The management of pituitary tumours and post-operative visual deterioration

Snare technique for the remodeling of the redundant arachnoid pouch to prevent cerebrospinal fluid rhinorrhea and hematoma collection during transsphenoidal surgery for suprasellar-extended pituitary tumors

OBJECTIVE Transsphenoidal surgery (TSS) is considered a most effective treatment for pituitary tumors with huge suprasellar extension. However, the chance of developing CSF leakage is relatively high, because tearing of the arachnoid membrane is common and there could be multiple tear points during the dissection of suprasellar tumors from the overlying arachnoid membrane. If there are multiple leaking points in the arachnoid membrane packing methods such as using fat or multilayered fascia graft may not be sufficient to seal off the leaking points. Moreover, the packing material may not provide sufficient tamponade to stop bleeding, and thus generates postoperative hematoma formation in the tumor resection cavity. To prevent these complications, the authors have developed a new technique for remodeling the redundant arachnoid pouch (the so-called snare technique) to reconstruct the diaphragm, seal off the CSF leak points completely, and reduce the dead space in the tumor resection cavity. METHODS In 9 patients with huge macroadenomas (> 2.5 cm in diameter) with suprasellar extension, the snare technique was used to remodel the arachnoid pouch after tumor removal via standard TSS between July 2009 and August 2014. Complications were investigated, including postoperative CSF rhinorrhea, postoperative hematoma collection, and visual compromise. RESULTS During the resection of the tumor, CSF leakage was encountered in 8 cases, all of which were sealed off using the snare technique. In 1 case without intraoperative CSF leakage, the snare technique was also applied after intentional puncturing of the arachnoid membrane to reduce the volume and tension of the arachnoid pouch. None of the 9 patients experienced postoperative CSF rhinorrhea. Lumbar CSF drainage was not required in any case. Magnetic resonance imaging studies performed 24 hours after surgery revealed a remarkable reduction in the height of the diaphragm in all cases. Visual deficits improved in all patients immediately after surgery. CONCLUSIONS Remodeling of the arachnoid pouch using the snare technique is simple and effective for completely sealing off the CSF leak point and preventing hematoma collection in the tumor resection cavity after TSS for huge pituitary tumors with suprasellar extension.

Transcranial surgery for pituitary adenomas

Following a century of evolution and refinements in standard surgical techniques, the vast majority of operations for pituitary adenoma to date are performed utilizing transsphenoidal approaches. From current large series one obtains the impression that certainly less than 10% of these tumors require craniotomies. However, still several tumors, which's volume is mainly localized outside of the sella require transcranial approaches, of which the pterional and subfrontal routes are the most widely used. The goal of surgical treatment is rapid eradication of the tumor mass, decompression of visual pathways and elimination of hormonal oversecretion whilst preserving the normal gland and avoiding potential surgical complications. Even with microsurgical techniques and standardized approaches, there is still some mortality associated with transcranial approaches and morbidity is undoubtly higher than with transsphenoidal operations. However, a selection bias must be considered, which shifts tumors with a larger size, less favourable prognosis and higher complication rate into the transcranial series. Moreover, with extended transsphenoidal approaches, lesions have become accessible for transsphenoidal surgery, which previously have been considered as contraindications. In this article current indications and limitations for transcranial surgery of pituitary adenomas, the preoperative workup, surgical techniques, results, and complications are briefly reviewed.

Need for intrasellar packing in sellar reconstruction of transsphenoidal surgery: less is more?

BACKGROUND

This study investigated patients with pituitary macroadenomas who received transsphenoidal surgery using two different sellar reconstruction methods, to determine the need for intrasellar packing.

METHODS

The authors reviewed 53 patients with pituitary macroadenomas at a single institution between January 1999 and November 2002. On tumour removal, the group 1 patients underwent traditional sellar reconstruction (intrasellar and sphenoid sinus packing), while the group 2 patients did not undergo intrasellar packing.

RESULTS

The two groups did not differ significantly in terms of complications. There was no mortality; notably, no delayed empty sella syndrome occurred in the group 2 patients.

CONCLUSIONS

Simplified reconstruction of the sella floor using only sphenoid bone without intrasellar packing is thought to be safe and effective. This technique obviates the need for a second surgical incision, risk of overpacking, complications associated with packing material and interference on postoperative magnetic resonance imaging.

Pituitary neurologic surgery: a unique subspecialty in evolution

OBJECTIVE

To review the evolving approaches to surgical management of pituitary tumors during the past century, which may predict future directions.

METHODS

We undertook a retrospective review of selected literature published during the past century and report the trends in the treatment of pituitary tumors.

RESULTS

Harvey Cushing's extraordinary influence on American neurosurgery and remarkably successful pituitary surgical series were the foundation for the development of a highly subspecialized neurosurgical operative field. Continued evolution in the treatment of pituitary tumors has been historically based on the following: (1) the development of exogenous cortisone and vasopressin; (2) the development of high-voltage and nuclear radiation therapy; (3) the experience gained from total hypophysectomy for "endocrine" driven malignant lesions and diabetic retinopathy; (4) the development of the image intensifier and television intraoperative fluoroscopic control; (5) the use of endoscopes in pituitary surgical procedures; (6) the application of the operating microscope to transsphenoidal approaches; (7) the development of the imaging modalities of computed tomographic scanning and subsequent magnetic resonance imaging; and (8) the concepts surrounding "minimally invasive" surgical techniques.

CONCLUSION

The pituitary surgical techniques of today have evolved primarily because of extraordinary past accomplishments. The approaches used continue to maximize tumor resection and preserve functioning pituitary tissue. New intraoperative imaging techniques will forge the future of the field of pituitary neurosurgery, and the expected outcomes will be improved surgical success and lower perioperative morbidity.)

Surgical treatment of pituitary tumors in the elderly: clinical outcome and long-term follow-up

Pituitary adenomas in the elderly represent an increasing proportion of pituitary tumors, making the surgical management of these patients of special importance. We therefore decided to review our experience with transsphenoidal surgery (TSS) in this age group, in order to better evaluate its efficacy, safety and outcome. A retrospective study was performed on 39 patients aged more than 70 years at the time of surgery (mean age 74.1 +/- 2.9 years) and with a minimum follow-up duration of 4 years at the time of the study. Thirty-one had a nonfunctioning pituitary adenoma, 5 had a GH-secreting adenoma and 3 a macroprolactinoma, respectively. The commonest presenting symptom was visual deterioration (60%), whereas hypopituitarism were present in 41% of patients. All patients underwent TSS without any major peri- and post-operative complications. Visual fields improved in 74% of patients. Post-operative radiotherapy was performed in 17 patients with partial surgical resection and/or persistent hormonal hypersecretion, whereas 22 patients with subtotal or total surgical resection were treated by surgery only. Long-term follow-up (mean 9.1 +/- 2.7 years) showed evidence for tumor regrowth in one irradiated (5.9%) and 3 non-irradiated patients (13.6%), respectively. A noticeable complication of radiotherapy was progressive hypopituitarism, which worsened or developed in 65% of patients. We conclude that TSS is safe and well tolerated even in elderly patients, with a low incidence of minor complications. The indications for post-operative radiotherapy in patients with incomplete tumor resection should be better defined.

[Prolactinomas: neurosurgical aspects]

We report our experience with 38 cases of prolactin secreting pituitary adenomas. The adenomas were divided in three different groups. The adenomas producing only prolactin tend to be microadenoma and they show the typical alterations of this type of tumor. The GH-PRL, GH-alpha subunit, the other combinations, and the pluri hormonal adenomas tend to present with visual symptoms. The treatment of the prolactinomas is initially clinical and the surgical indication for this type of adenomas is related to intolerance to the medication or to visual alterations. Surgical result with total resection of the tumor was possible in 50% of the cases.

Complications of transsphenoidal surgery: results of a national survey, review of the literature, and personal experience

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 chi 2 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.