Discussion
Caustic ingestion of household cleaner by children aged 2-6 years accounted for 80% of cases of caustic injury. The severity of the injury depends on a number of factors, such as the property (acid or base), state and quantity of the substance. Acids produce coagulation necrosis, causing cicatrices, while alkalis produce liquefaction necrosis, immediately leading to severe penetrating damage. As to physical form, the rapid flow of liquid substances not only damages the mouth and pharynx, but also causes digestive tract burns[2, 3]. Due to the protective effect of the epiglottis, the vocal cords are generally not damaged, which explains why hoarseness is uncommon in these patients.
Pharyngeal stenosis is a complication caused by ingestion of harmful substances, total laryngectomy, chemoradiation, or malignant tumors. The cases of pharyngeal stenosis surgery caused by caustic ingestion are few. Berlucchi M[4] and Velasco KJS[5] chose the same way of removing the stenosis directly and applying mitomycin C to prevent the stenosis. We sought improvement upon this foundation.
How to prevent fibrosis and recurrence postoperatively is always a challenge to surgeon. Whether using a cold instrument or CO2 laser, simple excision of the tissue increases the risk of postoperative recurrence and scar formation. Many researchers have worked on this problem. Placement of laryngeal stent and graft of intervening tissue has been proven to improve phonation[6, 7]. Yılmaz T[8] first proposed the concept of butterfly mucosal flap. The sutured flaps covered raw surfaces, thus diminishing the risk of reformation of web postoperatively. Subjective and objective voice indicators and ventilation were significantly improved with this technique. In opinion of the author, besides smearing chemical drugs like mitomycin and steroids, these methods are all about diminishing the contact of surgical wounds to prevent recurrence. This technique is based on the same principle.
In the surgical treatment of glottic web, the removal of excess mucosa is controversial. Schweinfurth[9] recommended removal of excess mucosa directly, while Yılmaz T[8] suggested that the mucosal flap was insufficient to cover all the exposed mucosal surface and thus should be preserved. However, this problem is absent in the hypopharyngeal stenosis area in consequence of the larger mucosal area. But there is a fact that the flap shrinks during the development process. It should be noted that the flap should not be too small and the tension should not be too high during the process of making the mucosal flap and suturing.
At the beginning of the operation, the anesthesiologist should stop supplying pure oxygen and instead supply mixed air to prevent the airway from burning due to the laser. Tracheotomy and insertion of nasogastric tube after pharyngoplasty are often difficult to avoid. In this case, the patient’s parents were very resistant to tracheotomy and nasal feeding. Finally, the patient did not suffer these means, and achieved satisfactory therapy effect.
It is the first case in which CO2 ablation and mucosal flap suture have been applied conjunctively to the treatment of pharyngeal stenosis caused by caustic ingestion. This new attempt yielded satisfactory results. Upholding the principle of covering the bare mucosal wound, the method could be applied to similar diseases, such as pharyngeal web, but it still needs more study and clinical practice.
Conclusion :
Pharyngoplasty with mucosal dislocation incision and complementary suture is an effective technique to resect stenosis and prevent the recurrence. More case studies are needed to practice and validate the effectiveness of this technology in treating pharyngeal adhesions and stenosis.