[Vein patency in patients with pacemaker implanted via subclavian vein: digital phlebography assessment]. / Pervietà venosa nei pazienti con pacemaker impaintati per via succlavia: controlli con flebografia digitalizzata.

Venous thrombosis is a well-known complication of permanent cardiac pacemaker implantation, particularly, chronic occlusion of the subclavian vein is reported to occur in 20-33% of the cases where the percutaneous approach is performed. We examined 135 asymptomatic patients with digital venography to asses the frequency of venous thromboses causing stenosis and occlusion of the subclavian or anonymous arteries in pacemaker carriers. We considered both one- (44) and two-chamber (91) pacemakers and investigated a possible statistically significant difference between them: we found 21 venous thromboses (15%), seven of them in one-chamber pacemakers (15.9%) and 14 two-chambers pacemakers (15.3%). None of our 94 male and 41 female patients was on anticoagulants or had any evidence of coagulation disorders. Venography was performed 39.3 months (mean) after pacemaker implantation (range: 3-120 months). We conclude that digital venography is a simple and relatively noninvasive method permitting better depiction of subclavian, anonymous and caval veins than Doppler US and also showing some vascular abnormalities which may complicate pacemaker implantation.

[Speed of calcaneal ultrasound attenuation in the identification of vertebral fractures in patients with senile osteoporosis]. / La velocità dell'attenuazione ultrasonora del calcagno nella determinazione delle fratture vertebrali nelle pazienti con osteoporosi senile.

Vertebral collapse is a frequent complication of osteoporosis with usually severe sequels. We examined a group of female patient with known senile osteoporosis to try to define a subgroup with atraumatic vertebral collapse on the basis of broadband ultrasound attenuation (BUA) values in the heel. 186 patients were submitted to calcaneal ultrasound densitometry and to radiography of the dorsolumbar spine; we also investigated the body mass index and postmenopausal and menopausal ages to identify the variable with the highest correlation with fracture, with the multiple regression statistical analysis. The regression model analysis showed a statistically significant correlation of BUA values (inverse relation) and weight (direct relation) with the risk of collapse (0.967 and 1.075 odds ratio, respectively). We subdivided the patients according to their body mass index and made the receiver operating characteristics (ROC) curves, thus increasing test accuracy, with 45 MHz BUA threshold, 66.67% sensitivity and 71.43% specificity. Calcaneal BUA is a good indicator of atraumatic vertebral collapse in senile osteoporosis patients; when the weight variable is associated, sensitivity, specificity and positive and negative predictive values (66.67%, 71.43% and 66.6% and 71%, respectively) increase, thus helping define this subgroup of patients.

[Spiral computerized tomography with tridimensional reconstruction (spiral 3D CT) in the study of maxillofacial pathology]. / La tomografia computerizzata spirale con ricostruzione tridimensionale (spiral 3DCT) nello studio della patologia maxillo-facciale.

Three dimensional computer reconstruction of CT scans provide head and neck surgeons with an exciting interactive display of clinical anatomy. The 3D CT reconstruction of complex maxillo facial anatomic parts permits a more specific preoperative analysis and surgical planning. Its delineation of disease extension aids the surgeon in developing his own mental three-dimensional image of the regional morphology. Three-dimensional CT permits a clearer perception of the extent of fracture comminution and resulting displacement of fragments. In the case of maxillo-facial tumors, 3D images provide a very clear picture of the extent of erosion involving the adjacent critical organs. Three-dimensional imaging in first generation 3D scanners did have some limitations such as long reconstruction times and inadequate resolution. Subsequent generations, in particular the spiral 3D CT, have eliminated these drawbacks. Furthermore, costs are comparable with those of other computer reconstruction technology that might provide similar images. Representative cases demonstrating the use of 3D CT in maxillofacial surgery and its benefits in planning surgery are discussed.