The traveling pelvic bullet: a case of retrograde ballistic migration through the venous system.

Migration of a ballistic missile through the vasculature is rare but important to recognize. It can lead to diagnostic confusion and seemingly unexplainable bullet trajectories. We have described the case of a young man with a gunshot wound to the axillary vein and initial embolus to the inferior vena cava. The bullet subsequently migrated to the right common iliac vein, allowing for straightforward retrieval.

A large series of true pancreaticoduodenal artery aneurysms.

INTRODUCTION: True pancreaticoduodenal artery aneurysms (PDAAs) are rare, and prior reports often fail to distinguish true aneurysms from pseudoaneuryms. We sought to characterize all patients who presented to our health system from 2004 to 2019 with true PDAAs, with a focus on risk factors, interventions, and patient outcomes. METHODS: Patients were identified by querying a single health system picture archiving and communication system database for radiographic reports noting a PDAA. A retrospective chart review was performed on all identified patients. Patients with pseudoaneurysm, identified as those with a history of pancreatitis, abdominal malignancy, hepatopancreaticobiliary surgery, or abdominal trauma, were excluded. Continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact tests. RESULTS: A total of 59 true PDAAs were identified. Forty aneurysms (68%) were intact (iPDAAs) and 19 (32%) were ruptured (rPDAAs) at presentation. The mean size of rPDAAs was 16.4 mm (median size, 14.0 mm; range, 10-42 mm), and the mean size of iPDAAs was 19.4 mm (median size, 17.5 mm; range, 8-88 mm); this difference was not statistically significant (P = .95). Significant celiac disease (occlusion or >70% stenosis) was noted in 39 aneurysms (66%). Those with rupture were less likely to have significant celiac disease (42% vs 78%; P = .017) and less likely to have aneurysmal wall calcifications (6% vs 53%; P = .002). Thirty-seven patients underwent intervention (63%), with eight (22%) undergoing concomitant hepatic revascularization (two stents and six bypasses) due to the presence of celiac disease. Eighteen patients with occluded celiac arteries underwent aneurysm intervention; of those, 11 were performed without hepatic revascularization (61.1%). Those with rPDAAs experienced an aneurysm-related mortality of 10.5%, whereas those with iPDAAs experienced a rate of 5.6%. One patient with celiac occlusion and PDA rupture who did not undergo hepatic artery bypass expired postoperatively from hepatic ischemia. rPDAAs showed a trend toward the increased need for aneurysm-related endovascular or open reintervention, but this was not statistically significant (47% vs 28%; P = .13). CONCLUSIONS: These findings support previous reports that the rupture risk of PDAAs is independent of size, their development is often associated with significant celiac stenosis or occlusion, and rupture risk appears decreased in patients with concomitant celiac disease or aneurysm wall calcifications. Endovascular intervention is the preferred initial treatment for both iPDAAs and rPDAAs, but reintervention rates are high in both groups. The role for hepatic revascularization remains uncertain, but it does not appear to be mandatory in all patients with complete celiac occlusion who undergo PDAA interventions.

The Hyperattenuating Crescent Sign Is Not Necessarily a Sign of Impending Aortic Aneurysm Rupture.

BACKGROUND: The "crescent sign" is a hyperattenuating crescent-shaped region on CT within the mural thrombus or wall of an aortic aneurysm. Although it has previously been associated with aneurysm instability or impending rupture, the literature is largely based on retrospective analyses of urgently repaired aneurysms. We strove to more rigorously assess the association between an isolated "crescent sign" and risk of impending aortic rupture. METHODS: Patients were identified by querying a single health system PACS database for radiology reports noting a crescent sign. Adult patients with a CT demonstrating a descending thoracic, thoracoabdominal, or abdominal aortic aneurysm and "crescent sign" between 2004 and 2019 were included, with exclusion of those showing definitive signs of aortic rupture on imaging. RESULTS: A total of 82 patients were identified. Aneurysm size was 7.1 ± 2.0 cm. Thirty patients had emergent or urgent repairs during their index admission (37%), 19 had elective repairs at a later date (23%), and 33 patients had no intervention due to either patient choice or prohibitive medical comorbidities (40%). Patients without intervention had a median follow up of 275 days before death or loss to follow up. In patients undergoing elective intervention, 6,968 patient-days elapsed between presentation and repair, with zero episodes of acute rupture (median 105 days). Patients undergoing elective repair had smaller aneurysms compared to those who underwent emergent/urgent repair (6.2 ± 1.3 vs. 7.7 ± 2.1 cm, P = 0.008). No surgical candidate with an aneurysm smaller than 8 cm ruptured. There were 31 patients with previous axial imaging within 2 years prior to presentation with a "crescent sign," with mean aneurysm growth rate of 0.85 ± 0.62 cm per 6 months [median 0.65, range 0-2.6]. Those with aneurysms sized below 5.5 cm displayed decreased aneurysm growth compared to patients with aneurysm's sized 5.5-6.5 cm or patients with aneurysms greater than 6.5 cm (0.12 vs. 0.64 vs. 1.16 cm per 6 months, P= 0.002). CONCLUSIONS: The finding of an isolated radiographic "crescent sign" without other signs of definitive aortic rupture (i.e., hemothorax, aortic wall disruption, retroperitoneal bleeding) is not necessarily an indicator of impending aortic rupture, but may be found in the setting of rapid aneurysm growth. Many factors, including other associated radiographic findings, aneurysm size and growth rate, and patient symptomatology, should guide aneurysm management in these patients. We found that patients with minimal symptoms, aneurysm sizes below 6.5 cm, and no further imaging findings of aneurysm instability, such as periaortic fat stranding, can be successfully managed with elective intervention after optimization of comorbid factors with no evidence of adverse outcomes.

Geographic and Socioeconomic Disparities in Major Lower Extremity Amputation Rates in Metropolitan Areas.

Background Rates of major lower extremity amputation in patients with peripheral artery disease are higher in rural communities with markers of low socioeconomic status, but most Americans live in metropolitan areas. Whether amputation rates vary within US metropolitan areas is unclear, as are characteristics of high amputation rate urban communities. Methods and Results We estimated rates of major lower extremity amputation per 100 000 Medicare beneficiaries between 2010 and 2018 at the ZIP code level among ZIP codes with ≥100 beneficiaries. We described demographic characteristics of high and low amputation ZIP codes, and the association between major amputation rate and 3 ZIP code-level markers of socioeconomic status-the proportion of patients with dual eligibility for Medicaid, median household income, and Distressed Communities Index score-for metropolitan, micropolitan, and rural ZIP code cohorts. Between 2010 and 2018, 188 995 Medicare fee-for-service patients living in 31 391 ZIP codes with ≥100 beneficiaries had a major lower extremity amputation. The median (interquartile range) ZIP code-level number of amputations per 100 000 beneficiaries was 262 (75-469). Though nonmetropolitan ZIP codes had higher rates of major amputation than metropolitan areas, 78.2% of patients undergoing major amputation lived in metropolitan areas. Compared with ZIP codes with lower amputation rates, top quartile amputation rate ZIP codes had a greater proportion of Black residents (4.4% versus 17.5%, P<0.001). In metropolitan areas, after adjusting for clinical comorbidities and demographics, every $10 000 lower median household income was associated with a 4.4% (95% CI, 3.9-4.8) higher amputation rate, and a 10-point higher Distressed Communities Index score was associated with a 3.8% (95% CI, 3.4%-4.2%) higher amputation rate; there was no association between the proportion of patients eligible for Medicaid and amputation rate. These findings were comparable to the associations identified across all ZIP codes. Conclusions In metropolitan areas, where most individuals undergoing lower extremity amputation live, markers of lower socioeconomic status and Black race were associated with higher rates of major lower extremity amputation. Development of community-based tools for peripheral artery disease diagnosis and management targeted to communities with high amputation rates in urban areas may help reduce inequities in peripheral artery disease outcomes.

Review of Type III Endoleaks.

Endoleak remains a significant challenge to endovascular aneurysm repair, particularly as evolving techniques and devices have allowed treatment of increasingly complex aneurysm anatomy with increasing number of device components. Intervention is recommended for both type I and III endoleaks due to their risk of rupture, and endovascular techniques are the favored modality with placement of a bridging endograft over the endoleak defect. Conversion to open surgical repair remains the definitive option in cases where less invasive methods have failed or are precluded. In this article, the authors review evidence on the etiology, incidence, diagnosis, and current techniques for type III endoleak management.

Endovascular Therapy of Vascular Trauma-Current Options and Review of the Literature.

OBJECTIVE: To review the current use of endovascular techniques in trauma. SUMMARY BACKGROUND DATA: Multiple studies have demonstrated that, despite current guidelines, endovascular therapies are used in instances of arterial trauma. METHODS: The existing literature concerning arterial trauma was reviewed. Studies reviewed included case reports, single-center case series, large database studies, official industry publications and instructions for use, and society guidelines. RESULTS: Endovascular therapies are used in arterial trauma in all systems. The use of thoracic endografts in blunt thoracic aortic trauma is accepted and endorsed by society guidelines. The use of endovascular therapies in other anatomic locations is largely limited to single-center studies. Advantages potentially include less morbidity due to smaller incisions as well as shorter operating room times. Many report using endovascular therapies even with hard signs of injury. Long-term results are limited by a lack of long-term follow-up but, in general, suggest that these techniques produce acceptable outcomes. The adoption of these techniques may be limited by resource and surgeon availability. CONCLUSIONS: The use of endovascular therapies in trauma has gained acceptance despite not yet having a place in official guidelines.

Retrievable inferior vena cava filters can always be removed using "fall-back" techniques.

OBJECTIVE: Retrievable inferior vena cava filters (IVCFs) left in place for a prolonged period can lead to complications including filter migration, fracture, and caval thrombosis. "Fall-back" techniques for IVCF retrieval that can be used when standard snaring is unsuccessful have been recently described. The purpose of this study was to analyze how incorporation of these new techniques affected the outcomes of IVCF retrievals at our institution during the past 5 years. METHODS: Data were collected of all patients undergoing IVCF removal by vascular surgeons at a tertiary academic medical center between 2009 and 2013, including demographics and procedural and filter characteristics. A standard technique of snaring the retrieval hook was attempted first in all cases; if this was unsuccessful, a number of fall-back techniques were employed, including the use of endoscopic graspers, 18F sheaths, and snaring a second wire below the collar of the filter to collapse it into the sheath. RESULTS: IVCF retrieval was attempted in 275 patients; 3 were excluded intraoperatively because of thrombus in the filter. Most filters (97%) were Günther Tulips (Cook Medical, Bloomington, Ind); 70% had been placed prophylactically before bariatric surgery. A total of 268 filters (98.5%) were retrieved successfully, 213 (79%) by standard snaring and 55 (21%) with fall-back techniques. In patients undergoing fall-back techniques, technical success was achieved 100% of the time. The median time since insertion was significantly longer in the fall-back group (173 days vs 83 days; P < .0001). Four intraoperative complications occurred; fractured wires embolized to the right atrium or pulmonary artery and were successfully removed endovascularly. The majority of the procedures (80%) were performed under sedation in both groups. CONCLUSIONS: Incorporation of fall-back techniques may allow 100% technically successful and safe removal of retrievable IVCFs and is especially useful in removing filters with prolonged dwell time.

Fate of the contralateral limb after lower extremity amputation.

OBJECTIVE: Lower extremity amputation is often performed in patients where both lower extremities are at risk due to peripheral arterial disease or diabetes, yet the proportion of patients who progress to amputation of their contralateral limb is not well defined. We sought to determine the rate of subsequent amputation on both the ipsilateral and contralateral lower extremities following initial amputation. METHODS: We conducted a retrospective review of all patients undergoing lower extremity amputation (exclusive of trauma or tumor) at our institution from 1998 to 2010. We used International Classification of Diseases-Ninth Revision codes to identify patients and procedures as well as comorbidities. Outcomes included the proportion of patients at 1 and 5 years undergoing contralateral and ipsilateral major and minor amputation stratified by initial major vs minor amputation. Cox proportional hazards regression analysis was performed to determine predictors of major contralateral amputation. RESULTS: We identified 1715 patients. Mean age was 67.2 years, 63% were male, 77% were diabetic, and 34% underwent an initial major amputation. After major amputation, 5.7% and 11.5% have a contralateral major amputation at 1 and 5 years, respectively. After minor amputation, 3.2% and 8.4% have a contralateral major amputation at 1 and 5 years while 10.5% and 14.2% have an ipsilateral major amputation at 1 and 5 years, respectively. Cox proportional hazards regression analysis revealed end-stage renal disease (hazard ratio [HR], 3.9; 95% confidence interval [CI], 2.3-6.5), chronic renal insufficiency (HR, 2.2; 95% CI, 1.5-3.3), atherosclerosis without diabetic neuropathy (HR, 2.9; 95% CI, 1.5-5.7), atherosclerosis with diabetic neuropathy (HR, 9.1; 95% CI, 3.7-22.5), and initial major amputation (HR, 1.8; 95% CI, 1.3-2.6) were independently predictive of subsequent contralateral major amputation. CONCLUSIONS: Rates of contralateral limb amputation are high and predicted by renal disease, atherosclerosis, and atherosclerosis with diabetic neuropathy. Physicians and patients should be alert to the high risk of subsequent amputation in the contralateral leg. All patients, but particularly those at increased risk, should undergo close surveillance and counseling to help prevent subsequent amputations in their contralateral lower extremity.

The current national criteria for carotid artery stenting overestimate its efficacy in patients who are symptomatic and at high risk.

BACKGROUND: The Centers for Medicare and Medicaid Services (CMS) have established guidelines that outline patients who are considered "high risk" for complications after carotid endarterectomy (CEA) for which carotid artery stenting (CAS) may provide benefit. The validity of these high-risk criteria are yet unproven. In this study, we stratified patients who underwent CAS or CEA by CMS high-risk criteria and symptom status and examined their 30-day outcomes. METHODS: A nonrandomized, retrospective cohort study was performed by chart review of all patients undergoing CEA or CAS from January 1, 2005, to December 31, 2010, at our institution. Demographic data and data pertaining to the presence or absence of high-risk factors were collected. Patients were stratified using symptom status and high-risk status as variables, and 30-day adverse events (stroke, death, myocardial infarction [MI]) were compared. RESULTS: A total of 271 patients underwent CAS, with 30-day complication rates of stroke (3.0%), death (1.1%), MI (1.5%), stroke/death (3.7%), and stroke/death/MI (5.2%). A total of 830 patients underwent CEA with 30-day complication rates of stroke (2.0%), death (0.1%), MI (0.6%), stroke/death (1.9%), and stroke/death/MI (2.7%). Among symptomatic patients, physiologic high-risk status was associated with increased stroke/death (6 of 42 [14.3%] vs 2 of 74 [2.7%]; P < .01), and anatomic high-risk status was associated with a trend toward increased stroke/death (5 of 31 [16.1%] vs 0 of 20 [0.0%]; P = .14) in patients who underwent CAS vs CEA. Analysis of asymptomatic patients showed no differences between the two groups overall, except for a trend toward a higher rate of MI after CAS than after CEA (3 of 71 [4.2%] vs 0 of 108 [0.0%]; P = .06) in those who were physiologically at high risk. Among symptomatic patients who underwent CAS, patients with physiologic and anatomic high-risk factors had a higher rate of stroke/death than non-high-risk patients (6 of 42 [14.3%] vs 0 of 24 [0.0%] and 5 of 31 [16.1%] vs 0 of 24 [0.0%], respectively; both P ≤ .05). CONCLUSIONS: Physiologic high-risk status was associated with increased stroke/death, whereas anatomic high-risk status showed a trend toward increased stroke/death in symptomatic patients undergoing CAS compared with non-high-risk patients undergoing CAS or physiologically high-risk patients undergoing CEA. Our results suggest that the current national criteria for CAS overestimate its efficacy in patients who are symptomatic and at high risk.

Ultrastructural evidence for co-localization of corticotropin-releasing factor receptor and mu-opioid receptor in the rat nucleus locus coeruleus.

Previous studies have shown that corticotropin-releasing factor (CRF), an integral mediator of the stress response, and opioids regulate the activity of the locus-coeruleus-norepinephrine (LC-NE) system during stress in a reciprocal manner. Furthermore, repeated opiate exposure sensitizes noradrenergic neurons to CRF. Previous studies have shown that mu-opioid receptors (muORs) are prominently distributed within somatodendritic processes of catecholaminergic neurons in the LC and axon terminals containing opioid peptides and CRF converge within the LC. To further examine cellular sites for interactions between CRF receptor type 1 (CRFr) and muOR, immunofluorescence and electron microscopic analysis of the rat LC was conducted. Triple immunofluorescence showed prominent co-localization of the CRFr and muOR in noradrenergic somata in the LC. Ultrastructural analysis confirmed dual localization of CRFr and muOR in common dendritic processes in the LC. Semi-quantitative analysis showed that of the dendrites exhibiting CRFr immunolabeling, 57% expressed muOR immunoreactivity. These data provide ultrastructural evidence that CRFr and muOR are co-localized in LC neurons, a cellular substrate that may underlie opiate-induced sensitization of brain noradrenergic neurons to CRF.

Pro-opiomelanocortin colocalizes with corticotropin- releasing factor in axon terminals of the noradrenergic nucleus locus coeruleus.

We previously demonstrated that the opioid peptide enkephalin and corticotropin-releasing factor (CRF) are occasionally colocalized in individual axon terminals but more frequently converge on common dendrites in the locus coeruleus (LC). To further examine potential opioid cotransmitters in CRF afferents we investigated the distribution of pro-opiomelanocortin (POMC), the precursor that yields the potent bioactive peptide beta-endorphin, with respect to CRF immunoreactivity using immunofluorescence and immunoelectron microscopic analyses of the LC. Coronal sections were collected through the dorsal pontine tegmentum of rat brain and processed for immunocytochemical detection of POMC and CRF or tyrosine hydroxylase (TH). POMC-immunoreactive processes exhibited a distinct distribution within the LC as compared to the enkephalin family of opioid peptides. Specifically, POMC fibers were enriched in the ventromedial aspect of the LC with fewer fibers present dorsolaterally. Immunofluorescence microscopy showed frequent coexistence of POMC and CRF in varicose processes that overlapped TH-containing somatodendritic processes in the LC. Ultrastructural analysis showed POMC immunoreactivity in unmyelinated axons and axon terminals. Axon terminals containing POMC were filled with numerous large dense-core vesicles. In sections processed for POMC and TH, approximately 29% of POMC-containing axon terminals (n = 405) targeted dendrites that exhibited immunogold-silver labeling for TH. In contrast, sections processed for POMC and CRF showed that 27% of POMC-labeled axon terminals (n = 657) also exhibited CRF immunoreactivity. Taken together, these data indicate that a subset of CRF afferents targeting the LC contain POMC and may be positioned to dually impact LC activity.