Objective To determine risk factors associated with postoperative hypoxemia after surgery for acute aortic dissection. Methods We retrospectively analyzed clinical data of 116 patients with acute aortic dissection who underwent endovascular stent-graft exclusion or open surgery in Qingdao Municipal Hospital from February 2007 to February 2012. All the 116 patients were diagnosed as acute aortic dissection by CT angiography （CTA），including 60 patients with Stanford type A aortic dissection and 56 patients with Stanford type B aortic dissection. According to whether they had postoperative hypoxemia，all the 116 patients with acute aortic dissection were divided into hypoxemia group［arterial partial pressure of oxygen （PaO2） /fraction of inspired oxygen （FiO2） ＜200 mm Hg］：33 patients including 28 males and 5 females with their age of 52.7±11.4 years； and non-hypoxemia group（PaO2/FiO2≥200 mm Hg）：83 patients including 66 males and 17 females with their age of 55.0±13.8 years. Perioperative clinical data were analyzed and compared between the two groups. Multivariate logistic regression was performed to identify risk factors of postoperative hypoxemia after surgery for acute aortic dissection. Results The incidence of postoperative hypoxemia after surgery for acute aortic dissection was 28.4% （33/116）. Perioperative death occurred in 13 patients（11.2%，including 8 patients in the hypoxemia group and 5 patients in the non-hypoxemia group）. Univariate analysis showed that preoperatively the percentages of patients with body mass index（BMI） ＞ 25 kg/m2，smoking history，duration from onset to operation ＜24 h，preoperative PaO2/FiO2≤300 mm Hg，and patients undergoing open surgery in the hypoxemia group were significantly higher than those in the non-hypoxemia group（P＜0.05）. Deep hypothermic circulatory arrest（DHCA） ratio，blood transfusion in 24 hours postoperatively，mechanical ventilation time，length of ICU stay and hospital stay in the hypoxemia group were significantly higher or longer than those in the non-hypoxemia group（P＜0.05）. Logistic multivariate regression identified BMI＞25 kg/m2（RR=98.861，P=0.006），DHCA（RR=22.487，P=0.007），preoperative PaO2/FiO2≤300 mm Hg（RR=9.080，P=0.037） and blood transfusion＞6 U in 24 hours postoperatively（RR=32.813，P=0.003） as independent predictors of postoperative hypoxemia for open-surgery patients，while BMI＞25 kg/m2 （RR=24.984，P=0.036） and preoperative PaO2/FiO2 ratio≤300 mm Hg （RR=21.145，P=0.042） as independent predictors of hypoxemia for endovascular stent-graft exclusion patients. Conclusion Postoperative hypoxemia is a common complication after surgery for acute aortic dissection. Early interventions for obesity and preoperative hypoxemia，and reducing perioperative blood transfusion may decrease the incidence of postoperative hypoxemia after surgery for acute aortic dissection.
Objective To investigate the effect of common iliac vein allograft replacing the portal vein-superior mesenteric vein transition area invaded by pancreatic cancer. Methods The clinical data of a patient with pancreatic cancer admitted to the Beijing Tsinghua Changgung Hospital in December 2021 who underwent pancreaticoduodenectomy combined with common iliac vein allograft replacing the junction of portal vein, superior mesenteric vein and splenic vein were analyzed retrospectively. The patient was a 77-year-old man who complained of “epigastric pain for 1 month and pancreatic mass was found for 1 week”. After admission, the patient was diagnosed with pancreatic cancer through inspection, and then the surgery was required. Preoperative examination and intraoperative exploration confirmed that the junction of portal vein, superior mesenteric vein, and spleen vein was invaded by tumor. In addition, the length of the invaded vessels measured by preoperative 3D reconstruction image was 5.5 cm, and the distance between the broken end of portal vein and the broken end of superior mesenteric vein measured was 4.5 cm during the operation. After tumor and vessels were resected, vascular anastomosis could not be performed directly. After accurate evaluation, pancreaticoduodenectomy combined with common iliac vein allograft replacing the junction of portal vein, superior mesenteric vein and splenic vein was performed. The operative time was 11 h, and the intraoperative blood loss was 400 mL. After the operation, the routine treatment was performed in ICU and was transferred to the general ward on the 7th day. Postoperative laboratory tests were performed to monitor liver function changes routinely, and imaging examination were was performed to monitor portal venous system blood flow. Results Postoperative complications such as biliary fistula, pancreatic fistula, hemorrhage, infection and thrombosis were not occurred. Postoperative pathological diagnosis: pancreatic ductal adenocarcinoma, medium-low differentiation. Enhanced CT reexamination on the 2nd and 13th day after the operation showed that the blood flow at the junction of portal vein, superior mesenteric vein and splenic vein of the common iliac vein allograft was unobstructed, and there was no stenosis or thrombosis at each anastomosis. Conclusions The application of common iliac vein allograft replacing the portal vein-superior mesenteric vein transition area invaded by pancreatic cancer is safe and feasible. The short-term efficacy is satisfactory, and long-term prognosis remains to be further observed.