Table 1.

Baseline characteristics of enrolled trials

Study	Country	Study design	PCNL patients		PCNL position	Lithotripsy technique	Outcomes	CEUS-PCNL technique	Contrast agent using	Follow-up time (day)	LE
			CEUS-guided	US-guided
Guo (2020) [8]	China	RCT	30	30	Prone	Holmium laser (Lumenis 60W, Germany)	1,2,3,4,5,6,7	After general anesthesia and prophylactic use of antibiotics, each patient was placed in the lithotomy position. An open-ended 5-F ureteral catheter was placed retrograde into the ipsilateral proximal ureter up to 25 cm under ureteroscope guidance. The patient was then placed in the prone position	Sulfur hexafluoride microbubbles (SonoVue; Bracco, Switzerland)	30	2b
Liu (2022) [9]	China	RCT	36	36	Flank	NA	1,2,3,4,5,6,7	Under general anesthesia and with the patient supine, an open-ended 6-F ureteral catheter was retrograde placed into the ipsilateral proximal ureter up to 25 cm under ureteroscopic guidance. Patients were then moved to a complete lateral decubitus position	Sulfur hexafluoride microbubbles (SonoVue; Bracco, Switzerland)	28	2b
Xia (2021) [10]	China	RCT	78	76	Prone	The laser energy used ranged from 30 to 60W (1.5–3.0 J*20 Hz)	1,2,3,4,5,6,7	Under general anesthesia and with the patient supine, an open-ended 5-F ureteral catheter was advanced retrograde into the ipsilateral proximal ureter up to 25 cm under cystoscopic guidance	Sulfur hexafluoride microbubbles (SonoVue; Bracco, Switzerland)	30	2b
Liu (2021) [11]	China	RCT	24	24	Flank	Holmium laser (LUME.PK)	1,2,4,5,6,7	Under general anesthesia and with the patient supine, an open-ended 6-F ureteral catheter was retrograde placed into the ipsilateral proximal ureter under ureteroscopic guidance	Sulfur hexafluoride microbubbles (SonoVue; Bracco, Switzerland)	7	2b

RCT: randomized controlled trial; US: ultrasonography; CEUS: contrast-enhanced ultrasound; PCNL: percutaneous nephrolithotomy; LE: level of evidence according to the Oxford Center for Evidence-based Medicine; NA: not available

1 = puncture time; 2 = stone-free rate; 3 = complications; 4 = hemoglobin loss; 5 = hospital stay; 6 = operation time; 7 = single-needle puncture success rate