Thoracic Trachea Research Articles

Successful tracheal autotransplantation with a vascularized omental flap

A major problem in tracheal transplantation is the restoration of an adequate vascular supply to the transplanted trachea. In 12 piglets, a segment (6 rings) of thoracic trachea was removed and the excised segment was then sutured back in place. In 9 animals (group A), a vascularized omental flap was wrapped around the autotransplanted trachea. In the other 3 pigs (group B), the omentum was not used. Eight of 9 group A pigs were killed, 1 or 2 months later, having had no signs of airway obstruction; the 9th pig was killed after 14 days because of airway obstruction. The 3 pigs in group B were killed after 11 to 13 days because of progressive respiratory obstruction. In the 8 asymptomatic pigs in group A, the omental flap was viable and tracheal growth was normal with no differences in diameter between normal and autotransplanted trachea. Histologically intact cartilage was lined with respiratory epithelium. In the one group A pig who was killed early, the omental flap was necrotic. In this pig and in the 3 group B animals, extensive tracheal necrosis and nonviable cartilage were observed. These findings indicate that in the pig, a 6-ring segment of trachea can be transplanted with vascularization provided by an omental flap.

Carinal Injury

Injury to the thoracic trachea is a potentially lethal condition in a patient with multiple injuries. Several clinical signs are commonly associated with this process: subcutaneous emphysema, aphonia, stridor, pneumothorax refractory to thoracostomy tube drainage, pneumomediastinum, and hemoptysis. The clinical appearance of tracheobronchial rupture may be delayed for hours or even weeks following injury. Standard treatment for disruption of the thoracic trachea is primary repair via a right thoracotomy. We describe a patient with a complex carinal injury following blunt thoracoabdominal trauma who was successfully managed with prompt surgical intervention.

Characterization of responses to cromakalim and pinacidil in smooth and cardiac muscle by use of selective antagonists

1. In dog isolated coronary artery (precontracted with endothelin, 10 nM) cromakalim (0.1-30 microM) and pinacidil (1-30 microM) produced concentration-dependent vasorelaxant responses. The effects of these compounds could be blocked by glibenclamide (3 microM), phentolamine (30 microM) or alinidine (30 microM) to a similar extent, indicating that both agents alter vascular tone through the same mechanism in this preparation. 2. The ability of the antagonists glibenclamide, phentolamine and alinidine to block the response to cromakalim in a number of smooth muscle types from the guniea-pig was determined. Cromakalim (0.1-30 microM) produced concentration-dependent relaxant responses in thoracic aorta (precontracted with endothelin, 30 nM), ileum (precontracted with K+, 25 mM) and trachea (spontaneously contracted). Responses to cromakalim in all tissues could be blocked by the three antagonists. However, significantly higher concentrations of the antagonists were required to block responses in the thoracic aorta than in the ileum or trachea. Given that the rank order of potency of the antagonists was similar in all tissues (i.e. glibenclamide greater than phentolamine = alinidine), this result may suggest vascular K+ channels opened by cromakalim are quantitatively but not qualitatively different in vascular compared with non-vascular smooth muscle. Glibenclamide was approximately 10 times more potent than phentolamine or alinidine. 3. Cromakalim had minimal functional effects on the rat spontaneously beating right atrial (rate) or electrically driven left ventricular strip (force) preparations. Similarly the three antagonists studied failed to alter force generation in the right ventricular strip. However alinidine and phentolamine did produce a dose-related bradycardia in the spontaneously beating right atria. This effect appears to be unrelated to blockade of the K+ channel opened by cromakalim since glibenclamide, the most potent K+ channel antagonist studied, failed to produce the same response. 4. It would appear that the K+ channel opened by cromakalim is present in a number of vascular and non-vascular smooth muscle. Based on the potency of the three antagonists studied, there appears to be little heterogeneity in the process activated by cromakalim in vascular and non-vascular smooth muscle.

Ultrafast CT of laryngeal and tracheobronchial obstruction in symptomatic postoperative infants with esophageal atresia and tracheoesophageal fistula.

We evaluated the role of ultrafast CT in the diagnosis and follow-up of nine consecutive, symptomatic infants with suspected laryngeal and tracheobronchial obstruction after surgery for esophageal atresia. With 80% or more area collapse as a criterion for the diagnosis of laryngomalacia and 50% or more for tracheomalacia, six patients had tracheomalacia, one had laryngomalacia, and two had both. Tracheomalacia was focal in four patients and diffuse, involving the thoracic trachea, in the other four. Associated bronchomalacia was present in two patients. The site and degree of abnormality were verified by endoscopy in five of nine patients. The degree of tracheal collapse did not always correlate with the size of the esophageal pouch or with the site of the tracheo-esophageal fistula. These findings support the concept that the larynx and/or tracheal walls are often abnormal in symptomatic infants with esophageal atresia, tracheoesophageal fistula, and airway obstruction. Ultrafast CT was a reliable technique for detecting and assessing the site, extent, severity, and dynamics of airway collapse in five of seven symptomatic infants with congenital tracheoesophageal anomalies when the imaging findings were compared with endoscopic findings and previously published normal standards.

Leiomyoma of the Trachea - An Unusual Tumour

A case of leiomyoma of the thoracic trachea is described in a 35-year-old man. The tumour was excised by sleeve resection and end-to-end anastomosis of the trachea was performed. Leiomyoma is a very rare benign tumour of the trachea. Only 15 cases have been reported in the English literature. Our case was not only confirmed by electron microscopy, but is the first reported case in the respiratory tract to be confirmed by positive immunostaining for desmin.

Transverse images of the human thoracic trachea during forced expiration.

The thoracic trachea and the proximal portion of the major bronchi were imaged in five normal volunteers during a forced expiration maneuver using a cine-computer-tomography system. Sixteen images of two contiguous slices were obtained in less than 1 is while expiratory flow was recorded at the mouth. The area of the thoracic trachea decreased rapidly as flow rate rose to its maximum and the wave of collapse propagated distally. The compressive narrowing of both the pars membranacea and the ventrolateral wall was asymmetric. A contact area appeared between the posterior and the left lateral walls. In one subject the trachea was imaged during the entire maneuver with a lower scan frequency. By 725 ms after the beginning of the forced expiration, the area had first decreased to 15% of its initial value and then reincreased to 46% of its initial value. It stayed constant for the remainder of the maneuver. The measured maximum air velocity was greater than the estimated local wave velocity.

Tracheal reconstruction for stenosis due to postintubation injury; a case report

A 43-year-old man was brought to our hospital because of acute dyspnea. He had been treated with ventilation through a tracheostomy tube for one month after accidental inhalation of wood chips. Chest x-ray film and bronchoscopy revealed stenosis of the thoracic trachea. Emergency operation was performed through a median sternotomy. Four rings of stenotic trachea were resected and reconstructed at the level of the aortic arch. The anastomosis was successful and the postoperative course was uneventful.Microscopic examination of the resected specimen revealed granulation and scar tissue with pathological cartilage formation. Wood chips were buried in the granulation tissue. The wood chips and assisted ventilation through tracheostomy apparently caused an inflammatory reaction which led to the stenosis.

Tracheal compression and the innominate artery: MR evaluation in infants.

Magnetic resonance (MR) imaging offers a noninvasive method of evaluating the mediastinum in infants with suspected compression of the trachea by the innominate artery. MR imaging was performed in 17 infants and children, aged 3-29 months, who had obstructive airway symptoms and who had undergone flexible fiberoptic tracheobronchoscopy. MR and endoscopic findings correlated in all cases but one. Of the remaining 16 patients, eight had endoscopic and MR evidence of tracheal compression at the level of the innominate artery, and eight had a normal upper thoracic trachea. In both groups, the innominate artery was situated anterior and to the left of the trachea with no difference in anatomic relationships. Measurements of the anteroposterior and transverse dimensions of the upper part of the mediastinum and the thymus failed to disclose significant differences between the two groups. Follow-up examinations of three patients showed decreasing tracheal compression without changes in tracheal-arterial relationships. This investigation disclosed no evidence of excessive mediastinal crowding. The findings support previous angiographic observations indicating that anterior tracheal compression is not due to an anomalous position of the innominate artery. Symptoms of tracheal compression may result from an intrinsic deficiency of the tracheal cartilage rather than an anatomic abnormality of the mediastinum or its vasculature.

Necrotizing tracheobronchitis. An ischemic lesion.

Neonates with necrotizing tracheobronchitis present a diverse clinical spectrum from asymptomatic disease to severe airway obstruction. A retrospective clinicopathologic study of 206 neonatal autopsy reports spanning a three-year period yielded 122 cases of necrotizing tracheobronchitis with an incidence of 59%. All study patients received treatment prior to the development of high-frequency ventilator jet, oscillator, or interruption. The site and submucosal depth of airway involvement was variable. The most commonly affected anatomic site was the middle or thoracic trachea (56%). The common cause identified was severe ischemia to the airway mucosa and submucosa, occurring with profound birth asphyxia and/or shock. The presence of ischemia supports the concept that decreased tracheoperfusion may be an important factor in the development of tracheobronchial abnormalities.

Circumferential tracheal replacement with costal cartilage

Long-term incorporation of foreign material or tissue in circumferential tracheal replacement will lead to progressive growth of granulation tissue, provoking either airway stenosis or a reduction of subepithelial blood supply and thereby preventing the appearance of functioning ciliated epithelium in the replaced segment. In experience with dogs, a 5 cm length of the thoracic trachea was replaced circumferentially with fresh autogenous untreated circularly positioned cartilage-perichrondrium strips. During the period of strengthening of this neotracheal wall, a temporary tracheal prosthesis made of tubular silicone rubber with absorbable sewing rings of polyglactin 910 placed 3 mm from the end of the tube served as a tracheal replacement. Six months after the cartilage transplantation, the neotracheal wall had stabilized sufficiently for the silicone rubber tube to be extracted with an endoscope. Four weeks after extraction of the silicone rubber tube the neotracheal segment was completely covered with ciliated epithelium over a thin subepithelial, well-vascularized layer. Subepithelial vessels had a diameter of 180 microm. They were a continuation of the intercartilaginous main vessels of the neotracheal wall. The presence of normal cilia on the epithelium was proved through transmission electron microscopy. Even the tubules of the cilia were arranged in the right order. In the ink test, movement of the transport marker across the neotracheal segment at a speed of 18 to 21 mm/min was proof of mucociliary clearance. In a process of migration starting from the margin of the trachea, the ciliated epithelium pervaded and replaced the preexisting temporary one-layer stratified squamous epithelium. This completely new technique of circumferential tracheal replacement with autogenous cartilage, avoiding permanent incorporation of foreign material, succeeds within the observation period of up to 7 months.

Systemic arterial blood supply to the trachea and lung in sheep.

We studied the systemic arterial blood supply to the trachea and lung in adult sheep. After anesthesia, sheep were exsanguinated and then studied by intra-arterial injection of one of the following materials: saline containing dyes of various colors (n = 24), Microfil (n = 8), or Batson's solution (n = 6). The systemic blood supply to the cervical trachea originated from the two common carotid arteries via three to four small branches (rami tracheales cervicales) on each side. A segment of the thoracic trachea between the thoracic inlet and the origin of the tracheal bronchus (bronchus trachealis) and the bronchial tree of the right cranial lobe (lobus cranialis dexter) were supplied by the tracheal bronchial branch (ramus bronchalis trachealis), which originated from the brachiocephalic trunk (truncus brachiocephalicus). A portion of thoracic trachea between the origin of the tracheal bronchus and the tracheal carina was supplied by the thoracic tracheal branch (ramus trachealis thoracica), arising from the bronchoesophageal artery (arteria bronchoesophagea) or directly from the thoracic aorta. The bronchial branch (ramus bronchalis) originated from the bronchoesophageal artery, and its branches supplied the remainder of the bronchial tree. At 120 cmH2O pressure (n = 8), the bronchial branch contributed approximately 50% and the other two approximately 25% each of the total tracheobronchial blood flow. These three branches also supplied the visceral pleura. Additionally, several small vessels (rami pleurales pulmonales) originated from the esophageal branch (ramus esophagea) of the bronchoesophageal artery, traversed the pulmonary ligaments, and supplied the visceral pleura.

Management of Airway Trauma II: Combined Injuries of the Trachea and Esophagus

Twenty-four consecutive patients with combined injuries of the trachea and esophagus were operated on at the Tulane University Hospital and the Charity Hospital of New Orleans between 1967 and 1983. Only 3 of the injuries resulted from blunt trauma, and 1 of these patients had a total transection of both the trachea and esophagus; the remaining injuries were due to penetrating trauma (20 gunshot wounds; 1 stab wound). The combined lesions involved the cervical region in 20 patients and the thoracic esophagus and trachea or bronchus in 4. All patients underwent bronchoscopy; in recent years all have had esophagoscopy, because our experience indicates that esophagrams, which patients also underwent, have a high rate (12.5%) of false negative results. Operative techniques included a two-layer closure of all esophageal injuries, closure of the trachea with nonabsorbable monofilament suture, and transthoracic or cervical drainage. Muscle flaps were used for suture line reinforcement. Associated operative procedures included tracheostomy (5), laparotomy (4), vascular procedures (5), neurologic procedures (2), and closed-tube thoracostomy (6). Five patients (21%) died in the perioperative period, 4 of 20 with combined cervical injuries, and 1 of the 4 with combined thoracic injuries. Deaths resulted from missed injuries to the esophagus (2 patients), a missed tracheal injury (1), associated vascular injury (1), and associated thoracoabdominal injury (1). Two patients experienced cervical esophageal suture line leaks, both of which sealed with conservative therapy. Clinical follow-up showed good results in 90% of the patients who survived. One patient had late neurologic sequela of the injury, including spinal cord trauma and recurrent nerve paralysis, and 1 had pharyngeal paralysis from extensive neurologic damage in the neck. No patient had esophageal or tracheal stenosis.

気管ならびに食道の先天性疾患と外科治療

Among various anomalies related to the trachea and esophagus, atretic and stenotic lesions are the most common and challenging objects in pediatric surgery. Tracheoplasty with the costal cartilage grafts is the treatment of choice for the extensive congenital stenosis of the thoracic trachea. We treated 4 cases of tracheal stenosis with this technique. Observation for following 2 years suggests that this technique is useful for such extensive lesions as an end-to-end anastomosis is not indicated.One hundred and thirty seven cases of esophageal atresia were treated at our institute with an overall mortality rate of 38%. Primary or staged end-to-end esophageal anastomosis was performed on 94 patients with a 20% mortality rate, whereas jejunal or colonic interposition was indicated for 13 patients with a mortality rate of 30%.The cause of stenosis of the esophagus was fibromuscular hypertrophy in 20, bronchial remnants in the esophageal wall in 7 and the ectopic gastric mucosa in 2 of our series of patients. Esophagoesophageal anastomosis was a possible procedure when the length of resection of the esophagus was limited to within 2.5cm. Intestinal interposition was, however, required when the esophagus was resected 3.5cm and more.

Cardiopulmonary bypass in tracheal surgery in infants and small children.

Five resections of the distal trachea with cardiopulmonary bypass were carried out in four children aged 6 weeks to 24 months. Only technical aspects are discussed, and the operative method is described in detail. The use of cardiopulmonary bypass and heparinization of the patients did not cause any problems. Cardiopulmonary bypass allows an easy and unhurried procedure. Although other authors do not regard cardiopulmonary bypass as necessary in similar circumstances, we believe that it is the safest way of providing optimal operative conditions and results in surgery of distal tracheal stenoses.

Management of Airway Trauma. I. Tracheobronchial Injuries

Abstract One hundred six consecutive patients with injuries to the tracheobronchial tree who were admitted to the emergency room of the Tulane Medical Center Hospital or the Charity Hospital of Louisiana at New Orleans over a period of almost 20 years were analyzed retrospectively. Penetrating trauma of the neck or chest was reported in 100 of the patients, and only 6 had blunt trauma to the neck or thorax as the cause of injury. There were 18 deaths among the 106 patients (16.98%), including 11 (13.75%) of 80 with injuries of the cervical trachea. Seven (53.8%) of 13 with principal injuries of the thoracic trachea died; all 13 patients with major bronchial injuries survived. On admission to the emergency room, all patients had signs of airway compromise such as tachypnea, dyspnea, cyanosis, subcutaneous emphysema, or an abnormal respiratory pattern. Severe airway compromise was evident in 46 patients; 24 (23%) were treated with oral or nasal intubation, 19 (18%) with emergency tracheostomy, and 3 (2%) with intubation of a tracheal injury. Hemoptysis was an unreliable signal of serious injury, being present in only 28 of the patients. Patients who had major vascular injuries combined with trachea involvement were generally not salvageable. In regard to morbidity and mortality, the most common preventable errors were delay in diagnosis and treatment of tracheobronchial injuries, missed esophageal injuries, massive aspiration of blood, and abdominal vascular injuries. Since major airway trauma should be suspected in all cases of blunt or penetrating trauma to the neck or chest, emphasis should be placed on control of the airway and on performing diagnostic bronchoscopy and esophagoscopy in all patients with complex tracheobronchial injuries.

New experimental method for the repair of tracheal defects.

The use of bovine carotid artery xenografts to repair partial defects of the cervical and thoracic canine trachea as well as the covering of bronchial stumps was observed up to 32 months after surgery. Healing occurred without problems, and scanning electron microscopy revealed subsequent ciliary epithelialization of the entire graft surface (2 X 2-5 X 1.9 cm). Functionally, the grafts replaced the tracheal wall adequately. The use of resorbable suture material facilitates healing and avoids excessive formation of inflammation and granulation tissue observed with nonresorbable suture material of any kind.

The successful reconstruction of thoracic tracheal defects with free periosteal grafts

A defect was created in the thoracic trachea in nine piglets (10 kg) by excising a segment from the entire thoracic trachea proximal to the right upper lobe bronchus (3 to 3.5 cm in length) and 30% of the circumference in width (1 to 1.5 cm). The defect was repaired with a free tibial periosteal graft (FPG) and in four piglets an omental pedicle graft (OPG) was applied to the surface of the FPG. An internal tracheal splint was inserted for 12 to 16 days to support the repair and prevent air leak. The splints were removed bronchoscopically. None of the pigs developed signs of airway obstruction at any stage following the repair. Eight were killed 3 months postoperatively when four to six times their original weight. One pig died on the 18th postoperative day of unknown cause. The tracheas were removed, x-rayed, and examined grossly and histologically. The results demonstrated normal tracheal growth with absence of either stenosis, collapse, or granulation tissue. All grafts were viable, bone formation was present, and the lumenal surfaces were lined with columnar and respiratory epithelium. The OPG did not improve vascularization of the FPG. This model suggests that tracheal stenosis in children may be surgically corrected by simply incising the stenotic segment longitudinally and enlarging the tracheal diameter by inserting a FPG into the defect.

Management of Airway Trauma I: Tracheobronchial Injuries

One hundred six consecutive patients with injuries to the tracheobronchial tree who were admitted to the emergency room of the Tulane Medical Center Hospital or the Charity Hospital of Louisiana at New Orleans over a period of almost 20 years were analyzed retrospectively. Penetrating trauma of the neck or chest was reported in 100 of the patients, and only 6 had blunt trauma to the neck or thorax as the cause of injury. There were 18 deaths among the 106 patients (16.98%), including 11 (13.75%) of 80 with injuries of the cervical trachea. Seven (53.8%) of 13 with principal injuries of the thoracic trachea died; all 13 patients with major bronchial injuries survived. On admission to the emergency room, all patients had signs of airway compromise such as tachypnea, dyspnea, cyanosis, subcutaneous emphysema, or an abnormal respiratory pattern. Severe airway compromise was evident in 46 patients; 24 (23%) were treated with oral or nasal intubation, 19 (18%) with emergency tracheostomy, and 3 (2%) with intubation of a tracheal injury. Hemoptysis was an unreliable signal of serious injury, being present in only 28 of the patients. Patients who had major vascular injuries combined with trachea involvement were generally not salvageable. In regard to morbidity and mortality, the most common preventable errors were delay in diagnosis and treatment of tracheobronchial injuries, missed esophageal injuries, massive aspiration of blood, and abdominal vascular injuries. Since major airway trauma should be suspected in all cases of blunt or penetrating trauma to the neck or chest, emphasis should be placed on control of the airway and on performing diagnostic bronchoscopy and esophagoscopy in all patients with complex tracheobronchial injuries.

Reflex partitioning of inputs from stretch receptors of bronchi and thoracic trachea

A selective block of slowly adapting stretch receptors in anesthetized rabbits was induced by exposing to SO 2 all thoracic airways (T) or the carina and bronchi alone (B). Increment of inspiratory time (T I) relative to control was 61% greater under B than T. The reverse would have happened if input responsible for Breuer-Hering inflation reflex originated from both bronchi and trachea. Hence, bronchial input activates inspiratory off-switch, while tracheal input delays its activation. During single inspiratory efforts with airways closed at end expiration diaphragm activity (Adi) decreased and T IO increased relative to control equally under B and T. Hence, the input facilitating central inspiratory activity at end expiratory volume does not stem from trachea. At end of inspiratory ramp Adi stopped within 43 msec at control and 57 msec under B and T. Hence, bronchial input speeds up off-switching of inspiration. Postinspiratory Adi was greater under B than T, and nearly nil at control. Hence, bronchial input inhibits postinspiratory Adi, while tracheal input facilitates it. Inspiratory and expiratory flows were more damped under B than T, and under T than at control.

The anatomy of the ferret paratracheal parasympathetic nerve-ganglion plexus.

Silver-impregnated preparations of the ferret paratracheal nerve-ganglion plexus were studied for description and quantitation of the general morphology of ganglia and nerve bundles and trunks. Most ganglia were found in one or two chains, separated by interganglionic nerve trunks, running the length of the trachea in close apposition to the trachealis muscle. Ganglia were flat, one cell deep, and characterized by irregular spacing and small and variable numbers of perikarya. Perifascicular, infrafascicular, and mixed types of ganglia were seen. The mean perikaryon density was 127 +/- 20/cm2 of trachealis muscle. In addition to connections to the interganglionic nerve trunk, more than 70% of ganglia were also apparently "connected" to nerve bundles running to the periphery and/or the center of the preparation, and the plexus seemed considerably more complex than originally described. There was no significant change in density, size or type, or connections of ganglia with nerve bundles in the cervical or thoracic trachea.