Background Anastomotic leakage remains a critical complication following esophagectomy, occurring in 8–20% of patients. While indocyanine green fluorescence imaging (ICG-FI) is commonly used to assess perfusion, it requires dye injection and does not directly measure tissue metabolism. This study evaluates a real-time, contrast-free spectral imaging (SI) system for quantifying gastric conduit oxygenation (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\mathrm {StO_{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">StO</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation>) and compares its performance to ICG-FI. Methods Intraoperative SI was successfully performed in 33 patients undergoing laparoscopic Ivor Lewis esophagectomy using a video-rate snapshot spectral camera, acquiring 16 spectral bands in the 460–600 nm range. A deep learning model estimated <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\mathrm {StO_{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">StO</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> of the gastric conduit and quantitative perfusion metrics were derived from ICG-FI time-intensity curves. Local capillary lactate levels were measured as a physiological reference for tissue hypoxia. Statistical analyses compared <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$\mathrm {StO_{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">StO</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> and ICG-FI metrics. Results SI successfully differentiated well-perfused from ischemic tissue (median <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$\mathrm {StO_{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">StO</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation>: <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$69.16\%$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>69.16</mn> <mo>%</mo> </mrow> </math></EquationSource> </InlineEquation> vs. <InlineEquation ID="IEq6"> <EquationSource Format="TEX">$31.58\%$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>31.58</mn> <mo>%</mo> </mrow> </math></EquationSource> </InlineEquation>, p < 0.001). The estimated <InlineEquation ID="IEq7"> <EquationSource Format="TEX">$\mathrm {StO_{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">StO</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> showed a strong negative correlation with local capillary lactate (r=-0.72, p < 0.001). While quantitative ICG-FI metrics (<InlineEquation ID="IEq8"> <EquationSource Format="TEX">$\mathrm {T_{1/2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">T</mi> <mrow> <mn>1</mn> <mo stretchy="false">/</mo> <mn>2</mn> </mrow> </msub> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq9"> <EquationSource Format="TEX">$\mathrm {AUC_{50\%}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">AUC</mi> <mrow> <mn>50</mn> <mo>%</mo> </mrow> </msub> </math></EquationSource> </InlineEquation>) revealed significantly reduced perfusion at the anastomosis site compared to well-perfused tissue (p < 0.001), they showed only a moderate correlation with <InlineEquation ID="IEq10"> <EquationSource Format="TEX">$\mathrm {StO_{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">StO</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> (r=0.50, p < 0.001). Notably, in a patient who developed anastomotic leakage, both modalities detected ischemia intraoperatively, but they show different transition borders, with SI indicating a more extensive hypoxic area than ICG-FI. Conclusion Snapshot SI provides a real-time, objective assessment of tissue oxygenation without the need for contrast agents. Its strong correlation with lactate suggests it may offer potential complementary value to dye-based perfusion imaging, potentially improving anastomotic site selection, although outcome-based validation studies in larger cohorts are needed.

Intraoperative spectral imaging versus ICG fluorescence for gastric conduit viability in esophagectomy

期刊论文
出版模式：

开放获取
发表日期：

2026年7月23日

查看全文

Jens De Winne,
Hanne Vanommeslaeghe,
Danilo Babin,
Hiep Luong,
Siri Luthman,
Elke Van Daele,
Wim Ceelen

摘要

Background

Anastomotic leakage remains a critical complication following esophagectomy, occurring in 8–20% of patients. While indocyanine green fluorescence imaging (ICG-FI) is commonly used to assess perfusion, it requires dye injection and does not directly measure tissue metabolism. This study evaluates a real-time, contrast-free spectral imaging (SI) system for quantifying gastric conduit oxygenation ( $\mathrm {StO_{2}}$ ${StO}_{2}$ ) and compares its performance to ICG-FI.

Methods

Intraoperative SI was successfully performed in 33 patients undergoing laparoscopic Ivor Lewis esophagectomy using a video-rate snapshot spectral camera, acquiring 16 spectral bands in the 460–600 nm range. A deep learning model estimated $\mathrm {StO_{2}}$ ${StO}_{2}$ of the gastric conduit and quantitative perfusion metrics were derived from ICG-FI time-intensity curves. Local capillary lactate levels were measured as a physiological reference for tissue hypoxia. Statistical analyses compared $\mathrm {StO_{2}}$ ${StO}_{2}$ and ICG-FI metrics.

Results

SI successfully differentiated well-perfused from ischemic tissue (median $\mathrm {StO_{2}}$ ${StO}_{2}$ : $69.16\%$ $69.16 %$ vs. $31.58\%$ $31.58 %$ , p < 0.001). The estimated $\mathrm {StO_{2}}$ ${StO}_{2}$ showed a strong negative correlation with local capillary lactate (r=-0.72, p < 0.001). While quantitative ICG-FI metrics ( $\mathrm {T_{1/2}}$ $T_{1 / 2}$ and $\mathrm {AUC_{50\%}}$ ${AUC}_{50 %}$ ) revealed significantly reduced perfusion at the anastomosis site compared to well-perfused tissue (p < 0.001), they showed only a moderate correlation with $\mathrm {StO_{2}}$ ${StO}_{2}$ (r=0.50, p < 0.001). Notably, in a patient who developed anastomotic leakage, both modalities detected ischemia intraoperatively, but they show different transition borders, with SI indicating a more extensive hypoxic area than ICG-FI.

Conclusion

Snapshot SI provides a real-time, objective assessment of tissue oxygenation without the need for contrast agents. Its strong correlation with lactate suggests it may offer potential complementary value to dye-based perfusion imaging, potentially improving anastomotic site selection, although outcome-based validation studies in larger cohorts are needed.