CLINICAL INVESTIGATION A Randomised Clinical Trial to Compare Coaxial and Noncoaxial Techniques in Percutaneous Core Needle Biopsy of Renal Parenchyma Ali Babaei Jandaghi 1 • Mohammadkazem Lebady 2 • Athar-Alsadat Zamani 2 • Abtin Heidarzadeh 3 • Ali Monfared 2 • Ramin Pourghorban 4 Received: 14 July 2016 / Accepted: 9 September 2016 Ó Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2016 Abstract Purpose To compare the coaxial and noncoaxial tech- niques of renal parenchymal core needle biopsy. Materials and Methods This is an institutional review board-approved randomised controlled trial comparing 83 patients (male, n = 49) who underwent renal parenchymal core biopsy with coaxial method and 83 patients (male, n = 40) with noncoaxial method. The rate of complica- tions, the number of glomerular proﬁles, and the procedural time were evaluated in a comparison of the two methods. Correlation between the presence of renal parenchymal disease and the rate of complication was also evaluated. Results The procedural time was signiﬁcantly shorter in the coaxial technique (coaxial group, 5 ± 1 min; noncoaxial group, 14 ± 2 min; p \ 0.001). The rates of complications for the coaxial method was signiﬁcantly lower than the noncoaxial method (coaxial group, 10.8 %; noncoaxial group, 24.1 %; p = 0.025). There was no signiﬁcant cor- relation between gender and the rate of complication. The number of glomerular proﬁles was signiﬁcantly higher in patents who underwent renal biopsy with the coaxial method (coaxial group, 18.2 ± 9.1; noncoaxial group, 8.6 ± 5.5; p \ 0.001). In the whole study population, the rate of complications was signiﬁcantly higher in patients with a pathologic renal parenchyma compared to those with a normal parenchyma (19/71 vs. 10/95; p = 0.006). Conclusions Renal parenchymal biopsy using a coaxial needle is a faster and safer method with a lower rate of complications. Keywords Kidney Á Image-guided biopsy Á Complications Á Coaxial Á Kidney glomerulus Introduction Renal parenchymal core biopsy can be done either with coaxial or noncoaxial technique. In coaxial technique, the introducing needle is placed in the target organ; then, multiple tissue samples can be performed through the same tract. Alternatively, in noncoaxial technique, biopsy needle is inserted repeatedly for each tissue sampling [1]. There is only one report by Hatﬁeld et al. [2] in the literature regarding the comparison of coaxial and noncoaxial methods of renal biopsy in their complication rate. How- ever, their study had a recognised limitation, and different operators with different level of experience at image-gui- ded biopsy had performed the renal biopsies in their investigation [2]. Nonetheless, the comparison of the two methods of renal biopsy in regard to the procedural time and the acquired glomerular proﬁles number has not yet been described to the best of our knowledge. Also, corre- lation between the presence of renal parenchymal disease and complication rate in regard to the biopsy method has not been studied to date. In this prospective study, the complication rate and procedural time of coaxial technique were compared with those of noncoaxial technique in & Ramin Pourghorban ramin_p2005@yahoo.com 1 Department of Radiology, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran 2 Urology Research Center, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran 3 Department of Community Medicine, Guilan University of Medical Sciences, Rasht, Iran 4 Department of Radiology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran 123 Cardiovasc Intervent Radiol DOI 10.1007/s00270-016-1466-3