“Above and Below” FESS: Simple Trephine with Endoscopic Sinus Surgery

Chapter 23 “Above and Below” FESS: 23 Simple Trephine with Endoscopic Sinus Surgery

Ankit M. Patel, Winston C. Vaughan

Core Messages Background

í In most cases of frontal sinus disease, en- Historically, frontal sinus disease was treated using doscopic approaches are favored; however, external approaches, with the first written reports of in some situations where an endoscopic frontal trephination dating back to the late 1800’s. In approach is insufficient, an “above and be- 1921,Lynch reported on his experience and technique low” approach may be suitable, serving as of external frontoethmoidectomy. In the 1950’s and an alternative to more invasive procedures 1960’s,Montgomery popularized the osteoplastic flap approach with obliteration of the frontal sinus. í Situations where this may be considered In the late 1970’s,Messerklinger and Wigand intro- include large or laterally-based frontal si- duced endoscopic sinus surgery. Since that time, in- nus cells, lesions of the frontal sinus lateral creased emphasis has been placed on atraumatic, to the plane of the lamina papyracea, trau- mucosal-sparing endoscopic techniques that incor- ma, revision surgery, and complicated in- porate the natural drainage pathways of the parana- fection sal sinuses–“functional” endoscopic sinus surgery (FESS). This led to improved healing, preservation of í Endoscopic frontal sinusotomy is per- the mucociliary transport, and better results. In the formed first, followed by trephination mid 1980’s, image-guided surgery was introduced. Over the last two decades, there have also been tremendous advances in imaging.With these advances in imaging, knowledge of endonasal anatomy, instrumentation, and image-guided surgery, there has been an overwhelming move away from external ap- Contents proaches toward minimally invasive endoscopic ap- Background ...... 211 proaches for frontal sinus surgery [1–6]. Functional endoscopic sinus surgery is now considered the first- Technique ...... 212 line approach for frontal sinus disease. Table 23.1 Illustrative Case ...... 213 summarizes the major approaches to the frontal si- Conclusion ...... 218 nus most often used. References ...... 218 However, there are cases when the endoscopic technique itself is insufficient. In these cases, an external approach with frontal sinus trephination (above), along with endoscopic sinus approach (below) can provide improved visualization and allow for 212 Ankit M. Patel,Winston C.Vaughan

Table 23.1. Surgery for frontal sinus disease: from least aggressive to most aggressive treatment Technique

Anterior ethmoidectomy Decongestant-soaked pledgets are placed in the nasal Frontal sinusotomy cavity. The image-guidance system, if being used, is Frontal sinus rescue procedure calibrated and verified using known landmarks. Im- “Above and below FESS” (trephine + endoscopic surgery) age-guided systems can also provide a guide for the Unilateral “frontal sinus drillout” initial brow incision and external entry site. If image- Endoscopic modified Lothrop, Transseptal frontal guidance is not being used, the position and size of 23 sinusotomy the frontal sinus is confirmed on preoperative CT External ethmoidectomy / Lynch approach scan in relation to the supraorbital rim or with 6-foot Osteoplastic flap without obliteration Caldwell templates. Typically, incision and trephina- Osteoplastic flap with obliteration tion location will be through the medial eyebrow at the supraorbital rim without shaving this region. The endoscopic portion of the surgery is done first. A complete uncinectomy is performed. Superi- more precise surgery. This technique is especially orly, a complete uncinectomy will create additional useful for cases where endoscopic surgery is insuffi- space for endoscopic work as well as help to create a cient, but the osteoplastic flap approach is too ag- larger frontal sinus outflow drainage pathway. The gressive. These situations may include cases where superior uncinate process may attach to the middle there are large or laterally-based frontal cells that turbinate, lamina papyracea, or skull base. Review of cannot be approached safely endoscopically.A lesion preoperative CT scan films will identify its attach- in the frontal sinus that is lateral to the plane of the ment point. lamina papyracea on preoperative coronal CT scan Maxillary antrostomy is then performed to serve may suggest the need for an “above and below” ap- as a landmark. The ethmoid bulla may then be re- proach. Potential applications for this combined ap- moved via the retrobullar recess. Superiorly, this is proach are listed in Table 23.2. traced to the skull base. The lamina papyracea should be identified and preserved. The anterior ethmoid artery may often be identified at the skull base Table 23.2. Relative indications for “Above and Below” FESS at this point as well. Preoperative review of coronal CT scans will reveal a medial dimpling of the lamina Electively, for visualization to facilitate endoscopic frontal sinusotomy papyracea at the location of the anterior ethmoid artery. The artery may be dehiscent or coursing from Inability to completely address disease endoscopically: medial to lateral at a position inferior to the skull Laterally-based frontal sinus lesions base. In both these instances, the artery is at risk for Type III or IV frontal cell, which cannot be addressed injury. endoscopically If complete sphenoethmoidectomy is planned, it Large tumors or inflammatory lesions involving frontal may be performed at this time, with removal of pos- sinus, including: terior ethmoid cells and sphenoidotomy. The skull Osteoma base should be identified posteriorly, at the sphenoid Inverted papilloma face. It then is traced from posterior to anterior with Fibrous dysplasia removal of ethmoid cells along the skull base. If com- Trauma with distorted frontal recess or need to evaluate plete sphenoethmoidectomy is not necessary, then posterior frontal wall dissection may stop at the basal lamella, which is Revision cases with extensive scarring or neo-osteogen- traced to the skull base. esis Key landmarks should always be reconfirmed for Distorted anatomy in the frontal recess frontal recess dissection. Pott’s puffy tumor “Above and Below” FESS Chapter 23 213

These are: beveled to parallel the hair shafts of the eyebrow. No electrocautery should be used in the superficial der- mis, to prevent injury to hair follicles. Bipolar cautery í Lamina papyracea medially or pressure is less traumatic. í Skull base superiorly A self-retaining retractor is placed into the inci- í Anterior ethmoid artery superiorly and poste- sion. The incision is carried down to bone. Deeper riorly, which marks the start of the frontal hemostasis is carefully achieved with bipolar cautery. recess Next, a 4-mm drill bit is used to perform the external í The middle turbinate and its attachment trephine. The trephine may be enlarged using Kerri- to the skull base son rongeurs.Angled endoscopes (adult or pediatric) í The nasofrontal bone / beak are used to visualize the frontal sinus through the trephine. The remaining pathology of the frontal sinus may then be addressed via the trephine, with the The agger nasi cell, which is present in a majority of trephine enlarged (max: 6–8 mm) to accommodate patients, should be identified. Endoscopically, it will both endoscope as well as instrumentation. appear as a bulge of the lateral nasal wall at the junc- If the frontal sinus outflow tract is still not seen tion of the lateral nasal wall and the middle turbi- endonasally, the frontal sinus can be irrigated nate. This must be removed downward (uncapping through the trephine. The endoscope is used within the egg) in its entirety. Next, the frontal recess is the middle meatus to visualize the draining irriga- opened with mucosal preservation. Any frontal re- tion fluid (this can be colored with methylene blue). cess cells, supraorbital cells, and intersinus cells are This will facilitate further dissection. The endoscope opened endoscopically. Review of sagittal preopera- is now placed back through the trephine, and angled tive CT scans or image-guided scans is critical to instruments from within the nose are used to com- maximize the diameter of the frontal sinus drainage plete frontal sinusotomy. If necessary, a stent may be pathway. The frontal recess can then be enlarged us- placed upon completion of the above-and-below ing a combination of curved mushroom punches, gi- procedure from below and visualized from above. raffe forceps,seekers and limited use of microdebrid- The external incision is closed in layers using ab- ers. The mucosa of the frontal sinus should be pre- sorbable suture for deep tissues and permanent 5–0 served as much as possible to maintain the function- sutures for the skin. al nature of FESS. Once the endonasal frontal sinusotomy has been completed to its full extent, then the external ap- Illustrative Case proach is begun. Sometimes, due to tumor, trauma, previous surgery, or the patient’s anatomy, endoscop- This patient has a laterally-based frontal sinus muco- ic frontal sinusotomy cannot be completed endo- cele with left forehead pain, and has failed medical scopically. In these cases, as much as possible of the treatment. There is a large obstructing type III fron- previously described dissection is performed in a tal cell. Because of the large size of the frontal cell, the safe fashion. Trephination and endoscopic visualiza- patient was counseled regarding the possible need tion through the trephine may also facilitate further for trephination in conjunction with FESS. Intraop- dissection from below. eratively, the lateral wall of the type III frontal cell The external approach field is now prepped. If im- could not be sufficiently opened endoscopically from age guidance is being used, it is used to confirm the below.“Above and below” FESS with the addition of a optimal eyebrow incision and frontal sinus entry simple trephine was performed, to remove more of point. Lidocaine with epinephrine is used to infiltrate the lateral border of the type III frontal cell and drain the eyebrow incision. A 1–2-cm incision is carried the mucocele.Figures 23.1–21.9 illustrate the anatomy through the medial eyebrow. The incision should be and technique. 214 Ankit M. Patel,Winston C.Vaughan

Fig. 23.1. A laterally-based mucocele, symptomatic and persistent despite medical management. A large, obstructing type III frontal cell is present

Fig. 23.2. Endoscopic approach, at the base of the type III frontal cell, above agger nasi and at the ‘beak’ “Above and Below” FESS Chapter 23 215

Fig. 23.3. Cross-hairs depict dissection of the type III frontal cell medially

Fig. 23.4. Laterally-based mucocele, endoscopic view. En- donasal instrumentation is insufficient to take down the lateral septa- tion sufficiently and drain the mucocele. At this point, trephination is needed to help facilitate more complete surgery 216 Ankit M. Patel,Winston C.Vaughan

Fig. 23.5. External approach. Im- age-guidance is used to confirm incision site and entry point of trephination through the medial eyebrow

Fig. 23.6. Trephination incision. Alcohol- prepped image-guidance headset is in place. This may be retracted and put back into position as needed “Above and Below” FESS Chapter 23 217

Fig. 23.7. Reverse 70° endoscope through trephine site. Curved (90°) giraffe forceps used endonasally under endoscopic visualization from above

Fig. 23.8. Angled endoscope through trephine looking down into recess from above. Angled image-guidance suc- tion from below, guided by endoscope from above 218 Ankit M. Patel,Winston C.Vaughan

Fig. 23.9. Additional instrumentation for frontal sinus trephination

Conclusion References t 1. Benoit CM, Duncavage JA (2001) Combined external and endoscopic frontal sinusotomy with stent placement: A ret- rospective review. Laryngoscope 111 (7) : 1246–1249 While endoscopic approaches are preferred for 2. Bent JP 3rd et al (1997) Combined endoscopic intranasal management of disease of the frontal sinus, in some and external frontal sinusotomy. Am J Rhinol 11 (5) : situations,transnasal techniques alone will not allow 348–354 sufficient access to the frontal sinus. One alternative 3. Chiu AG, Vaughan WC (2004) Revision endoscopic frontal in these cases to more aggressive open approaches sinus surgery with surgical navigation. Otolaryngol Head Neck Surg 130(3) : 312–318 is the “above and below” approach utilizing a small 4. El-Silimy O (1996) Combined endonasal and percutaneous trephination to assist the dissection. This technique endoscopic approach to Pott’s puffy tumour. Rhinology 34 allows access to lesions located cephalad and later- (2) : 119–122 ally in the frontal sinus,and may also be beneficial in 5. Gallagher RM, Gross CW (1999) The role of mini-trephina- the setting of trauma, revision surgery, and compli- tion in the management of frontal sinusitis. Am J Rhinol 13 (4) : 289–293 cated acute sinusitis. This simple technique is well- 6. Gerber ME, Myer CM 3rd, Prenger EC (1993) Transcutane- tolerated by patients and may be easily incorporat- ous frontal sinus trephination with endoscopic visualiza- ed into the rhinologist’s practice. tion of the nasofrontal communication. Am J Otolaryngol 14 (1) : 55–59