Anterior cervical discectomy and fusion for cervical spondylotic myelopathy [Neurosurgery Wiki]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
=====Anterior cervical discectomy and fusion for cervical spondylotic myelopathy=====
[[Anterior cervical discectomy and fusion]] (ACDF) procedures are performed to treat patients with [[cervical spondylotic myelopathy]] or [[cervical radiculopathy]]. 

Farrokhi et al., searched for evidence regarding the surgical approach to [[Cervical spondylotic myelopathy]] (CSM) in medical databases with articles dated from 1985 to 2016.

In patients with effective [[cervical lordosis]] (fewer than 3 levels of ventral disease), [[anterior cervical discectomy and fusion]] (ACDF) or [[cervical arthroplasty]] is preferred. 

In patients with straightened spine who have less than 3 involved levels, ACDF with a [[cervical plate]] is recommended.

In patients with irreducible kyphosis, if the number of involved levels is less than 2, ACDF is adequate, but if it is more than 2 levels, anterior [[cervical corpectomy]] and fusion should be performed using cervical magnetic resonance imaging for evaluation of the patency of the subarachnoid space (SAS). 

These approaches are based on the most recent evidence
((Farrokhi MR, Ghaffarpasand F, Khani M, Gholami M. An Evidence-Based Stepwise
Surgical Approach to Cervical Spondylotic Myelopathy: A Narrative Review of the
Current Literature. World Neurosurg. 2016 Oct;94:97-110. doi:
10.1016/j.wneu.2016.06.109. Review. PubMed PMID: 27389939.
)).

====Advantages====
They led to lower hospital charges, shorter hospital stays, and an increased likelihood of being discharged to home relative to [[posterior cervical fusion]] (PCF)
((Tanenbaum JE, Lubelski D, Rosenbaum BP, Benzel EC, Mroz TE. Propensity-matched
Analysis of Outcomes and Hospital Charges for Anterior Versus Posterior Cervical 
Fusion for Cervical Spondylotic Myelopathy. Clin Spine Surg. 2016 Jun 27. [Epub
ahead of print] PubMed PMID: 27352367.
)).

Both anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) are used to treat multilevel cervical spondylotic myelopathy (mCSM); however, which one is better treatment for mCSM remains considerable controversy. A meta-analysis was performed to compare clinical outcomes, radiographic outcomes, and surgical outcomes between ACDF and ACCF in treatment for mCSM.

The results suggest that both ACDF and ACCF are good plans in clinical outcomes; however, ACDF is a better choice in radiographic outcomes and total complications for the treatment of multilevel CSM
((Wang T, Wang H, Liu S, An HD, Liu H, Ding WY. Anterior cervical discectomy and
fusion versus anterior cervical corpectomy and fusion in multilevel cervical
spondylotic myelopathy: A meta-analysis. Medicine (Baltimore). 2016
Dec;95(49):e5437. PubMed PMID: 27930523.
)).

Patients treated with ACCF are more likely to need a revision than those treated with ACDF
((Puvanesarajah V, Jain A, Cancienne JM, Shimer AL, Singla A, Shen F,
Hassanzadeh H. Complication and Reoperation Rates Following Surgical Management
of Cervical Spondylotic Myelopathy in Medicare Beneficiaries. Spine (Phila Pa
1976). 2017 Jan 1;42(1):1-7. doi: 10.1097/BRS.0000000000001639. PubMed PMID:
27111765.
)).

====Disadvantages====

The national estimates for inpatient complications(25%), readmissions(9.9%), and reoperations(3.5%) are substantial after the surgical treatment of multi-level [[OPLL]]. An anterior approach resulted in significantly higher inpatient surgical complications, but this did not result in a longer hospital length of stay and the overall 90-day complication rates requiring readmission or reoperation was similar to those seen after a posterior approach. For patients requiring >3-level fusion, an anterior approach is associated with significantly higher risk for respiratory complications requiring mechanical ventilation and revision fusion surgery. Precise neurological complications and functional outcomes were not included in this database, and should be further assessed in future studies
((Lee NJ, Boddapati V, Mathew J, Fields M, Vulapalli M, Kim JS, Lombardi JM, Sardar ZM, Lehman RA, Riew KD. What Is the Impact of Surgical Approach in the Treatment of Degenerative Cervical Myelopathy in Patients With OPLL? A Propensity-Score Matched, Multi-Center Analysis on Inpatient and Post-Discharge 90-Day Outcomes. Global Spine J. 2021 Feb 19:2192568221994797. doi: 10.1177/2192568221994797. Epub ahead of print. PMID: 33601898.)).
----
ACDF with plate and [[cervical cage]] in treating two noncontiguous levels of CSM, two plates have to be used. Moreover, ACDF inevitably costs the loss of range of motion at involved levels. The loss of range of motion at the operated level is commonly compensated for at the adjacent levels and the compensatory stress within adjacent intervertebral discs also increases after fusion. When ACDF with two anterior plates and cervical cages was used in treating two noncontiguous levels of CSM, the intermediate segment will bear more stress, thereby the potential for accelerated the intermediate level disc degeneration will be raised. Worrying about this, some surgeons advocate including the normal level in the fusion construct in patients with noncontiguous CSM. However, it is not sensible to sacrifice the motion of normal level for preventing the possible intermediate level disc degeneration. Besides the adjacent segment degeneration (ASD), dysphagia is also a common complication of ACDF. It was reported that the adhesion formation around the plate was the reason for dysphagia
((Fountas KN, Kapsalaki EZ, Nikolakakos LG, Smisson HF, Johnston KW, Grigorian
AA, Lee GP, Robinson JS Jr. Anterior cervical discectomy and fusion associated
complications. Spine (Phila Pa 1976). 2007 Oct 1;32(21):2310-7. Review. PubMed
PMID: 17906571.)).

====Intraoperative neuromonitoring====
The goal of a study was to (1) evaluate the trends in the use of intraoperative neuromonitoring (ION) for anterior cervical discectomy and fusion (ACDF) surgery in the United States and (2) assess the incidence of neurological injuries after ACDFs with and without ION.

Somatosensory-evoked potentials (SSEPs) and motor-evoked potentials (MEPs) are the commonly used ION modalities for ACDFs. Controversy exists on the routine use of ION for ACDFs and there is limited literature on national practice patterns of its use.

A retrospective review was performed using the PearlDiver Patient Record Database to identify cases of spondylotic myelopathy and radiculopathy that underwent ACDF from 2007 to 2014. The type of ION modality used and the rates of neurological injury after surgery were assessed.

During the study period, 15,395 patients underwent an ACDF. Overall, ION was used in 2627 (17.1%) of these cases. There was a decrease in the use of ION for ACDFs from 22.8% in 2007 to 4.3% use in 2014 (P < 0.0001). The ION modalities used for these ACDFs were quite variable: SSEPs only (48.7%), MMEPs only (5.3%), and combined SSEPs and MMEPs (46.1%). Neurological injuries occurred in 0.23% and 0.27% of patients with and without ION, respectively (P = 0.84). Younger age was associated with a higher utility of ION (<45: 20.3%, 45-54: 19.3%, 55-64: 16.6%, 65-74: 14.3%, and >75: 13.6%, P < 0.0001). Significant regional variability was observed in the utility of ION for ACDFs across the country (West; 21.9%, Midwest; 12.9% (P < 0.0001).

There has been a significant decrease in the use of ION for ACDFs. Furthermore, there was significant age and regional variability in the use of ION for ACDFs. Use of ION does not further prevent the rate of postoperative neurological complications for ACDFs as compared with the cases without ION. The utility of routine ION for ACDFs is questionable
((Ajiboye RM, D'Oro A, Ashana AO, Buerba RA, Lord EL, Buser Z, Wang JC,
Pourtaheri S. Routine Use of Intraoperative Neuromonitoring During ACDFs for the 
Treatment of Spondylotic Myelopathy and Radiculopathy Is Questionable: A Review
of 15,395 Cases. Spine (Phila Pa 1976). 2017 Jan 1;42(1):14-19. doi:
10.1097/BRS.0000000000001662. PubMed PMID: 27120059.
)).
====Case series====
===2016===
In the series of Shen et al., for multilevel cervical spondylotic myelopathy combined with cervical kyphosis, ACDF can restore the lordosis better, fuse less levels but have more complications compared with  posterior laminectomy and fusion(LF). Patients treated with LF can get as good life quality as with ACDF and have less complications although fuse more levels compared with ACDF
((Shen QF, Xu TT, Xia YP. [Comparison of the outcomes between anterior cervical 
discectomy and fusion versus posterior laminectomy and fusion for the treatment
of multi-level cervical spondylotic myelopathy combined with cervical kyphosis]. 
Zhonghua Yi Xue Za Zhi. 2016 Dec 20;96(47):3800-3804. doi:
10.3760/cma.j.issn.0376-2491.2016.47.007. Chinese. PubMed PMID: 28057094.
)).
----
32 consecutive patients who underwent 4-level anterior cervical discectomy and fusion (ACDF) with cages and plates and were followed up for at least 5 years.

Records of 19 men and 13 women aged 48 to 69 years who underwent 4-level ACDF with cages and plates for myelopathy (n=11) or myeloradiculopathy (n=21) at C3 to C7 by a single surgeon and were followed up for a minimum of 5 years were reviewed. Clinical outcome was assessed using the visual analogue scale (VAS), Neck Disability Index (NDI), and modified Japanese Orthopaedic Association (JOA) score for pain or myelopathic symptoms. Radiographic evaluation included fusion rate, range of motion, cervical lordosis (C2-to-C7 Cobb angle), and disc height.

The mean follow-up was 66 months. All patients had good recovery of muscle strength and resolution of limb sensory disturbance, except for 4 who still had some numbness. The mean VAS for neck and arm pain improved from 14.2 to 6.84 (p=0.012); the mean NDI improved from 31.62 to 12.17 (p<0.01); and the mean JOA score improved from 10.1 to 13.9 (p=0.027). The mean percentage of recovery was 62.9. The mean Cobb angle improved from 10.24º to 1.28º (p=0.019); the mean disc height improved from 4.12 to 6.58 mm (p<0.01). 30 (94%) patients achieved solid fusion.

Multilevel ACDF using PEEK cages and plates is safe and effective for multilevel cervical spondylotic myelopathy and achieves satisfactory mid-term outcome
((Wang SJ, Ma B, Huang YF, Pan FM, Zhao WD, Wu DS. Four-level anterior cervical 
discectomy and fusion for cervical spondylotic myelopathy. J Orthop Surg (Hong
Kong). 2016 Dec;24(3):338-343. PubMed PMID: 28031502.
)).