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`Lateral Interbody Fusion Training Comes to Birmingham
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`Jane Ehrhardt
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`Donald A. Deinlein,
`MD
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`This August, ten more Alabama surgeons walked out of the Sheridan knowing how to
`perform the direct lateral interbody fusion (DLIF) technique. The training on this
`procedure to treat degenerative disc disease had been taught by Donald A. Deinlein,
`MD,associate professor of orthopedic surgery at UAB and, until this event, the only
`physician in Birmingham trained in the approach.
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`Two years ago, Deinlein had been intent on learning a lateral approach, so he traveled to
`three U.S. sites for training — Emory University, University of Maryland, and San
`Diego. Now, by offering the cadaver training on DLIF in Birmingham, he hopes to make
`it easier for other Alabama surgeons to offer the procedure to their patients.
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`Prior to the lateral approach, access to the spine had been through anterior or posterior incisions. But the
`new approach avoided the major muscle groups in the back and the major organs and blood vessels in
`the abdomen.
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`Deinlein first heard about the lateral access approach, known then as the alpha approach, in 2002 at a
`medical conference in France. The presenter spoke of a safe conduit to the discs through a patient's side
`between the nerves and blood vessels.
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`Though the open procedure had been performed in Europe since the '90s, it was difficult to reproduce
`accurately. "There was no special equipment to help with the surgery at that time," Deinlein says. So it
`required a large incision and skilled precision to avoid the nerves associated with the psoas muscle.
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`Then in 2004, Luiz M. Pimenta, a Brazilian neurosurgeon, revealed the extreme lateral interbody
`fusion® (XLIF) technique in collaboration with NuVasive. Using Pimenta's breakthrough equipment and
`instruments, surgeons could now electronically detect nerves in real-time, overcoming a major obstacle
`to the lateral approach and making the procedure easily reproducible.
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`With the XLIF dilators and retractor, surgeons could enlarge a one-inch incision to 18mm for clear
`viewing and entrance to the disc. "This changed the lateral approach from an open procedure to
`minimally invasive," Deinlein says. "With the dilators, there's minimal tissue destruction and blood loss,
`so patients are usually home the next day."
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`To perform either the XLIF or DLIF, the surgeon threads an EMG-based probe between the fibers of the
`muscle and down to the disc. The probe alerts the surgeon to nearby nerves by sounding an alarm. The
`surgeon then inserts a small guide wire through the probe, then wider and wider dilators are placed over
`the wire to enlarge the opening.
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`The retractor, placed over the final dilator, locks to the table and the patient's spine to create a large,
`stable opening. "The placement of the dilators and retractor is done with the aid of a fluoroscope, but the
`surgery is done with direct vision," Deinlein says.
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`The small incision enlarges enough to allow surgeons access to three levels of the spinal column.
`Deinlein adds that the fusion procedure can be backed up with posterior percutaneous screw fixation,
`also accomplished through the small incision. "Plates work too, but for multiple levels, it's easier to use
`screws," he says.
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`http://www.birminghammedicalnews.com/news.php?viewStoryPrinter=1302
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`4/24/2013
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`NUVASIVE 1052
`NuVasive, Inc. v. Warsaw Orthopedic, Inc.
`IPR2013-00206
`IPR2013-00208
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`Page 2 of 2
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`The greatest risk with the lateral approach, according to Deinlein, is injury to the bowel. "With the
`incursion of the retractor, it's possible at the higher levels to trap the bowel in the retractor, but
`fortunately this is not a common occurrence," he says.
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`In 2007, Medtronic released a new retractor, slightly altering the procedure, and calling it the direct
`lateral interbody fusion (DLIF) approach. Their retractor fixes to the spine with a pin, whereas the XLIF
`retractor fixes to the disc. "The fixation is more rigid with the DLIF, and I think it's a safer placement for
`the pin in my hands," Deinlein says. "I have done both procedures and prefer the smaller DLIF retractor.
`But this is purely a preference."
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`Neither the DLIF nor the XLIF approaches can be utilized below the 4th lumbar disc because of the
`pelvic crest. "You can go higher if you go between the ribs, but the implant which induces fusion is not
`yet approved at higher levels," Deinlein says.
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`So far, Deinlein has performed the DLIF on about 15 patients, covering 20 or more levels, with most of
`the multi-disc procedures being two or three levels. "When you do multiple levels, you have to move the
`retractor from one disc to the other, but you can still retract through the same incision," he says.
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`For Birmingham surgeons looking to learn the DLIF approach and percutaneous screw fixation,
`Medtronic hopes to hold a training seminar in Birmingham in about six months. For more information,
`contact Medtronic at Medtronic.com. For the XLIF training, surgeons travel to NuVasive headquarters
`in San Diego. For their schedule, visit nuvasive.com (www.nuvasive.com/surgeons/mvp.htm) or email
`mvp@nuvasive.com.
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`http://www.birminghammedicalnews.com/news.php?viewStoryPrinter=1302
`
`4/24/2013
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