2Endoscopic Ossiculoplasty: Technique and Evidence

FWhat endoscopic ossiculoplasty is

For most of the history of middle-ear surgery the operating microscope was the only way to see what the hands were doing. Endoscopic ossiculoplastyrebuilds the ossicular chain using a rigid endoscope passed down the ear canal instead — a totally transcanalreconstruction that needs no postauricular incision and, in the favourable ear, no drilling away of the bony canal. The surgeon works with a thin rigid telescope (most often 3 mm in diameter and 0° or 30°–45° angled) connected to a camera and a high-definition monitor, looking at the screen rather than down binoculars. Pioneered for cholesteatoma and tympanoplasty by Tarabichi and later developed for ossicular work by Marchioni, Presutti and others, the approach has matured from a curiosity into a mainstream option in many otology units [1999].

The reconstruction itself is unchanged. The same reconstructive ladder applies: bone cement or an incus interposition for a short incudostapedial defect, a partial ossicular replacement prosthesis (PORP) onto an intact stapes superstructure, and a total ossicular replacement prosthesis (TORP)onto a bare mobile footplate when the stapes arch is gone. Autologous cartilage, titanium and hydroxyapatite are all placed endoscopically, and the same biomechanical principles — vertical shaft, central drum contact, cartilage interposition to resist extrusion — still govern the result [2018]. What the endoscope changes is not the prosthesis or the mechanics but the access and the line of sight: how the middle ear is reached and what the surgeon can see while doing it.

FThe optical bargain: panorama for depth

The defining feature of the endoscope is a single distal lens held close to the target. That geometry buys a wide, panoramic field and, with an angled tip, the ability to look around corners— up and over the scutum into the attic, into the facial recess, and into the posterior retrotympanum, including the sinus tympani that the straight-line microscope reaches so poorly [2011]. For ossiculoplasty this matters because the integrity of the stapes superstructure, the state of the oval window, and the presence of residual disease around the prosthesis bed all sit in exactly these hidden recesses. The endoscope lets the surgeon inspect them directly rather than inferring them.

Nothing comes free. A standard rigid endoscope is monocular: it gives a two-dimensional image, so depth must be inferred from shadow, motion and experience rather than seen stereoscopically as it is through the binocular microscope. Worse, the scope occupies one hand, so the surgeon operates one-handed, without the continuous suction the free second hand provides under the microscope. The practical consequence is that bleeding is the chief enemy: because the lens sits close to the field, even minor oozing films it instantly, and there is no spare hand to keep the field clear. A meticulously bloodless field, achieved with careful positioning, topical vasoconstriction and patience, is therefore a prerequisite, not a luxury. The bargain, in short, is a panoramic angled view in exchange for stereoscopic depth and a second hand.

It follows that the microscope and the endoscope are complementary, not rivals. Many surgeons use the microscope for the two-handed, stereoscopic parts of an operation and reach for the endoscope to inspect or work in the recesses the microscope cannot survey — a so-called combined approach. A purely endoscopic ossiculoplasty is simply the version in which the whole reconstruction is done through the canal under endoscopic vision.

TPerforming the reconstruction transcanal

The operative sequence will be familiar to anyone who has done microscopic tympanotomy; only the ergonomics differ. After infiltration of the canal for haemostasis, a tympanomeatal flap is raised and the middle ear entered. The endoscope is steadied in the non-dominant hand, often resting the shaft lightly against the canal wall to damp tremor, while the dominant hand carries the dissector, suction or prosthesis. The angled scope is then used to inspect the chain and the recesses: the long process of the incus, the incudostapedial joint, the stapes superstructure and footplate, and the oval and round windows are all brought into clear view, and the attic and retrotympanum are checked for residual disease before anything is rebuilt.

Reconstruction then proceeds up the usual ladder. A small incudostapedial gap with a healthy stapes can be bridged with bone cement or a sculpted incus autograft. An absent or eroded long process with an intact, mobile stapes superstructure is reconstructed with a PORP seated on the stapes head; an absent superstructure with a mobile footplate calls for a TORP. The prosthesis is delivered and seated one-handed, and a cartilage shield— tragal or conchal — is interposed between the prosthesis head and the drum to distribute load and resist extrusion, exactly as under the microscope. A key practical tip is to measure and trim the prosthesis precisely before insertion, because fine one-handed adjustment within the middle ear is harder than with two hands; the panoramic view, however, makes judging the seating on the stapes and the angle of the shaft notably easier. The flap is then replaced and the canal packed. Reported series have completed this entirely transcanal, in selected patients even under local anaesthesia, with titanium PORPs and TORPs and with autologous cartilage [2018].

Two technical themes recur. First, haemostasis is everything: time spent achieving a dry field is repaid many times over, because a one-handed surgeon cannot fight a bloody one. Second, the endoscope rewards economy of movement— the lens is easily smeared, so deliberate, unhurried passes that keep the tip clean beat rapid fumbling. Both are learnable, and the learning curve is real; the gain, once climbed, is direct visual confirmation of structures the microscope can only infer.

TChoosing the right ear

Endoscopic ossiculoplasty is not a universal substitute; case selection is the difference between an elegant operation and a frustrating one. The ideal ear is a dry, well-aerated middle ear with a wide, straight canal and contained disease — the prototype being a planned second-stage reconstruction in an ear already cleared of cholesteatoma at a primary endoscopic procedure, where the field is clean and the recesses can be surveyed for residuum[2011]. An intact, mobile stapes superstructure that accepts a short PORP makes such a case nearly perfect, because the most stable and best-performing reconstruction is also the simplest to seat.

Against this stand the features that argue for a microscopic or combined approach. A narrow, tortuous or sclerotic canal physically obstructs the scope and instruments. A persistently bloody field— an inflamed, granular middle ear — defeats one-handed work. Most decisively, disease that extends beyond the aditus into the mastoid antrum lies outside transcanal reach and requires a mastoidectomy, which is a microscopic operation. A heavily scarred revision field, with distorted landmarks and dense adhesions, similarly favours two hands. The widget below turns these factors into a simple heuristic; it is a teaching aid, not a validated score, but it captures the trade-offs that experienced endoscopic surgeons weigh.

TWhat the evidence shows

The honest summary of the literature is one of equivalence in hearing with marginal gains in morbidity. When endoscopic and microscopic ossiculoplasty are compared head to head, audiometric outcomes are not significantly different. A systematic review of comparative studies in chronic otitis media found no significant difference in air-bone gap outcomes, with the endoscopic technique trending toward fewer complications and shorter operative time without reaching statistical significance [2021]. A consecutive series of 157 ossiculoplasties reported an air-bone gap within 20 dB in 72 % of endoscopic and 73 % of microscopic cases — effectively identical[2023]. A two-centre comparison of ossicular discontinuity likewise found no difference in pure-tone average, air-bone gap or word recognition once prosthesis type was controlled for [2017].

Pooled data tell the same story. A 2025 meta-analysis of five studies (504 patients) found comparable air-bone gap closure, postoperative pure-tone average and surgical success between the two approaches, with a shorter operative duration favouring the endoscope and qualitative advantages in visualisation, fewer supplemental incisions, better ergonomics and less postoperative pain [2025]. Large single-discipline cohorts corroborate the absolute results: a multicentre series of 292 endoscopic ossiculoplasties reported the mean air-bone gap falling from about 27 dB to 20 dB with a graft success rate above 94 % across mixed ossicular pathology[2025]. The evidence is largely observational rather than randomised, so it should be read with that caveat, but its direction is consistent: the endoscope does not buy better hearing, and it does not cost hearing either.

CWhere it fits and where it does not

For the clinician deciding how to counsel and operate, the take-home is that endoscopic ossiculoplasty is a route, not a different operation. Because the hearing result is governed by the ossicular defect, the prosthesis and the host middle ear — not by whether a scope or a microscope was used — the choice of approach should be made on access and morbidity, not on an expectation of superior hearing[2025]. The genuine advantages are real and worth offering the right patient: no postauricular incision, often no canalplasty, less postoperative pain, and direct vision of the recesses where residual cholesteatoma hides, which can reduce the need to drill simply to achieve exposure.

The limitations should be stated just as plainly. The technique is one-handed, it forfeits stereoscopic depth, and it is intolerant of bleeding; it has a real learning curve; and it cannot, by itself, follow disease into the mastoid. A pragmatic posture serves patients best: reserve the totally endoscopic reconstruction for the dry, contained, wide-canal ear — the staged second look being the model case — and keep the microscope, or a combined approach with mastoidectomy, for the bloody, scarred or extensively diseased ear[2021]. Used with that discipline, the endoscope earns its place in the ossiculoplasty toolkit: it trades the microscope’s depth and second hand for a panoramic view of the hidden anatomy, delivers equivalent hearing, and spares the patient an incision — precisely the bargain its panoramic optics promise.