Near-infrared fluorescence imaging with indocyanine green to assess the blood supply of the reconstructed gastric conduit to reduce anastomotic leakage after esophagectomy: a literature review

Visualization of cecal tumor by near-infrared laparoscopy and intraoperative colonoscopy

BACKGROUND

In laparoscopic colorectal surgery, accurate localization of a tumor is essential for ensuring an adequate ablative margin. Therefore, a new method, near-infrared laparoscopy combined with intraoperative colonoscopy, was developed for visualizing the contour of a cecal tumor from outside of the bowel. The method was used after it was verified on a model that employed a silicone tube.

CASE PRESENTATION

The patient was a 77-year-old man with a cecal tumor near the appendiceal orifice. Laparoscopy was used to clamp of the terminal ileum, and a colonoscope was then inserted through the anus to the cecum. The laparoscope in the normal light mode could not be used to identify the cecal tumor. However, a laparoscope in the near-infrared ray mode could clearly visualize the contour of the cecal tumor from outside of the bowel, and the tumor could be safely resected by a stapler. The histopathological diagnosis of the resected specimen was adenocarcinoma with an invasion depth of M and a clear negative margin.

CONCLUSIONS

This is the first report of the laparoscopic detection of the contour of a cecal tumor from outside the bowel. This technique is useful and safe for contouring tumors in laparoscopic colorectal surgery and can be used in various surgeries that combine endoscopy and laparoscopy.

Blood flow evaluation of reconstructed gastric tube in esophageal surgery using near-infrared imaging and retrospective time-intensity curve analysis

PURPOSE

Near-infrared fluorescence imaging using indocyanine green (ICG-NIFI) can visualize a blood flow in reconstructed gastric tube; however, it depends on surgeon's visual assessment. The aim of this study was to re-analyze the ICG-NIFI data by an evaluator independent from the surgeon and feasibility of creating the time-intensity curve (TIC).

METHODS

We retrospectively reviewed 97 patients who underwent esophageal surgery with gastric tube reconstruction between January 2017 and November 2022. From the stored ICG videos, fluorescence intensity was examined in the four regions of interest (ROIs), which was set around the planned anastomosis site on the elevated gastric tube. After creation the TICs using the OpenCV library, we measured the intensity starting point and time constant and assessed the correlation between the anastomotic leakage.

RESULTS

Postoperative leakage occurred for 12 patients. The leakage group had significantly lack of blood flow continuity between the right and left gastroepiploic arteries (75.0% vs. 22.4%; P < 0.001) and tended to have slower ICG visualization time assessed by the surgeon's eyes (40 vs. 32 s; P = 0.066). TIC could create in 65 cases. Intensity starting point at all ROIs was faster than the surgeon's assessment. The leakage group tended to have slower intensity starting point at ROI 3 compared to those in the non-leakage group (22.5 vs. 19.0 s; P = 0.087).

CONCLUSION

A TIC analysis of ICG-NIFI by an independent evaluator was able to quantify the fluorescence intensity changes that the surgeon had visually determined.

Blood flow ratio in the gastric conduit measured by laser Doppler flowmetry: A predictor of anastomotic leakage after esophagectomy

Background

Anastomotic leakage after esophagectomy is a common complication. Laser Doppler flowmetry (LDF) can quantitatively evaluate the blood flow in the gastric conduit.

Methods

A total of 326 patients who underwent thoracoscopic/robot-assisted esophagectomy followed by gastric conduit reconstruction and end-to-side anastomosis were enrolled. We divided the gastric conduit into zones I (dominated by the right gastroepiploic vessels), II (dominated by the left gastroepiploic vessels), and III (perfused with short gastric vessels). Before pulling up the gastric conduit to the neck, LDF values were measured at the pylorus, the border between zones I and II (zone I/II), the border between zones II and III (zone II/III), and the gastric conduit tip (tip). The blood flow ratio was calculated as the LDF value divided by the LDF value at the pylorus.

Results

Anastomotic leakage developed in 32 of 326 patients. Leakage was significantly associated with the blood flow ratio at the tip (p < 0.001), but not at zone I/II, zone II/III, and the anastomotic site. The receiver-operating characteristic curve analysis identified an anastomotic leakage cutoff ratio of 0.41 (at the tip). A multivariate Cox analysis showed that a blood flow ratio <0.41 at the tip was an independent risk factor for anastomotic leakage (p < 0.001).

Conclusion

Anastomotic leakage after esophagectomy was significantly associated with the blood flow ratio at the tip of the gastric conduit. Preservation of the blood supply to the tip via the gastric wall might contribute to a decreased incidence of anastomotic leakage.

Application of near-infrared fluorescence imaging in theranostics of gastrointestinal tumors

Gastrointestinal cancers have become an important cause of cancer-related death in humans. Improving the early diagnosis rate of gastrointestinal tumors and improving the effect of surgical treatment can significantly improve the survival rate of patients. The conventional diagnostic method is high-definition white-light endoscopy, which often leads to missed diagnosis. For surgical treatment, intraoperative tumor localization and post-operative anastomotic state evaluation play important roles in the effect of surgical treatment. As a new imaging method, near-infrared fluorescence imaging (NIRFI) has its unique advantages in the diagnosis and auxiliary surgical treatment of gastrointestinal tumors due to its high sensitivity and the ability to image deep tissues. In this review, we focus on the latest advances of NIRFI technology applied in early diagnosis of gastrointestinal tumors, identification of tumor margins, identification of lymph nodes, and assessment of anastomotic leakage. In addition, we summarize the advances of NIRFI systems such as macro imaging and micro imaging systems, and also clearly describe the application process of NIRFI from system to clinical application, and look into the prospect of NIRFI applied in the theranostics of gastrointestinal tumors.

The effect of anastomotic leakage on the incidence of recurrence after tri-modality therapy for esophageal adenocarcinomas

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRTx) reduces the incidence of recurrence, while anastomotic leakage has shown increase the risk of recurrence. The primary objective of this retrospective study was to investigate the incidence and pattern of recurrence and secondary median recurrence-free interval and post-recurrence survival in patients with and without anastomotic leakage after multimodal therapy for esophageal adenocarcinoma.

METHODS

Patients with recurrence after multimodal therapy between 2010 and 2018 were included.

RESULTS

Six hundred and eighteen patients were included, 91 (14.7%) had leakage and 278 (45.0%) recurrence. Patients with leakage did not develop recurrence more often (48.4%) than those without (44.4%, [p = 0.484]). Recurrence-free interval for patients with (n = 44) and without leakage (n = 234) was 39 and 52 weeks, respectively (p = 0.049). Post-recurrence survival was 11 and 16 weeks, respectively (p = 0.702). Specified by recurrence site, post-recurrence survival for loco-regional recurrences was 27 versus 33 weeks (p = 0.387) for patients with and without leakage, for distant 9 versus 13 (p = 0.999), and for combined 11 versus 18 weeks (p = 0.492).

CONCLUSION AND DISCUSSION

No higher incidence of recurrent disease was observed in patients with anastomotic leakage, however it is associated with a shorter recurrence-free interval. This could have implications for surveillance, as early detection of recurrent disease could influence therapeutic options.