Painful Z-joint synovial cysts can be successfully treated by percutaneous fluoroscopic synovial cyst rupture, helping some 80% of patients avoid surgery, according to study findings reported at the American Society of Anesthesiologists 2014 annual meeting (abstract 1045).
Researchers from Case Western Reserve University School of Medicine/MetroHealth Medical Center, in Cleveland, conducted a synovial cyst rupture on 30 patients with moderate to severe lower back pain who had documentation of an associated synovial cyst by magnetic resonance imaging. Lumbar synovial cysts, which occur due to spondylosis of the facet joints, can encroach on adjacent nerve roots and cause symptoms of radiculopathy.
The indication for cyst rupture was for the patient to avoid having surgery from radiculopathy in the leg, according to principal investigator Kutaiba Tabbaa, MD, director of pain management at MetroHealth Medical Center.
A 22-gauge 10- to 15-cm spinal needle was introduced into the joint under fluoroscopic guidance while patients were in the prone position. Aspiration of synovial fluid could be achieved if the cyst neck was widely connected to the facet joint. Then 1 to 2 mL of non-ionic contrast iohexol 300 mg/mL was injected into the facet joint to identify the intra-articular positioning of the needle and filling of the cyst, which confirmed the diagnosis of lumbar facet synovial cyst. The contrast agent and synovial fluids were aspirated, and 1 to 2 mL of preservative-free bupivacaine 0.5% was injected and trapped for three to four minutes.
To rupture the cyst, up to 10 mL of normal saline (sodium chloride 0.9%) was injected until a loss of resistance was felt. Then another 2 to 4 cc of iohexol 300 mg/mL was injected to identify free flow of the dye from the joint to the epidural space anteriorly and posteriorly. After satisfactory imaging of free flow of the dye, 80 to 120 mg of methylprednisolone acetate (DepoMedrol) with 1 to 2 cc of preservative-free bupivacaine 0.5% was injected.
The procedure resulted in an average reduction of 71% in pain severity. The mean Numerical Pain Rating Scale score before cyst rupture was 7.3. It dropped to 2.1 after the procedure, a mean difference of 5.2 that was statistically significant (P<0.0001).
The researchers used phone interviews to determine the long-term success of the cyst rupture and need for subsequent surgery to relieve symptoms. They found that 14 patients achieved pain relief for more than six months. Seven achieved pain relief between one and six months. Nine had synovial cyst recurrence that required repeat rupture. Six required surgical intervention for cyst removal. The procedure for one patient was aborted because the cyst could not be ruptured due to pain. No complications were reported among the 30 patients.
“Through this case series, we found that rupture of the synovial cyst in patients with lumbar radiculopathy was associated with immediate relief of radicular symptoms. In 80% of patients, synovial cyst rupture prevented future surgical interventions over the long term,” said study author Yashar Eshraghi, MD, an anesthesiology resident.
He noted that although this was a retrospective case series, he still considered it a good study because a 12-patient series was the largest among prior studies of this approach.
Michael Giovanniello, MD, a practicing physical medicine and rehabilitation physician at the SMART Clinic in Sandy, Utah, found the results impressive and that the procedure mirrors what he does in his own practice: He first ruptures the cyst with contrast and injects steroid after an appropriate rupture of the cyst.
“This study provides useful information that you can rupture a cyst by an injection. It indicates that surgery is not always necessary to manage patients with a synovial facet cyst. These patients can effectively be managed by a minimally invasive fluoroscopic-guided injection,” said Dr. Giovanniello.