Surgical Management of Thoracolumbar Adjacent Segment Disease: Techniques and Outcomes in 107 Patients Undergoing Surgical Intervention.

BACKGROUND: Adjacent segment disease (ASD) is a known sequela of thoracolumbar instrumented fusions. Various surgical options are available to address ASD in patients with intractable symptoms who have failed conservative measures. However, the optimal treatment strategy for symptomatic ASD has not been established. We examined several clinical outcomes utilizing different surgical interventions for symptomatic ASD. METHODS: A retrospective review was performed for a consecutive series of patients undergoing revision surgery for thoracolumbar ASD between October 2011 and February 2022. Patients were treated with endoscopic decompression (N = 17), microdiscectomy (N = 9), lateral lumbar interbody fusion (LLIF; N = 26), or open laminectomy and fusion (LF; N = 55). The primary outcomes compared between groups were re-operation rates and numeric pain scores for leg and back at 2 weeks, 10 weeks, 6 months, and 12 months postoperation. Secondary outcomes included time to re-operation, estimated blood loss, and length of stay. RESULTS: Of the 257 patients who underwent revision surgery for symptomatic ASD, 107 patients met inclusion criteria with a minimum of 1-year follow-up. The mean age of all patients was 67.90 ± 10.51 years. There was no statistically significant difference between groups in age, gender, preoperative American Society of Anesthesiologists scoring, number of previously fused levels, or preoperative numeric leg and back pain scores. The re-operation rates were significantly lower in LF (12.7%) and LLIF cohorts (19.2%) compared with microdiscectomy (33%) and endoscopic decompression (52.9%; P = 0.005). Only LF and LLIF cohorts experienced significantly decreased pain scores at all 4 follow-up visits (2 weeks, 10 weeks, 6 months, and 12 months; P < 0.001 and P < 0.05, respectively) relative to preoperative scores. CONCLUSION: Symptomatic ASD often requires treatment with revision surgery. Fusion surgeries (either stand-alone lateral interbody or posterolateral with instrumentation) were most effective and durable with respect to alleviating pain and avoiding additional revisions within the first 12 months following revision surgery. CLINICAL RELEVANCE: This study emphasizes the importance of risk-stratifying patients to identify the least invasive approach that treats their symptoms and reduces the risk of future surgeries.

Structure-sparing resection for the management of cervical chordomas: a retrospective institutional series.

OBJECTIVE: Chordomas are a rare and relatively slow-growing malignancy of notochordal origin with a nearly 50% recurrence rate. Chordomas of the cervical spine are particularly challenging tumors given surrounding vital anatomical structures. Although standard in other areas of the spine, en bloc resection of cervical chordomas is exceedingly difficult and carries the risk of significant postoperative morbidity. Here, the authors present their institutional experience with 13 patients treated with a structure-sparing radical resection and adjuvant radiation for cervical chordomas. METHODS: Records of the standing senior author and institutional database of spinal surgeries were retrospectively reviewed for surgically managed cervical and high thoracic chordomas between 1997 and 2022. Chordomas whose epicenter was cervical but touched the clivus or had extension to the thoracic spine were included in this series. Clinical and operative data were gathered and analyzed for the index surgery and any revisions needed. Outcome metrics such as recurrence rates, complication rates, functional status, progression-free interval (PFI) and overall survival (OS) were evaluated. RESULTS: The median patient age at diagnosis was 57 (range 32-80) years. The median modified Rankin Scale (mRS) score at the time of presentation was 1 (range 0-4). Approximately 40% of tumors were located in the upper cervical spine (occiput-C2). The median time from diagnosis to surgery was 74.5 (range 10-483) days. Gross-total resection was achieved in just under 40% of patients. All patients received adjuvant radiotherapy. The mean duration of follow-up was 4.09 years, with a mean PFI of 3.80 (range 1.16-13.1) years. Five patients experienced recurrence (38.5%). The mean OS was 3.44 years. Three patients died during the follow-up period; 2 due to disease progression and 1 died in the immediate postoperative period. One patient was lost to follow-up. A significant positive relationship was identified between high cervical tumor location and disease recurrence (p = 0.021). CONCLUSIONS: While en bloc resection is appropriate and feasible for tumors in the sacral spine, the cervical region poses a significant technical challenge and is associated with increased postoperative morbidity. Radical resection may allow for achievement of negative operative margins and, along with sparing postoperative morbidity following resection of cervical chordomas, maintaining a similar rate of recurrence when compared with en bloc resection while preserving quality of life.

Evaluating the potential role of determinants of health on encephalocele patient outcomes - a combined retrospective study and systematic review.

INTRODUCTION: To evaluate the outcomes and demographics of encephalocele patients who were born and received treatment in our neonatal ICU and conduct a PRISMA literature review. METHODS: An Institutional Review Board (IRB)-approved retrospective cohort study was undertaken to investigate the results of treating encephalocele patients at Jackson Memorial Hospital (JMH) from 1998 to 2022. The study focused on assessing outcomes and the impact of maternal socioeconomic factors, such as religion, age, and education, along with the timing of diagnosis, in connection with a systematic review. RESULTS: A total of 20 encephalocele patients were identified (13 females and 7 males), with 15 having available medical records for review. Most of these cases involved occipital encephaloceles (73.3%). Maternal ages at the time of delivery ranged from 15 to 42 years, with a mean age of 27.3 years. The average gestational age at birth was 37 weeks. Ten cases had a prenatal diagnosis documented, occurring between 12 and 24.5 weeks of gestation. Three of the surviving patients had records of prenatal counseling that included discussions about termination. No infections were reported. Among the 15 cases, 11 patients (73.3%) were alive at the last follow-up, with a mean age at follow-up of 4.12 years, ranging from 6 weeks to 15 years post-birth. Hydrocephalus was noted in 26.7%. Only 1 mother had completed high school. Most mothers were either on Medicaid (9 patients) or uninsured (3 patients), with only 3 having commercial insurance. Religious affiliations varied among the mothers, with 14 out of 15 identifying with a particular religion. The systematic review identified 22 articles from various countries, with 11 articles meeting the inclusion criteria for qualitative analysis. These articles revealed potential maternal risk factors for encephaloceles, including low-nutrient diets, inadequate folic acid intake, young maternal age, advanced maternal age, low socioeconomic status, and limited educational attainment. CONCLUSIONS: In the twenty-first century, there is a positive trend in the survival rates of children born with encephalocele. However, maternal factors such as low socioeconomic status and limited educational attainment remain prominent, affecting their ability to access timely prenatal care and impacting follow-up medical care for these children.

The importance of considering competing risks in recurrence analysis of intracranial meningioma.

BACKGROUND: The risk of recurrence is overestimated by the Kaplan-Meier method when competing events, such as death without recurrence, are present. Such overestimation can be avoided by using the Aalen-Johansen method, which is a direct extension of Kaplan-Meier that accounts for competing events. Meningiomas commonly occur in older individuals and have slow-growing properties, thereby warranting competing risk analysis. The extent to which competing events are considered in meningioma literature is unknown, and the consequences of using incorrect methodologies in meningioma recurrence risk analysis have not been investigated. METHODS: We surveyed articles indexed on PubMed since 2020 to assess the usage of competing risk analysis in recent meningioma literature. To compare recurrence risk estimates obtained through Kaplan-Meier and Aalen-Johansen methods, we applied our international database comprising ~ 8,000 patients with a primary meningioma collected from 42 institutions. RESULTS: Of 513 articles, 169 were eligible for full-text screening. There were 6,537 eligible cases from our PERNS database. The discrepancy between the results obtained by Kaplan-Meier and Aalen-Johansen was negligible among low-grade lesions and younger individuals. The discrepancy increased substantially in the patient groups associated with higher rates of competing events (older patients with high-grade lesions). CONCLUSION: The importance of considering competing events in recurrence risk analysis is poorly recognized as only 6% of the studies we surveyed employed Aalen-Johansen analyses. Consequently, most of the previous literature has overestimated the risk of recurrence. The overestimation was negligible for studies involving low-grade lesions in younger individuals; however, overestimation might have been substantial for studies on high-grade lesions.

Ventro-Lateral Meningioma of the Cervico-Thoracic Junction: 2-Dimensional Operative Video.

Meningiomas are one of the most common intradural extramedullary tumors.1 Symptoms often arise from cord compression, with gross total resection leading to the most optimal patient outcomes.2,3 Utilization of intraoperative neurophysiological monitoring can increase patient safety through real-time assessment of neural structures and reduce postoperative neurologic complications.4 In this video, we describe the operative techniques for the resection of a meningioma located at the cervico-thoracic junction. A 43-year-old female patient presented with 6 months of bilateral leg numbness and gait disturbances. MRI of the cervical spine demonstrated a cervical thoracic ventral meningioma causing severe cord compression from the bottom of the C6 lamina to the top of the T1 lamina. Surgical resection with intraoperative neuromonitoring with somatosensory-evoked potentials, motor-evoked potentials, and free-running electromyography was recommended. A partial C6-T1 laminectomy was routinely performed, and the dura was opened using a paramedian approach to allow for maximal tumor visualization. The tumor was carefully dissected and debulked, achieving gross total resection. Postoperatively, the patient experienced improvements in preoperative symptoms with no perioperative complications, and the final pathology confirmed the intradural lesion was a meningioma. This video illustrates the surgical technique and management of a spinal meningioma at the cervico-thoracic junction. Patient consent was obtained for their participation in this surgical video.

Predictors of clinical and structural outcomes after surgery for spinal nerve sheath tumor resection: a retrospective analysis.

OBJECTIVE: Resection of spinal nerve sheath tumors (SNSTs) typically necessitates laminectomy, often with facetectomy, for adequate exposure of tumor. While removal of bone affords a greater operative window and extent of resection, it places the patient at greater risk for spinal instability. Although studies have identified risk factors for fusion at the time of tumor resection, there has yet to be a study assessing long-term stability following SNST resection. In this study, the authors sought to identify preoperative and operative risk factors that predispose to long-term spinal instability and investigate clinical variables associated with greater risk for subsequent fusion in the time following initial SNST resection. METHODS: An institutional registry of spinal surgeries was queried at a single institution over a 20-year period. Demographic, clinical, and operative variables were recorded retrospectively and investigated for predictive value of several postoperative sequelae. RESULTS: A total of 122 SNST cases among 112 patients were included. At a mean follow-up time of 27.7 months, patients with a history of neurofibromatosis type 2 (NF2) (p = 0.014) and those who had undergone a laminectomy of ≥ 4 levels at the time of initial SNST resection (p = 0.028) were more likely to present with some degree of structural abnormality or neurological deficit following their initial surgery. The presence of facetectomy, degree of laminectomy, and level of spinal surgery were not found to be predictors of future instability. Ultimately, there was no significant predictor for true spinal instability following index surgery without fusion. A secondary analysis showed that an entirely extradural location (p = 0.044) and facetectomy at index surgery (p = 0.012) were predictive of fusion being performed at the time of tumor resection. Four of the 112 patients required fusion after their index SNST resection, 3 of whom underwent fusion for instability at the level of the index surgery. No variables were identified as predictive for future instrumentation. CONCLUSIONS: Ultimately, the authors conclude that resection of SNSTs does not always necessitate fusion, and good outcomes can be obtained with motion-preserving techniques and minimizing facetectomy when possible. Patients with a history of NF2 and those with SNSTs that required ≥ 4-level laminectomy were more likely to exhibit some degree of structural abnormality and/or neurological deficit localized to the index level defined as either new or worsening spinal instability and/or new or worsening neurological deficit at last follow-up; however, no variable was found to be predictive of true spinal instability. Furthermore, a complete facetectomy at initial SNST resection and entirely extradural tumor location were noted to be associated with fusion at index surgery. Lastly, the authors were unable to identify a clinical predictor for future instrumentation.

Use of intraoperative topical antibiotics to reduce intrathecal baclofen pump surgical site infections: a single institution's experience over 24 years.

OBJECTIVE: Patients requiring intrathecal baclofen (ITB) therapy are at high risk for surgical site infections (SSIs) given their poor functional status. After years of a nominal infection rate, there was an inexplicable increase in ITB pump infections at the authors' institution and multiple investigations offered no solution. Use of intraoperative topical antibiotics is well-documented in the orthopedic literature and was considered for ITB pump insertion. In this study, the authors investigated whether intraoperative vancomycin and tobramycin powder at the ITB pump site could reduce SSIs. METHODS: Operative and infection data were collected and analyzed retrospectively to determine the efficacy of this change. Patients were stratified into three cohorts (1998-2009, 2010-2012, and 2013-2021) to better understand the trends before and after implementation of intraoperative topical antibiotics. Each cohort had similar demographics. RESULTS: One hundred fifty-four patients underwent 272 ITB pump procedures between 1998 and 2021 (131 in 1998-2009, 49 in 2010-2012, and 92 in 2013-2021) for cerebral palsy (69.5%), spastic quadriparesis due to traumatic brain injury (7.1%), anoxic brain injury (6.5%), and other causes (16.9%). Infection rates were reduced from a high of 32% in 2010-2011 to 3.8% over the last 2.5 years (p = 0.0094). There were no adverse effects from the use of topical antibiotics. CONCLUSIONS: In the setting of an intractable rise in ITB pump infections, the addition of intraoperative topical antibiotics significantly reduced postoperative infections in a high-risk population. One could appreciate a significant drop each year in the rate of infections after the institution of intraoperative topical antibiotics. The reduction in SSIs significantly improved the long-term outcomes for these patients.

Percutaneous Direct Pars Repair in Young Athletes.

BACKGROUND: Lumbar pars defects are common in adolescent athletes and are often due to recurrent axial loading and traumatic stressors. OBJECTIVE: To present an updated case series of young athletes who underwent percutaneous direct pars repair after failure of conservative management. METHODS: A single-center, nonrandomized, retrospective observation study of athletes who were referred for minimally invasive direct pars repair after failure of at least 6 months of conservative management was performed. Summary demographic information, clinical features of presentation, perioperative and intraoperative radiographic imaging, and visual analog scale back pain scores were collected and analyzed. RESULTS: A total of 21 patients were included (mean age [± SD] 17.47 ± 3.02 years, range 14-25 years), 6 of whom were female (29%). All patients presented with bilateral pars fractures, with L5 being the most frequent level involved (n = 13). The average follow-up time was 31.52 ± 9.38 months (range 3-110 months). The visual analog scale score for back pain was significantly reduced from 7.62 ± 1.83 preoperatively to 0.28 ± 0.56 at the final postoperative examination (P < .01). Fusion was noted in 20 of the 21 patients on final follow-up (95%). CONCLUSION: Percutaneous direct pars repair is a safe and effective means in treating young adolescents who have failed conservative management. The advantages included minimized muscle and soft tissue dissection, reduced blood loss, and early mobilization and recovery. In young athletes who desire return to high-level physical activity, this surgical technique is of particular benefit and should be considered in this patient population.

Delayed subdural fluid collections after Ommaya reservoir placement.

BACKGROUND: Delayed subdural fluid collections can occur after Ommaya reservoir placement and can cause neurological symptoms and interfere with treatment. We performed a retrospective chart review to study risk factors for delayed subdural fluid collections and clinical outcomes. METHODS: Retrospective chart review was performed for patients undergoing Ommaya reservoir placement between 2010-2019 at our institution. RESULTS: Out of 53 patients who had Ommaya reservoir placement during the study period, 11 developed delayed subdural fluid collections (21%). HIV infection was the only statistically significant risk factor (P=0.001, Fisher's Exact Test). Thrombocytopenia, ventricle size, use of the reservoir, and suboptimal catheter placement were not associated with development of delayed subdural fluid collections. 2 patients, both HIV positive, required surgical evacuation. CONCLUSIONS: Delayed subdural fluid collections occur in a significant minority of patients after Ommaya reservoir placement, and some patients require surgical intervention. HIV infection is associated with a higher risk of development of delayed subdural fluid collections. This patient subpopulation may benefit from closer monitoring or adjustment of management protocols.

Transdural Approach for Resection of Craniovertebral Junction Cysts: Case Series.

BACKGROUND: Craniovertebral junction (CVJ) cysts, including retro-odontoid pseudotumors, are challenging pathologies to treat and manage effectively. Surgical intervention is indicated when these lesions result in progressive myelopathy, intractable pain, or instability. OBJECTIVE: To present a case series of older patients who underwent successful resection retro-odontoid lesions using transdural approach. METHODS: A single-center, retrospective observation study of older patients who underwent transdural resection of CVJ cysts at a single institution was performed. Summary demographic information, clinical presentation, perioperative and intraoperative imaging, and Nurick scores were collected and analyzed. RESULTS: Eight patients were included (mean age [±SD] 75.88 ± 9.09 years). All patients presented with retro-odontoid lesions resulting in severe cervical stenosis, cord compression, and myelopathy. The mean duration of surgery was 226 ± 83.7 minutes. The average intraoperative blood loss was 181.2 cc. The average hospital stay was 4.5 days ± 1.3 (range, 3-7 days). The average follow-up time was 12.5 ± 9.5 months. No intraoperative complications were encountered. The Nurick classification score for myelopathy improved at the final postoperative examination (2.38 ± 1.06 vs 1 ± 1.07). Three patients demonstrated a pre-existing deformity prompting an instrumented fusion. Both computed tomography and MRI evidence of complete regression of retro-odontoid cyst were noted in all patients on the final follow-up. CONCLUSION: Posterior cervical transdural approach for ventral lesions at the CVJ is a safe and effective means of treating older patients with progressive myelopathy. This technique provides immediate spinal cord decompression while limiting neurological complications commonly associated with open or endoscopic anterior transpharyngeal approaches.

Diaphragmatic Hernia With Incarcerated Spleen as a Complication After Lateral Anterior Column Realignment.

BACKGROUND: The creation of sagittal balance of the spine is critical in the treatment adult spinal deformity. Anterior column release (ACR) has gained traction as a minimally invasive alternative to pedicle subtraction osteotomy. By releasing the anterior longitudinal ligament, the anterior column can be lengthened and physiologic lordosis restored. Risks such as transient psoas weakness and thigh numbness have been well documented in the literature; however, diaphragmatic hernia has never been reported. OBJECTIVE: To highlight the difficulties encountered in diagnosing, managing, and treating iatrogenic diaphragmatic hernia in the setting of ACR and stress the relevant retropleural, retroperitoneal, and diaphragmatic structures during the surgical approach. METHODS: In this technical note, we discuss the relevant anatomy in a direct lateral approach to the thoracolumbar junction and the management of an iatrogenic diaphragmatic hernia, which occurred in a patient who underwent a L1 ACR. RESULTS: Three months after surgery, our patient was assessed in clinic and endorsed significant improvements in her pain and mobility. Her 3-month postoperative scoliosis x-rays demonstrated a significant improvement in her sagittal alignment, and she experienced no further negative sequelae from the iatrogenic hernia. CONCLUSION: Iatrogenic diaphragmatic hernia with an intrathoracic spleen after direct lateral ACR is a risk spine surgeons should be aware of and address promptly.

Direct Bypass Surgery for Moyamoya and Steno-occlusive Vasculopathy: Clinical Outcomes, Intraoperative Blood Flow Analysis, Long-term Follow-up, and Long-term Bypass Patency in a Single Surgeon Case Series of 162 Procedures.

BACKGROUND: Cerebral extracranial-intracranial (EC-IC) direct bypass is a commonly used procedure for the treatment of cerebral hypoperfusion secondary to chronic steno-occlusive vasculopathy. We sought to determine clinical outcomes, intraoperative blood flow analysis, long term follow up, and long term patency rates from a single surgeon's series of direct cerebral bypass for moyamoya disease, moyamoya syndrome, and steno-occlusive disease. METHODS: We reviewed clinical, demographic, operative and neuroimaging records for all patients who underwent a direct EC-IC bypass by the senior author between August 1999 and November 2020. Primary outcomes analyzed were functional long-term outcomes (by modified Rankin score [mRS]), surgical complications, and short-term and long-term bypass patency. RESULTS: A total of 162 revascularization procedures in 124 patients were performed. Mean clinical follow up time was 2 years 11 months. The combined immediate and long term postoperative stroke and/or intracerebral hemorrhage rate was 6.2%. There were 17 bypasses (10%) that were found to be occluded at long-term follow-up, all but one were asymptomatic. Long-term graft occlusion was correlated with presence of complete collateralization on preoperative angiography but not cut flow index (CFI). Overall, patients had a significant clinical improvement with a mean mRS score 1.8 preoperatively and 1.2 postoperatively. CONCLUSIONS: In our consecutive series of patients treated with direct EC-IC cerebral bypass, there was significant improvement in functional outcome as measured by the mRS. The long term patency rate was 90%. There was a statistically significant correlation between complete or incomplete angiographic collateralization patterns and long-term bypass occlusion. There was no correlation between bypass type, clinical syndrome, or CFI and long-term occlusions. The role of bypass surgery and the need for surgical expertise remain strong in the treatment of moyamoya variants and a select group of atherosclerotic steno-occlusive patients.

Microsurgical Management of Vestibular Schwannoma (Acoustic Neuroma): Facial Nerve Outcomes, Radiographic Analysis, Complications, and Long-Term Follow-Up in a Series of 420 Surgeries.

OBJECTIVE: The purpose of this study is to retrospectively evaluate the clinical and surgical outcomes of a large surgical series of vestibular schwannoma from North America over 20 years. METHODS: After institutional review board approval a retrospective review of the senior author's personal case logs to identify patients who had operations for vestibular schwannoma was performed. The clinical notes, operative record, preoperative and postoperative imagings, and long-term clinical follow-up notes were evaluated. RESULTS: A total of 415 patients who underwent 420 surgeries were identified from the years 1998-2021. The average length of follow-up was 3 years and 9 months. Overall, at last follow-up the rate of "good" facial nerve outcomes (House-Brackmann [HB] score I and II) was 86% and "poor" facial nerve outcomes (HB III-VI) was 14%. The amount of cerebellopontine angle extension (P = 0.023), tumor volume (P = 0.015), facial nerve consistency (P < 0.001), preoperative HB score (P < 0.001), and FN stimulation threshold at the end of the procedure (P < 0.001) were correlated to facial nerve function at the last follow-up. CONCLUSIONS: This study represents one of the largest recently reported surgical series of vestibular schwannoma in North American literature with available long term follow-up. Facial nerve outcomes correlated with cerebellopontine angle extension, tumor volume, facial nerve stimulation threshold, facial nerve consistency, preoperative facial nerve function, and history of a prior resection. Tumor recurrence remains significantly higher after subtotal resection. We believe the data supports a continuation of a strategy of general intent of gross total resection, greatly modifiable by intraoperative findings and judgment.

Radial Access Techniques.

Transradial access (TRA) has gained traction in neurointerventions as studies continue to demonstrate improved access site safety and equivalent end artery effectiveness when compared with traditional transfemoral techniques. Herein, we describe the technical nuances of obtaining TRA with a focus on distal TRA, left TRA, and sheathless TRA using larger bore catheters. We also discuss various strategies to avoid access site conversion if radial artery spasm or radial anomalies are encountered and offer some solutions for forming the Simmons catheter especially when it cannot be performed in the descending aorta. Lastly, we provide some insights regarding contraindications to TRA.

Conservative Management of Post-Operative Cerebrospinal Fluid Leak following Skull Base Surgery: A Pilot Study.

BACKGROUND/AIMS: Iatrogenic CSF leaks after endoscopic endonasal transsphenoidal surgery remain a challenging entity to manage, typically treated with CSF diversion via lumbar drainage. OBJECTIVE: To assess the safety and efficacy of high-volume lumbar puncture (LP) and acetazolamide therapy to manage iatrogenic CSF leaks. METHODS: We performed a prospective pilot study of four patients who developed iatrogenic postoperative CSF leaks after transsphenoidal surgery and analyzed their response to treatment with concomitant high-volume lumbar puncture followed by acetazolamide therapy for 10 days. Data collected included demographics, intra-operative findings, including methodology of skull base repair and type of CSF leak, time to presentation with CSF leak, complications associated with high-volume LP and acetazolamide treatment, and length of follow-up. RESULTS: Mean patient age was 44.28 years, with an average BMI of 27.4. Mean time from surgery to onset of CSF leak was 7.71 days. All four patients had resolution of their CSF leak at two- and four-week follow-up. Mean overall follow-up time was 179 days, with a 100% CSF leak cure rate at the last clinic visit. No patient suffered perioperative complications or complications secondary to treatment. CONCLUSION: Although our pilot case series is small, we demonstrate that a high-volume LP, followed by acetazolamide therapy for 10 days, can be considered in the management of post-operative CSF leaks.

Radial Long Sheath Angioplasty for Proximal Severe Flow-Limiting Radial Artery Spasm Using the Dotter Technique.

BACKGROUND: Although studies have continued to demonstrate the advantages of transradial access (TRA) for neurointervention, radial artery spasm (RAS) has remained a frequent cause of TRA failure. Dotter and Judkins initially described a technique to dilate areas of peripheral vascular stenosis by advancing sequentially larger catheters across the lesion over a guidewire. We have presented our institutional experience with the use of a modified Dotter technique with long radial sheaths to dilate areas of proximal flow-limiting RAS. In the present study, we reviewed the use of the Dotter technique for alleviating RAS in patients undergoing TRA for neurointervention. METHODS: We performed a retrospective review of all patients undergoing TRA for neurointervention at our institution from 2018 to 2020 to identify patients with proximal flow-limiting RAS. For the identified patients, a modified Dotter technique had been used to dilate the stenosis. The demographic and periprocedural data were assessed to identify any adverse outcomes. RESULTS: Four patients with severe proximal flow-limiting RAS were identified. In each case, a hydrophilic long radial sheath and vascular dilator were sequentially advanced through the stenosis. In all cases, repeat angiography demonstrated improvement of the spasm, and the final radial angiograms demonstrated persistent improvement in caliber and regularity of the vessel. Each procedure was also completed via TRA with no periprocedural complications. CONCLUSIONS: Our modified Dotter technique was effective in bypassing areas of severe proximal flow-limiting RAS, obviating the need for access site conversion. Additional studies are warranted to understand the implication of the angioplasty-like effects seen within the radial artery after removal of the long radial sheaths.

Efficacy of Reverse and Modified Bohlman Technique for Lumbar Spondylolisthesis: A Systematic Review of the Literature.

OBJECTIVE: High-grade lumbar spondylolisthesis (HGLS) remains a challenging surgical entity, and there is no current consensus regarding optimal surgical approach. The purpose of this study was to systematically review the literature for studies utilizing the reverse or modified Bohlman technique for the treatment of HGLS to assess their safety and efficacy. METHODS: The authors performed a literature search of PubMed/MEDLINE electronic databases from their inception according to the PRISMA guidelines. RESULTS: A total of 8 studies were included. The studies comprised a total of 43 patients, with mean age of 41.4 ± 19.8 (range: 9-83) years. The mean follow-up was 38.2 ± 41.7 (range: 3-137) months. Most patients (81.4%) were classified as having grade III or higher spondylolisthesis. The most common presenting symptom was back pain (93%), followed by radiculopathy in roughly half of patients (41.9%). The majority of patients (93%) experienced complete resolution of symptoms as well as successful fusion (90.7%) on follow-up. Complications included cage/graft failure (7%), nerve injury (7%), wound infection (7%), pseudoarthrosis (2.3%), epidural hematoma (2.3%), and deep vein thrombosis (2.3%). Revision surgery was required in 4 (9.3%) patients. Slip percentage (60.2% vs. 43.2%, P < 0.0001) and slip angle (17.1° vs. 6.4°, P < 0.001) both decreased significantly following surgery. CONCLUSIONS: Our data demonstrate that reverse and modified Bohlman techniques appear to be effective in both improving slip angle/percentage and relieving symptoms with low risk of complications. These findings are limited by the small sample size of patients. The authors recommend larger series before formal recommendations can be made.