Bronchial artery embolization (BAE) using particles is an established treatment for hemoptysis. The use of polyvinyl alcohol (PVA) with a particle size of 300 µm or larger is thought to reduce the risk of non-target embolization but may result in more proximal vessel occlusion than is ideal, resulting in a high rate of early recurrent hemorrhage. This study evaluates the safety and efficacy of BAE using PVA particles with a size of less than 300 µm. All patients who underwent BAE between 2010 and 2022 at a tertiary center were included. Demographic data, etiology and volume of hemoptysis, technical and clinical success, procedure-related complications, and follow-up information were collected from patients’ electronic records. 150–250 µm PVA particles were used to commence embolization in all patients with the subsequent use of larger-sized particles in some individuals. The Kaplan–Meier method was used to estimate recurrence and survival rates. One hundred forty-four patients underwent 189 embolization procedures between 2010 and 2022 and were followed up for a median of 35 months [IQR 19–89]. 150 µm to 250 µm PVA particles were used as the sole embolic agent in 137 cases. Hemoptysis recurred within 30 days in 7

Primary hyperparathyroidism (PHPT) is a disorder characterized by hypercalcemia and an elevated or inappropriately normal parathyroid hormone level. Classic features include bone pain, fractures, renal impairment, nephrolithiasis, and mental disturbance. However, most cases of PHPT are now asymptomatic at diagnosis or associated with nonspecific neurocognitive changes. The most frequent cause of PHPT is a solitary adenoma that secretes parathyroid hormone without the normal suppressive effect of serum calcium. A smaller number of cases can be attributed to multigland disease. Parathyroidectomy is curative and is considered for nearly all affected patients. Although PHPT is primarily a clinical and biochemical diagnosis, imaging is key to the localization of adenomas, which can lie in conventional locations adjacent to the thyroid gland or less commonly at ectopic sites in the neck and mediastinum. In addition, accurate localization facilitates the use of a minimally invasive or targeted surgical approach. Frequently used localization techniques include US, parathyroid scintigraphy, and four-dimensional CT. Second- and third-line modalities such as MRI, PET/CT, and selective venous sampling with or without parathyroid arteriography can increase confidence before surgery. These localization techniques, along with the associated technical aspects, relative advantages, and drawbacks, are described. Local expertise, patient factors, and surgeon preference are important considerations when determining the type and sequence of investigation. A multimodality approach is ultimately desirable, particularly in challenging scenarios such as multigland disease, localization of ectopic adenomas, and persistent or recurrent PHPT. Online supplemental material is available for this article. ©RSNA, 2022.

Objectives: Primary aldosteronism is one of the most common causes of secondary hypertension. Distinguishing unilateral from bilateral disease is essential as those with unilateral adrenal disease will benefit from adrenalectomy. This is best achieved by adrenal vein sampling (AVS) which may be a difficult procedure with significant radiation to both patient and operator. This study aims to measure the radiation dose during AVS before and after the installation of a new angiography platform. Materials and Methods: The dose area product (DAP), air kerma, and fluoroscopy time were collected retrospectively together with demographic data for the first ten patients who underwent AVS between April and September 2018 following the installation of the Philips Azurion 7 M20 interventional platform. These results were compared with those from ten patients who underwent AVS before the installation of the new machine using the Philips Allura Xper FD20 platform. Mann–Whitney test was used to compare DAP, air kerma, and fluoroscopy time. P < 0.05 was considered statistically significant. Results: Successful bilateral adrenal vein catheterization was achieved in all cases in both groups. There was no significant difference in fluoroscopy time: 5.5 (3.3–10.8) min (new) versus 5.3 (4.5–8.4) min (old) (P = 0.9502). The DAP and air kerma were both significantly lower on the new machine: 11.3 (5.2–26.7) Gy.cm2 versus 45.5 (17.2–56.5) Gy.cm2 (P = 0.0089) and 201.5 (88.1–464.0) mGy versus 682.5 (300.5–998.5) mGy (P = 0.0115), respectively. Conclusion: The installation of the Philips Azurion 7 M20 interventional platform has allowed a significant reduction in radiation dose during AVS.

BACKGROUND Pancreas transplantation has proven to be the most effective therapeutic option for insulin-dependent diabetes mellitus. However, despite advances in surgical technique and continuously improving outcomes, pancreas transplantation has the highest complication rate among all solid-organ transplants. Vascular complications in particular can be catastrophic, with graft- and life-threatening potential. Ectopic variceal bleeding is less common and is rarely reported in the literature. CASE REPORT A 51-year-old man presented with recurrent intermittent gastrointestinal bleeding (GIB) associated with hepatic dysfunction and portal hypertension 4 years after a successful pancreas-after-kidney transplant. Apart from positive serology for hepatitis E virus, all the other liver disease screening results were negative. He was extensively investigated with 6 computed tomography (CT) scans, 3 esophago-gastro-duodenoscopies (EGD), 3 colonoscopies, and 1 visceral arteriogram before the plausible diagnosis of ectopic trans-anastomotic variceal bleeding involving the pancreas transplant was established. Selective variceal catheterization and embolization were done with 3% sodium tetradecyl sulphate (STD). He remained free of bleeding after embolization. CONCLUSIONS This case report adds to the scanty literature on the management of ectopic variceal bleeding in a pancreas transplant recipient. Diagnosis of ectopic varix is usually challenging and frequently requires a visceral arteriogram. We describe a novel minimally-interventional technique to obtain source control and also discuss the complexity involved in the management, along with future implications.

Objective: To examine the MRI safety of metallic coils and Amplatzer vascular plugs. Currently, concern regarding MR safety of devices used to treat pulmonary arteriovenous malformations (PAVMs) causes delays in performing emergency MRI in patients presenting with acute neurological symptoms. Methods: A retrospective audit was performed on all patients who underwent PAVM embolization at Hammersmith Hospital, London UK between 1984 and 2017. Outcomes of all MRI studies performed at our institution were recorded. In addition, known outcomes of all known MRI studies performed on patients treated with the earliest steel coils (1984-1995) were recorded. Results: At our institution, 20 patients underwent 1.5 T MRI after the insertion of 100 steel coils (15.5 - 28.6, median 22 years later), 140 coils designated MR-conditional (0.42 - 12.7, median 9.3 years later), and 54 MRI-conditional Amplatzer vascular plugs (0.17 - 8.0, median 0.75 years later), many in combination. The majority of scans were for cerebral indications, but other body regions scanned included spinal, thoracic, and pelvic regions. No adverse events were reported. Similarly, there were no adverse events in any MR scan known to have been performed in other institutions in seven further patients treated with the earliest steel coils (1984-1995). Again, the majority of scans were for cerebral indications. Conclusion: The findings demonstrate MR safety at 1.5 T of all PAVM embolization devices inserted in a main UK centre since inception in 1984. Advances in knowledge: MRI of patients who have had PAVMs treated by embolization can be implemented without contacting specialist pulmonary arteriovenous malformation treatment centres for approval.

ZusammenfassungPulmonale arteriovenöse Malformationen (PAVM) sind pathologisch dilatierte dünnwandige Gefäße, die eine direkte Verbindung zwischen pulmonalarteriellem und pulmonalvenösem Kreislauf herstellen. Das bedeutet, in diesem Bereich wird die Kapillardurchblutung mit Kontakt zur Alveole umgangen, und ein anatomischer Rechts-Links-Shunt resultiert. Dadurch können bei Patienten mit PAVM der Gasaustausch gestört (Folge: Hypoxämie) und die Filtration des venösen Blutes (Risiko für paradoxe Embolien) eingeschränkt sein. PAVM finden sich häufiger, als bisher angenommen. Dabei spielen die heute verbesserten radiologischen Untersuchungstechniken eine wesentliche Rolle.

The diagnosis of pulmonary arteriovenous malformations (PAVMs) on computerized tomography is usually straightforward, but there are several “mimics” that may cause confusion, the imaging features of which have been described previously ( 1 Gill S.S. Roddie M.E. Shovlin C.L. Jackson J.E. Pulmonary arteriovenous malformations and their mimics. Clin Radiol. 2015; 70: 96-110 Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar ). A rare vascular mimic is an acquired transpleural systemic artery-to-pulmonary artery communication, as described in this report.

Hereditary haemorrhagic telangiectasia (HHT) results in arteriovenous malformations (AVMs), most commonly in the lungs, liver and brain. Discussion of cerebral vascular malformations is an important element of patient management. The current study objectives were to examine uptake and results of screening cerebral magnetic resonance (MR) scans, excluding symptomatic patients requiring neurological investigations. The remaining non-symptomatic individuals received formal pretest counselling that differed according to family history. For the 603 patients with no neurological symptoms of concern, screening scan uptake was higher after publication of the ARUBA trial. Patients with a family history of cerebral haemorrhage were 4 to 14-fold more likely to have a screening scan than patients with no such family history. For patients without neurological symptoms suggesting cerebral AVMs, none of the 59 screening scans performed at our institution demonstrated a cerebral AVM. Four scans (6.8%) demonstrated small aneurysms. The most common abnormality was cerebral infarction (20/59, 33.9%), predominantly identified in patients with pulmonary AVMs. Of 29 pulmonary AVM patients with no previous history of clinical stroke, 16 (55.2%) had between one and five silent infarcts. For HHT patients with pulmonary AVMs, the most frequently affected sites were the cerebellum (40%) and thalamus (14.3%), and the age-adjusted odds ratio for an infarct was 21.6 (95% confidence intervals 3.7, 126), p = 0.001. We concluded that for cerebral screening programmes in HHT, the findings support informed patient choice incorporating understanding that cerebral AVMs are rare in non-symptomatic HHT patients, but that screening scans commonly detect silent cerebral infarction due to pulmonary AVMs.

Introduction and Objectives Patients with pulmonary arteriovenous malformations (PAVMs) are difficult to assess for anaesthetic risks. Generally, they display well-preserved exercise tolerance, yet may have very low oxygen saturation due to their anatomical intrapulmonary right-to-left shunts. During pre-operative assessments in the general population, anaerobic threshold and peak VO2, measured by cardiopulmonary exercise testing (CPET), are increasingly recommended to identify high-risk patients, and appropriately plan post-operative management. For example, “high-risk” for major abdominal surgery has been suggested as an anaerobic threshold Methods In order to evaluate “pre-operative” risk categories for PAVM patients, anaerobic threshold and peak VO2, measured by ethically approved research cardiopulmonary exercise tests, were evaluated. Results 26 PAVM patients underwent research CPET evaluations between April 2011-May 2017. Their median age was 57 years (interquartile range (IQR): 42–66). 16 (61.5%) were male. The median oxygen saturation (SaO2) was 92% (IQR: 88–95) and median haemoglobin 15.6 g/dl (IQR: 14.2–16.6). Overall, the PAVM group achieved a median 92% of the predicted maximum work (IQR: 67–106), anaerobic threshold ranged from 7.6–24.5 ml min-1 kg-1 (median: 12.35; IQR: 9.5–17.35), and peak VO2 ranged from 11.2–45.5 ml min-1 kg-1 (median: 19.8; IQR: 16.7–28.4). Anaerobic threshold placed 11/26 (42.3%) in the suggested high-risk category for major abdominal surgery. In this group, the anaerobic threshold ranged from 7.6–10.8 ml min-1 kg-1. Similarly, peak VO2 placed 14/26 (53.8%) in a high-risk category. Their peak VO2 ranged from 11.2–16.5 ml min-1 kg-1. There was full concordance between the categories determined by the 2 measurements. Notably, 6 patients were retested 3–31 months after embolization treatment resulting in increased SaO2. However, there was no increase in anaerobic threshold or peak VO2, and the 3 patients from this group initially in a higher risk category remained. Conclusion Anaerobic threshold and peak VO2 suggest high proportions of PAVM patients are in a high-risk pre-operative risk category. The data suggest an important role for anaesthetic assessments. Noting that 1 in 2600 people are estimated to have PAVMs, further study is recommended to develop appropriate clinical guidance, and allocate resources to optimise care.

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.

RATIONALE:PaO2 and SaO2 are commonly measured in respiratory practice, but arterial oxygen content (CaO2) refers to the volume of oxygen delivered to the tissues per unit blood volume. CaO2 is calculated from SaO2 and the hemoglobin concentration in blood, recognizing that each gram of hemoglobin can transport approximately 1.34 ml of oxygen when fully saturated. OBJECTIVES:To prospectively evaluate serial changes in CaO2 in humans, incorporating and excluding dynamic changes to oxygenation and hemoglobin parameters that may occur during life. METHODS:A cohort of 497 consecutive patients at risk of both hypoxemia and anemia were recruited. The patients had radiologically proven pulmonary arteriovenous malformations (PAVMs), which result in hypoxemia due to right-to-left shunting, and concurrent hereditary hemorrhagic telangiectasia, which placed them at risk of iron deficiency anemia due to recurrent hemorrhagic iron losses. Presentation SaO2 (breathing room air, by pulse oximetry), hemoglobin, red cell and iron indices were measured, and CaO2 calculated as SaO2 × hemoglobin × 1.34 ml/g. Serial measurements were evaluated in 100 cases spanning up to 32.1 (median, 10.5) years. RESULTS:Presentation CaO2 ranged from 7.6 to 27.5 (median, 17.6) ml/dl. CaO2 did not change appreciably across the SaO2 quartiles. In contrast, hemoglobin ranged from 5.9 to 21.8 g/dl (median, 14.1 g/dl), with a linear increase in CaO2 across hemoglobin quartiles. After PAVM embolization and an immediate increase in SaO2, hemoglobin fell and CaO2 was unchanged 1.6-12 (median, 4) months later. When hemoglobin fell because of iron deficiency, there was no change in SaO2. Similarly, when hemoglobin rose after iron treatment, there was no change in SaO2, and the expected CaO2 increment was observed. These relationships were not evident during pregnancy when hemoglobin fell, and PAVMs usually deteriorated: in pregnancy SaO2 commonly increased, and serial CaO2 values (incorporating hemodilution/anemia) more accurately reflected deteriorating PAVM status. An apparent fall in CaO2 with age in females was attributable to the development of iron deficiency. There was an unexplained increase in CaO2 with age in follow-up of males after embolization. CONCLUSIONS:Hemoglobin/CaO2 should be further incorporated into oxygenation considerations. More attention should be given to modest changes in hemoglobin that substantially modify CaO2.

Pulmonary arteriovenous malformations (PAVMs) are structurally abnormal vessels that provide direct capillary-free communications between the pulmonary and systemic circulations, and hence, right-to-left shunts [1]. Due to impaired gas exchange, hypoxaemia is common but exercise tolerance is usually preserved through haematological (erythrocytotic) and cardiovascular compensations [2, 3], and patients are frequently asymptomatic [1–3]. Treatment of PAVMs is recommended to prevent paradoxical embolic sequelae such as ischaemic strokes [4] and brain abscess [5], commonly improves migraine headaches [6], and is a successful emergency treatment for haemorrhage. Pulmonary AVM embolisation appears to improve nosebleed severity for nearly one in six people with HHT http://ow.ly/4mJqip

Background: Pulmonary arteriovenous malformations (AVMs) provide right-to-left shunts, resulting in hypoxaemia, paradoxical embolic events and other complications. Most are due to hereditary haemorrhagic telangiectasia (HHT), a condition that can also cause systemic AVMs, nosebleeds, and iron deficiency anaemia. Surprisingly, at 6 month follow up after pulmonary AVM embolisation, patients frequently reported that nosebleeds had improved after this apparently unconnected treatment. Methods: To examine in an objective, unbiased manner, relevant questions were included in a wider online HHT survey. For each assessment/intervention, participants were provided with tickbox options for “nosebleeds were …”no different really”; “seemed a bit better”; “seemed a bit worse”. Results: Of 706 individuals who completed the survey, 167 reported receiving treatment of pulmonary AVMs by embolisation (160/167, 96%), or surgery (20/167, 12%). 154 of the 167 (92%) reported nosebleeds, including 121 (73%) at least once per week and 64 (38%) at least once per day. Fewer than 1.75% reported nosebleed improvement after non-invasive investigations such as chest x-rays, blood tests or oximetry. In contrast, 28/160 (17.5%) reported that their nosebleeds seemed better after pulmonary AVM embolisation (p<0.001). In the wider population, nosebleed improvement was also commonly reported following treatment of other AVMs, and anaemia. Conclusion: Treatment of pulmonary AVMs, recommended to prevent paradoxical embolic strokes and brain abscess, appears to have an added benefit in improving HHT nosebleeds for a proportion of people with underlying HHT. Mechanisms deserve further evaluation.

Introduction: Understanding factors that reduce arterial oxygen content (CaO2) thus increasing cardiac demands, is important for clinical practice. Currently, attention is primarily directed to the partial pressure of oxygen (PaO2) and particularly haemoglobin saturation (SaO2), but CaO2 is also directly proportional to the haemoglobin concentration. Methods: Presentation data were evaluated on 497 consecutive patients with pulmonary arteriovenous malformations (AVMs) and hereditary haemorrhagic telangiectasia (HHT), at risk of both hypoxaemia and iron deficiency anaemia. Between 1999 and 2013, SaO2 was measured by pulse oximetry in the supine and erect postures, and the mean SaO2 calculated after 7, 8, 9 and 10 minutes standing. Same-day haemoglobin was measured in venous blood samples in 440 patients. Presentation CaO2 was calculated by the equation oxygen saturation (SaO2, %) x haemoglobin (gram/dL) x 1.34/100. Results: There was a four-fold difference in CaO2 across the 440 patients (range 7.6-27.5, median 17.6) mls of oxygen per decilitre (dL) of arterial blood. SaO2 ranged from 59-100% (median 94.8%), but CaO2 did not change appreciably across the SaO2 quartiles (median CaO2 17.1; 18.1; 17.7; 17.8mls/dL; p=0.34). In contrast, CaO2 was primarily determined by haemoglobin which ranged from 5.9-21.8g/dL (median 14.1g/dL). The median CaO2 across quartiles of haemoglobin were 14.1; 16.7, 18.5; and 20.5mls/dL (p<0.0001). For each 1g/dL rise in haemoglobin, there was a 10% increase in mls of oxygen per unit blood volume. Conclusions: Minor reductions in haemoglobin substantially reduce CaO2 and deserve greater attention in respiratory medicine.

Intro: Age related respiratory changes may decrease efficiency of ventilation and gas transfer resulting in reduced haemoglobin saturation (SaO2). The oxygen content of arterial blood (CaO2) relies on haemoglobin concentration and SaO2. Our aim was to examine serial changes in CaO2 in a cohort with hypoxaemia due to pulmonary arteriovenous malformations (PAVMs) Methods: Retrospective longitudinal follow-up data were collected for 100 consecutive patients in tertiary care between 1984-2001, reviewed until 2015. Subjects provided up to 30 annual datasets. SaO2 was measured by pulse oximetry. Mean SaO2 calculated after 7-10 minutes. CaO2 in mls of oxygen per decilitre (mls/dL) of blood was calculated by SaO2(%)xhaemoglobin(g/dL)x1.34/100. Data were analysed using STATA ICV13.1 Results: Age and treatment associated changes in SaO2 were usually accompanied by opposing changes in haemoglobin that maintained CaO2. Two major patterns were observed: one was the expected increase in haemoglobin with lower SaO2, due to secondary erythrocytosis and polycythaemia. The second, less well recognised was an increase in SaO2 when haemoglobin fell, most commonly when subjects developed iron deficiency and anaemia. Nevertheless, excluding participants with iron deficiency, CaO2 decreased with age(p<0.001) Conclusion: Despite well-known erythropoeitic feedback mechanisms, in patients with PAVMs, arterial oxygen content appears to decrease with age

ObjectiveTo evaluate if injection of intravenous particles may provoke migraines in subjects with right‐to‐left shunts due to pulmonary arteriovenous malformations (AVMs).BackgroundMigraine headaches commonly affect people with hereditary hemorrhagic telangiectasia (HHT), especially those with pulmonary AVMs that provide right‐to‐left shunts. In our clinical practice, patients occasionally reported acute precipitation of migraine headaches following injection of technetium‐labeled albumin macroaggregates for nuclear medicine scans.MethodsSelf‐reported migraine features and exacerbations were examined in HHT subjects with and without pulmonary AVMs, for a series of noninvasive and invasive investigations, using an unbiased online survey.ResultsOne hundred and sixty‐six subjects were classified as having both HHT and migraines. HHT subjects with migraines were more likely to have pulmonary AVMs (P < .0001). HHT subjects with pulmonary AVMs were more likely to report photophobia (P = .010), “flashes of light” (P = .011), or transient visual loss (P = .040). Pulse oximetry, x‐rays, ultrasound, and computerized tomography (CT) scans without intravenous contrast medium rarely, if ever, provoked migraines, but unenhanced magnetic resonance imaging (MRI) was reported to exacerbate migraines by 14/124 (11.2%) subjects. One hundred and fourteen subjects had both enhanced and unenhanced CT examinations: studies with contrast media were more commonly reported to start (9/114 [7.8%]), and/or worsen migraines (18/114 [15.7%]), compared to those undertaken without contrast medium (P < .01), or after simple blood tests (P < .05). Additionally, migraine exacerbation was reported by 9/90 (10%) after contrast echocardiography, 2/44 (4.5%) after nuclear medicine scans, and 10/154 (6.5%) after blood tests.ConclusionsHHT subjects frequently report migraine exacerbation following blood tests, contrast echocardiograms, MRI imaging, and CT studies performed with intravenous contrast medium. Since air emboli are recognized to complicate intravenous injections, particularly those given by a pressurized pump during contrast enhanced CT, future studies should re‐evaluate whether particulate emboli provoke migraines.

Gall, Tamara M. H. BSc, MRCS; Sodergren, Mikael H. PhD, MRCS; Frampton, Adam E. MSc, MRCS; Fan, Ruifang MD; Spalding, Duncan R. MD, FRCS; Habib, Nagy A. ChM, FRCS; Pai, Madhava MS, MSc, FRCS; Jackson, James E. FRCR; Tait, Paul FRCR; Jiao, Long R. MD, FRCS Author Information