The residual aneurysm rate is reported between 3,8% and 21% in the cases followed after intracranial aneurysm surgery. In the formation of the residual aneurysm, the risk factors include such structural characteristics as the size and lobulation of the aneurysm, posterior circulation, para-ophtalmic localisation and intra-operative rupture.
The rates and causes of postoperative residual aneurysms were analyzed in 186 intracranial aneurysm of 160 patients, including the possible effects of temporary clipping on the residual rates. The entire series demostrated a residual rate of 7%. It was found higher in the large lobulating aneurysms and intra-operative rupture. The residual rate considerably decreased to 4,2% in the aneurysms with temporary clipping.
The determination of residual aneurysms, identification of any risk factors and elimination of recoverable factors would allow improvement of surgical results in the treatment of the intracranial aneurysms in the future. Moreover we believe that these will be useful in development of the indications for alternative treatment methods.