Dr Swanson is a plastic surgeon in private practice in Leawood, KS.
Ann Plast Surg. 2023 Aug 1;91(2):301-306. doi: 10.1097/SAP.0000000000003549. Epub 2023 Jun 1.
The Keller funnel (Allergan; AbbVie Inc, North Chicago, IL) is commonly used to insert breast implants as part of a "no touch" protocol. Many plastic surgeons believe that this device reduces the risk of capsular contracture. This review was undertaken to evaluate the evidence regarding any reduction in capsular contracture rate, other possible benefits, safety and to investigate financial conflict of interest.
A PubMed electronic literature search was conducted to identify studies comparing capsular contracture rates with and without the Keller funnel. The Open Payments database was accessed for information regarding corporate payments to plastic surgeons.
Two retrospective historical case-control studies, published in 2016 and 2018, were identified. Both studies had important confounders, including implant type and placement, which are known to affect capsular contracture rates. Major financial conflicts of interest were present. Most authors did not disclose these conflicts, which totaled more than $1 million and were usually categorized as gifts from Allergan, which purchased the Keller funnel in 2017.
Financial conflict of interest, along with publication bias, creates a bias toward publication of positive findings. No reliable evidence supports a "no touch" technique, which is a misnomer because manual handling of implants is unavoidable, even when using a funnel. Recent microbiological studies do not support a specific bacterial etiology for capsular contracture. No evidence supports contamination by the surgeon touching the implant. Among other proposed benefits, such as reduced operating time, less contamination, a shorter incision, and less implant trauma, only a slightly shorter incision (1 cm) is supported by the evidence. The cost is $150 per funnel.
No reliable evidence supports the use of a Keller funnel to reduce the risk of capsular contracture. Both supportive studies contain confounding variables, limited follow-up time, and no plausible scientific basis for efficacy. Institutional review board approval of studies on human subjects is not optional. Financial conflicts of interest are extraordinary in their magnitude and potential for creating undue influence. Greater transparency and honest disclosures are needed.
凯勒漏斗（Allergan；AbbVie Inc，芝加哥，IL）通常用于插入乳房植入物，作为“无接触”方案的一部分。许多整形外科医生认为该装置降低了包膜挛缩的风险。本综述旨在评估有关包膜挛缩发生率降低、其他可能的益处、安全性的证据，并调查财务利益冲突。
对比较使用和不使用凯勒漏斗的包膜挛缩发生率的研究进行了 PubMed 电子文献检索。访问了 Open Payments 数据库，以获取有关向整形外科医生支付的公司款项的信息。
确定了 2016 年和 2018 年发表的两项回顾性历史病例对照研究。这两项研究都存在重要的混杂因素，包括植入物类型和位置，这些因素已知会影响包膜挛缩的发生率。存在重大财务利益冲突。大多数作者并未披露这些冲突，总额超过 100 万美元，通常归类为 Allergan 的礼物，Allergan 于 2017 年收购了凯勒漏斗。
财务利益冲突以及发表偏倚导致发表阳性结果的偏见。没有可靠的证据支持“无接触”技术，因为即使使用漏斗，也不可避免地要手动处理植入物。最近的微生物学研究并不支持包膜挛缩的特定细菌病因。没有证据支持外科医生接触植入物会造成污染。除了减少手术时间、减少污染、切口较短和减少植入物创伤等其他好处外，仅证据支持切口稍短（1 厘米）。成本为每个漏斗 150 美元。
没有可靠的证据支持使用凯勒漏斗来降低包膜挛缩的风险。两项支持性研究都包含混杂变量、随访时间有限，以及没有有效的科学依据支持疗效。机构审查委员会对人体研究的批准并非可选。财务利益冲突的规模和潜在影响非常大。需要更大的透明度和诚实披露。
