Percutaneous aspiration biopsy of renal allografts using ultrasound localization

Effectiveness and safety of two 18-gauge needle types on native and allograft renal biopsies

Percutaneous biopsy is a key diagnostic tool for both native and allograft kidney diseases. Adequacy criteria vary, but at a minimum, a biopsy should allow the pathologist to reach a diagnosis and provide prognostic information such as the degree of interstitial fibrosis and tubular atrophy (IF/TA) and percentage of glomerulosclerosis. Whereas most studies use glomerular counts as a surrogate for biopsy adequacy, the amount and preservation of tubulointerstitium is equally important, considering IF/TA is a major prognostic parameter for most medical renal diseases. Many studies have compared the diagnostic adequacy of different gauge needles; however few have investigated performance differences between same gauge needles. In this study, we retrospectively analyzed 235 renal biopsies performed at a single center in Canada over 2years to compare the utilization, safety, diagnostic and prognostic performance of two 18-gauge needles in native and allograft kidney biopsies. We found no significant difference in needle utilization between native and allograft kidneys, or between trainees and staff radiologists. The total tissue yielded area, glomerular counts, percentage of inadequate biopsies and number of passes were similar; however the number of cases in which IF/TA evaluation was deemed not possible was higher for biopsies using disposable instrument needles (4.3% vs. 0%; p=0.01). These also showed greater number of tissue fragments (median 4 for reusable vs 3 for disposable; p=0.04). We postulate that the increased tissue fragmentation might have impaired the pathologists ability to accurately assess interstitial fibrosis and tubular atrophy in biopsies obtained with the disposable instrument needles.

Percutaneous needle biopsy of the renal allograft using the automated needle system: evaluation of 87 procedures

Between April 1991 and February 1992 we obtained 87 percutaneous core needle biopsy specimens from 60 patients with the automatic biopsy gun. In 78 cases (89.7%) enough renal tissue was obtained for histological analysis. Acute rejection was present on 35 biopsies (40.3%) indicating antirejection therapy. No pathological signs of rejection were detected on 43 biopsies (49.4%). In 38 instances (43.7%) biopsy diagnosis differed from clinical presumptive diagnosis, affecting patient management, while in the remainder it was helpful to confirm clinical impressions. The only complication of the procedure was gross hematuria (requiring vesical irrigation in 1 patient). Due to its simplicity and low morbidity rate, renal biopsy with the automated needle system is the procedure of choice for evaluation and management of renal allograft dysfunction.

Arteriovenous fistula after biopsy of renal transplant: detection and monitoring with color flow and duplex ultrasonography

An asymptomatic intrarenal arteriovenous fistula was incidentally discovered by color flow and duplex ultrasonography approximately 2 weeks after a percutaneous biopsy of a renal allograft. On the basis of information obtained from the color flow image and pulsed Doppler analysis, the vascular communication could be characterized without the need for angiographic correlation. The patient was managed successfully with close observation aided by serial ultrasound examinations. Spontaneous resolution of the fistula occurred within 4 weeks after the biopsy and was evident on a follow-up ultrasound examination. Duplex ultrasonography in conjunction with color flow imaging proved to be a valuable noninvasive technique for diagnosing and monitoring this postbiopsy vascular complication.

Value of percutaneous core needle biopsy in the differential diagnosis of renal transplant dysfunction

The value of percutaneous core needle biopsy in the differentiation of rejection from other causes of renal allograft dysfunction, and its subsequent effect on patient management were assessed in 64 consecutive biopsies performed on 34 patients in whom the clinical diagnosis was was uncertain. A complete clinical, biochemical and radiographic assessment was made in each patient before biopsy. Only 1 biopsy (1.6 per cent) yielded tissue inadequate for evaluation, while another biopsy caused a renal artery pseudoaneurysm that ruptured and resulted in graft loss. In 27 of these 64 biopsies (42 per cent) the results differed from the pre-biopsy diagnosis and directly affected patient management, particularly the use of steroids. The remaining biopsy specimens were helpful to confirm uncertain clinical impressions, and allowed accurate counseling for patients and family. Biopsies were of special usefulness in separating acute rejection from complications, such as acute tubular necrosis, cytomegalovirus infections, recurrence of original disease, cyclosporin toxicity and acute superimposed-upon chronic rejection. Of 64 biopsies 22 (34.3 per cent) demonstrated the absence of rejection and 8 demonstrated chronic rejection (12.5 per cent), thereby averting the use of steroids in 46.8 per cent of the patients. All patients with evidence of severe small vessel disease and/or antibody-mediated rejection eventually lost the grafts, including 2 with cytomegalovirus glomerulopathy who also suffered such vascular changes. These data highlight the extreme usefulness of needle biopsy in the evaluation and management of renal allograft dysfunction.

Postbiopsy renal allograft arteriovenous fistula: therapeutic embolization

Two patients with large, postbiopsy renal allograft arteriovenous fistulae are presented. One patient also had a renal artery anastomotic stenosis. Prominent clinical features in these cases were deterioration of allograft function and severe hypertension. Following therapeutic embolization, combined with balloon angioplasty in the second patient, there was marked improvement in allograft function and a return to normal blood pressure.

Role of ultrasound in renal transplantation

Ultrasound examination of a renal transplant was performed in 27 patients over a period of 28 months; there were kidneys from 12 living and 15 cadaveric donors. The ultrasonic scans were performed over a period ranging from 2 days to 12 years following transplantation. We were able to observe and describe the echographic findings of the normal evolution of a well functioning renal transplant, acute tubular necrosis, acute and chronic rejection, perirenal fluid collection, and obstructive uropathy. Ultrasound evaluation of renal transplant was accurate in the diagnosis of postoperative complications together with clinical and laboratory findings. Ultrasound imaging is independent of renal function and can be performed quickly as often as necessary. Percutaneous procedures, including fine needle aspiration, biopsy, aspiration of fluid collection, and positioning of the pyelostomy catheter can be performed under ultrasonic guidance.