Testicular Torsion Case Based Review - SD

Testicular Torsion

These are some cases I've selected from part of the seminar that I give at the AFIP, which is the Armed Forces Institute of Pathology.

Testicular torsion is defined as a twist of the cord or it's a TE or the testes on its attachments. And it's important to remember that the degree of ischemia is relative to the amount of twisting. We begin with venous compromise and progress to arterial occlusion. A 360 degree twist may still have arterial inflow.

Torsion is most common in puberty, but also occurs in neonates and adults.

Anatomy of the Testes

The anatomy of the testes is what permits torsion to happen. In the seventh week of life, the testis is up in the abdomen and is being pulled down into the scrotal sac by the gubernaculum. By the 12th week there is a the formation of the processes vais, which is an infolding of the peritoneum which occurs in front of the testes. And by the ninth month this has been completed. And then the processes vaginalis will actually fuse at the inguinal ring and that leaves a potential space in front of the testes where hydros seals conform.

And here's the completed picture over here. Notice that the testes is bare in the back and is attached to the scrotum, but there is a potential space in front by this processes vais, which would allow fluid to form.

So here's an example both on MR and an ultrasound. Here's an MR image transverse. Here's the testes in the back. Here's this bear area, a little bit of the mediastinum testis here and you can see a hydros seal with this very large collection of white fluid. Is this patent, processes vaginalis with a lot of fluid collected in between and it's sort of a crescent shaped space.

Here is an example from a sagittal view. Here is the testis with the epididymus along in the back. And again you can see the hydros seal is in front and actually inferior to the testis. But this bare area in the back is where the normal testis should be fused with the scrotum.

Bell Clapper Deformity

A bell collaborative formity is caused by a failure effusion of these visceral and parietal layers to the scrotal wall. So the space completely encircles the epididymus, the distal spermatic cord in the testis rather than attaching to the posterolateral aspect of the scrotum. And this is a bilateral defect in most cases and as many as 12% of patients will be affected.

So here's a schematic, drawing the normal fused testis in the back with a tunica vais in the front. Here's the bell clapper deformity, failure of fusion, allowing the testis to hang free and then of course for the cord and its contents to twist.

Clinical Presentation

What do we know about torsion? The clinical presentation includes an acute onset of scrotal pain. It may be accompanied by anorexia nausea or vomiting, and there should be a lack of urinary symptoms or fever. However, as many as 35 to 50% of patients will experience a gradual onset of pain similar to epididimitis. And remember, the pain may be intermittent, which means there is torsion and detorsion, which confuses us.

Importance of Early Recognition

Why is it so important to recognize torsion early? The time from the onset of symptoms is associated with the salvage rate. If we can get the patient to the, or within five to six hours, there is an 80 to a hundred percent salvage rate. From six to 12 hours, it drops to 70% and after 12 hours it may be as low as 20%.

Gray Scale Patterns in Testicular Torsion

We have several gray scale patterns that are associated with testicular torsion. The one we'd like to see most is a normal gray scale testis because that indicates that the testis is viable. Once there's infarction, there may be a hypo coic pattern, which could be total or partial. If there's a partial infarct, if there's hemorrhage which complicates the infarction, the infarct may be hyper coic and have a he heterogeneous pattern. And once the infarction has been chronic, say several weeks to months, the testis becomes hypoechoic and small.

Doppler Patterns in Testicular Torsion

What are the doppler patterns to recognize? The most common one and the easiest to recognize is absent arterial and venous flow. But it's very important to recognize that there are two other patterns. One is an increased resistive index, which means that there's diminished or reversed diastolic flow and also that there's decreased flow velocity. And this is difficult to measure because we have very small vessels and we can't angle correct. But you can subjectively infer this by looking at the two testes side by side and you'll find small, small low amplitude flow on the symptomatic side.

Case Studies

Case 1: Acute Right Testicular Torsion

So let's look at some cases and see if we can put these rules to use. Our first case, we have a patient with sudden right-sided pain transfers image of the testes side by side symmetric gray scale. So the gray scale is normal. When we look on color doppler imaging, there is flow seen within the left testis on the right testis we see no flow in the testis. We do see flow in the EPIs. So our diagnosis, acute right testicular torsion with a viable testis. The important imaging findings, gray scale symmetry on the transverse images absent color flow in the affected testis but not in the epididymus. Why is this? The EPIs has an alternate blood supply and it may be perfused even if the testis is not.

Case 2: Chronic Left Testicular Torsion in a 7-Year-Old

Case two, we have a 7-year-old who presents with acute symptoms which side is abnormal. We see transfers. Imaging here is the right testis and the left testis left is larger, right is more hypoechoic. We need doppler and on doppler the flow on the right side is minimal, but we do see flow and a normal arterial waveform. On the left side we see tremendous flow in sagittal imaging. But when we go transverse there is no flow in the testis merely flow around it and the testis itself is heterogeneous. So what is our diagnosis? Chronic left testicular torsion with a hemorrhagic non-viable testis in young children. It's important to remember the testis may be small and hypoechoic the flow is often minimal. But note we saw a normal spectral waveform pattern. The abnormal side has markedly increased doppler flow, but it's around the testis not within it. It's always important to image in two planes and document flow within the actual testis. Remember, hemorrhage creates additional tissue planes and therefore additional echoes so it becomes hyper coic and heterogeneous. The hemorrhage is a result of the infarction and indicates a non-viable testis.

Case 3: Right-Sided Torsion with Preserved Flow

Our next case, case three, we have a patient with right-sided pain, nausea and vomiting. And the question is, is this torsion or epididimitis? So on the right testis mid transverse we have a doppler spectrum that shows a fairly low amplitude spectral doppler waveform with a systolic peak maybe at four or five centimeters per second, even though it's not angle corrected and virtually no diastolic flow. Meanwhile, on the left side we have at the same gain settings, we have much greater amplitude flow and good diastolic flow, which is a normal waveform pattern. So the diagnosis is torsion, it's torsion on the right and it had a 360 degree twist of the spermatic cord. So how can this be Torsion can be present with the preservation of doppler flow. It is not an all or none phenomenon. The venous obstruction occurs first and is indicated by a high resistance arterial spectral doppler waveform flow may be present even if the test is is twisted up to 720 degrees. And we see this now sometimes in studies which are being done with contrast. More flow will be detected with power doppler and also with ultrasound contrast in the future, the presence of flow does not exclude torsion.

So just to drive the case home, another patient left sided pain, you can again see this abnormal spectral doppler wave form and this is really all you need to see within the testis notice on the right side more easily detected flow. The important thing here is you can look up in the inguinal canal if you're worried or concerned and you're not convinced by the spectral doppler. And here you can see a twisted spermatic cord, the so-called whirlpool sign. And here is the gross picture at the time in the or you can see perfectly that this testis is not attached in the stroum and there is a a good large twist here. This patient of course still has some flow preserved to the testis and the testis is salvageable.

Case 4: Torsion and Detorsion with Increased Flow

Case four two hours of left-sided symptoms. This is a midline transverse image. And what do we see? We see a little bit more flow on the left testis than we see on the right side. So can this be torsion? Well let's look at the doppler on the left side we actually see very good flow, good diastolic flow and if anything the amplitude is a little bit greater on the left than on the right, But the answer is yes, it can be torsion. This is torsion and detorsion with increased flow post torsion. And what happened here was the patient had been detoured in the emergency room just before he came over for his examination. So now he was had some hyperemia and some ischemic response to the improved flow and he actually vasodilates his scrotal bed and we get increased flow on the affected side. So history is very, very important. It's critical classically the patient will tell you they have intermittent acute and sharp pain with some long symptom-free intervals. It's very important when you're examining these patients to know which side hurts and if it still hurts during the examination. If you scan the patient immediately after detorsion, the affected testis may show increased blood flow but the patient should feel better.

Case: Torsion and Detorsion with Focal Infarct

Here's another case. This patient had left-sided symptoms progressing over several days. He had had a prior ultrasound exam at another hospital which showed an enlarged EPIs with increased flow to the epidermis. We can see on ultrasound that he has slightly enlarged left testis and when we look carefully we do see flow in the testes but there is a crescentic shaped very hypo coic infarct at the lower pole, which is geographic in its margins. And this is a patient who had torsion and detorsion with a focal infarct. So when we think about torsion and detorsion, we wanna be looking for evidence of infarction because that clinches the diagnosis. These are focal hypoechoic areas with concave margins. If they're associated with normal or increased flow, you should be thinking about the possibility of intermittent torsion and frequently the EPIs will be enlarged and hyperemic. If you have patients with torsion detorsion it can be mistaken for epididimitis. So looking carefully at the testis for focal infarction can lead to the correct diagnosis.

Case: Difficult Differentiation Between Torsion and Epididymitis

Just one more case here, which is very difficult. This is a patient with a question of torsion or epididimitis. You can see here that he has increased flow slightly on the left hand side. He has easy detectable venous flow on the left, otherwise the right and left testis look fairly symmetric. He had eight hours of left sided acute pain and so the ultrasound shows this hyperemia and this could be construed as oras. However, when we keep looking at him, he also has a very enlarged epididymus on the left, as compared to the right and it's also hypervascular as compared to the more normal right side. Here he was 19 years old, not sexually active so there was no reason to suspect that he would have epididimitis. He'd had eight hours of acute pain and the clincher was he was somewhat relieved by the urologist's attempt at detour. So when he was surgically explored, this showed a dusky viable testis no longer tors. And in this case the history really equals the diagnosis because on the images alone it's very difficult to tell.

So this concludes part one of our discussion of torsion and detorsion. Stay tuned for part two where we'll discuss torsion mimics and pitfalls and other causes of in we'll be continuing with torsion mimics and pitfalls Other causes of infarction.

Torsion Mimics, Pitfalls, and Other Causes of Infarction

Things to consider when we have patients who are symptomatic is that we can have obstruction of the cord without torsion, which may lead to testicular ischemia and we can have impaired vascular supply without torsion or without obstruction. This can be at the arteriolar level, this can be due to anatomic variants. It can be due to primary venous thrombosis which can occur in hypercoagulable patients or even from edema from severe epididymal oras.

Case 5: Inguinal Hernia Causing Ischemia

So this is case five. This is a two month old who had pain a month ago but had a normal ultrasound exam but now he has new pain and right roal swelling for 18 hours. So what do we see when we look? Well, here's the right testis, here's the left. And on the right we see some background noise in this hydro seal but no flow within the testes to be sure. We're gonna put in spectral doppler and this tracing is simply noise. There's no arterial flow here at all. On the left side, the normal side, he has color doppler within the testes and as well he has spectral doppler tracing, which is a normal arterial waveform pattern. So what else do we see? We wanna look with our gray scale and if you look carefully you can see there is a mass which is adjacent to the testis and it actually has some flow within it. And this is actually an inguinal hernia with a loop of bowel that's come down and there's flow in the bowel loop but it's actually impinging upon the cord here and cutting off the blood supply to the testis. So there are multiple etiologies of altered testicular profusion including mass lesions which obstruct the spermatic cord. And it's important to remember that even in a newborn we should be able to get flow in the testis.

Case 7: Large Hydrocele and Torsion Evaluation

So case seven, this is a 40-year-old with a left hydros eal which is quite large. And the question is, is there left sided torsion? And the reason the clinicians are asking is because neonatal torsion often will present with a hydros eal. So we see first on the right side, which should be the normal side. We can see some power doppler signals within the testis and when we sample we see a waveform that is equal above and below the baseline. On the left side we also see a power doppler.in the testis with this similar pattern above and below the baseline. So is there torsion? Well when I ask residents, some say yes, some say no, but the actual answer is you can't tell. Why can't you tell? Because neither of these patterns actually is an arterial waveform pattern. So what should you do next? The answer is repeat the exam and change your parameters so that you get a tracing. So we sent somebody back to re-scan the patient and we still see these color blips. Notice we're using color doppler now not power. It really doesn't matter which you use. You just wanna be able to see something and get a true spectral waveform. And now there's color in both testes but more importantly there's a great waveform which is arterial and which is normal in both sides. So we can see on the left side, normal arterial waveform, normal arterial waveform on the right small hydro seal also on the right. So is there torsion? No there is not. What did we do differently? Well we always wanna use the highest frequency doppler that yields a signal without attenuation. Our initial examination was performed with a doppler frequency of five megahertz. Our repeat examination we use 10 megahertz. And remember it's also important to confirm a true arterial spectral waveform. The waveform on the initial examination was only noise. It could have been interpreted as no flow, but then you would've had to say that there was bilateral torsion.

Case 8: Bilateral Infarction Due to Polyarteritis Nodosa

This is case eight. This patient had acute left sided pain back in December of 2002 and we see side by side images transverse, flow within the right testis, no flow in the left testis. Same thing is shown on our sagittal images. Gray scale is normal. So your first thought would be this is torsion and you would send the patient to the OR and that would be correct. However, the patient goes to the OR and the testis at that point was not salvageable. And they did a left orchiectomy and they did a right orchiopexy and now the patient has right sided pain and this scan is done two days later. So what can we conclude? Well the patient has no reason to have torsion and in fact when the surgical record was reviewed, it was unclear whether there was torsion there, initially on the left and this was bilateral infarction in a patient with Polyarteritis Noosa. So it's important to remember there are other causes for ischemia and some of those include vasculitis. Of those, the two most common that we know of are poly arteritis Noosa or else systemic lu lupus erythema. Certainly severe edema from infection. Uncontrolled or unresponsive epione otitis can give you ischemia and also venous thrombosis can also give testicular ischemia.

Case: Venous Compromise Progression

This is a patient who actually has or with venous compromise. Just to show you an example, on day one the patient has left sided pain, you can actually see somewhat increased flow here compared to the right testis note. There's a small hydro seal with some reactive debris within it. On day two there is a very abnormal doppler waveform with reverse diastolic flow. And by day three we've cut the scale way down over here and now we are having more diastolic flow reversal. It's even more difficult to detect the flow in this left-sided testis. Three months later the patient actually returned and this is just to remind you what he looked like at initial presentation. The size of the testis approximately three centimeters, three months later the testis is down to about a centimeter in size. It's hypoechoic, it's small, it's infarcted.

Case: Epididymitis with Vascular Compromise

Here's another patient who came in with left testicular pain, rule out torsion. He obviously has an enlarged left epididymus. He has a very bulky body of the epididymus as we go down along the margin of the testis and the tail is increased in size and also in vascularity. So our diagnosis from the gray scale would be normal for the testis from color doppler we would call this epididimitis. However, when we put on the spectral doppler and look side by side, it's a very alarming picture. The right testis, the normal side has normal flow. The left testis has this very abnormal diastolic flow reversal and that means that there is tremendous re resistance to arterial flow and likely that the venous outflow is obstructed. So that suggests the possibility of vascular compromise and this patient needs to be treated aggressively. His epididymitis was presumed from urine reflux. He was given oral antibiotics for three weeks and sent home on two weeks follow up. He had decreased size of the testis. His urine was clear, but he still had persistent pain. At four weeks he still had persistent pain and came in for an ultrasound. And at that time you can see there is now no longer any flow remaining in the left testis. All the flow is around the outside and the testis itself is very heterogeneous with some areas of increased echogenicity. The path report at Orchiectomy said there was an abscess with acute and chronic oris and infarction. The portion of testicular parenchyma was almost entirely replaced by a soft gray green abscess.

Case: Venous Thrombosis in Protein S Deficiency

And lastly, another venous outflow obstruction case. This is a patient who has venous thrombosis and protein S deficiency. He's an 80-year-old male who presented with pain, swelling, and fever and was originally diagnosed with what was thought to be oras. He also had bilateral lower extremity deep venous thrombosis. He did not respond to antibiotics. Ultrasound of his testis was performed, which suggested infarction again noting this very high resistance systolic peak with no diastolic flow and he ended up going to surgery for pain control. At pathology, he had extensive venous thrombosis and no infection and he was subsequently tested and found to have protein S deficiency.

Torsion Mimics and Variants

For torsion mimics and variants, it's important to remember that infarction can present with pain which mimics torsion. We can have partial infarction from torsion and deep torsion from vasculitis or even from variant arterial anatomy. In some patients the epidermal artery, which is the branch of the testicular artery, will supply the superior and anterior pole of the testis. If this artery is small or hypoplastic, minimal obstruction of this artery can result in focal ischemia and then infarction involving the upper pole of the testis. Total infarction, as we saw in the cases with poly arteritis, is more unusual, but it should be suspected in patients with underlying vasculitis such as poly arteritis or lupus.

Case: Infarction Mimicking Torsion

So here's a patient who came in with severe left sided pain, very abnormal gray scale, and the clinical indication was rule out torsion. On our examination there were hypoechoic areas within the testis as well as areas of increased vascularity. And the gray scale, as we said, is very abnormal. And there were areas which were not very well perfused such as this one. A differential diagnosis would be an infarct or a tumor with hemorrhage. And so this patient was sent to the or he had a left orchiectomy to exclude tumor, but there was no torsion found and no tumor found and he was diagnosed with infarction. One year later he presented again this time with right-sided pain and notice that he has this area of decreased genicity, which is involving the superior pole of the testis and the rest of the testis is relatively intact. So this is an exam actually six days later. This is how he looked at presentation. We continued to follow him. And this area actually diminished and became less visible. And you could see that he has normal flow in the residual right testis. So this was left actually for him to heal. So in some patients, the epidermal artery, which is a branch of the testicular artery, supplies the superior and anterior pole, the testis. And so if this artery is hypoplastic, a small compromise or twist can result in focal infarction.

Take Home Messages for Testicular Torsion

These are the take home messages for testicular torsion. Torsion can be present despite testicular flow. So if you see diminished or high resistance flow, that should suggest torsion in the proper setting. History is critical. A history of intermittent symptoms should suggest torsion and detorsion and you should not mistake the corresponding hyperperfusion with epidermal oras. Other rare causes of decreased testicular perfusion include vasculitis and if torsion is not present appropriate, medical therapy should be pursued. Of course, if the patient's imaging looks like coercion and there is no known history of vasculitis, you would not deny any patient surgical exploration to exclude torsion.

Thank you for your attention.