|Year : 2022 | Volume
| Issue : 1 | Page : 1-5
Minimum access mastoidectomy
Mahendra Kumar Taneja
Department of ENT, Indian Institute of Ear Diseases, New Delhi, India
|Date of Submission||04-Dec-2021|
|Date of Acceptance||09-Dec-2021|
|Date of Web Publication||25-Apr-2022|
Mahendra Kumar Taneja
Department of ENT, Indian Institute of Ear Diseases, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Taneja MK. Minimum access mastoidectomy. Indian J Otol 2022;28:1-5
Ear surgery can be performed either by postaural, endaural, or permeatal route. The aim of surgery is to provide the patient with a dry, hearing, and a trouble free ear. We can achieve our goal by any approach or technique but what about morbidity or Success rate of our Surgery. Does the retaining of blood supply and lymphatic drainage makes a difference? For this, we have to understand the blood supply and different incisions in ear surgery and what may be the best for our patient. Three factors contribute to wound healing: (1) sterilization or prevention of infection and selecting a suitable antibiotic. One must go for vigorous sterilization and always get a culture sensitivity done in preoperative period. The most susceptible antibiotics recently reported are cefoperazone, sulbactam, and ciprofloxacin. We may not need an antibiotic if we have adequately taken out the disease, but augmentation of antibiotic is worth considering. A preoperative antibiotic prevents infection. (2) Body's immunity to say host defense is important in postoperative period; in general, anemia and factors responsible for Eustachian catarrh including deficiency of Vitamin D should be considered. The ear gets its blood supply from three vessels: (1) postauricular artery which is the main feeder and accounts for two-third of its blood supply; hence, a postaural incision will lead to the hampered blood supply and delayed wound healing. (2) Superficial temporal artery which is going to provide blood supply from anterior side, hence endaural incision to be avoided. These two vessels are going to make a plexus and take care of the vascularity of the pinna. (3) Deep auricular artery which is a branch from external carotid artery enters the ear in deep anterior inferior auditory bony canal wall [Figure 1]. We can take its advantage by preserving and utilizing the canal skin as a flap (meatal skin flap) to cover the raw bone postoperatively, especially the mastoid cavity.
Cholesteatoma is predominantly an attic disease. With changing socioeconomic conditions, education, and better surgical facilities, patient reports early to surgeon; hence, the size of the cholesteatoma sac is becoming smaller, resulting in decreased size of postoperative cavity. Disease is usually limited to attic or up to antrum. Again cholesteatoma is in sclerotic bone which restricts its speed of proliferation. Our principle is to trace the disease, remove the sac in Toto and if removal of disease is complete obliteration of cavity may be done. If the cavity size is small and obliterated, just adequate size meatoplasty is required. Hence, we can achieve anatomical and physiological ear.
The advantage of minimum access mastoidectomy is preserving the cortical bone of the mastoid, which is not removed unnecessarily. Removal of cortical bone may lead to a large weeping cavity requiring frequent postoperative visits.
In this way, we can do a small attico antrostomy or a large canal wall down mastoidectomy. Whatever surgery we perform even if we dissect up to the tip of mastoid, removal of cortical bone and size of cavity created is much smaller than post aural approach. If approach to mastoid tip is difficult, endaural incision may be extended superiorly, usually which is not required.
In canal wall up mastoidectomy, we maintain the superior and posterior canal wall and in canal wall down technique, aggressive saucerization of anterior cortical edges of mastoid that is most outer part with lowering of posterior, superior, and inferior canal wall is done. In both procedures, we focus on mastoid air cell, infected mucosa, and complete exenteration of disease. I prefer minimum access mastoidectomy in clinically and radiologically smaller size cholesteatoma, tracing the track, continuously assessing the size while drilling the superior wall (tegmen).
| Technique|| |
Endaural incision is given into the canal in incisura terminalis between helix and superior border of tragus, incision may be extended superiorly as and when required [Figure 2]. Conchal Meatoplasty incision, a horizontal incision only in skin is given at 9.0 O'clock extending on the concha posteriorly. Skin is elevated to expose the big chunk of conchal cartilage which is excised and preserved. The soft tissue and periosteum underneath also incised horizontally about a centimeter but make sure not to make a buttonhole in posterior wall skin of pinna [Figure 3].
Periosteum is reflected posterosuperiorly and posteroinferiorly to widely expose the lateral outer part, MacEwen's triangle, spine of Henle, supramastoid crest and Posterior outer bony canal wall [Figure 4]. The first canal incision a horizontal incision is given usually 4–5 mm medial to cartilagenobony junction extending posteriorly from 10° clock to 6° clock position and then laterally for 2 mm [Figure 5]. The periosteum is elevated and posterior cartilaginous part is retracted by the self-retaining mastoid retractor. The horizontal incision is extended anteriorly up to 2° clock position.
|Figure 4: Exposure of lateral Cortex MacEwen's Triangle, Spine of Henle & Supra Mastoid Crest|
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|Figure 5: Horizontal Canal incision 4-5 medial to cartilagenobony junction extended laterally|
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The canal skin is precious and healing depends on its preservation; hence, a pedicle flap is created in the canal. The second incision begins 2 mm lateral to annulus extending horizontally from 2° clock to 12° clock posteriorly and coming inferiorly up to 6° clock position. Both anterior end of incision at 2° clock position join by a vertical incision. [Figure 6]. Flap is raised, reflected by house/flag knife taking utmost care not to injure the flap. No suction is used on flap, suction should be done over the knife, or Brackmann suction is used [Figure 7]. The reflected flap is secured medially by a cotton ball or laterally in another retractor placed cephalocaudally at the right angle to first retractor securing the superior and inferior surface of canal wall soft tissue providing adequate exposure. On medial placement, flap may be trapped in moving high speed drill, secure the flap by placing aluminum foil over it, while lateral placement flap may get lacerated by traction of prongs of mastoid retractor.
|Figure 6: Horizontal Incision 2 mm lateral to annulus joining anteriorly by vertical incision|
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| Minimum Access Mastoidectomy|| |
The tympanic cavity, attic, is irrigated thoroughly, all debris cleaned. I prefer to irrigate the canal with topical antibiotic solution, preferably 1% povidone-iodine solution. The reason of irrigation is to make the field bacteria free specifically for collection of sterile bone pate which is to be used in postdrilling obliteration of the cavity.
Drilling is started with adequate size cutting burr, preferably a size smaller than what the surgeon prefers to avoid injury to canal skin because all working is in a compact area of dissection. Remember, preservation of canal skin is the key of early healing.
The author performs a type of wide superior and posterior wall canaloplasty before approaching the attic and if bony hump in inferior and anterior canal is also removed during canaloplasty, but anterior inferior part of annulus is always preserved for better conductive hearing results. Usually, a 2–3-mm overhang is left superiorly over the scutum, but certainly, change of color of bone is secured. As we go medially, the size of the burr becomes smaller and smaller, but smaller than 3-mm cutting burr is seldom required.
During skeletonization of superior wall, one must keep on observing the change of color of bone, it becomes pinkish, starts bleeding, and change in noise which becomes high pitch. A surgeon has to train himself for three dimensional observations, i.e., visual, tactile, and auditory.
At this stage, cholesteatoma sac is reassessed and inferior border of scutum is drilled away with 3-mm diamond burr or by cutting upward outward taking all precautions to preserve the sac intact. As soon as incus is visualized, extra precaution is taken not to touch the long process of incus with vibrating burr which may result in high-frequency sensorineural hearing loss.
Lateral attic wall is removed over the head of malleus and middle fossa dura (tegmen tympani).
On audiometry air–bone gap of more than 40 dB prompts condition of ossicular chain. High-resolution computed tomography temporal bone may give some idea, but it is good to raise the posterior annulus and visualize the incudostapedial joint if the tip of incus necrosed, we can do a brisk drilling lateral to annulus and chorda tympani nerve.
Now, drilling is extended posterosuperiorly to expose the antrum but be cautious of low-lying dura. By lowering the facial ridge we can visualize the posteroinferior limit of cholesteatoma, it is preferable to use diamond burr over the tegmen tympani and tegmen antri.
The anterior attic and anterior bony canal wall is thinned out and well saucerized for epithelization.
Gradually, drilling is advanced posterosuperiorly tracing the sac. If required incudostapedial joint is dislocated and head of the malleus is removed after cutting the neck of malleus by malleus nibbler.
If cholesteatoma erodes the annulus posteriorly drilling of the anterior aspect of posterior canal wall up to the annulus is Mandatory. Drill with 3.5 mm diamond burr under profuse irrigation. Drilling may be done further medially on posterior wall of mesotympanum for about 1.0 mm on the anterior aspect of Fallopian canal More Details to fully expose the facial recess. Always pack the tympanic cavity by gelfoam to prevent accumulation of bone dust in tympanic cavity.
Facial recess is a space bounded medially by promontory, laterally by Fallopian canal, superiorly by ponticulus; a bony ridge between promontory and pyramidal eminence, inferiorly by subiculum; a bony ridge between posterior wall and round window niche. Until we clear the facial and tympanic recess (sinus tympani), one is not going to achieve the goal of dry cavity. If one is going to reconstruct the superior wall, then our goal is to remove the disease/sac not to create a cavity. If entire sac removal is not a problem, anterior and posterior buttress are preserved. While dissecting the posterior canal wall, skeletonization is done from superior to inferior and medial to lateral side, leaving no overhang.
| Fallopian Canal Landmark|| |
Working (drilling) on posterior canal from anterior to posterior side, no conventional landmarks are available. Our landmarks are chorda tympani pyramid and annulus. Facial nerve is about 2.0 mm posterior to pyramid and at this level facial nerve is 3.0 mm deep (medial) to chorda tympani and posterior buttress/Notch of Rivinus. Facial nerve is always deep (medial) and posterior to the upper two-third of annulus, while at the posteroinferior end of annulus, nerve may be encountered anterior or lateral to annulus.
Posterosuperiorly, drilling is extended to sinodural angle. Angle is widened and cleaned. At this stage bridge is removed, necrosed incus is removed. Facial ridge and inferior wall is drilled to expose the mastoid tip; if required, all bony over hangs are removed.
Once the complete sac is removed, drilling is further continued to remove all cells and infected mucosa, specifically looking at sinodural angle and widening it, perilabyrinthine cells, retrofacial cells, and mastoid tip area. An attempt is made to polish the cavity like a pearl, which is going to provide an early healed trouble-free cavity.
If extensive work is required in breaking and polishing all septa of noninfected air cells, they may be obliterated by bone pate collected earlier, mainly to the retrofacial area, mastoid tip, and sinodural area. Mastoid tip may be obliterated by conchal cartilage procured in meatoplasty and inferior canal wall widening. All bone pate and cartilage should be covered by fascia graft.
If the cholesteatoma is reaching the tip, after drilling, tip has to be obliterated up to the level of the inferior canal wall for proper drainage and trouble-free dry cavity. Inferior canal wall should always be lowered up to the tip. After doing the inferior canal wall canaloplasty, one must make sure to remove the inferior wall cartilage, failing which drainage is hampered, secretion stagnates, and the goal of dry trouble-free cavity is defeated. It is always advantageous to thin out the inferior canal wall even if cholesteatoma is not reaching the tip. After meatoplasty or canaloplasty, no part of cartilage is left exposed, it may lead to perichondritis resulting in cicatrization and deformity of pinna.
I usually perform type III cartilage tympanoplasty. If the middle ear cavity is bleeding or mucosa is not healthy, there will be fibrosis and retraction of graft and prosthesis will be displaced defeating the results and hearing improvement will not be there. Preoperatively patient may be explained in case of bleeding a second stage revision ossiculoplasty may be needed. Injection platelet rich plasma and Gelfoam soaked in platelet rich plasma provide an early healing and may avoid two stage surgery.
Although it is difficult to differentiate between residual or recurrence, inadequate clearance of anterior attic, sinodural angle, mastoid tip area, and inadequate drainage due to insufficient lowering of facial ridge results in recurrence. Polishing the cavity like a pearl leaving no traps is key of success. Healing the cavity by granulation reduces the size of cavity by 60%. Dressing and filling the cavity with Gelfoam soaked by platelet-rich plasma may aggravate healing due to growth factor.
One may be reluctant to operate in a middle-aged or old person having a mixed deafness, not expecting good results in terms of hearing. I assure if one can take care of the associated factors, we can complement him with some improvement in hearing. These associated factors are treating anemia and cessation of smoking which leads to poor mucociliary flow resulting in Eustachian catarrh and mild negative pressure in the middle ear amounting to 5–10 dB hearing loss. Again, tobacco chewing is neurotoxic; a withdrawal with supporting treatment of neurotropic must be kept in mind. Vitamin D deficiency is attributed to redisposition of recurrent upper respiratory tract infection, Eustachian tube More Details dysfunction, and osteoporosis of cochlea. It also disturbs calcium channel in cochlear microphonics resulting in decreased generation of action potential, hence cochlear deafness., Apart from routine pure tone audiometry I perform loud speech testing after masking the other ear. It is better predictive of postoperative hearing gain. It is better to perform surgery in local anaesthesia in adult patients. Life style modification and pranayama may promote early wound healing by way of apoptosis and enhanced growth factor., Role of canaloplasty is unbiased and one of the key of success.
I conclude in cholesteatoma cases, when disease is suspected, up to antrum diseases should be followed, as it tracks in and minimum size self-cleansing cavity with nice polishing can be performed endomeatally. I personally feel in beginners and inexperienced hands, minimum access mastoidectomy is safer, less time-consuming, and better rewarding technique.
| References|| |
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Taneja MK. Role of platelet rich plasma in tympanoplasty. Indian J Otolaryngol Head Neck Surg 2020;72:247-50.
Taneja MK, Taneja V. Role of Vitamin D in prevention of deafness. Indian J Otol 2012;18:55-7. [Full text]
Taneja MK, Taneja V. Role of ENT surgeons in the national deafness program for prevention and control of deafness. Indian J Otol 2012;18:119-21. [Full text]
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]