gms | German Medical Science

Objective: Due to an increase in age and comorbidities, neurosurgeons are confronted with a rising number of patients treated with antiplatelet agents (AA). It is therefore crucial to determine the best operation date. As there are no controlled studies indicating how long AA need to be discontinued before neurosurgical interventions, a laboratory tool suitable for clinical routine to assess the individual platelet function would be desirable.

Method: We analyzed all neurosurgical patients admitted from June 2012 to June 2014 undergoing ADP/ epinephrine platelet aggregometry (PA) in a retrospective study, looking for the indication of AA, the time needed for platelet function normalization as well as the correlation with intra- and postoperative complications.

Results: PA was performed in 16 scheduled and 38 emergency admissions, including 41 spine, 4 CSDH, 3 NPH, and 6 brain tumor patients. Out of the 16 scheduled cases, 12 discontinued AA 7 days prior to admission. In 11 of these, the test was normal. Only in one case, the operation had to be postponed. In the emergency cases, duration from last AA intake to test normalization ranged from 0-19 days (40% 0-3 days, 35% 4-6 days, 9% 7 days, 16% >7 days). Indication to perform the test was treatment with AA in 47 cases only 26 of which had clear indications for platelet inhibition. In 4 cases, ASS was taken for pain. In the remaining cases, the test was performed as part of a coagulation analysis. The test was not reliable in 7 cases of thrombocytopenia and 3 cases of low hematocrit. Correlating test results and operative findings, diffuse bleeding despite a normal test was found in only three cases. In one of these, the test was not reliable due to thrombocytopenia, and in another, the test finally became normal 19 days after the last ASS intake, suggesting other coagulation problems. Only one patient with NHL sustained a postoperative bleeding requiring reoperation.

Conclusions: Taking into consideration the exclusion criteria of thrombocytopenia <150000 and hematocrit <35, in the remaining cases, the good correlation between a normal PA test and uncomplicated surgery suggested that the test might be a reliable tool to time the operation. With 75% of the patients needing less than the expected 7 days to regain normal platelet function, it might be helpful to reduce the preoperative waiting time. A larger number of patients will be evaluated to see whether these preliminary results can be confirmed.