45 Transsphenoidal Hypophysectomy: Postsurgical CT Findings Carol A. Dolinskas' Transsphenoidal surgery produces changes in the parana sal sinuses and sella that Frederick A. Simeone2 should be familiar to radiologists in view of the frequency of this type of surgery. Some of these changes, such as soft-tissue-density debris in the sinuses, are transient. Fat and other packing material identifiable in the sinuses and sella after surgery is perma­ nent. The procedure is associated with a variety of complications that are readily detectable by computed tomography (CT). These include bleeding, compression of para sellar structures by packing material, cerebrospinal fluid leaks, and pneumoceph­ alus. After a transsphenoidal procedure, with or without follow-up radiation therapy, residual enhancing intrasellar and parasellar lesions may still be identified. Transsphenoidal surgery is considered safe and effective and is the procedure of choice for removal of intrasellar lesions. In view of the frequency with which it is currently performed, the radiologist evaluating the computed tomographic (CT) scans of patients who have had transsphenoidal surgery should be aware of those changes normally produced by the procedure as well as those caused by compli­ cations. This report is based on a review of the posttransphenoidal CT studies in 50 patients and was initiated to attempt to define how a transsphenoidal hypophy­ sectomy alters the appearance of the sella and parasellar region . Transsphenoidal surgery is indicated with intrasellar tumors. It is also indicated when a sellar tumor is associated with cerebrospinal fluid (CSF) rhinorrhea, pituitary apoplexy, or primary extension into the sphenoid sinus [1] and when removal of the pituitary gland is performed for palliation of pain due to metastases [2 , 3] . It is an effective, rapid , decompressive procedure in situations where vi sion is severely compromised and transcranial manipulation of visual structures might endanger remaining vision [4, 5] . Even lesions with prominent suprasellar extension may be approached transsphenoidally as decompression of the mass, rather than complete removal of the tumor, is the primary goal of surgery [1 , 3, 5, 6]. The transsphenoidal approach is contraindicated when the sellar lesion involves the brain [7 , 8] , cavernous sinus, or middle fossa [1 ,7, 9] . Dumbbell-shaped tumors constricted at the diaphragm are best approached transcranially [1 , 4] . Relative contraindications to the trans sphenoidal approach include an incompletely pneu­ This article appears in the January/February matized sphenoid sinus [1 , 7], nasal or sinus infection [4], and a previous craniot­ 1985 issue of AJNR and the March 1985 issue of omy for a sellar lesion [9]. AJR. After the appropriate intrasellar procedure has been completed, pieces of muscle Received January 12, 1983; accepted after re­ vi sion July 2, 1984. or fat, usually taken from the patient's thigh or abdomen, or Gelfoam or Surgicel are used to pack the sella and sphenoid sinus. Pi eces of resected bone or Silastic 1 Department of Radiology, Pennsylvania Hos­ pital, Eighth and Spruce Sts., Philadelphia , PA material are frequently used to reconstruct the floor of the sella and the face of the 19107. Address reprint requests to C. A. Dolinskas. sphenoid sinus [1, 3, 7, 10, 11 ]. 2 Department of Neurosurgery, Pennsylvania Hospital, Philadelphia, PA 191 07. AJNR 6:45-50, January/February 1985 Materials and Methods 0195-6108/85/0601 - 0045 $00.00 © American Roentgen Ray Society We reviewed CT scans obtained between August 1976 and August 1983 and found 50 46 DOLINSKAS AND SIMEONE AJNR :6, Jan/Feb 1985 cases in which one or more examination was performed after trans­ apoplexy. In other reports, evidence of pituitary apoplexy has sphenoidal hypophysectomy. The postoperative studies were per­ been found in asymptomatic patients [12]. formed within hours to 5 years after surgery. In 29 patients, 33 All of the CT examinations in the immediate postoperative studies were performed within 1 week after transsphenoidal hypo­ period demonstrated changes in the sinuses related to the physectomy. In most of these cases, the development of symptoms procedure itself (fig. 1). In the maxillary and ethmoid sinuses, prompted the CT examination. In the rest, the studies were indicated as baseline examinations for evaluation of future therapy. soft-tissue density representing mucosal thickening, blood , Of the 94 available postoperative scans, 57 were obtained with and postoperative debris was found . The density in the sphe­ and without contrast enhancement (a bolus of 28.2-42.3 g I) and noid sinus ranged from fat to bone and depended on the type seven were obtained only after enhancement. In the other 30 cases, of packing material used during the procedure. The frontal contrast material was not used. sinuses were not involved. On follow-up studies, the density in the maxillary and ethmoid sinuses disappeared sponta­ neously within the first 2 months after surgery, but the ab­ Results normal density in the sphenoid sinus, especially the high At surgery, a spectrum of pathology was encountered (table density related to bone chips or Silastic material, persisted 1). Six of the patients had operative findings suggesting unchanged for years. previous pituitary apoplexy. In only one of these patients, In 23 cases low density in the range of fat was identified however, were symptoms and CT findings compatible with within the sella on CT examinations within 1 year after sur­ gery. In five cases, fat was present in the sella on studies 1 year or more after surgery. In eight cases in which intrasellar TABLE 1: Indications for Transsphenoidal Hypophysectomy fat could be identified on postoperative scans, the fat density eventually became smaller or disappeared. No. of Pathology Cases On the postoperative CT examinations of 23 patients, Functioning tumor: residual enhancing lesions were identified on studies 4 days Prolactin 5 to 5 years 8 months after surgery (fig. 2). Seven of these Growth hormone 8 patients had functioning adenomas (table 2), and in each case ACTH 4 elevated hormone levels were demonstrated postoperatively Subtotal 17 correlating with persistent tumor, as suggested by the pres­ Nonfunctioning tumor: ence of contrast enhancement. Most of the patients whose Adenomas . .. ...... 20 studies did not demonstrate residual tumor were not followed Pituitary carcinoma 1 and their endocrine status was not known. Metastatic 3 Craniopharyngioma . 1 Twelve patients with pituitary adenomas had CT examina­ tions after completion of postoperative radiation therapy. On Subtotal 25 the scans of four of these patients, obtained 1-4 years after Other: surgery, no intrasellar pathology was identified. In one case, Normal (hypophysectomy for relief of pain from metastases) . 2 the patient had a persistently elevated prolactin level despite Necrotic pituitary gland 4 lack of visualization of a lesion . No endocrine follow-up was Unknown .. .. ....... 2 available for the other three patients. Eight patients who had Subtotal 8 received postoperative radiation therapy had residual enhanc­ Total . 50 ing lesions on studies 100 days to 3.5 years after surgery, but in none of these cases was there evidence of growth of Fig. 1.-Contrast-enhanced trans­ verse axial (A) and coronal (8) scans 5 days after transsphenoidal hypophysec­ tomy. Soft-tissue-density material in eth­ moid and sphenoid sinuses (straight ar­ rows). Linear density (arrowheads) rep­ resenting piece of Silas tic material used to reconstruct sellar floor has been dis­ lodged, probably by aggressive packing of sphenoid sinus, and it is now within sella. Fat (curved arrows) used as pack­ ing material is also present within sella. AJNR:6, Jan/Feb 1985 TRANSSPHENOIDAL HYPOPHYSECTOMY 47 Fig . 2.-26-year-old man with prolac­ tin-secreting pituitary adenoma. A, Con­ trast-enhanced coronal scan before sur­ gery. Large intra sellar tumor has eroded sellar floor and fills sphenoid sinus (ar­ row). B-O, After surgery. B, Unenhanced transverse axial section. Enhanced coro­ nal (C) and transverse axial (0) scans. Persistence of large, enhancing lesion (straight solid arrow). Fat (arrowheads) and a Silastic bar (curved arrow). Small focus of bleeding (open arrow) at poster­ osuperior aspect of tumor. A B c o TABLE 2: Changes Seen on CT after Transsphenoidal the pituitary lesion on serial studies (fig . 3) . Of the patients Hypophysectomy with residual enhancing lesions, five had nonfunctioning ade­ nomas. Two patients with prolactin-secreting lesions and one No. of Patients (n Change = 50) with a growth-hormone-secreting tumor had persistent ele­ In sinus 35- vations of hormone levels after radiation therapy. Fat within sella . 23 Numerous complications of the surgical procedure were Residual enhancement: encountered in our series, and several of these produced Nonfunctioning tumor 11 demonstrable abnormalities on postoperative CT scans . In Prolactin-secreting tumor . 5t Growth-hormone-secreting tumor . _ . 2t six cases, the development of visual signs and symptoms Carcinoma . .......... 3 (new field abnormalities, diplopia, cranial nerve palsies) Unknown functional status .. .. 2 prompted the postoperative CT examinations. In one case, Total .......... .. .. .. 23 an excessive amount of fat was discovered in the suprasellar Other: cistern. In two cases, bone density was present in the supra­ Excess suprasellar fat ....... .. 1 sellar cistern . One of these patients required a second surgical