Indocyanine green fluorescence/thermography evaluation of intercostal muscle flap vascularization

Advantages and rational application of indocyanine green fluorescence in pulmonary nodule surgery: a narrative review

Background and Objective

The early detection and early treatment of high-risk pulmonary nodules directly affect the long-term survival rate of patients. However, conventional nodule localization methods, such as hook-wire, technetium-99m, and methylene blue are associated with issues such as a high-frequency of complications, low patient tolerance, serious side effects, and inability to identify pigmented lungs. For patients who require segmentectomy, there is often a lack of effective path planning, resulting in insufficient resection margins or excessive loss of lung function. Therefore, effective and rational nodule localization and surgical approaches are crucial. This narrative review aimed to evaluate the advantages of indocyanine green (ICG) fluorescence in pulmonary nodule surgery and clarify its application in various types of patients.

Methods

We searched the PubMed and Web of Science databases from January 2010 to January 2024 using the terms "localization of pulmonary nodules", "localization of pulmonary nodules AND indocyanine green", "localization of pulmonary nodules AND complication", "localization of pulmonary nodules AND surgical planning", and "localization of pulmonary nodules AND underlying lung disease". Information used to write this narrative review was from clinical phenomena, statistical data, and authors' conclusions.

Key Content and Findings

The commonly used localization methods of pulmonary nodule such as computed tomography (CT)-guided percutaneous placement of hook-wire are accompanied with serious complications: including hemopneumothorax and ache. Meanwhile, routine dye commonly fails to localize the nodules in patients with anthracosis. ICG with the enhanced permeability and retention (EPR) effect can be used effectively for preoperative and intraoperative localization of pulmonary nodules and its nature of allowing the observance of the condition of pulmonary blood vessels has gradually become a hotspot of research in this field.

Conclusions

For nodules with a depth of less than 1 cm, no penetration depth problem is encountered when ICG fluorescence is used. Percutaneous puncture can effectively identify the location of nodules at low cost. Compared with other localization methods, it can effectively avoid problems such as pain, radiation exposure, marker displacement, and the existence of anthrax lesions in the lungs. For patients on whom it is difficult to locate nodules due to tissue results, virtual bronchoscopy or electromagnetic navigation bronchoscopy can effectively identify nodules and reduce complications such as pneumothorax. For patients whose operation is postponed due to fever, sudden cardiovascular and cerebrovascular diseases, there is no risk of nodule localization material detachment by using ICG. ICG can also be used in patients with pulmonary physiological or pathological diseases. Meanwhile, in patients with deep pulmonary nodules, ICG fluorescence can help plan the surgical path, ensure the margin of resection, reduce lung function damage, and prevent bronchial fistula. Therefore, the rational use of ICG fluorescence technology can effectively locate nodules, assist surgeons in planning surgical methods, potentially reducing complications and ultimately improving patient prognosis.

Methods of bronchial stump buttressing in post-pneumonectomy bronchopleural fistula prevention: a systematic review

<b>Introduction:</b> The bronchopleural fistula (BPF) remains one of the most severe complications after pneumonectomy. Several surgical methods may enhance bronchial stump healing and reduce the occurrence of BPF. Usually, surgeons use tissue buttressing, such as intercostal muscle flap (IMF), parietal pleura, pericardium fat pad, or mediastinal fat, to reinforce the bronchial stump. This paper reviews the literature describing the impact of different buttressing tissues on the occurrence of early post-pneumonectomy BPF.<b>Material and methods:</b> We included all studies that described the use of bronchial stump buttressing in patients after pneumonectomy. Studies written in languages other than English were excluded. The search was performed using PubMed, Google Scholar, Embase, COCHRANE databases, and the clinical trial registry on December 1, 2023. We used the following search input: "lung cancer" AND "pneumonectomy" AND ("bronchopleural fistula" OR "BPF") AND ("tissue buttressing" OR "intercostal muscle flap" OR "mediastinal fat pad"). We analysed the types of studies, the numbers of patients, and the most important conclusions. We performed descriptive statistics.<b>Results:</b> Twenty-seven articles on the use of bronchial tissue buttressing were identified. Nine papers were rejected due to small sample size (< 20 patients), surgical operation other than pneumonectomy or lobectomy, or papers older than 30 years. Ultimately, 16 articles were included in the analysis. Among them, three papers highlighted the statistically significant influence of bronchial stump buttressing in reducing the risk of BPF formation. Descriptive statistics were reported in nine studies, and two papers included the assessment of the blood perfusion in the buttressing tissue. Only one study was a randomized trial featuring a control group for comparison.<b>Discussion:</b> Buttressing the bronchial stump remains a controversial issue in thoracic surgery. It could be beneficial for high-risk patients. Among different tissues, the ideal one has still not been identified. Future research should incorporate control groups and intraoperative assessments of the blood supply to the tissue employed for bronchial buttressing.

Real-time visualization of skeletal muscle necrosis in mice and swine through NIR-II/I fluorescence imaging

Avulsion often occurs in the limb due to heavy shearing forces which not only damage skeletal muscle but also main vessels, resulting in life-threatening muscle ischemia and necrosis. Defining muscle activity is vital for surgical repair. Currently, the color, capacity of blood, contractibility, and consistency (4C) are the primary principles for evaluating the activities of torn muscles. Based on clinical experiences, this standard turns out to be delayed diagnosis, which is not defined by specific parameters. Recently, near-infrared (NIR) fluorescence probes emitting within the second near-infrared window (NIR-II, 1000-1700 nm) have been widely used for non-invasive optical imaging because the tissue absorption and autofluorescence in the NIR-II region are negligible, thus allowing deeper penetration depths with micrometer-scale spatial resolution in vivo. As pathogenesis and development of muscle necrosis, necrosis-related protein may participate in this procedure. There is promising future for NIR-II to be used in evaluating muscle activity in avulsion. A new approach is developed based on experiments with mice and large animals (swine). Myoblasts were incubated with indocyanine green (ICG) to identify the necrosis muscles. The model of extremity damaged muscle was established for the real-time visualization and detection of developed necrosis muscle field under new equipment, both in balb/c mice (female) and long-haired swines. A visible NIR-II/I imaging system was first used in a large animal injured skeletal muscle-related model. Our NIR-II/I imaging system is suitable for evaluating the normal and injured skeletal muscle ICG cycle and pointing to the necrotic skeletal muscle tissue. NIR-II imaging is superior to NIR-I imaging in estimating skeletal muscle, best with 1100 nm filter. NIR-II fluorescence with 1100 nm filter is suitable for analyzing the progress of necrosis muscle tissue, leading to a new approach for intraoperative evaluation.

A case of laparoscopic sigmoidectomy using thermography for colonic blood flow assessment

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is widely used in gastrointestinal surgery and is considered useful for reducing anastomotic leakage; however, because ICG remains in the tissue for a certain amount of time, we occasionally must re-evaluate colonic blood flow over a short time period during surgery. Herein, we verify the usefulness of thermography (TG) for evaluating colonic blood flow in a patient who underwent a laparoscopic sigmoidectomy for sigmoid colon cancer.

CASE PRESENTATION

The patient is 43-year-old man who underwent laparoscopic resection of the sigmoid colon for colon cancer. After vascular treatment of the colonic mesentery, ICG/TG identified the boundary between ischemic and non-ischemic colon tissues. An additional 2 cm of colonic mesentery was resected because of the presence of a diverticulum noted at the intended site of oral anastomosis when attaching the anvil head. After additional vascular treatment of the colonic mesentery and administration of ICG, fluorescence was observed in the colon; however, TG identified the zone of the temperature transition on the surface of the colonic mesentery, even after additional colonic mesentery resection in the same region as previously observed. This zone was used as the cut-off line. There were no complications, such as anastomotic leakage, after the surgery.

CONCLUSION

Although accumulation of similar cases is necessary, TG has the potential for use as an auxiliary diagnostic tool in clinical practice. TG can depict the presence or absence of blood flow based on surface temperature without the use of imaging agents, and is inexpensive and easy to perform.

The technique of stump closure has no impact on post-pneumonectomy bronchopleural fistula in the non-small cell lung cancer-a cross-sectional study

Background

Pneumonectomy is a high-risk radical resection procedure, with bronchopleural fistula (BPF) being its most challenging and severe complication. This study aimed to assess the surgical risk factors and the impact of the bronchial stump closure technique on the incidence of the BPF.

Methods

This is a single-center, cross-sectional study of the medical records of 455 post-pneumonectomy patients operated due to non-small cell lung cancer (NSCLC) in 2006-2017. We analyzed the following variables and their influence on the occurrence of the BPF: operation side, surgical techniques (i.e., manual suture or the stapler), stump buttressing, the extension of pneumonectomy, comorbidities, and postoperative complications.

Results

BPF occurred in 7.47% of post-pneumonectomy patients. BPF was more prevalent in right-sided pneumonectomy versus left-sided (10.98% vs. 5.32%; P=0.026). The use of a stapler or manual suture was not associated with the incidence of the BPF (7.96% vs.7.09%, P=0.72). There were no significant differences in the occurrence of BPF among bronchial stump buttressing with the parietal pleura (P=0.80), intercostal muscle flap (IMF) (P=0.46), and pericardial fat pad (P=0.88). When comparing data from 2006-2012 with those from 2013-2017, we found a steady decrease in the number of performed stump reinforcements, but this was not associated with a higher risk of BPF.

Conclusions

The method used for stump closure, additional tissue buttressing of the bronchial stump and year of the surgery had no significant impact on the occurrence of BPF. Only right-sided pneumonectomy was associated with higher BPF occurrence.

The Role of ICG Angiography in Decision Making About Skin-Sparing in Pediatric Acute Trauma

BACKGROUND

Indocyanine green (ICG) angiography has proven useful in assessing skin flap perfusion in plastic and reconstructive surgeries. This research aimed to explore its role in decision making about skin-sparing in children's acute trauma.

METHODS

A total of 19 patients suffering with acute trauma from January 2019 to September 2021 were retrospectively assessed. Both ICG angiography and clinical judgment were performed to evaluate skin tissue viability. The intraoperative decisions for each case depended on the specific condition of the traumatic wound, including tissue perfusion, skin defect area, and location of the wound. Postoperative vascular imaging software was used to quantify the tissue perfusion, and the duration of postoperative follow-up was from 6 to 18 months.

RESULTS

Among them, 18 (94.7%) patients experienced treatments according to ICG angiography and did not develop postoperative necrosis. One case with right forearm trauma suffered from partial necrosis. Hypertrophic scar and local infection were the independent complications, which were managed by symptomatic treatment.

CONCLUSION

ICG angiography may reduce the risk of postoperative necrosis and renders a promising adjunctive technique for surgeons to make reasonable decisions in skin sparing in acute pediatric trauma.

Changes in pedicle pericardial fat tissue around the anastomotic site after tracheobronchoplasty

PURPOSE

Pericardial fat is appropriate tissue to cover the bronchial anastomotic site because its harvesting is minimally invasive. We investigated the changes in pericardial fat tissue around the anastomotic site after pulmonary resection with tracheobronchoplasty.

METHODS

The subjects of this study were 43 lung cancer patients who underwent pulmonary resection with tracheobronchoplasty. We measured the maximum cross-sectional area and average computed tomography (CT) values of the pedicle pericardial fat pad around the anastomotic site 1 week and then 6 months after the operation.

RESULTS

The average volume of the residual pedicle pericardial fat pad 6 months postoperatively was 61%. A body mass index (BMI) < 21.2 kg/m² (P = 0.031) and a blood albumin level < 3.4 g/dl (P = 0.005) were significant predictors of pedicle flap shrinkage. Patients with fat tissue shrinkage had significantly elevated CT values 6 months postoperatively (P = 0.029), whereas those without shrinkage maintained low CT values.

CONCLUSIONS

Preoperative nutritional conditions, reflected in high BMI and blood albumin levels, correlated with a high residual pedicle pericardial fat pad. Conversely, patients with pedicle flap shrinkage had significantly increased CT values, suggesting that the fat might have taken on another form such as scar tissue.

Intraoperative bronchial blood flow evaluation using indocyanine green fluorescence for bronchoplasty: A case report

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Indocyanine green fluorescence (ICG-FL) detects blood flow of the bronchial artery.

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ICG-FL is effective for blood flow evaluation after bronchial artery embolization.

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Bronchial blood flow evaluation may reduce the risk of anastomotic leakage.

Introduction and importance

Blood flow evaluation of bronchial arteries using indocyanine green fluorescence (ICG-FL) is rarely reported during pulmonary resection. We present the case of a patient with bronchiectasis and a history of bronchial artery embolization (BAE) for hemoptysis. Bronchial artery blood flow was evaluated using ICG-FL during lobectomy with bronchoplasty.

Case presentation

A 63-year-old woman presented with right middle lobe bronchiectasis (due to nontuberculous mycobacteriosis) and repeated hemoptysis, which had previously been corrected each time with hemostasis by BAE. Bronchoscopy revealed a swollen blood vessel proximal to the right middle lobe bronchus that was suspected of being the origin of bleeding. Right middle lobectomy with bronchoplasty was performed to prevent hemoptysis. ICG-FL was used to detect the patency of the right bronchial arteries, and the arteries surrounding the right middle lobe bronchus were ligated. The proximal side of the right middle lobe bronchus was cut in a deep wedge shape, and the bronchus was anastomosed. ICG-FL revealed that the blood supply was maintained at the bronchial anastomosis. No bronchial anastomotic leakage was observed after the surgery.

Clinical discussion

The key to successful bronchoplasty is the maintenance of blood flow. Bronchial artery blood flow theoretically decreases after BAE. In this case, ICG-FL was able to detect bronchial artery patency before cutting the bronchus as well as the maintenance of blood flow at the bronchial anastomosis after bronchoplasty.

Conclusion

Intraoperative blood flow evaluation of the bronchus using ICG-FL may reduce the risk of bronchial anastomotic leakage caused by ischemia after bronchoplasty.