Composite Hyoid-Sternohyoid Graft in the Correction of Established Subglottic Stenosis

A new technique for the treatment of subglottic stenosis is reported. A composite hyoid bone with sternohyoid muscle graft is used to replace the anterior arch of the cricoid, combined with a vertical split of the posterior lamina of the cricoid. Internal splinting is maintained with a Silastic mould. Ten patients with established subglottic stenosis, 7 from traumatic and 3 from non-traumatic causes, have been treated. All patients needed a tracheostomy for maintenance of an airway prior to operation. Nine patients were successfully decannulated two weeks after removal of the internal Silastic splint. Five of the 10 patients were children under the age of 13 years.

Novel management of an isolated comminuted cricoid cartilage fracture

Laryngeal trauma is a rare occurrence that can result in significant morbidity and mortality. Isolated cricoid cartilage fractures are exceedingly rare, and their treatment is highly variable. We describe a case of an isolated comminuted, uncalcified cricoid cartilage fracture in a 34-year-old man that responded well to novel management with suture and 2-octylcyanoacrylate tissue adhesive fixation intraoperatively and topical ciprofloxacin/dexamethasone applied to the airway postoperatively. We discuss the novel application of cyanoacrylate glue in laryngeal trauma and the potential benefits of topical ciprofloxacin/dexamethasone application to the airway.

Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral arytenoid dislocation

We report a case of cricoid cartilage fracture with unilateral arytenoid dislocation following a motorcycle accident. This 25 year old male sustained blunt injury to the head, face and neck. He presented late to the hospital with one week history of dysphonia. Laryngoscopy revealed cadaveric position of the non-functioning left vocal cord. CT and MRI showed laterally displaced left vocal cord. Displaced fractures were noted in the cricoid at the junction of lamina with the anterior arch on the left side and at the right side of the anterior arch, along with dislocated left arytenoid resulting in ipsilateral vocal cord palsy. Medialization thyroplasty was performed to improve his phonation. Laryngeal trauma warrants close monitoring because of the risk of airway compromise. Radiologists play a crucial role in early diagnosis and should always have high index of suspicion. Recognition of laryngeal injury is important for initial resuscitation as well as for long term airway and vocal function.

Cricoid chondronecrosis: a complication of endotracheal intubation

Stenosis of the subglottic area is a common complication of endotracheal intubation and external blunt trauma. Chondronecrosis of the cricoid cartilage is a rare but known complication of neck radiotherapy for laryngeal carcinoma. It has also been reported as a complication of prolonged endotracheal intubation. The clinical and bronchoscopic findings are non-specific and the diagnosis can not be accurately established without surgical evidence or computed tomographic (CT) findings. In addition to technical issues related intubation, multiple anatomic and host factors can contribute to the pathogenesis of this uncommon entity. In this report, we describe the clinical and radiographic findings of a recent case and review the literature. To our knowledge, this is the second case of cricoid chondronecrosis in an adult patient occurring after only a few hours of intubation.

Habitual non-traumatic cricothyroid joint dislocation: a rare case of rotated larynx

A case of a 21 year old gentleman is described, with no history of preceding trauma, presenting with intermittent dysphagia to solids and fluids for 4 years. Neck examination at rest was normal. However on deep inspiration, the right thyroid lamina protrudes or becomes more prominent. The patient is able to return the larynx to its normal position with manual manipulation. Laryngeal examination with fibreoptic scope during rest and deep breath shows gross rotation of the laryngeal structures for more than 60 degrees on deep breath, with the vocal cords axis rotated to the left side. Management was conservative.

Cricotracheal separation: a case of delayed diagnosis and treatment

A motorcyclist was involved in a motor vehicle accident and presented with respiratory distress and neck swelling with surgical emphysema. He sustained gross tracheal injury, severe pneumothoraces and lung contusions. As intubation was successful, the tracheal injury was not addressed immediately in view of the other severe respiratory problems. Evidence of aspiration lead to further investigations which confirmed the diagnosis 22 days post trauma. Thyrotracheal anastomosis was carried out without stenting. A complete cricotracheal separation is a rare event and can be easily overlooked in the emergency department.

Suspicion of cricohyoidopexy line rupture after supracricoid partial laryngectomy and the value of computed tomography to exclude this complication

We presented a 48-year-old man who underwent supracricoid partial laryngectomy with cricohyoidoepiglottopexy. He developed diffuse subcutaneous emphysema and saliva aspiration on the first postoperative day, arousing suspicion of a pexy line rupture. Palpation of the cricohyoid suture line and a lateral cervical X-ray were not helpful. Laryngeal computed tomography (CT) obtained demonstrated an undisturbed cricohyoidoepiglottopexy suture line. Some of the neck sutures were removed, a drain was placed under the neck flap, a tight dressing was applied, and surgical exploration was not necessary. Subcutaneous emphysema regressed in the following days and no other problem was seen. Subcutaneous emphysema was attributed to the air escape from the cricohyoid approximation line. Following supracricoid partial laryngectomy, rupture of the cricohyoidopexy line is a rare but serious complication that needs urgent exploration. Therefore, when there is suspicion, laryngeal CT is very important to rule out this condition. Moreover, a close cooperation is necessary with the radiologist who may not be familiar with disturbed anatomy by previous surgery.

Isolated cricoid fracture associated with blunt neck trauma

A 32-year-old woman without a remarkable history presented at the emergency department with strangulation of the neck. CT scans of the neck revealed a displaced cricoid fracture. Six days after admission to hospital, hoarseness and dyspnoea disappeared. On the 10th day, the patient was discharged without complications. The traditional treatment guidelines for laryngeal trauma have recommended an early surgical intervention after immediate tracheotomy in cases of displaced fractures of the cricoid cartilage. The patient could be treated successfully through continuous monitoring of airway obstruction without surgical management.

Changes in the Cricoarytenoid Joint Induced by Intubation in Neonates

OBJECTIVE

To characterize the histopathologic characteristics of the cricoarytenoid joint (CAJ) as a means to understand the mechanisms of vocal cord fixation in children after prolonged intubation.

DESIGN

Histologic analysis of laryngeal specimens obtained from infants who had died secondary to various causes and who had been intubated from 1 to 30 days.

MAIN OUTCOME MEASURE

Histopathologic characteristics of CAJ.

RESULTS

Laryngeal specimens from infants who had been intubated for prolonged periods of time demonstrated evidence of hemorrhage, infection, inflammation, and fibrosis within the CAJ. Furthermore, a statistical correlation was found between the length of intubation and the presence of these histologic abnormalities.

CONCLUSIONS

To our knowledge, this is the first study to demonstrate histologic changes in the CAJ in laryngeal specimens of children who have been intubated for prolonged periods of time. Such histological changes in the CAJ could explain the mechanism of vocal cord immobility in children after intubation.

[Quarter section cricoid split: its effect on cartilage growth in rabbits]

OBJECTIVE

To investigate the effect of the quarter-section cricoid split on cartilage growth.

METHOD

The rabbits were killed 8 months after surgery of anterior, anteroposterior and quarter section cricoid split. The larynxes were harvested and the cross sectional areas of the cricoid cartilage were calculated.

RESULT

There was no significant in the cross sectional area of the cricoid cartilage of any of the four groups.

CONCLUSION

The quarter section cricoid split has no adverse effect on subsequent growth of cricoid cartilage and animals.

Non-intubation traumatic laryngotracheal stenosis: management policies and results

Traumatic laryngotracheal stenosis (LTS) is increasing in clinical practice. Causes include external trauma, post-intubation, and iatrogenic injuries. It is a complex problem and many patients undergo multiple procedures to achieve a stable and well-protected airway with adequate voice. We present our experience at Ain-Shams University Hospitals on 15 patients followed-up for 7 years. All patients had traumatic LTS excluding post-intubation injuries. Patients were aged 4-58 years. Nine were the victims of road traffic accidents; five were occupational trauma victims; and one tried to commit suicide by strangulation. The patients underwent a total of 53 procedures (mean 3.5 per patient). A total of seven laryngotracheal reconstruction, six partial cricotracheal resection, and four laser recanalization with stenting were performed. Six patients have mean follow-up of 26.5 months (3-60 months). Six patients had normal speech (GRBAS 0-5), three had a moderate degree of voice disturbance (GRBAS 5-10), and five had severe dysphonia (GRBAS > 10). As regards tolerance for daily activities, we used a modification of the McMaster University asthma quality of life questionnaire [Rea et al. Eur J Cardiothorac Surg 22(3):352, 2002] (using the activities and emotional scores total 112). Four patients could perform above the 90th percentile; all the remaining patients were above the 50th percentile. No patient was totally handicapped as a result of their airway problem and they could tend for their basic activities. The aim of this work is to demonstrate that non-intubation traumatic LTS is a complex problem that usually needs a longer time for reconstruction and a different way of approach. However, most of the patients can be finally rehabilitated with a stable, protected airway and adequate voice albeit at the price of a prolonged series of interventions and a long follow-up.

Cricotracheal separation: a review and a case with bilateral recovery of recurrent laryngeal nerve function

Cricotracheal separation (CTS) is an uncommon injury, with a high index of suspicion required to establish the diagnosis. Computerized tomography (CT) plays a role in diagnosis but cannot necessarily be relied upon. Bilateral recurrent laryngeal nerve (RLN) palsies are usually associated with this type of injury. We recently treated a patient with CTS in whom one RLN was intact from the time of the injury and the other nerve recovered within three months. Computed tomography was inconclusive.

Early open repair of the injury and frequent follow-up examinations led to successful decannulation after six weeks and excellent short-term voice and airway outcomes.

A detailed discussion of this unusual case is followed by a review of the current literature on CTS, with particular emphasis on significant management dilemmas and controversies.

Clinical suspicion remains more sensitive than investigations in diagnosing CTS. Permanent bilateral RLN palsies are not inevitable following these injuries.

Internal fixation of comminuted cartilaginous fracture of the larynx with mini-plates

Acute laryngeal trauma is an uncommon injury. Such trauma is not generally encountered by oral and maxillofacial surgeons. We illustrate a patient who sustained a severe penetrating laryngeal injury. His subsequent management was optimised by the joint intra-operative surgical collaboration between otorhinolaryngology and maxillofacial disciplines.

Aphonia and dysphagia after gastrectomy

A 67-year-old male was referred to our otolaryngological clinic because of aphonia and dysphagia. His voice was breathy and he could not even swallow saliva following a total gastrectomy for gastric carcinoma performed 2 weeks previously. Laryngeal fiberscopy revealed major glottal incompetence when he tried to phonate. However, both vocal folds abducted over the full range during inhalation. The patient could not swallow saliva because of a huge glottal chink, even during phonation. Based on these findings, he was diagnosed as having bilateral incomplete cricoarytenoid dislocation after intubation. The patient underwent speech therapy; within 1 min his vocal fold movement recovered dramatically and he was able to phonate and swallow. There have been few case reports of bilateral cricoarytenoid dislocation, and no effective rehabilitation has been reported. We believe that our method of vocal rehabilitation serves as a useful reference for physicians and surgeons worldwide.

Effect of recombinant human BMP-2 on the repair of cricoid cartilage defects in young and adult rabbits: a comparative study

OBJECTIVE

The study evaluated the possible differences in the repair of cricoid cartilage defects treated with recombinant human BMP-2 in young and adult rabbits.

METHODS

A cricoid defect rabbit model was used. Thirty rabbits were randomly divided into eight groups. Two groups of young rabbits and two groups of adult rabbits were treated with rhBMP-2 delivered on an absorbable collagen sponge, while the other two groups of young rabbits and two groups of adult rabbits were used as controls. The rabbits were killed at 1 week or 4 weeks after surgery. A histomorphometric analysis and an evaluation of the expression of collagen types I, II, and X, and proliferating cell nuclear antigen as well as a study of distribution of calcified matrix, were performed.

RESULTS

rhBMP-2 induced a marked chondrogenesis in both experimental age groups. However, in young rabbits the newly formed cartilage appeared more elongate, and the length of perichondrium involved was greater. The host cricoid cartilage of adult rabbits was calcified in large areas and displayed a strong matrix expression of collagen type X as well as collagen type I in the perichondrium, compared to the cricoid of young rabbits. In spite of these differences no immunohistochemical differences were found in the newly formed cartilage of both age groups treated with rhBMP-2. The cricoid cartilage defect was filled with new bone at 4 weeks in both age groups treated with rhBMP-2. New bone tissue had a well-defined trabecular structure.

CONCLUSIONS

rhBMP-2 triggers appositional cartilage growth from the cricoid perichondrium of young rabbits more easily than from that of adult rabbits. The new bone induced by rhBMP-2 showed a similar immunohistochemical and morphological pattern in both age groups of rabbits.

[CT findings in isolated laryngeal trauma]

The purpose of this article is a retrospective analysis of cases with suspected laryngeal trauma. The clinical importance, possibilities and limits of computertomographic diagnostics in laryngeal trauma are discussed.

PATIENTS AND METHODS

Between 1992 and 2003 we performed high resolution computed tomography (CT) in 7 patients after an isolated laryngeal trauma with a standardized examination protocol.

RESULTS

Following CT findings we made: one fracture of the thyroid cartilage, two fractures of the cricoids cartilage, one luxation of the arytenoids cartilage and four extensive soft tissue swelling of the larynx. One of the patients showed no lesions on CT. In another patient we found an intensive increase of density of arytenoids cartilage as sign of an arytenoids necrosis.

CONCLUSION

High resolution spiral computed tomography is the method of choice to detect or exclude laryngeal fractures after an isolated neck trauma. Special parameters are necessary for detection of subtle pathological findings. In the estimation of mucosal or vocal cord changes the CT is inferior to endoscopy.

Intrinsic and extrinsic forces determine the distortion of the split cricoid ring

OBJECTIVE

An anterior cricoid split (ACS) causes an immediate distortion of the cricoid cartilage resulting in an anterior gap due to retraction of the cut ends. The objective of this animal study is to investigate: (1) to what extent the distortion after ACS is influenced by non-cartilaginous structures like tunica elastica, membranes, ligaments and muscles, which are connected to the cricoid; (2) how distortion is changing with further development; (3) in what way the distortion is affected by scoring of the internal surface of the cricoid; and (4) whether an immediate or late injury-induced distortion is related to age.

METHODS

Surgical interventions were performed in 20 young (8 weeks of age, 1300-1600 g) and 5 adult (28 weeks of age, 3500-4000 g) New Zealand White rabbits. The immediate effects were measured, and then the animals were followed for 20 weeks to study the long-term effects of the various procedures.

RESULTS

(1) The gap, immediately following an ACS, increased after additional transection of the cricothyroid ligament and the cricotracheal membrane, and even more when the cricovocal membrane was elevated from the inner surface of the cricoid arch. (2) The degree of distortion after various interventions in young animals appeared to increase substantially during further growth. (3) When the above-mentioned successive surgical steps were combined with scoring of the internal surface of the cricoid arch, a marked malformation of the split cricoid did develop with warping of the cut ends in lateral direction and a latero-cephalic rotation, the latter due to the action of the cricothyroid muscles. (4) The immediate distortion appeared to be similar in young and adult animals. During a follow-up of 20 weeks, a progressive distortion of the split cricoid ring was observed in the young growing rabbits. In adult animals, no significant progression of the distortion was found.

CONCLUSIONS

The immediate and long-term distortion of the split cricoid is determined by the release of intrinsic forces of the cartilage, and extrinsic forces from non-cartilaginous structures like ligaments, muscles, membranes and tunica elastica.

Structural characteristics of repair tissue of cricoid cartilage defects treated with recombinant human bone morphogenetic protein-2

We examined the structural characteristics of repair tissue induced by recombinant human bone morphogenetic protein-2 in a rabbit model of laryngotracheal reconstruction. Twenty-four New Zealand White rabbits were randomly divided into four groups of six rabbits. Two groups were treated with recombinant human bone morphogenetic protein-2 delivered on an absorbable collagen sponge, while two groups were used as controls. Rabbits were euthanized at 1 and 4 weeks after surgery. The larynx was removed, fixed, and sectioned. The sections were stained with hematoxylin-eosin, safranine O/fast green, and immunostained with an antibody for tissue inhibitor of metalloproteinases-1. In rabbits treated with bone morphogenetic protein-2, the defects were filled with new cartilage and bone at 4 weeks after surgery. There were no discontinuities or gaps at the margins of the cartilage defects. Proteoglycans were synthesized in new cartilage in rabbits treated with bone morphogenetic protein-2, and were present 4 weeks after surgery. The general aspects of the vascular pattern and the pattern of tissue inhibitor of metalloproteinases-1 expression were similar in control and treated rabbits, both 1 week and 4 weeks after surgery. The repair tissue induced by recombinant human bone morphogenetic protein-2 consisted of new cartilage and bone perfectly integrated with host tissue at the site of the cricoid cartilage defects. This new cartilage was able to mature and produce proteoglycans.

Unusual presentation of blunt laryngeal injury with cricotracheal disruption by attempted hanging: a case report

The management of a patient with traumatic disruption of the cricotracheal junction in an attempted suicide by hanging is described. Such injury is uncommon, and many patients die at the scene; detailed radiologic imaging is rare because of the urgency of airway management. The delayed complete disruption of the major airway in this patient allowed adequate imaging and corrective management. Associated soft-tissue injuries of the great vessels of the neck are also described.

[Voice evaluation after laryngeal trauma]

The authors present phoniatric voice assessment in 9 cases of laryngeal trauma. Vocal cord immobilisation due to iatrogenic cricoarytenoid subluxation was particularly considered.

[The valence of dilatational tracheotomy]

After standardizing surgical procedures around 1900 Shelden, Toye, Weinstein and Ciaglia developed the percutaneous dilational tracheotomy (PDT). At present it is recognized that about 50 % of the anesthesiological Intensive care Units (ICU) in Germany are using the PDT while favoring the Ciaglia-technique in the majority of cases. Further techniques are known as Griggs-, Fantoni-, Percu-Twist- and Blue-Rhino-method. Some of these are relatively new, therefore making critical comparison with other methods almost impossible due to lack of experience. The most feared complications of PDT are injury of the cricoid cartilage or of the rear tracheal wall as well as paratracheal positioning of a tracheotomy tube. Comparison between PDT and surgical techniques are difficult due to certain contraindications for PDT which are not valid for surgical procedures. Consecutively PDT will not be able to substitute surgical tracheotomy in the future. It furthermore can't be advocated as an alternative therapeutic option for mobile in-patients outside the ICU.

Arytenoid subluxation

BACKGROUND

Disruption of the cricoarytenoid joint is uncommon and possibly underdiagnosed.

AIM

To highlight the diagnosis of arytenoid subluxation and its management.

METHOD

Two case reports.

CONCLUSION

Arytenoid subluxation is a rare condition that should always be considered in patients presenting with symptoms following upper airway instrumentation or external trauma to the neck. Early diagnosis optimises the possibility of restoring normal voice and laryngeal function.

Age-related mechanisms of cricoid cartilage response to injury in the developing rabbit

OBJECTIVE

To evaluate age-related mechanisms of cricoid cartilage response to injury in an animal model.

STUDY DESIGN

A pilot study using monoclonal antibodies to chondrocyte proliferation markers collagen II, aggrecan, and proliferating cell nuclear antigen (PCNA) to evaluate age-related response of injured cricoid cartilage.

METHODS

Twenty-seven New Zealand white rabbits aged 4 weeks, 8 weeks, and 1.5 years were studied. Six animals in each age group underwent intracartilaginous injury through cricofissure and tracheofissure. Three animals of each group were used as control subjects. The animals were killed 4 weeks after injury, their cricoid cartilages harvested, and 7-microm sections of tissue obtained. The cricoid tissue sections were stained with immunofluorescent monoclonal antibody markers to collagen II, aggrecan, and PCNA.

RESULTS

In all age groups, no control animals had symptoms of airway compromise or immunohistochemical abnormality. For all three markers of chondrocyte proliferation, the 4-week-old animals showed markedly increased staining at the injured edges of cartilage. The 8-week-old animals showed mild increased extracellular staining, and the 1.5-year-old animals showed no increased staining compared with uninjured areas of the cricoid ring and with control animals.

CONCLUSION

There was a progressive, age-related attenuation of staining for markers of chondrocyte proliferation in the 8-week and 1.5-year-old rabbits compared with the 4-week-old rabbit cricoids.

Nasogastric tube syndrome: the unilateral variant

Nasogastric tube syndrome is an uncommon but a potentially life-threatening complication of nasogastric intubation. It presents as an acute upper airway obstruction secondary to bilateral abductor vocal cord dysfunction resulting from postcricoid chondritis. However, a unilateral variant has also been reported and may herald the development of bilateral pathology. The purpose of this report is to highlight early warning signals of impending crisis.

CLINICAL PRESENTATION

A case of unilateral vocal cord involvement secondary to postcricoid chondritis resulting from nasogastric intubation is presented. An additional feature, not reported previously, is the presence of two inflammatory nodular swellings over the cricoid cartilage.

Gross and histologic changes in the developing rabbit subglottis in response to a controlled depth of injury

OBJECTIVE

Our goal was to determine the effects of both perichondrial and intracartilaginous injury in the developing rabbit subglottis versus normal development.

DESIGN

We conducted a descriptive, pilot study of changes in the shape and histology of the subglottis after a controlled depth of injury in 27 New Zealand White rabbits, ages 4 weeks, 8 weeks, and 1(1/2) years.

INTERVENTION

Within each age group, 3 animals underwent no surgery, 3 underwent perichondrial injury, and 3 underwent intracartilaginous injury.

RESULTS

Perichondrially injured animals in the 4-week age group developed a marked abnormality in the shape of the cricoid cartilage in the injured region. Cartilage of the perichondriallly injured animals in the 8-week and 1(1/2)-year groups became histologically consistent with fibrous tissue. The cartilage of all animals that underwent intracartilaginous injury was replaced with fibrous tissue.

CONCLUSION

In this observational study, we identified 3 relevant findings. First, the responses of the cartilage to a perichondrial injury suggest that the luminal soft tissues may exert some morphologic control in developmentally young animals. Second, only the 4-week-old group's cartilage was tolerant of a perichondrial injury with continued growth of the ring. Third, no animal's cartilage could withstand an intracartilaginous injury regardless of age.

[Utility of spiral computed tomography in the study of dislocation of cricoarytenoid joint]

OBJECTIVE

To demonstrate the cricoarytenoid relationship presented with spiral computed tomography and to show that the reconstraction of arytenoid dislocation can be presented by using multiplanar reconstruction algorithms.

METHODS

Fifteen patients with arytenoid dislocation documented by fiberoptic laryngoscopy and strobovideolaryngoscopy and 10 normal person were displayed with spiral CT. A making design of our own has been used to diagnose arytenoid dislocation on axial CT image.

RESULTS

Dislocation of cricoarytenoid joint were consistently demonstrated on several of the overlapping thin axial reconstructions in each of the 15 patients, in whom asymmetry of the bilateral cricoarytenoid joints was noted on axial images. Especially, by means of ordinary protractor, it has been found on the glottic-fissure level that the basal angle of abnormal side in 8 patients is larger than the one of normal side, and smaller in 7 patients, the value-difference of two basal angles ranges from 5 to 45 in 15 patients, 13 of whom ranges from 10 to 30. Whereas right basal angle is equal to left one in 8 except 2 whose value-difference of two basal angles is very small, respectively 2 and 3, in 10 normal person. High-quality sagittal and coronal reconstructive images often were helpful in confirming or clarifying the complex arytenoid orientations.

CONCLUSION

The findings that two-side basal angle is not equal in triangle of glottic fissure can be used as a parameter to arytenoid dislocation. Spiral CT is a useful adjunct in diagnosing and treating dislocation of cricoarytenoid joint.

[Experimental study on repair of cricoid cartilage defect with cartilage grafts in rabbits]

OBJECTIVE

To investigate the effect of free cartilage fragment in repair of cricoid cartilage defect.

METHOD

One-third of cricoid cartilage was cut and repaired with free thyroid cartilage fragment and pedicled cartilage in rabbits. The pathological changes of the cartilages were observed.

RESULT

1. The free thyroid cartilage fragments were absorbed in two months, and were replaced by scars. 2. The pedicled cartilage fragments were not absorbed and healed with the cricoid cartilage. 3. No evidence of growth impairment of surgery-induced cricoid cartilage was observed.

CONCLUSION

In rabbits, both free cartilage fragments and pedicled cartilage fragments could repair the defect of cricoid cartilage effectively.

[The joint capsule of the cricoarytenoid joint: biomechanical and clinical aspects]

BACKGROUND

Impaired movement of the cricoarytenoid joint with hoarseness and immobility of the vocal ligament may occur as a consequence of laryngeal trauma and joint disease. Little is known to date about the cricoarytenoid joint capsule and its role in joint pathology.

METHODS

The present study analyses the structure of the cricoarytenoid joint capsule by means of histological, immunohistochemical, and scanning electron microscopical methods. Investigations are performed on larynges of 17 male and 16 female.

RESULTS

The cricoarytenoid joint was found to be lined by a wide and lax joint capsule consisting of a fibrous and a synovial membrane. The capsule was strengthened posteriorly by the cricoarytenoid ligament. As like the fibrous membrane the cricoarytenoid ligament consisted mainly of collagen types I and III. Moreover the ligament was found to be rich in elastic fibers. Unexpected large and intensively vascularized synovial folds projected into the joint cavity.

CONCLUSION

The capsule of the cricoarytenoid joint can be compared with the joint capsules of the limbs despite its structure and its involvement in joint pathology. Based on the laxity of the joint capsule it was concluded that invasive interventions at the respiratory tract with dislocation of the arytenoid cartilage can lead to incarceration of the synovial folds. After a trauma aero-synovitis or formation of hemarthrosis may occur, with subsequent fixation of the arytenoid in an abnormal position.

Obstructive suprastomal granulation tissue following percutaneous tracheostomy

Percutaneous dilatational tracheostomy is frequently performed as an alternative to traditional surgical open tracheostomy with many reported benefits. Despite its relative safety and widespread acceptance, complications can be associated with the procedure itself or long-term. We present four cases where there was difficulty with decannulation because of exuberant obstructive granulation tissue. In each case, the percutaneous tracheostomy involved the cricoid cartilage.

New insights into the pathomechanism of postintubation arytenoid subluxation

BACKGROUND

Impaired movement of the cricoarytenoid joint with hoarseness and immobility of the vocal ligament can occur as a consequence of endotracheal intubation. The biomechanics and pathomechanism of cricoarytenoid subluxation have not been demonstrated to date.

METHODS

The present study attempts to simulate the trauma that has been associated with arytenoid cartilage subluxation in intubation trials on 37 unfixed larynges in cadavers from persons aged 25 to 89 years. Larynges were intubated or extubated according to former conceptions of arytenoid subluxation, which assume that the arytenoid tip enters the lumen of the tracheal tube, or that a deflection of the arytenoid occurs during withdrawal of the endotracheal tube with the cuff of the tube only partially deflated. Also, manual attempts were carried out to subluxate the arytenoid cartilage. Subsequently after dissecting the left and right cricoarytenoid joint from each larynx, the morphologic changes induced experimentally were analyzed using gross microscopic and histologic methods.

RESULTS

Within the scope of the experiment, it proved impossible to produce any subluxation of a cricoarytenoid joint. Histologic analysis revealed injuries of synovial folds, joint-surface impressions of the articular cartilage, and fractures in the area of the subchondral bone in some joints.

CONCLUSIONS

Based on the morphologic results, it was concluded that intubation trauma of the cricoarytenoid joint does not cause subluxation per se, but rather that formation of a hemarthros or fractures of the joint bodies lead to fixation of the joint surfaces in an abnormal position. Subsequent ankylosis may occur.

[Glottal configuration and histological findings in vocal muscles following trauma to cricoarytenoid joint]

OBJECTIVE

The unilateral cricoarytenoid joints of the rabbits were traumatized bluntly to investigate the changes of glottal configuration and histology of the vocal muscles.

METHOD

10 New Zealand white rabbits divided into 4 groups were studied. Under direct laryngoscope, the unilateral cricoarytenoid joint of each rabbit was traumatized bluntly. The glottal configuration and histology of the true cords demonstrated atrophy of the vocal muscles. The remarkable atrophy of the vocal muscles was evaluated after 1, 3, 6 and 9 months.

RESULT

In 1 and 3 months after trauma, the glottal configuration of the rabbits showed no difference from that in the period of trauma. The histology of the vocal muscles was approximately normal. The lateral drift and deformity of the fixed vocal cord and wider glottal gap were seen 6 months after trauma. The histological sections of the vocal muscles were noted 9 months after trauma.

CONCLUSION

The atrophy of the vocal muscles may occur 6 months after trauma to cricoarytenoid jonint. This pathologic change may cause the lateral displacement and deformity of the vocal cord, which increases the glottal incompetence and affects voice recovery. The laryngeal electromyography may be influenced by the pathologic changes of the vocal muscles.

A biomechanical study of the human cricoarytenoid joint

OBJECTIVES/HYPOTHESIS

To develop a model to investigate the biomechanics of the cricoarytenoid joint and establish stiffness, laxity, and range of motion of the cricoarytenoid joint in adult human larynges.

STUDY DESIGN

Laboratory investigation of freshly frozen larynges from adult humans, measuring the stiffness, laxity, and range of motion in intact and injured cricoarytenoid joints.

METHODS

Eight normal-appearing frozen cadaver larynges from adult humans were studied. The cricoid cartilage was fixed to a load cell sensitive to forces in three dimensions. A probe was rigidly fixed to the arytenoid cartilage and attached to a frame to allow active rotation, rocking, and gliding of the arytenoid. A computer program simultaneously recorded forces generated by these motions and tracked the motion of the arytenoid in three dimensions. The joint was studied before and after injury to the posterior cricoarytenoid ligament, and the joint surfaces were digitized after completion of these studies.

RESULTS

A successful method of evaluating the biomechanical properties of the cricoarytenoid joint was developed. Comparing intact and injured joints confirmed that laxity and range of motion increased during rocking, gliding, and rotational motion when the cricoarytenoid ligament had been divided. Stiffness measurements for rocking, rotation, and gliding also were documented.

CONCLUSIONS

The model of study introduced in this report provides a significant and unique method of investigating the biomechanics of the cricoarytenoid joint, allowing insight into the basic joint characteristics and alteration in joint biomechanics related to injuries and surgical procedures. Dividing the cricoarytenoid ligament increases laxity and range of motion in sagittal rocking, gliding, and axial rotation. Secondary constraints on the joint provide significant stiffness of greater degrees of displacement. Further studies should provide insight into the significant secondary elements supporting the joint and into the mechanisms of cricoarytenoid injuries, as well as the effect of surgical procedures on the cricoarytenoid joint.

Comparison of 2 cricothyrotomy techniques: standard method versus rapid 4-step technique

STUDY OBJECTIVE

To compare the success rate, complication rate and time required for the rapid 4-step technique versus the standard technique for cricothyrotomy.

METHODS

We conducted a prospective, randomized crossover study. Twenty-seven emergency medicine interns, 1 junior medicine resident, and 4 senior medical students, without prior cricothyrotomy experience, were randomly divided into 2 groups. Group 1 was initially instructed in and then performed the standard technique; group 2 was initially instructed in and then performed the rapid 4-step technique. Each group was then instructed in and performed the alternate method. Cricothyrotomies were performed on preserved human cadavers.

RESULTS

A surgical airway was established in 28 of 32 attempts with the use of the rapid 4-step technique (88%); the average time elapsed before tube placement was 43 seconds. Thirty of 32 attempts involving the standard technique (94%) were successful; the average time to tube placement was 134 seconds (95% confidence interval for a difference of 91 seconds, 63 to 119; P < .001). Complications were identified in 12 attempts involving the standard technique (38%; 1 considered major) and in 12 involving the rapid four-step technique (38%; 3 considered major). The incidence of major complications was 6% higher for the rapid 4-step technique (95% confidence interval, -9% to 21%).

CONCLUSION

In a group of inexperienced subjects working on a preserved human cadaver model, the rapid 4-step technique for cricothyrotomy was performed in about one third the time required for performance of the standard technique. This finding was both clinically and statistically significant. Although the 2 techniques had similar success and complication rates, we noted a trend toward more severe complications in the rapid 4-step technique.

"Hidden" laryngeal injuries in homicidal strangulation: how to detect and interpret these findings

These studies were designed to demonstrate that the usual method of laryngeal dissection carries a significant risk of overlooking important laryngeal injuries. Formalin-fixed hyoid-larynx complexes were prepared in a prospective forensic study involving 191 cases of homicidal strangulation, 1984 to 1997. The basic steps of the applied method included: complete resection of the thyroid cartilage, a horizontal incision through the cricoid cartilage before opening the larynx dorsally, inspection of the laryngeal joints, and incisions of the laryngeal muscles. Using this procedure allowed us to detect the following injuries, which otherwise would have been destroyed or overlooked: (a) 17 incomplete fractures restricted to the dorsal surfaces of the thyroid laminae and 10 incomplete or non-dislocated fractures of the cricoid cartilage. In 7 cases, such a "hidden" fracture was the only laryngeal injury resulting from neck compression. (b) Extensive laryngeal muscle hemorrhages, especially of the vocal folds, were found in almost half of all cases, more rarely in strangulation by ligature and more frequently in manual strangulation. Gross hemorrhages were the decisive local laryngeal finding in 19 cases. (c) Laryngeal joint injuries (bleedings) were found in 18% to 52% of the different strangulation types. (d) Hemorrhages of the laryngeal mucosa were common findings that occur in about 60% of all cases; only in rare cases do such bleedings have a special diagnostic value. The quantity and significance of findings obtainable from complete preparation clearly document Camps's demand made in 1976 to dispense with the usual laryngeal dissection technique (dorsal scissor incision through the cricoid cartilage), at least in (questionable) strangulation cases.

Cricothyroid joint injury

Cricothyroid joint injuries may result in severe voice dysfunction and may be associated with laryngeal pain. Otolaryngologists and radiologists should be familiar with this rarely recognized injury.

The immediate effects of local trauma on the shape of the cricoid cartilage

Injury-induced abnormal development of the cricoid ring has been demonstrated in previous growth studies. In this study we focused on the immediate effects of various types of lesions to the cricoid, eliminating the influence of inserting muscles. In isolated, vital cricoids (cricoid explants) the anterior arch was split, creating a small gap between the cut ends. Previous injury to the internal surface of the cricoid ring resulted in a three to four fold increase of the diameter of the gap, actually widening the interrupted cricoid. On the contrary, injuring the external surface of the cricoid cartilage prior to anterior cricoid split, leads to an overlap of the cut edges, and a narrowing of the ring. These injury-specific changes in shape of the cricoid ring are ascribed to the release of interlocked stresses, present in the cartilage. It is suggested that the demonstrated methods to change the shape of the cricoid ring in a predictable way, are relevant for the treatment of patients with cricoid malformation.

Pneumomediastinum and pneumothorax from blunt cervical trauma in children

Minor blunt cervical injuries in children are relatively common occurrences leading to serious sequelae in only rare circumstances, yet sufficient impact of even a seemingly minor event may lead to a significant posterior tracheal wall laceration, resulting in pneumomediastinum with or without pneumothorax. Three cases demonstrate how the mechanism of injury does not always match either the severity of initial presentation or the consequent necessary level of emergent management. Pneumomediastinum without pneumothorax often can be treated conservatively; however, the onset of massive pneumomediastinum and pneumothorax may necessitate both tracheotomy and tube thoracostomy as initial treatment.

Growth dynamics of the cricoid cartilage and subglottic injury. An autoradiographic and histometric study in the rabbit

Earlier studies in young growing rabbits have suggested that post-traumatic developmental deformities of the cricoid might play a role in failing treatment in children with similar injuries. Specific patterns of malformations in the animals occurred preferentially at the anterior side of the cricoid ring. In this study, the growth dynamics of the cricoid were studied by histometry and autoradiography. Results indicated that (1) the cell/matrix ratio remains unchanged from 4 to 24 weeks of age, with both tissue components thus contributing equally to growth of the cricoid; (2) mitoses occur in cartilage and perichondrium, indicating interstitial as well as appositional growth; (3) mitotic activity is mainly restricted to the first 4 weeks of life, while cell hypertrophy is thereafter the dominant feature; (4) the highest degree of mitotic activity and cell hypertrophy is found in the anterior half of the cricoid ring which therefore can be considered as a growth center. This center might play a role in the development of trauma-induced deformation in the anterior part of the cricoid ring.

Fracture of the cricoid cartilage after Sellick's manoeuvre

We report a case of fracture of the cricoid cartilage associated with cricoid pressure during rapid sequence tracheal intubation in a patient with status asthmaticus. This patient had a history of laryngeal trauma 48 yr previously. Fracture of the cricoid cartilage has not been reported previously after cricoid pressure.

Injury- and age-linked differences in wound healing and stenosis formation in the subglottis

We studied the effects of superficial and deep endolaryngeal trauma of the subglottic airway in young and adult rabbits. In both age groups a soft stenosis was formed as long as the cartilaginous cricoid ring is not involved. This stenosis comprised a thickened subepithelial zone of scar tissue, separated from the cricoid cartilage by a layer of fatty tissue. Injury of the internal side of the cricoid cartilage induced a compact mass of scar tissue with local differentiation into fibrocartilage. In young animals only, injury of the cartilage led to remodelling of the cricoid ring (indentation or collapse of the traumatized sectors). On the basis of the differentiating effects of age and depth of the lesion, three histopathological types of subglottic stenosis were distinguished. The experimental results provide an explanation for the variability in the histopathological features of the wall of the stenotic subglottic airway, as observed in biopsies and postmortem specimens.

Arytenoid subluxation from blunt laryngeal trauma

Isolated arytenoid dislocation and subluxation are uncommon laryngeal injuries most often resulting from endotracheal intubation. However, these diagnoses must be entertained in all patients having sustained laryngeal trauma. Complaints of dysphonia, pain with phonation, or odynophagia in the setting of laryngeal trauma should include evaluation for possible arytenoid displacement after an airway is secured. Prolonged hoarseness or odynophagia after endotracheal intubation should alert the physician to the possibility of a cricoarytenoid joint injury. This represents the first reported case of isolated arytenoid injury resulting from blunt external trauma to the larynx. The patient had a stable airway without intervention, and the displaced joint spontaneously relocated with resolution of the cricoarytenoid edema and hemarthrosis. We propose that the cricoarytenoid joint was subluxed probably due to edema, hematoma, and/or cricoarytenoid hemarthrosis sustained from blunt laryngeal trauma. We furthermore propose that some cases of cricoarytenoid subluxation may be treated without operative intervention.