Advances in Cranial Surgery.

The landscape of the cranial neurosurgery has changed tremendously in past couple of decades. The main frontiers including introduction of neuro-endoscopy, minimally invasive skull base approaches, SRS, laser interstitial thermal therapy and use of tubular retractors have revolutionized the management of intracerebral hemorrhages, deep seated tumors other intracranial pathologies. Introduction of these novel techniques is based on smaller incisions with maximal operative corridors, decreased blood loss, shorter hospital stays, decreased post-operative pain and cosmetically appealing scars that improves patient satisfaction and clinical outcomes. The sophisticated tools like neuroendoscopy have improved light source, and better visualization around the corners. Advanced navigated tools and channel-based retractors help us to target deeply seated lesions with increased precision and minimal disruption of the surrounding neurovascular tissues. Advent of stereotactic radiosurgery has provided us alternative feasible, safe and effective options for treatment of patients who are otherwise not medically stable to undergo complex cranial surgical interventions. This paper review advances in treatment of intracranial pathologies, and how the neurosurgeons and other medical providers at the University of Missouri-Columbia (UMC) are optimizing these treatments for their patients.

Pituitary surgery as alternative to dopamine agonists treatment for microprolactinomas: a cohort study.

OBJECTIVE: Microprolactinomas are currently treated with dopamine agonists. Outcome information on microprolactinoma patients treated by surgery is limited. This study reports the first large series of consecutive non-invasive microprolactinoma patients treated by pituitary surgery and evaluates the efficiency and safety of this treatment. DESIGN: Follow-up of a cohort of consecutive patients treated by surgery. METHODS: Between January 2008 and October 2020, 114 adult patients with pure microprolactinomas were operated on in a single tertiary expert neurosurgical department, using an endoscopic endonasal transsphenoidal approach. Eligible patients presented with a microprolactinoma with no obvious cavernous invasion on MRI. Prolactin was assayed before and after surgery. Disease-free survival was modeled using Kaplan-Meier representation. A cox regression model was used to predict remission. RESULTS: Median follow-up was 18.2 months (range: 2.8-155). In this cohort, 14/114 (12%) patients were not cured by surgery, including ten early surgical failures and four late relapses occurring 37.4 months (33-41.8) after surgery. From Kaplan-Meier estimates, 1-year and 5-year disease free survival was 90.9% (95% CI: 85.6-96.4%) and 81% (95% CI: 71.2-92.1%) respectively. The preoperative prolactinemia was the only significant preoperative predictive factor for remission (P < 0.05). No severe complication was reported, with no anterior pituitary deficiency after surgery, one diabetes insipidus, and one postoperative cerebrospinal fluid leakage properly treated by muscle plasty. CONCLUSIONS: In well-selected microprolactinoma patients, pituitary surgery performed by an expert neurosurgical team is a valid first-line alternative treatment to dopamine agonists.

Outcome in pituitary apoplexy patients, stratified by delay between symptom appearance and surgery: A single center retrospective analysis.

BACKGROUND: There are surgical and conservative management strategies in pituitary apoplexy patients. The use of both methods may lead to delayed surgery in the treatment of pituitary apoplexy. The aim of this study was to evaluate the surgical indications and outcomes of a series of patients with pituitary apoplexy according to delay between surgery and symptom onset. METHODS: A retrospective analysis was performed of 2711 cases with sellar pathologies treated with endoscopic transsphenoidal surgery in a single centre. Inclusion criteria were histopathological confirmation of haemorrhage or necrosis, acute onset and at least one of the following: symptoms of endocrine dysfunction; visual impairment; ophtalmoplegia; headache; or altered consciousness. Patients were divided into three groups based on the number of days from initial symptoms to surgery: early (1-7 day), delayed (8-21 days) and late (>21 day). The indication for and outcome of surgery was reviewed according to symptoms and timing of surgery. RESULTS: Ninety-one patients with pituitary apoplexy underwent surgery. The median time from ictus until surgery was 16 days (1-120 days). Headache was the most common presenting symptom. Visual impairment and ophtalmoplegia were found in 26.4% and 23.1% of patients, respectively. Surgical intervention was successful in treatment of headache in 82 (97,6%) patients. In patients in the early or delayed groups a significant improvement was found between pre- and post-operative headache, ocular palsy, visual impairment, and hormone deficiencies. Patients in the late group also had a significant improvement in headache and visual symptoms after surgery. CONCLUSION: Surgery was sufficient in headache, endocrine, and neuro-ophthalmic outcomes at first 21 days (early and delayed groups). Beyond 21 days (late group), surgery was not effective on recovery of pituitary function.

Transclival approaches for intradural pathologies: historical overview and present scenario.

Recently, endoscopic transsphenoidal transclival approaches have been developed and their role is widely accepted for extradural pathologies. Their application to intradural pathologies is still debated, but is undoubtedly increasing. In the past five decades, different authors have reported various extracranial, anterior transclival approaches for intradural pathologies. The aim of this review is to provide a historical overview of transclival approaches applied to intradural pathologies. PubMed was searched in October 2018 using the terms transcliv*, cliv* intradural, transsphenoidal transcliv*, transoral transcliv*, transcervical transcliv*, transsphenoidal brainstem, and transoral brainstem. Exclusion criteria included not reporting reconstruction technique, anatomical studies, reviews without new data, and transcranial approaches. Ninety-one studies were included in the systematic review. Since 1966, transcervical, transoral, transsphenoidal microsurgical, and, recently, endoscopic routes have been used as a corridor for transclival approaches to treat intradural pathologies. Each approach presents a curve that follows Scott's parabola, with evident phases of enthusiasm that quickly faded, possibly due to high post-operative CSF leak rates and other complications. It is evident that the introduction of the endoscope has led to a significant increase in reports of transclival approaches for intradural pathologies. Various reconstruction techniques and materials have been used, although rates of CSF leak remain relatively high. Transclival approaches for intradural pathologies have a long history. We are now in a new era of interest, but achieving effective dural and skull base reconstruction must still be definitively addressed, possibly with the use of newly available technologies.

Continuous dural suturing for closure of grade 3 leaks after tumor removal via an endoscopic endonasal approach.

Cerebrospinal fluid (CSF) leakage is a major complication after extended endonasal transsphenoidal surgery (EETSS), which is commonly used in the treatment of anterior skull base tumors. Dural suturing and graded reconstruction are promising techniques to further decrease the incidence of postoperative CSF (poCSF) leakage. The effect of continuous dural suturing in endoscopic surgery was investigated in this retrospective study. A total of 79 EETSS patients were included; the procedures were performed for subdural tumor removal by a single endoscopic neurosurgical team. Comparisons were applied between patients who did and did not undergo endoscopic dural suturing after tumor removal. Multivariate logistic regression analysis was performed to identify variables that significantly influenced the incidence of poCSF leakage. In all, 79 adult patients developed Esposito's grade 3 intraoperative high-flow CSF leakage. Ten patients (12.7%) experienced poCSF leakage. One of the 36 patients who underwent intraoperative dural suturing developed poCSF leakage, compared with nine of 43 patients who did not undergo dural suturing (p = 0.016). Regression analysis showed that dural suturing could significantly decrease the incidence of poCSF leakage (p = 0.049, OR 0.108, 95% CI 0.013-0.899). Prophylactic lumbar drainage could also help decrease the CSF leakage rate. Dural suturing under endoscopy is a promising and effective method for application in skull base reconstruction after subdural skull base tumor removal. With future progress, lumbar drainage and even nasoseptal flap placement could be replaced in certain groups of patients undergoing EETSS.

Endoscopic-assisted surgery versus microsurgery for pineal region tumors: a single-center retrospective study.

Pineal region tumors are extremely deep-seated and surgically challenging. The exposure and visualization obtained by microscopic surgery are relatively limiting. The application of high-definition endoscopes has recently provided neurosurgeons with a much more magnified and clearer view of the anatomy in the pineal region. The present study was performed to compare endoscopic-assisted surgery (ES) with microsurgery (MS) for pineal region tumors. We retrospectively analyzed patients admitted to our hospital for treatment of pineal region tumors from January 2016 to June 2019. All patients consented to undergo tumor resection with ES or MS. We compared the extent of resection, postoperative rate of hydrocephalus, complications, and outcomes between the two groups to estimate the safety and efficacy of ES. In total, 41 patients with pineal region tumors were divided into 2 groups: the ES group (n = 20) and MS group (n = 21). The rate of gross total resection was significantly higher in the ES than MS group (90.0% vs. 57.1%, p = 0.04). The rate of postoperative hydrocephalus was significantly lower in the ES than MS group (11.8% vs. 52.9%, p = 0.03). No significant differences were found in complications or the Karnofsky Performance Score between the two groups. ES can be used to safely and effectively achieve complete resection of pineal region tumors. In patients with obstructive hydrocephalus, ES provides a new way to directly open the aqueduct for cerebrospinal fluid recovery following tumor resection.

A Historical Review of Endoscopic Spinal Discectomy.

As an essential component of minimally invasive spine surgery, endoscopic spine surgery (ESS) has continuously evolved and has been accepted as a practical procedure by the worldwide spine community. Especially for lumbar disc herniation (LDH), the percutaneous endoscopic or full-endoscopic discectomy technique has been scientifically proven through randomized controlled trials and meta-analyses to be a good alternative to open discectomy. The initial concept of endoscopic spine discectomy was concerned with indirect disc decompression using various instruments such as blind forceps, a nucleotome, laser, radiofrequency coblation, and some chemical agents. The main surgical field has been shifted from the intradiscal space to the epidural space. Precise and selective discectomy for extruded LDH in the epidural space under high-quality endoscopic visualization is now feasible. Furthermore, the medical applications of ESS is broadening to include spinal stenosis, segmental instability, infection, and even intradural lesions. In this review article, I describe the history of endoscopic spine discectomy and decompression techniques, as well as evolution of the paradigm. This history may help indicate the future of practical ESS.

The Evolution of Transforaminal Endoscopic Spine Surgery.

Transforaminal endoscopic spine surgery (T-ESS) has become a well-accepted technique. The first attempts at percutaneous discectomy by Kambin and Hijikata opened a new chapter of endoscopic spine surgery. By the last quarter of the twentieth century, spine surgeons had begun to adopt this novel technique. Many researchers helped advance endoscopic spine surgery, but the turning point was the description of a safe transforaminal triangle of safety by Parviz Kambin. Since then, the indications for T-ESS have increased as a result of the description of different surgical approaches such as inside-out, outside-in, and half-and-half. We present a review of crucial historical advancements in T-ESS and also discuss the evolution of endoscopes, the techniques used, development of endoscopic instruments and equipment, transforaminal thoracic endoscopy, transforaminal endoscopic interbody fusions, the growth of extended indications, and the future direction of T-ESS. This review provides a detailed description of key historical moments and a bird's-eye view of the vast scope of T-ESS.

Approach selection and outcomes of craniopharyngioma resection: a single-institute study.

Since there are many approaches for successful craniopharyngioma resection, how to choose a suitable approach remains problematic. The aim of this study was to summarize experience of approach selection and outcomes of craniopharyngioma resection in our institute. The data of 182 primary craniopharyngiomas between January 2013 and June 2019 were retrospectively reviewed. Craniopharyngiomas were classified into intrasellar, intra-suprasellar, suprasellar, and intra-third ventricle types based on the location. The surgical approaches, extent of resection, endocrine and ophthalmological outcomes, and complications were evaluated. Gross total resection (GTR) was achieved in 158 (86.8%) patients, near-total resection (NTR) in 20 (11%), and partial resection (PR) in 4 (2.2%). New-onset hypopituitarism occurred in 90 (49.5%) and new-onset diabetes insipidus in 48 (26.4%). Visual function was improved in 110 of the 182 patients, unchanged in 52, and deteriorated in 20. For intra-suprasellar and suprasellar tumors, patients in the endoscopic endonasal approach (EEA) group had higher GTR rate, lower incidence of new-onset hypopituitarism, and better visual outcome than patients in transcranial approach group, but no significant difference in the incidence of new-onset diabetes insipidus was found. There were no surgery-related deaths, and the common complications included permanent oculomotor nerve palsy, hemorrhage, and cerebrospinal fluid leaks. During the follow-up period, tumor recurrence or regrowth occurred in 6.6% of the cases. Tumor location is key for choosing an optimal surgical approach for craniopharyngioma resection. The EEA should be considered as the first choice for intra-suprasellar and suprasellar craniopharyngiomas to achieve better visual outcomes and fewer pituitary hormonal disorders.

Quality of life and olfactory function after suprasellar craniopharyngioma surgery-a single-center experience comparing transcranial and endoscopic endonasal approaches.

The endoscopic endonasal approach to suprasellar craniopharyngiomas has become popular as alternative to transcranial approaches. However, the literature lacks data regarding quality of life and olfactory function. The assessment of the long-term quality of life and olfactory function of all patients harboring a suprasellar craniopharyngioma who underwent surgery in our department has been done. Patient characteristics and perioperative data were gathered in a prospectively maintained database. At the last follow-up visit, the olfactory function and the quality of life (ASBQ, SNOT-22) as well as visual and pituitary function were assessed. Thirteen and 17 patients underwent surgery via a transcranial (T) and endonasal (E) route, respectively. No differences were seen in ASBQ, SNOT-22, and olfactory function between T and E, but in E were more full-time worker and less obesity. CSF leaks occurred in 15% of T and 29% of E (p = 0.43). Patients from group E had a superior visual outcome which was most pronounced in the visual field. The degree of new anterior and posterior pituitary gland deficiency after surgery and in the follow-up was lower in group E. The general and sinonasal quality of life and the olfactory function are equal in E and T. E is associated with a superior visual outcome, lower rates of diabetes insipidus, and lower rates of obesity, but has a higher risk for postoperative CSF leaks.

Recent Technical Advancements of Endoscopic Spine Surgery with Disparate or Disruptive Technologies and Patents.

There have been numerous technical advancements in the field of endoscopic spine surgery since it began in the 1980s and its use further expanded in the 1990s. At present, there are many newer technical advancements in this field, each trying to expand the indications and afford more accurate execution of this procedure. We predict some technologies which can be classified as being disruptive and have the potential of being game changers in this exciting field in the near future.

Suprasellar arachnoid cysts in adults: clinical presentations, radiological features, and treatment outcomes.

A tendency for suprasellar arachnoid cysts (SACs) to occur in young children is known. Data of adult SACs were rare in previous reports. The aim of this study is to discuss their clinical presentations, radiological features, and treatment outcomes based on 23 adult patients who underwent endoscopic fenestration in our hospital between January 2003 and December 2018. Preoperative cyst volume ranged from 12.3 to 72.5 cm3 (mean 39.8 ± 19.8). Endocrine disorders occurred in 7 (30.4%) patients. Hydrocephalus was observed in 20 patients. In the patients with hydrocephalus, the mean preoperative Evans' index (EI) (%) and frontooccipital horn ratio (FOHR) (%) were 44.8 (ranged 32.2-63.4) and 49.6 (ranged 36.7-59.8), respectively. A bivariate correlation showed significant positive association between preoperative cyst volume and preoperative EI or FOHR (Pearson correlation, r = 0.607, p = 0.005; r = 0.583, p = 0.007). The slit-valve phenomenon was observed in 13 (56.5%) patients. Pale/tenacious cyst walls were observed in 12 (52.2%) patients. Postoperatively, all patients achieved the improvement in clinical symptoms and a decrease in cyst size. The mean decreases in cyst volume, EI, and FOHR were 64.7%, 7.89%, and 5.8%, respectively. A bivariate correlation indicated the irrelevance between the postoperative cyst volume and postoperative EI or FOHR (Pearson correlation: r = 0.37, p = 0.11; r = 0.43, p = 0.054). These results reveal that there are a few differences in several aspects between adult patients and child patients. The severity of hydrocephalus is correlated with cyst size in adult patients. Additionally, the excellent outcomes in adult SACs can be obtained by endoscopic fenestration.

Surgical treatment of hypothalamic hamartomas.

Hypothalamic hamartomas are aberrant masses, composed of abnormally distributed neurons and glia. Along endocrine and cognitive symptoms, they may cause epileptic seizures, including the specific gelastic and dacrystic seizures. Surgery is the treatment of drug-resistant hamartoma epilepsy, with associated positive results on endocrine, psychiatric, and cognitive symptoms. Recently, alternatives to open microsurgical treatment have been proposed. We review these techniques and compare their efficacy and safety. Open resection or disconnection of the hamartoma, either through pterional, transcallosal, or transventricular approach, leads to good epileptological control, but its high complication rate, up to 30%, limits its indications. The purely cisternal peduncular forms remain the only indication of open, pterional approach, while other strategies have been developed to overcome the neurological, endocrine, behavioral, or cognitive complications. Laser and radiofrequency thermocoagulation-based disconnection through robot-guided stereo-endoscopy has been proposed as an alternative to open microsurgical resection and stereotactic destruction. The goal is to allow safe and complete disconnection of a possibly complex attachment zone, through a single intraparenchymal trajectory which allows multiple laser or radiofrequency probe trajectory inside the ventricle. The efficacy was high, with 78% of favorable outcome, and the overall complication rate was 8%. It was especially effective in patients with isolated gelastic seizures and pure intraventricular hamartomas. Stereotactic radiosurgery has proved as efficacious and safer than open microsurgery, with around 60% of seizure control and a very low complication rate. Multiple stereotactic thermocoagulation showed very interesting results with 71% of seizure freedom and 2% of permanent complications. Stereotactic laser interstitial thermotherapy (LiTT) seems as effective as open microsurgery (from 76 to 81% of seizure freedom) but causes up to 20% of permanent complications. This technique has however been highly improved by targeting only the epileptogenic onset zone in the hamartoma, as shown on preoperative functional MRI, leading to an improvement of epilepsy control by 45% (92% of seizure freedom) with no postoperative morbidity. All these results suggest that the impact of the surgical procedure does not depend on purely technical matters (laser vs radiofrequency thermocoagulation or stereotactic vs robot-guided stereo-endoscopy) but relies on the understanding of the epileptic network, including inside the hamartoma, the aim being to plan an effective disconnection or lesion of the epileptogenic part while sparing the adjacent functional structures.

Scientific View on Endoscopic Spine Surgery: Can Spinal Endoscopy Become a Mainstream Surgical Tool?

With the health care environment becoming increasingly patient centric and cost-conscious, interest levels in spinal endoscopy are at an all-time high. Patient demand for the least invasive procedures combined with surgeon desire to maximally shorten the postoperative recovery period has further driven this surgical evolution. Mounting scientific evidence demonstrates the noninferiority and perhaps even superiority of endoscopic techniques to more conventional spinal surgery for the treatment of spinal stenosis and disc herniations. Although higher level evidence is much needed to support the clinical utility of the latest endoscopic techniques and surgical indications, it appears that the entrance of spinal endoscopy into the mainstream arena of spinal surgery is inevitable.

Combination analysis on the impact of the initial vision and surgical time for the prognosis of indirect traumatic optic neuropathy after endoscopic transnasal optic canal decompression.

To analyze the impact of the initial vision and surgical time for endoscopic transnasal/transethmosphenoid optic canal decompression (ETOCD) in the treatment of indirect traumatic optic neuropathy (TON). This retrospective case series analysis included 72 patients with indirect TON who underwent ETOCD from August 2017 to May 2019. Visual acuity (VA) was compared before and after surgery to estimate the improvement rate. The overall VA improvement rate of ETOCD was 54.2%. There were 83.3% and 33.3% improvement rate of patients with residual vision and blindness, respectively. VA was improved in 60.9% of patients treated within 3 days, 61.5% treated within 7 days, and 35.0% treated later than 7 days. Of the blindness patients, 50.0%, 37.5%, and 0.0% were treated within 3 days, 3-7 days, and later than 7 days, respectively. Of patients with residual vision, 85.7%, 92.3%, and 70.0% were treated within 3 days, 3-7 days, and later than 7 days, respectively. A statistically significant difference was found between patients with residual vision and those with blindness (P < 0.01), as well as between patients who received ETOCD within 7 days and those who received ETOCD later than 7 days (P = 0.043). The improvement rate of blindness patients managed within 3 days (P = 0.008) and 3-7 days (P = 0.035) was significantly higher than that for patients managed beyond 7 days. Indirect TON patients can directly benefit from ETOCD, and patients with residual vision have better improvement rates. ETOCD should be performed as soon as possible to salvage the patient's VA, especially within the first 7 days. For blindness patients, it is necessary to carry out the surgery within 7 days with increased benefit seen before 3 days.

Endoscopic Endonasal Pituitary Surgery For Nonfunctioning Pituitary Adenomas: Long-Term Outcomes and Management of Recurrent Tumors.

INTRODUCTION: Endoscopic endonasal approaches (EEAs) provide improved access and operative visualization for resection of pituitary adenomas. Although the technique has gained wide acceptance, there is a paucity of data regarding late recurrence. OBJECTIVE: We aim to assess long-term outcomes of patients with nonfunctioning pituitary adenomas (NFPAs) who underwent EEA. METHODS: We reviewed 269 patients operated on for an NFPA between 2005 and 2015. Clinical and radiologic factors including those potentially related to higher chances of recurrence were analyzed. Progression-free survival was analyzed using the Kaplan-Meier method, and univariate and multivariate survival were analyzed using a Cox regression model. RESULTS: The study included 269 patients. The gross total resection rate was 46.0% (n = 124) but cavernous sinus involvement was present in almost half the patients (n = 115). The probability of recurrence at 5 years and 10 years was 22.0% and 47.2%, respectively. The median time to recurrence was 10 years for patients without cavernous sinus involvement and 6 years for those with cavernous sinus involvement. Univariate and multivariate analysis showed that tumor size, cavernous sinus invasion, anterior skull base extensions, and residual tumor were significantly associated with recurrence. CONCLUSIONS: Recurrence rate of NFPA remains high despite the better visualization offered by EEA, especially in those tumors involving the cavernous sinus and/or previously operated on. Repeat surgery is adequate for tumor debulking and decompression of the optic apparatus but is unlikely to achieve gross total resection if a successful previous EEA has been performed. Radiation therapy is an effective option for management of recurrent tumors.

Incorporating New Technologies to Overcome the Limitations of Endoscopic Spine Surgery: Navigation, Robotics, and Visualization.

Recently, spine surgery has gradually evolved from conventional open surgery to minimally invasive surgery, and endoscopic spine surgery (ESS) has become an important procedure in minimally invasive spine surgery. With improvements in the optics, spine endoscope, endoscopic burr, and irrigation pump, the indications of ESS are gradually widening from lumbar to cervical and thoracic spine. ESS was not only used previously for disc herniations that were contained without migration but is also used currently for highly migrated disc herniations and spinal stenosis; thus, the indications of ESS will be further expanded. Although ESS has certain advantages such as less soft tissue dissection and muscle trauma, reduced blood loss, less damage to the epidural blood supply and consequent less epidural fibrosis and scarring, reduced hospital stay, early functional recovery, and improvement of quality of life as well as better cosmesis, several obstacles remain for ESS to be widespread because it has a steep learning curve and surgical outcome is strongly dependent on the surgeon's skillfulness. A solid surgical technique requires reproducibility and ensured safety in addition to surgical outcomes. In this review article, how to improve ESS was investigated by grafting novel technologies such as navigation, robotics, and 3-dimensional and ultraresolution visualization.

A follow-up study on outcomes of endoscopic transsphenoidal approach for acromegaly.

OBJECTIVE: A thorough follow-up study in which the same clinic presents the change in the surgical outcomes of acromegaly over the years, is still lacking in the endoscopic era. In this study, we intended to evaluate the clinical characteristics, radiological features, surgical and late remission rates of newly diagnosed acromegaly patients treated in our clinic between 2014 and 2019 in order to delineate the surgical remission status according to radiological, microscopic, and hormonal features. As a follow-up to our initial report, we also aimed to display the change of surgical remission rates over time in a tertiary center. METHODS: A total of newly diagnosed 106 patients with acromegaly, who underwent endoscopic endonasal trans-sphenoidal approach (EETSA) in the last five years were retrospectively analyzed and presented in this study. Medical records were reviewed in clinical, biochemical, pathological, and radiological aspects to assess the relationship of preoperative patient characteristics with surgical remissions. RESULTS: The percentages of the giant pituitary adenomas (≥4 cm), adenomas with suprasellar extension and adenomas with surgically proven invasion of the cavernous sinus in the present series were 13%, 34%, and 20%, respectively. Gross total resection was achieved in 80% of the patients. Surgical remission and late remission rates were 66% and 86%, respectively. Nine (9.4%) patients in our current report had postoperative transient diabetes insipidus. The mean follow-up period in this series was 36.1 ±â€¯18.1 (range 12-59) months. CONCLUSION: The presented surgical results are considerably better than our published initial series of acromegaly patients operated in the same clinic between 2007 and 2014. The improvement in surgical remission rate support a positive surgical volume - remission rate relationship for acromegaly in the era of endoscopic endonasal skull base approaches. One possible factor for better results may be the increasing surgical experience in EETSA, which follows a trend toward gradual improvement of long-term late remissions via a multidisciplinary approach.

Current and Future of Endoscopic Spine Surgery: What are the Common Procedures we Have Now and What Lies Ahead?

The aging population around the world leads to increasing incidence of degenerative spinal conditions. There is a need for a minimally invasive technique in treatment for spinal conditions to meet the medical complexity and comorbidities that comes with aging. Principles of endoscopy are similar to minimally invasive surgery, which is to decrease pressure on soft tissue crushing from prolonged retraction, avoid soft tissue stripping and dissection, and bone and ligamentous preservation for optimal decompression without excessive destruction. Endoscopic spine surgery techniques started slowly in development in the 1970s to 2000s, with a rapid phase of development since the turn of the 21st century with endoscopic solutions developing in cervical, thoracic, and lumbar conditions with increasing complexity in nature of operation. Technological enhancement with progressively supportive literature is pushing boundaries of endoscopy from the early days of soft tissue procedure to current fusion procedures, endoscopic spine surgery techniques is covering more areas of spine than ever previously possible with good clinical results. We present a review on the current techniques available and postulated near future development for endoscopic spine surgery.