Study of Cells From Spinal Cavity of Patients With Low Back Pain

The pain group at TTUSOM has pioneered a treatment for low back pain with or without radiculopathy called epidural neurolysis (or other names, e.g.: lysis of epidural adhesions, the Racz procedure). This technique is now used worldwide. The treatment is based on substantial evidence that pathological processes within the epidural space innate and sustain pain. The goal of epidural neurolysis is to deposit therapeutic agents directly into the area of pathology (i.e., targeted drug delivery). The procedure involves documentation via epidurograms that radio opaque material injected into the epidural space prior to treatment does not enter the suspected area of pathology. This area is determined by signs and symptoms revealed by the patient history and physical examination.

After a filling defect that corresponds to the suspected area of pathology is documented by epidurography, a specially designed catheter is directed into the defect. Mechanical forces applied by the catheter and hydraulic forces applied by injection of isotonic saline through the catheter as well as injection of hyaluronidase, are used to enter and remove barriers to targeted delivery of drug. Next drugs, usually corticosteroid, local anesthetic and hypertonic saline, are injected to treat what is presumed to be inflammation and edema.

More recently, epiduroscopy has been introduced as an aid to epidural neurolysis. Epiduroscopy allows visual inspection of epidural tissue. Epiduroscopy is performed by inserting a flexible endoscope through the sacral hiatus. Using epiduroscopy, we and others have observed change in the epidural space that we believe are related to the etiology of the pain. We see changes consistent with various stages of inflammation either acute or chronic. We see increases in vascularity, displacement of fat by fibrous tissue as well as changes in the texture and color of peridural fat.

We have developed a method for retrieving cells from suspected areas of pathology and of culturing the cells via the working channel of the epiduroscope using a cytology brush. The collected cells are characterized to establish a diagnosis and to aid treatment.

To confirm areas which appear to be abnormal when viewed via epiduroscopy are involved in the painful condition for which the patient is seeking treatment, we test the area with hydrostatic pressure (saline injection) or by touching with the epiduroscope tip (mechanical stimulation). These stimuli do not normally elicit pain. However, when the stimulus does elicit pain in the region of the painful region of the patient's body, the abnormal appearing tissue in the epidural space is considered to be involved in painful process affecting the patient. This is similar to "pain mapping" done by others when electrical stimulation is used to search for the area of pathology. Adapting this approach, applying electrical stimulation via a stimulating probe (FDA approved) inserted through the working channel of the epiduroscope will allow more precise localization of pathological tissue than does the methods we currently use.

We will collect cells during epiduroscopy and characterize them in vitro. A new dimension of this project is to deliver electrical stimulation to more accurately locate the source of pain from where cells should be sampled.