Portuguese Version

Year:  2003  Vol. 69   Ed. 2 - (4º)

Artigo Original

Pages: 166 to 173

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Study on the microvascularization of the human vocal cord with cyst and contralateral nodule reaction by rigid laringeal endoscopy

Author(s): Jeferson Sampaio D'Avila[1],
Luiz Ubirajara Sennes[2],
Domingos Hiroshi Tsuji[3]

Keywords: vocal folds, microvascularization, rigid and contact endoscopy, cyst and nodular reaction.

Abstract:
Aim: The aim of this study was to analyze microvascular alterations that occur in the human vocal fold (VF), when damaged by cyst and contralateral nodule reaction. Material and Method: Through laryngoscope of suspension the VFs were analyzed by rigid endoscopy in anterior, medium, posterior and subglotic regions. The microvascular alterations were classified in four major groups: parallel, transversal, branched and puntiform. Theses were subdivided into twelve types. Result: In VFs damaged by cyst, the microvascular alterations were more frequent (93,1%) rather than in contralateral VFs damaged by nodule reaction (6,9%). In the occurrence of cyst were also observed multiple microvascular alterations (10 subtypes), having prevalence of sinuous and ectasical microvessels, while in VFs damaged by contralateral nodule reaction these microvessels alterations were less varied (3 subtypes). When straight related to nodular lesion, those were exclusively puntiform. Conclusion: Our findings emphasize that the presence of cyst in the blade itself interferes in the arrangements of the microvessels of the VFs, while nodular reaction that compromises the epithelium, which is more superficial than the vessels, interferes in a minor degree in the vascular architecture. Therefore in the occurrence of altered microvessels diagnosis of the cyst in more likely rather than the nodule reaction.

Introduction

Human vocal fold (VF) microvascularization is modified by the presence of organic abnormalities. The microvascularization, if normal, is classically formed by vascular arches in which the tendency to parallelism of vessels in relation to the longest axis of the VF is the main characteristic1. Laryngeal intra-operative endoscopy, either rigid (REMS) or contact (CEMS)2, enables the anatomical and histology analysis of the superficial laryngeal layer in situ and, specifically, in vivo. However, they have to be analyzed under general anesthesia, as part of suspension laryngology 3. Therefore, it is clear that they should no be conducted in normal patients, without diagnostic and/or surgical purposes indicating suspension laryngology. REMS provides differentiated visual characteristics that vary with the angle of the objectives2. The contact endoscope has a regulating handle for the focus and magnification of 60 to 150 times, requiring direct contact with the tissue2.

VF cyst is a congenital or acquired abnormality that affects the VF submucosa causing bulging of the epithelium and phonation abnormalities. The definite treatment is surgical. Even though cysts are frequently unilateral, the contralateral VF is almost always affected4. Since there is contact of both VF during phonation, the bulging determined by the cyst traumatizes the contralateral VF leading to onset of nodular reaction5, 6. Both the structural abnormalities that predisposes to its onset and the inflammatory process resultant from the phonation trauma can lead to microvessel abnormalities of the VF 7.

The purpose of the present study was to analyze the microvascularization of human vocal folds affected by cysts and to compare them to the contralateral vocal fold affected by nodular reaction in vivo and in situ using rigid and contact laryngeal endoscopy.

Material and Method

During January 1997 to July 2001 we selected 36 (thirty-six) patients with unilateral VF cyst and contralateral nodule reaction. Ages ranged from 8 to 57 years, mean age of 29.33 yeas and median of 31.50 years. As to gender, 24 patients were female and 12 were male subjects. We included only patients with complaints of marked chronic dysphonia, who presented unilateral VF cyst on videostroboscopic exam and contralateral nodular reaction with indication of surgical treatment. Cysts were considered as the presence of intracordal damage determining bulging of the mucosa and silent zone at stroboscopy, with formation of irregular or double spindle vocal chink. The contralateral nodular reaction was defined as the presence of epithelial thickness in a symmetrical position to the cyst, of smaller volume and without impairing the mobility of the mucosa at stroboscopy. The diagnostic confirmation was intra-operative, upon confirming the intracordal cystic damage aspects and contralateral epithelial thickness through microscopy, REMS and palpation. The cases that presented silent zone without bulging and had to be submitted to surgical exploration to have confirmed the presence of cyst and contralateral nodule reaction during the intra-operative period were also included in the study, regardless of its congenital or acquired nature.

We excluded patients who had bilateral cysts, history of chronic laryngitis, laryngeal disease by gastroesophageal reflux, tumors, traumas, laryngeal paralysis or stenosis. We also excluded patients previously submitted to laryngeal microsurgery, radiotherapy or prolonged intubation.

All patients were had complete anamnesis, according to the protocol, being compiled as data relative to age and gender. They were all submitted to suspension laryngology under general anesthesia, with REMS with rigid endoscope branded Karl-Storz. As the main objective of the study was to assess the microvascularization of the VF before any manipulation, we conducted an inspection using EMS, with the rigid endoscope utilization sequence of 0o, 30o, 70o, and 120o and the contact was 0º.

In order to standardize laryngeal analysis, to analyze the upper border, free borders and inferior border (subglottis) of the VF, the exam was divided into three parts:

a. Step 1 - Panoramic assessment of the glottic region (Figure 1).
b. Step 2 - Specific assessment of the glottic region, which was subdivided into 3 areas:

 Area I: corresponds to anterior commissure and anterior thirds of the VF (Figure 2).
 Area II: corresponds to the middle third of both vocal folds (Figure 3).
 Area III: corresponds to the posterior glottic region, especially on the posterior third of the VFs and the arythenoid regions (Figure 4).

c. Step 3 - Assessment of the subglottic aspects of the VFs (Figure 5).

a) Parallel: those that tend to parallelism concerning the VF longest axis, but with anatomical vascular defects:

a.1) Amputated Parallel: presents a sudden interruption.
a.2) Ectasic Parallel: presents widening in its gauge (Figure 6).
a.3) Mild Tortuous Parallel: despite parallelism tendency, it presents tortuous character.
a.4) Corkscrew Tortuous Parallel: despite the parallelism tendency, has marked tortuous appearance with a corkscrew aspect.
a.5) Parallel in Loop: forms a loop.
a.6) Parallel with anastomosis: presents lateral communication with other parallel vessels, forming a vascular network.

b) Transversal: those that present tendency to be perpendicular to the longest axis of the VF, but have anomalies of shape and/or quantity.
b.1) Single Transversal Sinuous: when it presents one single tortuous character (Figure 7).
b.2) Multiple Transversal Sinuous: when it presents multiple tortuous aspects, regardless of quantity.

c) Punctiform: when the microvessel presents the aspect of small hemorrhagic vessels. It is divided into:
c.1) Single Punctiform: when it is isolated and single (Figure 8).
c.2) Multiple Punctiform: when it presents multiplicity.

d) Ramified: when it presents ramifications, subdivided into:
d.1) Net Ramification: presents ramifications in small amount, forming a non-parallel vascular net.
d.2) Arachnoid Ramification: presents multiple and small ramifications coming from the concentric vascular point (Figure 9).

For the analysis of VF we separated the patients into two groups: Cyst group, corresponding to the VF affected by cyst, regardless of the side, and Nodular Reaction Group, corresponding to VFs affected by contralateral nodular reaction, topographically symmetrical.

We also individually analyzed the larynxes, correlating the findings of VF of those who had cysts and contralateral VF affected by nodular reaction, classified by areas and related to gender.

We used the chi-square and Fisher exact tests to check the presence of significant data, and adopted the significance level of 95% (p<0.05), as advocated by biological assay.

Results

The total number of abnormal microvessels found in the affected VFs by cysts and contralateral nodular reaction is represented in Table 1.

The occurrence of abnormal microvessels in VF affected by cysts and contralateral nodule reaction is represented in Graph 1.

The proportion of abnormal microvessels in VF affected by cysts and contralateral nodular reaction related to the areas is represented in Graph 2.

Table 1. Microvascular abnormalities observed in the vocal folds affected by cyst and contralateral nodule reaction.




Graph 1. Proportion of microvascular abnormalities observed in the vocal folds affected by cyst and contralateral nodule reaction.



Graph 2. Number of microvascular abnormalities observed in the vocal folds affected by cyst and contralateral nodule reaction, related by area.



Figure 1. Organ lesions and microvascular abnormalities detected by REMS 0° (arrow E - cyst and arrow D -contralateral nodule reaction). T -endotracheal tube.



Figure 2. Microvessel located in Area I and identified by REMS 30° (arrow - cyst). T - endotracheal tube.

Discussion

The laryngological semiotics is in a very advanced stage8, 9. Despite all technology advances, some laryngeal diseases are still difficult to define, such as differentiation of bilateral vocal nodules, bilateral cysts or unilateral cyst with contralateral nodular reaction10-16.

Since vascular abnormalities are intimately related with structural abnormalities and inflammatory diseases of the VF17-19, we studied the vascularization of the VF affected by unilateral cysts associated with contralateral nodular reaction (Figure 1).

Even though it would be ideal to compare the vascularization of the VFs with the control group of normal VF, it is not possible since REMS requires general anesthesia. Even if normal VF subjects were submitted to general anesthesia for any other surgical procedure, there would be no indication for the performance of suspension laryngology, which is a necessary condition for the performance of REMS. We are allowed to select patients that present a VF with cysts and another normal fold. However, the contralateral VF is almost always affected as well, resulting from the trauma applied to the normal VF, by the cyst bulging during phonation.

Since it is not possible to select a control group, we decided to compare VFs affected by cyst with contralateral affection by reaction nodular damage. These two conditions present distinct histopathology. Whereas the cyst affects the lamina propria where the VD vessels are located, the nodular reaction affects the epithelium which is superficial compared to the level of location of the blood vessels20. Therefore, we can analyze the vascular abnormalities resulting from different layers of the VF mucosa, which could justify the occurrence of larger amount of microvascular reactions following the cysts.

To that analysis, we used as the basic method the rigid endoscopy 2, 21, 23, since they allowed the assessment of vessels under magnification in vivo and in situ. Even though it is possible, such vessels are difficult to be detected under macroscopic assessment11.

Laryngeal vascularization presents specific characteristics. It derives from the external carotid arteries of the upper thyroid artery and the subclavial arteries (thyrocervical trunk) through the inferior thyroid artery which is close to the penetration in the organ, different from upper laryngeal, anterior-inferior and posterior-inferior arteries bilaterally1, 24, 25. In the VF assumes the distribution of vascular arches1, parallel to the free margin, followed by fibroelastic fibers, favoring the vibration movements of the vocal mucosa1, 26. In smaller amounts, some microvessels present transversal path to the long axis of VF, but they face the anatomical barrier of the vocal ligament, which is practically avascular and hinders the passage of vessels to the most superficial regions of the VF1, 26.

Anatomical anomalies of the VF mucosa, either congenital or acquired, can harm its vibration leading to dysphonia 18, 27, an occurrence observed in all patients of the present sample.

The VF vessels are located on the mucosal lamina propria, a layer located right below the vocal epithelium. The cyst is normally located in Reinke's space, which corresponds to the superficial layer of the lamina propria, which may reach the vocal ligament. This anatomical situation is related to the terminal and superficial portion of the vascular arches of the VF17, 28. Therefore, the cyst interacts directly with the vascularization, justifying the large number of abnormal vessels related to them.

This fact results from the mass effects caused by the cyst, displacing and blocking the microvessels of the lamina propria, or resulting from the primary irrigation nourishing the cyst, which does not respect the parallelism of the normal vessels. It would in part justify the heterogeneity of the types of microvessels observed in VF that contain cystic lesions (Table 1, Graph 1).

Figure 3. Microvessels locates in Area II and identified by REMS 0° (arrow E - cyst and arrow D -contralateral nodule reactions). T - endotracheal tube.



Figure 4. Microvessel located in Area III and identified by REMS 0° (arrow - cyst). T - endotracheal tube.



Figure 5. Microvessel located on the subglottic aspect of VF and identified by REMS 120°. T - endotracheal tube.



Figure 6. Ectasic parallel microvessel, identified by REMS 0° e CEMS, located in Area II.



Figure 7. Single Sinuous Transversal Microvessel, identified by REMS 0° and located in Area II.



Figure 8. Single Punctiform Microvessel, identified by REMS 70° and located in Area II.



Figure 9. Arachnoid Ramified Microvessel, identified by REMS 0° and CEMS; located in Area I.

Conversely, the reaction nodule lesions that affect the cyst contralateral VF are located on the external layer, that is, on the region of the epithelium, and they can reach the basal membrane5, 17, 27-29. Considering that this anatomical area is practically avascular, the likelihood of having affection to the normal distribution of vessels caused by the presence of nodular lesions is minimal, even when the cyst trauma during mucosa vibration can generate an inflammatory process. It justified the small number of abnormal microvessels observed in VF with nodular reaction detected in our assessment (Table 1, Graph 1).

The characteristic symptomatologic manifestation of organic lesions (cyst and contralateral nodular reaction) is dominated by dysphonia, exactly by the interposition of such lesions upon phonation. Since the cyst is frequently followed by vascular abnormalities, it is possible that they can harm the vibration of the vocal mucosa, contributing to the dysphonia2, 18.

The medium third of the VF was the most affected region by cysts and nodular reactions and also where we observed most of the vascular abnormalities (Figure 3). Such findings are in accordance with those by Pontes et al. (1994), who observed in this region a greater concentration of vessels in outpatient videoendoscopic exams. In addition to the possible structural etiology of the cyst (congenital), possible phonation traumas, repetitive infections and fistulations can lead to vascular abnormalities or exacerbate preexisting abnormalities29, 30. Therefore, we studied not only the region in which there was a lesion, but also the adjacent regions. Through such analysis, we assessed areas I, II, III and subglottic that also corresponded to the anterior, middle and posterior regions, in addition to subglottic aspect of the VFs (Figure 2 to 5).

REMS has telescope lenses with varied angles providing, in addition to proximity, a detailed analysis of the difficult-to-access areas of the endolarynx, enabling better analysis of the vascularization 2 (Figure 6).

To describe microvessels, we systematized a descriptive nomenclature of the various vascular abnormalities, based on previous publications7, 11, 19 and on the experience of the authors. In the studied literature, this nomenclature is variable using general terms such as ectasis, varices, vascular cord and hemorrhage for similar conditions.

In order to facilitate the understanding of the morphology of each abnormal microvessel, we created our own nomenclature. Of the total of 145 microvascular abnormalities detected, 135 (93.1%) were related to the cyst and 10 (6.9%) were related to the contralateral nodular reaction. We detected 10 types of microvascular abnormalities in the presence of cyst. Mild tortuous parallel microvessel was the most frequent one, followed by single sinuous transversal and ectasic parallel (Figure 6). Despite the prevalence of some microvascular abnormalities over the others, and the statistically significant differences, we could not overvalue them because of the less prevalent ones. The less prevalent microvessels can also be observed in other diseases and even be typical of the VF affected cyst (Figure 1). More specific studies about cysts and its comparison with other organic lesions will be useful for future understanding.

The mild tortuous parallel microvessel was the most frequent type both in the cyst and nodular reaction, followed by a nonspecific aspect, which can be related to the inflammatory process that follows such diseases and not necessarily a specific damage (Figure 4). Sinuous transversal (single or multiple) and ramified (in net or arachnoid) microvessels were frequently related to cysts and could be considered a strong indicator of the disease (Figures 7 and 9).

It is important to point out that in the studied literature there is no record of microvascular abnormalities following nodular lesions. In addition to the mild tortuous parallel type, we observed the occurrence of the types single and multiple punctiform, being that such were exclusively detected in the nodular reaction, which can suggest the particularity in this type of organic lesions (Figure 8).

Other fact that could influence more or less in the occurrence of abnormal microvessels is patients' gender. Women are more susceptible to vascular abnormalities, such as capillary frailty and thrombosis, which could generate vascular abnormalities in VFs of female subjects. However, we did not detect such correlation.

Our findings reinforce the presence of lamina propria cysts that interfere in the arrangement of VF microvessels, which happens at smaller degree when in the presence of contralateral nodular reaction, which affect the VF epithelium that is more superficial in relation to the vascular conformation. Therefore, when faced by difficulties to differentiate bilateral cysts, bilateral nodules or unilateral cyst with contralateral nodular reaction, the observation of abnormal microvessels rather than punctiform ones at laryngoscopy or laryngostroboscopy strongly suggest the presence of cystic lesion.

Conclusions

The vocal folds that are affected by cysts present more frequent and more varied microvascular abnormalities, than the contralateral vocal folds affected by nodular reaction. Whereas there is the predominance of tortuous and ectasic microvessels in the presence of cysts, there are punctiform vessels that occur exclusively in the nodular lesions.

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1 Professor, Head of the Discipline of Otorhinolaryngology, President of CEAOF/Sergipe, Master in Otorhinolaryngology, PUC-RJ, Ph.D. in Otorhinolaryngology, USP-SP.
2 Full Professor in Otorhinolaryngology, USP-SP, Full and Associate Professor, Discipline of Otorhinolaryngology, USP-SP.
3 Ph.D., in Otorhinolaryngology, USP-SP, Full Professor of the Discipline of Otorhinolaryngology, USP-SP.
Address correspondence to: Jeferson Sampaio D'Avila - Av. Beira Mar, 1270 ap. 1001 Aracaju Sergipe 49020-010
Tel (55 79)211-0609/ 211-1047 (C) - Fax (55 79)211-0978 - E-mail: jefersondavila@bol.com.br
Article submitted on December 18, 2002. Article accepted on February 27, 2003.

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