摘要： 目的 通过颈内动脉球囊闭塞试验（BTO）评估Willis环前循环和后循环侧支开放情况和代偿能力，以及患者对颈内动脉闭塞耐受能力。方法 纳入2016年6月至2021年9月在天津市环湖医院行颈内动脉BTO试验的85例（87侧）患者，BTO试验联合DSA观察前循环和后循环结构完整性、开放比例和代偿能力，对比分析不同组别BTO试验阳性率。结果 本组有8侧占9.20%（8/87）BTO试验阳性，前交通动脉缺如、闭塞侧完全胚胎型大脑后动脉、闭塞侧前后循环均不开放患者阳性率分别高于前交通动脉未缺如［3/5对6.10%（5/82）；Fisher确切概率法：P=0.005］、非完全胚胎型大脑后动脉［3/7对6.25%（5/80）；Fisher确切概率法：P=0.015］、前循环开放［3/6对6.17%（5/81）；Fisher确切概率法：P=0.009］和后循环开放［20%（5/25）对0（0/59）；Fisher确切概率法：P=0.002］患者；仅前循环开放患者阳性率高于前后循环均开放患者［13.04%（3/23）对0（0/3）；Fisher确切概率法：P=0.022］，前后循环均不开放患者亦高于仅前循环开放患者［2/2对13.04%（3/23）；Fisher确切概率法：P=0.033］和前后循环均开放患者［2/2对0（0/56）；Fisher确切概率法：P=0.001］。颈内动脉闭塞后，闭塞侧大脑前动脉供血区经单一前循环代偿74侧占88.10%（74/84）、经单一后循环代偿3侧占3.57%（3/84）、经前后循环共同代偿5侧占5.95%（5/84）且均为有效代偿［美国介入和治疗性神经放射学学会/美国介入放射学学会（ASITN/SIR）分级3~4级］，前后循环均未代偿2侧占2.38%（2/84，ASITN/SIR分级为零）；闭塞侧大脑中动脉供血区经单一前循环代偿23侧占27.38%（23/84）且有效代偿为22.62%（19/84），经单一后循环代偿14侧占16.67%（14/84）、经前后循环共同代偿45侧占53.57%（45/84）且均为有效代偿，前后循环均未代偿2侧占2.38%（2/84，ASITN/SIR分级为零）；4种代偿方式对大脑前动脉（χ²=53.000，P=0.000）和大脑中动脉（χ²=54.244，P=0.000）供血区的代偿能力差异有统计学意义，前后循环共同代偿能力高于单一前循环代偿（Z=6.754，P=0.000；Z=6.180，P=0.000）、单一后循环代偿（Z=2.277，P=0.023；Z=5.065，P=0.000）和前后循环均未代偿（Z=1.991，P=0.047；Z=2.478，P=0.013）。结论 大脑前循环开放比例较高且代偿能力较强，而前循环不开放尤其是前交通动脉缺如、闭塞侧完全胚胎型大脑后动脉、闭塞侧前后循环均不开放的患者无法耐受颈内动脉闭塞的风险，术中应注意保护颈内动脉。前后循环共同代偿能力高于单一前循环或后循环代偿，闭塞颈内动脉相对安全。

关键词: 动脉闭塞性疾病, 颈内动脉, 气囊阻塞, 大脑动脉环, 侧支循环

Abstract: Objective To analyze compensatory ability of the cerebral collateral circulation and relevant factors affecting cerebral ischemic tolerance for internal carotid artery (ICA) occlusion by Balloon Test Occlusion (BTO), providing reference basis for the selection of treatment methods in tumors or complicated aneurysms with ICA involved. Methods The clinical data of 87 cases BTO (85 patients, two of whom underwent bilateral BTO) of ICA in Tianjin Huanhu Hospital from June 2016 to September 2021 were analyzed retrospectively. The integrity of anterior or posterior of circulation structure, collateral compensatory capacity, tolerance to ICA occlusion and its influencing factors were analyzed. Results There were 8[9.20% (8/87)] BTO positive cases. The positive rate was of cases with incomplete anterior communicating artery was higher than those with complete anterior communicating artery[3/5 vs. 6.10% (5/82); Fisher's exact probability:P=0.005]. The positive rate of cases with complete fetal posterior cerebral artery (fPCA) which was higher than those without complete fPCA[3/7 vs. 6.25% (5/80); Fisher's exact probability:P=0.015]. The positive rate of cases with non-open anterior circulation which was higher than those cases with open anterior circulation[3/6 vs. 6.17% (5/81); Fisher's exact probability:P=0.009]. The positive rate of cases with non-open posterior circulation which was higher than those cases with open posterior circulation[20% (5/25) vs. 0 (0/59); Fisher's exact probability:P=0.002]. Only the positive rate of patients with anterior circulation opening was higher than that of patients with open anterior circulation and open posterior circulation[13.04% (3/23) vs. 0 (0/3); Fisher's exact probability:P=0.022], neither anterior nor posterior circulation opening were significantly higher than those with only anterior circulation opening[2/2 vs. 13.04% (3/23); Fisher's exact probability:P=0.033] and both anterior and posterior circulation opening[2/2 vs. 0 (0/56); Fisher's exact probability:P=0.001]. Once the ICA occluded, the anterior circulation, the posterior circulation, both of anterior and posterior circulation could provide anterior cerebral artery (ACA) supplied area with compensatory blood flow for 88.10% (74/84), 3.57% (3/84), 5.95% (5/84) cases, respectively. The anterior circulation, the posterior circulation, both anterior and posterior circulation could provide middle cerebral artery (MCA) supplied area with compensatory blood flow for 27.38% (23/84), 16.67% (14/84), 53.57% (45/84) cases, respectively. There were statistically significant differences in the compensatory capacity between ACA (χ²=53.000, P=0.000) and MCA (χ²=54.244, P=0.000). The combined compensatory capacity of both anterior and posterior circulation was higher than that of single anterior circulation (Z=6.754, P=0.000; Z=6.180, P=0.000), single posterior circulation (Z=2.277, P=0.023; Z=5.065, P=0.000) and neither anterior nor posterior circulation (Z=1.991, P=0.047; Z=2.478, P=0.013). Conclusions The anterior circle is functionally much more important than the posterior circle. Non-open anterior circulation, especial absence of anterior communicating artery, complete fPCA, neither anterior nor posterior circulation were highly predictive for intolerance to ICA occlusion. For these cases, attention should be paid to the protection of ICA or active blood flow reconstruction technology to reduce the occurrence of cerebral ischemia. Those cases with both opened anterior circulation and opened posterior circulation provided higher compensatory ability than those with single circulation. For those cases, the ICA of could be sacrificed.

Key words: Arterial occlusive diseases, Carotid artery, internal, Balloon occlusion, Circle of Willis, Collateral circulation