Postoperative free flap monitoring in reconstructive surgery—man or machine?

Abstract

Free tissue transfer is widely used for the reconstruction of complex tissue defects. The survival of free flaps depends on the patency and integrity of the microvascular anastomosis. Accordingly, the early detection of vascular comprise and prompt intervention are indispensable to increase flap survival rates. Such monitoring strategies are commonly integrated into the perioperative algorithm, with clinical examination still being considered the gold standard for routine free flap monitoring. Despite its widespread acceptance as state of the art, the clinical examination also has its pitfalls, such as the limited applicability in buried flaps and the risk of poor interrater agreement due to inconsistent flap (failure) appearances. To compensate for these shortcomings, a plethora of alternative monitoring tools have been proposed in recent years, each of them with inherent strengths and limitations. Given the ongoing demographic change, the number of older patients requiring free flap reconstruction, e.g., after cancer resection, is rising. Yet, age-related morphologic changes may complicate the free flap evaluation in elderly patients and delay the prompt detection of clinical signs of flap compromise. In this review, we provide an overview of currently available and employed methods for free flap monitoring, with a special focus on elderly patients and how senescence may impact standard free flap monitoring strategies.

Second sensor to improve near‐infrared spectroscopy flap monitor utility: A prospective study

“…There were only seven sentinel events, with the majority being related to hematoma formation. that in a darker complected patient population, clinical examination alone also has potential for monitoring issues and thus implementing objective data should be a focus for further investigation and may be impetus to perform dual monitoring in this patient population (Knoedler et al, 2023). In our study population only three of the 48 patients studied were Black or dark-skinned and none of these patients developed complications.…”

“…Older data demonstrated that NIRS technology had been shown to have reduced efficacy in darker skinned patients, however, in a recent session of the American Association for Hand Surgery, data were presented evaluating the use of NIRS for detecting induced digital ischemia in light and dark‐skinned patients and found that NIRS was accurate in predicting digital ischemia in both clinical scenarios (Isaac Fleming et al, n.d.; Wassenaar & Van den Brand, 2005). Prior work has demonstrated that in a darker complected patient population, clinical examination alone also has potential for monitoring issues and thus implementing objective data should be a focus for further investigation and may be impetus to perform dual monitoring in this patient population (Knoedler et al, 2023). In our study population only three of the 48 patients studied were Black or dark‐skinned and none of these patients developed complications.…”

The Impact of Technical Innovations and Donor-Site Mesh Repair on Autologous Abdominal-Based Breast Reconstruction—A Retrospective Analysis

“…In the current study, postoperative flap monitoring was performed through clinical examination and Doppler ultrasound. Further technical innovations such as dynamic infrared thermography, hyperspectral imaging, or laser speckle contrast analysis have been proposed to support and refine flap monitoring in recent years [41]. Although clinical examination in combination with acoustic Doppler sonography is still considered the gold standard, novel technologies can objectify the assessment and support the examiner in decision making.…”

From bench to bedside – current clinical and translational challenges in fibula free flap reconstruction

“…Further, the specific light source used to inspect the FFF and dark skin tone represent additional pitfalls when evaluating FFF failure ( 137 , 139 , 140 ). Monitoring of buried FFFs is even more challenging as there is no direct access postoperatively to the bony segment and the use of ADS is commonly limited to superficial vessels ( 141 ). To overcome such obstacles novel strategies in postoperative free flap monitoring were developed, namely (i) color duplex ultrasonography (CDS), (ii) flow coupler (FC), (iii) implantable doppler (ID), (iv) laser doppler flowmetry (LDF), (v) near-infrared spectroscopy (NIRS), and (vi) hyperspectral imaging (HSI).…”