How to perform the Wiltse posterolateral spinal approach: Technical note.

BACKGROUND: The paraspinal, posterolateral, or Wiltse approach is an old technique that observes the principles of an MIS procedure. The aim of this study was to provide a step-by-step description from the literature of the Wiltse paraspinal approach and analyze its main advantages and limitations.
METHODS: Here, we provide a step-by-step description of the Wiltse approach. Utilizing PubMed and Lilacs and the Mesh terms "Wiltse approach," "paraspinal approach," "muscle sparing approach," and "lumbar spine," we identified 10 papers. We then put together, based on these publications, a step-by-step analysis of the preparation, patient positioning, skin incision, fascial opening, dissection, bone identification, retractors, deperiostization, decompression, discectomy, instrumentation, arthrodesis, and closure for the Wiltse technique.
RESULTS: Most papers underscored the minimally invasive aspects of the typical Wiltse approach. Advantages included minimal intraoperative bleeding, a shorter hospital length of stay, and a low infection rate.
CONCLUSION: The classical approach described by Wiltse is essentially minimally invasive, sparing both the muscle planes and soft tissues, allowing for ample far lateral lumbar decompression, including discectomy and fusion, with a low complication rate.

BACKGROUND

This study provides a step-by-step analysis of the Wiltse paraspinal approach, along with its pros and cons.

This is an old technique described originally in 1968. In 1988, Wiltse described additional changes to the posterolateral approach to further access foraminal lumbar disc herniations, spinal stenosis, and spondylolisthesis. This procedure additionally provided access for the removal of spinal tumors and for performing posterolateral fusions, including pedicle screws.[78]

MATERIAL AND METHODS

For the period between 1968 and 2016, we utilized PubMed and Lilacs and the Mesh terms “Wiltse approach,” “paraspinal approach,” “muscle sparing approach,” and “lumbar spine” to evaluate the Wiltse procedure.

We then analyzed the pros and cons of the Wiltse approach along with the following technical details: patient preparation, incision, fascial opening, dissection, bone identification, retractors, deperiostization, decompression, discectomy, instrumentation, arthrodesis, and closure.

Surgical technique

Multiple steps in the Wiltse surgical technique were assessed including preparation, positioning, incision, fascial opening, dissection, bone identification, retractors, deperiostization, decompression, discectomy, instrumentation, arthrodesis, and closure.

These procedures should be performed under neurophysiological monitoring (e.g., continuous EMG, triggering, and selective radicular stimulation), and somatosensory evoked potential monitoring. In addition, anesthesia should utilize total intravenous anesthesia (TIVA). The steps for performing this procedure are outlined in Table 1. The patient is placed prone and a lateral X-ray is obtained. Bilateral access is provided thorough a midline skin incision or two paravertebral incisions [Figure 1]. A lateral vertical incision is made approximately 3–4 cm lateral to the spinous processes at the correct level, and the fascia is opened longitudinally [Figure 2].[24]

Table 1

Steps of the Wiltse approach

Figure 1

Note the skin marking with AP radioscopy following the pedicle line of the levels to be treated. IC: Iliac crest, ML: Midline

Figure 2

The drawing shows the midline skin incision and the two paravertebral fascia incisions. The opening of the superficial and deep fasciae exposes the musculature

Using blunt dissection, the medial multifidus is then separated from the lateral longissimus muscle. At the L5-S1 this exposure may be hampered by the distal insertion of the multifidus muscles [Figure 3]

Figure 3

(a) The drawing depicts in A after the fascial opening the digital location of the intermuscular plane: the multifidus is medially located, the longissimus is lateral. (b) The Meyerding retractors are placed in the deep plane, the area where the joint facet and the transverse process meeting is exposed

The junction of the facet joint and the transverse processes are then identified. A Bertola tweezer is then placed for radiological confirmation of the level [Figure 4]

Figure 4

See the Bertola tweezers anchored in the transverse processes to radioscopically check the level to be treated before deperiostization

A Quadrant® (Medtronic) or Meyerding retractor then facilitates exposure, which includes removal of the periosteum from the hemilaminae to the base of the spinous process. If instrumentation is to be performed, blunt dissection of the cephalad facet is also effected to reduce the risk of adjacent segment disease (ASD)

All pedicle screws are placed utilizing fluoroscopic guidance followed by application of the rods [Figure 5].

Figure 5

The drawing shows the muscular separation plane, with the implants in place, and the bone graft in the intertransverse plane and lateral to the pars interarticularis. See the multifidus muscle, which is more lateral at the level of the sacrum, which makes location of the access plane difficult. When the retractors are removed, the muscles go back to their original position, and cover the implants and the graft

Decortication of the transverse processes, pars, and lateral facets are performed with a high-speed drill, following which bone graft is applied [Table 2].

Table 2

Principal variables analyzed in each paper showing similarities and differences

DISCUSSION

Wiltse MIS paraspinal approach is muscle-sparing and has lower infection rates vs. midline approaches.[156]

Street et al.[6] using a midline approach found a lower infection rate (7.8% vs 1%), lower risk for adjacent segment disease requiring reoperations (14.6% vs 5.8%), and less intraoperative bleeding (703 ml vs 436 ml). For a posterolateral fusion, it provides excellent exposure of the transverse processes for applying bone graft while protecting the superior joint complex.

Although Wiltse et al.[8] initially described two incisions 3 cm parallel off the midline, he later recommended a single midline incision for better cosmesis and in case secondary surgery was required.

In 2006, Olivier et al.,[3] in a cadaver study, documented that incisions 3 cm off midline were in the middle of two vascular networks and offered greater skin protection against necrosis.

CONCLUSION

Here, we described the step-by-step Wiltse lumbar paraspinal approach to the far lateral compartment for the treatment of foraminal discs or instability warranting fusions.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.