A new transvenous approach to the carotid-cavernous sinus via the inferior petrooccipital vein

Object. The transvenous approach via the inferior petrosal sinus (IPS) is commonly used as the most appropriate for carotid-cavernous fistula (CCF) or cavernous sinus sampling. However, sometimes the IPS is not accessible because of anatomical problems and/or complications, therefore an alternative route is needed. In this paper, the authors present and discuss the utility of a transvenous approach to the cavernous sinus via the inferior petrooccipital vein. Methods. Four patients, 3 with dural CCFs and the other with Cushing disease, in whom endovascular surgical attempts failed using a conventional venous approach via the IPS, underwent a transvenous approach to the cavernous sinus via the inferior petrooccipital vein (IPOV). One dural CCF case had only cortical venous drainage, the second CCF also mainly drained into the cortical vein with slight inflow into the superior ophthalmic vein and inferior ophthalmic vein, and the third demonstrated drainage into the superior and inferior ophthalmic veins and IPOV. Results. In all cases, the cavernous sinus could be accessed successfully via this route and without complications. Conclusions. The transvenous approach to the cavernous sinus via the IPOV should be considered as an alternative in cases when use of the IPS is precluded by an anatomical problem and there are no other suitable venous approach routes. (DOI: 10.3171/2011.4.JNS102155)