Application of Micro‑Tech stents in malignant carinal stenosis

Abstract

Malignant carinal stenosis is a disease process that is not always suitable for treatment with a Y-shaped stent. When one of the main bronchi is completely obstructed and cannot be recanalized, or its distal lung tissue has lost function, inserting a Y-shaped stent is infeasible. In this complex condition, a cone-shaped stent is selected to maintain the patency of the trachea and the other main bronchus. The efficacy of the bare cone-shaped Micro-Tech stent to treat malignant carinal stenosis was evaluated in the current study. The medical records of 47 patients with malignant carinal stenosis who underwent Micro-Tech stent placement between January 2004 and October 2017 in Beijing Tian Tan Hospital (Beijing, China) were analyzed retrospectively. A total of 47 bare Micro-Tech stents (28 Y-shaped and 19 cone-shaped) were successfully inserted in the patients. Following stent placement, immediate satisfactory results were achieved in all patients, especially an improvement of dyspnea (100%), cough (81.1%) and stridor (100%). The Karnofsky scores were significantly increased (P<0.001), and the American Thoracic Society Dyspnea Index values were significantly decreased (P<0.001). Following a median of 88 days, initial bronchoscopic interventions were performed for tumor overgrowth (84.6%), stent fracture (7.7%) and granulation tissue (7.7%). Restenting was performed in two patients due to tumor progression (n=1) and stent fracture (n=1). Removal of a Y-shaped stent was attempted in one patient, but failed, as the stent had become partly embedded in the airway mucosa. In conclusion, cone-shaped Micro-Tech stent placement maintained tracheal-unilateral main bronchus patency and benefitted patients with malignant carinal stenosis in whom Y-shaped stents were not suitable for insertion.

Stents for small airways: current practice

“…There is a major issue regarding lobar stenosis; therefore, novel technology had to be used for these cases. Additionally, with microtech stents [21] we can also use fully encapsulated balloon-expandable vascular metallic stent PTFE-covered stainless steel stent dedicated for vascular stenosis. These stents are not self-expanding and maintain shape after dilation and come preloaded on a dilation balloon at the tip of a delivery catheter.…”