Less invasive bonnet bypass with subcutaneous tunneling method for common carotid artery occlusion - A technical note

Surg Neurol Int. 2024 Aug 23:15:300. doi: 10.25259/SNI_528_2024. eCollection 2024.

Abstract

Background: Common carotid artery occlusion (CCAO) sometimes requires vascular reconstruction. Ipsilateral superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is unsuitable due to insufficient blood flow to the external carotid artery. The bonnet bypass, one treatment option for CCAO, requires a long coronal incision and bone groove to prevent malposition and collapse of an interposition graft. However, this long incision might lead to skin complications and reduced collateral blood flow.

Methods: A 60-year-old man who experienced recurrent ischemic stroke presented with the right internal carotid artery occlusion and left CCAO. The left STA was unavailable; however, both branches of his right STA were well-developed. Minimizing skin invasion was a priority because the patient had diabetes mellitus. We performed a right STA parietal branch - right MCA anastomosis, followed by a right STA frontal branch - left radial artery graft (RAG) - left MCA bonnet bypass using small intermittent skin incisions.

Results: We drilled a bone groove extending across the entire length of the interposition graft through the small intermittent skin incisions. Furthermore, we applied a right STA-RAG end-to-side anastomosis instead of an endto-end anastomosis to preserve collateral skin anastomosis. Postoperatively, the bypass remained patent, and the patient was discharged without complications.

Conclusion: The bonnet bypass is a potential treatment for CCAO, but the procedure is invasive. Our modified bonnet bypass method enables less invasive management, preventing collapse and malposition of the interposition graft and minimizing skin complications.

Keywords: Common carotid artery occlusion; Intermittent skin incision; Interposition graft; Modified bonnet bypass; Subcutaneous tunnel.