CHAPTER SYNOPSIS:

This chapter describes a minimally disruptive spine procedure called the extreme lateral interbody fusion, or XLIF (NuVasive, Inc., San Diego, Calif.). This technique can be used to gain access to the lumbar spine via a lateral approach that passes through the retroperitoneal fat and psoas major muscle. Hence, the potential complications with an anterior transperitoneal approach to the lumbar spine can be avoided, major vessels are not encountered, an anterior access is not required, and the procedure can be done through two 3- to 4-cm incisions. Here we report the surgical technique, surgical pitfalls, results, and our conclusions.

IMPORTANT POINTS:

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  Benefits

  
  
  
  
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    Less tissue trauma and preservation of normal anatomic structures

    
    
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    Faster recovery

    
    
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    Adequate disc visualization

    
    
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    Reduced iatrogenic injury to abdominal neurovascular structures

  
  
  
  
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  Disadvantages

  
  
  
  
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    Learning curve associated with the procedure

    
    
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    Proper patient selection is vital

    
    
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    Not indicated for L5-S1 pathology

  
  

SURGICAL PEARLS:

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  Most levels, including L4-5, can be accessed with the patient in a lateral decubitus position on a bendable table.

  
  
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  For access to the L5-S1 level, it is easier to use a mini-open retroperitoneal or minimally invasive posterior approach.

  
  
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  Exposure need only be as wide as the disc space.

  
  
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  After disc space preparation, a Cobb elevator is passed along both end plates and completely through the contralateral annulus to facilitate distraction of the disc space, achieve proper coronal alignment, and place a large implant that spans the ring apophysis.

SURGICAL PITFALLS:

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  It is critical to maintain a 90-degree position when positioning the patient, which helps to ensure proper disc space access and placement of instruments.

  
  
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  The initial dissection with the index finger should be done in a careful manner to avoid perforating the peritoneum.

  
  
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  During the procedure, the necessary fluoroscopic images should be obtained to ensure the procedure is being performed at the appropriate level.

  
  
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  Postoperative rehabilitation conditioning of the psoas muscle is conducted during the first few postoperative days to reduce transitory hip flexion parenthesis.

VIDEO AVAILABLE:

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INDICATIONS

Indications for the XLIF technique are the same as those for any interbody fusion, with the limitation of access only at disc levels above L5. Such patients typically experience discogenic pain caused by segmental instability, disc degeneration, degenerative scoliosis, and/or grade 1 or 2 spondylolisthesis. It may also be applied to patients who have not responded successfully to prior decompressive surgery (i.e., discectomy, laminectomy, or both) and require interbody fusion, or in cases of adjacent level disease after prior fusion surgery, because in these revision cases, scarring may limit the ability to safely perform a more traditional fusion approach. Revisions of failed interbody fusions and failed lumbar total disc replacements have also been treated using the XLIF approach for retrieval and revision.

The XLIF approach has been successfully accomplished for levels above and including L4-5. Approaching the L5-S1 level using this technique is not recommended because of the risk for damage to the iliac blood vessels, as well as the difficulty of accessing the disc space because of the iliac crest. For the L5-S1 level, it is easier to use a mini-open retroperitoneal approach or minimal invasive posterior approach.

PREOPERATIVE PLANNING

As is appropriate for all patients who undergo a surgical procedure, we recommend preoperative medical and cardiovascular evaluations. In addition, preoperative radiographs help to define potential problems with the approach trajectory. For example, if the operative level will be L4-5, the height of the iliac crest should be checked to confirm that there will be clearance into the disc space. All L4-5 levels can be accessed laterally with appropriate patient positioning on a bendable surgical table. At upper levels, determination of rib location will help prevent any unsuspected surprises during the approach. At L1-2, the lower rib may need to be elevated superiorly away from the approach, or an intercostal approach may be necessary.

INSTRUMENTATION

The instruments necessary for performing the XLIF procedure are as follows:

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  MaXcess System of dilators and split-blade retractor: includes bifurcated light cable, articulating arm, retractor system with various length blades, and blade-extension shims

  
  
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  NeuroVision System for MaXcess-compatible stimulated and continuous electromyographic (EMG) monitoring of nearby nerves

  
  
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  Set of interbody instruments such as curettes, Kerrison rongeurs, and dissectors of different sizes (available within XLIF and General Instrument Sets, NuVasive, Inc.)

  
  
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  Light source for attachment to MaXcess bifurcated light cable

  
  
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  Radio-transparent surgical table with a flexible middle section and rail for articulating arm attachment

  
  
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  C-arm fluoroscope and image intensifier