Tsukuba Observership
I come to Tsukuba University Hospital from the kind invitation of Prof Yuji Matsumaru to refresh my neuroendovascular learning . I currently work at private hospital and one governmet public hospital with much challanges to develope neuroendovascular accordingly however my knowledge as physician must be updated and i took this opportunity in order to do so.
As for basic patient preparation that i noticed overall in here the patient foot is wrapped and care are taken to prevent DVT also the self made desk for neuroendovascular is something i should copy. The saline heparine ratio vary from where i have been in indonesia hospital some are 500 unit in 1000 ml (1000 unit in 1000ml usually). In Japan there is a special disposible basin case with adequate size for catheter and wire holding that makes preparation faster and convenient. Where our place the base we have is round metal basin.Some hospital even do not use any basin at all for diagnostic, that might impose certain risk for thrombus. While is not essential but the use of different color of syringe for contrast and saline also convenient.
The number of personel i see in a cathlab unit consist of radiologist, doctors and nurses. Anesthesiology only for treatment. I think the personnel required will reduce the time of treatment. In my place it is only one or two doctors for treatment and two nurses with no radiologist.
As for diagnostic i noticed that taking marker of puncture site and taking angiographic picture of illiac artery is an SOP before securing the sheath, which something i have to improve. It is also very helpful to have double view of AP and lateral simultaneously also with rotational injector for 3D image definitely significantly important in the case of neuroendovascular. For the imaging delayed time is important in setting., so first the time of first of imaging seen substracted with the images intended for further study divided with 3f rame per second data that we could obtained are size of devices in use like for example in carotid stenosis measure the occluded vessel, the distal and proximal part and do it at each side. Also measure cervical part of ICA to calculate the baloon protection size. In wide neck giant aneurysm at anterior circulation measure the length according to the architectural placing of the flow diverter. In dAVF and AVM get the picture of feeder and the access to nidus occlusion to see whether it would be trans arterial or transvenous to prepare the working plan. For operation planning interposition between arteries and vein system is beneficial for approach and planning.
We do not have to much option of diagnostic catheter, widely used is vertebra catheter , sometimes yashiro and then very rare is simmons. I found that the shape of JB 2 is very convenient for most procedure and hope we can obtain more catheter type in the future. Also diagnostic from radial artery is very rarely done as long as my observation by neuroendovascular neurosurgeon. It is essential for diagnostic catheter when doing procedure of multiple microcatheter at the femoral site and also when there is risky abnormality from the femoral site until the arcus. However the manipulation of wire and catheter from radial entry need extra training especially with use of simmons since the character of movement and manipulation differ from of femoral site.
In old patient with very tortus vessel manipulation catheter and wire is very difficult. Beside changing to wire and catheter where i found there is a new shapeable wire which is not widely available yet. Also technique like taking a deep breath and hold and also a bit of a vibration technique and having a bit of a tension help to selectively put the catheter in selected carotid vessel.
I found more about detailed information that we need to look in DSA tailored according the next treatment plan. Since the operation here is advanced and agressive .Test like wada test and baloon occlusion test and compression test are done.
Overall imaging are very extensive from comprehensive CT to comprehensive MRI to help defining lesion of diseases. We are still limited in examination that is not common for patient with suspected vascular disease to have functional MRI aor DTI . Mostly are CT and CT angiography.
As for treatment during my stay i encountered many case of dAvf and some AVM and aneurysma and one acute stroke.
For aneurysm most of the cases are unsuitable for simple coiling which is the most common way of practice in my place. I learn new technique about shaping of microcatheter (marathon )which will be very useful strategy for me. Marathon is very frequently used because of its characteristic in between flow directed and wire giuded. We dont have the torch only boiling water (steam) that will have to with 60 secondsat 100 degrees celcius. In some cases with important branches coming out in neck part of aneurysm, total embolization of the aneurysmis not achievable where placing a stent is also not possible than baloon assisted coiling is the option followed by continous monitoring . Tip aneurysm like basilar if somewhat total occlusion of aneurysm is difficult than changing the flow and make it as side aneurysm is one to consider.
In AVM firstly shoot wide in angiography to see the flow from ECA and ICA and also the draining vein. Depending on location check the possibility of dural relation and also posterior circulation connection in some cases. The target of AVM is occlusion of the nidus. Onyx is mostly used for AVM but for small and tortous vessel onyx is not reccommended. Whereas NBCA the concentration can be adjusted accordingly. If the catheter is somewhat far from the nidus because of the tortous and small vessel than the concentration is put low at 25 percent and sometimes it is put on heat with up and down maneuver for 30 second. If the nidus is near or into nidus than concentration is high 35 percent up. Also if it is high flow it is high concentration. For AVM total obliteration sometimes not always possible, but in this institute it is followed by surgery or radiotherapy. If radiotherapy is planned than the use of onyx is avoided because of artefax matter in images afterward.
Principle of dAVF is also nidus occlusion and cessation of feeder. dAVF firstly identified by feeder from ECA. Suspiscious feeder usually from Ascending pharyngeal or meningeal media. Also check the draining vein for pseudophlebitic pattern ( warning sign) that could be seen on SWI.
In closing nidus after sealing the feeder port the use of pushable coils are cheap alternative which is should look at.
In my place we have a lot of suspiciously dAvf caused of ich but not seen by conventional CT angio. To go to DSA is still not an SOP adopted by our system and so it is not always conducted. But sometimes even if it is conducted not all center have as good as phillips allura so there is possibility that dAvf is overlooked.
Catheter which are new for me among other are tactics which special feature is to breach narrowed diameter especially vein so very convenient for transvenous approach in dAVF also deflector which i assume is the smallest diamter among to go throung smallest vessel. Also the baloon from shouryu that also small in diameter which is feasible for delivering coil.
Intermediate catheter are limited in my country usually mostly from cardiac. Guiding sheath is not available but it is very good to have it since it allowed smaller inner diameter of catheter to accommodate several catheter.
Operation
I did not spend much time in operation unit to be honest. Iam very impressed with number of OR in the hospital. Also with facility in OR for neurosurgery. Its the first time to see the MRI hybrid operation room which i see the transphenoidal surgery collaboration between neurosurgery and ENT for recurrent cordoma. In which having the device is very useful for complete total resection of the tumor. I also saw the angio hybrid room which the AVM resection is later followed by endovascular confirmation.
Research
Tsukuba among other are known for its research resources and one of my interest which is about stroke has a body of research from acute phase considering the edaravone effectiveness , intermediate/inflamation phase and chronic phase with research about the use of gingival(ectodermal) for stem cell therapy in chronic stroke patient.