Physical Examination, Complementary Tests, and Functional Status Assessment

Advanced, unresectable esophageal cancer with airway invasion has a very poor prognosis (5 year survival rate <10%).¹ Patients with this disease have not only a limited life expectancy but also many potentially debilitating complications from the local effects of their tumors. These include dysphagia, dysphonia, dyspnea from airway involvement, chest pain, and, rarely, massive fatal hemorrhage from aortic erosion.^2,3 Airway involvement in the setting of esophageal carcinoma includes tissue invasion, infiltration, or the presence of an esophago-respiratory fistula (ERF).* Airway complications may be caused (1) by extrinsic compression on the airways by the tumor or by an esophageal stent and (2) by direct invasion by the tumor into the airways. These processes can result in severe airway narrowing or ERF. Among a large series of 372 patients seen over the 14 year study period, 74 (20%) were found to have airway involvement: 35 (47%) of these patients had an ERF; in the absence of ERF, airway involvement identified as invasion or infiltration was biopsy proven in 29 of 39 patients (74%).⁴ Other investigators report airway involvement in 10.9% to 62% of cases.^4,5 Because of the proximity of the major airways to the upper two thirds of the esophagus in the thorax, major airway obstruction is also common. In fact, patients with esophageal tumors above the level of the main carina have a worse prognosis than those with lower tumors because of this anatomic relationship with the large airways.⁶ Hence, up to 25% of patients with advanced esophageal cancer may require airway stent insertion to alleviate airway obstruction.^7–10 The mean duration of survival for patients requiring airway stent insertion for obstruction due to esophageal cancer reportedly ranges from only 35 to 121 days, with many patients dying at home or in hospice.⁹

Severe respiratory symptoms in these patients may occur because of ERF or severe airway narrowing. For tumors extending into the airway lumen, as is seen in our patient, primary goals of therapy include palliative relief of the malignant obstruction of the esophageal lumen and central airway. If present, attempts can be made to close fistulas between the esophagus and the central airway or, at the least, to alleviate or diminish risks of aspiration and inability to swallow. Recurrent aspiration pneumonia may be caused by dysphagia due to esophageal obstruction or by ERF and can lead to respiratory failure. Initial chest radiographs are often normal; in these cases, they are useful for excluding other causes of respiratory symptoms such as pneumonia, pneumothorax, and pleural effusion.¹¹ In our patient, for example, pneumonia was not evident on chest x-ray (CXR) nor was ERF on bronchoscopy. The critical airway obstruction was therefore the likely culprit for respiratory failure in view of notably high peak airway pressures and normal plateau pressures, which point to an airway resistance process. In the absence of evidence for bronchospasm, mucus plugging, or kinking of the endotracheal tube, the most plausible explanation for high peak airway pressures and respiratory failure in this patient was tracheal obstruction by the esophageal mass. This was probably worsened by the moderate sedation used for EGD.

On bronchoscopy, this patient’s central airway obstruction was classified as mixed because it comprised an endoluminal component and extrinsic compression (Figure 21-2).¹² In addition to bronchoscopy, computed tomography (CT) provides a noninvasive means of confirming the presence and severity of suspected airway involvement and is valuable in assessing the length of a stenosis, especially when a bronchoscope may not be passable beyond the stenosis. Before bronchoscopy, CT may help to determine whether double stent insertion is necessary (Figure 21-3). In cases of suspected ERF, a barium swallow is usually performed.

Figure 21-2 Central airway obstruction classification on the basis of mechanism. The bottom photos represent endoluminal papillomas (left), extrinsic compression from the sarcoma (center), and mixed extrinsic compression and endoluminal obstruction from the thyroid carcinoma (right).

Figure 21-3 A, Computed tomography shows severe tracheal obstruction in a patient with esophageal cancer scheduled for esophageal stent placement. B, In a different patient with left pneumonectomy, the lower trachea and the right mainstem bronchus were severely narrowed post esophageal stent placement, resulting in respiratory failure.

Comorbidities

It is possible that our patient had hypoventilation post EGD, caused by sedation-induced reduction in minute ventilation in the setting of critical tracheal obstruction, or possibly by upper airway obstruction unmasked by sedatives. The redundant pharyngeal and laryngeal tissues, as seen in patients with obstructive sleep apnea (OSA), may further lose tonicity, contributing to the hypoventilation and hypoxemia induced by moderate sedation, which potentially leads to respiratory failure and endotracheal intubation (see video on ExpertConsult.com) (Video V.21.1). Although not documented in his medical history, based on the bronchoscopic findings, we suspected OSA in our patient. This can also contribute to poor outcomes caused by perioperative complications. Indeed, evidence suggests that patients with OSA may have more postoperative hypoxemia, upper airway obstruction, cardiac arrhythmias, and myocardial infarction.¹³ Results of observational studies show that most patients with OSA who are undergoing surgery have not been diagnosed before surgery. In a study of 2877 elective surgery patients, 24% were found to be at risk for having OSA, and 81% of these had not been diagnosed previously.¹⁴ These data raise the question whether all patients undergoing surgery should be screened for OSA.

Support System

The patient had been married for 47 years and had no children. He had no living will and no advance health care directives. His wishes were not known.

Patient Preferences and Expectations

The prognosis was discussed with the patient’s wife. By investing in patient-centered conversations with family members, health care providers can better meet the needs of families and patients during a medical crisis such as respiratory failure or admission to the intensive care unit.¹⁵ His wife hoped he could be weaned from the ventilator, so she could speak with him about his wishes.

Indications

The primary goal was to restore airway patency to facilitate extubation and change the level of care. Interventional bronchoscopic procedures have been reported to facilitate weaning from mechanical ventilation.¹⁶ Relevant to this patient’s condition, in a study of 11 inoperable patients with esophageal carcinoma and airway involvement treated with a combination of rigid bronchoscopy, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser resection, and silicone stent placement, authors noted that 4 patients who required mechanical ventilation for respiratory failure were successfully weaned from mechanical ventilation after the procedure.⁹ Overall, airway stent insertion is considered a palliative intervention for airway complications in patients with unresectable esophageal cancer.⁹ Airway stents are effective for treating airway narrowing from both extrinsic compression and direct tumor invasion and have been shown to be useful in the treatment of ERF, if present.^4,17,18 The choice of stent depends on the clinician, the place of practice, financial or health care social policy circumstances, institutional biases, and equipment availability, as well as the particular needs of the individual patient. Clinician factors include personal training, familiarity with rigid and flexible bronchoscopy, and personal preference. Institution-related factors include costs (self-expanding metallic stents [SEMS] are generally more expensive), availability of operating theaters and anesthesiologists for emergency rigid bronchoscopy, and stent availability. In terms of patient factors, one might consider the fitness of the patient for general anesthesia, the risk of provoking complete airway occlusion outside of an operating theater while performing flexible bronchoscopy, and any foreseeable chance that a stent may need to be adjusted or replaced subsequently.¹¹

Contraindications

Owing to illness severity, high anesthesia risk, or surgical refusal, patients with advanced esophageal carcinoma may not be candidates for minimally invasive airway procedures, in which case comfort care and placement of a feeding tube, if warranted, may be offered. Except for the high likelihood of OSA, our patient had no obvious pulmonary or cardiac comorbidities that could have increased the risk for perioperative myocardial infarction. Nor did evidence reveal renal or hepatic dysfunction, which, in cases of interventional bronchoscopy under general anesthesia, could make perioperative fluid management difficult and increase risks for bleeding.

Expected Results

Stent insertion in the involved airway of esophageal cancer has been shown to improve the life quality and outcomes of patients with advanced esophageal cancer.⁴ In the largest case series to date, 66 airway stents (65 studded silicone stents and 1 Wallstent metal stent) were inserted in 51 patients with airway involvement from esophageal carcinoma. Forty stents were inserted in the trachea, 16 in the left main bronchus, and 10 in the right main bronchus. In 47 patients (92%), improvement in respiratory symptoms was significant. The mean survival was 107.7 days.⁸

Although some might say that bronchoscopic stent insertion is an unwarranted and potentially costly therapeutic alternative with patients with ultimately and rapidly fatal disease, we contend that stent insertion is a palliative intervention that always warrants consideration, not only because it results in greater comfort, even over the short term, but also because it improves quality of life, might allow withdrawal from mechanical ventilation so that patients can communicate more fully with their loved ones, and may result in a reduction in level of care or more rapid discharge from the intensive care or hospital setting. In the Netherlands, where euthanasia is a legal alternative to certain palliative therapies for patients with advanced cancer, 7 out of 12 patients with esophageal cancer who elected to have airway stents inserted were judged by their family physicians to have received “worthwhile” palliation in terms of quality of life during the terminal phase of their disease, despite their relatively short remaining survival time.¹⁹

Team Experience

In high esophageal tumors and in locally invasive tumors with evidence of ERF, a shared interdisciplinary care approach between gastroenterology and pulmonary teams is recommended.²⁰ The type of airway stent selected may depend on the level of team experience and training in the technique of rigid bronchoscopy.²¹ Bronchoscopic resectional techniques such as laser, electrocautery, cryotherapy, argon plasma coagulation (APC), and photodynamic therapy (PDT), in addition to metal or silicone stent insertion, were available at our institution. Therefore in our case, the choice of treatment was guided by (1) a need for immediate improvement in airway patency to facilitate extubation, (2) a need to maintain airway patency in view of extrinsic compression, and (3) a desire for a stent that could be removed or changed easily in case of changes in clinical illness. Thus we elected to perform our procedure using a resection technique such as Nd:YAG laser for possible hemostasis and photocoagulation of tumor in conjunction with coring out, and to insert a silicone rather than a covered metal stent because of its greater expansile force.^22,23

Therapeutic Alternatives for Restoring Airway Patency

Alternative therapeutic modalities include insertion of SEMS, radiation therapy, chemotherapy, surgical intervention (esophageal bypass, diversion, and attempted resection), and comfort measures. This patient was not considered a candidate for surgical intervention given his advanced disease, poor functional status, and respiratory failure. Less invasive palliative interventions considered included other palliative bronchoscopic options such as mechanical debridement, dilation, laser ablation, electrocautery, cryotherapy, photodynamic therapy, and brachytherapy alone.²⁴ Without stent insertion, however, restoration of airway patency may not be immediate or long-lasting. In addition, any remaining extrinsic compression after debulking would require stent placement to maintain patency.