Transplant surgeons at Johns Hopkins have evidence that hospitals performing at least 20 lung transplant procedures a year, on average, have the best overall patient survival rates and lowest number of deaths from the complex surgery.
Researchers say their latest findings, to be presented Jan. 27 at the 45th annual meeting of the Society of Thoracic Surgeons in San Francisco, could serve as a patient safety benchmark or national standard for all hospitals to meet. The study is believed to be the first overall assessment since the procedure was perfected and widely adopted in the 1990s of how each of the 79 U.S. and Canadian medical centers licensed to perform lung transplantation measure up.
Institutions performing 20 more lung transplants annually, the researchers say, see the chances of an organ recipient surviving the critical first month of recovery plateau, at over 95 percent. Chances of recipients surviving the first year post-surgery are practically the same, at 83 percent. The contrast is sharp for the three-quarters of hospitals performing significantly fewer lung transplants. Then, an organ recipient's chances of dying within the first month after surgery nearly doubles, dropping survival rates to 90 percent if the hospital performs two or less per year, and to 73 percent after one year.
This, researchers say, occurred despite lower-volume centers having less severely ill patients than higher-volume centers.
"Lung transplantation is an incredibly complex procedure, and our results show that the so-called '-center-effect-' is a very real phenomenon: Hospitals that do more, do them better," says study senior investigator and transplant surgeon Ashish Shah, M.D., who has performed over 100 lung transplants in the past decade "For best patient outcomes, you need the right staff operating at peak skill level, with patient support systems ingrained in both their clinical operations and their organization's culture."
More than 1,400 lung transplants occurred in the United States in 2007, the last full year for which statistics are available. Thirty-nine percent of patients have survived for at least a year; 6 percent died within a month of surgery. Another 2,000 Americans remain on lung waiting lists, while 90 more are waiting for both a heart and lung.
Shah, an associate professor at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute, says lung transplantation is unlike other kinds of transplant surgery. The lungs are at increased risk of infection during the procedure because the organ is exposed to the outside air and potential bacteria. Recuperation also takes longer than with other types of organ transplant, such as kidney, with patients often spending up to a week in post-surgical intensive care, plus many more months of specialized physical therapy.
The actual surgery, he points out, can cost $150,000 to $300,000 and involves a team of roughly 20 specially trained personnel, such as surgeons, an anesthesiologist, critical care specialists, many specially trained nurses, physical, respiratory and speech therapists, and dietitians.
As part of the latest analysis, researchers reviewed 10,494 patient records for all single-lung and double-lung transplants performed in the United States and Canada from 1998 to 2007. The data came from the United Network for Organ Sharing (UNOS), a national network that allocates donated organs across the country.
"Our findings do not mean that only high-volume centers should perform lung transplantation," says lead study investigator Eric Weiss, M.D., a postdoctoral research fellow in cardiac surgery at Hopkins
"But it does mean that patients should consider consistently high volumes when evaluating their choices of where to have their transplant done, and it does mean that lower-volume centers really do need to learn from the higher-volume hospitals, taking a careful look at what they are doing right to raise their survival rates and lower a recipient's chances of dying or suffering complications from surgery," says Weiss.
Weiss also performed a similar analysis of the center-volume effect in heart transplants, presented at the same meeting held last year.
"Our hope is that this evidence will be useful in establishing budgets and staffing objectives so that low-volume centers, too, can steadily improve their patient outcomes in lung transplantations," says Shah.
Roughly 20 institutions perform 20 or more lung transplants annually, on average. They include The Johns Hopkins Hospital, with 25 in 2006, 21 in 2007 and 15 in 2008. On average, one-year survival rates at The Johns Hopkins Hospital, Shah says, have risen consistently with volume increases, from 70 percent in the early 1990s to 95 percent in 2007.
Funding for the study was supplied in part by The Johns Hopkins Hospital.
In addition to Shah and Weiss, other Johns Hopkins researchers involved in this study were Robert Meguid, M.D.; Nishant Patel, B.A.; Christian Merlo, M.D., M.P.H.; Jonathan Orens, M.D.; William Baumgartner, M.D.; and John Conte, M.D.
(Presentation title: The center effect in lung transplantation, a volume outcome analysis of over 10,000 cases)
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Video clips of Shah and Weiss commenting about the study can be found online Jan. 27 at www.hopkinsmedicine.org.