Laryngotracheal stenosis is an umbrella term for a wide and heterogeneous group of very rare conditions. The population incidence of adult post-intubation laryngotracheal stenosis which is the commonest benign sub-type of this condition is approximately 1 in 200,000 adults per year. The main causes of adult laryngotracheal stenosis are:

The optimal management of laryngotracheal stenosis is not well defined, depending mainly on the type of the stenosis.

General treatment options include

1. Tracheal dilation using rigid bronchoscope

2. Laser surgery and endoluminal stenting

3. Tracheal resection and laryngotracheal reconstructionr

Tracheal is used to temporarily enlarge the airway. The effect of dilation typically lasts from a few days to 6 months. Several studies have shown that as a result of mechanical dilation (used alone) may occur a high mortality rate and a rate of recurrence of stenosis higher than 90%.

Thus, many authors treat the stenosis by endoscopic excision with laser (commonly either the carbon dioxide or the neodymium: yttrium aluminum garnet laser) and then by using bronchoscopic dilatation and prolonged stenting with a T-tube (generally in silicone).

There are differing opinions on treating with laser surgery.

In very experienced surgery centers, tracheal resection and reconstruction (anastomosis complete end-to-end with or without laryngotracheal temporary stent to prevent airway collapse) is currently the best alternative to completely cure the stenosis and allows to obtain good results. Therefore, it can be considered the gold standard treatment and is suitable for almost all patients.

The narrowed part of the trachea will be cut off and the cut ends of the trachea sewn together with sutures. For stenosis of length greater than 5 cm a stent may be required to join the sections.

Late June or early July 2010, a new potential treatment was trialed at Great Ormond Street Hospital in London, where Ciaran Finn-Lynch (aged 11) received a transplanted trachea which had been injected with stem cells harvested from his own bone marrow. The use of Ciaran's stem cells was hoped to prevent his immune system from rejecting the transplant, but there remain doubts about the operation's success, and several later attempts at similar surgery have been unsuccessful.

"Prenatal diagnosis (fetal ultrasound):"

Today the diagnosis of double aortic arch can be obtained in-utero in experienced centers. Scheduled repair soon after birth in symptomatic patients can relieve tracheal compression early and therefore potentially prevent the development of severe tracheomalacia.

"Chest X-ray:"

Plain chest x-rays of patients with double aortic arch may appear normal (often) or show a dominant right aortic arch or two aortic arches . There might be evidence of tracheal deviation and/or compression. Sometimes patients present with radiologic findings of pneumonia.

"Barium swallow (esophagraphy):"

Historically the esophagram used to be the gold standard for diagnosis of double aortic arch. In patients with double aortic arch the esophagus shows left- and right-sided indentations from the vascular compression. Due to the blood-pressure related movement of the aorta and the two arches, moving images of the barium-filled esophagus can demonstrate the typical pulsatile nature of the obstruction. The indentation from a dominant right arch is usually deeper and higher compared to the dent from the left arch.

"Bronchoscopy:"

Although bronchoscopy is not routinely done in patients with suspected or confirmed double aortic arch, it can visualize sites and severity of pulsatile tracheal compression.

"Echocardiography:"

In babies under the age of 12 months, echocardiography is considered to be sensitive and specific in making the diagnosis of double aortic arch when both arches are open. Non-perfused elements of other types of vascular rings (e.g. left arch with atretic (closed) end) or the ligamentum arteriosum might be difficult to visualize by echocardiography.

"Computed tomography (CT):"

Computed tomography after application of contrast media is usually diagnostically accurate. It shows the relationship of the arches to the trachea and bronchi.

"Magnetic resonance imaging (MRI):"

Magnetic resonance imaging provides excellent images of the trachea and surrounding vascular structures and has the advantage of not using radiation for imaging compared to Computed tomography.

"Cardiac catherization/aortography:"

Today patients with double aortic arch usually only undergo cardiac catherization to evaluate the hemodynamics and anatomy of associated congenital cardiac defects. Through a catheter in the ascending aorta contrast media is injected and the resulting aortography may be used to delineate the anatomy of the double aortic arch including sites of narrowing in the left aortic arch. Aortography can also be used to visualize the origin of all head and arm vessels originating from the two arches.

To prevent an TIF, intubation time should be limited to less than 2 weeks and proper techniques should be used when performing tracheotomies. The occurrence of an TIF can be reduced by using more flexible and blunt tracheostomy tubes and insuring that the tubes are properly aligned in the patients. Placing the tracheostomy between the second and third tracheal rings can minimize the risk of an TIF. Repetitive head movements, especially, hyperextension of the neck should be avoided as since this movement results in contact between the innominate artery and the underside of the tube.

Subglottic stenosis is a congenital or acquired narrowing of the subglottic airway. Although it is relatively rare, it is the third most common congenital airway problem (after laryngomalacia and vocal cord paralysis). Subglottic stenosis can present as a life-threatening airway emergency. It is imperative that the otolaryngologist be an expert at dealing with the diagnosis and management of this disorder. Subglottic stenosis can affect both children and adults.

Subglottic stenosis can be of three forms, namely congenital subglottic stenosis, idiopathic subglottic stenosis (ISS) and acquired subglottic stenosis. As the name suggests, congenital subglottic stenosis is a birth defect. Idiopathic subglottic stenosis is a narrowing of the airway due to an unknown cause. Acquired subglottic stenosis generally follows as an after-effect of airway intubation, and in extremely rare cases as a result of gastroesophageal reflux disease (GERD).

Subglottic stenosis is graded according to the Cotton-Meyer classification system from one to four based on the severity of the blockage.

Grade 1 – <50% obstruction

Grade 2 – 51–70% obstruction

Grade 3 – 71–99% obstruction

Grade 4 – no detectable lumen

Treatments to alleviate the symptoms of subglottic stenosis includes a daily dose of steroids such as prednisone, which reduces the inflammation of the area for better breathing. Other medications such as Methotrexate is also being tested by patients but results are pending.

Surgical correction is indicated in all double aortic arch patients with obstructive symptoms (stridor, wheezing, pulmonary infections, poor feeding with choking). If symptoms are absent a conservative approach (watchful waiting) can be reasonable. Children with very mild symptoms may outgrow their symptoms but need regular follow-up.

Diagnosis is via a careful history and physical examination, often supplemented by radiographic imaging studies. Pyloric stenosis should be suspected in any young infant with severe vomiting. On physical exam, palpation of the abdomen may reveal a mass in the epigastrium. This mass, which consists of the enlarged pylorus, is referred to as the 'olive', and is sometimes evident after the infant is given formula to drink. Rarely, there are peristaltic waves that may be felt or seen (video on NEJM) due to the stomach trying to force its contents past the narrowed pyloric outlet.

Most cases of pyloric stenosis are diagnosed/confirmed with ultrasound, if available, showing the thickened pylorus and non-passage of gastric contents into the proximal duodenum. Muscle wall thickness 3 millimeters (mm) or greater and pyloric channel length of 15 mm or greater are considered abnormal in infants younger than 30 days.

Although somewhat less useful, an upper GI series (x-rays taken after the baby drinks a special contrast agent) can be diagnostic by showing the narrowed pyloric outlet filled with a thin stream of contrast material; a "string sign" or the "railroad track sign". For either type of study, there are specific measurement criteria used to identify the abnormal results. Plain x-rays of the abdomen sometimes shows a dilated stomach.

Although UGI endoscopy would demonstrate pyloric obstruction, physicians would find it difficult to differentiate accurately between hypertrophic pyloric stenosis and pylorospasm.

Blood tests will reveal low blood levels of potassium and chloride in association with an increased blood pH and high blood bicarbonate level due to loss of stomach acid (which contains hydrochloric acid) from persistent vomiting. There will be exchange of extracellular potassium with intracellular hydrogen ions in an attempt to correct the pH imbalance. These findings can be seen with severe vomiting from any cause.

TIF is a rare condition with a .7% frequency, and an mortality rate approaching 100% without surgical intervention. Immediate diagnosis and intervention of an TIF is critical for the surgical intervention success. 25-30% of TIF patients who reach the operating room survive. Recently, the incidence of TIF may have declined due to advances in tracheostomy tube technology and the introduction of the bedside percutaneous dilatational tracheostomy (PDT).

Treatment of a laryngeal cleft depends on the length and resulting severity of symptoms. A shallow cleft (Type I) may not require surgical intervention. Symptoms may be able to be managed by thickening the infant's feeds. If symptomatic, Type I clefts can be sutured closed or injected with filler as a temporary fix to determine if obliterating the cleft is beneficial and whether or not a more formal closure is required at a later date. Slightly longer clefts (Type II and short Type III) can be repaired endoscopically. Short type IV clefts extending to within 5 mm below the innominate artery can be repaired through the neck by splitting the trachea vertically in the midline and suturing the back layers of the esophagus and trachea closed. A long, tapered piece of rib graft can be placed between the esophageal and tracheal layers to make them rigid so the patient will not require a tracheotomy after the surgery and to decrease chances of fistula postoperatively. Long Type IV clefts extending further than 5 mm below the innominate artery cannot be reached with a vertical incision in the trachea, and therefore are best repaired through cricotracheal resection. This involves separating the trachea from the cricoid cartilage, leaving the patient intubated through the trachea, suturing each of the esophagus and the back wall of the trachea closed independently, and then reattaching the trachea to the cricoid cartilage. This prevents the need for pulmonary bypass or extracorporeal membrane oxygenation.

Vessel restenosis is typically detected by angiography, but can also be detected by duplex ultrasound and other imaging techniques.

Phase contrast-MRI is an imaging method which is more sensitive than MRI for analysis of the pulsatile CSF flow in the ventricular system. This method takes multiple images of the ventricles within one cardiac cycle to measure the flow of CSF running past the area of acquisition. If no flow is seen, this is a reliable diagnosis of aqueductal stenosis as it implies that there is a blockage of CSF.

Ultrasonography can be used in utero to diagnose aqueductal stenosis by showing dilation of the lateral and third ventricles. A retrospective study found that diagnosis can be made as early as 19 weeks of gestation, and that on average diagnosis is made at 33 weeks. Unfortunately, prenatal diagnosis still has a poor prognosis even with immediate treatment upon birth.

MRI is considered the best method of detecting aqueductal stensosis because it can visualize the entire length of the aqueduct, can clearly depict tumors, and can show ventricle enlargement or other deformations. It is helpful in determining the extent of the aqueductal obstruction, particularly when multiple masses or lesions are present, and thereby aids in determining the most appropriate treatment method (i.e. surgery, shunt, or ETV). When constructive interference in steady state (CISS) or fast imaging employing steady-state acquisition (FIESTA) sequence are used, subtle abnormalities or partial obstructions in the aqueduct can be depicted in the MRI. For example, CISS can be used to determine if a thin membrane interfering with CSF flow is present.

The diagnosis of pulmonary valve stenosis can be achieved via echocardiogram, as well as a variety of other means among them are: ultrasound, in which images of the heart chambers in utero where the tricuspid valve has thickening (or due to Fallot's tetralogy, Noonan's syndrome, and other congenital defects) and in infancy auscultation of the heart can reveal identification of a murmur.

Some other conditions to contemplate (in diagnosis of pulmonic valvular stenosis) are the following:

- Infundibular stenosis

- Supravalvular pulmonary stenosis

- Dysplastic pulmonic valve stenosis

In terms of treatment for pulmonary valve stenosis, valve replacement or surgical repair (depending upon whether the stenosis is in the valve or vessel) may be indicated. If the valve stenosis is of congenital origin, balloon valvuloplasty is another option, depending on the case.

Valves made from animal or human tissue (are used for valve replacement), in adults metal valves can be used.

In peripheral procedures, rates are still high. A 2003 study of selective and systematic stenting for limb-threatening ischemia reported restenosis rates at 1 year follow-up in 32.3% of selective stenting patients and 34.7% of systematic stenting patients.

The 2006 SIROCCO trial compared the sirolimus drug-eluting stent with a bare nitinol stent for atherosclerotic lesions of the superficial femoral artery, reporting restenosis at 2 year follow-up was 22.9% and 21.1%, respectively.

A 2009 study compared bare nitinol stents with percutaneous transluminal angioplasty (PTA) in superficial femoral artery disease. At 1 year follow-up, restenosis was reported in 34.4% of stented patients versus 61.1% of PTA patients.

In boys, history and physical exam is adequate to make the diagnosis. In girls, VCUG (voiding cystourethrogram) is usually diagnostic. Other tests may include:

- Urine analysis

- Urine culture

- CBC, basic metabolic panel

- Renal and bladder ultrasound

Infantile pyloric stenosis is typically managed with surgery; very few cases are mild enough to be treated medically.

The danger of pyloric stenosis comes from the dehydration and electrolyte disturbance rather than the underlying problem itself. Therefore, the baby must be initially stabilized by correcting the dehydration and the abnormally high blood pH seen in combination with low chloride levels with IV fluids. This can usually be accomplished in about 24–48 hours.

Intravenous and oral atropine may be used to treat pyloric stenosis. It has a success rate of 85-89% compared to nearly 100% for pyloromyotomy, however it requires prolonged hospitalization, skilled nursing and careful follow up during treatment. It might be an alternative to surgery in children who have contraindications for anesthesia or surgery, or in children whose parents do not want surgery.

In females, meatal stenosis can usually be treated in the physician's office using local anesthesia to numb the area and dilating (widening) the urethral opening with special instruments.

In boys, it is treated by a second surgical procedure called meatotomy in which the meatus is crushed with a straight mosquito hemostat and then divided with fine-tipped scissors. Recently, home-dilatation has been shown to be a successful treatment for most boys.

If untreated, severe symptomatic aortic stenosis carries a poor prognosis with a 2-year mortality rate of 50-60% and a 3-year survival rate of less than 30%. Prognosis after aortic valve replacement for people who are younger than 65 is about five years less than that of the general population; for people older than 65 it is about the same.

Diagnosis is conducted according to the severity of the symptoms. Initially pulmonary function tests are administered. These tests include the lungs' capability of air intake and outtake, and gas flow of oxygen and carbon dioxide between the body and environment. Following these function tests a CT scan or bronchoscopy will be ordered. The results to the scan and bronchoscopy will display the status of the rare condition. A mild case of tracheobronchomalacia would be if the patient's trachea condenses 50% of its normal space when exhaling. Moderate tracheobronchomalacia would be 25% of the normal trachea space constricting and a severe case would be if the walls touch each other.

The treatment of choice is percutaneous balloon valvuloplasty and is done when a resting peak gradient is seen to be >60mm Hg or a mean >40mm Hg is observed.

Stenoses of the vascular type are often associated with unusual blood sounds resulting from turbulent flow over the narrowed blood vessel. This sound can be made audible by a stethoscope, but diagnosis is generally made or confirmed with some form of medical imaging.

If the symptoms are severe enough, treatment may be needed. These range from medical management over mechanical ventilation (both continuous positive airway pressure (CPAP), or bi-level positive airway pressure (BiPAP) to tracheal stenting and surgery.

Surgical techniques include aortopexy, tracheopexy, tracheobronchoplasty, and tracheostomy. The role of the nebulised recombinant human deoxyribonuclease (rhDNase) remains inconclusive.

The resulting syndrome depends on the structure affected.

Examples of vascular stenotic lesions include:

- Intermittent claudication (peripheral artery stenosis)

- Angina (coronary artery stenosis)

- Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes)

- Renal artery stenosis

The types of stenoses in heart valves are:

- Pulmonary valve stenosis, which is the thickening of the pulmonary valve, therefore causing narrowing

- Mitral valve stenosis, which is the thickening of the mitral valve (of the left heart), therefore causing narrowing

- Tricuspid valve stenosis, which is the thickening of the tricuspid valve (of the right heart), therefore causing narrowing

- Aortic valve stenosis, which is the thickening of the aortic valve, therefore causing narrowing

Stenoses/strictures of other bodily structures/organs include:

- Pyloric stenosis (gastric outflow obstruction)

- Lumbar, cervical or thoracic spinal stenosis

- Subglottic stenosis (SGS)

- Tracheal stenosis

- Obstructive jaundice (biliary tract stenosis)

- Bowel obstruction

- Phimosis

- Non-communicating hydrocephalus

- Stenosing tenosynovitis

- Atherosclerosis

- Esophageal stricture

- Achalasia

- Prinzmetal angina

- Vaginal stenosis

A spinal tap is performed in the low back with dye injected into the spinal fluid. X-Rays are performed followed by a CT scan of the spine to help see narrowing of the spinal canal.

This is a very effective study in cases of lateral recess stenosis. It is also necessary for patients in which MRI is contraindicated, such as those with implanted pacemakers.