title: Surgical management and alternative strategies for neighboring intracranial aneurysms.
abstract: OBJECTIVE
  Neighboring aneurysms are misidentified or named as a single multi-lobulated aneurysm, despite the demonstration of angiographic cleavage, because of the close proximity and different size. During surgery, neighboring intracranial aneurysms represent an interesting subset of aneurysms that may pose unique management challenges. Meticulous preoperative radiological planning is necessary to properly appreciate the local anatomy. Intraoperative microsurgical dissection of these aneurysm complexes may be difficult if a plane cannot be created between the neighboring lesions with dissection of the aneurysm necks and preservation of blood flow becoming a challenging situation.
  
  
  METHODS
  A retrospective review over a 10-year period, of all patients with intracranial aneurysms treated by our service was performed to identify those patients with neighboring aneurysms.
  
  
  RESULTS
  We encountered 73 instances of neighboring aneurysms (MCA-22, PCOMMA/AChA-20, ACOMMA-15, paraclinoid-5, upper basilar-4, pericallosal-3, ICA bifurcation-2, VB junction-2). Most patients were managed with either microsurgery for both aneurysms or coiling for both. Seven patients with severe SAH underwent coiling of the presumed ruptured (much larger) aneurysm with subsequent microsurgery for the neighboring aneurysm which was not considered amenable to endovascular therapy. In the setting of neighboring lesions, microsurgery was sometimes deemed significantly more difficult than usual, particularly when the aneurysm domes were adherent precluding optimal visualization of the local vascular anatomy. Temporary vascular occlusion was often helpful to allow for proper inspection and identification of all perforating vessels initially hidden by the adherent sacs.
  
  
  CONCLUSIONS
  Neighboring intracranial aneurysms represent an interesting subset of aneurysms that may pose unique management challenges. Careful evaluation of preoperative angiography is necessary to properly appreciate the local anatomy in these cases. Microsurgical dissection of these aneurysm complexes may be difficult if a plane cannot be created between the neighboring lesions. Because neighboring aneurysms tend to obscure the local anatomy, intraoperative angiography and innovative surgical strategies were useful in our experience.
authors.affiliation: National Brain Aneurysm Center, Saint Joseph Hospital, St. Paul, MN, USA. lnussbaum@comcast.net
authors.forename: E S
authors.initials: ES
authors.lastname: Nussbaum
authors.forename: A
authors.initials: A
authors.lastname: Defillo
mesh_terms: D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D057510:Endovascular Procedures / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D008866:Microsurgery / Q000379:methods*; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome