Objective: To compare the safety profiles of biportal endoscopic spinal surgery (BESS) and microscopic spinal surgery (MSS) for lumbar disc herniation and spinal stenosis by analyzing the associated adverse events. Methods: We pooled data from 2 prospective randomized controlled trials involving 220 patients (110 in each group) who underwent single-level lumbar surgery. Participants aged 20–80 years with radiating pain due to lumbar disc herniation or spinal stenosis were included in this study. Adverse events were recorded and analyzed over a 12-month follow-up period. Results: The overall adverse event rates were 9.1% (10 of 110) in the BESS group and 17.3% (19 of 110) in the MSS group, which were not statistically significantly different (p=0.133). Notably, wound dehiscence occurred in 8.2% of MSS cases but in none of the BESS cases. Both groups showed similarly low rates of complications, such as dural tears, epidural hematoma, and nerve root injury. The most common adverse event in the BESS group was recurrent disc herniation (2.7%), whereas that in the MSS group was wound dehiscence (8.2%). Conclusion BESS demonstrated a safety profile comparable to that of MSS for the treatment of lumbar disc herniation and spinal stenosis, with a trend towards fewer overall complications. BESS offers particular advantages in terms of reducing wound-related complications. These findings suggest that BESS is a safe alternative to conventional MSS and potentially offers the benefits of a minimally invasive approach without compromising patient safety.

Objective: To compare the safety profiles of biportal endoscopic spinal surgery (BESS) and microscopic spinal surgery (MSS) for lumbar disc herniation and spinal stenosis by analyzing the associated adverse events. Methods: We pooled data from 2 prospective randomized controlled trials involving 220 patients (110 in each group) who underwent single-level lumbar surgery. Participants aged 20–80 years with radiating pain due to lumbar disc herniation or spinal stenosis were included in this study. Adverse events were recorded and analyzed over a 12-month follow-up period. Results: The overall adverse event rates were 9.1% (10 of 110) in the BESS group and 17.3% (19 of 110) in the MSS group, which were not statistically significantly different (p=0.133). Notably, wound dehiscence occurred in 8.2% of MSS cases but in none of the BESS cases. Both groups showed similarly low rates of complications, such as dural tears, epidural hematoma, and nerve root injury. The most common adverse event in the BESS group was recurrent disc herniation (2.7%), whereas that in the MSS group was wound dehiscence (8.2%). Conclusion BESS demonstrated a safety profile comparable to that of MSS for the treatment of lumbar disc herniation and spinal stenosis, with a trend towards fewer overall complications. BESS offers particular advantages in terms of reducing wound-related complications. These findings suggest that BESS is a safe alternative to conventional MSS and potentially offers the benefits of a minimally invasive approach without compromising patient safety.

Objective: To compare the safety profiles of biportal endoscopic spinal surgery (BESS) and microscopic spinal surgery (MSS) for lumbar disc herniation and spinal stenosis by analyzing the associated adverse events. Methods: We pooled data from 2 prospective randomized controlled trials involving 220 patients (110 in each group) who underwent single-level lumbar surgery. Participants aged 20–80 years with radiating pain due to lumbar disc herniation or spinal stenosis were included in this study. Adverse events were recorded and analyzed over a 12-month follow-up period. Results: The overall adverse event rates were 9.1% (10 of 110) in the BESS group and 17.3% (19 of 110) in the MSS group, which were not statistically significantly different (p=0.133). Notably, wound dehiscence occurred in 8.2% of MSS cases but in none of the BESS cases. Both groups showed similarly low rates of complications, such as dural tears, epidural hematoma, and nerve root injury. The most common adverse event in the BESS group was recurrent disc herniation (2.7%), whereas that in the MSS group was wound dehiscence (8.2%). Conclusion BESS demonstrated a safety profile comparable to that of MSS for the treatment of lumbar disc herniation and spinal stenosis, with a trend towards fewer overall complications. BESS offers particular advantages in terms of reducing wound-related complications. These findings suggest that BESS is a safe alternative to conventional MSS and potentially offers the benefits of a minimally invasive approach without compromising patient safety.

Objective: To compare the safety profiles of biportal endoscopic spinal surgery (BESS) and microscopic spinal surgery (MSS) for lumbar disc herniation and spinal stenosis by analyzing the associated adverse events. Methods: We pooled data from 2 prospective randomized controlled trials involving 220 patients (110 in each group) who underwent single-level lumbar surgery. Participants aged 20–80 years with radiating pain due to lumbar disc herniation or spinal stenosis were included in this study. Adverse events were recorded and analyzed over a 12-month follow-up period. Results: The overall adverse event rates were 9.1% (10 of 110) in the BESS group and 17.3% (19 of 110) in the MSS group, which were not statistically significantly different (p=0.133). Notably, wound dehiscence occurred in 8.2% of MSS cases but in none of the BESS cases. Both groups showed similarly low rates of complications, such as dural tears, epidural hematoma, and nerve root injury. The most common adverse event in the BESS group was recurrent disc herniation (2.7%), whereas that in the MSS group was wound dehiscence (8.2%). Conclusion BESS demonstrated a safety profile comparable to that of MSS for the treatment of lumbar disc herniation and spinal stenosis, with a trend towards fewer overall complications. BESS offers particular advantages in terms of reducing wound-related complications. These findings suggest that BESS is a safe alternative to conventional MSS and potentially offers the benefits of a minimally invasive approach without compromising patient safety.

Objective: To compare the safety profiles of biportal endoscopic spinal surgery (BESS) and microscopic spinal surgery (MSS) for lumbar disc herniation and spinal stenosis by analyzing the associated adverse events. Methods: We pooled data from 2 prospective randomized controlled trials involving 220 patients (110 in each group) who underwent single-level lumbar surgery. Participants aged 20–80 years with radiating pain due to lumbar disc herniation or spinal stenosis were included in this study. Adverse events were recorded and analyzed over a 12-month follow-up period. Results: The overall adverse event rates were 9.1% (10 of 110) in the BESS group and 17.3% (19 of 110) in the MSS group, which were not statistically significantly different (p=0.133). Notably, wound dehiscence occurred in 8.2% of MSS cases but in none of the BESS cases. Both groups showed similarly low rates of complications, such as dural tears, epidural hematoma, and nerve root injury. The most common adverse event in the BESS group was recurrent disc herniation (2.7%), whereas that in the MSS group was wound dehiscence (8.2%). Conclusion BESS demonstrated a safety profile comparable to that of MSS for the treatment of lumbar disc herniation and spinal stenosis, with a trend towards fewer overall complications. BESS offers particular advantages in terms of reducing wound-related complications. These findings suggest that BESS is a safe alternative to conventional MSS and potentially offers the benefits of a minimally invasive approach without compromising patient safety.

Methods: In retrospectively collected data, 149 patients who underwent single-level ACDF for degenerative disease were enrolled and divided into non-plating (n=66) and plating (n=83). Interspinous motion (ISM) at the arthrodesis segment, Numeric Rating Scale (NRS) for neck pain, and Neck Disability Index (NDI) were serially evaluated at 3, 6, and 12 months postoperatively. Predictable factors for fusion, including age, sex, plating, diabetes, smoking, and type of grafts, were investigated, and fusion was defined as ISM <1 mm. Results: In both groups, ISM was the highest at 3 months and gradually decreased thereafter, and the plating group showed significantly lower serial ISM than the non-plating group at 12 months. The plating group had lower NRS and NDI scores than the nonplating group at 12 months, and the difference in the NRS scores was statistically significant, particularly at 3 and 6 months, although that of the NDI scores was not. In a multivariate analysis, plating was the most powerful predictor for fusion. Conclusions Plating significantly decreases the serial ISM compared with non-plating in single-level ACDF, and such decreased motion is correlated with decreased neck pain until 12 months postoperatively, particularly at 3 and 6 months. Given that plating was the most predictive factor for fusion, we recommend plating even in single-level ACDF for better early clinical outcomes.

Background: The commercially available design of a three-dimensional (3D)–printed titanium (3D-Ti) cage can be divided into two types according to the presence of a window: a cage with a window that allows filling of bone graft materials and a non-window cage for stand-alone use. This prospective observational case series study aimed to explore the clinical feasibility of using a nonwindow type 3D-Ti cage in cases of combined window and non-window cage implantation. Furthermore, we evaluated the bone in growth patterns of non-window cages and their correlation with published fusion grading systems. Methods: A total of 31 consecutive patients who underwent single-level posterior lumbar interbody fusion surgery were included. Two 3D-Ti cages with different designs were inserted: a non-window cage on the left side and a window cage on the right side.Radiographic fusion was defined by the segmental angle between flexion and extension radiographs (F-E angle) and cage bridging bone (CBB) scores on computed tomography. The association between the F-E angle and osteointegration scoring system including the surface osteointegration ratio (SOR) score was analyzed. Results: Radiographic fusion was achieved in 27 of 31 patients (87%) at 12 months postoperatively. Among the non-window cages, 23 of 31 (74.2%) had fair SOR scores, while 19 of 31 (61.3%) window cages had fair intra-cage CBB scores. The higher the SOR score was, the smaller the flexion-extension angle (SOR 0 vs. SOR 1: 6.30° ± 2.43° vs. 1.95° ± 0.99°, p < 0.001; SOR 0 vs. SOR 2: 6.03° ± 2.43° vs. 0.99°± 0.74°, p < 0.001). Conclusions The clinical feasibility of using a non-window 3D-Ti cage during lumbar interbody fusion might be acceptable. Furthermore, a newly suggested fusion criterion for the use of the non-window cage, the SOR score, showed a significant association with the published fusion grading systems, demonstrating its feasibility in determining interbody fusion in lumbar spinal surgery.

Background: The application of biportal endoscopic spinal surgery (BESS) in spine surgery is increasing. However, the clinical results of related studies have been inconsistent. In this study, the perioperative and clinical outcomes of two techniques in singlelevel lumbar decompression surgery were compared using the perspective of a spine surgeon experienced in microscopic surgery but inexperienced in BESS. Methods: This is a retrospective study performed with prospectively collected data. From April 2019, 50 consecutive patients who underwent a single-level lumbar decompression surgery with BESS were evaluated. Additionally, the data of 150 consecutive patients who underwent the same microscopic surgery before April 2019 were collected. We performed 1 : 1 ratio propensity score matching for these two groups to adjust for baseline variables. The postoperative patient-reported outcome measures included the Oswestry Disability Index (ODI) and numeric rating scale for the back and leg preoperatively and at 6 months after surgery. The laboratory data (C-reactive protein [CRP, mg/L] and hemoglobin [Hb, g/dL]) were measured preoperatively and 3 times (1, 2, and 3 or 4 days) postoperatively. In these periods, the peak and lowest CRP and Hb concentrations were evaluated. The perioperative outcomes, operation time (from skin incision to dressing), length of hospital stay, drainage (for 24 hours after surgery), and surgeryrelated complications were also evaluated. Results: Forty-seven patients (27 men and 20 women) were included in each group. The postoperative 6-month ODI was significantly lower in the BESS group than in the microscope group (6.90 ± 5.98 vs. 11.54 ± 9.70). The peak CRP concentration (16.63 ± 19.41 vs. 42.40 ± 37.73, p < 0.001) and CRP increment (peak CRP minus preoperative CRP, 14.69 ± 19.47 vs. 40.71 ± 37.32, p < 0.001) were significantly higher in the microscope group. Operation time (83.72 ± 35.71 vs. 70.27 ± 23.24, p = 0.047) was significantly longer in the BESS group. Surgery-related complications were found in 6 and 3 cases in the BESS group (3 revisions, 2 dural tears, and 1 conversion to open surgery) and microscope group (2 revisions and 1 hematoma), respectively. Conclusions BESS as a new technique resulted in satisfying short-term outcomes. It was a well-tolerated option for surgical treatment of single-level lumbar degenerative disease. The relatively high incidence of recurrence at the index level and incidental dural tears should be considered for surgeons new to BESS; however, these were manageable complications.

Purpose: An adequate minimal surgical margin for partial nephrectomy (PN) has not yet been conclusively established. Therefore, we aimed to compare PN recurrence rates according to surgical margin status and to establish an adequate minimal surgical margin. Materials and Methods: We retrospectively studied patients with clinically localized renal cell carcinoma who underwent PN between 2005 and 2014. Surgical margin width (SMW) was assessed for all surgical tissues and divided into three groups: SMW <1 mm, SMW ≥1 mm, and positive surgical margin (PSM). The data were analyzed using the Kaplan-Meier method with log-rank tests and multivariate Cox regression models. Results: Of 748 patients (median age, 55 years; interquartile range, 46–64 years; 220 female), 704 (94.2%) and 44 (5.8%) patients had negative and PSMs, respectively. Recurrence-free survival was significantly lower in patients with PSMs (p<0.001) and was not significantly different between SMW ≥1 mm and <1 mm groups (p=0.604). PSM was a significant predictor of recurrence (hazard ratio: 8.03, 95% confidence interval: 2.74–23.56, p<0.001), in contrast to SMW <1 mm (p=0.680). Conclusion A PSM after PN significantly increases the risk of recurrence. We discovered that even a submillimeter safety surgical margin may be enough to prevent recurrence. To maximize normal renal parenchyma preservation and to avoid cancer recurrence in renal parenchymal tumor patients, PN may be a safe treatment, except for those with a PSM in the final pathology.

Purpose: Adjuvant radiotherapy (RT) has been performed to reduce locoregional failure (LRF) following radical cystectomy for locally advanced bladder cancer; however, its efficacy has not been well established. We analyzed the locoregional recurrence patterns of post-radical cystectomy to identify patients who could benefit from adjuvant RT and determine the optimal target volume. Materials and Methods: We retrospectively reviewed 160 patients with stage ≥ pT3 bladder cancer who were treated with radical cystectomy between January 2006 and December 2015. The impact of pathologic findings, including the stage, lympho-vascular invasion, perineural invasion, margin status, nodal involvement, and the number of nodes removed on failure patterns, was assessed. Results: Median follow-up period was 27.7 months. LRF was observed in 55 patients (34.3%), 12 of whom presented with synchronous local and regional failures as the first failure. The most common failure pattern was distant metastasis (40%). Among LRFs, the most common recurrence site was the cystectomy bed (15.6%). Patients with positive resection margins had a significantly higher recurrence rate compared to those without (28% vs. 10%, p=0.004). The pelvic nodal recurrence rate was < 5% in pN0 patients; the rate of recurrence in the external and common iliac nodes was 12.5% in pN+ patients. The rate of recurrence in the common iliac nodes was significantly higher in pN2–3 patients than in pN0–1 patients (15.2% vs. 4.4%, p=0.04). Conclusion Pelvic RT could be beneficial especially for those with positive resection margins or nodal involvement after radical cystectomy. Radiation fields should be optimized based on the patient-specific risk factors.