Postoperative pain in Sprague Dawley rats after liver biopsy by laparotomy versus laparoscopy

The grimace scale: a useful tool for assessing pain in laboratory animals

Accurately and promptly assessing pain in experimental animals is extremely important to avoid unnecessary suffering of the animals and to enhance the reproducibility of experiments. This is a key concern for veterinarians, animal caretakers, and researchers from the perspectives of veterinary care and animal welfare. Various methods including ethology, immunohistochemistry, electrophysiology, and molecular biology are used for pain assessment. However, the grimace scale, which was developed by taking cues from interpreting pain through facial expressions of non-verbal infants, has become recognized as a very simple and practical method for objectively evaluating pain levels by scoring changes in an animal's expressions. This method, which was first implemented with mice approximately 10 years ago, is now being applied to various experimental animals and is widely used in research settings. This review focuses on the usability of the grimace scale from the "cage-side" perspective, aiming to make it a more user-friendly tool for those involved in animal experiments. Differences in facial expressions in response to pain in various animals, examples of applying the grimace scale, current automated analytical methods, and future prospects are discussed.

The application of a novel platform of multiparametric magnetic resonance imaging in a bioenvironmental toxic carbon tetrachloride-induced mouse model of liver fibrosis

The use of multiparametric magnetic resonance imaging (MRI) to distinguish complex histopathological changes in liver fibrosis has not yet been systematically established. The purpose of this study is to gauge the efficacy of a cutting-edge MRI platform for evaluating ecotoxicologically hazardous carbon tetrachloride (CCl4) induced liver fibrosis, while also scrutinizing the relationship between MRI and its histopathological features. Thirty-six mice were randomly divided into 6 groups, each with 6 mice. Control mice received an intraperitoneal injection of olive oil, while the experimental mice received different doses of intraperitoneal injection of CCl4. Both sets underwent this process twice per week over a duration of 5 weeks. MRI measurements encompassed T1WI, T2WI, T1 mapping, T2 mapping, T2* mapping. Liver fibrosis and inflammation were assessed and classified using Metavir and activity scoring systems. CCl4 successfully induced liver fibrosis in mice, showing an increasing extent of liver fibrosis and liver function damage with the increasing dosage of CCl4. Compared with the control group, T1, ΔT1, and T2 in the experimental group were considerably elevated (P < 0.05) than those in the control group. Spearman's correlation showed that the correlation of Native T1 and △T1 with fibrosis (r = 0.712, 0.678) was better than with inflammation (r = 0.688, 0.536). T2 correlation with inflammation (r = 0.803) was superior to fibrosis (r = 0.568). ROC analysis showed that the AUC of Native T1 was highest (0.906), followed by ΔT1 (0.852), while the AUC increased to 0.945 when all relevant MRI parameters were combined. T1 is the most potent MRI parameter for evaluating CCl4-induced liver fibrosis, followed by ΔT1. Meanwhile, T2 may not be suitable for evaluating liver fibrosis but is more suitable for evaluating liver inflammation.

Laparoscopic-Assisted Colorectal Resection Can Reduce the Inhibition of Immune Function Compared with Conventional Open Surgery: A Retrospective Clinical Study

Background: Immune function is an important indicator for assessing postoperative recovery and long-term survival in patients with malignancy, and laparoscopic surgery is thought to have a less suppressive effect on the immune response than open surgery. This study aimed to investigate this effect in a retrospective clinical study. Methods: In this retrospective clinical study, we enrolled 63 patients with colorectal cancer in the Department of General Surgery of the First Affiliated Hospital of Soochow University and assessed the changes in their postoperative immune function by measuring CD3+T, CD4+T, CD8+T lymphocytes, and CD4+/CD8+ ratio. Results: Compared with open surgery, laparoscopic colorectal surgery was effective in improving the postoperative decline in immune function. We determined that the number of CD4+, CD8+T lymphocytes, and the CD4+/CD8+ ratio was not significantly reduced in the laparoscopic group. Conclusion: Laparoscopic-assisted colorectal resection can reduce the inhibition of immune functions compared with conventional open surgery.

Grimace scale, burrowing, and nest building for the assessment of post-surgical pain in mice and rats-A systematic review

Several studies suggested an informative value of behavioral and grimace scale parameters for the detection of pain. However, the robustness and reliability of the parameters as well as the current extent of implementation are still largely unknown. In this study, we aimed to systematically analyze the current evidence-base of grimace scale, burrowing, and nest building for the assessment of post-surgical pain in mice and rats. The following platforms were searched for relevant articles: PubMed, Embase via Ovid, and Web of Science. Only full peer-reviewed studies that describe the grimace scale, burrowing, and/or nest building as pain parameters in the post-surgical phase in mice and/or rats were included. Information about the study design, animal characteristics, intervention characteristics, and outcome measures was extracted from identified publications. In total, 74 papers were included in this review. The majority of studies have been conducted in young adult C57BL/6J mice and Sprague Dawley and Wistar rats. While there is an apparent lack of information about young animals, some studies that analyzed the grimace scale in aged rats were identified. The majority of studies focused on laparotomy-associated pain. Only limited information is available about other types of surgical interventions. While an impact of surgery and an influence of analgesia were rather consistently reported in studies focusing on grimace scales, the number of studies that assessed respective effects was rather low for nest building and burrowing. Moreover, controversial findings were evident for the impact of analgesics on post-surgical nest building activity. Regarding analgesia, a monotherapeutic approach was identified in the vast majority of studies with non-steroidal anti-inflammatory (NSAID) drugs and opioids being most commonly used. In conclusion, most evidence exists for grimace scales, which were more frequently used to assess post-surgical pain in rodents than the other behavioral parameters. However, our findings also point to relevant knowledge gaps concerning the post-surgical application in different strains, age levels, and following different surgical procedures. Future efforts are also necessary to directly compare the sensitivity and robustness of different readout parameters applied for the assessment of nest building and burrowing activities.

Multiparameter magnetic resonance imaging of liver fibrosis in a bile duct ligation mouse model

BACKGROUND

Bile duct ligation (BDL) in animals is a classical method for mimicking cholestatic fibrosis. Although different surgical techniques have been described in rats and rabbits, mouse models can be more cost-effective and reproducible for investigating cholestatic fibrosis. Magnetic resonance imaging (MRI) has made great advances for noninvasive assessment of liver fibrosis. More comprehensive liver fibrotic features of BDL on MRI are important. However, the utility of multiparameter MRI to detect liver fibrosis in a BDL mouse model has not been assessed.

AIM

To evaluate the correlation between the pathological changes and multiparameter MRI characteristics of liver fibrosis in a BDL mouse model.

METHODS

Twenty-eight healthy adult male balb/c mice were randomly divided into four groups: sham, week 2 BDL, week 4 BDL, and week 6 BDL. Multiparameter MRI sequences, included magnetic resonance cholangiopancreatography, T1-weighted, T2-weighted, T2 mapping, and pre- and post-enhanced T1 mapping, were performed after sham and BDL surgery. Peripheral blood and liver tissue were collected after MRI. For statistical analysis, Student’s t-test and Pearson’s correlation coefficient were used.

RESULTS

Four mice died after BDL surgery; seven, six, five and six mice were included separately from the four groups. Signal intensities of liver parenchyma showed no difference on TI- and T2-weighted images. Bile duct volume, ΔT1 value, T2 value, and the rate of liver fibrosis increased steadily in week 2 BDL, week 4 BDL and week 6 BDL groups compared with those in the sham group (P < 0.01). Alanine aminotransferase and aspartate transaminase levels initially surged after surgery, followed by a gradual decline over time. Strong correlations were found between bile duct volume (r = 0.84), T2 value (r = 0.78), ΔT1 value (r = 0.62), and hepatic fibrosis rate (all P < 0.01) in the BDL groups.

CONCLUSION

The BDL mouse model induces changes that can be observed on MRI. The MRI parameters correlate with the hepatic fibrosis rate and allow for detection of cholestatic fibrosis.

Comparison of intra- and postoperative variables between laparoscopic and open ovariectomy in rabbits (Oryctolagus cuniculus)

OBJECTIVE

To compare intraoperative and short-term postoperative variables pertaining to laparoscopic ovariectomy (LapOVE) and open ovariectomy (OVE) in rabbits (Oryctolagus cuniculus).

ANIMALS

Twelve 4- to 5-month-old female New Zealand White rabbits.

PROCEDURES

Rabbits were randomly assigned to undergo LapOVE (n = 6) or OVE (6), with a vessel-sealing device used to seal and transect the ovarian pedicles. Laparoscopic ovariectomy was performed with a 3-port approach. Variables were measured during surgery (surgery and anesthesia times and incision lengths) and for up to 7 days after surgery (food consumption, feces production, body weight, vital parameters, blood glucose and cortisol concentrations, abdominal palpation findings, facial grimace scale scores, and ethograms).

RESULTS

Mean surgery (43.2 vs 21.7 minutes) and anesthesia (76.2 vs 48.8 minutes) times were longer and mean incision length was shorter (24.0 vs 41.5 mm) for LapOVE versus OVE. No significant differences in postoperative variables were identified between groups. During LapOVE, small intestinal perforation occurred in 1 rabbit, which was then euthanized. Postoperative complications for the remaining rabbits included superficial incisional dehiscence (LapOVE, 1/5; OVE, 2/6), subcutaneous emphysema (LapOVE, 1/5; OVE, 0/6), and seroma formation (LapOVE, 1/5; OVE, 0/6).

CONCLUSIONS AND CLINICAL RELEVANCE

Surgery time for LapOVE was twice that of OVE, and LapOVE resulted in unique complications in rabbits. No evidence of a reduction in pain or faster return to baseline physiologic status was found for LapOVE. Further evaluation of LapOVE in rabbits is warranted, with modification to techniques used in this study or a larger sample size.

Grimace Scores: Tools to Support the Identification of Pain in Mammals Used in Research

The 3Rs, Replacement, Reduction and Refinement, is a framework to ensure the ethical and justified use of animals in research. The implementation of refinements is required to alleviate and minimise the pain and suffering of animals in research. Public acceptability of animal use in research is contingent on satisfying ethical and legal obligations to provide pain relief along with humane endpoints. To fulfil this obligation, staff, researchers, veterinarians, and technicians must rapidly, accurately, efficiently and consistently identify, assess and act on signs of pain. This ability is paramount to uphold animal welfare, prevent undue suffering and mitigate possible negative impacts on research. Identification of pain may be based on indicators such as physiological, behavioural, or physical ones. Each has been used to develop different pain scoring systems with potential benefits and limitations in identifying and assessing pain. Grimace scores are a promising adjunctive behavioural technique in some mammalian species to identify and assess pain in research animals. The use of this method can be beneficial to animal welfare and research outcomes by identifying animals that may require alleviation of pain or humane intervention. This paper highlights the benefits, caveats, and potential applications of grimace scales.

The development and use of facial grimace scales for pain measurement in animals

The measurement of pain in animals is surprisingly complex, and remains a critical issue in veterinary care and biomedical research. Based on the known utility of pain measurement via facial expression in verbal and especially non-verbal human populations, "grimace scales" were first developed a decade ago for use in rodents and now exist for 10 different mammalian species. This review details the background context, historical development, features (including duration), psychometric properties, modulatory factors, and impact of animal grimace scales for pain.

Laparoscopic ovariectomy in guinea pigs: A pilot study

OBJECTIVE

To assess the feasibility and safety of laparoscopic ovariectomy in guinea pigs utilizing 3-mm minilaparoscopic instruments.

STUDY DESIGN

Experimental pilot study.

ANIMALS

Guinea pigs (n = 3).

METHODS

The guinea pigs were sedated, placed under general anesthesia, and intubated under endoscopic visualization. A 3-port technique was used with a 3.9-mm cannula for the endoscope and two 3.5-mm cannulas accommodating 3-mm endoscopic instruments including a 3-mm vessel sealing device, grasping forceps, and endoscopic scissors. The abdomen was insufflated with CO₂ to a pressure of 6-8 mm Hg. The guinea pigs were manually tilted 90° laterally to visualize the dorsally positioned ovaries.

RESULTS

The procedure was successfully performed in all 3 animals. The surgery times were 120, 45, 45 minutes for the 3 guinea pigs, and anesthesia times were 186, 90, and 76 minutes, respectively. Placing the animals in complete lateral recumbency was found to be critical to visualize and manipulate the ovaries. The guinea pigs recovered smoothly from anesthesia.

CONCLUSION

Laparoscopic ovariectomy with 3-mm minilaparoscopic instrumentation using a 3-port technique was feasible in guinea pigs.

CLINICAL SIGNIFICANCE

Laparoscopic ovariectomy can be considered as an alternative to open ovariectomy as an elective surgical technique to prevent reproductive disorders in guinea pigs.

Influence of tramadol on functional recovery of acute spinal cord injury in rats

PURPOSE

To evaluate the influence tramadol on functional recovery of acute spinal cord injury in rats.

METHODS

Ten rats were divided into two groups (n = 5). All animals were submitted by a laminectomy and spinal cord injury at eighth thoracic vertebra. In control group, the rats didn't receive any analgesic. In tramadol group, the rats received tramadol 4mg/Kg at 12/12h until 5 days by subcutaneous. Animals were following by fourteen days. Was evaluated the Basso, Beattie, Bresnahan scale (locomotor evaluation) and Rat Grimace Scale (pain evaluation) at four periods.

RESULTS

There no difference between the groups in locomotor evaluation in all periods evaluated (p>0.05) and in both groups there was a partial recover of function. The tramadol group show a lower pain levels at the first, third and seventh postoperatively days when comparing to the control group.

CONCLUSION

The tramadol as an analgesic agent don't influence on functional recovery of acute spinal cord injury in rats.

The care dependency of patients after laparoscopic abdominal surgery and associated factors in China

PURPOSE

The outcome after laparoscopic surgery is dependent on self-care behaviors. Whether or not the patients after laparoscopic abdominal surgery in China are care-dependent is still unclear. Thus, the studies try to analyze influence factors of care dependence on patients with laparoscopic abdominal surgery, to provide reference for personalized care for the patient.

METHODS

In our study, two hundreds and forty-two cases were selected and investigated by using the exercise of self-care agency scale and care dependency scale. And correlation analyses between care dependency and self-care agency, age or hospital stay duration was made by Spearman correlation analysis. The analysis of associated factors was made by multivariable linear regression model.

RESULTS

The mean age of participants is 42.12±12.67 (ranged from 18 to 73years), and 134 patients (55.37%) in the study were older than 50years. Among the 242 participants, 59.09% is male. Our data found that the average self-care agency score was 115.72±30.13. And 64.88% participates are in the median level of self-care agency. Care dependency correlated with self-care agency (r=-0.85, P=0.009), age (r=-0.71, P=0.001) and hospital stay duration (r=-0.69, P=0.003) negatively. The linear regression was found between gender, age, educational level, days of hospital stay and care dependency. The model is care dependency=99.533+5.02×(gender)-0.795×(age)+0.512×(educational level)-0.239×(days of hospital stay).

CONCLUSION

Patients after laparoscopic surgery take notice of self-care. Gender, age, educational level and days of hospital stay affect care dependence.

Exotic Mammal Laparoscopy

Laparoscopy is an evolving field in veterinary medicine, and there is an increased interest in using laparoscopic techniques in nondomestic mammals, including zoo animals, wildlife, and exotic pets. The aim of this article is to summarize the approach to laparoscopic procedures, including instrumentation, patient selection and preparation, and surgical approaches, and to review the current literature on laparoscopy in exotic mammals.