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Abstract BACKGROUND Patients recovering from decompressive laminectomy without fusion may require assistance with activities of daily living and physical/occupational therapy upon hospital discharge. OBJECTIVE To examine comorbidities and perioperative characteristics of patients undergoing lumbar decompression for associations with discharge status using a multicenter database. METHODS A multicenter database was used for this retrospective cohort analysis. Patients admitted from home with degenerative spine disease for lumbar decompression without fusion were included. Thirty-day outcomes and operative characteristics were compared as a function of patient discharge using chi-square and Wilcoxon Rank Sum tests. Multivariable logistic regression was used to determine factors associated with discharge to a nonhome facility. RESULTS Of the 8627 patients included for analysis, 9.7% were discharged to a nonhome facility. On multivariable analysis, age (85+ vs <65, odds ratio [OR] 13.59), number of levels of decompression (3+ vs 1, OR 1.75), African American race vs Non-Hispanic or Hispanic White (OR 1.87), female vs male gender (OR 1.97), body mass index (BMI) (40+ vs 18.5-24.9, OR 1.74), American Society of Anesthesiologists physical classification status (4 vs 1 or 2, OR 2.35), hypertension (OR 1.29), dependent functional status (OR 3.92), diabetes (OR 1.47), smoking (OR 1.40), hematocrit (<35 vs 35+, OR 1.76), international normalized ratio (≥1.3 vs <1.3, OR 2.32), and operative time (3+ h vs <1 h, OR 5.34) were significantly associated with an increased odds of discharge to nonhome facilities. CONCLUSION Preoperative status and operative course variables can influence discharge disposition in lumbar decompression patients. Identifying specific factors that contribute to a greater likelihood of dismissal to skilled facility or rehabilitation unit can further inform both surgeons and patients during preoperative counseling and disposition planning.

OBJECTIVEThe mechanism by which greater institutional case volume translates into improved outcomes after surgical clipping of unruptured intracranial aneurysms (UIAs) is not well established. The authors thus aimed to assess the effect of case volume on the rate of various types of complications after clipping of UIAs.METHODSUsing information on the outcomes of inpatient admissions for surgical clipping of UIAs collected within a national database, the relationship of institutional case volume to the incidence of different types of complications after clipping was investigated. Complications were subdivided into different categories, which included all complications, ischemic stroke, intracerebral hemorrhage, medical complications, infectious complications, complications related to anesthesia, and wound complications. The relationship of case volume to different types of complications was assessed using linear regression analysis. The relationships between case volume and overall complication and stroke rates were fit with both linear and quadratic equations. The numerical cutoff for institutional case volume above and below which the authors found the greatest differences in mean overall complication and stroke rate was determined using classification and regression tree (CART) analysis.RESULTSBetween October 2012 and September 2015, 125 health care institutions reported patient outcomes from a total of 6040 cases of clipping of UIAs. On linear regression analysis, increasing case volume was negatively correlated to both overall complications (r2 = 0.046, p = 0.0234) and stroke (r2 = 0.029, p = 0.0557) rate, although the relationship of case volume to the complication (r2 = 0.092) and stroke (r2 = 0.067) rate was better fit with a quadratic equation. On CART analysis, the cutoff for the case number that yielded the greatest difference in overall complications and stroke rate between higher- or lower-volume centers was 6 cases/year and 3 cases/year, respectively.CONCLUSIONSAlthough the authors confirm that increasing case volume is associated with reduced complications after clipping of UIAs, their results suggest that the relationship between case volume and complications is not necessarily linear. Moreover, these results indicate that the effect of case volume on outcome is most evident between very-low-volume centers relative to centers with a medium-to-high volume.

Background Patients with an acute ischemic stroke (AIS) due to large vessel occlusion often require transfer to an endovascular center for treatment. Objective To assess the effect of hospital transfer on outcomes after endovascular revascularization. Methods Outcomes of endovascular revascularization were compared between directly admitted and transferred patients using data from a national database and our own institution. Results 118 institutions within the database reported outcomes of 8533 inpatient admissions for endovascular treatment of AIS. Mortality rate (14.9% vs 18.6%; p=0.049) and mortality index (1.1 vs 1.6; p=0.048) were significantly lower among directly admitted patients than among transferred patients. Within our institutional cohort of 140 patients who underwent endovascular therapy, directly admitted patients had a significantly faster time to revascularization than transferred patients (277.4 vs 420.4 min; p≤0.0001). Among transferred patients, an increasing distance of transferred hospital to our home institution was associated with an increasing risk of mortality (unit OR=1.26, 95% CI 1.07 to 1.54; p=0.0061). Conclusions Outcomes of revascularization may improve with methods to identify patients with large vessel occlusion before hospital admission, thus increasing the likelihood of initial triage to a comprehensive stroke center for patients eligible for endovascular intervention.

OBJECTIVE With improving medical therapies for chronic conditions, elderly patients increasingly present as candidates for operative intervention for degenerative diseases of the spine. To date, there is a paucity of studies examining complications in lumbar decompression, without fusion, that include patients older than 80 years. Using a multicenter national database, the authors of this study evaluated lumbar decompression in the elderly, including octogenarians, to evaluate for associations between age and patient outcomes. METHODS The 2011–2013 American College of Surgeons' National Surgical Quality Improvement Program data set was queried for patients 65 years and older with diagnosis and procedure codes inclusive of degenerative spine disease and lumbar decompression without fusion. Morbidity and mortality within the 30-day postoperative period were the primary outcomes. Secondary outcomes of interest included unplanned readmission within 30 days or discharge to a nonhome facility. Outcomes and operative characteristics were compared using chi-square tests, Kruskal-Wallis tests, and multivariable logistic regression models. RESULTS A total of 8744 patients were identified; of these patients 4573 (52.30%) were 65 years and older. Elderly patients were stratified into 3 age categories: 85 years or older (n = 314), 75–84 years (n = 1663), and 65–74 years (n = 2596). Univariate analysis showed that, compared with age younger than 65 years, increased age was associated with the number of levels (≥ 3), readmissions within 30 days, nonhome discharge, any complication, length of stay, and blood transfusion (all p < 0.001). On multivariable analysis and with younger than 65 years as the reference, increased age was associated with any minor complication (p < 0.001; ≥ 85 years: OR 3.47, 95% CI 1.69–7.13; 75–84 years: OR 2.34, 95% CI 1.45–3.78; and 65–74 years: OR 1.44, 95% CI 0.94–2.20), as well as discharge location other than home (p < 0.001; ≥ 85 years: OR 13.59, 95% CI 9.47–19.49; 75–84 years: OR 5.64, 95% CI 4.33–7.34; and 65–74 years: OR 2.61, 95% CI 2.05–3.32). CONCLUSIONS The authors' high-powered, multicenter analysis of lumbar decompression without fusion in the elderly, specifically including patients older than 80 years, demonstrates that increased age is associated with more extensive operations, resulting in longer hospital stays, increased rates of nonhome discharge, and minor complications.

OBJECTIVEHypoplasia of the A1 segment of the anterior cerebral artery is frequently observed in patients with anterior communicating artery (ACoA) aneurysms. The effect of this anatomical variant on ACoA aneurysm morphology is not well understood.METHODSDigital subtraction angiography images were reviewed for 204 patients presenting to the authors' institution with either a ruptured or an unruptured ACoA aneurysm. The ratio of the width of the larger A1 segment to the smaller A1 segment was calculated. Patients with an A1 ratio greater than 2 were categorized as having A1 segment hypoplasia. The relationship of A1 segment hypoplasia to both patient and aneurysm characteristics was then assessed.RESULTSOf 204 patients that presented with an ACoA aneurysm, 34 (16.7%) were found to have a hypoplastic A1. Patients with A1 segment hypoplasia were less likely to have a history of smoking (44.1% vs 62.9%, p = 0.0410). ACoA aneurysms occurring in the setting of a hypoplastic A1 were also found to have a larger maximum diameter (mean 7.7 vs 6.0 mm, p = 0.0084). When considered as a continuous variable, increasing A1 ratio was associated with decreasing aneurysm dome-to-neck ratio (p = 0.0289). There was no significant difference in the prevalence of A1 segment hypoplasia between ruptured and unruptured aneurysms (18.9% vs 10.7%; p = 0.1605).CONCLUSIONSOur results suggest that a hypoplastic A1 may affect the morphology of ACoA aneurysms. In addition, the relative lack of traditional risk factors for aneurysm formation in patients with A1 segment hypoplasia argues for the importance of hemodynamic factors in the formation of ACoA aneurysms in this anatomical setting.

Introduction Vertebral artery injury is a rare but serious complication of cervical spine surgery with an overall incidence rate of 1.4% (Rampersaud, 2006). Iatrogenic injury of the vertebral artery can lead to serious complications including lateral medullary (Wallenberg) syndrome, quadriparesis, and mortality. The high rate of vertebral artery anomalies in the general population mandates assessment via advanced imaging modalities in the preoperative period (Schroeder, 2013). The rarity of this complication makes it difficult to set expectations after an injury is encountered. This study utilized a multi-center database to compile outcomes data after vertebral artery injury during a cervical spine procedure. Materials and Methods A multi-center retrospective case series was compiled involving 23 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005–2011 and who sustained a vertebral artery injury. IRBs were obtained from all institutions and data was sent to a private research organization that collected and collated all of the data. Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36). Results Vertebral artery injuries were identified in a total of 14 of 16,582 total patients screened (8.4 per 10,000). The mean age of patients with vertebral artery injury was 59 years (+/− 10) with a female predominance (78.6%). Diagnoses of affected patients included 7 with myelopathy, 3 with radiculopathy, 1 with cervical instability, and 2 with metastatic disease. The mean duration of operative time for cases was 4.7 hours (+/− 1.8). Vertebral artery injury was also associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior only approach, 3 cases with posterior only approach, and 4 during circumferential approach. Average length of hospital stay for these patients was 10 days (+/− 8). Notably, 13 of the 14 (92.86%) cases reportedly resolved without residual deficits. Compared with preoperative baseline NDI, Nurick, and SF-36 physical and mental component scores for these patients, there were no observed changes after surgery ( p = 0.20 Ð 0.94). Conclusion Vertebral artery injuries are potentially catastrophic complications that can be sustained from either anterior or posterior cervical spine approaches. This adverse event is associated with an increase in hospital stay and functional disability measured on NDI score. However, the data from this study suggests that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits (13 out of 14). Preoperative imaging studies may provide insight into VA anomalies and anatomic variations and are vital to the preoperative assessment. Furthermore, although surgeons should expect increased blood loss once a vertebral artery injury is encountered, patients do not often require a blood transfusion.

OBJECTIVE Prospective longitudinal outcomes registries are at the center of evidence-driven health care reform. Obtaining real-world outcomes data at 12 months can be costly and challenging. In the present study, the authors analyzed whether 3-month outcome measurements sufficiently represent 12-month outcomes for patients with degenerative lumbar disease undergoing surgery. METHODS Data from 3073 patients undergoing elective spine surgery for degenerative lumbar disease were entered into a prospective multicenter registry (N2QOD). Baseline, 3-month, and 12-month follow-up Oswestry Disability Index (ODI) scores were recorded. The absolute differences between actual 12- and 3-month ODI scores was evaluated. Additionally, the authors analyzed the absolute difference between actual 12-month ODI scores and a model-predicted 12-month ODI score (the model used patients' baseline characteristics and actual 3-month scores). The minimal clinically important difference (MCID) for ODI of 12.8 points and the substantial clinical benefit (SCB) for ODI of 18.8 points were used based on the previously published values. The concordance rate of achieving MCID and SCB for ODI at 3-and 12-months was computed. RESULTS The 3-month ODI scores differed from 12-month scores by an absolute difference of 11.9 ± 10.8, and predictive modeling estimations of 12-month ODI scores differed from actual 12-month scores by a mean (± SD) of 10.7 ± 9.0 points (p = 0.001). Sixty-four percent of patients (n = 1982) achieved an MCID for ODI at 3 months in comparison with 67% of patients (n = 2088) by 12 months; 51% (n = 1731) and 61% (n = 1860) of patients achieved SCB for ODI at 3 months and 12 months, respectively. Almost 20% of patients had ODI scores that varied at least 20 points (the point span of an ODI functional category) between actual 3- and 12-month values. In the aggregate analysis of achieving MCID, 77% of patients were concordant and 23% were discordant in achieving or not achieving MCID at 3 and 12 months. The discordance rates of achieving or not achieving MCID for ODI were in the range of 19% to 27% for all diagnoses and treatments (decompression with and without fusion). The positive and negative predictive value of 3-months ODI to predict 12-month ODI was 86% and 60% for MCID and 82% and 67% for SCB. CONCLUSIONS Based on their findings, the authors conclude the following: 1) Predictive methods for functional outcome based on early patient experience (i.e., baseline and/or 3-month data) should be used to help evaluate the effectiveness of procedures in patient populations, rather than serving as a proxy for long-term individual patient experience. 2) Prospective longitudinal registries need to span at least 12 months to determine the effectiveness of spine care at the individual patient and practitioner level.

OBJECTIVE The purpose of this study was to report the long-term clinical outcomes following 3- and 4-level anterior cervical discectomy and fusion (ACDF). METHODS A retrospective review of all adult neurosurgical patients undergoing elective ACDF for degenerative disease at a single institution between 1996 and 2013 was performed. Patients who underwent first-time 3- or 4-level ACDF were included; patients with previous cervical spine surgery, those undergoing anterior/posterior approaches, and those with corpectomy were excluded. Outcome measures included perioperative complication rates, fusion rates, need for revision surgery, Nurick Scores, Odom's criteria, symptom resolution, neck visual analog scale (VAS) pain score, and persistent narcotics usage. RESULTS Seventy-one patients who underwent 3-level ACDF and 26 patients who underwent 4-level ACDF were identified and followed for an average of 7.6 ± 4.2 years. There was 1 case (3.9%) of deep wound infection in the 4-level group and 1 case in the 3-level group (1.4%; p = 0.454). Postoperatively, 31% of patients in the 4-level group complained of dysphagia, compared with 12.7% in the 3-level group (p = 0.038). The fusion rate was 84.6% after 4-level ACDF and 94.4% after 3-level ACDF (p = 0.122). At last follow-up, a significantly higher proportion of patients in the 4-level group continued to have axial neck pain (53.8%) than in the 3-level group (31%; p = 0.039); the daily oral morphine equivalent dose was significantly higher in the 4-level group (143 ± 97 mg/day) than in the 3-level group (25 ± 10 mg/day; p = 0.030). Outcomes based on Odom's criteria were also different between cohorts (p = 0.044), with a significantly lower proportion of patients in the 4-level ACDF group experiencing an excellent/good outcome. CONCLUSIONS In this study, patients who underwent 4-level ACDF had significantly higher rates of dysphagia, postoperative neck pain, and postoperative narcotic usage when compared with patients who underwent 3-level ACDF. Pseudarthrosis and deep wound infection rates were also higher in the 4-level group, although this did not reach statistical significance. Additionally, a smaller proportion of patients achieved a good/excellent outcome in the 4-level group than in the 3-level group. These findings suggest a significant increase of perioperative morbidity and worsened outcomes for patients who undergo 4- versus 3-level ACDF.