Comparison Study of Iliac Branch Endoprosthesis when Used on and off Label.

BACKGROUND: The aim of this study is to compare how instructions for use (IFU) affected perioperative and intermediate term outcomes for common iliac artery aneurysms (CIAA) treated with the Gore Excluder iliac branch endoprosthesis (IBE). METHODS: A retrospective analysis was performed of all patients treated at two affiliated academic centers from September 2016 to May 2020. Outcomes were compared between IFU and nonIFU IBE cases. Criteria for nonIFU included: (1) use with a nonGore aortic endoprosthesis (n = 10), (2) isolated IBE (n = 3), and (3) requiring nondedicated covered stents for additional extension into a more suitable landing zone in the ipsilateral internal iliac artery or one of its branches (n = 11). Perioperative and intermediate term data were collected for both groups. The primary end points were free from the major adverse event (MAE) at 30 days and primary effectiveness at 1 year. RESULTS: A total of 51 CIAA (39 patients) were treated with an IBE. Overall, 15 patients were treated under IFU and 24 under nonIFU. The IFU group mean age was older (72 vs. 67 years, P = 0.03), and males (97%) were primarily treated. Comorbidities were similar except nonIFU had more patients with previous endovascular abdominal aortic aneurysm repair on presentation (0 vs. 4 cases, P = 0.04). Procedure (178 vs. 264 min, P = 0.02) and fluoroscopy (52 vs. 74 min, P = 0.04) times were longer in the nonIFU group. Technical success was 100% for both groups, and there was no difference in device related reintervention at 30 days (0 vs. 1, P = 0.44). There was no MAE in either group at 30 days. Intervention for any endoleak was similar between the groups (2 vs. 3, P = 0.94). Percent CIAA sac regression was similar between the groups (19% vs. 18%, P = 0.21). There was no difference for primary effectiveness at 1 year (93% vs. 92%, P = 0.85). There was one death per group at one year not related to an aortic or iliac cause. CONCLUSIONS: In properly selected patients with complex anatomy, IBE can be used with nondedicated aortic and internal iliac components with good early term outcomes.

Carbon Dioxide Pyelography: A Convenient and Safe Alternative to Both Room Air and Iodinated Contrast Pyelography During Endourologic Procedures.

Introduction/Background: There are increasing reports of serious complications related to the air pyelography technique, which raise concerns about the safety of room air (RA) injection into the renal collecting system. Carbon dioxide (CO2) is much more soluble in blood than nitrogen and oxygen and thus considerably less likely to cause gas emboli. Iodinated contrast medium (ICM) is expensive, and supplies may not be as reliable as previously assumed. CO2 pyelography (CO2-P) techniques using standard fluoroscopy and digital subtraction fluoroscopy (CO2 digital subtraction pyelography [CO2-DSP]) are described. Materials and Methods: During the endourologic stone cases, 15 to 20 mL of CO2 gas was typically injected into the renal pelvis through a catheter or sheath. Imaging was usually obtained with endovascular CO2 digital subtraction angiography settings using either a traditional fluoroscopy system (TFS) or robotic arm multiplanar fluoroscopy system (RMPFS) (Artis Zeego Care+Clear®; Siemens). Results: CO2-P was performed in 22 endoscopic stone treatment cases between March 2021 and August 2022, primarily using digital subtraction settings in 20 cases. CO2-DSP overall provided higher quality images of the renal pelvis and collecting system than CO2-P, but with a relatively higher radiation dose. Following a quality intervention, fluoroscopy doses for CO2-DSP cases were decreased by 81% overall. The use of CO2-P avoided fluoroscopic or intraoperative CT (ICT) artifacts seen with intraluminal ICM. Conclusions: CO2-P allows the urologist to obtain imaging of the renal collecting system without ICM and with much lower risk of air embolism compared with RA pyelography. CO2 is a nearly cost-free alternative to ICM. Because CO2 is widely available and the technique is easy to perform, we propose that CO2-P should be favored over traditional air pyelography to improve patient safety.

Morbidity of endovascular abdominal aortic aneurysm repair is directly related to diameter.

OBJECTIVE: Previous randomized controlled trials have defined specific size thresholds to guide surgical decision-making in patients presenting with an abdominal aortic aneurysm (AAA). With recent advances in endovascular techniques, the anatomic considerations of AAA repair are rapidly changing. Our specific aims were to evaluate the most recent national population data to compare anatomic differences and perioperative outcomes in patients with AAA. METHODS: The American College of Surgeons National Surgical Quality Improvement Program was queried from 2011 to 2015 using the targeted vascular public use file. Patients with AAA undergoing elective open or endovascular repair were included. Risk factors and outcomes were stratified by size and divided into quartiles for categorical comparison. A logistic regression model was used to compare the impact of size on morbidity and mortality with each technique. A risk adjustment model used all preoperative criteria to generate observed and expected values for open and endovascular repair. RESULTS: There were 10,026 patients who underwent elective AAA repair, 8182 (81.6%) endovascular and 1844 (18.4%) open. Repairs were divided into density quartiles for a logistic analysis: smallest quartile, 3.5 to 5 cm; second quartile, 5.01 to 5.5 cm; third quartile, 5.51 to 6.2 cm; and largest quartile, >6.2 cm. Patients with larger aneurysms (>6.2 cm) were more likely to be male, to have a dependent functional status, and to have increased blood urea nitrogen concentration and American Society of Anesthesiologists score (P < .05). Larger aneurysms had longer operative time (162 vs 135 minutes) and greater extension toward the renal and iliac vessels (all P < .05). Risk adjustment revealed an observed/expected morbidity plot that favored endovascular repair throughout the size range but confirmed lack of size effect within the open repair category. The adjusted increase in morbidity with endovascular repair is 9.7% per centimeter increase in size of AAA. These trends remained true with an infrarenal subgroup analysis. CONCLUSIONS: Patients with a larger AAA have comorbidities and anatomic factors associated with a more difficult repair. The higher morbidity seen with larger aneurysms represents both anatomic and patient factors but seems to have a greater impact on endovascular repairs. However, endovascular repair still results in fewer near-term complications than open repair across all size strata.

Nonatherosclerotic limb ischemia: Prompt evaluation and diagnosis.

Limb ischemia is most often associated with atherosclerosis and older age. When a younger patient without risk factors for atherosclerosis presents with symptoms of limb ischemia, vascular occlusion may not be suspected initially, thus delaying diagnosis and treatment. Delayed diagnosis can lead to a poor outcome. Here, we describe several uncommon causes of limb ischemia and their initial presentations, workup, and treatment to help guide the practitioner in making a timely diagnosis in this unusual patient population.

Measures to reduce unplanned readmissions after vascular surgery.

Hospital readmissions are increasingly utilized as a measure of health care quality. Unplanned readmissions in surgical patients are viewed as a marker of poor care quality, and are associated with significant expense both to the health care system and to the patient. Interventions aimed at reducing readmissions have been the focus of several prospective randomized trials addressing medical conditions like congestive heart failure, but few data exist on efforts to reduce readmissions in surgical patients. Vascular surgery patients have been found to be at a particularly high risk for readmission, and a number of groups have reported on the risk factors for readmission in these patients. However, measures to reduce unplanned readmissions after vascular surgery have not be thoroughly investigated. Here, we summarize the existing data on risk factors for readmission in vascular surgery patients, review interventional studies in medical patients aimed at reducing readmissions, and suggest interventions that may be helpful in reducing readmissions in vascular patients. Further investigative work is needed to ascertain practical approaches to reducing unplanned readmissions in vascular surgery patients and thus improve the quality of care they receive.

Vascular injury is associated with increased mortality in winter sports trauma.

BACKGROUND: Trauma is the leading cause of injury and death for individuals aged 1-44 years. Up to 8% of the US population participates in winter sports, and although vascular injuries are uncommon in these activities, little is published in this area. We sought to identify the incidence, injury patterns, and outcomes of vascular injuries resulting from winter sports trauma. METHODS: Patients with winter sports trauma and the subset with vascular injuries were identified by accessing the National Trauma Data Bank querying years 2007-2010. Patients with and without vascular injuries were then compared. Admission variables included transport time, emergency department hypotension (systolic blood pressure < 90), Glasgow Coma Scale ≤ 8, Injury Severity Score ≥ 25, fractures, solid organ injury, and vascular injury. Outcomes were analyzed and associations with vascular injuries were determined. RESULTS: A total of 2,298 patients were identified with winter sports-related trauma and 28 (1.2%) had associated vascular injuries. Overall, the top 3 injuries were head trauma (16.7%), thoracic vertebral fractures (5.5%), and lumbar vertebral fractures (5.1%). The most common associated vascular injures were to the popliteal artery (17.7%), splenic artery (14.7%), and brachial blood vessels (14.7%). In the entire cohort, 1 patient (0.04%) suffered an amputation and 15 patients (0.7%) died. There were no amputations in the vascular injury group. Mortality was 0.6% in patients without a vascular injury compared with 7.1% of those with a vascular injury (P = 0.01). CONCLUSIONS: Although vascular injury is an uncommon associated finding in winter sports trauma, it is associated with a significant increase in mortality. These findings highlight the need for rapid identification of traumatic vascular injuries, which predicts worse overall outcomes in this patient population.

The 5-lipoxygenase pathway is required for acute lung injury following hemorrhagic shock.

The cellular and biochemical mechanisms leading to acute lung injury (ALI) and subsequent multiple organ failure are only partially understood. To study the potential role of eicosanoids, particularly leukotrienes, as possible mediators of ALI, we used a murine experimental model of ALI induced by hemorrhagic shock after blood removal via cardiac puncture. Neutrophil sequestration, as shown by immunofluorescence and protein leakage into the alveolar space were measured as markers of injury. We used liquid chromatography coupled to tandem mass spectrometry to unequivocally identify several eicosanoids in the bronchoalveolar lavage fluid of experimental animals. MK886, a specific inhibitor of the 5-lipoxygenase (5-LO) pathway, and transgenic mice deficient in 5-LO were used to determine the role of this enzymatic pathway in this model. Leukotriene B4 and leukotriene C4 were consistently elevated in shock-treated mice compared with sham-treated mice. MK886 attenuated neutrophil infiltration and protein extravasation induced by hemorrhagic shock. 5-Lipoxygenase-deficient mice showed reduced neutrophil infiltration and protein extravasation after shock treatment, indicating greatly reduced lung injury. These results support the hypothesis that 5-LO, most likely through the generation of leukotrienes, plays an important role in the pathogenesis of ALI induced by hemorrhagic shock in mice. This pathway could represent a new target for pharmacological intervention to reduce lung damage following severe primary injury.

Leukotriene b4 and its metabolites prime the neutrophil oxidase and induce proinflammatory activation of human pulmonary microvascular endothelial cells.

Leukotrienes are proinflammatory lipid mediators, derived from arachidonic acid via 5-lipoxygenase (5-LO). Leukotriene B4 (LTB4) is an effective polymorphonuclear neutrophil (PMN) chemoattractant, as well as being a major product of PMN priming. Leukotriene B4 is rapidly metabolized into products that are thought to be inactive, and little is known about the effects of LTB4 on the pulmonary endothelium. We hypothesize that LTB4 and its metabolites are effective PMN priming agents and cause proinflammatory activation of pulmonary endothelial cells. Isolated PMNs were primed (5 min, 37°C) with serial concentrations 10 to 10 M of LTB4 and its metabolites: 6-trans-LTB4, 20-OH-LTB4, and 20-COOH-LTB4, and then activated with fMLP. Primary human pulmonary microvascular endothelial cells (HMVECs) were incubated with these lipids (6 h, 37°C, 5% CO2), and intercellular adhesion molecule 1 was measured by flow cytometry. Polymorphonuclear neutrophil adhesion was measured by myeloperoxidase assays, and to ensure that these reactions were specific to the LTB4 receptors, BLT1 and BLT2 were antagonized with CP105,696 (BLT1) or silenced with siRNA (BLT1 and BLT2). Leukotriene B4 and its metabolites primed PMNs over a wide range of concentrations, depending on the specific metabolite. In addition, at high concentrations these lipids also caused increases in the surface expression of intercellular adhesion molecule 1 on HMVECs and induced HMVEC-mediated adhesion of PMNs. Silencing of BLT2 abrogated HMVEC activation, and blockade of BLT1 inhibited the observed PMN priming activity. We conclude that LTB4 and its ω-oxidation and nonenzymatic metabolites prime PMNs over a range of concentrations and activate HMVECs. These data have expanded the repertoire of causative agents in acute lung injury and postinjury multiple organ failure.