Table 1.

Characteristics of studies included in the review.

Study	Type of study	Levels of evidence	Number of patients	Objective of the study
Kruck et al. [2]	Retrospective	3b	482	Mini-PCNL
De et al. [3]	Meta-analysis	1a	727	PCNL, mini-PCNL, micro-PCNL
Kirac et al. [4]	Retrospective	3b	37	Mini-PCNL
Prakash et al. [11]	Retrospective	3b	86	PCNL
Purkait et al. [13]	Retrospective	3b	44	PCNL
Waingankar et al. [17]	Review	4	221	PCNL
Srivastava et al. [18]	Retrospective	3b	44	PCNL
Gücük and Üyetürk [19]	Review	4	259	PCNL
Zhang et al. [20]	Meta-analysis	1a	2142	PCNL
Siev et al. [22]	Retrospective	3b	101	PCNL
Yuan et al. [24]	Meta-analysis	1a	6881	PCNL
Derisavifard et al. [26]	Review	4	NA	PCNL
Hatipoglu et al. [29]	Retrospective	3b	200	PCNL
Sharma et al. [30]	Review	4	NA	Access technique
Sorensen et al. [31]	Prospective	3b	18	Ultrasound detection
Li et al. [32]	Prospective	3b	NA	Access technique
Rodrigues et al. [33]	Review	4	NA	Puncture technique
Isac et al. [35]	Retrospective	3b	159	Access technique
Ritter et al. [39]	Prospective	3b	27	Puncture technique
Tepeler et al. [42]	Prospective	3b	20	Microperc, PCNL
Gao et al. [43]	Meta-analysis	1a	1279	Mini-PCNL, ultramini-PCNL, micro-PCNL
Ruhayel et al. [44]	Systematic review	3a	NA	Mini-PCNL, PCNL
Schilling et al. [45]	Review	4	NA	Nomenclature proposal
Sabnis et al. [46]	Randomized controlled trial	2b	35	Microperc
Wang et al. [47]	Retrospective	3b	216	Mini-PCNL, PCNL
York et al. [51]	Randomized controlled trial	2b	201	PCNL
El-Nahas et al. [50]	Randomized controlled trial	2b	70	PCNL

PCNL, percutaneous nephrolithotomy.

NA, no available number of patients in the studies.