Persistent Thrombocytopenia Indicates Endoleak After Complex Endovascular Aneurysm Repair

High-pressure endoleaks (types I or III) after fenestrated-branched endovascular aneurysm repair (F-BEVAR) pose an ongoing risk of rupture. Early identification of such endoleaks may facilitate appropriate reintervention and mitigate that risk. The purpose of this study was to determine if persistent thrombocytopenia after F-BEVAR correlates with the presence of a high-pressure endoleak in the early postoperative period. Sequential patients enrolled in a physician-sponsored investigational device exemption study of physician modified and Cook manufactured F-BEVAR endografts were evaluated. Patients with type I endoleak or type III endoleak identified on computed tomography imaging within the first 6 months of follow-up were categorized as high-pressure endoleaks; any type II endoleaks were classified as low-pressure endoleaks. Univariable and multivariable analysis was performed to assess if thrombocytopenia was associated with the presence of endoleaks. We treated 185 patients. Twenty-six patients (14%) developed a high-pressure endoleak and 30 (16%) developed a low-pressure endoleak (Table I). Age, gender, race, indications for the procedure, and preoperative medications did not significantly differ between the endoleak groups. To maximize sensitivity and clinical utility, we selected a cut point of daily average platelet count of <100,000/μL (Table II). The proportion of high-pressure endoleak patients with platelet counts of <100,000/μL was significantly greater compared to patients with low-pressure and no endoleaks on postoperative day (POD) 1 through 4 (POD 4: high-pressure 42%, low-pressure 27%, no endoleak 10%; P ≤ .001). After adjusting for demographics and comorbidities, patients with high-pressure endoleak were over 12-times more likely to have a platelet count of <100,000/μL on POD 4 compared to patients with no endoleak (odds ratio, 12.3; 95% confidence interval, 3.5-43.0). F-BEVAR patients who developed high- or low-pressure endoleak were significantly more thrombocytopenic in the postoperative period. Consideration should be made to perform computed tomography imaging in patients with platelet counts of <100,000/μL persisting at POD 4 after F-BEVAR as these patients have a 35% chance of having a high-pressure endoleak requiring reintervention.Table IProportion of patients with platelet count under 100,000/μL at preoperative (day 0), and postoperative days (POD) 1-7 after F-BEVAR among the type I, II, and III endoleak and no endoleak groupsDay 0Day 1Day 2Day 3Day 4Day 5Day 6Day 7No endoleak (n = 125)12 (10)17 (14)27 (22)28 (22)13 (10)11 (9)4 (3)4 (3)T1E/T3E (n = 26)7 (27)12 (46)15 (58)12 (46)11 (42)3 (12)1 (4)1 (4)T2E (n = 30)5 (17)10 (33)11 (37)13 (43)8 (27)5 (17)3 (10)1 (3)P value.06<.001.001.02<.001.8.6a1.0aT1EL/T3EL, Type I endoleak/type III endoleak; T2EL, type II endoleak.Data presented as number (%).aFisher's exact was used. Open table in a new tab Table IIComparison of the test characteristics of a cutpoint of <100,000/μL at different postoperative days (POD) for predicting the presence of a high-pressure endoleakSensitivity (95% CI)Specificity (95% CI)PPV (95% CI)NPV (95% CI)ROC area (95% CI)Average platelets <100,000/μL on POD 30.46 (0.29-0.66)0.77 (0.70-0.84)0.30 (0.18-0.46)0.87 (0.80-0.92)0.61 (0.51-0.72.)Average platelets <100,000/μL on POD 40.42 (0.26-0.63)0.89 (0.83-0.94)0.45 (0.29-0.67)0.88 (0.82-0.93)0.66 (0.55-0.76)Average platelets <100,000/μL on POD 3 or 40.50 (0.33-0.70)0.76 (0.68-0.83)0.31 (0.19-0.47)0.87 (0.80-0.93)0.62 (0.52-0.73)95% CI, 95% Confidence interval; NPV, negative predictive value; PPV, positive predictive value; ROC, receiver operating characteristic. Open table in a new tab