Systemic Artery to Pulmonary Artery Shunt Mimicking Acute Pulmonary Embolism, Unmasked by a Multimodality Imaging Approach

In this report, we describe the functional imaging findings of systemic artery to pulmonary artery shunt in V/Q SPECT CT imaging. A 63-year-old man with small-cell lung cancer underwent CT pulmonary angiography (CTPA) for suspected acute pulmonary embolism (PE). The CTPA showed an isolated segmental filling defect in the right lower lobe, which was initially interpreted as positive for PE but was actually the consequence of a systemic artery to pulmonary artery shunt due to the recruitment of the bronchial arterial network by the adjacent tumor. A V/Q SPECT/CT scan was also performed, demonstrating a matched perfusion/ventilation defect in the right lower lobe.

Carotid Web Phenotype Is Uncommonly Associated With Classic Fibromuscular Dysplasia: A Retrospective Observational Study

Background and Purpose: Carotid web (CaW) is an intimal form of fibromuscular dysplasia (FMD) involving the carotid bulb which has been increasingly recognized as a potential cause of recurrent ischemic strokes. It is overlooked as a separate entity and often dismissed if no coexistent signs of classic FMD changes are observed. We aim to evaluate the frequency of classic FMD in high-yield vascular territories in patients with symptomatic CaW. Methods: This was a retrospective analysis of a symptomatic CaW database of 2 comprehensive stroke centers (spanning September 2014–October 2020). The diagnosis of a CaW during a stroke workup was defined as the presence of a shelf-like linear filling defect in the posterior aspect of the carotid bulb on computed tomography angiography in patients with acute ischemic stroke or transient ischemic attack of undetermined cause after a thorough evaluation. Neck computed tomography angiography and renal conventional angiography images were independently evaluated by two readers blinded to the laterality and clinical details to inspect the presence of underlying classic FMD. Results: Sixty-six patients with CaW were identified. Median age was 51 years (interquartile range, 42–57), and 74% were women. All patients had neck computed tomography angiography (allowing for bilateral vertebral and carotid evaluation), whereas 47 patients had additional digital subtraction angiography (which evaluated 47 carotids ipsilateral to the stroke and 10 contralateral carotids). Internal carotid artery classic FMD changes were noted in only 6 out of 66 (9%) in the ipsilateral carotids. No contralateral carotid or vertebral artery classic FMD changes were observed. Renal artery catheter-based angiography was obtained in 16 patients/32 arteries and only 1 patient/2 renal arteries demonstrated classic FMD changes. Conclusions: CaW phenotype is uncommonly associated with classic FMD changes. Coexistent classic FMD does not constitute a useful marker to corroborate or exclude CaW diagnosis.

Identification of Carotid Artery Microstructure and Plaque Rupture Using C-Arm Cone-Beam CT: A Case Report

C-arm cone-beam computed tomography (CBCT) offers a high imaging resolution with a wide range of contrast to visualize vessels, soft tissue, and bone. We report the usefulness of CBCT in observing neovascularization, microcalcification, and plaque rupture. A 56-year-old man presented with vertigo and complain of an unsteady gait for 5 months. Catheter angiography demonstrated right severe carotid stenosis with irregular filling defect, which on high-resolution MRI showed vessel wall enhancement. The CBCT showed high density structures and linear contrast enhancement from the vascular lumen to the plaque, related to microstructure and plaque rupture. Carotid endarterectomy was performed, and histopathology confirmed that the high-density areas represented neovascularization and microcalcification, with linear enhancement representing plaque rupture. This is the first report showing that microcalcifications and plaque rupture can be identified by CBCT. Thus, CBCT can be used as a promising supplement to current imaging modalities to evaluate plaque components more accurately.

P-BN59 Danger is there, do we want to know about it? Routine intra operative cholangiography highlights dangerous biliary anatomy for safer cholecystectomy

Background Normal biliary anatomy is uncommon. Different classification for biliary anatomy has been described, with Huang Types A4 & A5 of great interest for laparoscopic cholecystectomy (LC) due to the proximity of aberrant bile duct to Cystic duct (CD). These types of dangerous anatomy might contribute to bile duct injury. This study aims to analyse the prevalence of dangerous biliary anatomy. Methods Prospectively collected data for all patients who underwent laparoscopic cholecystectomy was analysed. All LC were performed by single surgeon or under his direct supervision, between 01/07/2020 and 20/08/2021. Index admission and single session management of cholelithiasis disease with routine Laparoscopic cholecystectomy + intra operative cholangiography (IOC) +/- LCBD exploration were standard practice. Results Laparoscopic cholecystectomy was performed in 137 patients. Mean age was 56y (17-84). 62% were females. 66% of Laparoscopic cholecystectomies were emergency. IOC was performed in 92% of cases. Abnormal biliary anatomy was found in 54% : Huang A1 - 48%, A2 - 29%, A3 - 12%, A4 - 9.7% and A5 - 0.7%. Dangerous anatomy (A4 and A5) was found in 10.5%, 78 % were females. Female with dangerous anatomy were younger than males 49 y, 60y respectively. Nassar difficulty grading for dangerous anatomy was as follows: G2 28%, G3 42% and G3 28% Abnormal cholangiogram was found in 48%, due to filling defect in 58%, no contrast flow into duodenum in 4%, Cystic duct stone in 4%, and short CD in 8%. CBD stones were treated using transcystic approach in 92% of cases. No intra-operative or post operative complications were recorded for patients with dangerous anatomy. Conclusions This study demonstrates that dangerous biliary anatomy, that could lead to bile duct injury is relatively common, occurring in 10.7% of LCs. Routine intra-operative cholangiography highlights these high-risk variations in biliary anatomy and may prevent inadvertent bile duct injury in such cases.

The Effect of Limiting the Scan Range of Computed Tomography Pulmonary Angiography (to Reduce Radiation Exposure) on the Detection of Pulmonary Embolism: A Systematic Review

(1) Background: Computed tomography pulmonary angiography (CTPA) is the standard imaging test for the evaluation of acute pulmonary embolism (PE), but it is associated with patients’ exposure to radiation. Studies have suggested that radiation exposure can be reduced without compromising PE detection by limiting the scan range (the z-axis, going from up to down); (2) Methods: A literature search was conducted in MEDLINE and EMBASE on 17 July 2021. Studies were included if they enrolled patients who had undergone a CTPA and described the yield of PE diagnoses, number of missed filling defects and/or other diagnoses using a reduced z-axis in comparison to a full-length scan. To assess risk of bias, we modified an existing risk of bias tools for observational studies, the Newcastle-Ottawa Scale. Results were synthesized in a narrative review. Primary outcomes were the number of missed PE diagnoses (based on at least one filling defect) and filling defects; the secondary outcome was the number of other missed findings; (3) Results: Eleven cohort studies and one case-control study were included reporting on a total of 3955 scans including 1025 scans with a diagnosis of PE. Six different reduced scan ranges were assessed; the most studied was from the top of the aortic arch to below the heart, in which no PEs were missed (seven studies). One sub-segmental PE was missed when the scan coverage was 10 cm starting from the bottom of the aortic arch and 14.7 cm starting from the top of the arch. Five studies that reported on other findings all found that other diagnoses were missed with a reduced z-axis. Most of the included studies had a high risk of bias; (4) Conclusions: CTPA scan coverage reduction from the top of aortic arch to below the heart reduced radiation exposure without affecting PE diagnoses, but studies were generally at high risk of bias.

Discarded old antibiotics as a new arsenal for multi-resistant isolates in diabetic foot ulcer infections: therapeutic value of parenteral colistin versus multi-resistant Pseudomonas species isolate strains: case report

Antimicrobial resistance to current novel antibiotics is posing a major threat to both human and zoonotic life. In the absence of new novel antibiotics molecules, clinicians have resorted into a desperate last resort to review and re-introduce prior discarded antibiotics as their new weaponry in the fight against multi-resistant gram negative bacteria. We reported a case of a 77 year old bed ridden diabetic and hypertensive with renal impairment diagnosed with bilateral lower limbs wet gangrene. She underwent transfemoral on her right and transtibial amputation on her left lower limb. She developed surgical site infection on her right stump and wet gangrene on her left stump. Pus swab on her right stump revealed carbapenem resistant strains of Pseudomonas aeruginosa. She was instituted on parenteral colistin and showed no bacterial growth 7 days post treatment. She suffered an ischaemic cerebral vaso-occlusive stroke during her hospital stay. CT angiography of lower lung fields showed a large filling defect in the right main pulmonary artery extending to the lower lobe branches suggestive of right-sided pulmonary embolism. Our patient succumbed from her co-morbidities. Despite our patient succumbing to her multiple co-morbidities we reported this case to highlight the isolation of carbapenem resistant strains of P. aeruginosa and the efficacy and safety of colistin as a salvage antibiotic in renal impaired patients. Colistin can be safely used as a last reserve antibiotic for multi-resistant strains of P. aeruginosa infection even in patients with renal impairment.

Anticoagulation may contribute to antimicrobial treatment of Lemierre syndrome: a case report

Background Lemierre syndrome (LS) is characterized by multisystemic infection beginning in the oropharynx, local thrombophlebitis (typically, of the internal jugular vein) and peripheral embolism. No evidence-based guidelines exist for the management of this disease, and the use of anticoagulation therapy remains particularly controversial. Case presentation A 61-year-old man presenting with left neck swelling, odynophagia, and dyspnea underwent emergency surgery and received intravenous antibiotics. The primary infection was controlled on hospital day 5, but on day 6 sudden leukocytosis and hypoxemia were observed. CT angiography revealed an intraluminal filling defect in the pulmonary artery on day 8. LS was diagnosed and anticoagulation therapy was initiated. The WBC count, which had maintained its peak values in the previous 2 days, decreased instantly after initiation, and follow-up controls showed thrombus resolution. Conclusions Our case supports the notion that anticoagulation therapy may be a valid supplement to antimicrobial therapy in LS, especially in the presence of a possibly young thrombus as suggested by clinical worsening.

Abstract 1122‐000072: Mechanical Thrombectomy for Cerebral Venous Sinus Thrombosis in the setting of APL

Introduction : 28 year‐old woman with newly diagnosed acute promyelocytic leukemia (APL) undergoing chemotherapy with tretinoin and arsenic trioxide developed new onset headache and binocular diplopia. Neurologic exam was significant for bilateral papilledema and bilateral abducens nerve palsies. MR venogram showed incomplete opacification of the right and left transverse sinuses consistent with thrombosis. Therapeutic dose enoxaparin was started and she was taken to the neuroangiography suite. Methods : The left internal jugular vein was catheterized, and the microcatheter was advanced to the opacified left sigmoid sinus. A stent retriever was then deployed and suction thrombectomy was performed, with improvement of the filling defect. Next, the right internal jugular vein was catheterized and the right sigmoid sinus was accessed. Suction thrombectomy was performed, but due to residual thrombus, a stent retriever was deployed in the right transverse sinus and suction thrombectomy was reattempted, with improved recanalization. Results : Patient returned to the unit and continued therapeutic enoxaparin. Three days post‐procedure, she developed worsening headache and syncope. She was again taken to neuroangiography suite and the RIJ vein was again catheterized. Venogram after advancing the catheter to the right sigmoid sinus showed multiple filling defects in the proximal right transverse sinus. The catheter was advanced to the sigmoid sinus and a stent retriever was introduced; multiple attempts were made to remove the thrombus. Follow‐up venogram showed significant improvement in recanalization. The LIJ vein was then catheterized and venogram was performed, showing worsening filling defect in the left sigmoid sinus. A stent retriever was deployed in the left transverse sinus and suction thrombectomy was performed, however there was still significant residual thrombus. Suction thrombectomy, another stent retriever attempt and finally balloon angioplasty were then performed with some improvement of patency.. Follow‐up CTV 5 days post‐procedure showed stable venous sinus filling defects. Patient reported gradual improvement of headaches and was transitioned to apixaban. On follow‐up evaluation 3 months post‐procedure, patient reported resolution of headaches and diplopia. Conclusions : CVST is generally treated with systemic anticoagulation based on data from two randomized trials, however, ISCVT showed that 13% still decline on anticoagulation. Data regarding the safety and efficacy of MT for CVST is lacking, as well as data regarding patient selection. Our initial decision to treat with MT was due to involvement of posterior fossa and signs of increased intracranial pressure, which are potential prognostic factors for clinical decline with anticoagulation alone from ISCVT. Our patient was initially treated with therapeutic enoxaparin, however developed neurologic deterioration, so she was taken back to the neuroangiography suite. This case report illustrates an example of successful utilization of endovascular therapy for CVST in a patient with acute neurologic deterioration, with good neurologic outcome following recanalization

EP.TH.665Where’s the gallbladder? A rare case of gallbladder agenesis with cystic duct stone

Aims Gallbladder agenesis is a rare congenital anatomical malformation with an incidence of 0.007-0.0027%. Although usually asymptomatic, clinically it may present similarly to biliary colic. There may be increased risk of de novo biliary duct stone formation due to biliary dyskinesia, subsequent duct dilatation and biliary stasis. We present a case of incidental gallbladder agenesis identified during intended laparoscopic cholecystectomy. Methods A 68 year-old female with no significant comorbidities presented with a 16 hour history of colicky right upper quadrant pain and vomiting. She had been awaiting cholecystectomy for increasingly symptomatic gallstones, most recently visualised within a contracted gallbladder on ultrasound two months prior. Recurrently obstructive LFT’s warranted urgent magnetic resonance cholangiopancreatography (MRCP), which identified a poorly-visualised contracted gallbladder and a 10mm common bile duct without filling defect. At index laparoscopic cholecystectomy, a very small thick-walled structure resembling the gallbladder was identified and safely excised in retrograde; a stone was seen within. Results Macroscopic examination revealed a 27 x 9 x 11mm piece of dark brown tissue containing soft orange material. Microscopic histological examination confirmed this to be cystic duct focally lined by mucinous epithelium with chronic inflammation. Findings were consistent with gallbladder agenesis. Conclusions Although rare, it is important for surgeons to maintain an index of suspicion for gallbladder agenesis, particularly if repeated imaging demonstrates a poorly-visualised or ‘contracted’ gallbladder despite adequate fasting. Furthermore, as in this case, the presence of ‘gallbladder’ stones radiologically does not preclude gallbladder agenesis. Anticipation of this malformation may aid interpretation of biliary anatomy, if incidentally found intra-operatively.

MASSIVE MURAL AORTIC ARCH THROMBUS.

Mural aortic thrombus is a rare pathology that is more frequently seen in severe atherosclerotic aortic walls, in aneurysms and acute aortic syndrome(1). However this can be found in patients without aortic disease, and be responsible for systemic or cerebral emboli. A 54-year-old male was admitted to our institution for syncope and aphasia, he was found in the street with ethylic intoxication. After neurological examination mixed type aphasia was observed, cerebral and supra aortic arteries CT angiography were performed. Cerebral CT showed focal filling defect of left middle cerebral artery. Supra aortic arteries CT angiography was completed with toracoabdominal CT because massive ascending and arch thrombus was found. The thrombus measured 130 x 33 x 15 mm (Figures 1A and 1B and 1C), and covered from mid ascending aorta to 40 mm distal to the ostium of left subclavian artery. The patient was referred to our unit for urgent surgical treatment. Surgery was performed throw median sterntomy, cardiopulmonary bypass with moderate hypothermic arrest and anterograde cerebral perfusion via right axillary artery. Longitudinal aortotomy was made and 140 x 30 x 15 mm thrombus (Figure 2), attached to posterior mid ascending aorta, was found and resected, the aortic wall did not show any abnormality. The patient had an eventful recovery and was discharged 9 days later with oral anticoagulation and aspirin.