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External Approaches in Sinus Surgery
Carlos D. Pinheiro-Neto
Carl H. Snyderman
Open approaches to the nasal cavity and paranasal sinuses are based on facial, scalp, and/or sublabial incisions to expose the facial skeleton and provide adequate space for osteotomies. The development of endoscopic endonasal techniques in sinus surgery has dramatically reduced the indications for external approaches. However, persistent indications for open approaches to the facial skeleton include facial trauma surgery, orthognathic surgery, and external anterior ethmoidal artery ligation. In some circumstances, the open approach is combined with endoscopic endonasal techniques to treat sinonasal pathologies and skull base lesions. Therefore, even with the evolution of endoscopic endonasal surgery, it is imperative for a sinonasal surgeon to be familiar with external approaches. In this chapter, the current indications and techniques of open approaches in sinus surgery are presented according to specific anatomic sites.
In the late 19th century, two surgeons working independently described the external approach to the maxillary sinus. George Caldwell and Henri Luc were the first to describe the procedure to access the maxillary sinus to remove infection and inflamed mucosa (1
). According to the authors, a maxillary antrostomy in the inferior meatus was routinely performed to establish a new drainage pathway for the sinus. The Caldwell-Luc procedure remained the principal surgical intervention to treat inflammatory maxillary sinus disease until the advance of endoscopic endonasal techniques in the mid-1980s and the concept of a middle meatus antrostomy at the natural ostium of the maxillary sinus (2
). Notwithstanding the procedure is not performed anymore as originally described, the term Caldwell-Luc still remains and is often used to refer to the anterior transmaxillary approach, which requires an incision in the superior gingivolabial sulcus and anterior maxillary antrostomy to access the maxillary sinus.
Following infiltration with local anesthetic with vasoconstrictor, a sublabial incision is carried from the canine tooth to the first molar. It is important to leave a 5-mm cuff of mucosa above the gingiva to facilitate closure of the mucosa at the end of the procedure. Dissecting in the subperiosteal plane, the soft tissue of the cheek is elevated to the level of the infraorbital nerve. The ideal place to open
the maxillary sinus is the canine fossa, which is an area of thin bone just superior to the root of the canine tooth. A small hole is made with a drill or osteotome and enlarged with a bone rongeur to the margins of the sinus (pyriform sinus, orbital rim, maxillary alveolus). Care is taken to avoid injury to the infraorbital nerve superiorly and dental roots inferiorly. In pediatric patients, unerupted teeth are at risk for exposure. In case an extended lateral exposure is needed, the entire lateral buttress of the maxilla can be removed.
TABLE 41.1 SURGICAL INDICATIONS FOR OPEN APPROACHES TO THE SINUSES
Sinonasal tumors (involvement of the anterior, inferior, and posterolateral walls of the maxillary sinus)
Infraorbital nerve resection (adenoid cystic carcinoma, squamous cell carcinoma).
Corridor to reach the pterygopalatine fossa, lateral recess of the sphenoid sinus, masticator space, and infratemporal fossa.
Juvenile nasopharyngeal angiofibromas
Augmentation of the maxillary alveolus.
Open reduction and repair of comminuted orbital floor fractures
Osteoplastic flap for frontal sinus obliteration.
Osteomyelitis (frontal bone)
Sinonasal tumors (lateral extension or involvement of the anterior wall of the frontal sinus)
Displaced fractures of the anterior table
Posttraumatic CSF leaks
Displaced fractures of the posterior table
Resection of malignant tumors
Repair of complex midfacial fractures
External ligation of the anterior ethmoidal artery
Adjunct to frontal sinus surgery
Microscopic pituitary surgery
After the anterior maxillary antrostomy is completed, the surgeon can work in the maxillary sinus under direct or endoscopic visualization. Depending on the case, the posterior maxillary wall can be removed providing access to the pterygopalatine fossa and infratemporal fossa. The medial wall gives access to the nasal cavity, and the roof to the orbit. At the end of the procedure, the anterior wall is not reconstructed and the incision is closed in one layer with absorbable suture (Fig. 41.1
Because of the complex anatomy of the frontal sinus drainage pathway, surgery to restore frontal sinus function is one of the most challenging aspects of sinus surgery. The frontal recess is a narrow stricture between the frontal sinus and the ethmoidal infundibulum. The recess is limited anteriorly by the agger nasi
and posteriorly by the bulla ethmoidal and/or suprabullar cells. In 1914, Lothrop described a procedure to enlarge the frontal recess using an external approach. The aim of the Lothrop procedure was to create a common drainage pathway for both frontal sinuses (5
). Because of the removal of portions of the lamina papyracea, orbital fat tissue would commonly prolapse medially, obstructing the frontal drainage and contributing to high failure rates (6
In the 1950s, Montgomery popularized the operation to permanently obliterate the frontal sinus using an open approach (7
). Frontal sinus obliteration has been considered the final surgical attempt in cases of refractory frontal sinusitis (8
). The principle of this operation is to obliterate the frontal sinus using a variety of autologous tissues and alloplastic materials and block the frontal recess. Although frontal sinus obliteration has a high success rate of 93% at 8 years, complications are relatively high, occurring in over 20% of patients (9
With the advent of endoscopes in sinus surgery, it was feasible to approach the frontal recess and restore the function of the frontal sinus avoiding obliteration. In the 1990s, Draf (11
) modified the surgical concept described by Lothrop using endoscopic endonasal techniques to resect the frontal sinus floor and create a common drainage pathway for both frontal sinuses.
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