Comparison of the total and hidden blood loss in patients undergoing single-level open and unilateral biportal endoscopic transforaminal lumbar interbody fusion: a retrospective case control study.

PURPOSE: This study aimed to compare total blood loss (TBL) and hidden blood loss (HBL) in patients undergoing single-level open transforaminal lumbar interbody fusion (O-TLIF) and unilateral biportal endoscopic transforaminal lumbar interbody fusion (ULIF). METHODS: A total of 53 patients who underwent ULIF and 53 patients who underwent O-TLIF from March 2020 to July 2022 were retrospectively reviewed. The Nadler's formula was employed to estimate the patient's blood volume (PBV), Gross's formula to estimate TBL, and Sehat's formula to estimate HBL. The obtained data were then analyzed with independent t test, chi-squared test, and analysis of covariance. RESULTS: TBL and measured blood loss (MBL) in ULIF group (326.86 ± 223.45 ml, 99.00 ± 72.81 ml) was significantly lower than O-TLIF group (427.97 ± 280.52 ml, 270.66 ± 102.34 ml). Nevertheless, the HBL in ULIF group was higher than that in O-TLIF group (227.86 ± 221.75 ml vs 157.31 ± 268.08 ml), however this was not statistically significant (p = 0.143). The HBL was 69.71 ± 23.72% of TBL in ULIF group and 36.76 ± 18.79% of TBL in O-TLIF group. Patients in ULIF group had lower TBL and MBL, shorter duration of drainage, lower postoperative anemia, and shorter postoperative hospital stay compared to those in O-TLIF group. CONCLUSIONS: Perioperative HBL should not be neglected in patients undergoing ULIF or O-TILF, as it accounts for a large percentage of TBL in both groups. ULIF is associated with lower TBL and MBL, postoperative anemia, shorter postoperative hospital stays compared with O-TLIF.

Clinical comparison of three-dimensional exoscope vs. operative microscope in transforaminal lumbar interbody fusion: A retrospective case-control study.

Purpose: Here, we sought to determine the safety and feasibility of three-dimensional exoscope (3D EX). We compared data on surgery, complications, postoperative drainage, hematology, and clinical outcomes in the group that underwent transforaminal lumbar interbody fusion (TLIF) using an operative microscope (OM) relative to those treated using 3D EX. Methods: We retrospectively reviewed records on 74 patients who underwent one- or two-level TLIF from August 2019 to October 2020. Repeated measures analysis of variance was used to compare pre- and post-operative visual analogue scale (VAS) scores and oswestry disability index (ODI). We used analysis of covariance to compare pre- and post-operative erythrocyte count (RBC), hemoglobin (Hb), and hematocrit (Hct). Independent sample t-tests was used to compare postoperative drainage volume, total blood loss (TBL), visible blood loss (VBL) and hidden blood loss (HBL). Results: There were no significant differences in VAS and ODI scores between the two groups at all time points (all p > 0.05). RBC and HBL did not differ significantly between the two groups (all p > 0.05). There were significant differences in postoperative drainage volume,TBL, Hb, and Hct values when using 3D EX relative to OM in two-level TLIF (all p < 0.05), but not for one-level TLIF (all p > 0.05). The two groups differed significantly with regards to VBL when used for one- or two-level TLIF (all p < 0.05). Conclusion: Our data show that 3D EX is a suitable alternative to OM in TLIF. Relative to OM, 3D EX has important strengths in reducing perioperative bleeding in two-level TLIF.