The percutaneous native kidney biopsy: a nephrologist’s perspective

Introduction Kidney biopsy is one of the most important diagnostic tools in a nephrologist’s armamentarium. It has been shown that performance of a kidney biopsy in the appropriate clinical setting has the potential to alter the clinical diagnosis as well as change the therapy in many cases. Current biopsy practice is very safe with minimal complications and has the ability to obtain adequate tissue for histological diagnosis in more than 95% of cases. It is important for nephrologists to know about the various indications, contraindications and modifications in the procedure as well as the complications. All the trainees are supposed to learn the proper technique of kidney biopsy not only because of the importance of the procedure, but because of the fact that kidney biopsy is one of the triggers that enable the development of nephrology as a separate subspecialty. In this article, we critically review various aspects of a kidney biopsy that is important for practice by nephrologists. Conclusion Percutaneous kidney biopsy is a relatively safe procedure because of the development of many advances like ultrasound-guided and automated biopsy needles. Complication rates following the procedure are minimal and have been decreasing over a period of time. Introduction The procedure of obtaining the renal tissue for histopathological examination, ‘the kidney biopsy’, is perhaps one of the turning points in nephrology practice that enabled it to develop as a separate subspecialty1. The widespread acceptance and performance of this procedure has been brought about by refinements in the existing practices and introduction of newer developments. This has led to a more successful tissue yield that resulted in a more accurate histological diagnosis and has also made the procedure reasonably safe. The kidney biopsy is used for evaluation of many renal diseases and occasionally becomes the only answer to many complex disorders. The aim of this critical review is to discuss the native kidney biopsy through a nephrologist’s perspective. Discussion In this review, the authors have referenced some of their own studies. These referenced studies have been conducted in accordance with the Declaration of Helsinki (1964) and the protocols of these studies have been approved by the relevant ethics committees associated to the institutions in which they were performed. All human subjects, in these referenced studies, gave informed consent to participate in the studies. Evolution of the biopsy procedure The earliest histological examinations of the renal tissue were secondary to examination of tissues obtained during renal decapsulation procedures performed between 1900 and 19301. Kidney biopsy as an acceptable and valid medical procedure started to evolve following the seminal work published by Iverson and Brun2 in 1951 and Alwall3 in 1952. These initial reports were aspiration biopsies performed with the patient in the sitting position and using imaging (X-ray or intravenous pyelogram) for surface marking of the kidney. Adequate tissue collection in these two initial reports was found to be only 50% and 77%, respectively. In 1954, Kark and Muehrcke used an exploring needle to localise the kidney after placing the patient in the prone position and used the Franklin-modified Vim-Silverman needle for biopsy. The technique used by them can be described as a ‘blind procedure’4. This modification resulted in development of more successful biopsies and a larger core of tissue for examination. Subsequently imaging modalities have been used for localising the kidneys and ultrasound-guided (USG) is used most commonly. Initially used for surface marking and approximating the needle direction and depth, the USG has gradually been adopted to conduct the entire biopsy procedure under real-time guidance. Biopsies conducted under the USG management are safer than a blind procedure and can also result in more successful biopsies with a better tissue sample5,6. Th e automated biopsy devices In the 1980s, the spring loaded, automated, cutting-needle biopsy guns were developed7. The advantages of safety, better tissue yield with minimal tissue disruption and ease of the procedure enabling use of a real-time USG imaging with one hand and the biopsy gun with another, made these automated devices readily acceptable and the Tru-Cut needles were gradually phased out8–12. Adequate tissue for a Di ag no si s * Corresponding author Email: [email protected] Department of Nephrology, Institute of Postgraduate Medical Education and Research, 244 AJC Bose Road, Kolkata, India-20