STA-MCA/STA-PCA Bypass Using Short Interposition Vein Graft

Abstract

The STA main trunk has a larger diameter than the distal branch; therefore, it would be expected to have a significantly higher flow capacity than its branches. STA main trunk to proximal MCA/PCA bypass using short interposition vein grafts can provide sufficient blood flow, and may be a reasonable alternative to ECA to MCA/PCA bypass using long vein grafts.

Interposition Grafts and Aneurysms

“…The rationale for the use of the proximal STA as a donor has been that the STA stump, through intraoperative flow measurements, has been shown to provide sufficient flow when the distal STA branches are unsuitable for bypass (2,6). The current article adds to this quantitative literature by measuring preoperative and postoperative stump diameter on angiography.…”

“…The basilar artery can be bypassed with short SV or RA interposition grafts between the internal carotid artery, the middle cerebral artery, or the stump of the STA and the posterior cerebral artery or the superior cerebellar artery (5,6). Bypass for ACA aneurysms presents unique challenges because of the large number of significant branches arising from the anterior communicating complex.…”

“…The use of the STA also eliminates the need for a second incision and the associated postoperative pain. However, circumstances arise in which the STA may be too small to supply adequate flow to the target area, in which case other interposition graft sources are necessary (6). RA and SV grafts are high-flow conduits but require a second surgical incision, may not be efficiently harvested in emergent situations, and can have diameters unsuitable for intracranial target vessels (11).…”

“…Multiple strategies have been described in the literature, including complex clip constructs, parent vessel sacrifice with or without accompanying bypass, surgical excision and vessel reconstruction, and the use of interposition grafts along with aneurysm trapping. The authors of the article entitled, "The efficacy of bypass surgery using short interposition grafts for the treatment of intracranial complex aneurysm" in this issue of WORLD NEUROSURGERY relate their experience with the last of these surgical options.Successful use of the superficial temporal artery (STA) proximal to its bifurcation as a donor for a short radial artery (RA) or saphenous vein (SV) interposition graft has been previously described (2,6, 9,14,15). The rationale for the use of the proximal STA as a donor has been that the STA stump, through intraoperative flow measurements, has been shown to provide sufficient flow when the distal STA branches are unsuitable for bypass (2, 6).…”

“…Successful use of the superficial temporal artery (STA) proximal to its bifurcation as a donor for a short radial artery (RA) or saphenous vein (SV) interposition graft has been previously described (2,6, 9,14,15). The rationale for the use of the proximal STA as a donor has been that the STA stump, through intraoperative flow measurements, has been shown to provide sufficient flow when the distal STA branches are unsuitable for bypass (2, 6).…”