title: Intraoperative middle cerebral artery pressure measurements during superficial temporal artery to middle cerebral artery bypass procedures in patients with cerebral atherosclerotic disease.
abstract: OBJECTIVE No previous study has monitored middle cerebral artery (MCA) pressure during the superficial temporal artery (STA)-MCA bypass procedure for cerebral atherosclerotic disease. In this paper, the authors describe their method of monitoring MCA pressure and report their initial data on intraoperative MCA pressure and its relationship with hemodynamics prior to and after the bypass procedures. METHODS The results from a total of 39 revascularization procedures performed between 2004 and 2014 were analyzed. The patient group included 27 men and 12 women, and their mean age at surgery was 67.6 years (range 39-83 years). The authors investigated the MCA pressure via the STA during STA-MCA bypass procedures. After one branch of the STA was anastomosed to the MCA, the other branch was connected to an arterial line, and a clip was placed temporally on the main STA trunk to monitor the pre-anastomosis MCA pressure. Simultaneously, the radial artery (RA) pressure was determined before removing the temporal clip to measure the post-anastomosis MCA pressure. The relationship between MCA pressures and single photon emission computed tomography findings and the risk factors for hyperperfusion after STA-MCA bypass were analyzed. RESULTS The MCA/RA (%) pressure was significantly correlated with that of the resting stenotic/normal side cerebral blood flow (CBF) ratio (%) in the linear regression analysis (slope 1.200, r2= 0.3564, F = 20.49, p < 0.0001). The intraoperative MCA pressure was 39.3% of RA pressure in patients with Powers' Stage 2 cerebral atherosclerotic disease. After 1 branch of the STA was anastomosed, the intraoperative MCA pressure increased to 75.3% of the RA pressure. The rate of increase in pressure was significantly correlated with the increase in the STA diameter in the linear regression analysis (slope 2.59, r2= 0.205, F = 9.549, p = 0.0038). Hyperperfusion occurred in 2 cases. When mean values for these 2 patients were compared with those for the 37 patients without hyperperfusion, significant differences were found in the stenotic/normal side CBF ratio (p = 0.0001), pre-anastomosis MCA pressure (p = 0.02), rate of increase in pressure (p = 0.02), pre-anastomotic MCA/RA pressure ratio (p = 0.01), vascular reserve (p = 0.0489), and STA diameter (p = 0.0002). CONCLUSIONS The measurement of intraoperative MCA pressure may be a useful technique to assess cerebral perfusion and for predicting the risk of hyperperfusion. Monitoring MCA pressure is recommended during STA-MCA bypass procedures for atherosclerotic disease.
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Matano
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Murai
authors.affiliation: Department of Neurosurgery, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Rokuya
authors.initials: R
authors.lastname: Tanikawa
authors.affiliation: Department of Neurosurgery, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kamiyama
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Tateyama
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Tamaki
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Mizunari
authors.affiliation: Department of Radiology, Toho University Omori Medical Center, Tokyo; and.
authors.forename: Sunao
authors.initials: S
authors.lastname: Mizumura
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Shiro
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Akira
authors.initials: A
authors.lastname: Teramoto
authors.affiliation: Department of Neurological Surgery, Nippon Medical School.
authors.forename: Akio
authors.initials: A
authors.lastname: Morita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002548:Cerebral Revascularization / Q000379:methods*; D005260:Female; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging / Q000601:surgery*; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000502:physiology* / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013699:Temporal Arteries / Q000601:surgery*; D015899:Tomography, Emission-Computed, Single-Photon
keywords: 123I-IMP = N-isopropyl [123I]-p-iodoamphetamine; 3D-SSP = 3D stereotactic surface projection; CBF = cerebral blood flow; CPP = cerebral perfusion pressure; ICA = internal carotid artery; JET = Japan Extracranial-Intracranial Bypass Trial; MCA = middle cerebral artery; RA = radial artery; ROI = region of interest; SPECT; SPECT = single photon emission computed tomography; STA = superficial temporal artery; cerebral blood flow; middle cerebral artery; rCBF = regional CBF; superficial temporal artery; vascular disorders