Reversibility of the Enlargement of the Pulmonary Artery in COVID-19 Pneumonia as a Marker of Remission of the Disease.

Coronavirus disease 2019 (COVID-19) pneumonia is associated with extensive pulmonary microangiopathy and the enlargement of the pulmonary artery (PA), while its progression after the remission of the disease has not been investigated yet. The aim was to assess the diametral increase in the PA in COVID-19 pneumonia, as revealed on chest computed tomography (CT), and further investigate its progression. This was a retrospective cohort study of patients with COVID-19 pneumonia, without prior history of pulmonary hypertension, who underwent CT pulmonary angiography before, during, and after the infection. Pulmonary embolism was excluded in all cases. The main PA diameter (MPAD) was assessed in consecutive chest imaging. Statistical analysis was performed with the non-parametric Wilcoxon and Kruskal-Wallis tests, while correlations were performed with the non-parametric Spearman test. A mean ± SD MPAD of 3.1 ± 0.3 cm in COVID-19 pneumonia was significantly decreased to 2.8 ± 0.3 cm in the post-infectious state after 2-18 months in 31 patients (p-value: <0.0001). In a subgroup of six patients with more than one post-COVID-19 CT, a significant further decline in the diameter was observed (p-value: 0.0313). On the other hand, in accordance with the literature, a significant increase in the MPAD during COVID-19 pneumonia was noted in a group of 10 patients with a pre-COVID-19 CT (p-value: 0.0371). The enlargement of the PA is a common finding in COVID-19 pneumonia that regresses after the remission of the disease, indicating that this reversible cardiovascular event is a potential marker of disease activity, while its course in long COVID is yet to be determined.

MDCT angiography assessment of renal artery in-stent restenosis: can we reduce the radiation exposure burden? A feasibility study.

AIM: We explored the feasibility of renal artery multidetector computed tomography (MDCT) and detection of in-stent restenosis at low exposure settings. PATIENTS/METHODS: Sixteen patients with 19 renal artery stents underwent CT angiography. A biphasic protocol was performed including arteriographic acquisition at standard 120 kVp and a late-arterial scan at 100 kVp (n=9) or 80 kVp (n=7). Images were reconstructed under various algorithms. Signal-to-noise and contrast-to-noise ratios (SNR, CNR) were determined within stent, aorta and renal arteries. Image quality and the presence of restenosis were assessed. Volume CT dose-index was recorded and dose reduction (DR%) between phases was calculated. RESULTS: Ten patients presented with Hounsfield values >250 HU in all segments, phases and reconstructions and were further evaluated. The 120 kVp protocol performed better in all vessels and reconstruction algorithms. SNR at 120 kVp (B31f) did not differ significantly compared to 100 kVp (B31f). CNR within stent was borderline compromised at 100 kVp (p=0.042). All but two image sets (at 80 kVp) were considered diagnostic. Minor loss of subjective image quality was noticed at 100 kVp. No difference in assessment of restenosis was observed between 120 kVp and the diagnostic low-exposure scans. Mean DR% was estimated 45% at 100 kVp and 77% at 80 kVp. CONCLUSIONS: Renal MDCT angiography and stent-restenosis assessment are feasible at 100 kVp with minor loss of image quality and almost half radiation exposure.

Endovascular treatment of a ruptured profunda femoral artery branch after fogarty thrombectomy of a femoro-femoral crossover arterial graft: a case report and review of the literature.

We present a very rare case of a life-threatening rupture of a profunda femoral artery distal branch after a Fogarty thrombectomy of a thrombosed crossover synthetic graft between the ipsilateral common femoral artery and a contralateral iliac-popliteal graft; the bleeding profunda femoral artery branch was successfully embolized with metallic coils through the axillary artery approach.

Preliminary experience with cutting balloon angioplasty for iliac artery in-stent restenosis.

PURPOSE: To report our preliminary experience using cutting balloon angioplasty (CBA) in symptomatic iliac artery in-stent restenosis (ISR). METHODS: Fourteen cases of hemodynamically significant iliac artery ISR (4 common and 10 external) were treated in 12 men (mean age 64 years, range 55-75). Of the 14 stents involved, 8 were balloon-expandable models and 6 were self-expanding. All patients had symptomatic deterioration of at least 1 clinical category over an average period of 50.2 months (range 6-120) post stenting. The mean length of ISR was 11.9 mm (range 2-48), and the average stenosis was 75.4% (range 52%-98%). Nine ISR lesions were focal (<10 mm), 4 were diffuse (>10 mm), and 1 extended outside the stent margins. RESULTS: CBA was performed after conventional angioplasty failure in 7 lesions and as a primary treatment method in 7 lesions. Single (9 focal lesions) or multiple overlapping (5 diffuse or proliferative lesions) inflations were performed using 6-x10-mm (1 lesion), 7-x10-mm (3 lesions), and 8-x10-mm (10 lesions) devices. There was 1 contained rupture treated with a covered stent. In the remainder of the cases, the cutting balloons allowed successful treatment without further stent implantation. During a mean follow-up of 23.6 months (range 12-60), no patient showed clinical deterioration, and no recurrent ISR was detected with color duplex. CONCLUSION: CBA shows high immediate technical and midterm clinical success in symptomatic iliac artery ISR.

Late migration of two covered biliary stents through a spontaneous bilioenteric fistula in a patient with malignant biliary obstruction.

We report a case of simultaneous late migration of two ePTFE-FEP covered biliary endoprostheses (Viabil, W.L. Gore, Flagstaff, AZ, USA) that were percutaneously implanted for the treatment of malignant obstructive jaundice. The first Viabil covered stent was placed successfully without any evidence of dislocation or other complication during follow-up. Occlusion of the stent occurred 4 months later and was treated with the placement of a second stent of the same type. Thirteen months later the patient became symptomatic. Percutaneous transhepatic cholangiography (PTC) revealed the presence of a choledocho-duodenal fistula and the disappearance of the two endoprostheses previously implanted. A third metallic stent was then percutaneously positioned through the bilioenteric fistula. The computed tomography scan that followed for the detection of the metallic bodies did not reveal the dislocated metallic stents. Stent migration is a well-known complication of uncovered metallic stents, though Viabil stent migration is assumed to be most unlikely to happen due to the stent's anchoring barbs. Furthermore, the stent had already been tightly fixed by tumor over- and ingrowth, as recognized in previous imaging. This is a very unusual case, describing the disappearance of two metallic foreign bodies encapsulated by tumor.

A decoupled fluid structure approach for estimating wall stress in abdominal aortic aneurysms.

Abdominal aortic aneurysm (AAA) is a localized dilatation of the aortic wall. The lack of an accurate AAA rupture risk index remains an important problem in the clinical management of the disease. To accurately estimate AAA rupture risk, detailed information on patient-specific wall stress distribution and aortic wall tissue yield stress is required. A complete fluid structure interaction (FSI) study is currently impractical and thus of limited clinical value. On the other hand, isolated static structural stress analysis based on a uniform wall loading is a widely used approach for AAA rupture risk estimation that, however, neglects the flow-induced wall stress variation. The aim of this study was to assess the merit of a decoupled fluid structure analysis of AAA wall stress. Anatomically correct, patient specific AAA wall models were created by 3D reconstruction of computed tomography images. Flow simulations were carried out with inflow and outflow boundary conditions obtained from patient extracted data. Static structural stress analysis was performed applying both a uniform pressure wall loading and a flow induced non-uniform pressure distribution obtained during early systolic deceleration. For the structural analysis, a hyperelastic arterial wall model and an elastic intraluminal thrombus model were assumed. The results of this study demonstrate that although the isolated static structural stress analysis approach captures the gross features of the stress distribution it underestimates the magnitude of the peak wall stress by as much as 12.5% compared to the proposed decoupled fluid structure approach. Furthermore, the decoupled approach provides potentially useful information on the nature of the aneurysmal sac flow.