Delayed Postoperative Hyponatremia Following Endoscopic Transsphenoidal Surgery for Non-Adenomatous Parasellar Tumors

Little is known about delayed postoperative hyponatremia (DPH) accompanied with transsphenoidal surgery for non-adenomatous skull base tumors (NASBTs). Consecutive data on 30 patients with parasellar NASBT was retrospectively reviewed with detailed analyses on perioperative serial sodium levels. Serological DPH (sodium ≤ 135 mmol/L) was observed in eight (27%), with four (13%) of them being symptomatic. DPH developed on postoperative day 7–12 where the mean sodium levels were 134 mmol/L (a mean of 7 mmol/L drop from the baseline) in asymptomatic and 125 mmol/L (a mean of 17.5 mmol/L drop from the baseline) in symptomatic DPH. Serological DPH was accompanied with “weight loss and hemoconcentration (cerebral salt wasting type)” in four (50%), “weight gain and hemodilution (syndrome of inappropriate antidiuretic hormone secretion type)” in three (38%), and no significant weight change in one. Intraoperative extradural retraction of the pituitary gland was the only significant factor for serological DPH (p = 0.035; odds ratio, 12.25 (95% confidence interval, 1.27–118.36)). DPH should be recognized as one of the significant postsurgical complications associated with TSS for NASBTs. Although the underlying mechanism is still controversial, intraoperative extradural compression of the pituitary gland and subsequent dysregulation of the hypothalamo-hypophyseal axis may be responsible.

Clinical characteristics and outcomes in elderly patients undergoing transsphenoidal surgery for nonfunctioning pituitary adenoma

OBJECTIVELife expectancy has increased over the past century, causing a shift in the demographic distribution toward older age groups. Elderly patients comprise up to 14% of all patients with pituitary tumors, with most lesions being nonfunctioning pituitary adenomas (NFPAs). Here, the authors evaluated demographics, outcomes, and postoperative complications between nonelderly adult and elderly NFPA patients.METHODSA retrospective review of 908 patients undergoing transsphenoidal surgery (TSS) for NFPA at a single institution from 2007 to 2019 was conducted. Clinical and surgical outcomes and postoperative complications were compared between nonelderly adult (age ≥ 18 and ≤ 65 years) and elderly patients (age > 65 years).RESULTSThere were 614 and 294 patients in the nonelderly and elderly groups, respectively. Both groups were similar in sex (57.3% vs 60.5% males; p = 0.4), tumor size (2.56 vs 2.46 cm; p = 0.2), and cavernous sinus invasion (35.8% vs 33.7%; p = 0.6). Regarding postoperative outcomes, length of stay (1 vs 2 days; p = 0.5), extent of resection (59.8% vs 64.8% gross-total resection; p = 0.2), CSF leak requiring surgical revision (4.3% vs 1.4%; p = 0.06), 30-day readmission (8.1% vs 7.3%; p = 0.7), infection (3.1% vs 2.0%; p = 0.5), and new hypopituitarism (13.9% vs 12.0%; p = 0.3) were similar between both groups. Elderly patients were less likely to receive adjuvant radiation (8.7% vs 16.3%; p = 0.009), undergo future reoperation (3.8% vs 9.5%; p = 0.003), and experience postoperative diabetes insipidus (DI) (3.7% vs 9.4%; p = 0.002), and more likely to have postoperative hyponatremia (26.7% vs 16.4%; p < 0.001) and new cranial nerve deficit (1.9% vs 0.0%; p = 0.01). Subanalysis of elderly patients showed that patients with higher Charlson Comorbidity Index scores had comparable outcomes other than higher DI rates (8.1% vs 0.0%; p = 0.006). Elderly patients’ postoperative sodium peaked and troughed on postoperative day 3 (POD3) (mean 138.7 mEq/L) and POD9 (mean 130.8 mEq/L), respectively, compared with nonelderly patients (peak POD2: mean 139.9 mEq/L; trough POD8: mean 131.3 mEq/L).CONCLUSIONSThe authors’ analysis revealed that TSS for NFPA in elderly patients is safe with low complication rates. In this cohort, more elderly patients experienced postoperative hyponatremia, while more nonelderly patients experienced postoperative DI. These findings, combined with the observation of higher DI in patients with more comorbidities and elderly patients experiencing later peaks and troughs in serum sodium, suggest age-related differences in sodium regulation after NFPA resection. The authors hope that their results will help guide discussions with elderly patients regarding risks and outcomes of TSS.

Electrolyte disorders after endoscopic transnasal neurosurgical interventions

Background: Disorders of water and electrolyte balance, hyper- and hyponatremia, are common postoperative complications of transsphenoidal neurosurgical interventions and are found in up to 30–40% of cases. At the same time, delayed hyponatremia is the main cause of repeated hospitalizations of patients, and the risk factors/pathogenetic mechanisms responsible for the development of postoperative hyponatremia have not been fully investigated. Aim: To determine the frequency of water-electrolyte disturbances and to identify predictors of dysnatriemia states in patients after transnasal adenomectomy. Materials and methods: A retrospective single-site study included an analysis of electronic medical records of patients who underwent transnasal neurosurgical interventions for benign tumors of the pituitary gland (n = 416). The diagnostic and prognostic factors for the development of postoperative water-electrolyte disorders were evaluated. Results: The prevalence of hyponatremia in the total group of patients was 7.2%, and for hypernatremia it was 3 times higher – 24.3%, with these indicators being kept stable through the years of surgery (p > 0.05; χ2 with the Yeats correction). 66 (16%) of the operated patients, the sodium level in the early (0–5 day) and 157 (38%) patients in the later (6+ day) postoperative period was not determined, which may underestimate the identification of the most dangerous delayed postoperative hyponatremia. When analyzing the main clinical and laboratory characteristics of patients with hypo-, normo- and hypernatremia, no statistically significant differences were found between the parameters characterizing natremia, the osmolality of blood and urine, the frequency of determining blood sodium in different time intervals of the postoperative period. Complications of the main diagnosis (diabetes mellitus, coronary heart disease and arterial hypertension), selected parameters of pathological examination (identification of neurohypophysis cells, adenohypophysis, oxyphilic, basophilic or chromophobic cells, as well as other structures that are not part of the pituitary gland) and the operation protocol (bleeding, coagulation of sellar structures, liquorrhea, excision of the pituitary gland), did not differ between groups. In the hypernatremia group, the tumor volume in quantitative representation was lower than in the normo- and hyponatremia groups (1.0 ml vs. 1.5 and 1.5 ml, respectively). The number of neurosurgical interventions performed in a patient did not differ between the study groups. Conclusions: After transnasal adenomectomy, hypo- and hypernatremia occur in 7.2% and 24.3%, respectively, and do not depend on the presence of complications of the underlying disease, the parameters of the pathomorphological protocol, the appearance of postoperative hypopituitarism or the course of the operation itself. For the timely detection of disorders of water and electrolyte metabolism, the implementation of blood sodium testing in the early and late (6+ day) postoperative period is necessary in management of patients after transnasal adenomectomy.

Outcomes Following Transsphenoidal Pituitary Surgery in the Elderly: A Retrospective Single-Center Review

BACKGROUND Transsphenoidal surgery (TSS) for pituitary adenomas (PAs) is performed on elderly patients with increasing frequency. More research is necessary to assess the risk factors that are associated with TSS in an aging population. OBJECTIVE To perform a retrospective study on postoperative safety outcomes following TSS in the elderly population stratified by decade of life. METHODS A retrospective chart review of the USC Pituitary Database was conducted to identify patients ≥70 yr, who underwent TSS for PAs between 1995 and 2017. Surgical outcomes were analyzed in elderly (≥70 yr) vs nonelderly (&lt;70 yr) patients. Elderly patients were additionally stratified according to age 70 to 79 vs ≥80 yr. RESULTS The cohorts included 115 elderly patients (70-79 yr: 94 patients; ≥80 yr: 21 patients) and 770 nonelderly patients. Elderly patients presented with more vision loss (62% vs 38%, P &lt; .0001), dizziness (17% vs 6%, P = .0001) and altered mental status (7.3% vs 3%, P = .0451). Overall rates of surgical, medical, and endocrine complications were similar; however, elderly patients had significantly higher rates of postoperative hyponatremia (9.3% vs 4.7%, P = .0401) and lower rates of transient diabetes insipidus (0.9% vs 7.9%, P = .0038). Patients ≥ 80 yr had significantly more surgical complications (26.3%) compared to the 70 to 79 group (7.87%; P = .021) and &lt;70 group (12.5%; P = .04). CONCLUSION Patients &gt;70 yr are appropriate surgical candidates for TSS given the similar safety outcomes as younger patients. Given the higher propensity for surgical complications; however, a higher level of operative selectivity should be maintained in octogenarian patients.