Cesarean Section US & CT of Acute and Chronic Complications - SD

Introduction

My name is Dr. Mindy Harrow. I'm a radiologist in Philadelphia, Pennsylvania at the Albert Einstein Medical Center.

I'm going to be talking about the acute and chronic complications related to cesarean sections and predominantly through ultrasound and some CT.

In this lecture I will be discussing ultrasound and CT of acute and chronic complications related to cesarean section.

Cesarean section, at least in the United States now accounts for approximately one third of all births.

Typical symptoms requiring postoperative imaging acutely would be fever with a poor response to antibiotics dropping hemoglobin or unexpected pain or bleeding.

Acute diagnoses are a variety from relatively benign things such as small hematomas and wound infections to much more significant issues related to uterine dehiscence and possible rupture.

Then there are a whole variety of more chronic related issues that are caused by cesarean section and because of the increased incidence of cesarean section deliveries, we are seeing these much more often on ultrasound and need to be aware of them as a result.

I might add when we do pelvic ultrasound in women, we specifically ask them if they have had a history of a cesarean section acute complications.

The overview for this section will include the spectrum of normal after a cesarean section, hematomas and infections, other non-related or other related, but non GYN issues such as ureteral and bowel injuries.

I won't be discussing today the choice of imaging modality because I'm going to be discussing issues of ultrasound and CT, depends upon the clinical situation, cost, availability, contraindications, et cetera.

And so there are a variety of different imaging modalities that can be used, including MR.

My experience is predominantly with ultrasound and CT and hence that is what will be covered in this lecture.

Normal Findings After Cesarean Section

These are images from four different patients who have essentially normal studies.

And what might look grossly abnormal in other patients is really within the spectrum of normal after a cesarean section.

So in case number one, you can actually see the sutures from the incision of the cesarean section with some overlying skin thickening.

In this situation within the uterus there's a little bit of slightly high density material and that's blood in the endometrial canal, which is not unexpected.

This case has a small focus of air in the endometrium or it could be in the cervix and a few tiny foci centrally located within a few days of surgery are also normal.

This last image is a sagittal reformat of the uterus in a patient a few days after cesarean section.

So the front of the patient is here and the spine is in the back.

This is a nice sagittal view of the uterus.

The low density region right here is where the cesarean cut was performed for the incision and so that's a normal finding here between the bladder and the anterior aspect of the uterus is a very small hematoma that is called a bladder flap hematoma.

It's a little bit of a misnomer.

It's not really in the bladder wall, but the key point here is that a small amount of hematoma in this location is just in the spectrum of normal in these type of patients.

Here's CT and ultrasound of the same patient after cesarean section with similar normal findings.

So a sagittal reformat shows the area where the cesarean section was made with a little bit of a hematoma and this is the bladder in transverse.

You can see these low density areas in the part that had the incision and notice if you will, that the incisions are not always smack in the middle of the uterus.

They may seem off to the side.

Remember, the uterus was cut initially when it was quite enlarged.

This is the same uterus in a transvaginal view and the fundus is here.

This is the place where this cesarean section was made and not only can you see a little bit of fluid and low and mixed high echogenicity material in this region, but you can see in the sagittal and even better in the transverse view these little bright linear echoes.

And this is the suture material which you can't really appreciate on the CT scan because of the resolution, but it's quite normal at this stage to still see all the little suture material in this location and this would not be considered an unusual finding.

Small myometrial and extrauterine hematomas are shown in these two sagittal views after cesarean section.

These the fundus of the uterus is here and there's a small echogenic hematoma in the myometrium exactly where the incision was made and a small component outside in the adjacent fat.

Here's the bladder. So the same process.

This patient was four days after a cesarean section that was performed because of twins in breach position and there was also an abruption of the placenta.

The patient has a fever, that is not responding well to antibiotics.

This is the transverse view and the sagittal reformat in this patient.

First you can notice that you can see the uterine incision.

It looks rather prominent, and there is a fair amount of blood products within the uterine cavity at this point, but the incision itself is fairly routine.

The canal is expanded with the complex fluid and there's air in the subcutaneous incisions and there's actually a little focus of air in the bladder.

So these are also within the realm of normal imaging on CT.

In the immediate post C-section patient, you can typically see the uterine discontinuity and other common findings which are really not important include small amounts of air, small amounts of blood in the uterus, small omera collections, and small bladder flap hematomas.

If there are less than two centimeters, they're within the range of normal.

Our recommendation and if you notice from these slides is if you're using CT for evaluation, intravenous contrast should really be used if for whatever reason IV contrast cannot be given to the patient, CT may not be the study of choice at that point.

In addition, it is best to evaluate the uterus perpendicular to the plane of the incision and typically that requires making sagittal and coronal reformatted views of the uterus.

So it may be quite difficult to interpret what is exactly happening in the axial images that come from the source.

As far as ultrasound imaging after cesarean section in the immediate postoperative period, the linear echogenic foci that are seen in the incision are the sutures and that's a typically normal thing.

There may be a mass like area which is a small hematoma also common and a normal finding similar to the CT, small bladder flap hematomas are not uncommon and it's fairly common to see some mixture of clot and debris with a few foci of air within the endometrial cavity.

Therefore, the appearance of endometritis and a normal endometrium completely overlap and that diagnosis should be really considered a clinical diagnosis.

Our recommendation for ultrasound imaging is to use whatever variety of transducers and transducer frequencies necessary to obtain the optimal images.

Remember, the uterus is still fairly large at this point and transvaginal imaging may or may not be optimal.

Transabdominal imaging will be fine often even without a full bladder and the woman may not be able to maintain a full bladder.

You may actually be able to use a higher frequency curve transducer than usual.

Acute Complications

Hematomas

Now let's look at some cases in which there truly is more than just the normal findings.

This patient, is being imaged after an acute cesarean section because of a decreasing hemoglobin and in this situation the hematomas are out of the spectrum of normal.

In this transverse axial view, the uterus is here and in front of it is a larger than should be bladder flap hematoma.

It's about the same density as the uterus in the sagittal view.

This is the bladder. Here's the uterus with a small amount of fluid in the endometrial cavity, which nicely outlines the scar, the incision point and you can see a little bit of the hematoma.

There's also some blood within the peritoneal cavity on either side, so this would be more than normal.

Sometimes these hematomas can become infected.

These are images from a sonogram in such a patient who has a gas containing collection in the bladder flap region and was having persistent pain and fever.

On the transabdominal view, you can see a little bit of urine in the bladder.

This is the uterus and so sort of between the bladder and the uterus is a fairly large complex fluid collection.

There are foci of air with a little bit of dirty shadowing and some other echoes within as well.

On the transvaginal, it's actually a little bit harder to see the whole uterus because it was large and out of the plane, but you can see the collection with the bubbles of gas which are now rising up.

The patient is lying down and a little bit of complex fluid in the endometrial cavity.

Bladder flap hematomas are a complication of the incision from the cesarean section.

This is covered by a fold of peritoneum.

Bleeding from the incision comes into this region and is usually confined by the peritoneum, but if large can extend beyond, as you saw into the ligaments, the retroperitoneum and the peritoneum, these are considered in the range of normal.

If they're relatively small and are not infrequent, surgical evacuation requires actually an incision of the peritoneum.

Now let's take a look at some other hematomas.

This is a patient, you can see the uterus here and the sagittal reformat and the bladder and these hematomas are more anterior in the subfascial region and within the abdominal wall.

Again, at about the level where the incision was made for the cesarean section, this patient has infected rectus muscle hematomas and extending into the subfascial region.

You can see the bubbles of gas and good sized hematomas in this area.

Here in the sagittal reform is the uterus, the bladder a sort of slightly larger than normal bladder flap hematoma, but a much larger hematoma in the rectus muscle containing some gas.

Subfascial hematomas are an extra peritoneal form of the hematoma you're typically related to the, to bleeding from the epigastric vessels and their branches and a fair amount of blood can accumulate in the pre vesical space in the rectus muscle posterior to it.

And all of these areas, often several liters and they may not really be clinically apparent because of the big uterus and the patient's body habitus, these can be evacuated without entering the peritoneal cavity.

Infections and Gas-Containing Collections

This patient had a history of premature rupture of the membranes and chorioamnioitis and was running persistent fevers on the transabdominal images.

This is the uterus in transverse and this is another image more superficially.

You can see that there are little bright echoes within the incision in the uterus more than you would expect just from sutures which you typically don't see transabdominally.

And so this represents some gas in the incision.

Then there is a collection anterior to the uterus, mostly fluid but also with some bubbles and bright echoes and some funny little artifacts.

And so this is in the location of the bladder flap hematoma, but with gas at this location as well as in the uterus, the corresponding CT which was performed subsequently shows the same thing, the long line of gas within the myometrium and extending into the bladder flap hematoma.

This is considered to be a uterine dehiscence and an infected bladder flap hematoma.

The patient higher up on the CT also had dilated loops of bowel and an ileus.

The infection was resolved with conservative management.

A catheter was placed into the bladder flap hematoma.

It was eventually evacuated.

The gas resolved and this is the follow-up CT several days later.

Unfortunately, the patient was readmitted 12 days later for new purulent drainage and distension and has gone on to develop a larger bladder flap abscess even than before, which probably had ruptured outside of the uterus.

There were smaller collections elsewhere, gas where it shouldn't be and unfortunately the patient required a hysterectomy.

Uterine Dehiscence

Uterine dehiscence is therefore defined as infected necrotic material in the uterine incision leading to a dehiscence at the suture line, but that continues to have an intact serosa.

It's a difficult diagnosis to make after a cesarean section because there is some overlap with the normal incision that as you saw, the gas is the major change between the two.

There are unfortunately not a lot of series and large group reports in the literature.

People some claim that MR is preferred over CT because of the multiplanar capabilities and better soft tissue contrast.

We find that with multi detector CT you can obtain good coronal and sagittal views and that often CT is just more available acutely in these patients.

The tip off that there may be a uterine dehiscence is the presence of a large bladder flap hematoma, especially if it has gas and appears infected, but there is difficulty differentiating partial and complete dehiscence.

Mind you despite its name, it can often be treated medically with drainage and not require a hysterectomy.

So our recommendation is to look for gas in the incision and any extrauterine incision and use the reformatted images.

Uterine Rupture

This is a situation that has got progressed beyond simple dehiscence in which the uterus has actually ruptured and there's a hematoma in the broad ligament and fairly large extra peritoneal hematomas.

The uterine incision is in this approximate area and you can see that there's a large hematoma coincident with the uterus extending out of it higher up on the CT scan.

The uterus was deviated towards the right and there was still a very large hematoma in the extra and then retroperitoneal space.

Amazingly enough, despite how awful this looked, the patient was treated conservatively, the hematomas resolved and this is the follow-up in this patient you can see as is common, the uterus often becomes tethered to the anterior abdominal wall.

This is the sonogram of that patient.

You can see the bladder and there's a little bit of an adhesion at the site of the incision, but amazingly everything has healed quite well.

Uterine rupture therefore is defined as a complete muscular separation of the myometrium.

It is typically accompanied by some degree of hemoperitoneum or other hematomas in the area and in this situation the morbidity and even the mortality significantly increase.

It is more frequent in patients who are attempting a vaginal delivery after a cesarean section, but any patient who has had a cesarean section potentially is at risk for this complication.

Wound Infections

Here's another patient with fever after cesarean section and this situation, the uterus is fairly normal in appearance.

There is some loa centrally, there's no gas in the uterus but there's too much gas and increased, haziness and almost flags change at the in the subcutaneous tissues.

Here's another patient with a wound infection and the wound itself is dehiscing, not the uterus.

You can see in the scalp film from the CT scan this gas at the incision site and this is the axial image showing that the incision is opening up and that there's gas.

There's small hematomas with gas in these locations.

Retained Products of Conception and Abscesses

Another patient had increased bleeding and persistent fever one week after a cesarean section.

And these are the CT images.

The arrow points to the approximate location of where the incision was made and you can see that there's an infected hematoma, alongside of it.

In addition with enhancement, there is a focal area here that's quite brilliantly enhancing in the endometrium, in the endometrium, so that's more than just the lower soft tissue density I've shown before that was blood.

This is actually retained products of conception and that trophoblastic material, it brightly enhances with contrast.

This is the abscess on the side.

This patient had fever, abdominal pain and free air on a chest x-ray two weeks after a routine cesarean section.

And these are the CT images starting from below.

You can see the uterus.

There's a large bladder flap hematoma with multiple foci of air, clearly infected as we progress, higher in the CT scan.

There's gas here at the level of the umbilicus and even higher multiple foci of gas in the upper abdomen, so an infected bladder flap abscess infected ascites and infiltration of the omentum and pneumoperitoneum.

This is due to a rupture of the bladder flap abscess.

Extrauterine infections therefore include infected hematomas, true abscesses there can be cellulitis there, often can be an infection at the region of the incision which can extend elsewhere and the frequency and severity of these infections are significantly greater after cesarean section compared to vaginal deliveries.

Septic Pelvic Thrombophlebitis

This patient had a history of chorioamnioitis and failure to progress at 41 weeks gestation requiring a cesarean section.

She came with fever and these are the CT images in the sagittal reformat.

Again, you can see where the cesarean section scar is only a small amount of hematoma in the bladder flap region.

But if you notice this is a transverse higher up the aorta inferior vena cava and this is the right ovarian vein.

It's dilated and there's a central area of hypodensity.

This is a coronal reformat, the inferior vena cava and its branches and this is the ovarian vein coming towards it.

And again, you can see this low density material.

This patient has a septic thrombophlebitis of the right ovarian vein.

In addition, you may have noticed a small high density focus here at the endometrium junctional zone that was retained products of conception.

This sonogram was performed in a patient with unexplained postpartum fever.

Uterus is still a bit enlarged, perhaps a little too large for this stage.

There's a little bit of complex fluid in the endometrial cavity, but nothing terribly unusual in the right adnexal region.

However, separate from the ovary, which is down here, we could see this little round echogenic structure with a cystic center and this is a transverse view of one of the ovarian veins filled with thrombus.

Other vessels in this area do have flow.

The CT was performed for confirmation and so you can see the right ovary.

And here's the little vessel with the brighten enhancing wall and the low density center and you can see on the lower image as well.

These are much more difficult to see sonographically than they are on CT, but if you know what to look for, you may be able to figure it out.

The right ovarian vein, should be close to the ovary.

Other patients sometimes show diffuse septic pelvic thrombophlebitis in any number of the veins in the pelvis, and they look like these little cheerios, these little echogenic round structures with low density centers.

In contrast, here's the external iliac artery and vein and this vein is completely and normally enhancing.

These veins have thrombi in them and you can see them here as well.

In addition, you might notice that this patient had a, a breakdown of the incision and herniation of the enlarged uterus at the site.

Septic pelvic thrombophlebitis occurs at least probably in one out of 600 deliveries in the United States, though possibly underestimated it is commonly unilateral for some reason the right more than the left and the thrombus in the right ovarian vein can extend two and even higher in the inferior vena cava.

CT and MR have become the techniques of choice.

It is more difficult to appreciate on ultrasound, but if this is the only modality available or appropriate for the patient, you can use it.

Findings include the enlarged ovarian and other pelvic veins with low density thrombus.

Often the vessel wall is enhancing or inflamed in appearance and there also may be adjacent inflammation in the surrounding fat.

Chronic Complications

Now we'll turn to chronic complications following cesarean section.

So these are patients well out of the immediate postoperative, time period, we'll look at what the scar looks like long term after, cesarean section on both ultrasound and CT, and then a variety of issues related to that scar.

Adhesions and Uterine Distortion

In some patients, for whatever reason, the adhesions and scarring can cause significant distortion in the position of the uterus.

Because of the tethering of the anterior uterus to the anterior abdominal wall, the cervix becomes elongated and the lower uterus is stuck there.

Transvaginal imaging therefore allows an excellent visualization of the cervix, but often the body of the uterus is somewhat out of the plane and far from the transducer and difficult to visualize.

Unfortunately, in this situation, transabdominal imaging is also limited because the distended bladder will no longer serve as a sonographic window.

In this situation, our recommendation is to try a higher frequency transabdominal transducer to see the body of the uterus assuming that the patient's body habitus permits.

So let's take a look at this.

Here is transabdominal images of the uterus in a patient with a history of prior cesarean section.

This is a transverse view and a sagittal view, and the uterus looks very distorted.

Instead of being smooth and round, you can actually have a sense that the anterior lower portion is pulled up and stuck to the anterior abdominal wall.

In the sagittal view, you have vagina, cervix, somewhat elongated the bladder and this is where the adhesion is and no matter how big the bladder would get, it would just keep pushing up at the uterus and never cover the uterus to provide sonographic window.

These are CTs and a diagram to explain the problem that happens in transvaginal imaging in these patients.

So in this axial image, the uterus is here and this is the adhesion to the anterior abdominal wall.

In a sagittal reformat, the cervix is elongated.

The body of the uterus then sort of falls posteriorly and you can actually see the small adhesion to the anterior abdominal wall.

Imagine now if we put a transvaginal probe right here, and this is the section that we are able to image the distance that we can see, the transvaginal image will predominantly show the cervix and much of the body of the uterus will be well out of our field of view.

So if I flip the CT image, the way we look at ultrasound images, you can see that and we put them side by side on the transvaginal.

I have a wonderful view of the cervix better than we usually see, but that unfortunately the much of the uterus is poorly imaged because this is the part that's fallen back.

This is another patient.

She had higher, cesarean sections and the position of the uterus is not distorted, but the person scanning was concerned that there was a round mass in the anterior uterus and consider that this may have been a myoma.

However, if you look carefully, this is the location of the scar from the cesarean section right here.

And sometimes because it is pulled up, it causes some distortion in the adjacent myometrium and makes it look like a round mass, which can be mistaken as a myoma.

Another patient with prior C-section.

The question is, is there some sort of odd endometrial abnormality?

The endometrium is seen nicely here and is smooth and right here it looks a little thicker and perhaps a little irregular.

Could this be a polyp?

These are naan cysts In transverse you have this odd sort of, sort of triangular shape of the endometrium at this location and once you realize that this is the site of this cesarean section scar, it's clear that the endometrium is being pulled into the site of the scar where there is thinning and irregularity of the overlying myometrium.

So there's nothing intrinsically wrong with the endometrium, it's just pulled and tethered into the scar.

Cesarean Scar Niche and Bleeding

To take this one step further, if there there's endometrium in the scar, then clearly blood could accumulate in that region related to menses or potentially to some other procedures, and this blood can accumulate and be in this location as of reservoir providing, a means for or causing inter menstrual bleeding.

These are two separate patients and you can see the blood in the lower endometrial cavity and a little bit in the cervix extending to the cesarean section scar.

Here's another patient. You can see the blood almost seems to extend all the way through the myometrium to the serosal edge.

Both of these patients when asked, gave a history of spotting after menses.

They, they complained of the menses being too prolonged depending on the position of the uterus.

You have to look in different places.

Here's the retroverted retroflexed uterus and so the scar is over here.

This is the transvaginal view of that patient and there's fluid in the scar which is here.

And the patient also had, bleeding after menses.

This patient came with a history of very heavy menses and some inter menstrual bleeding on transvaginal imaging.

We had a hard time seeing the endometrium because there seemed to be a large mass with shadowing in this region.

And so the patient came to have a sonohysterogram.

Fluid was instilled into the endometrial cavity via a catheter and you can see very nicely outlined this in fairly, almost completely intracavitary myoma.

In addition, however, the fluid also filled this little niche or scar from the prior cesarean section during the sonohysterogram.

This cesarean scar pouch or niche as some authors have described, can be filled with fluid and the fluid may be there during the routine transvaginal scanning.

If fluid fills this area during sonohysterography, it can allow one to actually measure the size of the defect and people have found that this correlates well on hysteroscopy.

This scar can therefore act as a reservoir for blood and cause abnormal bleeding in patients.

What percentage of women with a cesarean section will actually have a demonstrable niche is unknown, but if the patients give this history, it's important to look for the possibility of this niche.

Malpositioned IUD

This patient happened to have an immediate post section CT after the, the cesarean section which occurred in 2005 and the incision was actually off to the side at about nine o'clock in this uterus.

She returned in 2006 and was having a CT scan for other reasons and in between she had had an intrauterine contraceptive device placed.

If you notice, here's the IUD and it's exactly at about the location of the site of the prior cesarean section incision.

It should have been in the endometrial cavity, which is this place right over here and in the sagittal reformat you can see it's in the, in the lower uterus but none of the IUD was located in the upper uterus.

This is an example of an IUD that is malpositioned related to the cesarean section scar.

The patient went on to have a transvaginal and a transabdominal sonogram and again demonstrates most of the IUD was in the lower uterus and a portion of one of the side portions of it was stuck in the scar from the prior cesarean section.

This is the transvaginal and this is the transabdominal of the same patient.

Clearly important for the patient who is not fully protected given the location of the IUD.

Here's another patient with a malpositioned IUD at the cesarean section scar again most of the IUD in the cervix and here are the side portions of it at the level of the cesarean section scar.

This patient did end up with the complication related to this because when we scanned her she was pregnant and here's the gestational sac, higher up in the uterus.

She was not protected by this IUD.

Cesarean Scar Ectopic Pregnancy

This patient is another one who had had a CT scan several days after a cesarean section for unexplained fever.

This is the coronal reformat showing the incision.

This is the bladder, this is the axial image and there was a fairly normal looking site of the incision.

There was no complication here.

Several months later the patient returns for imaging.

She's now pregnant and she's having some bleeding.

This is the transvaginal view of her uterus.

There is a gestational sac and it's located right here so it is in the uterus, but if you look very carefully, it's not exactly where you would expect it in the uterus.

This is the endometrium and this is the gestational sac.

You can see the yolk sac.

This is a gestation that is implanted in the cesarean section scar.

It is a cesarean section scar ectopic.

The patient was treated with systemic methotrexate and five days later had a follow-up which unfortunately showed that the pregnancy was growing appropriately.

There was now not only a yolk sac, but now we could visualize an embryo that had cardiac activity and again, you can see the measurement being made here of the thickness of the myometrium that overlies this gestational sac.

And from having seen the other images I showed, this is clearly at the location of the cesarean section, so she was given a second dose of methotrexate.

Unfortunately, two days after that the pregnancy was still alive and surgery was required.

Another patient with a history of only one prior cesarean section came in.

She was pregnant and having bleeding.

There is a gestational sac low in the uterus and it was empty and interpreted as an abortion in progress.

She returned however one month later with bleeding and this is the transabdominal view of her uterus.

The endometrium is normal.

There's no gestational sac, but there's sort of a mixed complex low and high echogenicity collection exactly at the location of this gestational sac.

On the prior study when we put color doppler on, it was exuberant, beautifully vascular in this region.

So what we're dealing with here is a patient who had a cesarean scar implantation, but most of the sac passed in a spontaneous abortion.

Unfortunately, the retained products of conception are at the site of the cesarean section scar.

This type of ectopic pregnancy is rare, but increasing in incidence as the number of cesarean sections increases.

It is defined as a gestation completely surrounded by myometrium, but separate from the endometrium and separate from the fallopian tube.

Several reports show that this can occur within months of the delivery and therefore incomplete healing of the scar may contribute to it.

The ultrasound findings are those of an empty uterine cavity, an empty cervical canal, and a gestational sac in the lower uterus.

The differential diagnosis as you can see, includes a spontaneous abortion in progress and a cervical ectopic pregnancy.

The problem is that rupture can occur and often the diagnosis is delayed in part due to lack of education about the possibility of this, but also the overlap with the other diagnoses.

It's despite an increased incidence, it is still such a rare ectopic pregnancy that are, there are no specific guidelines for treatment.

Medical therapy can be tried, but often a surgical therapy for removal is required.

Placenta Accreta Spectrum

This patient was 30 weeks pregnant and started to have gross hematuria and this is ultrasound imaging of the lower uterus and bladder.

This case was graciously lent to me by Dr. Sandra Allison of Georgetown University.

If you look at the posterior wall of the bladder, you can see these cystic areas which with color doppler show that they are vessels and exuberant flow on transverse imaging through here.

There's echogenic material and cystic areas with blood flow.

This is an example of a placenta percreta or placental invasion of the bladder and it is related to the prior cesarean section.

So these are all in the realm of placenta accreta and accreta is when the villi are in direct contact with the myometrium without any intervening decidua increta is a deeper myometrial invasion and percreta is invasion to the serosa and occasionally, to the bladder and bowel.

The major risk factor nowadays is prior cesarean section, but obviously instrumentation, can, also, predisposed to this.

It can result in life-threatening hemorrhage at delivery or even before because the placenta will not separate from the myometrium modalities that can be used to make this diagnosis include ultrasound and MR.

It's usually done without gadolinium If the patient, when the patient is pregnant, it's unclear which has better sensitivity and specificity because it is an unusual and I must say a difficult diagnosis to make if the placenta is anterior ultrasound is better.

If the placenta is posterior MR may be better.

The criteria for suspecting placental invasion on ultrasound include loss of the retro placental hypoechoic myometrial zone, numerous vascular lacuna in the placenta, a disruption of the echogenic boundary and nodular projections beyond the uterine edge.

If you think about it, there are some similarities between placenta accreta, which is myometrial invasion of placenta and a c-section ectopic, which is an abnormal implantation site of the actual pregnancy.

Endometriosis in the Cesarean Scar

This patient who had prior cesarean sections gave a history of increasingly pain of increasing pain and a small mass at the cesarean section site and imaging with a high frequency transducer at the level of the umbilicus showed a lobulated hypoechoic mass with some flow.

You can see the muscles on either side and this is an example of endometriosis in the cesarean section scar another patient with a similar problem.

You can see the uterus is pulled up anteriorly.

This is the adhesion and here's the enhancing nodular endometrial implant exactly at the site.

This is the sagittal view showing you the adhesion of the uterus to the anterior abdominal wall.

Do the endometrial implants can occur related to the scar and as a spread of the during the surgical procedure, patients often have pain and tenderness that come with the cycle and have with their menses.

The appearance can be variable, but it's typically relatively solid.

There may be vasculature, as well.

There are, fibrous tumors that can have a similar appearance and these will usually enhance with contrast.

Ventral Hernia

And this is the last situation to show This patient had a history of three prior cesarean sections and as you can see, has a defect in the anterior abdominal wall and this ventral hernia is, has incarcerated bowel in it at the site of the prior cesarean section.

Conclusion

Thank you very much.