Endoscopic endonasal surgery is a type of procedure used to treat problems such as tumours at the front or base of the brain or at the top of the spinal cord. A surgeon inserts a thin tube (endoscope) and small instruments through the nose to conduct the surgery, rather than cutting into the skull (open surgery). This allows it to reach areas that are otherwise difficult to access. Recovery is also quicker and less painful than with open surgery.  

During the procedure:  

1. The patient will lie down on a table. The patient will be given medication (anaesthesia) to help him/her sleep through the procedure. 

2. The surgeon will insert the endoscope into the nostrils and paranasal sinuses. The narrow endoscope fits through the natural openings in these areas. The camera sends images to a computer screen. 

3. The surgeon will also enter small instruments into the nose. This is often done through the same nostril as the endoscope. The instruments will be used to remove a tumour or treat the problem area, as needed.

4. Once the surgery is over, the instruments and the endoscope will be removed. You may have your nose and sinuses filled with nasal packing. This material is taken out one or two days later. You will stay in hospital overnight or longer after surgery, depending on the procedure performed. 

The risks of endonasal endoscopic surgery include the following:  

• Insufficient healing at the surgical site 

• Leakage of cerebrospinal fluid from the nose 

• Air trapped inside the head (pneumocephaly) 

• Excessive bleeding 

• Blood clot in the head 

• Infection in the head, including tissue surrounding the brain and spinal cord 

• Damage to blood vessels and nerves in the area 

• Pain 

• Crusting inside the nostrils and paranasal sinuses that last for weeks or months 

• Difficulty breathing through the nose

• Reaction to anaesthesia

Pure endonasal endoscopic resection is a safe and effective approach for tumours of the sellar (pituitary) region that offers several advantages over the surgical microscopic approach.  

Pituitary tumours, generally benign, are the most common pathology of the sellar region, accounting for approximately 15% of benign intracranial tumours and are found incidentally in 5-20% of cases. Rathke's pouch cysts, usually asymptomatic, may expand and give compressive symptoms such as campimetric defects or hormonal disturbances; they are then amenable to surgical treatment.  

The treatment of choice for many of these lesions is surgical; the initially transcranial approach has evolved from the transsphenoidal microscopic approach to the Endoscopic Endonasal Transsphenoidal (EET) approach.  

Today's endoscopes are based on the design by Harold H. Hopkins in the 1950s. In the 1990s, its use was introduced in the endonasal approach to naso-sinus pathology and also as an auxiliary instrument to the surgical microscope used in neurosurgery.  

The TEE approach has advantages over the microscopic approach, such as reduced operating time and hospitalization period. In our centre, as in others with experience in the TEE approach, this way is preferred for the treatment of sealing and parasellar tumour pathology.

Classically in neurosurgery, those lesions located deep in what is known as the base of the skull have represented one of the greatest surgical challenges faced by neurosurgeons. The classic approach involves contact with a series of vital structures that can be damaged, as they are close to the lesion or in the surgical access trajectory, so that morbidity and postoperative sequelae can be one of the factors that prevent this type of surgery from being performed.  

However, with the advent of new microsurgical techniques assisted by neuronavigation, neurophysiological monitoring and with the use of neuroendoscopy, the approach to deep skull base lesions becomes possible, as it is a minimally invasive technique in which access is simplified and the incidence of postoperative sequelae is greatly minimized.

An acoustic neurinoma, also known as a vestibular schwannoma, is a rare, non-cancerous and usually slow-growing tumour that forms on the main (vestibular) nerve leading from the inner ear to the brain. The branches of this nerve directly affect balance and hearing, so pressure from an acoustic neuroma can cause hearing loss, ringing in the ear and unsteadiness.  

Acoustic neurinoma typically arises from the Schwann cells that cover this nerve and grows slowly or not at all. In rare cases, it can grow rapidly and become large enough to press against the brain and hamper vital functions.  

Treatments for acoustic neuroma are periodic monitoring, radiation, and surgical removal.  

The surgeon may use one of many techniques for the removal of an acoustic neuroma depending on the size of the tumour, hearing condition and other factors. 

The goal of surgery is to remove the tumour and preserve the facial nerve to prevent facial paralysis. In certain cases, it may not be possible to remove the entire tumour, for example, if the tumour is too close to important parts of the brain or the facial nerve. Surgery for an acoustic neuroma is done using general anaesthesia and involves removal of the tumour through the inner ear or an incision in the skull. However, with the advent of new microsurgical techniques assisted by neuronavigation, neurophysiological monitoring and with neuroendoscopy, the approach to these lesions has become safer, as it is a minimally invasive technique in which access is simplified and the incidence of postoperative sequelae is greatly minimized.

Gliomas are primary tumours of the central nervous system, characterized by their infiltrative growth, usually involving so-called eloquent areas, which makes their surgical treatment a challenge. There is evidence favouring early and total resection to prevent progression and thus change the natural history of the disease. The highest survival is achieved with early maximal safe resection, irrespective of histological subtype. 

A considerable proportion of gliomas are found in brain areas traditionally defined as eloquent (language, motor, sensory). Resection in these areas must be associated with preservation of function. In addition, as they are highly infiltrating tumours, cells can be found beyond the borders of the tumour visualized on MRI.

The growth of these lesions causes reorganization of the brain cytoarchitecture modifying the functional anatomy, which cannot be reliably assessed on imaging (even on functional MRI). This has led to the proposal of a new concept called “onco-functional” balance: To achieve the maximum resection together with the preservation of brain functions, performing a resection according to functional and non-imaging margins, considering that although they are pre-malignant or malignant lesions, they can have long survival times and during these years the objective must be to preserve the patient's quality of life.

In order to monitor brain functions, the technique of intraoperative Direct Electrical Stimulation (DES) has been used with awake patients in surgery procedures who undergo a series of neurophysiological tests depending on the location of the lesions in order to assess one by one the brain functions to be preserved. Intraoperative DES is a technique that allows mapping of eloquent cortical functions and also of subcortical white matter fascicles, as well as increasing the limits of tumour resection.

Wake craniotomy and subcortical cortical stimulation for guided functional resection of low-grade gliomas has been available since 1990. Image-guided resections first existed with neuronavigation since 1997 and with robotic assistance since 2015.

Anaesthetic technique has evolved over the years, and today there are basically two modalities: local anaesthesia associated with conscious sedation and general anaesthesia with intraoperative wakefulness, commonly referred to in the literature as asleep-awake-asleep… In our institution we have opted for the second alternative, an option that for the anaesthesiologist translates into the challenge of maintaining diverse levels of sedation and analgesia depending on the stage of the surgery.   The asleep-awake-asleep technique offers the advantage of sparing the patient from experiencing the positioning of the head support points and above all of the craniotomy, which is consistently referred to as the most uncomfortable moment of the entire surgery by those who have experienced conscious sedation. Once the craniotomy and durotomy have been performed, drug infusions are tapered to wake the patient up. When the patient is awake, the anaesthesiologist removes the laryngeal mask as long as ventilation is spontaneous and gives the go-ahead to continue with the clinical assessment considered for surgery and brain mapping. After the assessment is complete, the anaesthetic infusion is restarted, the airway is reassured, and the lesion is excized.

Surgery plays a key role in the treatment of many types of brain tumours. Removing as much of the tumour as possible is especially important because, in some types of brain tumour, this procedure can help people live longer and feel better. However, removal of a brain tumour in some cases may be difficult because the tumour resembles normal brain tissue or is close to brain tissue that is needed for normal functioning. New methods of visualizing tumours during surgery (called imaging) have been developed to help surgeons better differentiate a tumour from normal brain tissue.

Diagnostic imaging interventions used during surgery include:  

• fluorescent dye (5-aminolaevulinic acid) to distinguish the tumour 

• preoperative imaging to identify the location of the tumour, which was then used at the time of surgery to guide the resection (neuronavigation)

• imaging during surgery to assess the amount of tumour remaining

Fluorescence-guided resection with aminolaevulinic acid (5-ALA) has been available as a standard method since 2008 in Europe. In 2013 more than 564 neurosurgery departments with more than 1000 neurosurgeons were authorized to use Gliolan.  

5-ALA is a precursor for the synthesis of the haem group. Its administration can induce the accumulation of fluorescent porphyrins in tumour cells, so that when tumour tissue is illuminated with violet-blue light (wavelength between 375 and 440 nm), a red fluorescence resulting from the excitation of accumulated protoporphyrin IX can be seen. This allows intraoperative distinction of pathological tissue, which facilitates tumour resection and helps to achieve higher rates of complete resection by detecting tumour remnants that might otherwise go undetected.

The introduction of robotics in healthcare has brought great advances and benefits to the medical sector. In most cases, the use of robots in the field of surgery eliminates the risk of human failure and allows for less invasive interventions, reducing both operating and post-operative time. In addition, this recent technology increases the safety of the process and eliminates any kind of improvisation from the operating theatre.  

This is the case of the team of neurosurgeons at the Neuroinstitut, which in 2015 incorporated robotics in skull and spine surgery.  

A brain biopsy is a procedure to remove a sample of tissue from the brain. The sample can be tested for cancer, infection, or brain disease. In the case of robotic brain biopsy, a small hole is made in the skull guided by transoperative imaging and/or image fusion and the assistance of a robot to minimize the margin of error in obtaining brain tissue.

Surgery for epilepsy may be an option when medications do not control seizures. This condition is known as refractory or drug-resistant epilepsy. The goal of epilepsy surgery is to stop seizures or limit their severity. Surgery is also done to reduce seizure-related deaths, the use of anticonvulsant drugs and possible side effects of the drugs.  

Poorly controlled epilepsy can lead to many complications and health risks, including the following:  

1. Physical injuries during a seizure 

2. Drowning, if seizures occur during bathing or swimming 

3. Depression and anxiety  

4. Developmental delay in children 

5. Sudden death, a rare complication of epilepsy  

6. Worsening of memory or other thinking skills  

Types of epilepsy surgery 

Epileptic seizures are the result of abnormal activity of neurons. The type of surgery needed depends on the location of the neurons triggering the seizure and the age of the patient. Types of surgery include:  

• Resective surgery is the most common surgery for epilepsy and involves removing a small part of the brain. The surgeon cuts brain tissue from the area of the brain where the seizures occur, which is usually the site of a tumour, brain injury or malformation. Resective surgery is frequently performed on one of the temporal lobes, an area of the brain that controls visual memory, language comprehension and emotions.  

• Interstitial laser thermal therapy is less invasive than resective surgery. It uses a laser to precisely target and destroy a small portion of brain tissue. Magnetic resonance imaging (MRI) is used to guide the laser.

• Deep brain stimulation involves the use of a device that is permanently placed deep in the brain to release regularly timed electrical signals that alter seizure-inducing activity. Magnetic resonance imaging is used to guide this procedure. The generator that sends the electrical pulses is implanted in the chest.

• Callosotomy is surgery to remove all or part of the part of the brain that connects the nerves in the right and left hemispheres of the brain, called the corpus callosum. It is typically used in children who have abnormal brain activity that spreads from one hemisphere of the brain to the other.

• Hemispherectomy is a procedure to remove one side (hemisphere) of the brain, called the cerebral cortex. In general, this surgery is performed only in children who present with seizures originating from multiple sites in one hemisphere, usually due to a condition present at birth or in early childhood.

• Functional hemispherectomy is a procedure used mainly in children that removes the connecting nerves without removing actual parts of the brain.     

The detailed surgical plan, previously planned on computers and in partnership with neurology specialists, is taken to the operating theatre where, depending on the needs, we use Robotics or neuronavigation systems, which allow us to faithfully follow the plan, aided by neurophysiological control and O-Arm imaging.

The main advantages of robotics over conventional surgery are greater precision and safety. “The patient benefits from increased safety because there is greater precision. Planning is also more precise. Nothing has to be decided to on-the-go, everything is planned in advance.”  

In cases of epilepsy, for example, the robot is used in 20-30% of patients suffering from incurable epilepsy, one of the most common neurological diseases. The Renishaw Neuromate procedure allows 7 to 20 electrodes to be placed inside the brain to determine the exact area causing the seizures and then remove it with sub-millimetre precision, without risk to the normal function of the brain, allowing you to cure your epilepsy: “The robot gives us the right direction and depth, but the neurosurgeon always does the final technique.” Electrode implantation was already possible without the robot. “The difference is that the number of points in the brain that can be studied is much smaller. At the same time, the precision of the study is also lower, so that only simpler or easier patients can be treated.”     

After the electrodes are implanted, the patient's usual seizures are recorded during the following days with a 256-channel SEEG (stereo electroencephalogram) system. With SEEG, the brain areas to be removed or damaged are “precisely delimited through brain stimulation without affecting brain functions.” Depending on the results of the study, this is done either by a second surgery or by coagulation of the selected areas, thus achieving better control of the crises.”

The main advantages of robotics over conventional surgery are greater precision and safety. “The patient benefits from increased safety because there is greater precision. Planning is also more precise. Nothing has to be decided to on-the-go, everything is planned in advance.”  

In cases of epilepsy, for example, the robot is used in 20-30% of patients suffering from incurable epilepsy, one of the most common neurological diseases. The Renishaw Neuromate procedure allows 7 to 20 electrodes to be placed inside the brain to determine the exact area causing the seizures and then remove it with sub-millimetre precision, without risk to the normal function of the brain, allowing you to cure your epilepsy: “The robot gives us the right direction and depth, but the neurosurgeon always does the final technique.” Electrode implantation was already possible without the robot. “The difference is that the number of points in the brain that can be studied is much smaller. At the same time, the precision of the study is also lower, so that only simpler or easier patients can be treated.”     

After the electrodes are implanted, the patient's usual seizures are recorded during the following days with a 256-channel SEEG (stereo electroencephalogram) system. With SEEG, the brain areas to be removed or damaged are “precisely delimited through brain stimulation without affecting brain functions.” Depending on the results of the study, this is done either by a second surgery or by coagulation of the selected areas, thus achieving better control of the crises.”

Thanks to the Renishaw Neuromate, more than 80% of patients with lesional temporal lobe epilepsies with less than two years of disease progression are seizure-free after surgery.  

Epileptic patients are not the only ones who have benefited from the advantages of robotics. The Neuroinstitut was also a pioneer in performing the first brain surgery in Spain on a Parkinson's patient using the Renishaw Neuromate. An operation in which electrodes are implanted in the brain to enable sufferers to better control their movements.  

In this case, the great advantage of the robot is the “increase in precision compared to classic techniques. It also allows the surgery to be done while the patient is asleep: it is once again a comfortable surgery, without having to be aware of anything.” This type of brain surgery is already performed in other hospitals, but mostly manually, without robots, which means that the patient has to be woken up during the procedure to check the correct manual implantation of the electrodes. In our centre, however, after subjecting the patient's brain to a Computerized Axial Tomography (CAT) scan, the robot locates the exact coordinates where to place the electrodes, one on each side of the brain, with a margin of error of less than 0.3 millimetres, an improvement over the millimetre error that occurs in a manual operation.

Unlike other surgical treatments for dystonia, deep brain stimulation (DBS) therapy is possibly reversible and adjustable. It uses an implanted device that stimulates specific areas of the brain, allowing the circuits that control movement to function better. This can alleviate the symptoms of this disease.  

WHAT IS IT? 

DBS therapy for dystonia uses a surgically implanted medical device, similar to a cardiac pacemaker, to deliver electrical stimulation to defined areas of the brain.

Deep brain stimulation (DBS) is FDA-approved to treat obsessive compulsive disorder in adults aged 18 years and older who do not respond to traditional treatment approaches. Deep brain stimulation involves implanting electrodes in certain areas of the brain. These electrodes produce electrical impulses that can help regulate abnormal impulses.  

WHAT IS IT? 

DBS therapy for dystonia uses a surgically implanted medical device, similar to a cardiac pacemaker, to deliver electrical stimulation to defined areas of the brain.

The treatment of a patient with a vascular malformation, irrespective of the diagnosis, is a coordinated effort between an endovascular interventional radiologist, a vascular neurosurgeon and a stereotactic radiosurgeon. Our centre has highly qualified specialists who work on these diseases in a coordinated way to obtain the best result for the patient.

Interventional Radiology is a subspecialty of Radiology, whose focus is on the diagnosis and treatment of a broad spectrum of diseases using minimally invasive techniques.  

In most cases, Interventional Radiology treatments involve shorter hospitalization periods and are often performed under local anaesthesia, which means lower risks, less pain and reduced convalescence compared to traditional surgery.  

The procedures are conducted with the help of the following imaging techniques: 

• X-rays 

• Ultrasound 

• Computerized Tomography (CT) 

• Magnetic Resonance Imaging (MRI) 

• Angiography   

With the help of a guide wire with a diameter of only 1–2 millimetres, catheters are inserted into the blood vessels or other ducts to guide them to the location of the vascular lesions so that they can be treated.  

Vascular neurosurgery is the part of neurosurgery that treats injuries that have caused or may cause haemorrhages or infarctions in the brain or spinal cord. It is an extraordinarily complex subspecialty because of the high technical requirements, its relatively low frequency and the consequences these injuries can have on the patient's life and function. It generally deals with arterial aneurysms, vascular malformations and dural arteriovenous fistulas. Not only that, but it also treats cavernomas, which are halfway between vascular and tumour lesions, and some diseases that can cause cerebral infarctions, such as Moya-Moya disease.  

Stereotactic radiosurgery is an advanced method for treating some types of tumours, vascular malformations, and certain types of functional disorders (pain, movement disorders, etc.). Stereotactic radiosurgery removes or shrinks tumours or vascular malformations using radiation beams. It is not surgery in the traditional sense, as there is no incision. Instead, stereotactic radiosurgery uses three-dimensional imaging to direct high doses of radiation to the affected area with minimal impact on surrounding healthy tissue.

When the pain stems from the abnormal position of an artery so that it is compressing a cranial nerve, it can be relieved by a surgical intervention called vascular decompression. This procedure is performed as a treatment for trigeminal neuralgia, hemifacial spasms or glossopharyngeal neuralgia.  

This procedure is ideal for cases that do not respond positively to drugs or when the side effects of taking medication are severe.  

Basically, microvascular decompression involves the relocation or removal of blood vessels that are in contact with the nerve root. This stops the “malfunctioning” of the nerve.  

For this, as a doctor, we make an incision behind the ear where the pain occurs. Then, through a small hole in the skull, we move away the arteries that are in contact with the nerve and place a soft patch between the nerve and the arteries. In addition, if a vein is compressing the nerve, we can remove it. Finally, it is also possible to cut a part of the trigeminal nerve (neurectomy) during this procedure if the arteries are not pressing on the nerve.

Instability and vertigo are common symptoms in peripheral and central vestibular pathology, often associated with vegetative symptoms, gait and postural imbalance. As a consequence of the significant impact of this symptomatology on the quality of life, a state of anxiety or depression is frequently added.  

Vestibular neurectomy is a surgical procedure in which the vestibular nerve is selectively severed. It is this nerve that transmits the balance disorder from the ear to the brain, causing the symptom of vertigo. The operation is indicated especially in disabling Meunière's disease, but also in some patients with chronic and disabling vestibular problems.  

As an operation involving the opening of the cranial cavity, it is considered delicate and should therefore only be performed in patients who are incapacitated and do not respond to other treatments.     

How is Neurectomy performed?  

The procedure lasts approximately 2 to 3 hours and requires a 5 to 7 day stay in the clinic. During microsurgery, the vestibular nerve is located, and the hearing nerve and the facial nerve are preserved and monitored in all cases. In our practice, the risks of this procedure will be discussed with the patient in each case, because although it is a safe and remarkably effective procedure and the risks are low, it is still a delicate intervention.  

What can I expect after surgery?  

The success and resolution rate for vertigo attacks is over 95%. Initially, there will be instability as a result of the nerve section, which will gradually compensate and where rehabilitation can be of significant help.

One of the most recent advances in the approach to deep lesions of the central nervous system is the application of endoscopy, which is highly developed in other areas of medicine. The simultaneous rapid development of various areas of medicine, technological innovations and their application to the nervous system has led to reduced morbidity and mortality, shorter surgical procedures, and anaesthesia with a more benign postoperative period, even allowing some procedures to be performed under local anaesthesia. It is a minimally invasive technique that has benefited the patient and significantly improved the treatment of some conditions. 

The instrumentation required for the neurosurgical application of neuroendoscopic techniques includes:

1. The endoscope, which can be flexible, rigid, and semi-rigid.

2. The camera, which should provide good image quality and good depth resolution. The size of the camera must be appropriate to fit very thin endoscopes (5 to 1.5 mm).

3. The light source must be extremely intense, 300 watts of xenon.

4. Instrumentation should include cautery, coagulation, irrigation, bipolar coagulation, radiofrequency, and laser. The same unipolar or bipolar coagulation, laser, microscissors, needle or guides and dilators are used for cutting. Specially designed micro forceps and suction systems are used for biopsy or lesion removal.

5. In addition, stereotactic equipment and multiple endoscopes and lasers can be attached.

6. The most recent development is robot-assisted neuro-endoscopy.

Robotic surgery, or robot-assisted surgery, allows doctors to perform many types of complex procedures with greater precision, flexibility, and control compared to conventional techniques. Robotic surgery is generally associated with minimally invasive surgery, procedures performed through small incisions. In addition, it is sometimes used in certain traditional open surgical procedures.

The most widely used clinical robotic surgical system features a camera arm and mechanical arms, and surgical instruments mounted on them. The surgeon controls the arms while seated at a computer console near the operating table. The console provides the surgeon with a high-definition, three-dimensional augmented view of the surgical site. The surgeon directs other members of the team who assist during the operation.

Why it is done

Surgeons using the robotic system find that in numerous procedures it improves precision, flexibility, and control during the operation, and allows them to see the site better than with traditional techniques. By using robotic surgery, surgeons can perform delicate and complex procedures that might be difficult or impossible to perform with other methods.

Often, robotic surgery makes minimally invasive surgery possible. The benefits of minimally invasive surgery include the following:

• Fewer complications, such as infection at the site where the surgery is performed

• Less pain and blood loss

• Shorter hospitalization and faster recovery

• Smaller and less visible scars

Thanks to technology and the facilities offered by new advances, it is possible to conduct comprehensive treatment planning for patients, as well as to design and manufacture the customized devices to be used during surgery for cranial reconstruction. The two-dimensional CT images are used for 3D reconstruction of the cranial structures. This serves as a guide to facilitate the distinct phases of the intervention, and the model is used to define the cutting guides and prepare the reconstruction with material tailored to the patient. The 3D tools we use allow us to manufacture any guide or medical device using biocompatible resins.