'What's in a name', a systematic review of the pterional craniotomy for aneurysm surgery and its many modifications with a proposal for simplified nomenclature

BACKGROUND

The pterional or frontosphenotemporal craniotomy has stood the test of time and continues to be a commonly used method of managing a variety of neurosurgical pathology. Already described in the beginning of the twentieth century and perfected by Yasargil in the 1970s, it has seen many modifications. These modifications have been a normal evolution for most neurosurgeons, tailoring the craniotomy to the patients' specific anatomy and pathology. Nonetheless, an abundance of variations have appeared in the literature.

METHODS

A search strategy was devised according to the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. To identify articles investigating the variations in the pterional approach, the following search terms were applied: (pterional OR minipterional OR supraorbital) AND (approach OR craniotomy OR technique).

RESULTS

In total, 3552 articles were screened with 74 articles being read in full with 47 articles being included for review. Each article was examined according the name of the technique, temporalis dissection technique, craniotomy technique and approach.

CONCLUSION

This systematic review gives an overview of the different techniques and modifications to the pterional craniotomy since it was initially described. We advocate for the use of a more standardised nomenclature that focuses on the target zone to simplify the management approach to supratentorial aneurysms.

Clip Ligation of Midsegment M1 Artery Aneurysm through a Lateral Supraorbital Approach: 2-Dimensional Operative Video

Lenticulostriate middle cerebral artery (MCA) aneurysms are rare and often involve perforating vessels, making endovascular treatment difficult. When projecting superiorly, aneurysm rupture can likely cause intraparenchymal hemorrhage in basal ganglia. Consequently, surgical clip ligation requires control not to aggressively elevate the frontal lobe to avoid intraoperative injury. We report a case of a growing right midsegment MCA aneurysm treated with clip ligation via a lateral supraorbital approach (LSO). The patient is a 71-year-old female found to have a 4 mm × 3 mm right M1 aneurysm in 2014 on workup for headaches. Subsequent imaging demonstrated aneurysm growth to 6 mm × 3.1 mm with peaked-dome appearance. The growth and location of the aneurysm led us to recommend open surgical treatment; the patient provided informed written consent to proceed. We performed a standard right-sided LSO approach.¹ Microdissection was performed to split the sylvian fissure distally and then proximally to expose the MCA on either side of the aneurysm. Dissecting the aneurysm revealed a perforating artery at the proximal neck. Using minimal frontal lobe dynamic retraction, microsurgical clip ligation was performed. We ensured the clip was placed in line with the MCA trunk to avoid kinking the parent artery and subsequent stroke. Intraoperative micro-Doppler and indocyanine green injection confirmed the patency of vasculature. Postoperative angiogram confirmed complete aneurysm ligation. The patient clinically did well and was discharged home on postoperative day 2. Our video demonstrates safe and effective surgical treatment of a rare aneurysm² through a small LSO craniotomy approach (Video 1).