9-year study from SBI

[jerseygirl]

Hi,

I think this study was posted somewhere before but I can't find it, just the mention that it was ready for publication. Anyway,  here is a link:
http://www.medicalnewstoday.com/articles/204655.php

I am going to call SBI and see if I can get the entire study that is going to be printed. Comments, anybody?

                           Eve

[Jim Scott]

Eve ~

This is very encouraging.  

I've long thought that endoscopic surgery to remove an acoustic neuroma was going to be the Next Big Thing in neurosurgery.  The medical community, especially when it comes to brain surgery, is very cautious and slow to embrace innovation due to the inevitable risks and possible unintended negative consequences of that advance.  However, the study, self-serving in the respect that SBI performed it and the results are positive for endoscopic surgery on ANs, will, no doubt, be criticized by some - but it has to be considered.  I think younger surgeons and those who welcome better ways of removing an acoustic neuroma in a way that offers the patient the best opportunity for a good outcome that doesn't negatively impact their quality of life will begin to think seriously about moving forward, studying and eventually employing endoscopic surgery on AN patients.  This SBI study could act as a catalyst for such advancement.  

Jim

[Tumbleweed]

Interesting, but I am skeptical until I learn more.

The report states that "100% of patients experienced preservation of their facial nerve." It doesn't explain whether that means anatomical continuity or 100% preservation of function. In fact, the nerve may be left completely intact by conventional surgical approaches such as retrosigmoid, yet the function of the nerve may (or may not) be severely impacted despite the nerve being physically intact.

Similarly, claims of hearing preservation are unqualified in the report. The term "hearing preservation" has been bandied about by many neurosurgeons and practitioners of radiosurgery/radiotherapy alike. It does not mean 100% preservation of hearing, but can mean one of two things (depending on who is making the statement): 1. Some useful hearing (however little) remains, or 2. hearing may have deteriorated significantly but not enough to move the patient into a different hearing Class (a Class denotes a range of hearing and is a more broad and less stringent characterization than a specific response in decibels in a given frequency band).

Lest I be misunderstood, SBI's work is of great interest to me and I would consider choosing them for my surgery should I ever have to go under the knife for an AN or other brain tumor. All I'm saying is I want to see more stringently worded details in their report. As it reads in the linked article, the wording is too broad and generalized to get me overly excited.

Nevertheless, I really appreciate Eve posting the link to the article. I'm excited to learn more when the full report comes out.

Sincerely,
TW

[captoats]

I have a PDF of the study but its too long to copy and paste to the forum and looses formating for the charts, etc.   If someone can tell me how to post a PDF file, I would be glad to do so.  Might have to upload it to a hosting site and create a link.  I can also e-mail it to someone that can post a link.

[jerseygirl]

TW,

I am of exactly the same opinion as you but before I comment on the results, I would like to take a look at the study itself because medicalnewstoday could have misinterpreted the results.

Captoats,

I will  PM you with my e-mail address so that you can send me the study. I will then cut and paste some extracts of the study on the forum and will not call SBI on Monday.

Eve

[captoats]

Hi Eve, I sent you the PDF. Let me know how you can post something like that

[jerseygirl]

Hi everybody,

Captoats e-mailed me the 9-year old study from SBI and here are the excerpts:

Population: The subjects consist of 527 patients with unilateral VS who have undergone fully endoscopic surgical resection of their tumors from October, 2001 to July, 2010. Patients with NFT2 were excluded from this study. This series included 44 cases that had undergone previous Gamma Knife radiosurgery and 61 cases with purely intracanalicular VS(s).
                Note: VS stands for vestibular schwannoma, another name for AN (Eve)

Age: 30-71  Tumor Size: 0.3 – 5.8cm Completeness of removal: 94%

Methods: Assessment was based upon clinical, radiological, and audiometric examinations. Pre- and postoperative data was collected and evaluated in a database for patients who have undergone fully endoscopic VS resections at the Skull Base Institute in Los Angeles, California.

Facial Nerve Preservation: Anatomical preservation of the facial nerve was achieved in 527/527 (100%) cases. One year after tumor removal, facial nerve function was re-assessed. Out of 527 patients with anatomically preserved facial nerves, 491/527 (93%) showed excellent facial nerve function (H-B grade 1/2); while 21/527 (4%) showed intermediate function (H-B grade 3/4); and 15/527 (3%) showed poor function (H-B grade 5/6).

Hearing Preservation: Functional hearing preservation, being defined as measurable hearing (serviceable/some), was possible in 213/374 (57%) of the same group.

Post operative complications:  CSF leak from the wound occurred in 17 cases, either re-suturing of the wound or bone waxing air cells stopped the leak (lumbar drain was not required) in all but one patient who required a subtotal petrosectomy.
One patient developed postoperative ventricular dilatation on the second day of surgery and was obtunded; a temporary ventricular catheter for diversion of CSF was placed for 5 consecutive days and the condition resolved. Exposure keratitis occurred in 9 patients and was treated with a “gold-weight” placed over the affected eyelid in 3 patients and aggressive ointment and artificial tears in the other 6 patients until facial nerve function eventually improved. Superficial wound infection was encountered in 13 patients and was treated conservatively in 4 patients; the other 9 patients required re-opening of the wound for irrigation, disinfection and overall debridement.
Cerebellar and brain stem injuries are the major and most feared complications of the retrosigmoid approach.30,33 Postoperative complications excluding those related to cranial nerves were minimal (Table 4). Major complications such as postoperative hemorrhage, quadriparesis, hemiparesis, meningitis or death did not occur.

I copied and pasted from the study because it is too big to post in its entirety. There is also a fascinating but very detailed discussion of cochlear nerve preservation. If anybody is interested, I will be happy to post an excerpt dealing with it.

Eve

 

[Tumbleweed]

Eve:

Thanks so much for taking the time to post this report. It is fascinating!

As the report shows, endoscopic surgery entails more risk than what the article at medicalnewstoday.com inferred. Still, I'd be willing to bet that most of the complications occurred with removal of the larger tumors and older patients.

What is lacking in the report is an accounting of how many patients 1. suffered no degradation whatsoever in facial-nerve function after surgery and 2. did not have their hearing worsen to the degree that they were in a different hearing Class five years after surgery (which period would allow direct comparisons to published five-year studies for patients who had radiosurgery).

Thanks again, Eve.

Best wishes,
TW

[jerseygirl]

Hi TW,

What is also missing from the study is whether or not recurrences/regrowths were included and if not, how did these people fare. I bet many of these did suffer some complications. The report also does not give any tally of lower cranial nerve damage which can be very disabling because it can lead to voice and swallowing issues. Intubation for a long time  can lead to vocal cord damage but during endoscopic surgery this risk is minimized because the surgery times are so short. 

I will post everything the article contains on hearing. Maybe, it will answer your questions.

                 Eve

[jerseygirl]

Excerpts from the study on everything that concerns hearing preservation:

Cochlear nerve (hearing) preservation

Cochlear nerve preservation has been reported by many authors10,11,18,29,30 in the recent past, but there is a lot of ambiguity on the criteria for useful hearing. In addition, there are some who believe that the goal of gross total tumor removal cannot be achieved with cochlear nerve preservation.31
In this report, our rate of functional hearing preservation (213/374) (57%) reflects the better outcome associated with better visualization by the angled and zero-degree high-definition endoscopes. The fact that most tumors in this series were less than 4 cm in diameter and presented early with minimal symptoms also has a direct impact on the surgical outcome and prognosis.

Functional hearing preservation, being defined as measurable hearing (serviceable/some), was possible in 213/374 (57%) of the same group. One patient with a right sided intracanalicular VS, 10 mm in diameter and with a small portion of it protruding into the CPA, initially had “some” hearing and regained a “serviceable” hearing one week postoperatively. Another patient had an improvement of > 20 db in his hearing postoperatively

Table 3 : Cochlear Nerve (Hearing) Preservation

                        Serviceable/Some      Total Deafness
Preoperative               374                   153
Postoperative             213                    314


More regarding facial nerve function:

In this series, at the time of discharge from the hospital, most of the patients had satisfactory facial nerve function with complete eye closure. After one year, 491/527 (93%) showed excellent facial nerve function (H-B grade 1/2), and 21/527 (4%) showed intermediate function (H-B grade 3/4).
In spite of the high rate of facial nerve preservation in this study, anatomical preservation of the facial nerve with complete tumor removal, especially in patients with large tumors, is still a challenge. Facial nerve monitoring has greatly aided separation of the facial nerve from the tumor.10,11,28-30


Hope it helps.


                         Eve

[PaulW]

There is a lot of evidence emerging that radiation is a better option for small AN's than traditional surgery.
I wonder what their results would look like if they combined technolgies, debulked the AN with endoscopic surgery and then left the last little bit to radiation?
Could this potentially provide the best outcome of all for patients with large AN's?

Thanks Jerseygirl for the info....

[FLsunshine]

Very interesting report.... thanks JerseyGirl for posting.  I've got a few years before the big decision on surgery vs radiation so keeping my fingers crossed that new treatments like this will have provden themselves by then.

[Tumbleweed]

Thanks a lot for the additional excerpts, Eve. So my suspicions about the report's interpretation of "hearing preservation" are confirmed. What it comes down to is this: 57% of the patients retained some useful hearing, while 43% of those who had useful hearing prior to surgery were left completely deaf on the AN side following the operation. This again confirms that surgical resection -- no matter what the approach -- is less likely to preserve hearing than the various forms of radiation treatment.

The SBI report also infers that (at least) 4% of the patients suffered decreased function of the facial nerve (the report is a bit vague here). This is at least 4x worse outcome than with CK on average.

If I had a large tumor that couldn't be treated with radiation, I would seriously consider endoscopic surgery at SBI. But from a purely statistical point of view, radiation presents a far lesser chance of damage to hearing (at least in the short term) and especially facial-nerve function for small and medium-size tumors.

Best wishes,
TW

[jerseygirl]

Flsunshine,

I hope you will never have to make a decision regarding AN treatment. That's the best way.

TW,

Short term is the key here. In the short term, radiation stats look better. In the long term (10,15,20) years, the picture is probably not so rosy. Nevertheless, those extra years of perfect hearing and facial function are of enormous value to most people. Now we are down to an argument: radiation vs. surgery!  I really think that all forms of AN treatment have value. I am pro- newbie education : know the benefits and risks associated with each type of treatment and make an educated choice that is in one's favor.

Eve

[Tumbleweed]

I agree that hearing preservation with radiation treatments is often short-term. In fact, hearing loss may occur within only 5 years of being treated. For many patients, however, hearing is preserved in the long-term.

No disrespect meant for those who choose surgery. God no. It's just that I have had such an extraordinary outcome with CK that I can't help advocating radiation. Had I undergone surgery, I would've been deaf in one ear and possibly (31% chance) paralyzed on one side of my face. Instead, my hearing is relatively good and I've never had any facial symptoms.

All that said, surgery is the most comfortable (and depending on tumor size, sometimes the only) choice for some people. All I hope for here is to share statistics and my personal experience. Too many people choose one form of treatment without investigating all their options thoroughly. In fact, I was initially completely opposed to receiving radiation; wouldn't even consider it. But as I looked further at all my options -- and the risks associated with each -- I became convinced that CK was the right personal choice for me.

Best wishes,
TW