Objective To explore the characteristics and advantages of the rat model of lumbar nerve root com -pression established via modified hemilaminectomy approach .Methods Forty Sprague Dawley ( SD) rats were randomly divided into two groups ( experimental group and control group ) for establishing a rat model of lumbar nerve root compres-sion.Modified hemilaminectomy apprpoach was used in the experimental group , while total laminectomy was applied in the control group.Duration of operation, estimated blood loss, wound healing status, postoperative mortality, motor function of the lower extremities , pathological changes and the gray level of cytoplasmic TNF-αand IL-1 expression were observed to e-valuate the characteristics and reliability of the two operation approaches in establishing a rat model of lumbar nerve root compression.Results Compared with the control group , duration of operation , estimated blood loss , wound healing sta-tus, postoperative mortality were significantly better in the experimental group (P<0.01), whereas there was non-signifi-cant difference between two groups with regard to motor function of the lower extremities , pathological changes and gray lev-el of the cytoplasmic expression of TNF-αand IL-1 between the two groups .Moreover, the soft tissue structural alterations were reduced in the experimental group , which might be helpful for the rat postoperative rehabilitation .Conclusions Modified hemilaminectomy approach is a reliable alternative method for establishing a rat model of lumbar nerve root com -pression, which is beneficial to shorten the operative time , improve wound healing status , reduce estimated blood loss and damages of soft tissue , and decrease mortality rate .Moreover , this modified method is more consistent with the principles of animal ethics .

Objective:To analyze the correlation between nutritional status and frailty and sarcopenia in geriatric inpatients (GIPs) planning to receive major hepatopancreatobiliary (HPB) surgery.Methods:From December, 2020 to September, 2022, GIPs who were planning to receive major HPB surgery were recruited. Nutritional assessment was performed using nutritional risk screening 2002 (NRS-2002) and Global Leadership Initiative on Malnutrition (GLIM) criteria. Frailty and sarcopenia assessment were performed using Fried frailty phenotype (FFP) and Asian Working Group for Sarcopenia (AWGS) 2019 consensus on sarcopenia diagnosis and treatment. The prevalence and concurrence of malnutrition, frailty and sarcopenia were investigated, and the correlation between nutritional status and frailty and sarcopenia was analyzed.Results:A total of 144 participants at the mean age of (70.10±7.44) years were included. The prevalence of nutritional risk, malnutrition, and severe malnutrition were 73.6% ( n ?=?106), 68.1% ( n ?=?98), and 34.7% ( n ?=?50) respectively. The prevalence of frailty was 20.8% ( n ?=?30) and that of sarcopenia was 35.4% ( n ?=?51). The prevalence of severe malnutrition increased significantly in older participants and the prevalence of nutritional risk, malnutrition and severe malnutrition decreased significantly with higher BMI. The prevalence was 35.4% (51/144) for concurrent sarcopenia and malnutrition, 19.4% (28/144) for frailty and malnutrition, 14.6% (21/144) for sarcopenia and weakness, and 14.6% (21/144) for sarcopenia, malnutrition, and weakness. There was a positive correlation between nutritional risk and frailty ( r = 0.603, P < 0.001). The risk of pre-frailty and frailty in the nutritional risk group was higher than that in the non-nutritional risk group ( χ 2 = 31.830, P < 0.001). The risk of pre-frailty and frailty in the malnutrition group was higher than that in the normal nutrition group ( χ 2 = 36.727, P < 0.001). Logistic regression analysis showed that the risk of frailty in patients with severe malnutrition was 12.303 times higher than that in patients with normal nutrition status (95% CI: 2.592 to 58.409, P = 0.002). The risk of sarcopenia in the nutritional risk group was higher than that in the non-nutritional risk group ( χ 2 = 13.982, P < 0.001). The risk of sarcopenia in the malnutrition group was higher than that in the normal nutrition group ( χ 2 = 37.066, P < 0.001). Conclusions:The prevalence and concurrence rate of malnutrition, frailty, and sarcopenia are high in GIPs undergoing major HPB surgery. GIPs with malnutrition are susceptible to frailty.