Treatment of bilateral vocal cord paralysis following permanent recurrent laryngeal nerve injury

Bilateral vocal cord paralysis is a serious illness requiring emergency intervention to resolve the potentially life-threatening respiratory distress. Several surgical procedures were proposed to help improve the airway and to eliminate the tracheostoma in those patients with permanent paralysis. All the procedures have their own advantages and disadvantages. We conducted a retrospective study of 30 patients affected by bilateral vocal cord paralysis following total thyroidectomy. All the patients underwent total thyroidectomy for benign thyroid pathology. In 26 patients (86.6%), cord paralysis occurred during the perioperative stage; and in the remaining 4 cases (13.3%), it occurred within the following 6 months. We treated all these bilateral recurrent laryngeal nerve paralysis patients with arytenoidectomy alone in 5 patients and arytenoidectomy with concomitant true and false posterior cordectomy in the remaining 25 patients. Twenty-four of the 25 patients who underwent the combined procedures (96%) reported subjective respiratory improvement and were decannulated within 60 days, being able to return to their normal daily activities. This study demonstrates that arytenoidectomy associated with posterior cordectomy is a satisfactory surgical treatment of bilateral vocal cord paralysis because it leads to a considerable and stable enlargement of the breathing space.     

Intraoperative recurrent laryngeal nerve monitoring in revision thyroidectomy

Recurrent laryngeal nerve (RLN) palsy is one of the most important complications after thyroid and parathyroid surgery. There is controversy in the literature regarding whether or not intraoperative nerve monitoring decreases the risk of injury. We report our experience using Nerve Integrity Monitoring (NIM) system in cases of revision thyroidectomy, providing clear indications for its use. A series of 97 patients who underwent revision thyroidectomy with and without intraoperative NIM alternately was evaluated. There were 121 RLN patients at risk. Use of NIM during revision thyroidectomy was not statistically significant compared to revision operation without monitoring (p value = 0.059). Furthermore, comparison of operative times either with or without NIM showed that use of NIM led to statistically significant prolonged operation time (p value <0.001). There is no strict indication to use RLN monitoring during thyroid surgery, especially as there is no statistical evidence that the use of this technique decreases the incidence of RLN palsy, although there is a trend especially in difficult revision cases.     

Recurrent laryngeal nerve paralysis after thyroidectomy

AIM: The paper's aim is to examine and analyse the incidence rate of postoperative pareses of N. recurrens in 1311 operated thyroid sides and 909 patients. PATIENTS AND SURGICAL TECHNIQUE: In histology we found nodular changes in 92.6% of 840 operated benignant strumata. In 69 malignant strumata the papillary thyroid carcinoma was the most common. The surgical concept changed within the last years from subtotal resections and enuclations to functional and total resections. RESULTS: Preoperative pareses of N. recurrens were seen in 5.3% of the patients, which emphasizes the demand for a preoperative laryngologic examination. Surgery on relapsed benignant strumata were followed by permanent unilateral pareses of N. recurrens in 9.9%, surgery on malignant strumata in 7.5% of the cases. After surgery of relapsed malignant strumata we found 2 permanent pareses in 21 reoperated thyroid sides. During a regular follow-up over the period of 12 months at least, we saw 22 transitory pareses of N. recurrens, which corresponds to a reversibility rate of 35%. In first surgical interventions with benignant histology the reversibility rate was 49%. Depending on first or relapse surgery, the histological findings and chosen surgical method the rate of permanent unilateral pareses of N. recurrens was only 1.7% in relation to the first time operated sides of benignant strumata.     

Histopathology of vocal cord palsy from recurrent laryngeal nerve damage

The detailed postmortem laryngeal findings of a man with an established vocal cord palsy from an inoperable bronchial carcinoma is presented. Fine dissection of the monoblock specimen from skull base to superior mediastinum allowed sampling of vagus, recurrent and superior laryngeal nerves at different levels for fiber counts in order to compare the affected left and unaffected right side. Horizontal slicing of the whole larynx showed that the main cause of lateral displacement of the paralyzed left cord was gross atrophy of the underlying intrinsic laryngeal muscles. Cricothyroid muscle and superior laryngeal nerves were unaffected. Lateral cord drift due to underlying muscle atrophy is a better explanation of paralyzed cord position in this case than the Wagner and Grossmann theory of cord palsy.     

Bilateral vocal cord paralysis associated with laryngeal myxedema

For managing dyspnea caused by bilateral vocal cord paralysis as a complication of thyroidectomy in the acute postoperative period, reversible vocal cord lateralisation is performed at the authors’ departments. However, in the later postoperative period of thyroidectomy when there is no chance for recovery of the recurrent laryngeal nerves, they perform irreversible procedure. Applying these operative techniques satisfactory breathing can be achieved in about 95% of cases avoiding tracheostomy. In 5% of cases there are other comorbidities in the background of unsuccessful operative results which can cause potential dyspnea as well. From these complications the authors emphasize the role of laryngeal obstruction and myxedema as a consequence of hypothyroidism developed after thyroidectomy. Management of severe dyspnea caused by association of these two complications of thyroidectomy means a great therapeutic challenge. Between 01 Jan 1989 and 30 Nov 2008 the authors performed 161 reversible and 135 irreversible vocal cord lateralisations to manage dyspnea caused by bilateral vocal cord paralysis as a complication of thyroidectomy. From these cases four patients had further obstruction due to laryngeal myxedema. By performing endoscopic laryngeal surgeries and applying levothyroxine replacement therapy sufficiently wide glottic chink has been achieved in all the cases. According to the experience of the authors dyspnea caused by bilateral vocal cord paralysis after thyroidectomy needs complex, interdisciplinary therapeutic approach beside glottis widening operations.     

Value of recurrent laryngeal nerve monitoring in the operative strategy during total thyroidectomy and parathyroidectomy

ObjectiveThe purpose of this study was to assess the role of recurrent laryngeal nerve (RLN) monitoring in the operative strategy during total thyroidectomy and parathyroidectomy. Due to the risk of serious respiratory complications of bilateral recurrent nerve paralysis, two-stage surgery may be considered in the case on negative stimulation of the first side.Patients and methodsThis prospective study was conducted in 100 consecutive patients between May 2007 and March 2011. Translaryngeal monitoring was performed. When stimulation of the RLN on the first side dissected was negative, dissection of the other side was deferred to avoid the risk of bilateral RLN paralysis.ResultsThe main surgical indications were thyroid carcinoma (34%), Graves’ disease (27%), multinodular goitre (27%) and parathyroid hyperplasia (9%) with seven cases of redo surgery. Four RLN identified on the first side gave a negative response to stimulation and surgery to the other side was therefore deferred. Transient unilateral RLN paralysis was observed in these four patients and two cases of RLN paralysis were observed among patients with positive RLN stimulation. Among the 96 contralateral RLNs tested, two were not visualized (one case of transient RLN paralysis, one case of permanent RLN paralysis), two gave a negative response to stimulation (two cases of permanent RLN paralysis) and 92 gave a positive response to stimulation (nine cases of transient RLN paralysis, including two cases associated with transient paralysis of the first side, and one case of permanent RLN paralysis). The incidence of RLN paralysis by nerve was 9.6% for transient RLN paralysis and 2% for permanent (unilateral) RLN paralysis.ConclusionWhen bilateral RLN dissection is planned, RLN monitoring is particularly useful to limit the risk of bilateral RLN paralysis. Two-stage thyroidectomy, following functional recovery of the damaged RLN, can therefore be proposed. The risk of bilateral RLN paralysis was avoided in four patients, while transient bilateral RLN paralysis was observed in two patients despite positive stimulation.     

甲状腺手术喉返神经损伤危险因素及应对策略

目的探讨甲状腺手术出现喉返神经损伤的危险因素及避免损伤的方法。方法回顾性分析1902例甲状腺患者,按手术科别、性别、麻醉方法、病变性质、术中是否常规解剖喉返神经、手术次数及手术范围分组,观察喉返神经损伤率,进行单因素分析及多因素回归分析。结果喉返神经总损伤率为1.84%。单因素分析显示,在甲状腺恶性病变患者、多次手术及甲状腺广泛性手术中喉返神经损伤率升高有统计学意义(χ2分别为1.096、1.893、1.467,P<0.05)。在甲状腺广泛性手术中,术中显露喉返神经可有效降低喉返神经损伤率(χ2=1.758,P<0.05);而在保守性手术中,术中是否显露喉返神经,喉返神经损伤率的差异无统计学意义(χ2=0.638,P>0.05)。Logistic回归分析显示,多次手术及甲状腺广泛性手术是喉返神经损伤的重要危险因素。结论对于病变范围较小的甲状腺良性肿瘤,术中不显露喉返神经、保留部分甲状腺背侧组织是安全可靠的。而对于广泛性甲状腺切除手术,术中应常规解剖喉返神经。     

Vincristine-induced recurrent laryngeal nerve paralysis.

Vincristine-sulfate-related vocal cord paralysis has been reported infrequently in the literature. The neurotoxicity of the vinca alkaloids is well-known; however, the potential for cranial nerve involvement is not widely recognized. Given the complexity of the typical patient receiving such a chemotherapeutic agent, the potential for misdiagnosis is high. Many patients have primary tumors or metastatic lesions in sites that could cause the clinician to overlook this reversible cause of neurologic dysfunction. This study describes the first three reported pediatric cases of vincristine-induced vocal cord paralysis. Two patients developed increasing stridor secondary to bilateral vocal cord paralysis; the third developed a unilateral vocal cord paralysis. All resolved spontaneously upon withdrawal of the vincristine. Vinca-alkaloid-induced vocal cord paralysis is a potentially dangerous but reversible lesion. Otolaryngologists should be aware of the association between these agents and cranial nerve neuropathies.     

甲状腺手术显露喉返神经保留甲状腺动脉

目的探讨显露喉返神经及保留甲状腺动脉手术方法对预防喉返神经损伤及甲状旁腺功能低下的临床价值。方法回顾分析247例甲状腺手术患者,55例行甲状腺全切及次全切除术,192例行甲状腺部分切除术。术中均保留甲状腺上、下动脉,常规显露喉返神经,术前及术后均行电子喉镜检查,血钙及甲状旁腺素检测。结果247例患者,术后均无声嘶症状出现,无术后出血并发症发生,均无手足抽搐及麻木症状出现,术后检测血钙及甲状旁腺素均在正常范围,术后电子喉镜显示无声带麻痹。随访4～36个月,所有患者均未发生永久性甲状旁腺功能低下及声带麻痹症状。结论术中显露喉返神经及保留甲状腺动脉可以避免喉返神经损伤,保全甲状旁腺功能,值得在甲状腺手术方法上推广。     

Causes of recurrent laryngeal nerve paralysis.

The recurrent laryngeal nerve in its course from the brain stem to the larynx follows a path that brings it in proximity to numerous structures. These structures can interfere with its function by pressure or by disruption of the nerve caused by disease invading the nerve. The various causes of recurrent laryngeal nerve paralysis that I have observed during the past 24 years are reported. In 134 patients with recurrent laryngeal nerve paralysis, the left recurrent nerve was most commonly involved. Malignant neoplasms of the lung and pulmonary tuberculosis were the most frequent causes of the paralysis.     

Causes of recurrent laryngeal nerve paralysis.

OBJECTIVE: Persistent hoarseness due to recurrent laryngeal nerve paralysis (RLNP) reduces the quality of life unless it is adequately treated. This study examined the indications for phonosurgical intervention in patients with RLNP. MATERIALS AND METHODS: The medical records of the Ehime University Hospital, Ehime, Japan, from October 1976 until December 1997 were reviewed retrospectively to identify patients with RLNP. The data collected included age, gender, paralyzed side, and cause of paralysis. RESULTS: Four hundred and sixty-six patients with RLNP were identified: 262 males and 204 females. Unilateral RLNP was present in 422 patients, while 44 presented with bilateral RLNP. The incidence was relatively high in the 7th and 8th decades, and was twice as high in male patients as in female patients. The 466 patients were divided into 2 groups: Group 1 included 225 patients seen before January 1987, and Group 2 included 241 patients seen after this date. The number of patients with postoperative RLNP was significantly higher in Group 2 (124 of 239 patients) than in Group 1 (65 of 227 patients) (P<0.05). Surgery for cardiovascular disease, esophageal cancer, and skull base and thyroid gland tumors contributed to this increased incidence of postoperative RLNP. CONCLUSIONS: Patients with persistent unilateral RLNP require appropriate treatment for hoarseness, regardless of its cause. Since the incidence of RLNP related to surgery was significantly increased in Group 2, phonosurgery has become more important for improving the quality of life of these patients.     

Immediate recurrent laryngeal nerve reconstruction and vocal outcome

OBJECTIVE: The objective of this prospective study was to assess the long-term effects of immediate reconstruction of the recurrent laryngeal nerve (RLN) during thyroid cancer extirpation on postoperative phonatory function. SUBJECTS AND METHODS: The subjects were 22 patients with advanced thyroid cancer who underwent resection of the primary lesion and involved RLN. RLN paralysis was seen in 12 patients preoperatively and involvement of the RLN was noted intraoperatively in 10. Immediate reconstruction of the RLN was performed on eight patients using the great auricular nerve and one underwent direct anastomosis of the RLN stumps (group I). Nine patients opted not to have phonosurgical procedures (group II). The remaining four had arytenoid adduction immediately after cancer extirpation (group III). Phonatory function (stroboscopy, maximum phonation time [MPT], mean airflow rate [MFR], harmonics-to-noise ratio [HNR], jitter, and shimmer) was followed for at least 9 months. RESULTS: Minimal or no glottal gap during phonation was observed in six patients in group I, whereas the patients in group II had a large gap along the entire fold. HNR, MPT, and MFR were significantly better in group I (17.7 +/- 3.6 dB, 15.1 +/- 6.3 s, and 100 +/- 32 mL/s, respectively) than in group II (12.1 +/- 2.9 dB, 5.4 +/- 3.1 s, and 430 +/- 207 mL/s, respectively). Patients in group III had a gap of varying degrees along the membranous fold. Although HNR, shimmer, and MPT in group III were comparable to group I, the other parameters were less favorable than in group I. CONCLUSION: Immediate RLN reconstruction at the time of thyroid cancer extirpation can provide excellent postoperative phonatory function.