Predictive value of portal venous phase computed tomography parameters for anastomotic stricture after D2 gastrectomy

Abstract

BACKGROUND

The most common complication in D2 gastrectomy for gastric cancer is the anastomotic stricture, with reported incidence between 3% and 15%. Appropriate tissue perfusion is essential at all time points during the inflammatory, proliferative, and remodeling phases of anastomotic healing. Portal venous phase computed tomography (CT), a study universally indicated for preoperative staging and postoperative re-evaluation, is an objective assessment of visceral hemodynamic status that may impact anastomotic healing. Yet the predictive value of preoperative CT portal venous parameters for risk of anastomotic stricture has not yet been investigated, and reliable preoperative stratification tools are urgently needed. Deep learning-based portal venous CT parameters have been particularly well-studied for liver cirrhosis and portal hypertension, but this is the first time they have been studied in predicting gastrointestinal anastomotic complications.

AIM

To prospectively explore the predictive power of preoperative enhanced CT portal venous phase quantitative parameters for anastomotic stricture after D2 gastrectomy for gastric cancer to establish a combined prediction model.

METHODS

Clinical data from 199 patients who underwent D2 gastrectomy for gastric cancer at our institution between January 2022 and June 2024 were retrospectively analyzed. Patients were categorized into stricture group (n = 23) and non-stricture group (n = 176) based on whether anastomotic stricture occurred within 12 months postoperatively. On preoperative enhanced CT portal venous phase images, main portal vein (PV) CT value (PV-HU), splenic vein CT value, hepatic parenchyma, and abdominal aorta were measured. Derived parameters including normalized PV-HU (nPV-HU) and PV-to-abdominal aorta CT value (aorta-HU) ratio were calculated. Multivariate logistic regression analysis was employed to identify independent predictive factors. Receiver operating characteristic curves were constructed to evaluate predictive performance, and a combined prediction model was developed.

RESULTS

The postoperative anastomotic stricture rate was 11.6% (23/199). The stricture group demonstrated significantly lower PV-HU, splenic vein CT value, PV-to-aorta-HU ratio, and nPV-HU compared to the non-stricture group (P < 0.05). Multivariate logistic regression analysis revealed that body mass index ≥ 25 kg/m², diabetes mellitus, total gastrectomy, 25 mm stapler diameter, decreased nPV-HU, and decreased PV-to-aorta-HU ratio were independent risk factors for anastomotic stricture (P < 0.05). For predicting anastomotic stricture, nPV-HU yielded an area under the curve (AUC) of 0.812, with an optimal cutoff value of 42.5%, sensitivity of 78.3%, and specificity of 72.7%; PV-to-aorta-HU ratio yielded an AUC of 0.768, with an optimal cutoff value of 1.45, sensitivity of 73.9%, and specificity of 71.0%. The combined prediction model incorporating clinical factors and CT parameters achieved an AUC of 0.893, with sensitivity of 87.0%, specificity of 80.1%, and negative predictive value of 97.9%.

CONCLUSION

Preoperative enhanced CT portal venous phase quantitative parameters nPV-HU and PV-to-aorta-HU ratio can effectively predict the risk of anastomotic stricture following D2 gastrectomy for gastric cancer. The prediction model combining clinical risk factors demonstrates high diagnostic performance and provides a strong imaging-based rationale for preoperative risk stratification, potentially guiding personalized perioperative management strategies.

Keywords: Gastric cancer; D2 gastrectomy; Anastomotic stricture; Enhanced computed tomography; Portal venous phase; Prediction model

Core Tip: Preoperative quantitative perfusion indicators of portal venous phase computed tomography (CT) relevant to the anastomotic healing. Increased risk of postoperative anastomotic stricture after D2 gastrectomy was significantly associated with decreased normalized portal vein (PV) CT value and reduced PV-to-aorta CT value ratio. Other independent risk factors included body mass index ≥ 25, diabetes, total gastrectomy and use of a 25-mm stapler. Among single markers, the normalized PV-HU value exhibited best predictive performance and a good clinical-imaging combined model showed an area under the curve of 0.893 and high negative predictive value (97.9%). These CT parameters provide preoperative risk stratification with the potential to assist in identifying patients who may benefit from increased surveillance or surgical management alteration. The CT-based tool is simple, non-invasive and tailored to each subject’s perioperative management in gastric cancer surgery.