The present study showed that the perioperative risk of TSS did not increase in elderly patients. Recovery of sGHD after TSS was expected in patients younger than 55 years of age; however, pseudocapsular resection in elderly patients was not associated with the deterioration of GH secretion. To the best of our knowledge, the present study is the first report to focus on pseudocapsular resection in elderly patients.
Past studies have described the safety and the successful application of TSS in elderly patients, reporting that the outcomes were similar to those in younger patients. However, studies of large series have shown that elderly patients have a higher incidence of morbidity and inpatient mortality after pituitary surgery . As TSS is generally less invasive than transcranial surgery and is associated with a lower incidence of perioperative complications, it is difficult to detect the difference between younger and elderly patients in small series of patients undergoing TSS. Although we also showed the safety of TSS in elderly patients with NFPA in this study, additional large studies are required to determine the effects of aging on TSS.
Pseudocapsular resection has contributed to the improvement of endocrinological remission rates in patients with FPA ; hence, this surgical technique is absolutely essential in the treatment of FPA. On the other hand, whether this technique should be applied to NFPA is controversial. We clarified the safety of pseudocapsular resection in patients with NFPA in a previous report , and this subsequent report confirmed the safety of pseudocapsular resection in elderly patients with NFPA.
The rate of recurrence in elderly patients was reported to be lower than that in younger patients , and the tumor volume doubling time of residual NFPA in elderly patients (≥61 years of age) was approximately 2-fold longer than that in younger patients (<61 years of age) . From the viewpoint of prevention of tumor recurrence, pseudocapsular resection might not be so important in some elderly patients, while some tumors may recur at older age and require additional treatments, such as radiotherapy or re-operation when the patient is older. Moreover, we would like to emphasize the importance of pseudocapsular resection in hemorrhagic tumors causing postoperative hematoma, and hard or fibrous tumors. Pseudocapsular resection cannot be conducted in all cases; however, pseudocapsular resection can contribute to reducing the surgical risk and reducing the incidence of tumor recurrence in some cases without increasing the perioperative risk. In the present study, we showed that pseudocapsular resection was not associated with the deterioration of the pituitary functions in elderly patients with NFPA; moreover, pseudocapsular resection might reduce the risk of postoperative hemorrhage. Further studies are needed to confirm the advantage from the aspect of the recurrence rate.
We showed that it was difficult to improve sGHD in elderly patients. Jahangiri et al. reported that younger age predicted the recovery from preoperative pituitary dysfunction after TSS for NFPA . Liu et al. also reported that elderly patients had significantly more difficulty in recovering from preoperative hypopituitarism . No studies in the relevant literature have reported that elderly patients show superior recovery from preoperative hypopituitarism. We also showed that the elderly patients (≥55 years of age) were not likely to recover from preoperative sGHD after surgery. On the other hand, the improvement of sGHD was obtained especially in younger patients, especially those with pseudocapsular resection. This result was probably associated with the background characteristics of patients with pseudocapsular resection, who tended to have small-size tumors . From the beginning, younger patients who received pseudocapsular resection were likely to recover from sGHD, irrespective of whether the pseudocapsule was resected. We recognize that pseudocapsular resection does not contribute to recovery from preoperative hypopituitarism, but that appropriate pseudocapsular resection procedures have no negative influence on the pituitary function, even in elderly patients. These results also suggest that the application of pseudocapsular resection can be considered in elderly patients with FPA. We assume that pseudocapsular resection is not necessary for all elderly patients with NFPA, but that surgeons should not be hesitant in applying this technique because of their elderly age.
The present study was associated with some limitations. First, the number of elderly patients was relatively small. The incidence rates of perioperative complications are intrinsically low in TSS; thus, studies in larger populations are needed to assess the safety of TSS in elderly patients. Second, the application of pseudocapsular resection is depends on the pituitary surgeon. The selection of patients with pseudocapsular resection is not free from some bias. Third, some patients did not receive preoperative and postoperative pituitary provocation tests. The incidence of sGHD would be affected by the selection bias in the patients who receive provocation tests.