INFRATENTORIAL (POSTERIOR FOSSA) TUMOR REMOVAL SURGERY

Informed Consent Form

Form No: AOF-012	Rev. No / Date: 2026 v09 / 10.07.2026

PATIENT PROTOCOL NO	DATE
TURKISH ID / PASSPORT NO	DATE OF BIRTH
PATIENT'S NAME–SURNAME	SEX
DIAGNOSIS	(wide single cell)

1. Dear Patient,

It is your most natural right to be informed about your medical condition and about all medical / surgical treatments and diagnostic procedures recommended to you for the treatment of your illness. After learning the benefits and possible risks of medical treatments and surgical interventions, it is again your own decision to consent or not to consent to the procedure to be performed. The purpose of this explanation is not to frighten or worry you, but to involve you more consciously in the decisions to be made about matters concerning your health. If you wish, all information and documents concerning your health can be given to you or to a relative you deem appropriate. Although this form has been designed to meet the needs of most patients under many circumstances, it should not be considered a document containing the risks of all forms of treatment. Depending on your personal health condition, your physician may give you different or additional information. After learning the benefits and possible risks of diagnosis, medical treatment and surgical interventions, it is your own decision to accept or not to accept the procedures to be performed. Except in situations of legal and medical necessity, you may refuse to be informed or may withdraw your consent at any time. This form has been prepared to inform you about the risks of the surgery and about alternative treatment methods. Please read this form completely and carefully, and sign this consent form only after you have read it and all your doubts regarding the procedure in question have been resolved by the physician.

2. General Information About the Disease and Its Treatment

The infratentorial region is the name given to the lower part of the brain — the structures called the cerebellum and the brainstem — and the area surrounding these structures. Because this area has a smaller volume compared to the brain, space-occupying formations here can create much faster and life-threatening problems.

The surgery to remove tumors located infratentorially, that is, in the lower part of the brain, begins with the craniotomy procedure, which means removing a portion of bone from the skull and putting it back in place at the end of the surgery. I know that my doctor who will perform my surgery needs to perform a craniotomy (lifting of the skull bone in the relevant region) in order to remove the tumor. I know that, before the craniotomy, my doctor who will perform my surgery will incise the area of the scalp overlying the tumor. A piece of the skull called the "bone flap" will be cut out and removed with a surgical saw (although rare, a craniectomy may be performed; this procedure is the permanent removal of the skull bone in the relevant region). Depending on the location of the tumor, my doctor will incise the dura, the thick membrane surrounding the brain, in order to better see the underlying brain tissue. After as much tumor tissue as can be removed has been removed, the dura will be closed, the bone flap will be put back in place, and the scalp incision will be sutured. However, if the brain is more swollen than necessary, my surgeon may decide not to put the bone back in place.

The aim of this procedure is to remove as much of the tumor as possible and to relieve the pressure on the brain, while preserving or improving neurological function as far as possible. There is no guarantee that the results of this procedure will be good or that the entire tumor will be removed. Your doctor, having evaluated your condition in detail, has decided on the most appropriate surgical treatment method for you and has recommended this approach to you.

3. Alternatives to the Surgery, If Any

As alternatives to the surgery, I have considered the following options:

As explained to me verbally by my physician, accepting all risks and not having this surgery,
Accepting all risks and follow-up with computed tomography, magnetic resonance imaging or other examinations,
Trying to resolve the problems through medical drug therapy and periodic radiological examinations,
Application of chemotherapy or radiotherapy,
Stereotactic radiosurgery (Gamma Knife) (targeted radiation therapy),
Endovascular treatment (intravascular interventions),
Other possible treatment options…

I have also considered the other treatment methods explained to me by my doctor. The advantages and disadvantages of these alternative methods have also been explained to me by my doctor.

4. Expected Benefits of the Surgery

It is an improvement in the patient's current neurological condition and complaints. The surgery is performed with the aim of eliminating the complaints and with the expectation of preserving or improving the function of the nervous system.

WITH THE SURGERY TO BE PERFORMED;

to relieve the neural structures under compression,
the aim is to completely resolve, or to halt the worsening of, the neurological deficits present before the surgery (paralysis-loss of strength-numbness-loss of reflexes-urinary incontinence, etc.) and your complaints such as pain-spasm, through the surgical treatment to be applied.

I am aware that there is no guarantee that the results of this procedure will be good or that the entire tumor will be removed, but I accept the intervention.

5. Estimated Duration of the Surgery

The duration of the procedure to be performed may vary according to the condition of the disease and of the patient, and is on average 2-6 hours. In addition, the procedures to be performed on patients before and after the surgery by the anesthesia doctors are not included in this duration. The procedure may take longer than the stated duration depending on the condition of the case. Your doctor will give you detailed information at the end of the procedure.

6. Risks and Complications of the Surgery

In addition to the benefits of the surgical procedure to be performed, there are also risks that may arise.

Anesthesia risk: There are risks during and after local and general anesthesia procedures (due to the position given to the patient during the surgery). In addition, in every form of anesthesia and in sedation, there are also complications and harms that may occur due to the medications. The anesthesia procedure to be applied and the related risks and complications have been explained to me, and I approve the recommended procedure in this regard.
Bleeding: Although very rare, I am aware of the existence of a risk of bleeding, which may be severe, during or after my surgery. In case of bleeding, additional treatment or blood transfusion may be needed. In such a case, I approve the necessary blood transfusion and other treatments. Some medications that I use and/or that need to be used during my treatment may increase the risk of bleeding through drug interactions and/or side effects. In some cases, it may be necessary to use blood-thinning medications earlier than expected, and this may also increase the risk of bleeding.
Blood clot formation: Blood clots may form after any type of surgery. Clots forming in the bleeding area may obstruct blood flow and lead to complications such as pain, edema, inflammation or tissue damage. If the use of blood thinners is discontinued, the risk of clotting may increase.
Postoperative Neurological Deterioration: Nervous system functions may deteriorate after the surgery due to problems such as bleeding at the surgical site, brain edema (pressure on the brain as a result of fluid accumulation) or vasospasm (narrowing of the vessels).
Respiratory problems: After the surgery, respiratory distress, which is usually temporary, or pneumonia may be seen. Pulmonary embolism (obstruction of the blood vessels of the lungs) may be seen. Respiratory distress may occur through brainstem damage during surgery, and after surgery through the compressive effect of a clot on the brainstem or spinal cord causing lung infection (pneumonia), and through the effect of a clot in the pulmonary artery (pulmonary embolism). Additional treatment may be required.
Cardiac complications: The surgery carries a low risk of leading to an irregular heart rhythm or a heart attack.
Failure of the surgery: The tumor may not be completely removed by the surgery. In addition, the neurological condition and complaints present before the surgery may not improve after the surgery and may even worsen.
Increase in the pain complaint: Although rare, the pain complaint may increase after the surgery. Pain originating from the intravenous lines and from the wounds in the skin and bone where the surgical intervention was performed may be seen. Headache due to the craniotomy may be seen after the surgery, over periods that may extend from 1 week to 1 month.
Infection: Infection may occur at the skin incision site as well as in the surgical field, and even in the bone within the surgical field. Risks related to infection include meningitis (inflammation of the membranes surrounding the brain and spinal cord) and empyema-abscess formation (accumulation of pus).
Nerve root injury: Nerve root injury may cause pain in the leg, weakness in the relevant muscle groups, and sensory disturbances in the relevant dermatomes (nerve areas).
Spinal cord injury: Although very rare, paralysis due to spinal cord injury may occur during the surgery.
Risk of cerebrospinal fluid leakage: After the surgery, cerebrospinal fluid may leak from the wound site to the outside. For its treatment, a spinal (spinal cord) catheter or an additional intervention to repair the same wound site again may be required.
Recurrence, Residue (Remnant): After the surgery, the symptoms may reappear and additional surgery may be required. There is a risk of recurrence from the former site of the tumor; however, this situation may vary depending on the type of the tumor or the extent to which it could be removed in the first surgery.
Seizure Activity: Abnormal electrical activity may arise in the brain, and this may lead to epileptic (epilepsy) seizures.
Hydrocephalus: After the surgery, the intracranial circulation pathways of the cerebrospinal fluid may become obstructed, and the placement of a device called a shunt may be required.
Cerebral Vasospasm (narrowing of the vessels): In patients with hemorrhage or following bleeding that may occur during the surgery, before or after the surgery there may be a decline in nervous system functions due to ischemia in the brain (impairment of the brain's blood supply).
Neuropsychological Disorders: After the surgery, there is a small possibility of loss of intellectual (mental) capacity or depression.
Balance Problems: Balance disturbance and/or dizziness may originate from the tumor itself, and the tumor removal surgery may also lead to these. Nausea and/or vomiting may be seen after the surgery.
Hearing Loss: Hearing loss of various degrees may be encountered after the surgery.
Loss of Nerve Function: The facial nerve may be affected, and drooping of the face, inability to close the eyelid, and dryness of the eye may develop. Due to loss of the swallowing nerves, inability to swallow (necessitating feeding through a catheter placed into the stomach), inability to produce voice, and the need to breathe through a catheter placed into the windpipe may develop.
Brain damage: Due to unexpected anatomical features, damage may develop in the important nerves and vessels of the brain, leading to the patient not waking up, or remaining in intensive care for a long time and having permanent sequelae.
Paralysis: Paralysis or partial weakness may occur after the surgery.
Death: Although a very rare complication, complications resulting in death that have been reported in the literature may develop. Sudden death may occur, and undesirable problems resulting in death due to the above complications may also develop.
I have also understood the possibility that, during my surgery, in the face of an unexpected situation such as bleeding, injury to an adjacent tissue or organ, etc., my doctor may perform other procedures required for my health apart from the planned procedure, and I approve this.

I have understood and accept all the risks written above that may occur during and after the surgical procedure to be performed on me.

7. Consequences to Be Faced If the Surgery Is Not Performed

The patient's current complaints and clinical condition may not improve, and there may be a worsening. Sudden decline in consciousness, tendency to sleep, speech and swallowing disorders and movement disorders, and loss of strength in the arms and legs may develop.

8. Important Characteristics of the Medications to Be Used

If you have a previously identified drug allergy, you must inform your physician and your nurse about this. During your current treatment process, medications appropriate to the patient's medical condition (painkillers, antibiotics, medications supporting the circulation and the heart, blood products, fluid therapies, medications specific to your disease) will be given according to the reason for your admission or newly developing conditions. During the use of medications, side effects may emerge and cause damage to the heart, kidneys and other organs. New medications will be added to the treatment to correct organ damage. ANTIEPILEPTIC MEDICATION: After brain surgeries, seizure-preventing medications called antiepileptics are used to prevent epileptic seizures. PROPHYLAXIS: Before and after your surgery, appropriate protective antibiotic therapy is applied with the aim of reducing the risk of surgical site infection. USE OF BLOOD-THINNING MEDICATION: If you are using anticoagulant, blood-thinning medications, different medication therapies or blood products may be given to you to counteract the effects of these medications. INTRACRANIAL MASS, HYDROCEPHALUS, HEMORRHAGE CASES: Medications may be given to lower the pressure in the brain (intracranial pressure) and the blood pressure, and to prevent spasm (narrowing) in the vessels and seizures. In the presence of tumor-related brain edema and progressive clinical symptoms, anti-edema medications may be used. HEMORRHAGED CASES-VASOSPASM: If narrowing of the vessels-vasospasm develops after the treatment, medications supporting the circulation may be used to keep the blood pressure high. These medications may disturb the water-salt balance and damage the heart, kidneys and other organs. PITUITARY/HORMONAL INVOLVEMENT: During the surgery, the hormonal balance may be disturbed; appropriate medications may be used to maintain the body's water and salt balance. INTENSIVE CARE-DELIRIUM: In elderly patients and during prolonged intensive care stays, for psychological symptoms that may emerge in patients, mental health-regulating medications recommended by a psychiatrist and neurologist may be used. These medications may damage the heart, kidneys and other organs. SHUNT INFECTION, EVD: As a result of a CSF infection, appropriate antibiotics recommended by the infectious diseases department will need to be started. Among these treatments, the method in which medications are administered into the brain ventricles by means of an EVD, expressed as intraventricular treatment, may also be used. In addition to these, medications related to anesthesia are used. The general anesthetic medications given during the surgery may have toxic (poisonous) effects / side effects on organs such as the lungs, heart, brain, kidneys and liver. For this reason, DANGER OF DEATH may arise. I have informed my doctor about all my known allergies. I have also informed my doctor about the prescription medications I use, over-the-counter medications, herbal medicines, dietary supplements, illegal drugs, alcohol and narcotics/intoxicants. The effects of the use of these substances before and after the surgery have been explained to me by my doctor and recommendations have been made. During my stay in the hospital, I have received information about the important characteristics of the medications to be used for diagnosis and treatment (what they are used for, their benefits, their side effects, how they are to be used).

9. Lifestyle Recommendations Critical for Patient Health

Tobacco and Tobacco Products: It has been explained to me that smoking tobacco and tobacco products (cigarettes, waterpipe, cigars, pipe, etc.) before or after my surgery may cause my recovery process to be prolonged. Anesthesia risks are higher in patients who smoke; death due to anesthesia is seen more frequently. If you smoke, you should know that the success of the treatment/surgery will be lower than the general success average.

Follow your doctor's recommendations (exercise, nutrition program, etc.) and, if applicable, do not neglect your outpatient clinic check-up on the date requested of you.

I have received information about what I need to do regarding my lifestyle after my treatment/surgery (diet, bathing, medication use, mobility status and/or restriction status).

10. Patient-Specific Section

The patient's individual specific circumstances are recorded at the end of the form under Section 14 — Signatures.

11. How to Access Medical Assistance on the Same Matter When Needed

Not accepting the application of the treatment/surgery is a decision you will make of your own free will. If you change your mind, you may personally reapply to our hospital/hospitals capable of performing the treatment/surgery in question.

I have received information about how to access medical assistance on the same matter when needed (my own physician, a different physician, the clinic where I was treated, and in emergencies, 112).

12. Permissions

I authorize the Head of the Surgical Team, Responsible Specialist Doctor Dr. Özgür Akşan, and his team to perform my surgery.

I understand that this intervention is performed with the aim of eliminating my complaints and with the intention of preserving or improving the function of the nervous system. I confirm that my doctor has explained all the information above, that I have understood this information, and that all my questions regarding this intervention have been answered. Therefore, I give my consent for INFRATENTORIAL (POSTERIOR FOSSA) TUMOR REMOVAL SURGERY and for all different or additional surgeries and additional treatment interventions deemed necessary by my doctor.

Use of tissue: Any tissue not required for medical diagnosis may be used for medical research within the framework of ethical rules. I give my consent to the use of any tissue, medical device or body parts that may have been removed during the surgical procedure.

Medical research: I give my consent to the review of clinical information from my medical records for the advancement of medical study, medical research and doctor training, provided that confidentiality rules are observed.

Photography/Observers: I consent to the photographing or video recording of the surgery to be performed for scientific, medical or educational purposes, provided that the images do not reveal my identity.

13. Consent Verification

I know the alternative treatment methods and their risks.
I know the risks and side effects of the intervention.
I know the possibility of success and failure.
I know what may happen if I am not treated.
I understand that the procedure to be performed may not carry a guarantee of cure.
I have understood everything that has been told to me.
My doctor has answered all my questions.
My doctor has explained to me what is written here, item by item, in a clear, understandable and explanatory manner that I can comprehend.
I know the meaning of the Informed Consent form.
I have been informed about the approximate cost of the treatment.
I am making my decision of my own free will.
I had enough time before the intervention to obtain a second opinion within a reasonable period.
I have read and understood the content of the Informed Consent form.
All the blanks on this form were filled in before I signed it, and I have received a copy.

14. Signatures

A) Patient-Specific Circumstances

The patient writes, in his/her own handwriting, his/her individual specific circumstances (allergies, medications used, previous surgeries, etc.). If there are no specific circumstances, it is sufficient to write "NONE".

B) Handwritten Declaration

The patient writes the following sentence in his/her own handwriting:

"I have read this form carefully, I have been informed about THE SURGERY TO BE PERFORMED, my questions have been answered, and I give my consent to this procedure of my own free will."

C) Signatures

	Name – Surname	Signature	Date / Time
Patient
Legal Representative / Relative <br>(Degree of kinship: ……………………)
Head of the Surgical Team, Responsible Specialist Doctor	Dr. Özgür Akşan

Notes

Consent is obtained from the patient himself/herself if over 18 years of age; from the patient himself/herself and additionally from his/her legal representative if between 15-18 years of age; and from the legal representative in the case of an unconscious patient, a patient under 15 years of age lacking decision-making capacity, and in medical emergencies.
All pages of the Information and Consent form must be signed by the person concerned, with the note "I have read it" written by hand.
This form must bear the signatures of the physician providing the information, the patient himself/herself and/or the patient's legal representative.
This form must be printed in two copies, and after both are signed, one must be given to the patient and the other placed in the patient's file.
This form has been prepared based on Nöroşirürjide Aydınlatılmış Rıza Formları [Informed Consent Forms in Neurosurgery] (2025, ISBN 978-605-4149-28-5), published by the Türk Nöroşirürji Derneği (Turkish Neurosurgical Society).