Rates of Postoperative Complications and Approach-related Neurological Symptoms After L4-L5 Lateral Transpsoas Lumbar Interbody Fusion Compared With Upper Lumbar Levels.

STUDY DESIGN: This was a retrospective comparative study. OBJECTIVE: To compare the likelihood of approach-related complications for patients undergoing single-level lateral lumbar interbody fusion (LLIF) at L4-L5 to those undergoing the procedure at upper lumbar levels. SUMMARY OF BACKGROUND DATA: LLIF has been associated with a number of advantages when compared with traditional interbody fusion techniques. However, potential risks with the approach include vascular or visceral injury, thigh dysesthesias, and lumbar plexus injury. There are concerns of a higher risk of these complications at the L4-L5 level compared with upper lumbar levels. MATERIALS AND METHODS: A retrospective cohort review was completed for consecutive patients undergoing single-level LLIF between 2004 and 2019 by a single surgeon. Indication for surgery was symptomatic degenerative lumbar stenosis and/or spondylolisthesis. Patients were divided into 2 cohorts: LLIF at L4-L5 versus a single level between L1 and L4. Baseline characteristics, intraoperative complications, postoperative approach-related neurological symptoms, and patient-reported outcomes were compared and analyzed between the cohorts. RESULTS: A total of 122 were included in analysis, of which 58 underwent LLIF at L4-L5 and 64 underwent LLIF between L1 and L4. There were no visceral or vascular injuries or lumbar plexus injuries in either cohort. There was no significant difference in the rate of postoperative hip pain, anterior thigh dysesthesias, and/or hip flexor weakness between the cohorts (53.5% L4-L5 vs. 37.5% L1-L4; P =0.102). All patients reported complete resolution of these symptoms by 6-month postoperative follow-up. DISCUSSION: LLIF surgery at the L4-L5 level is associated with a similar infrequent likelihood of approach-related complications and postoperative hip pain, thigh dysesthesias, and hip flexor weakness when compared with upper lumbar level LLIF. Careful patient selection, meticulous use of real-time neuromonitoring, and an understanding of the anatomic location of the lumbar plexus to the working corridor are critical to success.

Comparing Outcomes and Billing Costs of Middle Cranial Fossa and Transmastoid Approaches for Otogenic Encephalocele and Cerebrospinal Fluid Leak Repair.

OBJECTIVE: Comparison of outcomes and billing costs of patients treated at our institution using transmastoid (TM), middle cranial fossa (MCF), and combined approaches for repair of otogenic cerebrospinal fluid (CSF) leaks and encephaloceles. STUDY DESIGN: Retrospective cohort review. SETTING: Tertiary-care hospital. PATIENTS: Seventy-seven cases of otogenic CSF leaks or encephaloceles. INTERVENTIONS: Surgical repair of an otogenic encephalocele or CSF leak using either a TM, MCF, or combined approach. MAIN OUTCOME MEASURES: Success of repair, length of operation, cost of operating room materials, postoperative need for intensive care, and postoperative length of stay. RESULTS: Forty cases (52%) were performed by the TM approach, 27 (35%) by MCF, and 10 (13%) by combined TM/MCF. Mean length of stay was not statistically different amongst TM patients (2.1 d), MCF patients (3.3 d), and combined TM/MCF patients (3.70; p = 0.112). Only 3/40 TM cases required intensive care during their admission while all MCF and combined TM/MCF approach cases were admitted to the intensive care unit for at least one night ( p < 0.001). On follow-up, CSF leak recurred in 3/77 (4%) cases: 3/27 (11%) MCF, 0/40 TM, and 0/10 combined TM/MCF patients ( p = 0.056). The mean cost of operating room materials charged to the patient was significantly greater in the MCF group ($9,883) than the TM group ($3,748; p = 0.001). CONCLUSIONS: In carefully selected patients, the TM approach is an effective and less costly alternative to MCF approaches for repair of otogenic CSF leaks and encephaloceles.

Cervical Alignment Analysis Comparing Two-Level Cervical Disc Arthroplasty with Anterior Cervical Discectomy and Fusion with Anterior Plate Fixation.

OBJECTIVE: This study assesses cervical alignments after 2-level cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) with anterior plate fixation. METHODS: Eighty-two patients who underwent 2-level CDA or ACDF in 2014-2019 were identified. Cervical alignment parameters were compared between the 2 cohorts. Subgroup analyses were performed to determine factors that differentiate alignment outcomes between the 2 procedures. RESULTS: Although both cohorts achieved significant focal lordosis (FL) and overall cervical lordotic (CL) gains, CDA cohorts achieved significantly greater 12-month FL gain (P = 0.022). However, in a multivariate analysis controlling for preoperative variables, FL gain was no longer significant. Although the CDA cervical sagittal vertical axis (cSVA) significantly improved at 3 (P = 0.030) and 12 (P = 0.007) months, these improvements were not superior to the ACDF cSVA. Male patients undergoing CDA achieved greater 12-month CL gain. Patients undergoing CDA with body mass index >25 kg/m2 achieved greater 12-month FL gain. Patients undergoing CDA with symptom duration >12 months achieved greater FL gain at 3 and 12 months. Patients undergoing CDA with high baseline T1 slope or cSVA achieved greater 12-month cSVA reduction. Clinical outcomes were comparable between the 2 cohorts. Unlike the ACDF group, CL gain in the CDA group was significantly correlated with the cSVA reduction, which was associated with significant improvement in the Neck Disability Index, arm pain, and 12-Item Short-Form Mental Component Scores. Heterotopic ossification was not found to significantly affect patient outcome and cervical alignment in both cohorts. CONCLUSIONS: ACDF and CDA are viable options for 2-level degenerative disc disease in carefully selected patients. Both approaches produced equivalent postoperative alignment changes in a 2-level operation.

Transmastoid Repair of Otogenic Encephaloceles in Patients With Canal Wall Down Mastoidectomy.

OBJECTIVE: Description of a series of cases in which otogenic encephaloceles in patients requiring canal wall down (CWD) mastoidectomies were repaired via a transmastoid approach. STUDY DESIGN: Case series. SETTING: Tertiary-care hospital. PATIENTS: Eleven cases of otogenic encephaloceles in patients requiring CWD mastoidectomy for chronic ear disease. INTERVENTIONS: Surgical repair of an otogenic encephalocele using a transmastoid approach. MAIN OUTCOME MEASURES: Success of repair, number and size of defects, materials used for repair, complications encountered in surgery, pure tone average air-bone gap (PTA-ABG). RESULTS: Eleven cases were identified. Two of these patients had a prior CWD cavity while the remainder received CWD mastoidectomy simultaneously with encephalocele repair. None of the patients required revision of encephalocele repair. Mean preoperative PTA-ABG was 30 dB and mean postoperative PTA-ABG was 28 dB (p = 0.66). CONCLUSIONS: A single-stage strictly transmastoid approach to otogenic encephalocele repair may be effective in patients with prior CWD mastoid cavities or requiring concurrent CWD mastoidectomy for chronic ear disease and/or cholesteatoma.

Prevalence and anatomical characteristics of the human massa intermedia.

Massa intermedia (MI), also known as interthalamic adhesion is an inconsistent bridge connecting the two thalami. Recent studies suggest MI contains functional neuronal tissue and is responsible for interhemispheric communication. Absence of MI has been linked to cognitive differences and psychiatric disorders. However, MI is naturally absent in up to 35 percent of cases but its true prevalence during life in humans is unknown. High resolution anatomical MR studies of 1410 subjects aged 2 months to 93 years were reviewed and those with MI were identified. Prevalence and characteristics of MI were identified and grouped by gender and decade of life. MI was present in 87.3% of the studied subjects. Absence of MI was noted in as early as first decade of life as well as all decades of life, but its absence increased with age, suggesting additional factors during life as mediators. Females had 2.75 times higher likelihood of MI presence than males. Size of MI decreased with increasing age up to age 70. Size of MI was best predicted by third ventricular width and age mediating a larger MI with smaller third ventricular size and younger age. MI is present in 87.3% of the population as determined in this MRI study. Absence of MI is identifiable in very early years of life, suggesting a congenital cause. MI's prevalence, however, was also found to decrease with advancing age, suggesting a dynamic process of MI disappearance during life.

DAXX Suppresses Tumor-Initiating Cells in Estrogen Receptor-Positive Breast Cancer Following Endocrine Therapy.

Estrogen receptor (ER)-positive breast cancer recurrence is thought to be driven by tumor-initiating cells (TIC). TICs are enriched by endocrine therapy through NOTCH signaling. Side effects have limited clinical trial testing of NOTCH-targeted therapies. Death-associated factor 6 (DAXX) is a newly identified marker whose RNA expression inversely correlates with NOTCH in human ER+ breast tumor samples. In this study, knockdown and overexpression approaches were used to investigate the role of DAXX on stem/pluripotent gene expression, TIC survival in vitro, and TIC frequency in vivo, and the mechanism by which DAXX suppresses TICs in ER+ breast cancer. 17ß-Estradiol (E2)-mediated ER activation stabilized the DAXX protein, which was required for repressing stem/pluripotent genes (NOTCH4, SOX2, OCT4, NANOG, and ALDH1A1), and TICs in vitro and in vivo. Conversely, endocrine therapy promoted rapid protein depletion due to increased proteasome activity. DAXX was enriched at promoters of stem/pluripotent genes, which was lost with endocrine therapy. Ectopic expression of DAXX decreased stem/pluripotent gene transcripts to levels similar to E2 treatment. DAXX-mediated repression of stem/pluripotent genes and suppression of TICs was dependent on DNMT1. DAXX or DNMT1 was necessary to inhibit methylation of CpGs within the SOX2 promoter and moderately within the gene body of NOTCH4, NOTCH activation, and TIC survival. E2-mediated stabilization of DAXX was necessary and sufficient to repress stem/pluripotent genes by recruiting DNMT1 to methylate some promoters and suppress TICs. These findings suggest that a combination of endocrine therapy and DAXX-stabilizing agents may inhibit ER+ tumor recurrence. SIGNIFICANCE: Estradiol-mediated stabilization of DAXX is necessary and sufficient to repress genes associated with stemness, suggesting that the combination of endocrine therapy and DAXX-stabilizing agents may inhibit tumor recurrence in ER+ breast cancer.