What is a “saddle region”? “Saddle region” is the name of an anatomical area in the skull, located in the very center of the skull, including the pituitary fossa, as well as the suprasellar and paraspinal regions. It is customary to collectively refer to occupying lesions in this region as “saddle region occupations”, which include neoplastic as well as non-neoplastic lesions such as cysts. This includes tumor and non-tumor lesions such as cysts. Saddle region tumors (including supratentorial tumors) account for about 15-20% of all intracranial tumors in children, and are the most common and high risk group of intracranial tumors in children. The three most common childhood saddle region tumors include craniopharyngiomas, optic tract gliomas, and germ cell tumors, while pituitary adenomas and meningiomas, which are common in adults, are rarer in children. The pituitary gland and hypothalamus are important adjacent structures in the saddle region, including the pituitary gland, pituitary stalk, hypothalamus, internal carotid artery and its major branches (middle cerebral artery, anterior cerebral artery, anterior communicating artery, etc.), optic nerve, optic crossings, and cavernous sinus. The tumor itself, surgery, radiotherapy and other treatments may affect the function of the pituitary hypothalamus in the saddle region, which is mainly manifested in the disturbance of water-electrolyte balance, low endocrine hormones, fat metabolism disorders in the later stage of the disease, as well as the future height and pubertal development of the child, etc. The postoperative management of the child needs to be completed by neurosurgeons, endocrinologists, and the parents of children. Improper postoperative management may affect the quality of life or cause fatal harm. I. What problems may occur after saddle zone surgery? 1.Ureaplasia, water electrolyte disorders Antidiuretic hormone is one of the important hormones secreted by the posterior pituitary gland, which is in charge of the excretion and absorption of water by the kidneys, and is involved in the regulation of water electrolytes and blood pressure. Decreased secretion of antidiuretic hormone can cause increased urine output and blood concentration, manifested as dysuria and elevated blood sodium, and even blood potassium abnormality, which is often the earliest endocrine disorders during the perioperative period of saddle region surgery, and some children have a sharp increase in urine output during the surgery. After surgery, doctors will strictly monitor the children’s daily or even hourly water intake and urine output, and check the blood sodium level 1-2 times a day or even more, and doctors and nurses will instruct parents to develop the habit of recording the correct amount of water intake and output. Afterwards, the doctor will adjust the intake and output of the child and the blood sodium level according to the results of the monitoring. Hypothyroidism Thyroid hormone has the effect of raising the metabolic level of the human body, increasing the metabolic excitability of the human body systems, and promoting growth and development, in a nutshell, it is a kind of hormone that “makes people excited”. In children, thyroxine levels are higher than in adults due to the demands of growth and development. When the pituitary gland fails to produce enough thyroid stimulating hormone, downstream thyroid hormone levels are lowered and the child may appear to be in poor spirits, reluctant to eat or move around, slow to speak, and have memory loss. If hypothyroidism is already present prior to surgery, the child will need to be kept on thyroxine tablets (Euthyrox, Ractis). If the test results are normal before surgery, the doctor will add thyroxine tablets about 1 week after surgery according to the thyroid function test results. 3.Low level of glucocorticoid hormone Glucocorticoid hormone is an important “stress hormone” in human body, which participates in many endocrine changes in human body during the process of stress, and can be regarded as an important substance for human body to protect itself. When the glucocorticoid level is low, the child will also have poor spirit, poor appetite, weight loss, skin darkening and other manifestations, and the serious reduction can be fatal. High glucocorticoid levels can also cause problems, such as centripetal obesity with a “full moon face, buffalo back, and thin limbs”, which can lead to hyperglycemia, hypertension, osteoporosis, acne, poor wound healing, and blood clotting disorders. In the perioperative period, glucocorticoids are often supplemented before the child’s surgery to help the child pass more smoothly through the stressful phase of surgery, and higher doses of glucocorticoids are often needed intravenously for a short period of time to minimize postoperative reactions. Later, the doctor will gradually reduce the hormone dosage and eventually maintain a small, long-term oral dose. There are many types of glucocorticosteroids, including hydrocortisone, prednisone, methylprednisolone, dexamethasone and so on, which are different in the nature of the drug, but all of them follow the principle of “the anti-inflammatory effect of one tablet is comparable”. Parents need to pay attention to the name of the drug used by their children, and accurately communicate with the clinic doctor about their condition. In the long-term follow-up, often not glucocorticoid deficiency, but glucocorticoid overdose, the children have become “little fat”, diabetes and other problems, which is often caused by long-term oral hormone amount of bias. 4, short stature Growth hormone is a hormone secreted by the pituitary gland, which is very important for children’s growth and development, and not only affects the development of height, but also affects the proportion of muscle and fat (that is, the stature), and the lack of growth hormone may also cause fatty liver and abnormal liver function. For children with tumors in the saddle region, when it is clear that the tumor has disappeared and has not recurred (usually more than 1 year after surgery), the endocrinologist will refer to the child’s current height, bone age, and the results of insulin-like growth factor 1 (IGF-1) laboratory tests, and add growth hormone to the child. Parents should be reminded that there is a time window for the administration of growth hormone. If the bone age film shows that the epiphysis has already closed (mostly after puberty), then growth hormone supplementation will not be able to increase the child’s height. Therefore, for children with short height, obesity or fatty liver after surgery, parents should consult the endocrinology department in time, so that specialists can help their children to evaluate whether they have the conditions for growth hormone supplementation. Sex hormone is also an important hormone secreted by the pituitary gland, which plays an important role in the development of children’s secondary sexual characteristics and the maintenance of fertility. After puberty, for children with low level of sex hormones, exogenous supplementation of hormones is needed to ensure the normal development of sex signs during puberty, which is very important for both boys and girls. How should parents take care of their children after discharge from the hospital? In most cases, what the neurosurgeon accomplishes is only the surgical treatment of the tumor in the saddle region and short-term endocrine management after surgery. Some children need to continue radiotherapy or chemotherapy after surgery, parents should strictly follow the recommendations of neurosurgeon, radiotherapist and oncologist on postoperative radiotherapy and chemotherapy, and should regularly review the head imaging (including enhanced MRI, CT, etc.). On this basis, visit the endocrinologist as soon as possible. 2. Water, urine, electrolytes Severe water and electrolyte disorders can be fatal. Parents should learn and develop the habit of recording the daily water intake and urine output of their children. In the early postoperative period, they should record the intake and output on an hourly basis, monitor the blood sodium level on a daily basis, and also gradually teach their children to complete the record by themselves. The following table can be used as a reference. It is necessary to fix the child’s daily water intake (usually around 2,000-2,500 ml per day), and monitor the urine output and blood sodium on this basis, in order to accurately reflect the function of the antidiuretic hormone and the effect of the medication used in Micronomicin, and to precisely adjust the medication according to this result. Milrin is a hormone drug that helps control urine output, and should be taken at minimum intervals of 6-8 hours; too frequent use of the drug will not bring more benefits. Eating should be avoided for 1 hour before and after administration to avoid interfering with the absorption of the medication. Micronutrient can also be taken sublingually, which has the same effect as taking it orally. Special attention needs to be paid to the fact that the body’s water loss includes not only urination, but also sweating and defecation. Strenuous activities, a lot of sweating, a lot of watery diarrhea, the child will have a short-term rapid water loss, aggravate the water electrolyte disorders, and therefore should try to avoid strenuous exercise, hot springs, sauna and other activities, fever, diarrhea should be appropriate to increase the amount of hydration, and if necessary, should be to the emergency room to the doctor to help complete. 3, monitoring physical development After discharge, children should be monitored weekly for height and weight to objectively assess the level of development and trends. In the short term after surgery, many children will experience rapid weight gain, which is related to hormone fluctuations and glucocorticoid application, so it is more important to monitor closely. If the weight is high, or there is a tendency of accelerated weight gain, it is necessary to control the weight in combination with diet and exercise. After the glucocorticoid medication is gradually reduced, the child’s weight will generally stabilize. Appropriate thyroxine level and growth hormone addition can also help the child to adjust the body composition ratio and promote height development. For the assessment of height growth potential, the level of insulin-like growth factor 1 (IGF-1) and bone age X-ray should be referred to, and parents can bring their children for regular checkups. Six months after surgery for saddle region tumors, an endocrinologist may be asked to assist in assessing the need and potential for additional growth hormone. After epiphyseal closure, it is generally not possible to help height growth through growth hormone supplementation, but it does not mean that adults no longer need growth hormone. Recent studies have shown that small-dose long-term supplementation of growth hormone is positively helpful for the regulation of blood lipids, bones, liver function, cardiovascular and mood. 4, glucocorticoid replacement therapy Short-term postoperative glucocorticoid dosage is generally larger, replaced with oral medication before discharge from the hospital, and can be reduced to a smaller dose at a faster rate after discharge to maintain treatment. It is generally recommended to reduce the dose by half a tablet every 3 days, prioritizing the reduction of afternoon dosing. Nighttime dosing is generally not recommended because glucocorticoids may interfere with the child’s sleep. Gradually reduce the dose in an orderly manner until a small maintenance dose (no more than half a tablet to one tablet per day) is achieved. If symptoms such as poor mental performance or loss of appetite occur after tapering, the dose may need to be increased again. If the child develops an acute illness such as a cold or fever, the glucocorticoid dosage may need to be increased, and parents should take their child to the emergency room of the local hospital! During the application of glucocorticosteroids, many children will have elevated blood glucose, and in severe cases, ketoacidosis and other emergencies, which can be life-threatening, and thus blood glucose is one of the indicators that need to be monitored daily after discharge from the hospital, and this is especially true for the children who are overweight. 5, thyroid hormone replacement therapy In the perioperative stress state, the human body will appear stress-related hypothyroidism, so this time to monitor the thyroid function is not accurate. Thyroid hormone supplementation can be started 7 days after surgery, and thyroid function is rechecked 1 month after discharge to assess the appropriateness of the dose of medication. During the follow-up, the doctor is most concerned about the level of the indicator free T4 (FT4). 6. Sex hormone replacement therapy For children entering puberty, sex hormone supplementation is needed in conjunction with development and sex hormone test results to maintain the development of secondary sex characteristics. For girls with reproductive needs in adulthood, hormonal adjustments can also be made to complete childbirth and become a mother. Monitoring] Daily recording of blood flow and glucose, weekly height and weight measurements, regular electrolyte, hormone and head imaging checks [Daily life] Rationed water intake, appropriate exercise, weight control [Treatment] Surgical treatment of the primary disease is the first key element, and germ cell tumors and gliomas of the optic pathway often require chemo-radiotherapy, with blood flow and Na adjusted to compensate for coagulation, and low dose glucocorticoids to maintain the condition, and thyroxine adjusted according to laboratory tests. Glucocorticoids are maintained at low doses, thyroxine is adjusted according to laboratory tests, growth hormone needs are assessed at six months, and sex hormones are added at puberty.