Commentary on: Laminectomy plus fusion versus laminectomy alone for lumbar spondylolisthesis by Ghogawala Z, Dziura J, Butler WE, Dai F, Terrin N, Magge SN, et al. NEJM 2016;374 (15):1424-34

Comparison of Lumbar Laminectomy Alone, Lumbar Laminectomy and Fusion, Stand-alone Anterior Lumbar Interbody Fusion, and Stand-alone Lateral Lumbar Interbody Fusion for Treatment of Lumbar Spinal Stenosis: A Review of the Literature

Lumbar spinal stenosis is defined as narrowing of the lumbar spinal canal, which causes compression of the spinal cord and nerves. Spinal stenosis can cause leg pain and potentially back pain that can affect the quality of life. Ultimately, surgical decompression is required to alleviate the symptoms. In this review, we first utilize several important studies to compare lumbar laminectomy alone versus lumbar laminectomy and fusion. We also compare the effectiveness of more novel surgical approaches, stand-alone anterior lumbar interbody fusion (ALIF), and stand-alone lateral lumbar interbody fusion (LLIF). These techniques have their own advantages and disadvantages in which many factors must be taken into account before choosing a surgical approach. In addition, the patient’s anatomy and pathology, lifestyle, and desires should be analyzed to help determine the ideal surgical strategy

Decreased estimated blood loss in lateral trans-psoas versus anterior approach to lumbar interbody fusion for degenerative spondylolisthesis

Background

The goal of the current study was to compare the perioperative and post-operative outcomes of eXtreme lateral trans-psoas approach (XLIF) versus anterior lumbar interbody fusion (ALIF) for single level degenerative spondylolisthesis. The ideal approach for degenerative spondylolisthesis remains controversial.

Methods

Consecutive patients undergoing single level XLIF (n=21) or ALIF (n=54) for L4-5 degenerative spondylolisthesis between 2008-2012 from a single academic center were retrospectively reviewed. Groups were compared for peri-operative data (estimated blood loss, operative time, adjunct procedures or additional implants), radiographic measurements (L1-S1 cobb angle, disc height, fusion grade, subsidence), 30-day complications (infection, DVT/PE, weakness/paresthesia, etc.), and patient reported outcomes (leg and back Numerical Rating Scale, and Oswestry Disability Index).

Results

Estimated blood loss was significantly lower for XLIF [median 100; interquartile range (IQR), 50-100 mL] than for ALIF (median 250; IQR, 150-400 mL; P<0.001), including after adjusting for significantly higher rates of posterior decompression in the ALIF group. There were no significant differences in rates of complications within 30 days, radiographic outcomes, or in re-operation rates. Both groups experienced significant pain relief post-operatively.

Conclusions

The lateral trans-psoas approach is associated with diminished blood loss compared to the anterior approach in the treatment of degenerative spondylolisthesis. We were unable to detect differences in radiographic outcomes, complication rates, or patient reported outcomes. Continued efforts to directly compare approaches for specific indications will minimize complications and improve outcomes. Further studies will continue to define indications for lateral versus anterior approach to lumbar spine for degenerative spondylolisthesis.

Lumbar spinal stenosis: comparison of surgical practice variation and clinical outcome in three national spine registries

BACKGROUND CONTEXT

Decompression surgery for lumbar spinal stenosis (LSS) is the most common spinal procedure in the elderly. To avoid persisting low back pain, adding arthrodesis has been recommended, especially if there is a coexisting degenerative spondylolisthesis. However, this strategy remains controversial, resulting in practice-based variation.

PURPOSE

The present study aimed to evaluate in a pragmatic study if surgical selection criteria and variation in use of arthrodesis in three Scandinavian countries can be linked to variation in treatment effectiveness.

STUDY DESIGN

This is an observational study based on a combined cohort from the national spine registries of Norway, Sweden, and Denmark.

PATIENT SAMPLE

Patients aged 50 and older operated during 2011-2013 for LSS were included.

OUTCOME MEASURES

Patient-Reported Outcome Measures (PROMs): Oswestry Disability Index (ODI) (primary outcome), Numeric Rating Scale (NRS) for leg pain and back pain, and health-related quality of life (Euro-Qol-5D) were reported. Analysis included case-mix adjustment. In addition, we report differences in hospital stay.

METHODS

Analyses of baseline data were done by analysis of variance (ANOVA), chi-square, or logistic regression tests. The comparisons of the mean changes of PROMs at 1-year follow-up between the countries were done by ANOVA (crude) and analysis of covariance (case-mix adjustment).

RESULTS

Out of 14,223 included patients, 10,890 (77%) responded at 1-year follow-up. Apart from fewer smokers in Sweden and higher comorbidity rate in Norway, baseline characteristics were similar. The rate of additional fusion surgery (patients without or with spondylolisthesis) was 11% (4%, 47%) in Norway, 21% (9%, 56%) in Sweden, and 28% (15%, 88%) in Denmark. At 1-year follow-up, the mean improvement for ODI (95% confidence interval) was 18 (17-18) in Norway, 17 (17-18) in Sweden, and 18 (17-19) in Denmark. Patients operated with arthrodesis had prolonged hospital stay.

CONCLUSIONS

Real-life data from three national spine registers showed similar indications for decompression surgery but significant differences in the use of concomitant arthrodesis in Scandinavia. Additional arthrodesis was not associated with better treatment effectiveness.

Cost-effectiveness of lumbar fenestration surgery in the Japanese universal health insurance system

BACKGROUND

Healthcare costs are a global concern, and cost-effectiveness analyses of interventions have become important. However, data regarding cost-effectiveness are limited to a few medical fields. The purpose of our study was to examine the Japanese universal health insurance system cost per quality-adjusted life year (QALY) for lumbar fenestration surgery.

METHODS

Forty-eight patients who underwent fenestration for lumbar degenerative spinal canal stenosis between July 2013 and September 2015 were included. Effectiveness was evaluated by measuring the EuroQOL 5-dimension (EQ-5D), Short-Form 8 physical component summary (PCS), and visual analog scale (VAS). Cost was analyzed from the perspective of the public healthcare payer. Effectiveness and cost were measured 1 year after surgery. QALYs were calculated by multiplying the utility value (EQ-5D) and life years. Only direct costs based on actual reimbursements were included. Cost per QALY with a 5-year time horizon with a 2% discount rate was estimated. Sensitivity analysis was performed by varying the time horizon (2 years or 10 years).

RESULTS

Mean total cost 1 year after fenestration surgery was 1,254,300 yen (standard deviation [SD], 430,000 yen; median, 1,172,300 yen). Operative cost was 406,800 yen (SD, 251,500 yen; median, 363,000 yen). Mean gained score was 0.21 for EQ-5D (SD, 0.18; median, 0.24), 11 for PCS (SD, 10; median, 12), and -43 for VAS (SD, 34; median, -38). Cost per QALY was 1,268,600 yen. Sensitivity analysis demonstrated that cost per QALY with a 10-year time horizon was 679,300 yen and that with a 2-year time horizon was 3,004,600 yen.

CONCLUSIONS

Cost per QALY of lumbar fenestration with a 5-year time horizon was 1,268,600 yen (11,532 US dollar), which was below the widely accepted benchmark (cost per QALY <5,000,000-6,500,000 yen (50,000 US dollars)). Fenestration is a cost-effective intervention.

A sheep model of cystic fibrosis generated by CRISPR/Cas9 disruption of the CFTR gene

Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. The major cause of limited life span in CF patients is progressive lung disease. CF models have been generated in 4 species (mice, rats, ferrets, and pigs) to enhance our understanding of the CF pathogenesis. Sheep may be a particularly relevant animal to model CF in humans due to the similarities in lung anatomy and development in the two species. Here, we describe the generation of a sheep model for CF using CRISPR/Cas9 genome editing and somatic cell nuclear transfer (SCNT) techniques. We generated cells with CFTR gene disruption and used them for production of CFTR-/- and CFTR+/- lambs. The newborn CFTR-/- sheep developed severe disease consistent with CF pathology in humans. Of particular relevance were pancreatic fibrosis, intestinal obstruction, and absence of the vas deferens. Also, substantial liver and gallbladder disease may reflect CF liver disease that is evident in humans. The phenotype of CFTR-/- sheep suggests this large animal model will be a useful resource to advance the development of new CF therapeutics. Moreover, the generation of specific human CF disease-associated mutations in sheep may advance personalized medicine for this common genetic disorder.

Nursing review of diagnosis and treatment of lumbar degenerative spondylolisthesis

Background:

In the lumbar spine, degenerative spondylolisthesis or degenerative (not traumatic) slippage of one vertebral body over another is divided into 4 grades – grade I (25%), grade II (50%), grade III (75%), and grade IV (100%). Dynamic X-rays, magnetic resonance (MR), and computed tomography (CT) scans document the slip secondary to arthritic changes of the facet joint plus stenosis, ossification of the yellow ligament, disc herniations, and synovial cysts. MR best demonstrates soft tissue pathology whereas CT better delineates ossific/calcified disease.

Methods:

Grade I degenerative spondylolisthesis, typically found at the L4–L5 level followed by L3–L4 and L5S1, is more common in females (ratio 2:1) over the age of 65. Symptoms include radiculopathy (root pain) and neurogenic claudication (e.g., pain with ambulation, requiring the patient to stop, rest, sit down). Symptoms/signs may include unilateral/bilateral radiculopathy and uni/multifocal motor, reflex, and sensory deficits in. Some may also present with a cauda equina syndrome (e.g., paraparesis/sphincter dysfunction).

Results:

Surgery for grade I-II spondylolisthesis may include laminectomy alone, laminectomy/noninstrumented fusion or with an instrumented fusion. Older patients with osteoporosis are more likely to have no fusion or a noninstrumented fusion. All fusions utilize autograft harvested from the laminectomy that may or may not be combined with a bone graft expander (to increase the fusion mass) combined with autogenous bone marrow aspirate. The fusion mass is placed over the transverse processes following decortication.

Conclusions:

Patients with multilevel spinal stenosis and degenerative spondylolisthesis may require decompressive lumbar laminectomies alone or in combination with noninstrumented or instrumented fusions.