Assessment of Routine Esophagram for Detecting Anastomotic Leak After Esophagectomy

Oesophageal fluoroscopy in adults-when and why?

Oesophageal fluoroscopy is a radiological procedure that uses dynamic recording of the swallowing process to evaluate morphology and function simultaneously, a characteristic not found in other clinical tests. It enables a comprehensive evaluation of the entire upper gastrointestinal tract, from the oropharynx to oesophagogastric bolus transport. The number of fluoroscopies of the oesophagus and the oropharynx has increased in recent decades, while the overall use of gastrointestinal fluoroscopic examinations has declined. Radiologists performing fluoroscopies need a good understanding of the appropriate clinical questions and the methodological advantages and limitations to adjust the examination to the patient's symptoms and clinical situation. This review provides an overview of the indications for oesophageal fluoroscopy and the various pathologies it can identify, ranging from motility disorders to structural abnormalities and assessment in the pre- and postoperative care. The strengths and weaknesses of this modality and its future role within different clinical scenarios in the adult population are discussed. We conclude that oesophageal fluoroscopy remains a valuable tool in diagnostic radiology for the evaluation of oesophageal disorders.

Contrast-Enhanced Radiologic Evaluation of Gastric Conduit Emptying After Esophagectomy

BACKGROUND

Nasogastric tube (NGT) insertion is the standard of care in many hospitals after esophagectomy for gastric conduit decompression. An upper gastrointestinal contrast passage evaluation (UGI-CE) is a diagnostic test to evaluate passage through the gastric conduit. The authors hypothesized that introducing routine UGI-CE after esophagectomy results in earlier removal of the NGT and resumption of oral intake.

METHODS

This retrospective study evaluated two consecutive series of patients undergoing esophagectomy, one before (control group) and one after the introduction of a routine UGI-CE on postoperative day (POD) 3 or 4 (UGI-CE group). If contrast passage was found on the UGI-CE, the NGT was capped and removed. In the control group, the NGT was routinely capped and removed on day 5 after surgery. The primary outcome was the POD on which oral diet was initiated. The secondary outcomes were the day of NGT removal, NGT reinsertions, postoperative complications, and length of hospital stay.

RESULTS

Each cohort included 74 patients. In the UGI-CE group, the contrast test was performed on median POD 3.5 (IQR, 3-4). The median day of NGT removal, initiation of clear liquids, and full liquid and solid intake was 1 to 2 days earlier in the UGI-CE group than in the control group (i.e. POD 4, 4, 5, and 6 vs. POD 5, 5, 6.5, and 8; all p < 0.001). The study found no significant differences in NGT reinsertions, pneumonias, anastomotic leakages, or hospital stay.

CONCLUSION

The routine use of a UGI-CE after esophagectomy led to earlier removal of the NGT and earlier resumption of oral intake.

Development of a Deep Learning System to Detect Esophageal Cancer by Barium Esophagram

Background

Implementation of deep learning systems (DLSs) for analysis of barium esophagram, a cost-effective diagnostic test for esophageal cancer detection, is expected to reduce the burden to radiologists while ensuring the accuracy of diagnosis.

Objective

To develop an automated DLS to detect esophageal cancer on barium esophagram.

Methods

This was a retrospective study using deep learning for esophageal cancer detection. A two-stage DLS (including a Selection network and a Classification network) was developed. Five datasets based on barium esophagram were used for stepwise training, validation, and testing of the DLS. Datasets 1 and 2 were used to respectively train and test the Selection network, while Datasets 3, 4, and 5 were respectively used to train, validate, and test the Classification network. Finally, a positioning box with a probability value was outputted by the DLS. A region of interest delineated by experienced radiologists was selected as the ground truth to evaluate the detection and classification efficiency of the DLS. Standard machine learning metrics (accuracy, recall, precision, sensitivity, and specificity) were calculated. A comparison with the conventional visual inspection approach was also conducted.

Results

The accuracy, sensitivity, and specificity of our DLS in detecting esophageal cancer were 90.3%, 92.5%, and 88.7%, respectively. With the aid of DLS, the radiologists’ interpretation time was significantly shortened (Reader1, 45.7 s vs. 72.2 s without DLS aid; Reader2, 54.1 s vs. 108.7 s without DLS aid). Respective diagnostic efficiencies for Reader1 with and without DLS aid were 96.8% vs. 89.3% for accuracy, 97.5% vs. 87.5% for sensitivity, 96.2% vs. 90.6% for specificity, and 0.969 vs. 0.890 for AUC. Respective diagnostic efficiencies for Reader2 with and without DLS aid were 95.7% vs. 88.2% for accuracy, 92.5% vs. 77.5% for sensitivity, 98.1% vs. 96.2% for specificity, and 0.953 vs. 0.869 for AUC. Of note, the positioning boxes outputted by the DLS almost overlapped with those manually labeled by the radiologists on Dataset 5.

Conclusions

The proposed two-stage DLS for detecting esophageal cancer on barium esophagram could effectively shorten the interpretation time with an excellent diagnostic performance. It may well assist radiologists in clinical practice to reduce their burden.

Routine Radiologic Assessment for Anastomotic Leak Is Not Necessary in Asymptomatic Patients After Esophagectomy for Esophageal Cancer

BACKGROUND

Anastomotic leaks (AL) are a major source of post-esophagectomy morbidity and patients are often initially asymptomatic. Debate exists on timing and utility of imaging to detect AL post-esophagectomy. We sought to evaluate the efficacy and timing of radiographic AL evaluation in esophageal cancer patients post-esophagectomy.

METHODS

A retrospective database of esophageal cancer patients who underwent esophagectomy at a single institution from 2004 to 2020 was used to determine the utilization, timing, and sensitivity of radiologic testing for AL post-esophagectomy.

RESULTS

Seventy-six patients were identified of which 37 (49%) had a cervical anastomosis. Sixty-four (84%) underwent 71 "asymptomatic radiographic leak tests" (ARLT), 7 of which had 2 different tests, including: 41 fluoroscopic esophagrams (58%), 18 CT-esophagrams (25%), and 12 upper GI studies (17%). Seventeen patients (22%) developed clinical signs of AL (hemodynamic instability, leukocytosis) and underwent "symptomatic radiographic leak tests" (SRLT) with fluoroscopic esophagram (n = 9, 12%), CT-esophagram (n = 7, 9%), or upper GI study (n = 1, 1%). ARLT and SRLT were positive in 2/64 (3%) and 17/17 (100%) patients, respectively, for 19 total ALs (25%). Among the 17 SRLT( +) patients, 1 was also ARLT( +), 13 were initially ARLT( -), and 3 were not evaluated by ARLT. The median postoperative day for ARLT and SRLT was 4.0 (IQR 3.0-5.5) and 9.0 days (IQR 6.0-13.0), respectively, with a statistically significant difference (p < 0.005). The sensitivity and specificity of ARLT for detecting AL were 13.3% and 100.0%, respectively.

CONCLUSIONS

Based on the low ARLT sensitivity, routine use of imaging to detect asymptomatic ALs post-esophagectomy may be limited. Symptomatic ALs were often present in a delayed fashion, even after initial negative imaging.