Triantafyllou George, Tsiouris Christos, Chrysanthou Ioannis, Paschopoulos Ioannis, Tsakotos George, Kalamatianos Theodosis, Piagkou Maria
Department of Anatomy, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, 11527 Athens, Greece.
Department of Neurosurgery, Evangelismos Hospital, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, 10676 Athens, Greece.
Diagnostics (Basel). 2024 Aug 26;14(17):1862. doi: 10.3390/diagnostics14171862.
The present systematic review with meta-analysis is a significant contribution to the understanding of the morphological variability of the facial nerve (FN) extratemporal segment, i.e., the facial trunk (FT) variability, its division, and terminal branching patterns. The study also provides a comprehensive overview of the clinical significance of the FN extracranial division.
Four online databases were utilized to conduct the systematic review according to evidence-based anatomy guidelines. A meta-analysis of the studies included was carried out using R programming software. The combined prevalence of the FN variants was calculated, along with subgroup and cumulative analysis.
From the systematic review, 29 studies were retrieved as eligible for our initial purpose. However, 19 studies followed the same classification system and were selected for the meta-analysis, with a total sample of 2453 nerves. The most common pattern of the FN morphology was the FT bifurcation (typical pattern), with a pooled prevalence of 94.1% and a single interconnection (IC) between the temporofacial and cervicofacial branches (23.1% pooled prevalence). Two ICs between these branches were the rarest pattern (8.9% pooled prevalence).
Our findings underscore the extensive morphological variability of the FN extratemporal anatomy, which has led to confusion among researchers. While several classification systems have been developed, none accurately represent the typical and variant anatomy. Our meta-analysis provided a small range between 8.9-23.1% for the rarest and most common pattern; thus, diversity is the rule. Therefore, it is not safe to conclude the typical morphology of FN extratemporal anatomy for its whole distribution before the FT's division (proximally) and its terminal branches (distally). Nevertheless, the bifurcation of the FT can be considered the typical morphology, and it is far more constant than the distal branching pattern. These findings have significant implications for surgical procedures, particularly parotidectomy, where surgeons must exercise utmost caution due to the potential clinical implications of FN injury.
本项系统评价及荟萃分析对理解面神经颞外段的形态变异具有重要意义，即面神经主干（FT）的变异、其分支及终末分支模式。该研究还全面概述了面神经颅外分支的临床意义。
根据循证解剖学指南，利用四个在线数据库进行系统评价。使用R编程软件对纳入的研究进行荟萃分析。计算面神经变异的合并患病率，并进行亚组分析和累积分析。
通过系统评价，检索到29项符合我们初始目的的研究。然而，19项研究采用了相同的分类系统，被选入荟萃分析，样本总数为2453条神经。面神经形态最常见的模式是FT分叉（典型模式），合并患病率为94.1%，颞面支和颈面支之间有单一连接（IC）（合并患病率为23.1%）。这些分支之间有两个IC是最罕见的模式（合并患病率为8.9%）。
我们的研究结果强调了面神经颞外解剖结构广泛的形态变异，这在研究人员中造成了困惑。虽然已经开发了几种分类系统，但没有一种能准确代表典型和变异的解剖结构。我们的荟萃分析得出最罕见和最常见模式的范围在8.9%-23.1%之间；因此，多样性是常态。因此，在FT分支（近端）及其终末分支（远端）之前，就其整个分布推断面神经颞外解剖结构的典型形态是不安全的。然而，FT分叉可被视为典型形态，并且远比远端分支模式更恒定。这些发现对手术操作具有重要意义，尤其是腮腺切除术，由于面神经损伤可能产生的临床影响，外科医生必须格外小心。
