Unilateral subfrontal approach to anterior communicating artery aneurysms: A review of 28 patients

Dear Editor,

The authors present the named “unilateral subfrontal approach” for anterior communicating aneurysms, analyzed in a small clinical series. The authors present this approach mainly as an alternative to the pterional approach. This approach was previous described as the “superciliar keyhole approach” or the “lateral supraorbital approach” for the treatment not only of vascular disease but also for tumors.[2] The authors present their approach as a “tailored” pterional approach. Nevertheless, there are some aspects that are subject of criticism as the rutinary use of external ventriculostomy or lumbar drainage; these are procedures that carry additional risks: Intraoperative rebleeding, frontal lobe lesion among others. We strongly recommend the microsurgical wide opening of the basal cisterns and the fenestration of the lamina terminalis to obtain CSF drainage and brain relaxation during the surgery, we do not see the silvian fissure opening as an additional source of complications as the authors pointed out. Additionally, these microsurgical simple procedures are implicated in the prevention of the hydrocephalus and vasospasm in the subarachnoid hemorrhage secondary to ruptured aneurysms.[1] The four advantages that the authors provided are at least uncertain. In the number 4 we can say that the pterional approach provide a corridor to see up to the contralateral middle cerebral artery bifurcation. Another important issue is that they have a 50% of resection of the gyrus rectus in unruptured and 61% in ruptured aneurysms, so the approach does not avoid this designed resection of the frontal lobe; we only use a small gyrus rectus resection in the anterior communicating artery (ACoA) aneurysms superiorly projected located between the two A2 segments, especially in the large or giant lesions, in all the other cases we split the interhemispheric cistern, which is possible using the pterional approach. The authors point out that the pterional approach leave a cosmetic defect at the level of the pterion, but in their own series the leave two burr holes in the frontal bone visible in the forehead.

Salma et al.[3] recently published a cadaveric anatomical study comparing this two approaches, in their paper they analyzes the qualitative and quantitative anatomic evaluation between this two approaches, showing that this kind of approach can eventually reduce the temporalis muscle trauma, and offers and equivalent access and exposure of the anterior communicating artery complex, optic nerve, optic chiasm, and sellar areas. However, like all the anatomical cadaveric models, they do not consider the role of the cisternal and ventricular opening using these anatomical corridors as the natural pathways to reach the pathology, in this case ACoA aneurysms.

We think that in patient's ruptured aneurysms with hematoma or subarachnoid hemorrhage (SAH) of high Fisher grade this approach is not a good choice, because it does not allow a wide opening of the sylvian fissure for cleansing the blood clots and relaxing the brain. Hence, this approach would be useful just for treating the aneurysm, but not to deal with the SAH, without reducing neither the risk of vasospasm nor the hydrocephalus.