Pressing Issues in COVID-19: Probable Cause to Seize SARS-CoV-2 for Its Preferential Involvement of Posterior Circulation Manifesting as Severe Posterior Reversible Encephalopathy Syndrome and Posterior Strokes.

Since December 2019, a novel Severe Acute Respiratory Syndrome coronavirus 2 from China has rapidly spread worldwide. Although respiratory involvement is the mainstay of coronavirus disease 2019 (COVID-19), systemic involvement has recently drawn more attention. In particular, a number of recent articles have shed light on the nervous system as one of the possible targets. At our institution, we observed 15 patients with acute brain vascular manifestations; most interesting, we had a higher prevalence of the posterior circulation acute impairment. In our series, 7 patients had acute posterior cerebral injury: 1, hemorrhagic posterior reversible encephalopathy syndrome; 5, posterior circulation ischemic stroke; and 1, parieto-occipital hemorrhagic stroke. On the basis of our evidence and previous basic science reports, we believe a common etiopathogenetic thread may connect ischemic/hemorrhagic events of the posterior circulation and posterior reversible encephalopathy syndrome in the setting of COVID-19.

Comparative study of jaws with multislice computed tomography and cone-beam computed tomography.

PURPOSE: The aim of this study was to compare the dosimetric and diagnostic performance of multislice computed tomography (MSCT) and cone-beam computed tomography (CBCT) in the study of the dental arches. MATERIALS AND METHODS: Effective dose and dose to the main organs of the head and neck were evaluated by means of thermoluminescent dosimeters (TLDs) placed in an Alderson Rando anthropomorphic phantom and using a standard CBCT protocol and an optimised MSCT protocol. Five patients with occlusal plane ranging from 54 cm to 59 cm who needed close follow-up (range 1-3 months) underwent both examinations. Image quality obtained with CBCT and MSCT was evaluated. RESULTS: Effective dose and dose to the main organs of the head and neck were higher for MSCT than for CBCT. Image quality of CBCT was judged to be equivalent to that of MSCT for visualising teeth and bone but inferior for visualising soft tissues. Beam-hardening artefacts due to dental-care material and implants were weaker at CBCT than at MSCT. CONCLUSIONS: When panoramic radiography is not sufficient in the study of the teeth and jaw bones, CBCT can provide identical information to MSCT, with a considerable dose reduction. MSCT is, however, indicated when evaluation of soft tissue is required.

MDCT evaluation of the cardiac venous system.

PURPOSE: This study was undertaken to evaluate the usefulness of electrocardiographically (ECG)-gated multidetector-row computed tomography (MDCT) for the assessment of the coronary venous system and detection of its anatomical variants, in order to identify those suitable for lead placement in cardiac resynchronisation therapy (CRT). MATERIALS AND METHODS: We retrospectively examined the coronary MDCT studies of 89 patients (73 males, 16 females, average age 62.5 years, range 31-79) referred for suspected coronary artery disease. The cardiac venous system was assessed in all patients using three-dimensional (3D) postprocessing on a dedicated Vitrea workstation (five patients were excluded from the analysis). RESULTS: The coronary sinus, the great cardiac vein, the anterior interventricular vein and the middle cardiac vein were visualised in all cases. The lateral cardiac vein was visualised in 56/84 patients (67%) and the posterior cardiac vein in 63/84 patients (75%), never both missing. Along the postero-lateral wall of the left ventricle, only one branch was present in 44 cases, two branches in 21 cases and three or more branches in 19/84 cases (22%). Evaluation of the maximum diameter revealed that the lateral vein was dominant over the posterior vein in 20/40 cases. The small cardiac vein was visualised in 11/84 cases. CONCLUSIONS: MDCT provides good depiction of the cardiac venous system, enabling the study of the vessel course and the identification of anatomical variants. Hence, this imaging technique could be proposed for the preoperative planning of CRT in selected patients.

Image-guided percutaneous treatment of abdominal-pelvic abscesses: a 5-year experience.

PURPOSE: This study was undertaken to evaluate the efficacy of image-guided percutaneous drainage in treating abdominal and pelvic abscesses. MATERIALS AND METHODS: From August 2001 to August 2006, 95 patients (49 men and 46 women; mean age 61 years, range 25-92) with 107 abscesses underwent image-guided percutaneous drainage. Thirty-one abscesses were retroperitoneal (9 peripancreatic, 17 perirenal, 5 pararenal), 37 intraperitoneal (2 in communication with the small bowel), 8 intrahepatic (2 in communication with the extrahepatic biliary system and 2 with the intrahepatic biliary system), 4 perisplenic and 27 pelvic (4 in communication with the large bowel). Seventy-one of 107 procedures were performed with ultrasonographic (US) guidance and 36/107 with computed tomography (CT) guidance. All procedures were carried out with 8-to 14-Fr pigtail drainage catheters. RESULTS: Immediate technical success was achieved in 107/107 fluid collections. No major complications occurred. In 98/107 abscesses, we obtained progressive shrinkage of the collection (>50%) with consequent clinical success. In 9/107 cases, percutaneous drainage was unable to resolve the fluid collection. There were 12 cases of catheter displacement and six of obstruction. CONCLUSIONS: Percutaneous drainage is feasible and effective in treating abdominal and pelvic abscesses. It may be considered both as a preparatory step for surgery and a valuable alternative to open surgery. Failure of the procedure does not, however, preclude a subsequent surgical operation.

Imaging-guided percutaneous radiofrequency ablation of adrenal metastases: preliminary results at a single institution with a single device.

The aim of this study was to show the feasibility, safety, imaging appearance, and short-term efficacy of image-guided percutaneous radiofrequency ablation (RFA) of adrenal metastases (AM). Seven imaging-guided percutaneous RFA treatments were performed in six patients (two men and four women; mean age, 67.2 years; range, 55-74 years) with six AM who were referred to our institution from 2003 to 2006. One patient was treated twice for recurrence after first treatment. The average diameter of the treated AM was 29 mm (range, 15-40 mm). In all patients, the diagnosis was obtained with CT current protocols in use at our institution and confirmed by pathology with an image-guided biopsy. No major complications occurred. In one patient shortly after initiation of the procedure, severe hypertension was noted; another patient developed post-RFA syndrome. In five of six lesions, there was no residual enhancement of the treated tumor. In one patient CT examination showed areas of residual enhancement of the tumor after treatment. Our preliminary results suggest that imaging-guided percutaneous RFA is effective for local control of AM, without major complications and with a low morbidity rate related to the procedure. Long-term follow-up will need to be performed and appropriate patient selection criteria will need to be determined in future randomized trials.

Combined treatment of ablative therapy with percutaneous radiofrequency and cementoplasty of a symptomatic metastatic lesion of the acetabulum.

We report the case of a symptomatic metastatic lesion of the acetabulum from colon adenocarcinoma in an 82-year-old woman patient treated by a combined approach of thermal ablation with percutaneous radiofrequency and cementoplasty. We obtained an immediate technical success with a good control of pain without any complications at a 6-month clinical follow-up.

Fluoroscopically guided retrograde replacement of ureteral stents.

PURPOSE: We assessed the feasibility of fluoroscopically guided transurethral replacement of ureteral stents as an alternative to cystoscopy. MATERIALS AND METHODS: Over the last year, we replaced 27 double-J ureteral stents in 20 patients (10 men and 10 women; mean age 67.7 years, range 43-83); 15/20 patients had a native kidney, 3/20 had a transplanted kidney and 2/20 had a ureteroileal conduit. The procedures were performed in the angiography suite with the patient under sedation. All stents were grasped with a gooseneck snare under fluoroscopic control, and the distal end was withdrawn just outside the urethra; then a wire was advanced through the stent lumen and positioned in the renal pelvis. The stent was then removed and replaced with a new double-J stent. RESULTS: The procedures were successful in 26/27 cases. We observed 7 cases of mild haematuria that resolved spontaneously. During follow-up (1-16 months, mean 6.7), stent obstruction occurred in 4 cases, requiring an additional retrograde replacement. CONCLUSIONS: Transurethral fluoroscopically guided retrograde replacement of dysfunctioning ureteral stents is an effective and safe alternative to cystoscopy.

An innovative percutaneous technique for the removal and replacement of dysfunctioning plastic biliary endoprostheses (PBE) in the management of malignant billiary occlusions.

PURPOSE: The purpose of this study was to assess the feasibility and clinical impact of the percutaneous removal and replacement of dysfunctioning plastic biliary endoprostheses (PBE). MATERIALS AND METHODS: Over a period of 24 months, we observed eight patients (age 54-82 years; mean 65) with dysfunctioning PBE. After transhepatic cholangiography and bile duct catheterisation, the endoprostheses were grasped with a gooseneck snare and pushed into the duodenum using a long introducer sheath. Subsequently, we implanted six metallic stents in middle and distal occlusions and four plastic endoprostheses in two patients with proximal occlusion. Clinical and ultrasound followup was performed 1, 3 and 6 months after the procedure and then yearly. RESULTS: The procedure was technically successful in all patients. No major complication occurred. All patients were discharged without biliary drainage catheters. During the follow-up period (mean: 7.1 months), four patients died and two occlusions of metallic stents were treated by implanting a further metallic stent. CONCLUSIONS: Percutaneous removal of a dysfunctioning PBE is feasible and allows better quality of life owing to the absence of biliary drainage. Patency of metallic stents is higher than that of PBE. Larger studies are clearly required to validate this approach.

Popliteal artery pseudoaneurysm after a revision of total knee arthroplasty: endovascular treatment with a stent graft.

Injury to the popliteal artery during total knee arthroplasty is a very rare but dangerous complication. Several mechanisms are capable of generating a direct trauma to the vessel, like posterior retractor and oscillating saw. We report a case of popliteal artery pseudoaneurysm in a 52-year-old woman that occurred during revision of total knee arthroplasty, requiring emergency repair by means of percutaneous endovascular covered stenting.

Management and endovascular treatment of symptomatic abdominal aortic aneurysms.

PURPOSE: Our aim is to verify the feasibility and effectiveness of endovascular treatment for symptomatic abdominal aortic aneurysms (AAAs) in urgencies and emergencies. MATERIALS AND METHODS: Over the past 51 months, we treated 38 symptomatic AAAs with endovascular exclusion. In 23 haemodynamically stable patients, computed tomography (CT) angiography was performed before treatment, and AAA exclusion was carried out as an urgent procedure; 15 patients with haemorrhagic shock were examined by ultrasound (US) only in the emergency room whereas the procedure was carried out in emergency and planned using angiography. Time from presentation to treatment was 100 min on average (range: 50-150 min). We used 27 Excluder (Gore) and 11 Zenith (Cook) stentgrafts. The follow-up was performed with CT angiography after 1, 3, 6 and 12 months and yearly thereafter. RESULTS: The immediate technical success rate was 100%, and the perioperative mortality rate was 10.5%. At follow-up completed in 34 patients (range: 1-48 months, mean: 19.2), we observed five endoleaks (14%) (four type 2: two thrombosed spontaneously and two were under observation at the time of writing; one type 3, treated with stent-graft extension) and one occlusion of a stentgraft leg (treated by femorofemoral bypass). CONCLUSIONS: Endovascular treatment of AAAs is a good therapeutic alternative even in urgency and emergency conditions where correct planning ensures technical results comparable with those obtained under elective conditions.

Use of modified functional assays for activated protein C resistance in patients with basally prolonged aPTT.

Inherited resistance to activated protein C (APCr) is currently recognized as the most prevalent cause underlying venous thrombophilia, with an estimated prevalence around 20% in thrombotic patients and around 1.8-7% in the general population. A correct laboratory diagnosis of APCr is therefore essential. Two different diagnostic approaches are at present at our disposal: the semi-quantitative plasma test based on the measurement of two aPTTs (in the presence and absence of activated protein C), and the detection of the factor V Arg506 Gln mutation by DNA analysis. In this study we firstly evaluated sensitivity, specificity and diagnostic efficiency of an aPTT-based plasma clotting test (Chromogenix, Sweden) versus DNA analysis; then, since the APC resistance test is invalidated by a basally prolonged aPTT (i.e. during warfarin and heparin therapy or in patients with clotting factor deficiencies or in the presence of a lupus anticoagulant), patient plasmas were conveniently diluted in factor V deficient plasma in order to correct clotting factor abnormalities. Nevertheless, patients with a LA and an aPTT ratio range 1.8-3.17 were still all misclassified. We obtained correct diagnoses in LA positive patients by preincubating plasmas with a mixture of phospholipids; therefore we decided to perform a double modified clotting test adding a mixture of platelet derived phospholipids to samples previously diluted in factor V deficient plasma. The performance characteristics of this novel method with a different aPTT reagent (Behring, Germany) were also evaluated. With this double modified test all patients were correctly classified as negative or positive for factor V mutation in agreement with DNA analysis, irrespectfully of the basal aPTT value and the aPTT reagent employed. We propose this modified version of the APCr clotting test as an easily reproducible, reliable, very sensitive and specific screening test which possibly reduces the need for DNA analysis.

Reversal of doxorubicin resistance by the amiloride analogue EIPA in multidrug resistant human colon carcinoma cells.

Although multidrug resistance (mdr) may arise through a variety of mechanisms, the most widely studied and accepted form is associated with an increased concentration of P-glycoprotein (P-gp), a 170 kd protein found in the membrane fraction of a number of mammalian cells. Since mdr seems to be related to the ability of resistant cells to extrude drugs and the circumvention of mdr is supposed to be due to the restored ability to accumulate drugs, membrane has been regarded as the crucial site for such a regulation and an important role for membrane ion exchangers has been suggested. The aim of this work was to elucidate whether the Na+/H+ antiporter is involved in the mechanism of regulation and circumvention of mdr and if 5-(N-ethyl-N-isopropyl) amiloride (EIPA), a selective inhibitor of the Na+/H+ exchanger, can modulate the functional expression of the mdr phenotype. The effect of EIPA on doxorubicin (DX) resistant cells (LoVo/DX) obtained from a human colon adenocarcinoma cell line (LoVo) was studied. EIPA at concentrations ranging from 10 to 50 mu M was able to increase the antibiotic cytotoxicity in the resistant Lovo/DX cells. The reversal of DX resistance paralleled an increase of the ability of the cells to accumulate the drug. Both drug loading and sensitivity to the inhibitory effect of DX on cell proliferation were restored by EIPA in a dose-dependent way. These results suggest a new mechanism of mdr reversal and indicate that amiloride and its derivatives may be useful in reversing DX resistance and in enhancing the clinical effectiveness of chemotherapeutics.

Thymic dysfunction in childhood T-acute lymphoblastic leukemia: a possible linkage with a primary thymus involvement.

Experimental models, clinical and histopathological observations suggest a thymic origin of childhood T acute lymphoblastic leukemia (T-ALL). We studied thymic epithelial function in childhood T-ALL as compared to normal controls in order to improve our understanding of the cellular immunodeficiency mechanisms operating in a thymus-linked malignant process. The levels of Facteur Thymique Sérique (FTS) were measured in 9 patients at diagnosis, according to the rosette inhibition assay of Dardenne & Bach (1975). This method is based on the capacity of human serum containing FTS activity to confer on rosette-forming cells (RFC) from adult thymectomized mice a sensitivity to azathioprine identical to that of normal mouse RFC. All patients presented low age-corrected titres of FTS. No zinc deficiency was found, suggesting that low FTS levels are not related to unexpressed FTS biological activity. Plasma from all the children studied contained factors capable of inhibiting the biological activity of FTS in vitro. However, the nature of this inhibitor has not yet been elucidated. Our study shows the presence of a thymic dysfunction in childhood T-ALL, which could partially explain the immunodeficiency described in these patients. The linkage of the leukemic process with a primitive thymic involvement is discussed.