The diagnosis and treatment of peripheral lymphedema: 2020 Consensus Document of the International Society of Lymphology.

This International Society of Lymphology (ISL) Consensus Document is the latest revision of the 1995 Document for the evaluation and management of peripheral lymphedema (1). It is based upon modifications: [A] suggested and published following the 1997 XVI International Congress of Lymphology (ICL) in Madrid, Spain (2), discussed at the 1999 XVII ICL in Chennai, India (3), and considered confirmed at the 2000 (ISL) Executive Committee meeting in Hinterzarten, Germany (4); [B] derived from integration of discussions and written comments obtained during and following the 2001 XVIII ICL in Genoa, Italy as modified at the 2003 ISL Executive Committee meeting in Cordoba, Argentina (5); [C] suggested from comments, criticisms, and rebuttals as published in the December 2004 issue of Lymphology (6); [D] discussed in both the 2005 XX ICL in Salvador, Brazil and the 2007 XXI ICL in Shanghai, China and modified at the 2008 Executive Committee meeting in Naples, Italy (7,8); [E] modified from discussions and written comments from the 2009 XXII ICL in Sydney, Australia, the 2011 XXIII ICL in Malmö, Sweden, the 2012 Executive Committee Meetings (9); [F] discussions at the 2013 XXIV ICL in Rome, Italy, and the 2015 XXV ICL in San Francisco, USA, as well as multiple written comments and feedback from Executive Committee and other ISL members during the 2016 drafting (10); informal discussions at the XXVI ICL in Barcelona, Spain; and [G] discussions at a dedicated, focused Post-Congress session at the XXVII ICL in Iguazú, Argentina (2019) followed by additional written comments from the Executive Committee and others. The document attempts to amalgamate the broad spectrum of protocols and practices advocated worldwide for the diagnosis and treatment of peripheral lymphedema into a coordinated proclamation representing a "Consensus" of the international community based on various levels of evidence. The document is not meant to override individual clinical considerations for complex patients nor to stifle progress. It is also not meant to be a legal formulation from which variations define medical malpractice. The Society understands that in some clinics the method of treatment derives from national standards while in others access to medical equipment, technical expertise, and supplies is limited; therefore, the suggested treatments might be impractical. Adaptability and inclusiveness does come at the price that members can rightly be critical of what they see as vagueness or imprecision in definitions, qualifiers in the choice of words (e.g., the use of "may... perhaps... unclear", etc.) and mentions (albeit without endorsement) of treatment options supported by limited hard data. Most members are frustrated by the reality that NO treatment method has really undergone a satisfactory meta-analysis (let alone rigorous, randomized, stratified, long-term, controlled study). With this understanding, the absence of definitive answers and optimally conducted clinical trials, and with emerging technologies and new approaches and discoveries on the horizon, some degree of uncertainty, ambiguity, and flexibility along with dissatisfaction with current lymphedema evaluation and management is appropriate and to be expected. We continue to struggle to keep the document concise while balancing the need for depth and details. With these considerations in mind, we believe that this 2020 version presents a Consensus that embraces the entire ISL membership, rises above national standards, identifies and stimulates promising areas for future research, and represents the best judgment of the ISL membership on how to approach patients with peripheral lymphedema in the light of currently available evidence. Therefore, the document has been and should continue to be challenged and debated in the pages of Lymphology (e.g., as Letters to the Editor) and ideally will remain a continued focal point for robust discussion at local, national and international conferences in lymphology and related disciplines. We further anticipate as experience evolves and new ideas and technologies emerge that this "living document" will undergo further periodic revision and refinement as the practice and conceptual foundations of medicine and specifically lymphology change and advance. Copyright by International Society of Lymphology.