小脑后下动脉动脉瘤的手术入路

小脑后下动脉动脉瘤的手术入路

Surgical approach to posterior inferior cerebellar artery aneurysms

摘要

Abstract

背景：远外侧入路是用于夹闭小脑后下动脉（PICA）动脉瘤的标准化入路。基于动脉瘤形态、位置、破裂状态、小脑肿胀和手术医生偏好的不同，可以采用不同的入路变型处理动脉瘤。

Background The far-lateral is a standardised approach to clip aneurysms of the posterior inferior cerebellar artery (PICA). Different variants can be adopted to manage aneurysms that differ in morphology, topography, ruptured status, cerebellar swelling and surgeon preference.

方法：作者划分出5种范式入路，旨在处理近端未破裂型、近端破裂且需后颅窝减压（PFD）型、近端破裂但无需PFD型、远端未破裂型、远端破裂型等不同类型的动脉瘤。

Method We distinguished five paradigmatic approaches aimed to manage aneurysms that are: proximal unruptured; proximal ruptured requiring posterior fossa decompression (PFD); proximal ruptured not requiring PFD; distal unruptured; distal ruptured.

结论：在PICA动脉瘤手术中，术前计划对于实施有效与安全的操作程序、确保充分的PFD和处理动脉瘤前的最佳近端阻断至关重要。

Conclusions Preoperative planning in the setting of PICA aneurysm surgery is of paramount importance to perform an effective and safe procedure, to ensure an adequate PFD and optimal proximal control before aneurysm manipulation.

关键词：小脑后下动脉动脉瘤，PICA动脉瘤，远外侧入路，曲棍球棒切口，夹闭

Keywords Posterior inferior cerebellar artery aneurysm . PICA aneurysms . Far lateral approach . Hockey-stick . Clipping

手术相关解剖学

Relevant surgical anatomy

依据小脑后下动脉（PICA）与后组颅神经（LCNs）、延髓和小脑的关系，将其分为5段（图1）：P1段（延髓前段）位于椎-基底动脉交界处，贴近延髓腹侧面，毗邻舌下神经根；P2段（延髓外侧段）走行于橄榄与LCNs之间；P3段（扁桃体延髓段）亦即尾侧袢，首先向下走行至同侧小脑扁桃体下极，然后反折向上至两侧扁桃体之间的小脑溪；P4段（膜髓帆扁桃体段）亦即起自扁桃体延伸至扁桃体延髓裂的血管袢；P5段（皮质段）由终支组成。

The posterior inferior cerebellar artery (PICA) is divided into five segments (Fig. 1), depending on their relationship with lower cranial nerves (LCNs), medulla and cerebellum. The P1 segment (anterior medullary) is located at the vertebra-basilar junction, surfacing on the ventral medulla, close to the hypoglossal rootlets; P2 (lateral medullary) goes from the olive to the LCNs; P3 (tonsillo-medullary) corresponds to the caudal loop, which descends to the inferior pole of the homolateral tonsil and then ascends to the inter-tonsils space; P4 (telovelo-tonsillar) corresponds to the loop extended from the tonsil toward the tonsillo-medullary fissure; P5 (cortical segment) consists of the terminal branches.

图1：PICA解剖及其与周围重要神经结构（脑干、后组颅神经、

小脑扁桃体和小脑半球）关系示意图。PICA分段如图所示：P1——延髓前段，始自VA交界处，紧邻延髓腹侧面及舌下神经根；P2——延髓外侧段，自橄榄延伸至后组颅神经根；P3——扁桃体延髓段，首先环绕小脑扁桃体下极，进而反折向上至小脑溪的特征性血管袢；P4——膜髓帆扁桃体段，亦即颅袢，首先走行至第四脑室顶，然后反折向下至扁桃体延髓裂；P5——皮质段，由供应小脑蚓部和小脑半球表面的终支组成。

Fig.1 Illustrative representation of PICA anatomy and its relationship with the surrounding eloquent neuronal structures (brainstem, lower cranial nerves, cerebellar tonsils and hemispheres). PICA segments are illustrated as: P1—anterior medullary segment beginning at the VA junction, surfacing the ventral part of the medulla and hypoglossal rootlets; P2—lateral medullary segment, extending from the olive to the lower cranial nerves rootlets; P3—tonsillo-medullary segment surrounding with its characteristic loop the inferior pole of the cerebellar tonsil up to the inter-tonsils cistern; P4—telo-velo-tonsillar segment, which designates a cranial loop toward the roof of the fourth ventricle and then downwards to the tonsillo-medullary fissure; P5—cortical segment, consisting of terminal branches supplying the vermian and hemispheric surfaces

技术描述

Description of the technique

体位

Positioning

患者取公园长凳卧位，上肩向下倾斜约30°，头部转向床面约45°，将乳突置于术野最高点。