BACKGROUND:Collagen is the main component of extracellular matrix.With its stable triple helix structure,good biological characteristics and machinability,collagen is an ideal biomedical material and has been widely used in the field of medical devices.OBJECTIVE:To analyze the main product morphology,technical characteristics,preparation process,and clinical application of solid collagen-based materials.METHODS:The research on solid collagen-based materials in the field of medical devices included in PubMed and CNKI was searched by computer.The English and Chinese search terms were"collagen,collagen sponge,collagen membrane,collagen powder,collagen gel,decellularized extracellular martix,medical device,clinical application."After preliminary screening of all articles according to inclusion and exclusion criteria,92 articles with higher quality and relevance were retained for review.RESULTS AND CONCLUSION:Solid collagen-based materials from animal sources have been used as materials for the preparation of medical devices,and remarkable progress has been made in raw material extraction,preparation technology,and clinical application.Marine biological collagen and recombinant collagen have increased the selectivity of collagen sources.There are various types of solid collagen-based medical devices and various preparation methods,among which crosslinking modification is an important way to improve material properties,which is worthy of further study.In terms of product development ideas,research on solid collagen-based medical device products is developing in the direction of trivialization and biochemistry,and the research on compounding with other biological materials and drugs has also shown great potential.Although many collagen-based medical devices have been used clinically in China,product development in the fields of artificial skin,cartilage repair,and nerve injury repair is still insufficient,and further breakthroughs and innovations in technology and industrialization are needed.

Objective To predict the hospitalization expense of pneumonia patients using the CatBoost and LightGBM models and explore associated influencing factors,providing a scientific basis for reasonable control of medical expenses and alle-viating the financial burden on society and patients'families.Methods Data from 1407 inpatients with pneumonia admitted to a tertiary hospital between November 1,2021 and January 31,2023 were collected from the hospital information system.The Cat-Boost and LightGBM models were employed to predict the hospitalization expenses of pneumonia patients and analyze the influen-cing factors.Results The full-variable CatBoost model fitted better than the full-variable LightGBM model,with the R-square value of 0.859 and Mean Absolute Percentage Error(MAPE)of 0.352.The full-variable CatBoost model predicted better than the full-variable LightGBM model,with the R-square value of 0.820 and MAPE of 0.363.Notably,the average length of stay was the most important factor affecting the hospitalization expenses of pneumonia patients.Conclusion Compared to the LightGBM model,the CatBoost model indicated more advantages and higher accuracy in predicting hospitalization expenses for pneumonia patients.These accurate predictions of hospitalization expenses can provide decision-making references for hospital administra-tors.Therefore,on the premise of ensuring medical quality,reasonably reducing the length of hospitalization can effectively con-trol the increase in hospitalization expenses.

Objective:To evaluate the perioperative application effect of enhanced recovery after surgery (ERAS) clinical pathway in percutaneous vertebro plasty (PVP).Methods:The clinical data of 274 patients who underwent PVP treatment for osteoporotic vertebral compression fracture (OVCF) in Beijing Friendship Hospital, Capital Medical University from May 2023 to August 2024 were retrospectively analyzed. The patients were divided into two groups according to the different numbers of surgical segments: the single-segment group ( n=211) and the multisegment group ( n=63). Patients in the single-segment group underwent single-segment surgery, while patients in the multisegment group underwent surgery on ≥2 segments. The core points of the ERAS clinical pathway adopted in this study include perioperative education, pain management, early mobilization, application of "outfast", and joint guidance from the departments of nutrition and rehabilitation. Comparison was made between the two groups of patients in terms of visual analog scale (VAS) scores for low back pain at preoperative, 2 h, 6 h, 24 h postoperatively, and on the day of discharge; Oswestry disability index (ODI) scores preoperatively and on the day of discharge; time to first ambulation postoperatively, total length of hospital stay, postoperative length of stay, perioperative complications, and perioperative application of Opioid consumption. Measurement data were expressed as mean±standard deviation ( ± s), and the independent sample t-test was used for comparison between groups; count data were expressed as cases and percentage, and the Chi-square test was used for comparison between groups. The VAS pain scores at each stage of the perioperative period were evaluated using repeated measures analysis of variance or generalized estimating equations. Results:Compared with that before the operation [(6.17±0.93) points, (6.29±0.83) points], the VAS scores of low back pain of patients in the single-segment group and the multisegment group at 2 hours after surgery [(3.09±0.82) points, (3.27±0.65) points], 6 hours after surgery [(2.60±0.79) points, (2.62±0.55) points], and 24 hours after surgery [(1.89±0.77) points, (1.97±0.72) points] and on the day of discharge [(1.72±0.71) points, (1.81±0.64) points] were significantly decreased, and the differences were statistically significant ( P<0.05). At the same stage, the VAS scores of low back pain in both groups were not statistically significant ( P>0.05). The ODI scores of patients in the single-segment group and the multisegment group on the day of discharge [(24.21±2.35) points, (24.63±3.31) points] were significantly lower than those before the operation [(64.50±4.81) points, (65.52±4.08) points], and the differences were statistically significant ( P<0.05). There were no statistically significant differences in perioperative complications and the proportion of Opioid drug application between the two groups of patients ( P>0.05). Conclusion:For patients with single-segment or multisegment OVCF, PVP surgical treatment under ERAS clinical pathway management can achieve immediate pain relief, early ambulation exercise, and satisfactory perioperative efficacy.

Objective:Surgical site infection (SSI) is a common health care-related infection after gastrointestinal surgery. Once SSI occurs after surgery, it can significantly prolong the postoperative hospital stay, increase the cost burden of patients and society, and even endanger the life safety of patients. The purpose of this study was to investigate the clinical phenotypes of gastrointestinal surgery, identify the clinical characteristics of SSI, and provide reference for the prevention of SSI after gastrointestinal surgery.Methods:This is a multicenter prospective cohort study that collected clinical data from all adult patients undergoing gastrointestinal surgery from March 2021 to February 2022 at 42 hospitals in China, including baseline and perioperative characteristics. Based on the variables associated with SSI, latent class analysis (LCA) was used to explore the population characteristics of SSI.Results:In total, 16 087 patients were included in the study, of whom 345 (2.1%) developed SSI. LCA analysis revealed that patients undergoing gastrointestinal surgery were classified into four clinical phenotypes, including α (3851), β (1538), γ (6387), and δ (4311). Type α had minimal abnormality on related system functions (ASA score > 2: 4.5% [173/3851]), and mainly underwent appendix surgery (98.9% [3808/3851]). The postoperative SSI incidence of type α was 0.4% (16/3,851), which belonged to the group of SSI low risk. The abnormality of system functions of type β (ASA score > 2: 17.4% [268/1538]) was worse than that of type α. Type β mainly underwent stomach surgery (72.4% [1113/1538]), and its incidence of postoperative SSI was 1.2% (18/1538), belonging to the group of SSI medium risk. The ASA score of type γ (ASA score > 2: 18.0% [1148/6387]) was comparable to that of type β. Type γ mainly received colorectal surgery (colon surgery: 40.1% [2562/6387]; rectal surgery: 33.6%[2143/6387]), and its incidence of postoperative SSI was 1.7% (106/6387), belonging to the group of SSI medium risk. Type δ (ASA score > 2: 23.5%[1015/4311]) was the most serious type with the highest proportion of open surgery. Type δ mainly underwent small intestine (54.0%[2327/4311]) and stomach surgery (32.3% [1392/4311]) and had the highest incidence of SSI (4.8% [205/4311]) and the highest mortality rate (0.6% [24/4311]), belonging to the group of SSI high risk. Compared with type α and β, the median length of hospital stay (α, β, γ, and δ: 5.0 days, 9.6 days, 13.0 days, and 16.0 days, P<0.001) and postoperative hospital stay (α, β, γ, and δ: 4.0days, 6.0days, 8.3 days, and 10.0 days, P<0.001) of type γ and δ were significantly increased, and the median medical costs (α, β, γ, and δ: 14 178.7 yuan, 39 514.2 yuan, 62 893.0 yuan and 57 266.6 yuan, P<0.001) were also significantly increased. Conclusion:LCA analysis elucidated four clinical phenotypes of patients undergoing gastrointestinal surgery. Type α had a low risk of SSI. Type β and γ had a medium risk of SSI, and type δ had a high risk of SSI.

Objective To predict the hospitalization expense of pneumonia patients using the CatBoost and LightGBM models and explore associated influencing factors,providing a scientific basis for reasonable control of medical expenses and alle-viating the financial burden on society and patients'families.Methods Data from 1407 inpatients with pneumonia admitted to a tertiary hospital between November 1,2021 and January 31,2023 were collected from the hospital information system.The Cat-Boost and LightGBM models were employed to predict the hospitalization expenses of pneumonia patients and analyze the influen-cing factors.Results The full-variable CatBoost model fitted better than the full-variable LightGBM model,with the R-square value of 0.859 and Mean Absolute Percentage Error(MAPE)of 0.352.The full-variable CatBoost model predicted better than the full-variable LightGBM model,with the R-square value of 0.820 and MAPE of 0.363.Notably,the average length of stay was the most important factor affecting the hospitalization expenses of pneumonia patients.Conclusion Compared to the LightGBM model,the CatBoost model indicated more advantages and higher accuracy in predicting hospitalization expenses for pneumonia patients.These accurate predictions of hospitalization expenses can provide decision-making references for hospital administra-tors.Therefore,on the premise of ensuring medical quality,reasonably reducing the length of hospitalization can effectively con-trol the increase in hospitalization expenses.

Objective:Surgical site infection (SSI) is a common health care-related infection after gastrointestinal surgery. Once SSI occurs after surgery, it can significantly prolong the postoperative hospital stay, increase the cost burden of patients and society, and even endanger the life safety of patients. The purpose of this study was to investigate the clinical phenotypes of gastrointestinal surgery, identify the clinical characteristics of SSI, and provide reference for the prevention of SSI after gastrointestinal surgery.Methods:This is a multicenter prospective cohort study that collected clinical data from all adult patients undergoing gastrointestinal surgery from March 2021 to February 2022 at 42 hospitals in China, including baseline and perioperative characteristics. Based on the variables associated with SSI, latent class analysis (LCA) was used to explore the population characteristics of SSI.Results:In total, 16 087 patients were included in the study, of whom 345 (2.1%) developed SSI. LCA analysis revealed that patients undergoing gastrointestinal surgery were classified into four clinical phenotypes, including α (3851), β (1538), γ (6387), and δ (4311). Type α had minimal abnormality on related system functions (ASA score > 2: 4.5% [173/3851]), and mainly underwent appendix surgery (98.9% [3808/3851]). The postoperative SSI incidence of type α was 0.4% (16/3,851), which belonged to the group of SSI low risk. The abnormality of system functions of type β (ASA score > 2: 17.4% [268/1538]) was worse than that of type α. Type β mainly underwent stomach surgery (72.4% [1113/1538]), and its incidence of postoperative SSI was 1.2% (18/1538), belonging to the group of SSI medium risk. The ASA score of type γ (ASA score > 2: 18.0% [1148/6387]) was comparable to that of type β. Type γ mainly received colorectal surgery (colon surgery: 40.1% [2562/6387]; rectal surgery: 33.6%[2143/6387]), and its incidence of postoperative SSI was 1.7% (106/6387), belonging to the group of SSI medium risk. Type δ (ASA score > 2: 23.5%[1015/4311]) was the most serious type with the highest proportion of open surgery. Type δ mainly underwent small intestine (54.0%[2327/4311]) and stomach surgery (32.3% [1392/4311]) and had the highest incidence of SSI (4.8% [205/4311]) and the highest mortality rate (0.6% [24/4311]), belonging to the group of SSI high risk. Compared with type α and β, the median length of hospital stay (α, β, γ, and δ: 5.0 days, 9.6 days, 13.0 days, and 16.0 days, P<0.001) and postoperative hospital stay (α, β, γ, and δ: 4.0days, 6.0days, 8.3 days, and 10.0 days, P<0.001) of type γ and δ were significantly increased, and the median medical costs (α, β, γ, and δ: 14 178.7 yuan, 39 514.2 yuan, 62 893.0 yuan and 57 266.6 yuan, P<0.001) were also significantly increased. Conclusion:LCA analysis elucidated four clinical phenotypes of patients undergoing gastrointestinal surgery. Type α had a low risk of SSI. Type β and γ had a medium risk of SSI, and type δ had a high risk of SSI.

BACKGROUND:Collagen is the main component of extracellular matrix.With its stable triple helix structure,good biological characteristics and machinability,collagen is an ideal biomedical material and has been widely used in the field of medical devices.OBJECTIVE:To analyze the main product morphology,technical characteristics,preparation process,and clinical application of solid collagen-based materials.METHODS:The research on solid collagen-based materials in the field of medical devices included in PubMed and CNKI was searched by computer.The English and Chinese search terms were"collagen,collagen sponge,collagen membrane,collagen powder,collagen gel,decellularized extracellular martix,medical device,clinical application."After preliminary screening of all articles according to inclusion and exclusion criteria,92 articles with higher quality and relevance were retained for review.RESULTS AND CONCLUSION:Solid collagen-based materials from animal sources have been used as materials for the preparation of medical devices,and remarkable progress has been made in raw material extraction,preparation technology,and clinical application.Marine biological collagen and recombinant collagen have increased the selectivity of collagen sources.There are various types of solid collagen-based medical devices and various preparation methods,among which crosslinking modification is an important way to improve material properties,which is worthy of further study.In terms of product development ideas,research on solid collagen-based medical device products is developing in the direction of trivialization and biochemistry,and the research on compounding with other biological materials and drugs has also shown great potential.Although many collagen-based medical devices have been used clinically in China,product development in the fields of artificial skin,cartilage repair,and nerve injury repair is still insufficient,and further breakthroughs and innovations in technology and industrialization are needed.

Objective:To examine the clinical value of rapid detection of drug-resistant bacteria by immunochromatography and the effects of rapid detection on the prognosis of patients with severe intra-abdominal infection complicated by carbapenem-resistant Enterobacteriaceae (CRE) bloodstream infection.Methods:This was a retrospective cohort study. We analyzed clinical data of 73 patients with severe abdominal infections with sepsis or septic shock complicated by CRE bloodstream infection admitted to the general surgery department of Jinling Hospital between February 2022 and February 2023. Patients were divided into a colloidal gold immunochromatographic assay (GICA) group (17 patients) and conventional testing group (56 patients) based on whether a GICA for CRE had been performed on the patients' first blood culture sample during the diagnosis and treatment process. There were no statistically significant differences between the GICA and conventional testing groups in age ([55.9±17.3] vs. [47.6±16.4] years), sex ([16 men vs. one woman ] vs. [41 men vs. 15 women]), median Charlson comorbidity index (3.0[2.0,4.0] vs. 3.0[2.0, 4.8]), septic shock (10 vs. 39), or acute kidney injury (8 vs. 40) (all P>0.05). Both groups routinely underwent traditional bacterial identification and drug susceptibility testing. Additionally, patients in the GICA group were tested directly for positive blood cultures using a GICA carbapenemase test kit. The main outcomes were mortality rates on Days 28 and 90 after the first identification of CRE bloodstream infection in both groups. We also compared the microbial clearance rate, duration of hospitalization and intensive care unit stay, and time from onset of CRE bloodstream infection to initiation of targeted and appropriate antibiotics between the two groups. Results:The rate of microbial clearance of bloodstream infection was significantly greater in the GICA group than in the conventional testing group (15/17 vs. 34/56 [60.7%], χ 2=4.476, P=0.034), whereas the 28-day mortality tended to be lower in the GICA than conventional testing group [5/17 vs. 44.6% [25/56], χ 2=1.250, P=0.264). The 90-day mortality (8/17 vs. 53.6% [30/56], χ 2=0.222, P=0.638), median duration of hospitalization (37.0 [18.0, 46.5] days vs. 45.5 [32.2, 64.8] days, Z=-1.867, P=0.062), and median duration of intensive care unit stay (18.0 [6.5, 35.0] days vs. 32.0 [5.0, 51.8] days, Z=-1.251, P=0.209). The median time between the onset of bloodstream infection and administration of antibiotics was 49.0 (38.0, 69.0) hours in the GICA group, which is significantly shorter than the 163.0 (111.8, 190.0) hours in the conventional testing group ( Z=-5.731, P<0.001). The median time between the onset of bloodstream infection and administration of appropriate antibiotics was 40.0 (34.0, 80.0) hours in the GICA group, which is shorter than in the conventional testing group (68.0 [38.2, 118.8]) hours; however, this difference is not statistically significant ( Z=-1.686, P=0.093). Conclusions:GICA can provide information on carbapenemase- producing pathogens faster than traditional drug sensitivity testing, enabling early administration of the optimal antibiotics. The strategy of 'carbapenemase detection first' for managing bacterial infection has the potential to improve prognosis of patients and reduce mortality rate.

Objective:The purpose of this study was to analyze the course and outcome of patients with combined entero-atmospheric fistulas in open abdomen treatment.Methods:In this retrospective observational study, we collected data on 214 patients with open abdomen complicated by entero-atmospheric fistulas admitted to Research Institute of General Surgery, Jinling Hospital, Affiliated Hospital of Medical School from January 2012 to January 2021. We collected their basic characteristics, aetiology, treatment plan, and prognosis, including the durations of hospitalization and open treatment, time to resumption of enteral nutrition, duration and prognosis of definitive surgery, and overall prognosis.Results:Of the 214 patients with open abdomen complicated with entero–enteral fistulas, 23 (10.7%) died (11 of multiple organ failure caused by abdominal infection, five of abdominal cavity bleeding, four of pulmonary infection, one of airway bleeding, one of necrotizing fasciitis, and one of traumatic brain injury). The remaining 191 underwent definitive surgery at our hospital. The patients who underwent definitive surgery were predominantly male (156 patients, 81.7%); their age was (46.5±2.5) years. Trauma and gastrointestinal tumors (120 cases, 62.8%) predominated among the primary causes. The reasons for abdominal opening were, in order, severe abdominal infection (137 cases, 71.7%, damage control surgery (29 cases, 15.2%), and abdominal hypertension (25 cases, 13.1%). Temporary abdominal closure measures were used to classify the participants into a skin-only suture group (104 cases) and a skin-implant group (87 cases). Compared with the skin-implant group, in the skin-suture-only group the proportion of male patients was lower (74.7% [65/87] vs. 87.5% [91/104], χ 2=5.176, P=0.023), the mean age was older ([48.3±2.0] years vs. [45.0±1.9] years, t=-11.671, P<0.001), there were fewer patients with trauma (32.2% [28 /87] vs. 58.7% [61/104), χ 2=13.337, P<0.001), intensive care stays were shorter ([8.9±1.0] days vs. [12.7±1.6] days, t=19.281, P<0.001), total length of stay was shorter ([29.3±2.0] days vs. [31.9±2.0] days, t=9.021, P<0.001), there was a higher percentage of colonic fistulas (18.4% [16/87] vs. 8.7% [9/104], χ 2=3.948, P=0.047), but fewer multiple fistulas (11.5% [10/87] vs. 34.6% [36/104], χ 2=14.440, P<0.001). As to fistula management, a higher percentage of fistula sealing methods using 3D-printed intestinal stents were implemented in the skin-only suture group (60.9% [53/87] versus 43.3% [45/104], χ 2=5.907, P=0.015). Compared with the implant group, the skin-only suture group had a shorter mean time to performing provisional closure ( [9.5±0.8] days vs. [16.0±0.6] days, t=66.023, P<0.001), shorter intervals to definitive surgery ( [165.0±10.7] days vs. [198.9±8.3] days, t=26.644, P<0.001), and less use of biopatches (56.3% [49/87) vs. 71.2% [74/104], χ 2=4.545, P=0.033). Conclusions:Open abdomen complicated with entero-enteral fistulas is more common in male, and is often caused by trauma and gastrointestinal tumor. Severe intra-abdominal infection is the major cause of open abdomen, and most fistulae involves the small intestine. Collection and retraction of intestinal fluid and 3D-printed entero-enteral fistula stent sealing followed by implantation and skin-only suturing is an effective means of managing entero-enteral fistulas complicating open abdominal cavity. Earlier closure of the abdominal cavity with skin-only sutures can shorten the time to definitive surgery and reduce the rate of utilization of biopatches.