Biopsy - Renal and Urinary Tract Function

BIOPSY

Renal and Ureteral Brush Biopsy

Brush biopsy techniques provide specific information when ab-normal x-ray findings of the ureter or renal pelvis raise questions about whether the defect is a tumor, a stone, a blood clot, or an artifact. First, a cystoscopic examination is conducted. Then, a ureteral catheter is introduced, followed by a biopsy brush that is passed through the catheter. The suspected lesion is brushed back and forth to obtain cells and surface tissue fragments for histo-logic analysis.

After the procedure, intravenous fluids may be administered to help clear the kidneys and prevent clot formation. Urine may contain blood (usually clearing in 24 to 48 hours) from oozing at the brushing site. Postoperative renal colic occasionally occurs and responds to analgesics.

Kidney Biopsy

Biopsy of the kidney is used in diagnosing and evaluating the ex-tent of kidney disease. Indications for biopsy include unexplained acute renal failure, persistent proteinuria or hematuria, transplant rejection, and glomerulopathies. A small section of renal cortex isobtained either percutaneously (needle biopsy) or by open biopsy through a small flank incision. Before the biopsy is carried out, coagulation studies are conducted to identify any risk for post-biopsy bleeding. Contraindications to a kidney biopsy include bleeding tendencies, uncontrolled hypertension, and a solitary kidney.

PROCEDURE

The patient may be placed on a fasting regimen 6 to 8 hours be-fore the test. An intravenous line is established. A urine speci-men is obtained and saved for comparison with the postbiopsy specimen.

If a needle biopsy is to be performed, the patient is instructed to breathe in and hold that breath (to prevent the kidney from moving) while the needle is being inserted. The sedated patient is placed in a prone position with a sandbag under the abdomen. The skin at the biopsy site is infiltrated with a local anesthetic. The biopsy needle is introduced just inside the renal capsule of the outer quadrant of the kidney. The location of the needle may be confirmed by fluoroscopy or by ultrasound, in which case a special probe is used.

With open biopsy, a small incision is made over the kidney, allowing direct visualization. Preparation for an open biopsy is similar to that for any major abdominal surgery (NIDDK, 2001b).

NURSING INTERVENTIONS

After the tissue specimen is obtained, pressure is applied to the biopsy site. The patient may be kept in a prone position imme-diately after biopsy and on bed rest for 6 to 8 hours to minimize the risk of bleeding.

Monitoring and Managing Potential Complications. 

Potentialpostbiopsy complications include persistent hematuria, fistula or aneurysm formation, or laceration of organs or blood vessels ad-jacent to the kidney. The nurse monitors the patient closely for hematuria, which may appear soon after biopsy. The kidney is a highly vascular organ, and about one fourth of the entire cardiac output circulates through it in about 1 minute. The passage of the biopsy needle punctures the kidney capsule, and bleeding can occur in the perirenal space. Usually the bleeding subsides on its own, but a large amount of blood can accumulate in this space in a short time without noticeable signs until cardiovascular collapse is evident.

Nursing interventions after a kidney biopsy include:

·      Monitor vital signs every 5 to 15 minutes for the first hour to detect early signs of bleeding, and then with decreasing frequency as indicated.

·      Be alert for signs and symptoms that suggest bleeding, in-cluding a rise or fall in blood pressure, tachycardia, anorexia, vomiting, and the development of a dull, aching discomfort in the abdomen.

·      Immediately report any symptoms of backache, shoulder pain, or dysuria.

Flank pain may occur but usually represents bleeding into the muscle rather than around the kidney. Colicky pain similar to that of ureteral colic may develop when a clot is present in the ureter; there may be excruciating, sharp flank pain that radiates to the groin.

All urine that the patient voids is inspected for evidence of bleed-ing and compared with the prebiopsy specimen and subsequent voiding samples. If bleeding persists, as indicated by an enlarging hematoma, the abdomen should not be palpated or manipulated.

Hematocrit and hemoglobin levels are obtained within 8 hours to assess for changes; decreasing levels may indicate bleeding. Usually, the fluid intake is maintained at 3,000 mL/day unless the patient has renal insufficiency. If bleeding occurs, the patient is prepared for blood component therapy and surgical intervention to control the hemorrhage; surgical drainage or, rarely, nephrec-tomy (removal of the kidney) may be needed.

Patient Teaching. 

Because hemorrhage can occur up to severaldays after the biopsy, the patient is instructed to avoid strenuous activities, sports, and heavy lifting for at least 2 weeks. The patient and family are instructed to notify the physician or clinic if any of the following occur: flank pain, hematuria, light-headedness and fainting, rapid pulse, or any other signs and symptoms of bleeding.