LETTER Re: Zhaohui He, Fucai Tang, Zechao Lu, Ye He, Genggeng Wei , Fangling Zhong, Guohua Zeng, Weizhou Wu, Lemin Yan5, Zhibiao Li. “Comparison of Supracostal and Infracostal Access For Percutaneous Nephrolithotomy: A Systematic Review and Meta-Analysis” Urology Journal 2019 Junbo Liu, Guo Jiang, Tao Wu* Department of Urology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, Sichuan, P.R. China. *Correspondence: Department of Urology, Affiliated Hospital of North Sichuan Medical College, Wenhua road 57, Shunqing district, Nanchong, 637000, Sichuan, P.R. China. Tel: 2282023-0817; Fax: 2282023-0817; E-mail: alhawking@163.com Dear Editors, We read the article in your journal titled “Comparison of Supracostal and Infracostal Access For Percutaneous Nephrolithotomy: A Systematic Review and Meta-Analysis” by Zhaohui H. et al (1). The article conducts a comprehensive meta-analysis of existing evidence to quantify and compare the safety and efficacy of supracostal and infracostal access for percutaneous nephrolithotomy. This question is clear and important in clinical practice. This is a meaningful article. However, we would like to raise our concerns about the correct quotation of references in the article. Firstly, in the second paragraph of discussion, the authors mentioned that “Fan et al(2). previously reviewed the results of 98 mPCNLs and their results revealed that there was no negative effect on any intraopera- tive and postoperative parameters, or any increase complication rates when comparing supracostal and infracostal access”. However, after we read the article of Fan et al(2), we find there is something wrong. There are only 83 patients in the study of Fan et al(2), and the conclusion of Fan et al(2) is that “there were several advantages of in- fracostal access. These included accuracy in establishing a percutaneous tract, safety, quickness, convenience and flexibility in moving the patented sheath, and higher renal and upper ureteral stone clearance rate by one surgery.” That seems to be quite different from the description in the article of Zhaohui H et al(1). Secondly, in the second par- agraph of discussion, the authors mentioned that “However, Ozgor et al (3). reviewed 83 cases involving treatment with mPCNL and found that there were several advantages of infracostal access, including increased accuracy in establishing a percutaneous tract, safety, speed, convenience and flexibility in moving the patented sheath”. However, after we read the article of Ozgor et al(3), we find there is also something wrong. There are 98 cases in the study of Ozgor et al(3), and the conclusion of Ozgor et al.(3) is that “Our study demonstrated that mPNL resulted in acceptable stone-free rates whether accessed through either the supracostal or subcostal areas. Moreo- ver, the supracostal approach with mPNL had no negative effect on any intraoperative and postoperative parame- ters, nor did it increase complication rates”. That seems to be quite different from the description in the article of Zhaohui H et al(1). In other words, the description about Fan et al(2) and Ozgor et al(3) is reversed in the discussion of the article of Zhaohui H et al(1). Finally, in the second paragraph of discussion, the authors mentioned that “Sinha et al(4). performed a retrospective review of 777 patients who underwent PCNL and suggested that the avoidance of the supracostal approach was unnecessary, although there was an increase in thoracic complications when the supra 11th approach (between the 10th and 11th ribs) was used, compared with the infra- costal approach.” However, after we read the article of Sinha et al(4). We find there is something wrong. There is only 700 patients who underwent PCNL in the study of Sinha et al(4). This article is very meaningful, but the authors of this article seem to be a little careless. And if the researchers can revise these points that we men- tioned. The article will be a higher quality paper. CONFLICT OF INTERESTS The authors declare that there are no conflict of interests REFERENCES 1 .He Z, Tang F, Lu Z, et al. Comparison of supracostal and infracostal access for percutaneous nephrolithotomy: a systematic review and meta-analysis. Urol J. 2019; 16:107–114. 2. Fan D, Song L, Xie D, et al. A comparison of supracostal and infracostal access approaches intreating renal and upper ureteral stones using MPCNL with the aid of a patented system. BMC Urol. 2015; 15:102. 3. Ozgor F, Tepeler A, Basibuyuk I, et al. Supracostal access for miniaturized percutaneous nephrolithotomy: comparison of supracostal and infracostal approaches. Urolithiasis. 2018; 46:279-283. 4. Sinha M, Krishnappa P, Subudhi SK, Krishnamoorthy V. Supracostal percutaneous nephrolithotomy: A pro- spective comparative study. Indian J Urol. 2016; 32:45-9. Urology Journal/Vol 19 No. 2/ March-April 2022/ pp. 160-160. [DOI: 10.22037/uj.v18i.5811]