Vascular access puncture is one of the most critical aspects in haemodialysis patients (HD).1 The rope-ladder puncture2 is the most accepted technique and is recommended by guidelines. However, many times this technique cannot be applied, for different reasons, poor development of the vascular access, limited length of the vessel, presence of aneurisms or physical limitations in the anatomical condition of the patient; then, area punctures are necessary. The buttonhole (BH) puncture technique is an alternative to these punctures. This technique was described in 1972 by Dr Twardowski and involves the cannulation of the arterialised vein using blunt needles, at the same angle and at the same site, via a previously formed tunnel.3 Once the dialysis is completed, after the corresponding haemostasia, a scab is left at the puncture site which should be properly removed in the next HD session.4 Several studies have shown that it is possible to improve clotting times, which could help to reduce pain and may also help to maintain vascular access as compared to other techniques.5–8 However, other studies have shown a high incidence of infections, therefore its acceptance has been limited.9–12 Its application is widely established in some countries, especially in some northern European countries and in the USA, but not in Spain, where there are only few centres that use it. To our knowledge, our centre is the first in the Madrid Region to use this technique regularly. Here we are presenting our experience, over 3 years, after its instauration and the maintained used of this technique.

From 2012 to December 2015, all the patients who started the BH technique at our centre were evaluated. A retrospective study was carried out to analyse the characteristics of the patients, clinical evolution, the expected benefits of the technique and the possible drawbacks of its implementation.

The inclusion criteria for the BH technique were patients over the age of 18 years presenting with one of the following circumstances: patients with the option of home HD, patients with autologous arteriovenous fistulas (AVFs) that are difficult to puncture or with multiple unsuccessful punctures, or patients with significant pain or unable to deal with the fear for AVF puncture. Also included, were those who expressed an interest in the technique and had no contraindications. All patients were verbally informed with additional written information if requested.

The exclusion criteria were those with a prosthetic device for vascular access or those that did not came to the unit for prolonged periods of time and were incapable of self-cannulation since it could imply that they were treated at another centre not familiar with the BH technique.

Buttonhole technique

The buttonhole technique involves the creation of a subcutaneous tunnel as a permanent and invariable route of access to the AVF; once it is created a blunt needle can be inserted. The first puncture must be made using a conventional needle. The area should be selected, considering that the 2 puncture areas should be at least 6cm apart and, avoiding aneurysmal areas. Once the first HD session is finished, both needles are removed, and the site is left to form a clot without any haemostatic dressing. After the correct coagulation as been completed the area it is sterilised with aqueous chlorhexidine. After leaving it for a few minutes f to have an antiseptic effect, a 5mm-long polycarbonate device, similar to a peg, is used at the puncture site to stabilise the tunnel (BioHole® Nipro Corp)13,14 (Fig. 1). The BioHole is inserted using a sterile technique and covered with a transparent dressing. The BioHole remains in place until the next session. At the next session, the transparent dressing is removed without removing the BioHole, and it is sterilised with aqueous chlorhexidine, prior to and after manipulation (double asepsia). Once the BioHole is removed with the aid of tweezers and using sterile technique, the vascular access will be cannulated using a blunt needle once the tunnel is visible. The stabilisation BioHole should be inserted in 5–6 sessions, always using the same technique and by the same previously trained nurse.15

Fig. 1.

BioHole. Device for the creation of tunnel tracks for buttonhole cannulation.

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Over this 3y period 22 patients were evaluated. Table 1 describes their baseline characteristics. There were 15 male and 7 female patients with a mean age of 62 years. 9 patients received antiaggregation therapy and 7 were anticoagulated with acenocoumarol. Mean time on HD at the start of BH was 34 months (SD: 34; range: 3–136 months).

The types of vascular access and the puncture technique prior to the BH technique are shown in Table 2. The most common AVF was left radiocephalic AVF in 9 patients, followed by left humero-cephalic AVF in 8 patients, the other AVFs were: 2 right radiocephalic AVFs, 2 left humero-basilic AVFs and one right humero-cephalic AVF. The technique of the previous puncture was the rope-ladder in 10 cases, the area technique in 6 patients and in 6 other cases a combination of the area and rope-ladder techniques were used. Mean time of vascular access before the technique was changed was 41 months (SD: 55; median: 26; range: 3–252).

Haemostasis

Haemostasis times were analysed prior to installing the BH in all patients and at, 1, 6 and 12 months after regular use. Mean haemostasis time prior to the BH was 18.6min (SD: 8) and it was significantly reduced to 12.2min (SD: 3) at month 1 (p=0.0005) (Fig. 2). Mean haemostasis time at 6 months was 11.2min (SD: 2; p=0.001; n=16 patients) and at 12 months it was 10.9min, (SD: 4; p=0.05; n=9 patients).

Fig. 2.

Haemostasis times prior to and following the buttonhole technique. The median time (interquartile range) until onset of haemostasis using the technique prior to BH (pre-BH) was 15 (15–20) min, and after a month of the BH technique (post-BH) the median was 10 (10–15) min (p<0.005).

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The majority of observational studies describe that with BH technique there is a reduction of pain, a lower number of punctures, less bruising and a reduced formation of aneurysms.16,17 However, systematic reviews focused on this technique have shown that current evidence does not support these results and that the risk of infection is greater in patients with BH.12,18,19 In spite of that, the BH technique may be a valid alternative in some situations. Area puncture complications are well-known and on many occasions rope-ladder punctures are difficult to achieve.1 We decided to include the BH technique as an additional option of puncture techniques at our centre.

The draw back of BH technique is the higher incidence of infections. The rate of bacteraemia described in previous studies was 0.15–0.6 per 1000 patients/day or 0.05–0.2 per patient/year.5,6,20 The review conducted by Muir et al. put forward evidence for this, though it was conducted on a population on home HD, which could mean less control of asepsis.18 However, the Alberta group's published in 2014 more complete review, covering patients on conventional HD, indicating that the risk of infections was greater, without a clear benefit in other respects. The authors concluded that this did not exclude the use of BH in certain specific situations.19

In our experience of 3 years of follow-up we have not observed any bacteraemia and we have had only one local infection confirmed by culture Similar results were described in the randomised clinical trial conducted by Vaux et al., which included 70 patients on the BH technique. No bacteraemia was observed during the follow-up period and only 2 infections were noted at the puncture site.21 In the Chan et al., 2014 study, found no significant differences in infection between the BH technique and the rope-ladder puncture technique (bacteraemia with BH: 5 [11%] vs. conventional: 3 [8%]; p: 0.62).22 Double asepsis was maintained at our unit and thorough monitoring was carried out by the nursing staff as key considerations for avoiding infections. Although some studies showed a potential benefit with topical mupirocin prophylaxis, this was not applied routinely in our population.23

Incidentally, we observed a single case of thrombosis in our group. Although our study was not designed to compare BH with other techniques, some studies have shown greater survival of vascular access with the BH technique.21 However, recent publications, such as that of MacRae, a randomised clinical trial that included 70 patients with BH, or the aforementioned of Chan et al. study, have not shown such a potential benefit.22,24

One of the aspects assessed in our study is the reduction in clotting time at the end of the HD session, which was significant in our population (Fig. 2). In our study, the fact that 75% of patients received anticoagulation or antiplatelet therapy has made it possible to predetermine our results, as they were patients with a higher risk of bleeding. Grau et al. observed a reduction in haemostasis time with the BH technique, although the sample was very small.8 In turn, in the aforementioned Vaux et al. study, bleeding time with the BH technique vs the conventional technique was also reduced: median 7.9 (6.3–10.4) vs. 9.1min (6.9–11.3) respectively, but without reaching statistical significance.21 However, other studies have not proven a reduction in clotting times and some studies have even observed an increased bleeding time, which determined the abandonment of the BH technique.7,24,25

At the same time, the inclusion of the BH technique has led to 5 patients to perform self-cannulation. Although the results are contradictory, especially in terms of home HD, self-cannulation offers benefits to the patient: increasing their autonomy less anxiety when the professional performing the puncture regularly is changed, as well as reducing the number of puncture attempts.5,18,24 The BH technique could be a way of facilitating the option of self-cannulation.

In terms of pain management, in our experience, changing to the BH technique has benefitted our patients. This is a biased population, which may determine our results. Some observational studies, such as that by Ward et al., have also observed a reduction of up to 81% in pain perception with this technique as compared to conventional techniques; however others, such as the van Loon et al. study, did not observe any differences in pain probably due to the routine use of local anaesthetics in classic punctures (30% use in rope-ladder punctures vs 8% in BH punctures; p<0.001).6,26 In randomised clinical trials differences in pain have not been demonstrated, and some studies have shown even an adverse effect of the BH technique.10,21

Finally, the presence of BH-associated complications, such as the need to change BH tunnels due to problems during cannulation, is not widely described. In our study, it was necessary to change the technique in 2 cases after admission to other centres where the BH was not used. Once the patients returned to our unit, it was necessary to restart the process. In the other 7 cases, the need to change the tunnel, was likely due to a change in professionals and this is despite the organisational efforts of the unit and the nursing staff's commitment. This is an essential aspect for the development of these techniques at our institutions, where in addition to the constant turnover of professionals there is an absence of specific training in the field of HD.

Our study has the usual limitations of an observational study without a control group and with a relatively short follow-up period. The patient selection present significant bias. However, broadening the range of puncture alternatives and improving knowledge of other techniques are relevant aspects of our results. Furthermore, although the follow-up period is not very long and the number of patients is reduced, our experience is the broadest in our community to date.

The BH technique may be a valid puncture alternative for patients on HD, especially in some situations in which the alternative is area puncture. It may offer some benefits such as facilitating self-cannulation or reducing waiting times at the end of HD sessions. However, to improve this technique, it is necessary both to increase dissemination and to reduce the negative aspects that have been detected, and to have motivated professional nursing staff. It is likely that the frequent turnover of staff, absence of HD specialisation and lack of training in the technique may be resolved with a greater institutional commitment to healthcare professionals and, therefore, to patients.

Ms Laura Baena has been a lecturer on different courses sponsored by Nipro Corp.

Dr José L. Merino has been a lecturer on different courses sponsored by Nipro Corp.

The other authors declare they have no conflicts of interest.

Nipro Corp. has not taken part in the design, analysis or drafting of this study.