Renal vein thrombosis

Renal vein thrombosis
Transplant with Renal Vein Thrombosis: Gross; natural color, opened kidney and vein. Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
ICD-10	I82.3
ICD-9	453.3
DiseasesDB	11359
MedlinePlus	000513

For patient information page, click here

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Saeedeh Kowsarnia M.D.[2]

Overview

Renal vein thrombosis (RVT) is the formation of a clot or thrombus obstructing the renal vein.

Historical perspectives

• In 1837, thrombosis of renal vein was first described in nephrotic patients by Rayer in postmortem evaluations.
• In 1843, Robinson induced renal vein thrombosis in rats.
• In 1876, Buchwald and Litten observed renal vein thrombosis in dogs.
• In 1939, Derow, Schlesinger and Savitz presented a case of renal vein thrombosis in nephrotic syndrome.

Classification

• Renal vein thrombosis is classified based on the onset of the symptoms:

Renal vein thrombosis
Onset	Presentation	Etiology
Acute	Renal infarction Renal failure Proteinuria (rarely)	Trauma Dehydration Hypercoagulable state
Chronic	Asymptomatic Pulmonary embolism Worsening proteinuria or renal function	Nephrotic syndrome Malignancy

• Based on the location RVT may be unilateral or bilateral. Left renal vein involvement is more common.

Pathophysiology

Mechanisms which are responsible for developing renal vein thrombosis are classified into three categories: Vascular damage, venous stasis, and hypercoagulable state.

• Vascular endothelial damage: Vascular injury leads to exposure of tissue factor, collagen, and endothelium to the blood, causing activation of the extrinsic pathway of coagulation .

• Stasis: Normal endothelium has anticoagulation activity driven by thrombomodulin, endothelial protein C receptor ( EPCR), tissue factor pathway inhibitor and heparin like proteoglycans. The major determinant of anticoagulation activity in the blood is the ratio of endothelial cell surface to blood volume . Stasis of blood in greater vessels means decreased exposure of anticoagulants of endothelial surface to the blood which results in promoting thrombi formation.

• Hypercoagulable state: As a definition, any laboratory abnormalities or clinical conditions which can be associated with an increased risk of thrombosis or clinical presentation of recurrent thrombosis without predisposing factors is considered hypercoagulability. Hypercoagulability (thrombophilia) includes hereditary and acquired conditions which enhance a tendency for developing thrombi in the veins, arteries, or both. Renal vein thrombosis can also be secondary to nephrotic syndrome, particularly membranous nephropathy due to loss of proteins in urine like antithrombins.

Causes

Causes

Classification	Conditions
Vascular damage	Homocystinuria, trauma (kidney biopsy, endovascular intervention), surgery
Hypercoagulability	Oral contraceptive pills, Hypovolemia, systemic lupus erythematosus, antiphospholipid syndrome (the most prevalent hypercoagulable state), dehydration especially in male pediatric cases, inherited coagulopathy, anticoagulation therapy , thromboembolic events (septic emboli), factor V Leiden (FVL) mutation, prothrombin gene G20210A mutations, elevated factor VIII, and hyperhomocysteinemia, protein C and protein S deficiency, nephrotic syndrome, disseminated malignancy, sepsis, blood disorders (PNH)
Stasis	compression (retroperitoneal processes such as retroperitoneal fibrosis and abdominal neoplasms), malignancy (especially renal cell carcinoma )

• Vascular damage: Homocystinuria, trauma (kidney biopsy, endovascular intervention), and surgery
• Hypercoagulability: Oral contraceptive pills, Hypovolemia, Inherited coagulopathy, anticoagulation therapy , systemic lupus erythematosus, antiphospholipid syndrome (the most prevalent hypercoagulable state), dehydration especially in male pediatric cases, thromboembolic events (septic emboli), factor V Leiden (FVL) mutation, prothrombin gene G20210A mutations, elevated factor VIII, and hyperhomocysteinemia, protein C and protein S deficiency, nephrotic syndrome, disseminated malignancy, sepsis, blood disorders (PNH)

• Stasis: compression (retroperitoneal processes such as retroperitoneal fibrosis and abdominal neoplasms), malignancy (especially renal cell carcinoma )
• Kidney transplant
• Liver transplant
• Pyelonephritis
• Behçet's syndrome

Epidemiology and Demographics

Malignancy especially renal cell carcinoma is the most common etiology consists of

Prevalence of renal vein thrombosis in nephrotic syndrome is 5 to 60% .Membranous nephropathy is responsible for 20 to 60 % of the cases which makes it the most common cause of renal vain thrombosis among nephrotic syndromes. Other etiologies like minimal change disease, membranoproliferative glomerulonephritis, and focal segmental glomerulosclerosis cause 10 to 50 % of the cases.

Risk Factors

• Nephrotic syndrome
  • Those with membranous nephropathy and protein excretion above 10 g/day
  • Serum albumin concentration below 2 g/dL (20 g/L))
  • The risk of thromboembolic event is greater with lower serum albumin
• Hypercoagulation state
• Infection

Screening

• Screening should be done for patients
  • Who present with signs of renal infarct
  • Who has chronic bilateral RVT with worsening creatinine and proteinuria to see weather anticoagulation is necessary
• There is no beneficial evidence regarding screening in patients with nephrotic syndrome and overt embolism.

Diagnosis

Signs and Symptoms

• Asymptomatic
• Renal infarct    
  • Flank pain
  • Nausea and vomiting
  • Fever
  • Microscopic or gross hematuria
  • Marked elevation in serum lactate dehydrogenase (without change in transaminases)
  • Increase in renal size on radiographic study
• Renal failure (bilateral RVT 60% of cases)
• Proteinuria (rarely)
• Pulmonary embolism

Imaging

• Doppler ultrasonography: Diagnostic screening
• Renal venography: Gold standard test for RVT diagnosis
• CT angiography: 100% sensitive for diagnosis
• Spiral computed tomography (CT) with contrast
• Magnetic resonance imaging (MRI)

Treatment

Therapy in RVT:

Classification	Condition
Fibrinolytic therapy and catheter thrombectomy	Systemic: not recommended, ↑ risk of bleeding Local: For acute RVT Patients with nephrotic syndrome will benefit the most
Surgery	Acute bilateral RVT Acute renal failure who cannot be treated with percutaneous thrombectomy and/or thrombolysis Nephrectomy for life-threatening complications
Anticoagulation therapy	Prophylaxy: Nephrotic syndrome: With additional risk factors: Prior idiopathic thromboembolic event, immobilization, severe heart failure, morbid obesity, surgery ( abdominal, orthopedic or gynecologic), genetic thrombophilia (factor V Leiden variant), atrial fibrillation With serum albumin concentration < 2.0 g/dL (20 g/L) and a low to moderate bleeding risk(calculate the risk of bleeding with ATRIA score†) Membranous nephropathy: With serum albumin < 3.0 g/dL (30 g/L) and low risk for bleeding With serum albumin < 2.0 g/dL (20 g/L) and intermediate risk of bleeding (ATRIA score†) Regimen: Warfarin, heparin, or aspirin.
	Asymptomatic RVT
	Thrombotic events: DVT or PE with or without RVT in high risk cases and acute RVT with or without other thrombotic events (DVT, PE) Inferior vena cava filters: Suprarenal IVC filters are used in patients with pulmonary embolism and documented renal vein thrombosis with contraindications to anticoagulation Regimen: Unfractionated or low-molecular-weight heparin is the initial drug and then warfarin. Treatment is given for a minimum of 6 to 12 months and continues as long as the patient remains nephrotic.

† ATRIA risk score = Anticoagulation and Risk Factors in Atrial Fibrillation

ATRIA score for predicting bleeding associated with warfarin:

Anemia
Severe renal dysfunction
Age ≥ 75
Prior episodes of hemorrhage
Diagnosed hypertension

Score:

Related Chapters

• Nephrotic syndrome

Renal vein thrombosis in pediatrics

Renal vein thrombosis as one of the venous thromboebolic event, is more common in pediatric population due to lower renal perfusion pressure, anticoagulant deficiency, and renal venous anatomy .

Rate	Prevalence: 15–20% of neonatal VTE Incidence of neonatal RVT: ~2.2/100,000 live birth Nearly 21% of pediatric renal transplantation failure is due to RVT (leading cause) Neonatal RVT: Unilateral in 70% of cases (64% of those occurred in left side), males in 67% of cases
Risk factors	Neonatal risk factor: Perinatal asphyxia, hypotension, sepsis, congenital heart disease, and thrombophilia Maternal risk factors: Diabetes, hypertension, and polyhydramnios Graft-associated RVT: Young recipient age, pre-transplant peritoneal dialysis, previous transplant
Cause	FV Leiden the most common inherited coagulopathy in neonatal RVT
Presentation	macroscopic hematuria, thrombocytopenia, and palpable abdominal mass
Diagnosis	Doppler ultrasonography is the modality of choice
Natural history	First presentation: Enlarged kidney with loss of cortico-medullary differentiation and perivascular echogenic streaking within the arcuate and interlobular veins Next, thrombosis can be seen in the renal vein and IVC. Eventually, a significant proportion of kidneys become atrophic
Outcome	kidney dimensions as predictive of outcome. Each 1 mm increase in kidney length predicts a 3 mL/min/1.73m2 loss in glomerular filtration rate
Complications	In the next 3.7 years: 71% progress renal atrophy, 19% develop hypertension,3% require renal replacement therapy
Treatment	Supportive care with serial imaging vs. 6–12 weeks anticoagulation for unilateral RVT with no renal dysfunction and no IVC extension Anticoagulation for unilateral RVT with extension into the IVC for 6–12 weeks Thrombolysis followed by anticoagulation vs. anticoagulation alone for bilateral RVT with evidence of renal dysfunction RVT risk assessment scale for follow-up the cases biannually for ≥5 years to assess renal function

References

Template:WikiDoc Sources