Hello in this blog we're going to talk about kidney stones or urinary stones have many names including urolithiasis which is the actual formation of stones along the urinary tract or Nephrolithiasis which is stones forming specifically in the nephron or the kidneys to make things even more confusing urinary or kidney stones can also be called renal or urinary calculi essentially means stones however these words are used interchangeably but essentially mean the same thing kidney stones in order to understand kidney stones we have to revise the anatomy here the adrenal glands which are endocrine glands sit above the kidneys form urine will then travel down the ureter and be stored in the bladder can stretch and once full we urinate the urine will flow through the urethra and then out the ureter has three sites of constriction where it contracts the smooth muscle and these are important to know because these are the sites where narrowing can occur and also the site where urinary stones can Lodge the sites of ureteric constriction include the pelvic ureteric junction the pelvic brim and the vesicular ureteric Junction the Vesicoureteric Junction is actually the the connection between the ureter and the urinary bladder which is sort of behind and under the urinary bladder the kidney is the organ responsible for filtering the blood and disposing of waste it's important for regulating blood pressure and regulating electrolyte balance it is also responsible for producing some important hormones such as erythropoietin and activation of vitamin D here is the adrenal glands which are again the endocrine glands that sit above our kidneys here is the ureter looking inside the kidney it consists of pyramids called the medulla pyramids surrounding the medulla pyramids is the cortex the medulla pyramids joins the tip of the medulla pyramids joins and forms the calyx then joined together and form and drain into the renal pelvis has a renal artery and renal vein entering and exiting it residing around and within the medullary pyramids are the functional units of the kidneys called nephrons, Nephrons are structures which filter our blood they secrete wastes and allow re-absorption of things into the bloodstream thus it has a main role in regulating electrolyte and fluid balance in our body the head of the nephron is the Bowman's capsule where the afferent arteriole brings blood in forming the glomerulus and then we have the efferent arteriole leaving the glomerulus once filtering has occurred within the Bowman's capsule the filtrate will travel along the tube you'll of the nephron firstly it will pass the proximal convoluted tubules then it will go down towards the loop of Henle the distal convoluted tubules and then finally the collecting duct looking more closely at the tube you'll the cells that line the nephron tubules are predominantly cuboidal epithelial cells within the tube you'll of the nephrons crystal like structures can fall the crystal like structures are essentially precipitance of some electrolytes that have accumulated there this crystal is actually a urinary stone if the crystal is small it will just pass in the urine but if it remains in the kidneys in the nephron it can grow bigger and become a kidney stone a kidney stone again is basically a big crystal the kidney stone can lead to an obstruction the obstruction within the tube you'll can create a buildup of pressure in the tube, Coarse textured with irregular margins and bulky left lobe & caudate this pressure can cause irritation and this irritation is read by the brain as renal colic there is also an inflammatory process going on due to the obstruction and this also leads to the renal colic the pain we feel when there is urinary stones in the body alternatively the urinary stone can lodge or get stuck within the ureter remember the sites of constriction of the ureter well the stones can get stuck there and when this happens irritation and pain can occur due to stretching of the fibers that are there that which are caused again by the increase in pressure within the ureter with this increase in pressure proximally to the site of obstruction and with the irritation going on edema can occur and the ureter will contract more vigorously trying to push the stone out this is called hyper peristalsis and so with this in mind the clinical presentation of kidney stones can include acute flank pain which can radiate to the back or towards the groin and the flanks there can be associated ever because of the inflammation and nausea and vomiting there can be also urinary frequency and urgency hematuria the person may present to be obese the risk factors for developing a kidney stone include a high-protein diet high salt diet male.
Caucasian obesity
dehydration medications including antacids and carbonic anhydrase inhibitors
sodium and calcium containing medications also increases the risk of developing
kidney stones crystal urea is also risk factor as well as having a family
history these risk factors will lead to a number of things first some of these
risk factors will increase urinary solute concentration
including concentration of calcium uric acid and calcium oxalate and sodium
some of these risk factors will also decrease the stone forming inhibitors
which include citrate and magnesium the increase in urinary solutes and the
decrease in urinary stone inhibitors causes urine super-saturation leading to
urinary crystal formation or urinary stone formation a decrease in urinary
volume such as in dehydration and an excessive increase or decrease in urinary
pH also contributes to urine super-saturation so in summary urine super-saturation
with stone-forming salts results in crystal formation urinary stone formation
and as I mentioned there are a lot of types of urinary forming salts such as
calcium uric acid and oxalate and because of this there are many types of
stones kidney stones the stone pathology can be broadly divided into five
different types these include calcium oxalate stones which make up the majority
75% there is also the calcium phosphate as well Struvite is common in chronic urinary tract infections there are also uric acid stones and cysteine stone investigations for suspected renal calculi
renal stones include a full blood count CRP magnesium calcium phosphate levels urinalysis which
may show hematuria a 24-hour urine calcium level phosphate level oxalate urates
cysteine and xanthine levels and this can show us what type of kidney stone he might
be x-ray can be performed to detect a kidney stone an ultrasound can also detect a
kidney stone an ultrasound may show a stick shadowing ultrasound
may also reveal hydronephrosis if the obstruction is within the ureter causing
backflow of urine which will dilate the ureter approximately finally a CT scan
can also be used which can show kidney stones let's look at an algorithm again
the clinical presentation of kidney stones include fever nausea vomiting acute flank pain radiating to the groin or
the back the pain is often described as stabbing and severe there is
tachycardia with or without hematuria the triad for urinary or kidney stones
some say is fever vomiting and acute flank pain so in an acute setting
analgesia is given with or without an antiemetic to prevent vomiting IV fluids
are administered carefully most urinary stones if
small less than half a centimeter will pass spontaneously without any
intervention however if intervention is required it is either done electively
or as soon as possible by intervention I mean surgical management and surgical
management will depend on how big the kidney stone is as well as where the
kidney stone is if it is within the ureter or within the actual kidney
percutaneous 'no Frasca me allows placement of a small flexible
rubber tube a catheter through the skin and into the kidney and this is in
order to drain urine out if there are signs of obstruction this is more of symptomatic
relief in terms of removal of the kidney stone there is ureteric stent
insertion here is the ureter and let us say the stone is lodged within the
ureter well a stent a rod can be fed up
through the urethra through the bladder and up the ureter to the side of obstruction and the
stent can be placed there the stent will allow drainage of the urine
essentially bypassing the blockage the urine can then just drain straight into
the bladder if the urinary stone is within the kidney a procedure called a
percutaneous nephrology Atum ii can be performed
in this procedure the aim is to remove the stone from the kidney by a small puncture
wound through the skin it is most suitable for removal of stones that are more
than let's say 2 centimeters in size and which are present around the pelvic
region of the kidney another surgical procedure that can be done for urinary
stones within the ureter or within the kidneys is a simple endoscopic procedure
that will break down the stone within the kidneys or the ureter alternatively
there is open surgery to remove and break the stone finally there is the extra
corporeal shock wave lithotripsy uses
shock waves to break up stones that form in the kidneys to enable easy passage
of these fragments out of the body within urine.Thank you
