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-β1/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.

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.

Controlled synthesis of dicalcium phosphate dihydrate (DCPD) from metastable solutions: insights into pathogenic calcification

Calcium phosphate (CaP) compounds may occur in the body as abnormal pathogenic phases in addition to their normal occurrence as bones and teeth. Dicalcium phosphate dihydrate (DCPD; CaPO₄·2H₂O), along with other significant CaP phases, have been observed in pathogenic calcifications such as dental calculi, kidney stones and urinary stones. While other studies have shown that polar amino acids can inhibit the growth of CaPs, these studies have mainly focused on hydroxyapatite (HAp; Ca₁₀(PO₄)₆(OH)₂) formation from highly supersaturated solutions, while their effects on DCPD nucleation and growth from metastable solutions have been less thoroughly explored. By further elucidating the mechanisms of DCPD formation and the influence of amino acids on those mechanisms, insights may be gained into ways that amino acids could be used in treatment and prevention of unwanted calcifications. The current study involved seeded growth of DCPD from metastable solutions at constant pH in the presence of neutral, acidic and phosphorylated amino acid side chains. As a comparison, solutions were also seeded with calcium pyrophosphate (CPP; Ca₂P₂O₇), a known calcium phosphate inhibitor. The results show that polar amino acids inhibit DCPD growth; this likely occurs due to electrostatic interactions between amino acid side groups and charged DCPD surfaces. Phosphoserine had the greatest inhibitory ability of the amino acids tested, with an effect equal to that of CPP. Clustering of DCPD crystals giving rise to a "chrysanthemum-like" morphology was noted with glutamic acid. This study concludes that molecules containing an increased number of polar side groups will enhance the inhibition of DCPD seeded growth from metastable solutions.

Diagnostic performance of fractional flow reserve derived from computed tomography in the stented coronary arteries

Background

The current system of HeartFlow fractional flow reserve derived from computed tomography (FFRCT) is not available for stented coronary arteries. However, the latest version of HeartFlow FFRCT has the potential of rendering an accurate assessment for stented coronary arteries.

Objectives

To evaluate the feasibility of FFRCT for the stented coronary arteries.

Methods

We retrospectively enrolled patients with a history of coronary stent implantation who underwent invasive fractional flow reserve (FFR) for the stented coronary arteries within 3 months after coronary computed tomographic angiography (cCTA). As a subgroup analysis, we analyzed optical coherence tomography (OCT) images in patients who underwent OCT for stented vessels. OCT was performed as a part of the Kobe University Hospital OCT registry, which is a single-centre registry of consecutive patients who underwent OCT for the coronary arteries. The diagnostic performance of HeartFlow FFRCT for stented vessels was evaluated by comparing with that of cCTA alone. Minimum lumen area (MLA) within stent segments derived from cCTA was also compared with MLA derived from optical coherence tomography (OCT).

Results

A total of 30 vessels in 23 patients were studied. The diagnostic accuracy, sensitivity, specificity, positive and negative predictive value of FFRCT for myocardial ischemia using invasive FFR as a reference standard was 73.3%, 88.9%, 67.7%, 53.3% and 93.3%, respectively. FFRCT provided superior diagnostic performance than cCTA alone (p=0.016). FFRCT was significantly correlated with the invasive FFR (r=0.620, p<0.001), and Bland-Altman plot showed a mean bias of −0.041 with 95% limit of agreement of −0.173 to 0.092 (Figure 1). Among a total of 30 studied vessels, OCT was available for 25 vessels. MLA derived from cCTA correlated significantly with that derived from OCT (r=0.695, p<0.001), and Bland-Altman plot showed a mean bias of −0.32 mm2 with 95% limit of agreement of −2.89 to 2.25 mm2 (Figure 2).

Conclusions

The latest version of the HeartFlow FFRCT has the potential to be available for stented coronary arteries. Further investigation is required to elaborate our results.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

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.

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.

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.

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.

Efficacy and safety of PAC-14028 cream - a novel, topical, nonsteroidal, selective TRPV1 antagonist in patients with mild-to-moderate atopic dermatitis: a phase IIb randomized trial

Background

Transient receptor potential vanilloid subfamily, member 1 (TRPV1) may play an important role in pruritus and inflammation induction in atopic dermatitis (AD). The treatment effect of TRPV1 antagonist via topical application in patients with AD remains unknown.

Objectives

To assess the clinical efficacy and safety of PAC‐14028, a TRPV1 antagonist, via topical application in patients with AD.

Methods

In this 8‐week, phase IIb, randomized, double‐blind, multicentre, vehicle‐controlled study, patients with mild‐to‐moderate AD were randomized to receive PAC‐14028 cream 0·1%, 0·3%, 1·0% or vehicle cream twice daily. The primary efficacy end point was the Investigator's Global Assessment (IGA) success rate defined as the percentage of patients with an IGA score of 0 or 1 at week 8. The secondary efficacy end points included the severity Scoring of Atopic Dermatitis (SCORAD) index and Eczema Area and Severity Index (EASI) 75/90.

Results

A total of 194 patients were enrolled. IGA success rates at week 8 were 14·58% for vehicle cream, 42·55% for PAC‐14028 cream 0·1% (P = 0·0025 vs. vehicle), 38·30% for PAC‐14028 cream 0·3% (P = 0·0087 vs. vehicle) and 57·45% for PAC‐14028 cream 1·0% (P < 0·001 vs. vehicle). In particular, statistically significant differences were found between the vehicle and treatment groups in the IGA success rates with two‐grade improvement. The SCORAD index, EASI 75/90, sleep disturbance score and pruritus visual analogue scale showed a trend towards improvement. No significant safety issues were reported.

Conclusions

PAC‐14028 cream may be an effective and safe treatment modality for the treatment of patients with mild‐to‐moderate AD.

What is already known about this topic?

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases characterized by pruritic erythematous skin lesions and barrier dysfunction.

Transient receptor potential vanilloid subfamily, member 1 (TRPV1) antagonists suppress the release of pruritic and proinflammatory mediators.

The preclinical results demonstrate the feasibility of TRPV1 as a potential therapeutic target for the treatment of AD.

What does this study add?

TRPV1 regulates inflammation and pruritus in patients with AD.

PAC‐14028 cream, a novel TRPV1 antagonist, was superior to vehicle in improving clinical symptoms and signs with a favourable safety profile in adults with mild‐to‐moderate AD.

TRPV1 antagonism may play a role as a promising nonsteroidal topical treatment target for AD with a new mechanism of action.

Linked Editorial:https://doi.org/10.1111/bjd.17777.

https://doi.org/10.1111/bjd.17802 available online

https://www.bjdonline.com/article/

Endoscopic Spine Surgery

Surgical treatment of the degenerative disc disease has evolved from traditional open spine surgery to minimally invasive spine surgery including endoscopic spine surgery. Constant improvement in the imaging modality especially with introduction of the magnetic resonance imaging, it is possible to identify culprit degenerated disc segment and again with the discography it is possible to diagnose the pain generator and pathological degenerated disc very precisely and its treatment with minimally invasive approach. With improvements in the optics, high resolution camera, light source, high speed burr, irrigation pump etc, minimally invasive spine surgeries can be performed with various endoscopic techniques for lumbar, cervical and thoracic regions. Advantages of endoscopic spine surgeries are less tissue dissection and muscle trauma, reduced blood loss, less damage to the epidural blood supply and consequent epidural fibrosis and scarring, reduced hospital stay, early functional recovery and improvement in the quality of life & better cosmesis. With precise indication, proper diagnosis and good training, the endoscopic spine surgery can give equally good result as open spine surgery. Initially, endoscopic technique was restricted to the lumbar region but now it also can be used for cervical and thoracic disc herniations. Previously endoscopy was used for disc herniations which were contained without migration but now days it is used for highly up and down migrated disc herniations as well. Use of endoscopic technique in lumbar region was restricted to disc herniations but gradually it is also used for spinal canal stenosis and endoscopic assisted fusion surgeries. Endoscopic spine surgery can play important role in the treatment of adolescent disc herniations especially for the persons who engage in the competitive sports and the athletes where less tissue trauma, cosmesis and early functional recovery is desirable. From simple chemonucleolysis to current day endoscopic procedures the history of minimally invasive spine surgery is interesting. Appropriate indications, clear imaging prior to surgery and preplanning are keys to successful outcome. In this article basic procedures of percutaneous endoscopic lumbar discectomy through transforaminal and interlaminar routes, percutaneous endoscopic cervical discectomy, percutaneous endoscopic posterior cervical foraminotomy and percutaneous endoscopic thoracic discectomy are discussed.

Antibody-Based Cancer Therapy: Successful Agents and Novel Approaches

Since their discovery, antibodies have been viewed as ideal candidates or "magic bullets" for use in targeted therapy in the fields of cancer, autoimmunity, and chronic inflammatory disorders. A wave of antibody-dedicated research followed, which resulted in the clinical approval of a first generation of monoclonal antibodies for cancer therapy such as rituximab (1997) and cetuximab (2004), and infliximab (2002) for the treatment of autoimmune diseases. More recently, the development of antibodies that prevent checkpoint-mediated inhibition of T cell responses invigorated the field of cancer immunotherapy. Such antibodies induced unprecedented long-term remissions in patients with advanced stage malignancies, most notably melanoma and lung cancer, that do not respond to conventional therapies. In this review, we will recapitulate the development of antibody-based therapy, and detail recent advances and new functions, particularly in the field of cancer immunotherapy. With the advent of recombinant DNA engineering, a number of rationally designed molecular formats of antibodies and antibody-derived agents have become available, and we will discuss various molecular formats including antibodies with improved effector functions, bispecific antibodies, antibody-drug conjugates, antibody-cytokine fusion proteins, and T cells genetically modified with chimeric antigen receptors. With these exciting advances, new antibody-based treatment options will likely enter clinical practice and pave the way toward more successful control of malignant diseases.

Percutaneous Transpedicular Lumbar Endoscopy: A Case Report

INTRODUCTION

Since Kambin introduced the concept of percutaneous transforaminal disc surgery in 1973, there has been numerous advances in the field of spine endoscopy and the concept of central debulking of the disc has changed to targeted fragmentectomy and disc preservation. The lumbar disc fragments which are down migrated and to the medial aspect of the pedicle are extremely challenging to deal by transforaminal approach even after foraminoplasties and by various other approaches. Therefore most spine surgeons prefer open procedures which requires extensive removal of pars and facet leading to the risk of instability.

AIMS AND OBJECTIVES

To describe a safe and effective technique for lumbar intra-canal high grade down migrated disc herniation, medial to the pedicle by transpedicular endoscopy.

METHODS AND TREATMENT

Two patients underwent percutaneous transpedicular lumbar endoscopy under local anaesthesia for high grade down migrated disc herniation and for discal cyst at the medial aspect of pedicle respectively.

RESULTS

We achieved the complete successful decompression by percutaneous transpedicular lumbar endoscopy.

CONCLUSION

Authors found this technique very promising in complete removal of disc material under direct visualisation for high grade down disc herniations.

Molecular identification and phylogenetic analysis of important medicinal plant species in genus Paeonia based on rDNA-ITS, matK, and rbcL DNA barcode sequences

This study was performed to identify and analyze the phylogenetic relationship among four herbaceous species of the genus Paeonia, P. lactiflora, P. japonica, P. veitchii, and P. suffruticosa, using DNA barcodes. These four species, which are commonly used in traditional medicine as Paeoniae Radix and Moutan Radicis Cortex, are pharmaceutically defined in different ways in the national pharmacopoeias in Korea, Japan, and China. To authenticate the different species used in these medicines, we evaluated rDNA-internal transcribed spacers (ITS), matK and rbcL regions, which provide information capable of effectively distinguishing each species from one another. Seventeen samples were collected from different geographic regions in Korea and China, and DNA barcode regions were amplified using universal primers. Comparative analyses of these DNA barcode sequences revealed species-specific nucleotide sequences capable of discriminating the four Paeonia species. Among the entire sequences of three barcodes, marker nucleotides were identified at three positions in P. lactiflora, eleven in P. japonica, five in P. veitchii, and 25 in P. suffruticosa. Phylogenetic analyses also revealed four distinct clusters showing homogeneous clades with high resolution at the species level. The results demonstrate that the analysis of these three DNA barcode sequences is a reliable method for identifying the four Paeonia species and can be used to authenticate Paeoniae Radix and Moutan Radicis Cortex at the species level. Furthermore, based on the assessment of amplicon sizes, inter/intra-specific distances, marker nucleotides, and phylogenetic analysis, rDNA-ITS was the most suitable DNA barcode for identification of these species.

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.

Molecular identification of the traditional herbal medicines, Arisaematis Rhizoma and Pinelliae Tuber, and common adulterants via universal DNA barcode sequences

Methods to identify Pinelliae Tuber and Arisaematis Rhizoma are required because of frequent reciprocal substitution between these two herbal medicines and the existence of several closely related plant materials. As a result of the morphological similarity of dried tubers, correct discrimination of authentic herbal medicines is difficult by conventional methods. Therefore, we analyzed DNA barcode sequences to identify each herbal medicine and the common adulterants at a species level. To verify the identity of these herbal medicines, we collected five authentic species (Pinellia ternata for Pinelliae Tuber, and Arisaema amurense, A. amurense var. serratum, A. erubescens, and A. heterophyllum for Arisaematis Rhizoma) and six common adulterant plant species. Maturase K (matK) and ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) genes were then amplified using universal primers. In comparative analyses of two DNA barcode sequences, we obtained 45 species-specific nucleotides sufficient to identify each species (except A. erubescens with matK) and 28 marker nucleotides for each species (except P. pedatisecta with rbcL). Sequence differences at corresponding positions of the two combined DNA barcodes provided genetic marker nucleotides that could be used to identify specimens of the correct species among the analyzed medicinal plants. Furthermore, we generated a phylogenetic tree showing nine distinct groups depending on the species. These results can be used to authenticate Pinelliae Tuber and Arisaematis Rhizoma from their adulterants and to identify each species. Thus, comparative analyses of plant DNA barcode sequences identified useful genetic markers for the authentication of Pinelliae Tuber and Arisaematis Rhizoma from several adulterant herbal materials.

Integration of reverse transcriptase loop-mediated isothermal amplification with an immunochromatographic strip on a centrifugal microdevice for influenza A virus identification

A novel centrifugal microdevice which could perform reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) and immunochromatographic strip (ICS) based amplicon detection was demonstrated for simple and cost-effective influenza A virus identification. The proposed centrifugal microdevice consists of the sample and running buffer loading reservoirs, the RT-LAMP chamber, and the ICS for detecting gene expression. The entire process could be completed sequentially and automatically by simply controlling the rotation speed and by optimizing the microfluidic design. Monoplex and multiplex RT-LAMP reactions targeting H1 and/or M gene were executed at 66 °C for 40 min, and the resultant amplicons were successfully analysed on the ICS within 15 min. Influenza A H1N1 virus was subtyped by detecting H1 and M gene on the ICS even with 10 copies of viral RNAs. Highly specific and multiplex viral typing of the integrated RT-LAMP-ICS microdevice was also demonstrated. The combination of the rapid isothermal amplification with the simple colorimetric detection on a strip in a single centrifugal microdevice will provide an advanced genetic analysis platform in the field of on-site pathogen diagnostics.

Transcorporeal cervical foraminotomy: description of technique and results

OBJECTIVE: Retrospective analyses of 216 patients undergoing foraminal decompression with transcorporeal approach and review of the surgical technique. METHOD: 216 patients with minimum follow-up of 2 years and an average of 41.8 months were included in the study. The clinical records of these patients were reviewed for complications, NDI (neck disability index) and VAS (visual analogue scale). Pre and post-operative radiographs were used to evaluate the disc height. RESULTS: At the end of follow-up patients had significant clinical improvement with reduction of NDI of 88.3% and 86.5% and 68.3% of the VAS for neck and upper limb, respectively (p<0.05). A reduction of 8.8% of the disc height was observed without other complications associated (p<0.05). CONCLUSION: Radicular decompression through a transcorporeal approach is an alternative that provides good clinical results without the need for a fusion and with few complications.

Working channel endoscope in lumbar spine surgery

Percutaneous endoscopic lumbar discectomy (PELD) is a well established modality in the treatment of patients with herniated lumbar discs. Since the time of its inception towards the end of 20th century, this technique has undergone significant modifications. With better understanding of the patho-anatomy and development of instrumentation the indications for PELD are on the rise. In the modern era of knowledge exchange there have been considerable variations among different endoscopic surgeons about classical indications and the implications of a particular technique pertaining to those indications. During last 15 years of experience in practicing endoscopic surgery, Choi has published many articles, regarding the techniques of PELD, across many scientific journals. In our practice there has been considerable shift from central debulking to discectomy to selective fragmentectomy. With further advancements the span of this technique is definitely on the rise. Here, we wish to share all the published data along with my current practice trends in more precise manner to help newer endoscopic spine surgeons understand the implications and limitations of a working channel endoscope in lumbar spine pathologies.

Clinical results of XMR-assisted percutaneous transforaminal endoscopic lumbar discectomy

Background

Although percutaneous endoscopic lumbar discectomy (PELD) has shown favorable outcomes in the majority of lumbar discectomy cases, there were also some failures. The most common cause of failure is the incomplete removal of disc fragments. The skin entry point for the guide-needle trajectory and the optimal placement of the working sleeve are largely blind, which might lead to the inadequate removal of disc fragments. The objective of this study was to present our early experiences with image-guided PELD using a specially designed fluoroscope with magnetic resonance imaging-equipped operative suite (XMR) for the treatment of lumbar disc herniation.

Methods

This prospective study included 89 patients who had undergone PELD via the transforaminal approach using an XMR protocol. Pre- and postoperative examinations (at 12 weeks) included a detailed clinical history, visual analogue scale (VAS), Oswestry disability index (ODI), and radiological workups. The results were categorized as excellent, good, fair, and poor according to MacNab's criteria. At the final follow-up, the minimum follow-up time for the subjects was 2 years. The need for revision surgeries and postoperative complications were noted on follow-up.

Results

Postoperative mean ODI decreased from 67.4% to 5.61%. Mean VAS score for back and leg pain improved significantly from 4 to 2.3 and from 7.99 to 1.04, respectively. Four (4.49%) patients underwent a second-stage PELD after intraoperative XMR had shown remnant fragments after the first stage. As per MacNab's criteria, 76 patients (85.4%) showed excellent, 8 (8.89%) good, 3 (3.37%) fair, and 2 (2.25) poor results. Four (4.49%) patients had remnant disc fragments on XMR, which were removed during the same procedure. All of these patients had either highly migrated or sequestrated disc fragments preoperatively. Four (4.49%) other patients needed a second, open surgery due to symptomatic postoperative hematoma (n = 2) and recurrent disc herniation (n = 2).

Conclusions

This prospective analysis indicates that XMR-assisted PELD provides a precise skin entry point. It also confirms that decompression occurs intraoperatively, which negates the need for a separate surgery and thus increases the success rate of PELD, particularly in highly migrated or sequestrated discs. However, further extensive experience is required to confirm the advantages and feasibility of PELD in terms of cost effectiveness.

Asian venous thromboembolism guidelines: prevention of venous thromboembolism

Venous thromboembolism (VTE) prophylaxis is under-utilized in Asia because of the misconception that its incidence is lower in Asians as compared to the Caucasians. The available data on VTE in Asia is limited due to the lack of well-designed multicenter randomized controlled trials as well as non-standardized research designs, making data comparison difficult. Emerging data indicates that the VTE incidence is not low in Asia, and is comparable to that reported in the Western literature in some instances. There is also a trend towards increasing incidence of VTE, as demonstrated by a number of hospital-based studies in Asia. This could be attributed to lifestyle changes, ageing population, increasing awareness of VTE and wider availability of Duplex ultrasound. The risk of VTE in hospitalized patients remain the same in Asians and Caucasians, even though there may be factors that are inherent to patients in Asia that influence the slight variation in incidence. The utilization rate of VTE prophylaxis remains suboptimal in Asia. The Asian Venous Thrombosis Forum (AVTF) comprises participants from various countries such as China, Hong Kong, India, Indonesia, Korea, Malaysia, Philippines, Singapore, Taiwan, Thailand and experts from Australia and Europe. The forum evaluated the available data on VTE from the Asian region and formulated guidelines tailored to meet the needs of the region. We recommend that serious considerations are given to VTE prophylaxis especially in the at-risk group and a formal hospital policy be established to facilitate the implementation. On admission to the hospital, we recommend assessing the patients for both VTE and bleeding risk. We recommend mechanical prophylaxis for patients at increased risk of bleeding and utilizing it as an adjunctive measure in combination with pharmacological prophylaxis in patients with high risk of VTE. For patients undergoing general or gynecological surgery and with moderate risk for VTE, we recommend prophylaxis with one of the following: low dose unfractionated heparin (LDUH), low molecular weight heparin (LMWH), fondaparinux or intermittent pneumatic compression (IPC). For the same group of patients at high risk of VTE, we recommend pharmacological or combination of pharmacological and mechanical prophylaxis. For patients undergoing major orthopedic surgeries like total hip replacement, total knee replacement and proximal hip fracture surgery, we recommend using one of the following: LMWH, fondaparinux, rivaroxaban, apixaban, edoxaban, dabigatran, warfarin or aspirin with IPC. For patients admitted to the hospital with acute medical illness and has moderate risk of VTE, we recommend prophylaxis with LDUH, LMWH or Fondaparinux. For the same group at high risk of VTE, we recommend combination of pharmacological and mechanical prophylaxis.

A case report of "spinal cord apoplexy" elicited by metastatic intramedullary thyroid carcinoma

A 31-year-old man presented with acute onset of paraplegia. The patient's history was significant for thyroid carcinoma that had been treated 2 years earlier by thyroidectomy. A magnetic resonance imaging scan showed an enhancing intramedullary lesion at T7-8. Patient underwent surgical treatment and a tumor with hematoma was resected via posterior midline myelotomy. Postoperatively, the patient's motor weakness was improved to grade 3. The lesion showed typical histologic features consistent with papillary thyroid carcinoma. Early diagnosis and microsurgical resection can result in improvement in neurological deficits and quality of life of patients with an ISCM.

Foraminoplastic ventral epidural approach for removal of extruded herniated fragment at the L5-S1 level

The 'foraminoplastic' ventral epidural approach and its advantages in the treatment of extruded disk herniation at the L5-S1 level are described. Percutaneous endoscopic lumbar discectomy is a minimally invasive procedure applicable to various types of lumbar disk herniation, but the L5-S1 disk space is still challenging to access due to anatomic limitations such as high iliac crest or severely narrowed foramen. The 'foraminoplastic' ventral epidural approach was performed in 25 patients with herniated disk radiculopathy at L5-S1 from March 2003 to May 2004. Their mean age was 39.2 years (range 20-67 years) and the mean follow-up duration was 32.5 months (range 28-42 months). During the procedure, 'foraminoplasty' was performed by undercutting the hypertrophic superior facet with the endoscopic bone cutter under C-arm guidance. The clinical result was assessed according to the visual analogue scale (VAS) and Oswestry disability index (ODI). Preoperative mean VAS score of 7.4 for leg pain fell to 1.6 postoperatively and mean preoperative ODI of 55.5% improved to 16.9% postoperatively, both showing significant improvements (p < 0.001). Mean hospital stay was 14.2 hours. Twenty-two patients had the favorable outcomes. Two patients required conversion to open microdiscectomy due to incomplete decompression and recurrent disk herniation. The 'foraminoplastic' approach is a safe and efficient surgical option for L5-S1 disk herniation even in patients with high iliac crest and narrow foramen.

Adjacent Segment Degeneration After Lumbar Interbody Fusion With Percutaneous Pedicle Screw Fixation for Adult Low-Grade Isthmic Spondylolisthesis: Minimum 3 Years of Follow-up

BACKGROUND:

Although favorable clinical outcomes have been reported for instrumented lumbar interbody fusion (LIF), adjacent segment degeneration (ASD) has been reported as a long-term complication after LIF.

OBJECTIVE:

To investigate ASD after instrumented LIF performed at a single level and only for the homogeneous disease of adult low-grade isthmic spondylolisthesis.

METHODS:

A total of 128 patients who had undergone LIF for the treatment of adult low-grade isthmic spondylolisthesis involving the lower lumbar spine at our institution between February 2001 and December 2004 were retrospectively reviewed by chart review and telephone survey. Of them, 103 patients with a minimum of a 36-month follow-up period were enrolled in this study. The mean age was 48.5 years. The average follow-up period was 59 months. Clinical and radiological data related to segmental lordosis (SL), whole lumbar lordosis, sacral slope, pelvic tilt, pelvic incidence, and L1 axis S1 distance were analyzed to identify significant risk factors for ASD.

RESULTS:

The overall incidence of ASD was 10.6% (11/103). The incidences of radiographic and symptomatic ASD were 8.7% (9/103) and 1.9% (2/103), respectively. All patients improved clinically and functionally during the follow-up period. Postoperative SL, preoperative SL, whole lumbar lordosis, and L1 axis S1 distance were significant risk factors for ASD. Only SL was a significant risk factor for both the preoperative and postoperative states.

CONCLUSION:

ASD may occur at a relatively lower incidence in adult low-grade isthmic spondylolisthesis compared with other degenerative lumbar spinal diseases. SL is significantly correlated with ASD, whereas mechanical alterations caused by LIF are less likely to affect the adjacent segment. Restoration of normal SL is important for preventing ASD, and long-term follow-up is necessary.

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.