General Considerations

The surgical approach for cartilage tympanoplasty does not differ from the approach for traditional otologic surgery and is dictated by the extent and location of the disease. The postauricular approach is used in most patients because these cases, by definition, tend to have more extensive middle ear pathology. A small, localized, posterior retraction or perforation can be performed through a transcanal or endaural incision, but great care must be taken to ensure that the depths of the retraction can be reached. Likewise, the placement of the cartilage graft uses the underlay technique, so no special tympanomeatal flaps or skin incisions are required.

Some general observations should be made regarding the differences in cartilage that occur with aging. The cartilage thickness of the tragus and cymba are not appreciably different between children and adults, but the perichondrium seems to be more adherent in children. For this reason, when the perichondrium is removed from one side when fashioning the graft (described later), care must be taken to ensure the correct plane is dissected, especially in children. Likewise, cartilage is more pliable in children, making it slightly easier to work with than adult cartilage, which can become brittle in patients older than 65 years. For this reason, during the fashioning of the graft, it is generally a good practice to manipulate and hold the cartilage with fingers instead of forceps, and toothed forceps should never be used to grasp the cartilage to avoid fracture.

The perichondrium generally is left attached to the side of the cartilage that faces the ear canal, regardless of which technique is used. It is believed that the perichondrium improves graft stability and facilitates ingrowth of fibrous tissue and epithelialization. With the palisade technique, however, perichondrium occasionally has been removed from both sides of the cartilage because of untoward curling of the graft, which typically curves toward the side with the perichondrium. No ill effect has been noted, other than increased fragility of the graft during formation and placement.

Perichondrium/Cartilage Island Flap

The general technique of reconstruction using the perichondrium/cartilage island flap begins with harvest of the cartilage from the tragal area (see Video Clip 10-1).²¹ This cartilage is ideal because it is thin, flat, and in sufficient quantities to permit reconstruction of the entire tympanic membrane. The cartilage is used as a full-thickness graft and is typically slightly less than 1 mm thick in most cases. Although it has been suggested that a slight acoustic benefit could be obtained by thinning the cartilage to 0.5 mm,²² this advantage is offset by the unacceptable curling of the graft, which occurs when the cartilage is thinned, and perichondrium is left attached to one side.

An initial cut through skin and cartilage is made on the medial side of the tragus, leaving a 2 mm strip of cartilage in the dome of the tragus for cosmesis (Fig. 10-1). The cartilage, with attached perichondrium, is dissected medially from the overlying skin and soft tissue by spreading a pair of sharp scissors in a plane that is easily developed superficial to the perichondrium on both sides. It is necessary to make an inferior cut as low as possible to maximize the length of harvested cartilage. The cartilage is grasped and retracted inferiorly, which delivers the superior portion from the incisura area. The superior portion is dissected out while retracting, which produces a piece of cartilage typically measuring 15 × 10 mm in children and larger in adults.

FIGURE 10-1 Harvest of cartilage, leaving small rim of cartilage in dome for cosmesis (right ear).

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

The perichondrium from the side of the cartilage farthest from the ear canal is dissected off, leaving the thinner perichondrium on the reverse side. A perichondrium/cartilage island flap is constructed in the following manner. Using a round knife, cartilage is dissected from the graft to produce an eccentrically located disc, approximately 7 to 9 mm in diameter, which is used for total tympanic membrane reconstruction. A flap of perichondrium is produced posteriorly that eventually drapes over the posterior canal wall. A complete strip of cartilage 2 mm wide is removed vertically from the center of the graft to accommodate the entire malleus handle (Fig. 10-2). The creation of two cartilage islands in this manner is essential to enable the reconstructed tympanic membrane to bend and conform to the normal conical shape of the tympanic membrane. When the ossicular chain is intact, an additional triangular piece of cartilage is removed from the posterosuperior quadrant to accommodate the incus. This excision prevents the lateral displacement of the posterior portion of the cartilage graft that sometimes occurs because of insufficient space between the malleus and incus.

FIGURE 10-2 Prepared perichondrium/cartilage island graft, showing strip of cartilage removed to facilitate malleus.

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

The entire graft is placed in an underlay fashion, with the malleus fitting in the groove and pressing down into and conforming to the perichondrium (Fig. 10-3). The cartilage is placed toward the promontory, with the perichondrium immediately adjacent to the tympanic membrane remnant, both of which are medial to the malleus. Failure to remove enough cartilage from the center strip causes the graft to fold up at the center instead of lying flat in the desired position. Likewise, if the strip is insufficient, the cartilage may be displaced medially instead of assuming a more lateral position in the same plane as the malleus.

FIGURE 10-3 Lateral line drawing showing proper placement of graft.

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

Absorbable gelatin sponge (Gelfoam) is packed in the middle ear space underneath the anterior annulus to support the graft in this area, and the posterior flap of perichondrium is draped over the posterior canal wall. Middle ear packing is avoided on the promontory and in the vicinity of the ossicular chain. One piece of Gelfoam is placed lateral to the reconstructed tympanic membrane, and antibiotic ointment is placed in the ear canal (Fig. 10-4).

FIGURE 10-4 Postoperative ear with perichondrium/cartilage island graft (left ear).

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

Palisade Technique

When the palisade technique is used for reconstruction of the tympanic membrane, cartilage can be harvested from either the tragus or the cymba (see Video Clip 10-2). Cartilage from the cymba area of the conchal bowl is used if the surgical approach involves a postauricular incision. Tragal cartilage is used if the approach is transcanal or endaural. The cartilage of the cymba is similar to the cartilage of the tragus in that it has an acceptable thickness of about 1 mm, in contrast to other areas of the concha, which are thicker and irregular. Cymba cartilage is more curved, however, which makes it particularly suitable for this technique because, in contrast to the perichondrium/cartilage island flap technique, it does not require one large, flat piece of cartilage.

The cartilage is cut into several slices that are subsequently pieced together, similar to a jigsaw puzzle, to reconstruct the tympanic membrane (Figs. 10-5 and 10-6). A large area of conchal eminence can be exposed by elevating the subcutaneous tissue and postauricular muscle from the conchal perichondrium. The cymba cartilage is the prominent bulge at the superior aspect of the concha (Fig. 10-7). A circumferential cut the size of the anticipated graft is made through the perichondrium and cartilage, but not through the anterior skin. The perichondrium is removed from the postauricular side, and the cartilage, with the perichondrium on the anterior aspect, is dissected from the skin. This technique is also used for harvesting cartilage for canal wall reconstruction when the retrograde mastoidectomy technique is used for cholesteatoma surgery.

FIGURE 10-5 A and B, Schematic of palisade technique (right ear). TM, tympanic membrane.

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

FIGURE 10-6 Schematic illustrating location of cymba cartilage (left ear).

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

FIGURE 10-7 Harvesting of cymba cartilage with postauricular incision (right ear).

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

The technique described here differs from the palisade tympanoplasty of Heermann and colleagues.²³ Instead of placing rectangular strips of cartilage side to side, an attempt is made to cut one major piece of cartilage in a semilunar fashion, which is placed directly against the malleus on top of the prosthesis (Fig. 10-8A and B). This piece of cartilage acts to reconstruct a major portion of the posterior half of the tympanic membrane, and serves as a foundation for the rest of the cartilage pieces. A second semilunar piece is placed between this first piece and the canal wall to reconstruct the scutum precisely (Fig. 10-8C). Any spaces that result between this cartilage and the canal wall or scutum are filled in with small slivers of cartilage to prevent prosthesis extrusion and recurrent retraction (Fig. 10-8D). The reconstruction is covered with the previously harvested perichondrium draped over the posterior canal wall (Fig. 10-9).

FIGURE 10-8 Sequence of palisade reconstruction (left ear). A, Total ossicular replacement prosthesis in place. B, Initial cartilage placement. C, Reconstruction of the scutum. D, Reconstruction of remainder of posterior tympanic membrane.

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

FIGURE 10-9 Postoperative appearance of tympanic membrane after palisade reconstruction (right ear).

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

Although this technique can be used for tympanic membrane reconstruction without ossicular reconstruction, it is favored when ossiculoplasty is performed in a situation with the malleus present, and is especially suitable for cholesteatoma surgery. Because the prosthesis is placed before the cartilage reconstruction, the palisade technique allows direct visualization and contact of the notched prosthesis to the manubrium handle, which has been shown to provide superior hearing results.²⁴ The prosthesis acts as a scaffolding on which the cartilage is placed, which serves to reconstruct the tympanic membrane and prevent prosthesis extrusion. It likewise allows a precise and watertight fit between the reconstructed tympanic membrane and the canal wall in the posterior area, where recurrent cholesteatoma most frequently occurs. Typically, in these situations, the anterior half of the tympanic membrane is not altered or is grafted with conventional materials to allow cholesteatoma surveillance and possible intubation in the postoperative period if necessary.

Intraoperative Complications

Intraoperative difficulties center around poor graft fit or difficult graft placement. If the perichondrium/cartilage island graft is inadvertently made too small, the problem can be rectified in one of two ways. The most effective is to piece leftover cartilage slivers between the cartilage island and annulus using the palisade technique combined with the island technique. This approach works particularly well when the posterior island is too small. The second way to rectify a graft that is too small is to cover the entire graft with the perichondrium that was previously harvested from one side and tuck it under the annulus as an underlay graft. Although this approach results in two layers of perichondrium over the cartilage, no detrimental effect on hearing has been noticed with this slightly thicker graft, and it is used occasionally.

Poor fit more commonly results when the island flap is made too large, especially the anterior island. Because the bony annulus is blunt and thicker anteriorly and superiorly, if the anterior island is too large, it is pushed medially by the ridge of bone, making a step-off just anterior to the malleus neck. Although at first it may seem that this problem could be rectified by additional Gelfoam packing anteriorly, grasping the graft with cup forceps and pulling it laterally through and into the defect would reveal that it is actually being held medially by the anterior bony annulus. When this problem is identified, it is easily corrected by making the graft smaller and ensuring a precise fit to the bony annulus.

A problem with placement can occur with an intact chain exhibiting a medially rotated malleus, which is usually encountered with the atelectatic ear. This problem can be overcome in one of two ways. The first is to remove 1 mm of the manubrium at the umbo with the malleus head amputator (malleus “nippers”). This does not affect hearing and allows medial placement of the graft. Attempting to lateralize the malleus with an intact chain should be discouraged because of the possibility of acoustic trauma. The second way to resolve this problem is to remove a slightly wider strip of cartilage (2 mm) to facilitate the malleus handle. The more medial malleus can indent further into the perichondrium, allowing the cartilage plates to move more laterally in the reconstruction and avoiding contact with the promontory. This solution also allows the anterior island of cartilage more flexibility in positioning, which is necessary to make good contact with the anterior annulus. It has been the author’s experience that the reconstructed tympanic membrane frequently pulls the malleus laterally during healing, even when the graft is making contact with the promontory at the level of the malleus manubrium after graft placement.

The other pitfall specific to the atelectatic ear concerns management of the atrophic tympanic membrane. After elevating the atrophic tympanic membrane off the promontory, it is tempting to insert the cartilage medial to the intact tympanic membrane. It is important, however, to remove at least a portion of the atrophic tympanic membrane anterior and posterior to the malleus to ensure that the cartilage flap is incorporated into the reconstructed tympanic membrane.

Postoperative Complications

The most significant complication seen in the postoperative period is persistent effusion with conductive hearing loss, requiring intubation of the reconstructed eardrum. This effusion is seen in about 7% to 10% of cases and can be problematic in cases where the entire tympanic membrane is reconstructed with the cartilage/perichondrium island flap. (As mentioned earlier, the tympanogram, generally low-volume type B, often is unreliable in the postoperative situation because of the noncompliant graft. The hearing result is the best indicator of middle ear function, and, in some cases, especially when the conductive loss is intermediate or difficult to ascertain, a CT scan may be needed to assess the middle ear.)

Although the tympanic membrane remains relatively insensate after cartilage reconstruction, it is often necessary to take the patient to the operating room for eardrum intubation because tube placement can be difficult. If enough room exists between the anterior annulus and the cartilage graft, a traditional myringotomy can be made, with more depth frequently found in the anterosuperior quadrant. It is more often necessary, however, to remove an ellipse of cartilage with a sickle knife or laser for adequate tube fit. Because of the thickness of the cartilage graft, grommet tubes are not applicable to this situation, and silicone elastomer (Silastic) T-tubes are more frequently used. More recently, a titanium tube (Razrbac Tube; Grace Medical Inc, Memphis, TN) has been designed specifically for use in ears reconstructed with cartilage tympanoplasty. The tube extends through the cartilage, but has more rigidity than a Silastic tube to prevent compression by the rigid graft.

In cases of more pervasive eustachian tube dysfunction, such as in patients with craniofacial abnormalities (including Down syndrome), previous head and neck cancer involving the nasopharynx, or a history of multiple ear surgeries, a T-tube is inserted in the cartilage graft during the initial surgery. The perichondrium/cartilage island graft is harvested and prepared as previously described. Using a round knife, a window that is large enough to allow placement of a Xomed Modified Goode T-tube (Xomed Surgical Products, Jacksonville, FL) is cut into the anterior cartilage island. A straight pick is placed into the cartilage window to dilate the perichondrium to allow tube placement. Before insetting the graft, the tube is placed into the cartilage window and brought out through the perichondrial surface. If the malleus is present, the end of the tube is first angled under the manubrium with small alligator forceps. After hooking the tube under the malleus, the graft is slid forward into place. If the malleus is absent, the graft/tube complex is slid directly into its final position (Fig. 10-10).

FIGURE 10-10 Technique of cartilage tympanoplasty with intraoperative placement of T-tube.

(From Dornhoffer JL: Cartilage tympanoplasty: Indications, techniques, and outcomes in a 1000-patient series. Laryngoscope 113:1844-1856, 2003.)

If a T-tube is removed either accidentally or purposely from an ear reconstructed with cartilage, the tympanic membrane heals with a monomeric membrane; however, the cartilage defect remains. If tube reinsertion is needed, a myringotomy is first performed through the monomeric membrane. The tube is reinserted at the original site by grasping the end of the T-tube with alligator forceps and pushing the flanges through the cartilage defect. Because the tympanic membrane is rigid from the cartilage reconstruction, it does not medialize when pressure is placed laterally. This increased rigidity greatly facilitates secondary tube insertion.

Another problem that may occur postoperatively concerns a patient with reconstruction after cholesteatoma removal. One serious disadvantage of using cartilage for reconstruction in cholesteatoma surgery is that it creates an opaque tympanic membrane posteriorly, which could potentially hide residual disease. This is a problem that should be recognized, and surgical discretion should be used. If major disruption of the cholesteatoma sac occurs at extirpation, one must consider the advisability of performing a second-look surgery at a later date. This consideration applies to cholesteatoma surgery in general, not only in cases where cartilage is used in the reconstruction. One must also recognize the fact that most residual disease occurs in the epitympanum, an area that is hidden by the bony canal wall and scutum when canal wall-up surgery of any type is performed.²⁵ Although posterior cartilage tympanic membrane reconstruction can delay the diagnosis of residual cholesteatoma, the disease becomes manifest either anteriorly or as a recurrence of a conductive hearing loss, and there should be no major complications because of this delay in diagnosis.^26,27

Revision surgery after cartilage tympanoplasty is generally straightforward. The tympanomeatal flap is elevated in the usual fashion, and the fibrous annulus is identified. The mucosa is incised, the middle ear is entered, and the posterior portion of the eardrum is lifted up. This technique is similar to elevating a tympanic membrane with posterior myringosclerosis as long as an adequate strip of cartilage was removed to facilitate the malleus in the initial surgery; this allows the graft to hinge at the malleus during revision surgery. Removing the perichondrium from the medial surface of the graft before placement allows the smooth surface of the cartilage to become mucosalized, and prevents adhesions similar to Silastic sheeting, so scarring is generally less than seen with other graft materials, especially in cases with mucosal disruption on the promontory.