BACKGROUND: Pulmonary arteriovenous malformation (PAVM), also known as pulmonary arteriovenous fistula, is a rare vascular developmental anomaly. Most cases of PAVM are associated with hereditary hemorrhagic telangiectasia (HHT). Hemothorax associated with PAVM is even rarer, and management concerning this complication still challenges.
METHODS: A 55-year-old man with sudden onset of dyspnea and chest pain was admitted to our hospital. He had a medical history of epistaxis, intraperitoneal germ cell tumor and PAVM. Chest unenhanced CT revealed the left-sided pleural effusion together with partial passive atelectasis and gradual increase at the interval of six days. Diagnostic thoracocentesis further revealed hemorrhagic effusion. CT angiography (CTA) showed tortuously dilated lumen of the left lower pulmonary artery and PAVM with the formation of aneurysm. Due to his family\'s refusal of surgery, the patient underwent transcatheter embolization therapy. However, the left pleural effusion did not significantly reduce and there was a slow drop in hemoglobin value even after interventional treatment, indicating the possibility of ongoing active bleeding. Eventually, the patient received lobectomy of the left lower lobe with a satisfactory outcome.
CONCLUSIONS: Massive hemothorax resulting from PAVM rupture into the pleural space can lead to fatal outcomes. CTA can accurately diagnose this pathologic condition. Transcatheter embolization is frequently used in the treatment of PAVM, but it may be challenging to achieve the desirable effect in patients with hemothorax. Combined with our case and literature review, direct radical surgery can lead to a successful outcome when PAVM complicated with hemothorax and a large diameter of the draining vein.

Pulmonary arteriovenous malformations, previously considered a rare condition, have been increasingly identified in asymptomatic patients over the past 2 decades. Usually congenital and associated with hereditary hemorrhagic telangiectasia, these fistulae result in right-to-left shunting of blood by abnormal communication of pulmonary arteries and veins lacking capillary beds. Clinical findings of right-to-left shunting in the presence of feeding and draining vessels identified on imaging confirm the diagnosis, for which the first-line therapy is embolization. This report highlights the presentation and management of a large asymptomatic PAVM detected incidentally in a patient who was lost to follow-up for 10 years and represented with acute hypoxic respiratory failure secondary to a viral infection with an interval increase of PAVM size.

Despite embolization being now considered the preferred treatment for PAVM, surgical intervention may be considered if the malformation involves large vessels.

Arteriovenous malformation (AVM) of the gastrointestinal tract is a rare anomaly, mostly due to congenital reasons. Patients with pancreatic AVM can live without experiencing symptoms. It can present with gastrointestinal bleeding or portal hypertension, and diagnosis can be made by computed tomography (CT) or angiography. CT findings include multiple discrete intrapancreatic vessels. A 48-year-old man complained of abdominal pain with a sensation of fullness that radiated to the back for a month, associated with shortness of breath, loss of appetite, and unintentional weight loss of 33% in one month without nausea or vomiting. On physical examination, the abdomen was soft and lax with epigastric tenderness and a negative Murphy sign. Laboratory investigations showed high amylase with normal liver and kidney functions. CT showed pancreatic AVM. He underwent partial pancreatectomy and splenectomy. After the surgery, the patient reported an improvement in symptoms. All follow-up visits were uneventful. Pancreatic AVM is a rare disease, and the most significant chief complaint of most patients is gastrointestinal tract bleeding. It requires imaging depending on the signs and symptoms. The primary imaging modality is CT, with subtraction angiography for confirmation. Surgical treatment is the standard of management for most patients when tolerable. Additionally, early detection of these rare anomalies can avoid massive gastrointestinal tract bleeding and the development of resistance portal hypertension and can save patients\' lives if bleeding occurs.

OBJECTIVE: To evaluate the safety, technical success and short-term effectiveness of polyurethane-covered stent (PK Papyrus, BioTronik, Berlin) in the treatment of pulmonary arteriovenous malformations (PAVMs) that are not amenable to embolotherapy.
METHODS: In this IRB-approved, retrospective study, data from patients who received polyurethane-covered stents for exclusion of PAVMs were analyzed. The study included 5 patients (all women) with a median age of 40 years (range 25-60). Patients presented with hypoxemia, TIAs, and/or epistaxis; 4 were confirmed to have HHT. All had multiple PAVMs diagnosed on chest CT and underwent embolization with other devices in addition to the polyurethane-covered stent. The indication for stent placement in all cases was a short and/or tortuous feeding artery. Safety was assessed by immediate or short-term complications, e.g., migration, stent thrombosis, and fracture. Technical success was defined as the ability to accurately place the stent at the intended location. Effectiveness was defined as successful exclusion of PAVM with no perfusion across the AVM.
RESULTS: Technical success of stent placement was 100%. AVM exclusion rate was 80% after single stent deployment; in the case of incomplete exclusion, success was achieved using an overlapping stent to completely cover a second feeding artery. During the median follow-up period of 5 months (range 2-10), all stents remained patent, and AVMs were excluded without other complications.
CONCLUSIONS: Exclusion of PAVMs with polyurethane-covered stents is technically feasible, safe, and shows short-term effectiveness for PAVMs with a short/tortuous feeding artery when traditional embolization techniques are not possible.

OBJECTIVE: Pulmonary arteriovenous malformations (PAVMs) may cause recurrent brain abscess. The primary aim was to determine the prevalence of PAVM amongst survivors of brain abscess. The proportion with cardiac right-to-left shunts was also assessed post hoc.
METHODS: This was a cross-sectional population-based study of adult (≥18 years) survivors of cryptogenic bacterial brain abscess in Denmark from 2007 through 2016. Patients were invited for bubble-echocardiography to detect vascular right-to-left shunting and, if abnormal, subsequent computed tomography thorax for diagnosis of PAVM. Data are presented as n/N (%) or median with interquartile range (IQR).
RESULTS: Study participation was accepted by 47/157 (30%) eligible patients amongst whom two did not appear for scheduled bubble-echocardiography. The median age of participants was 54 years (IQR 45-62) and 19/57 (33%) were females compared with 59 years (IQR 48-68, p = 0.05) and 41/85 females (48%, p = 0.22) in non-participants. Bubble-echocardiography was suggestive of shunt in 10/45 (22%) participants and PAVM was subsequently confirmed by computed tomography in one patient with grade 1 shunting. The corresponding prevalence of PAVM was 2% (95% confidence interval 0.06-11.8) amongst all examined participants. Another 9/45 (20%) were diagnosed with patent in persistent foramen ovale (n = 8) or atrial septum defect (n = 1), which is comparable with the overall prevalence of 25% amongst adults in the Danish background population.
CONCLUSIONS: Undiagnosed PAVM amongst adult survivors of cryptogenic bacterial brain abscess is rare but may be considered in select patients. The prevalence of cardiac right-to-left shunts amongst brain abscess patients corresponds to the prevalence in the general population.

Pulmonary arteriovenous malformation (PAVM) is a rare vascular anomaly characterized by abnormal communication between the pulmonary artery and vein. It is a rare cause of hemoptysis. Computed tomographic angiography (CTA) has become the preferred and dependable diagnostic approach for identifying PAVM. PAVM embolization is the primary recommended treatment for this condition. We present a case of a 43-year-old male with a complex PAVM in the left lower lobe presenting with hemoptysis treated with an endovascular approach. Following the procedure, the patient\'s symptoms resolved.

OBJECTIVE: To determine the prevalence of hemoptysis secondary to post-embolization systemic collaterals and review the recurrence rate and treatment outcomes.
METHODS: The records of 930 patients with PAVM (801 with known or possible HHT), from a single HHT center between July 2, 1996 and July 22, 2021, were searched for a single lifetime episode of hemoptysis secondary to post-embolization systemic collaterals. Embolization was performed with permanent particles or gelatin slurry. Clinical features and treatment outcomes of identified patients were reviewed.
RESULTS: Twenty-eight embolization procedures have been performed in 9 patients with post-PAVM embolization systemic artery collateral reperfusion. This included 8 patients with known HHT. Permanent particles were used in 5 cases and gelatine slurry was used in 19 cases. Due to the recurrence of hemoptysis, four patients required four embolizations each, two patients required three embolizations and two patients required two embolizations. Chronic unresolving hemoptysis was the presentation in 5 patients and massive hemoptysis requiring ICU admission in 4. The lifetime prevalence and incidence of hemoptysis secondary to systemic artery reperfusion in HHT patients was estimated to be 1.0% and 0.05%, respectively. Bronchial artery origin was most common (8 patients). In the first patient treated at this center, a major adverse event resulting in myocardial infarct and stroke occurred with the use of 300-500-micron permanent particles. This was presumed to be due to left-to-right shunting and subsequent systemic embolization. Subsequent patients were treated with gelatin sponge slurry without adverse events. This patient ultimately expired due to large volume hemoptysis, in the setting of bilateral diffuse PAVMs. A second patient, with history of childhood bronchial artery coil embolization, expired from large volume hemoptysis while awaiting lobectomy. In two cases, patients underwent surgery, including one lobectomy and one pneumonectomy, for recurrent hemoptysis (requiring at least five hospital admissions). The remaining five patients achieved prolonged resolution of hemoptysis with endovascular treatment alone.
CONCLUSIONS: Lifetime prevalence of hemoptysis secondary to PAVM post-embolization systemic collaterals is rare, but recurrence is high. In this limited series, embolization with gelatin sponge slurry appeared safe, although surgical resection may ultimately be required in refractory and multifocal disease.

Pulmonary arteriovenous malformations (PAVMs) are uncommon, predominantly congenital direct fistulous connections between the pulmonary arteries and pulmonary veins, resulting in a right to left shunt. Patients with PAVMs are usually asymptomatic with lesions detected incidentally when radiological imaging is performed for other indications. In this review, we discuss the classification and radiological features of PAVMs as well as their treatment and follow-up options, with a particular focus on percutaneous endovascular techniques and the evolution of the available equipment for treatment.

Pulmonary arteriovenous malformations (PAVMs) may manifest with bleeding or embolic events necessitating intervention. Transcatheter coil embolization through the pulmonary artery (PA) is an established approach. We present a case of recurrent PAVMs despite numerous PA coil embolizations. PAVM occlusion was achieved through plug placement by a transseptal and pulmonary venous approach. (Level of Difficulty: Advanced.).