Introduction: Introduction: Large patient cohort analysis on intracerebral bypass patency is rarely reported in the literature. We analyzed the long-term patency of extracranial to intracranial (EC-IC) and intracranial to intracranial (IC-IC) bypass procedures.
Methods: Methods: All intracranial bypass procedures performed 1997-2016 by senior author (M.T.L.) were screened. Patients with a postoperative radiological imaging were included and grouped into immediate (<7 days), short-term (<1 year), and long-term (>1 year) follow-up (FU) groups. Data on patient demographics, bypass type, interposition graft type, bypass indication, and radiological patency were collected.
Results: Results: In total, 340 out of 355 (95.8%) patients had a postoperative radiological FU (FU time [mean±SD]: 0.88±2.26 years, range: 0-16.95 years). Among the 340 patients 399 bypass procedures were performed. The patency rate was 96% in the immediate (n=245, FU: 1.88±1.36 days), 97% in the short-term (n=75, FU: 0.284±0.31 years), and 98% in the long-term (n=79, FU: 4.15±3.53 years) FU groups. Patients who presented with aneurysms had a lower rate than those with moyamoya disease or occlusion (p-value=0.039). Low-flow bypasses had a significantly higher patency rate than high-flow bypasses (p-value=0.04) with its main effect in the immediate FU group (p-value=0.01). Bypasses with one anastomosis site compared to two sites showed significantly higher patency at short-term FU (p-value=0.020). No differences were seen between radial artery and saphenous vein interposition grafts in EC-IC or IC-IC bypasses.
Conclusions: Conclusion: Overall bypass patency of 96% indicates a high likelihood of success with microsurgical revascularization. Surgical indication (ischemia), low flow, and number of anastomoses (one site) were associated with higher patency rates. IC-IC and EC-IC bypasses have equal patency rates, supporting the use of intracranial reconstructive techniques. Bypasses that remain patent postoperatively and have the opportunity to mature have a high likelihood of remaining patent long-term. Meticulous microsurgical technique is essential to achieving high bypass patency rates.
Patient Care: Our large consecutive series of bypass procedures with long-term follow-up data supports that patients presenting with cerebrovascular diseases can be safely treated with microsurgical revascularization.
Learning Objectives: By the conclusion of this session, participants should be able to: describe the importance of intracranial reconstructive techniques and identify patient cohorts with high patency rates of revascularization.