Blunt abdominal aortic injury.

BACKGROUND: Blunt abdominal aortic injury (BAAI) is a rare injury with less than 200 cases in the current reported world literature, mostly in case report format. We sought to describe the experience of a high-volume trauma center and to provide a contemporary review of the literature to better understand the natural history and management of this injury. METHODS: This was a retrospective review of patients with BAAI between 1996 and 2010. Data collected included demographics, mechanism of injury, associated injuries, type of intervention, subsequent imaging, and follow-up. BAAI was classified by the presence of external aortic contour abnormality noted as an intimal tear, large intimal flap, pseudoaneurysm, or free rupture. Abdominal aorta zones of injury were classified by possible surgical approaches as zone I (diaphragmatic hiatus to superior mesenteric artery [SMA]), zone II (includes SMA and renal arteries), and zone III (from the inferior aspect of the renal arteries to the aortic bifurcation). RESULTS: We identified 28 individuals (68% male) with BAAI (median age, 28.5; range, 6-61 years). The median injury severity score was 45 (range, 16-75), and 39% were hypotensive at presentation. BAAI presented as intimal tear (21%), large intimal flap (39%), pseudoaneurysm (11%), and free rupture (29%). Zone III was the most common location of injury. Management depended on the location and type of injury: nonoperative (32%), open aortic repair (36%), endovascular repair (21%), and multimodality (10%). Overall mortality was 32%. Most deaths occurred during the initial operative exploration. The mortality rate of free aortic rupture was 100%. Intimal tears resolved or remained stable. Median follow-up was 15.5 months (range, 8 days-7.5 years). Vascular complications due to repair included a thrombosed access femoral artery during an endovascular repair and death of a patient who underwent a hybrid repair. CONCLUSIONS: This is the largest BAAI series described in the English literature at one institution. BAAIs range from intimal tears to free rupture, with outcomes and management correlating with type and location of injury. Nonoperative management with blood pressure control using ß-blockers coupled with antiplatelet therapy and close follow-up is successful in individuals with intimal tears with minimal thrombus formation because they remain stable or resolve on follow-up. Free rupture remains a devastating injury, with 100% mortality. For all other categories of aortic injury, successful repair correlates with a favorable prognosis.

A new classification scheme for treating blunt aortic injury.

BACKGROUND: There are numerous questions about the treatment of blunt aortic injury (BAI), including the management of small intimal tears, what injury characteristics are predictive of death from rupture, and which patients actually need intervention. We used our experience in treating BAI during the past decade to create a classification scheme based on radiographic and clinical data and to provide clear treatment guidelines. METHODS: The records of patients admitted with BAI from 1999 to 2008 were retrospectively reviewed. Patients with a radiographically or operatively confirmed diagnosis (echocardiogram, computed tomography, or angiography) of BAI were included. We created a classification system based on the presence or absence of an aortic external contour abnormality, defined as an alteration in the symmetric, round shape of the aorta: (1) intimal tear (IT)-absence of aortic external contour abnormality and intimal defect and/or thrombus of <10 mm in length or width; (2) large intimal flap (LIF)-absence of aortic external contour abnormality and intimal defect and/or thrombus of ≥10 mm in length or width; (3) pseudoaneurysm-presence of aortic external contour abnormality and contained rupture; (4) rupture-presence of aortic external contour abnormality and free contrast extravasation or hemothorax at thoracotomy. RESULTS: We identified 140 patients with BAI. Most injuries were pseudoaneurysm (71%) at the isthmus (70%), 16.4% had an IT, 5.7% had a LIF, and 6.4% had a rupture. Survival rates by classification were IT, 87%; LIF, 100%; pseudoaneurysm, 76%; and rupture, 11% (one patient). Of the ITs, LIFs, and pseudoaneurysms treated nonoperatively, none worsened, and 65% completely healed. No patient with an IT or LIF died. Most patients with ruptures lost vital signs before presentation or in the emergency department and did not survive. Hypotension before or at hospital presentation and size of the periaortic hematoma at the level of the aortic arch predicted likelihood of death from BAI. CONCLUSIONS: As a result of this new classification scheme, no patient without an external aortic contour abnormality died of their BAI. ITs can be managed nonoperatively. BAI patients with rupture will die, and resources could be prioritized elsewhere. Those with LIFs do well, and currently, most at our institution are treated with a stent graft. If a pseudoaneurysm is going to rupture, it does so early. Hematoma at the arch on computed tomography scan and hypotension before or at arrival help to predict which pseudoaneurysms need urgent repair.

Influence of comorbidities and age on outcome following burn injury in older adults.

Despite advances in medical and surgical techniques, older adults tend to be at high risk for adverse outcomes following burn injury. The purpose of this study was to examine the relative impacts of age and medical comorbidities on outcome following injury in a cohort of older adults. This was a retrospective study of all patients age 55 and over admitted to the University of Washington Burn Center from 1999 to 2003. To examine the effect of baseline medical comorbidities on outcome, a Charlson Comorbidity Index score was calculated for each patient. Multivariate regression analyses were used to examine the impact of age and comorbidities on mortality and other complications. Patient records were also matched with the National Death Index to determine the effects of age and comorbidities on mortality within 1 year following hospital discharge. A total of 325 patients who were of 55 years and older were admitted to the burn center during the 5-year study period. The overall mortality rate was 18.5%. Mortality was independently associated with age, inhalation injury, and burn size. One-year mortality was significantly associated with those older than age 75 and the Charlson score. Longer length of stay was significantly associated with burn size, inhalation injury, and total number of in-hospital complications. This study demonstrates that patient age-independent of baseline medical comorbidities-and TBSA burn are the most significant factors impacting in-hospital mortality risk following burn injury. Higher number of medical comorbidities was associated with increased mortality risk within 1 year following discharge.

Analysis of a marsupial MHC region containing two recently duplicated class I loci.

A 37-kb cosmid containing two complete major histocompatibility complex (MHC) class I alpha chain loci from the opossum Monodelphis domestica was isolated, fully sequenced, and characterized. This sequence represents the largest contiguous genomic sequence reported for the MHC region of a nonplacental mammal. Based on particular conserved amino acid residues, and limited expression analyses, the two MHC-I loci, designated ModoUB and ModoUC, appear to encode functional MHC-I molecules. The two coding regions are 98% identical at the nucleotide level; however, their promoter regions differ significantly. Two CpG islands present in the cosmid sequence correspond to the two coding regions. Twelve microsatellites and six retroelements were also present in the cosmid. The retroelements share highest sequence homology to the CORE-SINE family of retroelements. Due to high sequence identity, it is very likely that ModoUB and ModoUC loci are products of recent gene duplication that occurred less than 4 million years ago.