Rare Complication After Spinal Fusion

Any surgery is done knowing there are risks involved. The most serious risk is death. But sometimes the unusual happens. In this case report, a 70 year-old-woman who had spine surgery ended up with a rare condition called man-in-the-barrel syndrome (MIBS). The surgeons involved in the case present what happened in order to help other surgeons be aware of such a complication.

Man-in-the-barrel syndrome (MIBS) presents as complete loss of movement in the arms. This symptom is referred to as brachial diplegia. She could feel pain but could not move in response to it. Her legs were unaffected, so she could move those freely.

Other symptoms associated with this problem include flat affect (no facial expressions), mild cognitive deficits (decreased mental function), and poor balance while walking. MIBS gives a patient the appearance of being confined within a barrel.

Her medical history included several spine surgeries for degenerative scoliosis (curvature of the spine) and lumbar stenosis (narrowing of the spinal canal). The scoliosis was causing her to become stooped forward (kyphosis). The stenosis was putting pressure on her spinal cord and spinal nerve roots causing back and leg pain.

Other pertinent information about her medical history included the fact that she had high blood pressure, elevated cholesterol, and low thyroid function. A year earlier, she had what’s known as a transient ischemic attack (TIA). This means some part(s) of the brain is temporarily deprived of blood supply (and therefore oxygen).

The first operation she had was a fusion from T11 down to S1. That means the spine was fused from the bottom of the thoracic spine down to the top of the sacrum. Postoperative complications from that procedure included infection, nonunion (fusion didn’t take), and spondylolisthesis.

Spondylolisthesis means there was a crack in the pars interarticularis, a supportive column of the vertebra. The crack opened and separated, allowing the vertebral body to slide forward over the vertebra below. The spinal canal was then compromised contributing to spinal stenosis. This positioning of one vertebra (displaced forward over the one below it) can pull on the spinal cord and/or spinal nerve roots causing painful symptoms.

She had a second surgery to stabilize the spine. This was done by performing an anterior lumbar interbody fusion at L45 and refusing the T11 to S1 segments. In addition, iliac screws were added to link the lumbar spine with the pelvis.

There were even more problems after this operation. This time, she developed a progressive kyphosis to the point that she could no longer stand up. The hardware at the L5S1 failed (probably due to the position of her body).

The third surgery was done to remove the hardware put in during the previous fusion operations. The surgeon took out the bone around the spinal nerve roots in a procedure called a laminectomy. Then, the surgeon placed screws from T3 all the way down to the ilium (pelvis). During this third operation, her blood pressure dropped requiring medication to increase the blood pressure.

She was also given a blood transfusion and cell saver blood. Cell saver blood refers to the fact that blood lost during the procedure was collected during and after the surgery using a device commonly known as the cell saver. Then it was reinfused into the body.

The brachial diplegia occurred right after a 30-minute episode of hypotension (very low blood pressure). All of this happened six hours after the surgery. She was tested right away with CT scan, MRI, and other contrast-enhanced imaging studies. All the findings were negative. There was no obvious cause of her symptoms. A cardiac workup was also within normal limits given her age and history with nothing to explain the paralysis.

Fortunately, the patient gradually returned to normal in all areas (muscle control, mental ability) with reduced pain and improved daily function. The authors suspect she developed this problem as a result of a loss of blood supply to the region of the brain that controls the arms. They suggest the area between the anterior and middle cerebral arteries supplying the temporoparietal region of the brain was the key area affected.

The underlying event leading to this complication was the sudden loss of blood pressure. Rapid fall in blood pressure can result in brain damage. Her previous history of high blood pressure probably contributed to the problem. Since her neurologic signs were normal right after surgery, they suspect the problem developed during recovery.

The prognosis for man-in-the-barrel syndrome is usually good. If the blood loss is identified early and treated right away, the condition is completely reversible. That’s why it’s so important for surgeons to be aware of this possible (though rare) adverse effect. Prognosis depends on how severe the blood loss is and how long it lasts. The sooner the blood supply can be restored, the more likely it is that the patient will experience a total recovery.