Percutaneous renal biopsy is not only used to diagnose the pathology of in situ kidney or transplanted kidney, but also helps to further understand the occurrence, development and regression of the disease, providing more information to guide the treatment and determine the prognosis. Percutaneous renal biopsy is the most common diagnostic tool for in situ and transplanted kidney disease. The classical method of percutaneous renal biopsy is negative pressure suction method, real-time ultrasound guidance can be more accurate positioning and reduce complications.
Indications
1. Episodic nephrotic syndrome with or without renal insufficiency.
2.Nephritis syndrome with or without renal insufficiency, including glomerular hematuria with or without proteinuria.
3, all types of persistent asymptomatic urinalysis abnormalities identified as a result of diffuse chronic renal unit disease.
4, when chronic renal failure due to non-posterior renal factors and incomplete atrophy of the kidney volume (kidney length diameter > 8 cm measured by ultrasound).
5, acute renal failure caused by non-simple post-renal factors.
6, acute progressive nephritis syndrome.
7, all kinds of non-surgical factors caused by transplanted kidney insufficiency, delayed functional recovery, tubular necrosis, cyclosporine nephrotoxicity, chronic rejection and recurrent disease.
Contraindications]
Patients with the above indications who have severe bleeding disorders or significant bleeding tendency (including patients with thrombocytosis with bleeding tendency and severe thrombocytopenia [<50,000/mm3] with coagulation dysfunction) should be considered as absolute contraindications for renal biopsy. It has been reported that transvascular renal biopsy can be used in such cases, but there are still more bleeding complications.
Relative contraindications include: isolated kidney, active renal infectious disease, pyelonephritis, renal abscess, renal hemangioma, hydronephrosis, uncontrolled hypertension or hypotension, severe anemia, uremia, large renal tumor, current combined cystic kidney disease, and psychiatric disease that prevents cooperation.
Preoperative preparation
1.After clarifying the indications for renal biopsy, explain to the patient the necessity and safety of renal biopsy, and briefly explain the operation procedure to eliminate their concerns and strive for the best cooperation.
2. Explain to the patient or/and his/her relatives or guardians the various complications that may arise from renal biopsy, and explain the relevant precautions.
3.Pre-operative examination includes two or more blood pressure measurements, active control of hypertension if hypertension is present; careful examination of the whole body skin and mucous membrane bleeding tendency and the local skin of the selected needle site; routine skin preparation for those with multiple body hairs; routine examination of blood routine and coagulation function.
4, pre-operative anticoagulation therapy should be discontinued anticoagulant drugs for at least three days.
5. Preoperative ultrasound examination of both kidneys should be performed to understand the kidney image observed at the puncture site and the route of needle insertion.
6. Patients are required to have a bowel movement within 12-24 hours prior to surgery.
7.No severe cough, abdominal pain or diarrhea caused by any reason before surgery.
8.Non-emergency renal biopsy should avoid menstrual period as much as possible.
9.Anxious people and those who cannot cooperate can be sedated as appropriate; patients who are expected to have a higher possibility of hemorrhagic complications are treated with vitamin K and anti-hemorrhagic treatment before surgery.
Operation steps
1, the patient under examination to take a loose prone position (kidney transplant patients to take supine body), the lower abdominal wall under a 5-10cm high cotton pillow to fix the kidney.
2.Monitoring and medication to control severe hypertension due to tension, reassure the patient and eliminate tension.
3, ultrasound positioning guide with sterile probe sitting on the left side of the subject, the surgeon standing on the right side of the subject.
4.Strict skin disinfection, usually two times with iodofur disinfectant, laying the towel.
5.Real-time ultrasound localization is performed to show the lower pole of the kidney in the largest longitudinal section and to determine the needle entry point on the surface of the kidney.
6, Determine the skin-kidney distance and fix the needle depth with a depth fixation card.
7, Intradermal local anesthesia and subcutaneous local anesthesia along the route of needle insertion.
8.The needle piston is completely inserted into the needle tube, and the needle is inserted to the surface of the kidney through the needle slot of the ultrasound needle fixator and under the guidance of real-time ultrasound, the needle piston is removed, the needle latch is placed, negative pressure is connected, and the patient is asked to hold his breath when the kidney is in the best puncture position, and the needle is inserted into the kidney to a predetermined depth while creating negative pressure, and then the needle is quickly plucked out and the kidney biopsy is pushed out with saline in the negative pressure syringe.
9.The tissues were divided and processed according to the requirements of the pathological examination and sent for examination immediately.
10.The length of the kidney biopsy taken is usually required to reach 1,2-2,0cm, and the qualified material should contain the renal cortex and medulla.
Postoperative treatment
1.After the renal puncture dressing is applied to the wound, gauze is applied, and adhesive tape is fixed.
2.Pressure is applied by hand to the body surface area where the needle was inserted, usually 2-3 minutes with the palm of the hand for autologous kidney biopsy.
3, the patient will be sent back to the ward and carefully flattened to the bed, the postoperative patient to adopt a lying down state, strict lumbar brake for 4 hours (limbs can be relaxed and slow small amplitude activities, while turning and twisting the waist is strictly prohibited), autologous renal biopsy requires patients to be bedridden for 24 hours after surgery.
4. Blood pressure, pulse, urine color, skin blood color, sweating, lumbar and abdominal symptoms and signs should be routinely monitored in the early stage.
5.The blood pressure should be checked repeatedly when there is a drop in blood pressure or meatus hematuria, and ultrasound examination can be done for those with significant pain in the lower back and abdomen.
6.Avoid or promptly deal with constipation, diarrhea and violent cough. Forbid violent physical activities within 3 weeks after surgery.
Precautions】
1.It is not advisable to get out of bed prematurely after surgery, and avoid doing large movements of lumbar twisting within one week, otherwise delayed bleeding is likely to occur.
2. Pay attention to the preoperative blood pressure control and eliminate the patient’s tension.
Complications and treatment
1, hematuria: microscopic hematuria almost always occurs, the incidence of carnal hematuria is 1%-12%, most disappear within 2 days, prompt more urine discharge to maintain the patency of the urethra, to prevent thrombus clots blocking the urethra, such as hematocrit and hemoglobin further decline, the need for timely blood transfusion, selective renal artery intervention embolization and surgical procedures (local hemostasis or renal removal) to control hemorrhage.
2, perirenal hematoma formation: more common, mostly small hematoma, can be absorbed and dissipated by bed rest without sequelae, larger hematoma is absorbed within 3 months, perirenal hematoma infection is less common.
3, postoperative urinary retention: most patients have urinary retention after surgery due to recumbency and emotional stress, and quite a few patients need help and use catheterization measures. Those who have visual hematuria and urinate more blood clots are prone to blockage of the urinary tract by blood clots and cause severe urinary retention.
4, perirenal pain: mostly mild dull pain. For those who have severe pain after surgery, blood pressure and heart rate changes should be closely observed and the hematocrit and hemoglobin concentration should be measured in time.
5, arteriovenous fistula: A few patients have arteriovenous fistula after surgery, which can be diagnosed by Doppler ultrasound or renal arteriography, and most patients can absorb it by themselves within 1-2 years.
6. Occasionally, other organs are accidentally penetrated and should be examined by ultrasound in time. The consequences of accidental injury to blood vessels are serious, and active hemostatic measures should be taken. Perirenal infections and urinary tract infections are extremely rare.