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PC046. Intraluminal Thrombus Is Associated With Aortic Wall Weakening in Small Ruptured Abdominal Aortic Aneurysms
JOURNAL OF VASCULAR SURGERY June Supplement 2016
166S Abstracts
well as longer LOS and lower rate of discharge to home. Multivariable models showed that small AAAs had a decreased risk of LOS >2 days (OR, 0.8; 95% CI, 0.70.96; P ¼ .02) whereas large AAAs had an increased risk of LOS >2 days (OR, 1.7; 95% CI, 1.5-2.0; P < .001). Additionally, large AAAs were independently associated with higher rates of 30-day mortality (2.1% vs 1.1%; OR, 1.8; 95% CI, 1.0-3.2; P ¼ .046) and major morbidity (OR, 1.4; 95% CI, 1.1-1.7; P < .01). Conclusions: A large-diameter AAA predicts increased risk of morbidity and mortality. Additionally, more than one-third of elective EVAR are performed for small AAAs. While mortality rate remains very low after repair of small and medium aneurysms, there is no incremental perioperative mortality benefit from repair of small aneurysms. Author Disclosures: S. E. Deery: Nothing to disclose; D. W. Jones: Nothing to disclose; A. Meltzer: Nothing to disclose; M. L. Schermerhorn: AnGes, Cordis, and Endologix: consulting fees (eg, advisory boards); D. B. Schneider: Bard, Cook Medical, and W. L. Gore: contracted research, Boston Scientific, Medtronic, and W. L Gore: consulting fees (eg, advisory boards); K. E. Shean: Nothing to disclose; P. A. Soden: Nothing to disclose; S. L. Zettervall: Nothing to disclose. PC044. PC044 Validation of the Harborview Preoperative Ruptured Abdominal Aortic Aneurysm Risk Score With a Community Data Set Spencer K. Hansen, MD1, Patrick Danaher, PhD2, Harris W. Hollis, MD1, Omar Mubarak, MD3, Brandon T. Garland, MD3. 1Saint Joseph Hospital, Denver, Colo; 2 NanoString Technologies, Seattle, Wash; 3Vascular Institute of the Rockies, Denver, Colo Objectives: Currently available scoring systems for predicting mortality in patients with ruptured abdominal aortic aneurysms (rAAA) have typically included intraoperative variables. This limits their utility as preoperative predictors of mortality. Investigators at Harborview Medical Center in Seattle, Washington, have recently published a risk assessment tool using preoperative data that can facilitate decision making and patient counseling. The purpose of this study was to validate the Harborview score using an independent data set from a community hospital and compare it to the VSGNE scoring criteria. Methods: Data on consecutive patients presenting with rAAA between January 1, 2009, and December 31, 2015, were collected. Logistic regression analysis was used to evaluate the association between risk score and odds of death. Confidence intervals were calculated using the Wilson method. A comparison was made to other predictive models by calculating the area under the receiver operating characteristic (ROC) curves. Results: A total of 37 patients comprised the study population. Using the Harborview group scoring system, preoperative variables used to predict 30 day mortality after repair of a rAAA included age >76 years, creatinine >2.0, pH <7.2, and SBP ever <70 mm Hg. Assigning 1 point for each variable, patients were stratified according to the preoperative rAAA mortality risk score (range, 0-4). For all repairs, patients with 0 points suffered 10% mortality, 1 point
33% mortality, and 2 points 33% mortality. No patients with 3 or 4 points survived. In this retrospective study, each unit increase in score is associated with a 3.07-fold (95% CI, 1.24-7.58; P ¼ .015) increase in the odds of death at 30 days. The VSGNE score also statistically significantly predicted patient outcome and had a correlation with the Harborview group score of 0.81. Conclusions: Data from our rAAA database accurately validated predicted mortality using the VSGNE scoring system, but this accuracy relied on intraoperative variables. The Harborview rAAA mortality risk score accurately predicted mortality preoperatively. Accurate preoperative prediction of mortality provides the surgeon with an additional tool that may be advantageous when counselling patients and their families for emergency repair of rAAA in the EVAR first era. Author Disclosures: P. Danaher: Nothing to disclose; B. T. Garland: Nothing to disclose; S. K. Hansen: Nothing to disclose; H. W. Hollis: Nothing to disclose; O. Mubarak: Nothing to disclose. PC046 PC046. Intraluminal Thrombus Is Associated With Aortic Wall Weakening in Small Ruptured Abdominal Aortic Aneurysms Stephen J. Haller, BS, Jeffrey D. Crawford, MD, Gregory Landry, MD, Cherrie Z. Abraham, MD, Gregory L. Moneta, MD, Amir Azarbal, MD, Sandra Rugonyi, PhD, MS. Oregon Health & Science University, Portland, Ore Objectives: The implications of intraluminal thrombus (ILT) in abdominal aortic aneurysm (AAA) are unclear. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing peak wall stress (PWS), while other studies have associated ILT with aortic wall weakening. In this study, we sought to explore the association between the amount of ILT and risk of AAA rupture in small high-risk aneurysms. Methods: Patients treated at our institution from 2001 to 2014 for ruptured AAA (rAAA) were retrospectively identified. Patients with small rAAA (<60 mm) with high-resolution computed tomography angiography (CTA) available for study were included. These patients were considered high-risk aneurysms given that they ruptured at relatively small AAA diameters. For comparison, a low-risk cohort of patients with large non-rAAA ($60 mm) with high-resolution preoperative CTA were subsequently identified from the same time period. Nine small rAAAs were identified and compared with 15 sequentially collected large non-rAAAs. The three-dimensional AAA anatomy was digitally reconstructed for each patient, and ILT percent volume was computed (ILT percent volume h (volume ILT/[volume ILT + volume lumen]) 100). Finite element analysis (FEA) was then performed to calculate AAA wall stress distributions for each patient with an assumed systolic blood pressure of 120 mm Hg. Results: Three dimensional AAA reconstruction and FEA was successfully preformed for all patients selected (see Table for patient demographics and results summary). Patients with small rAAA had greater ILT percent volume compared to patients with large non-rAAA (68.8% 6 11.6% vs 56.7% 6 11.6%; P ¼ .022; Fig, A). Patients
JOURNAL OF VASCULAR SURGERY Volume 63, Number 6S
Abstracts 167S
Table. Patient demographics and results summary
AAA diameter, mm Age, years Male Hypertension Smoker ILT Volume, mL Volume, % Thickness, mm MWS, kPa PWS, kPa
Large non-rAAA (n ¼ 15), No. (%) or mean 6 SD
Small rAAA (n ¼ 9), No. (%) or mean 6 SD
68.1 6 11.9 70.8 6 9.7 13 (86.7) 9 (60.0) 15 (100.0)
52.1 6 7.6 67.9 6 5.7 6 (66.7) 8 (88.9) 9 (100.0)
161 56.7 8.1 72 237
6 6 6 6 6
79 11.6 2.3 19 96
92 68.8 8.4 47 119
6 6 6 6 6
32 11.6 2.3 17 40
P .002 NS NS NS NS .007 .022 NS .003 <.001
AAA, Abdominal aortic aneurysm; ILT, intraluminal thrombus; NS, not significant; rAAA, ruptured abdominal aortic aneurysm; MWS, mean wall stress; PWS, peak wall stress; SD, standard deviation.
with small rAAA had lower mean wall stress (MWS; 47 6 17 kPa vs 72 6 19 kPa; P ¼ .003) and PWS (119 6 40 kPa vs 237 6 96 kPa; P < .001) compared to patients with large non-rAAA (Fig, B). Increased ILT percent volume was associated with both decreased MWS and decreased PWS (Fig, C and D). Conclusions: Although increased ILT percent volume is associated with lower MWS and PWS, it is also associated with AAA rupture at smaller diameters. Therefore, the protective biomechanical advantage of ILT in lowering PWS seems to be outweighed by weakening of the AAA walld particularly in patients with small rAAA. While further studies are needed to determine the mechanism of AAA wall weakening in the presence of increase ILT, this study suggests a stronger correlation between aortic wall weakening and relative ILT volume than previously reported. Author Disclosures: C. Z. Abraham: Nothing to disclose; A. Azarbal: Nothing to disclose; J. D. Crawford: Nothing to disclose; S. J. Haller: Nothing to disclose; G. Landry: Nothing to disclose; G. L. Moneta: Nothing to disclose; S. Rugonyi: Nothing to disclose. PC048 PC048. Contemporary Management of Isolated Chronic Infrarenal Abdominal Aortic Dissections Christopher M. Faries, BA1, Rami O. Tadros, MD2, Paul S. Lajos, MD3, Ageliki Vouyouka, MD3, Peter L. Faries, MD2, Michael L. Marin, MD2. 1Mount Sinai Health System, Rye, NY; 2Icahn School of Medicine at Mount Sinai, New York, NY; 3Mount Sinai Health System, New York, NY
Fig. A, Intraluminal thrombus (ILT) percent volume for large non-ruptured abdominal aortic aneurysm (rAAA) and small rAAA groups (mean 6 standard deviation). B, Mean wall stress (MWS) and peak wall stress (PWS) for large non-rAAA and small rAAA groups (mean 6 standard deviation). C, MWS vs ILT percent volume. D, PWS vs ILT percent volume.
Objectives: This study reports the presentation, treatment, and follow-up of isolated infrarenal aortic dissections. Methods: A review of 37 patients with isolated infrarenal aortic dissections was performed. Computed tomography scans with intravenous contrast were examined for all patients, and catheter-based angiograms, magnetic resonance angiograms, and duplex ultrasound were used selectively. In dissections associated with the development of abdominal aortic aneurysm, the aneurysm growth rate was determined by measuring the change in maximum
166S Abstracts
well as longer LOS and lower rate of discharge to home. Multivariable models showed that small AAAs had a decreased risk of LOS >2 days (OR, 0.8; 95% CI, 0.70.96; P ¼ .02) whereas large AAAs had an increased risk of LOS >2 days (OR, 1.7; 95% CI, 1.5-2.0; P < .001). Additionally, large AAAs were independently associated with higher rates of 30-day mortality (2.1% vs 1.1%; OR, 1.8; 95% CI, 1.0-3.2; P ¼ .046) and major morbidity (OR, 1.4; 95% CI, 1.1-1.7; P < .01). Conclusions: A large-diameter AAA predicts increased risk of morbidity and mortality. Additionally, more than one-third of elective EVAR are performed for small AAAs. While mortality rate remains very low after repair of small and medium aneurysms, there is no incremental perioperative mortality benefit from repair of small aneurysms. Author Disclosures: S. E. Deery: Nothing to disclose; D. W. Jones: Nothing to disclose; A. Meltzer: Nothing to disclose; M. L. Schermerhorn: AnGes, Cordis, and Endologix: consulting fees (eg, advisory boards); D. B. Schneider: Bard, Cook Medical, and W. L. Gore: contracted research, Boston Scientific, Medtronic, and W. L Gore: consulting fees (eg, advisory boards); K. E. Shean: Nothing to disclose; P. A. Soden: Nothing to disclose; S. L. Zettervall: Nothing to disclose. PC044. PC044 Validation of the Harborview Preoperative Ruptured Abdominal Aortic Aneurysm Risk Score With a Community Data Set Spencer K. Hansen, MD1, Patrick Danaher, PhD2, Harris W. Hollis, MD1, Omar Mubarak, MD3, Brandon T. Garland, MD3. 1Saint Joseph Hospital, Denver, Colo; 2 NanoString Technologies, Seattle, Wash; 3Vascular Institute of the Rockies, Denver, Colo Objectives: Currently available scoring systems for predicting mortality in patients with ruptured abdominal aortic aneurysms (rAAA) have typically included intraoperative variables. This limits their utility as preoperative predictors of mortality. Investigators at Harborview Medical Center in Seattle, Washington, have recently published a risk assessment tool using preoperative data that can facilitate decision making and patient counseling. The purpose of this study was to validate the Harborview score using an independent data set from a community hospital and compare it to the VSGNE scoring criteria. Methods: Data on consecutive patients presenting with rAAA between January 1, 2009, and December 31, 2015, were collected. Logistic regression analysis was used to evaluate the association between risk score and odds of death. Confidence intervals were calculated using the Wilson method. A comparison was made to other predictive models by calculating the area under the receiver operating characteristic (ROC) curves. Results: A total of 37 patients comprised the study population. Using the Harborview group scoring system, preoperative variables used to predict 30 day mortality after repair of a rAAA included age >76 years, creatinine >2.0, pH <7.2, and SBP ever <70 mm Hg. Assigning 1 point for each variable, patients were stratified according to the preoperative rAAA mortality risk score (range, 0-4). For all repairs, patients with 0 points suffered 10% mortality, 1 point
33% mortality, and 2 points 33% mortality. No patients with 3 or 4 points survived. In this retrospective study, each unit increase in score is associated with a 3.07-fold (95% CI, 1.24-7.58; P ¼ .015) increase in the odds of death at 30 days. The VSGNE score also statistically significantly predicted patient outcome and had a correlation with the Harborview group score of 0.81. Conclusions: Data from our rAAA database accurately validated predicted mortality using the VSGNE scoring system, but this accuracy relied on intraoperative variables. The Harborview rAAA mortality risk score accurately predicted mortality preoperatively. Accurate preoperative prediction of mortality provides the surgeon with an additional tool that may be advantageous when counselling patients and their families for emergency repair of rAAA in the EVAR first era. Author Disclosures: P. Danaher: Nothing to disclose; B. T. Garland: Nothing to disclose; S. K. Hansen: Nothing to disclose; H. W. Hollis: Nothing to disclose; O. Mubarak: Nothing to disclose. PC046 PC046. Intraluminal Thrombus Is Associated With Aortic Wall Weakening in Small Ruptured Abdominal Aortic Aneurysms Stephen J. Haller, BS, Jeffrey D. Crawford, MD, Gregory Landry, MD, Cherrie Z. Abraham, MD, Gregory L. Moneta, MD, Amir Azarbal, MD, Sandra Rugonyi, PhD, MS. Oregon Health & Science University, Portland, Ore Objectives: The implications of intraluminal thrombus (ILT) in abdominal aortic aneurysm (AAA) are unclear. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing peak wall stress (PWS), while other studies have associated ILT with aortic wall weakening. In this study, we sought to explore the association between the amount of ILT and risk of AAA rupture in small high-risk aneurysms. Methods: Patients treated at our institution from 2001 to 2014 for ruptured AAA (rAAA) were retrospectively identified. Patients with small rAAA (<60 mm) with high-resolution computed tomography angiography (CTA) available for study were included. These patients were considered high-risk aneurysms given that they ruptured at relatively small AAA diameters. For comparison, a low-risk cohort of patients with large non-rAAA ($60 mm) with high-resolution preoperative CTA were subsequently identified from the same time period. Nine small rAAAs were identified and compared with 15 sequentially collected large non-rAAAs. The three-dimensional AAA anatomy was digitally reconstructed for each patient, and ILT percent volume was computed (ILT percent volume h (volume ILT/[volume ILT + volume lumen]) 100). Finite element analysis (FEA) was then performed to calculate AAA wall stress distributions for each patient with an assumed systolic blood pressure of 120 mm Hg. Results: Three dimensional AAA reconstruction and FEA was successfully preformed for all patients selected (see Table for patient demographics and results summary). Patients with small rAAA had greater ILT percent volume compared to patients with large non-rAAA (68.8% 6 11.6% vs 56.7% 6 11.6%; P ¼ .022; Fig, A). Patients
JOURNAL OF VASCULAR SURGERY Volume 63, Number 6S
Abstracts 167S
Table. Patient demographics and results summary
AAA diameter, mm Age, years Male Hypertension Smoker ILT Volume, mL Volume, % Thickness, mm MWS, kPa PWS, kPa
Large non-rAAA (n ¼ 15), No. (%) or mean 6 SD
Small rAAA (n ¼ 9), No. (%) or mean 6 SD
68.1 6 11.9 70.8 6 9.7 13 (86.7) 9 (60.0) 15 (100.0)
52.1 6 7.6 67.9 6 5.7 6 (66.7) 8 (88.9) 9 (100.0)
161 56.7 8.1 72 237
6 6 6 6 6
79 11.6 2.3 19 96
92 68.8 8.4 47 119
6 6 6 6 6
32 11.6 2.3 17 40
P .002 NS NS NS NS .007 .022 NS .003 <.001
AAA, Abdominal aortic aneurysm; ILT, intraluminal thrombus; NS, not significant; rAAA, ruptured abdominal aortic aneurysm; MWS, mean wall stress; PWS, peak wall stress; SD, standard deviation.
with small rAAA had lower mean wall stress (MWS; 47 6 17 kPa vs 72 6 19 kPa; P ¼ .003) and PWS (119 6 40 kPa vs 237 6 96 kPa; P < .001) compared to patients with large non-rAAA (Fig, B). Increased ILT percent volume was associated with both decreased MWS and decreased PWS (Fig, C and D). Conclusions: Although increased ILT percent volume is associated with lower MWS and PWS, it is also associated with AAA rupture at smaller diameters. Therefore, the protective biomechanical advantage of ILT in lowering PWS seems to be outweighed by weakening of the AAA walld particularly in patients with small rAAA. While further studies are needed to determine the mechanism of AAA wall weakening in the presence of increase ILT, this study suggests a stronger correlation between aortic wall weakening and relative ILT volume than previously reported. Author Disclosures: C. Z. Abraham: Nothing to disclose; A. Azarbal: Nothing to disclose; J. D. Crawford: Nothing to disclose; S. J. Haller: Nothing to disclose; G. Landry: Nothing to disclose; G. L. Moneta: Nothing to disclose; S. Rugonyi: Nothing to disclose. PC048 PC048. Contemporary Management of Isolated Chronic Infrarenal Abdominal Aortic Dissections Christopher M. Faries, BA1, Rami O. Tadros, MD2, Paul S. Lajos, MD3, Ageliki Vouyouka, MD3, Peter L. Faries, MD2, Michael L. Marin, MD2. 1Mount Sinai Health System, Rye, NY; 2Icahn School of Medicine at Mount Sinai, New York, NY; 3Mount Sinai Health System, New York, NY
Fig. A, Intraluminal thrombus (ILT) percent volume for large non-ruptured abdominal aortic aneurysm (rAAA) and small rAAA groups (mean 6 standard deviation). B, Mean wall stress (MWS) and peak wall stress (PWS) for large non-rAAA and small rAAA groups (mean 6 standard deviation). C, MWS vs ILT percent volume. D, PWS vs ILT percent volume.
Objectives: This study reports the presentation, treatment, and follow-up of isolated infrarenal aortic dissections. Methods: A review of 37 patients with isolated infrarenal aortic dissections was performed. Computed tomography scans with intravenous contrast were examined for all patients, and catheter-based angiograms, magnetic resonance angiograms, and duplex ultrasound were used selectively. In dissections associated with the development of abdominal aortic aneurysm, the aneurysm growth rate was determined by measuring the change in maximum