Superficial Temporal Artery-Middle Cerebral Artery Bypass Combined with Internal Carotid Ligation in Treating Complex Internal Carotid Aneurysms. The Willis Polygon Score is an Effective Solution for Developing Countries

Abstract

Internal carotid complex aneurysms (ICCAs) management is challenging. Ligating the internal carotid artery (ICA) combined with STA-MCA anastomosis is an effective treatment option. Balloon test occlusion (BTO) assessments for preoperative decision-making are unaffordable in developing countries. This article discusses the study of Willis polygon segments as an option and suggests a score for decision-making. Herein, we report the outcomes of a series of patients treated for ICCA aneurysms at a single institution. From September 2016 to December 2020, we conducted a retrospective cohort study that analyzed data from patients with ICCAs. Among them, nine patients received treatment involving ICA ligation combined with STA-MCA anastomosis. Partial or total carotid ligation was determined by using the Willis polygon score (WPS). All Patients underwent STA-MCA anastomosis, in addition to total ICA ligation in seven patients and partial ICA ligation in two patients with a WPS of 7 and 5, respectively. Patients with partially ligated carotid arteries were referred to an overseas neurointerventional center 12 months after surgery. As the BTO test was negative, they underwent ICA occlusion by coiling. Postoperative clinical outcomes did not change in 8/9 patients. In one patient, we reported a minor parietal stroke; the patient recovered completely after 6 months. Total aneurysm exclusion by thrombosis was achieved in 7/9 patients after total ICA ligation alone and in 2/9 patients after partial ICA ligation combined with coiling. Limited access to endovascular assessment techniques such as BTO poses challenges in managing ICCAs. The Willis polygon score for decision-making appears to be a simple and safe option. In addition to STA-MCA bypass surgery, total or partial ICA ligation may be proposed depending on the Willis polygon score. After 12 months, patients with low WPS who underwent partial ICA ligation combined with bypass had postoperative normal BTO.