Myringotomy Instruments: Knives, Grommets and Forceps

A paediatric grommet list is one of the shortest operations in ENT and one of the least forgiving. The surgeon is working down a canal 7 mm wide through a microscope, the patient is a three-year-old under a short general anaesthetic, and there are perhaps four minutes per ear. Every instrument that reaches the hand has to be right first time — right speculum diameter, right blade angle, jaws that hold a 1.2 mm silicone tube without flicking it into the canal.

That is the standard the tray has to meet. Below is what actually belongs on it, why each pattern exists, and the specification points worth checking before you sign a purchase order.

The Standard Myringotomy Tray

Sets vary between units, but the working core is remarkably consistent across the UK, European and North American patterns we manufacture against. A typical tray carries:

Seven instruments. That is the whole procedure. The discipline of a good ventilation tube set is refusing to pad it out — a tray with 20 items on it takes longer to count, longer to reprocess, and gives the scrub nurse more to hunt through mid-case.

Aural Specula: The Access Decision

The speculum is the single most underrated item in the set. Choose one too small and you lose the peripheral view of the annulus; too large and it will not seat past the isthmus of a paediatric canal.

Stock the full ladder — 3, 4, 5, 6 and 7 mm. Paediatric grommet work lives at 3 to 5 mm; adult aural toilet and foreign body work sits at 5 to 7 mm. Named patterns differ mainly in wall taper and length:

• Hartmann — the general workhorse, moderate taper, oval mouth.
• Gruber — longer barrel, useful for deep or tortuous canals.
• Politzer — shorter and more sharply flared, easy on tight paediatric meatus.
• Toynbee — round-section, traditional pattern still specified in Commonwealth sets.
• Boucheron — thin-walled, maximises internal diameter for a given external size.

One specification point buyers routinely miss: internal versus external diameter. A speculum labelled 5 mm may be 5 mm at the mouth externally, with a working bore closer to 4.3 mm once wall thickness is accounted for. Ask which dimension a supplier is quoting. Thin-wall patterns like Boucheron exist precisely to close that gap.

The internal surface should be matte black or bead-blasted, never mirror-polished. A polished bore throws microscope light straight back at the operator and washes out the view of the drum. We supply aural specula with an internal matte finish as standard for this reason. There is more on the wider aural set in our guide to ear specula, Jobson Horne probes and Tilley forceps.

Making the Incision: Knives and Paracentesis Needles

Three approaches are in current use, and they demand different things from the tray.

Reusable myringotomy knives. The classic instrument — a fine shaft carrying a lance or sickle blade, most often in the Lucae or Politzer pattern. The advantage is a controlled, deliberate cut and no disposable cost. The burden is sharpening: a myringotomy blade that has lost its edge does not cut the pars tensa, it tents and tears it. Blade geometry here is unforgiving — a lance tip cutting edge on these instruments is ground to a very fine included angle, which is why they hold an edge poorly compared with a Mayo scissor and need scheduled service. Our note on surgical instrument sharpening covers how that cycle should be managed.

Beaver-type chuck handle with a disposable blade. A round knurled handle takes a proprietary angled myringotomy blade. You get a fresh edge every case and the handle stays in the set. This is the most common arrangement in high-volume paediatric units.

Needle and syringe. An 18-gauge needle bent on a tuberculin syringe is a documented improvisation for in-office use where a formal set is unavailable. It works, but the bevel is not designed for a radial drum incision and control is poorer.

Whatever is chosen, the shaft matters as much as the tip. A myringotomy shaft should be slim enough that it does not obscure the incision as it is being made — the operator has to see the anterior-inferior quadrant while cutting it. Bayonet or gently angled shafts exist for exactly this reason.

Crocodile Forceps and Grommet Handling

Crocodile forceps are the instrument that makes or breaks a grommet list. The pattern is distinctive: a right angle between the ring handles and a long straight shaft, with jaws that open in the plane of the shaft rather than across it. That geometry lets the operator hold the forceps below the line of sight down the speculum instead of blocking it.

Working length is typically around 12 cm. Jaw serrations run horizontally across the grasping faces, and this detail is not cosmetic — a fluoroplastic or silicone tube is slippery, small, and expensive to lose in a canal. Smooth jaws let it rotate; horizontal serrations do not.

Two jaw options are worth stocking:

• Serrated jaws — the default for grommet delivery and grasping soft material.
• Cupped or toothed jaws — better for granulation tissue, small foreign bodies, and biopsy of canal lesions.

Inspect the jaw closure under magnification on receipt. Held to the light, a good pair shows no daylight along the closed serrated faces and the tips meet before the shanks bottom out. A pair that closes tip-last will drop tubes.

Seating the Tube: Micro Hooks

Once the tube is presented to the incision, the inner flange has to be rotated through the drum so the grommet straddles the tympanic membrane rather than sitting on it. A 1.5 mm hook at 45° is the standard instrument for this. Some surgeons prefer a 90° hook for posterior-inferior placements.

The hook must be genuinely blunt at the tip. A sharp micro hook will catch the drum edge and extend the myringotomy — a longer incision means a shorter tube retention time and a higher chance of residual perforation.

Suction: Small Bore, Finger Control

Effusion in chronic otitis media with effusion ranges from thin serous fluid to material with the consistency of rubber cement. One suction size will not manage both.

Stock 3, 5 and 7 French otologic tips. The 3 Fr passes through a small myringotomy for thin fluid; the 7 Fr is what actually clears glue ear. Zoellner and Baron patterns both carry a thumb-controlled side port so the surgeon can modulate vacuum without asking for the machine to be adjusted — essential when suctioning a few millimetres from the ossicular chain.

Suction tubes are the item in this set most likely to be condemned early. They are narrow-lumen, they carry protein-rich material, and if they are not flushed immediately after use the lumen blocks and no washer-disinfector cycle will recover it. Lumen brushing at the point of use is not optional. Our guidance on ultrasonic cleaning of surgical instruments covers the limits of what ultrasonics can reach in a narrow bore.

Grommets: What the Tube Demands of the Instruments

The set has to match the tube. Short-term ventilation tubes — Shepard and Armstrong-type designs — have inner diameters broadly in the 1.0 to 1.5 mm range and are placed and forgotten. Longer-term T-tubes have flexible flanges that need to be folded and fed rather than pushed, which asks more of the forceps jaw and often calls for a finer crocodile pattern.

Materials vary: fluoroplastic, silicone, titanium and stainless steel are all in clinical use. Titanium and steel tubes are rigid and grip well; silicone T-tubes are compliant and will squirt out of a smooth-jawed forceps. If a unit is switching tube type, the forceps should be reviewed at the same time.

Theatre Set Versus In-Office Set

The same procedure is done in two very different settings, and the instrument requirement is not identical.

In theatre, under general anaesthesia and an operating microscope, the patient is still. The surgeon can use a longer speculum, a two-handed technique with suction in one hand and forceps in the other, and can take the extra thirty seconds to seat a T-tube flange properly.

In the office, under topical anaesthesia in an awake adult, none of that holds. Working distance is shorter, illumination is usually a headlight rather than a microscope, and the patient will move. In-office sets accordingly favour:

• Shorter, wider-flare specula that seat quickly and stay put.
• A disposable-blade chuck handle over a reusable knife — no risk of discovering a dull edge mid-procedure.
• A single 5 Fr suction rather than a graded set.
• Crocodile forceps with a slightly heavier shaft, which tolerates the incidental lateral load an awake patient generates.

Departments running both should hold two distinct trays rather than one compromise set. The counting and reprocessing overhead of a second small tray is trivial against the cost of an aborted office procedure.

Steel, Finish and Reprocessing

Myringotomy instruments are small, thin-sectioned and repeatedly autoclaved, which puts particular demands on material selection under ISO 7153-1.

• Cutting instruments — knives and sharp curettes are made from martensitic AISI 420-grade stainless, hardened and tempered to hold a fine edge.
• Non-cutting instruments — specula, hooks and suction tubes are typically AISI 410 or, where non-magnetic behaviour and maximum corrosion resistance are wanted, austenitic 316L.
• Finish — satin or matte on anything in the light path; polished only on external surfaces.

Thin sections are where passivation failure shows first. A 1.5 mm hook shaft has very little metal to lose before it is structurally compromised, so pitting corrosion that would be cosmetic on a retractor is terminal here. Fizza Surgical passivates every instrument after final grinding and polishing; the background to that step is set out in our article on surgical instrument passivation.

Store the set in a rigid container or a tray with silicone retainers. Loose myringotomy instruments in a wrapped pack will bend, and a bent hook or a tip-sprung crocodile forceps is scrap, not a repair.

Buying Notes for ENT Departments

Four checks before committing to a set:

1. Confirm speculum bore, not label size. Ask the supplier to quote internal diameter at the mouth.
2. Test forceps on the actual tube you use. Have the supplier demonstrate a grommet pick-up with your grommet, not a generic sample.
3. Check suction lumen patency on delivery. Pass a cleaning stylet through every tip in the consignment before acceptance.
4. Buy duplicates of the crocodile forceps. On a list of eight bilateral cases it is the one instrument you cannot substitute if it fails.

Fizza Surgical manufactures ENT and otologic instruments in Sialkot under an ISO 13485 quality management system, CE marked to EU MDR. Our surgical instruments range includes aural specula, myringotomy knives, crocodile forceps and otologic suction in the standard European and UK patterns, and we manufacture to customer drawings for units running non-standard sets. Certification documentation is available on our certifications page.

Related Reading

Grommet insertion sits at one end of a wider otologic and ENT instrument family. For the surgical steps beyond ventilation tubes, see our guide to the mastoidectomy instrument set. For paediatric airway and adenotonsillar work that often shares the same theatre list, our comparison of adenoid curettes covers the St Clair Thomson, Beckmann and Barnhill patterns.