Introduction:
The hypopharynx accounts for just three to five percent of head and neck region squamous cell carcinomas. The posterior pharyngeal wall is the most uncommon subsite for hypopharyngeal carcinoma. Few investigations on carcinoma of the posterior wall of the hypopharynx have been reported. Primary surgery and postoperative radiotherapy remain critical tools in treating carcinoma of the posterior pharyngeal wall.
What Is Carcinoma of the Posterior Pharyngeal Wall?
Lesions affecting the tonsillar origin, pyriform sinus, and nasopharyngeal vault cannot be accurately distinguished from those affecting the pharyngeal wall in cases of pharyngeal cancer. A 36.4 % overall survival rate for isolated pharyngeal wall lesions is reported independent of treatment technique. However, the survival percentage for those managed by definitive surgical excision is 62.5 %, whereas, in a similar series, primary surgery patients have a 50 % survival rate. Thus, it is suggested that primary surgical care, with or without scheduled preoperative radiation, may offer a greater chance of cure than prior radiotherapy, with surgery reserved for still-operable failures.
Which Carcinomas Are Seen in the Posterior Pharyngeal Wall?
- Most posterior pharyngeal wall cancers are epidermoid carcinomas.
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However, lymphomas, small salivary gland tumors, and various adenocarcinomas are also seen.
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Because the mucosa of this area is an endodermal offshoot, carcinomas of a less well-differentiated kind are seen here.
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Still, they are slightly more differentiated than those found in the mouth.
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These lesions are frequently multicentric and have a solid propensity to migrate vertically in the submucosal plane, appearing as seemingly independent lesions at some distance from the parent lesion.
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As a result, diagnostic assessment should include numerous biopsies at various locations, followed by supravital staining with toluidine blue to detect skip regions.
How Is the Exposure of the Posterior Pharyngeal Wall Obtained?
First-stage nodal metastases are often the retropharyngeal nodes, which should be covered by surgical resection of the initial lesion. The anterior spinal ligament's resistance to direct invasion is essential in determining operability. There are numerous methods for obtaining adequate exposition of the posterior pharyngeal wall. Transhyoid, transoral, or lateral pharyngotomy may be appropriate for highly tiny lesions.
Larger lesions have often been treated with laryngectomy, followed by partial or whole pharyngotomy and appropriate pharyngoesophageal reconstruction. Even when this structure is not directly involved, laryngectomy is recommended because of the following reasons:
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This maneuver yields excellent exposure for excision and reconstruction.
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The patient will be unable to swallow satisfactorily after extensive removal of the pharyngeal wall, presumably due to loss of pharyngeal mobility and aspiration.
Most cancers affecting the posterior pharyngeal wall arise from or in association with initial lesions of surrounding tissues such as the base of the tongue, tonsil, or larynx. However, isolated cancers of the pharyngeal wall without direct involvement with nearby tissues have been observed occasionally. Adequate exposure for surgical excision has been challenging to get in all, but the tiniest of such lesions, and it has typically been regarded as necessary to sacrifice the larynx, even when it was not directly implicated. However, experience with surgical care of these lesions has shown that one of three surgical methods can provide optimal exposure while still preserving the larynx.
What Are the Indications for Elective Neck Dissection?
The indications for an elective neck dissection are when there is a clinically palpable node present on ipsilateral or staged contralateral radical neck dissection, or both are necessary. However, in the absence of palpable adenopathy, the surgeon must take an expectant strategy or do bilateral neck dissections. This lesion has no particular bias for spreading to one side of the neck or the other.
What Is Labiomandibuloglossotomy in the Midline?
It involves the midline lip, jaw, and tongue-splitting pharyngeal approach. This method takes advantage of the midline's relative avascularity, resulting in significant exposure down until the arytenoid cartilage level, at least the soft palate. Adding a larynx splitting process to this operation enhances exposure even below this level; however, it is unnecessary. Furthermore, a lesion needing such a limited level of resection would benefit from a more thorough resection. The aesthetic outcomes of labiomandibuloglossotomy are outstanding, and speech is unaffected following extensive excision of the main section down to the anterior spinal ligament. The wound was just left exposed. In addition, cricopharyngeal myotomy is done to help with deglutition (swallowing).
What Are the Precautions Taken During Surgery?
Proper surgical care of head and neck cancer necessitates, among other things, enough exposure to allow correct en bloc excision of the primary lesion and its metastatic region, as well as appropriate reconstruction. Because of the challenging location of the posterior pharyngeal wall lesions and the predicted complications with deglutition, it has been widely accepted that the larynx should be sacrificed even when not directly implicated. Such a procedure provides good exposure; large margins are reserved to eliminate swallowing issues.
What Are the Complications of Laryngopharyngectomy?
The surgical approaches that seek to conserve the neutral larynx demonstrate that careful patient selection and reconstructive process design can be beneficial. However, preserving the uninvolved larynx adds to the dangers of complete laryngopharyngectomy. They are as follows:
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A lack of resection may lead to recurrence.
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Issues with deglutition.
Swallowing problems may be prevented by performing a proper cricopharyngeal myotomy and retaining the superior laryngeal nerves, resulting in an intact laryngeal reflex closure during deglutition. It is crucial to emphasize that this strategy, like other conservation operations, entails a higher risk of problems than more conservative approaches. This must be balanced against the potential advantages in each situation, and the patient must be aware of the added dangers.
Conclusion:
The posterior pharyngeal wall is the most minor expected location for hypopharyngeal carcinomas. According to the complete surgical management of cancer of the posterior pharyngeal wall carcinoma, cure rates can be higher than those reported for radiation. However, it has been widely accepted that in most of these situations, even the neutral larynx must be sacrificed to get enough exposure and avoid postoperative deglutition difficulties.
