Implant Pump a Boost to Treatment of Diabetes : Medicine: Experimental device automatically releases a programmed amount of insulin into a patient’s system.
Gary Ellenor, a diabetic, watched his cousin lose first a leg, then a kidney and finally his life to diabetes.
Ellenor, 47, vowed that the fate of his cousin, only a year older, would never be his.
Since his disease was diagnosed when he was 15 years old, Ellenor has scrupulously taken care of his body, monitored his insulin levels, exercised regularly and avoided sweets.
He will soon take one more step that he hopes will bring him closer to living normally and making sure diabetes doesn’t cut his life short.
On Sept. 17, Ellenor will undergo a simple surgery that may one day become routine for diabetics: An insulin pump the size of a hockey puck will be implanted just under the skin above his abdominal cavity. The experimental pump will automatically release a carefully programmed amount of insulin into his system.
“My cousin provided me with a good lesson as far as what could happen if you don’t control your diabetes,” said Ellenor, a Carlsbad resident. “I promised my mom, I am not going to be like him. I’m going to control it.”
With this operation, San Diego’s Sharp Cabrillo Diabetes Treatment and Research Center will become one of 14 centers in the United States to use the experimental pumps on patients like Ellenor who have Type 1 diabetes. The only other Southern California facility--UC Irvine--to participate in the study has stalled in its efforts since one of its principal investigators left for France.
About 14 million Americans have diabetes, of which there are two types: juvenile- and maturity-onset, which develops later in life. Juvenile, or Type 1 diabetes, afflicts about 1.5 million people who are diagnosed anywhere from infancy to young adulthood.
In a normal body, the pancreas releases insulin when the level of sugar in the bloodstream rises after eating. Insulin enables the body’s cells to convert the sugar for energy. In a Type 1 diabetes patient, the body does not produce insulin. With Type 2 diabetes, either the body produces an insufficient amount of insulin, or it’s unable to adequately utilize the insulin.
The Department of Veterans Affairs Medical Center in La Jolla--and five other V.A. facilities outside California--have launched a study using these implanted pumps on patients with maturity-onset diabetes. But officials with MiniMed Technologies, the Sylmar-based manufacturer of the pump, expect that the device will first become available to juvenile-onset patients, among whom most of the tests are conducted here and in France. If all goes according to schedule, company officials say, the implantable insulin pump will be on the market within two years.
The implanted pump holds the promise of better control of the disease, which may mean not only longer but healthier lives for diabetics, doctors say.
“If this turns out to be as good as it appears, then it will be a tremendous step forward,” said Dr. Eric Gold, who will be Sharp Cabrillo’s principal investigator in the study it will launch this fall.
And those who have already begun using the pumps say they are impressed. Dr. Steven Edelman, assistant professor of medicine at UC San Diego’s School of Medicine and a physician at the V.A. Medical Center, started implanting the pumps in his patients last winter. Today, 10 of his maturity-onset diabetes patients are using the device (including two who received it two weeks ago).
For a study, Edelman is following one group of patients who depend on the pump and another who give themselves insulin injections. So far, the patients using the pump seem healthier and suffer fewer complications than their counterparts, Edelman said.
“The main difference is that the group on the shots are requiring more insulin, and their blood sugar control isn’t as good,” Edelman said.
Some experts believe the high levels of insulin contribute to the buildup of cholesterol in arteries, which, in turn, could cause the high incidence of strokes and heart attacks suffered among maturity-onset diabetics. (Maturity-onset diabetics suffer about six times more heart attacks and strokes than non-diabetics, Edelman said.)
With the implanted pump, however, a diabetic requires less insulin because it is reaching its target more directly. This has led to lowered cholesterol levels, Edelman said.
Among Edelman’s small group of patients, he is also seeing other differences. The patients who are giving themselves insulin injections have gained about 10 to 15 pounds; those on the pump have not put on weight.
And finally, the patients depending on insulin shots experience swings in their blood sugar levels (which can cause fatigue)--a phenomenon not experienced by their counterparts, Edelman said.
Most diabetics control their insulin levels by giving themselves injections. A smaller number use an external insulin pump, a credit card-sized device that can fit on a belt like a beeper that some patients describe as cumbersome and is not waterproof.
Ellenor, for instance, has used the external pump for about 10 years. But Ellenor, a clinical pharmacist, likes to swim and surf. Since the external pump is not waterproof, he must take it off and give himself insulin injections every two hours when he’s at the beach.
External pumps also deliver constant amounts of insulin, but deposit it under the skin. The implanted pump infuses the insulin into the membrane surrounding abdominal organs, where it is better absorbed and utilized.
“With this (implantable) pump, the pitcher throws directly to the catcher rather than to the first baseman who relays it on to the catcher,” said Gold, a Montreal native.
Gold and others believe the pump will enable diabetics to more precisely and quickly receive the amount of insulin that their body requires, which, in turn, could reduce the number of complications that diabetics can suffer.
Indeed, the few Californians who have the implanted pump--like Michael Martin--tout its virtues. Eight years ago, Martin took his physical exam to retire from the Navy after almost 23 years of service and learned he had maturity-onset diabetes.
Martin, now 47, initially tried to deny that he had the disease. But he quickly felt its grip. His blood sugar level yo-yoed up and down. He always felt thirsty and fatigued. He constantly felt the need to urinate. He gained weight, his vision began to blur. But scariest of all, he began to lose feeling in his feet because of nerve damage.
“This is a diabetic’s greatest fear--if you don’t get it in control, you can lose your feet,” said Martin, an Imperial Beach resident.
Today, Martin is one of 10 maturity-onset diabetics at the V.A. Medical Center who opted for the implanted pump. The device, he says, turned his life around.
About 50% of the feeling has returned to his feet. He’s lost 40 pounds. He no longer experiences fatigue or blurred vision. For the first time in four years, he’s planning to leave town for a vacation--something he stopped doing because he was concerned about being away from his doctor. And he no longer gives himself insulin injections throughout the day.
“Now I feel I can travel again. It’s just like leading a normal life,” said Martin, who received his pump in January. “As far as I’m concerned, there are no downsides to this pump.”
There are, however, some disadvantages. Some patients are disconcerted by the slight bulge after it’s implanted--a factor that Martin says is outweighed by its benefits.
“I just tell people it’s my $12,000 hockey puck,” said the father of three, referring to the expected commercial price. “It doesn’t bother me at all.”
Although the pump is powered by a battery that keeps it going for five years, it does require insulin refills every three months. These refills are done at the doctor’s office where the physician pierces the patient’s skin with a needle and simply injects insulin directly into the pump, a 10-minute procedure.
And there are other drawbacks to the implanted pump:
* It requires a 20-minute surgery to put it in place.
* The pump is expensive. Though it is free for participants in the two San Diego studies, it could cost as much as $12,000 when it becomes commercially available.
* The catheter connected to the pump can clog. About 10% of patients with implanted pumps experience some blockage in the catheter during the first year, Gold said. Surgery may be needed to replace the clogged catheter or the pump.
But Gary Ellenor is not fazed by these possibilities. At first, he was concerned about what the pump would look and feel like under his skin. Because he goes to the gym three times a week, he wondered how the muscles would react. What would it be like doing sit-ups, he mused.
“Is this going to be comfortable? “ he asked himself.
But he decided to go ahead with the implant the next month. “My feeling is: nothing ventured, nothing gained.”
Though the implanted pump offers better control of diabetes, Gold, Edelman and others say there will be one more crucial step after this. The goal, they say, is a pump equipped with a sensor that can monitor the blood sugar levels and direct the pump accordingly.
Such a device would revolutionize the lives of diabetics, eliminating the need for numerous daily injections.
“It’s still an open loop system. We just don’t have the durable glucose sensor that works on a continuous basis,” Edelman said. “I basically see these pumps being FDA-approved and being normal therapy for any patient with diabetes. We need an implantable glucose sensor. We need to close the loop in the system.”
