Clinical and surgical experience with the minipterional craniotomy.

Abstract

To the Editor: We have read carefully and with great interest the paper “The Minipterional Craniotomy for Anterior Circulation Aneurysms: Initial Experience With 72 Patients” by Caplan et al recently published in Operative Neurosurgery.1 In this study, the authors describe their surgical experience with 82 unruptured anterior circulation aneurysms.1 They conclude that minipterional (MPT) craniotomy is a worthwhile alternative to the standard pterional (PT) craniotomy. No surgical or anatomic restrictions or suboptimal exposure were found when applying MPT in this group of patients. As the authors acknowledge, our group was the first to describe this new technique.1,2 The MPT rationale is based upon the findings of a previous anatomic work that demonstrates that microsurgical dissection of the sylvian fissure beyond the anterior ascending ramus does not improve surgical exposure.3 Since those seminal papers,2-11 we have performed MPT for more than 100 ruptured and unruptured cerebral aneurysms. Our experience differs from that of Caplan and coauthors in many aspects. First, we have employed the MPT approach to operate on both ruptured and unruptured anterior circulation aneurysms. Second, we have also successfully operated on anterior communicating artery aneurysms. Third, we have not operated on carotid ophthalmic artery aneurysms due to the theoretical risk of jeopardizing the drilling of the anterior clinoid process when using a smaller opening. Nonetheless, 2 cases of carotid artery ophthalmic aneurysms, interpreted as posterior communicating artery aneurysms in the preoperative angiogram, were operated on without additional difficulty. Caplan et al's work will motivate us to use the MPT craniotomy to treat these lesions. Fourth, we have performed postoperative angiograms in all cases to document complete obliteration of the aneurysmal sac. In 3 cases, aneurysm remnants were identified, but in only 1 case was reoperation required. The complete occlusion of the lesion has not been documented in Caplan et al's paper. This data is mandatory to demonstrate the effectiveness of the MPT technique. Our clinical results were very similar to those of Caplan and coauthors. However, deaths occurred in the ruptured group due to complications related to the subarachnoid hemorrhage. We usually carry out interfascial dissection as a bulky temporalis muscle may jeopardize exposure. We think the cosmetic results thus do not significantly differ when compared to a single myocutaneous flap. We agree with the authors that extending the craniotomy medially may ameliorate exposure. However, this may be not indicated or desirable in patients harboring a large frontal sinus. An advantage over the PT is that the MPT never violates the frontal sinus, thus minimizing risks of cerebrospinal fluid leakage and postoperative infections. Contrary to the author's statements, we have not experienced any additional difficulty when approaching anterior communicating artery and carotid artery bifurcation aneurysms, even for ruptured and unruptured lesions. The authors should be commended for reporting their experience. Their results coupled with our own indicate that MPT is a safe and effective technique. Based on this experience, we think the MPT craniotomy should be the first choice in the surgical clipping of ruptured and unruptured anterior circulation aneurysms. However, a conventional PT opening could be reserved for cases with large hematomas or for patients with giant aneurysms. Disclosure The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.