ORIGINAL ARTICLES   

International Angiology 2000 December;19(4):308-13

Copyright © 2001 EDIZIONI MINERVA MEDICA

lingua: Inglese

The value of computer analysis in predicting the long-term outcome of deep vein thrombosis

O’Shaughnessy A. M. * °, Fitzgerald D. E. *

From the * Vascular Medicine Unit, James Connolly Memorial Hospital, Blanchardstown, Dublin and ° Department of Anatomy, Trinity College, Dublin, Ireland

Background. The use of stan­dar­dised com­pu­ter­ised ultra­sound imag­es is an objec­tive and quan­ti­ta­tive meth­od of deter­min­ing the echog­e­nic­ity of throm­bus. This meth­od had been ­applied to study the nat­u­ral his­to­ry of 100 acute throm­bi over a peri­od of one year to deter­mine if early chang­es in echog­e­nic­ity could indi­cate wheth­er the throm­bus would lyse, par­tial­ly recan­al­ise or ­remain occlu­sive.
Methods. A con­sec­u­tive ­series of 100 above knee deep vein throm­bo­ses (DVT’s) were ana­lysed over a peri­od of one year. The pres­ence of a DVT was initial­ly diag­nosed by ­duplex scan­ning and the ­patients under­went fol­low-up scans at one week, one month, six ­months and at one year. A grey scale image of the throm­bus was trans­ferred to a com­put­er at each exam­ina­tion and its grey scale ­median (GSM) was meas­ured. The mean GSM’s were cal­cu­lat­ed for each exam­ina­tion and com­pared. At one year the ­patients were divid­ed into ­groups accord­ing to their final out­come (i.e. lysis, rec­a­nal­isa­tion or occlu­sion) and the mean GSM val­ues from each group were com­pared.
Results. There were 100 prox­i­mal DVT’s from 89 ­patients. At one year 14% of the ­patients had died and 23% were lost to fol­low-up. The mean GSM val­ues ­increased over the one year peri­od from 25.87±18.33 to a final value of 64±25.52 at one year. A total of 21 throm­bi had fully ­resolved but there was no sig­nif­i­cant dif­fer­ence in their GSM val­ues ­before res­o­lu­tion when com­pared to the other ­patients. Twenty-four ­patients had par­tial­ly recan­al­ised throm­bi and 18 ­remained total­ly occlud­ed. There was no sig­nif­i­cant dif­fer­ence in mean GSM val­ues ­between these two ­groups until after six ­months when the per­ma­nent­ly occlud­ed ­venous seg­ments had high­er GSM val­ues than those which par­tial­ly recan­al­ised.
Conclusions. Measurement of GSM is an objec­tive meth­od of deter­min­ing the ­degree of organ­isa­tion of a throm­bus and ­describes the sub­jec­tive chang­es of indi­vid­u­al throm­bi. However, the organ­isa­tion of a throm­bus is a dynam­ic pro­cess and mean GSM val­ues did not ­reflect these chang­es. Early chang­es in GSM could not pre­dict the final out­come of the throm­bus i.e. lysis, rec­a­nal­isa­tion or occlu­sion.