Slides
Transcript
Thanks, Dennis. One of the problems of being at a meeting with too many colleagues from your same institution is they, several of them, have told me that I should rename my talk “Causing CSF Leaks.” But it’s a pleasure to be here. It’s a pleasure to be in Wouter’s motherland and really enjoying it. I have no disclosures to present.
And despite popular belief, the CSF leak program is not the only program at Cedars-Sinai Medical Center. This is a shameless plug for our acoustic neuroma and lateral skull base program, which is a multidisciplinary group of otologists and radiation oncologists, radiologists, and neurosurgeons to treat this complex disease.
High-risk procedures where prevention is critical for CSF leak include skull base surgeries of meningioma resections, pituitary adenoma resections, and acoustic neuroma removal as well. Acoustic neuromas constitute about 8% of brain tumors and are diagnosed in roughly 1 to 3.5 patients out of 100,000 people in the US. Recent research suggested that 1 in 2,000 or 1 in 500 adults by the age of 70 will be diagnosed with an acoustic neuroma in their lifetime.
Symptoms can be mild or severe and usually start with symptoms of hearing and/or tinnitus. The first signs are usually subtle, but sometimes we can diagnose patients with very large tumors and very symptomatic. The goals of care are to avoid complications that are associated with large tumors, control symptoms like vertigo and balance, and preserve function such as hearing, and minimize complications like loss of facial strength with surgery and/or radiosurgery.
This is our plan of care for patients that are diagnosed with acoustic neuromas. We’ll repeat an MRI in 6 months, and if they demonstrate growth then we will discuss treatment of either surgery or radiosurgery. Otherwise, we will continue to follow them up with yearly MRIs and treat them when they demonstrate growth or symptoms.
Hearing loss is usually the thing that we are most concerned with during observation, and sudden hearing loss can be treated with either steroids given orally or intratympanically. Patients should discuss this with their physicians while they are being followed.
The goals of care of observation is to treat as soon as we establish growth of the tumor or symptoms, and we recommend being evaluated by a balance expert that we have in-house to treat with vestibular therapy if needed. We try to preserve hearing during observation and treat sudden loss with steroids, and try to minimize complications associated with treatment like facial nerve weakness and loss of hearing.
There are three microsurgical approaches for acoustic neuromas. The first is a translabyrinthine approach for patients who have already lost hearing, because their hearing is sacrificed with this approach. It’s of benefit because we don’t have to retract any of the cerebellum, so you don’t get the risk of swelling in the cerebellum with retraction.
The retrosigmoid approach is used for tumors that are more medially placed so that they can be resected through this approach, and oftentimes we can preserve hearing with this approach, particularly for smaller tumors in patients that have intact hearing.
The middle fossa approach is a third approach for smaller tumors that are located in the canal, and this may be used to preserve hearing as well as facial nerve function. And so the translabyrinthine approach is through the labyrinthine vestibules and sacrifices hearing, but is good for larger tumors so as not to require retraction of the cerebellum.
This is a case of a translabyrinthine approach with fat placed in the skull base after the approach.
The retrosigmoid approach is for patients who have hearing and more medially placed tumors, and this is an example of a patient where hearing was preserved.
The middle fossa approach is one that’s used for smaller tumors in the canal, and one of the challenges is that the facial nerve is above the tumor. So that one needs to go around the facial nerve to resect these tumors from the canal.
So the goals of microsurgery are to treat relatively soon after establishing the tumor’s growth and minimize cerebellar retraction through the retrosigmoid approach and to preserve hearing for smaller tumors with patients that have intact hearing and to minimize complications such as cerebellar retraction and facial nerve loss.
The neurosurgical methods to prevent CSF leaks for these procedures include meticulous technique, closure strategies, materials used during surgery for skull base surgeries, and the strategies aim to maintain the integrity of the dura and protect the membranes around the brain and spinal cord, especially when it’s been opened. And so we use watertight closure and we have great residents that do this all the time, and the microsurgical techniques to avoid tension in the gaps of the dura. And when primary closure is impossible, we use autologous grafts such as pericranium or allografts such as cadaveric dura, and synthetic materials like DuraGen and fibrin glue, or synthetic sealants are also used along the suture line to prevent CSF leaks.
This is an example of a patient, a 59-year-old male, who had a translabyrinthine removal of an acoustic neuroma, who had a complete resection but developed CSF otorrhea 2 weeks after resection. And the CSF was actually tracking, dissecting between the ear canal bone and the skin and exiting the ear through this canal opening. And it resolved when our otology colleague conservatively placed an expandable sponge in the external ear canal and allowed the skin to push back into the EAC against the bone of the EAC, and this along with Diamox treated the CSF leak without any further surgery.
Prevention of elevated intracranial pressure is another important component to treat conditions like hydrocephalus or pseudotumor cerebri, which reduces the strain of fluid trying to escape during dural repair or after dural repair, and so shunts or ICP-lowering medications can be used in these selected patients.
So this is a patient, a 41-year-old female, who had left facial numbness, weakness, and left extremity weakness following subtotal resection at an outside hospital. As you can see, the patient on the left pre-operatively had significant hydrocephalus. Although this wasn’t treated pre-operatively, by resecting the tumor the hydrocephalus resolved, and we prevented a CSF leak post-op in this case with some lumbar drain. The tegmen is the region anterior to the petrous part of the temporal bone, and it’s overlying the tympanic cavity and the mastoid atrium, and this keeps CSF out of the middle cranial fossa and the mastoid.
In this patient, a 61-year-old male with bilateral deafness secondary to CSF leak, he had a history of recurrent ear infections with pain and drainage, history of Eustachian tube balloon dilation in December of 2024, left myringotomy in January of 2025, left mucopurulence with MRSA which resolved with Bactrim, and he had a persistent bilateral middle ear effusion. You can see the encephalocele on the left ear as well as fluid bilaterally in the mastoids, and he had no hearing bilaterally.
We did a left middle fossa craniotomy and we repaired the dural defect with DuraGen Tisseel, which is a fibrin glue type of sealant. A cadaveric graft was used to bolster the temporal lobe above the middle fossa and to elevate the brain over the cochlea so that the cochlear mechanism could remain intact without an encephalocele going into it. The patient had bilateral effusions responding to this treatment and could hear well bilaterally and so needed no further treatment on the other side.
Skull base reconstruction is important during endoscopic endonasal skull base surgery, and the use of nasoseptal flaps and fat grafts and mucosal grafts are used to reconstruct the defect. We rely on our nasal surgeons and rhinologists, and in a couple of the cases I’ll be showing, Dr. Tang was involved. It really requires multilayer closure to prevent the high risk of CSF leaks. And minimally invasive techniques such as endoscopic approaches are used for pituitary tumors and other anteriorly based skull base tumors.
Intraoperatively we test for CSF leaks by Valsalva maneuvers by our anesthesia colleagues, and occasionally we use fluorescein dye to detect subtle leaks. A lumbar drain can be used to prevent increased CSF pressure associated with some of these leaks.
This is a 73-year-old female with vision loss and macroadenoma with a cavernous sinus invasion on the right. As you can see, we did an endonasal approach here and really got most of the tumor out except for some just lateral to the carotid. This patient required a nasoseptal flap by Dr. Tang and had no CSF leak and got a really good outcome.
This was a 57-year-old male from Saudi Arabia with double vision, facial numbness, weakness on the right, loss of hearing, and vision loss with a clival chordoma which had grown rapidly over the course of a month during his travel to the States. You can see the tumor really going all the way back to the 7th, 8th nerve complex which was causing his facial weakness and hearing loss. We did a transnasal approach and resected this tumor. Most of it was extradural thankfully, and we also opened the dura to get some intradural components. With Dr. Tang’s nasoseptal flapping and multilayer closure, he experienced no CSF leak and we got a good resection with some residual around the cavernous sinus.
This is a 45-year-old female with a history of right-sided CSF leak with biopsy of an external ear canal mass which was biopsied and showed a meningioma. A right temporal craniotomy was performed with a middle fossa approach for repair of the CSF leak and removal of the meningioma. You can see here that the meningioma is really on block and growing along the skull base and so we really couldn’t remove most of this. We did a temporalis flap with plastic surgery that allowed the temporalis to be placed down in the tegmentum area to prevent further CSF leak. She did very well and had a stable serviceable hearing post-op and underwent stereotactic radiotherapy to the residual en bloc meningioma.
So those are the cases that I had to present and thank you very much.