Emile M. Hiesiger, MD

SYNOVIAL CYST MINIMALLY INVASIVE DECOMPRESSION - A NEW OUTPATIENT TREATMENT 

Synovial cysts are fluid filled firm structures arising from the facet joints in the lower (lumbar) spine, pressing on nerves, causing disabling leg pain. They occur most commonly in patients in the mid-60’s and are located typically in the L4-5 and to a lesser extent, the L5-S1 levels—the two lowest spinal segments above the pelvis. Less commonly the L3-4, and to a lesser extent the L2-3 segments, may also produce cysts. Very rarely they may occur in the cervical spine–neck. They arise from wear and tear on the facet joints — stabilizing structures of the spine– as part of the degenerative process. Associated with worn down, stabilizing facet joints, the cysts are associated with some slippage of the bones of the spine — vertebra– in up to 40% of cases. The cyst is composed of the covering of the facet joint.

Medication may help some patients with symptomatic cysts –causing sciatica — function with less pain. However, in many cases of cyst induced pain, unlike pain due to new disc herniations, even potent narcotics and oral steroids may not sufficiently relieve back and leg pain due to these cysts. Seventy-to-eighty percent of herniated discs may shrink in 2-3 months, with relief of leg pain. Unfortunately, most cysts do not regress spontaneously.

Epidurals are not very useful in treating pain induced by these cysts and certainly don’t eliminate the chronic pressure on the nerves caused by the cysts. Usually, most patients with these cysts are treated with surgery, akin to that used for removal of a herniated disc. At times, if they occur in conjunction with spinal instability and slippage, the cysts may be removed surgically, but a fusion of the spine becomes a necessary part of the operation to prevent further instability.

Over the last several years, I have developed a minimally invasive, effective means of treating many of these symptomatic cysts. This procedure is performed on an outpatient basis, using intravenous anesthesia, under CT guidance. Patients return to work the following day.

In two thirds of 21 carefully selected patients I have treated, I have successfully decompressed the cysts I treated resulting in permanent relief of sciatica. In follow-up MRI s on some of my patients, obtained for evaluation of other spinal problems months to years later, there was no evidence of residual cyst. My procedure will not help patients with a nerve compressing cyst also suffering from stenosis or spinal instability at the site of the cyst. Patients with these problems and a cyst may well need surgery to address their complicated multi-factorial problem. However, my technique may allow 66% of those with simple symptomatic synovial cysts to have pain relief permanently while avoiding surgery. My technique is not to be confused with other needle-based techniques involving simple cyst puncture.  It is well documented in the medical literature that attempts at treating pain-inducing cysts by puncturing them with a needle, under fluoroscopy,  and injecting them with various substances, have failed.