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Hidden
Benefits? A new access for peritoneal dialysis -
(full conference transcript)
(Click here to go back to the summary page for this speech).
Maggi Steele
Research Sister, Renal Unit, St Helier Hospital, Carshalton Surrey.
EDTNA representative on the British Renal Society.
As you are well aware, one of the main reasons patients who have chosen
peritoneal dialysis as their form of renal replacement therapy have to
transfer to haemodialysis is because of access-related infections, be
they exit-site infections or peritonitis. And that’s most unfortunate,
particularly since you have chosen that particular kind of therapy and
we want to be able to keep you on it for as long as possible. The LifeSite
device is a fully subcutaneous system in which all aspects of the device
and the catheter are implanted under the skin and there is no external
portion. And it is this feature which may reduce the incidence of access-associated
infections in peritoneal dialysis. As you can see in this top picture
(not shown), this is one of our control patients who had the standard
Tenckhoff
inserted and unfortunately soon got an exit site infection. But of course
that doesn’t happen to everyone. And the picture here (see diagram,
right)
shows the Life 
Site
patient and the device is placed here on this patient and
there
is nothing
to be seen externally other than a small bump over the iliac crest there.
So it’s this design feature together with the access procedure itself
which may have the hidden benefit of reducing line-associated infections. And
the other potential benefit for patients is in terms of body image because
many patients actually do not like to have this external portion at all. So
there is the obvious benefit in terms of improved body image.
Before going on to describe the device and what the access procedure actually entails for patients, I’d first like to put our experience with it within context. We are conducting a very small scale clinical study and we’re approaching patients who are just in the run-up to reaching end stage who have already chosen peritoneal dialysis as their form of maintenance therapy and inviting them to take part in the study if they meet the inclusion and exclusion criteria. We’re going to be randomising those patients, about 20 in total, and ten will receive the Life Site device and ten the standard Tenckhoff, so that we can try and compare the efficacy of the two systems. As part of the study all patients are actually going to be receiving APD therapy. We’ve standardised it so that as far as possible we can compare like with like. After an initial training period to do the manual exchanges, patients are being trained to use the Baxter Home Choice machine. We’re going to be following the patients six months, with monthly visits during that six-month period, and then observing them over the long term for as long as the access remains in place. So the main objectives that we’re going to be looking at are acceptance of the device by patients and the medical staff, any episodes of infection, and any episodes of mechanical problems related to the access.
Very briefly, the standard inclusion criteria – patients being over 18 years of age, and being able to give informed consent – are obviously followed. But just to emphasise that these are patients new to peritoneal dialysis. We’re not excluding anyone who may need a spell of acute haemodialysis just approaching the placement of the access. Obviously issues regarding good hand eye co-ordination and manual dexterity are also very important. We do emphasise that in this as opposed to some other procedures the patient is carrying out the access procedures themselves. Under certain circumstances a carer may be the person that actually carries out the procedure but we do try and get the patients to be looking after the access themselves.
In terms of exclusion criteria (this again is for this study so that we can compare like with like) we’re choosing patients that are relatively well and free from any concurrent infections and the other key aspect is that we are choosing patients who have never had any abdominal surgery at all. So when the results of the study are finally assessed, we will be able to say with confidence that any differences between patient groups in terms of the delivery of dialysis won’t be because one group had a higher incidence of patients having had previous abdominal surgery and possibly reduced peritoneal membrane surface area, resulting in a less well dialysed patient. And likewise we’re not choosing anyone who is currently immuno-suppressed. As you are no doubt aware, many patients have immuno-suppressant therapy, be it steroid therapy to suppress the original cause of kidney complaint, but because there may be an increased risk of infection. We are not choosing patients who are immuno-suppressed, although in the future if the device is accepted generally, then that’s not to say that these patients will be refused this form of access.
So what does it consist of? There’s the standard Tenckhoff catheter
and a titanium metal device – all of them are placed subcutaneously (see
diagram, left). The
titanium device has an internal pinch clamp and how that is accessed
is with a standard fistula needle – a 14 gauge needle, which has a special
connector which is able to 
be
connected to the dialysate line. This
gives an internal view of what is actually happening in the device (not
shown). There’s
a couple of – I call them ball bearings – which are parted only when
the 14 gauge needle goes in place and this in turn operates a spring
mechanism so that once the needle is in place there’s continuity between
the dialysate lines externally and the internal catheter. The access
procedure itself causes a buttonhole site to be formed, because the needle
is going in exactly the same place every time it is accessed. The best
way to liken it is to pierced ears – not exactly like that but it’s a
very good analogy. It becomes after one or two needles a painless process. We
call the formation of the button hole site mature after one or two weeks
of access being performed and this process destroys some of the pain
nerves and so facilitates the painless needling process. Once the needle
is removed, the natural interstitial pressure of the skin causes initial
closure and then we just ask patients to put a small dressing in place. And
that’s it.
I talked about one of the potential benefits being derived from the access procedure itself, and this is the key aspect, which is the installation of isopropyl alcohol solution which I stress is not going into the catheter and into the peritoneal cavity at all, because it is administered using a 25 gauge needle which is very very fine indeed, and has absolutely no influence on the ball-bearing aspect of the device at all. So when it is installed it is just going into the device, filling this dead space and any excess is spilling out into what we call the pocket area, the tissue surrounding the device and up the tract and on to the skin surface.
I just had to put this picture (not shown) in to emphasise again that this is a procedure that is inserted under general anaesthetic with laproscopic control so it’s not an option to have this inserted medically under local anaesthetic. Also our surgical team like to get in on the act as well.
The very first needle that is ever placed is placed by the surgeon, just to check the integrity of the system after the catheter and the device have been inserted.
So that does this device ask of you? We begin by asking patients to clean the site topically with an isopropyl alcohol solution. This patient here (not shown) - it’s about two weeks after she had the access inserted, so you can very faintly see here the incision line and below that where the device is sited, so she’s cleaning in an outward spiral motion for about five inches diameter over about a 30 second period, just to make sure the skin surface is nice and clean. Patients are all given dialysis packs to use at home and delivered by Unicare in the normal way. You can see that she has put on a pair of sterile gloves now, and she’s doing the cleansing procedure with the 25 gauge needle, with one mil. of the isopropyl alcohol solution.
Here
you can see the cannulation actually happening, with the 14 gauge needle
(see diagram, right). It’s
inserted and then a quarter turn of the needle in any direction actually
securely locks it in place. You can
really tug it and it’s
not going to come out at all if it’s put in correctly. After the access
is performed, she would then connect the distill end to the dialysate
line. Then we just ask patients just to wrap some alcohol-soaked gauze
around the site whilst dialysis is being performed.
Once the procedure is ended, and dialysis has taken place, the needle is removed, and the removal is just by rotating the needle very gently and it’s as if the ball-bearings lose their grip of the needle and it’s easily slid out. And then we ask patients to repeat the cleansing procedure yet again, to clean the skin topically and put in another one mil. of the isopropyl alcohol to fill the dead space yet again, and then put on a small dressing.
I’ve got some slides of other patients performing dialysis (not shown).
This is the needle in place just before she’s going to wrap the gauze around it. All these pictures were taken when patients were training, and to begin with they learn manual exchanges and that also allows us to use the site and for patients to have several needles inserted and have the button-hole site well established before they are discharged home looking after the site themselves.
This was the very first patient who ever had the device inserted. He’s chosen a very different position. The other patient chose low down round about the bikini line just over the hip. This patient actually chose to have the device sited just over his lower ribs. In choosing the site for the access it’s very much up to the patient where they feel more comfortable. We have a special belt with an access device sewn in that we ask patients to put round a very unsophisticated Velcro belt so that they can adopt various positions bearing in mind they are all going to be using APD. We get them to take that home with them and they can adopt the most comfortable position for them whilst they’re sleeping and see whether it’s going to interfere with their sleep pattern. He chose up on his rib cage. He had good hand-eye co-ordination. It wouldn’t suit women – there’s a piece of anatomy that gets in the way there, so I think that’s why women choose a bit lower down.
Here you can see him putting in the 14 gauge needle. When we first began the study we had just standard fistula needles supplied to us, before the company had actually started manufacturing the needles with the dedicated dialysate endpiece to connect on to the lines, so it’s a much better design now.
In fact this patient took complete control of the first access procedure and wanted to do absolutely everything himself. He was in a room surrounded by about half a dozen PD nurses, several medical staff and a representative from the Vasca company as well. We were ready to do the first access, we were all on a very steep learning curve, both the patients and ourselves, with this being such a novel device, and he took control completely for himself – he wouldn’t let us do anything. He even administered local anaesthetic that we tend to use for the first one or two needles, because obviously the very first needle will be painful and so local anaesthetic helps patients get over that initial reticence they may have in performing the procedure. But he took everything away from us and the nurse who was training him in all other aspects of dialysis actually had to beg him on the last day of training for her to have a go.
In this one, some of the bruising is because the site has just been used in the initial period. You can see there are no hands on the syringe, this is using the very fine 25 gauge needle. Once that’s in place and it is fully bedded down it is held in place itself, and she’s just about to inject the one ml solution. Now you can see the forcing needle in place and it’s getting a good tug just to check that it is completely seated within the device.
So where are we in the study? So far we’ve approached 31 patients and talked to them in detail about coming on to this study, and of this 31 only three patients that have actually refused participation, and two of those patients actually chose not to have APD. They just felt that being attached to the Home Choice machine overnight wouldn’t suit their lifestyle. The third patient later, after initially choosing peritoneal dialysis and staff approached them and talked about the study, chose haemodialysis. Once they knew there was an option of the LifeSite device they actually found the possibility of having an external catheter unacceptable to them. Unfortunately the Life Site device is only available as part of the study and patients come on to the study knowing that they would be randomised to receive the standard Tenckhoff.
Of the17 patients that have been taken on to the study and have been randomised, the tenth Life Site patient was randomised very recently, and seven have been randomised with standard Tenckhoff. The division is, as in most dialysis units, more males/females, the average age is 47, but the range is from 27 to 69. Of the remaining 11 patients two weren’t taken on to the study because our transplant team are doing a fabulous job and many patients are being lined up for live related and unrelated transplants, so if we know or believe that the transplant work-up is going to be finalised very soon after the initiation of dialysis may be required then we’re not taking these patients on to the study.
Three patients have not yet required access but they’re waiting to come on to the study when their symptoms dictate the need for initiating dialysis. Five patients were eventually excluded. We approached patients early on once they’ve chosen PD as their form of maintenance therapy, but obviously other illnesses may lead to their being excluded, and also careful assessment of just how good patients’ hand-eye co-ordination and their ability to self-care with this device may need reassessment at regular intervals.
So where we are in assessing this study at the moment, we haven’t got complete data, the patient numbers are very small, and the longest that anyone has had the Life Site device is11 months. Mostly patients have been taken off the study because a cadaveric transplant becomes available. One patient had to have the device removed because of a recurrent staph peritonitis, but interestingly enough that patient asked could she please have the device back again. In terms of how patients feel about it, that speaks for itself. Even after experiencing peritonitis events that required removal of the device, she wanted to have the device reinserted, and did indeed have a second device.
So part of the study is looking at the patients’ acceptance and there is a very simple questionnaire that we are administering at baseline and this is the baseline information that we’ve gathered from patients – from the Tenckhoff patients and the Life Site patients. They’re filling in the baseline questionnaire before they’ve actually been randomised. I have to make a phone call to America where Vasca, the company that manufactures the device, are based. They’re the ones that actually randomises patients for me. In terms of body image six patients said that this was important to them, how they felt about themselves, their body image. Ten said it was moderately important. Only one said it was actually insignificant.
Ease of use of any system: 16 said how easy it was to handle was important and only one said it was moderately important. Nobody said that this was insignificant, how complex a system was. In terms of their partner’s reactions to the form of access, eight said it was important, seven moderate, and only two patients said it was insignificant. This is very interesting and very reassuring. In terms of choice of access, infection is rated extremely highly. In terms of needle use, seven said it was an important aspect, six said it was moderately important and only four said it was insignificant.
We did have one patient whom I talked to on several occasions about the access and he had attempted using the needles on the device, had the belt I spoke about earlier and used that at home, and unfortunately in the training phase he was unable to perform his own needling. He could get as far as doing the very fine needle, but when faced with the 14 gauge needle he would faint. It transpired that he actually had a needle phobia which he had never admitted to. He would self administer his Epo and he firmly believed it wouldn’t be an issue, but obviously his blood pressure wasn’t good enough to hold up long enough for him to be able to place the 14 gauge needle. We were willing obviously to stop the study and transfer him to haemodialysis and exchange the Life Site device for a Tenckhoff because again he really wanted to do PD at home. Later on he got haemodialysis line infection whilst he was waiting for the surgery and he approached us again, could he have hypnotherapy to get over this phobia of his?. We felt that this was really not an option. It was a lot to ask of him to conquer this greater fear. Later on he came to us and said would it be possible for his wife to perform the access procedure. Again, we don’t want to go down that road of increasing the burden of partners or changing any kind of balance of power or relationships, so we gave him every option to change his mind but he felt they had talked about it fully and she was willing to take over the cannulation. That’s what we did and we have had one husband and wife team with the wife performing the access procedure itself.
In terms of the needle insertion, all have said it is easy, virtually painless, with very little discomfort. The discomfort comes – I don’t know if any of you have had a paper cut and then used the alcohol hand rub- it’s a similar sensation, very brief, about ten seconds but it is quite painful. The exit site care in terms of the Life Site device they found relatively easy. All patients have been satisfied with their access.
Just to summarise – so far no-one has actually refused to take part in the study because of the requirement to use needles, even the person who found he was needle-phobic. Actually, he didn’t report needles in the initial questionnaire as being important. The initial training period for both the CAPD and APD procedure is not extended for the Life Site patients. Patients do confirm that it is a virtually painless access procedure although the isopropyl alcohol does sting. After a couple of weeks (one thing I didn’t mention earlier) is that we introduce a dull needle – it’s blunted so it’s not as sharp as the standard fistula needle and that increases patients’ comfort.
In terms of how well the dialysis is delivered, we’re retrieving data from the Home Choice Pro machines and there hasn’t been any significant difference, although formal statistical analysis is still awaited. And we’ve seen that body image is important to patients in terms of choice of access. So it may be that an element in the future in terms of access will be for patients to have this choice. We don’t know, we’ll have to see what initial results are. Very briefly, over in America this device is used for haemodialysis and the device for haemodialysis does have FDA approval, and patients now number in the 5,000s that have haemodialysis access using the Life Site device. Their studies do show improved rates of line-associated infections, so we need to see if this is going to be the case with peritoneal dialysis as well.
Finally, I’d just like to thank all the patients who have kindly allowed us to learn from them and have me take their photographs.
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