Transcolumellar Transcrural Approach to Transsphenoidal Hypophysectomy

Thr Laryngoscope Lippincott Williams & Wilkins, Inc., Philadelphia 0 1999 The American Laryngological, Rhinological and Otological Society, Inc.

How I Do It

Head and Neck and Plastic Surgery A Targeted Problem and its Solution

Transcolumellar Transcrural Approach to Transsphenoidal Hypophysectomy __ -

Richard L. Arden, MD; Raza Pasha, MD; Murali Guthikonda, MD

INTRODUCTION Evolution and refinements of surgical approaches to the sella turcica have spanned just over a century, with the first approach credited to Caton and Pau1,l who used a lateral subtemporal craniotomy. The need for improved visualization of the optic chiasm prompted the successful clinical application of frontal craniotomy for this purpose by Krause in 19092. The potential for reducing the inherent operative morbidity of a transcranial procedure was realized by Cushing,3who developed the sublabial transseptal transsphenoidal approach. Around this time, Hirsch4 described the more direct but limited endonasal transseptal approach. As clinical experience with the transsphenoidal route grew, largely through the influence of Hardy,5 concurrent with technical improvements in optics and instrumentation, interest in other techniques that further reduced morbidity and improved exposure evolved. Transseptal approaches to the sphenoid can broadly be categorized into three initial routes: sublabial, transcolumellar, and endonasal (Table I). With the sublabial approach, wide midline exposure is achieved without external scarring, but at the expense of increased operating distance and soft tissue collapse within the field of vision. Furthermore, the sublabial premaxillary dissection necessary for exposure contributes to soft tissue trauma, sensory disturbances of the upper central dentition, potential interference with denture wear, and possible disturbances of nasal form (with maxillary cresthasal spine resections). Transcolumellar approaches also provide wide midline access to the sphenoid at shorter operating distances and without manipulaFrom the Departments of Otolaryngology-Head and Neck Surgery and Neurosurgery (M.G.), Wayne State University School of Medicine, Detroit, Michigan. Editor's Note: This Manuscript was accepted for publication June 1, 1999. Send Correspondence to Richard L. Arden, MD, Department of Otolaryngology-Head and Neck Surgery, 4201 St. Antoine, UHC-5E, Detroit, MI 48201, U.S.A. (H.L.A., H.P.)

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tions of the upper lip, maxillary crest, or anterior nasal spine. Depending on the method chosen, an external scar is created with or without sensory changes of the nasal tip or potential for a weakened tip support structure. Endonasal approaches minimize operating site morbidity through limited septal incisions, but with compromise in three-dimensional exposure. The excellent direct midline exposure, expediency, and minimal morbidity associated with the transcolumellar, transcrural approach to the caudal septum has prompted us to adopt this method of transseptal access for a wide variety of pituitary lesions and nasal morphologic types. This report details our current operative technique and discusses the relative advantages and disadvantages in the context of other transseptal approaches.

TECHNIQUE In preparation for the procedure, preoperative nasal instillation of oxymetazoline is used to provide prolonged mucosal decongestion. Intraoperative nasal preparation includes infiltration of the columella, premaxilla, septum, and lateral nasal wall with 1%Xylocaine with 1:100,000 epinephrine. Gram-positive coverage is given prophylactically (1 g cefazolin), and a pharyngeal pack placed to protect the lower airway. Following proper head positioning and fluoroscopic placement, an inverted V (Rethi type) incision is marked along the narrowest portion of the columella. A No. 11 blade is used to incise the full thickness of the columellar skin only and is connected posteriorly to a complete septal transfixion incision (Fig. 1). To avoid the tendency for postoperative notching of the columellar closure line, the medial crura are transected several millimeters above the skin incision by upward dissection of the columellar skin flap (Fig. 2). Retention sutures of 3-0 silk are employed t o distract the columellar stumps superiorly and inferiorly, to optimize exposure of the caudal septum. Bacitracin ointment is applied to the stump ends to avoid desiccation Arden et at.: Transsphenoidal Hypophysectomy

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TABLE I. Transseptal Approaches to Sphenoid

-

Incisions(s)

Sublabial

Exposure

Morbidity

Upper half sphenoid sinus; midline

Good; potentially limited by depth and upper lip overhang

Potential numbness upper incisors Edema, ecchymosis/ hematoma upper lip Potential interference with denture wear

Rethi type + complete transfixion Rethi type

Lower half sphenoid sinus; midline Lower half sphenoid sinus; midline

Excellent

Small external scar Potential loss tip support Small external scar Nasal tip numbness/edema (temporary)

Killian

Lower half sphenoid sinus; just off midline

Kenan modified Hirsch approach

Hemitransfixion 2 alotomy

Lower half sphenoid sinus; midline

Endoscopic

Hemitransfixion

Opposite nostrils; 15-20” offset between endoscope and instruments

Transcolumellar Transcrural Open rhinoplasty approach Endonasal Hirsch

~

Approach Angle

Denker

__

__

during the procedure. Submucoperichondrial and submucoperiosteal elevation o f the entire hemiseptum and nasal floor i s typically performed ipsilateral t o the side o f septal spurring or deflection to facilitate elevation (Fig. 3). Posterior and inferior releasing incisions f r o m t h e septal osseocartilaginous j u n c t i o n a n d m a x i l l a r y crest, respectively, are made t o allow for graft retrieval, o r to mobilize t h e septum as a “swinging door” when no graft i s required (Fig. 4).In either case, contralateral submucoperiosteal elevation f r o m t h e m a x i l l a r y crest and nasal floor i s required to optimize posterior exposure (following introduct i o n of the pituitary speculum) and lessen the likelihood o f mucosal flap perforation. A vomeroethmoidal bone graft i s harvested a t t h i s t i m e and is preferred to t h e cartilage autograft when obtained i n t a c t and o f sufficient size. I f t h e septa1 bone graft i s inadequate, 1 to 1.5 cm dorsal and

Excellent

Fair; limited by unilateral incision and anterior septal attachment Fair-good; limited by columellar-alar distensibility Least 3-dimensional visibility

As for septoplasty As for septoplasty External scar if alotomy used As for septoplasty (anterior nasal structures not violated)

caudal strut-preserving incisions can be made in t h e quadrangular cartilage t o allow for maximum graft harvest. I f the t u m o r i s large, or i s extending i n t o an aberrant sphenoid sinus, the m i d l i n e exposure may n o t be adequate t o visualize the l a t e r a l extent o f t h e tumor. In such cases, a u n i l a t e r a l o r bilateral p a r t i a l middle turbinectomy may be employed t o improve t h e l a t e r a l exposure. At t h i s point,

_.Fig. 1. Inverted-Vtranscolumellar and complete transfixion incisions through skin only and mucosa, respectively.

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Fig. 2. Caudal septal exposure obtained following stepped medial crural transection and columellar flap retraction.

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S

n

Fig. 5. Medial crural reattachment with horizontal mattress suture technique.

Fig. 3. Septa1 and nasal floor mucosal flap elevations highlighting

retained attachment against hemiseptal surface. the transseptal transsphenoidal dissection proceeds similar to the sublabial approach. At closure, the caudal septal strut is reapprohated onto the maxillary crest and anterior nasal spine with a permanent 3-0 transperiosteal suture. The medial crura are reapproximated with a 4-0 Monocryl horizontal mattress suture to maintain tip projection and prevent override (Fig. 5). Interrupted 6-0 nylon is used to evert and coapt the columellar skin flap edges. Next, several 3-0 chromic septocolumellar sutures are placed to favor tip support using a Keith needle (Fig. 6). Finally, the anterior septal mucosal flaps are repositioned in the midline and approximated using a running horizontal 4-0 plain catgut suture. Symmetrical intranasal placement of Bacitracin-impregnated Nu Gauze (Johnson and Johnson Medical, Arlington, “X)is used to secure septal flap position and maintain hemostasis for 4 to 5 days. Antibiotic coverage continues throughout pack duration.

RESULTS Thirteen patients comprised the treatment group with an average age of 49 years (range, 27-65 y) and distri-

Fig. 4.“Swingingdoor” quadrangular cartilage release from maxillary crest inferiorly and bony septum posteriorly.

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bution of 6 men and 7 women. Of the group, five patients had functional adenomas; four were growth hormone secreting, the other adrenocorticotrophic hormone secreting. Four tumors were classified as microadenomas (< 1 cm in diameter), of which three were functional. Of the nine macroadenomas, size ranged from 1.5 to 4.2 cm with an average diameter of 2.9 cm. Intraoperative tumor extension was noted to be suprasellar in six patients, into the cavernous sinus in four patients, eroding into the sphenoid sinus in one patient, and into the middle fossa in one. The sella and sphenoid sinus were obliterated in a variable fashion. Seven patients had both obliterated with fat, three had the sella but not the sphenoid obliterated, two had the sphenoid but not the sella obliterated, and one patient had neither structure obliterated. In all cases, the sellar floor was reconstruded with bone derived from the nasal septum. Preoperative anatomical disturbances in septal positioning were seen in 9 of 13 patients (69%), which included bony and/or cartilaginous components. One patient presented with an anterior septal perforation that was unchanged following surgery performed by the authors, and two patients developed perforation iatrogenically secondary to pituitary speculum repositioning. The most common complication seen was diabetes insipidus (38%).One patient developed parosmia 8 days after surgery, which resolved following antibiotic management of sinusitis. Inferior turbinate hypertrophy and mucosal congestion were seen in

Fig. 6. Final closure of columellar flap with interrupted sutures, and horizontal septocolumellar mattress sutures used to close complete transfixion incision.

Arden et al.: Transsphenoidal Hypophysectomy

another patient for several months postoperatively, but improved with the use of topical nasal steroids.

DISCUSSION The decision to choose a particular transseptal approach to the sella turcica should be guided by the technical facility and experience of the surgeon, by the exposure afforded, and by the ability to minimize patient morbidity. Although reliable, the traditional sublabial transseptal approach has several shortcomings relative to these surgical goals. Given an average distance and position of the sphenoid rostrum from the nasal sill of 7 cm and 30 degrees of inclination, respectively, sublabial placement of a pituitary speculum extends the working distance from its proximal end to the tumor interface. In addition, exposure may be compromised at either end, particularly in patients with disproportionate skull base morphologic characteristics (i.e., acromegaly). With increased anteroposterior dimensions of the nasal cavity, the distal placement of the speculum may be inadequate to reflect the nasal mucosa overlying the sphenoid sinus far enough laterally. In cases of large macroadenomas or those with suprasellar extension, the ability to perform lateral sphenoidectomy with identification of the carotid canal and cavernous sinus can be significantly impeded by medial collapse of the mucosal flaps. Distal positioning also favors overhang of the upper lip at the level of the speculum head, hrther obscuring visualization. Maneuvers designed to retract the lip upward or retroposition it contribute to local soft tissue injury (ie., ecchymosis,edema). The need for a sublabial incision and premaxillary dissection contributes to additional patient morbidity in the form of more protracted midface edema, local discomfort, and possible hypoesthesia involving the distribution of the anterosupen o r alveolar nerve. Furthermore, denture wear may be compromised by incisional pain around the gingivolabialsulcus. By contrast, the transcolumellar transeptal route provides more direct midline access to the sella by shortening the necessary distance between it and the speculum head. The ability to laterally displace the posterior mucosal flaps from the lateral sphenoidal walls has been consistently achieved. The columellar retaining sutures provide unimpeded working access through the speculum head. By avoiding manipulations of the upper lip and premaxilla, patient recovery times have been shortened by 3 to 5 days. The average operating time in our hands for exposure and closure are 30 to 40 minutes and 20 minutes, respectively, which compares favorably with the sublabial approach. The potential disadvantages of this approach include placement of an external scar and disruption of a major tip-supporting structure (i.e., medial crura). With reconstitution of the medial crura and placement of septocolumellar supportive sutures, tip ptosis or columellar retraction has not been observed to date in the 13 patients who have had this type of surgery. Furthermore, medial crural reduction, with the goal of deprojecting and counter-rotating the nasal tip (Lipsett procedure),has led to predictable results in esthetic rhinoplasty and involves similar reapproximating sutures. The transcolumellar scar, a necessary component of open rhinoplasty, has been widely accepted by patients and endorsed by many rhinoplastic surgeons whose goal has been esthetic enhancement. Laryngoscope 109: November 1999

Several other variations of the transcolumellar approach have been described. Koltai et a1.6 adopted an external rhinoplasty approach that involves a midcolumellar incision and dissection between the medial crura to gain submucoperichondrial access to the caudal septum. This technique, while preserving the integrity of the central footpod, requires more tissue plane dissection and predictably would lead to more nasal tip edema and hypoesthesia secondary to the undermining process. In addition, provision for inferior placement of the pituitary speculum head and an acceptable approach angle requires premaxillary dissection with its associated morbidity, otherwise bypassed in the transcrural approach. Peters and Zitsch7 described a columellar flap technique involving labiocolumellar crease and complete transfixion incisions. This approach, while similar to ours, creates a longer, more visible external incision that is away from the shadow zone of the columella. With proximity to the perioral musculature, local discomfort (albeit subtle) may be enhanced by lip and mouth movements. The endonasal approaches conceptually afford the least morbidity en route to the anterior septum but do so, by comparison with transcolumellar approaches, at the expense of three-dimensional exposure. If an alotomy incision is requireds (about one-third of cases), the advantage of avoiding an external incision is lost. Endoscopic approaches offer minimally invasive surgery by avoiding anterior cartilaginous septa1 dislocation and have been used successfully to debulk pituitary macroadenomas.9 As a newer technique, a safety profile has not been established. The need for additional specialized equipment, predictably steep learning curve, and increased operating time should be considered. As a contingency plan, some form of open transsphenoidalapproach must be mastered before employing an endoscopic alternative.

CONCLUSION An alternative approach to sublabial or endonasal transseptal transsphenoidal hypophysectomy is described and rationalized which we believe contrasts favorably. The benefits of improved operative exposure, reduced operating time, and decreased patient morbidity are realized at the expense of a 4-mm columellar scar.

BIBLIOGRAPHY 1. Caton R, Paul FT. Notes of a case of acromegaly treated by operation. BMJ 1893;2:1421-423. 2. Collins WF. Hypophysectomy history and personal perspective. Clin Neurosurg 1973;21:68-78. 3. Cushing H. The Pituitary Body and Its Disorders. Philadelphia: J B Lippincott, 1912. 4. Hirsch 0. Endonasal method of removal of hypophyseal tumors. JAMA 1910;55:772-774. 5. Hardy J . Transsphenoidal microsurgery of normal and pathological pituitary. Clin Neurosurg 1968;16:185-217. 6 . Koltai PJ, Goldstein JC, Parnes SM, Price JC. External rhinoplasty approach to transsphenoidal hypophysectomy. Arch Otolaryngol 1985;111:456-458. 7. Peters GE, Zitsch RP. Columellar flap for transseptal transsphenoidal hypophysectomy. Laryngoscope 1988;98: 897-899. 8. Kenan PD. The rhinologist and the management of pituitary disease. Laryngoscope 1979;89(Suppl 14):l-26. 9. Rodziewicz GS, Kelley RT, Kellman RM, Smith MV. Transnasal endoscopic surgery of the pituitary gland: technical note. Neurosurgery 1996;39(1):189-193.

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