Renal biopsy plays an irreplaceable role in the diagnosis and management of kidney disease. However, renal biopsy is an invasive examination that inevitably leads to bleeding, perirenal hematoma, and even renal venous thrombosis. All of the above complications may lead to the same clinical response - hematuria . So, if a renal biopsy patient develops hematuria, how should he be identified?
On September 9, 2022, BMC Nephrology published a case in which the patient had hematuria after undergoing a renal biopsy. After identification, it was found that the cause of the patient was perirenal hematoma and renal venous thrombosis. Unlike single complications, multiple complications may not only delay diagnosis, but may also have a greater impact on the patient's treatment. For example, the starting time of anticoagulation in patients requires not only consideration of perirenal hematoma, but also renal venous thrombosis, as well as the risk of peripheral thrombosis.
case details
patient, male, 23 years old, systemic lupus erythematosus (SLE) arthritis and skin involvement for 2 years. He visited the doctor 1 month ago due to foot edema, urine foam and other reasons.
auxiliary examination: 24h proteinuria is 3.34g, and the urine volume is 2500ml in 24h.
biomarker includes: serum sodium 138mmol /L, blood potassium 4.5mmol/L, urea 3.3mmol/L, creatinine 72umol/L, serum protein 34g/L, total cholesterol 8.4mmol/L. Connective tissue marker ANA positive, anti-dsDNA antibody 87.69IU/ml, C3 0.76g/L, C4 0.4g/L.
was diagnosed with active lupus nephritis (LN) with nephrotic syndrome .
patients took prednisolone (1 mg/kg) orally. After 2 weeks, they underwent percutaneous renal biopsy, but 1 day after surgery, deep venous thrombosis of the left leg left leg (DVT) occurred. At this time, the patient's clinical manifestation was still nephrotic syndrome, with serum albumin 26g/L and proteinuria of 24h 6.93g/L. Due to DVT, the patient received anticoagulant treatment. The first renal biopsy of
patients specimens were poor in and only contained 1 glomerulus, so is not suitable for interpreting . In view of this, the doctor decided to take the treatment first, and then based on clinical feedback, decided whether to perform renal biopsy again . According to the clinical manifestations of the patient, the doctor tentatively designated it as LN III or IV and began to give oral induction of mycophenolate twice a day at 1500 mg each time. After 12 months, the patient still had persistent, extensive proteinuria and repeated nephrotic syndrome. During the six consecutive months of high-dose oral prednisolone treatment, the patient also experienced typical glucocorticoid side effects such as facial swelling, "hormonal streaks" and weight gain. In addition, Doppler ultrasound showed persistent DVT in the left leg, and 24h urine protein worsened to 12.61g/L. In summary, the doctor advises the patient to undergo a renal biopsy again with .
Interventional radiology team used 18G semi-automatic biopsy needle for renal biopsy, and a total of 4 punctures were punctured. The doctor immediately found a hematoma around the right superior pole and along the needle tract of 3.4 cm × 5.1 cm. After a follow-up examination half an hour later, the hematoma did not expand. All patients were not uncomfortable, with blood pressure of 137/75mmHg and heart rate of 94 beats/min. During observation in the ward, hematuria was found. Computed tomography angiography (CTA) showed no evidence of active arterial hemorrhage, pseudo-aneurysms, fistula, or right renal angiography aggregation. Repeated coagulation characteristics are normal. Repeated antiphospholipid antibody screening results were negative. Even so, the patient's hematuria worsened significantly, which led to acute urinary retention of in , and the patient needed bladder flushing. Due to the above incident, the doctor did not initiate any anticoagulant treatment after the operation. Three weeks after
, the patient had obvious hematuria and dull pain. Although the patient has persistent hematuria, his hemoglobin level is still within the normal range and hemodynamics is stable. After renal ultrasound examination showed non-diffusion perirenal hematoma, CTA was checked again. CTA again showed a right perirenal hematoma and bilateral venous thrombosis . In view of this finding, despite the persistent hematoma and hematuria of the patient, the doctor decided to treat it with oral 5 mg warfarin and subcutaneous injection of enoxaparin sodium (1 mg/kg, twice a day). Two days after the re-initiation of anticoagulant treatment, the patient's hematuria completely subsided. One month later, the ultrasound hematoma, renal venous thrombosis and DVT of the right leg were reviewed. The second renal biopsy pathology analysis showed that the patient was in line with type IV LN.He began to receive cyclophosphamide treatment and partially relieved.
Discussion on the occurrence of dual complications after kidney biopsy of
is a very interesting learning opportunity. Hematuria after renal biopsy is a common symptom, that is, it is related to perirenal hematoma and also to renal venous thrombosis. The clinical manifestations of the two complications overlap, especially the late occurrence of venous thrombosis, which may delay diagnosis and treatment. The patient had long-term, obvious hematuria and ipsilateral low back pain, although radiologic evidence showed that the hematoma was stable and there was no visible vascular damage, so it was necessary to continue looking for the "culprit" that caused hematuria.
It is worth highlighting that this patient has increased risk of thromboembolic events such as persistent DVT, persistent nephrotic syndrome, and has been bedridden due to bladder flushing. Patients with SLE with antiphospholipid syndrome may develop acute thrombosis, but antiphospholipid antibodies are negative, so the cause of thrombosis is unlikely to be related to SLE.
At present, there is no broad consensus in the medical community about when to start anticoagulation after renal biopsy, but usually, it is acceptable to wait for 6 weeks to start anticoagulation again. However, there are also cases that spontaneous perirenal hemorrhage occurs in patients receiving anticoagulation. Therefore, be cautious about when this type of patient will resume anticoagulation treatment. For extrarenal hematomas, such as intracranial hematoma , the American Heart Association (AHA) and the American Stroke Association (ASA) recommend waiting for 4 weeks to start anticoagulation, although the evidence is only Grade IIb. Therefore, most doctors believe that it is appropriate for patients with perirenal hematoma to start anticoagulant treatment after 4 to 6 weeks. In this case, the doctor believed that his perirenal hematoma had stabilized, and persistent hematuria was associated with renal venous thrombosis. Therefore, anticoagulant treatment was restarted after 3 weeks of renal biopsy.
In short, percutaneous renal biopsy has a risk of hematuria. If necessary, other methods of obtaining renal tissue, such as jugular vein biopsy, have a lower risk of hematuria. When a patient with renal biopsy develops hematuria after surgery, the cause of hematuria in the patient should be identified based on his medical history, auxiliary examination and imaging examination results. It is worth noting that for patients with long-term hematuria with stable perirenal hematoma, it should be distinguished whether renal venous thrombosis is formed. The timing of the onset of anticoagulant treatment is related to the patient's cause, intra-renal and extra-renal conditions, and even the patient's medical history and individual differences need to be considered. This case shows that for patients with renal venous thrombosis and perirenal hematoma after renal biopsy, restarting anticoagulation treatment is slightly earlier than 4 weeks or a safe treatment behavior.
References:
1. Kamarudin MI, Nadarajan C, Daud MAM. Double trouble - management of perinephric hematoma and renal vein thrombosis post percutaneous renal biopsy. BMC Nephrol. 2022 Sep 9;23(1):310.
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