Becker's Spine Review

9 Minimally Invasive vs. Open Spine Surgery Sponsored by: S pine surgeons trained on traditional open procedures are transi- tioning to less invasive procedures as quality and cost-effectiveness studies show MIS not only has advantages for the patients but also healthcare spending. Vanderbilt University researchers have compared the outcomes and costs of minimally invasive TLIF versus open TLIF in more than 100 patients with low grade spondylolisthesis. Parker et al showed that MIS TLIF can lead to comparable outcomes with accelerated return to activity and direct and indi- rect cost savings of $1,758 and $8,474, respectivley. 1 "The question now becomes, how can we continue to push this innovation forward to a place where the instrumentation and techniques are used more widely so they become less expensive relative to the standard instruments," says David Hart, MD, director of the Neurosurgery Spine Center at Uni- versity Hospitals Case Medical Center in Cleveland. Over the past decade, innovation in the spine field has exploded to the point where several new technologies are on their way to becoming a standard of care. "We have gone from performing all our spine surgeries with inpatient hospi- tal stays to performing them as outpatient procedures," says Raed Ali, MD, an orthopedic spine surgeon at St. Jude Heritage Spine Center in Fullerton, Ca- lif. "The most common outpatient procedures are percutaneous, arthroscop- ic and mini-incision approaches. Surgeons are even doing less invasive spinal fusions and device companies' new product designs are making that easier." Challenges today One of the biggest challenges minimally invasive spine surgery faces is the learning curve, which can be daunting for experienced spine surgeons. "Sur- geons are faced with the choice of taking time out of their practice to go to courses and learn the new techniques, or [they] decide MIS isn't their thing," says Dr. Hart. "I think that challenge will fade away with the new generations of spine surgeons; over time that will drive the adoption of MIS techniques." Newer innovations also face challenges with gathering enough data and in- formation to prove effectiveness and show surgeons the benefits of new tech- niques. "If independent groups adopt newer technologies and collect their own data, they could prove their results," says Carl Lauryssen, MD, co-direc- tor of spine research and development at Olympia Medical Center in Los An- geles. "Unfortunately, funding is not available like it used to be for industry to sponsor clinical trials. The next best thing is for individual or multi-group surgeons to adopt these newer technologies and collect appropriate data to verify early success." New advancements Minimally invasive transforaminal decompressions are making strides forward for managing patients with spinal stenosis and stable grade 1 spondylolisthesis. "There is a subset of patients who have spondylolisthesis but do not need to be fused and for which we can do a decompression with a device such as Baxano's iO-Flex to preserve stability," says Dr. Lauryssen. "An appropriate decompression can not only reduce the radicular systems and neurogenic claudication but also reduce back pain without a fusion, based on my experi- ence and preliminary data from our clinical trial." The decompression is achieved without sacrificing the stability of the fac- et joint. "Using iO-Flex, we are able to decompress ipsi and contralaterally through a unilateral microdiscectomy approach," says Dr. Lauryssen. "Any other technique that does a decompression via a unilateral approach will re- sult in significantly more compromised facet joints, risking instability and poor outcomes." Advances in the direct lateral approach are continuing to drive the adoption of this fast growing segment of the spine surgery market. "Shallow docking retractors, such as the VEO system, are a key step forward," says Dr. Ali. "What has been learned, generally, is that shallow docking techniques may decrease morbidity by minimizing postoperative thigh paresthesia symptoms, which allows the patients to recover and leave the hospital more quickly." Advances in technology have also made it possible to perform less invasive surgery at L5/S1. Pre-sacral interbody fusion, which is the only new proce- dure in spine to obtain a Category I Code in the last five years, shows posi- tive short-term outcomes with low complications, thanks to its minimally invasive approach. A 2013 study from Yale University researcher Dr. Peter Whang compared pre-sacral interbody fusion to open anterior lumbar interbody fusion in 96 patients. Dr. Whang found similar rates of fusion — 85 percent for AxiaLIF and 79 percent for ALIF. The complication rate was 21 percent and 33 percent for pre-sacral interbody fusion and ALIF, respectively. Of note there were no bowel injuries in the pre-sacral interbody fusion group and there was one iliac laceration in the ALIF group. 2 Strides in Spine Surgery: Where We Are & Where We're Going By Laura Miller Dr. David Hart Dr. Raed Ali Dr. Carl Lauryssen

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