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Modified transnasal endoscopic lothrop procedure: Frontal drillout
MODIFIED TRANSNASAL ENDOSCOPIC LOTHROP PROCEDURE: FRONTAL DRILLOUT CHARLES W. GROSS, MD, FACS, WILLIAM E. GROSS, MD, DANIEL G. BECKER, MD
The Lothrop procedure resects the medial frontal sinus floor, superior nasal septum, and intersinus septum, creating a large frontonasal communication. However, the external approach often allows medial collapse of soft tissue and stenosis of the frontonasal communication. We describe a modified transnasal endoscopic Lothrop procedure, using drills for cases in which frontal recess exploration has failed to relieve obstruction of the frontal sinus. The lateral bony walls are preserved, and medial collapse does not occur. The mucosa of the posterior table and posterior nasofrontal duct is preserved, and a single common frontal opening is created. We have found this approach to be safe and reliable. Fourteen patients have undergone this procedure without complication, achieving resolution or improvement of their symptoms and maintaining wide patency of the frontonasal opening. We recognize that long-term follow-up will be required, but remain encouraged by our favorable results to date.
The condition of persistent frontal sinusitis is one of chronic inflammation in a natural bony cavity that has a single small opening. The major cause of continued frontal suppuration is inadequate drainage. Relief of such a condition may be obtained either by efficient drainage or obliteration of the cavity.l Many procedures exist for the treatment of persistent frontal sinusitis. These procedures can be categorized as restoring drainage versus obliteration, and transnasal versus external. Intranasal drainage of the frontal sinus was attempted early in the history of sinus surgery. Such procedures often resulted in surgical complications and treatment failures. 2-4 With the recent advent of sinus endoscopes and functional endoscopic sinus surgery, disease can be removed from the frontal recess of the ethmoid in most cases, thereby relieving the blockage of drainage of the frontal sinus. ~-6 When frontal recess exploration fails to relieve obstruction of the frontal sinus, external procedures are often performed. External procedures for frontal sinus drainage include the w e l l - k n o w n L y n c h - H o w a r t h f r o n t o e t h m o i d e c tomy. 7"8 This approach has been cited as having a high rate of recurrence (30%) and postoperative complications. 6 The osteoplastic flap with fat obliteration has emerged as a gold standard of treatment in the United States. This procedure, although formidable, has survived the test of time because it is relatively safe, is familiar to most otolaryngologist--head and neck surgeons, usually results in little cosmetic deformity, and has an acceptable success rate. 9 However, when residual or recurrent inflammatory disease occurs, evaluation of the patient after obliteration can be extremely difficult. Obliterative procedures also can involve significant morbidity. 9q~ From the Department of Otolaryngology-Head and Neck Surgery, University of Virginia Health Sciences Center, Charlottesville, VA, and Murfreesboro, TN, and the Department of Otolaryngology--Head and Neck Surgery, Vanderbilt University, Nashville, TN. Address reprint requests to Charles W. Gross, MD, Department of Otolaryngology, University of Virginia Medical Center, Box 430, Charlottesville, VA 22908.
Several centers around the world have developed a renewed interest in reestablishing drainage pathways from the frontal sinus. 11-13 Significant history of this approach dates to 1914 when Lothrop reported removing the intersinus septum along with the superior nasal septurn and nasal floor of the frontal sinus to join the two nasofrontal ducts into a common opening. 1 This was a combined approach, using transnasal drilling while visualizing through the defect afforded by external frontoethmoidectomy. His procedure was abandoned or not duplicated by other surgeons. Lothrop's 1914 description of his technique 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 creating a large f r o n t o n a s a l c o m m u n i c a t i o n . 1 Lothrop reported that an intranasal approach to his procedure was too dangerous because of lack of adequate visualization. However, the external approach often allowed medial collapse of orbital soft tissue and subsequent stenosis of the nasofrontal communication. With the advent of the computed tomography (CT) scan and of endoscopic techniques, and with the availability of advanced drill technology, we felt that it was reasonable to reassess the basic tenet of the Lothrop procedure (ie, removal of the intersinus septum, superior nasal septum, and nasal floor of the frontal sinus, thereby creating a large frontonasal communication that would essentially marsupialize the frontal sinus). We felt it feasible to introduce a modification to his procedure in which the approach was entirely intranasal. The lateral bony walls are preserved and medial collapse does not occur. Theoretical advantages of this procedure over frontal sinus obliteration include decreased morbidity, improved cosmesis, and the ability to endoscopically evaluate postoperative patients for recurrent disease. This modification was first studied in cadavers to quantify the potential size of the frontonasal opening. Subsequently, we pursued this approach in appropriate clinical candidates. Previously, we primarily relied on frontal sinus obliteration with fat via an osteoplastic flap approach to treat the majority of patients with medically
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 6, NO 3 (SEP), 1995: PP 193-200
193
FIGURE 1. Bone-cutting
suction drills (Linvatec Corporation, Largo, Florida) for modified Lothrop procedure (frontal drillout). refractive, chronic frontal sinusitis who had undergone unsuccessful endoscopic frontal sinusotomy. For the past 2 years, we have primarily used the modified transnasal Lothrop procedure for surgical management of patients with disease similar to that treated previously with an osteoplastic flap approach. We have described our clinical results elsewhere; 14 this report provides a detailed description of our technique.
MATERIALS AND METHODS Patient Selection Modified transnasal Lothrop procedure is performed primarily in patients with chronic recurrent frontal sinus disease that has been refractory both to aggressive medical therapy and to surgical correction via endoscopic frontal recess surgery. In addition, in selected patients with frontal sinus trauma we have performed a modified frontal drillout after direct visualization via osteoplastic flap. The patient with frontal sinus trauma involving the nasofrontal duct may not require obliteration. Goode and others have described the use of septectomy in cases of unilateral nasofrontal injury, lsq6 Similarly, an osteoplastic flap approach allows exploration of the sinus to ensure the status of the posterior table. The frontal opening may then be drilled from above and via the intranasal approach. Partial ethmoidectomy with removal of agger nasi cells endoscopically usually ensures adequate postoperative endoscopic visualization of the frontal opening.
tion, Largo, Fla). Rotational speeds range from 0 to 6,000 rpm. The footswitch has variable sensitivity control, which can be adjusted to the surgeon's preference. There are two handpieces. The "Microjoint" handpiece is for the smaller drills (2.0 m m to 3.5 mm). Generally, we use the standard handpiece, which is for the larger drills (3.5 mm to 8 mm). It weighs 385.5 grams. The cross-sectional shape of both handpieces is teardrop. The soft-tissue shavers and bone-cutting burrs range in diameter (Figs 1, 2). The ones designed for the Microjoint handpiece are 2.0 m m to 3.5 m m in diameter and are 8.9 cm in length, and the ones designed for the standard handpiece are 3.5 mm to 8.0 m m in diameter and 13.3 cm in length. The soft tissue cannulas have a blunt cannula tip and a lateral port. An oscillating or rotating inner cannula with a similar lateral port cuts and extracts soft tissue as it is suctioned through the side port of the cannula. The proximal and distal edges of the aperture are smooth. The lateral aspects of the aperture are smooth or serrated. The inner blade cuts and extracts soft tissue
Equipment We use standard 4-mm rigid 0~ and 30 ~ endoscopes and standard endoscopic equipment as described below. Once the location of the frontal recess has been identified, 5-gauge K-wires are used to mark it. We currently use the Apex Universal Drive System (Linvatec Corpora194
FIGURE 2. To minimize bleeding, the soft-•sue shavers are used to resect mucosa before bone drilling. MODIFIED TRANSNASAL ENDOSCOPIC LOTHROP
Middle turbinate
Nasal septum
FIGURE 3. The anterosuperior nasal septum is resected. as it is suctioned into the side port. The inner blade can oscillate, or it can rotate in forward or reverse. In oscillate mode, the blade rotates one 360~ arc in one direction before rotating in the opposite direction. Some of the soft tissue blades can be bent from 0~ to 30~ in any direction by the surgeon at the operating table. The cutting burrs consist of a burr affixed to a shaft of either 8.9 cm or 13.3 cm length. Spherical, tapered, or oval burrs are available. The shaft of the burr is protected by a sheath. The end of the sheath is beveled so that the "back" side of the burr is protected or guarded. As with the soft-tissue shavers, suction is applied through the sheath so that material can be suctioned free at the site of the burr. This enables the surgeon to adequately visualize the precise drilling site and keep the field clear of debris.
Operative Technique The modified transnasal Lothrop procedure is performed under general anesthesia. The nose is injected and topicalized with local anesthesia (lidocaine and epiGROSS ET AL
nephrine) in the usual fashion. The patient is positioned as for a conventional functional sinus surgery using endoscopes. The patient's CT scan is always in the room for reference.
Step 1: Resect agger nasi, superior uncinate, and anterior ethmoid cells. If agger nasi, superior uncinate, or anterior ethmoid cells are present, they are removed using conventional endoscopic instrumentation to enlarge access to the frontal recess. Any other revision endoscopic work that is necessary may be accomplished at this time.
Step 2: Locate the frontal recess. The frontal recess on one side is cannulated if possible. The procedure is typically bilateral so the more easily accessible frontal recess is chosen. When landmarks are obscured in these cases, we employ the C-arm to increase the surgeon's confidence in the exact identity of the frontal recess area. Alternatively, direct visualization from above via a small external incision and frontal trephine may be considered, although we have not found this necessary in our series to date. 195
Nasofrontal "beak" Larr papyr
middle inate
.eft uncinate process
Nasofron recess
Roof of ant. ethrr b l l lU;~
Nasal septum FIGURE 4. View after removal of anterosuperior nasal septum. Both nasofrontal regions are visible. A K-wire has been placed in the right frontal recess.
Step 3: Takedown of anterior-superior nasal septum. The superior septum in the region between the two frontal recesses, anterior to the nasofrontal isthmus, is resected (Fig 3). This is accomplished early in the procedure because it greatly increases exposure and provides a window to work through so that the endoscope placed through one nostril can visualize the drill tip placed through the opposite nostril. This produces broad exposure of the operative area and provides greater maneuverability. The septum is taken down posteriorly to just b e y o n d the anterior aspect of the middle turbinate. Experience has shown that w h e n the septum is not taken down inferiorly enough, crusts or sinus drainage may catch on the superior surface of the remaining septum. Septal takedown begins with mucosal takedown on both sides of the septum using the soft-tissue shave tip. This minimizes avulsion of mucous membrane, which is particularly important with regard to the olfactory region posterosuperiorly. We typically use the 4.2-ram soft tissue shaver, although a smaller cannula may occasionally be necessary. Bony and cartilaginous septum are taken down using conventional straight and back-biting forceps. Once the septum has been adequately taken down, the surgeon can visualize both frontal recess areas and the intranasal floor of the frontal sinus. Step 4: Preparation of frontal sinus floor for drilling. Using the endonasal soft-tissue shaver, mucosa is removed from the area of the frontal sinus floor between the two frontal recesses. The white remnant of cartilaginous septum 196
superiorly and just posteriorly to the area of drilling, serves as a midline marker.
Step 5: Placement of K-wire. A wire probe is placed through the nasofrontal isthmus into the frontal sinus to assist in anatomic orientation and to protect posterior structures (eg, anterior ethmoid artery) (Fig 4). Occasionally, both frontal recesses are obscured and this is not possible. As mentioned previously, we now use the C-arm if needed before drilling to help identify the exact location of the frontal recess. Step 5: Frontal drillout. The endonasal bone-cutting drill is used to remove bone from the anterior face of the frontal recess on one side, taking care to stay anterior to the probe within the frontal recess. This bone that is removed comprises part of what is known as the nasofrontal "beak" of bone (Fig 5). The endonasal drill is used to enter the floor of the frontal sinus anteriorly and just medially to the frontonasal isthmus, in an area named by Lothrop as the nasal crest. The nasal crest is removed and the frontal sinus is progressively opened (Fig 6). With the posterior table under direct visualization, drilling proceeds to the midline and beyond (Fig 7). Drilling continues until the contralateral frontal recess and isthmus are opened and in communication with the frontonasal opening. The 4.5-mm bone-cutting drill is typically used at the outset, although a smaller drill may occasionally be necessary at first. As the drillout is widened a 5.0-mm or larger drill bit may be used. An irrigation system such as Endoscrub (Xomed, JacksonMODIFIED TRANSNASAL ENDOSCOPIC LOTHROP
Nasofrontal " "beak"
Suction drill FIGURE 5. Sagittal view. The nasofrontal beak of bone is drilled. The bevelled shaft protects the posterior wall. Suction is applied through the shaft, providing a clear surgical field. ville, Fla.) is used to provide irrigation at the site of drilling and to maintain a clean endoscope. This procedure is best approached by identifying both nasofrontal recesses and drilling from both sides, although we have also drilled from one frontal recess across the midline to the opposite one in some cases. The surgeon removes as much bone as possible anteriorly, until only a thin bony shell around the frontonasal communication at the glabellar area remains. Mucosa of the posterior table and posterior nasofrontal duct mucosa are preserved, and a single common frontal opening that induces both nasofrontal ducts and the floor of the frontal sinus is created (Figs 8, 9). Using angled scopes, the entire contents of the frontal sinus can be visualized. The opening is typically semicircular or crescentic in shape.
Postoperative Care Frequent office visits for postoperative care are required to assure patency of the opening. This may require removal of clots, crusts, polyps, and granulation GROSS ETAL
tissue. The postoperative care is similar to that for the standard functional endoscopic sinus surgery. 17
RESULTS: FRONTAL DRILLOUT Our results have been described elsewhere. From October 1993 until October 1994 a modified transnasal Lothrop procedure was performed in 14 patients with persisting severe frontal sinus disease. All 14 patients have widely patent frontal openings at this time.
DISCUSSION Our initial results indicate the efficacy of this procedure. All 14 patients have widely patent frontal sinuses. Endoscopic visualization is easily accomplished in clinic, so early intervention is possible should it be necessary. We acknowledge that much longer follow-up will be re197
Right frontal sinus ;j #
Nasal septum
Suction drill
q~
"i o~d~~
FIGURE 6. Endoscopic view through left nostril. The drill was inserted through the right nostril, because drilling began on the right in this patient and proceeded toward the midline.
Interfrontal
Rig fron
sin~
FIGURE 7. Endoscopic view through the right nostril. As drilling progresses past the midline, the endoscope can be placed in the right nostril to allow continued drilling via the left nostril.
Interfrontal sinus septum
Right frontal sinus Lamina
Lamina . papyracea
Nasal septum
FIGURE 8. Endoscopic view through right nostril of completed drillout. This labelled drawing corresponds to the postoperative photograph in Figure 9. quired to demonstrate the ultimate efficacy of this procedure, but we are encouraged by our initial results. We believe that this procedure provides many advantages over the osteoplastic frontal sinus obliteration for patients with severe persisting frontal sinusitis. The Lothrop procedure offers the patient a less invasive procedure with a shorter hospitalization (discharge usually the same day), less pain, less frontal and orbital edema, and
FIGURE 9. Postoperative photograph. GROSS ET AL
improved cosmesis. It also offers the advantage of the ability to evaluate postoperatively for recurrent disease, thus avoiding the diagnostic dilemma of frontal pain after frontal sinus obliteration. One possible limitation of this procedure would be for the treatment of diseased supraorbital cells, which could be inaccessible by this approach (personal communication, W. Montgomery, October, 1994). We have not encountered this problem to date. Because of the high incidence of delayed failures caused by stenosis after the Lnych-Howarth frontoethmoidectomy6 and other procedures that recreate frontal drainage, we have sought to develop an alternative procedure. We believe that the approach described in this report produces the largest opening anatomically possible. We sought to achieve a frontonasal communication that would be so large that inevitable scar contracture would not cause significant stenosis. Furthermore, ease of endoscopic follow-up in clinic allows intervention when necessary to prevent significant stenosis. Preservation of the mucosa of the posterior table and posterior nasofrontal duct and avoidance of the loss of external skeletal support inherent in Lynch-type external procedures should improve long-term patency. The drill system has built-in suction at the site of resection, which leads to improved visibility. As in otologic surgery, advanced bone-cutting drills can allow increased precision 199
compared with rongeurs or curettes. The procedure des c r i b e d in t h i s r e p o r t c r e a t e s a u n i q u e l y l a r g e f r o n t o n a s a l communication. O u r a p p l i c a t i o n o f a d v a n c e d drill t e c h n o l o g y h a s e n a b l e d u s to p e r f o r m t h i s p r o c e d u r e s a f e l y and expeditiously.
9. 10.
11.
REFERENCES 12. 1. Lothrop HA: Frontal sinus suppuration Ann Surg 59:937-957, 1914 2. Lawson W: Frontal Sinus Surgery of the ParanasaI Sinuses, (ed 2). Philadelphia, PA, Saunders, 1991 3. Kasper KA: Nasofrontal connections: A study based on one hundred consecutive dissections. Arch Otolaryngol 23:322-343, 1936 4. Van Alyea OE: Frontal sinus drainage. Ann Otol Rhinol Laryngol 55:267-277, 1946 5. Schaefer SD, Close LG: Endoscopic management of frontal sinus disease. Laryngoscope 100:155-160, 1990 6. Rice DH: Chronic frontal sinus disease Otolaryngol Clin North Am 26:619-622, 1993. 7. Rubin JS, Lund VJ, Salmon B: Frontoethmoidectomy in the treatment of mucocoeles. Arch Otolaryngol Head Neck Surg 112:434436, 1986 8. Neel HB, McDonald TJ, Facer GW: Modified Lynch procedure for
200
13. 14.
15.
16.
17.
chronic frontal sinus disease: Rationale, technique, and long-term results. Laryngoscope 99:885-895, 1989 Hardy JM, Montgomery WW: Osteoplastic frontal sinusotomy: Analysis of 250 operations. Ann Otolaryngol 85:523-532, 1976 Kennedy DW, Josephson JS, Zinreich SJ, et al: Endoscopic sinus surgery for mucoceles: A viable alternative. Laryngoscope 99:885895, 1989 May M: Frontal sinus surgery: Endonasal endoscopic ostioplasty rather than external osteoplasty. Oper Tech Otolaryngol Head Neck Surg 2:247-256, 1991 Draf W: Endonasal micro-endoscopic frontal sinus surgery: The Fulda concept. Oper Tech Otolaryngol Head Neck Surg 2:234-240, 1991 Wigand M, Hoseman W: Endoscopic surgery for frontal sinusitis and its complications. Am J Rhinol 5:85-89, 1991 Gross WE, Gross CW, Becker DG, et al: Modified transnasal endoscopic Lothrop procedure as an alternative to frontal sinus obliteration. Otolaryngol Head Neck Surg (in press) Goode RL, Streslow V, Fee WE: Frontal sinus septectomy for chronic unilateral sinusitis. Otolaryngol Head Neck Surg 88:18-21, 1980 Pope TH, Thompson WR: Treatment of chronic unilateral frontal sinusitis by removal of the interfrontal septum. South Med J 69:755, 1976 Gross CW, Gross WE: Post-operative care for functional endoscopic sinus surgery. ENT J, 73:476-479, 1994
MODIFIED TRANSNASAL ENDOSCOPIC LOTHROP
The Lothrop procedure resects the medial frontal sinus floor, superior nasal septum, and intersinus septum, creating a large frontonasal communication. However, the external approach often allows medial collapse of soft tissue and stenosis of the frontonasal communication. We describe a modified transnasal endoscopic Lothrop procedure, using drills for cases in which frontal recess exploration has failed to relieve obstruction of the frontal sinus. The lateral bony walls are preserved, and medial collapse does not occur. The mucosa of the posterior table and posterior nasofrontal duct is preserved, and a single common frontal opening is created. We have found this approach to be safe and reliable. Fourteen patients have undergone this procedure without complication, achieving resolution or improvement of their symptoms and maintaining wide patency of the frontonasal opening. We recognize that long-term follow-up will be required, but remain encouraged by our favorable results to date.
The condition of persistent frontal sinusitis is one of chronic inflammation in a natural bony cavity that has a single small opening. The major cause of continued frontal suppuration is inadequate drainage. Relief of such a condition may be obtained either by efficient drainage or obliteration of the cavity.l Many procedures exist for the treatment of persistent frontal sinusitis. These procedures can be categorized as restoring drainage versus obliteration, and transnasal versus external. Intranasal drainage of the frontal sinus was attempted early in the history of sinus surgery. Such procedures often resulted in surgical complications and treatment failures. 2-4 With the recent advent of sinus endoscopes and functional endoscopic sinus surgery, disease can be removed from the frontal recess of the ethmoid in most cases, thereby relieving the blockage of drainage of the frontal sinus. ~-6 When frontal recess exploration fails to relieve obstruction of the frontal sinus, external procedures are often performed. External procedures for frontal sinus drainage include the w e l l - k n o w n L y n c h - H o w a r t h f r o n t o e t h m o i d e c tomy. 7"8 This approach has been cited as having a high rate of recurrence (30%) and postoperative complications. 6 The osteoplastic flap with fat obliteration has emerged as a gold standard of treatment in the United States. This procedure, although formidable, has survived the test of time because it is relatively safe, is familiar to most otolaryngologist--head and neck surgeons, usually results in little cosmetic deformity, and has an acceptable success rate. 9 However, when residual or recurrent inflammatory disease occurs, evaluation of the patient after obliteration can be extremely difficult. Obliterative procedures also can involve significant morbidity. 9q~ From the Department of Otolaryngology-Head and Neck Surgery, University of Virginia Health Sciences Center, Charlottesville, VA, and Murfreesboro, TN, and the Department of Otolaryngology--Head and Neck Surgery, Vanderbilt University, Nashville, TN. Address reprint requests to Charles W. Gross, MD, Department of Otolaryngology, University of Virginia Medical Center, Box 430, Charlottesville, VA 22908.
Several centers around the world have developed a renewed interest in reestablishing drainage pathways from the frontal sinus. 11-13 Significant history of this approach dates to 1914 when Lothrop reported removing the intersinus septum along with the superior nasal septurn and nasal floor of the frontal sinus to join the two nasofrontal ducts into a common opening. 1 This was a combined approach, using transnasal drilling while visualizing through the defect afforded by external frontoethmoidectomy. His procedure was abandoned or not duplicated by other surgeons. Lothrop's 1914 description of his technique 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 creating a large f r o n t o n a s a l c o m m u n i c a t i o n . 1 Lothrop reported that an intranasal approach to his procedure was too dangerous because of lack of adequate visualization. However, the external approach often allowed medial collapse of orbital soft tissue and subsequent stenosis of the nasofrontal communication. With the advent of the computed tomography (CT) scan and of endoscopic techniques, and with the availability of advanced drill technology, we felt that it was reasonable to reassess the basic tenet of the Lothrop procedure (ie, removal of the intersinus septum, superior nasal septum, and nasal floor of the frontal sinus, thereby creating a large frontonasal communication that would essentially marsupialize the frontal sinus). We felt it feasible to introduce a modification to his procedure in which the approach was entirely intranasal. The lateral bony walls are preserved and medial collapse does not occur. Theoretical advantages of this procedure over frontal sinus obliteration include decreased morbidity, improved cosmesis, and the ability to endoscopically evaluate postoperative patients for recurrent disease. This modification was first studied in cadavers to quantify the potential size of the frontonasal opening. Subsequently, we pursued this approach in appropriate clinical candidates. Previously, we primarily relied on frontal sinus obliteration with fat via an osteoplastic flap approach to treat the majority of patients with medically
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 6, NO 3 (SEP), 1995: PP 193-200
193
FIGURE 1. Bone-cutting
suction drills (Linvatec Corporation, Largo, Florida) for modified Lothrop procedure (frontal drillout). refractive, chronic frontal sinusitis who had undergone unsuccessful endoscopic frontal sinusotomy. For the past 2 years, we have primarily used the modified transnasal Lothrop procedure for surgical management of patients with disease similar to that treated previously with an osteoplastic flap approach. We have described our clinical results elsewhere; 14 this report provides a detailed description of our technique.
MATERIALS AND METHODS Patient Selection Modified transnasal Lothrop procedure is performed primarily in patients with chronic recurrent frontal sinus disease that has been refractory both to aggressive medical therapy and to surgical correction via endoscopic frontal recess surgery. In addition, in selected patients with frontal sinus trauma we have performed a modified frontal drillout after direct visualization via osteoplastic flap. The patient with frontal sinus trauma involving the nasofrontal duct may not require obliteration. Goode and others have described the use of septectomy in cases of unilateral nasofrontal injury, lsq6 Similarly, an osteoplastic flap approach allows exploration of the sinus to ensure the status of the posterior table. The frontal opening may then be drilled from above and via the intranasal approach. Partial ethmoidectomy with removal of agger nasi cells endoscopically usually ensures adequate postoperative endoscopic visualization of the frontal opening.
tion, Largo, Fla). Rotational speeds range from 0 to 6,000 rpm. The footswitch has variable sensitivity control, which can be adjusted to the surgeon's preference. There are two handpieces. The "Microjoint" handpiece is for the smaller drills (2.0 m m to 3.5 mm). Generally, we use the standard handpiece, which is for the larger drills (3.5 mm to 8 mm). It weighs 385.5 grams. The cross-sectional shape of both handpieces is teardrop. The soft-tissue shavers and bone-cutting burrs range in diameter (Figs 1, 2). The ones designed for the Microjoint handpiece are 2.0 m m to 3.5 m m in diameter and are 8.9 cm in length, and the ones designed for the standard handpiece are 3.5 mm to 8.0 m m in diameter and 13.3 cm in length. The soft tissue cannulas have a blunt cannula tip and a lateral port. An oscillating or rotating inner cannula with a similar lateral port cuts and extracts soft tissue as it is suctioned through the side port of the cannula. The proximal and distal edges of the aperture are smooth. The lateral aspects of the aperture are smooth or serrated. The inner blade cuts and extracts soft tissue
Equipment We use standard 4-mm rigid 0~ and 30 ~ endoscopes and standard endoscopic equipment as described below. Once the location of the frontal recess has been identified, 5-gauge K-wires are used to mark it. We currently use the Apex Universal Drive System (Linvatec Corpora194
FIGURE 2. To minimize bleeding, the soft-•sue shavers are used to resect mucosa before bone drilling. MODIFIED TRANSNASAL ENDOSCOPIC LOTHROP
Middle turbinate
Nasal septum
FIGURE 3. The anterosuperior nasal septum is resected. as it is suctioned into the side port. The inner blade can oscillate, or it can rotate in forward or reverse. In oscillate mode, the blade rotates one 360~ arc in one direction before rotating in the opposite direction. Some of the soft tissue blades can be bent from 0~ to 30~ in any direction by the surgeon at the operating table. The cutting burrs consist of a burr affixed to a shaft of either 8.9 cm or 13.3 cm length. Spherical, tapered, or oval burrs are available. The shaft of the burr is protected by a sheath. The end of the sheath is beveled so that the "back" side of the burr is protected or guarded. As with the soft-tissue shavers, suction is applied through the sheath so that material can be suctioned free at the site of the burr. This enables the surgeon to adequately visualize the precise drilling site and keep the field clear of debris.
Operative Technique The modified transnasal Lothrop procedure is performed under general anesthesia. The nose is injected and topicalized with local anesthesia (lidocaine and epiGROSS ET AL
nephrine) in the usual fashion. The patient is positioned as for a conventional functional sinus surgery using endoscopes. The patient's CT scan is always in the room for reference.
Step 1: Resect agger nasi, superior uncinate, and anterior ethmoid cells. If agger nasi, superior uncinate, or anterior ethmoid cells are present, they are removed using conventional endoscopic instrumentation to enlarge access to the frontal recess. Any other revision endoscopic work that is necessary may be accomplished at this time.
Step 2: Locate the frontal recess. The frontal recess on one side is cannulated if possible. The procedure is typically bilateral so the more easily accessible frontal recess is chosen. When landmarks are obscured in these cases, we employ the C-arm to increase the surgeon's confidence in the exact identity of the frontal recess area. Alternatively, direct visualization from above via a small external incision and frontal trephine may be considered, although we have not found this necessary in our series to date. 195
Nasofrontal "beak" Larr papyr
middle inate
.eft uncinate process
Nasofron recess
Roof of ant. ethrr b l l lU;~
Nasal septum FIGURE 4. View after removal of anterosuperior nasal septum. Both nasofrontal regions are visible. A K-wire has been placed in the right frontal recess.
Step 3: Takedown of anterior-superior nasal septum. The superior septum in the region between the two frontal recesses, anterior to the nasofrontal isthmus, is resected (Fig 3). This is accomplished early in the procedure because it greatly increases exposure and provides a window to work through so that the endoscope placed through one nostril can visualize the drill tip placed through the opposite nostril. This produces broad exposure of the operative area and provides greater maneuverability. The septum is taken down posteriorly to just b e y o n d the anterior aspect of the middle turbinate. Experience has shown that w h e n the septum is not taken down inferiorly enough, crusts or sinus drainage may catch on the superior surface of the remaining septum. Septal takedown begins with mucosal takedown on both sides of the septum using the soft-tissue shave tip. This minimizes avulsion of mucous membrane, which is particularly important with regard to the olfactory region posterosuperiorly. We typically use the 4.2-ram soft tissue shaver, although a smaller cannula may occasionally be necessary. Bony and cartilaginous septum are taken down using conventional straight and back-biting forceps. Once the septum has been adequately taken down, the surgeon can visualize both frontal recess areas and the intranasal floor of the frontal sinus. Step 4: Preparation of frontal sinus floor for drilling. Using the endonasal soft-tissue shaver, mucosa is removed from the area of the frontal sinus floor between the two frontal recesses. The white remnant of cartilaginous septum 196
superiorly and just posteriorly to the area of drilling, serves as a midline marker.
Step 5: Placement of K-wire. A wire probe is placed through the nasofrontal isthmus into the frontal sinus to assist in anatomic orientation and to protect posterior structures (eg, anterior ethmoid artery) (Fig 4). Occasionally, both frontal recesses are obscured and this is not possible. As mentioned previously, we now use the C-arm if needed before drilling to help identify the exact location of the frontal recess. Step 5: Frontal drillout. The endonasal bone-cutting drill is used to remove bone from the anterior face of the frontal recess on one side, taking care to stay anterior to the probe within the frontal recess. This bone that is removed comprises part of what is known as the nasofrontal "beak" of bone (Fig 5). The endonasal drill is used to enter the floor of the frontal sinus anteriorly and just medially to the frontonasal isthmus, in an area named by Lothrop as the nasal crest. The nasal crest is removed and the frontal sinus is progressively opened (Fig 6). With the posterior table under direct visualization, drilling proceeds to the midline and beyond (Fig 7). Drilling continues until the contralateral frontal recess and isthmus are opened and in communication with the frontonasal opening. The 4.5-mm bone-cutting drill is typically used at the outset, although a smaller drill may occasionally be necessary at first. As the drillout is widened a 5.0-mm or larger drill bit may be used. An irrigation system such as Endoscrub (Xomed, JacksonMODIFIED TRANSNASAL ENDOSCOPIC LOTHROP
Nasofrontal " "beak"
Suction drill FIGURE 5. Sagittal view. The nasofrontal beak of bone is drilled. The bevelled shaft protects the posterior wall. Suction is applied through the shaft, providing a clear surgical field. ville, Fla.) is used to provide irrigation at the site of drilling and to maintain a clean endoscope. This procedure is best approached by identifying both nasofrontal recesses and drilling from both sides, although we have also drilled from one frontal recess across the midline to the opposite one in some cases. The surgeon removes as much bone as possible anteriorly, until only a thin bony shell around the frontonasal communication at the glabellar area remains. Mucosa of the posterior table and posterior nasofrontal duct mucosa are preserved, and a single common frontal opening that induces both nasofrontal ducts and the floor of the frontal sinus is created (Figs 8, 9). Using angled scopes, the entire contents of the frontal sinus can be visualized. The opening is typically semicircular or crescentic in shape.
Postoperative Care Frequent office visits for postoperative care are required to assure patency of the opening. This may require removal of clots, crusts, polyps, and granulation GROSS ETAL
tissue. The postoperative care is similar to that for the standard functional endoscopic sinus surgery. 17
RESULTS: FRONTAL DRILLOUT Our results have been described elsewhere. From October 1993 until October 1994 a modified transnasal Lothrop procedure was performed in 14 patients with persisting severe frontal sinus disease. All 14 patients have widely patent frontal openings at this time.
DISCUSSION Our initial results indicate the efficacy of this procedure. All 14 patients have widely patent frontal sinuses. Endoscopic visualization is easily accomplished in clinic, so early intervention is possible should it be necessary. We acknowledge that much longer follow-up will be re197
Right frontal sinus ;j #
Nasal septum
Suction drill
q~
"i o~d~~
FIGURE 6. Endoscopic view through left nostril. The drill was inserted through the right nostril, because drilling began on the right in this patient and proceeded toward the midline.
Interfrontal
Rig fron
sin~
FIGURE 7. Endoscopic view through the right nostril. As drilling progresses past the midline, the endoscope can be placed in the right nostril to allow continued drilling via the left nostril.
Interfrontal sinus septum
Right frontal sinus Lamina
Lamina . papyracea
Nasal septum
FIGURE 8. Endoscopic view through right nostril of completed drillout. This labelled drawing corresponds to the postoperative photograph in Figure 9. quired to demonstrate the ultimate efficacy of this procedure, but we are encouraged by our initial results. We believe that this procedure provides many advantages over the osteoplastic frontal sinus obliteration for patients with severe persisting frontal sinusitis. The Lothrop procedure offers the patient a less invasive procedure with a shorter hospitalization (discharge usually the same day), less pain, less frontal and orbital edema, and
FIGURE 9. Postoperative photograph. GROSS ET AL
improved cosmesis. It also offers the advantage of the ability to evaluate postoperatively for recurrent disease, thus avoiding the diagnostic dilemma of frontal pain after frontal sinus obliteration. One possible limitation of this procedure would be for the treatment of diseased supraorbital cells, which could be inaccessible by this approach (personal communication, W. Montgomery, October, 1994). We have not encountered this problem to date. Because of the high incidence of delayed failures caused by stenosis after the Lnych-Howarth frontoethmoidectomy6 and other procedures that recreate frontal drainage, we have sought to develop an alternative procedure. We believe that the approach described in this report produces the largest opening anatomically possible. We sought to achieve a frontonasal communication that would be so large that inevitable scar contracture would not cause significant stenosis. Furthermore, ease of endoscopic follow-up in clinic allows intervention when necessary to prevent significant stenosis. Preservation of the mucosa of the posterior table and posterior nasofrontal duct and avoidance of the loss of external skeletal support inherent in Lynch-type external procedures should improve long-term patency. The drill system has built-in suction at the site of resection, which leads to improved visibility. As in otologic surgery, advanced bone-cutting drills can allow increased precision 199
compared with rongeurs or curettes. The procedure des c r i b e d in t h i s r e p o r t c r e a t e s a u n i q u e l y l a r g e f r o n t o n a s a l communication. O u r a p p l i c a t i o n o f a d v a n c e d drill t e c h n o l o g y h a s e n a b l e d u s to p e r f o r m t h i s p r o c e d u r e s a f e l y and expeditiously.
9. 10.
11.
REFERENCES 12. 1. Lothrop HA: Frontal sinus suppuration Ann Surg 59:937-957, 1914 2. Lawson W: Frontal Sinus Surgery of the ParanasaI Sinuses, (ed 2). Philadelphia, PA, Saunders, 1991 3. Kasper KA: Nasofrontal connections: A study based on one hundred consecutive dissections. Arch Otolaryngol 23:322-343, 1936 4. Van Alyea OE: Frontal sinus drainage. Ann Otol Rhinol Laryngol 55:267-277, 1946 5. Schaefer SD, Close LG: Endoscopic management of frontal sinus disease. Laryngoscope 100:155-160, 1990 6. Rice DH: Chronic frontal sinus disease Otolaryngol Clin North Am 26:619-622, 1993. 7. Rubin JS, Lund VJ, Salmon B: Frontoethmoidectomy in the treatment of mucocoeles. Arch Otolaryngol Head Neck Surg 112:434436, 1986 8. Neel HB, McDonald TJ, Facer GW: Modified Lynch procedure for
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13. 14.
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17.
chronic frontal sinus disease: Rationale, technique, and long-term results. Laryngoscope 99:885-895, 1989 Hardy JM, Montgomery WW: Osteoplastic frontal sinusotomy: Analysis of 250 operations. Ann Otolaryngol 85:523-532, 1976 Kennedy DW, Josephson JS, Zinreich SJ, et al: Endoscopic sinus surgery for mucoceles: A viable alternative. Laryngoscope 99:885895, 1989 May M: Frontal sinus surgery: Endonasal endoscopic ostioplasty rather than external osteoplasty. Oper Tech Otolaryngol Head Neck Surg 2:247-256, 1991 Draf W: Endonasal micro-endoscopic frontal sinus surgery: The Fulda concept. Oper Tech Otolaryngol Head Neck Surg 2:234-240, 1991 Wigand M, Hoseman W: Endoscopic surgery for frontal sinusitis and its complications. Am J Rhinol 5:85-89, 1991 Gross WE, Gross CW, Becker DG, et al: Modified transnasal endoscopic Lothrop procedure as an alternative to frontal sinus obliteration. Otolaryngol Head Neck Surg (in press) Goode RL, Streslow V, Fee WE: Frontal sinus septectomy for chronic unilateral sinusitis. Otolaryngol Head Neck Surg 88:18-21, 1980 Pope TH, Thompson WR: Treatment of chronic unilateral frontal sinusitis by removal of the interfrontal septum. South Med J 69:755, 1976 Gross CW, Gross WE: Post-operative care for functional endoscopic sinus surgery. ENT J, 73:476-479, 1994
MODIFIED TRANSNASAL ENDOSCOPIC LOTHROP