SAN FRANCISCO – Trauma centers that nonselectively performed angiography on patients with high-grade blunt splenic injury did not significantly reduce the likelihood of delayed splenectomy in a retrospective analysis of data on 6,870 patients treated at 267 hospitals.
On an individual patient level, however, use of angiography was associated with a reduced risk of delayed splenectomy (more than 6 hours after admission) after researchers controlled for the influence of multiple other factors, Dr. Ben L. Zarzaur and his associates reported at the annual meeting of the American Association for the Surgery of Trauma.
These somewhat conflicting findings suggest that "nonselective protocol-driven use of angiography at the hospital in the setting of high-grade blunt splenic injury does not benefit in terms of splenic salvage. Angiography use should be tailored to the individual patient," said Dr. Zarzaur of the University of Tennessee, Memphis.
"Attention should be paid to overall injury severity and splenic injury severity" because more severe injuries were associated with delayed splenectomy in the study, he said, adding, "Particular attention should be considered for screening for splenic vascular abnormalities."
The investigators used data from the National Trauma Data Bank (NTDB) on adults treated for high-grade blunt splenic injury at Level I or II trauma centers that admitted at least 10 such patients in 2007-2010, with high-grade injury defined as Abbreviated Injury Scale grade 3 or higher. They stratified hospital angiography use as none, low (in less than 20% of patients with high-grade blunt splenic injury), or high (in 20% or more of these patients).
Approximately 30% of patients at high-angiography centers underwent urgent splenectomy, compared with 33%-36% at hospitals with no or low-angiography use, a difference that was statistically significant. While the likelihood of a delayed splenectomy was 33% higher at low-angiography hospitals and 49% higher at hospitals without angiography, compared with high-angiography hospitals, these differences were not significant, Dr. Zarzaur reported.
The investigators used the classification of hospitals – no-, low-, or high-angiography use – to represent the three schools of thought that have developed over the past few decades regarding angiography for patients with blunt splenic injury who do not undergo immediate urgent splenectomy. The minimalist school of thought recommends using observation, not angiography for blunt splenic injury. The maximalist school of thought favors protocol-driven use of angiography for patients with certain grades of spleen injury. In between, physicians who favor a selective strategy use CT or clinical criteria or both to try and identify patients at high risk for delayed splenectomy, and reserve the risks of angiography for those patients, he said.
They chose a cutoff of 20% angiography use in patients with high-grade blunt splenic injury to discriminate between low- and high-angiography use because that represented the 90th percentile for all trauma centers in the study.
Nine percent of patients were treated at hospitals that did not use angiography for blunt splenic injury, 66% at low-angiography hospitals, and 25% at high-angiography hospitals.
Patients with grade 5 blunt splenic injury were more than twice as likely to need delayed splenectomy, compared with patients with grade 3 or 4 injury. Higher overall Injury Severity Scores (10 or higher) also doubled the risk for delayed splenectomy.
Patients with grades 4 or 5 blunt splenic injury were significantly more likely to undergo angiography at high-angiography centers than at low-angiography centers. High-angiography centers were more likely than were low-angiography centers to remove spleens with grade 5 injury after angiography, though this difference did not reach statistical significance.
Continuing controversy around the use of angiography for blunt splenic injury is illustrated by a 2011 survey of members of the American Association for the Surgery of Trauma. Members favored observation, not angiography, for grades 1 and 2 spleen injuries but showed no consensus on higher-grade injuries (J. Trauma 2011;70:1026-31).
A recent study of 1,275 patients treated for blunt splenic injury at four trauma centers that showed a significantly better chance of saving the spleen at hospitals with higher use of splenic artery embolization, especially in patients with higher-grade splenic injury (J. Trauma Acute Care Surg. 2013;75:69-74).
The current study excluded patients who died on arrival at the hospital, patients who were admitted more than 24 hours after injury, and patients who underwent splenectomy within 6 hours of admission (early splenectomy).
Dr. Zarzaur reported having no financial disclosures.
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