CASE REPORT Open Access

Microlaryngoscopic surgery for pyriformsinus fistulas in children: a report of twocasesAkiyoshi Nomura*, Koji Fukumoto, Masaya Yamoto, Toshiaki Takahashi, Kengo Nakaya, Akinori Sekioka,Yutaka Yamada and Naoto Urushihara

Abstract

Background: A pyriform sinus fistula (PSF) is a rare branchial anomaly that causes recurrent cervical infections.Open neck surgery has widely been accepted as a definitive treatment for PSFs, and endoscopic surgery hasbeen reported in recent years. However, both approaches are not satisfactory because of high recurrencerates and postoperative complications. Microlaryngoscopic surgery (MLS) is a transoral surgical techniqueinvolving the use of an operating microscope. In this report, we present a new procedure involving MLS forresection and closure of a PSF without a skin incision.

Case presentation: Technique: MLS was performed under general anesthesia with endotracheal intubation.The patient was placed in the supine position, and a direct laryngoscope was inserted to expose the pyriformsinus, which was then magnified using an operating microscope. The mucosal layer was carefully resectedusing scissors and cupped forceps with sharp edges. The fistula was securely sutured using absorbable suturematerial. Case 1: A 9-year-old boy with recurrent neck abscesses since 8 years of age presented to our hospital afterreceiving antibiotics and undergoing drainage in other hospitals. After admission to our hospital, bariumesophagography and oral contrast coronal computed tomography showed a PSF on the left side, and openneck surgery was performed to resect the fistula. He was eventually discharged from the hospital without anyproblem. However, a PSF recurred 2 weeks later. As reoperation with the cervical approach was considereddifficult owing to severe adhesions, we adopted MLS as a definitive operation. The postoperative course wasuneventful. No recurrence was observed during an 18-month follow-up. Case 2: A 10-year-old girl presentedto our hospital with recurrent left-sided neck swelling since 6 years of age. After inflammation control, a PSFwas identified on the left side on barium esophagography and computed tomography. MLS was performedsafely, and the postoperative course was uneventful. No recurrence was observed during a 10-month follow-up.

Conclusions: MLS allows excellent visualization and effective closure for PSFs, and this approach is suitable forrecurrence after open neck surgery. Therefore, MLS might become a first-line treatment for PSFs in children.

Keywords: Pyriform sinus fistula, Microlaryngoscopy, Children

* Correspondence: toufu320yen@yahoo.co.jpDepartment of Pediatric Surgery, Shizuoka Children’s Hospital, 860Urushiyama, Aoi-ku, Shizuoka City, Shizuoka Prefecture 420-8660, Japan

© The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link tothe Creative Commons license, and indicate if changes were made.

Nomura et al. Surgical Case Reports (2018) 4:113 https://doi.org/10.1186/s40792-018-0521-5

BackgroundA pyriform sinus fistula (PSF) is a rare congenital anom-aly caused by incomplete obliteration of the third orfourth pharyngeal bursa during the seventh week of ges-tation [1, 2]. A recent theory about the origin of thismalformation has suggested that it is derived from thethymopharyngeal duct [2–4]. The chief clinical presenta-tions include recurrent cervical abscesses and suppura-tive thyroiditis, which are predominantly left sided [5, 6].The diagnosis of a PSF is difficult because most patientshave a clinical history of recurrent cervical abscesses andhave already undergone some treatment for theseabscesses [7].The primary treatment for a PSF accompanied by

acute cervical infection involves antibiotic administra-tion and surgical abscess drainage. After inflammationcontrol, a definitive treatment is planned. Although openneck surgery for fistula resection has widely been ac-cepted as a definitive treatment, it is sometimes difficultto identify the fistula owing to severe adhesions associ-ated with recurrent infection or repetitive drainage treat-ments, and postoperative complications subsequentlyoccur.Several endoscopic techniques have recently been

developed to obliterate a PSF, and these haveadvantages with regard to the identification of the PSForifice and reduction of postoperative complications[8]. Most reports have mentioned chemical or electricalcauterization for the sinus tract; however, these ap-proaches sometimes result in complications and recur-rence. There are few reports on endoscopic resectionand closure of a fistula in children. Here, we present anew procedure involving microlaryngoscopic surgery

(MLS) with an operating microscope for resection andclosure of a PSF without a skin incision.

Case presentationMLS techniqueMLS is a common laryngeal operation involving the useof an operating microscope. Surgery is performed undergeneral anesthesia with endotracheal intubation. First,the patient is placed in the supine position, and a directlaryngoscope is inserted to expose the pyriform sinus,which is magnified using an operating microscope(Fig. 1). The fistula orifice is clearly visible in the binocu-lar view. Second, a circumferential incision is madearound the internal orifice using scissors and cuppedforceps with sharp edges, and the fistula wall is dissectedaway from the submucosal tissue. Finally, the internalorifice is securely sutured with a single layer of 4–0Vicryl® using a 13 mm needle and a knot pusher.

Case 1A 9-year-old boy presented to our hospital with a historyof recurrent neck abscesses since 8 years of age. He hadreceived antibiotics and had undergone drainage of theabscesses in other hospitals. He was admitted to ourhospital after control of inflammation. Barium esophago-graphy showed a PSF on the left side (Fig. 2a). Oral con-trast coronal computed tomography (CT) showed anair- and barium-containing fistula (Fig. 2b). He under-went open neck surgery for definitive treatment of thePSF. He quickly recovered, and he was discharged fromthe hospital 7 days after the surgery. However, 2 weekslater, he visited our hospital again because of a neck ab-scess. He received antibiotics and underwent drainage.

Fig. 1 Set-up for microlaryngoscopic surgery

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Barium esophagography revealed fistula recurrence at thesame location (Fig. 2c). As reoperation with the cervicalapproach was expected to be difficult owing to possiblesevere adhesions, MLS was planned. Although the internalorifice was detected easily (Fig. 3a), the fistula was foundto be wider and deeper than expected after resection ofthe fragile layer associated with inflammation (Fig. 3b).

The fistula was resected piecemeal because it could not beeasily inverted and peeled off. The entire mucosal remnantwas macroscopically removed. Although suturing was dif-ficult because of the wide internal orifice, the procedurewas completed uneventfully (Fig. 3c, d). Barium esophago-graphy was performed on the seventh postoperative day,and no issues were noted. He had an uneventful recovery,

a b c

Fig. 2 a Barium esophagography shows a pyriform sinus fistula (arrow) on the left side. b Oral contrast coronal computed tomography shows afistula (arrow). c Barium esophagography after open neck surgery shows recurrence of the pyriform sinus fistula (arrow)

dc

ba

Fig. 3 a Direct laryngoscopy shows the internal orifice at the left pyriform sinus. b The internal orifice is fragile owing to inflammation. A circumferentialincision is made around the internal orifice using scissors and cupped forceps. c The mucosal incision is sutured using 4–0 Vicryl®. d The pyriform sinusafter suturing

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and he was discharged 10 days after the surgery. No recur-rence was observed during an 18-month follow-up.

Case 2A 10-year-old girl presented to our hospital with a his-tory of recurrent left-sided neck swelling since 6 years ofage. After control of inflammation, barium esophagogra-phy was performed, and it showed a PSF on the left side.CT showed an air- and barium-containing fistula. MLSwas performed as first-line treatment. The fistula wasnarrow, and its tissue was not fragile (Fig. 4a). Therefore,we made the incision as small as possible (Fig. 4b, c),and the operation was completed uneventfully (Fig. 4d).Barium esophagography was performed on the fifthpostoperative day, and no leakage was noted. Free oralintake was started on the same day. She had an unevent-ful recovery, and she was discharged 7 days after the sur-gery. No recurrence was observed during a 10-monthfollow-up.

DiscussionA PSF consists of a thin, fragile membranous tract thatis closely associated with important structures, such asthe recurrent laryngeal nerve, and with acute inflamma-tion, and surrounding scar tissue is always an issue. Thedefinitive treatment for a PSF involves complete excisionof the fistula and closure of the internal orifice. Open

neck surgery is the most reliable and commonly usedprocedure. However, the open neck surgical procedure issometimes difficult because of the anatomical and histo-logical characteristics of the fistula. In addition, adhe-sions associated with recurrent infection and repetitivedrainage could make this procedure difficult [9] and theprocedure has some risks such as vocal cord paralysis.Moreover, infection often recurs when the fistula is notcompletely excised [10]. In a review of 177 publishedreports on PSFs, among 377 patients who underwentopen neck surgery, the recurrence rate was 15% after theinitial procedure. Furthermore, the complication ratewas 10% in patients who were aged 8 years or younger[7]. Vocal cord paralysis was the most common compli-cation. Higher rates of complications in young childrenmight be associated with anatomical factors and tech-nical difficulties in open surgical excision.Endoscopic techniques have been developed as alterna-

tives to open neck surgery for PSFs to avoid surgicalcomplications [2, 3, 5, 11]. The most widely used proced-ure is endoscopic electrocauterization of the fistula tract,which was first described in 1998 [12]. Laser cauterizationand chemical cauterization using trichloroacetic acid orsilver nitrate and fibrin have also recently been reported[13–15]. Endoscopic approaches have been reported to beless invasive and have better cosmetic outcomes whencompared with open neck surgery. However, endoscopic

dc

ba

Fig. 4 a The internal orifice of the fistula is clearly visible using forceps. It is narrow and durable. b After making an incision around the orifice,the mucosal layer is dissected using scissors. c The fistula after complete mucosal resection. d The pyriform sinus after suturing

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surgery is not satisfactory for PSFs. Approaches involvingchemicals might cause tissue inflammation and edema ofthe nerve, leading to temporary paresis. Vocal fold immo-bility after endoscopic chemocauterization has been re-ported in two cases [16]. In addition, chemocauterizationhas a risk of chemical leakage into the esophagus, whichcan result in strictures [17]. Moreover, electrocauteriza-tion has a risk of pyriform sinus mucosa penetration,which can lead to further abscess formation [18]. Al-though laser cauterization has the advantage of a thermaleffect with less penetration [19], there is no evidence forthe superiority of electrocauterization, laser cauterization,or chemocauterization [13]. It has been speculated thatendoscopic procedures might retain epithelial remnants ofa PSF after cauterization of the tract [3], which can causerecurrence.Recently, Kamide et al. [20] reported that transoral

videolaryngoscopic surgery was effective for adult PSFs.Their procedure avoided recurrence as it involved resec-tion without remnant mucosa and closure of the internalorifice. MLS with an operating microscope is a commontransoral approach in laryngeal surgery. MLS can mag-nify the working space sufficiently in the binocular view,which can ensure mucosal resection and internal orificeclosure through direct manipulation in children. There-fore, we believe that MLS for PSFs can help avoid severecomplications and recurrence. However, MLS has somelimitations. First, en bloc resection of the fistula is oftentechnically challenging because of the limited space.Moreover, the infectious fistula may not be easilyinverted and peeled off, and there is a possibility of enbloc resection not being successful. Second, when thePSF is very large, all fistula tracts may not be visible. Be-cause PSFs in children are sometimes large, resectionshould be carefully performed. Therefore, complete re-section is important so that the entire fistula can be suf-ficiently confirmed via microlaryngoscopy. Although enbloc resection is ideal for fistula, it is challenging be-cause of such limitations. Conversion to piecemeal re-section is also useful in difficult cases. Completeresection could be performed via piecemeal resec-tion, and our patient was successfully treated usingMLS. Conversely, in case of very large cyst that can-not be completely removed even via piecemeal resec-tion or when a fistula tract cannot be graspedproperly, MLS is not considered as first-line treat-ment for PSF. We previously reported that MLS canbe applied in infants aged less than 1 year [21], andwe believe that a similar procedure can be per-formed for PSFs in young children.Although there are many MLS cases, the number of

PSF cases is still small. More PSF cases should be col-lected, and further assessments of MLS for PSFs shouldbe performed.

ConclusionsMLS allows excellent visualization and effective closureof PSFs. Moreover, the procedure is suitable for recur-rence after open neck surgery. Therefore, MLS can beconsidered as a safe and minimally invasive procedure,and it might become a first-line treatment for PSFs inchildren.

AbbreviationsCT: Oral contrast coronal computed tomography; MLS: Microlaryngoscopicsurgery; PSF: Pyriform sinus fistula

Authors’ contributionsNA acquired the data and drafted the manuscript. NA and FK performed theoperations. All other authors attended the patient postoperatively. All authorsread and approved the final manuscript.

Ethics approval and consent to participateThe publication of the present study was undertaken in accordance with theethical standards of our institution (2017133).

Consent for publicationInformed consent was obtained from the patients and their families for thepublication of this report.

Competing interestsThe authors declare that they have no competing interests.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims in publishedmaps and institutional affiliations.

Received: 23 July 2018 Accepted: 3 September 2018

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