Surgeons preference for lumbar disk surgery: a discrete choice experiment.

PURPOSE: Multiple surgical techniques are practiced to treat sciatica caused by lumbar disk herniation. It is unknown which factors surgeons find important when offering certain surgical techniques. The objective of this study is threefold: 1) determine the relative weight surgeons place on various characteristics of sciatica treatment, 2) determine the trade-offs surgeons make between these characteristics and 3) identify preference heterogeneity for sciatica treatment. METHODS: A discrete choice experiment was conducted among members of two international neurosurgical organizations. Surgeons were asked on their preferences for surgical techniques using specific scenarios based on five characteristics: effectiveness on leg pain, risk of recurrent disk herniation, duration of postoperative back pain, risk of complications and recovery period. RESULTS: Six-hundred and forty-one questionnaires were filled in, the majority by neurosurgeons. All characteristics significantly influenced the preferences of the respondents. Overall, the risk of complications was the most important characteristic in the decision to opt-in or opt-out for surgery (35.7%). Risk of recurrent disk herniation (19.6%), effectiveness on leg pain (18.8%), postoperative back pain duration (13.5%) and length of recovery period (12.4%) followed. Four latent classes were identified, which was partly explained by the tenure of the surgeon. Surgeons were willing to trade-off 57.8% of effectiveness on leg pain to offer a treatment that has a 1% complication risk instead of 10%. CONCLUSION: In the context of this discrete choice experiment, it is shown that neurosurgeons consider the risk of complications as most important when a surgical technique is offered to treat sciatica, while the risk of recurrent disk herniation and effectiveness are also important factors. Neurosurgeons were prepared to trade off substantial amounts of effectiveness to achieve lower complication rates.

Quality of conscious sedation using dexmedetomidine during full-endoscopic transforaminal discectomy for sciatica: a prospective case series.

INTRODUCTION: Percutaneous transforaminal endoscopic discectomy (PTED) is increasing in popularity as a minimally invasive procedure to treat sciatica caused by lumbar disc herniation. The objective of the current study is to evaluate safety of and satisfaction with the use of local anesthesia and conscious sedation during PTED. METHODS: During a 12-month inclusion period, patients were prospectively included in this single center case series. Inclusion criteria consisted of sciatica lasting for at least 6 weeks, which was not responsive to conservative treatment. PTED was performed using dexmedetomidine as sedative and lidocaine as local anesthesia. Measurements included the numeric rating scale (NRS, from 0 to 10) for leg pain, back pain, COMI-back, and NRS for anxiety of anesthesia and perioperative continuously monitored hemodynamics. Furthermore, satisfaction with the sedation was scored by patients, surgeons, and anesthesiologists. RESULTS: Ninety-two consecutive patients were enrolled. Of all patients, 18.5% had anxiety for undergoing surgery under local anesthesia. All but one patient underwent PTED successfully. There was one case of conversion due to severe, uncontrollable back pain during surgery. Throughout the procedure, hemodynamic parameters showed no clinically relevant change compared to baseline. Anesthesiologic complications were three cases (3.4%) of self-limiting hypoxia and five cases (8.6%) of nausea and/or vomiting. Surgeons and anesthesiologists had a high satisfaction rate (> 87%) with the conscious sedation during the procedure, while satisfaction with sedation was scored 8.4 ± 2.2 by patients. CONCLUSIONS: PTED performed under local anesthesia and conscious sedation is safe and effective to treat sciatica and yields high satisfaction rates from surgeons, anesthesiologists, and patients.

Cost-effectiveness of full endoscopic versus open discectomy for sciatica.

OBJECTIVE: To assess the costs and cost-effectiveness of percutaneous transforaminal endoscopic discectomy (PTED) compared with open microdiscectomy among patients with sciatica. METHODS: This economic evaluation was conducted alongside a 12-month multicentre randomised controlled trial with a non-inferiority design, in which patients were randomised to PTED or open microdiscectomy. Patients were aged from 18 to 70 years and had at least 6 weeks of radiating leg pain caused by lumbar disc herniation. Effect measures included leg pain and quality-adjusted life years (QALYs), as derived using the EQ-5D-5L. Costs were measured from a societal perspective. Missing data were multiply imputed, bootstrapping was used to estimate statistical uncertainty, and various sensitivity analyses were conducted to determine the robustness. RESULTS: Of the 613 patients enrolled, 304 were randomised to PTED and 309 to open microdiscectomy. Statistically significant differences in leg pain and QALYs were found in favour of PTED at 12 months follow-up (leg pain: 6.9; 95% CI 1.3 to 12.6; QALYs: 0.040; 95% CI 0.007 to 0.074). Surgery costs were higher for PTED than for open microdiscectomy (ie, €4500/patient vs €4095/patient). All other disaggregate costs as well as total societal costs were lower for PTED than for open microdiscectomy. Cost-effectiveness acceptability curves indicated that the probability of PTED being less costly and more effective (ie, dominant) compared with open microdiscectomy was 99.4% for leg pain and 99.2% for QALYs. CONCLUSIONS: Our results suggest that PTED is more cost-effective from the societal perspective compared with open microdiscectomy for patients with sciatica. TRIAL REGISTRATION NUMBER: NCT02602093.

How to Identify Responders and Nonresponders to Dorsal Root Ganglion-Stimulation Aimed at Eliciting Motor Responses in Chronic Spinal Cord Injury: Post Hoc Clinical and Neurophysiological Tests in a Case Series of Five Patients.

OBJECTIVE: While integrity of spinal pathways below injury is generally thought to be an important factor in the success-rate of neuromodulation strategies for spinal cord injury (SCI), it is still unclear how the integrity of these pathways conveying the effects of stimulation should be assessed. In one of our institutional case series of five patients receiving dorsal root ganglion (DRG)-stimulation for elicitation of immediate motor response in motor complete SCI, only two out of five patients presented as responders, showing immediate muscle activation upon DRG-stimulation. The current study focuses on post hoc clinical-neurophysiological tests performed within this patient series to illustrate their use for prediction of spinal pathway integrity, and presumably, responder-status. MATERIALS AND METHODS: In a series of three nonresponders and two responders (all male, American Spinal Injury Association [ASIA] impairment scale [AIS] A/B), a test-battery consisting of questionnaires, clinical measurements, as well as a series of neurophysiological measurements was performed less than eight months after participation in the initial study. RESULTS: Nonresponders presented with a complete absence of spasticity and absence of leg reflexes. Additionally, nonresponders presented with close to no compound muscle action potentials (CMAPs) or Hofmann(H)-reflexes. In contrast, both responders presented with clear spasticity, elicitable leg reflexes, CMAPs, H-reflexes, and sensory nerve action potentials, although not always consistent for all tested muscles. CONCLUSIONS: Post hoc neurophysiological measurements were limited in clearly separating responders from nonresponders. Clinically, complete absence of spasticity-related complaints in the nonresponders was a distinguishing factor between responders and nonresponders in this case series, which mimics prior reports of epidural electrical stimulation, potentially illustrating similarities in mechanisms of action between the two techniques. However, the problem remains that explicit use and report of preinclusion clinical-neurophysiological measurements is missing in SCI literature. Identifying proper ways to assess these criteria might therefore be unnecessarily difficult, especially for nonestablished neuromodulation techniques.

The Dorsal Root Ganglion as a Novel Neuromodulatory Target to Evoke Strong and Reproducible Motor Responses in Chronic Motor Complete Spinal Cord Injury: A Case Series of Five Patients.

OBJECTIVES: Current strategies for motor recovery after spinal cord injury (SCI) aim to facilitate motor performance through modulation of afferent input to the spinal cord using epidural electrical stimulation (EES). The dorsal root ganglion (DRG) itself, the first relay station of these afferent inputs, has not yet been targeted for this purpose. The current study aimed to determine whether DRG stimulation can facilitate clinically relevant motor response in motor complete SCI. MATERIALS AND METHODS: Five patients with chronic motor complete SCI were implanted with DRG leads placed bilaterally on level L4 during five days. Based on personalized stimulation protocols, we aimed to evoke dynamic (phase 1) and isotonic (phase 2) motor responses in the bilateral quadriceps muscles. On days 1 and 5, EMG-measurements (root mean square [RMS] values) and clinical muscle force measurements (MRC scoring) were used to measure motor responses and their reproducibility. RESULTS: In all patients, DRG-stimulation evoked significant phase 1 and phase 2 motor responses with an MRC ≥4 for all upper leg muscles (rectus femoris, vastus lateralis, vastus medialis, and biceps femoris) (p < 0.05 and p < 0.01, respectively), leading to a knee extension movement strong enough to facilitate assisted weight bearing. No significant differences in RMS values were observed between days 1 and 5 of the study, indicating that motor responses were reproducible. CONCLUSION: The current paper provides first evidence that bilateral L4 DRG stimulation can evoke reproducible motor responses in the upper leg, sufficient for assisted weight bearing in patients with chronic motor complete SCI. As such, a new target for SCI treatment has surfaced, using existing stimulation devices, making the technique directly clinically accessible.

Isotopic Scintigraphy in Intrathecal Drug Delivery Failure: A Single-Institution Case Series.

BACKGROUND: The aim of this study was to assess the feasibility and diagnostic accuracy of an optimized 111 Indium-diethylenetriamine-penta-acetic-acid single-photon-emission computed tomography (CT) (111 In-DTPA SPECT-CT) examination in patients with suspected intrathecal drug delivery (ITDD) failure. MATERIALS AND METHODS: Retrospective analysis of routinely collected observational data from a case series of patients in the setting of the academic Center for Pain Medicine, Departments of Radiology and Nuclear Medicine and Neurosurgery. Twenty-seven patients participated between January 2014 and January 2019. Thirty-six optimized examinations including standardized pump flow rate with additional SPECT-CT imaging and a stepwise standardized analysis were performed. A 10 mL mixture of medication and 20 MBq 111In-DTPA was injected into the pump reservoir. Planar and SPECT-CT images were acquired at 24, 48, and 72 hours (h) after injection and at 96 hours and/or seven days, if needed. All images were reassessed by the first two authors using an optimized procedure. RESULTS AND CONCLUSIONS: Twenty-two abnormalities were identified in 21 examinations, with these abnormalities consisting of leakage (n = 7), spinal catheter obstruction (n = 7), and cerebrospinal fluid flow obstruction (n = 8). Interventions (n = 19) confirmed the cause of ITDD failure. A false-positive finding at follow-up (n = 1) and a false-negative finding (n = 1) were encountered. Sensitivity was 95% (20/21) and the specificity 93% (14/15). A significant difference (p < 0.001) was found between the accuracy of the conventical and the optimized analysis. The optimized 111 In-DTPA SPECT-CT examination is a powerful diagnostic tool for detecting the cause of ITDD failure.

Experiences of neurological surgeons with malpractice lawsuits.

OBJECTIVE: As a specialty that treats acute pathology and refractory pain, neurosurgery is at risk for high liability, making the practice of defensive medicine quite common. The extent to which the practice of defensive medicine is linked to experience with malpractice lawsuits remains unclear. The aims of this study were to clarify this by surveying neurosurgeons about the frequency of experiencing medical lawsuits and to show how neurosurgeons reflect on facing such lawsuits. METHODS: A survey consisting of 24 questions was distributed among members of the Congress of Neurological Surgeons. The survey consisted of four parts: 1) demographics of participants; 2) the way malpractice lawsuits affect the way respondents practice medicine; 3) experiences with medical malpractice lawsuits; and 4) the effect of the medical malpractice environment on one's own practice of medicine. RESULTS: There were a total of 490 survey respondents, 83.5% of whom were employed in the US. Of the respondents, 39.5% stated they were frequently or always concerned about being sued, and 77.4% stated their fear had led to a change in how they practice medicine. For 58.4%, this change led to the practice of defensive medicine, while for others it led to more extensive documentation (14.3%) and/or to referring or dropping complex cases (12.4%).Among the respondents, 80.9% at some time were named in a medical malpractice lawsuit and 12.3% more than 10 times. The main concerns expressed about being sued included losing confidence and practicing defensive medicine (17.8%), personal assets being at risk (16.9%), and being named in the National Practitioner Data Bank (15.6%). Given the medical malpractice environment, 58.7% of respondents considered referring complex patient cases, whereas 36.5% considered leaving the practice of medicine. The fear of being sued (OR 4.06, 95% CI 2.53-6.51) and the consideration of limiting the scope of practice (OR 3.08, 1.80-5.20) were both independently associated with higher odds of considering leaving the practice of medicine. CONCLUSIONS: The current medicolegal landscape has a profound impact on neurosurgical practice. The fear of being sued, the financial aspects of practicing defensive medicine, and the proportion of neurosurgeons who are considering leaving the practice of medicine emphasize the need for a shift in the medicolegal landscape to a system in which fear of being sued does not play a dominant role and the interests of patients are protected.

Catheter Access Port (Computed Tomography) Myelography in Intrathecal Drug Delivery Troubleshooting: A Case Series of 70 Procedures.

OBJECTIVES: Intrathecal drug delivery is used for the treatment of intractable spasticity, dystonia, and pain. When the symptomatology fails to respond to therapy, the cause could be failure of the medication infusion. The purpose of this study is to assess pump catheter access port (CAP)-myelography and CAP-CT-myelography as advanced imaging methods in treatment failure. MATERIALS AND METHODS: We analyzed observational routinely collected data of 70 CAP procedures with 2D/3D reconstructions and additional imaging of 53 adult patients where the cause of treatment was unclear between November 2013 and November 2018. CAP-myelography and CAP-CT myelography were performed with postprocessing 2D/3D reconstructions. When myelography could not be obtained or when the result did not reveal the cause of the treatment failure, additional procedures, such as noncontrast CT, MRI, lumbar puncture CT, and 111Indium-DTPA SPECT-CT, were performed. RESULTS: CAP fluid aspiration prior to contrast medium injection was not possible (N = 17). In one case, contrast was injected into the pump pocket unintentionally (N = 1). Of 70 procedures, 24% were unaspiratable. The remaining CAP myelography examinations (N = 52) had limited value for the diagnosis. CAP-CT myelography (N = 50) was normal (N = 31). The abnormal results (N = 19) were dorsal dural leak (N = 5), subdural catheter position (N = 2), limited rostral flow of contrast material (N = 4), limited and abnormal contrast distribution (N = 3), obstruction of rostral flow (N = 2), a leak at the pump-catheter connection (N = 1), and a sheared catheter localized in the pump pocket (N = 2). Limited contrast distributions were found to be false positive findings (N = 2). Four normal CT-CAP myelographic procedures were false negatives, as the reference tests revealed a cause of intrathecal drug delivery (ITDD) failure. The CAP-CT procedures resulted in a sensitivity of 81% (17/21) and a specificity of 93% (27/29). CONCLUSIONS: CAP-CT myelography with 2D/3D reconstructions is an essential step in the diagnostic algorithm for cases involving ITDD failure.

Neurosurgeons' opinions on the prenatal management of myelomeningocele.

OBJECTIVE: Improvements in imaging and surgical technological innovations have led to the increasing implementation of fetal surgical techniques. Open fetal surgery has demonstrated more favorable clinical outcomes in children born with open myelomeningocele (MMC) than those following postnatal repair. However, primarily because of maternal risks but also because of fetal risks, fetal surgery for MMC remains controversial. Here, the authors evaluated the contemporary management of MMC in the hope of identifying barriers and facilitators for neurosurgeons in providing fetal surgery for MMC. METHODS: An online survey was emailed to members of the Congress of Neurological Surgeons (CNS) and the International Society for Pediatric Neurosurgery (ISPN) in March 2019. The survey focused on 1) characteristics of the respondents, 2) the practice of counseling on and managing prenatally diagnosed MMC, and 3) barriers, facilitators, and expectations of fetal surgery for MMC. Reminders were sent to improve the response rate. RESULTS: A total of 446 respondents filled out the survey, most (59.2%) of whom specialized in pediatric neurosurgery. The respondents repaired an average of 9.6 MMC defects per year, regardless of technique. Regardless of the departments in which respondents were employed, 91.0% provided postnatal repair of MMC, 13.0% open fetal repair, and 4.9% fetoscopic repair. According to the surgeons, the most important objections to performing open fetal surgery were a lack of cases available to become proficient in the technique (33.8%), the risk of maternal complications (23.6%), and concern for fetal complications (15.2%). The most important facilitators according to advocates of prenatal closure are a decreased rate of shunt dependency (37.8%), a decreased rate of hindbrain herniation (27.0%), and an improved rate of motor function (18.9%). Of the respondents, only 16.9% agreed that open fetal surgery should be the standard of care. CONCLUSIONS: The survey results showed diversity in the management of patients with MMC. In addition, significant diversity remains regarding fetal surgery for MMC closure. Despite the apparent benefits of open fetal surgery in selected pregnancies, only a minority of centers and providers offer this technique. As a more technically demanding technique that requires multidisciplinary effort with less well-established long-term outcomes, fetoscopic surgery may face similar limited implementation, although the surgery may pose fewer maternal risks than open fetal surgery. Centralization of prenatal treatment to tertiary care referral centers, as well as the use of sophisticated training models, may help to augment the most commonly cited objection to the implementation of prenatal closure, which is the overall limited caseload.

A novel noninstrumented surgical approach for foramen reconstruction for isthmic spondylolisthesis in patients with radiculopathy: preliminary clinical and radiographic outcomes.

OBJECTIVE The health care costs for instrumented spine surgery have increased dramatically in the last few decades. The authors present a novel noninstrumented surgical approach for patients with isthmic spondylolisthesis, with clinical and radiographic results. METHODS Charts of patients who underwent this technique were reviewed. The procedure consisted of nerve root decompression by reconstruction of the intervertebral foramen. This was achieved by removal of the pedicle followed by noninstrumented posterolateral fusion in which autologous bone graft from the right iliac crest was used. Outcomes regarding radicular complaints, bony fusion, progression of the slip, and complications were evaluated using patient history and radiographs obtained at follow-up intervals of 3-18 months after surgery. RESULTS A total of 58 patients with a mean age of 47 years were treated with this method. Partial removal of the pedicle was performed in 93.1% of the cases, whereas in 6.9% of the cases the entire pedicle was removed. The mean duration of surgery was 216.5 ± 54.5 minutes (range 91-340 minutes). The mean (± SD) duration of hospitalization was 10.1 ± 2.9 days (range 5-18 days). After 3 months of follow-up, 86% of the patients reported no leg pain, and this dropped to 81% at last follow-up. Radiographic follow-up showed bony fusion in 87.7% of the patients. At 1 year, 5 patients showed progression of the slip, which in 1 patient prompted a second operation within 1 year. No major complications occurred. CONCLUSIONS Treatment of isthmic spondylolisthesis by reconstruction of the intervertebral neuroforamen and posterolateral fusion in situ is a safe procedure and has comparable results with the existing techniques. Cost-effectiveness research comparing this technique to conventional instrumented fusion techniques is necessary to evaluate the merits for both patients and society.

How I do it: percutaneous transforaminal endoscopic discectomy for lumbar disk herniation.

BACKGROUND: Percutaneous transforaminal endoscopic discectomy (PTED) has emerged as a less invasive technique to treat symptomatic lumbar disk herniation (LDH). PTED is performed under local anesthesia with the advantage of immediate intraoperative feedback of the patient. In this paper, the technique is described as conducted in our hospital. METHODS: PTED is performed under local anesthesia in prone position on thoracopelvic supports. The procedure is explained stepwise: e.g. marking, incision, introduction of the 18-gauge needle and guidewire to the superior articular process, introduction of the TomShidi needle and foraminotomy up to 9 mm, with subsequently removal of disk material through the endoscope. Scar size is around 8 mm. CONCLUSION: PTED seems a promising alternative to conventional discectomy in patients with LDH and can be performed safely.

Current practice of cervical disc arthroplasty: a survey among 383 AOSpine International members.

OBJECTIVE The use of cervical disc arthroplasty (CDA) in spinal practice is controversial. This may be explained by the lack of studies with a large sample size and long-term outcomes. With this survey the authors aimed to evaluate the opinions of spine surgeons on the use of CDA in the current treatment of cervical disc herniation (CDH). METHODS A web-based survey was sent to all members of AOSpine International by email using SurveyMonkey on July 18, 2016. A single reminder was sent on August 18, 2016. Questions included geographic location; specialty; associated practice model; number of discectomies performed annually; the use of CDA, anterior cervical discectomy (ACD), and anterior cervical discectomy and fusion (ACDF); and the expectations for clinical outcomes of these procedures. RESULTS A total of 383 questionnaires were analyzed. Almost all practitioners (97.9%) were male, with a mean of 15.0 ± 9.7 years of clinical experience. The majority of responders were orthopedic surgeons (54.6%). 84.3% performed ACDF as the standard technique for CDH. 47.8% of the surgeons occasionally used CDA, whereas 7.3% used CDA as standard approach for CDH. The most common arthroplasty device used was the ProDisc-C. Low evidence for benefits and higher costs were the most important reasons for not offering CDA. The risk of adjacent-level disease was considered smaller for CDA as compared with ACDF. However, ACDF was expected to have the highest effectiveness on arm pain (87.5%), followed by CDA (77.9%), while ACD had the least (12.6%). CONCLUSIONS In this survey, CDA was not considered to be the routine procedure to treat CDH. Reported benefits included the reduced risk of adjacent-level disease and preservation of motion of the neck. Lack of enough evidence on its effectiveness as well as higher costs were considered to be disadvantages of CDA. More research should be conducted on the implementation impact of CDA and the cost-effectiveness from society's perspective.

Anterior cervical discectomy without fusion for a symptomatic cervical disk herniation.

BACKGROUND: Cervical radiculopathy is characterized by dysfunction of the nerve root usually caused by a cervical disk herniation. The most important symptom is pain, radiating from the neck to the arm. When conservative treatment fails, surgical treatment is indicated to relieve symptoms. During the last decades, multiple fusion techniques have been developed, although without clinical evidence for added value of fusion over non-fusion. METHODS: The surgical procedure of anterior cervical discectomy without fusion is performed step by step, leading to removal of the entire intervertebral disk. CONCLUSION: Anterior cervical discectomy without fusion is a safe and effective treatment for cervical disk herniation.

Incomplete spinal cord injury following minor trauma in two siblings with spondylocostal dysostis type 6.

Biallelic pathogenic variants of the RIPPLY2 gene have been recognized to cause a subtype of autosomal recessive spondylocostal dysostosis (SCDO6), characterized by predominant cervical spine malformation with minor or absent involvement of the ribs. To date, RIPPLY2 associated SCDO6 has been described in ten patients in five studies with accompanying clinical symptoms varying from transient and recurrent torticollis to flaccid quadriplegia. Here, we describe two additional patients in one family in which the c.A238T:p.Arg80* RIPPLY2 mutation in the homozygous state, was associated with severe malformation of the posterior elements of the cervical vertebral column. In both cases neurological symptoms occurred early in life due to spinal cord compromise. These two cases, in keeping with previous reports, highlight the early and progressive natural history of cervical deformity in this rare skeletal dysplasia and the need for close neurological and radiological surveillance. Surgical decision-making needs to carefully balance the need for early intervention to protect spinal cord function on one hand, with the problem of bone malformation and skeletal immaturity on the other.

Case report: High-resolution, intra-operative µDoppler-imaging of spinal cord hemangioblastoma.

Surgical resection of spinal cord hemangioblastomas remains a challenging endeavor: the neurosurgeon's aim to reach total tumor resections directly endangers their aim to minimize post-operative neurological deficits. The currently available tools to guide the neurosurgeon's intra-operative decision-making consist mostly of pre-operative imaging techniques such as MRI or MRA, which cannot cater to intra-operative changes in field of view. For a while now, spinal cord surgeons have adopted ultrasound and its submodalities such as Doppler and CEUS as intra-operative techniques, given their many benefits such as real-time feedback, mobility and ease of use. However, for highly vascularized lesions such as hemangioblastomas, which contain up to capillary-level microvasculature, having access to higher-resolution intra-operative vascular imaging could potentially be highly beneficial. µDoppler-imaging is a new imaging modality especially fit for high-resolution hemodynamic imaging. Over the last decade, µDoppler-imaging has emerged as a high-resolution, contrast-free sonography-based technique which relies on High-Frame-Rate (HFR)-ultrasound and subsequent Doppler processing. In contrast to conventional millimeter-scale (Doppler) ultrasound, the µDoppler technique has a higher sensitivity to detect slow flow in the entire field-of-view which allows for unprecedented visualization of blood flow down to sub-millimeter resolution. In contrast to CEUS, µDoppler is able to image high-resolution details continuously, without being contrast bolus-dependent. Previously, our team has demonstrated the use of this technique in the context of functional brain mapping during awake brain tumor resections and surgical resections of cerebral arteriovenous malformations (AVM). However, the application of µDoppler-imaging in the context of the spinal cord has remained restricted to a handful of mostly pre-clinical animal studies. Here we describe the first application of µDoppler-imaging in the case of a patient with two thoracic spinal hemangioblastomas. We demonstrate how µDoppler is able to identify intra-operatively and with high-resolution, hemodynamic features of the lesion. In contrast to pre-operative MRA, µDoppler could identify intralesional vascular details, in real-time during the surgical procedure. Additionally, we show highly detailed post-resection images of physiological human spinal cord anatomy. Finally, we discuss the necessary future steps to push µDoppler to reach actual clinical maturity.

Assessing the Learning Process of Transforaminal Endoscopic Discectomy for Sciatica.

OBJECTIVE: Percutaneous transforaminal endoscopic discectomy (PTED) is gaining popularity by both surgeons and patients as a less invasive treatment option for sciatica. Concerns, however, exist for its learning curve. No previous study has assessed the learning process of PTED. Hereby we present the learning process of 3 surgeons learning PTED. METHODS: This analysis was conducted alongside a multicenter randomized controlled trial. After attending a cadaveric workshop, 3 spine-dedicated surgeons started performing PTED, initially under the supervision of a senior surgeon. After each 5 cases, and up to case 20, the learning process was evaluated using the validated questionnaires (objective structured assessment of technical skills [OSATS], global operative assessment of laparoscopic skills [GOALS]) and a 10-step checklist specifically developed for PTED. RESULTS: In total, 3 learning curve surgeons performed a total of 161 cases. Based on self-assessment, surgeons improved mostly in the domains "time and motion," "respect for tissue," and "knowledge and handling of instruments." Learning curve surgeons were more able to detect differences in performances on the OSATS than the senior surgeon. Based on the GOALS, the biggest improvements could be seen in "depth-perception" and "autonomy." Based on the 10-item specific checklist, all surgeons performed all 10 steps by case 10, while only 1 surgeon performed all steps adequately by case 15. CONCLUSION: Based on these study results, PTED appears to be successfully adopted stepwise by 3 spine-dedicated surgeons. From 15 cases on, most steps are performed adequately. However, more cases might be necessary to achieve good clinical results. Validated tools are needed to determine the cutoff when a surgeon should be able to perform PTED independently.

Surgeons Learning Curve of Transforaminal Endoscopic Discectomy for Sciatica.

OBJECTIVE: Full-endoscopic spine surgery is gaining interest as a less-invasive alternative to treat sciatica caused by a lumbar disc herniation. Concerns, however, exist with the learning curve as percutaneous transforaminal endoscopic discectomy (PTED) appears to be more difficult to be performed compared to other techniques. In this study, the clinical outcomes during and after the learning curve are presented of 3 surgeons naïve to PTED. METHODS: In the first phase of a randomized controlled, noninferiority trial comparing PTED with microdiscectomy, 3 surgeons were trained in the PTED-procedure by a senior surgeon. After performing up to 20 cases under supervision, they started performing PTED on their own. Results of the early cases were compared to the later cases (>20). Furthermore, complications and reoperations were compared. Finally, differences in clinical outcomes between surgeons were compared. RESULTS: At 12 months of follow-up, 87% of the patients had follow-up data available. In general, there were no significant differences in patient-reported outcomes between the early and later PTED cases. Furthermore, outcomes of the early PTED cases were comparable to the outcomes of microdiscectomy, while the later PTED cases had small, but more favorable outcomes compared to microdiscectomy. Two learning curve surgeons had substantially higher rates of reoperations within 1 year, compared to the senior surgeon or the microdiscectomy group. Duration of surgery was also longer for all learning curve surgeons. Finally, when comparing clinical outcomes of patients undergoing PTED versus microdiscectomy, there appears to be some statistically significant differences in outcomes compared between the senior and 3 learning curve surgeons. CONCLUSION: PTED appears to be safe to be adopted by surgeons naïve to the procedure when they are initially supervised by an experienced senior surgeon. Duration of surgery and risk of repeated surgery are increased during the learning curve, but patient-reported outcomes of the early PTED cases are similar to the outcomes of later PTED cases, and similar to the outcomes of microdiscectomy cases. This study underlines the need for an experienced mentor for surgeons to safely adopt PTED.

Body Image and Cosmesis after Percutaneous Transforaminal Endoscopic Discectomy versus Conventional Open Microdiscectomy for Sciatica.

STUDY DESIGN: Randomized controlled trial. OBJECTIVE: Percutaneous transforaminal endoscopic discectomy (PTED) was introduced as a less invasive procedure to treat sciatica. Even though the PTED has a small scar size, it is unknown if PTED also leads to better scar-related patient-reported outcomes. Therefore, we aimed to compare scar-related outcomes between patients undergoing PTED vs open microdiscectomy. METHODS: Patients with at least 6 weeks of radiating leg pain were randomized in a 1:1 ratio to PTED or open microdiscectomy. Scar-related patient-reported outcomes were measured using the Body Image Score (BIS), Cosmesis Scale (CS) and a 0-10 numeric rating scale (NRS) on scar esthetic. RESULTS: Of the 530 included patients, 286 patients underwent PTED and 244 underwent open microdiscectomy as allocated. At 12 months of follow-up, 95% of the patients had data available. At 12 months, the BIS was 6.2 ± 1.7 in the PTED-group and 6.6 ± 1.9 in the open microdiscectomy group (between-group difference .4, 95% CI .2 to .7). CS was 21.3 ± 3.0 in the PTED-group and 18.6 ± 3.4 in the open microdiscectomy group (between-group difference -2.7, 95% CI -3.1 to -2.3). Average NRS for scar esthetic was 9.2 ± 1.3 and 7.8 ± 1.6 in the PTED and open microdiscectomy groups, respectively (between-group difference -1.4, 95% CI -1.6 to -1.2). CONCLUSIONS: PTED leads to a higher self-rated scar esthetic as compared to open microdiscectomy, while self-reported body image seems to be comparable between both groups. Therefore, from an esthetic point, PTED seems to be the preferred technique to treat sciatica.

Patient preferences for treatment of lumbar disc herniation: a discrete choice experiment.

OBJECTIVE: Lumbar discectomy is a frequently performed procedure to treat sciatica caused by lumbar disc herniation. Multiple surgical techniques are available, and the popularity of minimally invasive surgical techniques is increasing worldwide. Clinical outcomes between these techniques may not show any substantial differences. As lumbar discectomy is an elective procedure, patients' own preferences play an important role in determining the procedure they will undergo. The aims of the current study were to determine the relative preference weights patients apply to various attributes of lumbar discectomy, determine if patient preferences change after surgery, identify preference heterogeneity for choosing surgery for sciatica, and calculate patient willingness to pay for other attributes. METHODS: A discrete choice experiment (DCE) was conducted among patients with sciatica caused by lumbar disc herniation. A questionnaire was administered to patients before they underwent surgery and to an independent sample of patients who had already undergone surgery. The DCE required patients to choose between two surgical techniques or to opt out from 12 choice sets with alternating characteristic levels: waiting time for surgery, out-of-pocket costs, size of the scar, need of general anesthesia, need for hospitalization, effect on leg pain, and duration of the recovery period. RESULTS: A total of 287 patients were included in the DCE analysis. All attributes, except scar size, had a significant influence on the overall preferences of patients. The effect on leg pain was the most important characteristic in the decision for a surgical procedure (by 44.8%). The potential out-of-pocket costs for the procedure (28.8%), the wait time (12.8%), need for general anesthesia (7.5%), need for hospitalization (4.3%), and the recovery period (1.8%) followed. Preferences were independent of the scores on patient-reported outcome measures and baseline characteristics. Three latent classes could be identified with specific preference patterns. Willingness-to-pay was the highest for effectiveness on leg pain, with patients willing to pay €3133 for a treatment that has a 90% effectiveness instead of 70%. CONCLUSIONS: Effect on leg pain is the most important factor for patients in deciding to undergo surgery for sciatica. Not all proposed advantages of minimally invasive spine surgery (e.g., size of the scar, no need of general anesthesia) are necessarily perceived as advantages by patients. Spine surgeons should propose surgical techniques for sciatica, not only based on own ability and proposed eligibility, but also based on patient preferences as is part of shared decision making.

Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial.

OBJECTIVE: To assess whether percutaneous transforaminal endoscopic discectomy (PTED) is non-inferior to conventional open microdiscectomy in reduction of leg pain caused by lumbar disc herniation. DESIGN: Multicentre randomised controlled trial with non-inferiority design. SETTING: Four hospitals in the Netherlands. PARTICIPANTS: 613 patients aged 18-70 years with at least six weeks of radiating leg pain caused by lumbar disc herniation. The trial included a predetermined set of 125 patients receiving PTED who were the learning curve cases performed by surgeons who did not do PTED before the trial. INTERVENTIONS: PTED (n=179) compared with open microdiscectomy (n=309). MAIN OUTCOME MEASURES: The primary outcome was self-reported leg pain measured by a 0-100 visual analogue scale at 12 months, assuming a non-inferiority margin of 5.0. Secondary outcomes included complications, reoperations, self-reported functional status as measured with the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery. Outcomes were measured until one year after surgery and were longitudinally analysed according to the intention-to-treat principle. Patients belonging to the PTED learning curve were omitted from the primary analyses. RESULTS: At 12 months, patients who were randomised to PTED had a statistically significantly lower visual analogue scale score for leg pain (median 7.0, interquartile range 1.0-30.0) compared with patients randomised to open microdiscectomy (16.0, 2.0-53.5) (between group difference of 7.1, 95% confidence interval 2.8 to 11.3). Blood loss was less, length of hospital admission was shorter, and timing of postoperative mobilisation was earlier in the PTED group than in the open microdiscectomy group. Secondary patient reported outcomes such as the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery, were similarly in favour of PTED. Within one year, nine (5%) in the PTED group compared with 14 (6%) in the open microdiscectomy group had repeated surgery. Per protocol analysis and sensitivity analyses including the patients of the learning curve resulted in similar outcomes to the primary analysis. CONCLUSIONS: PTED was non-inferior to open microdiscectomy in reduction of leg pain. PTED resulted in more favourable results for self-reported leg pain, back pain, functional status, quality of life, and recovery. These differences, however, were small and may not reach clinical relevance. PTED can be considered as an effective alternative to open microdiscectomy in treating sciatica. TRIAL REGISTRATION: NCT02602093ClinicalTrials.gov NCT02602093.