颞底内侧区后部小脑上经小脑幕入路手术的显微解剖学研究

Study on the microsurgical anatomy of supracerebellar transtentorial approach to the posterior mediobasal temporal region

目的观察颞底内侧区后部小脑上经小脑幕入路手术的显露范围、解剖结构及其位置关系,拟为临床应用提供解剖学依据。方法5具（10侧）国人男性尸头标本,模拟颞底内侧区后部小脑上经小脑幕入路,于手术显微镜下观察经该入路手术的显露范围、解剖结构,以及颞底内侧区后部脑沟、脑回和动静脉之间的解剖关系。选择3例颞底内侧区后部肿瘤患者,施行小脑上经小脑幕入路手术,观察手术疗效及预后。结果小脑上经小脑幕入路手术可直接到达颞底内侧区后部,显露海马旁回后部、舌状回前部、梭状回及大脑后动脉P3段及其颞下分支。5具（10侧）尸头标本均存在鼻状沟和侧副沟,但是二者不连续,鼻状沟于前部将海马旁回与梭状回分开,侧副沟于后部将二者分开,前距状沟将海马旁回与舌状回分开,扣带回峡、舌状回前部分别与海马旁回后部汇合,枕颞沟将梭状回与颞下回分开。颞底内侧区后部主要由大脑后动脉颞下分支供血,其中3具（4侧）自大脑后动脉P2段发出颞下总动脉,后者发出颞下前动脉和颞下后动脉供应颞底;2具（2侧）自大脑后动脉P2段发出颞下中动脉和颞下后动脉供应颞底;3具（4侧）自大脑后动脉发出海马动脉、颞下前动脉和颞下后动脉供应颞底。静脉均引流入基底静脉。3例星形细胞瘤患者施行小脑上经小脑幕入路颞底内侧区后部肿瘤切除术,完全切除肿瘤,疗效满意。结论小脑上经小脑幕入路手术能够较好显露颞底内侧区后部解剖结构,熟练掌握该入路的解剖学知识有助于处理颞底内侧区后部病变。

Objective To investigate the exposure area, anatomical structures and position relation-ship of supracerebellar transtentorial （SCTT） approach to the posterior mediobasal temporal region in order to provide the evidence for clinical application. Methods Mimetic procedure of the SCTT approach to the posterior mediobasal temporal region was performed on 5 Chinese adult cadaveric heads （10 sides）. Red silicone was injected through carotid and vertebral artery, blue silicone was injected through jugular vein. The exposure area, anatomical structures and position relationship of sulcus, gyrus and arteries or veins in the posterior mediobasal temporal region were observed under operating microscope. Three cases with tumors located in the posterior mediobasal temporal region were selected and treated via the SCTT approach, and the surgical effect and prognosis were observed. Results The SCTT approach provided a direct path to the posterior mediobasal temporal region and exposed the posterior parahippocampal gyrus, anterior lingual gyrus and fusiform gyrus in all cadaveric heads. The P3 segment of posterior cerebral artery （PCA） and its subtemporal branches could be reached. The rhinal sulcus and collateral sulcus were present but not consistent in all 5 cadaveric heads （10 sides）. The parahippocampal gyrus was separated from the fusiform gyrus by the rhinal sulcus anteriorly and by the collateral sulcus posteriorly. The lingual gyrus was separated from the parahippocampal gyrus by the anterior calcarine sulcus. The isthmus of cingula gyrus and the anterior lingual gyrusjoined with the posterior parahippocampal gyrus respectively. The fusiform gyrus was seperated from the inferior temporal gyrus by the occipitotemporal sulcus. In all 5 cadaveric heads （10 sides）, the arterial supply of posterior mediobasal temporal region mainly came from the subtem-poral branches of PCA. The anterior and posterior inferior temporal branches of common temporal artery, and middle and posterior inferior temporal arteries which all originating from P2 segment of PCA supplied the blood to the basitemporal in 3 heads （4 sides） and 2 heads （2 sides）, respectively. The blood supply of basitemporal region in 3 heads （4 sides） came from hippocampal artery, anterior and posterior inferior temporal arteries originating from PCA. The veins of the posterior mediobasal temporal region all drained into the basal vein. In 3 patients with astrocytomas, the tumors located in the posterior mediobasal temporal region were totally resected through the SCTT approach, and the therapeutic effect was satisfactory. Conclusion The SCTT approach provides a viable surgical route to the posterior mediobasal temporal region in the cadaveric studies. A thorough understanding of the anatomy of the SCTT approach is essential in treating the lesion in the posterior mediobasal temporal region.