Diagnostic Radiology
The Tracheo-esophageal Stripe and the Posterior Tracheal Band 1 Max J. Palayew, M.D., F.R.C.P.(C)
While recognizing the importance of the posterior tracheal band as described previously, the author wishes to emphasize the separate characteristics of the tracheo-esophageal stripe and emphasize its importance as a sign of air in the esophagus as well as possible underlying esophageal pathology. Any such band or stripe measuring 3 mm or more in the cervical or thoracic region should be viewed with some suspicion. INDEX TERMS :
(Chest contents, fundamental observation, 6[0] .910) • Esophagus , 7[ 1].920 • Trachea, 6[71] .920
Radiology 132: 11-13, July 1979
HE
tracheo-esophageal stripe is a sharply demarcat-
1a,b
Ted line which may be seen behind the trachea in the
cervical or thoracic region on the lateral chest radiograph (Fig. 1, a). It is formed by the posterior wall of the trachea and the anterior wall of the air-containing esophagus, which are separated by fat. Theoretically any of these three components can be thickened; however, I have not seen any cases of thickening of the posterior tracheal wall. Thickening of the esophagus or intervening tissues may be due to an underlying disease process (Fig. 2). Depending on the length of the air-containing esophagus, the stripe can be at least 3 mm wide and 1%to 11 cm long. In 1969, Figley (2) discussed the importance of the tracheoesophageal stripe as a sign of air in the esophagus, frequently associated with esophageal pathology. I have commented previously on this finding (3, 4), as have Bachman and Teixidor (1), whose "posterior tracheal band" also fits this general description. They speak of a thin band of uniform width, up to 3 (rarely 4) mm thick, which they observed in the lateral projection in 91 % of their cases . This band is bounded by two interfaces, an internal junction between the tracheal wall and air in the lumen and an external junction between the adventitial surface of the right posterior wall of the trachea and aerated lung in the retrotracheal recess (Figs. 2 and 3). Any pathological process in the mediastinum, pleura, or medial portion of the right upper lobe which affects the external interface causes the posterior tracheal band to change in appearance or disappear altogether. Since air in the esophagus would be one cause of this finding (indeed the most common cause in my experience), I suggest that the term "tracheo-esophageal stripe" be applied to this common variant of Bachman's "posterior tracheal band." The fact that the tracheo-esophageal stripe is seen in the cervical region, well above the lung (Fig. 4), also indiFig. 2.
Fig . 1. a. Thick tracheo-esophageal stripe (arrowheads) seen on the lateral chest radiograph in a patient with achalasia. b. Esophagram shows distal tapering.
LUNG
.----.- -- -TES
LUNG
Diagrammatic representation of the posterior tracheal band
=
(PTB) and the tracheo-esophageal stripe (TES). S superior vena cava; T = trachea; E = esophagus; V = vertebral body. The arrows indicate
the tracheo-esophageal recess . 1 From the Departments of Radiology of Jewish General Hospital and McGill University , Montreal, Quebec, Canada. Presented at the Sixty-third Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago, III., Nov. 27-Dec. 2, 1977. Received June 21, 1978; accepted and revision requested Sept. 13; revision received Nov. 30. sjh
11
12
MAX
J.
July 1979
PALAYEW
7
Fig. 3. Normal posterior tracheal band (arrowheads) seen on a routine lateral chest radiograph of an asymptomatic pat ient.
Fig . 4. Tracheo-esophagela str ipe (arrowheads) seen well above the lung in a patient with achalasia. C7 is indicated .
..... Fig. 5.
CT scan of a patient with a tracheo-esophageal stripe and an air-containing nondilated esophagus .
cates that it is separate from the classic posterior tracheal band. The presence of such a finding simply implies air in the esophagus and is not pathognomonic of esophageal dilatation as suggested by Bachman and Teixidor, though such dilatation may be present. For example , Figure 5 shows one case in which air is present and yet the esophagus is not dilated. A similar stripe may be observed when a nasogastric tube is in place (Fig . 6). However, as Bachman points out , thickening of the posterior tracheal wall or adjacent pleuroparenchymal disease could cause the band to be altered. I have seen several asymptomatic patients with a very thick tracheal band and normal esophagrams who may have had air behind the esophagus, i.e ., lung interposed between the esophagus and the spine. Putman et al. (6) suggested that a tracheal band wider than 4-4.5 mm is an early sign of squamous-cell carcinoma of the esophagus, representing lymphatic dilatation due to obstruction or tumor infiltration of the paratracheal and/or paraesophageal lymphatics . However, this observation was largely based on patients with esophageal carcinoma, so that the fact that 20 of their 31 patients had a thick tracheo-esophageal stripe (:::;4.5 mm) does not
Fig. 6. Trachea-esophageal stripe (arrowheads. left) in a patient w ith a nasogastric tube (arrowheads. right) in a nondilated esophagus.
establish thickening as pathognomonic of squamous-cell carcinoma. Indeed, I have seen a stripe measuring 4.5 mm
Vol. 132
TABLE I:
TRACHEO-ESOPHAGEAL STRIPE AND POSTERIOR TRACHEAL BAND
13
Diagnostic Radiology
MEASUREMfNTS OF THE TRACHEO-ESOPHAGEAL STRIPE IN VARIOUS CONDITIONS No. of Patients
Condition Squamous-cell carcinoma Adenocarcinoma' Other primary neoplasms Metastatic neoplasm Achalasia Stricture associated with hiatus hernia or of unknown etiology Vascular anomaly Systemic sclerosis Miscellaneous
Width of Stripe (mm) Range Average
10 6 2 4 10 10
3-7 4-6 5-12 4-5 3-8 3-6
4.7 5.0 8.6 4.9 4.7 4.6
6
3-6 3-4 3-6
4.3 3.6
5 6
7a
4.4
• Includes both adenocarcinoma of the fundusof the stomach extending into the lower esophagus and adenocarcinoma of the lower esophagus
7b,c
or more in a number of patients with air in the esophageal lumen, including normal persons; thus widening of the stripe is not necessarily an indication of underlying pathology (Fig. 7). As the data in TABLE I show, the range and average width of the tracheo-esophageal stripe in both benign and malignant conditions are very similar. The average for "other primary neoplasms" is high, but this is due to a patient with malignant melanoma of the esophagus who had a stripe measuring 12 mm. Conversely, the low figures for systemic sclerosis probably reflect the muscular atrophy of the esophagus seen in this condition. While Bachman and Teixidor observed a posterior tracheal band in 91 % of their patients, in my series the incidence was less than 50 %, as in the series reported by Proto (5). Therefore , I feel that failure to visualize such a band is not as reliable a sign of illness as an altered, or, more important, a thickened band. From my experience, I would say that the upper limits of normal for a posterior tracheal band should be 2 to 3 mm, compared with 3 mm or more for a tracheo-esophageal stripe. Any such band or stripe measuring 3 mm or more should be considered a sign of a possible underlying pathological process.
2'V
ACKNOWLEDGMENTS: I would like to thank Dr. Marvin Rosenbloom for his critical rev iew . Margaret Stocker and Doris Zaget for their clerical assistance, and David Saxe and Christine Lalonde for their photography and illustrations.
Department of Radiology Jewish General Hospital 3755 Cote St. Catherine Road Montreal, Quebec H3T 1E2 Canada
Fig. 7. a. Tracheo-esophageal stripe (arrowheads) in an asymptom atic 76-year-old diabetic man . band c. Esophagrams show air swallowing and slightly altered peristalsis.
REFERENCES 1. Bachman AL, Teixidor HS: The posterior tracheal band: a reflector of local superior mediastinal abnormality. Br J Radiol 48:352 -359 , May 1975 2. Figley M: Mediastinal minutiae. Semin Roentgenol 4:22 -32, Jan 1969 3. Palayew MJ: The tracheo-esophageal stripe. Presented at the 38th annual meeting of the Canadian Association of Radiologists, Toronto, Ontario, May 11-15,1974 4. Palayew MJ: The tracheo-esophageal stripe. New radiographic sign frequently associated with esophageal pathology. Scientific exhibit pre sented at the 61st annual meeting of the RSNA, Chicago, III., Nov . 30-Dec. 5, 1975 5. Proto AV: The lateral chest film revisited. Scientific exhibit presented at the 63rd annual meeting of the RSNA, Chicago , III., Nov 27-Dec. 2, 1977 6. Putman CE, Curtis AMB, Westfried M: Thickening of the posterior tracheal stripe: a sign of squamous cell carcinoma of the esophagus. Radiology 121:533-536, Dec 1976
The Tracheo-esophageal Stripe and the Posterior Tracheal Band 1 Max J. Palayew, M.D., F.R.C.P.(C)
While recognizing the importance of the posterior tracheal band as described previously, the author wishes to emphasize the separate characteristics of the tracheo-esophageal stripe and emphasize its importance as a sign of air in the esophagus as well as possible underlying esophageal pathology. Any such band or stripe measuring 3 mm or more in the cervical or thoracic region should be viewed with some suspicion. INDEX TERMS :
(Chest contents, fundamental observation, 6[0] .910) • Esophagus , 7[ 1].920 • Trachea, 6[71] .920
Radiology 132: 11-13, July 1979
HE
tracheo-esophageal stripe is a sharply demarcat-
1a,b
Ted line which may be seen behind the trachea in the
cervical or thoracic region on the lateral chest radiograph (Fig. 1, a). It is formed by the posterior wall of the trachea and the anterior wall of the air-containing esophagus, which are separated by fat. Theoretically any of these three components can be thickened; however, I have not seen any cases of thickening of the posterior tracheal wall. Thickening of the esophagus or intervening tissues may be due to an underlying disease process (Fig. 2). Depending on the length of the air-containing esophagus, the stripe can be at least 3 mm wide and 1%to 11 cm long. In 1969, Figley (2) discussed the importance of the tracheoesophageal stripe as a sign of air in the esophagus, frequently associated with esophageal pathology. I have commented previously on this finding (3, 4), as have Bachman and Teixidor (1), whose "posterior tracheal band" also fits this general description. They speak of a thin band of uniform width, up to 3 (rarely 4) mm thick, which they observed in the lateral projection in 91 % of their cases . This band is bounded by two interfaces, an internal junction between the tracheal wall and air in the lumen and an external junction between the adventitial surface of the right posterior wall of the trachea and aerated lung in the retrotracheal recess (Figs. 2 and 3). Any pathological process in the mediastinum, pleura, or medial portion of the right upper lobe which affects the external interface causes the posterior tracheal band to change in appearance or disappear altogether. Since air in the esophagus would be one cause of this finding (indeed the most common cause in my experience), I suggest that the term "tracheo-esophageal stripe" be applied to this common variant of Bachman's "posterior tracheal band." The fact that the tracheo-esophageal stripe is seen in the cervical region, well above the lung (Fig. 4), also indiFig. 2.
Fig . 1. a. Thick tracheo-esophageal stripe (arrowheads) seen on the lateral chest radiograph in a patient with achalasia. b. Esophagram shows distal tapering.
LUNG
.----.- -- -TES
LUNG
Diagrammatic representation of the posterior tracheal band
=
(PTB) and the tracheo-esophageal stripe (TES). S superior vena cava; T = trachea; E = esophagus; V = vertebral body. The arrows indicate
the tracheo-esophageal recess . 1 From the Departments of Radiology of Jewish General Hospital and McGill University , Montreal, Quebec, Canada. Presented at the Sixty-third Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago, III., Nov. 27-Dec. 2, 1977. Received June 21, 1978; accepted and revision requested Sept. 13; revision received Nov. 30. sjh
11
12
MAX
J.
July 1979
PALAYEW
7
Fig. 3. Normal posterior tracheal band (arrowheads) seen on a routine lateral chest radiograph of an asymptomatic pat ient.
Fig . 4. Tracheo-esophagela str ipe (arrowheads) seen well above the lung in a patient with achalasia. C7 is indicated .
..... Fig. 5.
CT scan of a patient with a tracheo-esophageal stripe and an air-containing nondilated esophagus .
cates that it is separate from the classic posterior tracheal band. The presence of such a finding simply implies air in the esophagus and is not pathognomonic of esophageal dilatation as suggested by Bachman and Teixidor, though such dilatation may be present. For example , Figure 5 shows one case in which air is present and yet the esophagus is not dilated. A similar stripe may be observed when a nasogastric tube is in place (Fig . 6). However, as Bachman points out , thickening of the posterior tracheal wall or adjacent pleuroparenchymal disease could cause the band to be altered. I have seen several asymptomatic patients with a very thick tracheal band and normal esophagrams who may have had air behind the esophagus, i.e ., lung interposed between the esophagus and the spine. Putman et al. (6) suggested that a tracheal band wider than 4-4.5 mm is an early sign of squamous-cell carcinoma of the esophagus, representing lymphatic dilatation due to obstruction or tumor infiltration of the paratracheal and/or paraesophageal lymphatics . However, this observation was largely based on patients with esophageal carcinoma, so that the fact that 20 of their 31 patients had a thick tracheo-esophageal stripe (:::;4.5 mm) does not
Fig. 6. Trachea-esophageal stripe (arrowheads. left) in a patient w ith a nasogastric tube (arrowheads. right) in a nondilated esophagus.
establish thickening as pathognomonic of squamous-cell carcinoma. Indeed, I have seen a stripe measuring 4.5 mm
Vol. 132
TABLE I:
TRACHEO-ESOPHAGEAL STRIPE AND POSTERIOR TRACHEAL BAND
13
Diagnostic Radiology
MEASUREMfNTS OF THE TRACHEO-ESOPHAGEAL STRIPE IN VARIOUS CONDITIONS No. of Patients
Condition Squamous-cell carcinoma Adenocarcinoma' Other primary neoplasms Metastatic neoplasm Achalasia Stricture associated with hiatus hernia or of unknown etiology Vascular anomaly Systemic sclerosis Miscellaneous
Width of Stripe (mm) Range Average
10 6 2 4 10 10
3-7 4-6 5-12 4-5 3-8 3-6
4.7 5.0 8.6 4.9 4.7 4.6
6
3-6 3-4 3-6
4.3 3.6
5 6
7a
4.4
• Includes both adenocarcinoma of the fundusof the stomach extending into the lower esophagus and adenocarcinoma of the lower esophagus
7b,c
or more in a number of patients with air in the esophageal lumen, including normal persons; thus widening of the stripe is not necessarily an indication of underlying pathology (Fig. 7). As the data in TABLE I show, the range and average width of the tracheo-esophageal stripe in both benign and malignant conditions are very similar. The average for "other primary neoplasms" is high, but this is due to a patient with malignant melanoma of the esophagus who had a stripe measuring 12 mm. Conversely, the low figures for systemic sclerosis probably reflect the muscular atrophy of the esophagus seen in this condition. While Bachman and Teixidor observed a posterior tracheal band in 91 % of their patients, in my series the incidence was less than 50 %, as in the series reported by Proto (5). Therefore , I feel that failure to visualize such a band is not as reliable a sign of illness as an altered, or, more important, a thickened band. From my experience, I would say that the upper limits of normal for a posterior tracheal band should be 2 to 3 mm, compared with 3 mm or more for a tracheo-esophageal stripe. Any such band or stripe measuring 3 mm or more should be considered a sign of a possible underlying pathological process.
2'V
ACKNOWLEDGMENTS: I would like to thank Dr. Marvin Rosenbloom for his critical rev iew . Margaret Stocker and Doris Zaget for their clerical assistance, and David Saxe and Christine Lalonde for their photography and illustrations.
Department of Radiology Jewish General Hospital 3755 Cote St. Catherine Road Montreal, Quebec H3T 1E2 Canada
Fig. 7. a. Tracheo-esophageal stripe (arrowheads) in an asymptom atic 76-year-old diabetic man . band c. Esophagrams show air swallowing and slightly altered peristalsis.
REFERENCES 1. Bachman AL, Teixidor HS: The posterior tracheal band: a reflector of local superior mediastinal abnormality. Br J Radiol 48:352 -359 , May 1975 2. Figley M: Mediastinal minutiae. Semin Roentgenol 4:22 -32, Jan 1969 3. Palayew MJ: The tracheo-esophageal stripe. Presented at the 38th annual meeting of the Canadian Association of Radiologists, Toronto, Ontario, May 11-15,1974 4. Palayew MJ: The tracheo-esophageal stripe. New radiographic sign frequently associated with esophageal pathology. Scientific exhibit pre sented at the 61st annual meeting of the RSNA, Chicago, III., Nov . 30-Dec. 5, 1975 5. Proto AV: The lateral chest film revisited. Scientific exhibit presented at the 63rd annual meeting of the RSNA, Chicago , III., Nov 27-Dec. 2, 1977 6. Putman CE, Curtis AMB, Westfried M: Thickening of the posterior tracheal stripe: a sign of squamous cell carcinoma of the esophagus. Radiology 121:533-536, Dec 1976
