{'fraction_non_alphanumeric': 0.018436109345200253, 'fraction_numerical': 0.009535918626827717, 'mean_word_length': 4.682310469314079, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Use of the ALN permanent/removable vena cava filter. A multi-centre experience.

AIM
Vena cava filters are used for the prevention of pulmonary embolism in cases of contraindication, failure or complications of the anticoagulant therapy. There are no certain data in the literature concerning the effectiveness of vena cava filters and, above all, the possible long-term complications are not known. For this reason increasing attention is paid to permanent/removable filters that permit exploitation of the short-term advantages of vena cava interruption, eliminating the possible long-term complications. We have reported the results of a multicentre experience concerning ALN permanent/removable vena cava filters in a total of 276 patients.


METHODS
Vena cava filters were placed in 276 patients via the jugular, femoral and brachial vein. The filter was removed in 43 patients after 3 months and in 28 patients after 6 months.


RESULTS
In 1 case, due to incomplete opening of the filter, immediate percutaneous removal was performed and another filter was positioned. In 5 cases it was not possible to remove the filter, in 1 case due to inexperience and in the remaining cases due to adhesion of the head or claws of the filter to the wall of the vein. No problems occurred in the other cases.


CONCLUSIONS
The ALN vena cava filter is safe, easy to position and remove even a long time after placement. Currently permanent filters should be used only for patients with poor survival expectancy whereas in all other cases the use of removable filters is preferable.