Outcomes Associated With Aortic Balloon Occlusion Time in Patients With Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to cause clinically relevant systemic ischemic burden with long durations of aortic occlusion (AO). We aimed to examine the association between balloon occlusion time and clinical complications and mortality outcomes in patients undergoing zone 1 REBOA. METHODS: A retrospective cohort analysis of American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acuteregistry patients with Zone 1 REBOA between 2013 and 2022 was performed. Patients with cardiopulmonary resuscitation on arrival or who did not survive past the emergency department were excluded. Total AO times were categorized as follows: <15 min, 15-30 min, 31-60 min, and >60 min. Clinical and procedural variables and in-hospital outcomes were compared across groups using bivariate and multivariate regression analyses. RESULTS: There were 327 cases meeting inclusion criteria (n = 51 < 15 min, 83 15-30 min, 98 31-60 min, and 95 > 60 min, respectively). AO >60 min had higher admission lactate (8 ± 6; P = 0.004) compared to all other time groups, but injury severity score, heart rate, and systolic blood pressure were similar. Group average times from admission to definitive hemorrhage control ranged from 82 to 103 min and were similar across groups (85 min in AO >60 group). Longer AO times were associated with greater red blood cell, fresh frozen plasma transfusions (P < 0.001), and vasopressor use (P = 0.001). Mortality was greatest in the >60 min group (73%) versus the <15 min, 15-30 min, and 31-60 min groups (53%, 43%, and 45%, P < 0.001). With adjustment for injury severity score, systolic blood pressure, and lactate, AO >60 min had greater mortality (OR 3.7, 95% CI 1.6-9.4; P < 0.001) than other AO duration groups. Among 153 survivors, AO >60 min had a higher rate of multiple organ failure (15.4%) compared to the other AO durations (0%, 0%, and 4%, P = 0.02). There were no differences in amputation rates (0.7%) or spinal cord ischemia (1.4%). acute kidney injury was seen in 41% of >60 min versus 21%, 27%, and 33%, P = 0.42. CONCLUSIONS: Though greater preocclusion physiologic injury may have been present, REBOA-induced ischemic insult was correlated with poor patient outcomes, specifically, REBOA inflation time >60 min had higher rates of mortality and multiple organ failure. Minimizing AO duration should be prioritized, and AO should not delay achieving definitive hemostasis. Partial REBOA may be a solution to extend safe AO time and deserves further study.

Vascular Reconstruction and Limb Loss in Military Tibial Artery Injuries.

BACKGROUND: Selective operative management of injuries to the tibial arteries is controversial, with the necessity of revascularization in the face of multiple tibial arteries debated. Tibial artery injuries are frequently encountered in military trauma, but revascularization practices and outcomes are poorly defined. We aimed to investigate associations between the number of injured vessels and reconstruction and limb loss rates in military casualties with tibial arterial trauma. METHODS: A US military database of lower extremity vascular injuries from Iraq and Afghanistan (2004-2012) was queried for limbs sustaining at least 1 tibial artery injury. Injury, intervention characteristics, and limb outcomes were analyzed by the number of tibial arteries injured (1, T1; 2, T2; 3, T3). RESULTS: Two hundred twenty one limbs were included (194 T1, 22 T2, 5 T3). The proportions with concomitant venous, orthopedic, nerve, or proximal arterial injuries were similar between groups. Arterial reconstruction (versus ligation) was performed in 29% of T1, 63% of T2, and universally in T3 limbs (P < 0.001). Arterial reconstruction was via vein graft (versus localized repair) in 62% of T1, 54% of T2, and 80% of T3 (P = 0.59). T3 received greater blood transfusion volume (P = 0.02), and fasciotomy was used universally (versus 34% T1 and 14% T2, P = 0.05). Amputation rates were 23% for T1, 26% for T2, and 60% for T3 (P = 0.16), and amputation was not significantly predicted by arterial ligation in T1 (P = 0.08) or T2 (P = 0.34) limbs. Limb infection was more common in T3 (80%) than in T1 (25%) or T2 (32%, P = 0.02), but other limb complication rates were similar. CONCLUSIONS: In this series of military lower extremity injuries, an increasing number of tibial arteries injured was associated with the increasing use of arterial reconstruction. Limbs with all 3 tibial arteries injured had high rates of complex vascular reconstruction and eventual amputation. Limb loss was not predicted by arterial ligation in 1-vessel and 2-vessel injuries, suggesting that selective reconstruction in these cases is advisable.

Association between time to revascularization and limb loss in military femoropopliteal arterial injuries.

OBJECTIVE: Expeditious revascularization is key to limb salvage after arterial injuries, but the relationship between time to revascularization and amputation risk is not well-defined. We aimed to explore amputation risk based on time to revascularization in a cohort of military femoropopliteal arterial injuries. METHODS: A database of vascular injuries from Iraq and Afghanistan casualties (2004-2012) was queried for femoral (common, superficial, or deep) and/or popliteal arterial injuries that underwent revascularization. Time from injury to initial revascularization (via shunt or reconstruction) was divided into groups of <3 hours, 3 to 6 hours, 6 to 9 hours, and >9 hours, and bivariate comparisons were performed. RESULTS: Revascularization times were available for 120 cases. Injury and treatment characteristics by time group were generally similar between time groups. Shunting and vein injuries were more common in limbs revascularized earlier, whereas blast mechanism and fasciotomy were more common with later revascularization. Ten cases (8%) underwent revascularization in less than 3 hours, 63 (53%) were revascularized in 3 to 6 hours, 33 (28%) in 6 to 9 hours, and 14 (12%) after 9 hours. Amputation rates within the cohorts were 10%, 21%, 24%, and 50%, respectively (P = .085, χ2 of amputation rates across time groups). The mean ± standard deviation revascularization time for amputated limbs was 442 ± 348 minutes vs 347 ± 183 minutes for salvaged limbs (P = .057). Amputation was performed in 19% of limbs revascularized in <6 hours and in 32% revascularized >6 hours from injury (P = .112). The >9-hour group, however, had a 50% amputation rate vs 21% for those with revascularization in <9 hours (P = .016). Fractures were more common in >9-hour limbs than <9-hour limbs (79% vs 44%; P = .016), but other limb injury characteristics were similar, with no difference in limb injury severity scores. Among 91 salvaged limbs, neither vascular nor other complications were predicted by time to revascularization. All seven >9-hour limbs had a limb complication, most commonly infection (71%), and three (42%) required a skin graft to close their fasciotomies. CONCLUSIONS: Increasing time from injury to initial revascularization was associated with increasing rates of limb loss. Revascularization within 3 hours of injury resulted in a low amputation rate, whereas one-half of limbs treated after 9 hours were amputated. Arterial shunting was associated with earlier revascularization and should be considered a mainstay of combat casualty vascular care. Forward-deployed surgical assets play a pivotal role in providing early revascularization and reducing rates of limb loss in modern combat casualty care.

Arterial Access Complications Following Percutaneous Femoral Access in 24-Hour Resuscitative Endovascular Balloon Occlusion of the Aorta Survivors.

INTRODUCTION: With the use of resuscitative endovascular balloon occlusion of the aorta (REBOA) comes the potential for vascular access site complications (VASCs) and limb ischemic sequelae. We aimed to determine the prevalence of VASC and associated clinical and technical factors. METHODS: A retrospective cohort analysis of 24-h survivors undergoing percutaneous REBOA via the femoral artery in the American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute care surgery registry between Oct 2013 and Sep 2021 was performed. The primary outcome was VASC, defined as at least one of the following: hematoma, pseudoaneurysm, arteriovenous fistula, arterial stenosis, or the use of patch angioplasty for arterial closure. Associated clinical and procedural variables were examined. Data were analyzed using Fisher exact test, Mann-Whitney-U tests, and linear regression. RESULTS: There were 34 (7%) cases with VASC among 485 meeting inclusion criteria. Hematoma (40%) was the most common, followed by pseudoaneurysm (26%) and patch angioplasty (21%). No differences in demographics or injury/shock severity were noted between cases with and without VASC. The use of ultrasound (US) was protective (VASC, 35% versus no VASC, 51%; P = 0.05). The VASC rate in US cases was 12/242 (5%) versus 22/240 (9.2%) without US. Arterial sheath size >7 Fr was not associated with VASC. US use increased over time (R2 = 0.94, P < 0.001) with a stable rate of VASC (R2 = 0.78, P = 0.61). VASC were associated with limb ischemia (VASC, 15% versus no VASC, 4%; P = 0.006) and arterial bypass procedures (VASC 3% versus no VASC 0%; P < 0.001) but amputation was uncommon (VASC, 3% versus no VASC, 0.4%; P = 0.07). CONCLUSIONS: Percutaneous femoral REBOA had a 7% VASC rate which was stable over time. VASC are associated with limb ischemia but need for surgical intervention and/or amputation is rare. The use of US-guided access appears to be protective against VASC and is recommended for use in all percutaneous femoral REBOA procedures.

Analysis of Concomitant and Isolated Venous Injury in Military Lower Extremity Trauma.

BACKGROUND: The implications of major venous injury to the lower extremity are not well established. We aimed to determine the significance of concomitant and isolated femoropopliteal venous injury and assess the impact of surgical management strategies on limb outcomes. METHODS: The Fasciotomy and Vascular Injury Outcomes database was queried for limbs sustaining femoropopliteal arterial, venous, or concomitant injuries in Iraq or Afghanistan between 2004 and 2012. Demographics, injury patterns and severity, interventions, and outcomes were compared between patients sustaining isolated arterial injuries (IAIs) and concomitant arteriovenous injuries (AVIs). In limbs with any venous injury, outcomes were compared between those undergoing venous repair and venous ligation. RESULTS: Three hundred thirty patients (133 IAIs, 135 AVIs, 62 isolated venous injuries [IVIs]) were included. AVI was associated with greater limb injury severity: median extremity Abbreviated Injury Scale (AVI 4 vs. IAI 3, P = 0.01), Mangled Extremity Severity Score >7 (25.9% vs. 13.5%, P = 0.01), and multilevel vascular injury (6.7% vs. 0.8%, P = 0.01) and with greater fasciotomy use (83.0% vs. 69.2%, P = 0.01). No differences were present in tourniquet use/time, shunting, or nature of arterial repair. No differences in vascular or limb complications (71.1% vs. 63.9%, P = 0.21) or amputation rate (25.9% vs. 18.8%, P = 0.16) were present, though the limb deep venous thrombosis rate was 12.6% in AVIs versus 7.5% in IAIs (P = 0.17). Limbs with IVI had a 12.9% amputation and a 74.2% complication rate. Repair (n = 103) versus ligation (n = 94) of venous injuries was not associated with a difference in amputation (18.4% vs. 25.5%, P = 0.23) or limb complication rates (71.8% vs. 72.3%, P = 0.94). CONCLUSIONS: Despite higher extremity injury severity and more frequent fasciotomies, concomitant venous injury was not associated with poorer limb salvage or complications. With nontrivial amputation and complication rates, IVI is indicative of severe limb trauma. Repair of femoropopliteal venous injuries does not appear to influence limb outcomes.

Early Fasciotomy and Limb Salvage and Complications in Military Lower Extremity Vascular Injury.

BACKGROUND: Military guidelines endorse early fasciotomy after revascularization of lower extremity injuries to prevent compartment syndrome, but the real-world impact is unknown. We assessed the association between fasciotomy and amputation and limb complications among lower extremitys with vascular injury. METHODS: A retrospectively collected lower extremity injury database was queried for limbs undergoing attempted salvage with vascular procedure (2004-2012). Limbs were categorized as having undergone fasciotomy or not. Injury and treatment characteristics were collected, as were intervention timing data when available. The primary outcome measure was amputation. Multivariate models examined the impact of fasciotomy on limb outcomes. RESULTS: Inclusion criteria were met by 515 limbs, 335 (65%) with fasciotomy (median 7.7 h postinjury). Of 212 limbs, 174 (84%) with timing data had fasciotomy within 30 min of initial surgery. Compartment syndrome and suspicion of elevated pressure was documented in 127 limbs (25%; 122 had fasciotomy). Tourniquet and shunt use, fracture, multiple arterial and combined arteriovenous injuries, popliteal involvement, and graft reconstruction were more common in fasciotomy limbs. Isolated venous injury and vascular ligation were more common in nonfasciotomy limbs. Fasciotomy timing was not associated with amputation. Controlling for limb injury severity, fasciotomy was not associated with amputation but was associated with limb infection, motor dysfunction, and contracture. Sixty-three percent of fasciotomies were open for >7 d, and 43% had multiple closure procedures. Fasciotomy revision (17%) was not associated with increased amputation or complications. CONCLUSIONS: Fasciotomy after military lower extremity vascular injury is predominantly performed early, frequently without documented compartment pressure elevation. Early fasciotomy is generally performed in severely injured limbs with a subsequent high rate of limb complications.

Utility of the Mangled Extremity Severity Score in Predicting Amputation in Military Lower Extremity Arterial Injury.

BACKGROUND: Effective amputation prediction may help inform appropriate early limb salvage efforts in military lower extremity (LE) arterial injury. The Mangled Extremity Severity Score (MESS) is the most commonly applied system for early amputation prediction but its utility in military trauma is unknown. METHODS: Retrospective cohort study of Iraq and Afghanistan casualties with LE arterial injury who underwent a vascular limb salvage attempt. Retrospectively assessed MESS was statistically explored as an amputation predictor and MESS component surrogates (mechanism, vascular injury characteristics, tourniquet use, and transfusion volume) were used to characterize limb injuries by presenting characteristics and evaluated for amputation prediction. RESULTS: A total of 439 limbs were included with 99 (23%) amputations, 29 (7%) within 48 hr of injury. Median MESS was 5 (interquartile range 4-6) among salvaged limbs and 7 (5-9) among amputations (P < 0.0001). An MESS cutoff of ≥7 had a better receiver operating characteristic sensitivity/specificity profile (area under the curve 0.696 overall, 0.765 amputation within 48 hr) than MESS ≥8 (0.593, 0.621), but amputation rates were only 43% for MESS ≥7 and 50% for ≥8. MESS ≥7 was significantly associated with age, polytrauma, blast or crush mechanism, fracture, tourniquet use, distal (popliteal/tibial) and multiple arterial injuries, and massive transfusion. Amputation was significantly associated with polytrauma, blast or crush mechanism, fracture, and massive transfusion; however, 83 casualties had all 4 characteristics with an amputation rate of only 46%. CONCLUSIONS: In combat casualties with arterial injury, LE amputation after attempted vascular limb salvage is inadequately predicted by existing scoring systems or the presenting characteristics available in this registry. Limb loss is predominantly late and likely because of factors not projectable at initial presentation.

Outcomes of Arterial Grafts for the Reconstruction of Military Lower Extremity Arterial Injuries.

INTRODUCTION: Lower extremity (LE) arterial injuries are common in military casualties and limb salvage is a primary goal. Bypass grafts are the most common reconstructions; however, their specific outcomes are largely unreported. We sought to describe the outcomes of LE arterial grafts among combat casualties and their association with limb loss. METHODS: Retrospective cohort study of 2004-2012 Iraq/Afghanistan casualties with LE arterial injury undergoing bypass graft from a database containing follow-up until amputation, death, or military discharge. Primary outcome was composite graft complications (GC-thrombosis, stenosis, pseudoaneurysm, blowout, and/or arteriovenous fistula). RESULTS: Two hundred and twenty-two grafts were included (99 femoral, 73 popliteal, 48 tibial). 56 (26%) had at least one GC; thrombosis was most common in femoral, stenosis most common in popliteal and tibial. GC was not associated with graft level but was associated with synthetic conduit (P = 0.01) and trended towards an association with multiple-level arterial injuries (P = 0.07). Four of eight (50%) synthetic grafts had amputations, all within 72h. Two of the eight synthetic grafts thrombosed, and both limbs were amputated. There were 52 total amputations. Amputation was performed in 13 (23%) of limbs with a GC and 24% of those without (P = 0.93) Overall, 24 (11%) of grafts thrombosed, 16 within 48h and 13 (25%) in limbs undergoing amputation (P = 0.001 for association of thrombosis with amputation). CONCLUSION: GC are common among LE bypass grafts in combat casualties but are not associated with limb loss. Thrombosis is predominantly early and is associated with amputation. Closer attention to ensuring early patency may improve limb salvage.

Endovascular Embolization Techniques in a Novel Swine Model of Fatal Uncontrolled Solid Organ Hemorrhage and Coagulopathy.

BACKGROUND: Endovascular embolization is increasingly used in treating traumatic hemorrhage and other applications. No endovascular-capable translational large animal models exist and coagulopathy's effect on embolization techniques is unknown. We developed a coagulation-adaptable solid organ hemorrhage model in swine for investigation of embolization techniques. METHODS: Anesthetized swine (n = 26, 45 ± 3 kg) had laparotomy and splenic externalization. Half underwent 50% isovolemic hemodilution with 6% hetastarch and cooling to 33-35°C (COAG group). All had controlled 20 mL/kg hemorrhage and endovascular access to the proximal splenic artery with a 4F catheter via a right femoral sheath. Splenic transection and 5 min free bleeding were followed by treatment (n = 5/group) with 5 mL gelfoam slurry, three 6-mm coils, or no treatment (n = 3, control). Animals received 15 mL/kg plasma resuscitation and were monitored for 6 hr. Splenic blood loss was continuously measured and angiograms were performed at specified times. RESULTS: Coagulopathy was successfully established in COAG animals. Pre-treatment blood loss was greater in COAG (11 ± 6 mL/kg) than non-COAG (7 ± 3 mL/kg, P = 0.04) animals. Splenic hemorrhage was universally fatal without treatment. Non-COAG coil survival was 4/5 (326 ± 75 min) and non-COAG Gelfoam 3/5 (311 ± 67 min) versus non-COAG Control 0/3 (82 ± 18 min, P < 0.05 for both). Neither COAG Coil (0/5, 195 ± 117 min) nor COAG Gelfoam (0/5, 125 ± 32 min) treatment improved survival over COAG Control (0/3, 56 ± 19 min). Post-treatment blood loss was 4.6 ± 3.4 mL/kg in non-COAG Coil and 4.6 ± 2.9 mL/kg in non-COAG Gelfoam, both lower than non-COAG Control (18 ± 1.3 mL/kg, P = 0.05). Neither COAG Coil (8.4 ± 5.4 mL/kg) nor COAG Gelfoam (15 ± 11 ml/kg) had significantly less blood loss than COAG Control (20 ± 1.2 mL/kg). Both non-COAG treatment groups had minimal blood loss during observation, while COAG groups had ongoing slow blood loss. In the COAG Gelfoam group, there was an increase in hemorrhage between 30 and 60 min following treatment. CONCLUSIONS: A swine model of coagulation-adaptable fatal splenic hemorrhage suitable for endovascular treatment was developed. Coagulopathy had profound negative effects on coil and gelfoam efficacy in controlling bleeding, with implications for trauma and elective embolization procedures.

Differing Resuscitation With Aortic Occlusion in a Swine Junctional Hemorrhage Polytrauma Model.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) and Abdominal Aortic and Junctional Tourniquet (AAJT) have received much attention in recent as methods for temporary control of junctional hemorrhage. Previous studies typically used the animal's shed blood for resuscitation. With current interest in moving REBOA to prehospital environment, this study aimed to evaluate the hemodynamic and metabolic responses to different resuscitation fluids used with these devices. METHODS: In swine (Sus scrofa), shock was induced using a controlled hemorrhage, femur fracture, and uncontrolled hemorrhage from the femoral artery. Infrarenal REBOA or AAJT was deployed for 60 min during which the arterial injury was repaired. Animals were resuscitated with 15 mL/kg of shed whole blood (SWB) or fresh frozen plasma (FFP) or 30 mL/kg of a balanced crystalloid (PlasmaLyte). RESULTS: Animals in the AAJT and REBOA groups did not show any measurable differences in hemodynamics, metabolic responses, or survival with AAJT or REBOA treatment; hence, the data are pooled and analyzed among the three resuscitative fluids. SWB, FFP, and PlasmaLyte groups did not have a difference in survival time or overall survival. The animals in the SWB and FFP groups maintained higher blood pressure after resuscitation, (P < 0.001) and required significantly less norepinephrine to maintain blood pressure than those in the PlasmaLyte group (P < 0.001). The PlasmaLyte resuscitation prolonged prothrombin time and decreased thromboelastography maximum amplitude. CONCLUSIONS: After 60 min, infrarenal REBOA or AAJT aortic occlusion SWB and FFP resuscitation provided better blood pressure support with half of the resuscitative volume of PlasmaLyte. Swine resuscitated with SWB and FFP also had a more favorable coagulation profile. These data suggest that whole blood or component therapy should be used for resuscitation in conjunction with REBOA or AAJT, and administration of these fluids should be considered if prehospital device use is pursued.

Analysis of Limb Outcomes by Management of Concomitant Vein Injury in Military Popliteal Artery Trauma.

BACKGROUND: Despite aggressive limb salvage attempts, military popliteal artery injuries are associated with high amputation rates. Combined arterial and venous injuries present a management dilemma for military surgeons in austere settings, and the impact of vein injury management strategy on limb outcomes is not clear. METHODS: Military casualties sustaining combined ipsilateral popliteal artery and vein injuries from 2003 to 2016 were identified from a military vascular injury database. Limbs were grouped based on whether venous ligation or repair was initially performed. The primary outcome was secondary amputation; the secondary outcomes included limb and vascular/graft complications. RESULTS: Fifty-six limbs were included; of which, 27 (48%) were managed with vein ligation and 29 (52%) with repair. Veins were repaired primarily in 13 (45%) cases with the remainder being treated with interposition grafts. Median injury severity score was higher in the ligation group (19 vs 15, P = 0.09), but vascular and concomitant limb injury characteristics were similar. Amputation rates did not differ by vein treatment (45% repair vs. 41% ligation, P = 0.76), and this held with injuries above and below the knee considered independently. Most (71%) amputations were performed <30 days from injury. Amputation was indicated more frequently for vascular repair failure in the ligated group (55% vs 15%, P = 0.04). Four graft infections were all in the repair group (P = 0.07 vs ligation). Arterial graft complications were more frequent with vein repair (45%) than ligation (30%), but this did not reach significance (P = 0.24). Only one deep vein thrombosis was diagnosed in each group (P = 0.96). CONCLUSIONS: Type of management of concomitant popliteal vein injury was not associated with early or late amputation in this series of military popliteal artery injuries. Vein injury management may have had implications for the development of arterial graft and limb complications, however. Surgical decision-making regarding popliteal vein treatment should balance short-term contingencies with long-term limb salvage issues.

Impact of Staged Vascular Management on Limb Outcomes in Wartime Femoropopliteal Arterial Injury.

BACKGROUND: By necessity, wartime arterial injuries undergo staged management. Initial procedures may occur at a forward surgical team (role 2), where temporary shunts can be placed before transfer to a larger field hospital (role 3) for definitive reconstruction. Our objective was to evaluate the impact of staging femoropopliteal injury care on limb outcomes. METHODS: A military vascular injury database was queried for Iraq/Afghanistan casualties with femoropopliteal arterial injuries undergoing attempted reconstruction (2004-2012). Cases were grouped by initial arterial management: shunt placed at role 2 (R2SHUNT), reconstruction at role 2 (R2RECON), and initial management at role 3 (R3MGT). The primary outcome was limb salvage; secondary outcomes were limb-specific complications. Descriptive and intergroup comparative statistics were performed with significance defined at P ≤ 0.05. RESULTS: Of 257 cases, all but 4 had definitive reconstruction before evacuation to Germany (median, 2 days): 46 R2SHUNT, 84 R2RECON, and 127 R3MGT; median Mangled Extremity Severity Score was 6 for all groups. R2SHUNT had median extremity Abbreviated Injury Scale--vascular of 4 (other groups, 3; P < 0.05) and was more likely to have concomitant venous injury and to undergo fasciotomy. Shunts were used for 5 ± 3 hr. About 24% of R2RECON repairs were revised at role 3. Limb salvage rate of 80% was similar between groups, and 62% of amputations performed within 48 hr of injury. Rates of limb and composite graft complications were similar between groups. Thrombosis was more common in R2SHUNT (22%) than R2RECONST (6%) or R3MGT (12%) (P = 0.03). Late (>48 hr) thrombosis rates were similar, whereas 60% of R2SHUNT thromboses occurred on day of injury (P = 0.003 vs. 25% and 0%). CONCLUSIONS: Staged femoropopliteal injury care is associated with similar limb salvage to initial role 3 management. Early thrombosis is likely because of shunt failure but does not lead to limb loss. Current military practice guidelines are appropriate and may inform civilian vascular injury management protocols.

Response of the popliteal artery to treadmill exercise and stress positioning in patients with and without exertional lower extremity symptoms.

OBJECTIVE: Functionally limiting exertional lower extremity pain and neurologic symptoms are commonly encountered in military and civilian settings. Exertional muscle compression of the popliteal artery (PA) and tibial nerve in the proximal calf (the "popliteal outlet") can be associated with these symptoms but is rarely investigated as a cause. Exertional ankle-brachial index (EABI) and dynamic PA ultrasound imaging may be suitable to screen for this syndrome of "functional" popliteal entrapment, but neither has been rigorously studied. Our objective was to characterize the response of the PA to lower extremity exertion and dynamic ankle positioning in symptomatic and asymptomatic limbs. METHODS: Limbs characterized as symptomatic (n = 29) or asymptomatic (n = 61) had duplex ultrasound PA diameter and peak systolic velocity measurements with the ankle neutral and maximally plantar flexed. EABIs were obtained at rest and 1 minute and 5 minutes after walking (5 minutes, 3 mph, 10-degree incline) and running (5 minutes, 6 mph, 0-degree incline). Significance was set at P ≤ .05. Data are expressed as mean ± standard error of the mean. RESULTS: Plantar flexion resulted in PA occlusion and changes in diameter and peak systolic velocity in symptomatic (three occluded, -2.4 ± 0.34 mm, +49 cm/s) and asymptomatic (six occluded, -1.6 ± 0.21 mm, +65 cm/s) limbs. The difference in percentage change was significant between groups only for diameter change. EABIs in both groups were similar at rest, decreased with running and walking at 1 minute, and were not fully recovered by 5 minutes. Symptomatic limbs had a greater decrease in ABI than did asymptomatic limbs with both running and walking. The decrease was greatest at 1 minute after running and significantly more pronounced in symptomatic (-0.18) than in asymptomatic (-0.02) limbs. CONCLUSIONS: EABI decrease at 1 minute after running and PA diameter decrease with dynamic ankle plantar flexion are significantly greater in limbs with than without exertional lower extremity symptoms. These noninvasive measurements may be valuable in the workup of such symptoms. PA and tibial nerve compression at the popliteal outlet may be a more frequent cause of functionally limiting exertional lower extremity pain and neurologic symptoms than previously recognized.

Large Animal Models of Proximal Aortic Balloon Occlusion in Traumatic Hemorrhage: Review and Identification of Knowledge Gaps Relevant to Expanded Use.

BACKGROUND: The aim of this study was to review and summarize the large animal data on resuscitative endovascular balloon occlusion of the aorta (REBOA) for traumatic hemorrhage and identify knowledge gaps pertinent to the proposed broader use of the technique in prehospital situations. METHODS: A review of published large animal models of traumatic hemorrhage incorporating REBOA with a primary outcome of the effect of aortic occlusion was performed. Data were collected on experimental protocols, hemodynamic effects, resuscitation requirements, mortality, metabolic and tissue consequences of induced ischemia-reperfusion, and effects on hemorrhage volume and other injuries. RESULTS: A limited number of REBOA studies exist, and there is variability in the species and size of animals used. Various controlled and uncontrolled hemorrhage protocols have been studied, and a number of balloon devices used. Hemodynamic effects of occlusion were consistent as were basic systemic physiological effects. Minimal study of the effects of partial aortic occlusion and hemodynamic and metabolic physiology distal to the balloon has been performed, and partial or complete occlusion times >90 min have not been studied. CONCLUSIONS: Significant knowledge gaps exist, which are potentially relevant to the expanded use of REBOA. Investigation into the physiology of partial occlusion and the metabolic effects and potential mitigation strategies for large-scale ischemia and reperfusion are particularly needed.

Identifying content gaps in health status measures for intermittent claudication using the International Classification of Functioning, Disability and Health.

OBJECTIVE: The Walking Impairment Questionnaire (WIQ) and Intermittent Claudication Questionnaire (ICQ) are commonly used patient-reported functional outcome measures for intermittent claudication, but their functional representation has not been characterized. The World Health Organization's International Classification of Functioning, Disability and Health (ICF) framework comprehensively describes health-related function and has been used to evaluate health status and quality of life (QOL) measures. We applied a content analysis technique commonly used in functional rehabilitation research to evaluate ICF domains represented by WIQ and ICQ to characterize their health status and functional representation. METHODS: The overall perspective of each question was assigned as health status-function, health status-disability, Environment-facilitator, Environment-barrier, or QOL. All meaningful concepts in each question were identified and linked to the most appropriate and precise ICF code from the hierarchy of component, chapter, or category using the validated technique. A 20% random sample of questions was secondarily coded with disagreements resolved by discussion. RESULTS: Codability was agreed upon for 87% of questions; agreement was 100% on component and chapter and 88% on category. WIQ contains 18 concepts among 14 questions (1.3 concepts per question); all questions are from the health status-disability perspective. All WIQ concepts are from the "Activities/Participation-d" ICF component, "Mobility-d4" chapter. "Walking long distances" (d4501, >1 km) is omitted. ICQ contains 37 codable concepts among 16 questions (2.3 concepts per question). Thirteen questions are from health status-disability perspective, three from QOL. Sox of the nine chapters of the "Activities/Participation-d" ICF component are represented by 20 of 37 concepts; 11 of 20 in the "Mobility-d4" chapter. The other "Activities/Participation-d" chapters and categories in ICQ are "Learning/applying knowledge" ("thinking-d163"), "General tasks/demands" ("carrying out daily routine-d230"), "Domestic life" ("shopping-d6200," "doing housework-d640"), "Major life areas" ("Maintaining a job-d8451"), and "Community life" ("socializing-d9205," "hobbies-d9204"). "Body Functions-b" ICF component is represented 11 times, covering pain, numbness, emotion, mood, and cardiovascular functions. "Body Structures-s" is represented three times as lower extremity. Neither WIQ nor ICQ specifically addresses "Walking on different surfaces," (64,502) "Walking around obstacles" (d4503), or "Moving around using equipment" (d465), which includes assistive devices. Walking on an incline is not addressed in WIQ, ICQ, or the ICF. CONCLUSIONS: Applying this ICF-based content assessment methodology to patient-reported vascular disease outcome measures is feasible, representing a novel method of assessing such instruments. WIQ's scope is limited; it does not address functional capacity and covers only health status pertaining to walking disability. The ICQ is more inclusive, but concept density may obscure meaning. Neither instrument is functionally comprehensive and both have significant omissions that should be considered for inclusion.

Thirty-Day Outcomes after Elective Percutaneous or Open Endovascular Repair of Abdominal Aortic Aneurysms.

BACKGROUND: Percutaneous endovascular aneurysm repair (PEVAR) has become accepted as a suitable alternative to open EVAR (OEVAR) in the treatment of abdominal aortic aneurysms (AAAs). Direct comparisons between the 2 techniques have been infrequently reported and have predominantly focused on immediate procedural outcomes. The objective of this study was to compare contemporary 30-day postoperative outcomes between successfully completed elective PEVAR and OEVAR. METHODS: The 2012 National Surgical Quality Improvement Program database was queried for all elective primary AAA repairs. Procedures on ruptured AAAs and those involving adjunctive thoracic, abdominal, or extremity procedures were excluded. Cases completed with at least one surgical exposure of the femoral artery for access (OPEN) were compared with those completed without such exposure (PERC). Preoperative, intraoperative, and 30-day postoperative variables were compared using appropriate univariate statistical tests. A P value of ≤0.05 was considered significant for all comparisons. RESULTS: A total of 1,589 (51%) OPEN and 1,533 (49%) PERC cases met inclusion and exclusion criteria. Preoperative characteristics did not differ between groups. OPEN cases took significantly longer (150 ± 69 min) than PERC cases (134 ± 65 min, P < 0.001). No significant differences were found between the groups in any postoperative occurrence, but the rate of venous thromboembolism twice as high in OPEN (16, 1.0%) than PERC cases (7, 0.5%, P = 0.07). In addition, wound complications (36, 2.3% OPEN vs. 23, 1.3% PERC, P = 0.11) were more common in OPEN cases but were diagnosed a week sooner on average in PERC cases (19 days OPEN and 12 days PERC). Median postoperative length of stay was 2 days among OPEN cases versus 1 day in PERC cases (P = 0.11). Female gender and obesity predicted wound complications in the OPEN group but not in the PERC group. CONCLUSIONS: Successfully completed PEVAR and OEVAR have similar rates of overall complications. Female gender and obesity predict wound complications in OEVAR but not in PEVAR, which appears to be a safe alternative to OEVAR. PEVAR has the advantage of shorter operative time and the potential for a shorter postoperative stay, and may offer the advantage of fewer wound complications in females and obese patients.

Acute Aortic Syndromes from Diagnosis to Treatment-A Comprehensive Review.

This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an "aorta code". Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in "aortic centres" improves long-term outcomes and decreases mortality rates.

Recent advances and the future of abdominopelvic and lower extremity vascular injury management.

Despite advances in open and endovascular management of trauma, vascular injuries remain a source of devastating outcomes. This narrative review of the literature between 2018 and 2023 explored recent advances in abdominopelvic and lower extremity vascular injury management. New conduit choices, use of temporary intravascular shunts, and advances in endovascular management of vascular trauma were reviewed. Although endovascular techniques are being applied more frequently, there is a paucity of reporting on long-term outcomes. Open surgery is durable and effective and remains the gold standard for repairing most abdominal, pelvic, and lower extremity vascular injuries. Vascular reconstruction conduit options are currently limited to the autologous vein, prosthetic grafts, and cryopreserved cadaveric xenografts; each type has its own application challenges. The temporary intravascular shunts can be used to restore early perfusion to ischemic limbs and increase the chances of limb salvage, or when transfer of care is needed. Resuscitative balloon occlusion of the inferior vena cava has been a research-heavy topic to investigate the possible implications in patients with trauma. Early diagnosis, appropriate use of technology, and time-sensitive management can make all the difference in the lives of patients with vascular trauma. Endovascular management of vascular trauma is evolving and gaining wider acceptance for treatment of vascular injuries. Computed tomography angiography is widely available and is the current gold standard for diagnosis. Autologous vein remains the gold standard for conduit with the future promise of new innovative conduits. Vascular surgeons have an important role in vascular trauma management.

Analysis of 5-year Mortality following Lower Extremity Amputation due to Vascular Disease.

Mortality rates following major lower extremity amputations (LEAs) 30 days-365 days postoperative have decreased, but 5-year rates remain high at 40.4%-70%. These data may not reflect recent advances in peripheral arterial disease (PAD) care, and comorbidities of chronic PAD may lead to mortality more frequently than the amputation itself. Mortality rates between diabetic and nondiabetic patients were also analyzed. Methods: The California Office of Statewide Health Planning and Development hospital database was queried for patients admitted January 1, 2007-December 31, 2018. ICD-9-CM codes identified patients with vascular disease and an amputation procedure. Results: There were 26,669 patients. The 30-day, 90-day, 1-year, and 5-year major LEA mortality rates were 4.82%, 8.62%, 12.47%, and 18.11%, respectively. Weighted averages of 30-day, 90-day, 1-year, and 5-year major LEA mortality rates in the literature are 13%, 15.40%, 47.93%, and 60.60%, respectively. Mortality risk associated with vascular disease after amputation (hazard ratio = 22.07) was 11 times greater than risk associated with amputation-specific complications from impaired mobility (hazard ratio = 1.90; P < 0.01). Having diabetes was associated with lower mortality at 30 days, 90 days, and 1 year (P < 0.01) but not at 5 years (P = 0.22). Conclusions: This study suggests that people may be living longer after their major LEA than was previously thought. This study suggests that patients' PAD may play a bigger role in contributing to their mortality than complications from loss of mobility postamputation. Although having diabetes was associated with lower postamputation mortality, the difference was no longer significant by 5 years.