Minimally Invasive Spine Surgery Research Articles

Navigation Techniques in Endoscopic Spine Surgery.

Endoscopic spine surgery (ESS) advances the principles of minimally invasive surgery, including minor collateral tissue damage, reduced blood loss, and faster recovery times. ESS allows for direct access to the spine through small incisions and direct visualization of spinal pathology via an endoscope. While this technique has many applications, there is a steep learning curve when adopting ESS into a surgeon's practice. Two types of navigation, optical and electromagnetic, may allow for widespread utilization of ESS by engendering improved orientation to surgical anatomy and reduced complication rates. The present review discusses these two available navigation technologies and their application in endoscopic procedures by providing case examples. Furthermore, we report on the future directions of navigation within the discipline of ESS.

Clinical Features and Management of Seizure After Percutaneous Endoscopic Spine Surgery: A Retrospective Case Series Analysis

To describe the perioperative clinical features, management, and outcomes of patients with seizure after percutaneous endoscopic spine surgery (PESS). Patients who experienced seizure after PESS in a tertiary orthopedic hospital between January 2016 and June 2022 were retrospectively recruited, and patient charts were reviewed. Twenty-nine patients were recruited, and the incidence of seizure after PESS was 0.52%. The operation time was 110.0 minutes (interquartile range [IQR], 82.5-235.0 minutes) and the irrigation speed was 109.0 mL/minute (IQR, 86.5-145.5 mL/minute). Definitive dural tears were reported in 15 patients (51.7%). In addition to agitation and myotonia, significant increased respiratory rate (29.9 ± 6.5 breaths/minute), tachycardia (112.1 ± 20.6 beats/minute), and hypertension (systolic, 189.5 ± 21.9 mm Hg; diastolic, 98.3 ± 10.6 mm Hg) were observed. Arterial blood gas analysis showed hypocapnia, metabolic acidosis, and hyperlactatemia. All patients received analgesia and sedation as well as hyperosmolar therapy. The estimated duration of seizure was 3.0 hours (IQR, 2.5-4.0 hours) and the postoperative length of hospital stay was 3.0 (IQR, 3.0-5.5) days. The Japanese Orthopaedic Association score and visual analog scale score improved markedly within 6 months after surgery. Despite the low incidence and short duration, seizure after PESS should be considered a critical and urgent syndrome. Management strategies for seizure mainly involve intensive care, securing the airway, analgesia and sedation, hyperosmolar therapy, and negative fluid balance. No significant adverse effects of seizure on clinical outcomes were observed during 6 months of follow-up.

211. Assessing the economic benefit of robotic and navigational assistance in surgical treatment of L4-L5 spondylolisthesis: is higher upfront equipment cost worth the operative and safety benefits?

<h3>BACKGROUND CONTEXT</h3> The use of robotic or navigational guidance has seen tremendous growth in recent years in minimally invasive spine surgery (MISS) due to its ability to reduce operative time, increase patient safety, and aid in surgical accessibility, especially in high incidence pathologies. However, there remain considerable gaps in the literature in regards to the cost-effectiveness of robotic or navigational guidance in the surgical treatment of L4-L5 spondylolisthesis. <h3>PURPOSE</h3> To assess differences in patient outcomes and relative cost effectiveness in L4-L5 spondylolisthesis patients treated using robotic or navigational guidance in MISS procedures. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospective MISS database. <h3>PATIENT SAMPLE</h3> A total of 524 MISS patients. <h3>OUTCOME MEASURES</h3> HRQLs, complications, surgical factors. <h3>METHODS</h3> MISS patients with preoperative diagnoses of L4-L5 spondylolisthesis and baseline (BL) and 2-year (2Y) postoperative radiographic/HRQL data were included. Patients were split between those operated on using robotic or navigational guidance (Robotic+) or not (Robotic-). Means comparison analysis assessed differences in radiographic and clinical outcomes at BL, 1Y and 2Y postoperatively. Costs were calculated using the PearlDiver database through estimates from Medicare payscales for services within a 30-day window, including estimates regarding costs of postoperative complications, outpatient healthcare encounters, revisions and medical related readmissions. Quality-adjusted life years (QALYs) was calculated using NDI mapped to SF6D using validated methodology and utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). <h3>RESULTS</h3> Eighty-eight patients (54.40±12.49 years, 40% female, 30.93±6.52 kg/m², mean CCI: 2.23±1.55) with L4-5 spondylolisthesis were included. At baseline, patients were comparable in age, gender, BMI and CCI (all p>.05). Similarly, patients did not differ significantly in baseline regional nor global radiographic deformity (all p>.05). Perioperatively, Robotic+ patients were significantly less likely to undergo corpectomy (p=.006), and also demonstrated significantly lower EBL (p=.013) and operative time (p=.009). Economic analysis revealed broad cost savings for Robotic+ patients. Specifically, Robotic+ patients demonstrated increased utility gained per QALYs at 1Y (p=.028), as well as Life Expectancy QALYs (p=.002). Furthermore, Robotic+ patients were significantly more likely to demonstrate increased QALYs gained by 2Y (p=.029). Conversely, overall cost per QALY by 2Y was significantly higher for Robotic- patients, which resulted in an approximately 6.5x greater cost per QALY for such patients (76,848 vs 11,839 USD). Overall, Robotic+ patients demonstrated significantly higher cost-effectiveness by 2Y (p<.001). <h3>CONCLUSIONS</h3> Corrective procedures for the treatment of L4-L5 spondylolisthesis and other common spinal pathologies has seen significant growth in the uptake of novel technologies such as robotic or navigational assistance. Though robotic and navigational assistance systems have a significantly higher upfront cost compared to existing techniques, our findings demonstrate reductions in intraoperative invasiveness and OR time pay great dividends in demonstrating the 2Y cost-effectiveness of such novel technologies in minimally-invasive adult spinal deformity surgery. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

219. Comparative analysis of prone lateral versus single position lateral decubitus positioning in achieving optimal outcomes and reducing complication rates in minimally invasive spine surgery

<h3>BACKGROUND CONTEXT</h3> Recent literature has pointed to the rising use of prone lateral versus lateral decubitus positioning in minimally invasive spine surgery (MISS) as a method to reduce operative time, increase patient safety, and aid in surgical accessibility. However, there is a paucity of literature as to how prone lateral and lateral decubitus positioning compares in terms of reaching optimal postoperative outcomes and reducing complication rates. <h3>PURPOSE</h3> To assess differences between prone lateral and single-position lateral decubitus positioning compares in terms of reaching optimal postoperative outcomes and reducing complication rates. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospective MIS database. <h3>PATIENT SAMPLE</h3> A total of 524 MIS patients. <h3>OUTCOME MEASURES</h3> HRQLs; complications; surgical factors. <h3>METHODS</h3> MISS patients with BL) and 2-year(2Y) postop radiographic/HRQL data were included. Patients positioned in the prone latera (PL) or single-position lateral decubitus (LD) position were isolated. At 2Y, an optimal outcome score was calculated using 4 equally weighted criteria: 1) achieving ideal PT per SRS-Schwab at 2Y, 2) Achieving ideal PI-LL per SRS-Schwab at 2Y, 3) No complication requiring reoperation, 4) Achieving NRS MCID by Salaffi et al. criteria; optimal score threshold was set at meeting 2 of 4 criteria. Means comparison analysis assessed differences in radiographic and clinical outcomes at BL and 1Y postoperatively. ANCOVA assessed estimated marginal means adjusting for BL age and revision status. <h3>RESULTS</h3> Thirty-four PL and 36 LD patients were included (54.40±12.49 years, 40% female, 30.93±6.52 kg/m2, mean CCI: 2.23±1.55) were included. At baseline, patients were comparable in age, gender, BMI and CCI (all p>.05). Perioperatively, PL patients demonstrated significantly lower operative time (200.09 vs 284.54 min, p=.007) and EBL (332.35 vs 192.05 mL, p=.027). Though optimization scores were equivalent between groups (p=.160), PL patients demonstrated significantly lower perioperative complication rates (p=.012), neurological complication rates (p=.006), and had a fewer number of total complications by 2Y (p=.014). When controlling for BL age and revision status, the PL patients demonstrated consistently fewer intra- and perioperative complications as well (both p<.015). In terms of patient-reported outcomes, PL patients also demonstrated significantly improved NRS-Leg scores compared to LD patients by 1Y (p=.038). <h3>CONCLUSIONS</h3> Patients placed in the PL position during minimally-invasive adult spinal deformity surgery demonstrate decreased mean operative times and decreased intraoperative invasiveness and blood loss versus patients operated on via single-position LD positioning. Though overall rates of achieving optimal outcome remain comparable, PL approach should be considered as there may be significant additional benefit in reducing peri- and postoperative complications by 2Y. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

220. An analysis of intraoperative neurophysiological monitoring events during single position minimally invasive spine surgery

<h3>BACKGROUND CONTEXT</h3> The single position minimally invasive (MIS) lateral approach allows access to the anterior and posterior columns with the patient positioned in the lateral decubitus position. The purpose of this approach was to mitigate complications associated with open procedures while achieving circumferential fusion. More recently, an alternative prone-lateral technique has been developed streamlining surgical access with potential advantages. The purpose of this study was to identify differences in intraoperative neurophysiological monitoring (IOM) event rates between single position lateral decubitus and prone-lateral patients during MIS spine surgery. <h3>PURPOSE</h3> To determine if lateral decubitus positioning will correlate with the occurrence of neurophysiological monitoring events during MIS spine surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort. <h3>PATIENT SAMPLE</h3> A total of 524 MIS patients were included. <h3>OUTCOME MEASURES</h3> Intraoperative neurophysiological monitoring, lateral decubitus, prone lateral. <h3>METHODS</h3> MIS spine surgery patients with available surgical positioning and IOM data were included if they were in a single position. Patients were stratified into 2 groups based on operative positioning: lateral decubitus (Lat) and prone lateral (PL). IOM was performed using somatosensory evoked potentials (SSEPs) and electromyography (EMG) techniques. An abnormal event was defined as any confirmed loss of signal during the operative period in the anatomical distribution of the surgery. Means comparison tests and multivariable logistic regression analysis assessed differences between patient groups. <h3>RESULTS</h3> Of 524 patients eligible, 226 (43.1%) had available positioning and IOM data. Of these, 88 met inclusion criteria (52 Lat and 36 PL). The majority were male (49, 55.7%), mean age of 49.2 yrs and 2.0 levels fused and 18 (20.5%) undergoing an osteotomy. In total, 19 (21.6%) patients had an abnormal IOM event. There was a significant difference in abnormal IOM event rates for patients who were in Lat (31%) and PL (8%) positioning, p=0.012. Multivariable analysis adjusting for surgical invasiveness showed that PL patients were 76.8% less likely to experience an abnormal IOM event than Lat patients (OR .232 [CI .060-.905], p=.035). Of the Lat patients with an abnormal IOM, 6.3% had postoperative sensory loss in the saphenous nerve. <h3>CONCLUSIONS</h3> Lateral decubitus positioning appears to be independently associated with abnormal intraoperative neurophysiological monitoring events when compared to prone lateral positioning during MIS. This has the potential to help with risk stratification in the future when determining patients undergoing a single position procedure. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

112. The effect of preoperative rehabilitation on minimally invasive spine surgery patient outcomes

<h3>BACKGROUND CONTEXT</h3> Minimally invasive (MIS) spine surgery techniques were developed to mitigate complications associated with open procedures while achieving functional outcomes. More recently, preoperative rehabilitation programs have been implemented to prepare patients for surgery and to promote patient health. The purpose of this study was to identify the effect of preoperative rehabilitation on MIS spine surgery patient outcomes. <h3>PURPOSE</h3> Identify if preoperative rehabilitation influences patient outcomes following MIS spine surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort. <h3>PATIENT SAMPLE</h3> This study included 524 MIS patients. <h3>OUTCOME MEASURES</h3> Preoperative rehabilitation, perioperative complications, patient outcomes. <h3>METHODS</h3> MIS spine surgery patients with baseline (BL) and two-year (2Y) follow-up were included if they had preoperative rehabilitation data. Patients were divided into two groups: those who had preoperative rehabilitation [Prehab] and those who did not [no Prehab]. Prehab consisted of physical and mental components, ie, physical therapy for 3 months, 3 days a week for core, paraspinal and leg strengthening, with a review of postop protocols to do at home, including gait and balance training. Patients were also referred for cognitive behavioral therapy for 2 weeks to prepare for the stress of surgery. Patients were excluded if they presented with any of the following at baseline: severe neurological deficit (< 3/5), minimal ambulation, or current depression/anxiety. Means comparison tests and logistic regression analysis controlling for age, CCI, ASA grade, and invasiveness assessed differences between patient groups. Conditional inference tree (CIT) analysis determined thresholds for continuous variables. <h3>RESULTS</h3> A total of 216 patients met inclusion criteria (76 Prehab, 140 no Prehab). The majority were male (97, 44.9%), mean age of 55.17 years, and 2.3 levels fused and 28 (13.0%) undergoing 3-CO. There was a significant difference in LOS for patients who had (3.6 days) and didn't have (5.3 days) Prehab, p <.05. Multivariate regression showed that Prehab was an independent predictor of a shorter LOS (OR .686 [CI .484-.972], p=.034). CIT analysis determined Prehab patients were 85.0% less likely to have a LOS greater than 2.0 days (OR .015 [CI .001-.258], p=.004). By 2 years, Prehab patients had lower rates of readmissions (6.7% vs 20.0%) and reoperations (4.0% vs 15.3%) than no Prehab patients, both p <.05. <h3>CONCLUSIONS</h3> Preoperative rehabilitation appears to be independently associated with a shorter length of stay following minimally invasive spine surgery. Patients who had preoperative rehabilitation also had lower rates of readmissions and reoperations by two years postoperatively. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P117. An evaluation of preoperative patient weight and body mass index during single-position minimally invasive spine surgery

<h3>BACKGROUND CONTEXT</h3> The single position minimally invasive (MIS) approach allows access to the anterior and posterior columns with the ability to mitigate complications associated with open procedures while achieving circumferential fusion. The purpose of this study was to identify if patient weight or body mass index (BMI) leads to differences in intraoperative event rates. <h3>PURPOSE</h3> To determine if patient weight and BMI will correlate with the occurrence of intraoperative events during MIS spine surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort. <h3>PATIENT SAMPLE</h3> A total of 524 MIS patients. <h3>OUTCOME MEASURES</h3> Weight (kg), BMI (kg/m2), Aborted procedures, estimated blood loss (EBL), operative time (OpTime). <h3>METHODS</h3> Of 524 patients eligible, 226 (43.1%) had available data. Of these, 88 met inclusion criteria (52 Lat and 36 PL). The majority were male (49, 55.7%), mean age of 49.2 yrs and 2.0 levels fused and 18 (20.5%) undergoing an osteotomy. Lat patients with a weight > 130 kg had significantly longer OpTime (p=0.003) and more EBL (p=0.019). There was a significant difference in mean weight for lat patients with (121.8 kg) and without (97.7 kg) an aborted procedure, p=0.021. There was also a significant difference in mean BMI for lat patients with (35.3 kg/m2) and without (29.6 kg/m2) an aborted procedure, p=0.015. Multivariable analysis showed that weight (OR 1.03 [CI 1.01-1.06], p=.020) and BMI (OR 1.15 [CI 1.02-1.30], p=.026) were independent predictors for aborted procedures in lat patients. In an analysis of PL patients, there was one aborted case (weight > 120 kg), but no significant findings for EBL or OpTime. <h3>RESULTS</h3> Of 524 patients eligible, 226 (43.1%) had available data. Of these, 88 met inclusion criteria (52 Lat and 36 PL). The majority were male (49, 55.7%), mean age of 49.2 yrs and 2.0 levels fused and 18 (20.5%) undergoing an osteotomy. Lat patients with a weight > 130 kg had significantly longer OpTime (p=0.003) and more EBL (p=0.019). There was a significant difference in mean weight for lat patients with (121.8 kg) and without (97.7 kg) an aborted procedure, p=0.021. There was also a significant difference in mean BMI for lat patients with (35.3 kg/m2) and without (29.6 kg/m2) an aborted procedure, p=0.015. Multivariable analysis showed that weight (OR 1.03 [CI 1.01-1.06], p=.020) and BMI (OR 1.15 [CI 1.02-1.30], p=.026) were independent predictors for aborted procedures in lat patients. In an analysis of PL patients, there was one aborted case (weight > 120 kg), but no significant findings for EBL or OpTime. <h3>CONCLUSIONS</h3> Weight and BMI appear to be independently associated with aborted procedures for patients in the lateral decubitus position during minimally invasive spine surgery. Patients in the lateral decubitus position who weighed 130 kg or more had on average longer operative times and more estimated blood lost. This study has the potential to help with risk stratification in the future when determining patients undergoing a single position procedure. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

197. Subtherapeutic perioperative levels of cefuroxime inside cannulated pedicle screw commonly used in spine surgery: results from an experimental microdialysis study

BACKGROUND CONTEXT Despite minimal invasive spine techniques, postoperative implant associated vertebral osteomyelitis remains a risk of great morbidity for the patient. Perioperative antibiotic prophylaxis is important for prevention of postoperative infection and local tissue concentrations can be measured with microdialysis. We hypothesized that cefuroxime concentrations in relation to a cannulated pedicle screws may be insufficient for prevention of postoperative infection. PURPOSE The aim was to compare perioperative cefuroxime concentrations inside a cannulated pedicle screw to the adjacent noninstrumented lumbar vertebral pedicle. STUDY DESIGN/SETTING In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model. PATIENT SAMPLE Not applicable. OUTCOME MEASURES The primary end-point was the time above cefuroxime clinical breakpoint minimal inhibitory concentration for Staphylococcus aureus of 4 µg/mL (T>MIC4) METHODS Microdialysis probes were placed in a cannulated pedicle screw and the adjacent non-instrumented lumbar vertebral pedicle (L1) in 8 female pigs through a surgical posterior open lumbar approach. Following a single-dose intravenous cefuroxime administration (1.5 g), microdialysates and plasma were dynamically sampled over 8 hours. RESULTS Mean T>MIC4 (range) was 123 min (112-175) in plasma, 101 min (68-144) in the non-instrumented vertebral pedicle and 0 min (0-0) inside the cannulated pedicle screw. CONCLUSIONS A single-dose intravenous cefuroxime administration (1.5 g) seems insufficient for antibiotic prophylaxis inside a cannulated pedicle screw placed in the lumbar spine. Sufficient concentrations were achieved in the adjacent non-instrumented vertebral pedicle for up to 1.5-2 hours. Therefore, alternative dosing regimens should be considered in minimal invasive spine surgery longer than 1.5 hours and additional prophylactic strategies against infection may be applied in high-risk patients. FDA DEVICE/DRUG STATUS Cefuroxime (Approved for this indication) Despite minimal invasive spine techniques, postoperative implant associated vertebral osteomyelitis remains a risk of great morbidity for the patient. Perioperative antibiotic prophylaxis is important for prevention of postoperative infection and local tissue concentrations can be measured with microdialysis. We hypothesized that cefuroxime concentrations in relation to a cannulated pedicle screws may be insufficient for prevention of postoperative infection. The aim was to compare perioperative cefuroxime concentrations inside a cannulated pedicle screw to the adjacent noninstrumented lumbar vertebral pedicle. In vivo experimental pharmacokinetics study of cefuroxime concentrations in an acute preclinical porcine model. Not applicable. The primary end-point was the time above cefuroxime clinical breakpoint minimal inhibitory concentration for Staphylococcus aureus of 4 µg/mL (T>MIC4) Microdialysis probes were placed in a cannulated pedicle screw and the adjacent non-instrumented lumbar vertebral pedicle (L1) in 8 female pigs through a surgical posterior open lumbar approach. Following a single-dose intravenous cefuroxime administration (1.5 g), microdialysates and plasma were dynamically sampled over 8 hours. Mean T>MIC4 (range) was 123 min (112-175) in plasma, 101 min (68-144) in the non-instrumented vertebral pedicle and 0 min (0-0) inside the cannulated pedicle screw. A single-dose intravenous cefuroxime administration (1.5 g) seems insufficient for antibiotic prophylaxis inside a cannulated pedicle screw placed in the lumbar spine. Sufficient concentrations were achieved in the adjacent non-instrumented vertebral pedicle for up to 1.5-2 hours. Therefore, alternative dosing regimens should be considered in minimal invasive spine surgery longer than 1.5 hours and additional prophylactic strategies against infection may be applied in high-risk patients.

Use of Minimally Invasive Spine Surgery in the Management of High-grade Thoracolumbar Spine Injuries

Objective: Spinal fractures often have devastating sequelae. Thoracolumbar fractures are classified using the Thoracolumbar Injury Classification and Severity score (TLICS) to determine the severity of injury and to guide treatment. Recently advancements in minimally invasive spine surgery (MISS) have led to new approaches to high-severity fractures. Studies have suggested that MISS may yield similar outcomes to conventional, more invasive procedures while producing several benefits.Methods: This retrospective study involves 46 patients treated from 2005 through 2020 for high grade thoracolumbar trauma from T2 to L5 with a minimum follow-up of 6-months treated with MISS techniques using percutaneous instrumentation. Results: Average TLICS was 7.5. Patient derived outcome measures with average length of follow-up of 602 days included Oswestry Disability Index 28.9, Patient Satisfaction Index 4.2, Short Form-12 Mental Component Score 51.9, and Short Form-12 Physical Component Score 37.7. Average estimated blood loss was 119.2 mL.Conclusion: The TLICS is a validated tool used to guide surgical intervention in high grade trauma. The utilization of MISS techniques for the treatment and stabilization of thoracolumbar trauma is efficacious and a viable alternative to traditional open approaches.

Minimally Invasive Spinal Treatment (MIST)-A New Concept in the Treatment of Spinal Diseases: A Narrative Review.

In the past two decades, minimally invasive spine surgery (MISS) techniques have been developed for spinal surgery. Historically, minimizing invasiveness in decompression surgery was initially reported as a MISS technique. In recent years, MISS techniques have also been applied for spinal stabilization techniques, which were defined as minimally invasive spine stabilization (MISt), including percutaneous pedicle screws (PPS) fixation, lateral lumbar interbody fusion, balloon kyphoplasty, percutaneous vertebroplasty, cortical bone trajectory, and cervical total disc replacement. These MISS techniques typically provide many advantages such as preservation of paraspinal musculature, less blood loss, a shorter operative time, less postoperative pain, and a lower infection rate as well as being more cost-effective compared to traditional open techniques. However, even MISS techniques are associated with several limitations including technical difficulty, training opportunities, surgical cost, equipment cost, and radiation exposure. These downsides of surgical treatments make conservative treatments more feasible option. In the future, medicine must become “minimally invasive” in the broadest sense—for all patients, conventional surgeries, medical personnel, hospital management, nursing care, and the medical economy. As a new framework for the treatment of spinal diseases, the concept of minimally invasive spinal treatment (MIST) has been proposed.

Risk factors for hidden blood loss in unilateral biportal endoscopic lumbar spine surgery.

BackgroundUnilateral biportal endoscopic (UBE) spine surgery is a minimally invasive procedure for treating lumbar disorders. Hidden blood loss (HBL) is easily ignored by surgeons because blood loss is less visible. However, there are limited studies on HBL in UBE spine surgery. This study aimed to evaluate HBL and its possible risk factors in patients undergoing UBE spine surgery.MethodsPatients with lumbar disc herniation or lumbar spinal stenosis who underwent unilateral biportal endoscopic surgery between December 2020 and February 2022 at our hospital were retrospectively analyzed. Patient demographics, blood loss-related parameters, and surgical and radiological information were also collected. Pearson or Spearman correlation analysis was conducted to determine the association between clinical characteristics and HBL. Multivariate linear regression analysis was used to determine the independent risk factors for HBL.ResultsFifty-two patients (17 males and 35 females) were retrospectively enrolled in this study. The mean total blood loss (TBL) volume was 434 ± 212 ml, and the mean HBL volume was 361 ± 217 ml, accounting for 77.9% of the TBL in patients who underwent UBE surgery. Multivariate linear regression analysis revealed that HBL was positively associated with operation time (P = 0.040) and paraspinal muscle thickness at the target level (P = 0.033).ConclusionsThe amount of HBL in patients undergoing UBE surgery should not be neglected. Operation time and paraspinal muscle thickness at the target level may be independent risk factors for HBL.

Comparison of the efficacy of fully endoscopic spine surgery using transforaminal and interlaminar approaches in the treatment of prolapsed lumbar 4/5 disc herniation

BackgroundThere is still much controversy about whether transforaminal or interlaminar fully endoscopic spine surgery can better treat lumbar 4/5 disc herniation. Therefore, this study intends to compare the clinical efficacy of fully endoscopic spine surgery through transforaminal and interlaminar approaches in the treatment of lumbar 4/5 disc herniation.MethodsSeventy-six patients with lumbar 4/5 disc herniation admitted from March 2019 to June 2020 were divided into the transforaminal approach group (endoscopic transforaminal lumbar discectomy, ETLD; 54 cases) and the interlaminar approach group (endoscopic interlaminar lumbar discectomy, EILD; 22 cases) according to different surgical methods. The general clinical data and clinical evaluation scale of the patients were compared.ResultsThe post-operative ODI and VAS scores were significantly better in the EILD group (P < 0.05). The VAS and ODI scores of patients with upper-shoulder and sub-axillary types in the EILD group were superior to those in the ETLD group (P < 0.05), while the VAS and ODI scores of patients with the pre-radicular type were better when they underwent ETLD rather than EILD (P < 0.05). Patients with Lee zone III type in the EILD group had better post-operative ODI scores than those in the ETLD group (P < 0.05), but there was no significant difference in VAS scores (P > 0.05). Patients with Lee zone IV type who underwent EILD had better VAS and ODI scores than those who underwent ETLD (P < 0.05).ConclusionsFor patients with a prolapsed intervertebral disc that belongs to the upper-shoulder type, sub-axillary type, or Lee III or IV type, EILD can achieve better outcomes.

How I do it: biportal endoscopic spinal surgery for revision of adjacent segment disease after instrumented lumbar fusion.

Lumbar fusion with rigid fixation can be complicated by adjacent segment degeneration, which may cause neurological deficits and back pain, and occasionally necessitates revision surgery. This type of revision surgery is difficult to perform in a minimally invasive manner because it requires the revision of the original internal fixation instruments. We describe a biportal endoscopic spinal surgery (BESS) procedure for revision surgery due to adjacent segment disease after lumbar fusion with rigid fixation instruments. The radiological images and complete surgical procedure are presented. BESS effectively enabled nerve decompression, intervertebral fusion, and revision of lumbar fusion with fixation instruments in a minimally invasive manner.

Lumbosacral Interbody Fusion Using a Biportal Endoscopic Technique for Patients with Multilevel Severe Degenerative Lumbosacral Spondylosis: Technical Note and Case Presentations.

Open decompression and posterior interbody fusion are standard surgical interventions for multilevel degenerative lumbosacral spondylosis (DLS). Despite their clinical efficacy, intraoperative and postoperative complications have led to the demand for a minimally invasive approach. A biportal endoscopic approach is an advanced minimally invasive surgical option. The data of two patients with multilevel DLS who had undergone biportal endoscopic spine surgery (BESS) were retrospectively analyzed. Parameters such as surgical difficulty, duration of operation, blood loss, length of hospital stay, and postoperative complications were reviewed. Pain and functionality were assessed using the visual analog scale (VAS) and the Oswestry Disability Index (ODI), respectively. Both patients were women and aged 75 and 73 years; they complained of back pain, claudication, pain and weakness in the lower extremities, and gait disturbance. The symptoms lasted 5 and 8 years, respectively. The multilevel BESS approach was applied bilaterally. Dissection, laminofacetectomy, decompression, excision, cage insertion, and screw implantation were performed. The operation durations were 170 and 160 minutes with blood loss of 500 and 650 mL, respectively. Back pain, leg pain, and ODI scores significantly improved; no pseudoarthrosis or additional neurologic deficits were noted on follow-up. The presented BESS technique is a minimally invasive treatment option for patients with multilevel DLS, which typically requires a complicated surgical approach. Randomized controlled studies with larger sample sizes and longer follow-up periods are needed to verify the superiority of this operation.

Minimally invasive mini-hemilaminectomy-corpectomy in cadaveric dogs: evaluation of the accuracy and safety of a three-dimensionally printed patient-specific surgical guide

BackgroundAs the frequency of spine surgery increases in the veterinary field, many studies have been conducted on minimally invasive spine surgery (MISS). Although many studies have been conducted on the thoracolumbar spine about MISS in animals, several problems and limitations have emerged regarding this method. Therefore, we developed a three-dimensional (3D) printed patient-specific surgical guide (3DPSSG) using 3D printing technology to overcome these problems. We aimed to evaluate the accuracy and safety of the 3DPSSG in minimally invasive mini-hemilaminectomy-corpectomy (MI-MHC).MI-MHC using 3DPSSG and an endoscopic system was performed at L1–L2 in 15 cadaveric dogs. The procedure of fixing the surgical guide to the vertebral body through screws and the surgical procedure using the guide were performed by two surgeons with different experiences. Postoperative computed tomography was used to measure planned and postoperative screw trajectories (angle, protruding from the far cortex) and to create 3D rendering images of vertebrae to evaluate the direction of bone window formation, corpectomy slot length, depth, and height ratio.ResultsThe two groups which performed by two surgeons with different experiences did not differ in terms of screw angle deviation and length of the screw protruded from the far cortex. The corpectomy slot-length ratio was not different between the two groups; however, the slot-depth and height ratios were different.ConclusionsNo differences were detected in screw trajectory and corpectomy slot-length ratio between the two groups. The 3DPSSG for MI-MHC is classified as accurate and safe; therefore, it can be an alternative to the conventional technique in dogs.

Biportal endoscopic spine surgery for cervical disk herniation: A technical notes and preliminary report.

Biportal endoscopic spine surgery (BESS) for cervical disk herniation (CDH) has been rarely reported. The aim of the article is to describe a novel BESS as a posterior approach for CDH and report the preliminary outcomes and complications. This single-centered retrospective chart review included 109 consecutive patients who underwent BESS for symptomatic single-level CDH. Working and viewing portals were created in each unilateral paravertebral area at the target disk level. Endoscopic exploration allowed for effective and minimally invasive decompression via safe access to the medial foramen with minimal laminectomy and facetectomy. Clinical outcomes, including the visual analog scale, neck disability index, Macnab criteria, and the motor function of the involved arm, were evaluated at 4, 8, 12, and 24 postoperative weeks. Visual analog scale and neck disability index improved significantly at 24 weeks postoperatively (P < .01). According to the Macnab criteria, “excellent,” “good,” and “fair” results were obtained for 55.9%, 30.3%, and 13.8% of patients, respectively. The post 24-week distribution of the involved upper extremity strength grade was significantly improved compared to the initial value (P = .02). One patient had a motor weakness with a decreased grade over 4 weeks from excessive irrigation. The posterior approach of BESS was efficient and feasible for the treatment of CDH.

Minimally Invasive Surgery for Spinal Metastases

The incidence of metastatic spine disease (MSD) is on the rise and is currently present in 70% of patients presenting with systemic cancer. The majority of patients with MSD present with clinical symptoms such as neurological deficit, pathological fracture causing pain and spinal instability. Management of MSD is a multidisciplinary endeavor that involves surgery, radiotherapy (RT), and chemotherapy. The conventional open spine surgery approach has evolved into a less invasive surgery model categorized as minimally invasive spine surgery (MISS) or minimal access spine surgery. This evolution was brought about to address the complications associated with open surgery such as longer hospital stays and wound-related problems. MISS has been now widely explored in MSD due to lower wound-related complications, decreasing operative time, less neurological complications, and shorter hospital stays. Decompression and stabilization still remain the core concepts in MISS. Kyphoplasty/vertebroplasty, percutaneous pedicle screw fixation, separation surgery, and radiofrequency ablation are some of the minimally invasive techniques and procedures for surgical management of MSD. MISS is used in conjunction with other modern techniques like intraoperative neuromonitoring to help identify any adverse neurological events. MIS techniques will evolve with time, extending their application for the management of hypervascular tumors with significant anterior cord compression and recurrent tumors in which the open surgery currently remains the choice of approach.

Effectiveness and outcome of spinal decompression surgery in overweight and obese patients

Objectives: Minimal invasive spinal surgery (MISS) is a relatively new surgical approach that minimizes tissue damage, reduces blood loss, and promises faster post-operative recovery compared to the traditional open approach. The current retrospective study aimed to assess and compare the surgical time, blood loss during the procedures, post-operative mobility, hospital stay, post-operative pain, and post-surgery patient satisfaction between the two groups. Methods: Forty patients who underwent decompression procedures at our institute were included in this retrospective study. The patients were interviewed by a phone call by a single coinvestigator 1 year after surgery to survey their satisfaction. Results: Thirteen patients (32.5%) underwent MISS and 27 (67.5%) underwent traditional surgery. The mean operative time and blood loss volume for MISS and traditional surgery were found to be 166.08 ± 44.75 min and 193.14 ± 58.67 min, and 69.23 ± 25.31 mL and 367 ± 451.5, respectively. The hospital stay was 3.62 ± 1.38 days for the MISS and 6.48 ± 4.57 days for the traditional surgery. Post-operative mobilization was found to be the 1st day for MISS and the 1.78th day for the traditional surgery group. Statistical significance difference (P &lt; 0.05) was observed in blood loss volume, hospitalization time, post-operative mobilization, and pain level after surgery in favor of MISS. Conclusion: MISS in obese patients was found superior to traditional (open) surgery in blood loss, operative time, post-operative mobilization, and post-operative pain.

Challenges Hindering Widespread Adoption of Minimally Invasive Spinal Surgery

Minimally invasive spinal surgery (MISS) techniques offer several beneficial prospects and are being increasingly requested by patients. However, these techniques have not been uniformly adopted by spinal surgeons, and they remain controversial among some. Several barriers have prevented widespread adoption of MISS. These include concerns regarding high start-up costs, limited evidence base, and lack of surgeon training. In addition, the unique approaches involved in MISS expose spinal surgeons to unfamiliar anatomy. Further, while MISS can address a growing spectrum of spinal pathology, some conditions, as well as complications encountered during MISS procedures, require open surgery. This requires surgeons to not only acquire the new and specialized MISS skillset but also maintain their ability to perform open surgery. These factors present challenges common to developing and innovative surgical techniques. Here, we review the barriers preventing wider adoption of MISS and present a framework to promote the safe and effective growth of MISS.

Minimally Invasive Spine Surgery: An Overview

Spinal surgery is undergoing a major transformation toward a minimally invasive paradigm. This shift is being driven by multiple factors, including the need to address spinal problems in an older and sicker population, as well as changes in patient preferences and reimbursement patterns. Increasingly, minimally invasive surgical techniques are being used in place of traditional open approaches due to significant advancements and implementation of intraoperative imaging and navigation technologies. However, in some patients, due to specific anatomic or pathologic factors, minimally invasive techniques are not always possible. Numerous algorithms have been described, and additional efforts are underway to better optimize patient selection for minimally invasive spinal surgery (MISS) procedures in order to achieve optimal outcomes. Numerous unique MISS approaches and techniques have been described, and several have become fundamental. Investigators are evaluating combinations of MISS techniques to further enhance the surgical workflow, patient safety, and efficiency.