Drs. Andrew Hecht and Sean McCance work on the cutting edge of minimally invasive back surgery.

 

By P.H.I.Berroll

For Sean McCance, one of the biggest innovations in his field, spinal surgery, over the last ten years has been the XLIF cage. XLIF, or lateral lumbar interbody fusion, is a minimally invasive surgical procedure performed through the patient’s side, in order to avoid the major back muscles. The cage, a small rectangular-shaped device, is inserted between the patient’s vertebrae to provide support.

“The cage is put into a very small incision,” Dr. McCance explains, “through a special tubular retractor that allows you to get a large implant into in a small space. The older approach, with a large incision, tended to cause muscle denervation [the interruption of nerve impulses to the muscles] and lead to out-pouching of the abdominal wall and maybe some scar pain. But with this technique, there’s less scarring, less risk of side effects. It can be used for older scoliosis patients who can’t tolerate a big open surgery, and can save younger patients the morbidity of a big incision.”

Dr. McCance, who is Co-Director of Spine Surgery in the Leni and Peter W. May Department of Orthopaedics, regards the XLIF cage as a major advance in his field – and a paradigm for his mission as a surgeon: “To perform the same or better surgery through a smaller incision.”

Indeed, this is the primary goal of Dr. McCance and his co-director, Dr. Andrew Hecht, who have led Mount Sinai’s spinal surgery program since 2005. For both practitioners, minimally invasive surgery has become a key component of their work. They are in the forefront of a wave of innovation that has revolutionized spinal surgery – to the point where procedures once considered high-risk are now commonly performed on both elite professional athletes and people in less physically stressful lines of work.

“Minimally invasive techniques have had a very positive impact of on our field in the last decade,” says Dr. McCance. “They’ve given us the ability to address a broader array of pathologies with less morbidity.”

The Extraordinary Tube

In addition to his work at Mount Sinai, Dr. Hecht is the spine surgical consultant to the New York Jets, the New York Islanders and numerous collegiate teams. This has given him a unique perspective on the growing popularity of minimally invasive spinal surgery, first with big-name athletes – this past May, Indianapolis Colts quarterback Peyton Manning had a microdiscectomy, which is performed through a one- to one-and-a-half-inch incision in the lower back, to relieve the pain of a pinched nerve – and now with the general public. “A lot of these techniques,” he says, “are applicable to many different groups of patients.”

Like Dr. McCance, he speaks with great enthusiasm about the use of tubular retractors – which he says “have enabled us to do some very extraordinary things” – in several types of lumbar and pelvic surgery.

Tubular retractors enable surgeons to enhance their view of the spine without the invasiveness of traditional surgery. “Instead of making a larger incision and dissecting all the way down to the spine,” Dr. Hecht explains, “we make a small incision and through a series of dilators, insert what is basically a tube. Then, with the use of a microscope, we’re able to look down the axis of this tube and see things that we normally see with open surgery. Some of these tubes at the very bottom are able to be expanded or dilated further to improve visibility.

“This allows us to avoid the extensive dissection, the tissue exposure, of open spine surgery. You’re minimizing the muscle damage, shortening the length of stay, and minimizing the post-operative pain, particularly in the short term. The patient can be out of the hospital and getting on with his life much more quickly.”

Dr. Hecht also cites prosthetic cervical disc replacement, used to treat patients suffering from herniated discs, as “a very advantageous development.” He and the other members of his team, Sheeraz Qureshi, M.D. and Samuel Cho, M.D., have frequently performed this procedure.

“It’s a big advantage over traditional fusion treatments, where the disc is removed and the surgeon performs a fusion with a bone graft and a titanium anterior fixation plate,” he says. “With prosthetic replacement, motion is preserved – patients can start moving right away, they don’t need to wear a brace. As a result, we don’t worry about problems such as muscle atrophy above or below the area where they would have had a fusion.”

From Cages to Proteins

In addition to the XLIF cage, Dr. McCance speaks highly of a similar device, the self-distracting cage (“distract” in this context means to separate or spread apart) – which, he says, “allows us to do ‘more with less.’

“When we put this cage into the spine,” he explains, “it allows us to elevate the space and restore height to the vertebrae with less maneuvering and tissue manipulation than with older technologies – because the cage itself actually jacks up, almost like a car jack. So you don’t have to do a lot of opening, spreading, etc. to expand the space, which makes it safer for the surrounding neural tissues.”

One tool about which both Dr. Hecht and Dr. McCance are enthusiastic is neither a device nor a procedure, but a substance: Bone morphogenetic protein (BMP), a molecule which can literally grow bone.

Dr. McCance, who calls himself “the largest user of BMP at Mount Sinai,” says, “It can be used as a replacement for iliac crest [a major segment of the group of bones around the pelvis, from which bone material is often used in grafts], and studies suggest that it holds up just as well. So it’s been a step forward in saving some patients the need to harvest their own bone.”

Dr. Hecht concurs: “We’re able to achieve a solid fusion through a tiny incision, only a centimeter or two long, by inserting BMP, where in the past you’d have these massive incisions. For certain types of patients, this is a very effective treatment.”

The two surgeons are closely following the development of other minimally invasive techniques that could prove useful in their work. For example, Dr. McCance predicts that more surgeons will be inserting screws in the spine percutaneously [through wires and tubes] during procedures, rather than the traditional approach of insertion through an incision.

“So if you have a sick patient who maybe can’t tolerate a full open surgery, you can do part of it percutaneously and part of it open,” he says. “That’s another minimally invasive technique that potentially is a step forward for patients.”

Dr. Hecht and Dr. McCance both feel that minimally invasive surgery has enhanced the success of their practice – and the personal satisfaction they take from their work.

“For both cervical and lumbar surgery, we’ve showed a substantial ability to help people,” says Dr. Hecht. “Mount Sinai has one of the largest spine services in Manhattan, and has emphasized treating patients with all kinds of spinal disorders, and trying to get them back to a full life. I think the kinds of surgeries we’re doing, and the outcomes we’re having, are testament to that.”

Originally published in Mount Sinai Science & Medicine magazine, 2012.