Bibliometric analysis and description of research trends on transforaminal full-endoscopic approach on the spine for the last two-decades.

OBJECTIVE: The study aims to assess the current development status of transforaminal full-endoscopic spine surgery (TFES) by exploring and analyzing the published literature to obtain an overview of this field and discover the evolution and emerging topics that are underrepresented. METHODS: Using Bibliometrix, CiteSpace, and VOSviewer, we analyzed the bibliometric data selected from the Web of Science Core Collection between January 2002 and November 2022. The descriptive and evaluative analyses of authors, institutes, countries, journals, keywords, and references are compiled. The quantity of research productivity was measured by the number of publications that were published. A quality indicator was thought to be the number of citations. In the bibliometric analysis of authors, areas, institutes, and references, we calculated and ranked the research impact by various metrics, such as the h-index and m-index. RESULTS: A total of 628 articles were identified in the field of TFES by the 18.73% annual growth rate of research on the subject from 2002 to 2022, constituting the documents are by 1961 authors affiliated with 661 institutions in 42 countries or regions and published in 117 journals. The USA (n = 0.20) has the highest international collaboration rate, South Korea has the highest H-index value (h = 33), and China is ranked as the most productive country (n = 348). Brown univ., Tongji univ., and Wooridul Spine represented the most productive institutes ranked by the number of publications. Wooridul Spine Hospital demonstrated the highest quality of paper publication. The Pain Physician had the highest h-index (n = 18), and the most cited journal with the earliest publication year in the area of FEDS is Spine (t = 1855). CONCLUSION: The bibliometric study showed a growing trend of research on transforaminal full-endoscopic spine surgery over the past 20 years. It has shown a significant increase in the number of authors, institutions, and international collaborating countries. South Korea, the United States, and China dominate the related areas. A growing body of evidence has revealed that TFES has leapfrogged from its infancy stage and gradually entered a mature development stage.

Association between PAI-1 Polymorphisms and Ischemic Stroke in a South Korean Case-Control Cohort.

Stroke is the second leading cause of death in the world. Approximately 80% of strokes are ischemic in origin. Many risk factors have been linked to stroke, including an increased level of plasminogen activator inhibitor-1 (PAI-1). PAI-1 levels increase and remain elevated in blood during the acute phase of ischemic stroke, which can impair fibrinolytic activity, leading to coronary artery disease and arterial thrombotic disorders. Here, we present a case-control study of 574 stroke patients and 425 controls seen for routine health examination or treatment for nonspecific dizziness, nonorganic headache, or anxiety for positive family history of stroke at the Bundang Medical Center in South Korea. Polymorphisms in PAI-1 were identified by polymerase chain reaction/restriction fragment length polymorphism analysis using genomic DNA. Specifically, three variations (-675 4G>5G, 10692T>C, and 12068G>A) were linked to a higher overall prevalence of stroke as well as a higher prevalence of certain stroke subtypes. Haplotype analyses also revealed combinations of these variations (-844G>A, -675 4G>5G, 43G>A, 9785A>G, 10692T>C, 11053T>G, and 12068G>A) that were significantly associated with a higher prevalence of ischemic stroke. To the best of our knowledge, this is the first strong evidence that polymorphic sites in PAI-1 promoter and 3'-UTR regions are associated with higher ischemic stroke risk. Furthermore, the PAI-1 genotypes and haplotypes identified here have potential as clinical biomarkers of ischemic stroke and could improve the prognosis and future management of stroke patients.

Abducens nerve palsy as a postoperative complication of minimally invasive thoracic spine surgery: a case report.

BACKGROUND: Thoracic disc surgeries make up only a small number of all spine surgeries performed, but they can have a considerable number of postoperative complications. Numerous approaches have been developed and studied in an attempt to reduce the morbidity associated with the procedure; however, we still encounter cases that develop serious and unexpected outcomes. CASE PRESENTATION: This case report presents a patient with abducens nerve palsy after minimally invasive surgery for thoracic disc herniation with an intraoperative spinal fluid fistula. A literature review of all cases related to this complication after spine surgery is included. Despite the uncommon nature of this type of complication, understanding the procedure itself, the principle occurrences and outcomes following the procedure, the physiopathogical features of abducens nerve palsy, and the possible adverse effects of spinal surgery, including minimally invasive procedures, can enable an early diagnosis of complications and facilitate the procedure. CONCLUSIONS: In spite of being very rare and multifactorial, uni- or bilateral abducens nerve paralysis carries significant morbidity and can occur as a postoperative complication after conventional or minimally invasive spine surgery. This condition requires an accurate diagnosis and adequate multidisciplinary follow up.

The maintenance mechanism of hematopoietic stem cell dormancy: role for a subset of macrophages.

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in nichemediated LT-HSC maintenance. KAI1 activates TGF-ß1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LTHSCs that regulates dormancy through interaction with DARCexpressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LTHSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia. [BMB Reports 2023; 56(9): 482-487].

Full-Endoscopic Lumbar Discectomy Approach Selection: A Systematic Review and Proposed Algorithm.

STUDY DESIGN: A systematic review of the literature to develop an algorithm formulated by key opinion leaders. OBJECTIVE: This study aimed to analyze currently available data and propose a decision-making algorithm for full-endoscopic lumbar discectomy for treating lumbar disc herniation (LDH) to help surgeons choose the most appropriate approach [transforaminal endoscopic lumbar discectomy (TELD) or interlaminar endoscopic lumbar discectomy (IELD)] for patients. SUMMARY OF BACKGROUND DATA: Full-endoscopic discectomy has gained popularity in recent decades. To our knowledge, an algorithm for choosing the proper surgical approach has never been proposed. MATERIALS AND METHODS: A systematic review of the literature using PubMed and MeSH terms was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Patient samples included patients with LDH treated with full-endoscopic discectomy. The inclusion criteria were interventional research (randomized and nonrandomized trials) and observation research (cohort, case-control, case series). Exclusion criteria were case series and technical reports. The criteria used for selecting patients were grouped and analyzed. Then, an algorithm was generated based on these findings with support and reconfirmation from key expert opinions. Data on overall complications were collected. Outcome measures included zone of herniation, level of herniation, and approach (TELD or IELD). RESULTS: In total, 474 articles met the initial screening criteria. The detailed analysis identified the 80 best-matching articles; after applying the inclusion and exclusion criteria, 53 articles remained for this review. CONCLUSIONS: The proposed algorithm suggests a TELD for LDH located in the foraminal or extraforaminal zones at upper and lower levels and for central and subarticular discs at the upper levels considering the anatomic foraminal features and the craniocaudal pathology location. An IELD is preferred for LDH in the central or subarticular zones at L4/L5 and L5/S1, especially if a high iliac crest or high-grade migration is found.

Novel Biomarker Panels Discriminating between Pancreatic Ductal Adenocarcinoma and Extrahepatic Bile Duct Carcinoma.

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) and extrahepatic bile duct carcinoma (EBDC) are distinct entities with different clinicopathological implications. Therefore, research to differentiate between the two diseases is compulsory. In this study, four biomarkers were selected (Hippocalcin-like 1 (HPCAL1); annexin A10 (ANXA10); MUC5AC; sodium/potassium-transporting ATPase subunit beta-1 (ATP1B1)) and focus was placed on clarifying the diagnostic performance of each biomarker and pioneering novel-combined biomarker panels to discriminate between PDAC and EBDC. PROCEDURES: An immunohistochemical microarray analysis of HPCAL1, ANXA10, MUC5AC, and ATP1B1 was conducted for surgically resected 55 PDACs and 77 EBDCs. The diagnostic performance discriminating between PDAC and EBDC was evaluated using four biomarkers and the combined biomarker panels. RESULTS: PDACs exhibited more positive expressions for HPCAL1, ANXA10, and MUC5AC, whereas EBDCs exhibited more ATP1B1-positive expressions. The PDAC panel with the best diagnostic performance was the profile of (+ in ≥ 2 among HPCAL1, ANXA10, MUC5AC)/ATP1B1-. The immunophenotype pattern of (- in ≥ 1 among HPCAL1, ANXA10, MUC5AC)/ATP1B1+ is the EBDC panel with the most excellent discriminating power. CONCLUSION: The suggested combined biomarker panels demonstrate the distinguishing diagnostic ability between PDAC and EBDC is better than previous studies. Therefore, for differentiation between PDAC and EBDC, these panels are expected to help unravel the clinicopathological enigma as promising biomarker panels in the future.

Prognostic implications of immune classification using IDO1 expression in extrahepatic bile duct carcinoma.

Indoleamine 2, 3-dioxygenase 1 (IDO1) is an immunomodulatory enzyme that catalyzes the degradation of tryptophan to kynurenine and induces immune tolerance in tumor cells. The effects of IDO1 on extrahepatic bile duct carcinoma (EHBDC) are poorly understood. Therefore, the present study aimed to investigate the expression and prognostic significance of IDO1 in EHBDC. An immunohistochemical microarray analysis of IDO1 expression was performed for 76 surgically resected cases of EHBDC. CD8+ tumor infiltrating lymphocytes (TILs) were also investigated through a combination analysis with IDO1 expression. IDO1 was highly expressed in 25 of 76 (32.9%) cases. High expression of IDO1 was associated with decreased numbers of CD8+ TILs (P=0.008), a higher pN category (P=0.007), an advanced overall stage (P=0.001) and frequent recurrence (P=0.018). When IDO1 expression was further stratified with CD8+ TIL state, the IDO1high/CD8low subgroup was decreased in terms of overall survival (P=0.025) and disease-free survival (P=0.015) compared with IDO1high/CD8high, IDO1low/CD8high and IDO1low/CD8low subgroups. High IDO1 expression was associated with a decreased number of CD8+ TILs and associated with a poor prognosis. As IDO1 may be a new target of immunotherapy applications, IDO1/CD8+ TIL subgrouping can be a useful prognostic and predictive tool in patients with EHBDC.

Modified transcorporeal anterior cervical microforaminotomy assisted by O-arm-based navigation: a technical case report.

This study was done to present our surgical experience of modified transcorporeal anterior cervical microforaminotomy (MTACM) assisted by the O-arm-based navigation system for the treatment of cervical disc herniation. We present eight patients with foraminal disc herniations at the C5-C6, C6-C7, and C7-T1 levels. All patients had unilateral radicular arm pain and motor weakness. The inclusion criteria for the patients were the presence of single-level unilateral foraminal cervical disc herniation manifesting persistent radiculopathy despite conservative treatment. Hard disc herniation, down-migrated disc herniation, concomitant moderate to severe bony spur and foraminal stenosis were excluded. We performed MTACM to expose the foraminal area of the cervical disc and removed the herniated disc fragments successfully using O-arm-based navigation. Postoperatively, the patients' symptoms improved and there was no instability during the follow-up period. MTACM assisted by O-arm-based navigation is an effective, safe, and precise minimally invasive procedure that tends to preserve non-degenerated structures as much as possible while providing a complete removal of ruptured disc fragments in the cervical spine.

Risk of developing seizure after percutaneous endoscopic lumbar discectomy.

STUDY DESIGN: A retrospective analysis in patients who underwent percutaneous endoscopic lumbar discectomy (PELD) and developed seizures during the procedure; and to identify the risk of developing seizure during PELD by measuring cervical epidural pressure. OBJECTIVE: To evaluate clinical significance, characteristics, and risk factors for developing seizure and neck pain in patients undergoing PELD. SUMMARY AND BACKGROUND DATA: Increased epidural pressure during PELD has been reported earlier. Risk of developing intraoperative seizure has not been investigated till date. We experienced some unexpected complication such as, seizures during PELD, and, therefore, we correlated it with the prodromal symptom and the strategies to avoid such complications during PELD. METHODS: Four of the total 16,725 patients who underwent PELD between 2000 and 2008 developed intraoperative seizures. A review of their medical records and radiologic files were correlated with the complication. Factors evaluated were the type of seizures, prodromal symptoms, comorbidities and clinical outcome. To postulate a pathophysiologic cause of seizure, we designed a study to monitor the intraoperative cervical epidural pressure in 33 patients undergoing PELD. RESULTS: A striking feature of the 4 patients in this series was that they all complained of neck pain before the seizure event. There was no identifiable pattern of seizure observed. The duration of the procedure in these patients was longer than uninvolved cases. None of the patients developed any type of sequel subsequent to seizure. The outcome of surgery has been similar with the patients that did not have any type of complications after PELD. In the subsequent study of cervical epidural pressure, no patients developed seizure. However, there was occurrence of neck pain in the group with increased cervical epidural pressure. CONCLUSIONS: Although rare (0.02%), seizure can occur in patients undergoing PELD, occurrence of neck pain is correlated with increase in cervical epidural pressure, which should be considered as prodromal sign and alert the surgeon. Duration of procedure and speed of infusion are associated risk factor.

Castleman disease of the abdomen--single-center experience of 13 surgically treated patients over 11 years.

BACKGROUND/AIMS: Castleman disease (CD) is a lymphocytic hyperplastic disease, also known as angiofollicular lymphoid hyperplasia and giant lymph node hyperplasia, which rarely occurs in the abdomen. We analyzed the clinical manifestations in 13 patients treated surgically at our center for abdominal CD lesions. METHODOLOGY: We retrospectively reviewed the medical records of 13 patients with abdominal CD who underwent surgery at our institution in the 11-year period from January 1998 to May 2009. RESULTS: Of the 13 patients, 8 were women; their mean +/- SD age was 47.1 +/- 12.0 years. CD was incidentally found in seven patients with no symptoms. Only 3 patients were preoperatively suspected of CD, with 10 suspected of other diseases. Twelve of the 13 patients (92.3%) underwent excisional surgery, with 11, 1 and 1 undergoing R0, R1, and R2 resections, respectively. Eleven tumors were hyaline vascular type and two were plasma cell type. After a mean follow-up of 63.3 months, only one patient showed recurrence, but this patient remains progression-free 7 years after repeat resection. CONCLUSIONS: Abdominal CD is a rare disease that is often misdiagnosed due to the absence of specific clinical manifestations. Definitive diagnosis requires histologic examination of the surgical specimen. Excisional surgery is the method of choice for unicentric abdominal CD, and is associated with a low incidence of recurrence.

Transforaminal Endoscopic Thoracic Discectomy: Technical Review to Prevent Complications.

For all the spine surgeons, thoracic disc herniations (TDHs) entrust a real challenge in terms of patient diagnosis, proper selection, surgical technique, and potential adverse events. TDHs are relatively uncommon compared to the lumbar and cervical levels. Literature reports a variable prevalence of TDHs around 6% to 40%, but less than 1% of all disk herniations are symptomatic TDHs, evidencing as a relatively unusual condition. Nowadays, transforaminal endoscopic thoracic discectomy (TETD) has been implemented as an alternative to classic open procedures with results that are as good as and, in some situations, better than those in traditional discectomy. However, the surgeon must be familiar with endoscopic lumbar spine surgery before opting to perform a TETD, considering that the learning curve is much harder. We describe all the steps and safety considerations during TETD based on the anatomic differences compared to lumbar endoscopic procedures. TETD is an effective and safe method that yields more benefits, provides a direct route to the lesion with less morbidity, and is performed in a minimally invasive way. Many severe complications related to the thoracic region could be avoided having the proper knowledge, adequate technique, and safety routes and considerations.

Telemedicine Center of Korean Medicine for treating patients with COVID-19: a retrospective analysis.

BACKGROUND: Since January 2020, novel coronavirus (SARS-Cov-2) - infected pneumonia (COVID-19) rapidly spread in Korea. This study aimed to introduce the Korean Medicine (KM) telemedicine center for treatment of COVID patients in Korea. METHODS: This work was a retrospective review of medical records on patients who received at least one telemedicine session from March 9, 2020 to April 12, 2020 provided by the COVID-19 telemedicine center of Korean Medicine. Data on demographic characteristics, treatment frequency, number of consultation were collected. A descriptive statistical analysis was conducted to report characteristics of patients. RESULTS: A total of 1742 patients underwent consultation through KM telemedicine centers. Despite the rapid increase in the number of patients, the telemedicine center provided treatments to an average of 192 patients per day by about an average of 15 doctors. Furthermore, 4552 herbal medicines were prescribed through telemedicine center, among which 1366 cases (30%) being Qing-Fei-Pai-Du-tang. Telemedicine care also has shown that even with patient's residence transition, medical care can be continued without pause. CONCLUSION: These results show some advantages of the telemedicine center's implementation in terms of the effective use of medical resources and continuous treatment for patients.

Surgeon training and clinical implementation of spinal endoscopy in routine practice: results of a global survey.

BACKGROUND: Training of spine surgeons may impact the availability of contemporary minimally invasive spinal surgery (MIS) to patients and drive spine surgeons' clinical decision-making when applying minimally invasive spinal surgery techniques (MISST) to the treatment of common degenerative conditions of the lumbar spine. Training requirements and implementation of privileges vary in different parts of the world. The purpose of this study was to analyze the training in relation to practice patterns of surgeons who perform lumbar endoscopic spinal surgery the world over. METHODS: The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) please indicate your training? (II) What type of MISST spinal surgery do you perform? (III) How would you rate your experience in MIS lumbar spinal surgery and what percentage of your practice is MISST? And (IV) which avenue did you use to train for the MISST you currently employ in your clinical practice today? Descriptive statistics were applied to count responses and cross-tabulated them to the surgeon's training. Pearson Chi-square measures, kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS version 25.0. RESULTS: A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14% (41/292) of surgeons had completed a fellowship. Surgeons rated their skill level 33.5% of the time as master and experienced surgeon, and 35.6% of the time as novice or surgeon with some experience. There were more master (64.6% versus 29.2%) and experienced (52% versus 40%) surgeons amongst orthopaedic surgeons than amongst neurosurgeons at a statistically significant level (P=0.11). There were near twice as many orthopaedic surgeons (54.3%) using endoscopic procedures in the lumbar spine as their favorite MISST than neurosurgeons (35.4%; P=0.096). Endoscopic spine surgeons' main sources of knowledge acquisition were (I) learning in small meetings (57.3%), (II) attending workshops (63.1%), and (III) national and international conferences (59.8%). CONCLUSIONS: The majority of spine surgeons reported more than half of their cases employing MISST at a high skill level. Very few MISST surgeons are fellowship trained but attend workshops and various meetings suggesting that many of them are self-thought. Orthopaedic surgeons were more likely to implement endoscopic spinal surgery into the routine clinical practice. As endoscopic spine surgery gains more traction and patient demand, minimal adequate training will be part of the ongoing debate.

Surgeon motivation, and obstacles to the implementation of minimally invasive spinal surgery techniques.

BACKGROUND: This study aimed to analyze the motivators and obstacles to the implementation of minimally invasive spinal surgery techniques (MISST) by spinal surgeons. Motivators and detractors may impact the availability of MISST to patients and drive spine surgeons' clinical decision-making in the treatment of common degenerative conditions of the lumbar spine. METHODS: The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Descriptive statistics were employed to count the responses and compared to the surgeon's training. Kappa statistics and linear regression analysis of agreement were performed. RESULTS: A total of 430 surgeons accessed the survey. The completion rate was 67.4%. A total of 292 surveys were submitted by 99 neurosurgeons (33.9%), 170 orthopaedic surgeons (58.2%), and 23 surgeons of other postgraduate training (7.9%). Personal interest (82.5%) and patient demand (48.6%) were the primary motivators for MISST implementation. High equipment (48.3%) and disposables (29.1%) cost were relevant obstacles to MISST implementation. Local workshops (47.6%) and meetings in small groups (31.8%) were listed as the primary knowledge sources. Only 12% of surgeons were fellowship trained, but 46.3% of surgeons employed MISST in over 25% of their cases. CONCLUSIONS: The rate of implementation of MISST reported by spine surgeons was found to be high but impeded by the high cost of equipment and disposables. The primary motivators for spine surgeons' desire to implement were personal interest and patient demand.

Regional variations in acceptance, and utilization of minimally invasive spinal surgery techniques among spine surgeons: results of a global survey.

BACKGROUND: Regional differences in acceptance and utilization of MISST by spine surgeons may have an impact on clinical decision-making and the surgical treatment of common degenerative conditions of the lumbar spine. The purpose of this study was to analyze the acceptance and utilization of various minimally invasive spinal surgery techniques (MISST) by spinal surgeons the world over. METHODS: The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) Do you think minimally invasive spinal surgery is considered mainstream in your area and practice setting? (II) Do you perform minimally invasive spinal surgery? (III) What type of MIS spinal surgery do you perform? (IV) If you are performing endoscopic spinal decompression surgeries, which approach do you prefer? The responses were cross-tabulated by surgeons' demographic data, and their practice area using the following five global regions: Africa & Middle East, Asia, Europe, North America, and South America. Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS Version 25.0. RESULTS: A total of 586 surgeons accessed the survey. Analyzing the responses of 292 submitted surveys regional differences in opinion amongst spine surgeons showed that the highest percentage of surgeons in Asia (72.8%) and South America (70.2%) thought that MISST was accepted into mainstream spinal surgery in their practice area (P=0.04) versus North America (62.8%), Europe (52.8%), and Africa & Middle East region (50%). The percentage of spine surgeons employing MISST was much higher per region than the rate of surgeons who thought it was mainstream: Asia (96.7%), Europe (88.9%), South America (88.9%), and Africa & Middle East (87.5%). Surgeons in North America reported the lowest rate of MISST implementation globally (P<0.000). Spinal endoscopy (59.9%) is currently the most commonly employed MISST globally followed by mini-open approaches (55.1%), and tubular retractor systems (41.8%). The most preferred endoscopic approach to the spine is the transforaminal technique (56.2%) followed by interlaminar (41.8%), full endoscopic (35.3%), and over the top MISST (13.7%). CONCLUSIONS: The rate of implementation of MISST into day-to-day clinical practice reported by spine surgeons was universally higher than the perceived acceptance rates of MISST into the mainstream by their peers in their practice area. The survey suggests that endoscopic spinal surgery is now the most commonly performed MISST.

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures.

STUDY DESIGN: International consensus paper on a unified nomenclature for full-endoscopic spine surgery. OBJECTIVES: Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers. METHODS: The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology. RESULTS: We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD). CONCLUSIONS: We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Radiological findings of spinal schwannomas and meningiomas: focus on discrimination of two disease entities.

This study evaluates the effectiveness of CT and MR imaging in differentiating intradural extramedullary spinal schwannomas and meningiomas in a large group of patients. In addition, the study correlates tumour location, morphologic characteristics and enhancement pattern. From January 2000 to June 2007, we retrospectively reviewed 128 consecutive patients (51 male, 77 female; mean age at admission 53.8 years; range 17-83 years) with spinal intradural extramedullary tumours (92 schwannomas, 36 meningiomas) at our institution. Fifty-one of ninety-two schwannomas (55.4%) showed fluid signal intensity on T2-weighted MR images. Twenty-two of thirty-six meningiomas (61.1%) showed hyperintense signal intensity and thirteen of thirty-six meningiomas (36.1%) showed isointense signal on T2-weighted MR images. Fifty-four schwannomas (58.7%) showed rim enhancement and thirty-three meningiomas (91.7%) showed diffuse enhancement on contrast-enhanced T1-weighted MR imaging. Twenty-one meningiomas (58.3%) showed dural tail sign in contrast-enhanced T1-weighted MR imaging. Twenty-one meningiomas (58.3%) showed calcification on CT images. MR and CT imaging results are therefore useful for the differentiation of schwannomas from meningiomas of the spine.

Removal of discal cyst using percutaneous working channel endoscope via transforaminal route.

Discal cyst is a very rare lesion that can cause refractory low back pain and radiating leg pain. Although there are some reports to remove this lesion, there has been no report of discal cyst removed by percutaneous endoscopic transforaminal approach. Two young patients manifested left gluteal and leg pain due to a discal cyst at L5-S1 level and L4-5 level, respectively. Percutaneous endoscopic transforaminal approach was performed to remove the discal cyst, achieving complete decompression of the nerve root. The symptom was relieved and the patient was discharged the next day. Percutaneous endoscopic transforaminal approach could be a good alternative option in selected cases for the treatment of lumbar discal cyst.

Angiography-Based Machine Learning for Predicting Fractional Flow Reserve in Intermediate Coronary Artery Lesions.

Background An angiography-based supervised machine learning ( ML ) algorithm was developed to classify lesions as having fractional flow reserve ≤0.80 versus >0.80. Methods and Results With a 4:1 ratio, 1501 patients with 1501 intermediate lesions were randomized into training versus test sets. Between the ostium and 10 mm distal to the target lesion, a series of angiographic lumen diameter measurements along the centerline was plotted. The 24 computed angiographic features based on the diameter plot and 4 clinical features (age, sex, body surface area, and involve segment) were used for ML by XGBoost. The model was independently trained and tested by 2000 bootstrap iterations. External validation with 79 patients was conducted. Including all 28 features, the ML model with 5-fold cross-validation in the 1204 training samples predicted fractional flow reserve ≤0.80 with overall diagnostic accuracy of 78±4% (averaged area under the curve: 0.84±0.03). The 12 high-ranking features selected by scatter search were involved segment; body surface area; distal lumen diameter; minimal lumen diameter; length of a lumen diameter <2.0 mm, <1.5 mm, and <1.25 mm; mean lumen diameter within the worst segment; sex; diameter stenosis; distal 5-mm reference lumen diameter; and length of diameter stenosis >70%. Using those 12 features, the ML predicted fractional flow reserve ≤0.80 in the test set with sensitivity of 84%, specificity of 80%, and overall accuracy of 82% (area under the curve: 0.87). The averaged diagnostic accuracy in bootstrap replicates was 81±1% (averaged area under the curve: 0.87±0.01). External validation showed accuracy of 85% (area under the curve: 0.87). Conclusions Angiography-based ML showed good diagnostic performance in identifying ischemia-producing lesions and reduced the need for pressure wires.

Epidural Fluid Collection After Percutaneous Endoscopic Lumbar Discectomy.

OBJECTIVE: The frequency and extent of epidural fluid collection after percutaneous endoscopic lumbar discectomy (PELD) have not been previously described. The purpose of this study was to evaluate the significance of epidural fluid collection after PELD. METHODS: From March 2008 to November 2015, immediate postoperative magnetic resonance imaging (MRI) of 464 consecutive patients, comprising 284 men and 180 women, were obtained after PELD. The mean age of the patients at the time of admission was 43.1 years (range, 18-81 years). We also performed 24-hour follow-up MRIs after PELD in 35 patients to evaluate the morphologic changes on epidural fluid collection and to identify whether the collection was due to saline accumulation or cerebrospinal fluid leak. RESULTS: The level of disc herniation was at L4-5, L5-S1, L3-4, and L2-3 in 245 (52.8%), 173 (37.3%), 37 (8.0%), and 9 (1.9%) patients, respectively. Of 464 patients, 418 (90.1%) had abnormal epidural fluid collection, 404 (87.1%) patients had ventral epidural fluid collection, 393 (84.7%) patients had dorsal epidural fluid collection, and 10 patients had epidural hematoma as per immediate postoperative MRI. According to the 24-hour follow-up MRI findings, 30 patients had epidural fluid collection; the epidural fluid collection in 28 patients (93.3%) resolved with time, and a minimal amount of fluid remained in 2 patients, but the lesion size decreased compared with that on the previous day. CONCLUSIONS: Epidural fluid collection usually occurs after percutaneous endoscopic discectomy, which is mainly due to saline accumulation and typically resolves with time, without treatment or complications.