Your Guide to Spinal Fusion

The traditionally inpatient reconstructive is transitioning to the outpatient arena. 
Here’s what you need to know.
By Sanjay Kumar Khurana MD
Outpatient Surgery Magazine – November, 2007  

Anterior cervical discectomy and fusion surgery have traditionally been performed in a hospital setting. While some cervical spine conditions involving severe spinal cord compression and complicated deformity will continue being performed in hospital settings, most relatively young and healthy patients with nerve root compression or soft cervical disk herniationss are routinely being treated with anterior cervical discectomy and fusion in an outpatient surgery setting. The relatively avascular and intermuscular approach to the anterior cervical spine combined with the illumination and magnification provided by new-generation operating microscopes have made one and two level anterior cervical fusion and disk arthroplastys a safe and predictable surgery in the outpatient setting. Here's an update.

Lumbar Reconstruction and Stabilization

The array of lumbar reconstructive and stabilization procedures you can perform in the outpatient surgery setting is increasing rapidly. Traditionally, pedicle screw placement for spondylolisthesis or scoliosis has been accomplished via significant muscular snipping and blood loss. The internuscular approach of Wiltse, which was initially described as a surgical approach to lateral disk herniation has now become the workhorse surgical approach for placement of pedicle screws. The advantages of this approach include the minimal surgical trauma associated with surgical exposure and the ease this approach allows for pedicle screw placement and decortication of the intertransverse gutter. With newer, motion-preserving, flexible and articulated rods, this approach can be a very atramatic method of dynamically stabilizing a lumbar segment. Adjunctive intralaminar decompression can be easily accomplished using this approach
as well.

The interspinous space also represents a heretofore un-utilized surgical interval that is increasing its use in the outpatient setting. The X-Stop interspinious spacer was the first FDA approved and commercially available device for indirect decompression and stabilization of spondylolisthesis. This procedure can be done under local sedation with adjunctive local anesthesia. Patients can be discharged the same day or overnight. The early outcomes of this procedure and device appear promising. Newer interspinous devices are being investigated and this approach will certainly be increasingly utilized for lumbar stenosis and lumbar degenerative disk disease.

Lumbar interbody fusion in the outpatient setting is also being performed at an increasing rate. Utilizing the same paraspinal internuscular approach for pedicle screw placement, a transforaminal window can be utilized to prepare the disk space and place an interbody device. An interbody spacer can be utilized with off-label use of bone morphogenic protein to effect a rapid fusion and avoid the morbidity associated with iliac crest bone harvest. Technically, performing transforaminal interbody fusion (TUF) through a Wiltse approach does require a learning curve and, as with the cervical fusions, extensive personal experience and evaluation of patient outcomes is recommended before performing these cases in an outpatient setting.

The extreme lateral extracavitary approach to multiple intervertebral disk spaces is the most radical surgery that is being performed in the outpatient surgical environment. This approach utilizes a retroperitoneal interval requiring minimal incision length and minimal muscle division, but provides an extensive exposure to lumbar disk spaces and permits the placement of large anterior interbody devices.

The lateral approach to the spine by its anatomic approach avoids division of the large stabilizing ligament, the anterior longitudinal ligament, and therefore can be performed as a stand-alone procedure, or performed in a staged fusion with supplemental posterior fixation. As with the TLIF approach, the interbody devices can be packed with bone morphogenic protein to hasten osseous fusion and avoid iliac crest harvest.

In the Midst of an Evolution

 While significant deformities may still require a hospital setting, select deformities and spine conditions can safely be treated in an outpatient setting. As studies further bear out long-term outcomes of our limited stabilization interventions, our surgical tactics will continue to progress. Improved technology and our deeper understanding of the spine will certainly provide further substrate for this evolution.

Study: Outpatient Anterior Cervical Discectomy and Fusion Feasible and Safe

 It's feasible and safe to perform anterior cervical discectomy and fusion (ACDF) with instrumentation on an outpatient basis, says a group of researchers that studied the safety and feasibility of single, two- and three-level ACDF with instrumentation performed on an outpatient or 23-hour observation basis.

The study included 103 patients enrolled over a two-year period. All patients underwent ACDF with plating for neck pain and/or radiculopathy. Researchers evaluated intraoperative and perioperative complications, which were reported for up to six months follow-up. Researchers also looked at any unplanned post-op visits.

They used both neurological examination and radiographic evaluation to assess complications. All patients underwent pre-op testing and clearance with cardiac risk assessment and pulmonary evaluation to determine if they were suitable candidates for surgery. Pre-op cardiology

clearance is necessary to prepare higher-risk patients for surgery, which can be a critical step in decreasing the length of hospitalization or deciding whether a patient is suitable for an outpatient surgery, says lead researcher Alan T. Villavicencio, MD, of Boulder Neurosurgical Associates in Boulder, Colo.

There were 60 single-level, 39 two-level and 4 three-level procedures performed under general endotracheal anesthesia. Ninety-nine patients had no intraoperative or immediate post-op complications and were discharged home in a stable condition in less than 15 hours (median time: 8 hours; range: 2 to 15 hours) after their surgeries. Four patients who underwent three-level ACDF procedures were discharged after a 23-hour observation period.

The overall complication rate was 3.8 percent (four patients). One patient had a left anterior vertebral body fracture at C5, which was diagnosed at a three-month follow-up visit. The patient was symptomatic, did not require surgical intervention and the fracture healed before a six-month follow-up visit. Another patient who had a single-level surgery was readmitted into the hospital several days after surgery for dehydration and moderate chest pain. The patient was treated with intravenous fluids and was discharged the following day without further incident.

One other patient developed a post-op C5 nerve root palsy, which was treated conservatively with medications and epidural steroid injections and resolved completely. Six patients (5.8 percent) had transient dysphagia and four (3.9 percent) were hoarse.

These are common side effects of ACDF (up to 50 percent) that usually improve over time without treatment. The researchers' hardware-related complication rate (0 percent) compared favorably with previously reported rates identified through meta-analysis (0.5 percent). The same was true for the overall complication rate, which was not found to be significantly different compared to the 0.95 percent rate observed in the meta-analysis comparison group (P=0.12).

"Overall complication rates are typically low, and our low outpatient complication rate lends weight to the argument that instrumented ACDF is safe as an ambulatory procedure," say researchers.

Study summarized by Outpatient Surgery Magazine