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Retropharyngeal node dissection
Operative Techniques in Otolaryngology (2004) 15, 180-183
Retropharyngeal node dissection Nilesh R. Vasan, MD, Jesus E. Medina, MD From the Department of Otorhinolaryngology, The University of Oklahoma College of Medicine, Oklahoma City, Oklahoma. The retropharyngeal lymph nodes (RPLN) lie within a fat pad located behind the posterior wall of the pharynx and anterior to the prevertebral fascia and the cervical sympathetic trunk and ganglion. This fat pad extends from about the level of the carotid bifurcation to just below the skull base. The RPLN are divided into medial and lateral groups; the medial group of nodes lies behind the pharyngeal midline at a level between the first and fourth cervical vertebrae (Figure 1). The lateral group, better known as the nodes of Rouviere,1 are the nodes removed in a retropharyngeal lymph node dissection. They are contained within a sliver of fatty tissue located immediately medial to the internal carotid artery. The surgical anatomy of the retropharyngeal region is shown in Figure 2. The RPLN receive lymphatic drainage from the nasopharynx, tonsillar fossa, oropharyngeal and hypopahryngeal walls, and the posterior ethmoidal sinuses. Clinically, involvement of the retropharyngeal nodes by tumor may be signaled by pain and stiffness in the neck. More ominous and characteristic, however, is an ipsilateral occipito-parietal headache described by the patient as pain located behind the eye. Also ominous is the presence of a Horner’s syndrome that results from tumor involvement of the cervical sympathetic trunk.
Indications The significance of retropharyngeal lymph node metastases and their surgical management was first pointed out by Ballantyne in 1964; he described a series of 34 patients with advanced squamous cell carcinoma of the pharyngeal walls, 15 (44%) of whom had pathologically proven metastases in the RPLN.2 More recently, Hasegawa and Matsuura reported their findings in 24 patients with stage III–IV squamous cell carcinoma of the oropharynx and hypopharynx in whom Address reprint requests and correspondence: Jesus E. Medina, MD, University of Oklahoma Health Sciences Center, Department of Otorhinolaryngology, PO Box 26901, WP 1360, Oklahoma City, OK 73190-3048.
1043-1810/$ -see front matter © 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2004.04.003
they had performed a RPLN dissection. The prevalence of pathologically proven metastases in the RPLN was 50% overall, 36% for oropharyngeal, and 62% for hypopharyngeal tumors.1 Interestingly, metastases in the RPLN were not found in patients whose neck was staged N0, whereas the prevalence of RPLN metastases in patients whose neck was staged N⫹ was 30% in those with oropharyngeal tumor and 72% in those with hypopharyngeal tumor.1 In a retrospective study designed to assess the frequency of RPLN metastases in 774 patients with squamous cell carcinoma of the nasopharynx, oropharynx, hypopharynx, and supraglottis, and which used enlargement of the RPLN on computed tomography scans as an indicator of the presence of metastases, McLaughlin et al found an overall incidence of radiologically “positive” RPLN of 9%.3 The highest incidence was seen in patients with cancer of the nasopharynx (74%) and the pharyngeal walls (19%). They also noted that in patients with advanced cancer of the oropharyngeal walls and hypopharynx, the incidence of radiologically positive RPLN was higher in patients with cervical metastases (N⫹ necks) than in those with an N0 neck (pharyngeal wall: N⫹ 21%, N0 16%; hypopharynx: N⫹ 9%, N0 0%).3 Amatsu et al studied 82 patients who had RPLN dissection for squamous cell carcinoma of the hypopharynx and cervical esophagus.4 They reported finding metastases in the RPLN in 16 patients (20%).4 Fourteen of these patients had hypopharyngeal cancer, and the posterior pharyngeal wall was involved in 57% of them. In keeping with the studies mentioned previously, the majority of patients with RPLN metastases had an N⫹ neck. However, in 15% of the patients with RPLN metastases, the neck was staged N0.4 In these studies, the presence of RPLN metastases did not appear to influence survival.1,2 Recently, Gross et al5 found no statistically significant difference in the rate of local/regional recurrence, survival, or distant metastases between patients with RPLN metastases and those without them. These authors attribute this finding to the more aggressive multimodality treatment these patients frequently receive, and they advocate performing RPLN in patients
Vasan and Medina
Retropharyngeal Node Dissection
Figure 1
181
Location of the retropharyngeal nodes in relation to the pharynx and skull base.
with advanced tumors of the oropharynx, hypopharynx, and supraglottic larynx.5 Based on our experience and a review of the literature, it is clear that the highest incidence of RPLN metastases is
associated with advanced cancers of the oropharynx and hypopharynx presented with neck metastases. Therefore, elective RPLN dissection is indicated when these patients are treated surgically. A RPLN dissection should also be performed in patients in whom imaging studies suggest the presence of metastases in the RPLN. A RPLN dissection should also be considered in patients with advanced cancer of the oropharynx and hypopharynx who are treated with organ preservation protocols, have an incomplete response of the tumor in the neck, and require a neck dissection. A RPLN dissection in these situations is likely to afford the patient what is perhaps the last opportunity to prevent recurrence in the RPLN.
Surgical technique
Figure 2 Anatomic structures related to the retropharyngeal region: (a) retropharyngeal nodes; (b) cervical sympathetic chain and superior cervical ganglion; (c) vagus nerve; (d) common carotid artery; (e) internal carotid artery; (f) internal jugular vein; (g) hypoglossal nerve; (h) lingual artery; (i) hyoid bon; (j) thyroid ala.
Dissection of the retropharyngeal nodes can be performed separately or in continuity with resection of the primary tumor. When it is done electively, this operation is relatively simple and it takes only a few minutes. On the other hand, when the RPLN are grossly involved by tumor, the operation may be difficult and sometimes not feasible. The proximity of the nodes to the internal carotid artery and prevertebral structures is such that these structures may be involved as soon as tumor extends beyond the capsule of the lymph nodes (Figure 2). After completion of the neck dissection, the posterior belly of digastric and the hypoglossal nerve should be clearly visible. With a Sool or a Deaver retractor placed
182
Operative Techniques in Otolaryngology, Vol 15, No 3, September 2004
Figure 5 The prevertebral fascia is incised medially to the carotid bifurcation. Figure 3 After neck dissection is completed, exposure of the retropharyngeal region is accomplished by retracting the posterior belly of the digastric and “styloid” muscles, as well as the hypoglossal nerve.
between the carotid artery laterally and the pharynx medially, these structures are retracted superiorly (Figure 3). Occasionally, division of the posterior belly of the digastric and styloid muscles is necessary to facilitate the dissection (Figure 4). Identification and dissection of the retropharyn-
Figure 4 Occasionally, exposure of the retropharyngeal region requires dividing the posterior belly of the digastric and styloid muscles.
geal space is much easier after a laryngopharyngectomy because the retropharyngeal space has already been identified and removal of the larynx facilitates retraction of the suprahyoid musculature. The anterior most layer of the prevertebral fascia is incised at a point immediately medial to the carotid bifurcation (Figure 5). The retropharyngeal fat pad is then located and dissected out with tenotomy scissors (Figure 6). The dissection of this fat pad is continued in a cephalad direction (Figure 7). In so doing, the cervical sympathetic
Figure 6 The dissection of the retropharyngeal fat pad begins inferiorly.
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Retropharyngeal Node Dissection
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Figure 7 The dissection proceeds upward, medial to the internal carotid and to the cervical sympathetic chain.
ganglion can be easily mistaken for an enlarged retropharyngeal node; thus, it is preferable to identify it and keep it under vision. Likewise, to avoid inadvertent injury to the internal carotid artery, it is best to be constantly aware of its location or to have it under direct vision. If the dissection is carried in the right plane, it is usually bloodless, with the exception of a few parapharyngeal veins. These are controlled with either ties or bipolar diathermy. Because of the close proximity of the sympathetic trunk, monopolar cautery is not recommended. It is also preferable to avoid ligaclips because they can produce artifact that interfere with future imaging studies of the area. The final cut, below the base of the skull, is made with scissors and the specimen is delivered (Figure 7). The completed dissection is shown in Figure 8. For central pharyngeal lesions, bilateral retropharyngeal nodal dissection may be required.
Figure 8 pleted.
The retropharyngeal node/fat pad dissection is com-
References 1. Hasegawa Y, Matsuura H: Retropharyngeal node dissection in cancer of the oropharynx and hypopharynx. Head Neck 16:173-180, 1994 2. Ballantyne AJ: Significance of retropharyngeal nodes in cancer of the head and neck. Am J Surg 108:500-504, 1964 3. McLaughlin MP, Mendenhall WM, Mancuso AA, et al: Retropharyngeal adenopathy as a predictor of outcome in squamous cell carcinoma of the head and neck. Head Neck 17:190-198, 1995 4. Amatsu M, Mohri M, Kinishi M: Significance of retropharyngeal node dissection at radical surgery for carcinoma of the hypopharynx and cervical esophagus. Laryngoscope 111:1099-1103, 2001 5. Gross ND, Ellington TW, Wax MK, et al: Impact of retropharyngeal lymph node metastases in head and neck squamous cell carcinoma. Arch Otolaryngol Head Neck Surg 130:169-173, 2004
Retropharyngeal node dissection Nilesh R. Vasan, MD, Jesus E. Medina, MD From the Department of Otorhinolaryngology, The University of Oklahoma College of Medicine, Oklahoma City, Oklahoma. The retropharyngeal lymph nodes (RPLN) lie within a fat pad located behind the posterior wall of the pharynx and anterior to the prevertebral fascia and the cervical sympathetic trunk and ganglion. This fat pad extends from about the level of the carotid bifurcation to just below the skull base. The RPLN are divided into medial and lateral groups; the medial group of nodes lies behind the pharyngeal midline at a level between the first and fourth cervical vertebrae (Figure 1). The lateral group, better known as the nodes of Rouviere,1 are the nodes removed in a retropharyngeal lymph node dissection. They are contained within a sliver of fatty tissue located immediately medial to the internal carotid artery. The surgical anatomy of the retropharyngeal region is shown in Figure 2. The RPLN receive lymphatic drainage from the nasopharynx, tonsillar fossa, oropharyngeal and hypopahryngeal walls, and the posterior ethmoidal sinuses. Clinically, involvement of the retropharyngeal nodes by tumor may be signaled by pain and stiffness in the neck. More ominous and characteristic, however, is an ipsilateral occipito-parietal headache described by the patient as pain located behind the eye. Also ominous is the presence of a Horner’s syndrome that results from tumor involvement of the cervical sympathetic trunk.
Indications The significance of retropharyngeal lymph node metastases and their surgical management was first pointed out by Ballantyne in 1964; he described a series of 34 patients with advanced squamous cell carcinoma of the pharyngeal walls, 15 (44%) of whom had pathologically proven metastases in the RPLN.2 More recently, Hasegawa and Matsuura reported their findings in 24 patients with stage III–IV squamous cell carcinoma of the oropharynx and hypopharynx in whom Address reprint requests and correspondence: Jesus E. Medina, MD, University of Oklahoma Health Sciences Center, Department of Otorhinolaryngology, PO Box 26901, WP 1360, Oklahoma City, OK 73190-3048.
1043-1810/$ -see front matter © 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2004.04.003
they had performed a RPLN dissection. The prevalence of pathologically proven metastases in the RPLN was 50% overall, 36% for oropharyngeal, and 62% for hypopharyngeal tumors.1 Interestingly, metastases in the RPLN were not found in patients whose neck was staged N0, whereas the prevalence of RPLN metastases in patients whose neck was staged N⫹ was 30% in those with oropharyngeal tumor and 72% in those with hypopharyngeal tumor.1 In a retrospective study designed to assess the frequency of RPLN metastases in 774 patients with squamous cell carcinoma of the nasopharynx, oropharynx, hypopharynx, and supraglottis, and which used enlargement of the RPLN on computed tomography scans as an indicator of the presence of metastases, McLaughlin et al found an overall incidence of radiologically “positive” RPLN of 9%.3 The highest incidence was seen in patients with cancer of the nasopharynx (74%) and the pharyngeal walls (19%). They also noted that in patients with advanced cancer of the oropharyngeal walls and hypopharynx, the incidence of radiologically positive RPLN was higher in patients with cervical metastases (N⫹ necks) than in those with an N0 neck (pharyngeal wall: N⫹ 21%, N0 16%; hypopharynx: N⫹ 9%, N0 0%).3 Amatsu et al studied 82 patients who had RPLN dissection for squamous cell carcinoma of the hypopharynx and cervical esophagus.4 They reported finding metastases in the RPLN in 16 patients (20%).4 Fourteen of these patients had hypopharyngeal cancer, and the posterior pharyngeal wall was involved in 57% of them. In keeping with the studies mentioned previously, the majority of patients with RPLN metastases had an N⫹ neck. However, in 15% of the patients with RPLN metastases, the neck was staged N0.4 In these studies, the presence of RPLN metastases did not appear to influence survival.1,2 Recently, Gross et al5 found no statistically significant difference in the rate of local/regional recurrence, survival, or distant metastases between patients with RPLN metastases and those without them. These authors attribute this finding to the more aggressive multimodality treatment these patients frequently receive, and they advocate performing RPLN in patients
Vasan and Medina
Retropharyngeal Node Dissection
Figure 1
181
Location of the retropharyngeal nodes in relation to the pharynx and skull base.
with advanced tumors of the oropharynx, hypopharynx, and supraglottic larynx.5 Based on our experience and a review of the literature, it is clear that the highest incidence of RPLN metastases is
associated with advanced cancers of the oropharynx and hypopharynx presented with neck metastases. Therefore, elective RPLN dissection is indicated when these patients are treated surgically. A RPLN dissection should also be performed in patients in whom imaging studies suggest the presence of metastases in the RPLN. A RPLN dissection should also be considered in patients with advanced cancer of the oropharynx and hypopharynx who are treated with organ preservation protocols, have an incomplete response of the tumor in the neck, and require a neck dissection. A RPLN dissection in these situations is likely to afford the patient what is perhaps the last opportunity to prevent recurrence in the RPLN.
Surgical technique
Figure 2 Anatomic structures related to the retropharyngeal region: (a) retropharyngeal nodes; (b) cervical sympathetic chain and superior cervical ganglion; (c) vagus nerve; (d) common carotid artery; (e) internal carotid artery; (f) internal jugular vein; (g) hypoglossal nerve; (h) lingual artery; (i) hyoid bon; (j) thyroid ala.
Dissection of the retropharyngeal nodes can be performed separately or in continuity with resection of the primary tumor. When it is done electively, this operation is relatively simple and it takes only a few minutes. On the other hand, when the RPLN are grossly involved by tumor, the operation may be difficult and sometimes not feasible. The proximity of the nodes to the internal carotid artery and prevertebral structures is such that these structures may be involved as soon as tumor extends beyond the capsule of the lymph nodes (Figure 2). After completion of the neck dissection, the posterior belly of digastric and the hypoglossal nerve should be clearly visible. With a Sool or a Deaver retractor placed
182
Operative Techniques in Otolaryngology, Vol 15, No 3, September 2004
Figure 5 The prevertebral fascia is incised medially to the carotid bifurcation. Figure 3 After neck dissection is completed, exposure of the retropharyngeal region is accomplished by retracting the posterior belly of the digastric and “styloid” muscles, as well as the hypoglossal nerve.
between the carotid artery laterally and the pharynx medially, these structures are retracted superiorly (Figure 3). Occasionally, division of the posterior belly of the digastric and styloid muscles is necessary to facilitate the dissection (Figure 4). Identification and dissection of the retropharyn-
Figure 4 Occasionally, exposure of the retropharyngeal region requires dividing the posterior belly of the digastric and styloid muscles.
geal space is much easier after a laryngopharyngectomy because the retropharyngeal space has already been identified and removal of the larynx facilitates retraction of the suprahyoid musculature. The anterior most layer of the prevertebral fascia is incised at a point immediately medial to the carotid bifurcation (Figure 5). The retropharyngeal fat pad is then located and dissected out with tenotomy scissors (Figure 6). The dissection of this fat pad is continued in a cephalad direction (Figure 7). In so doing, the cervical sympathetic
Figure 6 The dissection of the retropharyngeal fat pad begins inferiorly.
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Figure 7 The dissection proceeds upward, medial to the internal carotid and to the cervical sympathetic chain.
ganglion can be easily mistaken for an enlarged retropharyngeal node; thus, it is preferable to identify it and keep it under vision. Likewise, to avoid inadvertent injury to the internal carotid artery, it is best to be constantly aware of its location or to have it under direct vision. If the dissection is carried in the right plane, it is usually bloodless, with the exception of a few parapharyngeal veins. These are controlled with either ties or bipolar diathermy. Because of the close proximity of the sympathetic trunk, monopolar cautery is not recommended. It is also preferable to avoid ligaclips because they can produce artifact that interfere with future imaging studies of the area. The final cut, below the base of the skull, is made with scissors and the specimen is delivered (Figure 7). The completed dissection is shown in Figure 8. For central pharyngeal lesions, bilateral retropharyngeal nodal dissection may be required.
Figure 8 pleted.
The retropharyngeal node/fat pad dissection is com-
References 1. Hasegawa Y, Matsuura H: Retropharyngeal node dissection in cancer of the oropharynx and hypopharynx. Head Neck 16:173-180, 1994 2. Ballantyne AJ: Significance of retropharyngeal nodes in cancer of the head and neck. Am J Surg 108:500-504, 1964 3. McLaughlin MP, Mendenhall WM, Mancuso AA, et al: Retropharyngeal adenopathy as a predictor of outcome in squamous cell carcinoma of the head and neck. Head Neck 17:190-198, 1995 4. Amatsu M, Mohri M, Kinishi M: Significance of retropharyngeal node dissection at radical surgery for carcinoma of the hypopharynx and cervical esophagus. Laryngoscope 111:1099-1103, 2001 5. Gross ND, Ellington TW, Wax MK, et al: Impact of retropharyngeal lymph node metastases in head and neck squamous cell carcinoma. Arch Otolaryngol Head Neck Surg 130:169-173, 2004