Endoscopic Injection of Mitomycin C for the Treatment of Pharyngoesophageal Stenosis
Endoscopic Injection of Mitomycin C for the Treatment of Pharyngoesophageal Stenosis
Management of pharyngoesophageal stenosis (PES) in patients after head and neck cancer (HNC)
 treatment remains a challenge. There are some cases of strictures refractory to dilation
 sessions. This study aimed to evaluate the efficacy of Mitomycin C (MMC) endoscopic injection
 for the treatment of refractory pharyngoesophageal stenosis.

 Patients and methods: This is a prospective study in patients with dysphagia following head
 and neck cancer treatment, without evidence suggestive of tumor recurrence, and refractory to
 endoscopic treatment. Theses undergo endoscopic dilation of the stenotic segment with
 thermoplastic bougies, followed by the injection of MMC.
Management of pharyngoesophageal stenosis (PES) after cancer treatment in patients with head
 and neck cancer (HNC) remains a challenge. The etiology of PES in this group of patients is
 probably multifactorial, being associated with surgical manipulation, ischemic effects of
 radiotherapy and even cancer recurrence. It is estimated that up to 50% of patients treated
 for advanced HNC will present some degree of dysphagia. PES is a frequent cause of post
 treatment dysphagia of HNC patients. Although the exact prevalence is unknown, several
 retrospective series estimate that upper cervical stricture is present in 1% to 23% of the
 cases. The initial approach to PES is endoscopic dilation with a reported success rate
 ranging from 76% to 96%. In patients with refractory strictures to dilation sessions,
 endoscopic corticosteroid injection, such as triamcinolone, is usually added to the dilation
 sessions, which may increase the success of the endoscopic treatment. A relatively small
 group of patients will be refractory to the association of dilation and corticosteroid
 injection treatment. Metal stents may be considered in this scenario, but in the case of
 pharyngoesophageal stenosis, this approach is limited by cervical pain and foreign body
 sensation. Surgical reconstruction for pharyngoesophageal stenosis refractory to endoscopic
 treatment is the last therapeutic option (2). Previous radiotherapy, eventual reconstruction
 with cutaneous flaps make a surgical manipulation of the cervical region a real challenge,
 with increased adverse event rate, including restenosis.(2) Because of such difficulties,
 this prospective study aimed to evaluate the efficacy of Mitomycin C (MMC) endoscopic
 injection for the treatment of pharyngoesophageal stenoses in patients who were treated for
 head and neck cancer, refractory to endoscopic dilation treatment. There are descriptions of
 the use of Mitomycin C for scar prevention after ophthalmologic and otorhinolaryngological
 interventions (8). Its use in endoscopy has previously been described for the treatment of
 laryngeal and tracheal stenosis as well as refractory esophageal stenosis. Mitomycin C is a
 substance isolated from the bacterium Streptomyces caespitosus, which is used as a
 chemotherapeutic agent and has antiproliferative effects on fibroblasts, reducing fibroblast
 proliferation and collagen formation. Some studies demonstrated the ability to decrease
 fibroblast activity and consequent scar formation after the application of Mitomycin C on
 culture of fibroblasts in low concentrations (0.1 to 0.4 mg / ml) for 5 to 10 minutes,
 affecting their proliferation for over 3 weeks.
Inclusion Criteria:

 -  Patients with dysphagia following head and neck cancer treatment

 -  Patients without endoscopic or radiological evidence suggestive of tumor recurrence

 -  Patients refractory to endoscopic treatment

 Exclusion Criteria:

 -  Endoscopic or radiological signs suggestive of tumor recurrence