Part 1: Pushing the boundaries of neurointerventional surgery: A historical review of the work of Dr Gerard Debrun.

French-American neurointerventionalist and pioneer, Dr Gerard Debrun, laid the groundwork for treatments which have become irreplaceable in neurointerventional surgery today. This article aims to outline the career of Dr Debrun while highlighting his accomplishments and contributions to the field of neurointerventional surgery. We selected relevant articles from PubMed authored or co-authored by Dr Debrun between 1941 and 2023. All included articles discuss the accomplishments and contributions of Dr Debrun. Dr Debrun began his career in France by investigating neurointerventional techniques, most notably the intravascular Detachable Balloon Catheter (DBC). His work was recognized by renowned neurosurgeon Dr Charles Drake, who recruited him to London, Ontario. Dr Debrun created the foundation for homemade manufacturing of DBCs, building on one of the largest series for use of DBCs in cerebrovascular disease. Dr Debrun spent time as faculty at Massachusetts General Hospital (MGH) and Johns Hopkins Hospital, before arriving at the University of Illinois Chicago (UIC) where he remained until his retirement. Dr Debrun's subsequent contributions included the calibrated-leak balloon catheter, pioneering of glue embolization, setting the foundation for preoperative AVM embolizations, and as an early adopter of the Guglielmi detachable coil (GDC), including mastering the balloon remodeling technique for wide neck aneurysms. Dr Debrun established the first integrated neurointerventional surgery program at UIC, establishing a well sought-after fellowship program. Dr Debrun lectured extensively and was a prolific writer on neurointerventional surgery throughout this career. His contributions established the foundation for several techniques which have since become standard practice in present-day neurointerventional surgery.