Surgery News - May 2008 - (Page 16)

THORACIC SURGERY NEWS • M AY 2 0 0 8 Transapical Pericardial Valve Helps High-Risk Patients BY DAMIAN MCNAMARA Else vier Global Medical Ne ws F O R T L A U D E R D A L E , F L A . — Transcatheter insertion of a stented aortic valve through the left ventricular apex is possible for patients with critical valvular aortic stenosis, according to a multicenter study. Feasibility is based on a total of 36 procedures at three institutions. Valve recipients were high risk because they were aged older than 70 years, had significant comorbidities, and/or had a Society of Thoracic Surgeons Predicted Risk of Mortality score of 15% or more. “We have very few options for patients not able to undergo traditional valve replacement,” Dr. Lars G. Svensson said at the annual meeting of the Society of Thoracic Surgeons. Dr. Svensson and his associates conducted the FDA-approved study to assess feasibility of less invasive transcatheter delivery for such high-risk patients. Without surgery, 1-year survival is an estimated 30%. Also, 30%-60% of people with critical valvular aortic stenosis do not receive treatment, according to registry data in the United States and Europe. The study is a new arm of the PARTNER trial, an ongoing, randomized assessment of retrograde transfemoral arterial delivery of the same device, the Sapien THV Valve (Edwards Lifesciences). The device is a balloon expandable stainless steel stent with an internally mounted three-leaflet equine pericardial valve. FDA status is investigational. “This is pioneering work in a high-risk group of patients with a very challenging procedure,” said Dr. Thomas A. Vassiliades, a study discussant and surgeon in the division of cardiac surgery, Emory University, Atlanta. Surgeons begin with a check for calcium that might obstruct device insertion. Then the valve is crimped down and placed inside a loader before transcatheter insertion. The most common entry point in the study was via the sixth intercostal space. After placement, there is rapid pacing for balloon inflation. “Team cooperation is essential to success. A lot of cardiologists are also involved, and the procedure would not be as successful without them,” said Dr. Svensson, an ACS Fellow and thoracic surgeon at the Cleveland Clinic. Dr. Svensson serves on the executive committee board of Edwards Lifesciences but does not receive any financial compensation. Some study coauthors receive honoraria or research grants from the company. There was considerable hemodynamic and functional improvement, Dr. Svensson said. For example, a mean 1.6 cm2 orifice was achieved post operatively, an improvement over the baseline 0.62-cm2 mean valve area. Dr. Svensson showed a postangiogram from one case that confirmed the valve was not leaking. “Not all patients go this well,” he said. “There was one patient with a porcine aorta and the valve embolized. We tried to put a second valve in, and unfortunately, it happened again. We had to put the patient on a pump, and unfortunately the patient suffered a stroke.” Comorbidities were a “big factor” in patient outcomes, Dr. Svensson said. For example, 50% had prior coronary bypass surgery and approximately one-third had porcine aortas. There were four failed implants, for an overall implant success rate of 89%. Physicians converted these four failures to open procedures. There were six deaths within 30 days for a 16.7% mortality rate. One patient died from multiple organ failure and the other cause of death was the aforementioned stroke 5 days post operatively. Following balloon valvuloplasty (a), the new stent valve is There were four positioned across the native valve (b); the balloon mounted procedure-related stent valve is inflated to secure the new valve in position (c). deaths. Dr. Fred Crawford, an ACS Fellow who “We realize these are [very ill patients] and it is a complicated procedure, but we commented on the study, said that tranneed to know how many benefit by 6 scatheter insertion of an aortic valve months by having the device,” said Dr. prosthesis, either through the left venVassiliades, an ACS Fellow. He had no rel- tricular apex or the femoral artery, might evant financial disclosures, but his institu- have significant application in some hightion is participating in the transfemoral risk patients. Dr. Crawford, chair of the surgery dearm of the PARTNER study. At 6 months, survival was 59%, Dr. partment at the Medical University of South Carolina, Charleston, noted that Svensson replied. Dr. Vassiliades questioned a counterin- “standard aortic valve replacement has an tuitive finding that outcomes were better extremely long low operative mortality, among the first 20 patients in the series. even in elderly high risk patients, and the Dr. Svensson replied that it was necessary transcatheter technique must be comto relearn some aspects of the procedure pared to this gold standard.” “The high procedure mortality and following a 6-month downtime. “It was gratifying, at least in our hands, morbidity of the transapical approach that the incidence of stroke has been very make patient selection absolutely critilow. That is potentially an advantage with cal,” he added. “Nevertheless, with further this approach,” Dr. Svensson said. Al- device improvement, better patient selecthough the study demonstrates the feasi- tion, and improved operator experience, it bility of a left ventricular apex approach is likely that this procedure will be applicand a good functional outcome among able to an as yet not completely defined those who survive, “patient selection subset of patients with aortic stenosis who are truly not surgical candidates.” needs to be refined.” Pediatric Heart Donation Called Feasible After Cardiac Death course, only rarely possible. Supply is still woefully short of demand.” The protocol at the University of Colorado is based on F O R T L A U D E R D A L E , F L A . — Pediatric heart dona- the Maastricht criteria, a consensus developed in the tion is possible following cardiac death, according to three Netherlands. One controversial aspect is that an infant’s carotid pulse is checked at 60 seconds and successful cases presented at the annual meeting of the Society of Thoracic Surgeons. then rechecked at 75 seconds after cessation There is a well-known shortage of donor of cardiac function, Dr. Sade said. hearts, and a 20% mortality for infants on the “Initially our time was 3 minutes, which we wait list. Expansion of the donor pool to incut down to 75 seconds,” Dr. Kaza replied. clude children after cardiac death might help “Autoresuscitation or ‘the Lazarus effect’ is a to alleviate the shortage, Dr. Aditya K. Kaza concern generally only in people who have onsaid. going resuscitation attempts.” Intentional After experimental models demonstrated withdrawal of life support in the current casgood myocardial function in cardiac allografts es is an important distinction, he added. procured from non–heart-beating donors, re- An ethical concern An ethical concern would arise if the option searchers began testing feasibility in humans. to donate is discussed with parents before would arise if In fact, “non–heart-beating donors have been their decision to withdraw life support, said donation were used in Europe with good success for liver, Dr. Sade, professor of surgery at the Medical discussed before kidney, and lung transplantation,” Dr. Kaza University of South Carolina, Charleston. Dr. deciding to halt said. Kaza replied, “We separate the teams who life support. Parents have expressed interest in organ withdraw care and discuss donation after carDR. SADE donation despite their child’s not meeting diac death. We make sure this does not influbrain death criteria, said Dr. Kaza, a thoracic surgeon at ence the decisions of parents.” the University of Colorado and the Children’s Hospital, There is a need to educate parents about this approach Denver. to heart donation, Dr. Kaza said. Informed consent from “This report from the University of Colorado Chil- both the donor and recipient families is also important. dren’s Hospital breaks new ground,” study discussant Dr. Also, success requires a collaborative effort, particularly Robert M. Sade said. “The shortage of donated hearts with cardiologists. is still severe in all age groups. Live donation is, of Dr. Kaza presented three cases of neonates who were BY DAMIAN MCNAMARA Else vier Global Medical Ne ws doing well after receiving such a donated heart. His findings are supported by a grant from the Department of Health and Human Services. A follow-up echocardiogram at 3 years indicated good graft function in one child. This patient became a transplantation candidate because of severe cardiac dysfunction after an arterial switch operation. The second child, likewise, displayed good function 6 months after a transplantation was performed to correct hypoplastic left heart syndrome and severe polyvalvular dysplasia. The third patient in the series also had good echocardiographic findings 3 months after the operation, which was indicated because of dilated cardiomyopathy. “So far, in our experience, you can have good shortterm allograft function,” Dr. Kaza said. “This report of three such donations in patients under the age of 1 year is stunning,” Dr. Sade said. The nomenclature needs to be clarified, Dr. Kaza said. “After cardiac death” carries a negative connotation, and he prefers the term “procurement after cessation of circulation.” However, Dr. Sade said, “I would caution the authors in their own use of such a term. Use of the new term clearly would violate new organ recovery rules.” Dr. Sade asked how many infants’ lives would be saved if the protocol were to be adopted nationally. “In countries like the Netherlands, the ‘donation after cardiac death’ donors make up about half of the GI organs donated,” Dr. Kaza replied. “I can only estimate that it would double the number of hearts donated in this country.” CLEVELAND CLINIC/DR. LA

Table of Contents Feed for the Digital Edition of Surgery News - May 2008

Surgery News - May 2008 Contents New Lung Approach Speeds Extubation Innovative GI Procedures May Improve Diabetes Quality Programs Differ on Risk Data Crystal Ball Medical Modeling Ventricular Valve Taking Stock

Surgery News - May 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.