Incidence, causes and effect on postoperative results of premature rupture during surgery were analysed in 402 consecutive cases with ruptured cerebral aneurysm, on whom the operation was carried out with operative microscope. The operation was performed within 2 weeks after the last SAH in 194 cases (Group 1) and beyond 2 weeks in 208 cases (Group 2).
Incidence of premature rupture was 34/194 (17.5%) in Group 1 and 16/208 (8%) in Group 2. Most of the rupture occurred during dissection of the aneurysmal neck and at neck clipping in both groups (28 cases in Group 1 and 15 cases in Group 2), and others during retraction of frontal lobe in Group 1 (6 cases). The rupture was relatively frequent in cases with anterior communicating and middle cerebral aneurysms in both groups and was not affected by patient's conditions and timing of surgery in Group 1. Postoperative course was not affected by occurrence of the rupture in Group 2; only one case deteriorated postoperatively due to premature rupture. Overall morbidity and mortality in Group 2 were 8/208 (4%) and 4/208 (2%), respectively. However, mortality rate due to premature rupture was high in Group 1; 6/34 (18%) with the rupture vs. 15/160 (9%) without the rupture, particularly higher in cases operated on within 3 days after SAH and classified into Grade IV and V. Postoperative morbidity and mortality were not affected by use of temporary clips in both Group 1 and Group 2.
Use of temporary clips for a short time during dissection of aneurysm and at neck clipping is effective to prevent premature rupture and improve the results.
