[The hyoid bone and its preservation in the framework of supraglottic partial resection of the larynx]. / Das Zungenbein und seine Erhaltung im Rahmen der supraglottischen Teilresektion des Kehlkopfes.

BACKGROUND: Whether to remove the hyoid bone as part of the horizontal partial laryngectomy is a question which is discussed controversially. Pathohistological examination of the region involved should help to answer this question. MATERIAL AND METHODS: Regarding the involvement of the hyoid bone, 71 surgical specimens of supraglottic carcinoma invading the pre-epiglottic space were studied by whole-organ serial sections. RESULTS: Only four specimens demonstrated mandatory resection of the hyoid bone because of its proximity to the advancing border of the tumor. In these cases, large tumor masses were palpable directly under the thyrohyoid membrane after the strap muscles had been dissected during the operation. DISCUSSION: Except for these rare cases in which the tumor was already palpable from outside the larynx, preservation of the hyoid bone during horizontal supraglottic laryngectomy is oncologically safe. It provides a more secure closure of the pharyngotomy and promotes earlier return of the swallowing function because of the maintenance of the normal position of the larynx and pharynx.

Glottic-supraglottic barrier: fact or fantasy?

An anatomic structure that might act as a barrier between the glottic and supraglottic areas has never been demonstrated in whole organ serial section studies. Nevertheless, most squamous cell carcinomas arising on the supraglottic mucosa remain confined above the ventricle, and this fact is reflected in the high rate of local control obtained by surgeons performing horizontal supraglottic laryngectomy: 80.6% to 98%. Whole organ sections of laryngectomy specimens suggest that a tumor situated above and below the glottic level may have arrived there not by crossing the ventricle, but by encircling it. In so doing, part of the tumor is visible posterior to the ventricle or on the arytenoid cartilage-a finding that contraindicates conventional supraglottic laryngectomy, with or without limited mobility of the true vocal cord.

Relative prognostic importance of histologic invasion of the laryngeal framework by hypopharyngeal cancer.

This study assessed the relative prognostic importance of histologic invasion of the laryngeal framework by hypopharyngeal cancer. The laryngeal specimens and medical records of 55 patients found to have primary hypopharyngeal cancer between 1962 and 1988 were reviewed. Full 3-year follow-up information was obtained for 51 patients. The overall 3-year survival rate was 43% A(22/51). The 3-year survival rate was 55% (17/31) without histologic invasion versus 25% (5/20) with invasion (p < .05). To assess how invasion affected survival rates in conjunction with clinical predictors, we divided the cohort into two groups (mild versus severe illness) based on the presence or absence of anemia and comorbidity. Only in the group with mild illness did histologic invasion provide additional prognostic information. These results demonstrate that the inclusion of clinical variables in predictions of prognosis can strikingly alter the prognostic importance of invasion of the laryngeal framework.

Hyoepiglottic ligament in supraglottic cancer.

The hyoepiglottic ligament (HL) is a connective tissue structure that serves as the roof of both the paraglottic and the preepiglottic spaces and thereby anatomically separates the supraglottic larynx from the tongue base. Whole mount serially sectioned larynges with supraglottic cancer were reviewed to help clarify cephalad spread of cancer in this region. The whole mount slides were analyzed from 70 laryngectomy specimens that were resected for supraglottic cancer. The HL was breached by cancer in 13 specimens, and all of these displayed clinical and histopathologic invasion of the preepiglottic and paraglottic spaces. Invasion of the suprahyoid epiglottis was noted in 9 specimens, and invasion of the aryepiglottic fold in 4. There were no instances in which cancer escaped from the deep compartments of the supraglottic larynx to the tongue base without synchronous erosion of the suprahyoid epiglottis (insertion of the medial HL) or the pharyngoepiglottic fold (lateral HL). The HL is a resilient connective tissue barrier to the spread of cancer from the supraglottis to the tongue base. This investigation reinforced the concept that, typically, the HL acts as a deep cephalad surgical boundary in resecting supraglottic cancer that 1) is confined to the laryngeal membranes and 2) does not clinically invade the suprahyoid epiglottis.

Joseph H. Ogura Memorial Lecture. The vertebrate larynx: adaptations and aberrations.

The complex anatomy of the vertebrate larynx shows a steady progression from the simple slit on the floor of the lungfish's pharynx to the fine-tuned mechanism of the human vocal apparatus. The frog's larynx acts as a check valve to prevent collapse of the lungs during a dive, since the animal has no rib cage. The crocodile's laryngeal framework has acquired an epiglottic analogue which fits snugly into the nasopharynx and protects the lower respiratory tract from inundation while the animal drowns its prey. The snake's larynx lies intraorally and can be extended beyond the lower teeth while the reptile leisurely swallows its prey intact. The mammal has acquired a cricothyroid joint, allowing its membranous vocal folds to be stretched during phonation. In Homo sapiens, vocal performance has reached its highest degree of versatility, with a vocal fold capable of adjustment in length, tension and shape. In the course of organic evolution, man appears to have chosen the ability to speak and sing over the security that an intranarial epiglottis would have given him.

Pattern of gross displacement of the vocal fold in adduction and abduction movements.

The pattern of gross displacement of the vocal fold during adduction and abduction was studied in 4 adult fresh human larynges (2 males and 2 females). Markers were placed on specific sites along the edge of the vocal fold. Preliminary observations showed upward and lateral movement of the free edge during abduction. The vocal fold as a whole glides into and fills the cavity of the laryngeal ventricle. To quantify this observation 14 larynges (8 males and 6 females) were studied, using a technique designed to measure vertical and horizontal displacement of the vocal fold. An average of a 1.34 mm elevation and 4.43 mm lateral excursion were observed at midvocal fold level. A model for studying the pattern of vocal fold abduction is suggested and discussed.

Histo-anatomical structure of the human laryngeal ventricle.

A study of the microstructure of the human laryngeal ventricle and ventricular band was carried out on 20 human larynges in an attempt to up-date and elucidate the function of these structures. Celloidin and paraffin whole organ coronal serial sections were studied to clarify the epithelial, glandular as well as muscular structures of the ventricle and ventricular band. The present study showed that the superior thyro-arytenoid muscle was bilaterally present in 80% of cases. On the other hand, the ventricularis muscle was bilaterally present in 95% of cases. These ventricular muscular elements have been reported differently in the literature. The functional significance of these variations are discussed. The opening of the saccule into the ventricle is guarded anteriorly by the ventriculo-saccular fold. This fold was present in 19 out of 20 larynges. Neither the percentage of its presence, nor its orientation to the saccular opening has been reported in the literature. The function of this structure is discussed in the light of the present data.

The nasogastric tube syndrome.

The nasogastric tube can produce sudden, life-threatening bilateral vocal cord paralysis and is often an unrecognized cause of this clinical entity. The pathophysiologic mechanism is thought to be paresis of the posterior cricoarytenoid muscles secondary to ulceration and infection over the posterior lamina of the cricoid. Since our initial report of this entity in 1981, several cases have been photo-documented. Study of whole organ sections of an involved larynx have demonstrated the histopathology. Diabetic renal transplant patients appear to be particularly susceptible to the condition, due to prolonged gastroparesis and requirement for nasogastric tube drainage. Esophagoscopy should be performed promptly in these patients when pharyngodynia, hoarseness, or evolving stridor present in the postoperative period.

Laryngeal chondrosarcoma: incidence, pathology, biological behavior, and treatment.

Chondrosarcoma is the most common mesenchymal tumor of the larynx and approximately 200 cases have been collected in the world medical literature. It is less aggressive in the larynx than elsewhere: cervical or distant metastases are rare (8.5%), and although local recurrences are not uncommon, they are not catastrophic. A retrospective study was made on eight cases of laryngeal chondrosarcoma. Three cases had originally been diagnosed as idiopathic vocal cord paralysis, possibly because of early involvement of the cricoarytenoid joint or the distal portion of the recurrent nerve. This fact emphasizes the need for accurate laryngeal computed tomography in cases of vocal cord paralysis of unknown origin. Surgical excision is the treatment of choice for laryngeal chondrosarcoma, and conservative techniques may sometimes be appropriate. Supraglottic laryngectomy may be the technique of choice in the rare cases of epiglottic involvement.

Histology of Isshiki thyroplasty type I.

Isshiki thyroplasty type I, an open surgical procedure to medialize the true vocal cord, has been proposed as an alternative to Teflon injection in selected cases of recurrent nerve paralysis or vocalis muscle atrophy. This operation was performed in a man with a mediastinal tumor and a paralyzed vocal cord in an intermediate position. He died 1 month later, and his larynx and recurrent nerve were studied histologically. The gross and microscopic changes in the larynx caused by this operation are discussed, and the pathologic changes in the recurrent nerve leading to the paralysis are examined.

Fifteenth Daniel C. Baker, Jr, memorial lecture. What have whole organ sections contributed to the treatment of laryngeal cancer?

The study of whole organ sections of laryngectomy specimens has demonstrated the patterns by which cancer spreads from one part of the larynx and hypopharynx to another. These studies have also demonstrated the fibroelastic membranes and ligaments that form the boundaries of intralaryngeal compartments within which cancer is confined in its early stages. They thus have added support to the concept of partial laryngectomy for selected lesions and have illustrated the features of those types of laryngeal cancer that have not responded well to radiotherapy. Whole organ sections of laryngectomy specimens have allowed a more accurate interpretation of preoperative computed tomography and magnetic resonance imaging and have provided a reliable basis for clinical staging.

Anatomic foramina in the thyroid cartilage: incidence and implications for the spread of laryngeal cancer.

Anatomic openings in the posterosuperior portion of the thyroid lamina of the larynx were first described in the 19th century. In the present study of 121 coronally sectioned larynges, such openings were found in 47 (39%), appearing bilaterally in 15 and unilaterally in 32. In a separate study of 69 cadaver larynges, the openings were found in 39 (57%), appearing bilaterally in 16 and unilaterally in 23. In 51 laryngectomy specimens removed for squamous cell cancer and showing foramina, tumor was not observed to invade or traverse the foramen in a single case, even in those specimens with tumor overlying the foramen and displaying framework invasion at other sites. Invasion by cancer through the foramen appears to be prevented by a layer of fibroelastic tissue overlying the medial surface of the foramen, parallel to the inner surface of the thyroid lamina. This layer of fibroelastic tissue may represent perichondrium.

Intralaryngeal barriers to the spread of cancer.

Serial section studies were made of 412 surgical specimens removed by partial or total laryngectomy for laryngeal cancer. All sections were stained with hematoxylin and eosin. Selected sections were also stained for elastic tissue. Patterns of growth and spread of cancer within the larynx were found to be influenced by fibro-elastic ligaments and membranes which confined the tumor to anatomic compartments, and which provide margins of safety when performing partial laryngectomy.

A morphometric comparison of the changes in the laryngeal skeleton associated with invasion by tumor and by external-beam radiation.

Patterns of cartilage invasion by squamous carcinoma were examined in 40 laryngectomy specimens with particular reference to selective involvement of ossified cartilage. The study determines whether external radiation administered at therapeutic levels to the human larynx has selective effects on the osteoclast cell population and subsequent bone resorption. Radiated and nonirradiated tissues were compared as were cases with and without laryngeal framework involvement by cancer. Morphologic changes in ossified laryngeal cartilage showed that invasion is a largely indirect process dominated by local bone destruction with osteoclasts operating in front of the advancing tumor. Morphometric studies indicate that framework invasion correlates significantly with both increased numbers of osteoclasts and increased bone resorption. An original finding here was that radiation therapy resulted in similarly increased osteoclast activity among cases without framework involvement by cancer. In these cases radiation appeared to act independently of tumor in producing osteoclast activation.

Hunter's syndrome: a study in airway obstruction.

Hunter's disease is a genetically transmitted defect known to produce mucopolysaccharide infiltration of multiple organ systems. Upper airway obstruction is caused by an enlarged tongue, deformed pharynx, and short, thick neck. Its eventual lethal outcome by the second decade of life is known to result from an infiltrative cardiomyopathy leading to irreversible heart failure. Instead, our recent experience in the care of five patients with this disorder suggests the lethal event is related to progressive obstruction sequentially involving the upper, mid, and lower airway characterized by gradual deformation and collapse of the trachea. Autopsy and histopathologic whole organ sections demonstrate anteroposterior flattening of the trachea and bronchi with submucosal thickening producing structural alterations known only to this disease.

Avoiding problems in tracheotomy.

The surgeon can minimize postoperative problems that may develop after tracheotomy by 1. ligating the veins that cross the midline (over-dependence on cautery often results in postoperative bleeding); 2. dividing and suture-ligating the thyroid isthmus; 3. avoiding sharp dissection or blind clamping at the sternal notch; 4. leaving the deep layers of the wound open, to avoid subcutaneous or mediastinal emphysema; 5. avoiding a low horizontal skin incision; and 6. using guide sutures at tracheal opening in the infant.