Minimizing upper lip and incisor teeth paresthesias in approaches to transsphenoidal surgery

Minimizing upper lip and incisor teeth paresthesias in approaches to transsphenoidal surgery SCOTT R. SCHOEM, MD, FAAP,ANJUM KHAN, MD, FACS,WILLIAM R. WILSON, MD, FACS,and EDWARD R. LAWS,MD, FAC$, Bethesda, Maryland, Washington, D.C., and Charlottesville, Virginia Currently popular transsphenoidal approaches to the pituitary include sublabial, external rhinoplasty, alotomy, and transnasal techniques. The conventional sublabial approach remains the workhorse method despite postoperative lip edema, potential difficulty for denture wearers, and troublesome persistent upper lip and incisor teeth numbness. We traced the courses of the nasopalatine, infraorbital, and anterior superior alveolar nerves in 41 cadaveric half-head dissections to determine the exact contribution to upper lip and incisor teeth innervation. We then conducted a retrospective patient survey of 25 sublabial, 28 external rhinoplasty, 23 alotomy, and 12 transnasal approaches to the hypophysis to assess the incidence of upper lip and incisor teeth paresthesias lasting longer than I month. We conclude that rhinoplastic techniques are superior to the sublabial approach in limiting upper lip and incisor teeth numbness without compromising neurosurgical exposure for hypophysectomy. (Otolaryngol Head Neck Surg 1997;116:656-61 .) T h e pioneering efforts of Harvey Cushing and his impressive series of transseptal, transsphenoidal approaches to hypophyseal and sphenoidal lesions remain legendary neurosurgical advances of the twentieth century. 1 Since Cushing's first case report in 19092 of pituitary tumor removal in an acromegalic patient, the extracranial approach has been the preferred means of access to the hypophysis. Though Hirsch 3 and Dott and Bailey 4 were faithful adherents to this approach and reported large series of their own, Cushing eventually abandoned the technique because of technical limitations. Yet his keen insight predicted a return to this approach with appropriate scientific advances. With the advent of the surgical microscope, antibiotics, endocrine replacement therapy, and advanced From the UniformedServices Universityof the Health Sciences (Dr. Schoem), the GeorgeWashingtonUniversityMedical Center (Drs. Khan and Wilson); and the Department of Neurosurgery (Dr. Laws), Universityof Virginia. Presented at the Midwinter Southern Section Meeting of. the Triological Society,Boca Raton, Fla., Jan. 15, 1993. Reprint requests: Scott R. Schoem, MD, FAAP, Department of Otolaryngology, Children's National Medical Center, 111 Michigan Ave., NW, Washington, DC 20010-2970. Copyright © 1997 by the American Academy of OtolaryngologyHead and Neck SurgeryFoundation, Inc. 0194-5998/97/$5.00 + 0 2311/73201 656 imaging capability, Guiot 5 and Hardy 6 repopularized and refined the extracranial, sublabial approach. In 1958, Cottle et al.7 introduced the "maxilla-premaxilla" approach, which emphasizes "the nose before the lip" technique, whereby septal flaps are created before the lip incision is made. Calcaterra and Rand 8 and Laws and Kern 9 adopted and modified the technique with extensive intranasal dissection followed by connection to a sublabial incision and placement of the self-retaining speculum under the lip. The sublabial technique provides excellent exposure, albeit with significant disadvantages. These include an overhanging upper lip during surgery, postoperative lip edema, loss of nasal projection if the nasal spine is resected, and potential trouble from the sublabial incision itself for denture users. Recently, several surgeons have noted patient complaints of temporary-and occasionally permanent--upper lip and incisor teeth paresthesias. However, no author quantitates the degree and length of this discomfort. In a significant advance, Tucker and Hahn 1° described a totally transnasal, transseptal approach with requisite alatomy in one third of patients, They note absence of upper incisor teeth numbness in their series, but fail to mention why their technique eliminates this problem. The external rhinoplasty technique was developed in Europe by Rethi in 193411 and introduced to North America by Padovan in 1966.12 Koltai et al.13 reported OtolaryngologyHead and Neck Surgery SCHOEM et ai. 657 Volume 116 Number 6 Part 1 on the use of the external rhinoplasty approach to hypophysectomy in 1985. They claimed a decreased rate of upper incisor teeth numbness due to limited dissection around the nasal spine and piriform aperture. However, they do not provide data on the incidence of paresthesias, length of time and degree of numbness, and ultimate patient dissatisfaction. Wilson et al. 14 describe the advantages and disadvantages of several transseptal techniques based on a review of 147 patients. In this report, we further elucidate our previously published findings and compare new data with another transseptal technique, the transnasal approach. A two-part study was conducted to determine the incidence, degree, and length of time of upper lip and incisor teeth numbness after transsphenoidal surgery. The first part of the study included the anatomic dissection of 41 cadaveric half-head specimens to clearly define the course of the nasopalatine nerve (NPN), infraorbital nerve (ION), and anterior superior alveolar nerve (ASAN). Anatomic texts indicate the relative contribution of each nerve to the upper lip and incisor teeth, but do not demonstrate the degree of course variability or redundancy of innervation.15,16 The second part of the study was a retrospective questionnaire sent to 100 patients who had undergone transsphenoidal surgery by sublabial, external rhinoplasty, alotomy, and transnasal approaches. We queried specifically about postoperative incisor teeth and upper lip numbness persisting longer than 1 month. Through anatomic dissection and clinical correlation, we sought to determine which technique offered the lowest morbidity for these parameters. Furthermore, we wished to discover any modification in existing techniques to optimize nerve preservation. MATERIALS AND METHODS Part A Forty-one cadaveric half-head specimens were used to trace the courses of the infraorbital (ION), anterior superior alveolar (ASAN), and nasopalatine (NPN) nerves. Equipment consisted of an otologic microscope, curettes, otologic drill, and other standard dissecting instruments. Patterns of innervation were recorded for comparison with published texts. Dissection was performed in the anatomy laboratory at the Uniformed Services University of the Health Sciences (S. S.). Part B Questionnaires were sent to 100 serial patients who had undergone a transsphenoidal approach to the hypophysis for tumor resection between October 1988 Fig. I. Photograph demonstrating the usual ASAN innerration of the central and lateral incisor teeth. and October 1991. All surgery was per~'ormed jointly by the Division of Otolaryngology-Head and Neck Surgery (A. K. and W.R.W.) and the Department of Neurosurgery (E.R.L.) at the George Washington University Medical Center. Patients were asked to comment specifically on the degree, length of time, and resolution of both upper lip and incisor teeth paresthesias. Participants were further asked to describe if and how any numbness o1"tingling impaired their ability to perform their daily routines. Inclusion criteria were any subjective perceptions of numbness persisting longer than 1 month after surgery. RESULTS Plan A Of 41 cadaver specimens, 12 contained edentuIous maxillae and 10 had no septum in which to trace the NPN. In all specimens, the ION had no bony involvement in its course. The ION solely innervated the lip. There were no innervations of the incisor teeth and no anastomoses with the ASAN distal to the incisor teeth. OtolaryngologyHead and NeckSurgery June 1997 658 SCHOEM et al. Fig. 2. Photograph demonstrating the usual course of the NPN into the incisive foramen. Fig. 3. The unusual course of the NPN remains entirely extracanalicular innervates the central incisor tooth. The ASAN was identified in all 41 specimens. It was twice found to be externally dehiscent on the medial antral surface, In all cases, the ASAN innervated both the central and lateral incisor teeth (Fig. 1). Moreover, all specimens had a medial branch leading to the piriform aperture and nasal floor. The NPN was carefully and tediously traced in its anteroinferior course along the nasal septum. Twentytwo cases exhibited the traditional course into the incisive foramen (Fig. 2). However, in two of these cases a clearly identifiable extracanalicular terminal branch also innervated the ipsilateral central incisor tooth. And (arrow) and, thereby, in one separate cadaver specimen, the NPN completely remained extracanalicular with direct innervation of the central incisor tooth, providing dual innervation with the ASAN (Fig. 3). There was no evidence of contralateral incisor innervation by terminal branches. Part B Eighty-eight of 100 patients responded to the questionnaire. Of these, 25 had undergone the sublabial approach, 28 the external rhinoplasty approach, 23 the alotomy approach, and 12 the transnasal approach. In each operation, regardless of the particular technique OtolaryngologyHead and Neck Surgery SCHOEM et al. 659 Volume 116 Number 6 Part 1 Fig. 4. Sublabial transseptal approachmthis requires the greatest amount of soft tissue dissection, especially at the piriform apertures. Fig. 5. External rhinoplasty approach--notice the slightly more horizontal angle to the hypophysis than through the sublabial approach. Table 1. Postsurgical paresthesias Approach Sublabial ' External rhinoplasty AIotomy Transnasal No. of patients 25 28 23 12 Poresthesias at I month after surgery (%) Upper lip alone incisor teeth alone Both upper lip and incisor teeth 1 (4) 0 3 (12,9) 3 (24.9) for access to the hypophysis, the exposure was deemed adequate by the operating neurosurgeon. Ten patients in the sublabial group reported both incisor teeth and upper lip numbness (40%). One patient noted upper lip numbness alone (4%). Eight patients noted persistence of both incisor teeth and upper lip numbness for over 6 months. Two patients had upper lip numbness alone for over 6 months. The total incidence of upper lip numbness alone was 44%. One patient in the external rhinoplasty group reported both incisor teeth and upper lip numbness (3.6%). The lip numbness was described as limited to the region below the columella. The lip numbness alone persisted for over 6 months. One patient in the alotomy group reported both incisor teeth and upper lip numbness (4.3%). The tooth numbness alone lasted for over 6 months. Three patients noted upper lip numbness alone (12.9%). The total incidence of upper lip numbness was 17.2%. 0 0 0 0 10 (40) 1 (3.6) 1 (4.3) 1 (8.3) One patient in the transnasal group reported both incisor teeth and upper lip numbness (8.3%). Three patients noted upper lip numbness alone (24.9%). Two of these three patients noted persistence of symptoms for over 6 months. The total incidence of upper lip numbness was 33.2%. Table 1 summarizes these results. DISCUSSION It is not the purpose of this report to promote or denigrate a particular surgical approach for access to the hypophysis. In the evolution of operative technique, the pure sublabial method led to the transnasal-sublabiat, modified transnasal-sublabial, and then purely rhinoplastic techniques without compromising neurosurgical exposure. All methods provide adequate exposure of the sella for microscopic neurosurgical hypophysectomy. (Figs. 4-7 depict each technique.) A neurosurgeon who only occasionally performs this operation may OtolaryngologyHead and Neck Surgery June 1997 660 SCHOEM et al. Table 2. A d v a n t a g e s a n d d i s a d v a n t a g e s o f four transseptal a p p r o a c h e s \ Fig. 6. Transseptal approach with alotomy--this provides a well-hidden external scar, excellent for reoperation or previous septoplasty. % ' ,.,~ ., " Fig. 7. Transnasal transseptal--this is g o o d for use in the large nose, with a minimal external scar resulting. have a predisposition to the sublabial approach due to familiarity. Although rhinoplastic techniques do alter the angle of exposure to a slightly more horizontal plane, they do not limit access to the sella. Each approach has its particular advantages and disadvantages (Table 2). I. Sublabial transseptal approach A. Advantages 1. Relatively easy procedure 2. Retractor in midline at good angle to pituitary 3. No external scar 4. Minimal or no postoperative nasal deformity 5. Good for small and large noses B. Disadvantages 1. ©ral contamination of wound 2. Oral incision causes problems for denture wearers 3. Greatest chance of postoperative dental and lip numbness II. External rhinoplasty technique A. Advantages 1. Retractor in midline, angle to pituitary slightly lower than sublabial approach 2. Avoids oral cavity scar 3. Small external incision 4. Easier to dissect floor of nose than with sublabial approach because of direct vision 5. Able to correct preoperative nasal asymmetry 6. Good for small and large noses B. Disadvantages 1. 10% of columellar incisions are noticeable because of edema of upper columella or inaccurate reapproximation of skin incision 2. Requires more meticulous closure than sublabial approach 3. Requires more postoperative care than sublabial approach 4. Added potential for postoperative nasal deformity if poor healing Ill. Transseptal approach with alotomy A. Advantages 1. Avoids oral cavity scar 2. Septal incision can be placed either anteriorly or posteriorly at the ethmoid plate edge 3, Faster technique than sublabial or external rhinoplasty 4. Heals well with minimal external scar 5. Posterior eeptal incision ideal for reoperation or previous septoplasty B. Disadvantages 1. Requires a relatively large nose, especially for posterior incision 2. Retractor not directly in midline 3. Well-hidden but noticeable external scar IV. Transnasal transseptal A. Advantages 1. Avoids oral cavity scar 2. Fast technique with minimal intranasal dissection 3. Minimal postoperative care required 4. Heals very well with minimal external scar B. Disadvantages 1. Only in large noses 2. Retractor may be slightly off midline Yet some generalizations hold true. First, avoiding the sublabial incision eliminates upper lip numbness and poor postoperative fit for denture wearers. Second, limiting dissection laterally at the piriform apertures results in fewer incisor teeth paresthesias. OtolaryngologyHead and Neck Surgery Volume 116 Number 6 Part 1 Of all the techniques, the sublabial approach necessitates maximal dissection at the nasal spine and the piriform aperture. In contrast, the transnasal approach limits dissection at the nasal spine; however, disruption at the piriform aperture is almost unavoidable. Similarly, alotomy avoids dissection at the spine, but cannot circumvent dissection around the piriform aperture. Also, there exists greater potential for disruption of the ION and subsequent upper lip numbness. Therefore, one clear advantage of the external rhinoplasty technique over other methods becomes readily apparent. Using a higher plane of dissection within the nose, the external rhinoplasty limits nasal spine, maxillary crest, and piriform aperture disruption. Consequently, this should avoid incisor teeth paresthesias. In addition, as Tucker and Hahn have previously noted, 1° this slightly lower angulation of dissection within the nose may actually help protect the neurosurgeon from causing inadvertent injury to the optic chiasm or great vessels within the cavernous sinus. Also, lack of a sublabial incision should minimize upper lip numbness. The one patient in this group who developed upper lip numbness presumably sustained more extensive dissection than routinely performed for neurosurgical exposure. It is obvious that the N P N is not vital for tooth root innervation. Otherwise, every patient who underwent a septoplasty with separation of septal cartilage from the maxillary crest would be at risk for upper central incisor tooth paresthesias. This complication does occur, but rarely. Rather, the problem appears to be caused by disruption of the A S A N in its usual anteroinferior course at the piriform aperture and in the occasional external dehiscence on antral bone. Because the majority of patients do not develop upper lip or incisor teeth numbness, such numbness is most likely caused by contralateral A S A N rather than ipsilateral NPN innervation. In conclusion, the incidence of upper lip and incisor teeth paresthesias appears most with the sublabial approach and least with the external rhinoplasty technique. Other purely rhinoplastic methods provide intermediate results. Rhinoplastic approaches to the hypophysis, especially the external rhinoplastic method, optimize nerve preservation without limiting surgical exposure for neurosnrgical colleagues. Although the authors have experience with the endoscopic approach for biopsy of sphenoid and sellar SCHOEM et al. 66] tumors, none has attempted endoscopic curative resection at this juncture. Perhaps further evolution of the endoscopic method will eliminate the problem of paresthesias and other access-related morbidity. CONCLUSIONS First, all surgical approaches in this study provide adequate neurosurgical exposure for extirpation of pituitary neoplasms. The slight difference in angle afforded by each approach presents no difficulty in tumor resection for the experienced neurosurgeon. Second, the incidence of upper lip and incisor teeth paresthesias appears most with the sublabial approach and least with the external rhinoplasty technique. The alotomy and transnasal techniques provide intermediate results. We thank Ms. Diana Pino for her expert illustrations. REFERENCES l. Cushing H. Operative experiences with lesions of the pituitary body. Trans Am Surg Assoc 1913;31:467-8. 2. Cushing H. Partial hypophysectomy for acromegaly: with remarks on the function of the hypophysis. Ann Surg 1909;50:1002-17. 3. Hirsch O. Endonasal method of removal of hypophysealtumors: with report of two successful cases. JAMA 1910;55:772-4. 4. Dott NM, Bailey D. A consideration of the hypophysealedenomata. Br J Surg 1925;13:314-66. 5. GuiotG. Transsphenoidal approachin surgical treatment of pituitary adenomas: general principles and indications in non-functioning adenomas. Exerpta Medica International Congress 1973;Series No. 303:159-78. 6. Hardy J. Transsphenoidal Hypophysectomy. J Neurosurg 1971;34:582-94. 7. Cuttle MH, Luring RM, Fischer GG, et al. The "maxilla-premaxilla" approach to extensive nasal septum surgery. Arch Otolaryngot 1958;68:301-13. 8. Calcaterra TC, Rand RW. Current adjuncts for surgery of the sphenoid sinus and pituitary gland. Laryngoscope 1976;86:1692-8. 9. Laws ER, Kern EB. Complications of transsphenoidal surgery. Clin Neurosurg 1976;23:401-16. 10. Tucker HM, Hahn JE Transnasal, transseptal sphenoidal approach to hypophysectomy,Laryngoscope 1982;92:55-7. 11. RethiA. Operation to shorten an excessivelylong nose [abstract]. Rev Chir(plast) 1934;2:85. 12. PadovanI. External approachto rhinoplasty (decortication).Ann Otol Rhinol Laryngol 1966;354:3-4. 13. Koltai PJ, Goldstein JC, Parnes SM, et al. External rhinoptasty approach to transphenoidal hypophysectomy.Arch Otolaryngol Head Neck Surg 1985;111:456-8. 14. WilsonWR, KhanA, Laws ER. Transseptal approaches for pituitary surgery. Laryngoscope1990;100:817-9. 15. PernkopfE. Atlas of topographical and applied human anatomy. Vol. I: head and neck. 2nd ed. Baltimore: Urban and Schwarzenberg; 1980:148-53. 16. Hullinshead WH. Anatomy for surgeons: the head and neck, vol. I. 3rd ed. Philadelphia: Harper & Row, 1982:327-33.