The superior laryngeal nerve and the superior laryngeal artery

Length, diameter and anastomoses of the nervus vagus and its ganglion inferius were measured 44 halved heads. On the average, 8.65 fiber bundles of the vagus nerve leave the retro-olivary area. In the area of the jugular foramen is the near superior ganglion of the 10th cranial nerve. In this area were found 1.48 (mean value) anastomoses with the 9th cranial nerve. 11.34 mm below the margo terminalis sigmoidea branches off the ramus internus of the accessory nerve which has a length of 9.75 mm. Further anastomoses with the 10th cranial nerve were found. The inferior ganglion of the 10th nerve had a length of 25.47 mm and a diameter of 3.46 mm. Five mm below the ganglion the 10th nerve had a width of 2.9 and a thickness of 1.5 mm. The mean length of the superior sympathetic ganglion was 26.6 mm, its width 7.2 and its thickness 3.4 mm. In nearly all specimens anastomoses of the superior sympathetic ganglion with the ansa cervicalis profunda and the inferior ganglion of the 10th cranial nerve were found. The superior laryngeal nerve branches off about 36 mm below the margo terminalis sigmoidea. The width of this nerve was 1.9 mm, its thickness 0.8 mm on the right and 1.0 mm on the left side. The division in the internal and external rami was found about 21 mm below its origin. Between the n. vagus and thyreohyoid membrane the ramus internus had a length of 64 mm, the length of external ramus between the vagal nerve and the inferior pharyngeal constrictor muscle was 89 mm. Its mean length below the thyreopharyngeal part was 10.7 mm, 8.6 branchlets to the cricothyroid muscle were counted. The superior laryngeal artery had its origin in 80% of cases in the superior thyroideal artery, in 6.8% this vessel was a branch of the external carotid artery. Its average outer diameter was 1.23 mm on the right side and 1.39 mm on the left. The length of this vessel between its origin and the thyreohyoid membrane was 34 mm. In 7% on the right side and in 13% on the left, the superior laryngeal artery reached the larynx through a foramen thyreoideum. Ranges of diameters and lengths of vessels and nerves in the larynx are given.     

Anatomy of the recurrent laryngeal nerve in normal Iraqis

A study of the anatomy of the recurrent laryngeal nerve was made on 106 post-mortem cases and fixed dissecting-room cadavers. The usual position of the nerve was in the tracheo-oesophageal groove. The nerve lay posterior to the inferior thyroid artery on the left side in most cases, while its relation was very variable on the right side. The inferior cornu of the thyroid cartilage was the best guide to the site of entry of the nerve into the larynx.     

External laryngeal muscles--origin, insertion, length and potential force

Measurements have been given of the mm. cricothyreoideus, thyreohyoideus and inferior pharyngeal constrictor muscle. Also measured were the circumferences of these muscles for estimating their potential force. The course of the superior laryngeal nerve, external branch to the thyreopharyngeal muscle and the twigs of the nerve were examined.     

The posterior inferior cerebellar artery

The posterior inferior cerebellar artery has a curved course in the region of the medulla oblongata. Besides its frequent individual variations, this vessel exhibits three morphological types: in type 1 (the commonest type, i.e. more than 50% of the cases) it curves with its vertex turned upwards; in type 2, the posterior inferior cerebellar artery turns in a gentle arch on to the posterior surface of the medulla oblongata, so there is no real curve; in type 3, the posterior inferior cerebellar artery curves but its vertex turns downwards. In all of these cases, the artery is in close relationship with the last four cranial nerves. This relationship is most characteristic in the 1st and 3rd types. The morphological types could be recognised on the angiograms.     

Is there a caudal thyroid artery in the dog (Canis familiaris)?

Attempts have been made to establish extent of similarities as well as dissimilarities between the canine caudal thyroid and human inferior thyroid artery. On the basis of origin, course, relationship, branching pattern, major area of supply, level of anastomosis, occurrence, etc., it is proposed to rename the caudal thyroid of the dog as the tracheoesophageal artery.     

Responses of bulbospinal and laryngeal respiratory neurons to hypercapnia and hypoxia

The purpose was to evaluate activities of medullary respiratory neurons during equivalent changes in phrenic discharge resulting from hypercapnia and hypoxia. Decerebrate, cerebellectomized, paralyzed, and ventilated cats were used. Vagi were sectioned at left midcervical and right intrathoracic levels caudal to the origin of right recurrent laryngeal nerve. Activities of phrenic nerve and single respiratory neurons were monitored. Neurons exhibiting antidromic action potentials following stimulations of the spinal cord and recurrent laryngeal nerve were designated, respectively, bulbospinal or laryngeal. The remaining neurons were not antidromically activated. Hypercapnia caused significant augmentations of discharge frequencies for all neuronal groups. Many of these neurons had no change or declines of activity in hypoxia. We conclude that central chemoreceptor afferent influences are ubiquitous, but excitatory influences from carotid chemoreceptors are more limited in distribution among medullary respiratory neurons. Hypoxia will increase activities of neurons that receive sufficient excitatory peripheral chemoreceptor afferents to overcome direct depression by brain stem hypoxia. The possibility that responses of respiratory muscles to hypoxia are programmed within the medulla is discussed.     

Voice changes after thyroidectomy: role of the external laryngeal nerve.

Hitherto voice changes have been regarded as an infrequent complication of thyroidectomy and damage to the recurrent laryngeal nerve has been given as their major cause. Voice function was assessed in 325 patients after thyroidectomy. Permanent changes occurred in 35 (25%) after subtotal thyroidectomy and in 19 (11%) after lobectomy. The commonest cause of voice change appeared to be injury to the external laryngeal nerves on one or both sides. Damage to the recurrent laryngeal nerve, which was routinely identified and protected, was rarely a cause. When the external laryngeal nerves were identified and preserved, permanent voice changes occurred in only 5% of cases; this was similar to the incidence of 3% in controls after endotracheal intubation alone. The course of the external laryngeal nerve is variable, and consequently mass ligation of the vessels at the top of the upper pole will damage it in a high proportion of cases. To minimise this serious complication these nerves should be identified and protected as well as the recurrent nerves and voice function should be assessed early in the postoperative period by laryngoscopy and by a speech therapist.     

Effects of laryngeal nerve transection on squirrel monkey calls

Summary Six squirrel monkeys (Saimiri sciureus) were implanted with intracerebral electrodes yielding specific call types when electrically stimulated. Two animals then received bilateral transection of the recurrent nerve; in another two animals the external branch of the superior laryngeal nerve was cut bilaterally; two further animals received unilateral transection of either the recurrent or the external laryngeal nerve. In one animal with both recurrent nerves cut, the external laryngeal nerves were cut in addition 3 months later. The vocal changes caused by these transections were observed and can be summarized as follows:Unilateral interruption of the recurrent nerve causes only minor disturbances which are limited to low-pitched sounds. Bilateral interruption of the same nerve leads to a reduction of maximal intensities and durations in general. Whereas the frequency-time structure is severely disorganized in all harmonic calls with a fundamental below 1 kHz and all non-harmonic, noise-like calls, it remains unaffected in harmonic calls with a fundamental above 1 kHz. Unilateral transection of the external laryngeal nerve causes a drop of fundamental frequency in high-pitched calls to almost half. Bilateral transection of the same nerve abolishes all calls with a fundamental above 1 kHz. In wide-band frequency calls it is followed by a shift of main energy towards lower frequencies. Low-pitched harmonic as well as noise-like calls remain normal. Cutting both external laryngeal nerves in addition to recurrent nerves is followed by loss of all sounds except one coughing-like, abnormal call. All animals with transection of the external laryngeal nerve show recovery of the high-pitched calls which seems to be due to new innervation of the cricothyroid muscle from the pharyngeal plexus.     

Laryngeal nerves, branches in the interior of the larynx

The recurrent laryngeal nerve divides in the most cases outside of the larynx into 2 twigs. The thicker ventral branch has a posterior and an anterior twig. From the posterior one, we counted 6.22 (1 to 12) branches to the posterior cricoarytenoid muscle and 1.48 (1 to 3) to the arytenoid muscle. From the anterior branch 3.54 (1 to 6) twigs run to the lateral cricoarytenoid muscle and 2.06 (1 to 5) to the thyreo-arytenoid muscle. An Ansa GALENI was found in 66%. Its diameter was cranial greater than caudal, its length was measured with 73.6 (56 to 96) mm. A single anastomose was found in 54%, and in 12% numerous variations. We found 8.5 (3 to 13) thicker twigs, which divided themselves in 17 thinner twigs. To the mucous membrane we found 78.5% and to muscles 21.5%. In cases without anastomoses, 3.5 (2 to 5) twigs were running to muscles and 13.4 (1 to 25) to the mucous membrane. The diameter and length of the twigs and their course to muscles and mucous membrane have been estimated. The results are discussed with those of earlier authors.     

On the anatomical organization of the vagal nuclei

The neurons of origin of the right vagus and its components in both the monkey (Macaca fascicularis) and albino rats were localized by the retrograde transport of horseradish peroxidase (HRP) applied to the stomach wall, the vagal trunk and its recurrent laryngeal branch. An attempt was also made to localize the neurons forming the superior laryngeal nerve and those supplying the thoracic organs by a combination of operative procedures. The results showed that the stomach was innervated by neurons distributed throughout the entire rostrocaudal extent of the dorsal motor nucleus (DMN) on both sides of the brain stem. Neurons scattered throughout the entire extent of the DMN and nucleus ambiguus (NA) supplied the thoracic viscera. There did not appear to be any topographic arrangement in the DMN neurons supplying the abdominal and thoracic viscera as reported by other workers, and there was no clear evidence of crossing of vagal fibers in the monkey brain stem, though such crossing was seen in the rat brain stem. Both the superior and inferior ganglia of the vagus nerve were labeled following application of HRP to the vagal trunk. Neurons in the caudal part of the NA gave rise to fibers in the ipsilateral recurrent laryngeal nerve, at least on the right side. The neurons giving rise to the superior laryngeal nerve could not be delineated in this study. In all the experimental procedures described, the hypoglossal nucleus was labeled only after applying HRP to the hypoglossal nerve.     

Intimal thickenings in the inferior epigastric artery and coronary bypass

OBJECTIVE: To investigate the relationship between the inferior epigastric artery and the development of pathological intimal thickenings. MATERIAL AND METHODS: The inferior epigastric artery structure was studied with conventional histology techniques, histochemistry, immunohistochemistry and morphometry. RESULTS: The inferior epigastric artery develops 2 types of intimal thickenings: physiological and pathological. In our study, the pathological or atherosclerotic thickenings in this artery were not very common: they were present in 28% of the analysed cases. Vessel flow was not affected as shown by the intimal thickness index (I.T.I.) and the lumen reduction index (L.R.I.). The alpha-actin technique confirmed the role of the smooth muscle cells in the genesis of the thickening. Furthermore, histochemistry demonstrated that the extracellular matrix is rich in highly sulphated acid mucopolysaccharides. CONCLUSION: The inferior epigastric artery seems to be a good candidate for grafting in coronary revascularization because of the low susceptibility to thickening of its intima and the minimal repercussion on its blood flow.     

A rare origin of the superior thyroid artery

In the course of a classroom dissection of a negro male (height: 167 cm; weight: 56.8 kg), and anomalous right superior thyroid artery was noted. It arose from the common carotid artery 27 mm proximal to the bifurcation into external and internal carotids. Previous reports indicate that the incidence of origin of the superior thyroid from the common carotid or its bifurcation varies from 5 to 45%, depending on the population sampled. Moreover, a low origin is more common in females than males, and appears approximately twice as often on the left as on the right. Previous reports also indicate that the origin is only very rarely more than 1 cm proximal to the bifurcation, only one case having been reported of an origin 25 mm proximal. The present case appears to be the most proximal origin so far recorded, and the first far proximal origin in negroes. The implications of such a low origin for surgical approach to the thyroid are considerable.     

甲状腺术中喉返神经显露对暂时性喉返神经损伤发生率的影响

目的:探究甲状腺术中喉返神经显露对暂时性喉返神经损伤发生率的影响。方法:选择我院2016年10月-2018年10月收治的行甲状腺切除术的115例患者为研究对象,按照其入院顺序经随机数字表法分为两组,两组患者均行常规甲状腺切除术。其中,对照组58例患者未显露喉返神经;研究组57例患者常规显露喉返神经,记录并比较两组患者的手术时间、术中出血量、术后引流量、切口长度和住院时间等围术期手术指标,术后1d、4d、7d的甲状旁腺激素(PTH)水平、钙离子(Ca2+)水平,术后暂时性喉返神经损伤、术后声音嘶哑、低钙血症等并发症的发生情况。结果:研究组患者的手术时间、术中出血量、术后引流量均短于(少于)对照组(P0.05),但两组患者的切口长度和住院时间无显著性差异(P0.05);研究组患者术后1d、4d、7d的血清PTH、Ca2+水平均高于对照组(P0.05),暂时性喉返神经损伤、术后声音嘶哑、低钙血症发生率均低于对照组(P0.05)。结论:甲状腺术中喉返神经显露可有效预防暂时性喉返神经和甲状腺功能的损伤,降低术后并发症的发生率,且患者的围术期指标均显著改善。     

Computerized morphometric analysis of the fiber composition of the upper and lower laryngeal nerves in humans

Phonation troubles often arise after surgical operations on the antero-lateral region of the neck in which the recurrent laryngeal ILN), was respected. This fact allows to consider the possibility that the superior laryngeal nerve (SLN), contains also fibres responsible of the motor innervation of some intrinsic muscles of the larynx. According to the suggestion that the fibre-analysis may permit to distinguish a motor from a sensory nerve (Tomasch and Schwarzacher), a computerized morphometric analysis on the fibres of the superior and inferior laryngeal nerves in the man was carried out. The nerves investigated were taken away from five patients subjected to a total laryngectomy. The fibre perimeter and the maximum diameter were evaluated in 1500 fibres in each nerve. The histograms of the obtained data shows that: 1) Two groups of fibres are distinguishable in the SLN: the first is composed by small diameter fibres that show one spike for both the parameters considered. The second group of larger fibres shows a lower spike with a larger basis. 2) In the ILN only a spike corresponding to the greatest fibres we observed for both the parameters considered. In conclusion it seems that the number of fibres of large diameter present in the SLN can justify a motor function of this nerve for some intrinsic muscles of the larynx other than the cricotiroideus.     

Anomalous pattern of median artery in the forearm of Indians

Various anomalous relations between the brachial plexus or its branches and arteries are reported. The present study was conducted on 134 limbs to note the origin and course of the median artery and its relation to the median nerve. In 2 limbs (1.5%), the median artery split the median nerve into two roots in the forearm and the artery passed through the nerve. In both of these limbs (1.5%), the median artery arose from the ulnar artery. The median artery in these 2 limbs (1.5%) was considerably large and supplied the hand. Both the origin of the median artery from the ulnar artery and the splitting of the median nerve by the median artery are rare anomalies which have not been reported in the available literature.     

高频超声与喉镜检查对甲状腺癌侵犯喉返神经的术前评价价值分析

目的:比较高频超声与喉镜检查对甲状腺癌侵犯喉返神经(recurrent laryngeal nerve,RLN)的术前评价价值。方法:选择2012年2月到2019年8月在本院进行诊治的甲状腺癌患者207例,采用高频超声与喉镜进行术前评估侵犯喉返神经情况,记录超声特征并判断诊断价值(以病理检查作为金标准)。结果:在207例甲状腺癌患者中,术后病理学证实喉返神经侵犯52例(侵犯组),转移率为25.1%。侵犯组的性别、年龄、发病位置、体重指数、病程等与非侵犯组患者对比差异无统计学意义(P0.05)。侵犯组超声显示病灶形态、内部回声、边界、钙化、晕环等特征与非侵犯组对比差异有统计学意义(P0.05),主要表现为侵犯组的病灶形态不规则、无晕环、无钙化、边界不清晰、内部高超声均显著高于非侵犯组(P0.05)。侵犯组的峰值强度(Peak intensity,PI)值高于非侵犯组患者(P0.05),两组达峰时间(Peak time,TP)与AUC值对比差异无统计学意义(P0.05)。在207例患者中,高频超声判断为喉返神经侵犯43例,喉镜判断为喉返神经侵犯39例,高频超声与喉镜检查对甲状腺癌侵犯喉返神经的术前诊断敏感性为97.7%和97.4%,特异性为93.9%和91.7%,高频超声诊断的敏感性和特异性比喉镜检查稍优。ROC曲线显示高频超声诊断的AUC为0.903,喉镜检查的AUC为0.860。结论:高频超声与喉镜检查对甲状腺癌侵犯喉返神经的术前评价的应用价值相当,均有很高的敏感性与特异性,能准确反映患者侵犯喉返神经的情况。     

Gross (mesoscopic) and applied anatomy of the anterior inferior cerebellar artery in man with special reference to its course through the cerebellopontine angle region.

In the present paper, we describe anatomical variants of the anterior inferior cerebellar artery in man for applicative purposes. Our goal was to provide the surgeon with a detailed anatomical view of the region. This is similar to what he may observe through the surgical microscope using modern microsurgical techniques. We have focused our attention on the segments of the artery comprising its origin, its course until it reaches the cerebellum and its main collateral branches. Our results confirm the great variability of the elements under study, but enable the establishment of a few basic variational patterns. These patterns together with their relative frequency may be helpful in microsurgery.     

The anterior tibial artery flap: anatomic study and clinical application

Satisfactory replacement of skin defects over the lower leg remains a difficult problem. Various forms of coverage, including, local rotation flaps, muscle flaps, and fascial and free flaps, have their specific indications and inherent disadvantages. In this work, a new axial skin flap based on perforating vessels in the territory of the anterior tibial artery is described. A series of 50 lower leg dissections was carried out in 25 fresh cadavers after latex injection into the femoral artery. Detailed studies of the cutaneous distribution of the anterior tibial artery showed that three main arteries perfuse the anterior lateral portion of the lower leg. The superior lateral peroneal artery and the inferior lateral peroneal artery interseptal cutaneous perforators arise at an average of 25.6 and 17.2 cm from the lateral malleolus, respectively. The superior lateral peroneal artery was present in 100 percent of the specimens, whereas the inferior lateral peroneal artery was present in 70 percent of the specimens. In their course, they give several muscular branches to the peroneus longus and brevis prior to perforating the fascia and arborizing in the subcutaneous tissues of the anterolateral portion of the leg. The average external diameter was 1.6 cm for the superior and 1.4 cm for the inferior lateral peroneal artery. The superficial peroneal nerve accessory artery is the third artery which contributes to the skin of the lower leg. It arises from the superior lateral peroneal artery in 30 percent of cases, from the inferior lateral peroneal artery in 40 percent, and from both in 30 percent. The artery runs along with the superficial peroneal nerve and gives several cutaneous perforators along its descending course. Several cutaneous axial flaps can be fashioned around this anatomy. The operative technique along with demonstrative clinical cases is presented followed by pertinent discussion.     

Formaldehyde induced catecholamine fluorescence in the mouse inferior laryngeal paraganglion

Summary The presence of high concentrations of catecholamines is shown in the mouse's inferior laryngeal paraganglion by means of fluorescence histochemistry. In mice, the entire organ is composed of 20 to 25 small, intensely fluorescent cells of oval shape (about 15 m in diameter). The paraganglion is well provided with capillaries. The identification of catecholamines in the inferior laryngeal paraganglion, originally described as nonchromaffin (parasympathetic) paraganglion, presents additional evidence that all paraganglia store biogenic amines, are related to the sympathetic nervous system, and belong to the APUD cell series.Supported by the Deutsche Forschungsgemeinschaft, Project No: Bo 525/1     

Arterial blood supply to the laryngeal part of the pharynx]

The sources, anastomoses and variations of bloodsupply of the laryngeal part of the pharynx were studied in 100 corpses of different sex and age. It has been established that the fronto-lateral divisions of the laryngeal part of the pharynx are supplied with blood by pharyngeal branches of the superior and inferior paryngeal arteries. Ligation of the pharyngeal arteries during laryngectomy prior to their entering the larynx, i. e. before the divergence of the pharyngeal branches from them, as conventional, causes restriction of supply of these parts and can contribute to disjunction of the pharyngeal suture. The trunks of laryngeal arteries with their pharyngeal branches should be preserved, if possible. The posterior wall of the laryngeal part of the pharynx is divided into three zones depending on the main arterial sources (the ascending pharyngeal, superior and inferior thyroid arteries).