Interspinous Spacers for Spinal Stenosis Part I

Dr. Manfrè discusses his background and how he arrived at his current practice in Catania, Italy. His journey in medicine began with the intention of becoming an ophthalmologist. He then realized he didn’t want to pursue this path, and was told by a teacher he would be studying neuroradiology. He despised neuroradiology prior to this, but soon fell in love “at first sight”. He then went to Toronto to study under pioneers of pediatric neuroradiology. He dabbled in vascular IR before finally finding interventional spine. It began with injections for pain but he soon realized the potential of this field. At the time, surgery was becoming more minimally invasive, and as a radiologist, he knew he could leverage this momentum due to this unique background in radiology that his surgeon colleagues did not have.

Dr. Manfrè believed he could apply the same treatments that conventional spine surgeons were doing in a faster, more precise and less aggressive manner. Spine surgeons were beginning to place interspinous spacers for spinal stenosis, and he was interested in placing these using CT and fluoroscopy guidance. He selects his patients very precisely, because it is important to him to not be using a device on the wrong patient. He endorses collaboration with neurosurgeons and orthopedic surgeons and practices this frequently, often referring patients within his network of collaborators. He selects patients for interspinous spacer placement who have genetic lumbar spinal stenosis causing ligamentous compression of nerves.

His technique involves a combination of CT and fluoroscopy as it has been shown that using CT for procedural planning has been shown to reduce patient radiation exposure by 90%. He then uses fluoroscopy to insert the dilater over the guide wire, put in the spacer and open the spacer, which takes around 20 seconds of fluoro time. The interspinous spacer is a device that is placed in between two spinous processes to slow the progression of spinal stenosis and neurologic injury. The spacer cannot undo any prior neurologic injury, however, due to the progressive nature of this disease process. Surgical placement of a spacer is aggressive, involving general anesthesia in older patients with comorbidities, opening of the spinal canal, and laminectomy, which causes ligamentous instability that requires repair. It can be a three hour procedure, which involves extensive recovery and rehab. Dr. Manfrè places a spacer in 3 minutes, uses local anesthesia and midazolam, a 5mm incision, and no rehab. The primary reason for failure of the procedure is spinous process fracture and bone remodeling. He began performing spinoplasty, a procedure in which he injects 1cc of Polymethyl methacrylate (PMMA) in the adjacent posterior arch to determine if this would impact the success of the spacers. He now routinely performs spinoplasty 2 months prior to spacer placement and has enjoyed very low failure rates since implementation of this technique.