Nationwide Medical Survey on Regional Disparities in Secondary Lymphedema Surgical Treatment Covered by Health Insurance

Abstract

Background:

Lymphedema is a lifelong complication for cancer survivors, highlighting the need to address the regional disparities in its treatment. To assess the current regional disparities in surgical treatment for lymphedema, we conducted a comprehensive nationwide survey of medical institutions through questionnaires.

Methods:

Japanese surgical treatment facilities were categorized into 9 regions, distinguishing between designated cancer hospitals and other medical institutions, as well as high-volume and low-volume hospitals. We examined variations in the number of surgical procedures per capita across regions and analyzed differences in surgical indications between high-volume and low-volume hospitals based on the clinical classification of the International Society of Lymphology.

Results:

There was a 17.4-fold difference in the number of lymphedema surgical treatments per population between the region with the highest and lowest numbers. A strong correlation was found between the number of procedures in a region and the percentage of procedures performed at high-volume hospitals (ρ = 0.73, P = 0.03). High-volume hospitals had a significantly higher proportion of cases deemed suitable for surgery at an early stage of lymphedema than low-volume hospitals (P < 0.001 and P = 0.0032 in stages 0 and I in the upper extremity, and P < 0.001 in stages 0 and I in the lower extremity).

Conclusions:

Significant regional variations exist in both the frequency of lymphedema surgery and surgical indication patterns across healthcare facilities, even in an environment where surgical treatment is covered by insurance. Standardized studies evaluating treatment outcomes are needed to assess the appropriateness of treatment indications.

Takeaways

Question: Are there regional disparities in access to lymphedema surgery in Japan, despite insurance coverage?

Findings: A 17.4-fold regional difference in surgical rates was identified. Most procedures were performed at high-volume hospitals, and surgery was more likely to be recommended at early stages.

Meaning: Even under a universal insurance system, unequal access and inconsistent surgical indications exist. A nationwide registration system and standardized treatment criteria are urgently needed to ensure equitable and evidence-based care.

INTRODUCTION

Secondary lymphedema is most commonly seen as a complication of cancer treatment in developed countries, and even after cancer treatment is completed, the risk of developing lymphedema and the impairment of quality of life after onset continue for life.^1–5 Lymphedema is a significant issue for cancer survivors and a major economic burden on national healthcare systems.^6,7 Treatment for lymphedema should be available in acute-care hospitals during cancer treatment and in community medical facilities after cancer treatment has been completed.

Surgical therapy for lymphedema is increasingly recognized as an effective treatment option for managing lymphedema; however, it remains unstandardized, and there are uncertainties regarding its practical feasibility and efficiency, making it insufficiently implemented in society.^8,9 Surgical treatments for lymphedema include lymphaticovenous anastomosis (LVA), vascularized lymph node transplantation (VLNT), liposuction, and tissue resection. LVA and VLNT are categorized as functional procedures, and liposuction and tissue resection are categorized as physical volume reduction procedures. To ensure broad access to and effective provision of surgical treatment options, standardization of treatment methods and the establishment of a collaborative network among medical institutions are essential. Japan is one of the few countries where LVA is covered by health insurance, enabling its widespread use nationwide. However, the lack of a registration system for the surgical treatment of lymphedema hinders a comprehensive understanding of the actual treatment outcomes.

We hypothesized that, despite being a complication of cancer that can occur in anyone, access to lymphedema surgery varies depending on the region. We also considered that analyzing the factors contributing to disparities in treatment opportunities could provide valuable insights for future strategies. The purpose of this study was to assess the current status of facilities offering surgical treatment for lymphedema in Japan through a nationwide survey and to analyze the distribution of these facilities and their associated policies. The results of this study can be applied in various countries as a model for incorporating lymphedema surgery into insurance coverage. In addition, by pointing out current issues, the study emphasized the importance of establishing a case registration system for improving future treatment outcomes.

METHODS

Ethics Review and Questionnaire Implementation Method

This study was approved by the ethics committee of Chiba University School of Medicine (ethics review number M10663). We conducted a nationwide questionnaire survey on conservative and surgical treatments for lymphedema. As the research did not involve the use of personal patient information, an opt-out system was used for its implementation. All designated cancer hospitals in Japan, along with various academic societies related to lymphedema in Japan (Japanese Society of Lymphedema, the Japanese Society of Lymphedema Treatment, the Japanese Society of Lymphology, and the Japanese Society of Plastic and Reconstructive Surgery), agreed to use the survey results to enhance collaboration in lymphedema treatment in Japan and to publish the analysis results in scientific journals. Each facility designated 1 representative to understand the overall treatment situation at their facility and respond on behalf of their facility using Google Forms. Among the collected data, including complex decongestive treatments, the analysis presented in this article focused on questions related to surgical treatment. (See survey, Supplemental Digital Content 1, which displays the English translation of the questionnaire used in this study [original text in Japanese], https://links.lww.com/PRSGO/E463.)

Details of the Survey on Surgical Treatment for Lymphedema

All the facilities that responded were classified into 4 categories: those that do not offer lymphedema treatment, those that provide conservative treatment only, those that offer both conservative and surgical treatment, and those that specialize in surgical treatment. The questionnaire included specific inquiries regarding surgical treatment, as outlined in Supplemental Digital Content 1 (https://links.lww.com/PRSGO/E463) (Q16–Q27). The survey also gathered data on the total number of surgical procedures and the breakdown of each type of surgery conducted in 2022.

Comparison of Differences in Access to Lymphedema Surgical Treatment Between the Regions

As in other countries, Japan has both densely populated urban areas and sparsely populated nonurban areas (Table 1). A comparative analysis was conducted to assess the accessibility of lymphedema surgical treatment across different regions in Japan. The country was divided into 9 regions, namely Hokkaido, Tohoku, Kanto, Hokuriku, Chubu, Kinki, Chugoku, Shikoku, and Kyushu. The number of facilities capable of performing surgical procedures and the total annual procedures performed each year were compared on a per-1-million-population basis. The analysis of surgical procedures was limited to upper and lower limb procedures. LVA and VLNT procedures were categorized as functional procedures, and tissue resection and liposuction procedures were categorized as physical volume reduction procedures. All other responses were excluded from the analysis.

Table 1.

Number of Facilities Offering Surgical Treatment for Lymphedema and Number of Surgical Treatments per Year per Million People in 9 Regions of Japan

Region	Population, in Millions	No. Hospitals, per Million People (Total Number)	No. Surgical Treatments, per Million People (Total Number)
Hokkaido	5.140	1.167 (6)	16.148 (83)
Tohoku	8.426	0.712 (6)	3.204 (27)
Kanto	43.535	0.988 (43)	29.402 (1280)
Hokuriku	5.041	0.992 (5)	15.870 (80)
Chubu	15.845	1.136 (17)	14.137 (224)
Kinki	22.094	0.996 (22)	23.400 (517)
Chugoku	7.137	1.401 (10)	55.766 (398)
Shikoku	3.620	0.829 (3)	6.63 (24)
Kyushu	14.108	1.063 (15)	24.100 (340)

We hypothesized that the number of surgical treatments for lymphedema performed at designated cancer hospitals, which are major providers of cancer treatment, influences the number of lymphedema surgical treatments in the region, and we investigated this effect. Additionally, we hypothesized that the number of procedures performed at high-volume hospitals influences the overall lymphedema surgery treatment in the region and investigated this effect. Furthermore, if factors contributing to regional disparities in lymphedema were identified, we conducted an analysis to elucidate their details. We analyzed the distribution of designated cancer hospitals and nondesignated cancer hospitals across the 9 regions of Japan based on the number of surgical treatment facilities and procedures performed, as well as their classification into high-volume and low-volume hospitals. Additionally, we compared the management of surgical treatment between high-volume and low-volume hospitals. In a previous study using registration data from the Japanese Society of Plastic and Reconstructive Surgery’s National Clinical Database (NCD) for free flap surgery, high-volume centers were defined as facilities performing more than 50 cases annually, whereas low-volume centers performed 49 cases or fewer per year. Therefore, in our study, we defined high-volume hospitals as those conducting more than 50 lymphedema surgical procedures per year.¹⁰

Comparison With the NCD Registration Data

To determine if the responses obtained in this study significantly differed from the current surgical treatment practices for lymphedema in Japan, we compared them to the surgical treatment implementation status in the year of NCD registration. The NCD registration is mandatory for the management of the Japanese Society of Plastic and Reconstructive Surgeons’ specialist system, providing an overview of the number of procedures performed at medical education institutions in Japan. Discrepancies were analyzed between the NCD data and the study results in terms of total annual procedures, designated cancer hospitals, other facilities, high-volume and low-volume hospitals, and the distribution of procedures across the 9 regions of Japan.

Statistical Analysis

The statistical analysis was conducted using JMP version 17 software (SAS Institute Inc., Cary, NC). Spearman rank correlation coefficient was used to assess the relationship between the percentage of procedures performed at designated cancer hospitals and high-volume hospitals in each region and the number of procedures performed per population in each region. To compare the differences in the judgment of surgical indications between high-volume and low-volume hospitals for each of the 5 International Society of Lymphology stages, the Pearson χ² test was performed for each stage with Bonferroni correction applied. The Fisher exact test was used for cells with a value of less than 5. A P value of less than 0.05 was considered statistically significant.

RESULTS

Significant Variations Exist in the Number of Lymphedema Surgical Treatments per Population Across Different Regions

Questionnaires were distributed to 456 cancer hospitals, with responses received from 251 facilities (55.0%). The response rates by region are shown in Table 1. A χ² test revealed a significant regional difference in the response rate (P = 0.0223). Questionnaires were also sent to noncancer hospitals via a mass email from the academic society, with responses received from 121 facilities. Out of the total 372 facilities surveyed, 197 were cancer-designated hospitals and 76 were other medical facilities, totaling 273 facilities offering lymphedema treatment. Among these, 128 facilities conducted at least 1 surgical treatment for lymphedema annually, with 97 being cancer hospitals and 31, other facilities. The total number of surgical treatments for lymphedema performed in 2022 by the responding facilities was 2973. Separate responses were obtained regarding the number of major procedures performed on the upper and lower limbs. Surgical interventions were primarily indicated for the upper extremity in 911 cases (including 857 LVA, 12 VLNT, 24 tissue resection, and 18 liposuction), and for the lower extremity in 2011 cases (including 1798 LVA, 25 VLNT, 104 tissue resection, and 84 liposuction). We investigated the distribution of facilities performing surgical treatment for lymphedema and the number of procedures conducted annually across 9 regions in Japan. The disparity between the regions with the fewest and most facilities offering surgical treatment for lymphedema per million people was less than double (Table 1). Alternatively, there was a significant difference in the number of lymphedema surgical treatments per million people across regions, with the number of procedures per million people in each region as follows: Chugoku, 55.8; Kanto, 29.4; Kyushu, 24.3; Kinki, 23.4; Hokkaido, 16.1; Hokuriku, 15.8; Chubu, 14.1; Shikoku, 8.2; and Tohoku, 3.2 (Table 1). The number of procedures per population in Chugoku, the region with the highest number of procedures, was 17.4 times that of Tohoku, the region with the lowest number of procedures, indicating a substantial difference between regions. The number of procedures per capita was not necessarily higher in large cities with larger actual populations. LVA accounted for the majority of surgical procedures in all regions, and functional procedures accounted for 92.1% of the total number of procedures (Table 2).

Table 2.

Distribution of Surgical Procedures for Upper and Lower Limb Lymphedema in Each Region

Region	Functional Procedures		Physical Volume Reduction Procedures		Total	Functional Procedures Ratio
	LVA	VLNT	Tissue Resection	Liposuction
Hokkaido	84	0	4	1	89	0.94
Tohoku	27	1	1	0	29	0.97
Kanto	1162	24	95	18	1299	0.91
Hokuriku	76	5	1	18	100	0.81
Chubu	171	0	1	0	172	0.99
Kinki	388	1	0	13	402	0.97
Chugoku	391	1	25	48	465	0.84
Shikoku	20	1	0	1	22	0.95
Kyushu	336	4	1	3	344	0.99
Total	2655	37	128	102	2922	0.92

Functional procedure ratio = number of functional procedures/total number of procedures.

The Percentage of Cases of Surgical Treatment for Lymphedema at High-volume Hospitals Is Strongly Correlated With the Number of Cases in the Region

To investigate the factors influencing the variation in the number of procedures per million people, reflecting the frequency of surgical treatment indications across regions, all facilities were categorized into 2 groups based on their designation as cancer hospitals. A total of 1546 procedures (52.0%) were conducted at designated cancer hospitals, whereas 1427 procedures (48.0%) were performed at other hospitals (Table 3, Fig. 1). The proportion of procedures at nondesignated cancer hospitals was notably high in the 2 major metropolitan areas of Kanto and Kinki. In contrast, in Chugoku, which had the highest number of procedures relative to its population, the majority of procedures were conducted at designated cancer hospitals without a clear trend. Out of the 128 facilities analyzed, only 16 (12.5%) were classified as high-volume hospitals, yet these hospitals accounted for 63.0% of all procedures performed (Table 4, Fig. 2). In regions with higher surgery rates (Chugoku, Kanto, Kinki, Kyushu, and Hokkaido), the total number of procedures at high-volume hospitals exceeded those at low-volume hospitals. Conversely, in regions with lower surgery rates (Hokuriku, Chubu, Shikoku, and Tohoku), the majority of procedures were performed at low-volume hospitals. When comparing trends in surgical procedures across regions, physical volume reduction procedures were significantly more frequently performed in the regions with higher surgery rates than in regions with lower surgery rates in the χ² test (P = 0.0106, Table 2).

Table 3.

Annual Number of Procedures Performed at Designated Cancer Hospitals and Other Facilities in Each Region

Region	Designated Cancer Hospital	Other Types of Medical Institutions	Total
Hokkaido	80	3	83
Tohoku	17	10	27
Kanto	524	756	1280
Hokuriku	56	24	80
Chubu	219	5	224
Kinki	191	326	517
Chugoku	365	33	398
Shikoku	24	0	24
Kyushu	70	270	340
Total	1546	1427	2973

Fig. 1.

Annual number of lymphedema procedures per million population in each region of Japan, displayed as donut charts comparing designated cancer hospitals with other institutions.

Table 4.

Annual Number of Procedures Performed at High-volume and Low-volume Hospitals in Each Region

Region	Low-volume Hospital	High-volume Hospital	Total
Hokkaido	67	16	83
Tohoku	27	0	27
Kanto	945	335	1280
Hokuriku	80	0	80
Chubu	169	55	224
Kinki	212	305	517
Chugoku	148	250	398
Shikoku	24	0	24
Kyushu	90	2500	340
Total	1074	1899	2973

Fig. 2.

Annual number of lymphedema procedures per million population in each region of Japan, displayed as donut charts comparing high- and low-volume hospitals.

We analyzed the correlation between the percentage of procedures at designated cancer hospitals and high-volume hospitals and the number of procedures per population. There was no significant correlation between the ratio of designated cancer hospitals (number of designated cancer hospitals/total number of hospitals) and the number of procedures per population in each region (P = 0.22, Table 5). However, a significant and strong correlation was observed between the rate of procedures at high-volume centers (number of procedures at high-volume centers/total number of procedures) and the number of procedures per population in each region (ρ = 0.73, P = 0.03, Table 5).

Table 5.

Analysis of the Impact of the Number of Procedures Performed at Designated Cancer Hospitals and High-volume Hospitals on the Rate of Lymphedema Surgical Treatments per Population

	Surgery per Million Population	Proportion of Designated Cancer Hospitals	Proportion of High-volume Hospitals
Hokkaido	16.15	0.96	0.81
Tohoku	3.20	0.63	0.00
Kanto	29.40	0.41	0.74
Hokuriku	15.87	0.70	0.00
Chubu	14.14	0.98	0.25
Kinki	23.40	0.37	0.59
Chugoku	55.77	0.92	0.63
Shikoku	6.63	1.00	0.00
Kyushu	24.10	0.21	0.74
Spearman rank correlation ρ		−0.45	0.73
P		0.22	0.03

Surgical Treatment Is Recommended at High-volume Hospitals Not Only for Moderate to Advanced Stage Lymphedema but Also for Early-stage Cases

To investigate the reasons for the high number of procedures performed at high-volume hospitals, we analyzed the waiting period for conservative treatment before surgery and the disease stage at which surgery is recommended in both high-volume and low-volume hospitals. Among the 39 centers with a preoperative waiting period policy, high-volume hospitals had a significantly shorter waiting period than low-volume hospitals (5.07 ± 2.74 versus 2.89 ± 1.36 mo, P = 0.028).

For lower limb lymphedema, a higher proportion of high-volume hospitals considered surgery appropriate across all stages of the International Society of Lymphology clinical classification compared with low-volume hospitals. This difference was particularly significant in stage 0 and I (P < 0.001 for stages 0 I, Table 6). A similar trend was observed for upper limb lymphedema, with significant differences observed in stages 0 and I (P < 0.001 for stage 0 and P = 0.0032 for stage I, Table 7).

Table 6.

Clinical Stages Requiring Surgery at High-volume and Low-volume Hospitals for Lower Limb Lymphedema

ISL Stage	Indication for LVA	Low-volume Hospital (n = 16)	High-volume Hospital (n = 107)	P
0	Indicated	8	12	<0.001
	Not indicated	8	95
I	Indicated	15	50	<0.001
	Not indicated	1	57
II	Indicated	16	87	0.0716
	Not indicated	0	20
II late	Indicated	16	90	0.1241
	Not indicated	0	27
III	Indicated	13	52	0.0165
	Not indicated	3	55

The P value was calculated using the Pearson χ² test. If the value was less than 5, the Fisher exact test was applied. A Bonferroni-corrected P value of 0.01 (0.05/5) was used as the criterion for determining significance.

ISL, International Society of Lymphology.

Table 7.

Clinical Stages Requiring Surgery at High-volume and Low-volume Hospitals for Upper Limb Lymphedema

ISL Stage	Indication for LVA	Low-volume Hospital (n = 16)	High-volume Hospital (n = 106)	P
0	Indicated	8	11	<0.001
	Not indicated	8	95
I	Indicated	14	51	0.0032
	Not indicated	2	55
II	Indicated	15	85	0.2955
	Not indicated	1	21
II late	Indicated	16	88	0.1251
	Not indicated	0	18
III	Indicated	11	50	0.1787
	Not indicated	5	56

The P value was calculated with the Pearson χ² test. If the value was less than 5, the Fisher exact test was applied. A Bonferroni-corrected P value of 0.01 (0.05/5) was used as the criterion for determining significance.

ISL, International Society of Lymphology.

The Population Surveyed Reflects the Current State of Surgical Treatment for Lymphedema in Japan

In 2022, there were 177 facilities registered with NCD that collectively performed 2821 procedures. Of the 177 facilities, 124 were designated as cancer hospitals and conducted 1806 procedures, whereas the remaining 53 facilities performed 1015 procedures. High-volume centers, comprising 13 facilities, conducted 1274 procedures, whereas low-volume centers, totaling 164 facilities, performed 1547 procedures. The overall surgery rate per million people in Japan was 22.7. By region, the surgery rates per million people were 33.4 in Chugoku, 30.7 in Hokkaido, 30.3 in Kanto, 23.2 in Kyushu, 20.0 in Kinki, 19.0 in Shikoku, 12.1 in Hokuriku, 11.6 in Chubu, and 3.9 in Tohoku. Chugoku had the highest surgery rate per capita, which was 8.6 times higher than Tohoku, the region with the lowest rate. The number of high-volume hospitals that responded to the questionnaire slightly exceeded the number of NCD-registered hospitals. It was observed that some high-volume hospitals in the survey were not registered with NCD, whereas some low-volume hospitals registered with NCD did not participate in the survey. Despite these discrepancies, the distribution of procedures among regions was consistent between the questionnaire survey and NCD data, highlighting significant regional disparities.

DISCUSSION

In this study, we conducted a nationwide questionnaire survey to investigate the current status of surgical treatment for lymphedema in Japan. Our analysis revealed significant regional disparities in the implementation of surgical treatment, with a maximum variation of 17.4-fold. The primary factor influencing this distribution was the ratio of procedures conducted in high-volume hospitals. Regions with lower rates of surgical treatment have smaller populations compared with metropolitan areas, where high-volume hospitals are more prevalent. Furthermore, it was suggested that regions with fewer procedures per capita tend to have fewer options for surgical procedures. These suggest that patients in these regions may need to travel long distances to access surgical treatment for lymphedema, despite the fact that lymphatic surgery for lymphedema is covered by insurance. Given the chronic and progressive nature of lymphedema requiring long-term follow-up, establishing partnerships between designated cancer hospitals and other medical institutions, as well as training healthcare professionals in each region, will be essential. It is desirable to establish a focused education system targeting current low-volume centers so that high-volume centers are distributed in each region located in areas where patients can easily visit.

In general, surgical treatment is recommended only after adequate conservative therapy has been administered.¹¹ The findings of this study demonstrate that high-volume hospitals tend to have shorter preoperative conservative treatment periods and a broader range of surgical indications for lymphedema treatment. The preoperative conservative treatment period was significantly shorter in high-volume hospitals. These results might suggest that preoperative conservative treatment for lymphedema may achieve plateau treatment outcomes in a short period of time in patients with early clinical stages. However, these data merely indicate that treatment indications vary between facilities and are not standardized, and do not demonstrate the effectiveness of early treatment. Although some studies from high-volume centers suggest the effectiveness of surgical treatment for early-stage lymphedema, the standardization of surgical interventions for this condition lacks strong evidence.^12,13 Future research should focus on accumulating treatment data from multiple institutions through a registration system to establish the appropriate stage for surgical intervention in lymphedema and to determine effective preoperative management strategies.

A limitation of this study is that the survey data collected are not representative of the entire population of Japan, and the responses are self-reported by the respondents. The response rate for cancer hospitals as a whole was 55%, and there were regional variations in the response rates. These biases indicate that there are limitations to the accuracy of the results obtained from questionnaire surveys in terms of understanding the distribution. To assess the validity of the data collected in this study in relation to the overall state of surgical treatment dissemination and facility distribution in the country as a whole, we cross-referenced the treatment information recorded in the NCD. The NCD is a database that medical training institutions affiliated with the Japanese Society of Plastic and Reconstructive Surgery are required to register to obtain specialist certification. The number of facilities and high-volume hospitals identified in this study closely aligned with the data from the NCD, suggesting that the data collected in this study are reliable and suitable for analysis. However, there is a critical limitation in the data collected in this study: it is impossible to analyze treatment outcomes using the data obtained in this study. Currently, there is no standardized method for evaluating treatment outcomes in lymphedema surgery, making it impossible to collect data widely to verify treatment effects. Data on treatment efficacy are also essential when considering the indications for the surgical treatment of lymphedema. This is an important issue that must be addressed to ensure the quality of medical care provided under insurance coverage. We argue that the establishment of a registration system based on standardized criteria is necessary.

CONCLUSIONS

The data from this study revealed regional disparities in the availability of surgical treatment opportunities for patients with lymphedema, as well as variations in the treatment indications between the institutions in a country where lymphedema surgery is covered by insurance. In every country, it is important to establish a system that ensures that patients with secondary lymphedema have access to good treatment regardless of where they live. To understand the current state of treatment and address disparities, it is essential to establish collaboration between cancer treatment facilities and plastic surgeons, as well as to train skilled plastic surgeons. These are universal challenges that must be addressed worldwide. In the future, to improve the treatment of lymphedema in cancer survivors, it is crucial to ensure equitable access to surgical interventions and to standardize surgical treatment policies. The implementation of a registration system for lymphedema surgical procedures and the systematic collection of treatment outcomes are essential steps toward achieving uniformity in treatment indications and procedures in the future.

DISCLOSURES

The authors have no financial interest to declare in relation to the content of this article. This study was funded by the Health and Labour Sciences Research Grant for Cancer Policy Research (23EA1019) from the Ministry of Health, Labour and Welfare, Japan.