Fourth Tracheal Rings Research Articles

Colloid goitre in submental ectopic thyroid: a rare entity posing a diagnostic and therapeutic challenge

Ectopic thyroid is a rare entity in clinical practice. It results from defects at early stages of thyroid gland embryogenesis, during its passage from the base of the tongue to its final pre-tracheal position, anterolateral to second, third, and fourth tracheal rings. It is usually found along the course of the thyroglossal duct or laterally in the neck, also in distant places such as the mediastinum or very rarely in the sub-diaphragmatic organs. In our case, an 18-year old girl presented with a sub-mental swelling. There are various differentials for such swelling. A careful history, scrupulous clinical examination and investigations comprising ultrasonography of neck, MRI scan, Tc-99m pertechnetate thyroid scan and Fine needle aspiration cytology (FNAC) from the swelling revealed that it was a case of colloid goitre in the ectopic sub-mental thyroid and there was no thyroid tissue in its normal anatomic location. We initially treated the patient with supplemental levothyroxine trial for 6-months followed by surgical excision. We report this case as it is a rare phenomenon and also because diagnostic and therapeutic dilemma exists in its management.

Traditional landmark versus ultrasound guided tracheal puncture during percutaneous dilatational tracheostomy in adult intensive care patients: a randomised controlled trial.

IntroductionLong-term ventilated intensive care patients frequently require tracheostomy. Although overall risks are low, serious immediate and late complications still arise. Real-time ultrasound guidance has been proposed to decrease complications and improve the accuracy of the tracheal puncture. We aimed to compare the procedural safety and efficacy of real-time ultrasound guidance with the traditional landmark approach during percutaneous dilatational tracheostomy (PDT).MethodsA total of 50 patients undergoing PDT for clinical indications were randomly assigned, after obtaining informed consent, to have the tracheal puncture procedure carried out using either traditional anatomical landmarks or real-time ultrasound guidance. Puncture position was recorded via bronchoscopy. Blinded assessors determined in a standardised fashion the deviation of the puncture off midline and whether appropriate longitudinal position between the first and fourth tracheal rings was achieved. Procedural safety and efficacy data, including complications and number of puncture attempts required, were collected.ResultsIn total, 47 data sets were evaluable. Real-time ultrasound guidance resulted in significantly more accurate tracheal puncture. Mean deviation from midline was 15 ± 3° versus 35 ± 5° (P = 0.001). The proportion of appropriate punctures, defined a priori as 0 ± 30° from midline, was significantly higher: 20 (87%) of 23 versus 12 (50%) of 24 (RR = 1.74; 95% CI = 1.13 to 2.67; P = 0.006). First-pass success rate was 20 (87%) of 23 in the ultrasound group and 14 (58%) of 24 in the landmark group (RR = 1.49; 95% CI = 1.03 to 2.17; P = 0.028). The observed decrease in procedural complications was not statistically significant: 5 (22%) of 23 in the ultrasound group versus 9 (37%) of 24 in the landmark group (RR = 0.58; 95% CI = 0.23 to 1.47; P = 0.24).ConclusionsUltrasound guidance significantly improved the rate of first-pass puncture and puncture accuracy. Fewer procedural complications were observed; however, this did not reach statistical significance. These results support wider general use of real-time ultrasound guidance as an additional tool to improve PDT.Trial registrationAustralian New Zealand Clinical Trials Registry ID: ACTRN12611000237987 (registered 4 March 2011)Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0514-0) contains supplementary material, which is available to authorized users.

Common carotid artery surprise during percutaneous dilatational tracheostomy – A near miss, confirmed with ultrasound

The practice of percutaneous dilatational tracheostomy (PDT) has gained popularity and acceptance due to the ease in acquiring its skill and low probability of complications. Nevertheless, PDT is associated with a few complications, some really life-threatening. We present a case of an abnormally located common carotid artery encountered during PDT in our intensive care unit. The procedure was electively posted, in an old patient chronically ventilated after a revived cardiac arrest. While identifying the landmarks on palpation pulsation was felt similar to arterial pulsation. This was confirmed using bedside portable ultrasonography and found to be the right common carotid artery forming a loop anterior to the trachea at the level of the third and fourth tracheal rings. The patient had a past history of thyroidectomy and this was suspected to be the primary reason for the altered course of the right common carotid artery.

Chondrosarcoma of the larynx and trachea: A report of two rare cases

Results: Case 1 is an 80-year-old male who presented with cough and was found to have an exophytic mass that involved the first through fourth tracheal rings. Biopsy revealed grade I-II chondrosarcoma. He underwent composite resection with primary anastomosis and remained free of disease 36 months after surgery. Case 2 is a 45 year old male who presented with a neck mass and dysphonia and was found to have a large mass arising from the left thyroid ala. Histopathologic analysis revealed the clear cell variant of chondrosarcoma. The patient underwent partial laryngectomy with adjuvant radiation therapy. He remains free of disease 34 months after surgery.

Tracheo-Innominate Artery Fistula After Tracheostomy

Tracheo-Innominate Artery Fistula After Tracheostomy

Ectopic thyroid gland simulating a submandibular tumor

(Editorial Comment: The reporters call our attention to a rare situation in which a lateral neck mass is a benign ectopic thyroid.) Ectopic thyroid is any thyroid tissue not located anterior to the second, third, and fourth tracheal rings along the midline of the ventral portion of the neck. Submandibular location of the thyroid gland is a very rare congenital anomaly1 that results from the failure of the primitive thyroid premordium to descend from the foramen cecum in the embryo. The ectopic thyroid may be mistaken for a lymphadenopathy or any other mass (depending on the localization, eg, lymphangioma, ranula, salivary gland tumor, dermoid cyst, lipoma, or thyroglossal duct cyst). Surgical removal of an ectopic thyroid may lead to profound hypothyroidism, unless thyroid hormone replacement therapy is initiated, because 70% of patients with displaced thyroids

Evaluation of horizontal and vertical tracheotomy healing after short-duration tracheostomy in dogs

Purpose: The purpose of the study was to assess healing of horizontal and vertical tracheotomy after short-duration tracheostomy in dogs using clinical, radiographic, endoscopic, and histologic methods. Materials and Methods: Horizontal tracheotomy (n = 6) between the third and fourth tracheal rings or vertical tracheotomy (n = 6) across tracheal rings three through five was performed for airway management during laryngoplasty. Tracheostomy tubes were maintained for 6 hours with low-pressure cuff inflation time limited to the first 1.5 hours. Cervical radiographs and tracheoscopy were performed preoperatively and at postoperative weeks 2, 4, 8, and 12. Ten of the 12 dogs were killed 12 weeks after tracheostomy. Results: There was no significant difference in preoperative and postoperative tracheal diameter or change in endoscopic tracheal circumference at the tracheostomy site when dogs were compared based on type of tracheotomy. Three dogs with horizontal tracheotomies had evidence of scar (web) within the tracheal lumen 12 weeks after surgery. All vertical tracheotomies had a mild, ventral, triangular deformity. Histologic examination of vertical tracheotomy sites showed complete restoration of the pseudostratified columnar epithelium. Horizontal tracheotomies healed with a single layer of columnar epithelium. Intraluminal scar was composed primarily of loose connective tissue. Conclusion: Based on the results of this study, vertical tracheotomy shows more consistent healing compared with horizontal tracheotomy after short-duration tracheostomy. No evidence was found to support the preferential recommendation of horizontal tracheotomy for short-duration tracheostomy airway management.

Thyroid and parathyroid disease

The thyroid gland is located in the neck, behind the strap muscles and anterior to the larynx and trachea. Its normal weight is 20-25g. The isthmus of the thyroid overlies the second to fourth tracheal rings and there are two pear-shaped lateral lobes. The recurrent laryngeal nerve is located behind the thyroid. This supplies all the laryngeal muscles except the cricothyroid muscles. The thyroid gland consists of a large number of follicles, lined with cuboidal epithelial cells, and filled with colloid. The main component of the colloid is a glycoprotein called thyroglobulin. If the thyroid is enlarged, tracheal compression may result, even to the extent of causing difficulties in respiration. A retrosternal goitre of the thyroid extending into the thoracic inlet may also result in respiratory impairment. The thyroid may also extend superiorly, the so-called lingual thyroid. This is generally congenital. Carcinoma of the thyroid may involve and/or erode into trachea, oesophagus and carotid sheath.

Glomus Tumor of the Trachea: Immunohistochemical and Electron Microscopic Studies

Glomus tumor of the trachea which developed in a 51-year-old man was reported. He experienced frequent episodes of respiratory infections and hemoptosis for 9 months. Bronchofiberscopic study demonstrated a polypoid tumor in the upper trachea. Local resection of the tumor was performed and it arised from the membranous portion of the third and fourth tracheal rings. Histologically, the tumor was composed of medium-sized rounded cells, resembling carcinoid tumor. Desmin and myosin immunoreactivities were found in most of the tumor cells. Electron microscopic examination showed that the tumor cells contained fine filaments with focal density, numerous pinocytotic vesicles along the plasma membrane and abundant mitochondria. The patient is well without evidences of tumor recurrence 2 years after the resection. This is the fourth report of the tracheal glomus tumor with definitive evidences of smooth muscle differentiation of the tumor cells.

Tracheotomy in neonates.

AbstractFifty‐five tracheotomies have been performed on neonates. Forty suffered from respiratory distress syndrome and smaller groups had congenital defects and pneumonia. All tracheotomies were preceded by nasotracheal intubation for about 72 hours. Linear incision of the trachea from the second to fourth tracheal rings, insertion of lateral stay sutures and careful placement of the tube to allow aeration of both main bronchi have reduced complications. Eleven neonates developed pneumothorax as a result of high pressure ventilation; three had pneumonia, and one tracheotomy tube became temporarily” displaced. Fourteen of the neonates with respiratory distress syndrome recovered. Birth weight ranged from 1,200 G upward. Expert nursing is essential to ensure adequate humidification and suction.Neonates are defined as babies aged less than 28 days. This definition applies whether or not the birth is premature. Tracheotomies on young children have been reported in the past: Pickard1 on premature babies; Holinger2 on those younger than 12 months; and Bridges3 on those aged less than five years. In all these papers, both operative and postoperative problems have been stressed. Complications have been emphasized by Oliver, et al.,4 who, in a series of 294 tracheotomies, found all their operative complications and 85 percent of their postoperative difficulties in small infants. It must be assumed that in the past postoperative care especially has been difficult in many centers. Recent years have brought the development of more dependable apparatus for humidification and ventilation, and this has been applied to respiratory tract care in a large variety of conditions which were previously fatal in this age group. The care of such infants and the sophisticated apparatus used in treating them requires adequate numbers of highly‐trained medical and nursing staff available night and day. Such well‐staffed and well‐equipped Intensive Care Units, specializing in the treatment of neonates, are now found in many large hospital complexes throughout the United Kingdom and North America.

Simplified technique of tracheal fenestration

Tracheal fenestration was first developed by Rocky and his co-workers as a procedure in management of pulmonary suppuration. One of the authors (I.H., 1965) reported that the surgery was successfully applied to cases of bilateral recurrent laryngeal nerve paralysis. Since that time we have found a wide variety of the indication of tracheal fenestration: the operative procedure has been satisfactorily applied for cancer of the larynx (when hemilaryngectomy was done), tumors of the pharynx, tumors of the trachea, laryngeal stenosis, head injury, and disturbance in breathing after cardiac surgery, as well as bilateral recurrent laryngeal nerve paralysis.We have also noticed that a simple semicircular skin incision with the base cranial could be successfully employed instead of the complicated skin incision in Rocky's technique. Our simplified technique comprises a semicircular skin incision of three centimeter in diameter, seperation of strap muscles at the midline, dissection of the isthmus of the thyroid gland, quadrangular removal of the anterior wall of the trachea at the level of the third and fourth tracheal rings, and sutures of the skin and tracheal mucosa.

Incidence of Presence & Variation in Anatomical Position of Isthmus of Thyroid Gland in Bangladeshi Cadaver

Context: The thyroid gland is the first endocrine organ to evolve in the vertebrates. It has right and left lobes and connected by narrow median isthmus which lies over the second, third and fourth tracheal rings. A conical pyramidal lobe often ascends towards the hyoid bone from isthmus or the adjacent part of either lobe. It measures about 1.25 cm transversely and vertically. Its size and site vary greatly. Isthmus is topographically related with some important anatomical structures. So this study was carried out to determine the incidence of presence & variation in anatomical position of isthmus of thyroid gland of Bangladeshi people of different age groups to establish a normal standard. Study type: Descriptive cross-sectional study. Place and period of study: Department of Anatomy, Mymensingh Medical College. from October’2004 to February’2005. Materials: The study was carried out on 60 cadavers of different age groups age ranging from 11 to 70 years. Thyroid glands were collected from unclaimed dead bodies autopsied in Forensic Medicine Department of Mymensingh Medical College. Methods: The collected specimens were divided into age group A (upto 18 years), group B (18 to 45 years), group C (above45 years). All specimens were examined morphologically by fine dissection method. Result: In the present study isthmus was present in 41 (68.33%) cases. In those thyroids which were devoid of isthmus, lobes were found to be merged with each other in the midline but in one case two lobes were found completely separated from each other. It was evident that the posterior relations of isthmus were widely variable. In only 18% cases it was found at its usual position- against the 2nd, 3rd and 4th tracheal rings. In the present study more frequent location of isthmus was found at 1st, 2nd, 3rd and 2nd, 3rd, 4th tracheal rings. In both cases their incidences were 18.3%. Conclusion: The present study will help to increase the information pool on the anatomy of thyroid gland of Bangladeshi people. To establish a normal standard for Bangladeshi people, further studies with large samples from different zones of the country are suggested. Key Word- Isthmus; Human Thyroid gland; Incidence; Posterior relation; Bangladesh DOI: http://dx.doi.org/ 10.3329/bja.v9i1.8144 Bangladesh Journal of Anatomy January 2011, Vol. 9 No. 1 pp 26-29