Objective To explore the method for establishing a pig left lung orthotopic transplantation model. Methods A total of 4 male Yorkshire pigs weighing (40.0±2.5) kg underwent surgical procedures, including anesthesia, tracheal intubation, donor lung procurement, and recipient lung transplantation. Histological morphology and blood gas analysis of the transplanted lungs were assessed 2 hours after reperfusion to evaluate the histological changes and function of the transplanted lungs. Results The pigs underwent left lung in situ transplantation, effectively simulating conditions relevant to human lung transplantation. Two hours after the transplantation, arterial blood gas analysis showed that arterial partial pressure of oxygen was 155.4-178.6 mm Hg, arterial partial pressure of carbon dioxide was 53.1-62.4 mm Hg, and the oxygenation index was 310.8-357.2 mm Hg. Hematoxylin and eosin staining indicated a low degree of pulmonary edema and minimal cellular infiltration. Conclusion The pig left lung orthotopic transplantation model possesses strong operability and stability. Researchers can replicate this model according to the described methods and further conduct basic research and explore clinical translational applications.

BACKGROUND:Degenerative scoliosis is defined as a condition that occurs in adulthood with a coronal cobb angle of the spine>10° accompanied by sagittal deformity and rotational subluxation,which often produces symptoms of spinal cord and nerve compression,such as lumbar pain,lower limb pain,numbness,weakness,and neurogenic claudication.The finite element method is a mechanical analysis technique for computer modelling,which can be used for spinal mechanics research by building digital models that can realistically restore the human spine model and design modifications. OBJECTIVE:To review the application of finite element method in the etiology and treatment of degenerative scoliosis. METHODS:The literature databases CNKI,PubMed,and Web of Science were searched for articles on the application of finite element method in degenerative scoliosis published before October 2023.Search terms were"finite element analysis,biomechanics,stress analysis,degenerative scoliosis,adult spinal deformity"in Chinese and English.Fifty-four papers were finally included. RESULTS AND CONCLUSION:(1)The biomechanical findings from the degenerative scoliosis model constructed using the finite element method were identical to those from the in vivo experimental studies,which proves that the finite element method has a high practical value in degenerative scoliosis.(2)The study of the etiology and treatment of degenerative scoliosis by the finite element method is conducive to the prevention of the occurrence of the scoliosis,slowing down the progress of the scoliosis,the development of a more appropriate treatment plan,the reduction of complications,and the promotion of the patients'surgical operation.(3)The finite element method has gradually evolved from a single bony structure to the inclusion of soft tissues such as muscle ligaments,and the small sample content is increasingly unable to meet the research needs.(4)The finite element method has much room for exploration in degenerative scoliosis.

BACKGROUND:The highest incidence of spinal fracture is in the thoracolumbar segment,and its symptoms are back pain,posterior convexity deformity,activity limitation,or with spinal cord nerve injury causing lower limb pain,numbness,and even paraplegia and other complications.The finite element method is a digital computer modeling technique,which can simulate the physical model and carry out force analysis realistically.OBJECTIVE:To review the application of finite element method in thoracolumbar spine fractures.METHODS:We searched the Chinese and English literature databases PubMed,Web of Science,and CNKI for relevant literature on the application of the finite element analysis method in spinal thoracolumbar fracture published before March 2024.The search terms in Chinese and English were:finite element analysis methods,biomechanical phenomena,stress analysis,thoracolumbar fractures,spinal fractures.Finally,55 papers were included.RESULTS AND CONCLUSION:(1)The exploration of thoracolumbar fractures caused by different etiologies(osteoporotic,traumatic,and pathological)through the finite element method is conducive to a deeper understanding of the biomechanics of various types of thoracolumbar fractures,and to improve the individualized and fine-tuned treatment of thoracolumbar fractures.(2)The finite element analysis of a single sample or a small number of samples has the chance,and a larger number of samples are required for the future finite element analysis to reduce the chance caused by the sample.(3)The rigid structure of bones alone cannot meet the biomechanical working conditions of the integrity of the physical object,and future finite element models need to incorporate all the structures of the physical object(e.g.,soft tissues,such as muscles and ligaments)as far as possible.(4)The finite element method has been used in more studies on osteoporotic and traumatic thoracolumbar spine fractures,which will need to be more in-depth in the future,and less in the field of pathologic thoracolumbar fractures,which has a wider scope for future research.

BACKGROUND:The highest incidence of spinal fracture is in the thoracolumbar segment,and its symptoms are back pain,posterior convexity deformity,activity limitation,or with spinal cord nerve injury causing lower limb pain,numbness,and even paraplegia and other complications.The finite element method is a digital computer modeling technique,which can simulate the physical model and carry out force analysis realistically.OBJECTIVE:To review the application of finite element method in thoracolumbar spine fractures.METHODS:We searched the Chinese and English literature databases PubMed,Web of Science,and CNKI for relevant literature on the application of the finite element analysis method in spinal thoracolumbar fracture published before March 2024.The search terms in Chinese and English were:finite element analysis methods,biomechanical phenomena,stress analysis,thoracolumbar fractures,spinal fractures.Finally,55 papers were included.RESULTS AND CONCLUSION:(1)The exploration of thoracolumbar fractures caused by different etiologies(osteoporotic,traumatic,and pathological)through the finite element method is conducive to a deeper understanding of the biomechanics of various types of thoracolumbar fractures,and to improve the individualized and fine-tuned treatment of thoracolumbar fractures.(2)The finite element analysis of a single sample or a small number of samples has the chance,and a larger number of samples are required for the future finite element analysis to reduce the chance caused by the sample.(3)The rigid structure of bones alone cannot meet the biomechanical working conditions of the integrity of the physical object,and future finite element models need to incorporate all the structures of the physical object(e.g.,soft tissues,such as muscles and ligaments)as far as possible.(4)The finite element method has been used in more studies on osteoporotic and traumatic thoracolumbar spine fractures,which will need to be more in-depth in the future,and less in the field of pathologic thoracolumbar fractures,which has a wider scope for future research.

Objective:To investigate the impact of postoperative complications on adverse outcomes following curative-intent resection for gallbladder cancer (GBC).Methods:The multi-center real-world study was conducted. The clinicopathological data of 629 patients with GBC, who were admitted to 14 medical centers including The First Affiliated Hospital of Army Medical University from the national multicenter database of Biliary Surgery Group of Elite Group of Chinese Journal of Digestive Surgery, from April 2020 to April 2024 were collected. There were 225 males and 404 females, aged (64±10)years. Patients underwent open curative-intent resection for GBC. Observation indicators: (1)surgery, postoperative complica-tions and adverse outcomes; (2) analysis of risk factors affecting postoperative adverse outcomes in patients and population attributable fraction (PAF). Missing data in predictor variables were addressed using multiple imputation with chained equations, while cases with missing outcome variables were addressed using the "multiple imputation then deletion (MID)" strategy. The severity of multicollinearity among independent variables was assessed using the variance inflation factor (VIF) test. Multivariable possion regression models with log link and robust error variance were construc-ted incorporating restricted cubic splines (3 knots) to address nonlinear relationships in continuous variables, calculating adjusted relative risk ( RR) with corresponding 95% confidence interval ( CI). Adjusted PAF was calculated for each imputed dataset using the AF package of R software, with subsequent pooling performed according to Rubin's rules. Results:(1) Surgery, postoperative complications and adverse outcomes. All 629 patients underwent curative-intent resection for GBC, of which 143 cases had postoperative complications, including 68 cases of intra-abdominal ascites, 39 cases of pulmonary infection, 21 cases of bile leakage, 12 cases of intra-abdominal hemorrhage, 11 cases of liver failure, 10 cases of pan-creatic fistula, 10 cases of wound infection, 10 cases of gastroparesis, 7 cases of cholangitis, 7 cases of sepsis. The same patient could have more than one kind of complication. Of 629 patients, there were 19 cases of postoperative 90-day death and 11 cases of missing data, 42 cases with post-operative 90-day reoperation and 7 cases with missing data, 44 cases with postoperative 90-day readmission and 3 cases with missing data, 155 cases with prolonged postoperative hospital stay and 3 cases with missing data. (2) Analysis of risk factors affecting the postoperative adverse outcomes in patients and PAF. Results of multivariate analysis showed that pulmonary infection and liver failure were independent risk factors for postoperative 90-day mortality ( RR=3.74, 12.15, 95% CI as 1.18-11.83, 1.98-74.48, P<0.05). Pulmonary infection demons-trated the highest PAF as 4.61% (95% CI as 3.94%-5.28%, P<0.05). Intra-abdominal ascites, pulmonary infection, bile leakage, and intra-abdominal hemorrhage were independent risk factors for post-operative 90-day reoperation ( RR=4.80, 3.62, 3.46, 4.99, 95% CI as 2.49-9.26, 1.42-9.21, 1.34-8.92, 1.55-16.06, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 8.65% (95% CI as 8.22%-9.08%, P<0.05). Intra-abdominal ascites, bile leakage, and liver failure were independent risk factors for postoperative 90-day readmission ( RR=6.20, 3.33, 14.33, 95% CI as 3.21-11.95, 1.33-8.35, 3.72-55.28, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 9.11% (95% CI as 8.85%-9.37%, P<0.05). Intra-abdominal ascites, pulmonary infection, bile leakage, liver failure, and wound infection were independent risk factors for prolonged postoperative hospital stay ( RR=2.29, 2.21, 2.26, 2.14, 3.35, 95% CI as 1.63-3.23, 1.41-3.46, 1.32-3.86, 1.11-4.13, 1.70-6.60, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 6.03% (95% CI as 5.71%-6.35%, P<0.05). Conclusion:Pulmonary infection is the most significant risk factor for postoperative 90-day mortality after curative-intent resection for GBC, while intra-abdominal ascites is the most significant risk factor for postoperative 90-day reoperation, postoperative 90-day readmission, and prolonged postoperative hospital stay.

Background and Aims:Perihilar cholangiocarcinoma(pCCA)is associated with poor prognosis.Radical resection remains the mainstay of treatment;however,high recurrence rates and limited overall survival(OS)after surgery.Metabolic syndrome(MetS)has been linked to unfavorable outcomes in various malignancies,but its impact on postoperative outcomes in pCCA is unclear.This study aimed to evaluate the influence of MetS on perioperative and long-term outcomes in patients undergoing radical resection for pCCA.Methods:A retrospective analysis was conducted on 223 patients who underwent radical resection for pCCA at the First Affiliated Hospital of Army Medical University between January 2018 and December 2023.Patients were categorized into a MetS group(n=50)and a non-MetS group(n=173)according to diagnostic criteria.Perioperative complications,overall survival(OS),and recurrence-free survival(RFS)were compared between groups.Prognostic factors were identified using multivariate analysis.Results:No significant differences were observed between the two groups regarding median hospital stay,overall complications,or severe complications(all P＞0.05).The 1-,3-,and 5-year OS rates in the MetS group were 62.3％,22.3％,and 0,respectively,compared with 78.2％,39.5％,and 22.0％in the non-MetS group.Corresponding RFS rates were 46.2％,16.9％,and 0 in the MetS group vs.63.8％,29.6％,and 18.8％in the non-MetS group.Median OS and RFS were significantly shorter in the MetS group than in the non-MetS group(15.0 vs.27.0 months;12.0 vs.21.0 months;P=0.021 and P=0.037,respectively).Multivariate analysis identified MetS and major vascular invasion as independent predictors of OS,while MetS,jaundice,R0 resection,and major vascular invasion were independent predictors of RFS(all P＜0.05).Conclusion:MetS is significantly associated with worse long-term survival and higher recurrence risk after radical resection for pCCA.Incorporating MetS into preoperative assessment and postoperative management strategies may help improve patient outcomes.

Background and Aims:Perihilar cholangiocarcinoma(pCCA)is associated with poor prognosis.Radical resection remains the mainstay of treatment;however,high recurrence rates and limited overall survival(OS)after surgery.Metabolic syndrome(MetS)has been linked to unfavorable outcomes in various malignancies,but its impact on postoperative outcomes in pCCA is unclear.This study aimed to evaluate the influence of MetS on perioperative and long-term outcomes in patients undergoing radical resection for pCCA.Methods:A retrospective analysis was conducted on 223 patients who underwent radical resection for pCCA at the First Affiliated Hospital of Army Medical University between January 2018 and December 2023.Patients were categorized into a MetS group(n=50)and a non-MetS group(n=173)according to diagnostic criteria.Perioperative complications,overall survival(OS),and recurrence-free survival(RFS)were compared between groups.Prognostic factors were identified using multivariate analysis.Results:No significant differences were observed between the two groups regarding median hospital stay,overall complications,or severe complications(all P＞0.05).The 1-,3-,and 5-year OS rates in the MetS group were 62.3％,22.3％,and 0,respectively,compared with 78.2％,39.5％,and 22.0％in the non-MetS group.Corresponding RFS rates were 46.2％,16.9％,and 0 in the MetS group vs.63.8％,29.6％,and 18.8％in the non-MetS group.Median OS and RFS were significantly shorter in the MetS group than in the non-MetS group(15.0 vs.27.0 months;12.0 vs.21.0 months;P=0.021 and P=0.037,respectively).Multivariate analysis identified MetS and major vascular invasion as independent predictors of OS,while MetS,jaundice,R0 resection,and major vascular invasion were independent predictors of RFS(all P＜0.05).Conclusion:MetS is significantly associated with worse long-term survival and higher recurrence risk after radical resection for pCCA.Incorporating MetS into preoperative assessment and postoperative management strategies may help improve patient outcomes.

Background and Aims:Body mass index(BMI),an important indicator of nutrition and health,is closely associated with postoperative complications.This study was performed to investigate the relationship between preoperative BMI and severe complications in patients undergoing liver resection for hepatolithiasis,aiming to provide preoperative guidance for clinicians,reduce the risk of postoperative complications,and ensure surgical safety and efficacy.Methods:The clinical data of 484 patients with hepatolithiasis who underwent liver resection between May 2006 and December 2022 at the First Affiliated Hospital of Army Medical University and Beijing Tsinghua Changgung Hospital were retrospectively collected.Patients were classified into low BMI group(≤18.4 kg/m2),normal BMI group(18.5-24.9 kg/m2),and high BMI group(≥25.0 kg/m2)based on preoperative BMI.Baseline characteristics,overall complications,severe complications,and other postoperative outcomes were compared between the normal BMI group and the low group as well as the high BMI group.Risk factors for severe complications after liver resection were analyzed.Results:Among the 484 patients,79(16.3％)were in the low BMI group,328(67.8％)in the normal BMI group,and 77(15.9％)in the high BMI group.The high BMI group had significantly higher ASA score,preoperative albumin level,and proportion of hypertension compared to the normal BMI group(all P＜0.05).Baseline characteristics in the low BMI group showed no significant differences compared to the normal BMI group(all P＞0.05).The incidence rates of overall complications were not significantly among the three groups(P＞0.05).However,the high BMI group had significantly higher incidence rates of severe complications(Clavien-Dindo grade Ⅲ-Ⅳ),postoperative infections,liver failure,and bile leakage compared to the normal BMI group;the low BMI group had significantly higher rates of perioperative blood transfusion,postoperative infections,liver failure,and reoperation compared to the normal BMI group(all P＜0.05).Univariate and multivariate Logistic regression analyses identified high BMI and preoperative total bilirubin ≥54 pmol/L as independent risk factors for severe complications after liver resection in patients with hepatolithiasis(both P＜0.05).Conclusion:Preoperative BMI is closely associated with the occurrence of complications after liver resection in patients with hepatolithiasis,with high BMI being an independent risk factor for severe complications.To mitigate the risk of severe complications,clinical practice should prioritize monitoring and management of individuals with high BMI and other risk factors

Objective:To investigate the impact of postoperative complications on adverse outcomes following curative-intent resection for gallbladder cancer (GBC).Methods:The multi-center real-world study was conducted. The clinicopathological data of 629 patients with GBC, who were admitted to 14 medical centers including The First Affiliated Hospital of Army Medical University from the national multicenter database of Biliary Surgery Group of Elite Group of Chinese Journal of Digestive Surgery, from April 2020 to April 2024 were collected. There were 225 males and 404 females, aged (64±10)years. Patients underwent open curative-intent resection for GBC. Observation indicators: (1)surgery, postoperative complica-tions and adverse outcomes; (2) analysis of risk factors affecting postoperative adverse outcomes in patients and population attributable fraction (PAF). Missing data in predictor variables were addressed using multiple imputation with chained equations, while cases with missing outcome variables were addressed using the "multiple imputation then deletion (MID)" strategy. The severity of multicollinearity among independent variables was assessed using the variance inflation factor (VIF) test. Multivariable possion regression models with log link and robust error variance were construc-ted incorporating restricted cubic splines (3 knots) to address nonlinear relationships in continuous variables, calculating adjusted relative risk ( RR) with corresponding 95% confidence interval ( CI). Adjusted PAF was calculated for each imputed dataset using the AF package of R software, with subsequent pooling performed according to Rubin's rules. Results:(1) Surgery, postoperative complications and adverse outcomes. All 629 patients underwent curative-intent resection for GBC, of which 143 cases had postoperative complications, including 68 cases of intra-abdominal ascites, 39 cases of pulmonary infection, 21 cases of bile leakage, 12 cases of intra-abdominal hemorrhage, 11 cases of liver failure, 10 cases of pan-creatic fistula, 10 cases of wound infection, 10 cases of gastroparesis, 7 cases of cholangitis, 7 cases of sepsis. The same patient could have more than one kind of complication. Of 629 patients, there were 19 cases of postoperative 90-day death and 11 cases of missing data, 42 cases with post-operative 90-day reoperation and 7 cases with missing data, 44 cases with postoperative 90-day readmission and 3 cases with missing data, 155 cases with prolonged postoperative hospital stay and 3 cases with missing data. (2) Analysis of risk factors affecting the postoperative adverse outcomes in patients and PAF. Results of multivariate analysis showed that pulmonary infection and liver failure were independent risk factors for postoperative 90-day mortality ( RR=3.74, 12.15, 95% CI as 1.18-11.83, 1.98-74.48, P<0.05). Pulmonary infection demons-trated the highest PAF as 4.61% (95% CI as 3.94%-5.28%, P<0.05). Intra-abdominal ascites, pulmonary infection, bile leakage, and intra-abdominal hemorrhage were independent risk factors for post-operative 90-day reoperation ( RR=4.80, 3.62, 3.46, 4.99, 95% CI as 2.49-9.26, 1.42-9.21, 1.34-8.92, 1.55-16.06, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 8.65% (95% CI as 8.22%-9.08%, P<0.05). Intra-abdominal ascites, bile leakage, and liver failure were independent risk factors for postoperative 90-day readmission ( RR=6.20, 3.33, 14.33, 95% CI as 3.21-11.95, 1.33-8.35, 3.72-55.28, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 9.11% (95% CI as 8.85%-9.37%, P<0.05). Intra-abdominal ascites, pulmonary infection, bile leakage, liver failure, and wound infection were independent risk factors for prolonged postoperative hospital stay ( RR=2.29, 2.21, 2.26, 2.14, 3.35, 95% CI as 1.63-3.23, 1.41-3.46, 1.32-3.86, 1.11-4.13, 1.70-6.60, P<0.05). Intra-abdominal ascites demonstrated the highest PAF as 6.03% (95% CI as 5.71%-6.35%, P<0.05). Conclusion:Pulmonary infection is the most significant risk factor for postoperative 90-day mortality after curative-intent resection for GBC, while intra-abdominal ascites is the most significant risk factor for postoperative 90-day reoperation, postoperative 90-day readmission, and prolonged postoperative hospital stay.

Background and Aims:Body mass index(BMI),an important indicator of nutrition and health,is closely associated with postoperative complications.This study was performed to investigate the relationship between preoperative BMI and severe complications in patients undergoing liver resection for hepatolithiasis,aiming to provide preoperative guidance for clinicians,reduce the risk of postoperative complications,and ensure surgical safety and efficacy.Methods:The clinical data of 484 patients with hepatolithiasis who underwent liver resection between May 2006 and December 2022 at the First Affiliated Hospital of Army Medical University and Beijing Tsinghua Changgung Hospital were retrospectively collected.Patients were classified into low BMI group(≤18.4 kg/m2),normal BMI group(18.5-24.9 kg/m2),and high BMI group(≥25.0 kg/m2)based on preoperative BMI.Baseline characteristics,overall complications,severe complications,and other postoperative outcomes were compared between the normal BMI group and the low group as well as the high BMI group.Risk factors for severe complications after liver resection were analyzed.Results:Among the 484 patients,79(16.3％)were in the low BMI group,328(67.8％)in the normal BMI group,and 77(15.9％)in the high BMI group.The high BMI group had significantly higher ASA score,preoperative albumin level,and proportion of hypertension compared to the normal BMI group(all P＜0.05).Baseline characteristics in the low BMI group showed no significant differences compared to the normal BMI group(all P＞0.05).The incidence rates of overall complications were not significantly among the three groups(P＞0.05).However,the high BMI group had significantly higher incidence rates of severe complications(Clavien-Dindo grade Ⅲ-Ⅳ),postoperative infections,liver failure,and bile leakage compared to the normal BMI group;the low BMI group had significantly higher rates of perioperative blood transfusion,postoperative infections,liver failure,and reoperation compared to the normal BMI group(all P＜0.05).Univariate and multivariate Logistic regression analyses identified high BMI and preoperative total bilirubin ≥54 pmol/L as independent risk factors for severe complications after liver resection in patients with hepatolithiasis(both P＜0.05).Conclusion:Preoperative BMI is closely associated with the occurrence of complications after liver resection in patients with hepatolithiasis,with high BMI being an independent risk factor for severe complications.To mitigate the risk of severe complications,clinical practice should prioritize monitoring and management of individuals with high BMI and other risk factors