Endoscopic transsphenoidal pituitary surgery

Factors Limiting Complete Resection in the Subarachnoid Space in Endoscopic Surgery for Giant Pituitary Adenoma

OBJECTIVES

Giant pituitary adenomas (>4 cm, GPAs) have presented great challenges to surgeons because the residual tumor in the subarachnoid space can cause hemorrhage or vessel injury following apoplexy. This study aimed to investigate the factors limiting surgical success in endoscopic skull base surgery (ESS) for GPAs.

METHODS

ESS was performed on 67 consecutive patients with GPAs from 2010 to 2020. We retrospectively analyzed the clinical and radiologic features and surgical outcomes. Correlations between the tumor characteristics and extent of resection were statistically presented with odds ratios (ORs).

RESULTS

Preoperative visual and hormonal impairments were present in 59 (88.1%) and 55 patients (82.1%), respectively. Gross total resection (GTR) was achieved in 58.2% of patients, and the tumor remained on the lateral side of the subarachnoid space or the cavernous sinus when complete resection failed. The tumor volume, maximal diameter, multilobulated shape, cavernous sinus invasion, posterior fossa extension, and extent of suprasellar lateral extension of tumors were significantly correlated with incomplete resection. In tumors with subarachnoid lateral extension, greater distances from the medial wall of the proximal cavernous internal carotid artery to the most lateral tumor significantly increased the risk of incomplete resection for the suprasellar lateral portion of the tumor, with an OR of 1.21.

CONCLUSIONS

Considerable surgical planning in ESS for GPAs is crucial for complete resection and patient safety. We elucidated that lateral extension of tumors in the subarachnoid space hindered the surgical success of the suprasellar portion of the tumor.

Reoperative endoscopic endonasal surgery for residual or recurrent pituitary adenomas

OBJECTIVE

Regrowth of the lesion after surgical removal of pituitary adenomas is uncommon unless subtotal resection was originally achieved in the first surgery. Treatment for recurrent tumor can involve surgery or radiotherapy. Locations of residual tumor may vary based on the original approach. The authors evaluated the specific sites of residual or recurrent tumor after different transsphenoidal approaches and describe the surgical outcome of endoscopic endonasal transsphenoidal reoperation.

METHODS

The authors analyzed a prospectively collected database of a consecutive series of patients who had undergone endoscopic endonasal surgeries for residual or recurrent pituitary adenomas after an original transsphenoidal microscopic or endoscopic surgery. The site of the recurrent tumor and outcome after reoperation were noted and correlated with the primary surgical approach. The chi-square or Fisher exact test was used to compare categorical variables, and the Mann-Whitney U-test was used to compare continuous variables between surgical groups.

RESULTS

Forty-one patients underwent surgery for residual/recurrent pituitary adenoma from 2004 to 2015 at Weill Cornell Medical College. The previous treatment was a transsphenoidal microscopic (n = 22) and endoscopic endonasal (n = 19) surgery. In 83.3% patients (n = 30/36) there was postoperative residual tumor after the initial surgery. A residual tumor following endonasal endoscopic surgery was less common in the sphenoid sinus (10.5%; 2/19) than it was after microscopic transsphenoidal surgery (72.7%; n =16/22; p = 0.004). Gross-total resection (GTR) was achieved in 58.5%, and either GTR or near-total resection was achieved in 92.7%. Across all cases, the average extent of resection was 93.7%. The rate of GTR was lower in patients with Knosp-Steiner Grade 3–4 invasion (p < 0.0005). Postoperative CSF leak was seen in only one case (2.4%), which stopped with lumbar drainage. Visual fields improved in 52.9% (n = 9/17) of patients and were stable in 47% (n = 8/17). Endocrine remission was achieved in 77.8% (n = 14/18) of cases, 12 by surgery alone and 2 by adjuvant medical (n = 1) and radiation (n = 1) therapy. New diabetes insipidus occurred in 4.9% (n = 2/41) of patients—in one of whom an additional single anterior hormonal axis was compromised—and 9.7% (n = 4/41) of patients had a new anterior pituitary hormonal insufficiency.

CONCLUSIONS

Endonasal endoscopic reoperation is extremely effective at removing recurrent or residual pituitary adenomas that remain after a prior surgery, and it may be preferable to radiation therapy particularly in symptomatic patients. Achievement of GTR is less common when lateral cavernous sinus invasion is present. The locations of residual/recurrent tumor were more likely sphenoidal and parasellar following a prior microscopic transsphenoidal surgery and sellar following a prior endonasal endoscopic surgery.

Endonasal endoscopic pituitary surgery in the elderly

OBJECTIVE Pituitary adenomas are benign, slow-growing tumors that cause symptoms either through mass effect or hormone overproduction. The decision to operate on a healthy young person is relatively straightforward. In the elderly population, however, the risks of complications may increase, rendering the decision more complex. Few studies have documented the risks of surgery using the endonasal endoscopic approach in a large number of elderly patients. The purpose of this study was to audit a single center's data regarding outcomes of purely endoscopic endonasal transsphenoidal resection of pituitary adenomas in elderly patients and to compare them to the current literature. METHODS A retrospective review of a prospectively acquired database of all endonasal endoscopic surgeries done by the senior authors was queried for patients aged 60-69 years and for those aged 70 years or older. Demographic and radiographic preoperative data were reviewed. Outcomes with respect to extent of resection and complications were examined and compared with appropriate statistical tests. RESULTS A total of 135 patents were identified (81 aged 60-69 years and 54 aged 70 years or older [70+]). The average tumor diameter was slightly larger for the patients in the 70+ age group (mean [SD] 25.7 ± 9.2 mm) than for patients aged 60-69 years (23.1 ± 9.8 mm, p = 0.056). There was no significant difference in intraoperative blood loss (p > 0.99), length of stay (p = 0.22), or duration of follow-up (p = 0.21) between the 2 groups. There was a 7.4% complication rate in patients aged 60-69 years (3 nasal and 3 medical complications) and an 18.5% complication rate in patients older than 70 years (4 cranial, 3 nasal, 1 visual, and 2 medical complications; p = 0.05 overall and 0.013 for cranial complications). Cranial complications in the 70+ age category included 2 postoperative hematomas, 1 pseudoaneurysm formation, and 1 case of symptomatic subdural hygromas. CONCLUSIONS Endonasal endoscopic surgery in elderly patients is safe, but there is a graded increase in complication rates with increasing age. The decision to operate on an asymptomatic or mildly symptomatic patient in these age groups should take this increasing complication rate into account. The use of a lumbar drain or lumbar punctures should be weighed against the risk of subdural hematoma in patients with preexisting atrophy.