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Hello, everyone. Um, welcome to this evening sessions on urology stones. I'll just give it like a minute or two for everyone to join and we'll get started. Ok. We'll just give you one more minute, then we'll start. Ok. Uh I think we can get started. So welcome everyone. My name is Husson and I am an F one in Southampton and I'll be teaching us uh tonight all about uh urology stones. So, our learning objectives tonight is kind of understand how common are stones. Um, what are the, to the different types? What are the symptoms they can cause? Are there any emergencies we should worry about when it comes to stones, um, how we diagnose these and also the management. So stones is quite extensive, but I try to make it like as relevant as I can for the UK related and for your exams. So just to get everyone warmed up, uh, if we can just put it in the chart or if you'd like to shout out how many different types of kidney stones can you name? Yeah. Ok. No. Ok. Mhm. Ok. Stew. Right. That's correct. Calcium oxalate. Yep. That's correct as well. All done. So the many different types of stones we have, as you've mentioned, calcium oxalate and phosphate. Urate. Uric acid. Yep. True as well. Good job guys. So we have the two calcium oxalate and phosphate. We have uric acid stones, struvite and cysteine. And later on, we'll cover these in a bit more detail, but these are the main type of stones you patients can present with. And another question just to get us warmed up. How common do we think kidney stones are? Like, what percentage of the population do you think has stones? Mhm. Ok. You just have it a guess in the chat. Ok. Ok. This 15%. Um, that's a good estimate. Yeah, they're about, um, we're thinking of like lifetime prevalence. We're thinking around 11% in men and 9009% in women and roughly eight cases per 1000 adults and in western countries that the one we live in, we're seeing increasing incident. So they are quite common. Um, when I was in urology, if we had like 30 patients on the ward round a good 11 or 12 were coming in with stones. There was lots of outpatient appointments and elective cases. So they are very, very common. I think I was going to start off with a little bit of anatomy just so we can understand some of the complications that come with stones. So if we start the kidney, if you all know, it's one of the organs that filters our blood to remove urea and other toxins to form urine. This urine is made up of water, urea and inorganic salts and we just need to pop that in the back of our mind, the inorganic salts. This is a diagram on the left hand side where you can see um the real pelvis and that's where mainly the stones will start to form. As we can see the ureter drain down to the bladder. Ureters themselves are 3 to 4 millimeters in diameter. And they just transport urine from the kidney to the bladder. The most important thing to remember which I think comes up quite often in clinical practice and exams is there are three levels which the ureter constricts. So, you know, you have 3 to 4 millimeters, um it can constrict and that's where often you get stones stuck. And this would be the pelvic uric junction, the pelvic brain where it kind of covers over the common artery and the ureteral vesical junction where it plugs into the bladder. So these three areas are important because there are often places where stones can get stuck and then we can get the complications. Now, what causes the stones to form is like I mentioned when we make urine, we have some inorganic salts in the urine and sometimes these solutes can crystallize and you get stones. The term nephrolithiasis is just to describe the formation of stones in the kidney and it summarizes all the different types of stones. And the locations urethrolithiasis is when they exit the kidney and they travel downstream to the ureter. So it's basically uh kidneys filter blood, they remove the urea water and also lots of organic salts. And sometimes when they crystallize, they form stones. The way this happens is when you can get plaques of calcium deposited on the renal papilla. And these are called Randall plaques. As you can kind of see in that diagram there. And these serve as the building box for stones in many cases. So once you have these Rhino plaques, that's where all the different inorganic salts compounds can start forming around. And that's when you get stones. And as for, you know why you get them in some people and not others, there's different things that can kind of precipitate it. So one thing in the body is whenever you have static urine, it's not flowing well, you just have increased likelihood of solids crystallizing. And this can happen due to anatomical features like urethral stricture. Also, you commonly see in patients who have retention and they struggle to fully empty their bladder, you can get bladder stones for the same reason. Another thing is infection. So it's this double bar effect where a stone can increase the likelihood of an infection. But at the same time, an infection can precipitate a stone. And quite commonly you get struvite stones. Another thing is low urine volume. So a lot of times you'll see patients come in and they have typically people who are quite dehydrated most of the time and they have very poor intake. And other ones, you see increasing incidence of stones in, at the same time, diet can matter. If you have very high sodium and oxalate input, you can get increased risk of stones. And also genetics. If you talk to a patient and they have a family history of stones such as in their parents or grandparents increases their likelihood of forming stones themselves. Another thing is drugs. So certain drugs um increase the likelihood of stones forming. And you can split these into two broad categories. One category is where they cause metabolic abnormalities or changes in the metabolic make up of urine, which increases the chance of forming stones. And these are your loop diuretics like furosemide, the carbonic anhydrase inhibitors like acetoamide and also people who take a lot of laxatives. The other class of drugs are the drugs where they kinda form the main component of the stone unless you have your antibiotics like ciprofloxacin, antivirals, like indinavir, sulfonamides, and also magnesium trisilicate. So you have to also watch out for when a patient comes in just to have a quick look at their drugs to see if anything that can be causing the stones. Uh I thought I quickly mentioned cystinuria, as you mentioned earlier, cystine seven. So this is a genetic condition. It's autosomal recessive and it basically cystine is an amino acid. And in these patients with cystinuria, they just have large amounts of cystine in the urine. So they increase.