University Times

Wearable defibrillator being studied

Cardiologists at UPMC Health System's Cardiovascular Institute are leading a national multi-center study of the first vest-like wearable external defibrillator, designed to treat life-threatening abnormal heart beats.

Called the LIFECOR (WCD¨) Wearable Cardio-verter Defibrillator, the vest is lightweight, comfortable and is worn under the patient's clothing. Patients taking part in the study wear the device for 22-plus hours a day and only remove it for showering or bathing.

The device continually monitors the patient's heart activity from outside the body. If it senses abnormal heart beats, it gives a series of alarms and delivers a shock to return normal heart rhythm if the wearer does not respond to the alarms. It is designed to deliver the treatment shock in 30 to 60 seconds.

The device is expected to perform "better than calling 911 for emergency medical service," said Srinivas Murali, principal investigator at the Cardiovascular Institute. "If the initial treatment shock does not restore normal heart rhythm, it will recycle and deliver additional treatment shocks if necessary."

Between 150 and 300 people will be enrolled in the study, which will be conducted at up to 20 medical centers nationwide.

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Livers from children going to adults, Pitt review reveals

Nearly two-thirds of all livers donated by children since 1991 were transplanted into adults instead of other children on the national liver transplant waiting list, a Pitt analysis of nearly 30,000 liver transplants performed in the United States shows.

With fewer of these livers available for children, surgeons have been forced to look at alternative options, such as transplanting a piece of a liver. These types of procedures have increased dramatically, with adults — as either living or cadaveric donors — the primary source of these liver segments.

But such efforts have not had an impact either on the waiting list death rate or on the total number of transplants in children each year, Pitt researchers reported at the American Society of Transplantation meeting last month.

"How can we assure that children are better served?" asks Rakesh Sindhi, research assistant professor of surgery at the University of Pittsburgh's Thomas E. Starzl Transplantation Institute and Children's Hospital of Pittsburgh.

"One might propose a preferential allocation system that matches pediatric organs to the highest-risk children. Another option is the greater exploitation and broader sharing of split liver grafts. Such measures could enhance the survival of these children to levels similar to the entire transplant population,"

The review of the United Network for Organ Sharing (UNOS) Scientific Registry data of transplants performed between 1991 and 1998 showed that 4,288 of 6,028 pediatric livers were used in adults. While the number of adults who received livers from child donors increased each year (446 in 1991 to 544 in 1998), alternative procedures to combat the "shortage" of organs for children became more and more commonplace.

Of the 29,172 liver transplants reviewed from the UNOS registry, 25,534 were in adults and 4,186 were in children. Pediatric livers were transplanted into 4,288 adults and 2,707 children.

About 75 children have died each year on the waiting list since 1991.

Under the current organ allocation system, donated organs are preferentially used in the local area where they originate, even if there may be a patient — adult or child — in greater need elsewhere. Only if the organ is not placed locally is it offered on a regional, then national basis.

UNOS, which sets organ allocation policy, is being asked by the U. S. Department of Health and Human Services to de-emphasize geographic factors. By order of Congress, the Institute of Medicine of the National Academy of Sciences is reviewing the UNOS system and the government's proposal. The report is due out this summer.

The Pittsburgh study was co-authored by John Fung, professor of surgery and chief of transplantation at UPMC and the Starzl transplant institute, and Jorge Reyes, associate professor of surgery and chief of pediatric transplantation at Children's Hospital and the Starzl transplant institute.

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Intestinal transplants reported to be viable option

With a one-year survival rate of 72 percent, intestinal transplantation is a viable and a life-saving option for patients with intestinal failure, UPMC surgeons say.

They reported their results of 127 transplants — the most performed at any center — at the American Society of Transplantation meeting last month.

Children aged 2 to 18 had the best success, with a five-year survival rate of 68 percent, reported Kareem Abu-Elmagd, associate professor of surgery and director of intestinal transplantation at Pitt's Thomas E. Starzl Transplantation Institute.

In addition, 55, or 95 percent, of the 58 patients currently alive are off intravenous nutrition, are eating normal diets and have improved quality of life.

Surgeons reported that a number of factors have contributed to improved one-year survival, including: improved management of rejection with a three-drug cocktail of tacro-limus, steroids and daclizumab; refined donor and recipient selection criteria; and modification of the surgical procedure, including donor bone marrow augmentation.

These modifications have significantly improved survival for patients transplanted in the last four years, for whom there is a cumulative 65 percent survival rate.

In the last year, since adding the drug daclizumab to the anti-rejection drug regimen, surgeons have achieved a 92 percent one-year survival, Abu-Elmagd reported. The results are based on 14 patients.

Patients with intestinal failure must be sustained nutritionally with intravenous feedings called total parenteral nutrition (TPN). Liver failure often results after long-term use of TPN, hence the need for a life-saving combined liver and intestine transplant in some patients.

But as a preventive measure against the likelihood of liver failure and to improve the quality of life for patients who still have the option of TPN, a transplant of the small intestine is a more cost-effective alternative.

According to 1992 Medicare figures, TPN's annual price tag is $150,000, a figure that does not include associated costs for medical equipment, nursing- home health care and frequent hospitalizations. Today's costs are believed to be much higher.

"Based on these data, intestinal transplantation becomes cost-effective by the second year after transplantation," reported Abu-Elmagd.

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UPMC doctors implant metal cages into spine to treat chronic low back pain

Surgeons at UPMC Health System are implanting cylindrical metal cages into the spine to treat people disabled with chronic low back pain caused by degenerative disc disease.

The implants are hollow, threaded cylinders made of titanium alloy that are implanted in the disc space between two or more vertebrae.

Between each of the 24 vertebrae of the human spine is a vertebral disc, comprised of cartilage-like material that separates the vertebrae and allows flexibility of movement. Injury, aging or repeated stress can produce degenerative disc disease, which can lead to excessive motion in the spine, inflammation of the nerves in and around the spine, nerve dysfunction and severe debilitating pain.

"The discs act as spacers between the vertebrae," said William C. Welch, associate professor of surgery in the Department of Neurological Surgery.

During the minimally invasive surgery, portions of the disc and vertebral bones are removed to make room for the implants.

According to Welch, this type of surgery may offer several improvements over traditional techniques including less patient trauma, reduced operating time, shorter hospitalizations and reduced costs.

More than 5 million Americans are disabled due to chronic back pain.