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Fourth branchial pouch anomalies
International Journal of Pediatric Otorhinolaryngology 44 (1998) 5 – 10
Fourth branchial pouch anomalies A study of six cases and review of the literature R. Nicollas a, V. Ducroz b, E.N. Garabe´dian b, J.M. Triglia a,* a
Department of Pediatric Otolaryngology, La Timone Children’s Hospital, Boule6ard Jean Moulin, 13385 Marseille Ce´dex 5, France b Department of Pediatric Otolaryngology, Armand Trousseau Children’s Hospital, Boule6ard Arnold Netter, 75012 Paris, France Received 4 August 1997; received in revised form 15 January 1998; accepted 18 January 1998
Abstract A retrospective study in the ENT departments of the Timone Children’s Hospital in Marseille and the Armand Trousseau Hospital in Paris and a review of the literature was performed in order to update knowledge about fourth branchial pouch anomalies. Over the 12-year period studied, a total of six children were treated: three boys and three girls. The lesions were located on the left side in all cases and infection was the most common manifestation. Clinical presentation ranged from suppurative thyroiditis in most cases to stridor in a few newborns. The most useful diagnostic examinations are CT-scan of the neck and endoscopy of the pyriform sinus. The authors emphasize the need for complete surgical resection including the cyst and fistulous tract down to the pyriform sinus. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Fourth branchial pouch; Pyriform sinus; Suppurative thyroiditis; Cervical cysts
1. Introduction Cysts and fistulas of the fourth branchial pouch are uncommon. Fourth branchial pouch fistulas can be defined as the abnormal persistence of a canal between the pyriform sinus and the deep
* Corresponding author. Fax: + 33 0491387757; e-mail: [email protected]
side of the thyroid lobe [7]. The usual clinical manifestations are either acute thyroiditis or abscess, usually on the left side of the neck in children and young adults. Misdiagnosis exposes the patient to the risk of repeated infection and the dangers of inadequate management [3,7– 9,12]. The purpose of this retrospective review of six cases of fourth branchial pouch anomaly was to ascertain clinical features and proper management.
0165-5876/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0165-5876(98)00023-8
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R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
2. Patients and methods Between 1988 and 1997, six children underwent surgical removal of fourth branchial pouch anomalies in our departments at the Timone Children’s Hospital in Marseille (n =4) and the Trousseau Hospital in Paris (n =2). The records of these patients were reviewed to determine the side of occurrence, sex, age, clinical manifestations, and delay between discovery and adequate treatment. Endoscopy of the pharynx and larynx, and CT-scan were performed in all patients. Standard roentgenography, ultrasound imaging, and esophageal transit study were available in some cases. Surgical reports and histological findings were analyzed in all cases.
3. Results This series included three boys and three girls with a mean age of 60 months (range: 16 days to 12 years). In all cases, the malformation was located on the left cervical region at the level of the thyroid area. The delay between discovery and management in our departments was less than 3 weeks in five cases. In the remaining case the records mentioned only repeated thyroid abscesses without specifying any dates. Secondary infection of the malformation was observed in four patients. For two of these patients it was the first episode of infection, and for two, multiple episodes occurred; one of these two patients, in whom the initial diagnosis was adenitis, presented with massive purulent regurgitation with slight airway aspiration. The fifth patient was not clinically infected but proper diagnosis was initially suspected. In the sixth patient referred to one of our departments at the age of 16 days stridor and dyspnea were the first manifestations and differential diagnosis was proposed between fourth branchial pouch anomaly and cystic hygroma. Endoscopy of the pharynx and larynx was performed in all patients. In five out of six cases, a fistula was visualized at the apex of the pyriform sinus (Fig. 1). Compression of the larynx and/or trachea was observed in two cases.
In all patients, CT scan showed the presence of a left-sided tumor that demonstrated uneven uptake of contrast material (Fig. 2). In two patients ultrasound examination demonstrated a liquidfilled mass in contact with the thyroid. In one patient standard roentgenography was performed but did not provide any helpful diagnostic information. Gastrograffin contrast radiology was performed in two patients visualizing the course of the fistula tract and the cyst (Fig. 3). The surgical approach was left lateral cervicotomy in all six cases. The cyst, which was always infected to some degree, was dissected along with the fistulous tract up to the ipsilateral pyriform sinus. In three cases, the fistulous tract passed behind the inferior cornu of the thyroid cartilage and in one case it terminated within the inferior cornu of the thyroid cartilage. In the remaining two cases, information given in the operative report was insufficient to determine the course of the tract. The fistula was ligated at the pyriform sinus in five cases. The remaining case was the child whose tract terminated within the inferior cornu of the thyroid cartilage which was resected. Thyroid lobectomy was required to preserve the recurrent nerve in three cases. In the oldest patient, it was impossible to dissect the fistula from the thyroid lobe. Histological examination of surgical specimens confirmed the diagnosis of congenital cyst with a fistulous tract lined with squamous epithelium in all cases. In the oldest child of this series the thyroid had been invaded and partially destroyed by infection. Postoperative paralysis of the left vocal cord occurred in two cases. In one of these cases partial recovery was observed. The other case was the 12-year-old girl whose thyroid was invaded by infection and in whom only the lower part of the recurrent nerve could be identified. No recurrence of the fourth pouch anomaly has been observed in any patient with mean follow-up at 4 years (range: 5 months to 9 years).
4. Discussion Cysts and fistulas of the fourth branchial pouch are among the most uncommon congenital mal-
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
7
Fig. 1. Endoscopic view of the opening of a fourth branchial pouch fistula at the level of the left pyriform sinus (arrow: opening of the fistula; ac, left arytenoid cartilage; e, epiglottis); (A) initial view; (B) after compression of the neck, note the air bubble coming out of the opening.
formations of the neck. In their perusal of the worldwide literature between 1973 and 1993, Inigues et al. found a total of only 70 cases [6]. In a series of 106 patients with branchial tract anomalies, Ford et al. only reported one fistula of the fourth pouch [4].
Fistulas correspond to the persistence of the pharyngo-branchialis duct between the upper parathyroid gland and ultimobranchial body on one hand, and the pharynx, on the other. The fistulous tract begins at the apex of the pyriform sinus and runs in contact with the larynx and
8
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
trachea. The course of the tract can pass either behind the thyroid cartilage or through the zone of chondrification of the wing of the cartilage. After passing the cartilage the tract crosses the lower constrictor muscle of the pharynx and courses behind the body of the thyroid gland. The retrothyroid portion of the tract was responsible for the mass noted in all patients in this series. Unlike third branchial pouch fistulas which pass above the superior laryngeal nerve, fourth branchial pouch fistulas run below the superior laryngeal nerve [5]. Theoretically fourth branchial pouch fistulous tracts can continue in contact with the trachea into the mediastinum and contract close relations with the aortic arch on the left and the subclavian artery on the right [1,2,5]. In practice, however, most lesions are confined to the perithyroid area [6,7] as described by Liston (in [6]). In four out of the six patients in the present series, as well as in most previously reported cases [1 – 9,11,12], infection entered through the opening at the apex of the pyriform sinus. Left-sided presentation was observed in all patients in our series and has been almost consistently reported in the literature. Embryological events probably account
Fig. 2. Axial CT-scan section showing a fourth branchial pouch cyst (arrows). Note the heterogeneous appearance of the mass which is in contact with the left lobe of the thyroid. The trachea is deviated.
Fig. 3. Pharyngeal transit (frontal view) showing the fistula (arrow) running between the apex of the left pyriform sinus and the cyst.
for these findings. The opening of the fistula is located at the apex of the pyriform sinus because this region originates on both the right and left from the fourth branchial pouch. The thyroid and arytenoid cartilages, cricothyroid muscles and superior laryngeal nerves arise from the fourth branchial arch on both sides. From a vascular standpoint the fourth arch gives rise to the aortic arch on the left and the subclavian artery on the right. This asymmetrical development probably accounts for the predominance of left-side anomalies. Most congenital cyst anomalies are diagnosed following infection. In patients with fourth branchial pouch anomalies the most frequent clinical finding is perithyroid abscess. Anamnesis often reveals a history of infectious episodes
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
sometimes requiring surgical drainage. Respiratory signs can also be the first manifestation. Stridor was the presenting symptom in one patient in our series and in another case described by Sharma et al. [10]. Differential diagnosis of fourth branchial pouch anomalies can be difficult. Misdiagnosis as localized lobar thyroiditis has been reported by numerous groups [3,8,12]. Similar symptoms are observed in association with suppurative thyroiditis or adenitis and oesophageal duplication. Masses on the side of the neck can be produced by cystic hygroma in infants and external laryngocele in young adults. Endoscopy is the most useful diagnostic examination and should be performed in an operating room under general anesthesia in any child presenting with cervical abscess or suppurative thyroiditis especially if manifestations are recurrent and/or left-sided. Diagnosis can be confirmed by visualization of the opening of the fistulous tract at the apex of the pyriform sinus. However failure to visualize the opening does not rule out the possibility of an isolated cyst with no fistulous tract. This was the case in one patient in our series. CT scan provides important preoperative findings concerning the relationship of the anomaly with surrounding structures and in particular with the thyroid. Fistulography and transit studies are of little interest and have been largely abandoned although transit studies can be useful if oesophageal duplication is suspected. Thyroid scintigraphy is unnecessary unless associated thyroid disease is suspected. There is a general consensus that complete removal of the cyst and fistulous tract with ligature at the pyriform sinus is necessary to achieve permanent cure. Some controversy remains with regard to the need for thyroidectomy but most authors recommend thyroid lobectomy only if necessary to preserve the recurrent nerve [7,9]. Inigues et al. emphasized that the fistulous tract runs parallel to the lateral side of recurrent nerve [6]. In our series, laryngeal paralysis was observed despite thyroid lobectomy in two cases. In one of them it was transient.
9
5. Conclusion Cysts and fistulas of the fourth branchial pouch are uncommon but must be considered as a possible diagnosis in children or young adults with abscesses located on the left side of the neck in the vicinity of the thyroid gland and in patients presenting with recurrent cervical abscess regardless of age. Diagnosis of fourth branchial pouch fistulas can be confirmed by endoscopic visualization of an opening at the apex of the pyriform sinus. The relationship between the anomaly and surrounding structures can be ascertained by ultrasound imaging and CT-scan. Permanent cure requires complete resection of the cyst and the fistulous tract up to the pyriform sinus. Partial thyroidectomy may be required in some cases.
References [1] J. Andrieu-Guitrancourt, P. Narcy, J. Borde, Y. Melin, Y. Manac’h, D. Dehesdin, P. Desse, Duplications digestives de localisation pharynge´e ou fistules de la quatrie`me poche endobranchiale, Ann. Oto-Laryngol. (Paris) 96 (1979) 863 – 879. [2] D.N. Cote, G.J. Gianoli, Fourth branchial cleft cysts, Otolaryngol. Head Neck Surg. 114 (1996) 95 – 97. [3] M. Dellandrea, B. Montinet, R. Stringini, Ph. Claude, Pseudo-thyroı¨dites suppure´es et fistules de la quatrie`me poche branchiale, J. F. ORL 40 (1991) 56 – 58. [4] G.R. Ford, A. Balakrishnan, J.N.G. Evans, C.M. Bailey, Branchial cleft and pouch anomalies, J. Laryngol. Otol. 106 (1992) 137 – 143. [5] S.W. Gray, J.E. Skandalakis, Anomalies of the pharynx and its derivates, in: Embryology for Surgeons, Saunders, Philadelphia, PA, 1972, pp. 33 – 43. [6] J.P. Inigues, A. Rivron, J.P. Priou, L. Beust, G. Le Clec’h, J. Bourdinie`re, Fistules de la 4e poche endobranchiale, a` propos de 4 cas, Ann. Oto-Laryngol. (Paris) 110 (1993) 450 – 453. [7] Y. Manac’h, M.P. Morissaeu, A. Perrin, J.P. Aboucaya, P. Roulleau, Le fond du sinus piriforme dans le traitement chirurgical des fistules de la quatrie`me poche endobranchiale, Ann. Oto-Laryngol. (Paris) 105 (1988) 391 – 396. [8] Ph. Narcy, C. Aumont-Grosskopf, S. Bobin, Y. Manac’h, Fistulae of the fourth endobranchial pouch, Int. J. Pediatr. Otorhinolaryngol. 16 (1988) 157 – 165. [9] N. Nonomura, Surgical approach to piriform sinus fistula, Am. J. Otolaryngol. 14 (1993) 111 – 115.
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R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
[10] H.S. Sharma, A. Razif, M. Hamzah, A.S. Dharap, Z. Mahbar, M.Z.M. Kamal, et al., Fourth branchial pouch cyst: an unusual cause of neonatal stridor, Int. J. Pediatr. Otorhinolaryngol. 38 (1996) 155–161. [11] M.A. Shugar, G.B. Healy, The fourth branchial cleft
anomaly, Head Neck Surg. 3 (1980) 72 – 75. [12] F. Tovi, A. Gatot, J. Bar-Ziv, I. Yanay, Recurrent suppurative thyroiditis due to fourth branchial pouch sinus, Int. J. Pediatr. Otorhinolaryngol. 9 (1985) 89 – 96.
.
Fourth branchial pouch anomalies A study of six cases and review of the literature R. Nicollas a, V. Ducroz b, E.N. Garabe´dian b, J.M. Triglia a,* a
Department of Pediatric Otolaryngology, La Timone Children’s Hospital, Boule6ard Jean Moulin, 13385 Marseille Ce´dex 5, France b Department of Pediatric Otolaryngology, Armand Trousseau Children’s Hospital, Boule6ard Arnold Netter, 75012 Paris, France Received 4 August 1997; received in revised form 15 January 1998; accepted 18 January 1998
Abstract A retrospective study in the ENT departments of the Timone Children’s Hospital in Marseille and the Armand Trousseau Hospital in Paris and a review of the literature was performed in order to update knowledge about fourth branchial pouch anomalies. Over the 12-year period studied, a total of six children were treated: three boys and three girls. The lesions were located on the left side in all cases and infection was the most common manifestation. Clinical presentation ranged from suppurative thyroiditis in most cases to stridor in a few newborns. The most useful diagnostic examinations are CT-scan of the neck and endoscopy of the pyriform sinus. The authors emphasize the need for complete surgical resection including the cyst and fistulous tract down to the pyriform sinus. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Fourth branchial pouch; Pyriform sinus; Suppurative thyroiditis; Cervical cysts
1. Introduction Cysts and fistulas of the fourth branchial pouch are uncommon. Fourth branchial pouch fistulas can be defined as the abnormal persistence of a canal between the pyriform sinus and the deep
* Corresponding author. Fax: + 33 0491387757; e-mail: [email protected]
side of the thyroid lobe [7]. The usual clinical manifestations are either acute thyroiditis or abscess, usually on the left side of the neck in children and young adults. Misdiagnosis exposes the patient to the risk of repeated infection and the dangers of inadequate management [3,7– 9,12]. The purpose of this retrospective review of six cases of fourth branchial pouch anomaly was to ascertain clinical features and proper management.
0165-5876/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0165-5876(98)00023-8
6
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
2. Patients and methods Between 1988 and 1997, six children underwent surgical removal of fourth branchial pouch anomalies in our departments at the Timone Children’s Hospital in Marseille (n =4) and the Trousseau Hospital in Paris (n =2). The records of these patients were reviewed to determine the side of occurrence, sex, age, clinical manifestations, and delay between discovery and adequate treatment. Endoscopy of the pharynx and larynx, and CT-scan were performed in all patients. Standard roentgenography, ultrasound imaging, and esophageal transit study were available in some cases. Surgical reports and histological findings were analyzed in all cases.
3. Results This series included three boys and three girls with a mean age of 60 months (range: 16 days to 12 years). In all cases, the malformation was located on the left cervical region at the level of the thyroid area. The delay between discovery and management in our departments was less than 3 weeks in five cases. In the remaining case the records mentioned only repeated thyroid abscesses without specifying any dates. Secondary infection of the malformation was observed in four patients. For two of these patients it was the first episode of infection, and for two, multiple episodes occurred; one of these two patients, in whom the initial diagnosis was adenitis, presented with massive purulent regurgitation with slight airway aspiration. The fifth patient was not clinically infected but proper diagnosis was initially suspected. In the sixth patient referred to one of our departments at the age of 16 days stridor and dyspnea were the first manifestations and differential diagnosis was proposed between fourth branchial pouch anomaly and cystic hygroma. Endoscopy of the pharynx and larynx was performed in all patients. In five out of six cases, a fistula was visualized at the apex of the pyriform sinus (Fig. 1). Compression of the larynx and/or trachea was observed in two cases.
In all patients, CT scan showed the presence of a left-sided tumor that demonstrated uneven uptake of contrast material (Fig. 2). In two patients ultrasound examination demonstrated a liquidfilled mass in contact with the thyroid. In one patient standard roentgenography was performed but did not provide any helpful diagnostic information. Gastrograffin contrast radiology was performed in two patients visualizing the course of the fistula tract and the cyst (Fig. 3). The surgical approach was left lateral cervicotomy in all six cases. The cyst, which was always infected to some degree, was dissected along with the fistulous tract up to the ipsilateral pyriform sinus. In three cases, the fistulous tract passed behind the inferior cornu of the thyroid cartilage and in one case it terminated within the inferior cornu of the thyroid cartilage. In the remaining two cases, information given in the operative report was insufficient to determine the course of the tract. The fistula was ligated at the pyriform sinus in five cases. The remaining case was the child whose tract terminated within the inferior cornu of the thyroid cartilage which was resected. Thyroid lobectomy was required to preserve the recurrent nerve in three cases. In the oldest patient, it was impossible to dissect the fistula from the thyroid lobe. Histological examination of surgical specimens confirmed the diagnosis of congenital cyst with a fistulous tract lined with squamous epithelium in all cases. In the oldest child of this series the thyroid had been invaded and partially destroyed by infection. Postoperative paralysis of the left vocal cord occurred in two cases. In one of these cases partial recovery was observed. The other case was the 12-year-old girl whose thyroid was invaded by infection and in whom only the lower part of the recurrent nerve could be identified. No recurrence of the fourth pouch anomaly has been observed in any patient with mean follow-up at 4 years (range: 5 months to 9 years).
4. Discussion Cysts and fistulas of the fourth branchial pouch are among the most uncommon congenital mal-
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
7
Fig. 1. Endoscopic view of the opening of a fourth branchial pouch fistula at the level of the left pyriform sinus (arrow: opening of the fistula; ac, left arytenoid cartilage; e, epiglottis); (A) initial view; (B) after compression of the neck, note the air bubble coming out of the opening.
formations of the neck. In their perusal of the worldwide literature between 1973 and 1993, Inigues et al. found a total of only 70 cases [6]. In a series of 106 patients with branchial tract anomalies, Ford et al. only reported one fistula of the fourth pouch [4].
Fistulas correspond to the persistence of the pharyngo-branchialis duct between the upper parathyroid gland and ultimobranchial body on one hand, and the pharynx, on the other. The fistulous tract begins at the apex of the pyriform sinus and runs in contact with the larynx and
8
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
trachea. The course of the tract can pass either behind the thyroid cartilage or through the zone of chondrification of the wing of the cartilage. After passing the cartilage the tract crosses the lower constrictor muscle of the pharynx and courses behind the body of the thyroid gland. The retrothyroid portion of the tract was responsible for the mass noted in all patients in this series. Unlike third branchial pouch fistulas which pass above the superior laryngeal nerve, fourth branchial pouch fistulas run below the superior laryngeal nerve [5]. Theoretically fourth branchial pouch fistulous tracts can continue in contact with the trachea into the mediastinum and contract close relations with the aortic arch on the left and the subclavian artery on the right [1,2,5]. In practice, however, most lesions are confined to the perithyroid area [6,7] as described by Liston (in [6]). In four out of the six patients in the present series, as well as in most previously reported cases [1 – 9,11,12], infection entered through the opening at the apex of the pyriform sinus. Left-sided presentation was observed in all patients in our series and has been almost consistently reported in the literature. Embryological events probably account
Fig. 2. Axial CT-scan section showing a fourth branchial pouch cyst (arrows). Note the heterogeneous appearance of the mass which is in contact with the left lobe of the thyroid. The trachea is deviated.
Fig. 3. Pharyngeal transit (frontal view) showing the fistula (arrow) running between the apex of the left pyriform sinus and the cyst.
for these findings. The opening of the fistula is located at the apex of the pyriform sinus because this region originates on both the right and left from the fourth branchial pouch. The thyroid and arytenoid cartilages, cricothyroid muscles and superior laryngeal nerves arise from the fourth branchial arch on both sides. From a vascular standpoint the fourth arch gives rise to the aortic arch on the left and the subclavian artery on the right. This asymmetrical development probably accounts for the predominance of left-side anomalies. Most congenital cyst anomalies are diagnosed following infection. In patients with fourth branchial pouch anomalies the most frequent clinical finding is perithyroid abscess. Anamnesis often reveals a history of infectious episodes
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
sometimes requiring surgical drainage. Respiratory signs can also be the first manifestation. Stridor was the presenting symptom in one patient in our series and in another case described by Sharma et al. [10]. Differential diagnosis of fourth branchial pouch anomalies can be difficult. Misdiagnosis as localized lobar thyroiditis has been reported by numerous groups [3,8,12]. Similar symptoms are observed in association with suppurative thyroiditis or adenitis and oesophageal duplication. Masses on the side of the neck can be produced by cystic hygroma in infants and external laryngocele in young adults. Endoscopy is the most useful diagnostic examination and should be performed in an operating room under general anesthesia in any child presenting with cervical abscess or suppurative thyroiditis especially if manifestations are recurrent and/or left-sided. Diagnosis can be confirmed by visualization of the opening of the fistulous tract at the apex of the pyriform sinus. However failure to visualize the opening does not rule out the possibility of an isolated cyst with no fistulous tract. This was the case in one patient in our series. CT scan provides important preoperative findings concerning the relationship of the anomaly with surrounding structures and in particular with the thyroid. Fistulography and transit studies are of little interest and have been largely abandoned although transit studies can be useful if oesophageal duplication is suspected. Thyroid scintigraphy is unnecessary unless associated thyroid disease is suspected. There is a general consensus that complete removal of the cyst and fistulous tract with ligature at the pyriform sinus is necessary to achieve permanent cure. Some controversy remains with regard to the need for thyroidectomy but most authors recommend thyroid lobectomy only if necessary to preserve the recurrent nerve [7,9]. Inigues et al. emphasized that the fistulous tract runs parallel to the lateral side of recurrent nerve [6]. In our series, laryngeal paralysis was observed despite thyroid lobectomy in two cases. In one of them it was transient.
9
5. Conclusion Cysts and fistulas of the fourth branchial pouch are uncommon but must be considered as a possible diagnosis in children or young adults with abscesses located on the left side of the neck in the vicinity of the thyroid gland and in patients presenting with recurrent cervical abscess regardless of age. Diagnosis of fourth branchial pouch fistulas can be confirmed by endoscopic visualization of an opening at the apex of the pyriform sinus. The relationship between the anomaly and surrounding structures can be ascertained by ultrasound imaging and CT-scan. Permanent cure requires complete resection of the cyst and the fistulous tract up to the pyriform sinus. Partial thyroidectomy may be required in some cases.
References [1] J. Andrieu-Guitrancourt, P. Narcy, J. Borde, Y. Melin, Y. Manac’h, D. Dehesdin, P. Desse, Duplications digestives de localisation pharynge´e ou fistules de la quatrie`me poche endobranchiale, Ann. Oto-Laryngol. (Paris) 96 (1979) 863 – 879. [2] D.N. Cote, G.J. Gianoli, Fourth branchial cleft cysts, Otolaryngol. Head Neck Surg. 114 (1996) 95 – 97. [3] M. Dellandrea, B. Montinet, R. Stringini, Ph. Claude, Pseudo-thyroı¨dites suppure´es et fistules de la quatrie`me poche branchiale, J. F. ORL 40 (1991) 56 – 58. [4] G.R. Ford, A. Balakrishnan, J.N.G. Evans, C.M. Bailey, Branchial cleft and pouch anomalies, J. Laryngol. Otol. 106 (1992) 137 – 143. [5] S.W. Gray, J.E. Skandalakis, Anomalies of the pharynx and its derivates, in: Embryology for Surgeons, Saunders, Philadelphia, PA, 1972, pp. 33 – 43. [6] J.P. Inigues, A. Rivron, J.P. Priou, L. Beust, G. Le Clec’h, J. Bourdinie`re, Fistules de la 4e poche endobranchiale, a` propos de 4 cas, Ann. Oto-Laryngol. (Paris) 110 (1993) 450 – 453. [7] Y. Manac’h, M.P. Morissaeu, A. Perrin, J.P. Aboucaya, P. Roulleau, Le fond du sinus piriforme dans le traitement chirurgical des fistules de la quatrie`me poche endobranchiale, Ann. Oto-Laryngol. (Paris) 105 (1988) 391 – 396. [8] Ph. Narcy, C. Aumont-Grosskopf, S. Bobin, Y. Manac’h, Fistulae of the fourth endobranchial pouch, Int. J. Pediatr. Otorhinolaryngol. 16 (1988) 157 – 165. [9] N. Nonomura, Surgical approach to piriform sinus fistula, Am. J. Otolaryngol. 14 (1993) 111 – 115.
10
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5–10
[10] H.S. Sharma, A. Razif, M. Hamzah, A.S. Dharap, Z. Mahbar, M.Z.M. Kamal, et al., Fourth branchial pouch cyst: an unusual cause of neonatal stridor, Int. J. Pediatr. Otorhinolaryngol. 38 (1996) 155–161. [11] M.A. Shugar, G.B. Healy, The fourth branchial cleft
anomaly, Head Neck Surg. 3 (1980) 72 – 75. [12] F. Tovi, A. Gatot, J. Bar-Ziv, I. Yanay, Recurrent suppurative thyroiditis due to fourth branchial pouch sinus, Int. J. Pediatr. Otorhinolaryngol. 9 (1985) 89 – 96.
.