Anatomia microcirúrgica do nervo laríngeo recorrente: aplicações no acesso cirúrgico anterior à coluna cervical

Non-Recurrent Laryngeal Nerve: A Rare Anatomical Entity in a Patient Undergoing Hemithyroidectomy

A non-recurrent laryngeal nerve (NRLN) is a common anatomical modification with an occurrence rate ranging from 0.5% to 0.7% in surgical procedures related to thyroid pathology [1]. In this condition cervical vagus nerve reaches the larynx directly, increasing the likelihood of vocal cord palsy. Non-RLN injury can be reduced by anticipating it and identifying it early. This case report describes how a non-recurrent inferior laryngeal nerve was discovered intraoperatively during systemic dissection, averting intra-operative nerve injury. A 40-year-old female reported to the department of Otorhinolaryngology and Head and Neck Surgery Outpatient Clinic for a nodular tumor in her neck that has been increasing for the previous five years. The colloid multi-nodular thyroid of the right lobe was confirmed by a fine needle aspiration cytology (FNAC). The patient was lined up for a surgical procedure requiring resection of the right lobe of the thyroid. A non-recurrent right inferior laryngeal nerve was discovered during surgery. The operation and recovery went smoothly, and there was no change in his voice in subsequent follow-ups. For those who are related to this professional line, this presentation provides a summary of what a non-recurrent laryngeal nerve looks like during surgery. This is critical for anyone undergoing diagnostic and surgical procedures which demand to be invasive in the region involving the neck and upper thorax, as it lowers the risk of iatrogenic nerve injury. A solitary trauma of this nerve can induce irreversible hoarseness, whereas a multilateral lesion might result in aphonia and potentially deadly dysphonia.

Right- Versus Left-sided Exposures of the Recurrent Laryngeal Nerve and Considerations of Cervical Spinal Surgical Corridor: A Fresh-Cadaveric Surgical Anatomy of RLN Pertinent to Spine

STUDY DESIGN

Cadaveric study on fresh unprocessed, nonpreserved, undyed specimens which have not previously been reported.

OBJECTIVE

We aimed to perform surgically relevant exposures of the anterior cervical spine with particular attention to observing the potential vulnerabilities of the RLN on right and left.

SUMMARY OF BACKGROUND DATA

Vulnerability of the RLN in the anterior cervical spine approach on the right versus left is the subject of ongoing debate. Although most cadaveric studies focus on course variations, structural relations of RLN, they have been done in preserved (fixed) cadavers without relevance to the needs of spinal exposure.

METHODS

Twelve fresh undyed cadavers had extensive layer by layer dissections by 2 surgeons (one with extensive experience as anatomy dissector). Both sides were explored for vulnerability during cervical spinal procedures. Each dissection was carried out in a phased approach and deliberately explored beyond what can be afforded in live surgery to allow the reader to conceptualize a better view of the structures.

RESULTS

In all specimens, we consistently demonstrated that the right surgical corridor involved manipulation of the nerve and its branches especially below C5 to achieve optimum midline access: in the right corridor, the RLN is on its oblique course to the tracheoesophageal groove. On the left, RLN is already in the tracheoesophageal groove and out of the surgical field involving minimal direct mobilization of the nerve.

CONCLUSION

RLN surgical anatomy photographed here is novel in using fresh unprocessed cadaveric specimens which has previously not been reported.Right surgical corridor, below C5, involves retraction/manipulation of RLN for achieving optimum spinal midline access, highlighting potential surgical vulnerability of right RLN.

LEVEL OF EVIDENCE

3.

Analysis of the outcome in patients with cervical spondylotic myelopathy, undergone canal expansive laminoplasty supported with instrumentation in a group of Indian population - a prospective study

BACKGROUND

Chronic compression of the cervical spinal cord leads to a clinical syndrome of cervical spondylotic myelopathy (CSM). Clinical symptoms of cervical spondylotic myelopathy (CSM) or cervical myeloradiculopathies result in spinal cord and root dysfunction. The primary aims of surgical intervention for multilevel myelopathy are to decompress the spinal cord and maintain stability of the cervical spine. Secondary aims are to minimize complications which include long-term pain and motion loss. Laminoplasty as either single-door or double-door technique and with/without instrumentation is an established mode of surgical treatment. The purpose of our study was to evaluate the result of single-door laminoplasty technique, supported with instrumented fixation in patients with multilevel degenerative cervical spondylotic myeloradiculopathy.

METHODS

A prospective and without control study has been conducted in the institution in 17 patients with CSM, operated by canal expansive single-door laminoplasty (Hirabayashi technique) between April 2010 to April 2015. These patients were followed up for at least 3 years with both clinical and radiographic evaluations.

RESULTS

On clinical evaluation, 15 of the 17 patients (87%) experienced relief of their symptoms. According to the Nurick classification, 11 patients' demonstrated improvement by one grade, two patients improved by two grades, two patients were unchanged and two had worsening of the Nurick grade.

CONCLUSIONS

The results of this study regarding the use of open-door laminoplasty with instrumented fixation suggest that this technique is a satisfactory alternative for cases of multilevel cervical spondylotic myelopathy without deformation.

LEVEL OF EVIDENCE

Level III therapeutic study.

Carotid Endarterectomy

BACKGROUND:

Cranial nerve injury (CNI) is the most common neurological complication associated with carotid endarterectomy (CEA). Some authors postulate that the transverse skin incision leads to increased risk of CNI.

OBJECTIVE:

We compared the incidence of CNI associated with the transverse and longitudinal skin incisions in a high-volume cerebrovascular center.

METHODS:

We reviewed the charts of 226 consecutive patients who underwent CEAs between January 2007 and August 2009. Pre- and postoperative standardized neurological evaluations were performed by faculty neurologists and neurosurgeons.

RESULTS:

One hundred sixty nine of 226 (75%) CEAs were performed with the use of a transverse incision. The longitudinal incision was generally reserved for patients with a high-riding carotid bifurcation. Mean patient age was 69 years (range, 45–91 years); 62% were men; 59% of patients were symptomatic and had high-grade stenosis (70%-99%). CNI occurred in 8 cases (3.5%): 5 (3%) in transverse and 3 (5.3%) with longitudinal incisions (P = .42). There were 2 marginal mandibular nerve injuries, 1 (0.6%) transverse and 1 longitudinal; 5 recurrent laryngeal nerve injuries, 4 transverse and 1 longitudinal; and 1 case of hypoglossal nerve injury associated with longitudinal incision. One hematoma was associated with CNI. All injuries were transient. Fourteen wound hematomas required surgical evacuation.

CONCLUSION:

The transverse skin incision for CEAs is not associated with an increased risk of CNI (P =.42). In this study, the incidence of CNI associated with the transverse incision was 3% (n = 5) vs 5% (n = 3) for longitudinal incisions. All CNIs were temporary.

Papel da videoendoscopia da laringe no diagnóstico de lesão do nervo laríngeo recorrente na abordagem cervical anterior

INTRODUÇÃO: o reconhecimento da lesão do nervo laríngeo recorrente (NLR) após tratamento cirúrgico de hérnia discal cervical via anterior é importante na evolução clínica do paciente e, em especial, nos casos de reintervenção. O real papel da videoendoscopia da laringe (VEL) de rotina no pós-operatório não tem sido completamente estudado. OBJETIVO: identificar a prevalência de lesões do NLR em pacientes sintomáticos ou não através da VEL após cirurgia de hérnia cervical via anterior. MÉTODOS: no período de Junho de 2009 a Julho de 2010 selecionamos 30 pacientes submetidos a tratamento cirúrgico de hérnia discal no Hospital São Lucas da PUC-RS. Realizou-se avaliação por VEL no pré-operatório e no décimo dia após a cirurgia. Pacientes que apresentaram um resultado anormal da VEL foram considerados com lesão do NLR e foram reavaliados mensalmente até a recuperação espontânea, ou no período máximo de seis meses, quando a lesão foi considerada definitiva. RESULTADOS: encontramos evidência de lesão do NLR em 3/30 (10%) dos pacientes, sendo que todos se apresentavam assintomáticos no momento do exame. Dentre as lesões, 2/30 (66,6%) ocorreram após abordagem cirúrgica pelo lado direito e 1/30 (33,3%) pelo lado esquerdo. Não encontramos nenhuma lesão definitiva, sendo o período máximo de recuperação de 120 dias. CONCLUSÃO: a avaliação por VEL no período pós-operatório pode ser útil para diagnosticar lesões do NLR, principalmente em pacientes assintomáticos. A falta de suspeita clínica não exclui a possibilidade de lesão do LNR.

A non-recurrent inferior laryngeal nerve in a man undergoing thyroidectomy: a case report

INTRODUCTION

A non-recurrent variant of the inferior laryngeal nerve has been seldom reported. These reports are mostly based on cadaveric dissection studies or large chart review studies in which the emphasis is placed on the determination of the frequency of the variation, and not on the clinical appearance of this variant. We graphically describe the intraoperative identification of a non-recurrent inferior laryngeal nerve.

CASE PRESENTATION

A 44-year old Caucasian man was referred to the Head and Neck Surgery Outpatient Clinic with the diagnosis of a nodular mass in his left thyroid lobe that had been growing for one year. A fine needle aspiration puncture was compatible with thyroid papillary cancer. It was decided that the patient should undergo total thyroidectomy. During surgery, a non-recurrent right inferior laryngeal nerve was noted. This nerve emanated from the right vagus nerve, entering the larynx 3 cm after its origin. The nerve did not show a recurrent course. The nerve on the left side had a normal configuration. The surgery and post-operative period were uneventful, and the patient had no change in his voice.

CONCLUSION

This paper allows those interested to become acquainted with the normal intraoperative appearance of a non-recurrent inferior laryngeal nerve. This will undoubtedly be of significance for all of those performing invasive diagnostic and surgical procedures in the neck and upper thoracic regions, in order to minimize the risk of iatrogenic injury to this nerve. This is of extreme importance, since a unilateral lesion of this nerve may result in permanent hoarseness, and a bilateral lesion may lead to aphonia and life-threatening dyspnea.