Malignant Central Airway Obstruction Research Articles

1161P Clinical outcomes of bronchoscopic cryotherapy for malignant central airway obstruction in patients with non-small cell lung cancer

The Prognosis of patients with malignant central airway obstruction (MCAO) is very poor; nonetheless, the clinical outcome of bronchoscopic cryotherapy (BC) in patients with non-small cell lung cancer (NSCLC) is not well known. This study aimed to evaluate the clinical outcomes of BC and evaluate the factors associated with complication.

Clinical Study of Airway Stent Implantation in the Treatment of Patients with Malignant Central Airway Obstruction.

Background Airway stenting is a therapeutic option for malignant central airway obstructions (MCAO), including both intraluminal and extraluminal obstructions. The objective of this study is to investigate the clinical features and results of long-term improved prognosis for MCAO patients after airway stent implantation. Methods Ninety-eight MCAO patients who underwent stent placement in our hospital from January 2013 to April 2020 were included in this study. The data included baseline data, clinical characteristics, laboratory test data, stent implantation data, and treatment as well as survival after stent implantation. The survival rates among individuals were compared via log-rank tests. Potential prognostic factors were identified using multivariate cox hazard regression models. Results A retrospective analysis of these patients was generated. MCAO was mainly caused by lung cancer (53/98, 54.08%), esophageal cancer (22/98, 22.45%), and thyroid cancer (3/98, 3.06%). The median survival time of participants was 5.5 months. Univariate analysis indicated that the survival rate was related to primary disease, ECOG PS score, stent site, hemoglobin (Hb), albumin (ALB), and serum lactate dehydrogenase (LDH) (P < 0.05). The cox risk regression model showed that the survival rate was significantly influenced by ECOG PS score (OR = 3.468, 95%CI = 1.426–8.432, P = 0.006) and stent site (OR = 1.544, 95%CI = 1.057–2.255, P = 0.025). Conclusions Compared with the site of stent placement, the ECOG PS score is the primary factor in the survival rate of MCAO patients after airway stenting.

Comparison of operation time, efficacy and safety between through-the-scope stent and over-the-while stent in malignant central airway obstruction: a multi-center randomized control trial.

BackgroundSelf-expandable metallic (SEM) airway stents are an important approach to treating malignant central airway obstruction (CAO). Standard over-the-while (OTW) stent needs the guidance of a guide-wire. It should be implanted under flouroscopy or the guidance of bronchoscope visualization. In this study, we evaluated the operation time and safety between OTW stent and a novel through-the-scope (TTS) SEM airway stent.MethodsIn this multi-center, randomized, parallel-group superiority study, malignant CAO patients were enrolled randomly assigned (2:1) to the TTS stent implantation group (TTS group) or the standard OTW stent group (OTW group) in six sites across China. The entire process of all surgical procedures was recorded by video. Primary endpoint was the operation time of the airway stent implantation and secondary endpoint was the success rate of the stent implantation as well as its efficacy and safety.ResultsFrom May 15, 2017, to December 30, 2018, 148 patients were enrolled from the six sites. We analyzed 134 patients (including 91 patients from the TTS group and 43 patients from the OTW group) according to the per-protocol set. There were no significant differences in the ages, genders, underlying diseases, and stenosis sites between the two groups. The operation time in the TTS group was significantly shorter than that in the OTW group (104±68 vs. 252±111 seconds, P<0.001). Compared to the OTW group, the efficacy of stent implantation (97.80% vs. 90.70%, P=0.093) and rate of first-time successful stent implantation (78.02% vs. 74.42%, P=0.668) were higher in the TTS group, but did not reach statistically significance. The rates of granulation (28.57% vs. 41.86%, P=0.128) and restenosis (15.38% vs. 30.23%, P=0.064) in the TTS group were slightly lower as compared with the OTW group without achieving statistical significance.ConclusionsThe TTS stent implantation procedure time was significantly shorter than that of the OTW airway stent with similar efficacy and complications, which might reduce the risk and flexibility of stent implantation.Trial RegistrationChinese Clinical Trial Registry ChiCTR-IOR-17011431.

Self-Expandable Metal Stent in the Management of Malignant Airway Disorders.

BackgroundSelf-expanding metallic stent (SEMS) is a palliative therapy for patients with malignant central airway obstruction (CAO) or tracheoesophageal fistula (TEF). Despite this, many patients experience death shortly after SEMS placement.AimsWe aimed to investigate the effect of SEMS on the palliative treatment between malignant CAO and malignant TEF patients and investigate the associated prognostic factors of the 3-month survival.MethodsWe performed a single-center, retrospective study of malignant CAO or TEF patients receiving SEMS placement. Clinical data were collected using the standardized data abstraction forms. Data were analyzed using SPSS 22.0. A two-sided P-value <0.05 was statistically significant.Results106 malignant patients (82 CAO and 24 TEF) receiving SEMS placement were included. The body mass index (BMI), hemoglobin levels, and albumin levels in the malignant TEF group were lower than in the malignant CAO group (all P < 0.05). The procalcitonin levels, C-reactive protein levels, and the proportion of inflammatory lesions were higher in the malignant TEF group than in the malignant CAO group (all P < 0.05). The proportion of symptomatic improvement after the SEMS placement was 97.6% in the malignant CAO group, whereas 50.0% in the malignant TEF group, with a significant difference (P = 0.000). Three months after SEMS placement, the survival rate at was 67.0%, significantly lower in the malignant TEF group than in the malignant CAO group (45.8% vs. 73.2%, P = 0.013). Multivariate analysis revealed that BMI [odds ratio (OR) = 1.841, 95% certificated interval (CI) (1.155-2.935), P = 0.010] and neutrophil percentage [OR = 0.936, 95% CI (0.883–0.993), P = 0.027] were the independent risk factors for patients who survived three months after SEMS placement.ConclusionsWe observed symptom improvement in malignant CAO and TEF patients after SEMS placement. The survival rate in malignant TEF patients after SEMS placement was low, probably due to aspiration pneumonitis and malnutrition. Therefore, we recommend more aggressive treatment modalities in patients with malignant TEF, such as strong antibiotics, nutrition support, and strategic ventilation. More studies are needed to investigate the prognostic factors in patients with malignant airway disorders receiving SEMS placement.

Therapeutic bronchoscopy for malignant central airway obstruction: impact on quality of life and risk-benefit analysis.

Malignant central airway obstruction (CAO) is a common complication in cancer and confers significant symptom burden and reduction in quality of life. Multiple bronchoscopic interventions exist for malignant CAO. In this review, we discuss the role of therapeutic bronchoscopy in the management of malignant CAO, emphasizing its impact on symptom control and quality of life while balancing the risks and benefits of intervention. Significant practice variations exist among practitioners of therapeutic bronchoscopy, and limited data exist to guide real-time clinical decision-making. Recent analyses demonstrate that therapeutic bronchoscopy is effective for symptoms associated with malignant CAO with infrequent complications. These studies also show that many of the improvements in symptoms and quality of life are sustained after intervention and are associated with improved overall survival in patients with malignant CAO. Recent data have also shown that the improvement in symptoms associated with therapeutic bronchoscopy may enable more definitive cancer treatment, further improving patient outcomes. Therapeutic bronchoscopy is safe and effective at improving patient-centered outcomes in malignant CAO. Research is ongoing to better understand its optimal role in this setting, refine decision-making regarding advanced bronchoscopic interventions, and further improve patient outcomes.

Role of Endobronchial Electrocautery in Management of Neoplastic Central Airway Obstruction: Initial Experience with Seven Cases

Central airway obstruction (CAO) due to malignant and benign conditions is common. Tumour ablation by various techniques helps effective palliation of symptoms in such patients. Tumour ablation using endobronchial electrocautery (EBEC) with flexible bronchoscope (FB) is an established procedure. However, there is paucity of data from India on this topic. EBEC was performed in seven patients with CAO; six of these patients had malignant (non-small cell carcinoma) and one had benign aetiology (tracheal fibro-epithelial polyp) as the cause of CAO. Pre- and post-procedure assessment was done with the help of Speiser's symptomatic scoring. Mean age of the patients was 52.9 +/- 7.0 years; there were five males. All the patients had symptomatic relief after the procedure; in five of them the improvement in symptom scores was significant. No major complication was encountered in any patient. EBEC can be a safe, effective and cost-effective tool for palliation in patients with benign or malignant CAO. It is especially beneficial for centres where cost of bronchoscopic laser and cryotherapy is prohibitive.

Malignant Central Airway Obstruction: What's New?

Malignant central airway obstruction (MCAO) is a debilitating and life-limiting complication that occurs in an unfortunately large number of individuals with advanced intrathoracic cancer. Although the management of MCAO is multimodal and interdisciplinary, the task of providing patients with prompt palliation falls increasingly on the shoulders of interventional pulmonologists. While a variety of tools and techniques are available for the management of malignant obstructive lesions, advancements and evolution in this therapeutic venue have been somewhat sluggish and limited when compared with other branches of interventional pulmonary medicine (e.g., the early diagnosis of peripheral lung nodules). Indeed, one pragmatic, albeit somewhat uncharitable, reading of this article's title might suggest a wry smile and shug of the shoulders as to imply that relatively little has changed in recent years. That said, the spectrum of interventions for MCAO continues to expand, even if at a less impressive clip. Herein, we present on MCAO and its endoscopic and nonendoscopic management-that which is old, that which is new, and that which is still on the horizon.

Difference in the Overall Survival Between Malignant Central Airway Obstruction Patients Treated by Transbronchial Microwave Ablation and Stent Placement: A Single-institution Retrospective Study.

Transbronchial microwave ablation (MWA) can be performed safely in patients with malignant central airway obstruction (MCAO), under moderate sedation and a high fraction of inspired oxygen. We retrospectively evaluated the difference in the overall survival (OS) after transbronchial interventions (TBIs) between MCAO patients with endoluminal or mixed-type obstruction who were treated by MWA (MWA group, n=34) and those with extraluminal obstruction who were treated by stent placement (STP) (STP group, n=27). The OS was longer in the MWA group than in the STP group (10.2 months vs. 4.5 months, p=0.001). A significant difference in the OS between the two groups was observed in the patients who received post-TBI anticancer therapy (27.2 months vs. 6.0 months, p=0.002). The OS tended to be longer in the MWA group than in the STP group, among the patients who received best supportive care alone (3.8 months vs. 1.8 months, p=0.068). Nine patients (26%) of the MWA group underwent additional MWA when tumor regrowth into the airway lumen was noted (median of TBI sessions, 3). Multivariate analysis identified the adoption of MWA as the initial treatment procedure to be independently associated with a reduced risk of death in patients with MCAO (hazard ratio=0.473, p=0.031). Adoption of MWA as the initial treatment procedure is beneficial in MCAO patients with endoluminal or mixed-type obstruction, regardless of whether patients receive post-TBI anticancer therapy or not.

Microwave Ablation for Malignant Central Airway Obstruction: A Pilot Study

Background: Malignant central airway obstruction (CAO) is a debilitating complication of primary lung cancer and pulmonary metastases. Therapeutic bronchoscopy is used to palliate symptoms and/or bridge to further therapy. Microwave ablation (MWA) heats tissue by creating an electromagnetic field around an ablation device. We present a pilot study utilizing endobronchial MWA via flexible bronchoscopy as a novel modality for the management of malignant CAO. Methods: Therapeutic bronchoscopy with a flexible MWA probe was performed in 8 cases. We reviewed tumor size, previous ablative techniques, number of applications, ablation time, amount of energy delivered, rate of successful recanalization, complications, and 30-day follow-up. Results: Successful airway recanalization was achieved in all cases. No complications were noted. In 1 case, tumor in-growth within a silicone stent was ablated with no damage to the stent. Discussion: Endobronchial MWA is a novel technique for tumor destruction while maintaining an airway axis. The oven effect and air gap around a tumor allow for safe and effective tissue devitalization and hemostasis without a thermal effect on structures surrounding the airway.

Central airway obstruction treatment with self-expanding covered Y-carina nitinol stents: A single center retrospective analysis.

BackgroundCentral airway obstruction (CAO) is one of the most challenging, potentially lethal complications in malignant and benign respiratory diseases. Worsening dyspnea is also a relevant cause for reduced quality of life in such patients. Here, we present our data on the application of covered, self‐expanding Y‐carina nitinol stents due to benign and malignant diseases.MethodsWe retrospectively identified 27 patients who had undergone 31 rigid bronchoscopies with implantation of covered Y‐carina nitinol stents over a period of 10 years in order to evaluate indication, clinical course, and outcome.ResultsShort‐term survival of successfully stented patients with palliative and curative treatment goal did not differ, allowing for diagnosis independent indication. With respect to overall survival, patients with endoluminal obstruction benefited most compared to patients with fistula and/or external compression. Granulation tissue formation (61.3%) and mucus plugging (80.6%) were the most frequent complications. Material defect (6.5%) and migration (3.2%) were rare complications that could be handled by revisional rigid bronchoscopy and stent exchange in some cases.ConclusionsImplantation of self‐expanding covered Y‐carina nitinol stents via rigid bronchoscopy is a feasible and safe treatment option for benign and malignant central airway obstruction. Especially in palliative, malignant airway stenosis, stenting might facilitate additional treatment options and optimize dyspnea and eventually quality of life.

P12‐4: Interventional pulmonology for elderly patients with malignant central airway obstruction

P12‐4: Interventional pulmonology for elderly patients with malignant central airway obstruction

Beware of spurious tracheo-bronchial stents

ObjectiveTo present a case of accidental sheath removal of tracheo-bronchial self-expandable metallic airway stent in a patient with endotracheal tumour. MethodsDesign: Case Report; Setting: Tertiary care hospital; Patient: One. ResultsA 65 years male, follow up case of endotracheal tumor with tracheo-bronchial self-expandable metallic stenting done presented with dry cough and difficulty in breathing since 8–10 days and suddenly coughed out thin whitish paper-like material 2 days back (which later proved as sheath of metallic stent). Direct laryngoscopy with flexible videobronchoscopy was done which showed tracheal stent well placed and intact, coughed out sheath couldn't be replaced back. Procedure was uneventful and patient was discharged in satisfactory condition and is doing well on regular follow up. ConclusionSelf-expandable metallic airway stents (SEMAS) represents a standard method of airways stenting especially when employed for the management of malignant central airway obstruction. Despite the obvious stenting advantages, it may be complicated with stent migration and accidental removal or coughing out of stent especially in high tracheal stenosis. In our case, as a peculiar complication there was accidental removal of the tracheal stent sheath which couldn't be replaced back whereas stent was well in place and intact. We need to be beware of such spurious tracheo-bronchial stents.

Therapeutic Rigid Bronchoscopy Intervention for Malignant Central Airway Obstruction Improves Performance Status to Allow Systemic Treatment.

Malignant central airway obstruction may result in an Eastern Cooperative Oncology Group Performance Status (ECOG PS) that precludes treatment with systemic therapies. We sought to evaluate outcomes of patients undergoing rigid bronchoscopy for malignant central airways obstruction (MCAO) and its effect on access to systemic therapies including immunotherapy. We conducted a retrospective observational single-center study evaluating 77 consecutive patients who underwent rigid bronchoscopy from March 2015 to November 2019. Procedural details, preprocedural and postprocedural ECOG PS, complications, and proportions of patients receiving systemic therapy postprocedure were recorded. The majority of patients were ECOG PS 2 to 3 at diagnosis (62%). The most common indication was MCAO due to squamous cell carcinoma (35.1%). MCAO was managed with a debulking/dilatation procedure alone (51.9%) or in combination with stenting (48.1%). The laser was unavailable, electrocautery was used for hemostasis only not tumor ablation. Significant improvement in ECOG PS postprocedure in the group with baseline ECOG PS 3 to 4 (P<0.0001) and in those with baseline ECOG PS 0 to 4 (P<0.00001) was observed. The main complication was bleeding, controlled bronchoscopically with mechanical compression with a rigid bronchoscope and/or electrocautery (68.8% of patients). No deaths occurred. Overall, 70% of those presenting with ECOG 3 to 4 went onto receive systemic therapies that would have been contraindicated due to poor baseline ECOG PS. Therapeutic rigid bronchoscopy is safe and efficacious in the management of MCAO, improving ECOG PS allowing for the administration of systemic therapies. This is especially important in the era of immunotherapy and directed therapies, which have been shown to provide significant survival benefit over conventional therapies alone.

Advances in endobronchial ablative therapies

: Endobronchial ablative therapies are standard of care in therapeutic bronchoscopy for management of malignant and non-malignant central airway obstruction and of endobronchial bleeding. In malignant and non-malignant central airway obstruction with endoluminal involvement, a multi-modality bronchoscopic approach combining endobronchial ablative therapies, mechanical debulking, airway dilation, and airway stent placement is often first line treatment. Endobronchial ablative therapies can be utilized in conjunction with chemotherapy, radiation therapy, and surgery to improve quality of life and possibly long-term survival in malignant central airway obstruction. In select cases, endobronchial ablative therapies are treatment options with curative intent for endobronchial carcinoma in situ and early lung cancers. High quality clinical trials directly comparing the efficacy and safety profiles among endobronchial ablative therapies are lacking. Herein, endobronchial ablative therapies are reviewed.

Modeling the effect of tumor compression on airflow dynamics in trachea using contact simulation and CFD analysis

Malignant central airway obstruction can cause severe breathing difficulty in a patient that requires surgical intervention or stent implantation to alleviate it. A predictive model to identify the onset of this event as the central airway is progressively compressed by tumor growth will be helpful for clinicians to plan for medical intervention. We present such a model to simulate tumor compression of the trachea and the resulting change in airflow dynamics to estimate the level of stenosis that will cause severe breathing difficulties. A patient-specific model of trachea was generated from acquired Computed Tomography (CT) scans for the simulations. The compression of this trachea due to tumor growth is modeled using nonlinear contact simulations of ellipsoidal tumors with the trachea. Computational fluid dynamics (CFD) is employed to simulate the turbulent airflow during inhalation in the stenosed trachea. From the CFD simulated flow fields, the power loss due to airflow through the domain is calculated. The results show that when the obstruction in the trachea reaches 50%, compared to the undeformed model, the power loss can rise to more than 66%. A measure of breathing difficulty can be derived by correlating it with the power loss. Thus, medical intervention can be predicted based on the degree of stenosis if the induced power loss exceeds a threshold that causes severe breathing discomfort.

Tracheobronchial stents in patients with malignant airway disease: Finnish tertiary care experience.

Tracheobronchial stenting has an established role in the palliation of malignant central airway obstruction (CAO). The purpose of this study is to describe the experience with self-expanding metal airway stents in 2 tertiary referral centres, covering a third of the population of Finland. Patients referred to and treated with airway stenting for malignant CAO using self-expanding metal-stents were identified from electronic patient records, and data were collected using a structured Endoscopic Lower Airway Management instrument. Statistical analysis to reveal factors affecting patient benefit and survival was carried out. A total of 101 patients (mean age 65.8) and 116 procedures were identified. Procedure-related mortality was rare (3/101 patients) and complications infrequent. The median survival was 2.3 months [95% confidence interval (CI): 1.4-3.1). Stent benefit was not significantly affected by clinical characteristics. Survival was impacted by the use of adjunct procedures [hazard ratio (HR) 0.36, 95% CI: 0.23-0.58, P < 0.001), procedural urgency (HR 0.40; 95% CI: 0.23-0.71, P = 0.002) and post-treatment chemoradiotherapy (HR 0.29, 95% CI: 0.15-0.56, P < 0.001). The beneficial impact observed supports the further use of tracheobronchial stenting in malignant CAO. The use of self-expanding metal stents is encouraged.

Esophageal Cancer, Central Airway Obstruction, and Lots More: A Collaborative Approach to a Challenging Scenario.

Esophageal cancer is the most common cause of extrapulmonary malignant central airway obstruction (MCAO). MCAO is usually managed by a multidisciplinary approach involving tumor debulking, stent placement, and palliative radiotherapy. MCAO is a challenge in itself; here, it becomes even more challenging as it was accompanied by grade 3 oral submucous fibrosis, nasal synechiae, and multiple enlarged cervical nodes causing excessive compression of the trachea along with acute hypercapnic respiratory failure. Herein, a 65-year-old woman with multiple challenges, where death was imminent, managed with a collaborative approach involving awake nasal intubation in the sitting position and placement of a stent via a flexible bronchoscope, as rigid bronchoscopy was not possible in view of limited mouth opening. Overcoming these challenges led to completing the procedure successfully and palliating the symptoms.

Interventional Pulmonology: Diagnostic and Therapeutic Advances in Bronchoscopy.

Interventional pulmonology is a rapidly evolving subspecialty of pulmonary medicine that offers advanced consultative and procedural services to patients with airway diseases, pleural diseases, as well as in the diagnosis and management of patients with thoracic malignancy. The institution of lung cancer screening modalities as well as the search of additional minimally invasive diagnostic and treatment modalities for lung cancer and other chronic lung diseases has led to an increased focus on the field of interventional pulmonology. Rapid advancements in the field over the last 2 decades has led to development of various new minimally invasive bronchoscopic approaches and techniques for patients with cancer as well as for patients with chronic lung diseases. A review of literature was performed using PubMed database to identify all articles published up till October 2020 relevant to the field of interventional pulmonology and bronchoscopy. The reference list of each article was searched to look for additional articles, and all relevant articles were included in the article. Newer technologies are now available such navigation platforms to diagnose and possibly treat peripheral pulmonary nodules, endobronchial ultrasound in diagnosis of mediastinal and hilar adenopathy as well as cryobiopsy in the diagnosis of diffuse lung diseases. In addition, flexible and rigid bronchoscopy continues to provide new and expanding ability to manage patients with benign and malignant central airway obstruction. Interventions are also available for diseases such as asthma, chronic bronchitis, chronic obstructive pulmonary disease, and emphysema that were traditionally treated with medical management alone. With continued high quality research and an increasing body of evidence, interventional bronchoscopy has enormous potential to provide both safe and effective options for patients with a variety of lung diseases.

Clinical effects of cisplatin plus recombinant human endostatin (rh-endostatin) intratumoral injection on malignant central airway obstruction: a retrospective analysis of 319 cases.

BackgroundPrimary lung cancer with severe central airway obstruction (CAO) is often life-threatening. In this study, we investigated the clinical efficacy and safety of cisplatin plus recombinant human endostatin (rh-endostatin) intratumoral injection in treatment of malignant central airway obstruction (MCAO) caused by primary squamous cell lung cancer.MethodsWe retrospectively analyzed patients with MCAO caused by primary squamous cell lung cancer treated with and without bronchoscopic intratumoral injection of cisplatin plus rh-endostatin between January 2007 and June 2016.ResultsA total of 206 patients received cisplatin plus rh-endostatin intratumoral injection, and 113 without injection. Dyspnea grade, degree of stenosis, quality of life and lung function of all patients were significantly improved at 1 week after treatment compared with baseline. Both groups achieved good airway patency (97.1% vs. 93.8%, P=0.156). Followed up at 2 months, all parameters were improved in the injection group compared with baseline, while no statistical differences were observed in the non-injection group (P>0.05). The injection group achieved airway patency in 155 (75.2%) of 206 patients, which was significantly superior to the non-injection group [20 (17.7%) of 113, P<0.001]. In addition, the restenosis rate of the injection group was lower compared with the non-injection group (22.5% vs. 81.1%, P<0.001, respectively). No serious complications were observed in two groups.ConclusionsCisplatin plus rh-endostatin intratumoral injection is effective and safe for the therapy of MCAO caused by primary squamous cell lung cancer.

Contributions of Airway Stent for Long-term Outcome in Patients With Malignant Central Airway Stenosis or Obstruction.

Although an airway stent is used for malignant central airway stenosis or obstruction, long-term outcomes are unknown. In this study, we retrospectively analyzed the clinical features of patients who required stenting for malignant central airway stenosis or obstruction. We retrospectively analyzed clinical data from 116 patients with stenting for central airway stenosis or obstruction who underwent treatment at Toho University Hospital from 1998 to 2018. We evaluated the clinical features, prognoses, and complications for stenting in these patients. The distribution of the 116 patients was as follows: lung cancer, 53; esophageal cancer, 40; thyroid cancer, 8; and others, 15. Patients with thyroid cancer had a significantly higher rate of complications after stenting than patients with lung cancer (P=0.0062), esophageal cancer (P=0.0029), and others (P=0.0062). Patients with esophageal cancer had a significantly worse prognosis than patients with lung and thyroid cancer. In patients with lung cancer the prognosis was significantly different between patients who underwent additional treatment for lung cancer after stenting and patients with no treatment (P=0.0398), and patients who received chemoradiotherapy for lung cancer after stenting had a significantly better prognosis than patients with no treatment (P=0.0306). Stenting for airway stenosis/obstruction may improve prognosis in patients with lung or thyroid cancer, especially if patients with lung cancer undergo additional treatments after stenting, although airway stenting for patients with esophageal cancer was palliative. New treatment strategies may be necessary for patients with esophageal cancer after stenting to improve prognosis.