TO THE READERSHIP: An error appeared in the article by Burkhardt et al. ( Burkhardt J-K, Chua MH, Winkler EA, et al. Incidence, classification, and treatment of angiographically occult intracranial aneurysms found during microsurgical aneurysm clipping of known aneurysms. J Neurosurg . 2020;132(2):434–441 ). The affiliation listed for Drs. Burkhardt, Winkler, and Rutledge was incorrect. The correct affiliation for these authors is the Department of Neurological Surgery, University of California, San Francisco, California. The updated author and affiliation
Adib A. Abla and Michael T. Lawton
A neurysms that are too complex for conventional clipping or endovascular coiling often require bypass as part of a strategy that first revascularizes territories distal to the aneurysm and then occludes the aneurysm without risk of ischemic complications. This approach is particularly relevant to giant, dolichoectatic, and thrombotic aneurysms and has been applied with some success. Most aneurysms of the anterior cerebral artery (ACA) are amenable to conventional clipping or endovascular coiling, even when they are complex, and rarely require bypass
Ana Rodríguez-Hernández and Michael T. Lawton
D issection of PICA aneurysms is relatively simple because both the VA and PICA are identifiable landmarks that lead directly to the aneurysm. 10 The VA is identified under the dentate ligament, and the PICA is identified under the tonsil in the cerebellomedullary fissure. 6 One or both arteries are proximally traced to their convergence, and the aneurysm lies just beyond this convergence. 13 Arteries do not traverse a difficult fissure or require extensive dissection. The caudal loop of the PICA is apparent early or with minimal tonsillar retraction. The
John A. Anson, Michael T. Lawton, and Robert F. Spetzler
F usiform and dolichoectatic aneurysms are uncommon cerebral aneurysms, which often have clinical presentations and therapeutic considerations that differ from those associated with saccular aneurysms. There appears to be a spectrum of dolichoectatic aneurysms ranging from small fusiform aneurysmal dilations of a single vessel to giant dolichoectatic aneurysms filled largely with thrombus. The latter have also been described as giant serpentine aneurysms. These aneurysms, particularly the large partially thrombosed lesions, often produce clinical symptoms by
The future of open vascular neurosurgery: perspectives on cavernous malformations, AVMs, and bypasses for complex aneurysms
JNSPG 75th Anniversary Invited Review Article
Michael T. Lawton and Michael J. Lang
M y (M.T.L.) neurosurgical career spans more than one-third of the history of the Journal of Neurosurgery ( JNS ) and has included some of the most tumultuous events for the cerebrovascular specialty: the first Gamma Knife in the US in 1987, Guglielmi detachable coils in 1991, the International Subarachnoid Aneurysm Trial in 1999, the International Study on Unruptured Intracranial Aneurysms in 2003, Onyx liquid embolic material in 2005, and the Pipeline endovascular device in 2011. 5 , 16 , 36 , 37 , 41 , 69 A flurry of studies continued the innovative trend
Jason M. Davies and Michael T. Lawton
The “picket fence” clipping technique is a method for clipping large aneurysms when conventional clipping across the neck is not feasible, either due to complex anatomy, atherosclerosis, calcification, or compromise of branch origins. This has also been described as a dome fenestration tube. Parallel straight clips, simple and/or fenestrated, are stacked vertically from dome to neck with the tips reconstructing the neck. In this video, the “picket fence” clipping technique is demonstrated on a large middle cerebral artery (MCA) aneurysm. A total of 14 clips reconstructed the neck, completely occluding the aneurysm and preserving outflow in all branch vessels.
The video can be found here: http://youtu.be/0N5rYR6Op8Y.
Adib A. Abla, Cameron M. McDougall, Jonathan D. Breshears, and Michael T. Lawton
approach to bypass. In an analysis of IC-IC bypass as part of the management of complex brain aneurysms conducted 7 years ago, we compared our IC-IC bypass results in 35 patients with those of EC-IC bypass in 47 patients and found comparable bypass patency rates, aneurysm obliteration rates, and patient outcomes. 25 We have since adopted a practice that utilizes IC-IC bypass preferentially when revascularization is needed in the management of complex aneurysms. No aneurysm epitomizes this practice more than the posterior inferior cerebellar artery (PICA) aneurysm
Carlos A. David, A. Giancarlo Vishteh, Robert F. Spetzler, Michael Lemole, Michael T. Lawton, and Shahram Partovi
P ostoperative angiography is routinely used to evaluate patients who have undergone surgical obliteration of an aneurysm. It provides information on the results of clipping, the presence of residual unclipped aneurysm, other unclipped aneurysms, and the occlusion of major vessels. Apart from this initial evaluation, however, few surgeons pursue late angiographic follow-up review in patients surgically treated for aneurysms. Increasingly, the need for late outcome data related to various treatments has become apparent. In particular, the long-term efficacy of
Adib Adnan Abla, Dario J. Englot, and Michael T. Lawton
In this operative video, we demonstrate the approach to a 10-mm distal left vertebral artery and proximal basilar artery blister aneurysm in a 62-year-old male presenting with subarachnoid hemorrhage. He initially underwent clipping of the ruptured ACoA aneurysm and two incidental right MCA aneurysms. Ten days later, the posterior circulation aneurysms were clipped through an extended retrosigmoid approach, working between cranial nerves 9–11 inferiorly and 7–8 superiorly. The vertebral artery was accessible from its dural entry site to the vertebrobasilar junction with the rostral limit of the exposure at the level of the tentorium. He underwent uneventful clipping of all aneurysms without postoperative morbidity.
The video can be found here: http://youtu.be/O0lF0gkFZxc.
Report of three cases
Rene O. Sanchez-Mejia and Michael T. Lawton
A neurysms arising from perforating arteries are uncommon, and have been reported in anterior circulation locations like the lenticulostriate arteries and the perforating vessels along the A 1 segment of the anterior cerebral artery (also known as basal perforating vessels). 9 Aneurysms arising from perforating arteries have also been reported in the posterior circulation, particularly associated with thalamoperforating arteries at the basilar apex and the P 1 segment of the PCA. 2–4 Perforating artery aneurysms were categorized into two types by Maeda