Kidney Week

Abstract: FR-PO926

Tangential Approach: An Innovative Technique in Ultrasound-Guided Native Kidney Biopsy (KB)

Session Information

• Glomerular Diseases: Potpourri
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Sosa Barrios, Haridian, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Haridian Sosa Barrios, MD

• Riaza Ortiz, Cristina, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Cristina Riaza Ortiz, MD, DrMed, MEd

• Morán Magro, María del Pilar, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

María del Pilar Morán Magro

• Burguera, Victor, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Victor Burguera, MD

• Minguez, Irene, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Irene Minguez

• Sánchez, Jorge, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Jorge Sánchez, MD

• Fernandez-Lucas, Milagros, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Milagros Fernandez-Lucas, MD, PhD

• Rivera Gorrin, Maite, Hospital Universitario Ramon y Cajal, Madrid, Madrid, Spain

Maite Rivera Gorrin, DrMed, PhD

Background

KB is the gold standard to diagnose renal pathology, but not without complications. In the conventional approach (CA) the needle enters the kidney at 60-90 degrees. The tangential approach (TA) is proposed as an alternative since it minimizes crossing the renal sinus (angle less than 60 degrees) and vessels of larger caliber (Figure 1).
Objective: to demonstrate the non-inferiority of TA in native KB versus CA in terms of diagnostic yield and complications.

Methods

Retrospective single center study (May 2022-March 2024). Demographic data, KB and complications comparing CA vs TA were collected. The physician performing the KB chose one approach or the other according to the patient's anatomical characteristics and personal preferences.

Results

A total of 102 patients were biopsied, 65 (63.7%) male, mean age 54.18±17.3 years, 51% hypertensive. Twenty-two patients were anticoagulated/anti-aggregated and 24 required intravenous desmopressin preKB.
Lower pole was biopsied in all cases, 86.3% left kidneys and only in one case both were biopsied. The mean number of passes was 2.5 (N.S.), with a mean yield of 2 cylinders.
Cost-effectiveness of BR: Both the percentage of valid samples for diagnosis and the percentage of cortical obtained was statistically superior for AT, not so for the mean number of glomeruli obtained 18±11 vs 19±9 (p=0.647).
Complications
There were no statistically significant differences regarding major or minor complications.
- Major: One patient required embolization and transfusion of blood products (CA).
- Minor: We found statistically significant difference in the rate of asymptomatic arterio-venous fistulae (p=0.003), but not in minor hematoma or hematuria.

Conclusion

Native KB by TA is a novel technique. In our study, TA showed higher diagnostic yield without increasing complications, probably because large vessels are avoided during the procedure. We propose this alternative approach in selected cases, but larger prospective studies are needed.