Endoscopic Adenoidectomy with Microdebrider

Abstract

To evaluate the role of microdebrider in patients undergoing endoscopic adenoidectomy. Prospective interventional study. Tertiary referral hospital. Twenty patients requiring adenoidectomy were included in the study. Mean operative time was found to be 31.5 min. Mean blood loss was 29.45 ml. All the patients had complete removal of adenoid mass. None of the patients had any kind of collateral damage. It gives a complete clearance of obstructive adenoids under vision thus providing reliable restoration of nasopharyngeal patency.

Introduction

Adenoidectomy is one of the most common procedures performed in children today, either alone or in conjunction with tonsillectomy or insertion of ventilation tubes. The widely used conventional curette adenoidectomy was first described in 1885 [1]. Traditionally, it is carried out using blind technique of curettage, but damage to eustachian tube openings is known and the completeness of the procedure is difficult to assess. There are techniques employing direct vision with the advantage of reduced blood loss, and the ability to remove adenoid tissue from the choanae, while avoiding trauma to eustachian cushions [2]. Of these techniques those with largest clinical experience are the microdebrider and the suction coagulator, others are KTP laser, coblator plasma field device and harmonic scalpel. Single use instruments abolish any potential risk of infection transmission [3].

Coblator and harmonic scalpel are used satisfactorily in tonsillectomy but their use in adenoidectomy is limited. Coblator may work adequately for small adenoid pads; however, it may not be efficacious for large obstructive adenoid pads [4]. The coblator plasma field device may prove suitable for adenoidectomy, but as yet no published data are available [1]. Research is going to improve the coblator to enhance its capabilities to perform adenoidectomy. The KTP laser is associated with high incidence of postoperative nasopharyngeal stenosis and is not recommended for adenoidectomy [5].

Endoscopic adenoidectomy with microdebrider offers following advantages:

1. Improved field of vision.

2. Continuous suction of blood.

3. Extreme precision in removing the adenoid tissue.

4. Less complication rate.

Compared with the current practice which employs the curette or adenotome, it is possible with this technique to remove adenoid tissue in the most important areas that is the choanal and tubaric regions [6]. Due to the suction and shaving action of the microdebrider drawing the loose tissue into the window, it can remove the tissue down to a less vascular plane, as opposed to the pushing and cutting action of the curette which may leave bleeding tissue behind. The tissue dissection is more complete and to the appropriate depth with debrider, as opposed to being too shallow or too deep with curette. The present study was conducted to evaluate the role of microdebrider in patients undergoing endoscopic adenoidectomy.

Material and Methods

The present study was conducted in the Department of Otorhinolaryngology in our institute. Twenty consecutive cases between the ages of 6–14 years, requiring adenoidectomy for various indications were included in the study. Only those patients were included who had not responded to medical management. Adenoid hypertrophy was confirmed by a lateral soft tissue radiograph of nasopharynx. X ray grading was of three types. In grade 1 (mild) < 50% of palatal airway was obstructed with adenoid tissue, in grade 2 (moderate) more than half but not complete, in grade 3 (severe) whole of the nasopharynx was occupied by the adenoid tissue and no air column was seen on the postnasal space on radiograph [7].

Steps of Surgery

General anaesthesia was given with orotracheal intubation and a pharyngeal pack was put in. The theatre setup and positioning were as for a standard functional endoscopic sinus surgery. The nasal cavities were decongested by using pledgets soaked in 4% xylocaine and 0.1% xylometazoline. Using a 0° 2.7 mm rigid sinuscope (4 mm for older children), the posterior choanae and nasopharynx were assessed before the start of surgery. The grade of adenoid hypertrophy was assessed using the scale described by Clemens et al. where Grade I has adenoid tissue filling one third of the vertical height of the choanae, Grade II from one third to two thirds, Grade III from two thirds to nearly all but not complete filling of the choanae and Grade IV with complete choanal obstruction [4, 8]. Boyle–Davis mouth gag was applied. To retract the soft palate, nasal catheters were introduced through each of the nostrils and negotiated via nasopharynx and oropharynx and brought out of oral cavity and tied outside. Microdebrider was used in the oscillating mode with saline irrigation using speed up to 2400 rpm to shave off the adenoid tissue using curved adenoid blade.

Transoral approach was used where 45° sinuscope and special adenoid blade, both were introduced through mouth, after applying mouth gag. The special adenoid blade is longer, and has a window on convex side for use transorally to adapt to the roof of nasopharynx. Removal of adenoid tissue was started from the choanal vegetations and proceeded backwards along the vault towards the posterior wall of nasopharynx.

After the adenoidectomy, a tonsil sponge was placed in the nasopharynx for some minutes. After its removal nasopharyngeal cavity was checked for the presence of possible residual tissue and for the absence of bleeding. When haemostasis was achieved, mouth gag was removed and patient was returned back to anaesthetist for reversal of general anaesthesia and extubation.

Intraoperative parameters were observed regarding adenoid size, operative time, primary bleeding and collateral damage/ injury to the adjoining structures. Operative time was recorded. Operative time was calculated from the time patient handed over by the anaesthetist and included setting up of instruments, operative steps, packing and securing the bleeding. The measurement ended when the patient was handed back to anaesthetist. At the end of the procedure the material collected from the suction canister was filtered to remove tissue and the remaining fluid comprising of blood and sucked irrigating fluid was measured. The blood loss in milliliters was calculated as the difference between this amount and the amount of saline used for irrigation. Differential weight of the packages employed was added to it.

Patients were discharged on the next day. First follow up was done at first week and second follow up at 6 weeks. X-ray was done at 6 week and compared with the preoperative X-ray nasopharynx.

Results

Maximum number of patients were in 6–8 years of age group (70%). The mean age was 7.85 years.

65% of the patients were males and 35% of them were females.

The most common complaint of the children was mouth breathing, which was present in all the cases. The second most common complaint happened to be snoring which was found in 70% of children. Abnormal speech was found in only one patient, while hearing loss and post nasal discharge was present in 25% cases each.

Maximum patients had grade-II hypertrophy (65%), and 35%had grade-III hypertrophy of adenoids on X-ray.

On endoscopic grading 55% patients had grade-III and 45% had grade-IV adenoid hypertrophy. None of the patients were in grade-I or grade-II category.

Mean operative time was found to be 31.5 min. Initially, the operative time was more than 40 min, but with gain of experience, it reduced to as low as 12 min. In 65% of cases, operative time was between 20 and 40 min (Table 1).

Table 1.

Operative time (in minutes)

Time (min)	No. of patients	%Age
Less than 20	3	15
20–40	13	65
More than 40	4	20

Mean blood loss was 29.45 ml and in maximum number of patients, blood loss was found in between 20 and 40 ml. In only one patient blood loss was more than 40 ml (45 ml) (Table 2).

Table 2.

Intra-operative blood loss (in ml)

Blood loss (in ml)	Number	%Age
< 20	3	15
20–40	16	80
> 40	1	5

After 1 week of surgery, all patients reported adequate nasal breathing.

One patient had postoperative emesis. Fever was reported in 2 cases, which persisted only for 24 h on postoperative period.

45% of cases had pain which subsided completely on 3rd postoperative day. Neck stiffness was observed in 2 cases, which got resolved with adequate rest and analgesics. Swallowing problem was reported in only 2 patients which was secondary to pain and patients were completely relieved on 3rd day.

25% patients recovered completely after 3 days of surgery, while 75% of cases had a faster recovery (2 days). Mean recovery time was 2.25 days.

Second follow up was done at 6 week and none of the patients had complications like nasal obstruction, post nasal discharge, velopharyngeal insufficiency and nasopharyngeal stenosis and 100% of them had complete removal of adenoid mass. A less than 20% residual adenoids was regarded as complete removal, 20–50% as partial and more than 50% as suboptimal removal.

One patient had pulsating adenoids visualised by direct endoscopic vision. Surgery was postponed and he was advised CT angiography for aberrant vessel, but he was lost to follow up. He was not included in the study.

Discussion

Adenoidectomy is one of the most frequently performed operations in children. Though not considered a risky surgery, some complications do occur, the most important being bleeding (0.5–8% incidence) [9]. The surgical technique used can have considerable influence on the intraoperative bleeding, postoperative pain and the recovery time. This is important in day care surgeries like adenoidectomy. Also, complications like nasopharyngeal stenosis and eustachian tube stenosis though rare are difficult to handle, if they occur [10].

Traditionally adenoidectomy is done with a curette. The main disadvantage of this method is that it is relatively a blind technique that may lacerate the choanae, torus tubaris, and the nasopharyngeal mucosa or may leave behind obstructing tissue, particularly at the eustachian tube orifice, high in the nasopharynx and at intranasal protrusion [11].

The problem can be solved by preoperative visualisation of nasopharynx using a rigid nasal endoscope, and removal of adenoid tissue under direct vision. Canon et al. popularised Endoscopic Assisted Adenoidectomy (EAA) calling it “a natural progression of endoscopic technology to allow a more complete adenoidectomy.” They followed a conventional transoral adenoidectomy with endoscopic removal of residual adenoids [12]. Microdebrideris a powered instrument which provides an excellent, safe and thorough technique in endoscopic nasal surgery. It provides atraumatic dissection with minimal bleeding which enables decreased surgical time and faster postoperative healing. Koltai et al. have published the use of microdebrider for adenoidectomy using visualisation by a laryngeal mirror [11]. When both these methods are combined and endoscopic assisted powered adenoidectomy performed, advantages of both techniques should get pooled.

The mean operative time in our study was 31.5 min whereas it was 39.3 min in study by Datta et al., 12.5 min in study by Constantini et al., 5 min 15 s by Feng and Yin, 12.3 min in the study by Somani et al. and10.26 min in study by Stanislaw et al. [6, 8, 13–15] Initially in first few cases, operative time in our study was more than 40 min, but with time and gain of experience, it reduced to as low as 12 min. In 65% of cases, operative time was between 20 and 40 min.

Though the precise steps of adenoidectomy only take 4–5 min we felt that a true assessment of operative time should include all steps including preparing and setting up of instruments, packing and securing the bleeding and checking for haemostasis. As a result, the time taken in the present study may seem longer than some studies. Also, the overall operative time may be on the higher side as endoscopy was performed preoperatively and post procedure. Somani et al. considered operative time as beginning from fixing of mouth gag till mouth gag was removed [8]. Constantini et al. recorded start and stop time when the instrument touched and left the tissue [6]. Datta et al. defined intraoperative time as the time taken for completion of procedure from the time patient was handed over by the anaesthetist and included setting up of instruments, operative steps, packing and securing the bleeding. The measurement ended when the patient was handed back to the anaesthetist [13].

The mean blood loss in our study was 29.45 ml (range 15–45 ml). This is almost similar to the blood loss in study by Datta et al. which was 31.67 ml (range 10–60 ml) and study by Somani et al., where mean blood loss was 30 ml (range 24–42 ml) [8, 13]. Mean blood loss in study by Stanislaw et al. was 15 ml (range 2–90 ml) which was significantly lesser than our study [15]. In study by Constantini et al. mean blood loss was 28 ml and 50 ml in study by Feng and Yin [6, 14].

None of the patients had any kind of collateral damage in our study and surgeon was fully satisfied with the procedure. Similarly, Somani et al. reported no collateral damage to surrounding structures and surgeon satisfaction was high [8]. In study by Datta et al. there were no injuries/ damage in the nasopharynx, however 5 cases had mild trauma to the nasal mucosa over the septum and one case had epistaxis [13].

Complete airway patency and no remnants of adenoids were seen in all patients assessed at follow up both in our study and study by Somani et al. [8]. In study by Datta et al. there was complete removal of adenoids in 93% cases [13].

A surgical procedure performed blindly with the help, at best, of only palpation is no longer satisfactory. Good vision of the operating field is essential. In some cases, introduction of the catheters for suspending the soft palate can be rather difficult (especially in the presence of severe choanal obstruction), but they do offer considerable advantages. The duration of the procedure is slightly longer than that of adenoidectomy with the adenotome. The organization and preparation times are also longer, while ablation and haemostasis times are substantially the same. However, the slightly longer duration is more than compensated by the greater precision and confidence gained by the surgeon. Moreover, the continuous suction generated by the microdebrider maintains the field free from blood [6]. Magnified view also helps in identification of pulsations over adenoids if there is aberrant internal carotid artery nearby, as occurred in one of our patients.

Generally, the adenoid vegetations appear as a series of parallel cords of tissue with a longitudinal course, more voluminous along the median line and thinner toward the perimeter. The most lateral cord is generally in close contact with the torustubaris. The smooth point of the microdebrider can be introduced into the furrow between the side vegetations and the structures of the tubaric ostium and the tissue can be completely removed without damaging the mucosa covering the torus tubaris. The organization of the tissue becomes less regular and the colour turns progressively darker as one proceeds along the posterior nasopharyngeal wall, at the level of the projection of the floor of the choanal openings. Resection should be interrupted along this line demarcated by the passage from the regular adenoid vegetations to the more chaotic aspect of the lymphatic tissue in this zone (the Passavant ridge). From a functional point of view, removal can be considered complete at this point. The procedure also prevents transitory velo-pharyngeal insufficiency. It also avoids excessive bleeding that can occur following lesions of the larger vessels present in the lymphatic tissue [6].

A more complete resection should result in a better chance of resolving the disease process, be it nasal obstruction, adenoiditis, sinusitis, or otitis media. A common problem seen with tonsillectomy is the phenomenon of hyperplasia of any remaining tissue. The possibility of this phenomenon taking place in another portion of the Waldeyer ring is quite high. Therefore, it is likely that an incomplete resection subjects the patient to an increased risk of recurrence of symptoms owing to hyperplasia of the remaining tissue [15].

The role of such a procedure on selected cases where accurate removal of adenoids is of consequence may be important. Cases of submucous cleft palate and other cranio-facial anomalies may require adenoidectomy. However, for fear of causing velopharyngeal insufficiency, adenoidectomy is avoided. An accurate removal using endoscope and microdebrider may enable the surgeon to carefully excise part of the adenoids and leave the velopalpharyngeal sphincter untouched [16].

Use of microdebrider has a few disadvantages. It requires the use of expensive equipments including the cost of blades which require replacement. Another shortcoming is that the resected tissue is not available for histopathological examination [8].

Conclusion

Endoscopic power assisted adenoidectomy is a safe, precise procedure with minimal blood loss, less postoperative pain and faster recovery. It gives a complete clearance of obstructive adenoids under vision thus providing reliable restoration of nasopharyngeal patency. In addition to providing a good magnified view, the sinuscope with camera aids in recording and teaching. Greater control over tissue resection by microdebrider results in minimizing complications.

Compliance with Ethical Standards

Conflict of interest

The authors have no conflicts of interest to declare that are relevant to the content of this article.