[Comparison of efficacy between laparoscopic and open proximal gastrectomy with double-tract reconstruction for Siewert type â ¡ and â ¢ adenocarcinoma of the esophagogastric junction].

Objective: To compare the efficacy between laparoscopic and open proximal gastrectomy with double-tract reconstruction for Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). Methods: A retrospective cohort study was conducted. Inclusion criteria: (1) 18 to 80 years old; (2) Siewert II and III AEG was confirmed by preoperative gastroscopy and biopsy, which could not be resected by endoscopy; patients undergoing radical proximal gastrectomy with double-tract reconstruction; (3) contrast-enhanced abdominal CT staging was cT1-2N0M0; (4) Eastern Cooperative Oncology Group (ECOG) physical status score <2 points, American Association of Anesthesiologists (ASA) grade 1 to 2; (5) patients agreed to perform proximal gastrectomy and signed an informed consent. Those who had undergone neoadjuvant radiochemotherapy, suffered from serious mental diseases and had incomplete data were excluded. According to the above criteria, clinical data of 84 consecutive patients with Siewert II and III AEG undergoing surgery at General Surgery Department of The Affiliated Tumor Hospital of Zhengzhou University from October 2010 to December 2018 were collected and analyzed. Of 84 patients, 61 underwent open proximal gastrectomy with double-tract reconstruction (OPG group), while 23 underwent laparoscopic proximal gastrectomy with double-tract reconstruction (LPG group). The perioperative complications and postoperative reflux esophagitis of two groups were compared. A P-value of <0.05 was considered to be statistically significant. Results: Among 84 cases, 74 were male and 10 were female. There were 43 cases of Siewert type II and 41 cases of Siewert type III. There were no significant differences in age, gender, body mass index, comorbidities, Siewert type, and tumor staging between the two groups (all P>0.05). As compared to the OPG group, the LPG group had longer operation duration [(223±21) minutes vs. (161±14) minutes, t=15.352, P<0.001], less intraoperative blood loss [195 (150, 215) ml vs. 208 (192, 230) ml, Z=2.143, P=0.032], and shorter time to flatus [(2.8±0.7) days vs. (3.3±0.9) days, t=2.477, P=0.015]. There were no significant differences in the number of harvested lymph nodes, time to the first meal and postoperative hospital stay between the two groups (all P>0.05). Postoperative complications developed in 2 cases (8.7%, 1 case each for anastomotic leakage and intestinal obstruction) in the LPG group and 5 cases (8.2%, 1 case each for anastomotic leakage, anastomotic bleeding, and anastomotic stenosis, 2 cases of incision infection) in the OPG group (χ(2)=5.603, P=0.231). The median follow-up was 41.2 (12.8-110.5) months. One patient (1.6%,1/61) had obvious reflux symptoms in the OPG group, compared with none in the LPG group (χ(2)=0.644, P=0.422). Esophagitis occurred in 1 case (4.8%, 1/21) in LPG group, compared with 4 patients (7.1%, 4/56) in the OPG group, without significant difference between the two groups (χ(2)=0.505, P=0.477). Conclusion: Laparoscopic proximal gastrectomy with double-tract reconstruction is safe and feasible without increasing the risk of postoperative complication and reflux esophagitis.

Magnetic and electronic properties of CaCu3Cr4O12 and CaCu3Cr2Sb2O12 by first-principles density functional calculation.

The electronic and magnetic properties of CaCu3Cr4O12 and CaCu3Cr2Sb2O12 are investigated by the use of the full-potential linearized augumented plane wave (FPLAPW) method. The calculated results indicate that CaCu3Cr4O12 is a ferrimagnetic and half-metallic compound, in good agreement with previous theoretical studies. CaCu3Cr2Sb2O12 is a ferrimagnetic semiconductor with a small gap of 0.136 eV. In both compounds, because Cr4+ 3d (d2) and Cr3+ 3d (d3) orbitals are less than half filled, the coupling between Cr-Cu is antiferromagnetic, whereas that between Cu-Cu and Cr-Cr is ferromagnetic. The total net spin moment is 5.0 and 3.0 microB for CaCu3Cr4O12 and CaCu3Cr2Sb2O12, respectively. In CaCu3Cr4O12, the 3d electrons of Cr4+ are delocalized, which strengthens the Cr-Cr ferromagnetic coupling. For CaCu3Cr2Sb2O12, the doping of nonmagnetic ion Sb5+ reduces the Cr-Cr ferromagnetic coupling, and the half-filled Cr3+ t2g (t2g3) makes the chromium 3d electrons localized. In addition, the ordering arrangement of the octahedral chromium and antimony ions also prevents the delocalization of electrons. Hence, CaCu3Cr2Sb2O12 shows insulating behavior, in agreement with the experimental observation.