Introduction
After procedures for stone retrieval, both stent placement and performing a marsupialization reduces the risk of stricture to the duct or papilla. Salivary flow during the healing process is also maintained. Stenting is generally recommended after combined approaches, but is not necessarily the rule after uneventful endoscopic stone removal, except in cases where a complication arises or a case associated with stricture.
Material
Several salivary stents have been developed, but not all are available in all countries. These stents include those made by AD Tech Med, Hood Laboratories (Walvekar Stent, Schaitkin Stent), and a prototype soon to be manufactured by the Storz Company.
Currently, the author uses feeding tubes utilized by neonatology for tube-feeding. These exist in three different sizes: 4, 5, and 6 (1.2, 1.5, and 1.8 mm). The length should be measured and strictly adapted to each case. The internal tip is beveled to ease the introduction. The opposite tip is modified by removing a half diameter of the tube on the last 4 or 5 mm, to create a small fin. The sutures, which fix the stent to the floor of mouth, are passed through this fin and not through the tube, thus avoiding blockage or reducing the salivary flow ( Fig. 25.1 ).
Material
Several salivary stents have been developed, but not all are available in all countries. These stents include those made by AD Tech Med, Hood Laboratories (Walvekar Stent, Schaitkin Stent), and a prototype soon to be manufactured by the Storz Company.
Currently, the author uses feeding tubes utilized by neonatology for tube-feeding. These exist in three different sizes: 4, 5, and 6 (1.2, 1.5, and 1.8 mm). The length should be measured and strictly adapted to each case. The internal tip is beveled to ease the introduction. The opposite tip is modified by removing a half diameter of the tube on the last 4 or 5 mm, to create a small fin. The sutures, which fix the stent to the floor of mouth, are passed through this fin and not through the tube, thus avoiding blockage or reducing the salivary flow ( Fig. 25.1 ).
Stenting
The stent’s intended function is to serve as a scaffolding that will hold open salivary ductal tissue and prevent obstruction by postoperative edema. After a long period of ductal obstruction by stone(s), the glandular function is often reduced or non-existent and the possible restoration of the normal function takes 2–8 weeks. The stent is important when the salivary flow is reduced, keeping the duct patent.
The stent is usually inserted over a guidewire or a probe, or directly into the duct. Length is easy to adapt in the case of a combined approach under direct visualization. It must, however, be precisely measured after a purely endoscopic procedure. A stent inserted too deeply is painful. It is advised to insert the stent with direct visualization with the stent placed over a small diameter sialendoscope. Alternatively, the proximal position of the stent can be evaluated directly with the optical fiber of the Storz modular scope without the sheath. The stent should be fixed in the appropriate position with two deep sutures of nonabsorbable 4/0 monofilament and be kept in place for between 10 and 30 days, depending on the indication and the patient’s tolerance. Restenting, if the stent extrudes early after the procedure, is an ongoing matter of debate.
During interventional sialendoscopy for stones, stents can be used in three different ways: to facilitate the stone location; to help with duct reconstruction; and to secure the opening of the papilla in the floor of mouth, or the opening of the duct in the floor of mouth in cases of marsupialization.
Facilitates the Stone Location and the Duct Dissection
During selected cases, a stent can help locate a stone during a combined approach, especially in the proximal Wharton’s duct when the lithiasis is not really palpable (and not accessible for fragmentation). After precisely locating the stone endoscopically, the stent is inserted into the duct, with the tip in contact with the stone. The stent is fixed in this position to the floor of mouth mucosa. The stent facilitates the dissection and leads to the stone at its tip ( Fig. 25.2 ). This procedure may also be helpful in the parotid combined approach, to facilitate the duct’s dissection within the gland parenchyma.
