670 THE STERNO-TRACHEAL DISTANCE IS AN IMPORTANT FACTOR OF ANASTOMOTIC LEAKAGE OF RETROSTERNAL GASTRIC TUBE RECONSTRUCTION AFTER ESOPHAGECTOMY

Anastomotic leakage (AL) is a serious complication after esophagectomy. The retrosternal (RS) route has been selected majorly to reduce reflux and related pneumonia and considering mediastinal recurrences. AL has been developed more in RS than posterior mediastinal (PM) route reconstruction. Therefore, we suspected the sterno-tracheal distance (STD) might be related to AL and started the selection according to the STD from 2009. Methods A total of 221 patients who underwent a sub total esophagectomy with gastric tube reconstruction during January 2004—April 2017 were investigated. The patients were classified into the 'after STD selection' (A; n = 144) group and the 'before STD selection' (B, n = 77) group. The incidences of and the risk factors for AL between the two groups were compared. Results The incidence of AL was high in the B group (18.2%), and 78.6% of the patients who developed AL were treated with RS route reconstruction. The median STDs of the patients with AL and no AL were 10.3 mm and 14.5 mm, respectively (p = 0.001). These results demonstrated that the STD was a risk factor for AL in RS route. Based on these results, 13 mm was set as the cutoff value. After STD selection, the median STD increased from 14.0 mm to 17.3 mm (p = 0.001), and the incidence of AL decreased significantly from 26.2% to 11.1% in RS route (p = 0.037). Conclusion The STD was the independent risk factor for AL in the RS route. RS route reconstruction should be avoided for the patients with STD <13 mm.

Verification and Optimization of Metro Fare Clearing Models Based on Travel Route Reconstruction

How to verify and optimize metro fare clearing models efficiently and accurately is a research focus in metro operations. Metro fare clearing models are mostly based on probability distributions. In such models, the normal distribution of travel time corresponding to the section probabilities is used to calculate the route choice probabilities of passengers on a multi-route metro network. By integrating the operating mileage proportions of each metro line operator and the corresponding route choice probabilities, the fare clearing proportions are calculated for all the operators of the metro network. To verify the accuracy of the fare clearing proportions, we propose a travel route reconstruction approach based on cell phone data acquisition technique. With wireless access point (AP) sensors installed at transfer stations, the unique medium access control (MAC) address of the smart phone with Wi-Fi function turned on is recorded and transmitted to a data analysis platform. After matching the MAC address information with time and location, the travel route of the smart phone user is reconstructed. Then, the parameters in the fare clearing model are verified and optimized according to the travel route choice probabilities. The proposed methodology is applied in Hangzhou metro network for experiment, and the metro fare clearing model is verified and modified by reconstructing the actual travel routs of the local passengers.

62 THE STERNO-TRACHEAL DISTANCE IS AN IMPORTANT FACTOR OF ANASTOMOTIC LEAKAGE OF RETROSTERNAL GASTRIC TUBE RECONSTRUCTION AFTER ESOPHAGECTOMY

Background Anastomotic leakage (AL) is a serious complication after esophagectomy. The retrosternal (RS) route has been selected majorly to reduce reflux and related pneumonia and considering mediastinal recurrences. AL has been developed more in RS than posterior mediastinal (PM) route reconstruction. Therefore, we suspected the sterno-tracheal distance (STD) might be related to AL and started the selection according to the STD from 2009. Methods A total of 221 patients who underwent a subtotal esophagectomy with gastric tube reconstruction during January 2004—April 2017 were investigated. The patients were classified into the 'after STD selection' (A; n = 144) group and the 'before STD selection' (B, n = 77) group. The incidences of and the risk factors for AL between the two groups were compared. Results The incidence of AL was high in the B group (18.2%), and 78.6% of the patients who developed AL were treated with RS route. The median STDs of the patients with AL and no AL were 10.3 mm and 14.5 mm, respectively (p = 0.001). These results demonstrated that the STD was a risk factor for AL in the RS route. Based on these results, 13 mm was set as the cutoff value. After STD selection, the median STD increased from 14.0 mm to 17.3 mm (p = 0.001), and the incidence of AL decreased significantly from 26.2% to 11.1% in the RS route (p = 0.037). Conclusion The STD was the independent risk factor for AL in the RS route. RS route reconstruction should be avoided for the patients with STD <13 mm.