30 Quick Hits #3 - Final Edit

All right, greetings abscite nerds. By now you are probably sick and tired of studying, but fear not, we have a quick high yield review for you today. We got Nina back up. Let's talk about the foregut. Please describe for me Osafajeal anatomy. So the esophagus is made up of squamous epithelium on the inner layer with an inner circular muscle layer and an outer longitudinal muscle layer.

There's no serosa on the esophagus and notably the upper third is made up of striated muscle while the lower two thirds is made up of smooth muscle. The lower esophageal sphincter is about 40 centimeters from the incisors, and the vagus nerve is closely affiliated with the esophagus. So you think about the right and left vagus nerves.

The right goes posterior to the esophagus, especially distally, and the left vagus nerve runs anterior to the distal esophagus. There are a couple of anatomic areas of narrowing where Foreign bodies may get stuck in an abscite stem and those

include the upper esophageal sphincter, which is also the cricopharyngeus muscle, the left main stem bronchus or where the aortic arch cross over the esophagus or the diaphragmatic hiatus.

All right. So now I'm thinking about surgical access to the esophagus. I want to get access to the neck. Which side am I going on, Nina? In the neck, you're going to go for a left sided incision. Okay. How about in the upper two thirds of the chest? Heart gets in the way. Go to the right side. Okay, and the lower one third of the chest.

Back to normal. Go back to the left. Okay. So I have a false diverticulum between the cricopharyngeus and the pharyngeal constrictor muscles. What is that? It's a Zanker's diverticulum. So you treat that you treat that by doing a cricopharyngeal myotomy or a Zanker resection. Generally, I think about two options, endoscopic or open repair.

If it's less than three centimeters and the patients or the patients unable to extend their neck all the way, then you do an open surgical repair. If it's greater than three centimeters, they can get it repaired

endoscopically. What's the most common type of esophageal cancer? Also kind of a trippy question.

So this, in the United States, this is adenocarcinoma, which I think about because it's associated with obesity, GERD, Barrett esophagus, all those things we see pretty frequently in our foregut clinics. Elsewhere in the world, squamous cell carcinoma is the most common. Anatomy question. Please describe the blood supply to the stomach.

Yep. So the left gastric comes off of the celiac trunk, serves the stomach. The right gastric comes off of the common hepatic artery, the left gastro, loic, and short gastrics as shorties come right off the splenic artery. And finally, the right gastro epi loic comes off of the GTA. Okay, what cells secrete hydrochloric acid?

That would be the parietal cells. Okay. And what signals activate the, activate the secretion of hydrochloric acid from parietal cells. That would be acetylcholine, histamine, and gastrin. Okay, what's the medical treatment for a gist? That's going to be imatinib, which is

a tyrosine kinase inhibitor. I've seen it asked both ways, by mechanism and by name.

What's the first sign of leak following a bypass? Watch out for your tachycardic patients who just got a bypass. And what are the mineral and vitamin deficits that can occur following RuneWine gastric bypass? I think Dan already mentioned a few of these in the context of ileal resection for Crohn's, but you can get B12 deficiency because these patients lack intrinsic factor and you, they also might need an acidic environment to activate intrinsic factors.

So both of those might be lacking in Roux en Y patients. And then the second is iron, which is absorbed in the duodenum. All right, Dan, let's move on to HPB. What are the two most common hepatic artery variants? So, the most common is the right hepatic artery coming off the SMA, followed by the left hepatic artery coming off the left gastric.

What separates the left and right lobes of the liver? So this is that imaginary line called Cantley's line,

and it's a line between the middle of the gallbladder fossa going back to the IVC. Right, and then, so what separates the medial and lateral segments of the left lobe of the liver? That'd be the falciform ligament.

Less, the less imaginary dividing line. Describe for me briefly in your own words Coynaude's segments of the liver. Yeah, so I always think that this is best learned by looking at a picture. You can easily Google this, but another trick is to make a fist with your right hand, and the finger should be wrapped around your flexed thumb, and the fist should face you.

And then looking at all the segments, the segment 1 is the caudate, which is the thumb in the palm of your hand. Segment 2 is your index finger's proximal phalanx. Segment 3 is the index finger's middle phalanx. Segment 4a is the middle finger proximal Segment 4B is the middle finger middle phalanx.

Segment 5 is the ring finger middle phalanx. Segment 6 is the little finger middle phalanx. Segment 7 is the

little finger proximal phalanx. And Segment 8 is the ring finger proximal phalanx. Perfect. Which hepatocytes are most sensitive to ischemia? Yes. This is going back in the textbook here, but these are this, the hepatocytes in Asner zone three, the central lobular.

All right. I've seen a question on Gil Bears and the Raz Nihar syndrome versus rotors and Dubin Johnson syndromes. I butchered that, but. You all would too. So, yeah, so, so I group Gilbears and Krigler Nahar into the same group here. And these are problems with conjugation. And so with these patients, you see a high indirect bilirubin compared to Roeder's and Dubin Johnson syndrome, which are problems with excretion.

So in these patients, you have a high direct bilirubin. All right. What's the best indicator of synthetic function in a patient with cirrhosis? Yeah, so this is looking at the PT INR due to factor VII having the shortest half life. Normal portal vein pressure. So

normal portal vein pressure is 5 to 10 millimeters of mercury, but this is not to be confused with a hepatic venous pressure gradient.

which is the portal vein pressure minus the hepatic venous pressure, or RA pressure. And this has a normal value of 1 to 5 millimeters of mercury. Above 5 is considered mild portal hypertension, and over 10 is clinically significant portal hypertension. Excellent, thanks for bringing that up. Everything you need to know about hepatic adenomas, let's hear it.

Yeah, so most commonly in a question stem, you'll see a woman of reproductive age taking oral contraceptives. You may also see a male taking, using anabolic steroids. These are mostly benign, but they are associated with risk of hemorrhage and malignant transformation. On CT scan, these demonstrate early arterial enhancement, followed by isoattenuation during the portal and delayed phase imaging.

If a patient is female and the tumor is less than five centimeters and asymptomatic, you can do conservative

therapy, which is just stopping the oral contraceptives or anabolic steroid use. If it's a male patient, these are always resected. And if you have a and if you have a female patient with an adenoma greater than five centimeters, then you would do an elective resection.

Okay. So hepatic adenoma in a male, it comes out greater than five centimeters and feel female comes out. And if it's less than five centimeters in a female and they're asymptomatic, you can try conservative therapy, stop those contraceptives and or steroids. What's the most common malignant liver tumor?

Yeah, so this would be a metastasis. It's about twenty to one metastasis to primary. Okay. What medication contracts the sphincter of OD and what relaxes it? Yeah, so think of morphine as the contractor of the sphincter, and then glucagon relaxes it. Think that we give a one milligram dose of IV glucagon during cholangiogram if we can't push the stone out of the duct to help it relax.

Okay. I think of this one as

morphine is an opiate, which like contracts everything and makes people super constipated, including the gallbladder. And that's how I remember that. The old constipated gallbladder. Excellent. So what's the normal size for a common bile duct? Yeah, so patients under 65 years of age, we think less than 0.

8 centimeters. Patients over 65 years of age can be a little bit more dilated. So we think of less than 1. 1 centimeters. After a cholecystectomy, a patient can have normal common bile duct dilation up to about 1 centimeter. What factors increase bile excretion and what factors decrease it as well? Yes, so to increase it, think of cholecystokinin, secretin, and vagal input.

And decreasing, we think of somatostatin, VIP, and sympathetic input. Okay, you have a question stem in which the patient was found to have air in the biliary system. What could cause this? Yeah, so we want to make sure that they haven't had some sort of instrumentation usually an ERCP maybe cholangitis, and

maybe they have some fistula to the enteric tract caused by a gallstone.

What are the types of choledocal cysts? Which one is the most common, and how would you treat that? Yeah, so type one this is your most common. This is the cystic dilation of the common bile duct. And we treat this with resection and hepatic co J. Type two, you have a diverticular dilation anywhere along the extrahepatic duct.

Type three is also called a choledocoseal. This is dilation of the distal CBD. Type 4a, you have multiple dilations affecting both the intrahepatic and extrahepatic biliary tree. Type 4b, you have multiple dilations of the extrahepatic duct, and type 5, this is your Corollis disease, this is where you have multiple dilations of only the intrahepatic ducts.

Alright, I have a patient who has biliary disease, and they're found to be positive for antimitochondrial antibodies. What's the diagnosis? Yeah, so this is a primary

biliary cirrhosis which has no increased cancer risk and, but you do think about transplant. Fantastic. What's the most common bugs that cause cholangitis?

So most commonly you have E. coli followed by Klebsiella. And describe to me Charcot's triad. So this is right upper quadrant pain, fever, and jaundice. And Renan's pentad. So you have those same three, right upper quadrant pain, fever, and jaundice, but you add in altered mental status and shock. All right, and how do you treat cholangitis?

So these patients need urgent biliary decompression usually in the form of ERCP and sometimes PTC. Okay, I'm going to describe some findings on imaging you tell me what you think about. So a liver mass with peripheral to central enhancement on delayed phase CT. So this is a hemangioma. Okay, what if I see a central scar on imaging?

This is your focal nodular hyperplasia or FNH. A

heterogeneous poorly circumscribed mass with early arterial enhancement and quick washout with room enhancement on delayed images. This is concerning for hepatocellular carcinoma. Right, and it can be diagnostic for it as well. What issues can ceftriaxone cause when it comes to the biliary system?

So this is debatable among some surgeons, but we think of gallbladder sludge and cholestatic jaundice. What's the when it comes to the endocrine function of the pancreas? What do alpha cells do? So alpha cells are responsible for glucagon, and I just use the A in alpha and the A in glucagon. We have beta cells, which I just remember are always just insulin producing cells.

And then the delta cells, I think of somatostatin. Remember, delta and somatostatin. How are pancreatic enzymes activated? So here you have Entero kinase from the duodenum, which confer which converts the trypsinogen into trypsin, which then

activates the other pancreatic enzymes. Alright, what's the name of the pancreatic accessory duct?

So this is the duct of Santorini compared to the major duct, which is the duct of war sunk. And what's an annular pancreas? This is when the second portion of the duodenum is surrounded by pancreatic band. And to treat this we can do a duo duo ostomy, or a duo, Dino Duo ostomy. All right, what is Gray Turner's sign and Cullen's sign and what causes them?

So Gray Turner's sign is flank ecchymosis and I think of this as you need to turn her to see the flanks. And Cullen's sign is umbilical ecchymosis and these are both caused by hemorrhagic pancreatitis. All right, let's talk gallbladder polyps. So what's the number I need to know in my head when it comes to treatment plans?

Yeah, so you really want to think of a greater than 10 millimeters being concerning. And how do I diagnose biliary dyskinesia?

So the best test for this is a HIDA scan, where you're looking at an ejection fraction of less than 35 percent. And this is testing 20 minutes after CCK administration. You also want to make sure that there's an absence of stones or cholecystitis prior to making the diagnosis.

All right. Thanks for listening. I think we all need to go out for a stiff drink after talking to HPB. Keep your head up, everyone. Keep studying hard. You're going to do fantastic. The ab site is probably only a short while away. We have one more episode of Quick Review for you, so tune in next time. In the meantime, dominate the day.