Lymphoedema is a condition of abnormal accumulation of lymph in the arm, shoulder, breast or thoracic area that causes discomfort, pain, impaired function, and emotional distress in breast cancer survivors and is best managed at the earliest opportunity.1,2 Lymphoedema is one of the possible complications following treatment for breast cancer affecting approximately 21% of survivors.3 The risk of developing lymphoedema varies considerably, with the extent of intervention to the axilla by surgery and or radiotherapy, being a major determinant. Data shows that 0–3% of patients undergoing sentinel node biopsy (SNB) to up to 70% after modified radical mastectomy with regional lymph node radiation develop lymphoedema.3 In this cohort of patients, it is common and indeed expected that there will be fluctuations in the arm volume. The fluctuation is often associated with exercise, use or not of compression therapy, diligence in undertaking self-management, heat, general variations in hydration and diet.1,4,5

The Best Practice for the Management of Lymphoedema International Consensus Document lists exercise/movement as number one management strategy to enhance lymphatic and venous flow.6 In 2010 the American College of Sports Medicine developed exercise guidelines for cancer survivors, suggesting that exercise training is safe during and after cancer treatments and results in improvements in physical functioning, quality of life and cancer related fatigue in several cancer groups including breast cancer.7

Complex decongestive physical therapy is the mainstay of treatment for lymphoedema; this is a multimodal treatment protocol with exercise as one component.8 Aquatic therapy is frequently used as exercise treatment for edema management as it uses the principles of hydrostatic forces during immersion along with exercises in thermo-neutral water to stimulate the circulatory system.9 The hydrostatic pressure will create an upward squeezing action thereby encouraging the central flow of fluid.10

There are different approaches to aquatic therapy, from community aqua-aerobic classes to hospital programs. One modality less commonly known is Ai Chi, a slow pace water based activity first described by Sova and Konno.11 Ai Chi is an aquatic exercise sequence with the purpose of relaxation, balance and pain management.11,12 Tidhar et al., 13 have described another slow aquatic therapy approach of teaching women with breast cancer related lymphoedema (BCRL) a routine they term aqua lymphatic therapy (ALT) where patients do self massage in a hydrotherapy pool and this was shown to reduce affected arm oedema over the 14 month trial period.13 ALT was also described by Letellier et al.,14 in 2014 and was shown in their study to be beneficial in the reports of pain intensity. No differences in oedema volume were shown but no worsening either, showing that this program of aquatic therapy was safe in the BCRL population.14

There is some evidence for conventional hydrotherapy regimes however for the slowly performed activity of Ai Chi there has been no clinical trials published in the “at risk” or BCRL population. As Ai Chi uses diaphragmatic breathing, which has been shown to be effective in increasing lymphatic drainage through the thoracic duct4 and combines it with slow movements in the water, it is possible that this hydrotherapy modality would benefit patients with lymphoedema. Furthermore, different protocols (conventional or slow aquatic therapy) increase the options of therapy for therapists and clients to choose from. Clinicians specialized in treating women with lymphoedema after breast cancer treatment have anecdotally reported that arm volume increases when water exercise intervention is of a faster pace, and the same event is not reported after slower pace similar interventions. Therefore the anecdotal evidence seen in the clinical setting was the basis for the design of the current study. Thus the current study aimed to investigate whether slow aquatic exercise in the form of Ai Chi modified to include extra diaphragmatic breathing and lymph node massage is more effective than conventional (faster pace) aquatic therapy at reducing arm volume in women with breast cancer related lymphoedema. The intention of the study was to look at the short term effects of the intervention.

Baseline characteristics for participants are presented in Table 1. Participants had a mean age of 67.3 years; body mass index (BMI) varied from normal to extremely obese. Presentation of lymphoedema varied in stages (1–2; Table 1) and surgical procedure (wide local excision, mastectomy, sentinel node biopsy and axillary clearance; Table 1). Twenty participants agreed to be involved in the study however one participant dropped out of the study due to illness soon after randomization and one participant was unable to partake due to personal reasons and therefore was not randomized.

Volume of lymphoedema decreased for LSAE in comparison to CAE by an average of 140mL (95%CI 17mL to 263mL) immediately after intervention, however the difference was not sustained at 1h after the intervention (Table 2). For bioimpedance, the results showed no difference between LSAE and CAE either for the measurements Post-I and 1h-I (Table 2). Unfortunately, data from three participants, for all three assessments were not included due to equipment failure. For the dichotomous analysis (post hoc), 72% of participants after the LSAE intervention decreased arm volume compared to 28% after the CAE intervention at Post-I; with a NNT of 3 (95%CI 1.4–6.6). For the analysis at 1h-I, 61% of participants after the LSAE intervention decreased arm volume compared to 50% after the CAE intervention; with a NNT of 9 (95%CI −21.2 to 43.4; Fig. 3).

Figure 3.

Number of participants that improved or not, immediately (Post-I) and 1 hour (1h-I) after low speed aquatic exercise (LSAE) and conventional aquatic exercise (CAE). Data was calculated only for the affected arm.

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Return rate for the survey was 83%, with 15/18 returned. One respondent was strongly dissatisfied with the time commitment and her involvement in the LSAE part of the study. The remaining 93% of respondents agreed or strongly agreed that the time commitment and involvement in the project was acceptable. Most respondents (73%) agreed or strongly agreed they would prefer to attend a full class of Ai Chi or a class with Ai Chi as the cool down; 66% agreed or strongly agreed that they enjoyed the CAE intervention with standard cool down. Some comments regarding the Ai Chi were related to the feeling of getting cold when only exercising at slower speeds and a few participants mentioned that they preferred more active classes.

The current trial was set out to determine the effect of a slower pace aquatic intervention compared to the conventional, faster pace aquatic intervention, as usually adopted in rehabilitation settings. The results of the current study show that slow pace aquatic therapy, as presented in this study (Ai Chi combined with additional diaphragmatic breathing and lymph node massage) is a viable and more effective form of therapy to reduce arm volume in women with BCRL when compared to conventional aquatic therapy, immediately after therapy.

One possible explanation for the better results for the LSAE intervention is combination of diaphragmatic breathing and hydrostatic pressure. There is evidence suggesting that diaphragmatic breathing enhances central flow of venous and lymphatic fluids,23,24 thereby reducing the peripheral volume.25–27 Also, during the LSAE participants are immersed neck deep during the entire session, with arms fully submerged. In contrast, during the CAE participants are generally chest deep, with occasions when participants have their arms completely out of water. As a consequence the LSAE utilizes the positive benefits of hydrostatic pressure for longer periods, which is known to reduce peripheral volume.4,26,27 Therefore, although diaphragmatic breathing was present in both interventions, the combination of diaphragmatic breathing and hydrostatic pressure was likely a stronger feature in the LSAE.

Another possibility is that the speed of exercise in itself may account for the differences seen. The LSAE intervention included a rhythmic, slow and gentle intervention in time with the breath, while for the CAE participants were exercising at intermittent rates involving, walking, punching, cycling and jumping actions, all of which are faster and likely to increase blood flow. Although these water activities can be beneficial for other aspects of health, they could potentially be ineffective or increase arm volume.

Unfortunately, the results showed that the positive effect seen immediately after the LSAE intervention was not carried over after 1h, which can be seen as a negative outcome. However after looking at the post hoc analysis (Fig. 3), it seems that what could have happened is that during CAE, patients increase their arm volume, however after 1h that increase tends to subside to a condition prior to the intervention. If the water exercises are being conducted with the aim to improve other health aspects (for example cardiorespiratory fitness and general muscle strength), our findings could be an indication that undesirable increases in arm volume are unlikely to still be present 1h after the end of the treatment. This could be used as an incentive for these population to engage in water exercise with the aim to improve their general health. Further investigation should be conducted to confirm this possibility.

Interestingly the results from the bioimpedance analyses did not show the same benefits seen in volumetry. One possible explanation for this result is that sample size calculation was based on volumetry data, not on bioimpedance data. It is possible that our study was underpowered to find changes in bioimpedance, especially after the current results showed very small changes in bioimpedance. Future studies with larger samples could increase statistical power and give a clearer understanding of data from bioimpedance and the effects of the interventions over time.

Some study limitations need to be acknowledged. One possible limitation is the pragmatic approach to inclusion criteria. Our inclusion criteria were based on patients who are seen in the Bendigo Health Outpatient Rehabilitation Service (OPRS) as part of the routine service provision. This had the aim to increase external validity of the study, and although we may have achieved that, the large variation in participants characteristics could have decreased the level of control over the results, impacting interpretation of findings. Some of the characteristics that largely varied were time since surgery and regular use of compression garments. Regarding the use of compression garments, the pragmatic approach in this study could have also influenced results. The only instructions between Post-I and 1h-I was to have a non-caffeinated drink and to avoid sleeve use (if this was their usual habit). These could be considered as minimum control during the intervention and the hour awaiting for the 1h-I measurement. It is possible that the intervention would be more or less effective depending on how regularly the patient wore compression garment. Another limitation was that the equipment used for bioimpedance assessment was only capable of measuring extracellular fluid of the arm. Perhaps the use of an equipment with the capability of measuring extracellular fluid of other parts of the body would have given us a better understanding of how fluids shifted after the intervention. Also, the small sample size was another limitation. Increasing participant numbers to add to our data would certainly be beneficial for future studies, as would undertaking repeat measures over a longer period. However our intention was to look at immediate effects in this study. Another important point noted was that the level of lymphoedema prior to the interventions was generally smaller than expected (Table 2) and that could have an influence in the final results of the study. However, we were still able to identify a difference in volume between the groups, showing the positive effects of LSAE.

In this cohort of participants, there was a high proportion of participants with BMI greater than 25, including several with BMI above 40. Thermoregulation in these participants is likely to be compromised due to body heat retention and increased plasma sodium levels, which are related to lymphoedema volume.28 Had this study been undertaken on patients who had only recently commenced their management and possibly had more mobile lymphoedema, we may have seen more notable changes in the bioimpedance. Finally, future studies could be designed to investigate whether breathing alone or submersion alone would have an effect on the oedema. Also, larger studies focusing on comparing LSAE to land-based interventions such as yoga and tai chi (integration of breathing with slow body movements) could further enhance the understanding of the effects of low speed water exercise.

LSAE is a viable therapeutic option for women with breast cancer related lymphoedema as it has a positive immediate effect in reducing arm volume when compared to conventional aquatic therapy. However any difference in arm volume due to aquatic therapy seems to subside after 1h, which can be beneficial when water exercise does not aim to address arm volume.

The authors declare no conflicts of interest.