Endoscopically Based Endonasal and Transnasal Lasersurgery

The endoscopically based endonasal and transnasal laser surgery is a surgical procedure, which offers the ENT-specialist a safe and effective method to cure or to improve a number of diseases of the upper and middle airways. Coagulative lasers are used in contact and noncontact mode. Their light is mainly absorbed by hemoglobin but rarely by water. The laser–tissue interaction is performed via flexible glass fibers. For the delivery of the laser beam we use specially designed applicator sheaths, which incorporate the endoscope, the laser fiber and the suction channel. The procedure is controlled online via the endoscopic image on the monitor (“video-endoscopy”). The patient suffers less trauma using this treatment compared to the standard endoscopic surgery and the procedure is much quicker. Pre- and post-operative rhinomanometric and rhinoresistometric measurements reveal that the air flow rate of the nose can be improved effectively.


ranasal sinus
s are common all over the world.Most patients suffer from air-way blockage (anatomical abnormalities or mucosal), hypersecretion, hypo-or anosmia, an acute, recurrent or chronic sinusitis.As disturbances of the nasal function not only affect the quality of life but also the functions of the middle and lower airway structures such as pharynx, larynx, tracheal and bronchial system, ENT-specialists are often asked to take therapeutic action.Some problems can be cured with drugs, but surgical interventions are often needed in cases of: septal deviations, ridges and spurs, turbinal hyperplasia in environmental problems and in chronic mucosal hyperreactivity acute sinusitis with complications recurrent sinusitis chronic sinusitis with local or general mucosal hyperplasia and polyps mucoceles epistaxis, i.e. in Osler's disease

In the past two decades endoscopic or microscopic endonasal sinus surgery has replaced the radical forms of intervention and has become the "gold standard".Messerklinger 1-3], Wigand [4,5], Stammberger [6], Kennedy [7], Rudert [8] and others are the main contributors to the progress of this method.Through their work we have leamt more about the causes of chronic sinusitis.The micro-surgical procedure has led to a marked reduction in surgical trauma.

An additional reduction in surgical trauma could be a hieved by the use of lasers in combination with rigid or flexible endoscopes [9-27], a method which will be described in this paper.

With special lasers the surgeon is able to avoid bleeding almost totally without loss of surgical options.He can work prec sely and in very small areas using only a superficial anesthesia.There are cavernous bodies full of blood vessels in the three turbinates of each side of the nose and in parts of the septum.These vessels can be partly closed very effectively with the use of laser light, which is absorbed by hemoglobin.These lasers are also best for the closure of superficial vessels of the anterior nose or of branches of the sphenopalatine artery at the posterior areas of the nose in recurrent epistaxis or in Osler's disease.Lasers allow to perform surgical interventions even in patients with genetically fixed or drug-related hemophilia.

In some cases the nose is used as a transfer organ to naso-, oro-hypopharyngeal or laryngeal pathologies, especially cysts, pap llomas or edema formations after irradiation.Rigid or flexible endoscopes carry the glass fibers for the laser beam.

This article describes the surgical procedure, a selection of suitable lasers together with the potential risks involved in this treatment.Furthermore, we will give the outlook for the future of endo-and transnasal laser surgery.


MATERIALS AND METHODS


Lasers Used in Endo-and Transnasal Surgery

A wide variety of different lasers are applicable as surgic

hem are suitable for the endo-and transnasa
surgery.

We use lasers with wavelengths below 1200 nm that show a very low absorption of photons by water (Fig. 1A).The laser light, ther fore, passes through water, is scattered and delivers its energy relatively deep into the tissue.When the laser light has a wavelength in which there is a high or medium absorption by hemoglobin (450-600 nm; 800-950 nm), then the laser energy is concentrated in blood-vessels, arteries or veins, depending on the degree of absorption in oxygenated or desoxygenated blood (Fig. 1B).

For this purpose the best lasers are Diode lasers (810-980nm) (medial absorption by oxy-and desoxygenated hemoglobin), the Nd:YAG aser (1064nm) (no absorption in desoxygenated hemo- globin) and Argon laser (488/514 nm) as well as KTP- laser (532nm) (high absorption in oxy-and desoxygenized hemoglobin).

The light can be delivered in a non-contact mode.In this case, the surface of the tissue is less damaged, but the effect of ir adiation is inside the tissue and cannot be controlled so well.This type of laser surgery should be restricted to experienced surgeons.It is the preferred treatment method for Osler's disease, in which one should not touch the tissue because, otherwise, bleeding will occur immediately.

In the nose, usually a very high penetration depth is not desirable.In this case, we work in the contact mode.The tissue is touch d with the fiber, the tip of which has been pre-blackened with


FIGURE

(A) Relative photon absorption in water and hemoglobin.Wavelengths of Argon laser, Nd: YAG laser and CO2 laser. (B) Photon absorption of Argon laser (488 nm and 514 nm), diode laser (940 nm) and Nd: YAG laser (1064 nm) by oxygenated or desoxygenated blood and water.

carbon (irradiation of wood or cork causes carbon to be attached to the glass fiber).Carbon stops the wide spread of the laser beam at the tip of the fiber.In this case, the laser energy is deposited on the surface of the tissue and in the tissue just below.The effect of laser irradiation then can be observed and endoscopically c ntrolled much better than in the non-contact mode.The penetration depth is reduced and the risk of uncontrollable side effects is very low.

For the application of laser energy we use specially designed instruments (Fig. 2) with canals FIGURE 2 Laser applica ion sheath according to Scherer (Richard Wolf Comp., Germany) with exchangeable telescope, laser fiber channel, and plume suction channel.

for rigid endoscopes equipped with various viewing angles, for the laser fiber and for suction.Some of the applicators have Albarran levers, with which the laser fiber can be bent (Fig. 3A,B).The laser light can a continuous way or in a pulsed mode; during the intervals the tissue can cool down reducing the degree of coagulative impact if desired.

Nasal mucosa decongestion is achieved by naphazoline containing nose drops to allow better vision.In addition, the nasal mucosa is

on.Some minutes later lidocain g
l (5%) is applied onto the surgical target using cotton wool buds.


INDICATIONS AND SURGICA METHODS


Hyperplasia of Nasal Turbinates

Symptoms: Blockage of upper airway, hypersecretion, i.e. in pollinosis or during pregnancy.

There are three turbinates in the nose, the lower one is the largest.Below each turbinate is a meatus.The size of the lower turbinate is reduced by application of a stripe-like coagulation zone at its lower margin, its coagulation diameter is around l-2mm.The turbinate is touched at the rear end by the laser fiber, which is then slowly pulled anteriorly (Fig. 4A-C).A white zone ("blanching") around the fiber

rks the area where al
vessels have been closed.As long as one does not leave this zone during movement, no bleeding will occur.


Narrow Middle Meatus

Sym toms: Sinus-infections after a common cold, chronic sinusitis with mucosal swellings in the ethmoid system and maxillary sinuses.

The airway to the maxillary sinus and the ethmoid passes through the middle meatus.It is blocked by a hyperplasia of the middle turbinate, a pneumatized middle turbinate, which is thicker than normal (concha bullosa media) or a medialized lateral wall of the nose (bulla ethmoidalis, medialized uncinate process).In this case, the middle meatus is therapeutically enlarged by coagulating and vaporizing the lateral wall of the middle turbinate (Fig. 5A-F), or by opening a pneumatized middle turbinate (Fig. 6A-G).In a second laser assisted step, after primary wound healing, the ethmoid cell system is opened by resecting an ethmoid bulla or cutting off a medialized uncinate process.The sensit

e ostio-m
atal complex is usually left untouched.Topical corticosteroid medication is usually given after laser treatment.


Synechia

Synechias can be found as a result of preceding sinus surgery or as a result of trauma.Usually they are FIGURE 4 A-B.FIGURE 4 (A) Laser treatment of the right lower turbinate: Te

hing model showing strip
-like coagulation starting at the rear end of the lower turbinate.(B) Laser treatment of the right lower turbinate: stripe-like bloodless coagulation at the inferior rim of the turbinate with char formation in between the blanching area.(C) Laser treatment of the right lower turbinate: surgical result without decongestion.Markedly enlarged inferior nasal meatus by good size reduction of the turbinate six weeks after diode laser surgery.

found between turbinates and the septum or between turbinates and the lateral nasal wall (lateralized middle turbinate).Provided they are not too long, they can be resected quite easily (Fig. 7).


Septum Spurs and Ridges

Spu

and ri
ges are septal structures which either block or deviate the airway or irritate the nas l mucosa by direct contact with the turbinates.We cut the tip of such structures as shown in Fig. 8A.Usually the lower part of these structures contain bone.When bone is irradiated with a laser beam, and is heated up locally, it is converted into a white shining, "china like", fragile structure (Fig. 8B), which can be easily broken by using a little force using the laser fiber.This new structure is biologically inert and is well accepted by the mucosa during re-epithelialization. Granulation tissue in this area has only occasionally been observed (Fig. 8C).


Polyps

Polyps in the nose are due to a swelling of the mucosa, being a hyperreactive status.

They are treated locally by topical administration of corticosteroids and/or by resection.Depending on the pathogenesis of the polyps, recurrences are common.[-concha media, S. septum nasi].(A) Pre-operative situs; (B) positioning of the fiber under video-endoscopic control; (C) starting soft tissue vaporization in the pulsed mode, contact application; (D) reducing the size of the head of the middle turbinate; (E / F) continuous vaporization and coagulation of the lateral wall of the middle turbinate thus opening the access to the anterior ethmoid.Some patients are operated on several times without relief.In the post-operative period, one can treat new developing polyps with laser coagulation as well as small primary polyps in a chronic sinusitis.This treatment is not curative but it helps the patient and gives him the ability to breathe.Polyps covering a sinusoidal ostium can be entirely removed in a curative way (Fig. 9A-D) Mucoceles Mucoceles are encapsulated sinusoidal areas.Usually they are situated in the ethmoid or frontal sinus.They contain mucus and expand slowly due to ongoing mucus production.Quite often they penetrate into the orbital cavity from above or from the medial wall, causing a deviation of the eye globe.FIGURE 6 Laser assisted enlargement of the middle nasal meatus: opening and diode laser resection of the lateral wall of a concha bullosa media.(A) Positioning of the fiber under video-endoscopic control; (B) gentle surface coagulation (low power, contact application); (C) starting vertical soft and h rd tissue vaporization in the pulsed mode dissecting through the bone; (D) bloodless opening of the concha bullosa is just performed; (E + F) continuous vaporization and dissection of the lateral wall of the concha bullosa creating a wide access to the anterior ethmoid; (G) routine follow up 90 days after laser surgery: wide access to the ethmoid, perfect wound healing, no scar formation.

When the anterior wall of the mucocele is visible endoscopically, laser treatment is the therapy of choice with minimal effort and maximum effect.The wall is opened, as it is in a pneumatized middle turbinate (concha bullosa).The opening must be made big enough (Fig. 10A-E) so that scarring cannot close it up again (Fig. 10F-G) Epistaxis and Osler's Disease Conventional surgical treatment of epistaxis, especially in Osler's disease, is challenging and often disappointing because of intraoperative bleeding and common recurrence.Special laser such as KTP-, Argon-, Diode 940 nm aser provide photons, which are absorbed by oxygenated hemoglobin and thus heat up the vessels specifically.With this treatment in non- contact mode, most of the participating arteries can be closed without the occurrence of intraoperative bleeding.Bigger vessels in the anterior area of the nose are protected and temporarily compressed by a cooled glass spatula through which the laser beam is transmitted (Fig. l lA-D) ("

mpression-
oagulation-method").


Transnasal Laser Surgery

For endonasal laser surgery, interventions in the nasopharynx and at the rear side of the soft palate, rigid endoscopes are used quite exclusively.For some indications deep in the oropharynx or in the larynx, flexible endoscopes with a working canal are used, through which the laser fiber is guided.The following diseases are treated up to now with rigid endoscopes with flexible endoscopes chronic edema of the supraglottic region after irradiation cysts of the vallecula or of the false vocal cord lymphatic plaques at the base of the tongue or at the lateral pharyngeal wall (small areas)


RESULTS

adenoids in adults, chronic swelling of the pharyngeal opening of the Eustachian tube cysts of the nasop arynx papillomas of the backside of the soft palate

The effect of laser treatment was analyzed in 44 patients with rhinomano-, rhinoresisto-and acoustic rhinometric measurements.Thirty of them were treated with a coagulation of the lower turbinate only (group 1), 14 of them in combination with an   gentle superficial mucosal coagulation (low power, continuous mode) the vaporization in pulsed mode (high laser power, short exposure time, long intervals) is performed.Porcelain-like transformation of the bone during treatment; (C) situation one week after laser resection, complete re-epithelialization will happen within 3-6 weeks.prior therapy 1 month after 3 months after FIGURE 13 Rhinomanometric measurement of nasal air flow in 14 patients of group 2 (laser coagulation of the lower turbinate and laser assisted enlargement of middle meatus).enlargement of the middle meatus (group 2).The success rate concerning nasal air flow one and three months after treatment is shown in Figs. 12 and 13.It is higher and more permanent in patients, in whom, both the lower and the middle meatus were enlarged.

The percentages shown in Figs. 12 and 13 indicate the improvement after therapy.

Patients were asked to tell us their subjective success classification after 3,