A rare case of concurrent proximal and hilar renal artery aneurysm with renal arteriovenous fistula.

Renal artery aneurysm (RAA) and renal arteriovenous fistula are rare vascular pathologies with reported incidences of 0.3% to 1.0% and 0.04% in the general population, respectively. We describe a 61-year-old Caucasian man who presented to the hospital with symptoms of right flank pain. Imaging demonstrated a right RAA with concurrent hilar RAA and renal arteriovenous fistula. He ultimately underwent an open right nephrectomy, ligation of the fistula, and bovine patch repair of the aortic defect.

Resection of Anterior and Lateral Muscle Compartments Does Not Preclude Limb Salvage and Functions.

BACKGROUND: Fasciotomy with resection of nonviable muscle is often necessary when there is a delay in compartment syndrome (CS) diagnosis after revascularization. The reported rate of major amputation following missed CS or delayed fasciotomy ranges from 12% to 35%. Herein, the authors present a series of critically ill patients who experienced delayed CS diagnosis and required complete resection of the anterior and/or lateral compartments but still achieved limb salvage and function. METHODS: A retrospective chart review identified five patients from April 2018 to April 2019 within a single institution who met the inclusion criteria. Patient charts were reviewed for demographic data, risk factors, time to diagnosis following revascularization, muscle compartments resected, operative and wound care details, and functional outcome at follow-up. RESULTS: All of the patients developed CS of the lower extremity following revascularization secondary to acute limb ischemia and required two-incision, four-compartment fasciotomies. Further, they all required serial operative debridements to achieve limb salvage; however, there were no major amputations, and all of the patients were walking at follow-up. CONCLUSIONS: Delay in CS diagnosis can have devastating consequences, resulting in major amputation. In cases where myonecrosis is isolated to two or fewer compartments, complete compartment muscle resection can be safely performed, and limb preservation and function can be maintained with aggressive wound management and physical therapy.

Spontaneous Thrombosis of an Isolated Internal Iliac Artery Aneurysm.

BACKGROUND: Isolated internal iliac artery aneurysms (IIAAs) are uncommon but potentially morbid lesions that are a challenge to monitor and treat. However, given the small numbers of reported cases and high rates of incidentally discovered lesions, the natural history of isolated IIAAs is not well characterized. This case describes an atypical and previously unreported spontaneous thrombosis of an isolated IIAA, a lesion typically thought to progressively enlarge and rupture. METHODS: Medical records and imaging studies were retrospectively reviewed with the approval of our Institutional Review Board. A single patient underwent fluoroscopic angiography followed by computed tomography (CT) angiography, with no subsequent operative intervention. RESULTS: An isolated 5.5 cm left IIAA was discovered incidentally on CT scan and subsequently seen with fluoroscopic pelvic angiography. Three weeks following initial angiography, repeat pelvic angiography and CT scan demonstrated spontaneous thrombosis of the aneurysm. CONCLUSIONS: Isolated IIAAs are conditions for which the natural history remains uncertain despite their potential risk for rupture and mortality. Spontaneous thrombosis of these lesions is possible, suggesting that the natural history as previously described warrants further consideration.

Salvage of autogenous dialysis access with balloon-assisted thrombin injection.

Arteriovenous fistulas are known to be one of the most enduring and safe hemodialysis access modalities. However, access preservation can be challenging in the setting of degeneration, including the development of complex pseudoaneurysms. Prolonged compression or thrombin injection can risk thrombosis of the fistula, and covered stent use can predispose the access to infection and other stent complications. We present a case in which endovascular balloon occlusion was used to facilitate the use of ultrasound-guided thrombin injection to resolve a dialysis access pseudoaneurysm by transiently reducing flow and preventing thromboembolism. This method is a safe, effective, and minimally invasive technique that should be considered for salvage of autogenous access compromised by pseudoaneurysm development.

A cautionary tale of an emergency cerebrovascular procedure in the COVID-19 era.

The coronavirus disease 2019 pandemic has had an impact on system processes, with airway management being significantly affected. A 37-year-old woman diagnosed with stroke was found to have a filling defect at the origin of the right internal carotid artery. She was taken to the operating room urgently for carotid endarterectomy. The procedure was uneventful; however, anaphylaxis developed on extubation, subsequently attributed to sugammadex. Institutional policies and limited resources resulted in delayed reintubation. Fortunately, she did not have lasting deficits, but this highlights the potential of current policies to lead to complications and the need to improve policies to minimize harm.

The Structure and Biological Function of CREG.

The cellular repressor of E1A-stimulated genes (CREG) is a 220 amino acid glycoprotein structurally similar to oxidoreductases. However, CREG does not have enzymatic activities because it cannot bind to the cofactor flavin mononucleotide. Although CREG can be secreted, it is mainly an intracellular protein localized in the endocytic-lysosomal compartment. It undergoes proteolytic maturation mediated by lysosomal cysteine proteases. Biochemical studies have demonstrated that CREG interacts with mannose-6-phosphate/insulin-like growth factor-2 receptor (M6P/IGF2R) and exocyst Sec8. CREG inhibits proliferation and induces differentiation and senescence when overexpressed in cultured cells. In Drosophila, RNAi-mediated knockdown of CREG causes developmental lethality at the pupal stage. In mice, global deletion of the CREG1 gene leads to early embryonic death. These findings establish an essential role for CREG in development. CREG1 haploinsufficient and liver-specific knockout mice are susceptible to high fat diet-induced obesity, hepatic steatosis and insulin resistance. The purpose of this review is to provide an overview of what we know about the biochemistry and biology of CREG and to discuss the important questions that remain to be addressed in the future.

Synthetic cannabis and respiratory depression.

In recent years, synthetic cannabis use has been increasing in appeal among adolescents, and its use is now at a 30 year peak among high school seniors. The constituents of synthetic cannabis are difficult to monitor, given the drug's easy accessibility. Currently, 40 U.S. states have banned the distribution and use of some known synthetic cannabinoids, and have included these drugs in the Schedule I category. The depressive respiratory effect in humans caused by synthetic cannabis inhalation has not been thoroughly investigated in the medical literature. We are the first to report, to our knowledge, two cases of self-reported synthetic cannabis use leading to respiratory depression and necessary intubation.

CD8+ T cell priming by dendritic cell vaccines requires antigen transfer to endogenous antigen presenting cells.

BACKGROUND: Immunotherapeutic strategies to stimulate anti-tumor immunity are promising approaches for cancer treatment. A major barrier to their success is the immunosuppressive microenvironment of tumors, which inhibits the functions of endogenous dendritic cells (DCs) that are necessary for the generation of anti-tumor CD8+ T cells. To overcome this problem, autologous DCs are generated ex vivo, loaded with tumor antigens, and activated in this non-suppressive environment before administration to patients. However, DC-based vaccines rarely induce tumor regression. METHODOLOGY/PRINCIPAL FINDINGS: We examined the fate and function of these DCs following their injection using murine models, in order to better understand their interaction with the host immune system. Contrary to previous assumptions, we show that DC vaccines have an insignificant role in directly priming CD8+ T cells, but instead function primarily as vehicles for transferring antigens to endogenous antigen presenting cells, which are responsible for the subsequent activation of T cells. CONCLUSIONS/SIGNIFICANCE: This reliance on endogenous immune cells may explain the limited success of current DC vaccines to treat cancer and offers new insight into how these therapies can be improved. Future approaches should focus on creating DC vaccines that are more effective at directly priming T cells, or abrogating the tumor induced suppression of endogenous DCs.