Auris'Nasus'Larynx (Tokyo) 21, 38-43 (1994)

Surgical Treatment for Hypopharyngeal Cysts with a Side-Opened Direct Laryngoscope

Masahiro KAWAIDA, M.D., Hiroyuki FUKUDA, M.D.,* Akihiro SHIOTANI, M.D.,* and Naoyuki KOHNO, M.D.t

Department of Otolaryngology, Tokyo Metropolitan Ohtsuka Hospital, Tokyo, Japan; * Department of Otolaryngology, Keio University School of Medicine, Tokyo, Japan; and t Department of Otolaryngology, Juntendo University School of Medicine, Tokyo, Japan

Two cases of hypopharyngeal cyst are reported. Both cysts occurred in the piriform sinus of the hypopharynx. Histopathological examination indicated that both were retention cysts. These cysts were removed by laryngomicrosurgical technique using a side-opened direct laryngoscope. In the cyst with a distinct base, a laryngomicrosurgical snare was used for removal. In the wide-based cyst, the mucous membrane around the cyst was incised with an electrosurgical instrument and then detached to facilitate removal. In this paper, we describe our surgical procedure for removing hypopharyngeal cysts and discuss the causes of such cysts.

Cysts rarely developed in the hypopharynx. Removal of large cysts in this area by the oral approach can be difficult. It is thus preferable to remove such cysts by endopharyngeal microsurgery when they are still small. We previously described a side-opened direct laryngo­scope developed to facilitate bimanual manipulation. 1 We have reported a method for removing of an epiglottic cyst using this direct laryngoscope and snare. 2 Using this method, we performed microsurgery on two patients with cysts in the hypopharynx. We report these cases and describe the surgical procedure.

INSTRUMENTS AND SURGICAL PROCEDURE

We designed a side-opened direct laryngoscope that facilitated bimanual manipulation for laryngomicrosurgery. This direct laryngoscope, developed in collaboration with Nagashima Medical Instruments Co., Ltd., has a 5 mm opening from the anterior tip to the posterior end of the right side (Fig. 1). It measures 170 mm from the anterior tip to the posterior end. A laryngomicrosurgical snare (Nagashima Medical Instruments Co., Ltd.) and the longest electrosurgical instrument electrode presently available can be inserted through the right side opening of this direct laryngoscope. As the electrosurgical instrument, we used the Surgitron F.F.P.F.® (Ellmann Co., Ltd.) connected to a 20.5 cm supplementary electrode (Fig. 2).

The surgery is performed under inhalation anesthesia by endotracheal intubation. The anterior tip of the side-opened direct laryngoscope is introduced into the hypopharynx. When the cyst comes into view, the direct laryngoscope is self-retained with a holder and chest support. If the cyst is pedunculate, the snare is inserted from the right side opening of the direct laryngoscope. After leading a wire attached to the anterior tip of the snare to the base of the cyst, part of the cyst is grasped with a forceps held in the surgeon's other hand. The base of the cyst is then snared and resected. If the cyst is wide-based or buried, the mucous membrane near its base is incised with an electrosurgical instrument and detached with a forceps to expose the

Received 10 May 1993; accepted 20 September 1993. Correspondence should be addressed to: M. Kawaida, Department of Otolaryngology, Tokyo Metropolitan Ohtsuka Hospital, 8-1 Minamiohtsuka 2-chome, Toshima-ku, Tokyo, 170 Japan.

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Fig. 1. Side-opened direct laryngoscope. a: Overall view from the right side. The right side of this direct laryngoscope has an opening from the anterior tip to the posterior end. b: The external appearance of the posterior end resembles the letter C.

-b

Fig. 2. Electrosurgical instrument and 20.5 cm supplementary electrode. a: Surgitron F. F. P. F.® (EHmann Co., Ltd.). b: Handpiece with a 20.5 cm supplementary electrode connected.

cyst wall. The base of the lesion is then snared and excised. And the remaining lesion is then removed with forceps and hemostasis is induced by electrocoagulation. These surgical procedures are carried out under microscopic observation. After satisfactory hemostasis has been achieved, the direct laryngoscope is withdrawn.

CASE REPORTS

Case I In May 1989, a 59-year-old man experienced an abnormal feeling in the throat when

swallowing. This symptom persisted over the next year. He visited our clinic on 26 May 1990. Flexible laryngofiberscopic observation revealed a hemispherical cystic lesion with a pale red appearance that arose from the antero-medial region in the right piriform sinus of the hypopharynx (Fig. 3a). On 6 August 1990, he was admitted to our hospital. On 7 August, the lesion was removed with a side-opened direct laryngoscope and snare as described above. The cystic lesion was a hemispheric bulge about 1 cm in diameter based on the antero-medial region of the right piriform sinus (Fig. 4a). Its peduncle was snared and resected (Fig. 4, band c). For the purpose of hemostasis, the operative wound was electrocoagulated (Fig. 4d). Flexible laryngofiberscopy performed ten weeks postoperatively showed a complete disappearance of the lesion (Fig. 3b). There has been no recurrence.

Histopathological findings. The cystic cavity was covered by single or pseudostratified columnar ciliated epithelium. The lesion was diagnosed as a retention cyst (Fig. 5).

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Fig. 3. Flexible laryngofiberscopi­cal findings before and after surgery in Case 1. a (before surgery): A hemispheric cystic lesion was found in the antero-medial region of the right piriform sinus of the hypo­pharynx. b ( after surgery): The cyst disappeared completely.

Fig. 4. Surgical findings in Case 1. a: It was noted that a hemispheric cystic lesion is based on the antero-medial region of the right piriform sinus. b: The tip of a snare for laryngomicrosurgery was guided to the base of a cyst. c: Local findings immediately after a cyst was snared off and resected. d: The operative wound was electrocoagulated.

Case 2 In January 1991, a 51-year-old man suffered an abnormal feeling of the throat. The

symptom did not disappear and he visited our clinic on 7 February 1991. Flexible laryngofi-

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Fig. 5. Histopathological findings in Case I. Epithelium covering the cystic cavity is single or pseudostratified co­lumnar ciliated epithelium (H.E. X 1(0).

Fig. 6. Flexible laryngofiberscopi­cal findings before and after sur­gery in Case 2. a (before surgery) : A wide-based cystic lesion was found in the antero-medial region of the left piriform sinus of the hypopharynx. b (after surgery) : The cyst disappeared completely.

berscopy revealed a wide-based cystic lesion with a pale red appearance arising from the antero-medial region in the left piriform sinus of the hypopharynx (Fig. 6a). On 22 April 1991, the patient was admitted to our hospital. On 23 April, the lesion was removed as described in Case 1. The lesion was a wide-based hemispheric bulge about 1 cm in diameter on the antero-medial region of the left piriform sinus (Fig. 7a). Because the lesion was wide-based, the mucous membrane near its base was incised with an electrosurgical instrument. The cyst wall was then detached from the incised region and the cyst was removed (Fig. 7, b-d) . Local findings about ten weeks after the operation showed complete disappearance of the lesion (Fig. 6b). There has no recurrence.

Histopathological findings. The cystic cavity was covered by single or pseudostratified columnar ciliated epithelium. The lesion was diagnosed as a retention cyst (Fig. 8).

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Fig. 7. Surgical findings in Case 2. a: It was noted that a wide-based cystic lesion was based on the antero-medial region of the left piriform sinus. b: The mucous membrane around the cyst was incised with an electrosurgical instrument. c: The region around the cyst was detached with a cotton swab held by a forceps. d: Local findings of the operative wound after resection of the cyst was showed.

DISCUSSION

Fig. 8. Histopathological findings in Case 2. Epithelium covering the cystic cavity is single or pseudostratified co­lumnar ciliated epithelium (H.E. X 1(0).

It is very rare for a cyst to form in the hypopharynx, although cysts from the branchial apparatus and retention cysts in the hypopharynx have been occasionally reported. 3

,4 Hypo­pharyngeal cysts in our two cases were histopathologically diagnosed as retention cysts that were formed in the piriform sinus of the hypopharynx. Both were based on the antero-medial region of the piriform sinus near the arytenoid of the larynx.

The arytenoid of the larynx is known to abound with secretory laryngeal glands. 5,6 In our

two cases, cysts were formed on a region close to the arytenoid of the larynx, where secretory

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glands should be abundant. Physical stimulation during the swallowing of food may have obstructed a secretory gland, leading to development of a retention cyst.

We have already reported a method using a side-opened direct laryngoscope and snare for removal of an epiglottic cyst. 2 In the present study, we surgically treated two cases of hypopharyngeal cyst using that technique. There were no complications and no recurrence.

It is important to control bleeding when removing a cyst by the oral approach using a direct laryngoscope. Profuse bleeding will block the view and interfere with the complete removal of the cyst. Electrocoagulation is recommended when hemostasis cannot be achieved readily.

The surgical procedure is easy when a small cyst is being removed. In the case of a very large cyst, dyspnea is expected to occur and tracheostomy is needed in some cases. It may be necessary to reduce the size of a large cyst by puncturing and draining it before removal. 3,4

In our two cases, there has been no recurrence, and the postoperative course has been satisfactory.

SUMMARY

We treated two patients with hypopharyngeal retention cysts located on the antero-medial region of the piriform sinus near the arytenoid of the larynx. Laryngomicrosurgical technique using a side-opened direct laryngoscope was successful in removing the cysts in both cases. We described a surgical procedure for cysts of the hypopharynx and discussed the clinical picture and histopathological findings in these two cases.

REFERENCES

1. Kawaida M, Fukuda H, Kano S, et al: Laryngomicrosurgery by use of a side-opened direct laryngoscope. Inouye T, et al (eds): Recent Advances in Bronchoesophagology. pp 355-356, Elsevier Science Publishers B.Y., Amsterdam, 1990.

2. Kawaida M, Kohno N, Kawasaki Y, et al: Surgical treatment of large epiglottic cysts with a side-opened direct laryngoscope and snare. Auris·Nasus·Larynx (Tokyo) 19:45-50, 1992.

3. Boysen ME, De Besche A, Djupesland G, et al: Internal cysts and fistulae of branchial origin. J Laryngol Otol 93:533-539, 1979.

4. Aihara Y, Egami H, Kobayashi Y, et al: Hypopharyngeal cyst: A case report. Pract Otol 86:553-557, 1993.

5. Nassar YH, Bridger GP: Topography of the laryngeal mucous glands. Arch Otolaryngol 94:490-498, 1971.

6. Sato K: Three dimensional anatomy of the larynx: Investigation by whole organ sections. Otol Fukuoka 33:153-182, 1987.

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