Movement, Function, Pain, and Postoperative Edema in Axillary Web Syndrome Linda A. Koehler, Anne H. Blaes, Tuffia C. Haddad, David W. Hunter, Alan T. Hirsch and Paula M. Ludewig PHYS THER. Published online May 14, 2015 doi: 10.2522/ptj.20140377
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Running Head: Edema in Axillary Web Syndrome
Research Report
Movement, Function, Pain, and Postoperative Edema in Axillary Web Syndrome
Linda A. Koehler, Anne H. Blaes, Tuffia C. Haddad, David W. Hunter, Alan T. Hirsch, Paula M. Ludewig
L.A. Koehler, PT, PhD, CLT-LANA, Program in Physical Therapy, Physical Medicine and Rehabilitation Department and Masonic Cancer Center, University of Minnesota Medical School, Mayo Mail Code 388, 420 Delaware St SE, Minneapolis, MN 55455 (USA). Address all correspondence to Dr Koehler at: [email protected]. A.H. Blaes, MD, Department of Hematology/Oncology and Masonic Cancer Center, University of Minnesota. T.C. Haddad, MD, Department of Oncology, Mayo Clinic, Rochester, Minnesota. D.W. Hunter, MD, Department of Radiology, University of Minnesota. A.T. Hirsch, MD, Medicine Cardiology Division, University of Minnesota. P.M. Ludewig, PT, PhD, Program in Physical Therapy, Physical Medicine and Rehabilitation Department, University of Minnesota Medical School.
[Koehler LA, Blaes AH, Haddad TC, et al. Movement, function, pain, and postoperative edema in axillary web syndrome. Phys Ther. 2015;95:xxx–xxx.]
© 2015 American Physical Therapy Association Published Ahead of Print: xxxx 1
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
Accepted: May 1, 2015 Submitted: August 28, 2014
2
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
ABSTRACT Background: Axillary web syndrome (AWS) is a condition that may develop following breast cancer surgery which presents as a palpable axillary cord of tissue. Objective: The purpose of this study was to determine the clinical characteristics of AWS related to movement, function, pain, and post op edema and to define the incidence and risk factors of AWS within the first 3 months following breast cancer surgery. Design: This was a prospective cohort study with repeated measures design. Methods: Women who underwent breast cancer surgery with sentinel node biopsy or axillary lymph node dissection (n=36) were assessed for AWS, shoulder range of motion (ROM), function, pain, and post-op edema (using girth measurements, bioimpedance and tissue dielectric constant) at 2, 4, and 12 weeks. Demographic characteristics were used for risk analysis. Results: Seventeen women (47.2%) developed AWS, and AWS persisted in 10 participants (27.8%) at 12 weeks. Abduction ROM was significantly lower (p0.99), pain (p=0.82), or edema (p>0.05) at any time point. Trunk edema measured by dielectric constant was present in both groups with an incidence of 55%. Multivariate analysis determined lower BMI (body mass index) as being significantly associated with AWS (OR = 0.86; 95% CI, 0.74-1.00, p=0.09). Limitations: Limitations included a short follow up time and small sample size. Conclusion: AWS is prevalent following breast/axilla surgery for early stage breast cancer and may persist beyond 12 weeks. The early consequences include movement restriction, but the 3
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
long term effects of persistent AWS cords are yet unknown. Low BMI is considered a risk factor for AWS.
4
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
INTRODUCTION Breast cancer surgery with axillary lymph node dissection (ALND) or sentinel node biopsy (SNB) is considered standard treatment for management of early stage breast cancer.1 Breast cancer surgery can result in short and long term complications such as infection, arm weakness, motion restriction, pain, functional loss, lymphedema, and axillary web syndrome (AWS).2-12 Axillary web syndrome, also known as cording, is an often overlooked problem that has been reported to cause morbidity in the early post-operative period,10,11 and could be an initiating factor for some of the post-surgical breast cancer complications such as movement restriction, pain, functional loss, and lymphedema. The incidence of AWS has been poorly defined, with widely differing incidence rates ranging from 6-72% following breast cancer surgery.9,12,13 On physical examination, AWS has been characterized as a tight cord that is present in the underlying superficial tissue of the axilla, arm, or chest wall that causes pain and limits upper extremity movement.9-12 Figure 1 depicts a visible cord associated with axillary web syndrome. The cord frequently develops within weeks following surgery and has been proposed to resolve spontaneously by 3 months.10,11 Some investigators have suggested these cords may not completely resolve and lead to long term restriction of movement of the shoulder and upper extremity.12,13 Movement restrictions, functional loss, pain, and lymphedema are established chronic morbidities following surgical management in woman with breast cancer 10,14-16 and have been identified in patients having AWS.12 It is possible early post operative movement restrictions, functional deficits, pain, and edema may be associated with AWS development. Since AWS is considered a risk factor for lymphedema development,17 determining the clinical characteristics 5
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
unique to AWS would identify associations with established chronic morbidities and could lead to early identification and preventive or rehabilitation interventions. The purpose of this study was to determine the clinical characteristics and natural history of AWS related to movement, function, pain, and edema measures and to define the incidence of and risk factors for AWS within the first 12 weeks following breast cancer surgery. We hypothesized that participants with early onset of AWS would have persistent signs of AWS at 12 weeks, as well as greater movement restrictions, functional deficits, pain levels, and edema measures compared to participants without AWS. METHODS Design Based on previous literature with clinically meaningful differences in DASH scores of 20, and an effect size of 1.3, a power of 0.95 was determined a priori with a 0.05 significance level and 36 total subjects. A 2:1 allocation ratio (24 Non AWS: 12AWS) was anticipated based on past incidence rates, and power calculations were performed using the G-Power version 3.1 calculation (Kiel,Germany). The estimated total sample sizes for all other outcome measures were n=20 for shoulder ROM, n=10 for pain, n=24 for BIS, and n=26 for TDC to achieve a power of 0.80 with a 0.05 significance level using estimated effect sizes assuming a 2:1 allocation ratio. Girth measurement sample size was not calculated a priori. A total of 36 women undergoing breast cancer surgery were recruited from the University of Minnesota by the primary investigator (PI). Participants were recruited at the preoperative or first postoperative surgical visit and screened for eligibility. This prospective cohort study with repeated measures
6
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
design was approved by the University of Minnesota IRB. Written informed consent was obtained at the first post-operative visit. Participants Eligible participants included women who underwent surgical treatment (lumpectomy or mastectomy) for early stage breast cancer, including a minimum removal of one axillary lymph node by SNB. Contralateral prophylactic mastectomy (CPM) was allowed. Participants were excluded if they had undergone previous surgical treatment for breast cancer, surgery of either the axilla or shoulder, had synchronous bilateral breast cancer, a previous history of shoulder dysfunction in either shoulder, or history of upper extremity deep vein thrombosis. AWS Diagnostic Assessment The women were assessed for AWS at each study visit (2, 4 and 12 weeks post-operatively) by the PI (LK), a physical therapist and certified lymphedema therapist with over 15 years of clinical experience. Participants were defined as having AWS when a palpable or visible cord of tissue was present in the axilla, upper extremity, or trunk during maximal shoulder abduction at any data collection time point within 12 weeks following surgery. Such cords did not have to be associated with local pain or restriction of shoulder range of motion. Women who became aware of a cord by self-exam between visits were asked to schedule an immediate study visit to permit performance of an additional assessment. All clinical outcome variables were measured prior to AWS assessment to reduce bias in measures. Demographic Characteristics and Clinical Outcome Measures
7
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
Demographic characteristics were collected by self-report and validated by review of medical records. Function, pain, range of motion, and edema assessment were measured with validated tools at each study visit. Measurements of shoulder abduction active range of motion (AROM) were made bilaterally in the standing position using a standard goniometer method.18 Shoulder abduction passive range of motion (PROM) measurements were taken bilaterally in the supine position.18 The Disabilities of Arm, Shoulder, and Hand tool (DASH) was used to measure function and the Visual Analog Scale (VAS) was used to provide a subjective pain assessment of any new pain which developed after surgery. The DASH tool is a self-report questionnaire which measures functional activities of the whole arm in people with musculoskeletal disorders and has been recommended for use in patients with breast cancer.19,20,21 DASH scores range from 0-100, with zero reflecting no disability and a higher score indicating increased disability. The VAS scale has been reported to provide quantifiable, reliable (r=0.97) measures of pain ranging from 0100.22 The edema assessment included performance of upper extremity girth measurements, bioimpedance spectroscopy (BIS), and tissue dielectric constant measurements (TDC). Above normal edema measurements in this study were not considered a diagnosis of lymphedema since abnormal measurements at this early time period could be post-operative edema. Girth circumference was measured first followed by BIS and TDC. A non-stretch, flexible tape measure with a tension gauge was used to acquire the girth measurements. Girth measurements were obtained bilaterally at 8 cm increments from the distal portion of the ulnar styloid to the axilla in the supine position. Girth measurements were used to calculate volume for each upper 8
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
extremity using the truncated cone formula calculation: V=h/12π(C12+C1C2+C22).23 The volume difference between the extremities was calculated as a percent volume difference. Bioimpedance spectroscopy Dex U400 (ImpediMed, San Diego, CA) was used to measure upper extremity edema at each visit. Bioimpedance spectroscopy (BIS) measures the tissue resistance to an electrical current to determine the extracellular fluid volume which includes lymph fluid.24 The BIS technique has been previously described24-25 and measurements are expressed as an Ldex score with normal values ranging from -10 to 10. Local tissue water measurements of the trunk were taken using DelfinTechnologies MoistureMeter-D (Delfin Technologies, Kuopio, Finland). Tissue dielectric constant (TDC) is based on tissue electric properties and is dependent on the amount of water in the tissue which affects the value of the TDC.26-29 The value increases with the increase of water in the tissue. A cylindrical probe is placed on a localized area of the body and a high frequency (300 MHz), low power electromagnetic wave is emitted into the tissue. The reflected electromagnetic wave displays as a number related to the amount to water in the tissue.26, 27 The display value ranges from 1-80 with pure water having a value of about 78.5 and air about one.26 Comparing values in subjects with lymphedema, a TDC ratio is calculated by dividing the affected lymphedema side by the unaffected side.27,29 A proposed TDC ratio of 1.2 or higher is suggested as an above normal measure indicative of edema.27,29 Trunk edema was assessed by taking local tissue water measurements on the lateral chest wall 8 cm below the axillary fold bilaterally in the supine position. Upper extremity edema was defined when (a) the circumferential volume difference was more than 10% greater between the affected
9
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and unaffected arms,30 (b) the BIS L-Dex value was >10 or by an increase of >5 over time, or (c) by a TDC ratio of >1.2.29,31 Data analysis Clinical characteristics (shoulder abduction, function, pain, and edema) were analyzed with repeated measures ANOVA (group and time as factors) using a 0.05 significant level. A participant identified with AWS at any time point was consistently grouped into the AWS group for final analysis across all time points. The Mauchly test statistic32 was used to check for circularity, a test for homogeneity of variance. If the Mauchly criterion was violated, the statistical program automatically corrected the p-value using the Geisser Greenhouse correction.32 This correction reduced the chance of a Type I error. A Tukey-Kramer adjustment was performed for visit effect per group and group effect per visit if an interaction effect was identified. Descriptive analysis described cord presence at 12 weeks. A priori and with statistical consultation, the statistical plan was to analyze participant characteristics as risk factors using logistic regression with a more lenient p value of 0.10 if there was less than 20% loss to follow up. The rationale for this higher p-value was to not exclude a potentially important variable since the study sample size was low. A univariable logistic regression was used to determine possible risk factors for AWS. For ease of interpretation, age data was divided by 10 so it could be interpreted as every 10 year change in age if deemed a risk factor for AWS. A multivariable logistic regression was then applied to analyze the statistically significant variables from the univariable analysis to control for possible confounding variables between AWS and the factors that showed statistical significance using a 0.10 p-value. Analysis was performed using NCSS statistical program Version 9.0 (Kaysville, Utah).
10
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
RESULTS Thirty six women who underwent surgical treatment for breast cancer fulfilled eligibility criteria and consented to study participation. There was 100% compliance for all study visits (Fig 2). Demographic characteristics of the study cohort are presented in Table 1. Seventeen of 36 women (47.2 %) developed AWS within 12 weeks following surgery. One participant, initially presenting with AWS in the axilla, received an extra AWS assessment after developing an additional cord on her trunk. The prevalence of AWS in participants with SNB was 41% and ALND was 71%. Six out of seven women (85.7 %) undergoing CPM developed AWS. Ten women (27.8 %) continued to demonstrate signs of AWS at the 12 weeks post-operative visit. Of these, 8 participants had cords present at all three visits, and 2 presented with new evidence of cords at 12 weeks. Figure 1 portrays an image of a woman with persistent AWS at 12 weeks. Participants followed the institution’s normal practice patterns regarding provision of rehabilitation treatment for upper extremity physical impairments. Four participants (2 AWS: 2 non AWS) underwent rehabilitation treatment within 12 weeks after surgery which may have included treatment for AWS, ROM deficits, lymphedema, functional loss, and/or pain. Clinical measures Shoulder Abduction There was an interaction effect (Figure 3) between groups over time related to shoulder abduction AROM (p=0.02, F=4.23) and PROM (p
The online version of this article, along with updated information and services, can be found online at: http://ptjournal.apta.org/content/early/2015/05/06/ptj.20140377 E-mail alerts
Sign up here to receive free e-mail alerts
Online First articles are published online before they appear in a regular issue of Physical Therapy (PTJ). PTJ publishes 2 types of Online First articles: Author manuscripts: PDF versions of manuscripts that have been peer-reviewed and accepted for publication but have not yet been copyedited or typeset. This allows PTJ readers almost immediate access to accepted papers. Page proofs: edited and typeset versions of articles that incorporate any author corrections and replace the original author manuscript.
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
Running Head: Edema in Axillary Web Syndrome
Research Report
Movement, Function, Pain, and Postoperative Edema in Axillary Web Syndrome
Linda A. Koehler, Anne H. Blaes, Tuffia C. Haddad, David W. Hunter, Alan T. Hirsch, Paula M. Ludewig
L.A. Koehler, PT, PhD, CLT-LANA, Program in Physical Therapy, Physical Medicine and Rehabilitation Department and Masonic Cancer Center, University of Minnesota Medical School, Mayo Mail Code 388, 420 Delaware St SE, Minneapolis, MN 55455 (USA). Address all correspondence to Dr Koehler at: [email protected]. A.H. Blaes, MD, Department of Hematology/Oncology and Masonic Cancer Center, University of Minnesota. T.C. Haddad, MD, Department of Oncology, Mayo Clinic, Rochester, Minnesota. D.W. Hunter, MD, Department of Radiology, University of Minnesota. A.T. Hirsch, MD, Medicine Cardiology Division, University of Minnesota. P.M. Ludewig, PT, PhD, Program in Physical Therapy, Physical Medicine and Rehabilitation Department, University of Minnesota Medical School.
[Koehler LA, Blaes AH, Haddad TC, et al. Movement, function, pain, and postoperative edema in axillary web syndrome. Phys Ther. 2015;95:xxx–xxx.]
© 2015 American Physical Therapy Association Published Ahead of Print: xxxx 1
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
Accepted: May 1, 2015 Submitted: August 28, 2014
2
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
ABSTRACT Background: Axillary web syndrome (AWS) is a condition that may develop following breast cancer surgery which presents as a palpable axillary cord of tissue. Objective: The purpose of this study was to determine the clinical characteristics of AWS related to movement, function, pain, and post op edema and to define the incidence and risk factors of AWS within the first 3 months following breast cancer surgery. Design: This was a prospective cohort study with repeated measures design. Methods: Women who underwent breast cancer surgery with sentinel node biopsy or axillary lymph node dissection (n=36) were assessed for AWS, shoulder range of motion (ROM), function, pain, and post-op edema (using girth measurements, bioimpedance and tissue dielectric constant) at 2, 4, and 12 weeks. Demographic characteristics were used for risk analysis. Results: Seventeen women (47.2%) developed AWS, and AWS persisted in 10 participants (27.8%) at 12 weeks. Abduction ROM was significantly lower (p0.99), pain (p=0.82), or edema (p>0.05) at any time point. Trunk edema measured by dielectric constant was present in both groups with an incidence of 55%. Multivariate analysis determined lower BMI (body mass index) as being significantly associated with AWS (OR = 0.86; 95% CI, 0.74-1.00, p=0.09). Limitations: Limitations included a short follow up time and small sample size. Conclusion: AWS is prevalent following breast/axilla surgery for early stage breast cancer and may persist beyond 12 weeks. The early consequences include movement restriction, but the 3
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
long term effects of persistent AWS cords are yet unknown. Low BMI is considered a risk factor for AWS.
4
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
INTRODUCTION Breast cancer surgery with axillary lymph node dissection (ALND) or sentinel node biopsy (SNB) is considered standard treatment for management of early stage breast cancer.1 Breast cancer surgery can result in short and long term complications such as infection, arm weakness, motion restriction, pain, functional loss, lymphedema, and axillary web syndrome (AWS).2-12 Axillary web syndrome, also known as cording, is an often overlooked problem that has been reported to cause morbidity in the early post-operative period,10,11 and could be an initiating factor for some of the post-surgical breast cancer complications such as movement restriction, pain, functional loss, and lymphedema. The incidence of AWS has been poorly defined, with widely differing incidence rates ranging from 6-72% following breast cancer surgery.9,12,13 On physical examination, AWS has been characterized as a tight cord that is present in the underlying superficial tissue of the axilla, arm, or chest wall that causes pain and limits upper extremity movement.9-12 Figure 1 depicts a visible cord associated with axillary web syndrome. The cord frequently develops within weeks following surgery and has been proposed to resolve spontaneously by 3 months.10,11 Some investigators have suggested these cords may not completely resolve and lead to long term restriction of movement of the shoulder and upper extremity.12,13 Movement restrictions, functional loss, pain, and lymphedema are established chronic morbidities following surgical management in woman with breast cancer 10,14-16 and have been identified in patients having AWS.12 It is possible early post operative movement restrictions, functional deficits, pain, and edema may be associated with AWS development. Since AWS is considered a risk factor for lymphedema development,17 determining the clinical characteristics 5
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
unique to AWS would identify associations with established chronic morbidities and could lead to early identification and preventive or rehabilitation interventions. The purpose of this study was to determine the clinical characteristics and natural history of AWS related to movement, function, pain, and edema measures and to define the incidence of and risk factors for AWS within the first 12 weeks following breast cancer surgery. We hypothesized that participants with early onset of AWS would have persistent signs of AWS at 12 weeks, as well as greater movement restrictions, functional deficits, pain levels, and edema measures compared to participants without AWS. METHODS Design Based on previous literature with clinically meaningful differences in DASH scores of 20, and an effect size of 1.3, a power of 0.95 was determined a priori with a 0.05 significance level and 36 total subjects. A 2:1 allocation ratio (24 Non AWS: 12AWS) was anticipated based on past incidence rates, and power calculations were performed using the G-Power version 3.1 calculation (Kiel,Germany). The estimated total sample sizes for all other outcome measures were n=20 for shoulder ROM, n=10 for pain, n=24 for BIS, and n=26 for TDC to achieve a power of 0.80 with a 0.05 significance level using estimated effect sizes assuming a 2:1 allocation ratio. Girth measurement sample size was not calculated a priori. A total of 36 women undergoing breast cancer surgery were recruited from the University of Minnesota by the primary investigator (PI). Participants were recruited at the preoperative or first postoperative surgical visit and screened for eligibility. This prospective cohort study with repeated measures
6
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
design was approved by the University of Minnesota IRB. Written informed consent was obtained at the first post-operative visit. Participants Eligible participants included women who underwent surgical treatment (lumpectomy or mastectomy) for early stage breast cancer, including a minimum removal of one axillary lymph node by SNB. Contralateral prophylactic mastectomy (CPM) was allowed. Participants were excluded if they had undergone previous surgical treatment for breast cancer, surgery of either the axilla or shoulder, had synchronous bilateral breast cancer, a previous history of shoulder dysfunction in either shoulder, or history of upper extremity deep vein thrombosis. AWS Diagnostic Assessment The women were assessed for AWS at each study visit (2, 4 and 12 weeks post-operatively) by the PI (LK), a physical therapist and certified lymphedema therapist with over 15 years of clinical experience. Participants were defined as having AWS when a palpable or visible cord of tissue was present in the axilla, upper extremity, or trunk during maximal shoulder abduction at any data collection time point within 12 weeks following surgery. Such cords did not have to be associated with local pain or restriction of shoulder range of motion. Women who became aware of a cord by self-exam between visits were asked to schedule an immediate study visit to permit performance of an additional assessment. All clinical outcome variables were measured prior to AWS assessment to reduce bias in measures. Demographic Characteristics and Clinical Outcome Measures
7
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
Demographic characteristics were collected by self-report and validated by review of medical records. Function, pain, range of motion, and edema assessment were measured with validated tools at each study visit. Measurements of shoulder abduction active range of motion (AROM) were made bilaterally in the standing position using a standard goniometer method.18 Shoulder abduction passive range of motion (PROM) measurements were taken bilaterally in the supine position.18 The Disabilities of Arm, Shoulder, and Hand tool (DASH) was used to measure function and the Visual Analog Scale (VAS) was used to provide a subjective pain assessment of any new pain which developed after surgery. The DASH tool is a self-report questionnaire which measures functional activities of the whole arm in people with musculoskeletal disorders and has been recommended for use in patients with breast cancer.19,20,21 DASH scores range from 0-100, with zero reflecting no disability and a higher score indicating increased disability. The VAS scale has been reported to provide quantifiable, reliable (r=0.97) measures of pain ranging from 0100.22 The edema assessment included performance of upper extremity girth measurements, bioimpedance spectroscopy (BIS), and tissue dielectric constant measurements (TDC). Above normal edema measurements in this study were not considered a diagnosis of lymphedema since abnormal measurements at this early time period could be post-operative edema. Girth circumference was measured first followed by BIS and TDC. A non-stretch, flexible tape measure with a tension gauge was used to acquire the girth measurements. Girth measurements were obtained bilaterally at 8 cm increments from the distal portion of the ulnar styloid to the axilla in the supine position. Girth measurements were used to calculate volume for each upper 8
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
extremity using the truncated cone formula calculation: V=h/12π(C12+C1C2+C22).23 The volume difference between the extremities was calculated as a percent volume difference. Bioimpedance spectroscopy Dex U400 (ImpediMed, San Diego, CA) was used to measure upper extremity edema at each visit. Bioimpedance spectroscopy (BIS) measures the tissue resistance to an electrical current to determine the extracellular fluid volume which includes lymph fluid.24 The BIS technique has been previously described24-25 and measurements are expressed as an Ldex score with normal values ranging from -10 to 10. Local tissue water measurements of the trunk were taken using DelfinTechnologies MoistureMeter-D (Delfin Technologies, Kuopio, Finland). Tissue dielectric constant (TDC) is based on tissue electric properties and is dependent on the amount of water in the tissue which affects the value of the TDC.26-29 The value increases with the increase of water in the tissue. A cylindrical probe is placed on a localized area of the body and a high frequency (300 MHz), low power electromagnetic wave is emitted into the tissue. The reflected electromagnetic wave displays as a number related to the amount to water in the tissue.26, 27 The display value ranges from 1-80 with pure water having a value of about 78.5 and air about one.26 Comparing values in subjects with lymphedema, a TDC ratio is calculated by dividing the affected lymphedema side by the unaffected side.27,29 A proposed TDC ratio of 1.2 or higher is suggested as an above normal measure indicative of edema.27,29 Trunk edema was assessed by taking local tissue water measurements on the lateral chest wall 8 cm below the axillary fold bilaterally in the supine position. Upper extremity edema was defined when (a) the circumferential volume difference was more than 10% greater between the affected
9
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
and unaffected arms,30 (b) the BIS L-Dex value was >10 or by an increase of >5 over time, or (c) by a TDC ratio of >1.2.29,31 Data analysis Clinical characteristics (shoulder abduction, function, pain, and edema) were analyzed with repeated measures ANOVA (group and time as factors) using a 0.05 significant level. A participant identified with AWS at any time point was consistently grouped into the AWS group for final analysis across all time points. The Mauchly test statistic32 was used to check for circularity, a test for homogeneity of variance. If the Mauchly criterion was violated, the statistical program automatically corrected the p-value using the Geisser Greenhouse correction.32 This correction reduced the chance of a Type I error. A Tukey-Kramer adjustment was performed for visit effect per group and group effect per visit if an interaction effect was identified. Descriptive analysis described cord presence at 12 weeks. A priori and with statistical consultation, the statistical plan was to analyze participant characteristics as risk factors using logistic regression with a more lenient p value of 0.10 if there was less than 20% loss to follow up. The rationale for this higher p-value was to not exclude a potentially important variable since the study sample size was low. A univariable logistic regression was used to determine possible risk factors for AWS. For ease of interpretation, age data was divided by 10 so it could be interpreted as every 10 year change in age if deemed a risk factor for AWS. A multivariable logistic regression was then applied to analyze the statistically significant variables from the univariable analysis to control for possible confounding variables between AWS and the factors that showed statistical significance using a 0.10 p-value. Analysis was performed using NCSS statistical program Version 9.0 (Kaysville, Utah).
10
Downloaded from http://ptjournal.apta.org/ by Mark West on June 4, 2015
RESULTS Thirty six women who underwent surgical treatment for breast cancer fulfilled eligibility criteria and consented to study participation. There was 100% compliance for all study visits (Fig 2). Demographic characteristics of the study cohort are presented in Table 1. Seventeen of 36 women (47.2 %) developed AWS within 12 weeks following surgery. One participant, initially presenting with AWS in the axilla, received an extra AWS assessment after developing an additional cord on her trunk. The prevalence of AWS in participants with SNB was 41% and ALND was 71%. Six out of seven women (85.7 %) undergoing CPM developed AWS. Ten women (27.8 %) continued to demonstrate signs of AWS at the 12 weeks post-operative visit. Of these, 8 participants had cords present at all three visits, and 2 presented with new evidence of cords at 12 weeks. Figure 1 portrays an image of a woman with persistent AWS at 12 weeks. Participants followed the institution’s normal practice patterns regarding provision of rehabilitation treatment for upper extremity physical impairments. Four participants (2 AWS: 2 non AWS) underwent rehabilitation treatment within 12 weeks after surgery which may have included treatment for AWS, ROM deficits, lymphedema, functional loss, and/or pain. Clinical measures Shoulder Abduction There was an interaction effect (Figure 3) between groups over time related to shoulder abduction AROM (p=0.02, F=4.23) and PROM (p
