Table 2.

Preoperative-assessment-related studies included in the systematic review.

Study [Ref.]	Lumbar Segment	Preoperative Assessment	Surgical Technique	Anesthesia Type	Hospital Stay (h)
Liu et al. [15]	L3-L4 and L5-S1	The preoperative values were comparable between operative and contralateral sides.	TLIF	General anesthesia	72
Chen et al. [18]	L3-S1	View of the preoperative CT scans and magnetic resonance images is necessary, especially on the contralateral side.	Lumbar fusion	General anesthesia	72
Uchikado et al. [27]	L1–5 levels	The vascular anatomy surrounding the intervertebral foramen is extremely important to prevent complications	Percutaneous endoscopic lumbar discectomy	Local anesthesia	16
Demondion et al. [32]	L5-S1	-	Percutaneous endoscopic lumbar discectomy	General	12

TLIF, transforaminal lumbar interbody fusion; h, hours.