A new method of kidney biopsy using low dose CT-guidance with coaxial trocar and bard biopsy gun

Efficacy and Safety of CT-Guided Kidney Biopsy for the Diagnosis of Glomerular Diseases in Complicated Patients

INTRODUCTION

Kidney biopsy is the cornerstone for the diagnosis of glomerular diseases and to guide treatment. Percutaneous ultrasound-guided kidney biopsy is currently the gold standard to obtain cortical specimens. However, in cases where ultrasound-guided kidney biopsy is not deemed safe (obese patients, deep kidneys, or kidneys with a complicated anatomy), CT-guided kidney biopsy could be a convenient alternative to obtain renal tissue samples. The aim of this study was to describe the diagnostic yield and complications of CT-guided kidney biopsies in patients with glomerular diseases that were previously discarded for ultrasound-guided kidney biopsy.

MATERIAL AND METHODS

We performed a retrospective, single-center, observational study including patients who underwent CT-guided native kidney biopsies in our center after being contraindicated for ultrasound-guided biopsy. Patients' records were reviewed retrieving baseline characteristics and pre-biopsy clinical, laboratory parameters and concomitant medication. The biopsy needle gauge, site of puncture, and number of needle passes were recorded. The diagnostic yield was evaluated by the number of glomeruli obtained, the rate of specimens that were adequate to reach diagnosis, and the number of biopsies that had to be repeated. Complications were defined as minor (hypotension, hematoma) and major (arteriovenous fistulae, major bleeding requiring embolization, or nephrectomy). The diagnostic yield and complications were compared to ultrasound-guided native kidney biopsies performed during the same period.

RESULTS

56 CT-guided native kidney biopsies were performed during the study period. The number of glomeruli obtained per patient was 11.5 ± 6.3, which was inferior to that obtained from ultrasound-guided biopsies (14.08 ± 8.47, p < 0.05). However, the rate of specimens that were adequate to reach a diagnosis was similar (92.9% vs. 90.8%, p = 0.437). The number of needle passes was higher in CT-guided kidney biopsies (2.0 ± 0.7 vs. 1.7 ± 0.5, p < 0.05), as well as the incidence of post-biopsy perirenal asymptomatic hematomas (66.1% vs. 24.5%, p < 0.01). There were no significant differences in other post-biopsy minor complications (1.8% vs. 2.5%, p = 0.621). There were no major complications after CT-guided kidney biopsies.

CONCLUSIONS

CT-guided percutaneous kidney biopsy is a valid alternative for the diagnosis of glomerular diseases in patients with special characteristics such as obesity or deep kidneys that contraindicate ultrasound-guided biopsy. In this population, CT-guided kidney biopsies are safe and provide a high diagnostic yield, reaching a diagnosis in >90% of patients that had been previously discarded for ultrasound-guided biopsy.

Multidisciplinary Approach and Outcomes of Pretreatment Small (cT1a) Renal Mass Biopsy: Single-Center Experience

PURPOSE

We evaluated our experience of a multidisciplinary approach to renal mass biopsy (RMB) for small renal masses (SRM) employing in-office ultrasound (US) guided biopsy by urology (24%), computed tomography (CT) or US biopsy by interventional radiology (IR) (79%), and endoscopic ultrasound-guided biopsy by gastroenterology (GI) (4%).

METHODS

A single-institution retrospective review of patients who underwent RMB for SRM from May 2013 to August 2019 was conducted. Data regarding patient demographics, tumor characteristics, biopsy technique, histopathology, and management were collected. Diagnostic rates, concordance with final pathology, complications, and outcomes were analyzed.

RESULTS

Of the 192 biopsies reviewed, 63% biopsies were malignant, 20% were benign, and 17% were non-diagnostic. Based on biopsy results, 71 patients (37%) elected active surveillance. Thirty-eight (20%) patients underwent cryoablation, 56 (29%) underwent partial nephrectomy (PN), 14 (7%) underwent radical nephrectomy (RN) and the remaining patients were treated elsewhere. The rate of surgery for benign pathology after pretreatment RMB was 3%. The concordance rate between biopsy and final pathology was 99% for malignancy, 96% for specific pathology subtype, and 85% for RCC grade. Median time from diagnosis to definitive treatment was 97 days (urology: 76, IR: 110 and GI: 54, p=0.002). Three (1.6%) Clavien I complications were reported.

CONCLUSION

Our multidisciplinary approach to renal mass biopsy for clinical stage T1a demonstrated favorable safety and diagnostic rates, which effectively directed management strategies and minimized surgery for benign disease. Urologist performed office-biopsies significantly shortened the time from diagnosis to definitive treatment. Our experience with GI EUS biopsy has demonstrated feasibility and safety for tumors that were otherwise not accessible percutaneously.

Percutaneous renal biopsy: approach, diagnostic accuracy and risks

PURPOSE OF REVIEW

This article provides a review of recent advances and issues regarding the controversial topic of renal mass biopsy (RMB). The purpose of this review is to provide an update on the current status of renal biopsy based on recently published literature. Here, we particularly focus on articles that have been published within the last 12 months.

RECENT FINDINGS

The main topics covered in this review are the approach, diagnostic accuracy and risks related to RMB.

SUMMARY

Current literature suggests that improvements in both technique and technological advancements of RMB have led to greater diagnostic accuracy and low risks to the patient. Newer technologies are leading toward innovative and harmless ways to diagnose kidney cancer, including liquid and image-based biopsy. However, it appears that the question of whether or not to instate renal biopsy as standard clinical practice has remained a highly debated controversy.

Cost Comparisons Between Different Techniques of Percutaneous Renal Biopsy for Small Renal Masses

PURPOSE

To compare the costs associated with ultrasound (US)-guided hospital-based (UGHB), CT-guided hospital-based (CTG), and US-guided office-based (UGOB) percutaneous renal biopsy (PRB) for small renal masses (SRMs).

METHODS

We retrospectively analyzed patient demographics, tumor characteristics, R.E.N.A.L. nephrometry scores, and cost data of patients undergoing PRB for SRM at our institution from May 2012 to September 2015. Cost data, including facility costs, professional fees, and pathology, were obtained from the departments of urology, radiology, and pathology.

RESULTS

A total of 78 patients were included in our analysis: 19, 31, and 28 UGHB, CTG, and UGOB, respectively. There was no difference in age, gender distribution, or tumor size among the three groups (p-values 0.131, 0.241, and 0.603, respectively). UGOB tumors had lower R.E.N.A.L. nephrometry scores (p=0.008). There were no differences in nondiagnostic rates between the UGHB, CTG, and UGOB groups [4 (21%), 5 (16%), and 6 (21%)] (p=0.852). There were no differences in final tumor treatment strategies utilized among the UGHB, CTG, and UGOB groups (p=0.447). There were 0, 2 (6%), and 0 complications in the UGHB, CTG, and UGOB biopsy groups. Total facility costs were $3449, $3280, and $1056 for UGHB, CTG, and UGOB PRB, respectively (p<0.0001). There was no difference between the urologist's and radiologist's professional fees (p=0.066). Total costs, including facility costs, pathology fees, and professional fees, were $4598, $4470, and $2129 for UGHB, CTG, and UGOB renal biopsy, respectively (p<0.0001).

CONCLUSION

For select patients with less anatomically complex, exophytic, and posteriorly located tumors, UGOB PRB provides equivalent diagnostic and complication rates while being significantly more cost-effective than either UGHB or CTG renal biopsy.