Surgery News - January 2008 - (Page 16) VASCULAR SURGERY NEWS • J A N U A RY 2 0 0 8 Higher Use of EVAR Corresponds to Lower Mortality B Y M I C H E L E G. S U L L I VA N Else vier Global Medical Ne ws N E W O R L E A N S — Surgeons are increasingly turning to endovascular repair of ruptured abdominal aortic aneurysms, with better short-term patient outcomes than have been seen in open repair, according to a database review presented at the annual clinical congress of the American College of Surgeons. “We found a consistent change in the national trends of surgical repair of AAA, with endovascular repair increasing steadily since 2001,” Dr. Kelly Lesperance said. “Endovascular repair was associated with lower mortality, improved discharge disposition, and shorter hospital length of stay.” The biggest mortality benefit occurred when endovascular repair (EVAR) was performed at a teaching hospital, said Dr. Lesperance, a captain in the U.S. Army. “We found that benefit was lost when the repair was done at a nonteaching hospital.” Dr. Lesperance presented a retrospective study conducted by Dr. Matthew Martin, a colleague and ACS Fellow in the surgery department at Madigan Army Medical Center, Tacoma, Wash. Dr. Martin is currently serving as chief of trauma with the 28th Combat Support Hospital in Baghdad, Iraq. The investigators used data from the Nationwide Inpatient Sample for their study. They identified 19,500 patients who underwent a surgical abdominal aortic aneurysm (AAA) repair from 2001 through 2004. Of those, 18,000 procedures were open, and 1,500 were endovascular. The number of endovascular repairs rose steadily over the study period, from 6% in 2001 to 11% in 2004. Mortality for all ruptured AAAs remained constant, however, hovering at about 50% over the years. Overall, in-hospital mortality rates continued to improve with EVAR. In 2001, open-repair mortality was actually slightly better than EVAR mortality (40% vs. 43%), but by 2002, EVAR mortality was significantly better, and its benefit rose annually. (See chart.) The investigators found that more EVAR patients than open repair patients were discharged home in each of the study years. In 2001, the difference was small (33% EVAR vs. 27% open), but it increased significantly by 2002 (43% vs. 24%) and remained steady during the study period. Conversely, more open repair patients were discharged to a skilled nursing or rehabilitation facility. In 2001, the percentage of patients discharged to such a facility was equal between the two techniques (33%), but by 2002, the difference was significant (23% EVAR vs. 43% open repair), and those numbers remained steady. Patients In-Hospital Mortality From Ruptured who were not disAbdominal Aortic Aneurysm Repair charged home or to a Endovascular repair Open repair skilled nursing/rehabil(n = 1,500) (n = 18,000) itation facility were transferred to other facilities, including anoth45% er hospital, a ventilator 43% 43% 41% rehabilitation center, or another inpatient set40% 35% ting. The investigators also 31% 29% performed a subanalysis of the 2003-2004 data, during which time 10,000 ruptured AAAs 2001 2002 2003 2004 were repaired—1,000 Note: Based on data from the Nationwide Inpatient Sample. with EVAR and 9,000 Source: Dr. Martin with open surgery. There was no difference in average patient age between the two (69% vs. 37%). During this period, there groups (73 years). However, patients un- was a cost benefit, with total hospital dergoing open repair had more comorbid charges for EVAR averaging $97,000, illness and greater disease severity. “We compared with $110,000 for open repair. Interestingly, Dr. Lesperance said, there saw that the healthier patients were undergoing EVAR and the sicker ones tend- was a significant survival benefit when ed to have open repair,” Dr. Lesperance EVAR was performed at a teaching hospital: 21% EVAR mortality versus 38% said. The 2003-2004 data also showed that open repair mortality. But mortality rates EVAR was associated with shorter length for procedures performed at a nonteachof stay than open surgery (mean 9 vs. 13 ing hospital were 55% for EVAR versus days) and more patients discharged home 46% for open repair. ■ Endovascular Thoracic Aortic Repair: Promising but Risky B Y J E F F E VA N S Else vier Global Medical Ne ws graft repair of traumatic thoracic aortic Endovascular stentresult in siginjuries appears to nificantly lower in-hospital mortality and fewer blood transfusions than open repair, but still has considerable risk for serious device-related complications, according to findings from the largest comparison of the procedures to date. The multicenter, prospective study also found that surgeons tend to use endovascular devices more liberally among patients with traumatic injuries despite the lack of data on the long-term incidence of device-related complications and the durability of endovascular thoracic aortic repairs. “Although endovascular stent/ graft placement was initially used in high-risk multitrauma or elderly patients, in many centers it has now become the initial procedure of choice, even in young or low-risk patients. The reported experience with this procedure is very limited, and almost all published series include small numbers of retrospectively collected cases,” according to Dr. Demetrios Demetriades, an ACS Fellow at the University of Southern California, Los Angeles, and his colleagues. Dr. Demetriades presented the results of their 18-center, 26month study at the annual meeting of the American Association for the Surgery of Trauma. Patients who underwent endovascular repair were more than 8 times less likely to die in the hospital than open-repair patients. Endovascular repair was performed on a total of 125 patients and open repair on 68. Nine of the endovascular patients (7%) died, compared with 16 of the open patients (24%). This comparison was adjusted for age older than 55 years, Glasgow Coma Scale score of 8 or less, hypotension on admission, and the presence of critical extrathoracic injuries. The mean difference in the number of transfused blood units between the groups (5 units) reached statistical significance after adjustment for the same variables. Dr. Kenneth L. Mattox, an ACS Fellow and a discussant at the meeting, said that it is a “major concern” that a “significant number of the diagnoses [made by CT scan alone] were for trivial or minor injuries in the aorta. One of the major questions then is, ‘Are we inserting this very expensive graft in people who in former years with arteriogram would have had no surgery whatsoever?’ That question remains and is a significant one that has to be answered by further study.” Follow-up was conducted until death or discharge from the hospital, which occurred at a mean of 27 days after open repair and 21 days after endovascular repair. The surgeons used 92 TAG (Gore), 19 Zenith (Cook Medical), 4 Talent (Medtronic), and 2 Vanguard (Boston Scientific) stent graft devices. Dr. Demetriades, who reported no conflicts of interest with any of the manufacturers, and his coinvestigators found that stent grafts were placed in about 65% of all patients, including 60% of patients without major extrathoracic injuries and 57% of patients aged 55 years or younger who had no major extrathoracic injuries. Similar rates of systemic complications (pneumonia, acute respiratory distress syndrome, septicemia, urinary tract infection, deep-vein thrombosis, renal failure, and graft sepsis) and procedure-related paraplegia occurred in the two groups. But 25 patients who underwent endovascular repair developed 32 device-related complications, which included 18 endoleaks, 4 access vessel injuries, 4 occlusions of the left subclavian artery, 2 strokes, 1 paraplegia, 1 occlusion of the left common carotid artery, 1 partial collapse of the stent graft, and 1 vascular access site infection. The high incidence of injuries at the site of insertion of the stent graft, possibly caused by the use of too large an introducer or stent, also needs to be addressed, Dr. Mattox, chief of staff and surgery at Ben Taub General Hospital, Houston, said in an interview. Excessive oversizing of the stent graft relative to the diameter of the aorta probably caused the one case of stent infolding, which led to paraplegia and thrombosis of the aorta, said Dr. Mattox. “It is happening more often than is reported around the country; I am aware of a number of cases,” he said. “If we’re going to be using endografts, we have to have technology that matches the size of the aorta.” There were no significant changes to the results of those analyses when Dr. Demetriades and his colleagues stratified the groups according to the presence of critical extrathoracic injuries (those with an Abbreviated Injury Scale score greater than 3 for the head, abdomen, or extremities). Mortality in the stent-graft group did not differ between highvolume (15 or more procedures) and low-volume centers, but patients at high-volume centers had a significantly shorter mean length of hospital stays. And patients whose endovascular procedures were performed at highvolume centers had significantly fewer systemic and local compli- cations and shorter hospital stays than did those treated at low-volume centers. Because of these differences, the researchers advised performing these procedures in selected centers of excellence that monitor their results through the quality improvement process. “The lack of long-term results with endovascular stent grafts, especially in young patients, is of major concern and it might be prudent to be cautious with the liberal use of this endovascular technique until we learn more about the long-term behavior of these devices,” they cautioned. Patients with these injuries who are converted from a stent-graft approach to an open repair will come to define the group of patients who require open surgery rather than an endovascular procedure, Dr. Mattox said. This future cohort of open repair
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