86 results found
Boother EJ, Brownlow S, Tighe HC, et al., 2017, Cerebral abscess associated with odontogenic bacteremias, hypoxemia, and iron loading in immunocompetent patients with right-to-left shunting through pulmonary arteriovenous malformations., Clinical Infectious Diseases, Vol: 65, Pages: 595-603, ISSN: 1537-6591
Background: Cerebral abscess is a recognised complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Methods: Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with CT-scan confirmed PAVMs (including 403 (90.5%) with hereditary haemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression, and detailed peri-abscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier non-overlapping series. Results: Thirty-seven (8.3%) of the 445 patients experienced a cerebral abscesses at median age 50 (range 19-76) years. The rate adjusted for ascertainment bias was 27/435 (6.2%). 29/37 (78.4%) abscess patients had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. 21/37 (56.7%) suffered residual neurological deficits, most commonly memory/cognition impairment; hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events emphasised potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio 5.4 [95% confidence intervals 1.4, 21.1]); male gender; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Conclusions: Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower SaO2 and intravenous iron may be modifiable risk factors.
Dupuis-Girod S, Cottin V, Shovlin CL, 2017, The Lung in Hereditary Hemorrhagic Telangiectasia, RESPIRATION, Vol: 94, Pages: 315-330, ISSN: 0025-7931
Finnamore H, Silva BM, Hickson BM, et al., 2017, 7-day weighed food diaries suggest patients with hereditary hemorrhagic telangiectasia may spontaneously modify their diet to avoid nosebleed precipitants, ORPHANET JOURNAL OF RARE DISEASES, Vol: 12, ISSN: 1750-1172
Hosman AE, Shovlin CL, 2017, Cancer and hereditary haemorrhagic telangiectasia, JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY, Vol: 143, Pages: 369-370, ISSN: 0171-5216
Rizvi A, Macedo P, Babawale L, et al., 2017, Hemoglobin Is a Vital Determinant of Arterial Oxygen Content in Hypoxemic Patients with Pulmonary Arteriovenous Malformations, ANNALS OF THE AMERICAN THORACIC SOCIETY, Vol: 14, Pages: 903-911, ISSN: 1546-3222
Shovlin CL, Buscarini E, Hughes JMB, et al., 2017, Long-term outcomes of patients with pulmonary arteriovenous malformations considered for lung transplantation, compared with similarly hypoxaemic cohorts., BMJ Open Respir Res, Vol: 4, ISSN: 2052-4439
INTRODUCTION: Pulmonary arteriovenous malformations (PAVMs) may not be amenable to treatment by embolisation or surgical resection, and many patients are left with significant hypoxaemia. Lung transplantation has been undertaken. There is no guidance on selection criteria. METHODS: To guide transplantation listing assessments, the outcomes of the six patients who had been considered for transplantation were compared with a similarly hypoxaemic patient group recruited prospectively between 2005 and 2016 at the same UK institution. RESULTS: Six patients had been formally considered for lung transplantation purely for PAVMs. One underwent a single lung transplantation for diffuse PAVMs and died within 4 weeks of surgery. The other five were not transplanted, in four cases at the patients' request. Their current survival ranges from 16 to 27 (median 21) years post-transplant assessment. Of 444 consecutive patients with PAVMs recruited between 2005 and 2016, 42 were similarly hypoxaemic to the 'transplant-considered' cohort (SaO2 <86.5%). Hypoxaemic cohorts maintained arterial oxygen content (CaO2) through secondary erythrocytosis and higher haemoglobin. The 'transplant-considered' cohort had similar CaO2 to the hypoxaemic comparator group, but higher Medical Research Council (MRC) dyspnoea scores (p=0.023), higher rates of cerebral abscesses (p=0.0043) and higher rates of venous thromboemboli (p=0.0009) that were evident before and after the decision to list for transplantation. CONCLUSIONS: The non-transplanted patients demonstrated marked longevity. Symptoms and comorbidities were better predictors of health than oxygen measurements. While a case-by-case decision, weighing survival estimates and quality of life will help patients in their decision making, the data suggest a very strong case must be made before lung transplantation is considered.
Shovlin CL, Condliffe R, Donaldson JW, et al., 2017, British Thoracic Society Clinical Statement on Pulmonary Arteriovenous Malformations, THORAX, Vol: 72, Pages: 1154-1163, ISSN: 0040-6376
Shovlin CL, Condliffe R, Donaldson JW, et al., 2017, Pulmonary arteriovenous malformations emerge from the shadows, THORAX, Vol: 72, Pages: 1071-1073, ISSN: 0040-6376
Chamali B, Finnamore H, Manning R, et al., 2016, Dietary supplement use and nosebleeds in hereditary haemorrhagic telangiectasia - an observational study, INTRACTABLE & RARE DISEASES RESEARCH, Vol: 5, Pages: 109-113, ISSN: 2186-3644
Mollet IG, Patel D, Govani FS, et al., 2016, Low Dose Iron Treatments Induce a DNA Damage Response in Human Endothelial Cells within Minutes, PLOS ONE, Vol: 11, ISSN: 1932-6203
Patel T, Elphick A, Jackson JE, et al., 2016, Injections of Intravenous Contrast for Computerized Tomography Scans Precipitate Migraines in Hereditary Hemorrhagic Telangiectasia Subjects at Risk of Paradoxical Emboli: Implications for Right-to-Left Shunt Risks, HEADACHE, Vol: 56, Pages: 1659-1663, ISSN: 0017-8748
Shovlin CL, Awan I, Cahilog Z, et al., 2016, Reported cardiac phenotypes in hereditary hemorrhagic telangiectasia emphasize burdens from arrhythmias, anemia and its treatments, but suggest reduced rates of myocardial infarction, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 215, Pages: 179-185, ISSN: 0167-5273
Shovlin CL, Gilson C, Busbridge M, et al., 2016, Can Iron Treatments Aggravate Epistaxis in Some Patients With Hereditary Hemorrhagic Telangiectasia?, LARYNGOSCOPE, Vol: 126, Pages: 2468-2474, ISSN: 0023-852X
Shovlin CL, Patel T, Jackson JE, 2016, Embolisation of PAVMs reported to improve nosebleeds by a subgroup of patients with hereditary haemorrhagic telangiectasia, ERJ Open Research, Vol: 2, ISSN: 2312-0541
Gill SS, Roddie ME, Shovlin CL, et al., 2015, Pulmonary arteriovenous malformations and their mimics., Clin Radiol, Vol: 70, Pages: 96-110
Pulmonary arteriovenous malformations (PAVMs) are abnormal communications between the pulmonary arteries and veins, which result in a right-to-left (R-L) shunt with resultant hypoxemia, the severity of which will depend upon the size and number of lesions. Most PAVMs occur in individuals with hereditary haemorrhagic telangiectasia (HHT) and are a cause of serious morbidity and mortality largely related to cerebrovascular complications secondary to paradoxical embolization. The importance of their recognition and treatment by embolization, even in the absence of symptoms, is well known. Their appearances on chest radiographs are often, but not always, characteristic and the CT appearances are diagnostic; however, there are a number of both vascular and non-vascular diseases that can cause confusion. This review serves to highlight these PAVM "mimics".
Shovlin CL, 2015, Circulatory contributors to the phenotype in hereditary hemorrhagic telangiectasia, Frontiers in Genetics, Vol: 06, ISSN: 1664-8021
Shovlin CL, Awan I, Abdulla FN, et al., 2015, One in twenty patients with hereditary hemorrhagic telangiectasia report iron treatments precipitate nosebleeds, Publisher: SPRINGER, Pages: 566-567, ISSN: 0969-6970
Yasuda W, Jackson JE, Layton DM, et al., 2015, Hypoxaemia, sport and polycythaemia: a case from Imperial College London., Thorax, Vol: 70, Pages: 601-603, ISSN: 0040-6376
Devlin HL, Hosman AE, Silva BM, et al., 2014, Evaluation of anticoagulant and antiplatelet use in a haemorrhagic disorder, LANCET, Vol: 383, Pages: 40-40, ISSN: 0140-6736
Elphick A, Shovlin CL, 2014, Relationships Between Epistaxis, Migraines, and Triggers in Hereditary Hemorrhagic Telangiectasia, LARYNGOSCOPE, Vol: 124, Pages: 1521-1528, ISSN: 0023-852X
Howard LSGE, Santhirapala V, Murphy K, et al., 2014, Cardiopulmonary Exercise Testing Demonstrates Maintenance of Exercise Capacity in Patients With Hypoxemia and Pulmonary Arteriovenous Malformations, CHEST, Vol: 146, Pages: 709-718, ISSN: 0012-3692
Santhirapala V, Chamali B, McKernan H, et al., 2014, Orthodeoxia and postural orthostatic tachycardia in patients with pulmonary arteriovenous malformations: a prospective 8-year series, THORAX, Vol: 69, Pages: 1046-1047, ISSN: 0040-6376
Santhirapala V, Williams LC, Tighe HC, et al., 2014, Arterial Oxygen Content Is Precisely Maintained by Graded Erythrocytotic Responses in Settings of High/Normal Serum Iron Levels, and Predicts Exercise Capacity: An Observational Study of Hypoxaemic Patients with Pulmonary Arteriovenous Malformations, PLOS ONE, Vol: 9, ISSN: 1932-6203
Shovlin CL, 2014, Pulmonary arteriovenous malformations., Am J Respir Crit Care Med, Vol: 190, Pages: 1217-1228
Within the past decade, pulmonary arteriovenous malformations (PAVMs) have evolved from rare curiosities to not uncommon clinical states, with the latest estimates suggesting a prevalence of ~1 in 2,600. PAVMs provide anatomic right-to-left shunts, allowing systemic venous blood to bypass gas exchange and pulmonary capillary bed processing. Hypoxemia and enhanced ventilatory demands result, although both are usually asymptomatic. Paradoxical emboli lead to strokes and cerebral abscesses, and these commonly occur in individuals with previously undiagnosed PAVMs. PAVM hemorrhage is rare but is the main cause of maternal death in pregnancy. PAVM occlusion by embolization is the standard of care to reduce these risks. However, recent data demonstrate that currently recommended management protocols can result in levels of radiation exposure that would be classified as harmful. Recent publications also provide a better appreciation of the hematologic and cardiovascular demands required to maintain arterial oxygen content and oxygen consumption in hypoxemic patients, identify patient subgroups at higher risk of complications, and emphasize the proportion of radiologically visible PAVMs too small to treat by embolization. This review, therefore, outlines medical states that exacerbate the consequences of PAVMs. Chief among these is iron deficiency, which is commonly present due to concurrent hereditary hemorrhagic telangiectasia: iron deficiency impairs hypoxemia compensations by restricting erythropoiesis and increases the risk of ischemic strokes. Management of periodontal disease, dental interventions, pulmonary hypertension, and pregnancy also requires specific consideration in the setting of PAVMs. The review concludes by discussing to what extent previously recommended protocols may benefit from modification or revision.
Shovlin CL, 2014, Iron deficiency, ischaemic strokes, and right-to-left shunts: From pulmonary arteriovenous malformations to patent foramen ovale?, Intractable Rare Dis Res, Vol: 3, Pages: 60-64, ISSN: 2186-3644
Has the recent identification of iron deficiency as a risk factor for ischaemic stroke in patients with pulmonary arteriovenous malformations (AVMs) unmasked a new paradigm for stroke/infarct pathogenesis? This commentary reviews evidence that spans associations between iron deficiency and ischaemic strokes, iron deficiency enhancement of platelet aggregation in response to serotonin/5HT, settings in which plasma 5HT is elevated, and clinical trial confirmation that 5HT receptor antagonists prevent ischaemic stroke. The critical leap which directs attention away from atherothrombotic events at the neurovascular wall is that ischaemic strokes due to pulmonary AVMs are attributable to compromised pulmonary capillary bed filtration of venous blood. Right-to-left shunting is continuous through pulmonary AVMs, but also occurs intermittently in approximately 30% of the general population with intracardiac shunts such as patent foramen ovale (PFO). The testable hypothesis presented is that paradoxical embolism of venous platelet-based aggregates may constitute part of the causal chain between iron deficiency and ischaemic stroke, not only in the rare disease state of pulmonary AVMs, but also in major subgroups of the general population.
Shovlin CL, 2014, Curable hypoxia in an octogenarian with an undiagnosed inherited condition: a case commentary, Breathe, Vol: 10, Pages: 153-156
Shovlin CL, Chamali B, Santhirapala V, et al., 2014, Ischaemic Strokes in Patients with Pulmonary Arteriovenous Malformations and Hereditary Hemorrhagic Telangiectasia: Associations with Iron Deficiency and Platelets, PLOS ONE, Vol: 9, ISSN: 1932-6203
Shovlin CL, Ganesan V, 2014, Hereditary hemorrhagic telangiectasia, Up to Date in Clinical Medicine, Editors: Ternauer
Devlin HL, Hosman AE, Shovlin CL, 2013, Antiplatelet and Anticoagulant Agents in Hereditary Hemorrhagic Telangiectasia, NEW ENGLAND JOURNAL OF MEDICINE, Vol: 368, Pages: 876-878, ISSN: 0028-4793
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