听神经瘤的听力保留手术

听神经瘤的听力保留手术：长期随访 Surgery of small acoustic neuroma aims at minimal brain and facial nerve morbidity. The attempt to preserve hearing has become the next step in all the modalities of treatment, including surgery, radiotherapy or observation. Hearing preservation surgery (HPS) has made important progresses with an increase of good preserved hearing and minor chance of total loss of hearing. Nonetheless, the long-term stability preserved hearing is still unclear. The several reports on the stability of preserved hearing with widely divergent rates. Shelton et al. 1 significant long-term decline of hearing after middle cranial fossa approach in 56% of patients. In a later publication 2, no decline of preserved hearing was reported in 23 cases after 5 years of follow-up. Woodson et al. 3 reported minimal decline of hearing after a follow-up of at least two years. Divergent outcomes were reported with a retrosigmoid approach 4-8, with declines ranging from 40% 7 to 17.6% 6. No correlation was found 4 5 8 between the loss of hearing quality and patients age and symptoms, tumour size or preoperative hearing. 小听神经瘤的外科治疗目的是治愈脑和面神经病变。目前保留听力已经成为了治疗的下一 个目标，目前手段爆扣手术，放射治疗和观察。听力保留手术（HPS）已经取得了明显的进 展（包括保留良好的听力以及减少全听力丧失）然而，长期稳定的听力保留仍然未明确。 少数稳定的听力保留报道存在明显的分歧。Shelton et al，报道了 56%中颅窝入路的患者 明显长期的听力下降，在其后的报道中，经过 5年随访，23 例患者均无明显的保留听力下 降。Woodson et al报道了经过 2年的随访，最小的听力下降。在乙状窦后后入路的报道 中，听力下降程度存在明显的分歧，达到 40%-17.6%。听力损失的程度与病人的年龄，症 状，肿瘤大小，术前听力没有明显的关联。 Several theories for hearing decline have been proposed including microscopic tumour recurrence or disorder of blood supply to labyrinth or internal auditory canal. Fibrosis and scarring of the meatotomy area are a common finding at MRI, and may cause vascular insult. It is possible that the scarring is more pronounced as a consequence of fat or muscle graft packing of the internal auditory canal 1 6 7 acting either through a mechanical or a vascular insult. Endolymphatic hydrops secondary to damage of the endolymphatic duct has also been mentioned as a possible cause 9 有几个关于听力下降的理论，包括微小镜下肿瘤复发以及迷路及内听道血供紊乱。鼻部手 术区域的纤维化及疤痕化是MRI中常见发现。并且常发现血管紊乱。疤痕更明显的原因可能 是脂肪及肌肉的移植物包裹了内听道导致了血管侵入或机械因素。继发于淋巴管损伤的淋 巴水肿已经被题为可能的几个原因之一。 Our experience with HPS involves 322 cases of sporadic acoustic neuroma which underwent intervention in the same institution (ENT Department Ospedali Riuniti Bergamo) by the same surgeon (A.M.). Table I summarizes the cases from 1976 to 2009 as well as the three phases of HPS, each one characterized by increasingly restrictive criteria to select patients for hearing preservation. A study on long-term hearing outcome was carried out in 2006 on the first series of 200 cases, which was the object of a previous article 11 with shorter follow-up on the first 150 cases. Seven cases of intrameatal tumour operated upon with the middle cranial fossa approach were excluded due to their small number. The follow-up is 6 to 21 years as the first cases with preserved hearing date to 1985. There were 194 class A or B cases, 4 class C and 2 class D. Size of tumour was expressed in mm of the largest diameter in cerebello-pontine angle at contrast MRI and with the separate group of intrameatal tumours (Table II). The C class cases had a size of 1.5, 5 and 6 mm. The D class cases had sizes of 10 and 11 mm. The procedure used was a retrosigmoid approach with retrolabyrinthine meatotomy 10 as described earlier. Follow-up data are reported in Table III. 我们共进行了 322例听神经瘤的 HPS手术（在同一家研究中心中由同一人执刀） ，表 I总结 了 1976-2009年所有例数以及 HPS的三个阶段，每一例通过严格的限制性标准选择出来进 行听力保留。一项最初的 200例长期的听力研究结果在 2006年进行。是一篇之前的文章最 初进行的 150例短期随访的目的.7 例中颅窝进行鼻内肿瘤手术被排除在外（因为数量太少） 。随访年限从 6年至 21年（因为最初的听力保留案例发生于 1985） ，共有 194例 a和 b级， 4例 c和 d级。肿瘤大小用对照 MRI中小脑-桥脑角最大直径的 mm衡量以及道内肿瘤的分 离组。C 级案例有 1.5，5，6mm，D 级案例有 10，11mm，手术方案包括乙状窦后入路迷路后 道口切开术。 Ninety-four of 200 cases (47%) preserved measurable postoperative hearing, and 91 underwent long-term follow- up (97%). Table IV reports the short- and long-term global hearing outcomes. Each preoperative class either remained in the class or dropped to a lower class with a different rate depending on the previous level, i.e. a better class shows a trend to a lesser loss. The rate of class preservation was similar for class A or B, but if the change to the next lower class was considered, the trend to a loss of hearing was different. The A class cases stayed in A or B in 39 of 89 of cases (44%) in the short-term, and in 36 of 89 (40%) in the long-term. The class B cases stayed in class B or C in 25 of 100 patients (25%) in the short-term, and in 22 of 100 patients (22%) in the long-term. If the change of class was considered, class A cases stayed in A in 92% of patients (12 of 13), and class B cases remained in same class in 73% of patients (11 of 15). Altogether, cases in classes A-B remained in classes A or B in 87% (47 of 54) of cases. 94/200（47%）保留了可测量的术后听力，97%（91 例）进行了长期的随访。每一例术前等 级要么保留要么不同程度跌落几个等级（取决于之前的等级） ，比如较好的等级显示了较少 损失的趋势。等级保留的程度对于 a级 b级类似。但是如果发生了至较低级别的变化，损 失的发生是不同的。a 级保留在 a或 b短期随访发生了 44%*（39/89)，在长期随访发生了 40%（36/89),短期随访中 b级保留在 b或 c级发生于 25%（25/100)，长期随访中，22%。 如果考虑到等级变化，a 级留在 a级 12/13（92%） ，b 级留在 b级 73%（11/15).总共，ab 级留在 ab级 87%（47/54). Table V reports the outcome in relation to size of tumour in the group with measurable postoperative hearing and in the group of A or B cases in the short- and long-term. The 107 cases with a 10 mm tumour and class A or Bhearing remained in class A or B in 49 cases (33%) in the short-term and in 42 cases (27%) in the long-term. The patients with a small tumour preserved hearing class in about 1 in 3 cases, while hearing was preserved in patients with a large tumour in one over 6, 8 and 18 cases at the size limit of 15, 20 and 32 mm respectively. Change of class at short- to long-term follow-up occurred in 18 cases (19%) (Table VI), with three cases lost to follow-up (one was class B and two were class D at short-term, 23%). The change of class change was less in the A-B classes (8/54, 15%) or 9/54 (17%) if the lost case is included. The short-term A-B cases remained in class A or B (