Decompressive surgery for lumbar spinal stenosis across the Atlantic: a comparison of preoperative MRI between matched cohorts from the US and Norway.

BACKGROUND: There are no uniform guidelines regarding when to operate for Lumbar Spinal Stenosis (LSS). As we apply findings from clinical research from one population to the next, elucidating similarities or differences provides important context for the validity of extrapolating clinical outcomes. The aim of this study was to compare the morphological severity of lumbar spinal stenosis on preoperative MRI in patients undergoing decompressive surgery in Boston, USA, and Trondheim, Norway. METHODS: In this observational retrospective study, we compared morphological severity on MRI before surgical treatment between two propensity score-matched patient populations with single or two-level symptomatic LSS. We assessed the radiographic severity of LSS utilizing the Schizas classification (grade A to D). RESULTS: Following propensity score matching, demographics are balanced. In the Trondheim cohort, two levels decompression were present in 36.2% of the patients vs. 41.9% in Boston, (p = 0.396). There was no significant difference in grades A to D concerning central stenosis (p = 0.075). When dichotomized in mild/moderate (A/B) and severe /extreme (C/D), there were no significant differences in the rate of levels operated for high-grade stenosis (C/D), 67.6% in the Boston group compare to 78.1% in the Trondheim group (p = 0.088). CONCLUSIONS: Trondheim, Norway, and Boston, US, have similar radiographic thresholds of LSS for offering surgery.

Surgical management of lumbar spinal stenosis: a survey among Norwegian spine surgeons.

BACKGROUND: Symptomatic lumbar spinal stenosis (LSS) is the most common reason for lumbar surgery in the elderly. There is growing evidence that decompressive surgery offers an advantage over non-surgical management for selected patients with persistent severe symptoms. Based on treatment traditions, open laminectomy has been the gold standard surgical treatment, but various other surgical and non-surgical treatments for LSS are widely used in clinical practice. Therefore, we conducted a survey study to capture potential diversities in surgeons' management of LSS in Norway. METHODS: All spine surgeons in Norway were contacted by e-mail and asked to answer a 20-item questionnaire by using an Internet-based survey tool. We asked eight questions about the respondent (gender, surgical specialty, workplace, experience, number of surgeries performed per year, use of magnification devices) and 12 questions about different aspects of the surgical treatment of LSS (indication for surgery and preoperative imaging, different surgical techniques, clinical outcome). RESULTS: The questionnaire was answered by 51 spine surgeons (47% response rate). The preferred surgical technique for LSS in Norway is microdecompression via a unilateral approach and crossover technique, followed by microdecompression via a bilateral approach. Other techniques are not much used in Norway. CONCLUSIONS: Most Norwegian spine surgeons use minimally invasive decompression techniques in the surgical treatment of LSS, and unilateral microsurgical decompression with crossover decompression is the preferred technique. Where evidence is lacking (e.g., fusion procedures), there is a larger variation of opinions and preferred procedures among Norwegian spine surgeons.

Surgery for Lumbar Spinal Stenosis in Individuals Aged 80 and Older: A Multicenter Observational Study.

OBJECTIVES: To compare clinical outcomes after decompressive surgery for central lumbar spinal stenosis (LSS) in individuals aged 80 and older with those of individuals aged 18-79. DESIGN: Prospective data from the Norwegian Registry for Spine Surgery. SETTING: Multicenter observational study. PARTICIPANTS: Individuals with central LSS undergoing surgery at 36 orthopedic or neurosurgical departments (N = 1,503; 1,325 aged <80 (median 66, range 21-79); 178 aged ≥80 (median 82, range 80-95)). INTERVENTION: Laminectomy or microdecompression. MEASUREMENTS: Changes in Oswestry Disability Index (ODI), EuroQol 5D (EQ-5D), back pain numerical rating scale (NRS), and leg pain NRS at 1 year. Complications and duration of surgical procedures and hospital stays are reported. RESULTS: For all participants, there was a significant improvement in ODI (difference 16.60 points, 95% confidence interval (CI) = 15.59-17.61, P < .001). There were no differences between age cohorts in mean changes in ODI (0.2, 95% CI = -3.05-3.39, P = .92), EQ-5D (0.02, 95% CI = -0.04-0.09, P = .49), back pain NRS (-0.2, 95% CI = -0.7-0.4, P = .56), or leg pain NRS (-0.1, 95% CI = -0.7-0.5), P = .77). There were no differences in perioperative complications between age cohorts (4.9% vs 7.9%, P = .11). Participants aged 80 and older reported more complications occurring within 3 months (11.8% vs 7.5%, P = .02), mainly because of more urinary tract infections (9.6% vs 3.5%, P = .001). Mean duration of hospital stays was 1.3 days longer for participants aged 80 and (4.5 vs 3.2 days, P < .001). There were no differences in duration of single-level microdecompression (P = .94), two-level microdecompression (P = .53), single-level laminectomy (P = .78), or two-level laminectomy (P = .08). CONCLUSION: Individuals aged 80 and older experience improvement in self-reported outcomes similar to those of younger individuals after decompressive surgery for LSS.

Is There an Association Between Radiological Severity of Lumbar Spinal Stenosis and Disability, Pain, or Surgical Outcome?: A Multicenter Observational Study.

STUDY DESIGN: Observational multicenter study. OBJECTIVE: To evaluate if the severity of lumbar spinal stenosis (LSS) on magnetic resonance imaging (MRI) correlates with preoperative disability, pain, or surgical outcomes. SUMMARY OF BACKGROUND DATA: Surgeons use the morphological appearance of LSS on MRI for clinical decision making. However, the associations between radiological severity of LSS and disability, pain, or surgical outcomes remain unclear. METHODS: Evaluation of severity of LSS on preoperative MRI according to the Schizas morphological classification. Patient and treatment data were retrieved from the Norwegian Registry for Spine Surgery. Preopertaive outcome measures were Oswestry disability index (ODI) and numeric rating scale (NRS) scores for back and leg pain. Postopertive outcome measures were ODI and NRS scores for back and leg pain at 1 year, changes in ODI and NRS scores after treatment, duration of surgery, length of hospital stay, and perioperative complications. RESULTS: Of 202 patients included, 7 were found to have mild stenosis, 38 had moderate stenosis, 108 had severe stenosis, and 49 had extreme stenosis. The radiological severity of LSS was not linked to preoperative ODI (P = 0.089), NRS back pain (P = 0.273), or NRS leg pain (P = 0.282) scores. There were no differences in ODI (P = 0.933), NRS back pain (P = 0.652), or NRS leg pain (P = 0.912) scores after 1 year. The radiological severity of stenosis was not associated with change in ODI (P = 0.494), NRS back pain (P = 0.235), NRS leg pain (P = 0.790), duration of surgery (P = 0.661), length of hospital stay (P = 0.739), or perioperative complication rates (P = 0.467). CONCLUSION: Among patients who underwent decompressive surgery for LSS, radiological severity of stenosis was not associated with preoperative disability and pain, or clinical outcomes 1 year after surgery. In this patient group, the radiological severity of LSS has no clear clinical correlation and should therefore not be overemphasized in clinical decision making. LEVEL OF EVIDENCE: 2.

Does Obesity Affect Outcomes After Decompressive Surgery for Lumbar Spinal Stenosis? A Multicenter, Observational, Registry-Based Study.

OBJECTIVE: To evaluate the association between obesity and outcomes 1 year after laminectomy or microdecompression for lumbar spinal stenosis (LSS). METHODS: The primary outcome measure was the Oswestry Disability Index (ODI). Obesity was defined as body mass index (BMI) ≥ 30. Prospective data were retrieved from the Norwegian Registry for Spine Surgery. RESULTS: For all patients (n = 1473) the mean improvement in ODI at 1 year was 16.7 points (95% CI 15.7-17.7, P < 0.001). The improvement in ODI was 17.5 points in nonobese and 14.3 points in obese patients (P = 0 .007). Obese patients were less likely to achieve a minimal clinically important difference in ODI (defined as ≥ 8 points improvement) than nonobese patients (62.2 vs. 70.3%, P = 0.013). Obesity was identified as a negative predictor for ODI improvement in a multiple regression analysis (P < 0.001). Nonobese patients experienced more improvement in both back pain (0.7 points, P = 0.002) and leg pain (0.8 points, P = 0.001) measured by numeric rating scales. Duration of surgery was shorter for nonobese patients for both single- (79 vs. 89 minutes, P = 0.001) and 2-level (102 vs. 114 minutes, P = 0.004) surgery. There was no difference in complication rates (10.4% vs. 10.8%, P = 0.84). There was no difference in length of hospital stays for single- (2.7 vs. 3.0 days, P = 0.229) or 2-level (3.5 vs. 3.6 days, P = 0.704) surgery. CONCLUSIONS: Both nonobese and obese patients report considerable clinical improvement 1 year after surgery for LSS, but improvement was less in obese patients. Obese patients were less likely to achieve a minimal clinically important difference.

The Risk of Getting Worse: Predictors of Deterioration After Decompressive Surgery for Lumbar Spinal Stenosis: A Multicenter Observational Study.

OBJECTIVE: To investigate the frequency and predictors of deterioration after decompressive surgery for single and 2-level lumbar spinal stenosis. METHODS: Prospectively collected data were retrieved from the Norwegian Registry for Spine Surgery. Clinically significant deterioration was defined as an 8-point increase in Oswestry disability index (ODI) between baseline and 12 months' follow-up. RESULTS: There were 2181 patients enrolled in the study. Of 1735 patients with complete 12 months follow-up, 151 (8.7%) patients reported deterioration. The following variables were significantly associated with deterioration at 12 months' follow-up; decreasing age (odds ratio [OR] 1.02, 95% confidence interval [95% CI] 1.00-1.04, P = 0.046), tobacco smoking (OR 2.10, 95% CI 1.42-3.22, P = 0.000), American Society of Anesthesiologists grade ≥3 (OR 1.80, 95% CI 1.07-2.94, P = 0.025), decreasing preoperative ODI (OR 1.05, 95% CI 1.02-1.07, P = 0.000), previous surgery at the same level (OR 2.00, 95% CI 1.18-3.27, P = 0.009), and previous surgery at other lumbar levels (OR 2.10, 95% CI 1.19-3.53, P = 0.009). CONCLUSIONS: Overall risk of clinically significant deterioration in patient-reported pain and disability after decompressive surgery for lumbar spinal stenosis is approximately 9%. Predictors for deterioration are decreasing age, current tobacco smoking, American Society of Anesthesiologists grade ≥3, decreasing preoperative ODI, and previous surgery at same or different lumbar level. We suggest that these predictors should be emphasized and discussed with the patients before surgery.

Does daily tobacco smoking affect outcomes after microdecompression for degenerative central lumbar spinal stenosis? - A multicenter observational registry-based study.

BACKGROUND: There are limited scientific data on the impact of smoking on patient-reported outcomes following minimally invasive spine surgery. The aim of this multicenter observational study was to examine the relationship between daily smoking and patient-reported outcome at 1 year using the Oswestry Disability Index (ODI) after microdecompression for single- and two-level central lumbar spinal stenosis (LSS). Secondary outcomes were the length of hospital stays, perioperative and postoperative complications. METHOD: Data were collected through the Norwegian Registry for Spine Surgery (NORspine). RESULTS: A total of 825 patients were included (619 nonsmokers and 206 smokers). For the whole patient population there was a significant difference between preoperative ODI and ODI at 1 year (17.3 points, 95% CI 15.93-18.67, p < 0.001). There was a significant difference in ODI change at 1 year between nonsmokers and smokers (4.2 points, 95% CI 0.98-7.34, p = 0.010). At 1 year 69.6% of nonsmokers had achieved a minimal clinically important difference (≥10 points ODI improvement) compared to 60.8% of smokers (p = 0.008). There was no difference between nonsmokers and smokers in the overall complication rate (11.6% vs. 9.2%, p = 0.34). There was no difference between nonsmokers and smokers in length of hospital stays for either single-level (2.3 vs. 2.2 days, p = 0.99) or two-level (3.1 vs. 2.3 days, p = 0.175) microdecompression. Smoking was identified as a negative predictor for ODI change in a multiple regression analysis (p = 0.001) CONCLUSIONS: Nonsmokers experienced a significantly larger improvement at 1 year following microdecompression for LSS compared to smokers. Smokers were less likely to achieve a minimal clinically important difference. However, it should be emphasized that considerable improvement also was found among smokers.

Microsurgical decompression for central lumbar spinal stenosis: a single-center observational study.

OBJECTIVE: To assess outcomes and complications in patients undergoing microsurgical decompression for central lumbar spinal stenosis (LSS) without radiologic instability. METHODS: Prospective data for patients operated at the Department of Neurosurgery, St. Olavs University Hospital, Norway, were obtained from the Norwegian Registry for Spine Surgery (NORspine) from 2007 to 2012. The primary outcome was change in Oswestry disability index (ODI) at 1 year. The secondary endpoint was perioperative complications. Complications were graded according to the Ibanez classification system. RESULTS: For all patients (n = 125), the mean improvement in ODI at 1 year was 16.9 points (95% CI 13.5-20.2, p < 0.001). Seventy-six (71.7%) patients achieved a minimal clinically important difference in ODI (defined as ≥8 points improvement). The total number of complications within 3 months of surgery was 22 (17.6%). There were 14 medical and eight surgical complications, and all were Ibanez grade I or II (mild or moderate) complications. Four (3.2%) complications occurred while being admitted to the hospital and 18 (14.4%) occurred within 3 months following hospital discharge. The most common complication was urinary tract infection (n = 11, 8.8%). CONCLUSIONS: Microsurgical decompression for central LSS in the absence of radiological instability is an effective and safe treatment.

Minimally invasive decompression versus open laminectomy for central stenosis of the lumbar spine: pragmatic comparative effectiveness study.

OBJECTIVE: To test the equivalence for clinical effectiveness between microdecompression and laminectomy in patients with central lumbar spinal stenosis. DESIGN: Multicentre observational study. SETTING: Prospective data from the Norwegian Registry for Spine Surgery. PARTICIPANTS: 885 patients with central stenosis of the lumbar spine who underwent surgery at 34 Norwegian orthopaedic or neurosurgical departments. Patients were treated from October 2006 to December 2011. INTERVENTIONS: Laminectomy and microdecompression. MAIN OUTCOME MEASURES: The primary outcome was change in Oswestry disability index score one year after surgery. Secondary endpoints were quality of life (EuroQol EQ-5D), perioperative complications, and duration of surgical procedures and hospital stays. A blinded biostatistician performed predefined statistical analyses in unmatched and propensity matched cohorts. RESULTS: The study was powered to detect a difference between the groups of eight points on the Oswestry disability index at one year. 721 patients (81%) completed the one year follow-up. Equivalence between microdecompression and laminectomy was shown for the Oswestry disability index (difference 1.3 points, 95% confidence interval -1.36 to 3.92, P<0.001 for equivalence). Equivalence was confirmed in the propensity matched cohort and full information regression analyses. No difference was found between groups in quality of life (EQ-5D) one year after surgery. The number of patients with complications was higher in the laminectomy group (15.0% v 9.8%, P=0.018), but after propensity matching for complications the groups did not differ (P=0.23). The duration of surgery for single level decompression was shorter in the microdecompression group (difference 11.2 minutes, 95% confidence interval 4.9 to 17.5, P<0.001), but after propensity matching the groups did not differ (P=0.15). Patients in the microdecompression group had shorter hospital stays, both for single level decompression (difference 1.5 days, 95% confidence interval 1.7 to 2.6, P<0.001) and two level decompression (0.8 days, 1.0 to 2.2, P=0.003). CONCLUSION: At one year the effectiveness of microdecompression is equivalent to laminectomy in the surgical treatment of central stenosis of the lumbar spine. Favourable outcomes were observed at one year in both treatment groups.Trial registration ClinicalTrials.gov NCT02006901.

Comparative effectiveness of microdecompression and laminectomy for central lumbar spinal stenosis: study protocol for an observational study.

INTRODUCTION: This observational study is designed to test the equivalence between the clinical effectiveness of microdecompression and laminectomy in the surgical treatment of central lumbar spinal stenosis. Lumbar spinal stenosis is the most frequent indication for spinal surgery in the elderly, and as the oldest segment of the population continues to grow its prevalence is likely to increase. However, data on surgical outcomes are limited. Open or wide decompressive laminectomy, often combined with medial facetectomy and foraminotomy, was formerly the standard treatment. In recent years a growing tendency towards less invasive decompressive procedures has emerged. At present, many spine surgeons perform microdecompression for central lumbar spinal stenosis. METHODS AND ANALYSIS: Prospectively registered treatment and outcome data are obtained from the Norwegian Registry for Spine Surgery. The primary outcome measure is change in Oswestry disability index between baseline and 12-month follow-up. Secondary outcome measures are changes in health-related quality of life measured by the Euro-Qol-5D between baseline and 12-month follow-up, perioperative complications, and duration of surgical procedures and length of hospital stay. ETHICS AND DISSEMINATION: The study has been evaluated and approved by the regional committee for medical research in central Norway and all participants provided written informed consent. The findings of this study will be disseminated through peer-reviewed publications. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov (NCT02006901).

Patient selection and clinical outcomes in patients operated for brain metastases--is specialty of the referring physicians a prognostic factor?

INTRODUCTION: As median survival in patients with brain metastases is short, but with wide confidence intervals, it is crucial to select the appropriate therapy. Various specialists diagnose brain metastases and refer selected patients to neurosurgical departments. There is, however, no robust and objective instrument for clinical decision making in individual patients with brain metastases. In consecutive patients treated with open surgery, we aimed to explore if clinical outcomes differed between the specialties of the referring physicians. METHODS: We retrospectively included all adult (≥ 18 years) patients undergoing open surgery for brain metastases from 2004 through 2009 (n = 141). We divided the specialties of referring physicians in three groups; oncologists, pulmonologists and others. RESULTS: 59 patients (42%) were referred from oncologists, 24 (17%) referred from pulmonologists and 58 (41%) referred from other specialties. There was no significant association between the graded prognostic assessment score and clinical specialty (P = 0.366), reflecting similar referral practice. Twenty-four patients (17%) died within 3 months from surgery. There was no association between clinical specialty and 3 months mortality (P = 0.461). The perioperative mortality was 7% (n = 10), and we registered 19% (n = 27) complications. Risk of perioperative mortality (P = 0.448) or surgical complications (P = 0.330) were also not associated with the specialty of the referring clinician. CONCLUSION: Patient selection and clinical outcomes did not differ between the specialties of referring physicians. We believe patient selection and outcomes were fairly similar between groups as a result of the multidisciplinary work-up between referring physicians and neurosurgeons. However, with 17% 3-month mortality there is still room for improvement in patient selection.

The risk of getting worse: surgically acquired deficits, perioperative complications, and functional outcomes after primary resection of glioblastoma.

OBJECTIVE: Gross total resection (GTR) prolongs survival but is unfortunately not achievable in the majority of patients with glioblastoma multiforme (GBM). Cytoreductive debulkings may relieve symptoms of mass effect, but it is unknown how long such effects sustain and to what degree the potential benefits exceed risks. We explore the impact of surgical morbidity on functional outcome and survival in unselected GBM patients. METHODS: We retrospectively included 144 consecutive adult patients operated on for primary GBM at a single institution between 2004 and 2009. Reporting of adverse events was done in compliance with Good Clinical Practice Guidelines. RESULTS: A total of 141 (98%) operations were resections and 3 (2%) were biopsies. A decrease in Karnofsky performance status (KPS) scores was observed in 39% of patients after 6 weeks. There was a significant decrease between pre- and postoperative KPS scores (P < 0.001). Twenty-two (15.3%) patients had surgically acquired neurological deficits. Among patients who underwent surgical resection, those with surgically acquired neurological deficits were less likely to receive radiotherapy (P < 0.001), normofractioned radiotherapy (P = 0.010), and chemotherapy (P = 0.003). Twenty-eight (19.4%) patients had perioperative complications. Among patients who underwent surgical resection, those with perioperative complications were less likely to receive normofractioned radiotherapy (P = 0.010) and chemotherapy (P = 0.009). Age (P = 0.019), surgically acquired neurological deficits (P < 0.001), and surgical complications (P = 0.006) were significant predictors for worsened functional outcome after 6 weeks. GTR (P = 0.035), perioperative complications (P = 0.008), radiotherapy (P < 0.001), and chemotherapy (P = 0.045) were independent factors associated with 12-month postoperative survival. CONCLUSION: Patients with perioperative complications and surgically acquired deficits were less likely to receive adjuvant therapy. While cytoreductive debulking may not improve survival in GBM, it may decrease the likelihood of patients receiving adjuvant therapy that does.