Cell Biochem Biophys DOI 10.1007/s12013-014-0035-0
ORIGINAL PAPER
Isolated Frontal Sinusitis Treated Using an Anterior-to-Ethmoidal Bulla Surgical Approach Jun-feng Ji • You Cheng • Tian-you Wang • Kun-min Wu Man-jie Jiang • Wei Cheng • Zhi-yi Wang • Fei Xue • Yong Zhang • Qiu-ping Wang
•
Ó Springer Science+Business Media New York 2014
Abstract Traditional frontal sinus surgery is associated with a significant trauma. Herein, we have discussed the feasibility, technique, and efficacy of a minimally invasive anterior-to-ethmoidal bulla surgical approach performed under nasal endoscopy to treat isolated frontal sinusitis. Fifteen patients with isolated frontal sinusitis underwent the anterior-to-ethmoidal bulla surgical procedure under general anesthesia. The opening of the frontal sinus was located by frontal mini-trephination in 1 patient. The effects of the operation were evaluated by regular postoperative follow-up. The average postoperative follow-up period was 12.7 months (range 6–24 months). The postoperative symptom of headache was completely resolved in all 15 patients, and 12 patients had good opening of the frontal sinus and complete epithelization was observed by nasal endoscopy. The frontal sinus of 3 patients was not opened, but these patients did not show subjective symptoms. The anterior-to-ethmoidal bulla surgical approach is ideal for isolated frontal sinusitis.
Introduction
Keywords Nasal endoscope Ethmoidal bulla Frontal sinusitis Operation
We selected 435 patients with frontal sinus lesions due to nasal endoscopic surgery performed from 2004 to 2009 for this study. These included 15 patients with isolated frontal sinusitis, 11 of whom were men and 4 women. Their average age was 30.7 years (range 19–61 years), and the duration of disease ranged from 1–6 months. All 15 patients had symptoms of headache, from the forehead to the top of the head. Seven patients had a headache on the left side, 4 on the right (the same side as the lesion), and the other 4 patients were unable to distinguish the side of their headache. Four patients had nasal congestion designated alternative nasal congestion, and 3 patients had symptoms of postnasal drip. All patients did not appeal to pus-containing snot and dysosmia. The preoperative symptom of headache was
Jun-feng Ji and You Cheng contributed equally to this work. They are co-first authors. J. Ji Y. Cheng T. Wang K. Wu M. Jiang W. Cheng Z. Wang F. Xue Y. Zhang Q. Wang (&) Department of Otolaryngology and Head Neck Surgery, Jinling Hospital, 305, East Zhongshan Road, Nanjing, Jiangsu, China e-mail: [email protected]
Isolated frontal sinusitis is not commonly encountered clinically, but induced headache symptoms are always prominent. If conservative treatment fails, surgery is the main therapeutic approach adopted subsequently. However, traditional frontal sinus surgery is associated with significant trauma and often with poor outcomes, because it involves excision of the anterior ethmoidal sinuses and frontal sinusotomy. This study explores the feasibility, technique, and efficacy of a minimally invasive anterior-toethmoidal bulla surgical procedure performed under nasal endoscopic guidance for the treatment of isolated frontal sinusitis.
Materials and Methods Clinical Data
123
Cell Biochem Biophys Fig. 1 Preoperative sinus computed tomography. a Inflammation and frontal air cells of the frontal sinus in the axial position. b Vesicular middle turbinate with frontal air cells and Agger nasi cells shown in the coronal position. c Agger nasi and frontal air cells in an inflamed frontal sinus shown in the sagittal view. d The frontal sinus, frontal air cells, and Agger nasi cells extending down from the uncinate process air cells and the middle turbinate bubble shown in an oblique position. Filled circle frontal sinus, filled triangle frontal air cell, filled square Agger nasi cell, unfilled square middle turbinate bubble
assessed using visual analog scale and was again evaluated at the last postoperative follow-up visit. All patients underwent a preoperative 64-row spiral computed tomography (CT) scan of the paranasal sinuses, including coronal, sagittal, and oblique reconstructions. All were confirmed to have isolated frontal sinusitis with lesions confined to the frontal sinus or frontal recess (Fig. 1); the distribution and characteristics of the frontal recess cells ipsilateral to the lesion were also assessed. Ten patients had received 1 month of conservative treatment, including nasal steroids, antibiotics, and laxatives, without obvious remission; 4 patients underwent non-standard antibiotic therapy without any therapeutic effect; and 1 patient with a frontal recess osteoma did not receive any conservative treatment. Ethical Considerations The study protocol was approved by the ethics review board of the Jinling Hospital. We have obtained written informed consent from all study participants. All of the procedures were done in accordance with the Declaration of Helsinki and relevant policies in China.
123
Surgical Method An anterior-to-ethmoidal bulla surgical approach was used and proceeded as follows. (1) First, the middle nasal meatus was outlined and the polyp, polypoid tissues, or hypertrophic mucosa of the middle nasal meatus were cleared to aid visibility of the uncinate process, concha nasalis media, ethmoidal bulla, and half of the crack in the middle nasal meatus. (2) Two-thirds of the uncinate process was resected following the boundary; it was important to avoid cutting too deep to avoid damaging the lamina papyracea and ethmoidal bulla. At this time, the connection between one-third of the uncinate process and the ethmoidal bulla and middle turbinate was observed under nasal endoscopy. (3) The connection between the top of the uncinate process and the concha nasalis media was resected, and a dome-shaped opening was made in the upper part of the middle nasal meatus. The agger nasi cell inside and outside the uncinate process was then carefully observed. Air cells located outside the uncinate process known as agger nasi cells of the frontal recess could be observed easily. The uncinate process was always close to the concha nasalis media, and sometimes these were quite
Cell Biochem Biophys
close together. At this time, the basal plate of the uncinate process was removed to improve visibility of the air cells in the nasal passage. The frontal sinus was explored from back to front and from inside to outside using a probe with a blunt end. A feeling of depth was indicative of the probe being present in the frontal sinus. (4) The frontal sinus was then opened and cleared, and the basal plate of the uncinate process was cleared sagittally to fully expose the opening of the frontal sinus and open the frontal recess. Normally, the basal plate of the uncinate process, agger nasi cell, and the bony wall of the frontal air cell were removed using a probe or curette along the opening of the frontal sinus to fully expose this opening. (5) During the operation, the ethmoidal bulla was used as the safe boundary as it was a recognizable anatomical reference mark; all procedures were completed before the ethmoid bulla to protect it. (6) A frontal nail was used to identify the opening of the frontal sinus during the operation. Postoperative Follow-Up Treatment In the region of the frontal recess, a tourniquet with compound betamethasone ointment was packed at the fornices formed by the top of the concha nasalis media and the lateral wall of the nasal cavity along with other nasal packing depending on the extent of bleeding. The nasal packing was extracted from the nasal cavity 24–48 h after the operation. For 1 month after discharge, the surgical cavity was cleaned under nasal endoscopy every 1 or 2 weeks and then once every 2 or 4 weeks thereafter. The frequency of follow-up was based on sinus mucosa edema and inflammation and follow-up continued until complete epithelization of the sinus or until the symptoms disappeared.
Results CT of the Paranasal Sinus Ten patients had complete fuzzy coverage of the frontal sinus cavity, and 5 patients had partial fuzzy coverage and fluid content. All 15 patients had an agger nasi cell (100 % incidence), including 10 patients with excessive gasification. Five patients had a frontal bulla cell (33.3 %), including a type 1 cell (2 patients), type 2 cells (2 patients), type 3 cell (1 patient), and a middle turbinate bubble (4 patients). Observations During Surgery Of the 15 patients, 1 had a frontal fossa osteoma, 2 had a polyp at the top of the processus uncinatus, 4 had a middle
turbinate bubble, and 8 had inflammatory edema at the frontal fossae. Postoperative Efficacy No significant complications occurred during or after surgery in all 15 patients. The anterior-to-ethmoidal bulla surgical approach was applied in all 15 patients and helped retain the integrity of the ethmoidal bulla. The frontal sinus of 1 patient was opened by frontal nail positioning because the mouth of the frontal sinus was too small to identify. The duration of postoperative follow-up was 6–24 months, with an average of 12.7 months. Postoperative headache symptoms were alleviated in all 15 patients, and the severity of headache was assessed using a visual analog scale. The average score before the operation was 8.3 points, and the average score at the last follow-up visit was 0.3 points. Paired t-tests revealed a significant before-andafter difference. There were 12 cases of complete epithelization of the frontal sinus orifice observed under nasal endoscopy (Fig. 2), and 3 cases without complete opening of the frontal sinus. However, all patients were without subjective symptoms. Among the 3 cases without a complete opening, the frontal recess of 1 patient could not be observed by endoscopy because the top of the nasal passage was too narrow. We found 1 case with a frontal fossa scar without a clear opening, and the other case had frontal recess edema without purulent secretion. The patient with the frontal fossa scar underwent another CT scan of the paranasal sinuses to verify the lack of inflammation of the frontal sinus.
Discussion Frontal sinusitis is secondary to the inflammation of other sinuses, such as anterior ethmoid sinus inflammation and maxillary sinusitis. However, isolated frontal sinusitis is uncommon [1]. The frontal sinus is located above the 4 groups of paranasal sinuses, and the sinus cavity drains along a natural opening. The anatomical structure around this opening is complex, and there are a number of important adjacent structures that together are known as the frontal recess [2]. Mucociliary clearance of the frontal sinus differs from that associated with the other paranasal sinuses and follows a clear direction from inside to outside, and then drained from outside to inside near the opening of frontal sinus. The drainage cycle was repeated along the inside opening edge. The mucociliary clearance system of drainage of formation mechanism is not a reasonable explanation, but the drainage characteristics of easy leads into the frontal sinus secretions or foreign body, which could lead to the occurrence of frontal sinusitis [3].
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Fig. 2 Comparison of preoperative and postoperative images under endoscope. a The structure of uncinate process, ethmoid bulla etc. can not be seen in the middle meatus because of the obstruction of the over-pneumatized middle turbinate bubble preoperatively;
b postoperative endoscopic view after 6 month follow-up: wellepithelized ostim of frontal sinus with ethmoid bulla intact entirely. SP nasal septum, MT middle turbinate, EB ethmoid bulla, FS frontal sinus, LP papyracea lamina
However, the frontal sinus cavity is located above, and the opening of sinus is located below and is well hidden; therefore, frontal sinusitis alone is not common but occurs secondary to inflammation or lesion in the frontal recess. The occurrence of isolated frontal sinusitis may be correlated with a structural abnormality or with lesions of the frontal sinus opening and surrounding structures, such as middle turbinate hypertrophy, the presence of a polyp at the top of the uncinate process, or a frontal recess osteoma [4]. Due to the sinus opening becoming obstructed by inflammatory edema, polyps, or an osteoma, the pressure in the frontal sinus cavity is increased, and the posterior wall of the frontal sinus becomes tightly closed, which lead to inflammation of the duramater, and thus symptoms of headache are common in patients with isolated frontal sinusitis [5]. In these patients, nasal congestion and puscontaining snot are not obvious because the frontal sinus cavity is smaller than the maxillary sinus cavity, and the opening of the sinus is obstructed even without inflammation in nasal cavity. Minimally invasive surgery requires that the greatest efficacy be achieved with the smallest amount of trauma. For isolated frontal sinusitis, simple clearance of the ostium of the frontal sinus without damaging the surrounding structure is ideal. The advantages of the anterior-to-ethmoidal bulla surgical procedure performed under nasal endoscopy are as follows: (1) it maintains the integrity of the ethmoidal bulla and reduce damage to surrounding structures; (2) reduces damage to the nasal structure, avoid damaging nasal physiological functioning, and maintain the normal physiological function of the nasal cavity as far as is possible compared with traditional surgical
approaches; (3) reduces the difficulty associated with locating the ostium of the frontal sinus using this simple and direct positioning method; and (4) eliminates the possibility of injury to the anterior skull base, anterior ethmoid artery, and papyraceous lamina by retaining the ethmoidal bulla [4]. To estimate the range of a lesion, surgical difficulty, and the appropriate surgical instruments, a 64-row helical CT scan was routinely performed before surgery with coronal, sagittal, and oblique reconstructions to facilitate our understanding of the extent of the frontal sinus lesion at different angles, and of variations in the complex anatomy and adjacent anatomical characteristics, especially the agger nasi cell, frontal air cells, and the uncinate process [2]. Due to the narrow frontal recess and its complex anatomy, it is important that a suitable endoscopic surgical instrument be chosen. A variety of specialized equipment for frontal sinus surgery is available, including 40° and 60° frontal sinus long-necked tissue forceps, sharp strong cutting, long curved suction, and a frontal sinus probe. The ethmoidal bulla is the main reference mark during surgery, and was used as the safe boundary. Surgery was performed in front of the ethmoid bulla to minimize the risks [6]. Therefore, the integrity of the ethmoidal bulla was maintained during the operation. Treating the top of the uncinate process is the key to the operation, and whether it is completely resected or not is key to clearing the frontal drainage channel. The anatomical structure of the top of the uncinate process is complex and variable, and thus, so is the drainage of the frontal sinus. Landsberg’s coronal CT study identified 6 types of attachment to the basal plate of the uncinate process [7]. Further study confirmed the connection between the top of the basal plate of
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the uncinate process and the middle turbinate attachment and frontal gibbosity of the upper jawbone, which form the low, outer, and upper walls of the agger nasi cell. The attachment of the back of the basal plate of the uncinate process was similar to that observed by Han [8]. The upper part of the basal plate of the uncinate process is known as the ‘‘sieve funnel plate’’ and a sagittal connection between it and the agger nasi cell, and ethmoidal bulla was found by Kim et al. [9]. Therefore, careful identification and treatment of the connection of the top of the uncinate process and maintaining the integrity of the ethmoidal bulla is required during the anterior-to-ethmoidal bulla surgical procedure. The agger nasi cell is the most important cell to be influenced by the frontal sinus drainage channel. Wormald [10] emphasized the role of the agger nasi cell in frontal sinus opening operations, and recognized that complete resection of the top wall of the agger nasi cell is an important prerequisite for opening the frontal sinus. Therefore, correct handling of the agger nasi cell is the key step when opening the frontal sinus drainage channel. In the present study, the agger nasi cell was resected in all cases. The frontal bulla cell can arise from the agger nasi cell, but it is uncommon. However, there are some indications that the frontal bulla cell is the most important factor in the occurrence of frontal sinusitis [2]. Type 2 and type 3 frontal bulla cells in particular are crucial factors in frontal recess obstruction. In our study, 5 patients had a frontal bulla cell, including 2 with a type 2 cell and 1 with a type 3 cell. Treatment for a type 3 frontal bulla cell is difficult owing to the high position of the frontal sinus. In this condition, conventional instruments cannot easily reach the lesion. Additionally, a type 3 frontal bulla cell can be mistaken for the frontal sinus during nasal endoscopy owing to its high position. In the present study, a frontal drill was used in the patient with a type 3 frontal bulla cell [11] to verify the position of the type 3 frontal bulla cell recession and the frontal sinus opening. The anterior-to-ethmoidal bulla surgical procedure was able to preserve the normal structure of the nasal cavity and paranasal sinuses and reduce surgical trauma with faster
postoperative recovery and good efficacy, and could thus be the ideal surgical approach for isolated frontal sinusitis. Additionally, in order to obtain the desired effect, this technique requires that the surgeon master the local anatomy of the frontal sinus and frontal recess, ensure good patient selection, complete preoperative examinations, and perform the surgery appropriately. Conflict of interest interest.
The authors have declared no conflict of
References 1. Jacobs, J. B. (1997). 100 years of frontal sinus surgery. Laryngoscope, 107, 1–36. 2. Lee, W. T., Kuhn, F. A., & Citardi, M. J. (2004). 3D computed tomographic analysis of frontal recess anatomy in patients without frontal sinusitis. Otolaryngology, 131, 164–173. 3. Friedman, M., Bliznikas, D., Vidyasagar, R., et al. (2004). Frontal sinus surgery 2004: Update of clinical anatomy and surgical techniques. Operative Techniques in Otolaryngology, 15, 23–31. 4. Landsberg, R., Segev, Y., Friedman, M., et al. (2006). A targeted endoscopic approach to chronic isolated frontal sinusitis. Otolaryngology, 134, 28–32. 5. Seiden, A. M., & Martin, V. T. (2001). Headache and the frontal sinus. Otolaryngologic Clinics of North America, 34, 227–241. 6. Wang, Q., Ji, J., Li, Z., et al. (2006). Endoscopic frontal sinus surgery through the route anterior to ethmoidal bulla. Zhong Guo Er Bi Yan Hou Tou Jing Wai Ke Za Zhi, 13, 583–586. 7. Landsberg, R., & Friedman, M. (2001). A computer-assisted anatomical study of the nasofrontal region. Laryngoscope, 111, 2125–2130. 8. Han, D., Zhang, L., Ge, W., et al. (2008). Multiplanar computed tomographic analysis of the frontal recess region in Chinese subjects without frontal sinus disease symptoms. ORL: Journal of Oto-Rhino-Laryngology and Its Related Specialties, 70, 104–112. 9. Kim, K. S., Kim, H. U., Chung, I. H., et al. (2001). Surgical anatomy of the nasofrontal duct: Anatomical and computed tomographic analysis. Laryngoscope, 111, 603–608. 10. Wormald, P. J. (2003). The agger nasi cell: The key to understanding the anatomy of the frontal recess. Otolaryngology, 129, 497–507. 11. Cohen, A. N., & Wang, M. B. (2007). Minitrephination as an adjunctive measure in the endoscopic management of complex frontal sinus disease. American Journal of Rhinology, 21, 629–636.
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ORIGINAL PAPER
Isolated Frontal Sinusitis Treated Using an Anterior-to-Ethmoidal Bulla Surgical Approach Jun-feng Ji • You Cheng • Tian-you Wang • Kun-min Wu Man-jie Jiang • Wei Cheng • Zhi-yi Wang • Fei Xue • Yong Zhang • Qiu-ping Wang
•
Ó Springer Science+Business Media New York 2014
Abstract Traditional frontal sinus surgery is associated with a significant trauma. Herein, we have discussed the feasibility, technique, and efficacy of a minimally invasive anterior-to-ethmoidal bulla surgical approach performed under nasal endoscopy to treat isolated frontal sinusitis. Fifteen patients with isolated frontal sinusitis underwent the anterior-to-ethmoidal bulla surgical procedure under general anesthesia. The opening of the frontal sinus was located by frontal mini-trephination in 1 patient. The effects of the operation were evaluated by regular postoperative follow-up. The average postoperative follow-up period was 12.7 months (range 6–24 months). The postoperative symptom of headache was completely resolved in all 15 patients, and 12 patients had good opening of the frontal sinus and complete epithelization was observed by nasal endoscopy. The frontal sinus of 3 patients was not opened, but these patients did not show subjective symptoms. The anterior-to-ethmoidal bulla surgical approach is ideal for isolated frontal sinusitis.
Introduction
Keywords Nasal endoscope Ethmoidal bulla Frontal sinusitis Operation
We selected 435 patients with frontal sinus lesions due to nasal endoscopic surgery performed from 2004 to 2009 for this study. These included 15 patients with isolated frontal sinusitis, 11 of whom were men and 4 women. Their average age was 30.7 years (range 19–61 years), and the duration of disease ranged from 1–6 months. All 15 patients had symptoms of headache, from the forehead to the top of the head. Seven patients had a headache on the left side, 4 on the right (the same side as the lesion), and the other 4 patients were unable to distinguish the side of their headache. Four patients had nasal congestion designated alternative nasal congestion, and 3 patients had symptoms of postnasal drip. All patients did not appeal to pus-containing snot and dysosmia. The preoperative symptom of headache was
Jun-feng Ji and You Cheng contributed equally to this work. They are co-first authors. J. Ji Y. Cheng T. Wang K. Wu M. Jiang W. Cheng Z. Wang F. Xue Y. Zhang Q. Wang (&) Department of Otolaryngology and Head Neck Surgery, Jinling Hospital, 305, East Zhongshan Road, Nanjing, Jiangsu, China e-mail: [email protected]
Isolated frontal sinusitis is not commonly encountered clinically, but induced headache symptoms are always prominent. If conservative treatment fails, surgery is the main therapeutic approach adopted subsequently. However, traditional frontal sinus surgery is associated with significant trauma and often with poor outcomes, because it involves excision of the anterior ethmoidal sinuses and frontal sinusotomy. This study explores the feasibility, technique, and efficacy of a minimally invasive anterior-toethmoidal bulla surgical procedure performed under nasal endoscopic guidance for the treatment of isolated frontal sinusitis.
Materials and Methods Clinical Data
123
Cell Biochem Biophys Fig. 1 Preoperative sinus computed tomography. a Inflammation and frontal air cells of the frontal sinus in the axial position. b Vesicular middle turbinate with frontal air cells and Agger nasi cells shown in the coronal position. c Agger nasi and frontal air cells in an inflamed frontal sinus shown in the sagittal view. d The frontal sinus, frontal air cells, and Agger nasi cells extending down from the uncinate process air cells and the middle turbinate bubble shown in an oblique position. Filled circle frontal sinus, filled triangle frontal air cell, filled square Agger nasi cell, unfilled square middle turbinate bubble
assessed using visual analog scale and was again evaluated at the last postoperative follow-up visit. All patients underwent a preoperative 64-row spiral computed tomography (CT) scan of the paranasal sinuses, including coronal, sagittal, and oblique reconstructions. All were confirmed to have isolated frontal sinusitis with lesions confined to the frontal sinus or frontal recess (Fig. 1); the distribution and characteristics of the frontal recess cells ipsilateral to the lesion were also assessed. Ten patients had received 1 month of conservative treatment, including nasal steroids, antibiotics, and laxatives, without obvious remission; 4 patients underwent non-standard antibiotic therapy without any therapeutic effect; and 1 patient with a frontal recess osteoma did not receive any conservative treatment. Ethical Considerations The study protocol was approved by the ethics review board of the Jinling Hospital. We have obtained written informed consent from all study participants. All of the procedures were done in accordance with the Declaration of Helsinki and relevant policies in China.
123
Surgical Method An anterior-to-ethmoidal bulla surgical approach was used and proceeded as follows. (1) First, the middle nasal meatus was outlined and the polyp, polypoid tissues, or hypertrophic mucosa of the middle nasal meatus were cleared to aid visibility of the uncinate process, concha nasalis media, ethmoidal bulla, and half of the crack in the middle nasal meatus. (2) Two-thirds of the uncinate process was resected following the boundary; it was important to avoid cutting too deep to avoid damaging the lamina papyracea and ethmoidal bulla. At this time, the connection between one-third of the uncinate process and the ethmoidal bulla and middle turbinate was observed under nasal endoscopy. (3) The connection between the top of the uncinate process and the concha nasalis media was resected, and a dome-shaped opening was made in the upper part of the middle nasal meatus. The agger nasi cell inside and outside the uncinate process was then carefully observed. Air cells located outside the uncinate process known as agger nasi cells of the frontal recess could be observed easily. The uncinate process was always close to the concha nasalis media, and sometimes these were quite
Cell Biochem Biophys
close together. At this time, the basal plate of the uncinate process was removed to improve visibility of the air cells in the nasal passage. The frontal sinus was explored from back to front and from inside to outside using a probe with a blunt end. A feeling of depth was indicative of the probe being present in the frontal sinus. (4) The frontal sinus was then opened and cleared, and the basal plate of the uncinate process was cleared sagittally to fully expose the opening of the frontal sinus and open the frontal recess. Normally, the basal plate of the uncinate process, agger nasi cell, and the bony wall of the frontal air cell were removed using a probe or curette along the opening of the frontal sinus to fully expose this opening. (5) During the operation, the ethmoidal bulla was used as the safe boundary as it was a recognizable anatomical reference mark; all procedures were completed before the ethmoid bulla to protect it. (6) A frontal nail was used to identify the opening of the frontal sinus during the operation. Postoperative Follow-Up Treatment In the region of the frontal recess, a tourniquet with compound betamethasone ointment was packed at the fornices formed by the top of the concha nasalis media and the lateral wall of the nasal cavity along with other nasal packing depending on the extent of bleeding. The nasal packing was extracted from the nasal cavity 24–48 h after the operation. For 1 month after discharge, the surgical cavity was cleaned under nasal endoscopy every 1 or 2 weeks and then once every 2 or 4 weeks thereafter. The frequency of follow-up was based on sinus mucosa edema and inflammation and follow-up continued until complete epithelization of the sinus or until the symptoms disappeared.
Results CT of the Paranasal Sinus Ten patients had complete fuzzy coverage of the frontal sinus cavity, and 5 patients had partial fuzzy coverage and fluid content. All 15 patients had an agger nasi cell (100 % incidence), including 10 patients with excessive gasification. Five patients had a frontal bulla cell (33.3 %), including a type 1 cell (2 patients), type 2 cells (2 patients), type 3 cell (1 patient), and a middle turbinate bubble (4 patients). Observations During Surgery Of the 15 patients, 1 had a frontal fossa osteoma, 2 had a polyp at the top of the processus uncinatus, 4 had a middle
turbinate bubble, and 8 had inflammatory edema at the frontal fossae. Postoperative Efficacy No significant complications occurred during or after surgery in all 15 patients. The anterior-to-ethmoidal bulla surgical approach was applied in all 15 patients and helped retain the integrity of the ethmoidal bulla. The frontal sinus of 1 patient was opened by frontal nail positioning because the mouth of the frontal sinus was too small to identify. The duration of postoperative follow-up was 6–24 months, with an average of 12.7 months. Postoperative headache symptoms were alleviated in all 15 patients, and the severity of headache was assessed using a visual analog scale. The average score before the operation was 8.3 points, and the average score at the last follow-up visit was 0.3 points. Paired t-tests revealed a significant before-andafter difference. There were 12 cases of complete epithelization of the frontal sinus orifice observed under nasal endoscopy (Fig. 2), and 3 cases without complete opening of the frontal sinus. However, all patients were without subjective symptoms. Among the 3 cases without a complete opening, the frontal recess of 1 patient could not be observed by endoscopy because the top of the nasal passage was too narrow. We found 1 case with a frontal fossa scar without a clear opening, and the other case had frontal recess edema without purulent secretion. The patient with the frontal fossa scar underwent another CT scan of the paranasal sinuses to verify the lack of inflammation of the frontal sinus.
Discussion Frontal sinusitis is secondary to the inflammation of other sinuses, such as anterior ethmoid sinus inflammation and maxillary sinusitis. However, isolated frontal sinusitis is uncommon [1]. The frontal sinus is located above the 4 groups of paranasal sinuses, and the sinus cavity drains along a natural opening. The anatomical structure around this opening is complex, and there are a number of important adjacent structures that together are known as the frontal recess [2]. Mucociliary clearance of the frontal sinus differs from that associated with the other paranasal sinuses and follows a clear direction from inside to outside, and then drained from outside to inside near the opening of frontal sinus. The drainage cycle was repeated along the inside opening edge. The mucociliary clearance system of drainage of formation mechanism is not a reasonable explanation, but the drainage characteristics of easy leads into the frontal sinus secretions or foreign body, which could lead to the occurrence of frontal sinusitis [3].
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Fig. 2 Comparison of preoperative and postoperative images under endoscope. a The structure of uncinate process, ethmoid bulla etc. can not be seen in the middle meatus because of the obstruction of the over-pneumatized middle turbinate bubble preoperatively;
b postoperative endoscopic view after 6 month follow-up: wellepithelized ostim of frontal sinus with ethmoid bulla intact entirely. SP nasal septum, MT middle turbinate, EB ethmoid bulla, FS frontal sinus, LP papyracea lamina
However, the frontal sinus cavity is located above, and the opening of sinus is located below and is well hidden; therefore, frontal sinusitis alone is not common but occurs secondary to inflammation or lesion in the frontal recess. The occurrence of isolated frontal sinusitis may be correlated with a structural abnormality or with lesions of the frontal sinus opening and surrounding structures, such as middle turbinate hypertrophy, the presence of a polyp at the top of the uncinate process, or a frontal recess osteoma [4]. Due to the sinus opening becoming obstructed by inflammatory edema, polyps, or an osteoma, the pressure in the frontal sinus cavity is increased, and the posterior wall of the frontal sinus becomes tightly closed, which lead to inflammation of the duramater, and thus symptoms of headache are common in patients with isolated frontal sinusitis [5]. In these patients, nasal congestion and puscontaining snot are not obvious because the frontal sinus cavity is smaller than the maxillary sinus cavity, and the opening of the sinus is obstructed even without inflammation in nasal cavity. Minimally invasive surgery requires that the greatest efficacy be achieved with the smallest amount of trauma. For isolated frontal sinusitis, simple clearance of the ostium of the frontal sinus without damaging the surrounding structure is ideal. The advantages of the anterior-to-ethmoidal bulla surgical procedure performed under nasal endoscopy are as follows: (1) it maintains the integrity of the ethmoidal bulla and reduce damage to surrounding structures; (2) reduces damage to the nasal structure, avoid damaging nasal physiological functioning, and maintain the normal physiological function of the nasal cavity as far as is possible compared with traditional surgical
approaches; (3) reduces the difficulty associated with locating the ostium of the frontal sinus using this simple and direct positioning method; and (4) eliminates the possibility of injury to the anterior skull base, anterior ethmoid artery, and papyraceous lamina by retaining the ethmoidal bulla [4]. To estimate the range of a lesion, surgical difficulty, and the appropriate surgical instruments, a 64-row helical CT scan was routinely performed before surgery with coronal, sagittal, and oblique reconstructions to facilitate our understanding of the extent of the frontal sinus lesion at different angles, and of variations in the complex anatomy and adjacent anatomical characteristics, especially the agger nasi cell, frontal air cells, and the uncinate process [2]. Due to the narrow frontal recess and its complex anatomy, it is important that a suitable endoscopic surgical instrument be chosen. A variety of specialized equipment for frontal sinus surgery is available, including 40° and 60° frontal sinus long-necked tissue forceps, sharp strong cutting, long curved suction, and a frontal sinus probe. The ethmoidal bulla is the main reference mark during surgery, and was used as the safe boundary. Surgery was performed in front of the ethmoid bulla to minimize the risks [6]. Therefore, the integrity of the ethmoidal bulla was maintained during the operation. Treating the top of the uncinate process is the key to the operation, and whether it is completely resected or not is key to clearing the frontal drainage channel. The anatomical structure of the top of the uncinate process is complex and variable, and thus, so is the drainage of the frontal sinus. Landsberg’s coronal CT study identified 6 types of attachment to the basal plate of the uncinate process [7]. Further study confirmed the connection between the top of the basal plate of
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Cell Biochem Biophys
the uncinate process and the middle turbinate attachment and frontal gibbosity of the upper jawbone, which form the low, outer, and upper walls of the agger nasi cell. The attachment of the back of the basal plate of the uncinate process was similar to that observed by Han [8]. The upper part of the basal plate of the uncinate process is known as the ‘‘sieve funnel plate’’ and a sagittal connection between it and the agger nasi cell, and ethmoidal bulla was found by Kim et al. [9]. Therefore, careful identification and treatment of the connection of the top of the uncinate process and maintaining the integrity of the ethmoidal bulla is required during the anterior-to-ethmoidal bulla surgical procedure. The agger nasi cell is the most important cell to be influenced by the frontal sinus drainage channel. Wormald [10] emphasized the role of the agger nasi cell in frontal sinus opening operations, and recognized that complete resection of the top wall of the agger nasi cell is an important prerequisite for opening the frontal sinus. Therefore, correct handling of the agger nasi cell is the key step when opening the frontal sinus drainage channel. In the present study, the agger nasi cell was resected in all cases. The frontal bulla cell can arise from the agger nasi cell, but it is uncommon. However, there are some indications that the frontal bulla cell is the most important factor in the occurrence of frontal sinusitis [2]. Type 2 and type 3 frontal bulla cells in particular are crucial factors in frontal recess obstruction. In our study, 5 patients had a frontal bulla cell, including 2 with a type 2 cell and 1 with a type 3 cell. Treatment for a type 3 frontal bulla cell is difficult owing to the high position of the frontal sinus. In this condition, conventional instruments cannot easily reach the lesion. Additionally, a type 3 frontal bulla cell can be mistaken for the frontal sinus during nasal endoscopy owing to its high position. In the present study, a frontal drill was used in the patient with a type 3 frontal bulla cell [11] to verify the position of the type 3 frontal bulla cell recession and the frontal sinus opening. The anterior-to-ethmoidal bulla surgical procedure was able to preserve the normal structure of the nasal cavity and paranasal sinuses and reduce surgical trauma with faster
postoperative recovery and good efficacy, and could thus be the ideal surgical approach for isolated frontal sinusitis. Additionally, in order to obtain the desired effect, this technique requires that the surgeon master the local anatomy of the frontal sinus and frontal recess, ensure good patient selection, complete preoperative examinations, and perform the surgery appropriately. Conflict of interest interest.
The authors have declared no conflict of
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