Palatoglossal flap: a novel approach to cover herniated fat during tonsillectomy.
An important but under-reported complication of tonsillectomy is the herniation of parapharyngeal fat into the tonsillar bed. The presence of a connection between the parapharyngeal space and the oral cavity may lead to a deep neck infection, carotid injury/ blowout from salivary enzymes, or subcutaneous/intrathoracic emphysema, which can lead to infections or respiratory distress.
An understanding of the normal tonsillar anatomy is important in understanding how fat herniation can occur during a tonsillectomy. If one were to examine a cross-section of a healthy tonsil, it would reveal that a robust superior constrictor muscle (SCoM) separates the peritonsillar space from the parapharyngeal fat. The muscle density facilitates dissection of the palatine tonsil in the subcapsular plane. The anterior tonsillar pillar is the mucosa-covered palatoglossus muscle, and the posterior tonsillar pillar is the mucosa-covered palatopharyngeus muscle.
Conversely, if one were to examine a cross-section of a tonsil affected by severe chronic tonsillitis, it would demonstrate scarring and adhesion of the tonsillar capsule to the underlying scarred and thinned SCoM, thus obscuring the peritonsillar space. These changes increase the risk of creating a small breach, or dehiscence, of the SCoM during tonsillectomy, resulting in fat herniation into the tonsillar fossa.
While herniation of the parapharyngeal fat into the tonsillar fossa during a tonsillectomy is not a common occurrence, otolaryngologists should be equipped to close such defects. Since primary closure is not always feasible, we present this article to arm the surgeon with a novel approach using a local flap to repair this defect. We report the following case to illustrate the senior author's (J.W.T.) surgical approach to repairing a herniation of the parapharyngeal fat into the tonsillar fossa during a tonsillectomy.
A 12-year-old boy with a history of chronic tonsillitis was taken to the operating room for adenotonsillectomy. He had a history of 8 documented episodes of strep throat each year for 2 consecutive years, along with sporadic episodes of tonsillar infections in years previous. Two of his strep throat infections had been associated with the formation of a peritonsillar abscess on the right side that required drainage. He had no other significant medical or surgical history.
The patient was placed in the supine position with the head slightly extended. A Crowe-Davis mouth gag was used to gain exposure, and the patient was placed into suspension. A red rubber catheter was used to gently retract the soft palate. The tonsillectomy was performed with a monopolar Bovie cautery equipped with a guarded standard tip on the settings of 12 for spray coagulation and 5 for cut. Tonsillar traction was achieved with a straight tonsil grasper, and resection proceeded in a superior to inferior direction. Minor bleeding after the resection was controlled with the monopolar suction Bovie cautery on the settings of 12 for spray coagulation and 0 for cut. The adenoidectomy was performed with an adenoid curette followed by use of the suction Bovie cautery on the settings of 30 for spray coagulation and 0 for cut.
The adenoidectomy was uneventful, but during the tonsillectomy, the patient's right superior constrictor muscle dehisced near the center of the tonsillar fossa, resulting in fat herniation. Primary closure of the defect was attempted, but the thinned SCoM did not allow for an adequate closure. Therefore, a superiorly based palatoglossal flap was fashioned with a # 15 blade and rotated to cover the defect. The flap design provided enough width to capture the thicker lateral portions of the SCoM and incorporate them into the closure (figure). The flap was secured in place with 4-0 Vicryl sutures in an interrupted fashion. Often, primary repair of the defect in patients with a history of chronic tonsillitis is not possible because of the thin and weak nature of the SCoM. We propose the following grading system for SCoM defects during tonsillectomy:
* Type I: A minor amount of fat herniation is present; the surgeon can leave the defect unaddressed.
* Type II: A small amount of fat herniation is present; the surgeon can close the SCoM primarily.
* Type III: A significant amount of fat herniation is present; the surgeon cannot close the SCoM primarily.
* Type IV: A type III defect plus carotid exposure/ injury and/or subcutaneous emphysema are present.
For type III and IV defects, we advocate the use of a palatoglossal flap, which is based on branches of the ascending palatine artery. (1) The flap may be either superiorly or inferiorly based, and it should be wide enough to capture the thicker lateral segments of the SCoM within the fossa. We recommend fashioning the flap in place with the use of an absorbable suture that provides adequate strength (e.g., Vicryl).
The postoperative care of a patient with a type III or IV defect should include chest x-ray, adequate analgesia, a 1-week course of antibiotics that cover oral flora, and a minimum of 23 hours of observation. The physical examination should include (1) palpation of the neck and chest for subcutaneous emphysema, (2) oropharyngeal examination to assess flap integrity, bleeding, or clot, and (3) auscultation of the chest. A finding of subcutaneous air, gross oropharyngeal hemorrhage, persistent fever, or shortness of breath should prompt the surgeon to rule out a deep neck infection, carotid injury/blowout, and pneumothorax or pneumomediastinum.
The palatoglossal flap provides necessary protection of those structures located within and just beyond the parapharyngeal fat, most importantly including the glossopharyngeal nerve and carotid artery. We find this technique to be a safe and effective procedure with minimal associated morbidity.
(1.) Huang MH, Lee ST, Rajendran K. Clinical implications of the velopharyngeal blood supply: A fresh cadaveric study. Plast Reconstr Surg 1998;102(3):655-67.
Parker A. Velargo, MD; Jerome W. Thompson, MD
From the Department of Otolaryngology, University of Tennessee Health Science Center, Memphis.
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|Title Annotation:||PEDIATRIC OTOLARYNGOLOGY CLINIC|
|Author:||Velargo, Parker A.; Thompson, Jerome W.|
|Publication:||Ear, Nose and Throat Journal|
|Date:||Apr 1, 2012|
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