Volume 40, Number 2
February 1997
Interactive Article

TOPIC REVIEW

Complications of Transsphenoidal Surgery: Results of a National Survey, Review of the Literature, and Personal Experience

Ivan Ciric, M.D., Ann Ragin, Ph.D., Craig Baumgartner, P.A.-C., M.B.A., Debi Pierce, B.S.

Division of Neurosurgery, Evanston Hospital, Northwestern University Medical School, Evanston, Illinois

OBJECTIVE: The primary objectives of this report were, first, to determine the number and incidence of complications of transsphenoidal surgery performed by a cross-section of neurosurgeons in the United States and, second, to ascertain the influence of the surgeon's experience with the procedure on the occurrence of these complications. The secondary objective was to review complications of transsphenoidal surgery from the standpoint of their causation, treatment, and prevention.

METHODS: Questionnaires regarding 14 specific complications of transsphenoidal surgery were mailed to 3172 neurosurgeons. The data reported were analyzed from the 958 respondents (82%) who reported performing the operation. The neurosurgeons surveyed were asked to estimate the number of transsphenoidal operations performed, to identify any complications observed, and to estimate the percentage of operations that had resulted in any of the 14 specific complications. The 958 respondents were placed into three experience groups, based on the number of transsphenoidal operations performed. The data were analyzed by using X2 tests and Spearman correlation coefficients. The secondary objectives were met through a detailed review of the literature, in light of our experience.

RESULTS: Of the respondents, 87.3% reported having performed <200 operations and 9.7% reported 200 to 500 previous operations. The remaining 3% reported more than 500 previous operations. More extensive previous experience with transsphenoidal surgery was associated with a greater likelihood of having witnessed each specific complication. The mean operative mortality rate for all three groups was 0.9%. Anterior pituitary insufficiency (19.4%) and diabetes insipidus (17.8%) were complications with the highest incidence of occurrence. The overall incidence of cerebrospinal fluid fistulas was 3.9%. Other significant complications, such as carotid artery injuries, hypothalamic injuries, loss of vision, and meningitis, occurred with incidence rates between 1 and 2%. An inverse relationship was found between the experience group and the likelihood of complications, as indicated by significant negative Spearman correlation coefficients for all but 2 of the 14 complications listed in the survey (P < 0.05). Thus, increased experience with transsphenoidal surgery seems to be associated with a decreased percentage of operations resulting in complications. Some caution should be exercised in interpreting these data, because they are based on the respondents' estimates.

CONCLUSION: Transsphenoidal surgery seems to be a reasonably safe procedure, with a mortality rate of less than 1%. However, a significant number of complications do occur. The incidence of these complications seems to be higher, with statistical significance, in the hands of less experienced surgeons. The learning curve seems to be relatively shallow, because a statistically significantly decreased incidence of morbidity and death could be documented after 200 and even 500 transsphenoidal operations. Better understanding of the indications for transsphenoidal surgery and improved familiarity with the regional anatomy should further lower the incidence of death and morbidity resulting from this procedure in the hands of all neurosurgeons.

(Neurosurgery 40:225-237, 1997)

Keywords: Complications, National survey, Personal experience, Review of literature, Transsphenoidal surgery



The transfacial approach to the sella was first described by Giordano (27) in 1897. That report was followed by other, similar, operative techniques, all requiring extensive facial soft tissue and osseous resection (24, 39). Among these, Schloffer's operation, first described in 1907 (85), is the best known and most widely cited in the literature. In 1909, Kanavel (43) suggested a transnasal approach through a subnasal and lateral rhinotomy incision. The same year, Hirsch (37) introduced the endonasal technique, via an incision through the nares, thus avoiding lateral rhinotomy. Hirsch (38) continued to use this technique over a period of 5 decades, with excellent long-term results. The sublabial transnasal approach, a modification of Hirsch's operation, was first suggested by Halstead (31) in 1910. Cushing (17, 18) adopted the sublabial-transseptal technique of Halstead and used it in more than 200 of his early pituitary tumor operations, with a mortality rate of 5.2%. The confined and poorly illuminated operative field and the risk of meningitis eventually limited the usefulness of the transsphenoidal technique, until it was completely abandoned by Cushing in favor of the transfrontal operation. The availability of corticosteroids and antibiotics paved the way for reintroduction of the transsphenoidal operation by Dott and Bailey (22) and Guiot and Thibant (30). It was not until Hardy (32) and Hardy and Wigser (36) began using the operating microscope, however, that the transsphenoidal technique gained wider acceptance. The transsphenoidal operation is today the principal surgical technique used by pituitary surgeons for removal of pituitary tumors and other lesions enlarging or otherwise involving the sella. During the past 3 decades, transsphenoidal surgery has proven effective and safe, with most authors reporting mortality rates between 0 and 1% (8, 13, 25, 26, 52, 61, 71, 72, 77, 98, 101).

Nevertheless, the transsphenoidal operation can be a treacherous procedure, as evident from numerous case reports on various complications of this procedure (3, 4, 10, 11, 40, 60, 62, 69, 75, 76, 79, 84, 88, 91). In addition, Barrow and Tindall (6), Black et al. (8), Landolt (47), Onesti and Post (72), Post et al. (77), Tindall et al. (90), Laws (48), and Laws and Kern (54-56) have published detailed reviews on complications of transsphenoidal surgery and treatment. However, with the exception of an international survey on the results of transsphenoidal surgery performed by experienced pituitary surgeons (101), there are no literature data on the cross-sectional morbidity and mortality rates for transsphenoidal surgery as it is practiced across the United States. With this in mind, we thought that it might be of interest to survey the neurosurgeons in the United States regarding their experience with this procedure.

MATERIALS AND METHODS

Questionnaires regarding 14 specific complications of transsphenoidal pituitary surgery were mailed to 3172 neurosurgeons. The neurosurgeons surveyed were asked to estimate the number of transsphenoidal operations performed. They were further asked to identify any complication observed during the surgeon's entire history with the operation. Finally, for those complications that had been witnessed, the neurosurgeons were asked to estimate the percentage of operations that had resulted in any of the specific complications. There were 1162 respondents (37%). Data were analyzed from the 958 respondents (82%) who reported performing transsphenoidal surgery. The 958 respondents were classified into three experience groups, based on the number of transsphenoidal operations performed. Of the respondents, 826 (86.2%) reported having performed fewer than 200 transsphenoidal operations, and 88 (9.2%) reported 200 to 500 transsphenoidal operations. The remaining 27 (3%) reported experience with more than 500 transsphenoidal pituitary operations. Data regarding the number of reported complications in each experience group were analyzed by using the X2 test. The association between complications in the survey and experience was assessed with Spearman correlation coefficients.

RESULTS

Of all respondents, 939 (98%) reported having witnessed at least one or more of the 14 complications represented on the survey (Table 1). Diabetes insipidus (DI) (748 respondents), cerebrospinal fluid (CSF) fistula (590 respondents), anterior pituitary insufficiency (563 respondents), and nasal septum perforation (327 respondents) were the most frequently reported complications. Meningitis and postoperative visual loss were reported by 192 and 179 of the respondents, respectively. Of the respondents, 114 reported having injured the carotid artery. Operative death was reported by 129 of the respondents.

Data regarding the number of surgeons reporting complications within each experience group are shown in Table 2. As expected, surgeons with more extensive experience with transsphenoidal surgery were more likely to have witnessed each specific complication. The X2 tests indicated statistically significant group differences (P < 0.05) for each complication.


TABLE 1.Number of Surgeons Reporting Complications of Transsphenoidal Pituitary Surgery in the National Survey
ComplicationNo. of Surgeons Reporting Complication
Anesthetic complications84
Carotid artery injury114
Central nervous system injury83
Hemorrhage/swelling of residual tumor186
Loss of vision179
Ophthalmoplegia86
Cerebrospinal fluid leak590
Meningitis192
Nasal septum perforation327
Postoperative epistaxis98
Postoperative sinusitis242
Anterior pituitary insufficiency563
Diabetes insipidus748
Death129


TABLE 2. Number of Surgeons, in Three Experience Groups, Reporting Complications of Transsphenoidal Pituitary Surgery in the National Survey
No. of Surgeons Reporting Complication
Complication <200a (n = 836)200-500 (n = 93)>500 (n = 29)P
Anesthetic complications472116<0.001
Carotid artery injury742515<0.001
Central nervous system injury511814<0.001
Hemorrhage/swelling of residual tumor1254021<0.001
Loss of vision1203821<0.001
Ophthalmoplegia482216<0.001
Cerebrospinal fluid leak4838126<0.001
Meningitis1284222<0.001
Nasal septum perforation2366526<0.001
Postoperative epistaxis651815<0.001
Postoperative sinusitis1734722<0.001
Anterior pituitary insufficiency4657325<0.001
Diabetes insipidus64977220.50
Death783318<0.001
aNumber of previous operations.


TABLE 3. Percentage of Operations Resulting in Each Complication of Transsphenoidal Pituitary Surgery in the National Survey
Complication% of Operations Resulting in Complicationa
Anesthetic complications2.8
Carotid artery injury1.1
Central nervous system injury1.3
Hemorrhage/swelling of residual tumor2.9
Loss of vision1.8
Ophthalmoplegia1.4
Cerebrospinal fluid leak3.9
Meningitis1.5
Septum perforation6.7
Epistaxis3.4
Sinusitis8.5
Anterior pituitary insufficiency19.4
Diabetes insipidus17.8
Death0.9
aFor all respondents (estimation by participating neurosurgeons).


TABLE 4. Percentage of Operations, in Three Experience Groups, Resulting in Each Complication of Transsphenoidal Pituitary Surgery in the National Survey
% of Operations Resulting in Complicationa
Complication<200b200-500>500
Anesthetic complications3.51.90.9
Carotid artery injury1.40.60.4
Central nervous system injury1.60.90.6
Hemorrhage into residual tumor bed2.84.00.8
Loss of vision2.40.80.5
Ophthalmoplegia1.90.80.4
Cerebrospinal fluid leak4.22.81.5
Meningitis1.90.80.5
Nasal septum perforation7.64.63.3
Postoperative epistaxis4.31.70.4
Postoperative sinusitis9.66.03.6
Anterior pituitary insufficiency20.614.97.2
Diabetes insipidus19.0NAc7.6
Death1.20.60.2
aEstimation by participating neurosurgeons.
bNumber of previous operations.
cNA, not applicable.


Table 3 shows the percentage of operations resulting in the 14 specific complications for all of the respondents. The mean operative mortality rate was 0.9%. Carotid artery injuries occurred in 1.1% of all transsphenoidal operations reported. The overall incidence of CSF fistulas was 3.9%, with 1.5% of all operations being complicated by meningitis as well. A loss of vision was observed after 1.8% of the operative procedures reported. Anterior pituitary insufficiency (19.4%) and DI (17.8%) were complications with the highest incidence of occurrence.

Table 4 shows the percentage of operations resulting in the 14 specific complications for each of the three experience groups. Examination of the relationship between transsphenoidal surgical experience and the percentage of operations resulting in complications demonstrated an inverse relationship. Significant negative Spearman correlation coefficients were obtained for all but 2 of the 14 specific complications (P < 0.05) (Table 5). These findings suggested that increased transsphenoidal experience was associated with a smaller percentage of operations resulting in complications. Some caution should be exercised in interpreting these data, because they are based on the respondents' estimates. Table 6 shows the Evanston Hospital experience with complications of transsphenoidal surgery.

TABLE 5. Association between Experience and Respondents' Estimation of Percentage of Operations Resulting in Specific Complications
ComplicationSpearman CorrelationP
Anesthetic complications-0.360.001
Carotid artery injury-0.56<0.001
Central nervous system injury-0.33<0.001
Hemorrhage into residual tumor bed-0.30<0.001
Loss of vision-0.51<0.001
Ophthalmoplegia-0.57<0.001
Cerebrospinal fluid leak-0.17<0.001
Meningitis-0.490.003
Nasal septum perforation-0.16<0.001
Postoperative epistaxis-0.56<0.001
Postoperative sinusitis-0.30<0.001
Anterior pituitary insufficiency-0.16<0.001
Diabetes insipidus-0.18<0.001
Death-0.61<0.001

TABLE 6. Complications of Transsphenoidal Pituitary Surgery at the Evanston Hospital (638 Cases)
ComplicationNo. of Complications
Anesthetic complications1
Carotid artery injury0
Central nervous system injury0
Hemorrhage into residual tumor4
Loss of vision3
Ophthalmoplegia2
Cerebrospinal fluid leak7
Meningitis1
Septum perforation26
Postoperative epistaxis10
Diabetes insipidus22
Death2

DISCUSSION

Complications related to indications

Complications resulting from transsphenoidal surgery can be traced to a number of causes, including improper indications, a variety of intercurrent medical conditions, anesthesia, the anatomy surrounding the approach and pituitary, the endocrine systems involved, and, clearly, the surgical technique. The transsphenoidal approach is indicated for pituitary microadenomas, enclosed macroadenomas with predominantly symmetrical suprasellar extension, and some invasive pituitary tumors (principally into the sphenoid bone and clivus) (12, 26, 33, 36, 50, 61, 68, 71, 74, 77, 89, 94, 99). Saito et al. (83) suggested staged transsphenoidal removal of pituitary adenomas when the suprasellar extension is greater than 30 mm. The presence of a significant asymmetric suprasellar adenoma extension and of a constrictive diaphragma sellae may constitute a relative contraindication for the transsphenoidal approach, unless the magnetic resonance imaging results suggest a soft tumor consistency, hemorrhage into the tumor, or cyst formation (14, 66, 72, 87, 97). Adenomas with large and complex suprasellar extensions may require a two-stage or simultaneous transcranial-transsphenoidal removal (7). Cavernous sinus invasion by a pituitary adenoma does not constitute a contraindication for the transsphenoidal approach, except when the epicenter of the tumor is lateral to the carotid artery (2, 16, 25, 46, 78). Nonadenomatous lesions involving the sella or the sphenoid bone can also be approached transsphenoidally. However, a normal-sized sella is generally considered a contraindication for the transsphenoidal approach to any suprasellar lesion (Fig. 1) (13, 49, 72). The transsphenoidal approach is also contraindicated in patients with sphenoid sinusitis and intrasellar vascular anomalies (34, 54, 58, 72, 81, 96).

Anesthetic and perioperative general medical complications

Anesthetic complications associated with the transsphenoidal operative technique are relatively rare (65). Only one-tenth of the respondents in the national survey reported having witnessed an anesthetic complication. The transsphenoidal procedure is usually well tolerated by the elderly and by those with medical conditions such as cardiac or pulmonary disease or diabetes, as long as their functional and endocrine status has been evaluated by appropriate preoperative studies (53). Although a detailed analysis of all possible medical and anesthetic complications is beyond the scope of this article, note should be made of growth hormone-related cardiomyopathy in acromegalic patients (59). Preoperative treatment with somatostatin analogues is usually associated with remarkable improvement of the cardiomyopathy. Acromegalic patients are also more prone to having airway and postintubation difficulties. Because of these difficulties, they should remain intubated until they are fully awake after surgery (28, 64, 100). Finally, deep-vein thrombosis and pulmonary emboli have been reported to occur with relative frequency after transsphenoidal surgery (8, 72, 99, 101). The two operative deaths in our series occurred as a consequence of pulmonary emboli. Deep-vein thrombosis prophylaxis should therefore be a part of the surgical strategy and perioperative management for all patients undergoing transsphenoidal surgery.


FIGURE 1. Examples of tumors associated with normal-size sella. The transsphenoidal approach is contraindicated for a craniopharyngioma (left) and a diaphragma sellae meningioma (right).

Approach complications

Use of a sublabial incision and removal of the maxillary spine, which becomes necessary when it is very prominent, as in acromegalics, can result in anesthesia of the upper lip and anterior maxillary teeth (57, 67, 93). The decreased sensation, however, is temporary in more than 90% of patients (57, 67). We have not observed a case of columellar retraction as a result of maxillary spine removal (86). Removal of the cartilaginous septum, especially of its superior part, can result in a saddle nose (23, 44, 47, 54, 67).

According to the national survey, nasal septum perforation was observed by one-third of surgeons; it occurred more frequently with the least experienced surgeons (7.6 versus 3.3% in the most experienced group). The incidence of this complication in the literature ranges from 0.3 to 3% (52, 72, 99), with two authors reporting incidences of 7 and 40% (44, 67). A nasal septum perforation tends to occur more often during subsequent transsphenoidal operations (56). Prevention of a septum perforation requires familiarity with the nasal anatomy. In addition, the integrity of the nasal mucosa can be safeguarded by several technical maneuvers. These include submucous injection of a local anesthetic that helps elevate the nasal mucosal sac off the septum, creation of a superior-inferior submucous tunnel on one side of the septum before these tunnels are connected, formation of a posterior submucous tunnel on the opposite side, and dislocation of the nasal cartilage toward the opposite side as a single mucoperichondrial flap (Fig. 2) (51, 52, 67, 94). These maneuvers are designed to prevent formation of opposing bimucosal tears, the occurrence of which increases the possibility of a permanent postoperative septal defect.


FIGURE 2. Drawing showing that the nasal cartilage and right mucosal sac are dislocated laterally as a single mucoperichondrial flap.

The importance of midline and vertical orientation during dissection toward the sphenoid sinus has been emphasized in the past (34-36, 72). An undue superior dissection can cause anosmia (44, 92) and can injure the cribriform plate and cause a CSF leak (54). Vertical orientation is best achieved with televised fluoroscopy (30, 36, 52). The placement and opening of a bivalve speculum can be complicated, especially in the elderly, by a diastasis of the maxilla (29, 56) or, even worse, by a fracture of the orbit that can potentially result in blindness (Fig. 3) (6, 45, 54, 70, 72).

Postoperative sinusitis can also be considered an approach complication. In the national survey, this complication occurred with an incidence of 8.5%. Two series reported incidences of sinusitis of 15 and 9% (44, 61); the frequency ranged from 1 to 4% in most other series (8, 26, 82, 97). Earlier removal of the nasal packing and routine use of an oral antibiotic for 7 to 10 days postoperatively can reduce the incidence of this complication.

Intrasphenoidal complications

In the process of opening the sphenoid rostrum, bleeding can occur from the mucosal branch of the sphenopalatine artery. This artery can be the source of delayed postoperative epistaxis (8, 14, 82, 99, 101). Ligation or embolization of the internal maxillary artery may become necessary if the epistaxis persists or recurs. The estimated percentage of operations resulting in this complication in the national survey ranged from 0.4 to 4.3% in the three experience groups.

If the speculum is advanced too far interiorly into the sphenoid sinus, a fracture of the sphenoid body can occur, with the possibility of injuring the optic nerves and carotid arteries (6, 54). The inferior medial wall of the optic nerve canals protrudes into the superior lateral extent of the sphenoid sinus. The bony plate shielding the optic nerves can be extremely thin or it may be completely missing (81, 92). It is not surprising, therefore, that the optic nerves in this location are vulnerable not only to surgical manipulations but also to heat injury. Consequently, the use of monopolar coagulation should be avoided inside the sphenoid sinus. In addition, the bone over the anterior loop of the carotid artery that protrudes into the sphenoid sinus on either side of the anterior-inferior walls of the sella is missing in approximately 4% of cadaveric specimens, with the sphenoid sinus mucosa directly abutting the adventitia of the artery (56, 81, 86). This anatomic variant must be kept in mind in the process of removing the sphenoid sinus mucosa, a maneuver considered necessary by most neurosurgeons as a means of preventing formation of a sphenoid sinus mucocele (54, 72). In addition to midline orientation, vertical orientation should be carefully maintained in the sphenoid sinus and during opening of the sella, to avoid a too-high trajectory toward the planum or a too-low trajectory toward the clivus, which may be eroded or even missing in patients with destructive tumors (34).


FIGURE 3. Fracture of the left medial orbital wall resulting from improper speculum placement. Note air in the apex of the left orbit close to the superior rectus muscle.

Intrasellar complications

Operative manipulations in the sella can be associated with vascular injuries of the carotid artery in the cavernous sinuses. Death with such injuries has been reported (57, 72, 101). In the national survey, 114 surgeons reported having caused carotid artery injury. The percentage of transsphenoidal operations resulting in carotid artery injuries varied from 0.4% for the most experienced group to 1.4% for the least experienced surgeons, with the difference being statistically significant. The review of the literature revealed 35 additional cases of vascular injuries. Twenty-one of these cases resulted either in false or mycotic aneurysms (3, 10, 52, 72, 73, 79, 99, 101) or in carotid cavernous fistulas (3, 52, 60, 75, 76, 80, 89, 101). Furthermore, cases of postoperative vasospasm and of vascular occlusion (40, 52, 54, 72) have also been reported. A thorough preoperative assessment of the carotid artery position should be obtained and carefully studied in each case (3, 78). The carotid arteries can be found inside the sella (36, 54), and the distance between the two arteries is as short as 4 mm in some patients (57, 81). T1-weighted, infused magnetic resonance imaging of the sella and the pituitary can be relied on in most cases to delineate the anatomic relationships of the carotid artery. Magnetic resonance angiography or digital subtraction angiography may be indicated for patients in whom either a carotid artery anomaly or an aneurysm in the cavernous sinus or in the sella is suspected (96). If torrential hemorrhaging occurs during surgery, packing is virtually all one can do at that time. If the bleeding is controlled, postoperative angiography is imperative; if results are negative, angiography should be repeated after the packing is removed (3). If packing fails to control the bleeding, intraoperative endovascular occlusion of the carotid artery may become necessary. Endovascular occlusion and trapping are also the treatments of choice for false aneurysms and carotid cavernous fistulas (3, 9).

Although it is sometimes necessary to trace pituitary tumors into the medial compartments of the cavernous sinuses (16), this surgical maneuver can also result in an injury to one of the cranial nerves in the cavernous sinus, most often the VIth cranial nerve (14). In the national survey, injuries to the cranial nerves in the cavernous sinus occurred with an incidence of 0.4% for the most experienced group and 1.9% for the least experienced surgeons, with the difference being statistically significant. The reported incidence of this complication in the literature ranges from 0 to 1.2% (15, 25, 52, 56, 72, 99, 101).

Complications resulting from surgical maneuvers in the suprasellar space

Pituitary adenomas originate below the diaphragma sellae and thus outside the arachnoid membrane and the subarachnoid space (Fig. 4). As they grow larger and begin to reach the suprasellar space, they distend the dura ring of the diaphragma and displace the arachnoid membrane (Fig. 5). Consequently, pituitary adenomas, regardless of their size and shape and the direction of their suprasellar extension, remain confined to the extra-arachnoid space (Fig. 6). The displaced and elevated arachnoid membrane constitutes a distinct dissection plane along which even large and sprawling pituitary tumors can be removed completely or at least in gross total fashion (Fig. 7). That the transsphenoidal removal of a pituitary tumor can be performed entirely outside the arachnoid membrane, and thus without entering the subarachnoid space, is the fundamental reason for the benignity of this procedure. A violation of the arachnoid membrane, however, can occur in several circumstances. For example, the arachnoid membrane can be opened and the subarachnoid space entered in a patient with a low-lying anterior arachnoid recess, in the process of opening the dura and during operative maneuvers in the anterior-superior aspect of the sella exposure (14, 57). Furthermore, the arachnoid membrane can be injured in the process of removing a pituitary macroadenoma when the distended and elevated arachnoid membrane over the tumor dome begins to invert into the sella (Fig. 8) (14). Immediate recognition of this intraoperative event is essential to avoid penetration into the subarachnoid space. In most macroadenomas, there is an additional protective thin layer of residual normal anterior pituitary tissue attached to the undersurface of the arachnoid membrane.


FIGURE 4. Origin of pituitary microadenomas in the anterior lobe.


FIGURE 5. Growth of the pituitary adenoma, resulting in widening of the dura ring of the diaphragma sellae. The arachnoid membrane is displaced superiorly.

The incidence of CSF fistulas in the national survey ranged from 1.5% for the most experienced surgeons to 4.2% for the least experienced group. The incidence of this complication reported in the literature has been as high as 9 to 15% (42, 44, 82), although most authors describe an incidence between 1 and 4% (8, 14, 26, 52, 56, 61, 71, 72, 77, 97, 101). Failure to close a CSF fistula primarily or repair it secondarily can result in either a tension pneumocephalus (4, 11, 14, 72) or meningitis. Most authors report meningitis as occurring with a relatively low incidence, ranging from 0 to 2% (8, 14, 44, 77, 97, 101), although it can result in death (52).


FIGURE 6. Large pituitary adenoma with suprasellar extension. The dura ring of the diaphragma sellae is markedly distended and elevated. The dome of the tumor remains covered by a layer of arachnoid membrane.

The techniques of sella closure have been described in the literature (17, 35, 51, 52, 77, 90, 94, 99). Our technique has been to use an autologous fascia and fat graft along with an autologous fibrin glue to seal macroscopic openings in the arachnoid membrane. If there is no evidence of an intraoperative CSF leak, a fat graft admixed with pulverized Surgicel is used alone to pack the sella. Care is taken, however, not to pack the sella in a way that would result in an elevation of the arachnoid membrane above the anterior clinoids or cause a compression of the cavernous sinuses. A graft fashioned from a segment of the removed vomer, or in rare instances from a portion of the nasal or rib cartilages, is used to hold the pack in place, with placement as precise as possible between the dura and bony openings of the sella. Spinal drainage is used as the first treatment step in a patient with a persistent CSF fistula and then by reexploration and repacking if so indicated.


FIGURE 7. A, coronal magnetic resonance imaging scans of a large thyrotropin-secreting adenoma with significant suprasellar extension and right cavernous sinus invasion (left) removed transsphenoidally (right). Note that the cavernous sinus invasion is medial to the carotid artery. B, sagittal magnetic resonance imaging scans of the same patient before and after removal.


FIGURE 8. View through the operating microscope of redundant folds of arachnoid membrane inverted toward the sella floor. The anteriorly lying fold is still covered by an orange-reddish thin layer of residual normal anterior pituitary.

Penetration of the arachnoid membrane can also result in an injury to the intra-arachnoid neurovascular structures, including the hypothalamus, the optic nerves and chiasm, and the surrounding vessels. In two detailed reviews of complications of transsphenoidal surgery, hypothalamic injuries have been reported as the principal cause of operative death (51, 72, 101). In the national survey, 83 surgeons reported having caused a central nervous system injury. Visual loss can be another complication of penetration through the arachnoid membrane. In the national survey, 179 surgeons reported having had patients with a postoperative visual loss. The percentage of operations resulting in this complication was 0.4% for the most experienced group and 2.4% for the least experienced group of surgeons, with the difference again being statistically significant. Review of the literature shows that the incidence of visual deterioration after transsphenoidal surgery ranges from 0.6 to 1.6% (6, 14, 52, 61, 77, 82, 99, 101). The mechanism of visual loss can be either direct trauma or vascular compromise and insufficiency (1, 8). The potential for an injury to the optic nerves, chiasm, and hypothalamus is greater in patients undergoing transsphenoidal surgery for recurrent pituitary tumors (55), especially if they were previously operated on transcranially. With the transcranial approach to a pituitary tumor, the arachnoid membrane is opened before the tumor can be reached. This maneuver thus results in adhesions between the residual sella contents or tumor on one side and the optic apparatus and the hypothalamus on the other. Thus, subsequent transsphenoidal surgery and intrasellar maneuvers can potentially result in a traction injury, contusion, or vascular insufficiency of the optic nerves and chiasm (Fig. 9). It has been our practice, therefore, not to recommend the transsphenoidal approach for patients with large recurrent pituitary tumors previously operated on transcranially. Visual loss can also occur as a consequence of optic nerve and chiasm prolapse into an empty sella months or years after removal of a pituitary macroadenoma (41, 54). Chiasmapexy (20), however, rarely becomes necessary, because the loss of vision is frequently vague and nonprogressive.


FIGURE 9. Large recurrent pituitary adenoma (status after four previous transcranial operations) subsequently operated on transsphenoidally, resulting in loss of vision.

Surgical manipulations during removal of the suprasellar portion of the tumor, especially if associated with inadequate removal and decompression of the tumor, can cause hemorrhage and swelling in the residual tumor tissue, resulting in death, visual impairment, hydrocephalus, lethargy, or paresis (Fig.10) (8, 14, 21, 44, 72, 99, 101). The treatment depends on the severity and progression of symptoms and therefore varies from mere observation to the use of corticosteroids, placement of a ventriculoperitoneal shunt, or reexploration. These complications are more likely to occur in a patient with a constrictive diaphragma sellae and a dumbbell-shaped tumor (74), especially if the tumor contains numerous fibrous septi (14). Suprasellar tumor manipulations have also been reported to be associated with subarachnoid hemorrhage from aneurysmal or nonaneurysmal causes (54, 56, 62, 91), bilateral frontal epidural hematomas (84), and temporal lobe epilepsy (44, 99, 101).

Endocrine complications

DI and anterior pituitary insufficiency were the most frequent complications reported in the national survey. With the least experienced surgeons, one of five transsphenoidal operations resulted in both of these complications. In contrast, the incidence of these complications was lower in the hands of the most experienced surgeons.

Postoperative anterior pituitary insufficiency has been reported in the literature as being rare (72). Various series cite an incidence ranging from less than 1 to 10% (63, 97, 101), with one series reporting an incidence of 27% (82). Postoperative anterior pituitary insufficiency was also reported to occur more frequently after removal of larger tumors and in patients whose anterior pituitary functions were impaired preoperatively (63). The residual normal anterior pituitary tissue can be identified in the preoperative, T1-weighted, infused magnetic resonance imaging scans as a thin layer of enhanced tissue draping around the tumor, mostly over the upper pole of the tumor (Fig. 11). Every effort should be made to preserve this attenuated, residual, normal anterior pituitary tissue, because it can prove sufficient to maintain or even improve anterior pituitary functions in the postoperative period (64).


FIGURE 10. Magnetic resonance image from a 45-year-old man with postoperative worsening of vision resulting from inadequate tumor removal and overpacking of the sella with fat, resulting in compression of the optic apparatus.

Temporary post-transsphenoidal surgery DI has been reported to occur in 10 to 60% of cases (26, 68, 82). Permanent DI, however, seems to be relatively rare, with the reported incidence ranging in most large series from 0.5 to 15% (8, 26, 44, 52, 61, 68, 71, 97, 101). DI after removal of microadenomas usually occurs as a consequence of stalk manipulations. Vertically oriented vessels on the pale-reddish stalk are helpful landmarks for recognizing the stalk. In pituitary macroadenomas, the stalk and the posterior lobe are often not seen because they can be displaced in any direction, flattened, and covered by a fibrous layer. The latter finding explains the relatively low incidence of permanent postoperative DI in patients undergoing removal of pituitary macroadenomas.


FIGURE 11. Sagittal (left) and coronal (right) magnetic resonance imaging scans of a large pituitary adenoma with significant suprasellar extension. The necrotic soft tumor was removed transsphenoidally. Note a thin layer of enhancing tissue over the tumor dome and along the left side of the tumor, representing a thin layer of residual normal anterior pituitary tissue (arrowheads).

In addition, the postoperative course can be complicated by inappropriate secretion of the antidiuretic hormone, which occurs usually on the 6th or 7th postoperative day and thus frequently after the patient has been released from the hospital (5, 15, 19, 95, 97). One of the explanations for this phenomenon is presumed necrosis of a portion of the posterior lobe because of surgical trauma, resulting in a sudden release of the antidiuretic hormone.

CONCLUSIONS

A national survey on complications of transsphenoidal surgery was conducted. Among the 1162 neurosurgeons responding to the survey, 958 (82%) reported performing transsphenoidal surgery. Respondents were divided into three experience groups, according to the number of transsphenoidal operations performed. The estimated mortality rate of 0.9% and the mean incidence (from all of the respondents) of complications such as carotid artery injury (1.1%), central nervous system injury (1.3%), loss of vision (1.8%), CSF fistula (3.9%), meningitis (1.5%), nasal septum perforation (6.7%), and other complications suggested that transsphenoidal surgery, although reasonably safe, can be associated with potentially serious complications. In addition, the survey showed that more experienced surgeons witnessed a larger number of complications, most likely because of their greater case loads and perhaps because of their tendency to operate on more difficult tumors. The estimated incidences of death and morbidity, however, seemed to be higher with less experienced surgeons. This difference was statistically significant. These data were interpreted with caution, because they are based on estimates by the respondents. The complications of transsphenoidal surgery were also reviewed in light of the available literature and our personal experience.

ACKNOWLEDGMENTS

This work was supported by the Department of Surgery, Evanston Hospital, and the Bennett-Tarkington Chair in Neurosurgery, Evanston Hospital and Northwestern University Medical School.

Received, March 18, 1996.
Accepted, August 22, 1996.
Reprint requests: Ivan Ciric, M.D., Division of Neurosurgery, Evanston Hospital, 2650 Ridge Avenue, Evanston, IL 60201.

REFERENCES

  1. Adams CBT: The management of pituitary tumours and postoperative visual deterioration. Acta Neurochir (Wien) 94:103-116, 1988.
  2. Ahmadi J, North CM, Segall HD, Zee CS, Weiss MH: Cavernous sinus invasion by pituitary adenomas. AJNR Am J Neuroradiol 6:893-898, 1985.
  3. Ahuja A, Guterman LR, Hopkins LN: Carotid cavernous fistula and false aneurysm of the cavernous carotid artery: Complications of transsphenoidal surgery. Neurosurgery 31:774-779, 1992.
  4. Altinors N, Arda N, Kars Z, Turker A, Senveli E, Cepogluc C, Cinar N: Zero tension pneumocephalus after transsphenoidal surgery: Case report. Neurosurgery 23:516-518, 1988.
  5. Andrews BT, Fitzgerald PA, Tyrell JB, Wilson CB: Cerebral salt wasting after pituitary exploration and biopsy: Case report. Neurosurgery 18:469-471, 1986.
  6. Barrow DL, Tindall GT: Loss of vision after transsphenoidal surgery. Neurosurgery 27:60-68, 1990.
  7. Barrow DL, Tindall GT, Tindall SC: Perspectives in Neurological Surgery. St. Louis, Quality Medical Publishing, 1992, vol 3, pp 49-58.
  8. Black PMcL, Zervas NT, Candia G: Incidence and management of complications of transsphenoidal operation for pituitary adenomas. Neurosurgery 20:920-924, 1987.
  9. Britt RH, Silverberg GD, Prolo DJ, Kendrick MM: Balloon catheter occlusion for cavernous carotid artery injury during transsphenoidal hypophysectomy. J Neurosurg 55:450-452, 1981.
  10. Cabezudo JM, Carrillo R, Vaquero J, Areitio E, Martinez R: Intracavernous aneurysm of the carotid artery following transsphenoidal surgery: Case report. J Neurosurg 54:118-121, 1981.
  11. Candrina R, Galli G, Bollati A: Subdural and intraventricular tension pneumocephalus after transsphenoidal operation. J Neurol Neurosurg Psychiatry 51:1005-1006, 1988.
  12. Chandler WF: Sellar and parasellar lesions. Clin Neurosurg 37:514-527, 1991.
  13. Ciric I, Cozzens JW: Craniopharyngiomas: Transsphenoidal method of approach--For the virtuoso only? in Carmel PW (ed): Clinical Neurosurgery. Baltimore, Williams & Wilkins, 1980, vol 27, pp 605-625.
  14. Ciric I, Mikhael M, Stafford T, Lawson L, Garces R: Transsphenoidal microsurgery of pituitary macroadenomas with long-term follow-up results. J Neurosurg 59:395-401, 1983.
  15. Comtois R, Beauregard H, Somma M, Serri O, Aris-Jilwan N, Hardy J: The clinical and endocrine outcome of transsphenoidal microsurgery of nonsecreting pituitary adenomas. Cancer 68:860-866, 1991.
  16. Couldwell WT, Weiss MH: Pituitary adenomas: Pituitary macroadenomas, in Apuzzo MLJ (ed): Brain Surgery: Complication Avoidance and Management. New York, Churchill Livingstone, 1993, pp 295-312.
  17. Cushing H: Transsphenoidal methods of access, in Cushing H (ed): The Pituitary Body and Its Disorders. Philadelphia, J.B. Lippincott Co., 1912, pp 296-303.
  18. Cushing H: Intracranial Tumors: Notes upon a Series of Two-Thousand Verified Cases with Surgical Mortality Percentages Pertaining Thereto. Springfield, Charles C Thomas, 1932.
  19. Cusick JF, Hagen TC, Findling JW: Inappropriate secretion of antidiuretic hormone after transsphenoidal surgery for pituitary tumors. N Engl J Med 311:36-38, 1984.
  20. Decker RE, Carras R: Transsphenoidal chiasmapexy for correction of posthypophysectomy traction syndrome of optic chiasm: Case report. J Neurosurg 46:527-529, 1977.
  21. Decker RE, Chalif DJ: Progressive coma after the transsphenoidal decompression of a pituitary adenoma with marked suprasellar extension: Report of two cases. Neurosurgery 28:154-157, 1991.
  22. Dott NM, Bailey P: A consideration of the hypophysial adenomata. Br J Surg 13:314-366, 1925-1926.
  23. Eisele DW, Flint PW, Janas JD, Kelly WA, Weymuller EA Jr, Cummings CW: The sublabial transseptal transsphenoidal approach to sellar and parasellar lesions. Laryngoscope 98:1301-1308, 1988.
  24. von Eiselsberg A: The operative cure of acromegaly by removal of hypophysial tumor. Ann Surg 48:781-783, 1908.
  25. Fahlbusch R, Buchfelder M: Transsphenoidal surgery of parasellar pituitary adenomas. Acta Neurochir (Wien) 92:93-99, 1988.
  26. Faria MA, Tindall GT: Transsphenoidal microsurgery for prolactin-secreting pituitary adenomas. J Neurosurg 56:33-43, 1982.
  27. Giordano F: Compendio Chir Oper Ital 2:100, 1897.
  28. Goldhill DR, Dalgleish JG, Lake RHN: Respiratory problems and acromegaly. Anesthesiology 37:1200-1203, 1982.
  29. Grayson RJ, Johnson PA: Transsphenoidal hypophysectomy: An unusual complication. Va Med 113:294-295, 1986.
  30. Guiot G, Thibant B: L'extirpation des adenomes hypophysaires par voie trans-sphenoidale. Neurochirurgia 1:133-149, 1959.
  31. Halstead AE: Remarks on the operative treatment of the tumors of the hypophysis. Surg Gynecol Obstet 10:494-502, 1910.
  32. Hardy J: Transsphenoidal removal of pituitary adenomas. Union Med Can 91:933-945, 1962.
  33. Hardy J, Beauregard H, Robert F: Prolactin-secreting pituitary adenomas transsphenoidal microsurgical treatment. Clin Neurosurg 27:38-47, 1980.
  34. Hardy J, McCutcheon IE: Pituitary adenomas: Pituitary macroadenomas, in Apuzzo MLJ (ed): Brain Surgery: Complication Avoidance and Management. New York, Churchill Livingstone, 1993, pp 276-295.
  35. Hardy J, Vezina JL: Transsphenoidal Neurosurgery of Intracranial Neoplasm. New York, Raven Press, 1976, pp 261-275.
  36. Hardy J, Wigser SM: Transsphenoidal surgery of pituitary fossa tumors with televised radiofluoroscopic control. J Neurosurg 23:612-619, 1965.
  37. Hirsch O: Ueber methoden der operativen Behandlung von Hypophysistumoren auf endonasalem Wege. Arch Laryng Rhino 24:129-177, 1910.
  38. Hirsch O: Life-long cures and improvements after transsphenoidal operation of pituitary tumors (thirty-three patients followed for 20-37 years). Acta Ophthalmol Suppl 56:1-60, 1959.
  39. Deleted in proof.
  40. Hyde-Rowan MD, Roessmann U, Brodkey JS: Vasospasm following transsphenoidal tumor removal associated with arterial changes of oral contraception. Surg Neurol 20:120-124, 1983.
  41. Iwasa H, Miyagi K, Ishijima B: Downward migration of the optic system after transsphenoidal approach to a giant eosinophilic adenoma. No Shinkei Geka 7:593-597, 1979.
  42. James JA: Transethmosphenoidal hypophysectomy. Arch Otolaryngol 86:256-264, 1967.
  43. Kanavel AB: The removal of tumor of pituitary body by an intranasal route. JAMA 53:1701-1704, 1909.
  44. Kennedy DW, Cohn ES, Papel ID, Hilliday MJ: Transsphenoidal approach to the sella: The Johns Hopkins experience. Laryngoscope 94:1066-1074, 1984.
  45. Kirschner JA, VanGilder JC: Transethmoidal hypophysectomy: Some surgical landmarks. Trans Am Acad Ophthalmol Otolaryngol 80:391-396, 1975.
  46. Knosp E, Steiner E, Kitz K, Matula C: Pituitary adenomas with invasion of the cavernous sinus space: A magnetic resonance imaging classification compared with surgical findings. Neurosurgery 33:610-617, 1993.
  47. Landolt AM: Complications and pitfalls of transsphenoidal pituitary surgery. Neurosurgeons 4:395-404, 1984.
  48. Laws ER Jr: Complications of transsphenoidal microsurgery for pituitary adenoma, in Brock M (ed): Modern Neurosurgery I. Berlin, Springer-Verlag, 1982, pp 181-186.
  49. Laws ER Jr: Transsphenoidal microsurgery in the management of craniopharyngioma. J Neurosurg 52:661-666, 1980.
  50. Laws ER Jr: Surgical management of pituitary adenomas. Curr Prob Cancer 8:1-26, 1984.
  51. Laws ER Jr: Pituitary surgery. Endocrinol Metab Clin North Am 16:647-665, 1987.
  52. Laws ER Jr: Transsphenoidal approach to lesions in and about the sella turcica, in Schmidek HH, Sweet WH (eds): Operative Neurosurgical Techniques: Indications, Methods, and Results. Philadelphia, W.B. Saunders Co., 1988, pp 309-319.
  53. Laws ER Jr, Abboud CF, Kern EB: Perioperative management of patients with pituitary microadenoma. Neurosurgery 7:566-570, 1980.
  54. Laws ER Jr, Kern EB: Complications of transsphenoidal surgery. Clin Neurosurg 23:401-416, 1976.
  55. Laws ER Jr, Kern EB: Complications of transsphenoidal surgery, in Tindall GT, Collins WF (eds): Clinical Management of Pituitary Disorders. New York, Raven Press, 1979, pp 435-445.
  56. Laws ER Jr, Kern EB: Complications of transsphenoidal surgery, in Laws ER, Randall RV, Kern EB (eds): Management of Pituitary Adenomas and Related Lesions. New York, Appleton-Century-Crofts, 1982, pp 329-346.
  57. Lee KJ: The sublabial transseptal transsphenoidal approach to the hypophysis. Laryngoscope 88:1-65, 1978.
  58. Lee KJ, Kelly D: Intrasellar persistent trigeminal artery as associated with a pituitary adenoma. J Neurosurg 70:271-273, 1989.
  59. Lie JT: Pathology of the heart in acromegaly: Anatomic findings in 27 autopsied patients. Am Heart J 100:41-52, 1980.
  60. Lister JR, Sybert GW: Traumatic false aneurysm and carotid-cavernous fistula: A complication of sphenoidotomy. Neurosurgery 5:473-475, 1979.
  61. Mampalam TJ, Tyrell JB, Wilson CB: Transsphenoidal microsurgery for Cushing's disease: A report of 216 cases. Ann Intern Med 109:487-493, 1988.
  62. Matsuno A, Yoshida S, Basugi N, Itoh S, Tanaka J: Severe subarachnoid hemorrhage during transsphenoidal surgery for pituitary adenoma. Surg Neurol 39:276-278, 1993.
  63. McLanahan CS, Christy JH, Tindall GT: Anterior pituitary function before and after transsphenoidal microsurgical resection of pituitary tumors. Neurosurgery 3:142-144, 1978.
  64. Messick JM Jr, Cucchiara RF, Faust RJ: Airway management in patients with acromegaly. Anesthesiology 56:157, 1982 (letter).
  65. Messick JM Jr, Laws ER Jr, Abboud CF: Anesthesia for transsphenoidal surgery of the hypophyseal region. Anesth Analg 57:206-215, 1978.
  66. Mohr G, Hardy J, Comtois R, Beauregard H: Surgical management of giant pituitary adenomas. Can J Neurol Sci 17:62-66, 1990.
  67. Nabe-Nielsen J: Nasal complication after transsphenoidal surgery for pituitary pathologies. Acta Neurochir (Wien) 96:122-125, 1989.
  68. Nakane T, Kuwayama A, Watanabe M, Kageyama N: Transsphenoidal approach to pituitary adenomas with suprasellar extension. Surg Neurol 16:225-229, 1981.
  69. Newfield P, Albin MS, Chestnut JS, Maroon J: Air embolism during transsphenoidal pituitary operations. Neurosurgery 2:39-42, 1978.
  70. Newmark H III, Kant N, Duerksen R, Pribram HW, Newmark H: Orbital floor fracture: An unusual complication of trans-septal transsphenoidal hypophysectomy. Neurosurgery 12:555-556, 1983.
  71. Nicola G: Transsphenoidal surgery for pituitary adenomas with extrasellar extension. Prog Neurol Surg 6:142-199, 1975.
  72. Onesti ST, Post KD: Complications of transsphenoidal microsurgery, in Post KD, Friedman ED, McCormick P (eds): Postoperative Complications in Intracranial Neurosurgery. Chicago, Thieme Medical Publishers, 1993, pp 61-73.
  73. Onishi H, Ito H, Kuroda E, Yamamoto S, Kuboto T: Intracranial mycotic aneurysm associated with transsphenoidal surgery to the pituitary adenoma. Surg Neurol 31:149-154, 1989.
  74. Pasztor E, Kemeny AA, Piffko P: Transsphenoidal surgery for suprasellar pituitary adenomas. Acta Neurochir (Wien) 67:11-17, 1983.
  75. Paullus WS Jr, Norwood CW, Morgan HW: False aneurysm of the cavernous carotid artery and progressive external ophthalmoplegia after transsphenoidal hypophysectomy: Case report. J Neurosurg 51:707-709, 1979.
  76. Pigott TJD, Holland IM, Punt JAG: Carotico-cavernous fistula after transsphenoidal hypophysectomy. Br J Neurosurg 3:613-616, 1989.
  77. Post KD, Jackson IMD, Reichlin S: The Pituitary Adenoma. New York, Plenum Medical Book Co., 1980.
  78. Rao KCVG, Allen HA, Haney PJ, Yu R, Levine H: Vascular studies in the preoperative evaluation of pituitary adenomas before transsphenoidal surgery. Surg Neurol 21:175-181, 1984.
  79. Reddy K, Lesiuk H, West M, Fewer D: False aneurysm of the cavernous carotid artery: A complication of transsphenoidal surgery. Surg Neurol 33:142-145, 1990.
  80. Reiderer A, Wilmes E: Eine seltene Komplikation der Septum Operation: Arteria Carotis interna--Sinus Cavernous Fistel. Laryn Rhinol Otol (Stuttg) 66:583-585, 1987.
  81. Renn WH, Rhoton AL Jr: Microsurgical anatomy of the sellar region. J Neurosurg 43:288-298, 1975.
  82. Riche H, Jaboulay JM, Chiara Y, Peloux A: Complications post-operatoires de la voie trans-sphenoidale. Minerva Anestesiol 58:71-72, 1992.
  83. Saito K, Kuwayama A, Yamamoto N, Sugita K: The transsphenoidal removal of nonfunctioning pituitary adenomas with suprasellar extensions: The open sella method and intentionally staged operation. Neurosurgery 36:668-676, 1995.
  84. Saitoh Y, Mori S, Nii Y, Abekura M, Arita N, Hayakawa T, Moriwaki K, Mogami H: Bifrontal epidural hematoma after transsphenoidal operation: Report of a case with a rare complication. Neurosurgery 16:658-659, 1985.
  85. Schloffer H: Ergolgreiche Operation eines Hypophysentumors auf nasalem Wege. Wien Klin Wochenschr 21:621, 1907.
  86. Siegel MB, Hendrix RA: Transsphenoidal hypophysectomy: A critical review. Trans Pa Acad Ophthalmol Otolaryngol 42:1002-1007, 1990.
  87. Symon L, Jakubowski J, Kendall B: Surgical treatment of giant pituitary adenomas. J Neurol Neurosurg Psychiatry 42:973-982, 1979.
  88. Takahashi M, Killeffer F, Wilson G: Iatrogenic carotid cavernous fistula: Case report. J Neurosurg 30:498-500, 1969.
  89. Teasdale G: Surgical management of pituitary adenoma. J Clin Endocrinol Metab 12:789-823, 1983.
  90. Tindall GT, Woodard EJ, Barrow D: Pituitary adenomas: General considerations, in Apuzzo MLJ (ed): Brain Surgery: Complication Avoidance and Management. New York, Churchill Livingstone, 1993, pp 269-276.
  91. Tsuchida T, Tanaka R, Yokoyama M, Sato H: Rupture of anterior communicating artery aneurysm during transsphenoidal surgery for pituitary adenoma. Surg Neurol 20:67-70, 1983.
  92. Van Alyea OE: Sphenoid sinus: Anatomic study, with consideration of the clinical significance of the structural characteristics of the sphenoid sinus. Arch Otolaryngol 34:225-253, 1941.
  1. von Hochenegg J: Operative Geheilte Akromegalie bei Hypophysentumor. Vern Dtsch Ges Chir 37:80-85, 1908.
  2. Watson SW, Sinn DP, Neuwelt EA: Dental considerations in the sublabial transsphenoidal surgical approach to the pituitary gland. Neurosurgery 10:236-241, 1982.
  3. Weiss M: Pituitary tumors: An endocrinological and neurosurgical challenge. Clin Neurosurg 39:114-122, 1992.
  4. Whitaker SJ, Meanock CI, Turner GF, Smyth PJ, Pickard JD, Noble AR, Walker V: Fluid balance and secretion of antidiuretic hormone following transsphenoidal pituitary surgery: A preliminary series. J Neurosurg 63:404-412, 1985.
  5. White JC, Ballantine HT Jr: Intrasellar aneurysms simulating hypophyseal tumours. J Neurosurg 18:34-50, 1961.
  6. Wilson CB: Neurosurgical management of large and invasive pituitary tumors, in Tindall FT, Collins WF (eds): Clinical Management of Pituitary Disorders. New York, Raven Press, 1979, pp 269-276.
  7. Wilson CB: A decade of pituitary microsurgery: The Herbert Olivecrona Lecture. J Neurosurg 61:814-833, 1984.
  8. Wilson CB, Dempsey LC: Transsphenoidal microsurgical removal of 250 pituitary adenomas. J Neurosurg 48:13-22, 1978.
  9. Young ML, Hanson CW III: An alternative to tracheostomy following transsphenoidal hypophysectomy in a patient with acromegaly and sleep apnea. Anesth Analg 76:446-449, 1993.
  10. Zervas NT: Surgical results in pituitary adenomas: Results in an international survey, in Black PMcL, Zervas NT, Ridgway EC Jr, Martin JB (eds): Secretory Tumors of the Pituitary Gland. New York, Raven Press, 1984, pp 377-385.

COMMENTS

The authors present a national survey on the complications of transsphenoidal surgery. Although this is informative regarding the approximate incidence of these complications, readers must be aware that the respondents to the survey did not necessarily review their experience as the authors did. It may be that the information returned in such a survey is anecdotal. As an example, I find it odd that 41% of the respondents claimed that they had not seen anterior pituitary insufficiency in any of their postoperative patients. Equally odd is that 34% reported that they had never seen a nasal perforation. The authors have pointed out several times that the respondents to such a survey have probably not reviewed their material as the authors have done.

What is very clear, however, is that experience is important. The incidence of complications seems most closely related to the experience of the surgical team. This is extremely important to observe, particularly at a time when patients' choices are being threatened by health care managers.

Kalmon D. Post
New York, New York

The authors report valuable, if not completely valid, information regarding the incidence of various complications related to transsphenoidal surgery. The data are useful, because they reflect the observations of 958 surgeons of varying experience. They are of marginal statistical validity, because the numbers are only estimates by the surgeons. Having been one of the questionnaire respondents in the "over 500 operations" group, I can say that my data were from a compulsively kept computer database, but the authors have no quality control on any of the estimates by the respondents.

Overall, I think that the percentages of the various complications are reasonably accurate. It is not surprising that the complication rates are a bit lower for surgeons with greater experience. Fortunately, the incidence of any given complication is low for all groups reporting.

The authors also offer a valuable service to readers by providing a detailed discussion of all of the possible complications of this procedure. Although this is a low-risk procedure overall, it is important for practitioners to appreciate the various complications that can and will be encountered.

William F. Chandler
Ann Arbor, Michigan

This carefully performed review of the complications of transsphenoidal surgery provides an extraordinarily useful database for considering the risks and outcomes of surgery for pituitary tumors and related lesions. It contains careful categorization of the major different types of complications, some serious and some less devastating but all important.

The spectrum of complications of transsphenoidal surgery is clearly related to the technical aspects of the operation and to the basic aspects of pituitary disease. There is fairly solid evidence that for most complications, the incidence rate decreases significantly with increasing experience on the part of the surgeon. That 9% of the respondents stated that patients had experienced anesthetic complications was of great interest; this suggests that anesthesia for transsphenoidal procedures is more than a trivial event and that some aspects of pituitary disease, such as acromegaly, may increase the likelihood of such complications.

Clearly it would have been difficult to gather firm data regarding the incidence of misdirected surgical approaches. This complication does occur even with the best surgeons, and a misdirected approach that guides the surgeon intracranially through the cribriform plate or through the clivus below the sella is a significant hazard. Both aspects of the misdirected approach can, of course, produce both direct brain injury and cerebrospinal fluid (CSF) rhinorrhea.

A few comments regarding the avoidance of complications might be useful for consideration of the data presented here. First, careful anatomic analysis of the preoperative imaging studies is essential and is of great help in maintaining the midline approach. The preservation of midline structures whenever possible and the ability to keep them in view until the sella is open provide a great deal of safety and are, of course, confirmed in the lateral view with x-ray control. Meticulous surgical technique with careful hemostatis is also critical in preventing the obscuring of important anatomic details. Diabetes insipidus can best be precluded by avoiding manipulation of the pituitary stalk when operating on intrasellar tumors wherein the posterior pituitary and the pituitary stalk might be observed or traumatized. Preservation of the normal pituitary gland depends on the ability of the surgeon to recognize the sometimes membranous remnants of the normal pituitary and to preserve them carefully while thoroughly removing the tumor. It is our preference to use tissue packing (abdominal fat) of the tumor cavity or empty sella only when there has been a CSF leak (this includes overt CSF leaks and the "weeping" type of CSF leak that may be seen because of an arachnoidal diverticulum within the sella or a very thinned diaphragm). We have not found the addition of either fascia lata or fibrin glue to aid significantly in the security of the packing and in the prevention of postoperative CSF leaks. When there has been no CSF leak, it is our preference simply to pack the tumor cavity with Gelfoam. In both cases, careful reconstruction of the floor of the sella is accomplished by using septal cartilage or bone.

When a CSF leak does occur in the postoperative period, we favor immediate reexploration and repacking. Although we have had a few patients for whom the leak has stopped with prolonged lumbar drainage, it is such a simple process to reexplore fresh transsphenoidal cases that reexploration and repacking have been almost uniformly successful, avoiding the anxiety of maintaining lumbar drainage for the patients. We also recommend immediate reexploration for unanticipated visual loss or cranial nerve palsy when the patient awakens after surgery. This usually occurs either because the sella has been packed too tightly or because there has been some hemorrhaging, which can be removed.

Nasal septal perforations can be unpleasant complications in patients who are otherwise well. They usually occur because the nasal mucous membrane is damaged in similar areas on both sides of the septal cartilage. When this sort of mucosal damage occurs, the surgeon should make every possible attempt to perform a direct repair of the torn mucosa, at least on one side of the nasal septum. Delayed repair of a symptomatic nasal septal perforation can occasionally be accomplished with a silastic button, and we had one case in which a colleague, an ear, nose, and throat specialist, successfully repaired the perforation by using dural graft material.

It is clear that endocrine complications, such as iatrogenic hypopituitarism and diabetes insipidus, decrease with the experience of the surgeon with transsphenoidal procedures, and this is probably related to gentle technique and careful dissection within the sella itself. It will be interesting to see how the use of endoscopic techniques may alter the incidence and severity of these types of complications.

Carotid artery injuries can always occur. Careful analysis of the magnetic resonance imaging scans before the dura is incised is highly recommended. If the carotid artery is violated, the surgeon must be willing to acknowledge this, to stop the bleeding, and then to perform angiography as soon as possible after the operation. Even if the artery seems to be successfully repaired by packing (direct suture repair is obviously the most desirable management strategy if it can be accomplished), a subsequent angiogram should be planned because the majority of these patients develop false aneurysms and, if this late complication is untreated, the results are frequently catastrophic. Although endovascular techniques are usually successful in dealing with false aneurysms, we had one patient for whom direct repair within the cavernous sinus, through a craniotomy, was necessary.

For most surgical complications, the best strategy is avoidance. This depends on a thorough understanding of the disease, the surgery, and the techniques that need to be used to obtain optimal results.

Edward R. Laws, Jr.
Charlottesville, Virginia

This article presents an excellent overview of the complications that can be associated with transsphenoidal surgery. It is interesting to consider the findings in this perspective, with such a large number of cases presented. I am sure that there are many complications that most neurosurgeons have never encountered and some that occur frequently about which we have perhaps become a little too unconcerned. This is an important compilation of data.

William Shucart
Boston, Massachusetts

Please submit your thoughts or comments to William Chandler, Internet Moderator at wchndlr@umich.edu.

Return to Neurosurgery Home Page

To Subscribe

Return to the Waverly Home Page Search the Waverly Catalog
© 1997 Williams & Wilkins