Indocyanine green applications in plastic surgery: A review of the literature

A supramolecular colloidal system based on folate-conjugated β-cyclodextrin polymer and indocyanine green for enhanced tumor-targeted cell imaging in 2D culture and 3D tumor spheroids

Indocyanine green (ICG) is an FDA-approved medical diagnostic agent that is widely used as a near-infrared (NIR) fluorescent imaging molecular probe. However, ICG tends to aggregate to form dimers or H-aggregates in water and lacks physical and optical stability, which greatly decreases its absorbance and fluorescence intensity in various applications. Additionally, ICG has no tissue- or tumor-targeting properties, and its structure is not easy to modify, which has further limited its application in cancer diagnosis. In this study, we addressed these challenges by developing a supramolecular colloidal carrier system that targets tumor cells. To this end, we synthesized a water-soluble β-cyclodextrin (β-CD) polymer conjugated with folate (FA), denoted PCD-FA, which is capable of forming inclusion complexes with ICG in water through host-guest interactions between the β-CD moieties and ICG molecules. The inclusion complexes formed by PCD-FA and ICG, called ICG@PCD-FA, dispersed stably in solution as colloidal nanoparticles, greatly improving the physical and optical properties of ICG by preventing ICG dimer formation, where ICG appeared as monomers and even J-aggregates. This resulted in stronger and more stable absorption at a longer wavelength of 900 nm, which may allow for deeper tissue penetration and imaging with reduced interference from biological tissues' autofluorescence. Moreover, ICG@PCD-FA showed a targeting effect on folate receptor-positive (FR+) tumor cells, which specifically highlighted FR+ cells via NIR endoscopic imaging. Notably, ICG@PCD-FA further improved permeation and accumulation in FR+ 3D tumor spheroids. Therefore, this ICG@PCD-FA supramolecular colloidal system may have a great potential for use in tumor NIR imaging and diagnostic applications.

Head and neck reconstruction with the superficial circumflex iliac artery perforator (SCIP) free flap: Lessons learned after 73 cases

BACKGROUND

Head and neck tissue defects after ablative surgery often require complex and composite reconstructions. The superficial circumflex iliac artery perforator (SCIP) flap is an extremely versatile perforator-based flap with minimal donor site morbidity, which may represent the optimal procedure in this setting. Over the last 5 years, we collected a large base of experience, including both simple and chimeric SCIP-based reconstruction, making this flap our first choice for head and neck reconstructions.

PATIENTS AND METHODS

Seventy-three patients undergoing ablative head and neck surgery for oncologic pathologies were treated by means of a SCIP flap reconstruction. Patients' mean age was 67 years old (range 37-89), 51 were males and 22 were females. Fifty-eight flaps were simple and 15 were chimeric reconstruction patterns. Indocyanine green perfusion imaging was performed in all cases.

RESULTS

All the patients were successfully treated with no flap losses were encountered. Twelve patients encountered postoperative complications: in four cases revision surgery was required for venous congestion, while the remaining cases were managed conservatively (four wound dehiscence and three infections). No patients showed donor site complications. The mean follow-up period was 11 months (range 3-24).

CONCLUSIONS

Our case series demonstrates the reliability and versatility of the SCIP flap for different kinds of head and neck reconstructions. The chimeric options combined with bone, double skin paddle, and muscle offer a broad variety of functional reconstructive solutions for complex head and neck surgeries. Intraoperative indocyanine green perfusion examination provides a valuable tool to assess and ascertain proper vascularization and post-anastomosis vessel patency in complex microvascular flap-based reconstructions.

A Shaped Pectoralis Major Muscle Flap under Indocyanine Green Fluorescence Angiography for Sternal Wound Infection

The treatment of a sternal wound infection is challenging because it requires radical debridement and reconstruction with a well-vascularized flap. The defects after debridement are three-dimensionally complex, especially if synthetic grafts are involved. Although the pectoralis major muscle (PMM) flap is useful for reconstruction, it is difficult to fill up the complex dead space surrounding the vascular prosthesis when using a conventional PMM flap. Herein, we describe a new technique of splitting and shaping the PMM flap to fit the complex defect. Intraoperative indocyanine green fluorescence angiography was used to assess dynamic blood flow of the PMM supplied by internal mammary artery perforators. This technique allows the PMM flap to be split and shaped to securely fit the dead space, which may improve the healing rate.

The use of superficial circumflex iliac perforator (SCIP) pedicle vein for lymphovenous anastomosis to treat inguinal lymphatic fistula: A case report

The management of lymphatic fistulas following surgical procedures, in particular after inguinal lymphadenectomy, represents a significant clinical challenge. The current case report shows the novel use of the superficial circumflex iliac perforator (SCIP) pedicle vein for lymphovenous anastomosis (LVA) to treat a chronic inguinal lymphatic fistula in a 58-year-old male patient. This patient had developed a persistent lymphorrhea and wound dehiscence after a right inguinal lymph node biopsy performed for oncological reasons 1.5 months before. Pre-operative assessment with indocyanine green (ICG) lymphography confirmed a substantial lymphatic contribution to the wound discharge, thus guiding the surgical strategy. During the procedure, a pedicled tissue segment containing the SCIV was dissected and utilized to fill the wound's dead space and facilitate LVA with the leaking lymphatic vessel. Notably, a coupler device was employed for the anastomosis due to the large caliber of the lymphatic vessel involved, a technique not commonly reported in lymphatic surgeries. The result of the procedure was successful, with intra-operative ICG imaging confirming the patency of the anastomosis. After surgery the wound healed without complications. This case illustrates the potential of SCIV employment in lymphatic fistula repair in the inguinal region. While further research is needed to validate these findings, this report provides an unconventional approach to a relatively common problem in clinical practice.

Biomimetic NIR-II fluorescent proteins created from chemogenic protein-seeking dyes for multicolor deep-tissue bioimaging

Near-infrared-I/II fluorescent proteins (NIR-I/II FPs) are crucial for in vivo imaging, yet the current NIR-I/II FPs face challenges including scarcity, the requirement for chromophore maturation, and limited emission wavelengths (typically < 800 nm). Here, we utilize synthetic protein-seeking NIR-II dyes as chromophores, which covalently bind to tag proteins (e.g., human serum albumin, HSA) through a site-specific nucleophilic substitution reaction, thereby creating proof-of-concept biomimetic NIR-II FPs. This chemogenic protein-seeking strategy can be accomplished under gentle physiological conditions without catalysis. Proteomics analysis identifies specific binding site (Cys 477 on DIII). NIR-II FPs significantly enhance chromophore brightness and photostability, while improving biocompatibility, allowing for high-performance NIR-II lymphography and angiography. This strategy is universal and applicable in creating a wide range of spectrally separated NIR-I/II FPs for real-time visualization of multiple biological events. Overall, this straightforward biomimetic approach holds the potential to transform fluorescent protein-based bioimaging and enables in-situ albumin targeting to create NIR-I/II FPs for deep-tissue imaging in live organisms.

Qualitative use of ICG angiography and lymphography in periorbital surgery

PURPOSE

Open imaging fluorescence devices have been utilized in surgical oncology, vascular and plastic surgery; however, the role of indocyanine green (ICG) in periorbital surgery and lymphatics has not been explored.

METHODS

A prospective, single-center diagnostic study was conducted from 2021 to 2022 utilizing ICG to assess both the periorbital vasculature and lymphatics. Fluorescence was captured with open-imaging fluorescent devices. For ICG angiography, a total of 5-10 mg of ICG was given intravenously at various time points to visualize intraoperative blood flow to eyelid flaps, vascular tumors, or extraocular muscles. For ICG lymphography, 0.03-0.06 mg of ICG was injected subcutaneously to visualize the periorbital and facial lymphatic drainage.

RESULTS

Twenty-two patients underwent ICG angiography. Periorbital vascular supply was seen in eyelid reconstructions (n = 8), anophthalmic reconstructions (n = 2), lacrimal gland tumors (n = 2), orbital venous malformations (n = 2), tumor metastasis (n = 1) and benign tumors (n = 1). The anterior ciliary arteries were visualized to the extraocular muscles in fracture repairs (n = 3) and muscle biopsies (n = 2). Ten patients underwent ICG lymphangiography highlighting the global periorbital lymphatic system.

CONCLUSION

ICG allows for visualization of the vasculature of extraocular muscles and tumors, assessing perfusion of flaps during reconstruction and the global periorbital lymphatic drainage pathways.

How to Treat a Cyclist's Nodule?-Introduction of a Novel, ICG-Assisted Approach

BACKGROUND

Perineal nodular induration (PNI) is a benign proliferation of the soft tissue in the perineal region that is associated with saddle sports, especially road cycling. The etiology has not been conclusively clarified; however, repeated microtrauma to the collagen and subcutaneous fat tissue by pressure, vibration and shear forces is considered a mechanical pathomechanism. In this context, chronic lymphedema resulting in the development of fibrous tissue has been suggested as an etiological pathway of PNI. The primary aim of this study was to introduce and elucidate a novel operative technique regarding PNI that is assisted by indocyanine green (ICG). In order to provide some context for this approach, we conducted a comprehensive review of the existing literature. This dual objective aimed to contribute to the existing body of knowledge while introducing an innovative surgical approach for managing PNI.

METHODS

We reviewed publications relating to PNI published between 1990 and 2023. In addition to the thorough review of the literature, we presented our novel surgical approach. We described how this elaborate approach for extensive cases of PNI involves surgical excision combined with tissue doubling and intraoperative ICG visualization for exact lymphatic vessel obliteration to minimize the risk of recurrence based on the presumed context of lymphatic congestion.

RESULTS

The literature research yielded 16 PubMed articles encompassing 23 cases of perineal nodular induration (PNI) or cyclist's nodule. Of these, 9 cases involved females, and 14 involved males. Conservative treatment was documented in 7 cases (30%), while surgical approaches were reported in 16 cases (70%). Notably, a limited number of articles focused on histopathological or radiological characteristics, with a shortage of structured reviews on surgical treatment options. Only two articles provided detailed insights into surgical techniques. Similarly to the two cases of surgical intervention identified in the literature research, the post-operative recovery in our ICG assisted surgical approach was prompt, meaning a return to cycling was possible six weeks after surgery. At the end of the observation period (twelve months after surgery), regular scar formation and no signs of recurrence were seen.

CONCLUSION

We hope that this article draws attention to the condition of PNI in times of increasing popularity of cycling as a sport. We aimed to contribute to the existing body of knowledge through our thorough review of the existing literature while introducing an innovative surgical approach for managing PNI. Due to the successful outcome, the combination of tissue doubling, intraoperative ICG visualization and postoperative negative wound therapy should be considered as a therapeutic strategy in cases of large PNI.

An Effective Approach to Collecting Lymph Vessels Using a Small Diameter Wire for Lymphaticovenous Anastomosis in Upper Limb Lymphedema

Lymphaticovenous anastomosis (LVA), which involves connecting lymphatic vessels to veins under a microscope, is widely performed around the world as a surgical treatment for lymphedema due to its relatively low patient burden and consistent efficacy. One of the crucial points of LVA is identifying suitable lymphatic vessels from among many lymphatic vessels and connecting them at the most effective site, but in practice, this is not easy to do. To overcome this issue, we have been able to effectively drain lymph by connecting lymphatic vessels to veins just before the occluded site using a lymphatic wire that was just recently developed in Japan. The device guides the subcutaneous deep collecting lymphatic vessels from the peripheral relatively superficial lymphatic vessels. While this special wire is typically adapted in the lower limbs, we have confirmed its effectiveness in upper limb lymphedema as well. Overall, this approach shows promise for improving the accuracy and success rates of LVA procedures, which can have significant benefits for patients with upper limb lymphedema. In this article, we share our experience using lymphatic wire for upper limb lymphedema cases.

Mastectomy Skin Flap Stability Prediction Using Indocyanine Green Angiography: A Randomized Prospective Trial

BACKGROUND

The first step in successful breast reconstruction is obtaining a stable skin flap. Indocyanine green (ICG) angiography has recently been studied for its value and usefulness in predicting the stability of skin flaps; however, relevant prospective studies of its clinical efficacy are limited.

OBJECTIVES

The aim of this study was to prospectively investigate the clinical impact on breast reconstruction outcomes of the intraoperative use of ICG angiography.

METHODS

Between March and December 2021, 64 patients who underwent immediate breast reconstruction at the authors' institution were prospectively enrolled. They were classified into an experimental group (n = 39; undergoing ICG angiography) and a control group (n = 25; undergoing gross inspection alone). In the absence of viable skin, debridement was performed at the surgeon's discretion. Skin complications were categorized as skin necrosis (the transition of the skin flap to full-thickness necrosis) or skin erosion (a skin flap that did not deteriorate or become necrotic but lacked intactness).

RESULTS

The 2 groups were matched in terms of basic demographic characteristics and incision line necrosis ratio (P = .354). However, intraoperative debridement was significantly more frequent in the experimental group (51.3% vs 48.0%, P = .006). The authors additionally classified skin flap necrosis into partial- and full-thickness necrosis, with a higher predominance of partial-thickness necrosis in the experimental vs control group (82.8% vs 55.6%; P = .043).

CONCLUSIONS

Intraoperative ICG angiography does not directly minimize skin erosion or necrosis. However, compared to gross examination alone, it enables surgeons to perform a more active debridement during surgery, thereby contributing to a lower incidence of advanced skin necrosis. In breast reconstruction, ICG angiography may be useful for assessing the viability of the postmastectomy skin flap and could contribute to successful reconstruction.

LEVEL OF EVIDENCE

4.

Outcome analysis of free flap reconstruction for head and neck cancer with intraoperative indocyanine green angiography

BACKGROUND

Intraoperative indocyanine green (ICG) angiography is used in free flap surgery to evaluate the patency of vessel anastomosis. This study evaluated the outcomes of intraoperative ICG angiography in free flap surgery for head and neck cancer.

MATERIALS AND METHODS

This was a retrospective study of free flap reconstruction for head and neck cancer performed between 2015 and 2021. The outcomes analyzed were the total flap failure rate, re-exploration rate, and flap salvage rate. Differences in outcomes were compared in patients treated using intraoperative ICG angiography and those treated without.

RESULTS

Of the 520 free flap surgeries in the 486 enrolled patients, 259 cases underwent intraoperative ICG angiography. In this group, there were 10 (3.9%) cases of total flap failure. In the non-ICG group, there were 22 cases (8.4%). There were 35 (13.5%) cases requiring re-exploration in the ICG group and 40 (15.3%) in the non-ICG group. The difference was not statistically significant. The flap salvage rate was 75.8% (25/33) in the ICG group and 51.4% (18/35) in the non-ICG group, which was a significant difference.

CONCLUSION

We found that free flap surgery with intraoperative ICG angiography significantly decreased total flap failure rate and significantly increased salvage rate but did not significantly affect the re-exploration rate.

Dermal Nipple-Areola Complex Perfusion through Circumareolar Scars: A Delay Model in Two-Stage Nipple-Sparing Mastectomy

BACKGROUND

Nipple-sparing mastectomy (NSM) has evolved as a standard surgical option. The NSM complication rate remains high in large breasts. To reduce the risk of necrosis, several authors have proposed delayed procedures to enhance blood supply to the nipple-areola complex (NAC). The purpose of this study in a porcine model was to show adequate redirection of NAC perfusion by neoangiogenesis through circumareolar scars.

METHODS

Delayed two-staged NSM was simulated in 52 nipples (six pigs) with a 60-day interval. The nipples underwent a full-thickness, circumareolar incision onto the muscular fascia, with preservation of underlying glandular perforators. After 60 days, NSM was performed through a radial incision. A silicone sheet was introduced in the mastectomy plane to prevent NAC revascularization by wound bed imbibition. Digital color imaging was used to assess necrosis. Near-infrared fluorescence with indocyanine green was used to assess perfusion patterns and perfusion in real time.

RESULTS

No NAC necrosis was seen after 60 days' delay in any nipples. In all nipples, indocyanine green angiography showed complete alteration of the NAC vascular perfusion pattern from subjacent gland to a capillary fill following devascularization, exhibiting a predominant arteriolar capillary blush without distinct larger vessels.

CONCLUSIONS

NAC delay reverses glandular perfusion to adequate dermal neovascularization. Neovascularization through full-thickness scars provides sufficient dermal perfusion after 60 days' delay. Identical staged delay in humans may be a surgically safe NSM option and could broaden therapeutic NSM indications in difficult breasts. Large clinical trials are necessary to provide identical results in human breasts.

CLINICAL RELEVANCE STATEMENT

NAC delay reverses glandular perfusion to adequate dermal neovascularization. Neovascularization through full-thickness scars provides sufficient dermal perfusion after 60 days of delay. Identical staged delay in humans may be a surgically safe NSM option.

Prepectoral Versus Subpectoral Implant-Based Reconstruction: How Do We Choose?

Aspects of a patient's lifestyle, their state of health, breast size, and mastectomy skin flap quality are factors that influence the suggested plane of dissection in implant-based breast reconstruction. This article aims to review developments in prosthetic breast reconstruction and provide recommendations to help providers choose whether prepectoral or subpectoral reconstruction in the best approach for each of their patients.

Usefulness of indocyanine green angiography in the intraoperative evaluation of recipient vessels for microsurgical lower extremity reconstruction in ischemic vasculopathy: Report of three cases

Choosing reliable recipient vessels is crucial for successful free flap reconstruction of lower extremity defects, especially in patients with ischemic vasculopathy. This report describes our experience with the intraoperative use of indocyanine green angiography (ICGA) for selecting recipient vessels in lower extremity free flap reconstruction cases. Three patients with lower extremity defects and ischemic vasculopathy underwent free flap reconstruction. Intraoperatively, the candidate vessels were evaluated using ICGA. In the first case, a 10 × 6 cm defect on the anterior side of the lower third of the leg caused by minor trauma and associated with peripheral arterial occlusive disease was reconstructed using a super-thin anterolateral thigh flap based on one perforator. In the second case, a 12 × 8 cm defect on the posterior side of the right lower leg caused by a dog bite and associated with severe atherosclerosis throughout all three major vessels in the lower leg was reconstructed using a muscle-sparing latissimus dorsi myocutaneous flap. In the third case, a 13.5 × 5.5 cm defect on the right lateral malleolar region, where the peroneus longus tendon was exposed due to Buerger's disease, was reconstructed using a one perforator-based super-thin anterolateral thigh flap. In all cases, ICGA was used to evaluate the functionality of the candidate recipient vessels. In two cases, the candidate vessels showed acceptable blood flow, and the operations proceeded as planned. In the third case, the planned vessels of posterior tibial vessels were not identified to have sufficient blood flow, and one of their branches showing enhancement in ICGA was selected and used as a recipient vessel. All flaps survived completely. No adverse events occurred during the follow-up period of postoperative 3 months. Our results suggest that ICGA may be a valuable diagnostic tool for evaluating the quality of candidate recipient vessels in cases where their functionality cannot be guaranteed with conventional imaging modalities.

Flap perfusion assessment with indocyanine green angiography in deep inferior epigastric perforator flap breast reconstruction: A systematic review and meta-analysis

BACKGROUND

Indocyanine green angiography (ICG-A) has been widely applied for intraoperative flap assessment in DIEP flap breast reconstruction. However, the beneficial effect of ICG-A in DIEP flap breast reconstruction is still uncertain and no standardized protocol is available. This study aims to analyze the clinical outcome and comprehensively review protocols of this field.

METHODS

A systematic review was conducted in MEDLINE, EMBASE, and Cochrane CENTRAL databases until September 15, 2022. Studies on the utility of intraoperative ICG-A in DIEP breast reconstruction were included. Data reporting reconstruction outcomes were extracted for pooled analysis.

RESULTS

A total of 22 studies were enrolled in the review, among five studies with 1021 patients included in the meta-analysis. The protocols of ICG-A assessment of DIEP flap varied among studies. According to the pooled results, the incidence of postoperative fat necrosis was 10.89% (50 of 459 patients) with ICG-A and 21.53% (121 of 562 patients) with clinical judgment. The risk for postoperative fat necrosis was significantly lower in patients with intraoperative ICG-A than without (RR 0.47 95% CI 0.29-0.78, p = .004, I2  = 51%). Reoperation occurred in 5 of 48 patients (10.42%) in the ICG-A group and in 21 of 64 patients (32.82%) in the control group summarized from reports in two studies. The risk for reoperation was lower in the ICG-A group than in the control group (RR 0.41 95% CI 0.18-0.93, p = .03, I2  = 0%). Other complications, including flap loss, seroma, hematoma, dehiscence, mastectomy skin necrosis, and infection, were comparable between the two groups. Heterogeneities among studies were acceptable. No significant influence of specific studies was identified in sensitivity analysis.

CONCLUSIONS

ICG-A is an accurate and reliable way to identify problematic perfusion of DIEP flaps during breast reconstruction. Protocols of ICG-A differed in current studies. Intraoperative ICG-A significantly decreases the rate of fat necrosis and reoperation in patients undergoing DIEP breast reconstruction. The synthesized results should be interpreted sensibly due to the sample size limitation. RCTs on the outcomes and high-quality studies for an optimized ICG-A protocol are still needed in the future.

Differences in Transient Fluid Retention and Lymphedema With Breast Cancer Treatment for Lymphatic Microsurgery

BACKGROUND

Breast cancer-related lymphedema (BCRL) is a common complication. Repeated taxane-based chemotherapy has been shown to induce endothelial inflammation, leading to fluid retention. Patients with transient fluid retention only have upper limb edema without lymphatic dysfunction. Therefore, indocyanine green lymphography revealed linear findings, and lymphatic microsurgery is not required. This study aimed to investigate the difference between BCRL and fluid retention and present the indication for lymphatic microsurgery for these patients.

METHODS

The study population was divided into BCRL and fluid retention groups. Age, body mass index, laterality, surgery type (lymph node, breast, or no surgery), disease stage, regional lymph node irradiation, hormone therapy, chemotherapy type (taxane- or non-taxane-based group), and treatment with trastuzumab were compared.

RESULTS

The BCRL and fluid retention groups consisted of 168 and 73 patients, respectively. The BCRL group had significantly higher rates of axillary lymph node dissection (96.4%) and lymph node irradiation (51.8%) than the fluid retention group (53.4% and 24.7%, respectively; P < 0.001 for both). The fluid retention group had a significantly higher rate of taxane-based chemotherapy (100%) than the BCRL group (92.9%; P = 0.02). No significant differences in other characteristics, including treatments with hormone and trastuzumab, were observed.

CONCLUSIONS

Lymphatic microsurgery should be performed after confirming the diagnosis by indocyanine green lymphography, particularly for patients with fluid retention induced by taxane-based chemotherapy. Because the generalized swelling induced by taxane-based chemotherapy is resolved 6 months after chemotherapy, we should wait at least 6 months to perform lymphatic microsurgery.

Role of Indocyanine Green Angiography in Free Flap Surgery: A Comparative Outcome Analysis of a Single-Center Large Series of 877 Consecutive Free Flaps

Purpose  This study aims to assess and validate the role and cost-effectiveness of indocyanine green angiography (ICGA) in free flap surgery outcomes. A new intraoperative protocol of whole-body surface warming (WBSW) for all free flap surgeries during the strategic "microbreaks" is also described. Methods  A retrospective analysis of 877 consecutive free flaps, performed over 12 years, is presented. The results of the ICGA group ( n  = 438) were compared with the historical No-ICGA group ( n  = 439), and statistical significance was calculated for three crucial flap-related adverse outcomes and cost-effectiveness. ICGA was also used as a tool to show the effect of WBSW on free flaps. Results  ICGA showed a notably strong statistical significance in decreasing two outcome parameters, namely, partial flap loss and re-exploration rate. It was also cost-effective. ICGA also demonstrated the positive role of WBSW in increasing flap perfusion. Conclusions  Our study shows that the usage of ICGA for intraoperative assessment of flap perfusion can significantly reduce the partial flap loss and re-exploration rate in free flap surgeries in a cost-effective manner. A new protocol of WBSW is also described and recommended to increase flap perfusion in all free flap surgeries.

Application of indocyanine green in surgery: A review of current evidence and implementation in trauma patients

Background: Modern surgical medicine strives to manage trauma while improving outcomes using functional imaging. Identification of viable tissues is crucial for the surgical management of polytrauma and burn patients presenting with soft tissue and hollow viscus injuries. Bowel anastomosis after trauma-related resection is associated with a high rate of leakage. The ability of the surgeon’s bare eye to determine bowel viability remains limited, and the need for a more standardized objective assessment has not yet been fulfilled. Hence, there is a need for more precise diagnostic tools to enhance surgical evaluation and visualization to aid early diagnosis and timely management to minimize trauma-associated complications. Indocyanine green (ICG) coupled with fluorescence angiography is a potential solution for this problem. ICG is a fluorescent dye that responds to near-infrared irradiation. Methods: We conducted a narrative review to address the utility of ICG in the surgical management of patients with trauma as well as elective surgery. Discussion: ICG has many applications in different medical fields and has recently become an important clinical indicator for surgical guidance. However, there is a paucity of information regarding the use of this technology to treat traumas. Recently, angiography with ICG has been introduced in clinical practice to visualize and quantify organ perfusion under several conditions, leading to fewer cases of anastomotic insufficiency. This has great potential to bridge this gap and enhance the clinical outcomes of surgery and patient safety. However, there is no consensus on the ideal dose, time, and manner of administration nor the indications that ICG provides a genuine advantage through greater safety in trauma surgical settings. Conclusions: There is a scarcity of publications describing the use of ICG in trauma patients as a potentially useful strategy to facilitate intraoperative decisions and to limit the extent of surgical resection. This review will improve our understanding of the utility of intraoperative ICG fluorescence in guiding and assisting trauma surgeons to deal with the intraoperative challenges and thus improve the patients’ operative care and safety in the field of trauma surgery.

The magic mirror: a novel intraoperative monitoring method for parathyroid glands

The accurate detection of parathyroid glands (PGs) during surgery is of great significance in thyroidectomy and parathyroidectomy, which protects the function of normal PGs to prevent postoperative hypoparathyroidism and the thorough removal of parathyroid lesions. Existing conventional imaging techniques have certain limitations in the real-time exploration of PGs. In recent years, a new, real-time, and non-invasive imaging system known as the near-infrared autofluorescence (NIRAF) imaging system has been developed to detect PGs. Several studies have confirmed that this system has a high parathyroid recognition rate and can reduce the occurrence of transient hypoparathyroidism after surgery. The NIRAF imaging system, like a magic mirror, can monitor the PGs during surgery in real time, thus providing great support for surgeries. In addition, the NIRAF imaging system can evaluate the blood supply of PGs by utilizing indocyanine green (ICG) to guide surgical strategies. The NIRAF imaging system and ICG complement each other to protect normal parathyroid function and reduce postoperative complications. This article reviews the effectiveness of the NIRAF imaging system in thyroidectomies and parathyroidectomies and briefly discusses some existing problems and prospects for the future.

Comparison of Hand-Held Doppler and Indocyanine Green Angiography in Preoperative Design of Expanded Forehead Flaps for Nasal Reconstruction

BACKGROUND

Despite the different approaches for detection of perforators, methods of vascular mapping of the expanded forehead flap for nasal reconstruction are rarely described. This article aimed to present our experience in the preoperative design of the expanded forehead flap for nasal reconstruction and to compare the clinical practice of hand-held Doppler and indocyanine green angiography (ICGA) in vascular mapping for nasal reconstruction with the expanded forehead flap.

METHODS

From October 2019 to April 2022, 26 patients underwent nasal reconstruction using expanded forehead flap. The authors performed preoperative vascular mapping on 16 patients by hand-held Doppler alone, and on 10 patients by hand-held Doppler and ICGA primary outcomes considered were the visualization of the main vascular course of the flap obtained by hand-held Doppler or ICGA, intraoperative observation of the flap, and its postoperative complications.

RESULTS

Indocyanine green angiography provides a better detection in distal flap and the branches of the supratrochlear artery. Vein detection by ICGA generally corresponds to the results obtained by the combination of hand-held Doppler and transillumination test. In the group that only used hand-held Doppler, 2 patients presented hemodynamic complications in the margin of the flap and 1 patient presented partial necrosis postoperatively. No complication was found in the group that used ICGA.

CONCLUSIONS

It is recommended to use the ICGA for preoperative planning, as it yields highly accurate vascular courses. As an alternative to other methods, hand-held Doppler is also an effective tool.

LEVEL OF EVIDENCE

IV.

Indocyanine Green Angiography Overpredicts Postoperative Necrosis Compared to Multispectral Reflectance Imaging

BACKGROUND

Sufficient perfusion is foundational to successful reconstructive surgery. Various technologies have been developed to help determine whether tissue is adequately perfused, or whether it will be prone to necrosis postoperatively. Indocyanine green (ICG) angiography is one such method that uses fluorescence and analyzes tissue perfusion. Multispectral reflectance imaging (MSRI) is an alternative technology that analyzes optical properties of oxygenated and deoxygenated hemoglobin to determine tissue viability. Because tissue in low-perfusion states may still survive because of sufficient oxygenation, the authors hypothesized that compared to MSRI, ICG angiography overpredicts necrosis, potentially resulting in unnecessary resection of viable tissue. This study expands on preliminary work to investigate this hypothesis.

METHODS

This was a prospective cohort of patients undergoing prepectoral direct implant reconstruction at a single institution. Each patient was examined intraoperatively with both ICG angiography and MSRI. Decisions to resect tissue were made in conjunction with MSRI and ICG images collected purely for data analysis. Patients were followed postoperatively for at least 2 months for signs of postoperative necrosis.

RESULTS

Fifty-three cases were included. ICG angiography accurately predicted viability in 40 of 40 patients (100%) and incorrectly predicted necrosis in 11 of 13 patients (84.6%). Simultaneously, MSRI predicted necrosis in zero patients and accurately predicted viability in 51 of 53 patients (96.2%). There was no statistically significant difference in demographic data among patients predicted to experience necrosis by means of ICG angiography versus those predicted to have entirely viable tissue.

CONCLUSION

This study suggests that ICG angiography is prone to overpredicting postoperative necrosis in comparison to MSRI.

CLINICAL RELEVANCE STATEMENT

This study suggests that multispectral reflectance imaging may benefit practicing plastic surgeons in determining the likelihood of postoperative necrosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

[Complications and their management following axillary, inguinal and iliac lymph node dissection]

Irrespective of numerous technical developments, lymphadenectomy remains a necessary component of surgical tumor therapy. Depending on the extent and anatomical localization, complications associated with the lymph vessels such as lymphoceles, lymphatic fistulas or secondary lymphedema can occur with varying frequency, despite a meticulous dissection technique. Chronic lymph fistulas or lymphoceles often require interventional or surgical procedures. Pedicled or free microsurgical flaps are often required in the case of coexisting wound healing disorders or skin soft tissue defects, especially in an irradiated area. For secondary lymphedema a number of conservative and surgical treatment methods have been established. Adequate guideline-based conservative treatment is the method of first choice. If this does not lead to the desired result, microsurgical reconstructive, deviating or resecting procedures are available.

Quantifying the Impact of Signal-to-background Ratios on Surgical Discrimination of Fluorescent Lesions

PURPOSE

Surgical fluorescence guidance has gained popularity in various settings, e.g., minimally invasive robot-assisted laparoscopic surgery. In pursuit of novel receptor-targeted tracers, the field of fluorescence-guided surgery is currently moving toward increasingly lower signal intensities. This highlights the importance of understanding the impact of low fluorescence intensities on clinical decision making. This study uses kinematics to investigate the impact of signal-to-background ratios (SBR) on surgical performance.

METHODS

Using a custom grid exercise containing hidden fluorescent targets, a da Vinci Xi robot with Firefly fluorescence endoscope and ProGrasp and Maryland forceps instruments, we studied how the participants' (N = 16) actions were influenced by the fluorescent SBR. To monitor the surgeon's actions, the surgical instrument tip was tracked using a custom video-based tracking framework. The digitized instrument tracks were then subjected to multi-parametric kinematic analysis, allowing for the isolation of various metrics (e.g., velocity, jerkiness, tortuosity). These were incorporated in scores for dexterity (Dx), decision making (DM), overall performance (PS) and proficiency. All were related to the SBR values.

RESULTS

Multi-parametric analysis showed that task completion time, time spent in fluorescence-imaging mode and total pathlength are metrics that are directly related to the SBR. Below SBR 1.5, these values substantially increased, and handling errors became more frequent. The difference in Dx and DM between the targets that gave SBR < 1.50 and SBR > 1.50, indicates that the latter group generally yields a 2.5-fold higher Dx value and a threefold higher DM value. As these values provide the basis for the PS score, proficiency could only be achieved at SBR > 1.55.

CONCLUSION

By tracking the surgical instruments we were able to, for the first time, quantitatively and objectively assess how the instrument positioning is impacted by fluorescent SBR. Our findings suggest that in ideal situations a minimum SBR of 1.5 is required to discriminate fluorescent lesions, a substantially lower value than the SBR 2 often reported in literature.

Skin Cancer Pathobiology at a Glance: A Focus on Imaging Techniques and Their Potential for Improved Diagnosis and Surveillance in Clinical Cohorts

Early diagnosis is essential for completely eradicating skin cancer and maximizing patients' clinical benefits. Emerging optical imaging modalities such as reflectance confocal microscopy (RCM), optical coherence tomography (OCT), magnetic resonance imaging (MRI), near-infrared (NIR) bioimaging, positron emission tomography (PET), and their combinations provide non-invasive imaging data that may help in the early detection of cutaneous tumors and surgical planning. Hence, they seem appropriate for observing dynamic processes such as blood flow, immune cell activation, and tumor energy metabolism, which may be relevant for disease evolution. This review discusses the latest technological and methodological advances in imaging techniques that may be applied for skin cancer detection and monitoring. In the first instance, we will describe the principle and prospective clinical applications of the most commonly used imaging techniques, highlighting the challenges and opportunities of their implementation in the clinical setting. We will also highlight how imaging techniques may complement the molecular and histological approaches in sharpening the non-invasive skin characterization, laying the ground for more personalized approaches in skin cancer patients.

Techniques for Diagnosing Anastomotic Leaks Intraoperatively in Colorectal Surgeries: A Review

Colorectal cancer is one of the most common surgically curable malignancies worldwide, having a good prognosis even with liver metastasis. This improved patient outcome is marred by anastomotic leaks (AL) in operated patients of colorectal cancer despite a microscopically margin-negative resection (R0). Various risk factors have been attributed to causing this. Preoperative non-modifiable factors are age, male sex, cancer cachexia, and neoadjuvant chemo-radiotherapy, and modifiable factors are comorbidities, peripheral vascular disease, anemia, and malnutrition. Intraoperative risk factors include intraoperative surgical duration, blood loss and transfusions, fluid management, oxygen saturation, surgical technique (stapled, handsewn, or compression devices), and approach (open, laparoscopic, or robotic). Postoperative factors like anemia, infection, fluid management, and blood transfusions also have an effect. With the advent of enhanced recovery after surgery (ERAS) protocols, many modifiable factors can be optimized to reduce the risk. Prevention is better than cure as the morbidity and mortality of AL are very high. There is still a need for an intraoperative technique to detect the viability of anastomotic ends to predict and prevent AL. Prompt diagnosis of an AL is the key. Many surgeons have proposed using methods like air leak tests, intraoperative endoscopy, Doppler ultrasound, and near-infrared fluorescence imaging to decrease the incidence of AL. All these methods can minimize AL, resulting in significant intraoperative alterations to surgical tactics. This narrative review covers the methods of assessing of integrity of anastomosis during the surgery, which can help prevent anastomotic leakage.

Identification of lymph vessels using an indocyanine green camera-integrated operative microscope for lymphovenous anastomosis in the treatment of secondary lymphedema

OBJECTIVE

Lymphedema is a debilitating disease that impairs a patient's quality of life. Although lymphovenous anastomosis (LVA) can cure lymphedema, successful LVAs rely on the precise identification of the lymph vessels. In the present study, we assessed the use of a near-infrared camera-integrated operating microscope for preoperative mapping of the lymphatic vessels and evaluated the outcome of LVAs in patients with secondary lymphedema of a limb.

METHODS

We retrospectively reviewed patients with secondary unilateral lymphedema who had undergone LVA surgery with the lymph vessels identified using a near-infrared camera-integrated operating microscope (Moller 3-1000; Möller-Wedel Optical GmbH, Wedel, Germany) between 2020 and 2021. The lymph vessels identified using near-infrared fluorescence lymphography, diameter of the vessels used for anastomosis, anastomosis configuration, and perioperative limb circumference were recorded.

RESULTS

Overall, 35 LVAs were performed in six patients with secondary lymphedema, with a mean number of 5.8 LVAs per limb. The anastomotic configurations were end-to-end in 26 LVAs, side-to-end in 2 LVAs, and end-to-side in 7 LVAs. The diameter of the lymph vessels ranged from 0.3 to 0.9 mm (mean, 0.62 ± 0.18 mm) and that of the vein from 0.4 to 1.2 mm (mean, 0.75 ± 0.21 mm). The changes in the lymphedema index and estimated limb volume indicated a postoperative decrease in edema.

CONCLUSIONS

We found a near-infrared camera-integrated operating microscope useful for the preoperative identification of functional lymph vessels. Our results have shown that microsurgical LVAs can be performed using an integrated indocyanine green camera without an independent indocyanine green detector.

Spontaneous Lymph Flow Restoration in Free Flaps: A Pilot Study

BACKGROUND

Oncologic excision and trauma can be responsible for major defects and lymphedema. Free flaps are commonly used for reconstruction. We aimed to determine if lymphatic flow between flap and recipient site can be restored without lymphatic surgery.

METHODS

15 free flaps were performed in different patients in our center. Infrared-based lymphography was used to plan surgery. Indocyanine green (ICG) was injected in the flap's subdermal tissue and also at the edges of the skin defect. Circumferential lymphatic channels were marked 5 min after the ICG injection. Fluorescent images were recorded with an infrared camera system. The flap inset was obtained by putting side to side the flap markings and the recipient site markings. Infrared-based lymphography was performed on every patient one year after surgery. Spontaneous lymph flow restoration was judged positive if lymphatic connections were observed between the flap and the recipient site.

RESULTS

seven free ALT and eight DIEP flaps were performed. All ALT flaps were designed following the limb axis which is the lymphatic axiality. Spontaneous lymph flow restoration was observed for the seven ALT flaps. Eight DIEP flaps were designed upside down and one was designed following the lymph axiality. Spontaneous lymph flow restoration was only observed for the one designed following the lymph axiality.

CONCLUSIONS

designing reconstructive free flap regarding lymph axiality seems to improve spontaneous lymph flow restoration between flap and recipient site without any specific lymphatic surgery.

Delphi survey of intercontinental experts to identify areas of consensus on the use of indocyanine green angiography for tissue perfusion assessment during plastic and reconstructive surgery

BACKGROUND

In recent years, indocyanine green angiography (ICG-A) has been used increasingly to assist tissue perfusion assessments during plastic and reconstructive surgery procedures, but no guidelines exist regarding its use. We sought to identify areas of consensus and non-consensus among international experts on the use of ICG-A for tissue-perfusion assessments during plastic and reconstructive surgery.

METHODS

A two-round, online Delphi survey was conducted of 22 international experts from four continents asking them to vote on 79 statements divided into five modules: module 1 = patient preparation and contraindications (n = 11 statements); module 2 = ICG administration and camera settings (n = 17); module 3 = other factors impacting perfusion assessments (n = 10); module 4 = specific indications, including trauma debridement (n = 9), mastectomy skin flaps (n = 6), and free flap reconstruction (n = 8); and module 5 = general advantages and disadvantages, training, insurance coverage issues, and future directions (n = 18). Consensus was defined as ≥70% inter-voter agreement.

RESULTS

Consensus was reached on 73/79 statements, including the overall value, advantages, and limitations of ICG-A in numerous surgical settings; also, on the dose (0.05 mg/kg) and timing of ICG administration (∼20-60 seconds preassessment) and best camera angle (61-90^o) and target-to-tissue distance (20-30 cm). However, consensus also was reached that camera angle and distance can vary, depending on the make of camera, and that further research is necessary to technically optimize this imaging tool. The experts also agreed that ambient light, patient body temperature, and vasopressor use impact perfusion assessments.

CONCLUSION

ICG-A aids perfusion assessments during plastic and reconstructive surgery and should no longer be considered experimental. It has become an important surgical tool.

Investigation of the Association Between Breast Cancer-Related Lymphedema and the Side Effects of Taxane-Based Chemotherapy Using Indocyanine Green Lymphography

Background: Breast cancer-related lymphedema (BCRL) is a common complication. Docetaxel (DOC) and paclitaxel (PTX) have been used in taxane-based chemotherapy for breast cancer and to induce fluid retention. The purpose of this study was to investigate the association between lymphatic functionality and the side effects of taxane-based chemotherapy using indocyanine green (ICG) lymphography. Methods and Results: One hundred and eighty breast cancer cases who underwent full-dose taxane-based chemotherapy (DOC or PTX) and complained of upper extremity edema were enrolled in this study. BCRL was diagnosed exclusively on the basis of ICG lymphography results. The characteristics (age, body mass index, laterality, surgery type, regional lymph node irradiation, hormone therapy, and chemotherapy type) of patients diagnosed with BCRL (+) and BCRL (-; fluid retention only) were compared. The side effects were compared in eight categories (neutropenia, skin toxicity, nail changes, myalgia/arthralgia, peripheral neuropathy, stomatitis, dysgeusia, and digestive disease). BCRL (+) consisted of 116 patients and BCRL (-) consisted of 64 patients. BCRL (+) had significantly higher rates of axillary lymph node dissection (98.3%), lymph node irradiation (68.1%), neoadjuvant chemotherapy (14.7%), and DOC (62.9%) than BCRL (-) patients (56.3%, 20.3%, 3.1%, and 34.4%, respectively; p = 0.002 for neoadjuvant rate, p < 0.001 for the other rates). BCRL (+) patients had significantly higher rates of peripheral neuropathy (60.3%) than BCRL (-) patients (40.6%; p = 0.01). Conclusions: The occurrence rate of BCRL increased for the patients with peripheral neuropathy induced by taxane-based chemotherapy. This implies that peripheral neuropathy can induce BCRL.

Preventing Soft Tissue Complications in Secondary Aesthetic Breast Surgery Using Indocyanin Green Angiography

BACKGROUND

Secondary cosmetic breast surgery after primary augmentation with implant can be associated with an increased risk of adverse events. Partial/complete nipple areolar complex (NAC) necrosis is particularly feared. In this preliminary study, the authors propose the use of Indocyanine Green (ICG) angiography in order to assess the blood supply of breast tissue after implant removal.

OBJECTIVES

The main objective is to prevent skin and gland necrosis in revision breast surgery.

METHODS

We performed a retrospective comparative analysis of 33 patients undergoing secondary breast surgery between 2018 and 2021 by a single surgeon (M.S.). Breast tissue perfusion was assessed in 16 patients by intraoperative ICG-angiography at the end of implant removal and possible capsulectomy. Non-stained/non-fluorescent areas were judged to be low perfusion areas and were excised with short scar mastopexy.

RESULTS

In the ICG-angiography group, 7 patients (44%) showed an area of poor perfusion along the inferior pole, all of these patients underwent subglandular breast augmentation. Resection of the poor perfusion areas allowed an uneventful postoperative course. In the non ICG-angiography group (17 patients), 5 patients experienced vertical scar dehiscence/necrosis. We found a statistically significant association between non-ICG angiography group and vertical scar dehiscence/necrosis, and also between vertical scar dehiscence/necrosis and subglandular implant placement (P-value = 0.04).

CONCLUSIONS

Safer secondary surgery can be offered to patients undergoing secondary aesthetic breast procedures, especially when the first augmentation surgery is unknown e.g. implant plane, type of pedicle used, the implant is large and subglandular, and capsulectomy is performed.

Transcutaneous sentinel lymph node detection in cutaneous melanoma with indocyanine green and near-infrared fluorescence: A diagnostic sensitivity study

Sentinel lymph node (SLN) biopsy with preoperative radiocolloid-based lymphoscintigraphy and blue dye injection is considered the standard procedure for staging nodal metastases in early-stage cutaneous melanoma patients with clinically uninvolved lymph nodes. While this combination renders good accuracy in SLN detection, radiation exposure and the frequent allergic reactions to the blue dye are considered drawbacks of this technique. Indocyanine green (ICG) is a water-soluble fluorescent dye that can be identified through near-infrared fluorescence imaging (NIRFI). The aim of this prospective diagnostic sensitivity study was to assess the feasibility of ICG and NIRFI to identify SLNs in melanoma transcutaneously ("before skin incision") and to analyze the various factors influencing detection rate, in comparison to lymphoscintigraphy. This study included 93 patients undergoing SLN biopsy for cutaneous melanoma. The region and the number of the SLNs identified with lymphoscintigraphy and with ICG were recorded. Patients' characteristics, as well as tumor details were also recorded preoperatively. One hundred and ninety-four SLNs were identified through lymphoscintigraphy. The sensitivity of ICG for transcutaneous identification of the location of the SLNs was 96.1% overall, while the sensitivity rate for the number of SLNs was 79.4%. Gender and age did not seem to influence detection rate, but a body mass index >30 kg/m2 was associated with a lower identification rate of the number of SLNs (P = .045). Transcutaneous identification of SLNs through ICG and NIRFI technology is a feasible technique that could potentially replace in selected patients the standard SLN detection methodology in cutaneous melanoma.

Indocyanine green (ICG) fluorescence guide for the use and indications in general surgery: recommendations based on the descriptive review of the literature and the analysis of experience

Indocyanine Green is a fluorescent substance visible in near-infrared light. It is useful for the identification of anatomical structures (biliary tract, ureters, parathyroid, thoracic duct), the tissues vascularization (anastomosis in colorectal, esophageal, gastric, bariatric surgery, for plasties and flaps in abdominal wall surgery, liver resection, in strangulated hernias and in intestinal ischemia), for tumor identification (liver, pancreas, adrenal glands, implants of peritoneal carcinomatosis, retroperitoneal tumors and lymphomas) and sentinel node identification and lymphatic mapping in malignant tumors (stomach, breast, colon, rectum, esophagus and skin cancer). The evidence is very encouraging, although standardization of its use and randomized studies with higher number of patients are required to obtain definitive conclusions on its use in general surgery. The aim of this literature review is to provide a guide for the use of ICG fluorescence in general surgery procedures.

[The Significance of Oncoplastic Breast Reconstruction After Tumorectomy in Surgical Breast Cancer Therapy]

Breast-conserving therapy (BCT), meaning tumorectomy in combination with systemic therapy and locoregional radiation therapy has become the preferred method to treat early-stage breast cancer. With excellent long-term recurrence-free and overall survival rates, breast surgeons today must deliver du- rable and aesthetically appealing results that guarantee a good quality of life to meet the high patient expectations. Oncoplas- tic breast surgery (OPBS) is an innovative approach to improve the overall results of BCT. Often carried out by a team of a plastic surgeon and an oncologic breast surgeon, OPBS can actively prevent breast deformities without compromising oncological safety. In the following, an overview of the principles and techniques of oncoplastic breast surgery will be given due to its ever-increasing significance and its advantages and dis- advantages will be discussed in the context of reconstructive breast surgery.

Fluorescent Tracers for In Vivo Imaging of Lymphatic Targets

The lymphatic system continues to gain importance in a range of conditions, and therefore, imaging of lymphatic vessels is becoming more widespread for research, diagnosis, and treatment. Fluorescent lymphatic imaging offers advantages over other methods in that it is affordable, has higher resolution, and does not require radiation exposure. However, because the lymphatic system is a one-way drainage system, the successful delivery of fluorescent tracers to lymphatic vessels represents a unique challenge. Each fluorescent tracer used for lymphatic imaging has distinct characteristics, including size, shape, charge, weight, conjugates, excitation/emission wavelength, stability, and quantum yield. These characteristics in combination with the properties of the target tissue affect the uptake of the dye into lymphatic vessels and the fluorescence quality. Here, we review the characteristics of visible wavelength and near-infrared fluorescent tracers used for in vivo lymphatic imaging and describe the various techniques used to specifically target them to lymphatic vessels for high-quality lymphatic imaging in both clinical and pre-clinical applications. We also discuss potential areas of future research to improve the lymphatic fluorescent tracer design.

An Innovative Simulation Model for Microvascular Training

SUMMARY

Preclinical/clinical microsurgical training is essential for clinical practice. Therefore, various training models have been established, such as synthetic and cadaveric models. The most common limitation of these models is the lack of circulation, which limits the simulation of real intraoperative circumstances. Thus, the authors aimed to create a novel model that provides blood circulation with an extracorporeal perfusion device that they attached to rat cadavers for the reestablishment of a circulatory system. Patent blue and heparin were added to the perfusion fluid to visualize circulation and to dissolve thrombosis, and indocyanine green fluorescent imaging was applied to show the perfusion of the entire body. The femoral and brachial vessels were dissected, and an end-to-end anastomosis was performed on the femoral artery. The patency of the operated vessel was visualized with indocyanine green fluorescent imaging. Indocyanine green fluorescent imaging showed appropriate vessel patency and extremity perfusion through the anastomosis. The use of this novel rat model enables a solution for ethical problems encountered when using rats for surgical training courses. By practicing on these animal-sparing models with intact circulation, microsurgical skills can be improved. Future studies on further microsurgical techniques and vascular perfusion of organs or tumors may benefit from our model.

Recellularization of Bioengineered Scaffolds for Vascular Composite Allotransplantation

Traumatic injuries or cancer resection resulting in large volumetric soft tissue loss requires surgical reconstruction. Vascular composite allotransplantation (VCA) is an emerging reconstructive option that transfers multiple, complex tissues as a whole subunit from donor to recipient. Although promising, VCA is limited due to side effects of immunosuppression. Tissue-engineered scaffolds obtained by decellularization and recellularization hold great promise. Decellularization is a process that removes cellular materials while preserving the extracellular matrix architecture. Subsequent recellularization of these acellular scaffolds with recipient-specific cells can help circumvent adverse immune-mediated host responses and allow transplantation of allografts by reducing and possibly eliminating the need for immunosuppression. Recellularization of acellular tissue scaffolds is a technique that was first investigated and reported in whole organs. More recently, work has been performed to apply this technique to VCA. Additional work is needed to address barriers associated with tissue recellularization such as: cell type selection, cell distribution, and functionalization of the vasculature and musculature. These factors ultimately contribute to achieving tissue integration and viability following allotransplantation. The present work will review the current state-of-the-art in soft tissue scaffolds with specific emphasis on recellularization techniques. We will discuss biological and engineering process considerations, technical and scientific challenges, and the potential clinical impact of this technology to advance the field of VCA and reconstructive surgery.

Cell-Membrane Biomimetic Indocyanine Green Liposomes for Phototheranostics of Echinococcosis

Echinococcosis is an important zoonotic infectious disease that seriously affects human health. Conventional diagnosis of echinococcosis relies on the application of large-scale imaging equipment, which is difficult to promote in remote areas. Meanwhile, surgery and chemotherapy for echinococcosis can cause serious trauma and side effects. Thus, the development of simple and effective treatment strategies is of great significance for the diagnosis and treatment of echinococcosis. Herein, we designed a phototheranostic system utilizing neutrophil-membrane-camouflaged indocyanine green liposomes (Lipo-ICG) for active targeting the near-infrared fluorescence diagnosis and photothermal therapy of echinococcosis. The biomimetic Lipo-ICG exhibits a remarkable photo-to-heat converting performance and desirable active-targeting features by the inflammatory chemotaxis of the neutrophil membrane. In-vitro and in-vivo studies reveal that biomimetic Lipo-ICG with high biocompatibility can achieve in-vivo near-infrared fluorescence imaging and phototherapy of echinococcosis in mouse models. Our research is the first to apply bionanomaterials to the phototherapy of echinococcosis, which provides a new standard for the convenient and noninvasive detection and treatment of zoonotic diseases.

The American Venous Forum, American Vein and Lymphatic Society and the Society for Vascular Medicine expert opinion consensus on lymphedema diagnosis and treatment

BACKGROUND

Lymphedema imposes a significant economic and social burden in modern societies. Controversies about its risk factors, diagnosis, and treatment permeate the literature. The goal of this study was to assess experts' opinions on the available literature on lymphedema while following the Delphi methodology.

METHODS

In December of 2019, the American Venous Forum created a working group tasked to develop a consensus statement regarding current practices for the diagnosis and treatment of lymphedema. A panel of experts was identified by the working group. The working group then compiled a list of clinical questions, risk factors, diagnosis and evaluation, and treatment of lymphedema. Fifteen questions that met the criteria for consensus were included in the list. Using a modified Delphi methodology, six questions that received between 60% and 80% of the votes were included in the list for the second round of analysis. Consensus was reached whenever >70% agreement was achieved.

RESULTS

The panel of experts reached consensus that cancer, infection, chronic venous disease, and surgery are risk factors for secondary lymphedema. Consensus was also reached that clinical examination is adequate for diagnosing lymphedema and that all patients with chronic venous insufficiency (C3-C6) should be treated as lymphedema patients. No consensus was reached regarding routine clinical practice use of radionuclide lymphoscintigraphy as a mandatory diagnostic tool. However, the panel came to consensus regarding the importance of quantifying edema in all patients (93.6% in favor). In terms of treatment, consensus was reached favoring the regular use of compression garments to reduce lymphedema progression (89.4% in favor, 10.6% against; mean score of 79), but the use of Velcro devices as the first line of compression therapy did not reach consensus (59.6% in favor vs 40.4% against; total score of 15). There was agreement that sequential pneumatic compression should be considered as adjuvant therapy in the maintenance phase of treatment (91.5% in favor vs. 8.5% against; mean score of 85), but less so in its initial phases (61.7% in favor vs. 38.3% against; mean score of 27). Most of the panel agreed that manual lymphatic drainage should be a mandatory treatment modality (70.2% in favor), but the panel was split in half regarding the proposal that reductive surgery should be considered for patients with failed conservative treatment.

CONCLUSION

This consensus process demonstrated that lymphedema experts agree on the majority of the statements related to risk factors for lymphedema, and the diagnostic workup for lymphedema patients. Less agreement was demonstrated on statements related to treatment of lymphedema. This consensus suggests that variability in lymphedema care is high even among the experts. Developers of future practice guidelines for lymphedema should consider this information, especially in cases of low-level evidence that supports practice patterns with which the majority of experts disagree.

The Use and Technique of Sentinel Node Biopsy for Skin Cancer

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the indications for and prognostic value of sentinel lymph node biopsy in skin cancer. 2. Learn the advantages and disadvantages of various modalities used alone or in combination when performing sentinel lymph node biopsy. 3. Understand how to perform sentinel lymph node biopsy in skin cancer patients.

SUMMARY

Advances in technique used to perform sentinel lymph node biopsy to assess lymph node status have led to increased accuracy of the procedure and improved patient outcomes.

Case Report: Indocyanine Green-Based Angiography for Real-Time Assessment of Superficial Brachialis Axial Pattern Flap Vascularization in Two Dogs

This case report describes the method and feasibility of near-infrared angiography (NIRA) to improve the surgical procedure of two superficial brachial axial pattern flaps intraoperatively using two camera systems. Two client-owned dogs were treated for tumors on their antebrachia with wide surgical excision. The defects were closed with a superficial brachial flap in both cases. A different NIRA camera system was used for each case to identify the perforator vessel and flap margins accordingly. Case 1 developed a seroma and healed without further complications. Case 2 developed partial flap necrosis, underwent revision surgery, and healed by secondary intent. NIRA proved useful intraoperatively in identifying the perforator vessel and determining flap margins. As these are only two cases, caution should be used in extrapolating the results.

Delayed two-stage nipple sparing mastectomy and simultaneous expander-to-implant reconstruction of the large and ptotic breast

BACKGROUND

Large and ptotic breasts are considered an anatomical contraindication for nipple sparing mastectomy (NSM). Necrosis rates can be as high as 76%. The authors examined whether targeted preshaping mastopexy/reduction combined with simultaneous two-stage preshaping of the implant pocket prepares for an uneventful implant reconstruction.

METHODS

Macromastia and ptosis patients opting for risk-reducing NSM or having a peripherally localized carcinoma in situ, were offered a two-stage mastopexy/reduction simultaneously with preshaping of the implant pocket by subpectoral expansion. Only the inferior pedicle bearing the nipple-areola complex (NAC), remained. A delayed secondary NSM and tissue expander-to-implant reconstruction was scheduled 3 months later. The use of an acellular dermal matrix (ADM) was not necessary because the capsule around the expander created a hammock supporting the definite prosthesis. Follow up was at 2 weeks, 3 months, and 6 months.

RESULTS

Forty-one procedures were performed in 24 patients. The mean age was 45±12.08 years (range, 22 to 72 years). Patients' mean body mass index (BMI) was 26.79 kg/m2 (range, 19 to 35 kg/m2). One patient had diabetes and two smoked. One transient epidermolysis of the NAC occurred in each stage. No NAC or skin necrosis occurred; no implant had to be removed.

CONCLUSIONS

A two-stage mastopexy/reduction, simultaneously with preshaping of the implant pocket by tissue expansion and followed by a 3-month delayed secondary NSM with tissue expander-to-implant reconstruction is a safe technique in large ptotic breasts.

ICG lymphographic findings following immediate lymphatic reconstruction in breast cancer patients

BACKGROUND

Immediate lymphatic reconstruction (ILR), performed at the time of axillary lymph node dissection (ALND), has demonstrated promising reductions in breast cancer-associated lymphedema. However, questions remain over the effects of adjuvant therapies on the continued patency of the lymphaticovenous anastomosis. Our study aimed to assess lymphographic outcomes, including ICG pattern and LVB patency, in patients at high risk for breast cancer-associated lymphedema following axillary ILR.

METHODS

Baseline ICG lymphography studies performed during ILR of 15 patients were compared to repeat ICG studies obtained during second-stage breast reconstructive procedures to assess for changes in lymphatic flow patterns through the at-risk arm and transit into the axilla.

RESULTS

All 15 patients in this study demonstrated linear lymphatic flow in baseline lymphography. Repeat lymphographic studies showed linear lymphatic transit in 12/15 patients. Of these 12 patients, 10 received chemotherapy, and all 12 received post-mastectomy radiation (PMRT). Dermal backflow patterns were recorded in 3/15 patients. All 3 patients received chemotherapy and 2/3 underwent PMRT. Additionally, repeat ICG studies of 7/12 lymphedema-free patients demonstrated clear visualization of linear ICG flow from the lymphatics of the arm into the axilla.

CONCLUSION

We have demonstrated that ICG lymphography can be implemented as a postoperative tool to assess lymphatic function in patients who have undergone ILR in the axilla. Repeat ICG studies in the majority of patients demonstrated linear ICG flow similar to baseline studies. Additionally, ICG flow patterns through the axilla in repeat lymphography provided visual evidence supporting sustained LVB patency, despite axillary irradiation.

Breaking the technical barrier of microvascular anastomosis with high-speed videography: A prospective cohort study

BACKGROUND

Microsurgical anastomosis is technically difficult especially for less-experienced surgeons. Traditionally, surgeons in training could only accomplish these surgeries under intensive guiding and supervision from senior surgeons. This study presents and characterises a new method for microsurgical trainees to objectively evaluating the quality of vascular anastomosis intraoperatively.

MATERIALS AND METHODS

We conducted a prospective study to determine the utility of patency test of vascular anastomosis with assistance of high-speed video recording (PTHVR) to evaluate the quality of vascular anastomosis during microsurgery. To determine whether the use of PTHVR outperformed traditional supervision from senior surgeons (historical control), we compared the outcomes of microsurgeries including free flap transfer and replantation between the two groups.

RESULTS

A total of 211 patients were enrolled, of which 98 underwent surgery under traditional supervision and 113 underwent surgery with PTHVR. Of the 211 patients, 102 underwent digit replantation (48%), 22 underwent limb replantation (10%), and 87 underwent free flap transfer (42%). There was no statistical difference between the two groups in age, gender, BMI, pre-existing comorbidities, smoking status, alcohol consumption, and duration of surgery. Use of PTHVR as an intraoperative guide significantly decreased the rate of re-exploration surgeries (PTHVR, 8.0% [9/113]; control, 23.5% [23/98]; P = 0.002) and replantation/free flap failures (PTHVR, 8.8% [10/113]; control, 19.4% [19/98]; P = 0.029) compared with historical control under traditional supervision.

CONCLUSIONS

PTHVR is a useful tool for improving the success rate of microsurgery for less-experienced surgeons when compared with traditional supervision mode.

Relationship Between the Circumference Difference and Findings of Indocyanine Green Lymphography in Breast Cancer-Related Lymphedema

BACKGROUND

Breast cancer-related lymphedema (BCRL) is a common complication. Indocyanine green (ICG) lymphography has been performed to assess lymphatic functionality. We found that some BCRL patients had a difference in circumference in partial regions only. The purpose of this study was to evaluate the patients with BCRL about the correlation between the difference in circumference and the findings of ICG lymphography.

METHODS

One hundred fifty-five patients with unilateral BCRL were enrolled in this study. We evaluated the differences in circumference taken at 4 parts on the upper limb (at around the wrist, forearm, elbow, and brachium). The difference in circumference was evaluated between the affected part (Caf) and the unaffected part (Cun). We calculated the circumference difference rate (CDR) as follows: CDR = 100 (Caf - Cun)/Caf. First, we classified each part of all BCRL patients (620 parts) based on the findings of ICG lymphography (linear, collateral, dermal back flow [DBF], and no enhancement) and evaluated the correlation. Second, in the patients with partial volume change, we compared the mean CDR in each part.

RESULTS

One hundred six parts were of a linear pattern, 31 parts were collateral, 350 parts were DBF, and 133 parts had no enhancement. The mean CDR of each finding was 3.3% in linear, 4.0% in collateral, 9.6% in DBF, and 9.4% in no enhancement. There was no significant difference between linear and collateral (P = 0.62), DBF, and no enhancement (P = 0.89) patterns. However, there was a significant difference between linear or collateral and DBF or no enhancement (all P < 0.001). In the 22 patients with distal DBF and proximal linear, the CDR was significantly higher in the forearm compared with the brachium (6.4% and 3.0%; P = 0.003). In the 26 patients with distal linear and proximal DBF, the CDR was significantly higher in the brachium compared with the forearm (4.3% and 7.7%; P = 0.005).

CONCLUSIONS

There was a significant correlation between the difference in circumference and the severity of ICG findings.

Clinical Issues-January 2022

Cleaning the central core floor Key words: semirestricted area, cleaning practices, vacuum, flooring, mopping. Wearing a cooling vest under a sterile gown Key words: thermal comfort, thermal stress, cooling vest, scrubbed personnel, surgical attire. Fluorescence-guided surgery Key words: fluorescence-guided surgery (FGS), fluorescent agent, fluorophore, imaging, indocyanine green (ICG). Containment of used suture needles Key words: sharps injury, sharps containment device, suture packet, suture needle, needle return.

Use of Indocyanine Green Angiography to Identify the Superficial Temporal Artery and Vein in Forehead Flaps for Facial Reconstruction

ABSTRACT

The superficial temporal artery (STA) frontal branch flap is susceptible to venous congestion because of its unpredictable and variable outflow. The authors applied indocyanine green angiography in identifying the superficial temporal vessels to help surgeons with proper flap designs to avoid severe complications. A retrospective review from 2015 to 2020 was conducted. All the patients who underwent indocyanine green angiography before forehead flap transfer for facial defect reconstruction were reviewed. The STA and vein were observed using indocyanine green angiography preoperatively. The relationship between the artery and vein was investigated. The venous anatomy was analyzed to guide the pedicle design. The survival of the flap and complications were assessed. A total of 12 patients were identified and included in this study. Indocyanine green angiography allows clear visualization of the detailed anatomy of the STA and vein. The frontal branch of the vein had great variations and generally diverged from the arterial branch. The tiny venae comitantes provided sufficient drainage for 2 small forehead flaps. The frontal branch of the vein entered the forehead and was used as the outflow channel in 4 patients. The parietal branch of the vein, which consistently gave off secondary tributaries to the superior forehead, was included in the pedicle in 6 patients. All flaps survived without complications. Indocyanine green angiography provided accurate localization of the superficial temporal vessels. This technique may be helpful in the precise planning forehead flap surgeries and in avoiding the risk of venous congestion.

Assessing Soft Tissue Perfusion Using Laser-Assisted Angiography in Tibial Plateau and Pilon Fractures: A Pilot Study

OBJECTIVES

To determine whether skin perfusion surrounding tibial plateau and pilon fractures is associated with the Tscherne classification for severity of soft tissue injury. The secondary aim was to determine if soft tissue perfusion improves from the time of injury to the time of definitive fracture fixation in fractures treated using a staged protocol.

DESIGN

Prospective cohort study.

SETTING

Academic trauma center.

PATIENTS

Eight pilon fracture patients and 19 tibial plateau fracture patients who underwent open reduction internal fixation.

MAIN OUTCOME MEASURES

Skin perfusion (fluorescence units) as measured by LA-ICGA.

RESULTS

Six patients were classified as Tscherne grade 0, 9 as grade 1, 10 as grade 2, and 2 as grade 3. Perfusion decreased by 14 fluorescence units (95% confidence interval, -21 to -6; P < 0.01) with each increase in Tscherne grade. Sixteen patients underwent staged fixation with an external fixator (mean time to definitive fixation 14.1 days). The mean perfusion increased significantly at the time of definitive fixation by a mean of 13.9 fluorescence units (95% confidence interval 4.8-22.9; P = 0.01).

CONCLUSIONS

LA-ICGA perfusion measures are associated with severity of soft tissue injury surrounding orthopaedic trauma fractures and appear to improve over time when fractures are stabilized in an external fixator. Further research is warranted to investigate whether objective perfusion measures are predictive of postoperative wound healing complications and whether this tool can be used to effectively guide timing of safe surgical fixation.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.