Hypertrophic Pyloric Stenosis: Technical Aspects of Ultrasound of the Abdomen - HD

Introduction

My name is Ricardo Feingold.

I'm a pediatric radiologist at Montreal Children's Hospital, McGill University.

The title of this presentation is Hypertrophic Poly Stenosis, technical Aspects of Ultrasound of the Abdomen.

The objectives of this short presentation are to describe the clinical aspects of Hypertro pilar stenosis, discuss the criteria for hypertro pal stenosis and focusing in describing the technical aspects of ultrasound of a pilars.

In infants with projectile vomiting will provide images Nvidia of the normal pylos and infants with pyloric stenosis.

Clinical Presentation

Hypertrophic pric stenosis usually presents with non-ED projectile vomiting, in particularly male infants between two to eight weeks of age.

He consists of hypertrophy of the muscular layer of the pilars causing a gastric outlet obstruction if the polyus is palpable on the clinical exam.

This is also known as the palpable olive sign.

The imaging investigation of choice is of ultrasound of the abdomen, although in the past upper GI studies were performed, the surgical treatment of choice is pal myotomy, which could be performed via laparotomy or laparoscopically.

Ultrasound Criteria

The ultrasound criteria for pric stenosis consists in measuring the pric muscle thickness.

This can be measured in the longitudinal plane or under transverse plane and is considered pathological if more than three millimeters.

As you can appreciate the measurements in the image on the left and image on the right, The pilar length is demonstrated in the imaging on the left and is usually pathological if more than 15 millimeters.

As you can see the arrow parallel to the length of the pyloric canal.

Ultrasound Technique

With regards to technique it is important to choose appropriately the transducers.

Usually we use linear array probes between 12 and 20 megahertz.

According to the equipment available, the patient is in the supine position.

The transducer is placed in the epigastric region underneath the xiphoid process of the sternum.

Please note you should not slide the probe.

You should angle the probe coly until you find the landmarks adjacent to the palis such as S-M-A-S-M-V, the pancreatic head.

As you can see, the images on the left and on the right one showing the normal Polaris and the other showing an infant with hypertrophic poly stenosis.

You may also turn your transducer anti-clockwise to identify the gallbladder and the polys usually medial to the gallbladder.

As you can see on the image on the right, if the stomach is very distended, particularly with gas, it may be difficult to visualize the pyrus.

Therefore, place the patient in the right lateral decubitus and wait for the contents of the stomach to go through the pyrus.

Or you may use the liver as a window to visualize the S.

As you can see in the imaging on the right, the baby also may be given glucose water to better appreciate the contents going through the pulis and therefore outline the s.

Please note that sometimes the gastro physio junction may mimic the appearance of the S and you must be aware and pay attention to the landmarks because adjacent to the gastro junction, you may appreciate the aorta or the hepatic veins and the diaphragm or the cora.

Image and Video Examples

This video demonstrates the pyrus, which is obviously abnormal.

You can see the gallbladder adjacent to the pyrus and underneath the pyrus.

You can appreciate the superior mesenteric vein, the superior mesentary artery, and even part of the splenic vein.

The image on the left demonstrates a normal pyrus, which is adjacent to the gallbladder as identified by the arrows.

The image on the right, an additional case of a normal PIIs.

The maximal thickness of the PIIs is approximately two millimeters, and the length of the canal represented by the calipers is 10 millimeters, which is within the normal limits.

You can see some contents within the stomach as well.

This video represents a normal PIIs.

You can see the gastric contents going through the PIIs, which is abnormal thickness, similar to the thickness of the gastric wall.

Here are two examples of the gastro fial junction.

As I said before, that may mimic the pyrus.

You can see the arrows pointing to the GE junction.

The image on the left, you can see that it's a level of the hepatic veins and the image on the right.

You can see the G junction just at the level of the aorta.

Therefore, mimicking the appearance of the pilars.

But according to the anatomic landmarks, you're quite sure that this is indeed a gastro al junction.

This video demonstrates the GE junction, even with some reflex contents going back to the esophagus, you can see the pulsating aorta underneath the diaphragm, also noting the landmarks for the gastro fial junction.

Conclusion

In conclusion, we briefly define the clinical aspects and the criteria for parlo stenosis, and we focus in the description of the technical aspects of ultrasound parlo in infants with projectile vomiting, and I thank you for your attention.