Procedures and instrumentation to treat spine pathologies have co-evolved over decades to improve patient outcomes through more efficacious treatment and minimizing of the risk of adverse events. Typically, a new procedure is developed using implants and instruments available at the time. Later, devices are developed to help surgeons perform the procedure more easily, and the cycle repeats.
Methods to fuse the lumbar spine as a treatment for degeneration or deformity has literally come full circle from open posterior surgery to open anterior, then back posterior and anterior as minimally invasive approaches.
The latest stage in the evolution of lumbar spinal fusion is the oblique lumbar interbody fusion (OLIF) procedure. The procedure takes cues from traditional anterior procedures once used to treat tuberculosis-related spine pathologies in the late-1800s and early-1900s.
Recent interest in minimally invasive OLIF began in the late 1990s and has become more accessible in the last few years with presentations by experienced surgeons, such as Richard Hynes, M.D., F.A.C.S. from the BACK Center in Melbourne, Florida.
While daunting to some, surgeons currently employing this technique encourage experienced surgeons to give it a try and are hoping to get it into the hands of spine surgery fellows early in their training in the next few years.
Explaining the Oblique, Muscle Sparing Approach
As suggested by the name, the procedure takes an oblique approach to the anterior column; the surgical site is between those for the anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF).
Experienced surgeons recommend positioning patients laterally to give the best angle for the procedure. Lateral positioning also allows for access to the posterior elements to perform percutaneous fixation during the same OR session without repositioning the patient.
The surgical corridor used in OLIF is both done anterior to the psoas and retroperitoneal. In contrast to the LLIF, which requires splitting of the psoas to access the intervertebral space, OLIF avoids the muscle entirely.
ALIF often requires a transperitoneal approach, which requires the services of an anterior access surgeon before a spine surgeon is able to work. The OLIF uses a corridor that naturally forms in most patients as the peritoneal contents fall anteriorly due to gravity. The extension of the hip and knee, permitted by the lateral positioning, tenses the psoas pulling it more posteriorly revealing more of the anterior column.
Three retractor blades are typically used to maintain the working corridor, two laterally and one caudally to protect the blood vessels and provide the operating corridor. Retractors with an integrated light source are recommended due to the relatively narrow channel. Once retractors are placed and the disc is excised, an interbody device can be placed.
A common pain point for surgeons is the “orthogonal maneuver,” which involves rotating an anterior or lateral interbody cage properly from the oblique angle.
John Peloza, M.D., from the Center for Spine Care in Dallas, Texas and John Williams, M.D. from Ortho Northeast in Fort Wayne, Indiana, recently spoke about their experience learning and using the OLIF procedure. Both surgeons have about four years of experience in performing the OLIF procedure and claim that fusion of any lumbar level is possible, even L5-S1, with the OLIF procedure.
