-5].

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Figure 3:

3D transesophageal echocardiography: Mid-esophageal bicaval view showing the cardiac resynchronization therapy with defibrillator leads inside the right atrium, and there are threads like masses attached to it, mostly small thrombi.

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Figure 4:

Transesophageal echocardiography: Mid-esophageal two-chamber view showing the left atrial appendage with heavy spontaneous echo contrast and mass inside it, mostly thrombus.

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Figure 5:

Transesophageal echocardiography: Mid-esophageal bicaval view showing the cardiac resynchronization therapy with defibrillator leads inside the right atrium, and there are threads like masses attached to it, mostly small thrombi.

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The follow-up of serum creatinine and urine output is shown in Figures 6 and 7.

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Figure 6:

Total fluid intake and urine output during admission.

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Figure 7:

Progress of renal functions during admission.

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After that, the patient developed elevated transaminases and bilirubin, which were managed conservatively, as all related laboratory investigations and imaging procedures were normal.

The patient was discharged after 10 days with complete recovery of renal and liver functions while kept on warfarin with a target INR of 2–3.

DISCUSSION

Many conditions share manifestations with renal infarction, such as pyelonephritis, nephrolithiasis, mesenteric ischemia, cholecystitis, pancreatitis, or, as in our case, gastritis. That’s why the diagnosis of renal infarction is underestimated or missed.

Renal infarction can occur secondary to either local or distant conditions, but it is mostly due to thromboembolic conditions originating from a cardiac source; also, it can happen with any hypercoagulable condition or local dissection of the renal arteries.

The ideal treatment strategy is still debatable, as there are inadequate studies and evidence to support one specific strategy over another.

Revascularization is the main management procedure when a complete main RA thrombus is present, and the diagnosis is confirmed within <6 h. However, it can also be the best management option in patients with a solitary kidney or when there is a reduction in renal function. Another situation where revascularization remains the best option of treatment includes partial main RA occlusion of <24 h duration. This 24-h duration can be extended if it is associated with significant renal function impairment or with the development of HTN. Furthermore, revascularization can benefit patients in whom arterial dissection is the cause of renal infarction.^[5]

If the condition is diagnosed as early as <180 min, thrombolytic therapy comes as the best management option in this situation.^[3,6]

The outcome of any of these procedures depends on different aspects, such as the duration till the diagnosis is established, the presence of effective intrarenal collateral circulation, and the preexistence of chronic kidney disease.^[7]

In our case, due to late diagnosis, endovascular treatment was deferred, as the diagnosis was delayed. It was highly suspected that the left RA embolism was likely due to a thromboembolism from AF. Anticoagulation therapy alone led to a favorable outcome in the patient, resulting in the complete restoration of kidney function.

CONCLUSION

We present a case of a 61-year-old male patient diagnosed with unilateral RA thrombosis, after repeated presentation to the emergency department with vague epigastric and left loin pain, which caused AKI and successfully resolved with conservative measures in the form of anticoagulation only, which was primarily caused by thromboembolism originating from cardiac origin resulting from AF.