Wednesday, May 19, 2010

Nasal stents are they really useful ?


Formation of synechiae constitute one of the common complications following ESS. Conservative estimates place about 10 % of all patients who have undergone ESS as prone for synechiae. Dissection in the frontal sinus area is more prone for synechiae formation because of the difficult access. Dissection in this area is troublesome due to the difficult angle involved. True cutting instruments which cause little tissue damage have difficulty in reaching this area. Using powered shavers and debriders in this area has also not managed to reduce the risk of synechiae. Stents have been used with varying degree of success in preventing postop complications following ESS.

Functions of Stents following ESS:

1.The primary function of stent is to separate two edges of raw wound thus preventing the formation of fibrous band / synechiae. This is classically seen when there is lateralization of middle turbinate following ESS. Lateralization of middle turbinate can potentially obstruct middle meatus drainage. This can effectively be prevented by placing a stent between the middle turbinate and the lateral nasal wall.
2.Stents can potentially take up space which would otherwise be occupied by mucous/ clot. Presence of clot can lead to epithelial migration and synechiae formation.
3.Patients in whom stents have been placed have very little crust formation, hence frequent wound debridement is not needed.
4.Stents also serve as occlusal dressing facilitating better & faster wound healing. Occlusal dressings have known to reduce tissue necrosis.

Types of nasal stents:

1.Middle meatal stent
2.Frontal sinus stent
3.Drug containing stents

Middle meatal stents:

Role of middle meatal stents include:

1.Decrease synechiae formation
2.To prevent lateralization of middle turbinate
3.Since it fills up the ethmoid sinuses it effectively prevents clots, mucous or fibrin.

Stents of middle meatus is also known as spacers. Common spacers of middle meatus are made of glove fingers filled with polyvinyl acetyl sponge which are sutured together and tied with silk. Since this spacer is smooth it does not adhere to the surrounding tissue, thus serves as an occlusive dressing.

Foam made of biodegradable synthetic material like polyurethane can also be used to stent the middle meatus after surgery. This material is suitable for patients who does not tolerate other types of middle meatal stents.

               Image showing Freemann stent

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