1. Clinical outcomes similar between the two. A wide range of literature exists showing minimally invasive techniques can have equal or better outcomes than open techniques, but outcomes often depend on the surgeon’s skill level and patient selection. Minimally invasive techniques require a steep learning curve and surgeons with more experience are likely to achieve better outcomes.
Among experienced surgeons, minimally invasive techniques are designed for:
• Less blood loss
• Lower infection rate
• Less patient pain
• Quicker patient ambulation and return to work
Kern Singh, MD, a founder of the Minimally Invasive Spine Institute at Rush conducted a study comparing minimally invasive and open spine procedures. He found that open spine surgery takes around three hours and includes 400 to 500 mL of blood loss, compared to minimally invasive procedure that last around 75 minutes and have around 40 to 50 mL blood loss.
2. Overall lower costs for minimally invasive procedures. Overall costs for minimally invasive procedures are significantly lower than open procedure costs for appropriately indicated patients. A 2011 study published in SAS Journal showed cost for minimally invasive transforaminal lumbar interbody fusion was $14,183 on average, versus $18,633 for open lumbar fusion.
Less invasive procedures can be performed in the outpatient setting, including the ambulatory surgery center, which typically costs less than inpatient hospital stays and the hospital outpatient department. Eliminating the hospital stay and lowering the risk for complications and re-operations creates significant cost-savings for spinal procedures.
Another 2012 study published in the Journal of Spinal Disorders and Techniques compared patients undergoing either minimally invasive or open posterior lumbar fusions with the same implants. The patients undergoing minimally invasive procedures had a shorter hospital stay and costs were $760 less for one-level surgery and $2,105 less for two-level surgery than open procedures.
3. Minimally invasive spine device market growing. A Reporterlink analysis released in July 2013 reported the minimally invasive spine device market is expected to reach $3 billion by 2019. According to an iData report, the spinal implant market in the United States was worth $5.5 billion in 2013, with $1.5 billion attributable to minimally invasive spine implants.
Medtronic was the market leader last year in both minimally invasive and total spine implants, even though sales of its bone morphogenic protein product Infuse have been steadily declining over the past few years.
Reporterlink highlighted sacroiliac joint fusion as the fastest growing segment in the minimally invasive spine device market, although growth is expected in all segments.
The 2.3 percent excise tax on medical device companies that began on Jan. 1, 2013 has not been repealed and could stifle innovation in the spine field. Spine devices are considered among the more expensive devices on the market and downward pressure on reimbursements for spinal procedures will lead providers to select instrumentation and implants that are both high-quality and cost-effective.
4. New MIS techniques now have evidence-based backing. High-level data supporting new minimally invasive techniques, such as lateral spine surgery and disc replacements, has been published over the past few years. The five-year data for cervical disc replacements is now showing as good or better long term results when compared with spinal fusion.
A study presented by Robert Jackson, MD, at the Congress of Neurological Surgeons 2013 Annual Meeting cost-compared one- and two-level disc replacement with anterior cervical discectomy and fusion. He found secondary surgery rates were lower among the disc replacement patients, but device costs were much higher.
Studies comparing the effectiveness of lateral procedures for spine surgery to other techniques and open surgery show the approach is effective for various procedures. NuVasive initially launched the eXtreme Lateral Interbody Fusion system more than 10 years ago, but several other device companies over the past few years have launched lateral systems as well.
A 2010 study examining XLIF patients found procedures are generally performed with short OR times, minimal blood loss and few complications. The study also found XLIF a cost-effective procedure, and over the past four years several new insurers have announced they would cover the procedure.
5. Radiation exposure higher for MIS procedures, but new innovations coming. Most minimally invasive spine surgical techniques use fluoroscopic guidance which increases surgeon and patient radiation exposure. At the 2013 NASS Annual Meeting symposium on current trends and controversies in minimally invasive spine surgery, Alexander R. Vaccaro, MD, PhD, cited radiation exposure as one of the top reasons he has not adopted minimally invasive techniques.
A 2013 study published in Spine found that spine surgeons performing percutaneous endoscopic lumbar discectomy procedures reach the limit of allowable radiation exposure without a lead apron after 219 lumbar spinal discectomies per year. Surgeons with the apron are able to perform 5,379 per year safely.
Another study from 2011 published in Spine found that surgeons performing minimally invasive lumbar microdiscectomy were exposed to significantly more radiation than surgeons performing open microdiscectomy. Exposure to high dose of radiation may increase the risk of health complications for spine surgeons.
New technology and techniques are being developed to address this issue. A study published in early 2014 shows using robotic guidance shortened procedure time and radiation exposure by 74 percent when compared with fluoroscopy guidance and 50 percent when compared with navigated augmentation.
6. Goals of open spine surgery remain the gold standard. More spine surgeons are moving toward minimally invasive techniques, but the outcomes achieved with open spine surgery remain the gold standard. Residents and fellows continue to learn the open procedures first and then focus on less invasive techniques.
Fellowship and residency programs are struggling to ensure their faculty and trainees have enough experience with both minimally invasive and open techniques for proficiency. However, as new technology becomes available to treat even complex cases with minimally invasive approaches and patients seek out surgeons who use less invasive procedures, more young surgeons want training in those techniques.