Bowel ischemia as onset of COVID-19 in otherwise asymptomatic patients with persistently negative swab.

BACKGROUND: Asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can develop hypercoagulable conditions and acute vascular events. The objective of this study is to determine whether SARS-CoV-2 was present in resected specimens from patients with acute bowel ischemia, but asymptomatic for Coronavirus Disease 2019 (COVID-19) and with persistently real-time polymerase chain reaction negative pharyngeal swab. METHODS: Three consecutive patients presented severe abdominal symptoms due to extensive ischemia and necrosis of the bowel, with co-existent thrombosis of abdominal blood vessels. None had the usual manifestations of COVID-19, and repeated pharyngeal swabs tested negative. They underwent emergency surgery with intestinal resection. Immunohistochemical testing for SARS-CoV-2 on resected tissue was performed. RESULTS: All tested samples were strongly positive for SARS-CoV-2. CONCLUSIONS: This is the first case report in which patients with severe intestinal symptoms presented a marked SARS-CoV-2 positivity in the resected tissues, without any usual clinical manifestations of COVID-19. These results suggest that the patients might be infected with SARS-CoV-2 presenting acute abdominal distress but without respiratory or constitutional symptoms.

Intestinal Abnormalities in Patients With SARS-CoV-2 Infection: Histopathologic Changes Reflect Mechanisms of Disease.

Approximately 20% of patients with symptomatic syndrome-associated coronavirus-2 (SARS-CoV-2) infection have gastrointestinal bleeding and/or diarrhea. Most are managed without endoscopic evaluation because the risk of practitioner infection outweighs the value of biopsy analysis unless symptoms are life-threatening. As a result, much of what is known about the gastrointestinal manifestations of coronavirus disease-2019 (COVID-19) has been gleaned from surgical and autopsy cases that suffer from extensive ischemic injury and/or poor preservation. There are no detailed reports describing any other gastrointestinal effects of SARS-CoV-2 even though >3,000,000 people have died from COVID-19 worldwide. The purpose of this study is to report the intestinal findings related to SARS-CoV-2 infection by way of a small case series including one with evidence of direct viral cytopathic effect and 2 with secondary injury attributed to viral infection. Infection can be confirmed by immunohistochemical stains directed against SARS-CoV-2 spike protein, in situ hybridization for spike protein-encoding RNA, and ultrastructural visualization of viruses within the epithelium. It induces cytoplasmic blebs and tufted epithelial cells without inflammation and may not cause symptoms. In contrast, SARS-CoV-2 infection can cause gastrointestinal symptoms after the virus is no longer detected, reflecting systemic activation of cytokine and complement cascades rather than direct viral injury. Reversible mucosal ischemia features microvascular injury with hemorrhage, small vessel thrombosis, and platelet-rich thrombi. Systemic cytokine elaboration and dysbiosis likely explain epithelial cell injury that accompanies diarrheal symptoms. These observations are consistent with clinical and in vitro data and contribute to our understanding of the protean manifestations of COVID-19.

Bowel Ischemia in COVID-19 Infection: One-Year Surgical Experience.

BACKGROUND: COVID-19 is a deadly multisystemic disease, and bowel ischemia, the most consequential gastrointestinal manifestation, remains poorly described. Our goal is to describe our institution's surgical experience with management of bowel ischemia due to COVID-19 infection over a one-year period. METHODS: All patients admitted to our institution between March 2020 and March 2021 for treatment of COVID-19 infection and who underwent exploratory laparotomy with intra-operative confirmation of bowel ischemia were included. Data from the medical records were analyzed. RESULTS: Twenty patients were included. Eighty percent had a new or increasing vasopressor requirement, 70% had abdominal distension, and 50% had increased gastric residuals. Intra-operatively, ischemia affected the large bowel in 80% of cases, the small bowel in 60%, and both in 40%. Sixty five percent had an initial damage control laparotomy. Most of the resected bowel specimens had a characteristic appearance at the time of surgery, with a yellow discoloration, small areas of antimesenteric necrosis, and very sharp borders. Histologically, the bowel specimens frequently have fibrin thrombi in the small submucosal and mucosal blood vessels in areas of mucosal necrosis. Overall mortality in this cohort was 33%. Forty percent of patients had a thromboembolic complication overall with 88% of these developing a thromboembolic phenomenon despite being on prophylactic pre-operative anticoagulation. CONCLUSION: Bowel ischemia is a potentially lethal complication of COVID-19 infection with typical gross and histologic characteristics. Suspicious clinical features that should trigger surgical evaluation include a new or increasing vasopressor requirement, abdominal distension, and intolerance of gastric feeds.

A review of acute limb ischemia in COVID-positive patients.

This literature review discusses the current evidence on acute limb ischemia (ALI) in patients with COVID-19. Throughout the pandemic, these patients have been at increased risk of arterial thrombotic events and subsequent mortality as a result of a hypercoagulable state. The exact mechanism of thrombosis is unknown; however arterial thrombosis may be due to invasion of endothelial cells via angiotensin-converting enzyme 2 (ACE2) receptors, endothelial injury from inflammation, or even free-floating aortic thrombus. Multiple studies have been performed evaluating the medical and surgical management of these patients; the decision to proceed with operative intervention is dependent on the patient's clinical status as it relates to COVID-19 and morbidity of that disease. The interventions afforded typically include anticoagulation in patients undergoing palliation; alternatively, thrombectomy (endovascular and open) is utilized in other patients. There is a high risk of rethrombosis, despite anticoagulation, given persistent endothelial injury from the virus. Postoperative mortality can be high in these patients.

Bilateral Acute Lower Limb Ischemia Secondary to COVID-19.

COVID-19 has to date affected over 5 million people worldwide and caused in excess of 300000 deaths. One of the principal finding is that of a thrombotic tendency within the lungs leading to high mortality. There have been increasing number of reports of peripheral arterial thrombosis as well. Most cases of arterial thrombosis is noted in patient in intensive care setting. Here-in we report a case of acute bilateral lower limb arterial thrombosis in a patient recovering at home with mild COVID-19 symptoms, highlighting that patients with milder symptoms may also suffer from prothrombotic state resulting in acute arterial occlusions. Arterial thrombosis should be suspected in these patients despite the absence of predisposing factors.

[Acral ischaemia with multiple microthromboses and imminent gangrene in a 73-year-old woman with COVID-19].

This is a report of an atypical presentation of COVID-19. The patient had sparse pulmonary symptoms despite characteristic COVID-19 lesions on CT-thorax and developed severe acral ischaemic change, after a few days of hospitalisation. The condition could not be explained by classical sepsis with hypotension and hypoperfusion, disseminated intravascular coagulation, vasculitis, endocarditis or severe peripheral arteriosclerosis. A skin biopsy showed microthrombosis, interpreted as an activation of the coagulation system associated with COVID-19. Apparently, there are multiple COVID-19 phenotypes.

Human Adenovirus: An Unusual Causative Agent for Acute Retinal Necrosis Presented with Central Retinal Vascular Occlusion.

PURPOSE: We describe a case of acute retinal necrosis (ARN) with central retinal vascular occlusion caused by human adenovirus (HAdV). CASE REPORT: A 41-year-old man presented with a sudden decrease of visual acuity in his right eye since seven days. Visual acuity was hand movements and ophthalmic examination of the right eye revealed diffuse hemorrhagic retinal vasculitis with panuveitis. He was clinically diagnosed as ARN with central retinal vascular occlusion. An anterior chamber paracentesis and intravitreal ganciclovir injection were performed and intravenous ganciclovir has been initiated immediately. Polymerase chain reaction (PCR) analysis of aqueous humor identified HAdV DNA as a causative agent. Oral prednisolone was added to treatment 5 days after antiviral therapy. After 10 days of intravenous ganciclovir therapy, oral valganciclovir was given for 6 months. No recurrence or retinal detachment occurred during follow-up. CONCLUSION: HAdV known to cause acute epibulbar infections of the eye may also cause intraocular inflammation such as ARN.

Progressive human immunodeficiency virus-associated vasculopathy: time to revise antiretroviral therapy guidelines?

Cardiovascular abnormalities were appreciated early in the epidemic of the acquired immunodeficiency syndrome (AIDS), even before the aetiological agent, human immunodeficiency virus (HIV) was isolated and characterised. The aetiology and pathogenesis of cardiovascular disease in HIV infection is still the subject of intense speculation, and is likely multi-factorial. HIV affects every aspect of the cardiac axis, causing pericarditis, myocarditis, cardiomyopathy, coronary artery disease and microvascular dysfunction, valvular heart disease, pulmonary vascular disease and pulmonary hypertension, stroke and peripheral vascular disease. HIV-associated vasculopathy is an increasingly recognised clinical entity, causing high morbidity and increasing mortality in southern Africa, particularly from stroke and cardiovascular disease. HIV causes disease of the vascular tree, either by a direct effect on vascular or perivascular tissue, or indirectly via immune complex-mediated mechanisms, associated opportunistic infections and malignancies. As a result, highly active antiretroviral therapy (HAART) may have an important role in controlling disease progression. We report a case of histologically defined primary HIV vasculopathy in which the chance to start HAART was initially missed and in which the patient progressed to require bilateral amputations, but obtained disease quiescence upon commencement of HAART.

Eye findings in X-linked lymphoproliferative disorder.

BACKGROUND: X-linked lymphoproliferative disorder typically presents as an Epstein-Barr virus-specific immune defect with a poor prognosis. Herein we present the clinical and pathologic findings for the first known case of X-linked lymphoproliferative disorder with visual symptoms at initial presentation. METHODS: Retrospective chart review, clinicopathologic correlation (brain biopsy and postmortem brain and eye tissue), and literature review. RESULTS: An 18-year-old boy had a unique presentation of X-linked lymphoproliferative disorder with visual symptoms and retinal findings. He subsequently developed central nervous system vasculitis. He never had evidence of Epstein-Barr virus infection during his clinical course, but in situ hybridization was positive in scattered cells in the brain postmortem. Eye pathologic examination at autopsy showed ischemic changes, but no inflammation. CONCLUSION: When a young patient presents with cotton wool spots, a thorough workup must be done, and immunologic disorders should be considered in the differential diagnosis. X-linked lymphoproliferative disorder-associated eye findings may not always be associated with Epstein-Barr virus infection and, as demonstrated by this case, can be indicative of an underlying vasculitic process.

Parvovirus B19-associated catastrophic endothelialitis with a Degos-like presentation.

Parvovirus B19 is a single-stranded DNA virus exhibiting affinity for a variety of cell types including endothelial cells. The basis of the affinity is globoside expression, the receptor for B19. B19 endothelial cell parasitism accelerates endothelial cell apoptosis, potentially critical in inducing neoantigenicity and secondary antibody formation. A 38-year-old previously healthy male developed intestinal and cutaneous infarction, elevated creatinine phosphokinase (CPK) levels and progressive cytopenias. The basis of his clinical presentation was unclear until a skin biopsy suggested a potential role for virally mediated endothelial cell injury. Hematoxylin and eosin, immunohistochemical, immunofluorescent and reverse transcriptase in situ polymerase chain reaction studies were conducted on skin biopsies to assess for viral triggers. B19 viremia and localization of B19 RNA transcripts to vascular endothelium were uncovered. A diagnosis of catastrophic endothelial cell injury attributable to B19 infection was rendered. The patient showed significant improvement with intravenous immunoglobulin (IVIG). Parvovirus B19 is a ubiquitous virus that in the majority of affected patients remains asymptomatic. Nevertheless, because of its ability to infect endothelium it can cause severe multiorgan endothelial cell injury.

Cytomegalovirus colitis mimicking a colonic neoplasm or ischemic colitis 4 years after heart transplantation.

BACKGROUND: Cytomegalovirus (CMV) colitis is a polymorphous disease presenting in immunodepressed patients in a variety of clinical forms that can delay diagnosis and therapy. We report the case of a patient who presented with abdominal pain 4 years after heart transplantation; clinical and x-ray findings were suggestive of a neoplastic or ischemic stenosis, and histopathological examination likewise initially suggested an ischemic etiology. METHODS: Tissue samples were fixed in 10% formaldehyde, embedded in paraffin, cut, and stained with hematoxylin/eosin and periodic acid-Schiff-Alcian Blue. Immunohistochemistry with monoclonal antibodies was performed using an indirect immunoperoxidase method. RESULTS: CMV colitis was eventually diagnosed and resolved with surgery and specific anti-CMV therapy. CONCLUSIONS: CMV colitis should be suspected in any heart transplant patient with signs or symptoms of abdominal pathology, even without classical signs or symptoms of CMV infection. If stenotic lesions are present, surgery may be required not only to remove the obstruction but also to rule out malignancy.

Small intestinal perforation due to cytomegalovirus infection in patients with non-Hodgkin's lymphoma.

We describe two patients with non-Hodgkin's lymphoma (NHL) who suffered cytomegalovirus (CMV)-related small intestinal perforations during the course of chemotherapy. Surgical specimens from both patients revealed histologic evidence of occlusive vasculitis and tissue destruction caused by CMV-affected cells in the submucosa and muscular walls, that may have played an important role in the pathogenesis of these perforations. Although such intestinal perforations are rare complications in NHL patients, CMV infection should be recognized as a primary etiological factor in acute abdominal crises when treating NHL patients with pharmaceutical agents including steroids. Emergency surgery and the anti-CMV agent, ganciclovir, would improve the prognoses of such patients.