Automated thermographic detection of blood vessels for DIEP flap reconstructive surgery.

PURPOSE: Inadequate perfusion is the most common cause of partial flap loss in tissue transfer for post-mastectomy breast reconstruction. The current state-of-the-art uses computed tomography angiography (CTA) to locate the best perforators. Unfortunately, these techniques are expensive and time-consuming and not performed during surgery. Dynamic infrared thermography (DIRT) can offer a solution for these disadvantages. METHODS: The research presented couples thermographic examination during DIEP flap breast reconstruction with automatic segmentation approach using a convolutional neural network. Traditional segmentation techniques and annotations by surgeons are used to create automatic labels for the training. RESULTS: The network used for image annotation is able to label in real-time on minimal hardware and the labels created can be used to locate and quantify perforator candidates for selection with a dice score accuracy of 0.8 after 2 min and 0.9 after 4 min. CONCLUSIONS: These results allow for a computational system that can be used in place during surgery to improve surgical success. The ability to track and measure perforators and their perfused area allows for less subjective results and helps the surgeon to select the most suitable perforator for DIEP flap breast reconstruction.

Skin Cancer Detection Using Infrared Thermography: Measurement Setup, Procedure and Equipment.

Infrared thermography technology has improved dramatically in recent years and is gaining renewed interest in the medical community for applications in skin tissue identification applications. However, there is still a need for an optimized measurement setup and protocol to obtain the most appropriate images for decision making and further processing. Nowadays, various cooling methods, measurement setups and cameras are used, but a general optimized cooling and measurement protocol has not been defined yet. In this literature review, an overview of different measurement setups, thermal excitation techniques and infrared camera equipment is given. It is possible to improve thermal images of skin lesions by choosing an appropriate cooling method, infrared camera and optimized measurement setup.

Dynamic Infrared Thermography (DIRT) in DIEP flap breast reconstruction: A clinical study with a standardized measurement setup.

OBJECTIVE: Breast reconstructions with perforator flaps from the lower abdomen, commonly known as Deep Inferior Epigastric artery Perforator flap (DIEP-flap), have become the golden standard for autologous breast reconstruction after breast amputation. During this surgical procedure multiple challenging steps are encountered such as the selection of a suitable perforator that provides sufficient blood supply for the flap, surgical dissection of the chosen perforator, determination of perfusion area of the chosen perforator, microsurgical anastomosis, flap inset and shaping the flap into a breast. The current gold standard for perforator mapping is Computed Tomography Angiography (CTA). However, this is a relatively expensive imaging modality that requires intravenous contrast injection and exposes patients to ionizing radiation. More recently, Dynamic Infrared Thermography (DIRT) has been proposed as an alternative imaging modality for perforator identification. DIRT appears to be an ideal alternative technique not only for the identification of the dominant perforators, but also for the mapping of the individual influence of each perforator on the flap perfusion, to monitor integrity of the perforator after dissection and to monitor the patency of the pedicle of the free flap after the anastomosis, during flap inset and flap shaping. STUDY DESIGN: In this clinical study we present the results of the use of DIRT in 33 DIEP-flaps in 21 patients after mastectomy. The same standardized measurement set-up was used for all the flaps in the pre-, intra- and postoperative period. RESULTS: In the pre-operative period DIRT confirmed the location of the 69 perforators shown on the CTA. In the intra-operative period the rate and pattern of rewarming was successfully observed. One perforator was severely damaged during dissection and the DIEP flap was converted to a Muscle Sparing free Transverse Rectus Abdominis Muscle (TRAM) flap, after viability check of the flap by DIRT. DIRT diagnosed one kinking of the pedicle after microsurgical anastomosis. Two flaps were monitored successfully post-operatively. All 33 breast reconstructions were with good outcome. CONCLUSION: The use of DIRT with our standardized measurement setup is a useful, non-invasive tool during breast reconstructions with free DIEP-flaps in all the phases of the reconstruction (pre-, intra- and post-operative). This study confirms that DIRT with the standardized measurement setup provides information on perforator location, blood supply and patency of the anastomosis without interference with the operating surgeon.

DIEP flap breast reconstructions: thermographic assistance as a possibility for perforator mapping and improvement of DIEP flap quality.

In the modern world, one-third or more of breast cancer patients still undergo uni- or bilateral mastectomy. Breast cancer patients, in general, have a good prognosis and long-term survival. Therefore, the treatment must not only focus on survival but also on the quality of life. Breast reconstruction with an autologous free deep inferior epigastric artery perforator (DIEP) flap is one of the preferred options after mastectomy. A challenging step in this procedure is the selection of a suitable perforator that provides sufficient blood supply for the flap to prevent necrosis after anastomosis. In this pilot study, the possibilities for dynamic infrared thermography (DIRT) are investigated to select the best suitable perforator. The measurements are done with external cooling in the preoperative stage to accurately predict the location of the dominant perforators. During the surgery, in the peroperative stage, measurements are done for mapping the influence of a specific perforator on the perfused areas of the abdominal flap. Perforators are sequentially closed and opened again to map the influence of that perforator on the vascularization of the flap, visualized with the help of the thermographic camera. The acquired steady-state thermal images could help decide which parts of the abdominal flap to use for the reconstruction so that the chance of (partial) necrosis is reduced. In the postoperative stage, DIRT could visualize the arterial and or venous thrombosis before they become clinically obvious as (partial) necrosis. At present DIRT seems to be a valuable investigation for the pre-, per-, and postoperative phases of DIEP-flap reconstructions. Large, high-quality clinical studies are needed to determine its definitive role.