Evaluation of novel hemostatic agents in a coagulopathic swine model of junctional hemorrhage.

BACKGROUND: Hemostatic dressings are used extensively in both military and civilian trauma to control lethal noncompressible hemorrhage. The ideal topical hemostatic agent would provide reliable hemostasis in patients with profound acidosis, coagulopathy, and shock. This study aimed to compare next-generation hemostatic agents against the current military standard in a translational swine model of vascular injury and coagulopathy. METHODS: Female Yorkshire swine were randomized to eight groups (total n = 63; control n = 14, per group n = 7) of hemostatic agents and included: QuikClot Combat Gauze (Teleflex, Morrisville, NC), which served as the control; BloodSTOP IX (LifeScience Plus, Mountain View, CA); Celox Rapid (Medtrade Product, Crewe, United Kingdom); ChitoSAM 100 (Sam Medical, Tualatin, OR); EVARREST Fibrin Sealant Patch (Ethicon, Raritan, NJ); TAC Wrapping Gauze (H&H Medical, Williamsburg, VA); ChitoGauze XR Pro (Tricol Biomedical, Portland, OR); and X-Stat 30 (RevMedX, Wilsonville, OR). Hemodilution via exchange transfusion of 6% hetastarch was performed to induce acidosis and coagulopathy. An arteriotomy was created, allowing 30 seconds of free bleeding followed by application of the hemostatic agent and compression via an external compression device. A total of three applications were allowed for continued/recurrent bleeding. All blood loss was collected, and hemostatic agents were weighed to calculate blood volume loss. Following a 180-minute observation period, angiography was completed to evaluate for technical complication and distal perfusion of the limb. Finally, the limb was ranged five times to assess for rebleeding and clot stability. RESULTS: All swine were confirmed coagulopathic with rotational thromboelastography and acidotic (pH 7.2 ± 0.02). BloodSTOP IX allowed a significant increase in blood loss and number of applications required to obtain hemostasis compared with all other groups. BloodSTOP IX demonstrated a decreased survival rate (29%, p = 0.02). All mortalities were directly attributed to exsanguination as a result of device failure. In surviving animals, there was no difference in extravasation. BloodSTOP IX had an increased rebleeding rate after ranging compared with QuikClot Combat Gauze ( p = 0.007). CONCLUSION: Most novel hemostatic agents demonstrated comparable efficacy compared with the currently military standard hemostatic dressing, CG.

Next-Generation REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta) Device Precisely Achieves Targeted Regional Optimization in a Porcine Model of Hemorrhagic Shock.

INTRODUCTION: Limitations such as time-dependent distal ischemia have slowed the adoption of resuscitative endovascular balloon occlusion of the aorta (REBOA) for noncompressible hemorrhage. Next-generation REBOA technologies may allow for controlled partial flow, known as targeted regional optimization, to reduce distal ischemia. We aimed to characterize the efficacy of one such catheter in a porcine model of lethal hemorrhagic shock. METHODS: Noncompressible hemorrhage from an iliac injury was induced in anesthetized swine (Sus scrofa) (70-90 kg), targeting 30% total blood volume. Animals were then randomized to partial aortic occlusion (PO) with targeted distal mean arterial pressure (MAP) of 35-40 mm of mercury (mm Hg) and complete aortic occlusion (CO) (n = 8 per group) for 90 min. All groups were then resuscitated during a two-h critical care (CC) phase, with flow rate and MAP recorded continuously at the distal infrarenal aorta and proximal carotid artery, and analyzed with two-way repeated measures analysis of variance with S-N-K post-hoc test. RESULTS: During aortic occlusion, MAP distal to the balloon was consistently maintained at 35.8 ± 0.3 mm Hg in the PO group compared to 27.1 ± 0.3 mm Hg in the CO group (P < 0.05), which also corresponded to higher flow rates (202.9 ± 4.8 mL/min PO versus 25.9 ± 0.8 mL/min CO; P < 0.05). MAP proximal to the balloon was significantly higher with CO versus PO (109.2 ± 2.3 mm Hg versus 85.2 ± 2.3 mm Hg; P < 0.05). During the CC phase, distal aortic flow and MAP were not significantly different between groups. However, creatinine returned to baseline levels by the end of the study in the PO group, but not the CO group. One animal died in the CO group, whereas none died in the PO group. CONCLUSIONS: This is the first examination of the next-generation pREBOA-PRO in a porcine model of lethal hemorrhagic shock. We show technical feasibility of this technique to precisely achieve targeted regional optimization without device failure or complication. The ability to titrate balloon inflation and thus distal flow/pressure may extend the therapeutic window of REBOA by mitigating distal ischemia.

Advanced partial occlusion controller allows for increased precision during targeted regional optimization in a porcine model of hemorrhagic shock.

BACKGROUND: Targeted regional optimization (TRO), a partial resuscitative endovascular balloon occlusion of the aorta strategy, may mitigate distal ischemia and extend the window of effectiveness for this adjunct. An automated device may allow greater control and precise regulation of flow past the balloon, while being less resource-intensive. The objective of this study was to assess the technical feasibility of the novel advanced partial occlusion controller (APOC) in achieving TRO at multiple distal pressures. METHODS: Female swine (n = 48, 68.1 ± 0.7 kg) were randomized to a target distal mean arterial pressure (MAP) of 25 mm Hg, 35 mm Hg, or 45 mm Hg by either manual (MAN) or APOC regulation (n = 8 per group). Uncontrolled hemorrhage was generated by liver laceration. Targeted regional optimization was performed for 85 minutes, followed by surgical control and a 6-hour critical care phase. Proximal and distal MAP and flow rates were measured continuously. RESULTS: At a target distal MAP of 25 mm Hg, there was no difference in the MAP attained (APOC: 26.2 ± 1.05 vs. MAN: 26.1 ± 1.78 mm Hg) but the APOC had significantly less deviance (10.9%) than manual titration (14.9%, p < 0.0001). Similarly, at a target distal MAP of 45 mm Hg, there was no difference in mean pressure (44.0 ± 0.900 mm Hg vs. 45.2 ± 1.31 mm Hg) but APOC had less deviance (9.34% vs. 11.9%, p < 0.0001). There was no difference between APOC and MAN in mean (34.6 mm Hg vs. 33.7 mm Hg) or deviance (9.95% vs. 10.4%) at a target distal MAP of 35 mm Hg, respectively. The APOC made on average 77 balloon volume adjustments per experiment compared with 29 by manual titrations. CONCLUSION: The novel APOC consistently achieved and sustained precisely regulated TRO across all groups and demonstrated reduced deviance at the 25 mm Hg and 45 mm Hg groups compared with manual titration.

Targeted Regional Optimization in Action: Dose-dependent End-organ Ischemic Injury with Partial Aortic Occlusion in the Setting of Ongoing Liver Hemorrhage.

INTRODUCTION: Targeted regional optimization (TRO) describes partial resuscitative endovascular balloon occlusion of the aorta strategy that allows for controlled distal perfusion to balance hemostasis and tissue perfusion. This study characterized hemodynamics at specific targeted distal flow rates in a swine model of uncontrolled hemorrhage to determine if precise TRO by volume was possible. METHODS: Anesthetized swine were subjected to liver laceration and randomized into TRO at distal flows of 300 mL/min (n = 8), 500 mL/min (n = 8), or 700 mL/min (n = 8). After 90 min, the animals received damage control packing and were monitored for 6 h. Hemodynamic parameters were measured continuously, and hematology and serologic labs obtained at predetermined intervals. RESULTS: During TRO, the average percent deviation from the targeted flow was lower than 15.9% for all cohorts. Average renal flow rates were significantly different across all cohorts during TRO phase (P < 0.0001; TRO300 = 63.1 ±â€Š1.2; TRO500 = 133.70 ±â€Š1.93; TRO700 = 109.3 ±â€Š2.0), with the TRO700 cohort having less renal flow than TRO500. The TRO500 and TRO700 average renal flow rates inverted during the intensive care unit phase (P < 0.0001; TRO300 = 86.20 ±â€Š0.40; TRO500 = 148.50 ±â€Š1.45; TRO700 = 181.1 ±â€Š0.70). There was higher blood urea nitrogen, creatinine, and potassium in the TRO300 cohort at the end of the experiment, but no difference in lactate or pH between cohorts. CONCLUSION: This study demonstrated technical feasibility of TRO as a strategy to improve outcomes after prolonged periods of aortic occlusion and resuscitation in the setting of ongoing solid organ hemorrhage. A dose-dependent ischemic end-organ injury occurs beginning with partial aortic occlusion that progresses through the critical care phase, with exaggerated effect on renal function.

A multi-registry analysis of military and civilian penetrating cervical carotid artery injury.

INTRODUCTION: Penetrating cervical carotid artery injury is an uncommon but high-stake scenario associated with stroke and death. The objective of this study was to characterize and compare penetrating carotid injury in the military and civilian setting, as well as provide considerations for management. METHODS: Cohorts with penetrating cervical carotid artery injury from the Department of Defense Trauma Registry (2002-2015) and the American Association for the Surgery of Trauma Prospective Observation Vascular Injury Treatment Registry (2012-2018) were analyzed. A least absolute shrinkage and selection operator multivariate analysis using random forest-based imputation was performed to identify risk factors affecting stroke and mortality. RESULTS: There were a total of 157 patients included in the study, of which 56 (35.7%) were military and 101 (64.3%) were civilian. The military cohort was more likely to have been managed with open surgery (87.5% vs. 44.6%, p < 0.001) and to have had any procedure to restore or maintain flow to the brain (71.4% vs. 35.6%, p < 0.001), while the civilian cohort was more likely to undergo nonoperative management (45.5% vs. 12.5%, p < 0.001). Stroke rate was higher within the military cohort (41.1% vs. 13.9%, p < 0.001); however, mortality did not differ between the groups (12.5% vs. 17.8%, p = 0.52). On multivariate analysis, predictors for stroke were presence of a battle injury (log odds, 2.1; p < 0.001) and internal or common carotid artery ligation (log odds 1.5, p = 0.009). For mortality outcome, protective factors included a high Glasgow Coma Scale on admission (log odds, -0.21 per point; p < 0.001). Increased admission Injury Severity Score was a predictor of mortality (log odds, 0.05 per point; p = 0.005). CONCLUSION: The stroke rate was higher in the military cohort, possibly reflecting complexity of injury; however, there was no difference in mortality between military and civilian patients. For significant injuries, concerted efforts should be made at carotid reconstruction to reduce the occurrence of stroke. LEVEL OF EVIDENCE: Retrospective cohort analysis, level III.

Targeted Regional Optimization: Increasing the Therapeutic Window for Endovascular Aortic Occlusion In Traumatic Hemorrhage.

ABSTRACT: Resuscitative endovascular balloon occlusion of the aorta (REBOA) allows for effective temporization of exsanguination from non-compressible hemorrhage (NCTH) below the diaphragm. However, the therapeutic window for aortic occlusion is time-limited given the ischemia-reperfusion injury generated. Significant effort has been put into translational research to develop new strategies to alleviate the ischemia-reperfusion injury and extend the application of endoaortic occlusion. Targeted regional optimization (TRO) is a partial REBOA strategy to augment proximal aortic and cerebral blood flow while targeting minimal threshold of distal perfusion beyond the zone of partial aortic occlusion. The objective of TRO is to reduce the degree of ischemia caused by complete aortic occlusion while providing control of distal hemorrhage. This review provides a synopsis of the concept of TRO, pre-clinical, translational experiences with TRO and early clinical outcomes. Early results from TRO strategies are promising; however, further studies are needed prior to large-scale implementation into clinical practice.

Temporary intravascular shunt use improves early limb salvage after extremity vascular injury.

OBJECTIVE: The use of temporary intravascular shunts (TIVSs) allow for restoration of distal perfusion and reduce ischemic time in the setting of arterial injury. As a damage control method, adjunct shunts restore perfusion during treatment of life-threatening injuries, or when patients require evacuation to a higher level of care. Single-center reports and case series have demonstrate that TIVS use can extend the opportunity for limb salvage. However, few multi-institutional studies on the topic have been reported. The objective of the present study was to characterize TIVS use through a multi-institutional registry and define its effects on early limb salvage. METHODS: Data from the Prospective Observation Vascular Injury Treatment registry was analyzed. Civilian patients aged ≥18 years who had sustained an extremity vascular injury from September 2012 to November 2018 were included. Patients who had a TIVS used in the management of vascular injury were included in the TIVS group and those who had received treatment without a TIVS served as the control group. An unadjusted comparison of the groups was conducted to evaluate the differences in the baseline and outcome characteristics. Double robust estimation combining logistic regression with propensity score matching was used to evaluate the effect of TIVS usage on the primary end point of limb salvage. RESULTS: TIVS use was identified in 78 patients from 24 trauma centers. The control group included 613 patients. Unmatched analysis demonstrated that the TIVS group was more severely injured (mean ± standard deviation injury severity score, 18.83 ± 11.76 for TIVS vs 14.93 ± 10.46 for control; P = .002) and had more severely mangled extremities (mean ± standard deviation abbreviated injury scale, extremity, score 3.23 ± 0.80 for TIVS vs 2.95 ± 0.87 for control; P = .008). Logistic regression demonstrated that propensity-matched control patients had a three times greater likelihood of amputation compared with the TIVS patients (odds ratio, 3.6; 95% confidence interval, 1.2-11.1; P = .026). Concomitant nerve injury and orthopedic fracture were associated with a greater risk of amputation. The median follow-up for the TIVS group was 12 days (interquartile range, 4-25 days) compared with 9 days (interquartile range, 4-18 days) for the control group. CONCLUSIONS: To the best of our knowledge, the present study is the first multicenter, matched-cohort study to characterize early limb salvage as a function of TIVS use in the setting of extremity vascular injury. Shunts expedite limb perfusion and resulted in lower rates of amputation during the early phase of care. The use of TIVS should be one part of a more aggressive approach to restore perfusion in the most injured patients and ischemic limbs.

Management and outcomes of wartime cervical carotid artery injury.

BACKGROUND: Cervical carotid artery injuries entail high morbidity and mortality and are technically challenging to repair. This retrospective study describes the management and outcomes of cervical carotid injuries sustained during the recent wars in Iraq and Afghanistan. METHODS: The Department of Defense Trauma Registry was queried to identify US military personnel who sustained battle-related cervical carotid injury between January 2002 and December 2015. Retrospective chart reviews of the military Electronic Health Record were performed on patients identified. Demographics, injury characteristics, surgical management, and outcomes were reviewed. Statistical analysis was performed to identify associations between injury and management factors, as well as stroke and mortality. RESULTS: In total, 67 patients (100% male; age, 25 ± 7 years) were identified with cervical carotid artery injuries. Fifty-six patients (84%) sustained a common carotid artery (CCA) or internal carotid artery (ICA) injury, and 11 patients (16%) had an isolated external carotid artery (ECA) injury. The anatomic distribution of injury was as follows: CCA, 26 (38.8%); ICA, 24 (35.8%); CCA and ICA 2 (3%); ICA and ECA 3 (4.5%); and CCA, ICA, and ECA 1 (1.5%). Of the 56 CCA or ICA injuries, 39 underwent vascular repair, 9 (16%) were managed with ligation, 1 was treated with a temporary vascular shunt but succumbed to injuries before vascular repair, and 7 (13%) were treated nonoperatively. Seven (23%) of 30 ICA injuries were ligated compared with 2 (7.7%) of 26 injuries isolated to the CCA (p = 0.02). Compared with repair, ligation of the CCA/ICA was associated with a higher rate of stroke (89% vs. 33%, p = 0.003) and increased mortality without statistical significance (22% vs. 10%, p = 0.3). Every patient who underwent ICA ligation had a stroke (7/7). There was no difference in Injury Severity Score between the ligation and repair groups (23.8 ± 10.6 vs. 24.7 ± 13.4, p = 0.9). At a mean follow-up of 34.5 months, 10 of 17 stroke survivors had permanent neurologic deficits. CONCLUSION: In modern combat, penetrating injuries involving the cervical carotid arteries are relatively infrequent. In this experience, isolated ICA injuries were three times more likely to be ligated than those involving the CCA. As a surgical maneuver, ICA ligation resulted in stroke in all cases. LEVEL OF EVIDENCE: Retrospective cohort analysis, level III.

Carotid Endarterectomy for Ocular Ischemic Syndrome: A Case Report and Review of the Literature.

Ocular ischemic syndrome is a rare complication of carotid arterial disease that can lead to irreversible vision loss. The disease is related to ocular hypoperfusion secondary to carotid stenosis. Carotid endarterectomy (CEA) has been proven to reduce the risk of embolic stroke in specific patient populations; however, the role of CEA in the treatment of ocular ischemic syndrome or other flow-related symptoms is less well defined. We present a case of ocular ischemic syndrome successfully treated with carotid endarterectomy, and summarize the current literature regarding management of ocular ischemic syndrome.

Infraclavicular Thoracic Outlet Decompression Compared to Supraclavicular Thoracic Outlet Decompression for the Management of Venous Thoracic Outlet Syndrome.

BACKGROUND: The treatment of venous thoracic outlet syndrome (VTOS) requires surgical decompression often combined with catheter-directed thrombolysis and venoplasty. Surgical options include transaxillary, supraclavicular, or infraclavicular approaches to first rib resection. The optimal method, however, has yet to be defined. The purpose of this study is to compare the outcomes of patients who underwent infraclavicular versus supraclavicular surgical decompression for VTOS. METHODS: A retrospective review of patients who underwent surgical management for VTOS from December 2010 to November 2017 was performed. During the study period, supraclavicular and infraclavicular approaches were chosen according to surgeon preference. Patient demographics, pre- and postdecompression interventions, perioperative outcomes for each group of patients were analyzed. RESULTS: Thirty patients underwent surgical management of VTOS, of which 15 (50%) underwent infraclavicular decompression and 15 (50%) supraclavicular decompression. The mean age of patients was 32.1 ± 13.6 years and 80% were male. Twenty-six patients (86.7%) presented with thrombotic VTOS. Acute axillosubclavian vein thrombosis was present in 20 (76.9%) of these patients, 10 patients in each group. Subacute or chronic thrombosis was encountered in the remaining 6 (23%) patients, 2 patients in the infraclavicular group and 4 patients in the supraclavicular group. Preoperative thrombolysis was utilized in 7 (46.7%) and 6 (40%) patients in the infraclavicular and supraclavicular groups, respectively (P = 1.00). Patients without postdecompression venography were removed from analysis and included 1 patient in the infraclavicular group and 5 patients in the supraclavicular group. Initial postdecompression venogram, prior to any endovascular intervention, demonstrated a residual axillosubclavian vein stenosis of greater than 50% in 6 (42.9%) patients in the infraclavicular decompression group and 7 (70%) patients in the supraclavicular decompression group (P = 0.24). Crossing the stenosis after surgical decompression was more easily accomplished in the infraclavicular group, 14 (100%) versus 5 (50%), (P = 0.01). Following endovascular venoplasty, calculated residual stenosis greater than 50% was found in 0 (0%) and 3 (30%) patients in the infraclavicular and supraclavicular approaches, respectively (P = 0.047). Infraclavicular thoracic outlet decompression was associated with fewer patients with postoperative symptoms, 0 of 15 (0%) versus 8 of 15 (53.3%), (P = 0.0022), and infraclavicular thoracic outlet decompression demonstrated improved patency, 15 of 15 (100%) versus 8 of 15 (53.3%), (P = 0.028) at a mean combined follow-up of 8.47 ± 10.8 months. CONCLUSIONS: Infraclavicular thoracic outlet decompression for the surgical management of VTOS was associated with fewer postoperative symptoms and improved axillosubclavian vein patency compared to the supraclavicular approach. Prospective analysis is warranted to determine long-term outcomes following infraclavicular decompression.

Epidemiology of Upper Extremity Vascular Injury in Contemporary Combat.

BACKGROUND: The incidence of wartime upper-extremity vascular injury (UEVI) has been stable for the past century. The objective of this study is to provide a contemporary review of wartime UEVI, including epidemiologic characterization and description of early limb loss. METHODS: The Department of Defense Trauma Registry (DoDTR) was queried to identify US service members who sustained a battle-related UEVI in Afghanistan between January 2009 and December 2015. Anatomic distribution of injury, mechanism of injury (MOI), associated injuries, early management, and early limb loss were analyzed. RESULTS: Analysis identified 247 casualties who sustained 308 UEVIs. The most common injury was to the vessels distal to the brachial bifurcation (63.3%, n = 195), followed by the brachial vessels (27.3%, n = 84) and the axillary vessels (9.4%, n = 29). The predominant MOIs were penetrating explosive fragments (74.1%, n = 183) and gunshot wounds (25.9%, n = 64). Associated fractures were identified in 151 (61.1%) casualties and nerve injuries in 133 (53.8%). Angiography was performed in 91 (36.8%) casualties, and endovascular treatment was performed 10 (4%) times. Temporary vascular shunts were placed in 39 (15.8%) casualties. Data on surgical management were available for 171 injuries and included repair (48%, n = 82) and ligation (52%, n = 89). The early limb loss rate was 12.1% (n = 30). For all casualties sustaining early limb loss, the MOI was penetrating fragments from an explosion; the average injury severity score (ISS) was 32.3, and the mortality was 6.7% (n = 2). In those without amputation, the ISS and mortality were low at 20 and 4.6% (n = 10), respectively. Overall mortality was 4.9% (n = 12). CONCLUSIONS: The early limb loss rate was increased compared with initial descriptions from Operation Iraqi Freedom. Amputations are associated with a higher ISS. Improved data capture and fidelity, or differing MOIs, may account for this trend. Proficiency with open and endovascular therapy remains a critical focus for combat casualty care.

Delayed Presentation of Gluteal Compartment Syndrome due to Pseudoaneurysm Rupture: A Case Report.

CASE: We present a 26-year-old active duty man who sustained a coccygeal fracture and gluteus maximus hematoma after a fall from height during training. The patient returned 3 weeks postinjury with symptoms and physical examination findings concerning for gluteal compartment syndrome. An expanding gluteal hematoma was confirmed on imaging and the patient was taken to the operating room for emergent evacuation and endovascular hemostasis. CONCLUSIONS: This case of gluteal compartment syndrome is a unique contribution to the literature with respect to the specific vascular injury observed and the delayed presentation of gluteal compartment syndrome.

A contemporary, 7-year analysis of vascular injury from the war in Afghanistan.

OBJECTIVE: Vascular injury is a leading cause of death and disability in military and civilian trauma. Although a previous interim study defined the distribution of vascular injury during the wars in Iraq and Afghanistan, a contemporary epidemiologic assessment has not been performed. The objective of this study was to provide a current analysis of vascular injury during the final 7 years of the war in Afghanistan, including characterization of anatomic injury patterns, mechanisms of injury, and methods of acute management. METHODS: The Department of Defense Trauma Registry was analyzed to identify U.S. military service members who sustained a battle-related vascular injury and survived to be treated at a surgical facility in Afghanistan between January 1, 2009, and December 31, 2015. All battle-related injuries (nonreturn to duty) were used as a denominator to establish the injury rate. Mechanism and anatomic distribution of injury as well as the acute management strategies of revascularization, ligation, and use of endovascular techniques were defined. RESULTS: Of 3900 service members who sustained a battle-related injury, 685 patients (17.6%) had 1105 vascular injuries (1.6 vascular injuries per patient). Extremity trauma accounted for 72% (n = 796) of vascular injuries, followed by the torso (17%; n = 188) and cervical (11%; n = 118) regions. Lower extremity vascular injury was the most prevalent anatomic location (45%; 501/1105). Explosion with fragment penetration accounted for 70% (477/685) of injuries, whereas gunshot wounds accounted for 30% (205/685). Open repair was performed in 559 cases (57%; 554/981), whereas ligation was the initial management strategy in 40% (395/981) of cases. In addition, 374 diagnostic endovascular procedures were completed, 27 therapeutic endovascular interventions to include stent placement and angioplasty were performed and 55 inferior vena cava filters were placed. Mortality of the vascular injury cohort was 5%. CONCLUSIONS: The rate of vascular injury in modern combat is higher than that reported in previous wars. Open reconstruction is performed in half of cases, although ligation is an important damage control option, especially for minor or distal vessel injuries. Angiographic techniques are increasingly being used and documented within wartime registries more than ever. Proficiency with open and endovascular methods of vascular injury management remains a critical need for the U.S. military and will require partnership with civilian institutions to attain and maintain.

Critical Limb Ischemia Secondary to Antiphospholipid Syndrome in a Pediatric Patient: Case Report and Review.

BACKGROUND: Antiphospholipid syndrome (APS) is a condition that manifests as venous or arterial thrombosis, as well as complications of pregnancy. APS affecting primarily the arteries is less common when compared to venous complications. We present a case of arterial occlusion resulting in critical limb ischemia (CLI) in a pediatric patient. METHODS: A 14-year old boy presented with worsening right lower extremity pain and ulcerative lesions of his foot. Laboratory analysis revealed a diagnosis of APS. This case report and review of the literature expands our understanding of arterial manifestations of APS in the pediatric patient. RESULTS: The patient was discovered to have proximal occlusion of the superficial femoral artery (SFA), the distal popliteal artery, the anterior tibial artery at the mid-calf, and the posterior tibial artery at the ankle. He underwent a common femoral artery to above-knee-popliteal artery bypass with reversed greater saphenous graft. Follow up after over one-year demonstrated an ABI of 1.0 and no evidence of stenosis in the bypass graft on duplex ultrasound (DUS). CONCLUSIONS: APS is a complex syndrome with a variety of clinical presentations. This case highlights arterial manifestations of APS and reviews the expanding literature to guide improved patient outcomes.

A quality improvement project to improve inferior vena cava filter retrieval.

OBJECTIVE: Poor retrieval rates for retrievable inferior vena cava filters (R-IVCFs) have been reported throughout the literature, with poor follow-up a common cause. In 2009, we reported a retrieval rate of 18% despite an initial follow-up rate of 85%. Use of a registry has been shown to improve retrieval rates. As a quality improvement project, in May 2012, the vascular surgery fellowship implemented a reiterative registry to track R-IVCFs placed at Walter Reed National Military Medical Center to improve retrieval rates. We report the results in 125 patients after 38 months. METHODS: Patients receiving an R-IVCF were entered into a registry. All patients were reviewed monthly using an electronic health record. When there was no longer an indication for the R-IVCF, the patient was scheduled for an outpatient appointment with a vascular surgeon followed by retrieval. Rates of retrieval, technical success, dwell time, indication, complications, and demographics were collected. RESULTS: There were 125 R-IVCFs placed between May 2012 and June 2015; 52 filters were placed for therapeutic and 73 for prophylactic indications. Our follow-up rate improved to 94%. A total of 79 filters were retrieved (63% absolute retrieval rate). Excluding patients who died before retrieval and patients with a permanent indication, 77% of filters were retrieved. The average dwell time was 101.5 days (7-460 days), and 63% of successful R-IVCF retrievals were within 3 months of placement. Technical success for retrieval was 92%. There were two major complications from retrievals (1.5% of retrievals). CONCLUSIONS: The creation of an R-IVCF registry promoted ongoing follow-up with patients. In our earlier experience, retrieval rates were poor despite a high follow-up rate. The use of a reiterative registry improved our retrieval rate by 45% and increased our follow-up rate to 94%. These results emphasize the importance of repetitive follow-up for R-IVCFs. Despite a follow-up rate >90%, around a third of R-IVCFs were not retrieved.

Aortic Dissection as a Cause of Pulsus Bisferiens: A Case Report and Review.

We present a case of a 62-year-old woman who developed an aortic dissection after aortic valve replacement for aortic stenosis and supracoronary replacement of the ascending aorta for aneurysmal dilation. Dynamic compression of the distal aorta by the dissection flap was identified with the detection of abnormal continuous wave Doppler signals heard while performing ankle-brachial indices. Duplex ultrasound (US) and Doppler spectral waveforms confirmed dynamic compression of the distal aorta with each cardiac cycle. We review some of the characteristics of continuous wave Doppler signals, specifically discussing the distinguishing characteristics of pulsus bisferiens, and the use of duplex US in imaging the distal aorta.

Permacol interposition graft as an alternative to vein in contaminated wounds using a rabbit model.

BACKGROUND: Vascular injuries are common in trauma and often involve massive soft tissue injury and segmental arterial loss. Current practice uses either autogenous vein or polytetrafluorethylene (PTFE) for interposition grafting in arterial injuries. Decision making between autogenous or synthetic conduit pivots around the physiological state of the trauma patient. Vein is known to increase operative times in an already physiologically depleted patient, whereas synthetic graft can be simply pulled from the shelf. However, when used in contaminated wounds, PTFE is prone to chronic infection and subsequent graft failure. An alternative synthetic conduit resistant to infection would be ideal for such situations. Permacol (Tissue Science Laboratories, Inc, Andover, MA), a biosynthetic material, has demonstrated resistance to bacterial contamination in contaminated hernia repairs. When fashioned into a tubular structure, this material may be useful as an alternative vascular conduit in contaminated trauma wounds. METHODS: New Zealand white rabbits were randomized to one of 4 groups: Permacol graft (P) without bacterial contamination (n = 9), Permacol graft with bacterial contamination (CP; n = 9), autogenous vein graft without bacterial contamination (V; n = 9), or autogenous vein with bacterial contamination (CV; n = 9). All groups then underwent interposition grafting of the right common carotid artery. Grafts were contaminated by applying Staphylococcus aureus (1 × 10(5) colonies/0.1 mL) directly to the exposed surface of the graft on completion of the arterial repair. Each graft was then excised at day 42, and segments were collected for histologic evaluation, bacterial counts, and real-time polymerase chain reaction. RESULTS: Of the 36 rabbits used in this study, 3 animals in the CV group died within 72 hr of surgery. There was no difference in early mortality between P and V (0% vs. 0%; P = 1.0); however, early mortality was higher in the CV compared with the CP group (33% vs. 0%; P = 0.023). At 42 days, histologic evaluation of graft patency demonstrated no difference between P and V (67% vs. 33%; P = 0.157); however, patency was higher in CP than CV (56% vs. 12%; P = 0.040). In addition, no difference was found between the 2 contaminated groups in regard to the number of bacteria present on each graft material. CONCLUSIONS: Permacol as an interposition graft is a feasible alternative to vein in a contaminated setting and shows resistance to infection in a rabbit model. Future studies are needed to evaluate this material in larger animal models.