MASSIVE HEMORRHAGE (GENERAL)

Transport Time and Preoperating Room Hemostatic Interventions Are Important: Improving Outcomes After Severe Truncal Injury.

Holcomb JB

Crit Care Med. 2018 Mar;46(3):447-453

OBJECTIVES: Experience in the ongoing wars in Iraq and Afghanistan confirm that faster transport combined with effective prehospital interventions improves the outcomes of patients suffering hemorrhagic shock. Outcomes of patients with hemorrhagic shock and extremity bleeding have improved with widespread use of tourniquets and early balanced transfusion therapy. Conversely, civilian patients suffering truncal bleeding and shock have the same mortality (46%) over the last 20 years. To understand how to decrease this substantial mortality, one must first critically evaluate all phases of care from point of injury to definitive hemorrhage control in the operating room.

DATA SOURCES: Limited literature review.

DATA SYNTHESIS: The peak time to death after severe truncal injury is within 30 minutes of injury. However, when adding prehospital transport time, time spent in the emergency department, followed by the time in the operating room, it currently takes 2.1 hours to achieve definitive truncal hemorrhage control. This disparity in uncontrolled truncal bleeding and time to hemorrhage control needs to be reconciled. Prehospital and emergency department whole blood transfusion and temporary truncal hemorrhage control are now possible.

CONCLUSIONS: The importance of rapid transport, early truncal hemorrhage control and whole blood transfusion is now widely recognized. Prehospital temporary truncal hemorrhage control and whole blood transfusion should offer the best possibility of improving patient outcomes after severe truncal injury.

TOURNIQUETS / EXTREMITY BLEEDING

Application of tourniquet in civilian trauma: Systematic review of the literature.

Beaucreux C, Vivien B, Miles E, Ausset S, Pasquier P

Anaesth Crit Care Pain Med. 2018 Jan 5. pii: S2352-5568(17)30265-5. doi: 10.1016/j.accpm.2017.11.017.

 

INTRODUCTION: The effectiveness of a tourniquet (TQ) in case of extremity haemorrhages is well recognised to prevent deaths on the battlefield. However, little is known about the usefulness of TQ in civilian trauma settings, including terrorist attack situations. The aim of this systematic review was to analyse the evidence-based medical literature in order to precise the use of TQ in the management of extremity haemorrhages in civilian setting.

METHODS: Analysis of all studies published until 12/31/2016 on the Embase, Medline and Opengrey databases. To be included, studies had to contain descriptions, discussions or experiences of TQ application in civilian setting. The quality of the studies was evaluated using the PRISMA and the STROBE criteria.

RESULTS: Of the 380 studies identified, 24 were included. The overall level of evidence was low. Three thousand and twenty eight TQ placements were reported. Most of them concerned the Combat Application Tourniquet CAT. Haemorrhages implied in the use of TQ were almost exclusively traumatic, most of the time regarding young men (27-44 years old). Effectiveness rates of TQ varied between 78% and 100%. Complications rates associated with the use of TQ remained low, even when used in elderlies or patients with comorbidities. Finally, caregivers reported a common fear of adverse effects, while reported complications were rare (<2%).

CONCLUSION: This systematic review revealed TQ to be an effective tool for the management of extremity haemorrhages in civilian trauma, associated with few complications. Larger studies and dedicated training courses are needed to improve the use of TQ in the civilian standards of care.

Evaluation of extremity tourniquet designs during self-application in the hands of military service members.

Dory R, Bequette J, Cox D

Naval Medical Research Unit San Antonio;NAMRU-SA Report #2017-54

EXECUTIVE SUMMARY

BACKGROUND: Since doctrinal changes made in 2005, tourniquets have become standard issue equipment for the US warfighter operating in the tactical environment. Previous Joint Operational Evaluation of Field Tourniquets (JOEFT) studies have gathered performance data to compare commercially available tourniquet designs utilizing instrumented mannequin systems, as well as synthetic cadaver models of severe hemorrhage; however, human end-user testing remains critical for identifying those tourniquet designs best suited for use by our military service members.

OBJECTIVE: To compare the performance of three candidate tourniquets, theCombat Application Tourniquet® (CAT), Ratcheting Medical Tourniquet™ (RMT), and Tactical Mechanical Tourniquet (TMT), in the hands of military end-users during selfapplications.

METHODS: Fifty five volunteer participants (n=55) were first trained to correctly position and apply each tourniquet design, according to the manufacturers’ instructions for use, on instrumented mannequins designed for tourniquet training. Participants then self-applied each tourniquet once to their arm and once to their leg, halting at cessation of the distal pulse.Occlusion was maintained for one minute. Measurements included success/failure rate, applications time, discomfort, and participant preference and feedback. Results: Of the three tourniquet designs, the CAT achieved the highest combined success rate across arm and leg applications (97.27%), followed by the RMT (94.55%) and the TMT (90.91%). The CAT hadthe shortest arm application time (43.6 ± 18.2 sec) and was significantly faster (p < 0.05) than the TMT (67.6 ± 30.5 sec) but not the RMT (44.2 ± 22.3 sec). The CAT also had the shortest leg application time (40.4 ± 13.0) and was significantly faster (p < 0.05) than the RMT and TMT (47.4 ± 17.9 sec and 48.0 ± 13.2 sec, respectively). The three tourniquets did not differ inreported discomfort levels. The CAT was most often ranked the preferred tourniquet design for arm (51.9%) followed by the RMT (38.9%) and TMT (9.3%). The CAT also ranked most preferred for the leg (41.5%) followed by the RMT (30.2%) and TMT (28.3%).

CONCLUSIONS: Because buddy aid or aid from a medic or corpsman is never guaranteed, it is imperative that tourniquets can be quickly applied by those who must administer self-aid. The results of the present study provide data that differentiate the three tourniquet designs through measures of tourniquet success, application times, and user feedback. These data can be used to identify which current design(s) are best suited for use by our warfighter, and to identify opportunities to improve existing tourniquet features in subsequent generations of tourniquet designs.

Assessment of User, Glove, and Device Effects on Performance of Tourniquet Use in Simulated First Aid.

Kragh JF Jr, Aden JK 3rd, Lambert CD, Moore VK 3rd, Dubick MA.

J Spec Oper Med. Winter 2017;17(4):29-36.

BACKGROUND: The effects of users, glove types, and tourniquet devices on the performance of limb tourniquet use in simulated first aid were measured.

MATERIALS AND METHODS: Four users conducted 180 tests of tourniquet performance in eight glove groups compared with bare hands as a control.

RESULTS: Among tests, 99% (n = 179) had favorable results for each of the following: effectiveness (i.e., bleeding control), distal pulse stoppage, and tourniquet placement at the correct site. However, only 90% of tests ended with a satisfactory result, which is a composite outcome of aggregated metrics if all (patient status is stable, tourniquet placement is good, and pressure is good) are satisfactory. Of 18 unsatisfactory results, 17 (94%) were due to pressure problems. Most of the variance of the majority of continuous metrics (time to determination of bleeding control, trial time, overall time, pressure, and blood loss) could be attributed to the users (62%, 55%, 61%, 8%, and 68%, respectively). Glove effects impaired and slowed performance; three groups (cold gloves layered under mittens, mittens, and cold gloves) consistently had significant effects and five groups (examination gloves, flight gloves, leather gloves, glove liners, and glove liners layered under leather gloves) did not. For time to bleeding control and blood loss, performance using these same three glove groups had worse results compared with bare hands by 26, 18, and 17 seconds and by 188, 116, and 124mL, respectively. Device effects occurred only with continuous metrics and were often dominated by user effects.

CONCLUSION: In simulated first aid with tourniquets used to control bleeding, users had major effects on most performance metrics. Glove effects were significant for three of eight glove types. Tourniquet device effects occurred only with continuous metrics and were often dominated by user effects.

The Tourniquet Gap: A Pilot Study of the Intuitive Placement of Three Tourniquet Types by Laypersons.

Ross EM, Mapp JG, Redman TT, Brown DJ, Kharod CU, Wampler DA

J Emerg Med. 2018 Mar;54(3):307-314. 

 

BACKGROUND: The "Stop the Bleed" campaign in the United States advocates for nonmedical personnel to be trained in basic hemorrhage control and that "bleeding control kits" be available in high-risk areas. However, it is not clear which tourniquets are most effective in the hands of laypersons.

OBJECTIVES: The objective of this pilot study was to determine which tourniquet type was the most intuitive for a layperson to apply correctly.

METHODS: This project is a randomized study derived from a "Stop the Bleed" education initiative conducted between September 2016 and March 2017. Novice tourniquet users were randomized to apply one of three commercially available tourniquets (Combat Action Tourniquet [CAT; North American Rescue, LLC, Greer, SC], Ratcheting Medical Tourniquet [RMT; m2 Inc., Winooski, VT], or Stretch Wrap and Tuck Tourniquet [SWAT-T; TEMS Solutions, LLC, Salida, CO]) in a controlled setting. Individuals with formal medical certification, prior military service, or prior training with tourniquets were excluded. The primary outcome of this study was successful tourniquet placement.

RESULTS: Of 236 possible participants, 198 met the eligibility criteria. Demographics were similar across groups. The rates of successful tourniquet application for the CAT, RMT, and SWAT-T were 16.9%, 23.4%, and 10.6%, respectively (p = 0.149). The most common causes of application failure were: inadequate tightness (74.1%), improper placement technique (44.4%), and incorrect positioning (16.7%).

CONCLUSION: Our pilot study on the intuitive nature of applying commercially available tourniquets found unacceptably high rates of failure. Large-scale community education efforts and manufacturer improvements of tourniquet usability by the lay public must be made before the widespread dissemination of tourniquets will have a significant public health effect.

 

Evaluation of tourniquet application in a simulated tactical environment.

Sanak T, Brzozowski R, Dabrowski M, Kozak M, Dabrowska A, Sip M, Naylor K, Torres K.

Ulus Travma Acil Cerrahi Derg. 2018 Jan;24(1):9-15

 

BACKGROUND: Application of a tourniquet in a tactical environment is implemented in two ways: the so-called self-aid, which is the application of a tourniquet by the injured, and the so-called buddy aid, which is the application of a tourniquet by the person provide aid. This study aimed to test the quality of tourniquet use in a simulated situation, close quarter battle.

METHODS: The study involved 24 injured operators and 72 operators in the whole simulation, implying 12 sections of six individuals. To validate the application of tourniquets, the recommendations of the Committee of Tactical Combat Care of the Injured were used, and ultrasound with Doppler function was employed to assess the hemodynamic effect of applying tourniquets.

RESULTS: Native flow was observed in 15 operators; in three people, a trace flow was noticed, whereas in six people, a full flow was observed. No significant difference was found between the qualities of tourniquet application by theoperators themselves compared with those of tourniquet application by another person. The median distance of tourniquet application from the armpit was 9.5 cm for self-aid and buddy aid. In 16 participants the outer arrangement of tourniquets was observed, and in only eight participants tourniquets were correctly located on the internal part of the arm. In 18 participants, tourniquets were not correctly prepared for use in the tactical environment, whereas in only six participants, they were correctly prepared. Most operators with a negative ultrasound flow revealed negative distal observed pulse (DOP).  Positive DOP occurred in the majority of operators with full ultrasound flow.

CONCLUSION: The application of tourniquets poses a challenge even in case of specialized units; therefore, there is a need to provide regular training for implementing that procedure.

Influence of Personality Traits on the Effective Performance of Lifesaving Interventions: Example of the Tourniquet Application in Forward Combat Casualty Care.

Vuillemin Q, Schwartzbrod PE, Pasquier P, Sibille F, Trousselard M, Ferrer MH

Mil Med. 2018 Jan 1;183(1-2):e95-e103

 

Introduction: Health care delivery in military conflicts implies high-stress environments. Hemorrhage is the first cause of survivable death among combat casualties, and tourniquet application is one of the most critical lifesaving interventions on the battlefield. However, previous studies have shown high failure rates in tourniquet application. Our study aimed to assess the correlation between personality traits that may interfere with effective tourniquet application in a simulated extremity hemorrhage.

Materials: Seventy-two French soldiers, previously trained to forward combat casualty care, were evaluated by self-administered questionnaires and submitted to the simulation in group of six. We focused on measuring the empathic personality of the subjects, their peer-to-peer relationships (altruism), as well as their relationship to themselves (mindfulness and self-esteem). The effectiveness of the tourniquet was evidenced by the interruption of the popliteal artery flow Doppler signal. A composite variable called "efficiency" was defined by elimination of popliteal pulse Doppler signal in less than 60 s.

Results: Tourniquet application interrupted arterial flow in 37 participants (51.39%). Efficiency was obtained by 19 participants (26.39%). We observed that soldiers with high active altruism applied less-efficient tourniquet (odds ratio = 0.15; 95% confidence interval = 0.04-0.59). On the contrary, soldiers with high self-esteem scores applied more efficient tourniquet (odds ratio = 3.95; 95% confidence interval = 1.24-12.56). There was no significant difference concerning empathy and mindfulness scores.

Conclusion: Tourniquet application is technically simple but painful and may involve personal sensitivity. These initial findings highlight the necessity to further explore the psychological processes involved in lifesaving interventions. Self-esteem stands out as a real asset in terms of military competence and resilience, a major prerequisite in stressful situations. Changing altruistic motivations of soldiers is likely not desirable, but being aware of its potential effects may help to develop personal adaptive strategies and to optimize collective training.

Effects of Distance Between Paired Tourniquets.

Wall PL, Buising CM, Nelms D, Grulke L, Renner CH, Sahr SM.

J Spec Oper Med. Winter 2017;17(4):37-44.

 

BACKGROUND: In practice, the distance between paired tourniquets varies with unknown effects.

METHODS: Ratcheting Medical Tourniquets were applied to both thighs of 15 subjects distally (fixed location) and proximally (0, 2, 4, 8, 12cm gap widths, randomized block). Applications were pair, single distal, single appropriate proximal. Tightening ended one-ratchet tooth advance past Doppler-indicated occlusion. Pairs had alternating tightening starting distal.

RESULTS: Occlusion pressures were higher for: each single than respective individual pair tourniquet, each pair distal than respective pair proximal, and each single distal than respective single proximal (all p < .0001). Despite thigh circumference increasing proximally, occlusion pressures were lower with proximal tourniquet involvement (pair or single, p < .0001). Occlusion losses before 120 seconds occurred most frequently with pairs (0cm 4, 2cm 4, 4cm 6, 8cm 7, 12cm 5 for 26 of 150), in increasing frequency with increasingly proximal singles (0cm 0, 2cm 1, 4cm 1, 8cm 2, 12cm 6 for 10 of 150, p < .0001 for trend), and least with single distal (2 of 150, p < .0001). Paired tourniquets required fewer ratchet advances per tourniquet (pair distal 5 ± 1, pair proximal 4 ± 1, single distal 6 ± 1, single proximal 6 ± 1). Final ratchet tooth advancement pressure increases (mmHg) were greatest for singles (distal 61 ± 10, proximal 0cm 53 ± 7,  2cm 51 ± 9, 4cm 50 ± 7, 8cm 45 ± 7, 12cm 36 ± 7) and least in pairs (distal 41 ±  8, proximal 32 ± 7) with progressively less pair interaction as distance increased (pressure change for the pair tourniquet not directly advanced: 0cm 13 ± 4, 2cm 10 ± 4, 4cm 6 ± 3, 8cm 1 ± 2, 12cm -1 ± 2).

CONCLUSIONS: Occlusion pressures are lower for paired than single tourniquets despite variable intertourniquet distances. Very proximal placement has a pressure advantage; however, pairs and very proximal locations may be less likely to maintain occlusion. Increasingly proximal placements also increase tissue at risk; therefore, distal placements and minimal intertourniquet distances should still be recommended.

HEMOSTATICS

Hemostasis and Safety of a Novel Fibrin Dressing Versus Standard Gauze in Bleeding Cancellous Bone in a Caprine Spine Surgery Model.

Floyd CT(1), Padua RA(2), Olson CE(2).

Spine Deform. 2017 Sep;5(5):310-313

BACKGROUND: Decorticated bone is a significant source of blood loss in scoliosis surgery. Current hemostatic methods include packed gauze (GS), physical barriers such as bone wax, and xenograft collagen-based materials. We assessed the safety and efficacy of a novel fibrin dressing (dextran-thrombin-fibrinogen [DTF]) compared to GS. This dressing comprises lyophilized thrombin and fibrinogen embedded in an elastic electrospun nanofiber dextran matrix.

PURPOSE: The study tests the hypothesis that DTF is more efficacious than GS in control of bleeding from cancellous bone.

STUDY DESIGN: A preclinical Good Laboratory Practices (GLP) study.

METHODS: We enrolled 10 goats that were followed for 28 ± 1 days. Each animal was randomly assigned to the test or control group. Both test and control animals had 4 cancellous bone injuries. Test animal injuries were treated with DTF, whereas standard GS was used to control bleeding in the control animals. Bleeding at the bone injury site was characterized as either none, oozing, flowing, or pulsatile and was assessed at 4 and 8 minutes after dressing application. Goats were survived 28 ± 1 days and then necropsied.

RESULTS: Application of the fibrin dressing to bleeding cancellous bone, both posterior spinal lamina, and iliac crest graft sites, resulted in control of bleeding within 4 minutes at all injury sites. Eighty percent of control injury sites continued to bleed after 8 minutes and required application of bone wax to control bleeding. There were no differences in prothrombin time, partial thromboplastin time, or fibrinogen levels between test and control animals at 1 or 28 days. We observed no adverse histologic reactions at 28 days.

CONCLUSION: The fibrin dressing is an efficacious and safe method of controlling blood loss from cancellous bone in a spine surgery model.

Biomaterials and Advanced Technologies for Hemostatic Management of Bleeding.

Hickman DA, Pawlowski CL, Sekhon UDS, Marks J, Gupta AS

Adv Mater. 2018 Jan;30(4). doi: 10.1002/adma.201700859.

ABSTRACT:Bleeding complications arising from trauma, surgery, and as congenital, disease-associated, or drug-induced blood disorders can cause significant morbidities and mortalities in civilian and military populations. Therefore, stoppage of bleeding (hemostasis) is of paramount clinical significance in prophylactic, surgical, and emergency scenarios. For externally accessible injuries, a variety of natural and synthetic biomaterials have undergone robust research, leading to hemostatic technologies including glues, bandages, tamponades, tourniquets, dressings, and procoagulant powders. In contrast, treatment of internal noncompressible hemorrhage still heavily depends on transfusion of whole blood or blood's hemostatic components (platelets, fibrinogen, and coagulation factors). Transfusion of platelets poses significant challenges of limited availability, high cost, contamination risks, short shelf-life, low portability, performance variability, and immunological side effects, while use of fibrinogen or coagulation factors provides only partial mechanisms for hemostasis. With such considerations, significant interdisciplinary research endeavors have been focused on developing materials and technologies that can be manufactured conveniently, sterilized to minimize contamination and enhance shelf-life, and administered intravenously to mimic, leverage, and amplify physiological hemostatic mechanisms. Here, a comprehensive review regarding the various topical, intracavitary, and intravenous hemostatic technologies in terms of materials, mechanisms, and state-of-art is provided, and challenges and opportunities to help advancement of the field are discussed.

Early administration of fibrinogen concentrates improves the short-term outcomes of severe pelvic fracture patients.

Inokuchi K, Sawano M, Yamamoto K, Yamaguchi A, Sugiyama S

Acute Med Surg. 2017 Apr 2;4(3):271-277. doi: 10.1002/ams2.268. eCollection 2017 Jul.

Aim: Hemorrhage from pelvic fracture is a major cause of mortality after blunt trauma. Several studies have suggested that early fibrinogen supplementation improves outcomes of traumatic hemorrhage. Thus, we revised our massive transfusion protocol (MTP) in April 2013 to include early off-label administration of fibrinogen concentrate. The objective of this study was to evaluate the impact of the revision on the short-term outcomes of pelvic fracture patients.

Methods: This was a single-center, retrospective, cohort study. A total of 224 consecutive pelvic fracture patients hospitalized in Saitama Medical Center (Saitama, Japan), 115 before the revision (Group E) and 109 after (Group L), were enrolled. Characteristics of the patients were compared between the groups. Impacts of the revision were evaluated by hazard ratios adjusted for characteristics, injury severity, and coagulation status using Cox's multivariate proportional hazard model. The impact was also evaluated by log-rank test and relative risk of 28-day mortality between the groups.

Results: The characteristics were equivalent between the groups. The multivariate analysis revealed that the revision of MTP was significantly related to improved survival with an adjusted hazard ratio (95% confidence interval) of 0.45 (0.07-0.97). The log-rank test gave χ2-test values of 5.2 (P = 0.022) and 6.7 (P = 0.009), and the relative risks were 0.37 (0.15-0.91) and 0.33 (0.13-0.84), in patients with all Injury Severity Scores and Injury Severity Score ≥21, respectively.

Conclusion: The revision of MTP to include aggressive off-label treatment with fibrinogen concentrate was related to improved short-term outcomes of severe pelvic fracture patients. However, due to the limitations of the study, the improvement could not be attributed totally to the revision.

Freeze dried chitosan acetate dressings with glycosaminoglycans and traxenamic acid.

Carbohydr Polym. 2018 Mar 15;184:408-417 

Saporito F, Sandri G, Rossi S, Bonferoni MC, Riva F, Malavasi L, Caramella C, Ferrari F

 

Bleeding control plays an important role to increase survival in the early phase after a traumatic event. The aim of present work was the development of hemostatic sponge-like dressings based on chitosan, in association with glycosaminoglycans (GAG) (chondroitin sulfate or hyaluronic acid) and the improvement of their hemostatic performance by loading tranexamic acid (TA). The dressings were prepared by lyophilizazion and were characterized for mechanical, hydration, bioadhesion properties and morphology. Moreover, FTIR analysis was performed to understand the interactions between the different polyelectrolytes present in the dressings. Clotting was investigated in vitro by using rat whole blood. Moreover, in vitro biocompatibility and proliferation were evaluated towards fibroblasts. Ex vivo proliferation properties were assessed by using human skin. All the dressings were characterised by mechanical, hydration and bioadhesion properties suitable to be applied on bleeding wounds and to absorb bleeding or wound exudate, avoiding tissue dehydration. TA release was fast; TA and chitosan showed a synergic effect to speed up clotting. The dressings were biocompatible and able to sustain cell proliferation in vitro and ex vivo in human skin. In conclusion, sponge-like dressings based on chitosan and GAG and loaded with TA are an effective tool to enhance hemostasis and healing in bleeding wounds.

JUNCTIONAL HEMORRHAGE

Contemporary management of subclavian and axillary artery injuries-A Western Trauma Association multicenter review.

Waller CJ, Cogbill TH, Kallies KJ, Ramirez LD, Cardenas JM, Todd SR, Chapman KJ, Beckman MA, Sperry JL, Anto VP, Eriksson EA, Leon SM, Anand RJ, Pearlstein M, Capano-Wehrle L, Cothren Burlew C, Fox CJ, Cullinane DC, Roberts JC, Harrison PB, Berg GM, Haan JM, Lightwine K.

J Trauma Acute Care Surg. 2017 Dec;83(6):1023-1031

 

BACKGROUND: Subclavian and axillary artery injuries are uncommon. In addition to many open vascular repairs, endovascular techniques are used for definitive repair or vascular control of these anatomically challenging injuries. The aim of this study was to determine the relative roles of endovascular and open techniques in the management of subclavian and axillary artery injuries comparing hospital outcomes, and long-term limb viability.

METHODS: A multicenter, retrospective review of patients with subclavian or axillary artery injuries from January 1, 2004, to December 31, 2014, was completed at 11 participating Western Trauma Association institutions. Statistical analysis included χ, t-tests, and Cochran-Armitage trend tests. A p value less than 0.05 was significant.

RESULTS: Two hundred twenty-three patients were included; mean age was 36 years, 84% were men. An increase in computed tomography angiography and decrease in conventional angiography was observed over time (p = 0.018). There were 120 subclavian and 119 axillary artery injuries. Procedure type was associated with injury grade (p < 0.001). Open operations were performed in 135 (61%) patients, including 93% of greater than 50% circumference lacerations and 83% of vessel transections. Endovascular repairs were performed in 38 (17%) patients; most frequently for pseudoaneurysms. Fourteen (6%) patients underwent a hybrid procedure. Use of endovascular versus open procedures did not increase over the duration of the study (p = 0.248). In-hospital mortality rate was 10%. Graft or stent thrombosis occurred in 7% and graft or stent infection occurred in 3% of patients. Mean follow-up was 1.6 ± 2.4 years (n = 150). Limb salvage was achieved in 216 (97%) patients.

CONCLUSION: The management of subclavian and axillary artery injuries still requires a wide variety of open exposures and procedures, especially for the control of active hemorrhage from more than 50% vessel lacerations and transections. Endovascular repairs were used most often for pseudoaneurysms. Low early complication rates and limb salvage rates of 97% were observed after open and endovascular repairs.

LEVEL OF EVIDENCE: Prognostic/epidemiologic, level IV.