Near infra-red fluorescence identification of the thoracic duct to prevent chyle leaks during oesophagectomy

Does Thoracic Duct Ligation at the Time of Esophagectomy Impact Long-Term Survival? An Individual Patient Data Meta-Analysis

Background: Thoracic duct ligation (TDL) during esophagectomy has been proposed to reduce the risk of postoperative chylothorax. Because of its role in immunoregulation, some authors argued that it had an unfavorable TDL effect on survival. The aim of this study was to analyze the effect of TDL on overall survival (OS). Methods: PubMed, MEDLINE, Scopus, and Web of Science were searched through December 2023. The primary outcome was 5-year OS. The restricted mean survival time difference (RMSTD), hazard ratios (HRs), and 95% confidence intervals (CI) were used as pooled effect size measures. The GRADE methodology was used to summarize the certainty of the evidence. Results: Five studies (3291 patients) were included. TDL was reported in 54% patients. The patients' age ranged from 49 to 69, 76% were males, and BMI ranged from 18 to 26. At the 5-year follow-up, the combined effect from the multivariate meta-analysis is -3.5 months (95% CI -6.1, -0.8) indicating that patients undergoing TDL lived 3.5 months less compared to those without TDL. TDL was associated with a significantly higher hazard for mortality at 12 months (HR 1.54, 95% CI 1.38-1.73), 24 months (HR 1.21, 95% CI 1.12-1.35), and 28 months (HR 1.14, 95% CI 1.02-1.28). TDL and noTDL seem comparable in terms of the postoperative risk for chylothorax (RR = 0.66; p = 0.35). Conclusions: In this study, concurrent TDL was associated with reduced 5-year OS after esophagectomy. This may suggest the need of a rigorous follow-up within the first two years of follow-up.

Thoracoscopy-Assisted Esophagectomy for Esophageal Leiomyomatosis

INTRODUCTION

Diffuse esophageal leiomyomatosis is a rare esophageal tumor characterized by circumferential thickening of smooth muscle layers of the entire esophagus. CLINICAL CASE: Herein, we describe the case of a 19-year-old girl, who presented with a history of long-standing dysphagia. On evaluation she was found to have diffuse esophageal leiomyomatosis and was managed successfully by thoracoscopy-assisted esophagectomy with intra-nodal indocyanine green injection.

DISCUSSION

In this report, we discuss the pre-operative workup and our surgical approach to managing this rare entity. We also discuss the available literature on the subject and the lessons learnt in managing this complex condition.

A comparative study of indocyanine green instillation in inguinal node versus foot web space using da Vinci indocyanine green FireFly™ technology in identifying thoracic duct during robotic-assisted transthoracic oesophagectomy

INTRODUCTION

Chyle leak is a serious complication following oesophagectomy with incidence varies from 1% to 9%. Near infra-red fluorescence imaging of thoracic duct (TD) can provide real-time dynamic imaging during the surgery. In this study, we intend to compare indocyanine green (ICG) dye instillation through inguinal node with subcutaneous first web space instillation for visualisation of TD during robotic-assisted minimally invasive oesophagectomy (RAMIE) procedure.

PATIENTS AND METHODS

A prospective study of 50 patients underwent RAMIE with da Vinci X System. After general anaesthesia, patients were divided into inguinal node and foot first web space ICG instillation group. The former group had 1 ml of ICG dye instilled on bilateral inguinal nodes under ultrasound guidance and while the other group received 1 mL of ICG dye injected at bilateral foot first web space and then underwent surgery. TD was visualised using ICG FireFly™ fluorescence technology, first at the time of docking and subsequently for every 5 min until 60 min of instillation time and analysed.

RESULTS

Twenty-five patients were enrolled in each group. The mean docking time for thoracic phase was 13.76 ± 3.43 min. TD was visualised in 72% (18/25) of cases of first web space instillation group, whereas 100% in ultrasound guidance inguinal node instillation group. None of the patients had a chyle leak.

CONCLUSION

ICG FireFly™ fluorescence technology for the identification of TD during oesophageal mobilisation is safe and effective and provides real-time dynamic visualisation with high accuracy in ultrasound-guided bilateral inguinal node instillation group. It is an effective method for the surgeons planning to negotiate their initial learning curve in RAMIE procedures.

Application of near-infrared fluorescence imaging with indocyanine green in mediastinal surgery

Intraoperative near-infrared (NIR) fluorescence imaging has emerged in recent years and is now used in many surgical procedures. Intraoperative fluorescence imaging can guide surgeons in identifying and localizing specific structures and boundaries, which can facilitate the optimization of surgical procedures. The components of the mediastinum are complex and functionally important, making identifying and locating different structures intraoperatively challenging, and NIR fluorescence imaging has potential clinical value in mediastinal surgery. Here we review the applications of NIR fluorescence imaging technology in mediastinal surgery in recent years.

Impact of fluorescent thoracic duct lymphography via intranodal approach in minimal access esophageal cancer surgery

PURPOSE

Chyle leak resulting from thoracic duct (TD) injury poses significant morbidity and mortality challenges. We assessed the feasibility of using near-infrared (NIR) indocyanine green (ICG) imaging for intraoperative fluorescence TD lymphography during minimal access esophagectomy (MAE) in a semiprone position with inguinal nodal injection of ICG dye.

METHODS

Ninety-nine patients with esophageal or gastroesophageal junctional cancer undergoing MAE received inguinal node injections of 2.5 mg ICG dye (total 5 mg) under sonographic guidance during anesthesia induction. Stryker's 1688 AIM HD system was used in 76 cases, Karl Storz OPAL 1 S in 20, and in three cases the Karl Storz Rubina.

RESULTS

In 93 patients (94%), the TD was clearly delineated along its entire length; it was not visualized in 6 patients (6%). Fluorescence guidance facilitated TD ligation in 16 cases, while 3 cases required clipping of duct tributaries for oncological considerations. Twenty-eight patients exhibited minor duct variations. Fluorescence was sustained throughout surgery (median observation time 60 min post-injection; range 30-330). No patient experienced any chyle leak within 30 days post-surgery and no adverse reactions to ICG was evident.

CONCLUSIONS

Intraoperative fluorescence TD lymphography using ICG during MAE in a semiprone position with inguinal nodal injection proved safe, feasible, and effective, allowing clear visualization of the TD in almost all cases. This approach aids safe ligation and reduces chyle leak risk. It offers real-time imaging of TD anatomy and variations, providing valuable feedback to surgeons for managing TD injuries during MAE procedures and represents an excellent educational tool.

Quantification of Indocyanine Green Fluorescence Imaging in General, Visceral and Transplant Surgery

Near-infrared (NIR) imaging with indocyanine green (ICG) has proven to be useful in general, visceral, and transplant surgery. However, most studies have performed only qualitative assessments. Therefore, a systematic overview of all studies performing quantitative indocyanine green evaluation in general, visceral, and transplant surgeries should be conducted. Free term and medical subject heading (MeSH) term searches were performed in the Medline and Cochrane databases until October 2022. The main categories of ICG quantification were esophageal surgery (24.6%), reconstructive surgery (24.6%), and colorectal surgery (21.3%). Concordantly, anastomotic leak (41%) was the main endpoint, followed by the assessment of flap perfusion (23%) and the identification of structures and organs (14.8%). Most studies examined open surgery (67.6%) or laparoscopic surgery (23.1%). The analysis was mainly carried out using manufacturer software (44.3%) and open-source software (15.6%). The most frequently analyzed parameter was intensity over time for blood flow assessment, followed by intensity alone or intensity-to-background ratios for structure and organ identification. Intraoperative ICG quantification could become more important with the increasing impact of robotic surgery and machine learning algorithms for image and video analysis.

[ICG lymph node mapping in cancer surgery of the upper gastrointestinal tract]

The importance of the assessment of the N‑status in gastric carcinoma, tumors of the gastroesophageal junction and esophageal cancer is undisputed; however, there is currently no internationally validated method for lymph node mapping in esophageal and gastric cancer. Near-infrared fluorescence imaging (NIR) is an innovative technique from the field of vibrational spectroscopy, which in combination with the fluorescent dye indocyanine green (ICG) enables intraoperative real-time visualization of anatomical structures. The ICG currently has four fields of application in oncological surgery: intraoperative real-time angiography for visualization of perfusion, lymphography for visualization of lymphatic vessels, visualization of solid tumors, and (sentinel) lymph node mapping. For imaging of the lymph drainage area and therefore the consecutive lymph nodes, peritumoral injection of ICG must be performed. Several studies have demonstrated the feasibility of peritumoral injection of ICG administered 15 min to 3 days preoperatively with subsequent intraoperative visualization of the lymph nodes. So far prospective randomized studies on the validation of the method are still lacking. In contrast, the use of ICG for lymph node mapping and visualization of sentinel lymph nodes in gastric cancer has been performed in large cohorts as well as in prospective randomized settings. Up to now, multicenter studies for ICG-guided lymph node mapping during oncological surgery of the upper gastrointestinal tract are lacking. Artificial intelligence methods can help to evaluate these techniques in an automated manner in the future as well as to support intraoperative decision making and therefore to improve the quality of oncological surgery.

Intra-Nodal Indocyanine Green Injection to Delineate Thoracic Duct During Minimally Invasive Esophagectomy

INTRODUCTION

Post-operative chylothorax is a dreaded complication after esophagectomy; hence real-time identification of the thoracic duct (TD) may aid in avoiding its injury or promptly tackling injury when it occurs. We utilized intra-nodal injection of Indocyanine green (ICG) dye to delineate TD anatomy while performing esophagectomy for esophageal carcinoma.

METHOD

Two ml of 1 mg/ml solution of ICG was injected into the inguinal lymph nodes under ultrasound guidance. TD was checked with the laparoscopic Karl Storz IMAGE1 S^TM or Robotic da Vinci Xi system. The thoracic esophagus, periesophageal tissue, and lymph nodes were dissected. The TD was visualized throughout the dissection using Overlay^TM technology & Firefly mode™ and checked at the end to rule out any dye leak. TD was clipped if any dye leakage or TD injury (TDI) was noted using Near Infra-Red Spectroscopy.

RESULTS

Twenty one patients with M:F 13:8 underwent minimally invasive esophagectomy (MIE) [thoracoscopic assisted (n = 15) and robotic-assisted (n = 6)]. TD was visualized in all the cases after a median (IQR) time of 35 (30, 35) min. The median (IQR) duration of the thoracic phase was 150 (120,165) min. TDI occurred in 1 case, identified intra-operatively, and TD was successfully clipped. There were no post-operative chylothorax or adverse reactions from the ICG injection.

CONCLUSION

Intra-nodal ICG injection before MIE helps to identify the TD in real-time and is a valuable intra-operative aid to prevent or successfully manage a TD injury. It may help to prevent the dreaded complication of post-operative chylothorax after esophagectomy.