Indocyanine Green Fluorescence-Guided Enucleation via the Serosal Approach for Benign Subepithelial Tumors of the Gastroesophageal Junction
Article information
Abstract
Subepithelial tumors (SETs) located at the gastroesophageal (GE) junction remain technically challenging in minimally invasive surgery because the convergence of the esophageal sphincter, diaphragmatic hiatus, and gastric fundus creates a confined operative field. When a tumor is fully embedded within the muscular layer, its capsular margin is often indistinguishable from the serosal surface, making precise enucleation technically demanding. To address this limitation, we adopted a fluorescence-guided technique that enables accurate intraoperative localization of the tumor through indocyanine green (ICG) injection. After induction of anesthesia, approximately 0.1–0.2 mL (0.05–0.1 mg) of ICG diluted in normal saline is injected endoscopically into the submucosal plane at the tumor site for benign SETs. During surgery, near-infrared visualization provides a distinct fluorescent margin that guides safe serosal incision and enucleation while preserving the mucosa and the anatomy of the GE junction. This technique is particularly useful for benign, well-encapsulated lesions such as leiomyoma or ectopic pancreas, where clear dissection planes can be preserved. However, it should not be used for lesions with any suspicion of gastrointestinal stromal tumor or other malignant potential, because capsular or intratumoral injection may pose a theoretical risk of tumor cell dissemination. Careful peritumoral submucosal injection that avoids capsular disruption may be cautiously considered. In selected benign tumors, ICG-guided serosal enucleation provides clear localization, facilitates complete resection, and minimizes both functional and structural complications at the GE junction.
Introduction
Subepithelial tumors (SETs) located at the gastroesophageal (GE) junction represent one of the most technically challenging entities in minimally invasive gastric surgery. Standard procedures such as wedge resection carry a high risk of GE stricture, while enucleation increases the risk of leakage and mucosal injury, particularly for tumors originating from the muscularis propria with limited serosal exposure [1].
Fluorescence-guided surgery using indocyanine green (ICG) has recently emerged as a valuable adjunct for intraoperative visualization. Although ICG is widely used for perfusion assessment and lymphatic mapping, its selective injection near benign, encapsulated lesions such as insulinomas has also been shown to enhance tumor localization [2].
Gastric SETs encompass various entities, including gastrointestinal stromal tumors (GISTs), leiomyomas, schwannomas, and ectopic pancreas. While not suitable for all cases due to oncological concerns, ICG-guided enucleation may represent a useful option for benign, well-encapsulated tumors [3].
Herein, we describe our experience with ICG-guided serosal enucleation for benign SETs at the GE junction, which enables precise tumor localization and safe resection while preserving mucosal integrity and sphincter function.
Case Presentation
A 37-year-old female presented with intermittent abdominal discomfort. Esophagogastroduodenoscopy (EGD) performed 2 years earlier had revealed a small SET at the GE junction, which showed interval growth on follow-up EGD and abdomen computed tomography (3.6×1.8 cm). The lesion demonstrated homogeneous enhancement without ulceration, consistent with a leiomyoma. The patient underwent laparoscopic ICG-guided serosal approach enucleation (Video). After induction of anesthesia and before surgical draping, an intraoperative endoscopy was performed to confirm the lesion location and assess its endoluminal characteristics. In cases where the lesion is strongly suggestive of benign pathology—such as leiomyoma or ectopic pancreas, as in the present case—a small amount of ICG (approximately 0.1–0.2 mL, corresponding to 0.05–0.1 mg diluted in normal saline) is injected directly into the tumor. Although, in theory, the ideal approach would be to position the needle within the potential space between the capsule and the tumor, this is technically unrealistic because the true capsule is extremely thin and cannot be reliably visualized endoscopically. Therefore, in practical application, gently puncturing the tumor surface and injecting ICG intratumorally allows the dye to spread into the potential space between the capsule and the tumor. On laparoscopic near-infrared imaging, the capsule then becomes clearly delineated from the surrounding tissue, enabling successful enucleation of the tumor. In this case, a small mucosal defect was identified after enucleation and repaired with interrupted primary sutures, followed by continuous barbed suture closure of the seromuscular layer. Intraoperative endoscopy was used to check the GE junction for narrowing or bleeding, while an air leak test was performed laparoscopically. No air leakage was detected. The final pathology confirmed leiomyoma. The patient resumed oral intake on postoperative day 1 and was discharged on day 3 without complications. This study was approved by the Institutional Review Board (IRB) of Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea (approval number: KC25ZISI0817). The requirement for written informed consent was waived by the IRB because this single-patient case report used only anonymized data.
Discussion
Management of GE-junction SETs demands a balance of oncologic safety, functional preservation, and technical feasibility within a very restricted operative field. To address these challenges, various approaches—including laparoscopic transgastric enucleation [4], laparoscopic transgastric resection [5], and laparoscopic-endoscopic cooperative surgery [6]—have been described, although no standardized method has been established [7].
Serosal enucleation has emerged as a compelling alternative in appropriately selected patients. By preserving the gastric contour and maintaining mucosal and junctional integrity, this technique offers the promise of functionally superior outcomes [8]. However, a significant limitation remains: many SETs—particularly those originating from the muscularis propria—are deeply embedded and lack the external bulging necessary for visual identification. In such cases, blind dissection may increase the risk of mucosal perforation, incomplete resection, or altered junctional mechanics. Recent studies underscore this challenge in GE junction SETs, noting the heightened technical demands in achieving safe and effective enucleation at this location.
Fluorescence-guided surgery using ICG offers real-time demarcation of the capsular plane without disrupting the lesion. Selection submucosal injection at peritumoral or tumor site has been shown to improve intraoperative localization in benign, well-encapsulated tumors such as insulinoma, without oncologic signal for harm; by diffusing along loose connective tissue, ICG highlights dissection planes and may reduce unnecessary muscular injury [2,9,10].
However, this technique must be applied with caution: in lesions where malignancy cannot be excluded, injection into the capsule or tumor parenchyma remains contraindicated due to the theoretical risk of tumor cell dissemination. Therefore, this technique was applied to SETs that were histologically confirmed as benign through preoperative EGD- or endoscopic ultrasound (EUS)-guided biopsy, or strongly suspected to be benign based on EUS and/or computed tomography findings, such as leiomyoma or ectopic pancreas [3]. In cases of GISTs or lesions with malignant potential, a peritumoral submucosal injection—similar to the technique used for ICG lymphography during gastric cancer surgery—could be considered. Even a small-volume injection at the submucosal plane provides sufficient fluorescence to localize the tumor intraoperatively without compromising oncologic safety. Although not applicable to the present case, we have previously encountered situations where very small or flat lesions were not readily identifiable from the serosal surface; in those instances, peritumoral submucosal injection allowed accurate localization and facilitated safe enucleation.
Nevertheless, from a technical perspective, ICG-guided serosal enucleation delivers several advantages. It enhances visualization of deeply embedded lesions without serosal bulging, facilitates capsular-plane dissection for complete enucleation with minimal tissue injury, and helps preserve mucosal and junctional integrity, reducing leakage or stricture. In narrow GE junction, the technique enables safe closure with tension-free barbed suture techniques that further supports functional preservation.
In conclusion, ICG-guided serosal enucleation offers a practical, safe, and function-preserving surgical option for benign GE-junction SETs. Combining endoscopic ICG injection with near-infrared imaging enables accurate localization and complete resection while preserving junctional anatomy. Going forward, prospective studies will be essential to refine technique parameters and evaluate short and long-term outcomes.
Notes
Disclosure
No potential conflict of interest relevant to this article was reported.
Author contributions
Conceptualization: JHP, HSS, HHL; Data curation: JHP, SK; Resources: SK, HSS, KYS, HHL; Formal analysis: JHP; Investigation: JHP; Methodology: JHP, HSS, HHL; Supervision: KYS, HHL; Visualization: JHP; Writing–original draft: JHP; Writing–review & editing: JHP, SK, HSS, KYS, HHL.