Our next speaker, we're fortunate to have Dr. Mahmoud speaking on radionuclide shuntography for the evaluation of ventricular peritoneal shunt in children with hydrocephalus. And Dr. Mahmoud is from Nigeria. Thank you. Sorry, I think I clicked on the wrong. Yeah, thank you so much. I thank the WNS for inviting the Congress of African Neurosurgical Associations to be a part of the program. It's a wonderful collaboration, I guess. I would like to start by saying that the reason why we went into this study was the fact that in Africa, and I'm sure most of the parts of the world, there are cases of hydrocephalus or obstructive visions that are well-functioning, that are straightforward, that you really need to take out and then replace. But then there are some cases that are not that straightforward. So considering the fact that in Africa, the challenge of cost and also availability of the expertise is not as good as you would find elsewhere. So that's why we decided that I think it's better to go into reviewing, I mean, some of these cases of obstructive V visions using radionuclide shuntography as we have found that it's kind of cheap compared to other means. Sorry, how do I move this? Nice. Okay. This study is done in conjunction with a couple of my colleagues from the Nuclear Medicine Department of the National Hospital in Abuja, Nigeria. And these are just the disclosures. Radionuclide shuntography is a safe and simple method of determining CSF shunt patency and to analyze changes in CSF flow, which is a dynamic study. Shunts are most often permanent treatment options for patients with hydrocephalus. And there are various kinds of shunts, as we all know, ventricular peritoneal, ventricular pleural, ventricular atrial, ventricular jugular, and then gallbladder. However, the one that is most common has always been the ventricular peritoneal. We know the main causes of hydrocephalus, which I slightly enumerated here. And I don't know if the centers here get to see gross hydrocephalus as big as this. But we see things like this and sometimes much more enormous, actually, than this. And as we have said, ventricular peritoneal shunts are sometimes permanent options for hydrocephalus. There are surgical procedures which are invasive and not readily available in some parts of the developing countries and really requires lots of expertise. Shunt tubes are expensive, even though these days we have some cheaper forms of BP shunts made from India called Shabra shunts. But not many centers do have such. So when you see, sometimes come across the Medtronic type, which costs like $1,000, $1,005, it's really prohibitively expensive to most countries in developing world. There is significant improvement in the quality of life of patients with hydrocephalus post-shunt. There's no doubt about that. However, we know that complications do occur following that, most especially obstructions. Regular assessment of these shunts for function is therefore quite important. These are just pictures of the types of shunts. The shunts usually, as we all know, have three parts, the ventricular catheter, the reservoir, and the distal catheter. For the assessment of the dynamic function of the shunts, what we are going to concentrate on, actually, is on the reservoir and the distal catheter, not the proximal ventricular catheter. These are just a picture to show the different paths. Some shunts use this kind of reservoir and valve. And others, like the Shabra shunt we talk about, has this cylindrical valve and reservoir that you can see underneath the skin of the patient. Some of the causes of malfunction include infection, which usually occurs some weeks after surgery. And then most often we have mechanical failures, which could be as a result of inflammatory debris, fractures of the tubes, and failure of the valve system or the reservoir. They present with the classical features of hydrocephalus, which is head enlargement, headache, pain, visual problems, muscular weaknesses, and urinary incontinence. If one is met with a case like this, which is post-surgery, you know that, yeah, this patient really is straightforward, requires a review of his shunt. But however, like I said, it's not all cases that come to you this way. Some come, you're not too sure if it's actually obstructed, I mean, or malfunctioning or not. Could it be something else? So it's that class, the second class or category of patients that actually we subject through this kind of investigation that we are talking about today. So usually when we come across such kind of patients, we subject them through plane X-rays, transfrontal ultrasound, CT, and MRI. Classically, most of us do that. However, we discover that these are all, I would say, indirect means of assessing the functionality of the shunts. The only way that you can be able to determine the dynamic function of the shunt is using some radio tracers. And one of such is radionuclide shuntography. How we do this is under strict aseptic technique, and we use insulin syringe with a hypodermic needle, tilt the patient's head 30 to 45 degrees, and then inject into the reservoir. We would draw CSF, inject normal cell into a certain that the needle is actually in situ, and then inject radiopharmaceuticals, which is usually one millimeter of technetium-99 dPTA. And then we acquire dynamic images using dual-headed medisco camera, which is a gamma camera, for 20 minutes. If there's no peritoneal, it is expected that if there is no obstruction, between zero to 20 minutes, there should be peritoneal seepage, if there's no obstruction. However, if there's no peritoneal seepage within these 20 minutes, it means there is some form of obstruction. Then we now determine, is it a complete obstruction or partial obstruction? So, after the 20 minutes of continuous gamma camera image taking, which is dynamic imaging, then we now do images, static images this time, at one hour, three hours, and six hours. Then that's the end of the study. Then aftercare is quite important in these patients. This is one of the patients depicted here. The most important thing is to calm these patients down, make them very comfortable. Here you can see my colleague here, who is the nuclear physician, really calming the patients down, and here trying to inject the technician. This is the gamma camera, and this is our workstation, as we are taking the images. This is a close-up of the images, dynamic images on the workstation. So, if there is no obstruction, what you expect to find is complete spillage into the peritoneal cavity within 20 minutes. Here, this image shows that. You can see the tracts, and then there is complete emptying into the peritoneum within 20 minutes. However, when there's an obstruction, you can see this is static. I mean, it's stuck around the valve area throughout the length of the dynamic imaging. So, this picture shows a complete emptying of the contrast into the peritoneum. So, that's a complete spillage within 20 minutes, and such that at this time, when you take it around one hour after the initial injection, it has even been picked up by the parotid gland. It tells you that there is no obstruction at all. Here, this is some form of partial obstruction. These are dynamic images, and this is image at one hour, three hours, and at six hours. So, that tells you that there is some obstruction, yeah. Comparing that with the previous image, you would know that, yeah, there's some obstruction. Some people call this image coprophine. And this is a complete obstruction. You can see the technetium-99 is still stuck at this level around the area of the valve, and up to six hours post-injection, there is no spillage at all. So, that tells you that there's a complete obstruction. The likely complications to this are not much, but just for academics, you can have puncture of the reservoir, extravasation of radionuclide activity, bleeding, infection, and the loss. Optimal study is usually seen in uncooperative children, and we have seen two of such, as you will see when I come to show some of our results. There could be extravasation, bleeding, and in older children, the quantity of the technetium-99, what infuses, may be little. These are just the reports of that. So, in our experience, within three years, we have been able to do such a study on, which is a prelim study on 56 patients between the ages of five and 11 years, and we've got that out of the people that we were not sure whether they were actually, if there's complete shunt obstruction, you can see 18 have normal functioning shunts, and then that is equivalent to 32%. Then there's total blockage of the tube in 13%, and then partial blockage in 29%, and suboptimal in two patients who happen to have been uncooperative. So, radionuclide shuntography is a simple, cheap, safe, and non-invasive method of evaluating CSF function. There is no existing protocol at the moment, at least in our part of the world, for such to be done, so we are trying to develop such protocol at the moment. And I've seen in our series, 32 of such patients had a normal functioning shunt. So, who ordinarily, that's one-third of the study group. So, ordinarily, if we haven't done this, we would have subjected them through, maybe removing the shunts or replacing with another, and also with the attendant risks of all the risks of shunt revision. And this distinction is critical, considering the cost of replacement of the tube, the complications of re-operation, and the manpower time for surgery. Yeah, so that's the end of the talk. However, I would like to invite you all to the Cancer Congress in Abuja, which comes up from the 24th to 26th, just like my colleague, Dr. Soad, said. And thank you so much. Thank you. Yeah. Well, Dr. Fagagi is coming up. Any questions? Yes, sir. Can you go over the middle, please? Thanks. Thank you for your presentation. I was just wondering, why do you need to use a radionuclide dye? Why can't you use a simple water-soluble dye and just take a simple, plain X-ray, and that will tell you pretty much the same thing? That's what we do back home. Okay. Actually, going through literature, the amount of radioactive exposure one has from one single X-ray is maybe, what you get in this is less than half of that exposure of X-ray. So I think that's better in the child. Thank you. Yeah, Mark. So I just had two questions. It's a very nice talk. Do you wait for looking for renal excretion to look at the kidneys filling with the trace, or just to ensure that there's no oculation in the abdomen at all, or you haven't found that to be useful? We really haven't found that to be any useful at all. And usually before these patients are subjected through that, we must have done a good electrolytes, creatinine, and be sure that everything is fine. Yeah. So we haven't had any issues with that. Thanks. And then, just beyond the scope of your talk, but has endoscopic theraventriculostomy and choroid plexectomy affected your practice significantly, or is it still primarily shunt-based? We haven't looked at that, actually. Maybe this is something that we need to look at. Yeah. Great. Thank you. Thank you. Beautiful. Great job.

radionuclide shuntography

ventricular peritoneal shunt

hydrocephalus

CSF flow assessment

shunt patency