Key points
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The modified hemi-Lothrop procedure (Eloy IIC) involves an ipsilateral Draf IIB and an anterosuperior septectomy window for access to the lateral recess of the ipsilateral frontal sinus via the contralateral nasal cavity.
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The modified mini-Lothrop procedure (Eloy IID) involves a contralateral Draf IIB and a frontal intersinus septectomy.
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The modified subtotal-Lothrop procedure (Eloy IIE) involves an ipsilateral Draf IIB with a superior septectomy and frontal intersinus septectomy.
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The modified central-Lothrop procedure (Eloy IIF) involves resection of the frontal sinus floor bilaterally, with a superior septectomy and frontal intersinus septectomy, while preserving both frontal sinus recesses.
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These alterations represent expansion on the current Draf or nasofrontal classification systems and approaches.
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Introduction
The frontal sinus has proven to be anatomically challenging, both with respect to surgical access and management of chronic and recurrent disease. There exist numerous anatomic variations between patients and even between sides in the same patient. Treatments of frontal sinus disease range from conservative long-term medical management to aggressive open surgical procedures. Advances in frontal sinus surgery have allowed for movement away from the more invasive and potentially disfiguring open approaches to less aggressive, endonasal approaches.
The Lothrop procedure described in 1914 consisted of an intranasal ethmoidectomy followed by an external Lynch-type approach with resection of the medial frontal sinus floor, superior nasal septum, and intersinus septum, which created a large frontonasal communication. The microendoscopic and endoscopic modifications to Lothrop’s original technique have been described in the literature, notably by Draf, Gross and colleagues, and Close and colleagues. These investigators have detailed an endonasal approach similar in concept to Lothrop that also involves creating a large common drainage pathway between the paired frontal sinuses. Efforts to reduce invasiveness and preserve the natural architecture of the frontal sinus have led recently to the description of the modified hemi-Lothrop procedure, the modified mini-Lothrop procedure, and the modified subtotal-Lothrop procedure.
Introduction
The frontal sinus has proven to be anatomically challenging, both with respect to surgical access and management of chronic and recurrent disease. There exist numerous anatomic variations between patients and even between sides in the same patient. Treatments of frontal sinus disease range from conservative long-term medical management to aggressive open surgical procedures. Advances in frontal sinus surgery have allowed for movement away from the more invasive and potentially disfiguring open approaches to less aggressive, endonasal approaches.
The Lothrop procedure described in 1914 consisted of an intranasal ethmoidectomy followed by an external Lynch-type approach with resection of the medial frontal sinus floor, superior nasal septum, and intersinus septum, which created a large frontonasal communication. The microendoscopic and endoscopic modifications to Lothrop’s original technique have been described in the literature, notably by Draf, Gross and colleagues, and Close and colleagues. These investigators have detailed an endonasal approach similar in concept to Lothrop that also involves creating a large common drainage pathway between the paired frontal sinuses. Efforts to reduce invasiveness and preserve the natural architecture of the frontal sinus have led recently to the description of the modified hemi-Lothrop procedure, the modified mini-Lothrop procedure, and the modified subtotal-Lothrop procedure.
Discussion of techniques
Current and common methods of classification for endonasal frontal sinus drainage techniques include the Draf and nasofrontal approaches. The recent modifications of endonasal frontal sinus techniques are not included within these classification systems. For this reason, a new classification system consolidating the 2 previous methods and allowing for inclusion of the 3 recently published modifications (as well as a new modification) has been designed ( Table 1 ). This article discusses these modifications in the context of the new classification scheme.
| Draf | Nasofrontal Approach | Eloy’s Proposed Modifications | Description |
|---|---|---|---|
| I | I | I | Anterior ethmoidectomy with drainage of the frontal sinus recess without touching the frontal sinus outflow pathway |
| IIA | II | IIA | Removal of the anterior ethmoidal cells and frontal cells protruding into the frontal sinus outflow pathway creating an opening between the middle turbinate medially and the lamina papyracea laterally |
| IIB | III | IIB | Removal of the frontal sinus floor between the nasal septum medially and the lamina papyracea laterally |
| IIC | Ipsilateral removal of the frontal sinus floor between the nasal septum medially and the lamina papyracea laterally; superior septectomy for access from the contraletaral side and enhanced access to the lateral supraorbital frontal sinus and supraorbital ethmoid regions. This also provides binostril, bimanual manipulation; previously described as a modified hemi-Lothrop procedure. | ||
| IID | Contralateral removal of the frontal sinus floor between the nasal septum medially and the lamina papyracea laterally with addition of an intersinus septectomy for drainage of the diseased frontal sinus to the contralateral recess; previously described as a modified mini-Lothrop procedure | ||
| IIE | Ipsilateral removal of the frontal sinus floor between the nasal septum medially and the lamina papyracea laterally; superior septectomy for access from the contraletaral side and enhanced access to the lateral supraorbital frontal sinus and supraorbital ethmoid regions; intersinus septectomy for access to the entire posterior wall of the frontal sinus; preservation of the contralateral frontal sinus recess; previously described as a modified subtotal-Lothrop procedure | ||
| IIF | Central resection of the frontal sinus floor bilaterally, with a superior septectomy and frontal intersinus septectomy, while preserving both frontal sinus recesses; also termed a modified central-Lothrop procedure | ||
| III | IV | III | Bilateral removal of the floor of the frontal sinus anterior to the middle turbinates from 1 lamina papyracea to the next with superior septectomy and intersinus septectomy; also termed a modified Lothrop procedure |
Standard Frontal Sinus Approaches
Draf I (nasofrontal approach I or Eloy I): This procedure consists of an anterior ethmoidectomy for drainage of the frontal sinus recess without dissection of the frontal sinus outflow pathway ( Fig. 1 A ). This involves removal of obstructing disease inferior to the frontal sinus recess. In this technique, the anterosuperior ethmoidal cells (including the agger nasi) are resected without disrupting the frontal sinus outflow pathway.
Draf IIA (nasofrontal approach II or Eloy IIA): This procedure entails the removal of the anterior ethmoidal cells and frontal cells protruding into the frontal sinus outflow pathway, creating an opening between the middle turbinate medially and the lamina papyracea laterally ( Fig. 1 B). This in turn leads to enlargement of the frontal sinus outflow pathway.
Draf IIB (nasofrontal approach III or Eloy IIB): This procedure also enlarges the frontal sinus outflow pathway and consists of the removal of the frontal sinus floor between the nasal septum medially and the lamina papyracea laterally ( Fig. 1 C). The goal of this procedure is to achieve maximal opening of the frontal sinus outflow pathway on 1 side.
Draf III (nasofrontal approach IV or Eloy III): In this procedure, bilateral removal of the floor of the frontal sinus anterior to the middle turbinates from 1 lamina papyracea to the next is performed, with a superior septectomy and intersinus septectomy; this is also termed a modified Lothrop procedure ( Fig. 1 D). With this procedure, a contiguous bilateral enlargement of the frontal sinus drainage pathway is achieved.
Modified Hemi-Lothrop Procedure (Eloy IIC)
The modified hemi-Lothrop procedure (Eloy IIC) has previously been described as a technique used to improve access to the lateral recess (supraorbital extension) of an affected frontal sinus or supraorbital ethmoid cell ( Fig. 2 ). The procedure combines an ipsilateral Draf IIB (removal of the frontal sinus floor from the nasal septum medially to the lamina papyracea laterally) and a superior septectomy. The superior septectomy window allows insertion of an endoscope and instruments via the contralateral side, thus providing greater access and visualization of the lateral frontal sinus recess of the affected ipsilateral frontal sinus or supraorbital ethmoid. This technique also provides for binostril and bimanual instrumentation ( Fig. 3 ). The ability to perform binostril and bimanual dissection is of particular importance in cases of soft tissue tumors of the lateral frontal sinus recess or surpraorbital ethmoid.
