Cervical Trachea Research Articles

Evaluation of the Palmaz stent in the trachea and mainstem bronchi of normal dogs.

This study evaluates the efficacy of the Palmaz balloon expandable intraluminal stent in the trachea and mainstem bronchi of normal dogs. Effects of the stent were evaluated by physical examination, thoracic radiography, respiratory tract fluoroscopy and endoscopy, tracheal diameter measurement, postmortem examination, and airway histomorphometry. Ten normal beagle dogs. Stent size was estimated from thoracic radiographs in awake dogs. Group I dogs (n = 4) had two stents placed: one in the thoracic trachea (TT) plus a randomly chosen mainstem bronchus (MB). Group II dogs (n = 3) had stents placed in the MB (one stent), TT (one stent), and mid- or proximal cervical trachea (CT) (one or two stents). Three dogs were used as sham-operated controls (group III). Temperature, pulse, respiration, and cough were measured twice daily. Dogs were evaluated at 21 and 49 to 56 days after stent placement, euthanatized, and tissues were collected for histomorphometric analysis of stent integration and epithelial pathology. Mean tracheal diameters of awake (10.5 +/- 1.7 mm) and anesthetized dogs before stent implantation (13.9 +/- 2.0 mm) were significantly different (P < .01). Complications associated with stent placement included acute pulmonary edema (n = 2), stent migration (n = 7), stent collapse (n = 4 CT, 2 TT, and 1 MB), and positive tracheal culture (n = 10). Group II dogs coughed more at rest, exercise, and with tracheal palpation than dogs in other groups (P < .01). Group I dogs coughed more at rest than group III dogs (P < .01). Stent integration ranged from 0 to 91.3%. Squamous metaplasia and epithelial ulceration associated with stents ranged from 0 to 57.5% and 0 to 32.7%, respectively. Determination of stent size should be based on measurements taken on anesthetized dogs because use of inappropriately sized stents may promote stent migration, squamous metaplasia, and/or ulceration. Epithelialization over stent struts may occur if the stent is closely associated with tracheal epithelium. Palmaz stents do not appear to be appropriate for placement in the CT of dogs; however, with technical modifications, application in the TT and MB may be feasible.

Tracheal resection with end-to-end anastomosis for isolated postintubation cervical trachea stenosis: long-term results.

A 20-year experience with end-to-end tracheal resection and anastomosis for isolated postintubation stenosis of the cervical trachea, in a consecutive series of 32 adult patients, has been reviewed. Surgical death was never encountered. The overall incidences for superficial wound infection, pneumonia, and inferior left laryngeal nerve paralysis were 6.2%, 3.1%, and 3.1%, respectively. One-, 3- and 5-year actuarial anastomosis success rates were 96.7%, 93.3%, and 93.3%, respectively. Successful revision tracheal end-to-end anastomosis was performed once, resulting in an overall 96.9% success rate in our series. None of the following variables-sex, age, cause for intubation, intubation type (laryngotracheal and/or tracheotomy) and duration, delay from initial injury, presence of an open stoma, number of tracheal rings resected, and type of sutures used-were statistically related to the anastomosis success rate or the incidence of complications.

Nonadrenergic relaxation of the cat cervical trachea evoked by stimulation in the lateral hypothalamic area

The purpose of this study was to evaluate hypothalamic contributions to control of tracheal tone. We found hypothalamic sites where electrical stimulation (60–90 μA: 1 ms pulse duration: 50 Hz: 5–10 s) and microinjection of l-glutamate (5–50 nmol) produced tracheal relaxation responses along with decreased blood pressure and heart rate in anesthetized, spontaneously breathing cats. Responsive sites were located in anterior (LHAa) and tuberal (LHAt) regions of the lateral hypothalamic area, indicating that neuronal cells in those regions are responsible for development of tracheal relaxation. In a second experiment, we evaluated possible pathways mediating the tracheal relaxation response elicited by LHA stimulation. Tracheal relaxation was not attenuated by β-adrenergic blockade (propranolol i.v., 0.2–0.5 mg/kg); the response is mediated by nonadrenergic mechanisms. Muscarinic blockade (atropine i.v.) at doses of 0.05–0.1 mg/kg almost abolished tracheal tone during spontaneous breathing, and LHA stimulation evoked a small, insignificant reduction of tracheal tone. Cervical vagotomy completely abolished the tracheal tone, and LHA stimulation no longer evoked the tracheal relaxation. These results indicate the existence of a nonadrenergic descending pathway within the vagal efferents, which is linked with behavioral control arising from LHA, and causes tracheal relaxation.

Prefabrication of a free flap for tracheal reconstruction: an experimental study. Preliminary report.

The development of a prefabricated free flap that could have potential for tracheal reconstruction has been investigated in the goat model. Through a staged procedure, a composite cutaneous-chondromucosal premolded, prevascularized flap was obtained by prefabrication techniques. The procedure comprised three surgical stages. In the first stage, on day 0, the cartilaginous frame-work was constructed, along with the vascular pedicle (implantation of an arteriovenous fistula as a vascular carrier). In the second stage, on day 50, the inner surface of the neotrachea was lined with nasal mucosa. In the third stage, on day 60, the flap was elevated and free transferred to reconstruct a 15-cm circumferential defect in the cervical trachea. Ten animals were operated on, and the results were one infection, three early deaths, one free-flap failure with early tracheal stenosis, and five long-term survivors without significant stenosis. The structure of the neotracheal flap closely resembled that of the native trachea: internal respiratory epithelial lining, cartilage rings, and fibrovascular tissue. Fiberoptic bronchoscopy was done to all the animals at 10 and 60 days, revealing no significant stenosis in the long-term survivors.

Squamous cell carcinoma of cervical trachea

Primary tracheal tumours are very rare. So there is a paucity of experience both in the behaviour of these tumours and their responses to modern surgical treatment and radiotherapy. The commonest of the tracheal tumours are squamous cell carcinoma followed by Adenocarcinoma. A variety of benign tumours are also encountered very rarely. The symptoms of these tumours vary widely. They may be mistaken for bronchial asthma or pulmonary tuberculosis in the initial stages. Here we report a case of squamous cell carcinoma of cervical trachea. The patient presented with stridor. Patient evaluation and management is also discussed.

Assessment of an airway-to-pulmonary circulation reflex in cats

In anesthetized, mechanically ventilated cats we studied the effects on pulmonary circulation of sustained distension or increased air flow stream in an isolated, innervated upper airway segment constituted by the cervical trachea, the larynx and the pharynx. Direct and averaged pulmonary artery pressures and blood flows were measured. In intact cats, sustained distension as well as increased air flow stream in the upper airway segment induced significant, marked increase in pulmonary artery pressure with concomitant decrease in blood flow. No change in heart rate occurred. Section of the superior laryngeal nerves (SLNs), which denervated the tracheolaryngeal segment but not the epipharynx, markedly reduced and delayed the pulmonary vascular response to mechanical stimulation of the upper airways. The response was not found after cervical bivagotomy. The present observations demonstrate the existence of an airway-to-pulmonary circulation reflex, largely mediated through SLNs afferent pathways, the vagus nerve constituting the efferent arm of the reflex.

Tracheobronchial lacerations after intubation and tracheostomy

Although long-term complications of intubation and tracheostomy are well documented, little has been reported on acute complications of airway access techniques. Fourteen patients (1 male and 13 female patients) aged 15 to 80 years presented with tracheobronchial lacerations after single-lumen intubation (n = 9), double-lumen intubation (n = 1), or tracheostomy (n = 4). A left bronchial laceration after double-lumen intubation was discovered and repaired intraoperatively. A tracheal laceration after single-lumen intubation was recognized during induction of anesthesia. The remaining 12 were diagnosed within 6 to 126 hours (median, 24 hours) after injury. All patients had mediastinal and subcutaneous emphysema. At endoscopy, 12 injuries were located in the thoracic trachea and 1 in the cervical trachea. Twelve underwent primary repair through a right thoracotomy (n = 11) or left cervicotomy (n = 1), and 1 was treated conservatively. Two patients with tracheostomy injury died postoperatively. All repairs healed well but one. The latter was performed 5 days after the injury; a dehiscence occurred, but healed spontaneously. We conclude that prognosis of tracheal lacerations depends both on the general health of the patient and on the rapidity of diagnosis and treatment.

Mucociliary Clearance Following Segmental Tracheal Reversal

Ciliated tracheal epithelium is arranged in a polarized pattern oriented according to the inferior-superior axis of the trachea and is responsible for the transport of mucus toward the larynx. In this study, ciliary beat orientation and the influence of external factors on mucociliary clearance direction were studied in rabbit inverted cervical tracheas. The animals displayed normal respiration postoperatively. After 16 weeks, airway clearance was studied by observation of the movement of silicone particles placed in the inverted segment and in normal parts of the ciliated epithelium. Cilia exhibited unidirectional and coordinated movement within inverted tracheal segments. As shown by the direction of effective flow produced by beating cilia and by scanning electron microscopy, the cilia in the inverted segment beat in the opposite direction from the cilia in the remainder of the trachea. This study demonstrated that ciliary orientation is irreversibly determined, but the reversal of ciliary beating within the cervical trachea had no adverse effects on the survival of the animals.

気管食道科領域における鏡視下手術 気道系 胸腔鏡下の気管気管支形成手術―臨床および実験成績

Video-assisted thoracoscopic surgery (VATS) is rapidly replacing standard thoracotomy in thoracic surgery. We have discussed newer techniques in bronchoplasty for primary lung cancer using VATS. No anastomotic problems, such as dehiscence or overgrowth of granulation tissue, occurred in our experiment on the cervical trachea using a mechanical applicator. Based on this technique, we have proved the effectiveness of VATS in the intrathoracic trachea. A 65-yeaes-old man with squamous cell carcinoma underwent bronchoplasty using VATS. We speculate that the using of this mechanical applicator will help to easily connect the bronchus.

A Transtracheal Catheter for Recording the Static Tracheal Pressure in the Exercising Horse

After giving an account of the principles of pressure measurement in flowing air and a review of the literature on tracheal catheters, the authors describe the construction, the introduction and the function of their own transtracheal catheter. This is a teflon catheter with several side-ports which is introduced into the cervical trachea by a guide technique. After introduction, the catheter is stiffened by the insertion of 2 steel wires. The catheter was studied in model experiments concerning: a) the ability to measure the static pressure in flowing air, and b) the dynamic accuracy of a recording system built up around the catheter. The results indicated that the intratracheal pressure sensed in exercising horses well reflected the static pressure, and that the dynamic accuracy of the recording system was good to about 60 Hz. The present technique of recording the intratracheal pressure was used on 122 occasions in 69 exercising horses with only one complication referable to the catheter occurring. The transtracheal route of catheterisation may be superior, as catheters introduced by this route do not appear to influence the function of the pharynx and larynx. In contrast, nasotracheal catheters that traverse the larynx, might interfere with the respiratory function.

400 Radiotherapy for primary carcinoma of the cervical trachea: A report of 30 cases

Primary carcinoma of the cervical trachea is a rare malignancy whose treatment is not clearly defined. This work describes the experience of three radiation oncology centers over 30 years. Thirty patients (pts): 27 male, 3 female, median age 61 years, presenting with carcinoma of the cervical trachea (squamous cell in 27) have been treated by irradiation, as a definitive treatment in 26 pts, median dose 60 Gy (35 – 70 Gy), and postoperatively in 4 pts, median dose 58 Gy. The radiation response was assessable in 19 pts: 9 complete responses (2 for a dose lower than 60 Gy vs 7 for a dose of 60 Gy or more). The 5-year overall survival rate is 29% after definitive irradiation for a dose of 60 Gy or more compared to 0% for a lower dose, and 25% after postoperative irradiation. These results raise the question of further dose escalation, using endotracheal brachytherapy and/or conformal therapy, within prospective collaborative studies.

Experimental tracheal replacement using the esophagus and an expandable metallic stent.

An experimental study was conducted to investigate whether a segment of autogenous esophagus with its lumen supported by an expandable metallic stent (EMS) could be successfully used as a tracheal substitute. Seven rings of the cervical trachea were circumferentially removed and reconstructed by interposing a pedicled segment of the esophagus with an EMS in six mongrel dogs. The interposed esophagus was observed endoscopically at various stages after the operation. By 1 month, the EMS was found to be buried under the esophageal mucosa, and the lumen was patent. The dogs died 5, 17, 61, 92, 210, and 478 days after the operation, but the cause of death could not be determined by postmortem examination and no respiratory tract complications were detected. The results of this study indicated that a segment of the esophagus with its lumen supported by an EMS could work as a reliable tracheal substitute, though its practical use is not clinically feasible. Nevertheless, we conclude that some autogenous material other than the esophagus with its lumen supported by an EMS could provide a feasible method for tracheal replacement.

Minimal dose of cyclosporin A for tracheal allografts

Minimizing immunosuppression after allotransplantation is desirable. We assessed the minimal dose of cyclosporin A for viable tracheal allografts in 50 dogs. Each tracheal transplant, consisting of a six-ring segment of cervical trachea, was harvested and heterotopically implanted into the omentum. In group I (n = 10), transplantation into each dog's own omentum was performed as a control. The remaining 40 tracheal segments were randomly assigned to four recipient groups receiving either no treatment (group II, n = 10), 10 mg.kg-1.day-1 of cyclosporin A (group III, n = 10), 15 mg.kg-1.day-1 of cyclosporin A (group IV, n = 10), or 20 mg.kg-1.day-1 of cyclosporin A (group V, n = 10). After 10 or 28 days, the tracheal segments were evaluated histologically. Epithelial regeneration in group IV was significantly better than that in groups I, II, or III on posttransplantation day 10. Only group IV showed no difference in epithelial viability from group I on posttransplantation day 28. In terms of vascularity, groups IV and V exhibited no differences from group I as evidenced by vascular endothelial morphology. We conclude that an appropriate dose of 15 mg.kg-1.day-1 of cyclosporin A may be used to maintain tracheal allograft viability.

Reliable cryopreservation of trachea for one month in a new trehalose solution

We previously reported that trehalose, a reduced disaccharide, was effective in the preservation of lungs. In this study, we investigated the possibility of prolonged cryopreservation of tracheas in a preservative solution containing trehalose. Five rings of cervical trachea were removed and immersed in the preservative solution. The harvested tracheas were then cryopreserved and stored in a deep freezer at -85° C. One month later, five rings of mediastinal trachea were removed. The cryopreserved cervical tracheas were thawed and autotransplanted in place of the excised mediastinal trachea ( n = 6). The anastomotic site and graft were then covered with an omental pedicle. All six animals survived for more than 6 months. All grafts survived without any evidence of atrophy or stenosis. Microscopic examination of the grafts showed that the integrity of the tracheal tissues was maintained. Our findings show that consistent cryopreservation of the trachea for 1 month is possible in a preservative solution containing trehalose. (J T HORAC C ARDIOVASC S URG 1995;110:382-5)

Excision of adenoid cystic carcinoma of the cervical trachea via an anterior castellated approach

Adenoid cystic carcinoma of the cervical trachea is rare and its diagnosis and surgical management challenging. We report a case with an unusual presentation and discuss the diagnosis and management. The preferred surgical management is tracheal resection, however this is often not feasible and many alternative techniques have been used. Here an anterior castellated approach is described, a modification of that more commonly used for benign tracheal strictures. We found it gave excellent access to the posterior tracheal wall which we feel is superior to a straight vertical tracheal incision. It also facilitates a tracheal widening procedure if indicated, and safeguards the recurrent laryngeal nerves which are particularly vulnerable in the cervical part of the trachea.

Primary adenoid cystic carcinoma of the cervical trachea mimicking thyroid tumor: CT evaluation.

Our goal was to describe the CT characteristics of adenoid cystic carcinomas of the trachea mimicking thyroid tumors. Computed tomography of four patients with pathologically proved adenoid cystic carcinomas extending into the thyroid gland was retrospectively reviewed. One case was also examined with MR. The masses encircling the trachea and circumferential thickening of the tracheal wall were demonstrated in all four cases. The longitudinal extent of the tracheal wall thickening was also demonstrated in all cases. The tumors had a broad base on the trachea and convex margin on the thyroid gland. They were all homogeneous, generally smoothly marginated, and isoattenuating on postcontrast CT scans. Adenoid cystic carcinomas were usually seen on CT scans as homogeneous masses encircling the posterolateral trachea with thickening of the tracheal wall in the transverse and longitudinal planes. These CT characteristics may be helpful in the differential diagnosis of adenoid cystic carcinomas mimicking thyroid tumors.

Another Use for the Laryngeal Mask Airway--As a Blocker During Tracheoplasty

Another Use for the Laryngeal Mask Airway--As a Blocker During Tracheoplasty

Reconstruction of Laryngotracheal War Injuries with the Median Layer of the Deep Cervical Fascia

Surgical exploration and immediate reconstruction with the median layer of the deep cervical fascia (MLDCF) was performed in 8 of 22 patients with exogenous war injuries of larynx and cervical trachea. A surgical technique of reconstruction with the median layer of the deep cervical fascia is described. The 7 surviving patients had good respiration without signs of stenosis of the larynx and/or the trachea. Four had good and 3 satisfactory, phonation, and none had swallowing difficulties. Owing to the simplicity of the surgical approach, its size and biological properties, the median layer of deep cervical fascia proved itself to be a suitable material in the immediate reconstruction of exogenerous war injuries of the larynx and cervical trachea.

Neural control of tracheal smooth muscle during cough

Contraction of tracheal smooth muscle during mechanically induced coughing was studied in dogs. Recordings of smooth muscle tension were obtained from the cervical trachea, which is not influenced by intrathoracic pressure. We observed that during breathing at rest, tracheal smooth muscle contracts and relaxes in synchrony with phrenic nerve activity. When cough occurs, the tracheal smooth muscle contracts continuously and tonically with no rhythmic correlation to phrenic nerve activity. Sometimes the contraction starts before the phrenic nerve activity increases. A neuromuscular blocking agent caused a significant decrease in phrenic nerve activity in response to mechanical stimulation. The correlation between phrenic nerve activity and tracheal smooth muscle tension during normal breathing was also observed after afferent inputs from pulmonary mechanoreceptors were interrupted. During coughing, however, this correlation was lost. From these results we conclude that the neural control of tracheal smooth muscle is at least partially independent of phrenic nerve activity during coughing. Because coughing was attenuated by neuromuscular blocking agents, we speculate that there is a positive feedback mechanism from receptors in the chest wall or airway, which increases the magnitude of coughing.

Dacron-Urethane Composite for Reconstructive Surgery

AbstractA composite biocompatible material made of polyethyleneterephalate (Dacron) and polyetherurethane was fabricated as an aid to bone grafting for the reconstruction of large bony defects of the craniomaxillofacial regions. Bone graft material is placed within the confines of the Dacron-urethane implant and new bone forms to the shape imposed by the implant.The principle application of this material has been for the reconstruction of defects of the neurocranium and of the mandible [1–5]. A number of other applications have been studied including reconstruction of long bone discontinuity defects [6], reconstruction of an infant's anterior chest wall [19], the prosthetic replacement of large defects of the cervical trachea [7] and as a potential material for a thrombo-resistant small diameter vascular prosthesis [8].