Pelvic Intervention - The Time Has Come - HD

Introduction

Hello, my name is Dr. Caitlin McGregor. I'm an abdominal radiologist from Sunnybrook Health Science Center in Toronto, Ontario. I'm head of the ultrasound division and am an abdominal radiologist who also performs abdominal related intervention.

And today I'll be speaking about pelvic intervention. The time has come. I would like to thank sono world for inviting me to speak today about pelvic intervention. The time has come. I have no financial disclosures today, which is important because I will be discussing specific products during this talk.

And I should also confess that I'm not an interventional radiologist, but rather I'm an abdominal imager who does perform a significant amount of body related intervention. So today we will be discussing aspiration, drainage, and biopsy in the pelvis.

Traditional Routes vs. Ultrasound Guidance

The traditional route for these procedures is CT guided either via an anterior or a posterior gluteal approach. And certainly CT is excellent for depiction of anatomy. However, these routes are often limited anteriorly by the presence of bowel or bladder intervening on route to target or by things such as colostomies, anterior abdominal wounds, drains, et cetera.

The posterior trans gluteal route while quite efficient and easy to perform, is often very uncomfortable for the patient. And in particular, if the catheter will be indwelling for some time after the procedure, they are uncomfortable as they do traverse the gluteus muscle. And sometimes, unfortunately, the piriformis muscle.

Ultrasound, on the other hand, does not involve radiation and it offers unlimited planes of access. It does offer real-time visualization, which I, in fact prefer to CT and perform the vast majority of my procedures under ultrasound guidance, reserving CT only for select cases.

Ultrasound guided procedures are also extremely fast, which is not only advantageous for the operator, but certainly advantageous for the patient as well. In addition, ultrasound can often create a window that's not available on CT by using the transducer either transvaginally or transabdominally, to displace structures out of the way in particular bowel, which can give access to things such as mesenteric nodes, where a window to that node may not be available on ct.

Focus on Endocavitary Ultrasound-Guided Procedures

For the purposes of today's talk, we will be limiting our discussion to the endo cavitary ultrasound guided procedures, particularly via the transrectal and transvaginal route. And this route, in my mind is an excellent route to performing deep pelvic biopsies and aspirations because you're very close to target and really have to traverse very little normal tissue.

In addition, they're extremely quick procedures that are very well tolerated by the patient. The only caveat is that the transrectal route is not an option for sterile collections.

Components of Intervention

Now, the components of any intervention, regardless of where it's being performed, is to review the indication in all prior imaging to review the patient's coagulation status, to perform informed consent, to prepare both the patient and all equipment that will be necessary for the procedure and to ensure the patient comfort, probably most importantly, with our bedside manner and thoroughly explaining all aspects of the procedure to administer local anesthesia and to use IV sedation where appropriate.

Next step, of course, is to perform the procedure followed by looking after the patient afterwards and reviewing pathology reports to ensure that we have obtained an adequate sample and that our pathology results are concordant with the radiology.

Indications for Transvaginal and Transrectal Biopsy

The indications for transvaginal and transrectal biopsy are as follows. It's rare to perform these biopsies for the diagnosis of primary gynecologic malignancy, except in rare instances, particularly elderly patients who may not be surgical candidates.

However, for certain transrectal prostate biopsy is the cornerstone of the diagnosis of prostate cancer, but as we will see, is also very important for diagnosing other peri rectal non prostate malignancies.

In our department, we do a large number of transvaginal and transrectal biopsies for the diagnosis of recurrence in the pelvis, the diagnosis of metastatic disease, and for nodal staging. And in particular, this route can be quite helpful in accessing external iliac nodes that may not be accessible via ct.

Indications for Transvaginal and Transrectal Aspiration or Drainage

The indications for transvaginal and transrectal either aspiration or drainage are as follows. Tubal variant abscess in particular is well suited to these methods because the abscess is often immediately located adjacent to the vaginal fornix, but also other postoperative collections have a tendency to track down into the dependent pelvis and into the cul-de-sac.

And this is particularly true after gynecologic operations, but also after other operations as well. Appendicitis and diverticulitis will also often result in an abscess in the deep pelvis.

We also perform these procedures in select cases for symptomatic relief of ovarian cystic lesions, sometimes endometriomas and for para ovarian cysts and lymphic seals and in particular peritoneal occlusion cyst. But as stated, these are in select cases.

Coagulation Status Review

The next step is to review the coagulation status. I'm not gonna spend a lot of time on this, but I do have a few points to make. At Sunnybrook, we're very fortunate to have a standardized guideline that has been created in combination with our transfusion department, our thromboembolic embolism physicians and the radiology department, and we divide our procedures into five different groups with different thresholds depending on the risk of the procedure.

So we may allow an INR as high as 3.0 for some procedures where we would want it as low as 1.5 for others. For transvaginal and transrectal procedures, our guidelines are as follows, we would want platelets greater than 50. Understanding that that number doesn't necessarily indicate their function.

We do not hold aspirin or Plavix for these procedures in particular, if they're taking these medications for a known neurologic or cardiac indication for warfarin or coagulopathy, we want the INR less than 1.8. We will stop intravenous heparin two hours prior to the procedure, which is shorter than it is for some of our other procedures, in particular kidney biopsies, low molecular weight heparin.

If it's prophylactic, we do not hold for therapeutic doses. We'll stop 12 hours prior, which is equivalent to one dose. We will restart all oral anticoagulant medication or IV anticoagulant medication the next day and delay it if there's a post-procedure bleed or if the patient is at high risk.

I'm gonna take a moment now to just mention the new oral anticoagulant agents or the NOACs, which are becoming more common. These are replacing warfarin because of their wider therapeutic range. Their pharmacology is less complex. They don't require monitoring, which is advantageous for the patient, and they have a faster onset, which means that restarting them after a procedure is less complex than warfarin.

However, these agents do not have a reversal agent. There's two types direct thrombin inhibitors and factor 10 A inhibitors. And the two that we're coming across most often in Canada at the present time are PRS and Xarelto.

The important thing to understand that in addition to not having a reversal agent, the decision as to how far in advance to stop these agents prior to procedure depends on the patient's renal function. For a transvaginal or transrectal procedure at our institution, which we would consider a low risk procedure in a patient with normal renal function, we would stop it the day before and that duration would increase as the GFR decreases.

And this is just the chart from our own institution and the guidelines that we have created.

Patient Preparation and Equipment

I'm not gonna talk about obtaining consent today, and I'm going to move on to patient preparation and preparing the equipment that's necessary for transvaginal or transrectal procedures.

For any transvaginal procedure, whether it's an aspiration biopsy or drainage, the best position is to have the patient in the lithotomy position. And it's particularly advantageous if you have the luxury of using a gynecology stretcher with a drop away bed and stirrups.

The transrectal procedures can also be performed in this position as well. However, patients are probably more comfortable in the left lateral decubitus position. Their hips should be placed right at the edge of the stretcher with their knees brought towards their chest.

And placing the hips on the edge of the stretcher ensures that you have enough maneuverability of the probe without the stretcher getting in the way.

For transvaginal procedures, the next step is to clean the perineum with an iodine based solution because we are dealing with a mucosal membrane. And once the perineum has been prepared, I like to cover the patient with a large drape, in this case, a pediatric drape.

It's probably overkill in these situations because neither of these procedures are sterile procedures, but I do feel that this drape not only protects our own equipment from any possible contamination, but also gives the patient a better sense of being less exposed.

It's not necessary to clean the area with the iodine based solution. For transrectal procedures for a drainage, I will use the same drape for a biopsy. Usually I will drape the patient and cover them as much as possible with just the standards sheets that we have in our department.

For a transrectal drainage, all of those patients should be placed on antibiotic prior to the procedure by the referring physicians if this is a trans rectal biopsy. However, as an elective outpatient, these patients are treated with a fleet enema prior to the procedure to clean out the rectum, and they must be given antibiotic coverage similar to a prostate biopsy.

At our institution, we use three doses of Cipro 500 milligrams the night before the procedure, 500 milligrams the morning of and 500 milligrams the night after the procedure. There is a move toward using single dosing for prostate biopsies. We have not done that yet for our non prostate transrectal biopsies.

For all transvaginal or transrectal biopsies, we use an automated device to obtain a core sample using 18 gauge needles. Disposable devices can be used as well. It's not so important what device you use, but it is important to understand that you have to have a long enough needle.

And that's to account for the dead space that's inherent in any endo cavitary procedure. So a 20 centimeter needle is the minimum, and if the target is further away from the vaginal fornix or the rectal wall, then you might need to go up to a 25 centimeter needle, as we often do. If particularly if targeting the anterior transition zone in the prostate.

The next step is to prepare the probe. The probe can be covered with a standard condom. We tend to use this probe cover that is produced by civ o because it does provide greater coverage of the probe, including a portion of the cord.

Again, these are non-sterile procedures, so really this is more about protecting our probe than it is about protecting the patient. Once the probe cover is in place, the next step is to affix the needle guide to the spine of the probe. And this is a sample of that here.

Now, these needle guides are specific not only to the probe, but also to the machine. So they all look a little bit different, and there are many of them, depending on whether you're using the Toshiba, the I 22, ge, et cetera, et cetera. This is an example of the IU 22 transvaginal guide, and this is an example of the Phillips transrectal guide that we use at our institution.

The common denominator amongst all of these guides, regardless of the either the vendor of the machine or the probe type, is that the needle channel across the spine of the guide is closed. And we'll see why that's important as we move on to drainages.

Once the probe has been prepared and the needle guide affix, the next step is to insert the probe either into the rectum or the vagina. This is our phantom here. And by simply activating a button on the monitor, it's easy to activate the needle guide on the screen so that you know exactly where your needle will be introduced into the patient and where it will go as you advance towards the target.

Local Anesthesia and IV Sedation

The next step then is to administer local anesthetic and give IV sedation if needed. For transvaginal procedures, we use a Sheba needle. Again, you need at least a 20 centimeter needle, and we'll use a 22 gauge.

We insert this through the needle guide on the back of the probe, and you can see the needle tip enter the vaginal wall to freeze the vaginal wall. It's very difficult to freeze the vaginal wall, and it takes a fair amount of pressure on the plunger to get the anesthetic to infiltrate the wall because it's quite muscular.

So if there's no resistance, it means that your needle tip is in the wrong location, either in the lumen of the vagina or you've gone beyond the vaginal wall and into the peritoneal cavity. You can also freeze the wall of the abscess if you are doing a drainage, especially if it's a chronic abscess where the wall can be quite tender.

It's actually not necessary to freeze the rectal wall, but it can be done in a similar technique to freezing the vaginal wall. We do use freezing for our transrectal prostate biopsies, but here we freeze the capsule along the back of the prostate by infiltrating local anesthetic into the angle between the seminal vesicle and the base of the prostate.

It's important for all of these to withdraw on the plunger before injecting to be sure that you're not injecting intravascular because all of these structures are quite vascular.

A few brief notes about local anesthetic important to remember that there's an onset of action of two to five minutes, so give it a few minutes to work before you proceed with your procedure. And a quick reminder that the maximum dose is three milligrams per kilogram for 2% lidocaine for a total maximum of 300 milligrams. That's equivalent to 30 ccs of solution.

And really the only time that comes into play is if you're doing multiple drainages or procedures in the same patient for IV sedation, I think standard throughout most radiology departments in North America, we use ED and Fentanyl.

ED, I will only highlight that it has an onset of action of two to three minutes, and it peaks at 20 minutes, which is a fairly long peak. And this is just important to understand if you're going to be giving incremental doses and giving those doses prior to reaching the peak time so that those doses will stack.

And don't forget yet, you need to be careful in patients with either liver or renal dysfunction. Fentanyl comes as 50 microgram aliquots or ampules, which is equivalent to five milligrams of morphine. Here. The onset of action is one to two minutes with a peak of five minutes, so much sooner than verse said.

So as long as you're giving your aliquots every five minutes in increments, you will not have reached peak. Duration is more than enough for our routine procedures. Unlike ED, the patients to watch out for are patients with liver failure and renal failure is not an issue.

Performing Transvaginal Biopsies

So let's move on to performing now, the biopsies, and we'll start with transvaginal biopsies. The first thing to do for a transvaginal biopsy is to carefully scan the pelvis to be sure that there are no intervening structures on your route to target.

The first thing I like to look for is the cervix. So you wanna be sure that your probe is in fact not inserted here, as in this case where we see the cervix in the sagittal plane, but is actually off to the side in one of the other fornices.

And you wanna be sure that there's no intervening cervical tissue that you would be traversing when performing your biopsy. The next thing that I look for very carefully is the bladder. All of these patients should be done with an empty bladder.

And when the bladder is empty, it's very easy to overlook the fact that a small corner of the bladder has in fact slipped in between the target and the point of needle introduction. And it can be very easy to traverse a small corner of the bladder if you don't look for it specifically.

And so I look for it in both the sagittal and the transverse plane to be sure that I'm not missing a short segment of compressed bladder. The next structure that's easy to overlook is bowel. And this is particularly true if you're exerting firm pressure with the probe on the vaginal fornix.

You can compress the bowel down to only a few millimeters in thickness, making it very easy to overlook. Obviously, this loop of bowel is much more obvious, but if you were to compress this with the probe, it could compress down to only a few millimeters and you would not realize that you were traversing it with your biopsy.

It's possible with probe pressure to maneuver this loop of bowel out of the way so that you have a window free of bowel. And finally, the next structure to be very careful about are particularly the veins, as they are also quite compressible.

And with firm probe pressure, you could easily compress these veins down to nothing and not realize that they're immediately along the path of the biopsy. So usually what I do before I start is I just withdraw a little bit on the probe, with a little less pressure to be sure that there's nothing being compressed in the line on route to target.

So the first case is a young woman who has breast cancer. She had carcinomatosis and was unfortunately progressing on chemotherapy. She did have disease up in her cul-de-sac that would've been accessible with a trans hepatic biopsy, but it would've required two capsular punctures, which is not ideal.

She had disease elsewhere in her abdomen as well in Morrison's pouch, and along the lesser curvature of the stomach, not easily accessible either, but she did have a deposit in her cul-de-sac, which is one of the most common places for carcinomatosis to be seen.

And this was easily accessible with transvaginal ultrasound guided biopsy. And here it is in the sagittal plane on ultrasound. The deposit in the cul-de-sac was beautifully visible. The vaginal cuff is here, or the fornix is here. We're out of the way of cervix bowel bladder.

We do see some vessels here, but with manipulating the probe, we're easy. It's easy to get out of the way of those vessels. We activate the guide on the screen showing us exactly where our biopsy will be taken.

We took 18 gauge core biopsies of this, and unfortunately it came back as consistent with a pancreatic, a biliary primary explaining why she was progressing on chemo.

Another elderly woman who had a large cervical mass clinically suspected to be cervical carcinoma. The gynecology biopsy was performed and came back insufficient, but with lymphoid cells and certainly on imaging, we were also suspicious of lymphoma, a large cervical mass that was also infiltrating this lady's bladder.

Clearly anterior and posterior CT guided approaches were not possible here due to intervening bowel and the sagittal plane. Easy to see how this would be easily targeted with a transvaginal biopsy on ultrasound.

The anatomy was beautiful and very well visualized. Here's the thickened posterior wall of the bladder with urine in the lumen and a large mass infiltrating the anterior lip of the cervix with preservation of the posterior lip and compression of the small uterus posteriorly on Doppler interrogation.

It was quite a vascular mass, but with careful interrogation, we were able to find a relatively avascular plane. We activate the guide on the screen, showing us exactly where our biopsy is going to go.

And again, with an 18 gauge needle, we're able to take multiple core samples, which was adequate with sufficient sample for diagnosis of diffuse B-cell lymphoma. And this is the patient after treatment.

Performing Transrectal Biopsies

Moving on to some transrectal biopsy cases. Now these are actually better tolerated than transvaginal because the rectal wall is far less tender. These patients often do not require intravenous sedation.

Like I said, you can freeze the wall and again, we use an 18 gauge needle with an automated device to obtain core samples. This is a young woman who in 2006 had A-A-T-A-H-B-S-O for endometrioid carcinoma with a very elevated CA 1 25, and unfortunately four years later presented with an adnexal mass.

But at this time, her ca 1 25 was normal. Again, any CT guided routes were not ideal with bowel in the way and multiple blood vessels in the vicinity. However, this was easily visualized on transrectal ultrasound.

She was a virgin and did not want to have a transvaginal ultrasound, but was willing to undergo a transrectal ultrasound guided biopsy. So again, you could freeze the rectal wall.

We activate the guide on the screen and showing us exactly where our needle will advance through the needle guide, through the rectal wall, and into the solid component of this lesion. And this was positive for recurrent endometrioid adenocarcinoma.

Another young woman with a peri rectal mass. She had endoscopic ultrasound guided biopsy, which was insufficient. And so she came to us for a trans rectal core biopsy, an ultrasound, beautiful depiction of this solid vascular mass immediately adjacent to the low rectal wall.

Very easy to biopsy simply by inserting the rectal probe, activating the guide, and inserting the needle. And this case illustrates one thing that can be encountered during these procedures in that sometimes the needle does deviate slightly from the guide that's activated on the screen of the monitor.

This depends on the machine that you're using and also on the type of tissue that you're traversing. The time that this becomes important is when you're targeting very tiny lesions. This often happens to us in the prostate when we're trying to target seven millimeter or five millimeter lesions.

And then you need to account for and compensate for this if to reach your target accurately. Another final case for transrectal biopsies. This is a young woman that both on endoscopy and outside MRI was given a diagnosis of probable malignancy.

She had this lesion that was infiltrating the back wall of her uterus involving the anterior wall of the rectum. And on the sagittal plane, you can see how it's pulling the body and fundus of the uterus into retroversion involving the posterior wall of the uterus and the anterior wall of the rectum.

Now, I think most of us on MRI would be happy to call this an endometrioid plaque, but this poor woman had already been given a provisional diagnosis of malignancy and wanted to pursue a biopsy, which was very easily carried out with a trans rectal ultrasound.

So here we can see the rectal wall and we can see this lesion involving the outer serosal layer, an outer muscular layer of the rectum with preservation of the inner walls classic for an endometrioid plaque.

Very easy to target, again, activating the guide on the screen and taking an 18 gauge core biopsy. This came back positive for endometriosis.

Endocavitary Aspiration and Drainage

We're gonna move on now to endo cavitary aspiration and drainage, which can be a little bit more involved than biopsies. Any multipurpose catheter is sufficient for an endo cavitary drainage. It does offer sufficient length to coil the catheter within the collection, leaving enough length outside the patient to affix it to the upper thigh.

As with any abscess drain in the abdomen or pelvis. There are two techniques, the cell dinger and the trocar. And until recently, we did ours as a combination of both of these, either the seldinger or the technique or trocar technique.

This is a woman who had undergone a subtotal colectomy and an IOC colic anastomosis, complicated by a large postoperative infected hematoma. She was quite sick. The anterior route on CT was prevented by bowel that was really plastered all the way around this collection.

The transrectal route was available, but it was also immediately adjacent to the vaginal cuff, being the shortest route available, therefore, into this collection. So this one was done with the Seldinger technique, which is done with a combination of ultrasound and fluoroscopy.

The beginning of this procedure is exactly like doing a transvaginal biopsy in that the guide is affixed to the probe in exactly the same manner. The wall of the vagina is anesthetized with local anesthetic using a Sheba needle, and then an 18 gauge hollow bore needle with an inners stylet is advanced into the collection under direct visualization through the needle guide on the probe.

Once the needle is in the correct position, the inner stylet is removed, and an oh three eight guide wire is inserted through the hollow needle, and coiled safely within the collection. The probe and needle guide is then removed over the guide wire, and the remainder of the procedure is done under fluoroscopy.

Success of dilatations are done while monitoring the G wire with flora to ensure that you're not kinking the G wire. And that is probably one of the most important parts of this technique.

Once successive dilatation has been accomplished, the catheter is inserted over the guidewire, the pigtail locked within the collection, the guide wire removed and the procedure is finished.

The downside of this procedure is that it's quite lengthy, it's quite involved, and particularly for transvaginal, it's an extremely painful procedure. The dilatations are very difficult to perform as the vaginal wall is very tender and very muscular.

Transrectal drainages by this method are better tolerated. It's much easier to dilate through the rectal wall, but by both method, it is a more lengthy procedure and it does involve radiation.

The other downside of doing the Seldinger technique for an endo cavitary drainage is an, it is an inherent that your fingertips along the dilator are well away from the point of dilatation. And the basic te of any celling or technique, regardless of where you're performing it, is that your fingertips should be as close to the point of insertion as possible.

And as your fingertips move farther away along the dilator and away from the tip of the dilator, the more chance you have of kinking the G wire. And in an endo cavitary technique, by definition, your fingertips are quite far away from the point of dilatation.

And the danger in kinking your G wire is that then you will inadvertently insert your catheter outside of the collection in an undesired position. And this also comes with risk for damaging adjacent structures and in the pelvis, particularly the large vessels, including the internal iliac vessels.

So the second technique then is the trocar technique. And until recently, this technique was also quite cumbersome. The method that we used, and a method that's also been described in multiple locations in the literature is as follows.

It's you take the peel away sheath off of an internal jugular catheter, for example, and you affix it to the spine of the probe in the same location that the needle guide would go, and you affix it with two rubber bands so that it looks something like this.

This assembly then is inserted into either the rectum or the vagina and using a trocar technique. So now the catheter is loaded both with the inner stilet and the trocar. The catheter is advanced under direct visualization using the same needle guide on the screen that we showed for biopsies.

And under direct visualization with a single puncture, the tip of the catheter is inserted into the abscess. The catheter is fed off of the inner trocar, and the inner trocar and styl are removed.

The next problem becomes, however, in getting the probe and peel away sheath away from the catheter, leaving the catheter in good position. And this involves gradually peeling away the sheath at the same time as you're cutting the elastic bands with long scissors.

So you can imagine that this can be quite cumbersome, but it's definitely possible to do removing the probe from the catheter, leaving it in a good position. And this is such a case with a postoperative abscess, activating the needle guide and inserting the catheter with this trocar technique in good position within the abscess.

Recently, however, a new product has come on the market, it's produced by Civ Co. This is at the current time only available for either Phillips probes or GE probes. And the difference being that this needle guide that you affixed to the probe is open, along its top.

The bore is no longer closed. Again, this is probe specific, only available for Phillips and GE two parts. The roof of this will insert in along the top edge of the needle guide, and it in essence creates a covered bore along the top of this guide.

Once it's fully assembled, it is then affixed to the probe in the same manner as the needle guide for biopsies. This assembly is then inserted into the vagina or the rectum, and the trocar technique is used again.

The catheter is inserted with a single puncture under direct visualization. The catheters fed off the inner stilet. The stilet and the trocar are removed. The pigtail is locked safely within the collection.

And now very simply, this piece is removed so that this channel across the top of the device becomes opened. And the probe is easily lifted away from the catheter, leaving the catheter in good position, and the probe is easily removed from either the rectum or the vagina.

And this is a patient who had a laparoscopic hysterectomy with a very large postoperative collection, easily amenable to a transvaginal route. And this was very easily done, very fast, very safe, very efficient, and very well tolerated by the patient.

Pearls and Caveats for Pelvic Collections

Using a sim simple trocar technique just to finish with a few simple pearls and caveats. When coming to pelvic collections, this is a woman after a hysterectomy with pain. This is something that we run into quite often with our gynecologist, is that they use a fair amount of surgicel at the vaginal cuff, which on imaging can simulate an abscess.

And this was such a patient. This is not an abscess. This is surgicel at the vaginal cuff. So not all air at the vaginal cuff needs to be drained.

So how do you know then when it's simply surgicel and when it's surgicel that's complicated by abscess or infection? Well, this is a patient who had a splenectomy, and this is surgicel within the collection. But you'll notice here that there's also a fair amount of fluid.

So in general, surgicel should be more air than fluid. Whereas when surgicel has become complicated by an abscess, you'll begin to notice that there's more fluid than air. And if you see an air fluid level, that should raise your suspicion as well.

Another thing to keep in mind is the possibility of a oma. This is an elderly woman after a proctectomy who had a collection in her pelvis and was febrile. She underwent in this case a transabdominal ultrasound guided drainage.

When we aspirated the fluid, we noticed that it was suspiciously looking like urine. So we called the clinicians, they said to go ahead with the catheter, and then they gave her ureteric stents afterwards. This is just a picture of our stent in the collection.

This was inserted transabdominally under ultrasound guidance, but we did this CT scan to document and to quantify the leak. And so don't forget to always think about the possibility of a urine leak, particularly after gynecology surgeries and perform delayed scans when necessary.

Aftercare

In terms of aftercare, all of our transvaginal procedures, whether they're biopsies or drainages or aspirations, are monitored for four hours in our surgical day unit, in part because they all receive intravenous sedation.

Transrectal drainages by definition, are usually inpatients. And so they are also monitored after the procedure with the standard bedrest and vitals. Most of our elective outpatient transrectal biopsies, however, are only watched in the radiology department for 30 minutes to an hour after and then allowed to go home.

And that's because we do not use intravenous sedation for those in select cases where we feel like the target is farther away from the rectum or there are other structures in the way that we're concerned about, those patients may be monitored as well in the surgical day unit.

Take Home Points

So some take home points. Remember to give your sedation and your local anesthetic early to give it time to reach peak. It's often advantageous to give a little bit of sedation if you're going to use it before you give the local anesthetic, because the local anesthetic also can be painful.

Give your sedation in increments and go slow and remember that your doses will stack. Remembering your time to peak of five minutes for fentanyl and 20 minutes for ed.

We touched base on the new oral anticoagulant medications, which were coming across more and more often. Remember that there are no reversal agents. These patients will not be monitored, so there will not be INRs available prior to your procedure.

And that it's dependent on the GFR as to when these products should be discontinued prior to a procedure. Transrectal and transvaginal aspiration biopsy and drainages are very well tolerated and are very safe procedures.

The trocar method for transvaginal drainage with the new equipment that I've showed you is very easy and safe to do and very well tolerated by the patients. And in fact, I would say that transrectal and transvaginal procedures are the easiest ultrasound guided procedures that we do in our department.

Thank you very much.