SURGICAL TREATMENTS FOR PATULOUS EUSTACHIAN TUBE: AUTOLOGOUS FAT GRAFTING AND ARTIFICIAL EUSTACHIAN TUBE

Masahiro Morita, Masatsugu Masuda

Kyorin University School of Medicine, Department of Otolaryngology, Tokyo, Japan

Introduction

The origins of patulous Eustachian tube (PET) have not been fully elucidated. However, more than half of the patients with PET have experienced weight loss, and their CT imaging studies have shown a depletion of the soft tissue (i.e., fat tissue), surrounding the medial two-thirds of the cartilaginous portion in the Eustachian tube (ET). We had developed autologous fat grafting (AFG) techniques for the refractory PET and have been using them since 1999. In this study, we presented the methods of using our self-developed specialized needle instrument for the injection of fat into the sub-mucosal tissue surrounding the ET from the nasopharyngeal orifice. Moreover, we have developed an artificial Eustachian tube (AET) which is able to alleviate various types of tubal dysfunctions such as tubal stenosis and PET. The AET can restore the ventilatory and drainage functions of the ET. The AET can be inserted into the cartilaginous ET via the bony ET, through the tympanic membrane, or directly into the ET in the case of a tympanoplasty with a guide wire.

In the present study, efficacies of surgical treatment using AFG were evaluated, and the AET operation was added in some patients who had a low response to AFG.

Method

Fourteen cases (20 ears) of refractory PET, who complainwed of ear symptoms like ear fullness and auto-phony, were evaluated in this study. Diagnosis of PET was made with the ET functioning tests, which includes sonotubometry, and the tubo-tympanum-aerodynamogram (TTAG) with a Valsalva maneuver developed by Kumazawa et al. The effects of both treatments with AFG and AET on PET were also evaluated by using these ET functioning tests. Figure 1 shows the intra-tubal insertion point of fat on the orifice of the right ET. As shown in the right photo, injection from the intra-ET and into the infra-mucous membrane is in an upper-lateral direction.

We developed a specialized two-prong needle for autologous fat grafting techniques in order to improve the methods of injection over the currently used single needle. The top of the specialized needle is divided into two branches, one, a needle for fat injection, the other, a dichotomic stopper. A needle with a dichotomic stopper is an instrument for the injection of fat into the sub-mucosal tissue surrounding the ET at approximately a ten-mm distance from the nasopharyngeal orifice. This new type of needle with a dichotomic stopper is especially adapted for the injection of fatty tissue, from the intra-ET into the infra-mucous membrane of the ET cavity. The stopper helps to allow for a precise placement of the needle at the ideal injection point. The needle for the operation of AFG was inserted into the infra-mucous membrane from the intra-tubal cavity.

The AET was added to the AFG operation in some of those patients when the operation did not effectuate a ‘more than slightly effective’ result for the patients with refractory PET. The AET consists of a tubular body, and is made from polyurethane. The proximal end can be placed protruding out of the tympanic membrane, or just beneath, while the distal end is inserted into the cartilaginous ET passing through the isthmus.

image

Fig. 1. Intra-tubal insertion point of fat on the orifice of the right ET.

An AET was inserted into the ET through the incised tympanic membrane, as shown in Figure 2. The AET, equipped with an intra-tubal guide wire, could be inserted firmly along the curve of the bony ET. The distal end of the AET has micro-holes in the side near its tip facing the inside of the cartilaginous ET for ventilation.

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Fig. 2. Schematic illustration of AET: insertion of AET with a guide wire into the ET through the incised tympanic membrane.

Results

The effects of the AFG using the specialized needle were evaluated more than one year after the operation in 14 cases (19 ears). Effects classed as moderate or exceptional were observed in 74% of the ears including those receiving the operation more than once. Five ears (71%) improved after additional grafts, usually one operation, but up to three in certain cases, if the AFG effects were not evident after the initial graft.

The AET operation was added to the AFG operation in three cases (three ears) when the AFG operation did not effectuate a ‘more than slightly effective’ result for these patients with refractory PET. The AET operation in all three ears that did not get more than moderately effective by the AFG operation, was moderately or more than moderately effective. The combined results of the AFG and AFT operation had quite a high rate of effectiveness on PET patients. Total effects were 90%, which were moderately and remarkably effective as shown in Figure 3.

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Fig. 3. Combined results of AFG and additional AET operation.

Possible complications in this operation, like an impairment to opening the mouth, was not found at all in any of the 19 ears using our specialized needle, though some impairment, like temporal sensory weakness of the submandibular portion, was found in five out of 36 ears operated on using the current method of a single needle, in our past study. There was no complication, like diplopia, concerned with the central nerve associated with any of the ears treated with our specialized needle.

Discussion

Patients with severe PET, who have had ear symptoms more than half a day, usually tend to be very difficult to treat with any types of medication. We presented minimally invasive methods for the treatment of refractory PET that involves AFG into the ET lumen from the nasopharyngeal orifice, in combination with or without an AET from the middle ear.

Topical medical therapy, such as boric acid and salicylic acid powders, for treatment of PET is estimated to increase congestion of the nasopharyngeal ET orifice.1,2 However, most of these topical medications did not achieve remarkable relief in patients with severe PET, and tended to lose their effectiveness within several days, and needed to be administered repeatedly even in patients with mild PET. Therefore, we have developed a surgical procedure for the treatment of PET, and the effects of AFG and AET operations on refractory PET have been evaluated. Autologous fat grafting for the refractory PET had been reported by Doherty et al.3 They did not only treat with fat grafting, but also with other treatments of fat plugging, or cauterization the entire circumference of the ET orifice.

In other studies on surgical treatment, trans-tympanic insertion of a new silicone plug, developed by Ko-bayashi, seems to be useful for controlling a chronic PET.4

Poe reported that Endoluminal patulous ET reconstruction was performed by using the techniques with autologous cartilage graft.5

The effects of an AFG operation has only been reported of a few cases, probably because its injection point is very difficult to identify in an AFG operation, and for the placement and fixing at the adequate injection point, specialized skills are needed with the current method of a single needle.

We have found two factors that affect the outcome of the AFG operation. The first factor is age. In patients over 50 the outcomes were not as positive as those in patient under 50. Only three out of the13 ears (23%) of patients of 50 years and older showed either remarkable or moderate outcomes.

The second factor is BMI. Severe emaciation makes extraction of periumbilical adipose tissue very difficult, especially in males.

We conclude that we need to get much more clinical research for the expansion of these two types of treatment, AFG and AET.

References

1.O’Conner AF, Shea JJ. Autophony and the patulous Eustachian tube. Laryngoscope 91:1427–1435, 1981

2.Ogawa S, Satoh I, Tanaka H. Patulous Eustachian tube: a new treatment with infusion of absorbable gelatin sponge solution. Arch Otolaryngol 102:276–280, 1976

3.Doherty JK, Slattery WH 3rd. Autologous fat grafting for the refractory patulous Eustachian tube. Otolaryngol Head Neck Surg. 128:88–91, 2003

4.Sato T, Kawase T, Yano H, Suetake M, Kobayashi T. Trans-tympanic silicone plug insertion for chronic patulous Eustachian tube. Acta Otolaryngol 125:1158–1163, 2005

5.Poe DS. Diagnosis and management of the patulous Eustachian tube. Otol Neurotol 28:668–677, 2007


Address for correspondence: Masahiro Morita, Kyorin University School of Medicine, 6–20-2 Shinkawa, Mitaka-City, Tokyo 181–8611, Japan. ear@center.email.ne.jp

Cholesteatoma and Ear Surgery – An Update, pp. 37–40

Edited by Haruo Takahashi

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