Schematic image of an absorbable magnesium stent to manage ETD showing prevention of stent-induced tissue hyperplasia and maintaining the ET patency.

Schematic image of an absorbable magnesium stent to manage ETD showing prevention of stent-induced tissue hyperplasia and maintaining the ET patency.</p

Representative histological images of the porcine ET and histological findings.

(A) Histological images showing the submucosal tissue hyperplasia increased at two weeks and then significantly decreased at four weeks. (B) Histological results of the thickness of submucosal tissue hyperplasia and the degree of inflammatory cell infiltration in the proximal and distal portions of the stented ET over time after the Mg stent placement. Note. Mg, magnesium; ET, Eustachian tube.</p

Representative endoscopic and CT images of the stented ET over time.

(A) Endoscopic images taken immediately after stent placement, showing the proximal end of the Mg stent (arrows) in the porcine ET. The proximal end of the stent with mild secretion (arrows) is observed around the Mg stent at two weeks, while the Mg stent is not observed at four weeks (arrowheads). (B) 3D-reconstructed CT images of the degraded Mg stent showing a residual Mg stent with a collapsed distal end at two weeks and only a small piece of the Mg stent at four weeks. Note. CT, computed tomography; Mg, magnesium; ET, Eustachian tube.</p

Surface morphologies of the Mg stent and mass loss rates.

(A) SEM images showing the size and number of the cracks increasing over time (arrows) on the surface of Mg stent samples obtained at one, two, and four weeks, respectively. (B) The bridges (arrows) between the struts are disconnected, and the strut was sequentially separated. (C) A graph depicting the mass loss rates of the Mg stent over a four-week period. Note. Mg, magnesium; SEM, scanning electron microscopy.</p

The Mg stent and the technical steps of ET stent placement under endoscopic guidance.

Photographs showing (A) the Mg stent loaded onto a balloon catheter and (B) when fully expanded. (C) Endoscopic image showing the nasopharyngeal ostium (arrowheads). (D) The steerable guiding sheath (arrows) was inserted into the nasopharyngeal ostium. (E) The balloon catheter crimped with the Mg stent (arrowheads) is advanced into the ET. (F) The balloon catheter was fully inflated with saline. (G) After verifying the fully expanded stent (arrows), the sheath with the balloon catheter was removed. (H) An endoscopic image of the Mg stent (arrowheads) in the porcine ET. Note. Mg, magnesium; ET, Eustachian tube.</p