Ex vivo kidney machine perfusion: meta-analysis of randomized clinical trials.

BACKGROUND: Machine perfusion is an organ preservation strategy used to improve function over simple storage in a cold environment. This article presents an updated systematic review and meta-analysis of machine perfusion in deceased donor kidneys. METHODS: RCTs from November 2018 to July 2023 comparing machine perfusion versus static cold storage in kidney transplantation were evaluated for systematic review. The primary outcome in meta-analysis was delayed graft function. RESULTS: A total 19 studies were included, and 16 comparing hypothermic machine perfusion with static cold storage were analysed. The risk of delayed graft function was lower with hypothermic machine perfusion (risk ratio (RR) 0.77, 95% c.i. 0.69 to 0.86), even in kidneys after circulatory death (RR 0.78, 0.68 to 0.90) or brain death (RR 0.73, 0.63 to 0.84). Full hypothermic machine perfusion decreased the risk of delayed graft function (RR 0.69, 0.60 to 0.79), whereas partial hypothermic machine perfusion did not (RR 0.92, 0.69 to 1.22). Normothermic machine perfusion or short-term oxygenated hypothermic machine perfusion preservation after static cold storage was equivalent to static cold storage in terms of delayed graft function and 1-year graft survival. CONCLUSION: Hypothermic machine perfusion reduces delayed graft function risks and normothermic approaches show promise.

Fusion Length Requiring Spinopelvic Fixation in Lumbosacral Fusion with Anterior Column Support at L5-S1: Assessment of Fusion Status Using Computed Tomography.

Background: The lumbosacral (LS) junction has a higher nonunion rate than other lumbar segments, especially in long-level fusion. Nonunion at L5-S1 would result in low back pain, spinal imbalance, and poor surgical outcomes. Although anterior column support at L5-S1 has been recommended to prevent nonunion in long-level LS fusion, fusion length requiring additional spinopelvic fixation (SPF) in LS fusion with anterior column support at L5-S1 has not been evaluated thoroughly. This study aimed to determine the number of fused levels requiring SPF in LS fusion with anterior column support at L5-S1 by assessing the interbody fusion status using computed tomography (CT) depending on the fusion length. Methods: Patients who underwent instrumented LS fusion with L5-S1 interbody fusion without additional augmentation and CT > 1 year postoperatively were included. The fusion rates were assessed based on the number of fused segments. Patients were divided into two groups depending on the L5-S1 interbody fusion status: those with union vs. those with nonunion. Binary logistic regression analyses were performed to identify risk factors for LS junctional nonunion. Results: Fusion rates of L5-S1 interbody fusion were 94.9%, 90.3%, 80.0%, 50.0%, 52.6%, and 43.5% for fusion of 1, 2, 3, 4, 5, and ≥ 6 levels, respectively. The number of spinal levels fused ≥ 4 (p < 0.001), low preoperative bone mineral density (BMD; adjusted odds ratio [aOR], 0.667; p = 0.035), and postoperative pelvic incidence (PI) - lumbar lordosis (LL) mismatch (aOR, 1.034; p = 0.040) were identified as significant risk factors for nonunion of L5-S1 interbody fusion according to the multivariate logistic regression analysis. Conclusions: Exhibiting ≥ 4 fused spinal levels, low preoperative BMD, and large postoperative PI-LL mismatch were identified as independent risk factors for nonunion of anterior column support at L5-S1 in LS fusion without additional fixation. Therefore, SPF should be considered in LS fusion extending to or above L2 to prevent LS junctional nonunion.

In vivo Comparison of Positive Microbial Culture by Wound Irrigation Methods: Biportal Endoscopic versus Open Microscopic Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: This study aimed to evaluate the risk factors and prevalence of intraoperative contamination (IoC) through the microbial culture of superficial and deep samples obtained during surgery. SUMMARY OF BACKGROUND DATA: Surgical site infection (SSI) in spinal surgery is a serious complication. The prevalence of IoC may differ based on surgical approach and technique, even in the setting of the same procedure. METHODS: In this in-vivo study, microbial cultivation was performed with superficial (ligamentum flavum, LF) and deep (nucleus pulposus, NP) surgical specimens to evaluate IoC in 132 patients undergoing single-level transforaminal lumbar interbody fusion (TLIF). Biportal endoscopic (BE) TLIF was performed under continuous wound irrigation (group A, n=66), whereas open microscopic (OM) TLIF was performed under intermittent wound irrigation (group B, n=66). LF and NP specimens were homogenized, gram-stained, and cultured in aerobic and anaerobic media for 14 days. Microbial culture results and occurrence of SSI in the two groups were assessed. The Chi-square test and Fisher's exact test were used to determine significant differences among categorical variables. Logistic regression analysis was used to assess the influence of patient characteristics on the prevalence of positive microbial cultures. RESULTS: Of the 132 patients, 34 (25.8%) had positive microbial cultures, and positive culture required an incubation period of 72 h to 2 weeks in all these patients except for three. Overall positive culture was significantly higher in group B than in group A (P=0.029). The subgroups of LF- and NP-positive cultures were 18.18% (n=24) and 12.88% (n=17), respectively; the SSI was 0.76% (n=1). Group A had a significantly lower subgroup of NP-positive culture than group B (P=0.035). OM technique was an independent risk factor associatd with overall positive culture (P<0.05). The most common microorganism was Cutibacterium acnes (C. acnes). CONCLUSION: BE-TLIF with continuous wound irrigation showed significantly lower overall, and NP-positive cultures, than OM-TLIF with intermittent irrigation. The most common strain of positive culture was C. acnes. LEVEL OF EVIDENCE: II.

Biportal endoscopic discectomy versus tubular microscopic discectomy for treating single-level lumbar disc herniation in obese patients: a multicenter, retrospective analysis.

PURPOSE: In microscopic lumbar discectomy in obese patients, a correlation is found between the operation time and increase in estimated blood loss according to the increase in body mass index; however, no studies have investigated the outcomes of biportal endoscopic lumbar discectomy in obese patients. Therefore, this study aimed to compare the clinical and radiographic outcomes of microscopic and endoscopic discectomy in obese patients with lumbar herniated discs. METHODS: In this multicenter, retrospective study, clinical and radiological data were compared and analyzed in 73 obese patients with a body mass index of > 30 kg/m2 who underwent microscopic or biportal endoscopic lumbar discectomy. Clinical data on the visual analog scale (VAS), Oswestry disability index (ODI), and EuroQol-5D (EQ-5D) scores were measured, and radiological data were obtained using magnetic resonance imaging (MRI). RESULTS: This study enrolled 43 patients who underwent microscopic discectomy and 30 who underwent biportal endoscopic discectomy. The VAS, ODI, and EQ-5D scores in both groups improved after surgery compared with those before surgery, although there was no difference between the two groups. Although there was a difference in the incidence of recurrent disc herniation confirmed by MRI after surgery, no difference was found in the number of patients requiring surgery between the two groups. CONCLUSION: In obese patients with lumbar disc herniation that was not improved with conservative treatment, no significant clinical or radiological differences in outcomes were noted between microscopic and biportal endoscopic surgery methods. In contrast, minor complications were less common in the biportal group.

Biportal endoscopic paraspinal decompressive foraminotomy for lumbar foraminal stenosis: clinical outcomes and factors influencing unsatisfactory outcomes.

BACKGROUND: Lumbar foraminal stenosis (LFS) is an important pathologic entity that causes lumbar radiculopathies. Unrecognized LFS may be associated with surgical failure, and LFS remains challenging to treat surgically. This retrospective cohort study aimed to evaluate the clinical outcomes and prognostic factors of decompressive foraminotomy performed using the biportal endoscopic paraspinal approach for LFS. METHODS: A total of 102 consecutive patients with single-level unilateral LFS who underwent biportal endoscopic paraspinal decompressive foraminotomy were included. We evaluated the Visual Analogue Scale (VAS) score and the Oswestry Disability Index (ODI) before and after surgery. Demographic, preoperative data, and radiologic parameters, including the coronal root angle (CRA), were investigated. The patients were divided into Group A (satisfaction group) and Group B (unsatisfaction group). Parameters were compared between these two groups to identify the factors influencing unsatisfactory outcomes. RESULTS: In Group A (78.8% of patients), VAS and ODI scores significantly improved after biportal endoscopic paraspinal decompressive foraminotomy (p < 0.001). However, Group B (21.2% of patients) showed higher incidences of stenosis at the lower lumbar level (p = 0.009), wide segmental lordosis (p = 0.021), and narrow ipsilateral CRA (p = 0.009). In the logistic regression analysis, lower lumbar level (OR = 13.82, 95% CI: 1.33-143.48, p = 0.028) and narrow ipsilateral CRA (OR = 0.92, 95% CI: 0.86-1.00, p = 0.047) were associated with unsatisfactory outcomes. CONCLUSIONS: Significant improvement in clinical outcomes was observed for a year after biportal endoscopic paraspinal decompressive foraminotomy. However, clinical outcomes were unsatisfactory in 21.2% of patients, and lower lumbar level and narrow ipsilateral CRA were independent risk factors for unsatisfactory outcomes.

Stercoral Ulcer Presenting in a Patient with Cauda Equina Syndrome Secondary to Postoperative Epidural Hematoma.

Chronic constipation can lead to fecal impaction in the large bowel, which can cause pressure necrosis followed by perforation, known as a stercoral ulcer. In extensive posterior thoracolumbar surgery, a long operation time, large blood loss, and perioperative narcotic use may aggravate constipation. Moreover, sacral root palsy due to cauda equina syndrome (CES) can lead to the deterioration of fecal impaction. This report describes the case of a 77-year-old woman with CES who presented with saddle anesthesia, neurogenic bladder, bowel incontinence, and paraplegia. Five days prior, she had undergone extended posterior lumbar interbody fusion from L1 to L5. Lumbar magnetic resonance imaging (MRI) showed an extended epidural hematoma. After urgent neural decompression, she gradually recovered from the saddle anesthesia, leg pain, and paraplegia over 3 weeks. Thereafter, the patient suddenly developed massive hematochezia and hemorrhagic shock. Urgent colonoscopy was performed, and a stercoral ulcer in the sigmoid colon was diagnosed. After 4 weeks of intensive care for hemorrhagic shock, pneumonia, and systemic sepsis, the patient was transferred to a general ward for intensive rehabilitation. One year after the operation, she was able to walk with assistance, and her urinary and bowel incontinence completely recovered. Chronic constipation, a common clinical problem, can sometimes cause relatively obscure but potentially life-threatening complications such as stercoral ulceration. Possible factors including advanced age, extensive spinal surgeries, prolonged operation time, significant blood loss, perioperative narcotic use, and the presence of spinal cord injury might contribute to the development of this condition. It highlights the importance of recognizing the potential development of stercoral ulcers in patients with CES and emphasizes the need for prompt diagnosis and management to avert catastrophic complications.

Safe Optimal Tear Drop View for Spinopelvic Fixation Using a Three-Dimensional Reconstruction Model of the Pelvis.

Background: Spinopelvic fixation (SPF) has been a challenge for surgeons despite the advancements in instruments and surgical techniques. C-arm fluoroscopy-guided SPF is a widely used safe technique that utilizes the tear drop view. The tear drop view is an image of the corridor from the posterior superior iliac spine to the anterior inferior iliac spine (AIIS) of the pelvis. This study aimed to define the safe optimal tear drop view using three-dimensional reconstruction of computed tomography images. Methods: Three-dimensional reconstructions of the pelvises of 20 individuals were carried out. By rotating the reconstructed model, we simulated SPF with a cylinder representing imaginary screw. The safe optimal tear drop view was defined as the one embracing a corridor with the largest diameter with the inferior tear drop line not below the acetabular line and the lateral tear drop line medial to the AIIS. The distance between the lateral border of the tear drop and AIIS was defined as tear drop index (TDI) to estimate the degree of rotation on the plane image. Tear drop ratio (TDR), the ratio of the distance between the tear drop center and the AIIS to TDI, was also devised for more intuitive application of our simulation in a real operation. Results: All the maximum diameters and lengths were greater than 9 mm and 80 mm, respectively, which are the values of generally used screws for SPF at a TDI of 5 mm and 10 mm in both sexes. The TDRs were 3.40 ± 0.41 and 3.35 ± 0.26 in men and women, respectively, at a TDI of 5 mm. The TDRs were 2.26 ± 0.17 and 2.14 ± 0.12 in men and women, respectively, at a TDI of 10 mm. Conclusions: The safe optimal tear drop view can be obtained with a TDR of 2.5 to 3 by rounding off the measured values for intuitive application in the actual surgical field.

Biportal endoscopic extraforaminal lumbar interbody fusion using a 3D-printed porous titanium cage with large footprints: technical note and preliminary results.

PURPOSE: The aim of this study was to introduce biportal endoscopic extraforaminal lumbar interbody fusion (BE-EFLIF), which involves insertion of a cage through a more lateral side as compared to the conventional corridor of transforaminal lumbar interbody fusion. We described the advantages and surgical steps of 3D-printed porous titanium cage with large footprints insertion through multi-portal approach, and preliminary results of this technique. METHODS: This retrospective study included 12 consecutive patients who underwent BE-EFLIF for symptomatic single-level lumbar degenerative disease. Clinical outcomes, including a visual analog scale (VAS) for back and leg pain and the Oswestry disability index (ODI), were collected at preoperative months 1 and 3, and 6 months postoperatively. In addition, perioperative data and radiographic parameters were analyzed. RESULTS: The mean patient age, follow-up period, operation time, and volume of surgical drainage were 68.3 ± 8.4 years, 7.6 ± 2.8 months, 188.3 ± 42.4 min, 92.5 ± 49.6 mL, respectively. There were no transfusion cases. All patients showed significant improvement in VAS and ODI postoperatively, and these were maintained for 6 months after surgery (P < 0.001). The anterior and posterior disc heights significantly increased after surgery (P < 0.001), and the cage was ideally positioned in all patients. There were no incidences of early cage subsidence or other complications. CONCLUSIONS: BE-EFLIF using a 3D-printed porous titanium cage with large footprints is a feasible option for minimally invasive lumbar interbody fusion. This technique is expected to reduce the risk of cage subsidence and improve the fusion rate.

Learning curve for biportal endoscopic posterior cervical foraminotomy determined using the cumulative summation test.

BACKGROUND: Learning curves describe the rate of performance improvements corresponding to the surgeon's caseload, followed by a plateau where limited further improvements are observed. This study aimed to determine the learning curve for biportal full-endoscopic posterior cervical foraminotomy (BE-PCF) for the unilateral cervical foraminal disc. METHODS: The learning curve was evaluated using a learning curve cumulative summation test (LC-CUSUM). The goal for the operation time was set to 78 min, which is the mean operation time (mOT) of percutaneous full-endoscopic posterior cervical foraminotomy (PE-PCF) performed by a senior surgeon. Moreover, clinical outcomes and post-operative complications were compared between the early and late learning periods 1 year post-operatively. RESULTS: This study enrolled the first 50 patients who underwent single-level BE-PCF, performed by a single surgeon. The LC-CUSUM signalled competency for surgery at the 20th operation, indicating that sufficient evidence was obtained to prove that the surgeon was competent. The mOT was 71.29 ± 11.69 min in BE-PCF, 71.84 ± 12.61 min in the early learning period, and 67.83 ± 10.31 min in the late learning period (p = 0.254). There was no statistical difference in clinical outcomes, visual analogue scale scores, and neck disability index between both periods (p > 0.05). Four complications were recorded throughout the whole period, with three in the early period and one in the late period (p = 0.285). CONCLUSION: Our study shows that BE-PCF has a learning curve of 20 caseloads to achieve 90% proficiency, and it significantly reduces the operation time based on the performance of a senior surgeon proficient in PE-PCF.

Oblique Lumbar Interbody Fusion with Selective Biportal Endoscopic Posterior Decompression for Multilevel Lumbar Degenerative Diseases.

Oblique lumbar interbody fusion is a minimally invasive procedure for treating degenerative lumbar disease. Its advantages include correcting coronal and sagittal spinal alignment and indirect neural decompression. However, achieving a successful outcome is limited in some patients who need direct decompression for central canal lesions including hard stenotic lesions (endplate or facet articular osteophytes and ossification of posterior longitudinal ligaments) and sequestration of the disk. Biportal endoscopic spinal surgery is a minimally invasive technique, which directly decompresses the lesion. By taking advantage of two procedures, in a longlevel lumbar lesion, alignment correction and direct decompression can be both achieved. Herein, the authors introduce multilevel lumbar fusion through oblique lumbar interbody fusion and selective direct decompression through biportal endoscopic spinal surgery and discuss the surgical indications, surgical pitfalls, and recommendations for application. Consequently, it is regarded as a minimally invasive interbody fusion method for patients with multilevel lumbar degenerative degeneration.

Altered hearing function in mice with implanted cranial windows.

The cranial window technique has proven to be an effective method for in vivo imaging of cortical activity. However, given the invasive nature of this procedure, possible side effects could be expected in the nervous system. In this study, we evaluated the effects of unilateral cranial window surgery on auditory function in C57BL6 mice using electrophysiological and behavioral approaches. We found that one week after implantation, mice exhibited both increased thresholds and decreased amplitudes of their auditory brainstem responses. These changes were accompanied by a decrease in distortion product otoacoustic emissions, indicating a deterioration in cochlear function. In addition, behavioral testing of these mice revealed reduced suppression of their acoustic startle response by gap prepulse, suggesting a deficit in auditory processing or possibly the presence of tinnitus. The changes in auditory function appeared to be only partially reversible within four weeks after surgery. Thus, our findings suggest that cranial window implantation causes long-term functional changes in the auditory system that should be considered when interpreting data from optical imaging techniques.

Clinical and radiologic outcomes of biportal endoscopic lumbar discectomy in obese patients: a retrospective case-control study.

BACKGROUND: Obese patients have a higher risk of complications during spinal surgery than non-obese patients. To the best of our knowledge, no studies have examined the differences in clinical and radiological outcomes after biportal endoscopic lumbar discectomy (BELD) between obese and non-obese patients. The study evaluated the association between obesity and outcomes after BELD in patients with lumbar disc herniation. METHODS: This was a retrospective case-control study conducted from March 2017 to March 2021 at two hospitals with 360 patients who underwent BELD after showing no improvement with conservative treatment. Clinical and radiologic outcomes were retrospectively analyzed after BELD in the non-obese (body mass index [BMI] < 30 kg/m2) and obese (BMI ≥ 30 kg/m2) groups. Demographic data and surgery-related factors were compared between the two groups. Clinical outcomes were followed up for 12 months after surgery and analyzed for differences. RESULTS: A total of 211 patients were enrolled in this study, and through case-control matching, the data of 115 patients (29, obese group; 86, non-obese group) were analyzed. The two groups showed no significant differences in Oswestry Disability Index, European Quality of Life-5 Dimensions (EQ-5D), and visual analog scale scores measured immediately after BELD and 12 months after surgery. After surgery, back pain, radiating leg pain, and EQ-5D scores improved. However, there was no significant difference in improvement, residual herniated disc, hematoma, or recurrence between the groups. CONCLUSIONS: Obese patients who underwent BELD for lumbar disc herniation showed no significant difference in clinical and radiologic outcomes compared with non-obese patients.

Percutaneous Full-Endoscopic versus Biportal Endoscopic Posterior Cervical Foraminotomy for Unilateral Cervical Foraminal Disc Disease.

Background: The biportal endoscopic technique (BE) is a fast-growing surgical modality that can be applied to posterior cervical foraminotomy (PCF), as well as lumbar discectomy and decompressive laminectomy. It has several technical differences from the percutaneous full-endoscopic technique (PE), which has been standardized as the representative endoscopic spinal surgery technique. The purpose of this study was to compare the short-term clinical outcomes between BE-PCF and PE-PCF. Methods: A retrospective review was conducted on 66 patients who had single-level unilateral cervical foraminal disc disease (UCFD). All patients underwent PE- or BE-PCF. Clinical outcomes including visual analog scale (VAS)-arm, VAS-neck, and Neck Disability Index (NDI) were evaluated. Perioperative data including operation time, length of hospital stay (LOS), amount of surgical drain, postoperative complications, and reoperation were collected. Serum creatine phosphokinase (CPK) and C-reactive protein (CRP) levels were recorded. Results: A total of 65 patients were included in the final analysis: 32 with PE-PCF and 33 with BE-PCF. There was no statistically significant difference in demographic and preoperative data between the two groups. All patients had significant improvement in VAS-arm, VAS-neck, and NDI compared to the baseline value. The improvement of all parameters was comparable between the two groups at each point for 1 year after surgery (p > 0.05), except for the significantly lower VAS-neck at postoperative 2 days in PE-PCF (p = 0.005). The total operation time was significantly shorter in BE-PCF (p = 0.036). There were no statistically significant differences between the two groups in regard to LOS, amount of surgical drain, and serum CPK and CRP levels (p > 0.05). Reoperation and complications between the two groups were comparable (p > 0.05). Conclusions: The 1-year postoperative clinical outcomes of PE-PCF and BE-PCF for cervical pain and disability caused by UCFD were good and comparable. PE-PCF resulted in significantly less immediate postoperative neck pain, but BE-PCF required shorter total operation time.

Comparing the efficacy and safety of minimally invasive biportal endoscopic spine surgery versus conventional microscopic discectomy in single-level lumbar herniated intervertebral disc (ENDO-BH Trial): a multicenter, prospective, randomized controlled equivalence trial study protocol.

BACKGROUND: Biportal endoscopic surgery has recently been performed in lumbar discectomy, with advantages over conventional surgery, such as less skin scarring and muscle damage. However, the clinical results have not been established. Although previous studies reported no difference between the biportal endoscopic and microscopic discectomy clinical results, the evidence was weak. Therefore, this study aims to evaluate the efficacy and safety of the biportal endoscopic discectomy versus the microscopic discectomy. METHODS: This prospective multicenter randomized controlled equivalence trial is designed to compare the efficacy and safety outcomes of patients who underwent lumbar discectomy using biportal endoscopy or microscopy. We will include 100 participants (50 per group) with a lumbar herniated disc. The primary outcome will be the Oswestry Disability Index (ODI) score 12 months after surgery based on a modified intention-to-treat strategy. The secondary outcomes will include the visual analog scale score for low back and lower extremity radiating pain, the ODI score, the Euro-Qol-5-Dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scar, and surgery-related variables, such as postoperative drainage, operation time, admission duration, postoperative creatine kinase, and implementation status of conversion to open surgery. Radiographic outcomes will also be analyzed using magnetic resonance imaging (MRI) or computed tomography (CT) and simple radiographs. Safety will be assessed by evaluating all adverse and severe adverse events and surgery-related effects. The participants will be assessed by a blinded assessor before surgery (baseline) and 2 weeks and 3, 6, and 12 months after surgery. DISCUSSION: This trial will be the first prospective, multicenter, randomized controlled trial to analyze the efficacy and safety of biportal endoscopic discectomy in lumbar herniated disc. This trial is designed for evaluating the equivalence of the results between biportal endoscopic and microscopic discectomy including adequate sample size, blinded analyses, and prospective registration to reduce bias. This trial will provide enough data on the effectiveness and safety of biportal endoscopic surgery and will be an important study that allows clear conclusions. TRIAL REGISTRATION: Clinical Research Information Service (cris.nih.go.kr.) ( KCT0006191 ). Registered on 27 March 2021.

Evaluation of the efficacy and safety of conventional and biportal endoscopic decompressive laminectomy in patients with lumbar spinal stenosis (ENDO-B trial): a protocol for a prospective, randomized, assessor-blind, multicenter trial.

BACKGROUND: Recent studies on biportal endoscopic spine surgery in patients with lumbar spinal stenosis have reported good clinical results. However, these studies have been limited by the small sample sizes and use of a retrospective study design. Therefore, we aim to compare the efficacy and safety of biportal endoscopic decompressive laminectomy with those of conventional decompressive laminectomy in a multicenter, prospective, randomized controlled trial. METHODS: This study will include 120 patients (60 per group, aged 20-80 years) with 1- or 2-level lumbar spinal stenosis, who will be recruited from six hospitals. The study will be conducted from July 2021 to December 2024. The primary outcome (Oswestry Disability Index at 12 months after surgery) will be evaluated through a modified intention-to-treat method. The secondary outcomes will include the following: visual analog scale score for low back and lower extremity radiating pain, EuroQol 5-dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scars, and some surgery-related variables. Radiographic outcomes will be analyzed using magnetic resonance imaging or computed tomography. All outcomes will be evaluated before the surgery and at 2 weeks, 3 months, 6 months, and 12 months postoperatively. This protocol adheres to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines for reporting of clinical trial protocols. DISCUSSION: It is hypothesized that the efficacy and safety of biportal endoscopic and conventional decompressive laminectomy will be comparable in patients with lumbar spinal stenosis. The results of this trial will provide a high level of evidence for the efficacy and safety of the biportal endoscopic technique in patients with lumbar spinal stenosis and facilitate the development of clinical practice guidelines. Furthermore, the results of this study may indicate the feasibility of the biportal endoscopic technique for other types of spinal surgery. TRIAL REGISTRATION: The ENDO-B trial is registered at Clinical Research Information Service (CRIS, cris.nih.go.kr ) (KCT0006057; April 52,021).

Biportal endoscopic posterior lumbar decompression and vertebroplasty for extremely elderly patients affected by lower lumbar delayed vertebral collapse with lumbosacral radiculopathy.

BACKGROUND: Lower lumbar osteoporotic vertebral compression fracture in extremely elderly patients can often lead to lumbosacral radiculopathy (LSR) due to delayed vertebral collapse (DVC). Surgical intervention requires posterior instrumented lumbar fusion as well as vertebral augmentation or anterior column reconstruction depending on the cleft formation and intravertebral instability. However, it is necessary to decide on surgery in consideration of the patient's frail status, surgical invasiveness, and rehabilitation. In the lower lumbar DVC without intravertebral instability, biportal endoscopic posterior lumbar decompression and vertebroplasty (BEPLD + VP) can be simultaneously attempted. This study aimed to assess the clinical outcomes of BEPLD + VP for the treatment of DVC-related LSR. METHODS: This retrospective case series enrolled 18 consecutive extremely elderly (aged ≥ 75-year-old) patients (6 men and 12 women) who had lower lumbar (at or below L3) DVC-related LSR. Patients who require anterior column reconstruction, such as cleft formation accompanied by intravertebral instability and patients who have not been followed for more than 6 months, were excluded from this study. All patients underwent BEPLD + VP under epidural anesthesia. Clinical results were evaluated by the visual analog scale (VAS) score and the modified Japanese Orthopedic Association (mJOA) scores. RESULTS: Most of the patients had DVC affecting level L4, with the deformation being a flat type or concave type rather than a wedge type. The VAS score (back and leg) significantly decreased from 7.78 ± 1.17 and 6.89 ± 1.13 preoperatively to 2.94 ± 0.64 and 2.67 ± 1.08 within 2 postoperative days (p < 0.001). The mJOA score significantly improved from 4.72 ± 1.27 preoperatively to 8.17 ± 1.15 in the final follow-up (p < 0.001). The mean recovery rate (RR) in the last follow-up was 56.07% ± 9.98. Incidental durotomy was reported in two patients and epidural hematomas in another two patients; however, all patients improved with conservative treatment, and no re-operation was required. CONCLUSIONS: BELPD + VP was a type of salvage therapy that reduces surgical morbidity, requires major spine surgery under general anesthesia and provides good clinical outcomes in extremely elderly patients with DVC-related LSR.

Minimally invasive transforaminal lumbar interbody fusion using the biportal endoscopic techniques versus microscopic tubular technique.

BACKGROUND CONTEXT: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with microscopic tubular technique is an established surgical procedure with several potential advantages, including decreased surgical-related morbidity, reduced length of hospital stay, and accelerated early rehabilitation. A recently introduced biportal endoscopic technique for spine surgery presents familiar surgical anatomy and can be conducted using a conventional approach with a minimal footprint; it is also applicable to TLIF. PURPOSE: To compare the clinical and radiological outcomes of biportal endoscopic technique transforaminal lumbar interbody fusion (BE-TLIF) and microscopic tubular technique transforaminal lumbar interbody (MT-TLIF) in patients with single- or two-segment lumbar spinal stenosis with or without spondylolisthesis. STUDY DESIGN: A retrospective cohort study. PATIENT SAMPLE: One hundred two participants with neurogenic intermittent claudication or lumbar radiculopathy with single- or two-level lumbar spinal stenosis with or without spondylolisthesis. OUTCOME MEASURES: Clinical outcomes were assessed using the visual analog scale (VAS) score for the back and leg pain, Oswestry Disability Index (ODI), and the Short Form-36 health survey Questionnaire (SF-36). Demographic data, operative data (total operation time, estimated blood loss, amount of surgical drain, postoperative transfusion, and length of hospital stay), and laboratory results (plasma hemoglobin, serum creatine phosphokinase, and C-reactive protein) were also evaluated. The fusion rate was assessed using the Bridwell interbody fusion grading system. Postoperative complications were also noted. METHODS: Patients were divided into two groups: group A (BE-TLIF) and group B (MT-TLIF). The clinical outcomes, including VAS-Back and VAS-Leg, ODI, and SF-36 scores, were evaluated at 1 month, 6 months, and 1 year after surgery. Differences in demographics, operative data, and the laboratory and radiological results were assessed between the two groups. The fusion rate was assessed using standard standing lumbar radiographs and computed tomography scans conducted 1 year after surgery. RESULTS: Seventy-nine patients were analyzed in this study, 47 from group A and 32 from group B. Demographic and operative data were comparable for both the groups. The VAS-Back and SF-36 scores were more significantly improved in group A than in group B at 1 month after surgery. However, there were no significant differences between groups for the mean VAS-Back, VAS-Leg, ODI, and SF-36 scores at 1year after the surgery. Although the total operation time was significantly longer in group A, the estimated blood loss and the amount of surgical drainage was significantly higher in group B (p < .001). There were no between-group differences for the fusion rate and postoperative complications. CONCLUSION: Both BE-TLIF and MT-TLIF provided equivalent and favorable clinical outcomes and fusion rates. Further large-scale, randomized, controlled trials with long-term follow-ups are warranted.

THE NATIONWIDE INCIDENCE OF RETINAL ARTERY OCCLUSION FOLLOWING DIALYSIS AS A RESULT OF END-STAGE RENAL DISEASE: 2004 Through 2013.

PURPOSE: To examine the incidence and risk of retinal artery occlusion (RAO) in patients who have undergone dialysis in Korea. METHODS: A nationwide, population-based study using South Korean national health insurance data from 2004 to 2013 was used for analysis. All patients who began dialysis between 2004 and 2013 and the same number of control subjects were selected via propensity score matching. The incidence of RAO in the dialysis and control cohorts was calculated for 2004 to 2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to evaluate the risk of developing RAO in dialysis patients. Cumulative RAO incidence curves were generated using the Kaplan-Meier method. Whether dialysis modalities influenced the incidence of RAO was also evaluated. RESULTS: Seventy-six thousand seven hundred and eighty-two end-stage renal disease patients on dialysis were included in the dialysis cohort, and 76,782 individuals were included in the control cohort. During the study period, 293 patients in the dialysis cohort and 99 patients in the control cohort developed RAO. The person-years incidence of RAO was significantly higher in the dialysis cohort than in the control cohort (dialysis = 1.1/1,000 person-years; control = 0.3/1,000 person-years; P < 0.001). The incidence of RAO was not significantly different between the two methods of dialysis (hemodialysis vs. peritoneal dialysis; P = 0.25, log-rank test). CONCLUSION: The current study provided epidemiological evidence that undergoing dialysis for end-stage renal disease was associated with an increased risk of developing RAO. The incidence of RAO rapidly increased as the duration of dialysis increased. These results strengthen the significant role of the renal function in retinal vascular disease.

Renin-angiotensin system modulators and other risk factors in COVID-19 patients with hypertension: a Korean perspective.

BACKGROUND: While hypertension is the most common comorbid condition in patients with coronavirus disease 2019 (COVID-19) in Korea, there is a lack of studies investigating risk factors in COVID-19 patients with hypertension in Korea. In this study, we aimed to examine the effects risk factors in hypertensive Korean COVID-19 patients. METHODS: We selected patients from the database of the project #OpenData4Covid19. This information was linked to their 3-year historical healthcare data. The severity of the disease was classified into five levels. We also clustered the levels into two grades. RESULTS: The risk factors associated with COVID-19 severity were old age, diabetes mellitus, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), malignancy, and renal replacement therapy. The use of angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) both before and after a diagnosis of COVID-19 were not associated with COVID-19 severity. A multivariate analysis revealed that old age, male sex, diabetes mellitus, and renal replacement therapy were risk factors for severe COVID-19. CONCLUSION: The results suggest that in hypertensive patients with COVID-19, older age, male sex, a diagnosis of diabetes mellitus, and renal replacement therapy were risk factors for a severe clinical course. In addition, the use of ARBs and ACEIs before or after COVID-19 infection did not affect a patient's risk of contracting COVID-19 nor did it contribute to a worse prognosis for the disease. These results highlighted that precautions should be considered for hypertensive patients with those risk factors and do not support discontinuation of ARBs and ACEIs during COVID-19 pandemic.

Biportal Endoscopic Technique for Transforaminal Lumbar Interbody Fusion: Review of Current Research.

BACKGROUND: There are many types of minimally invasive lumbar interbody fusion procedures. Among them is the recently introduced biportal endoscopic lumbar interbody fusion surgery. Biportal endoscopic transforaminal lumbar interbody fusion (TLIF) might combine the advantages of minimally invasive TLIF and endoscopic spine approaches. However, clinical evidence in support of biportal endoscopic TLIF remains insufficient. METHODS: A comprehensive review of English-language literature on biportal endoscopic lumbar interbody fusion was performed. Articles on biportal endoscopic TLIF in PubMed, the Cochrane Library, and Web of Science were searched using the terms "unilateral biportal endoscopy," "biportal endoscopic spine surgery," "transforaminal," and "lumbar interbody fusion" as well as their combinations. The clinical and radiological outcomes of biportal endoscopic TLIF were analyzed and are summarized here. The biportal endoscopic lumbar interbody fusion surgical techniques are then described. RESULTS: There are 3 biportal endoscopic TLIF techniques. In the available literature, the postoperative 1-year outcomes of biportal endoscopic TLIF were comparable to those of posterior lumbar interbody fusion (PLIF) and minimally invasive (MIS)-TLIF. Clinical parameters were significantly improved after biportal endoscopic TLIF. Compared to PLIF or MIS-TLIF, biportal endoscopic-TLIF may have the advantage of a faster recovery. Biportal endoscopic TLIF showed no inferiority in fusion rates compared to PLIF or MIS-TLIF. The postoperative complications were usually minor. CONCLUSIONS: The postoperative 1-year clinical and radiological outcomes of biportal endoscopic TLIF were favorable compared to those of PLIF and MIS-TLIF. However, long-term outcomes should be investigated through prospective, randomized controlled trials in the future. CLINICAL RELEVANCE: This review article outlines the most current evidence-based medicine with regard to spinal surgery with an aim to introduce a new technique.