Renowned heart surgeon discusses transplant gains
Dr. William S. Pierce '58 |
Pierce graduated just four years after the world’s first open-heart surgery was performed in 1954. Since leaving Lehigh with a B.S. in chemical engineering, he has gained renown for his work with artificial hearts and mechanical devices at the Penn State Hershey Medical Center.
During reunion weekend last month at Lehigh, Pierce discussed the great strides in medical technology in the past five decades and the opportunities ahead for patients who need heart transplants.
At Alumni Reunion College, one of the events organized by the Lehigh University Alumni Association, Pierce gave a slide presentation titled “Heart Replacement: Current Status and Future Promise.” More than 60 classmates and guests attended the lecture in Linderman Library.
He began his talk by showing slides that chronicled the transplant of a natural human heart.
“It’s two o’clock in the morning right now,” Pierce told his audience. “Since brain death is usually declared at the end of a workday at 5 p.m., the donor heart retrieval and transport process ends up pushing the starting time of the heart transplant into the middle of the night. The heart cannot wait for the next day.”
Pierce used the slides to take his audience through the operation, starting with the transfer of the patient’s natural function to a heart-lung machine, then progressing to the cutoff of the in-flow area, to the sewing in of the new heart, and finally to the shock that is administered to stimulate the newly transplanted heart to begin beating.
The advanced technology of the procedure, Pierce said, is accompanied by intense medical ethics.
“Most donor hearts come as the result of an auto or industrial accident,” he said. “This is the difficult part as the person was well just a few days before. It’s a wonderful thing that families are willing to make the donation under those circumstances. At the other end, you have a recipient patient who may have been waiting for months in the hospital, hooked to a mechanical device.”
Pierce noted that the number of heart transplants worldwide peaked in 1997-98. Since then, surgeries have declined because of an increase in auto safety and stricter OSHA laws that have resulted in fewer accidental deaths and, as a result, fewer available donor hearts. Today, 2,200 transplants are being performed annually, while 4,500 patients wait for a donor. However, Pierce said he estimated the current need for transplants at 10,000 per year.
While many open-heart surgeries have become routine, Pierce described most of these operations as “spare-parts surgeries” that replace or repair only the damaged portion of the organ. The complete transplant, on the other hand, presents an entirely different set of risks and challenges, including infection, clotting and limited donor hearts. As a result, future transplants may rely on gene therapy and animal hearts, he said. While those options are being studied and developed, he said, full mechanical devices are valid alternatives.
Using a historic timeline, Pierce illustrated the medical advances that have followed the first open-heart surgery in 1954. Through the 1960s, risks remained significant that patients would die after the surgery because their hearts would not start beating again.
In the 1970s, Pierce and colleagues at Penn State Hershey Medical Center developed the Pierce-Donachy Ventricular Assist Device, or VAD, to aid circulation and to serve as a “bridge” to transplant. The device is clamped to a patient’s heart to help it beat until a complete transplant can take place.
“We developed it thinking its use would be about one week,” Pierce said. “But the longest a patient was bridged was 3.3 years.”
In 1982, Dr. William DeVries performed the first transplant of a pneumatic heart (the Jarvik7) into a patient at the University of Utah Medical Center. The device worked for 112 days.
In 1983, heart transplants started at Hershey under Pierce’s team; the facility has now completed more than 350 of the procedures.
More recently, Pierce said, the Arrow LionHeart LVAS (left ventricle assist system), product of a collaboration between the Penn State Hershey Medical Center and Arrow International Inc. of Reading, Pa., is showing progress. The fully implanted mechanical device is not a bridge, but rather a system for patients who are not eligible for a transplant. It has no lines or cables protruding through the skin, and it helps the heart’s left ventricle pump. The LVAS has been used in 30 patients in Europe and 10 in the United States.
Also, Penn State has teamed with Boston-based ABIOMED to create the AbioCor2 replacement heart, the first completely self-contained, totally artificial heart. The heart sustains the body’s circulation and is fully implantable. Infection risks are reduced as patients are not connected to external machinery and don’t experience tubes through the skin.
Pierce said the electro-hydraulic AbioCor2 has already sustained a patient for 519 days. In the future, he said the man-made device offers the best hope for patients with end-stage heart failure who cannot wait for a donor.
Pierce was one of four invited speakers at the Alumni Reunion College. The others were Samir Ghadiali, the Frank Hook Assistant Professor of Bioengineering in Lehigh’s department of mechanical engineering and mechanics; Richard M. Brandt, director of Lehigh’s Iacocca Institute; and Tom Markwell, associate vice president of Thomas P. Gohagan & Co., a Chicago-based international travel group.
Robert W. Wolfenden, director of alumni benefits and services for LUAA, spoke about the alumni association’s travel program.
-- Kate Santoro
Posted on:
Wednesday, June 11, 2008