Originally created 03/12/98

Breathing easy



Popcorn.

That's how Dennis Evins knew the surgery had corrected his chronically clogged and painful sinuses.

"I was in the upstairs part of the house and I could smell my wife making popcorn downstairs," said Mr. Evins, 46, a nuclear chemist and instructor at Savannah River Site. "I couldn't smell things like that before."

The throbbing sinus headaches and constant drippy infections that he suffered for four or five years were also gone.

But to get it cleared up, Mr. Evins had to go through a tricky and bloody surgery. Surgeon Alan Whitehouse hunted polyps and obstructions deep within the cavities behind Mr. Evins' face, working within millimeters of his brain, vital arteries and nerves. The risk for patients like Mr. Evins is being diminished, however, with the use of a new operating guidance system that gives surgeons the exact position of their instruments within the skull, even when the camera view is obscured or they stray into delicate areas.

The use of an endoscope, a long thin camera mounted on a cable and hooked up to a monitor, allowed surgeons about 10 years ago to see where they were when they entered the nasal passages and moved into the sinus. But even with that technology, there were limits, Dr. Whitehouse said.

The camera provided no depth perception, and some people have abnormally shaped passages or structures within that can confuse the surgeon. And, in the midst of surgery, the camera can't see through blood.

That's why Dr. Whitehouse and his partner Doug Harmon were excited to find the InstaTrak system from Visualization Technologies of Baldwin, Md. The system at University Hospital is one of only two in Georgia, and is among about 80 in hospitals across the country.

Approved by the Food and Drug Administration in April 1996, "this thing is really just starting to take off," said senior sales manager E. Michael Jones.

The $90,000 device is used in conjunction with a CT scan, which gives the surgeon several different views of the patient's skull and sinus cavities. Those views provide the road map for the system when they are loaded onto a computer screen. InstaTrak's half-moon collar contains electromagnetic points that create a field across the patient's skull. Another electromagnetic point is located on the surgeon's aspirator, or suction device. On the computer screen, it appears as a crosshair showing the location of the tip of the aspirator wherever it is inside the head.

As he worked on the sedated Mr. Evins, Dr. Whitehouse rarely looked down at the man lying on the table in front of him. Instead, his eyes darted from the screen showing the camera view of the endoscope to the nearby computer monitor where the InstaTrak system showed him where he was.

"You can get a little motion sickness watching this," Dr. Whitehouse said, as he moved the long snake-like tube of the endoscope into the nostril. The jerky view on the screen passed through a forest of nose hairs into a dark red room with rounded walls.

The view stopped on a rounded obstruction sticking out the right side of the sloping wall.

"He's got something back there," Dr. Whitehouse said. "I wasn't expecting this little spur." A quick check of the InstaTrak tells him it's not a vital structure, something that might worry him otherwise.

The actual cleansing of the sinuses is a grim business that resembles punching into thin red walls and vacuuming up bloody yellow bags. But the coarseness belies the delicate nature of the work. As he penetrates into the ethmoid sinus, Dr. Whitehouse is cutting through a honey-combed cavity to create a clear channel back to the nose. He skirts his way along a curved wall -- just millimeters from the optic nerve and the eye itself on the other side.

"The wall between the ethmoid sinus and the eye is the lamina papyracea, which is Latin for paper thin," Dr. Whitehouse said.

After clearing the ethmoid, he spots a small dark spot that leads him into the next chamber, the sphenoid sinus. Again he busts in and clears out the cavity. On screen, the crosshairs of the InstaTrak system dart back and forth in the circle of the sinus, which shows a dark bulge hanging toward the back.

"That's the pituitary gland," Dr. Whitehouse said. Someday, the InstaTrak may enable surgeons to go directly to the gland for surgery but today it is another vital piece of anatomy to be avoided. The polyps stretch back to the very edges of the sinus, and though he is relying on his knowledge and skill as a surgeon, Dr. Whitehouse is glancing at the InstaTrak.

"This is the part where we're chasing it to its limits, close to the base of the brain and close to the eye socket," Dr. Whitehouse said. Before, surgeons might have been hesitant to go too far in order to get it all, he said.

The circle that represents the sinus on screen remains clouded, but in the future the system might use a fluoroscope to give constantly updated images showing not only where the surgeon is but how the structures are changing, Dr. Harmon said.

And in the future, the technology will be widespread, Dr. Harmon said.

"I foresee in the next five or six years it being used on every endoscopic sinus surgery," Dr. Harmon said. "I believe it will just be a standard piece of equipment."

And for patients like Mr. Evins, who once would have had to endure a surgeon drilling through the outside to relieve clogged sinuses, it means going in with a little more piece of mind.

"(It) gave me a little more confidence, made me feel better about it," Mr. Evins said.

And instead of staying in the hospital, it means coming home to a house full of newly discovered aromas.