Sage Journals: Discover world-class research

Abstract

The refinement of surgical techniques represents a key opportunity to improve the welfare of laboratory rodents, while meeting legal and ethical obligations. Current methods used for monitoring intra-abdominal disease progression in rodents usually involve euthanasia at various time-points for end of study, one-time individual tissue collections. Most rodent organ tumour models are developed by the introduction of tumour cells via laparotomy or via ultrasound-guided indirect visualization. Ischaemic rodent models are often generated using laparotomies. This approach requires a high number of rodents, and in some instances introduces high degrees of morbidity and mortality, thereby increasing study variability and expense. Most importantly, most laparotomies do not promote the highest level of rodent welfare. Recent improvements in laparoscopic equipment and techniques have enabled the adaptation of laparoscopy for rodent procedures. Laparoscopy, which is considered the gold standard for many human abdominal procedures, allows for serial biopsy collections from the same animal, results in decreased pain and tissue trauma as well as quicker postsurgical recovery, and preserves immune function in comparison to the same procedures performed by laparotomy. Laparoscopy improves rodent welfare, decreases interanimal variability, thereby reducing the number of required animals, allows for the replacement of larger species, decreases expense and improves data yield. This review article compares rodent laparotomy and laparoscopic surgical methods, and describes the utilization of laparoscopy for the development of cancer models and assessment of disease progression to improve data collection and animal welfare. In addition, currently available rodent laparoscopic equipment and instrumentation are presented.

Keywords

Rodent mouse and rat laparoscopy mouse laparoscopy liver biopsy rodent model development refinement

Regulatory and ethical considerations in response to public demands have increased academic, industrial and governmental sensitivity to animal welfare in biomedical research. Investigators utilizing animals in research are required to design experiments with consideration to Russell and Burch's ‘Three Rs’ ... of refinement, reduction and replacement’.¹ Here, refinement is defined as the ‘reduction of the amount of stress imposed on animals being used’,¹ and reduction is defined as the ‘reduction in the number of animals used to obtain information of a given amount and precision’.¹ The initial definition of replacement meant a replacement of a living organism with a non-living organism.

However, it has been updated and subdivided into absolute replacement, which means complete replacement of animals, and relative replacement which involves utilization of ‘animals of lower neurophysiology sentience or animal tissues used’.² Within the last two decades, experimental study design has received significant attention in regard to implementation of biomethodologies, animal husbandry, pain assessment and humane endpoints to maximize rodent welfare in biomedical research.^3–6 In addition to elevating the standards for rodent care and use to match those mammalian species covered under the Animal Welfare Act, specific surgical procedures have been refined to meet the challenges presented by these smaller species.⁶

Rodent tumour models are becoming more complex with the widespread adoption of genetically-modified mice and rats.^7–10 Prior to the 1970s the majority of tumour experiments in rodents were performed by growing neoplastic cells subcutaneously or under the renal capsule.^11,12 During the late 1960s and 1970s orthotopic xenograft models were introduced, such as the co-injection of human breast carcinoma and stromal cells into the mammary fat pad of immunocompromised mice.^13–15 These models reproduce the host and tumour cellular interactions more accurately and thereby support the study of human disease progression in rodent models with higher dependability. By providing appropriate organ microenvironments, the chemosensitivity and metastatic behaviour of tumour cells are better preserved, allowing for the in vivo testing of potential drug compounds on a wide range of human tumours at physiologically relevant concentrations.^6,16–19 The chemotherapeutic activity in orthotopic xenograft models is often a good predictor of clinical efficacy, making such models particularly valuable. Such orthotopic models are typically more invasive than subcutaneous implantations and require a high degree of surgical skill and experience.^6,20 Because of these challenges, tumours are often implanted at more easily accessed locations which do not provide the local native tumour environment and limit the predictive value of these preclinical rodent data-sets.^18,21,22 An alternative to the performance of invasive abdominal surgeries was the development of ultrasound-guided injection of tumour cells into abdominal organs under indirect visualization.^23,24 However, this approach introduced experimental bias and confounding effects of inadvertent dissemination of tumour cells, depending upon the user skill.

In addition to providing animal models for investigating the complexities of intra-abdominal tumour biology (e.g. tumour development, metastasis, effects of immunity), rodents are widely used for toxicological, metabolic and inflammatory disease studies. A current requirement of such studies involves the euthanasia of rodents at various time-points to allow for gross, histopathological and molecular analyses of tumour progression. This experimental design requires a larger number of animals per study to obtain statistically significant data. Increased numbers of rodents at each time-point are also required to overcome the increased interanimal variability, morbidity and mortality associated with laparotomies.²⁵ Advances in non-invasive bioluminescent and fluorescent imaging allow longitudinal assessment of the growth and metastatic dissemination of orthotopic tumours but are limited by the inability to collect serial tumour samples.^26–31 Laparoscopy can augment these technologies by providing direct observation and assessment of gross and macroscopic morphology, and access to collect biopsies with high precision through direct visualization of target organs. Most importantly, the scientific community has a moral and legal responsibility to develop and implement methods that refine experimental models, minimize potential pain and stress, while providing quality data that meet study objectives.^4,32

Overview of laparoscopic surgery

Laparoscopic surgery, also referred to as minimally invasive surgery of the abdomen, is a surgical technique that involves making small incisions through which ports are placed. The camera and laparoscopic instruments are then introduced through the ports that allow access to the abdomen. The camera transmits an image of the organs onto a monitor, and the surgeon uses the image from the camera to perform the surgical procedure. Laparoscopy in human and veterinary medicine provides a powerful method to examine the abdominal cavity for neoplastic and inflammatory changes and to collect biopsies. Laparoscopy has become the gold standard in human medicine for many abdominal surgical procedures (e.g. cholecystectomy).^33–36 Laparoscopic surgery has several benefits over laparotomy (open surgery). Animals recover faster, as the potential for postoperative pain, inflammation and infection are reduced.^37–40 There is a quicker return to normal metabolic and behavioural activities, including intestinal transit recovery and subsequent normal food and water intake, than when the same procedure is performed by laparotomy. The laparoscopic approach allows for repeated visualization, biopsy collection and intervention within the same rodent which eliminates interanimal variability.²⁵ Biopsies of the liver, spleen, kidney, mesenteric lymph nodes and gonads can be performed safely, swiftly and easily in all rodents including mice and rats. Laparoscopic techniques can be easily standardized and reproduced, decreasing user bias. Laparoscopy increases the sensitivity of disease assessment relative to other techniques.^41–45 Laparoscopy can be especially useful in diseases such as alcoholic steatohepatitis, where it can be difficult to assess disease progression due to variations in disease severity between individual rodents.^25,46–48 Laparoscopic procedures allow the serial collection of biopsies, facilitating longitudinal studies of disease progression within the same animal, rather than relying on postmortem samples collected from replicates. This also permits the monitoring of early stages of diseases, when pathological changes are usually limited or non-existent.⁵ Direct, magnified laparoscopic visualization allows for the precise placement of tissue or tumour cells into target organs, promoting the study of disease development in its natural or xenogenic microenvironment.

Rodent laparoscopy

Rodent laparoscopic procedures have been reported in the literature but are not routinely used by the vast majority of biomedical researchers. This resistance to adopting this superior surgical approach has been mainly due to the need for specialized surgical skills and lack of available training, and the large expense and size of laparoscopic equipment needed to perform laparoscopic procedures in rodents. Laparoscopic towers typically include a transillumination unit for the laparoscope, a power source and monitor for a charge coupled-device camera, as well as an insufflation unit and tank. These stacks of equipment utilized in human and veterinary surgeries have traditionally been quite large and require spacious surgical suites for proper placement and use. This presents a challenge, since most institutions do not have dedicated rodent surgical suites, and procedures are often performed in areas that serve other purposes.^49,50 In addition, the use of existing veterinary and human laparoscopic instruments that typically range between 5 and 10 mm in diameter for rodent surgeries is inappropriate, as mouse and rat instrumentation should ideally be no wider than 3 mm in diameter.^51–54

Recent advances in the laparoscopic field have led to a significant reduction in the size and cost of equipment. New rodent laparoscopic towers are compact and mobile. They can easily fit on a bench top and be transported between procedure rooms or facilities (Figure 1). Specialization of instruments and miniaturization of optics have made many rodent procedures using laparoscopy now practical. Rodent-specific scopes provide high-quality imaging and are available as either viewing or working laparoscopes. Viewing laparoscopes allow only for visualization of the cavity without the ability to manipulate tissues and are available in diameters as small as 0.4 mm (images of various small sizes) (Figure 2). Whereas, a working laparoscope has a channel, or built-in working channel, through which laparoscopic operating instruments are introduced into the abdomen (Figure 2). These working laparoscopes are available in diameters as small as 1.9 mm and allow for the collection of intra-abdominal biopsies of sufficient size for histopathological and molecular analyses through a single incision (~2 mm) (Figure 3). This specialized instrumentation can also be used to perform various procedures such as ovariectomies through a single port. Additional minimally invasive techniques can be performed with this same instrument to produce renal or ovarian ischaemia models. The development of lighter and shorter instrumentation adapted for smaller species also reduces user fatigue, leading to a steadier hand. This is especially important in rodents, where a slight movement can result in inadvertent tissue trauma and poor surgical outcome. Traditional human and veterinary laparoscopes can be 30 cm or longer, whereas rodent laparoscopes are usually about 10 cm in length (Figure 4). These shorter instruments allow for better control, thereby decreasing the risk of complications. Improvements in rodent laparoscopic optics yield high-quality videos and images, which can be used for data collection, publication and teaching purposes. This can be especially important for good laboratory practice studies that have strict requirements for data collection.^55,56 Rodent laparoscopy allows for high precision injection of test compounds and neoplastic cells under direct visualization. These procedures can be performed serially in the same animal with minimal complications. Historically, many of these procedures were not feasible in these species and animals were euthanized to visualize the intra-abdominal organs or collect tissue samples. As a consequence, only indirect evidence of tumour development and disease progression, such as weight loss and poor hair coat, could be obtained prior to euthanasia. These clinical signs can also occur in response to stress or as a result of unrelated infections, especially when using immunocompromised mice and rats, rather than cancer-induced cachexia.

Figure 1

Compact laparoscopic tower (BioVision Technologies, Denver, CO, USA)

Figure 2

Laparoscopes with (a) working channel and (b) without working channel (BioVision Technologies)

Figure 3

Liver biopsy obtained with (a) 2 mm biopsy graspers (BioVision Technologies) and (b) removed with a 30-gauge needle (Fisher Scientific, Waltham, MA, USA)

Figure 4

Comparison of a 33 cm laparoscope and a 10 cm laparoscope (BioVision Technologies)

Harm–benefit and financials–benefit

Laparoscopy can and should be considered to replace or augment common procedures such as laparotomies and terminal tissue collections. Toxicology and longitudinal studies of neoplastic, inflammatory and metabolic diseases can greatly benefit from incorporating serial laparoscopic assessments. Doing so will improve surgical recovery, reduce postsurgical pain and preserve immune function. Performance of serial observations and biopsy collections within the same animal has the added benefits of reducing study variables and potentially reducing costs by increasing animal survival. The same test subject is utilized repeatedly, serving as its own control. Although an initial investment will need to be made to purchase the necessary laparoscopic equipment, the costs for rodent instruments and laparoscopic equipment are significantly less than for typical companion animal and human systems. Such initial expenditure is well worth the investment and the benefits to the animals and the researcher are many.

Adoption of laparoscopy in appropriate rodent models may allow for the cost-effective replacement of traditional large animal models. Mammalian species such as pigs or non-human primates have commonly been used for laparoscopic studies because their size closely approximates that of humans, and because human laparoscopic instruments could readily be used in these species. However, large animal models are expensive to maintain and limited by the number of institutions with appropriate housing.^57–62 Furthermore, species-specific reagents are necessary to carry out physiological, immunological and oncological assays. The availability of these assays and reagents for large species is quite limited, whereas they are usually readily available for mice and rats.^59,60,62 The ability to genetically alter rodents allows for development of lines with human genes. Such technology at present is limited in larger species.^63–66 Even for tumour studies, the number of cultured tumour cell lines developed for large animals is scarce, making it challenging to conduct such in vivo studies in these species.⁶² Because of the advantages of rodent models and advances in rodent laparoscopy, larger species can be potentially replaced with mice and rats, reducing study costs. However, it must be pointed out that sometimes there can be a conflict between the three Rs, especially between refinement and replacement.^67,68 Rodent laparoscopic procedures provide a refinement but they must be compared with conventional techniques and validated. This can lead to an increase in animal use, which is in opposition to ‘reduction’. Laparoscopy, as a new technique, has a learning curve in which the user needs to learn proficiency, otherwise poorly performed laparoscopic procedures can lead to additional numbers of animals required and potentially increasing animal suffering. However, the number of animals used during training can be reduced when a person is learning alongside an expert, and inanimate training models are used.

Consequently, there is a learning curve with any newly performed surgical technique, and surgeons should be proficient no matter what surgical modality is utilized.⁶⁹ Overall, it is important to keep in mind that a specific procedure, such as laparoscopy, will have a positive impact on three Rs, and the authors believe that laparoscopy would improve animal welfare.

Scientific aspects

Gas exposure

One aspect of laparoscopic procedures that is often not addressed is the decreased exposure of intra-abdominal organs and tissues to atmospheric air. Exposure to room air leads to exaggerated physiological alterations, e.g. interleukin (IL)-6 response.⁷⁰ The acidification of the peritoneum via CO₂ insufflation leads to attenuation of the inflammatory response through up-regulation of anti-inflammatory cytokines such as IL-10 and down-regulation of proinflammatory cytokines such as TNFΑ.^70–74 Acidaemia induced by CO₂ can be minimized by using the lowest intra-abdominal pressure necessary to expand the abdomen for visualization.⁷⁵ CO₂ pneumoperitoneum preserves cellular immune functions, lowers abdominal discomfort (feeling of retained gas in the abdomen) and offers better visibility during laparoscopy when compared with an open surgery.⁷⁶

Immune function

Laparotomy results in significant postoperative immune suppression, due to decreases in lymphocyte count and lymphocyte/macrophage interactions, neutrophil Chemotaxis, natural killer cell activity, alpha-2-macroglobulin release and delayed hypersensitivity responses.^77–82 This immune suppression compromises the rodent's defences at the time, when the risk for introducing pathogens is maximal and can lead to increased morbidity and mortality. This effect can last up to nine days after surgery, and is a specifically important confounding variable in cancer models, as immune suppression may effect tumour cell proliferation and engraftment rates.^76,79,83,84 Such immune suppression is directly proportional to the degree of surgical trauma. The higher the trauma, the greater the effect. Thus, the minimal invasiveness of laparoscopy, when compared with open surgery tends to preserve immune function by preserving T-cell mitogen response and monocyte release of tumour necrotic factor and superoxide.^85–87 Often the incision is smaller with laparoscopic surgery versus laparotomy, and larger incisions lead to postoperative decreases in animals’ abilities to mount effective cell-mediated immune responses.^83,88

Faster return to normal physiological status

Recovery of normal gastric emptying and normal intestinal motility is faster with laparoscopic surgery when compared with laparotomy.³⁷ Radiographic analyses demonstrate increased intestinal gas postlaparotomy, and histological analyses of the gastrointestinal tract postlaparotomy show pronounced serosal layer thickening in comparison with laparoscopy.³⁷ Postoperative adhesion formation has an impact on recovery since adhesions can cause intestinal obstructions and chronic pain.^89–93 In general, laparoscopy leads to less adhesion formation than laparotomy. A potential mechanism for this difference may be due to the introduction of room air during laparotomy. Increases in intra-abdominal partial oxygen tension above physiological levels is detrimental to serosal cells promoting the formation of reactive oxygen species and inflammatory reactions.⁹⁴ Transient introduction of room air into the abdomen by laparotomy can introduce a profound effect on subsequent tumour growth.

Tumour development and metastasis

Rodents often serve as intra-abdominal tumour models for studying hepatic, splenic or renal cancers. Most commonly cancer cells are injected into the liver or spleen or under the kidney capsule in mice and rats, after these target organs are visualized and/or exteriorized by laparotomy.^95–97 All of these techniques expose tissue to room air which induces an inflammatory response.⁹⁸ Jacobi et al.⁹⁹ have demonstrated that intra-abdominal tumour growth is higher when exposed to room air. Laparotomy can also accelerate tumour metastasis in these mouse models, while performing the same procedures by laparoscopy preserves the physiological abdominal environment for studying tumour growth and metastasis.¹⁰⁰

Surgical trauma can also impair cell-mediated immune responses and increase the risk of infection and metastatic spread.^101,102 Tsuchiya et al.¹⁰³ suggest that surgical stress-induced expression of proteinases in the target organ of metastasis enhance neoplastic metastasis. A laparoscopic approach may suppress haematogenous metastasis because of decreased surgical stress and reduced cytokine response.¹⁰⁰

Multiple surgeries

The Animal Welfare Act and the Guide of the Care and Use of Laboratory Animals (The Guide) states that a major surgery ‘penetrates and exposes a body cavity or produces a substantial impairment of physical or physiological function’.^104,105 Minor surgery is defined by The Guide as surgery which ‘does not expose a body cavity and cause little or no physical impairment’. Major surgery can be performed once per animal, unless it is scientifically justified and approved by Institutional Animal Care and Use Committees (IACUCs).^104,106 It has not been uniformly determined whether a laparoscopic surgery should be classified as a minor or major procedure. The Office of Laboratory Animal Welfare, which develops and monitors the Public Health Service Policy on Humane Care and Use of Laboratory Animals, recently added a guidance addressing laparoscopic procedures to their Frequently Asked Questions section.⁶⁹ This guidance allows the IACUCs to make a decision if specific laparoscopic procedures should be considered as minor or major at their respective institutions. Some IACUCs define all laparoscopic procedures as major surgeries, while others consider laparoscopic exploratory and biopsy procedures minor surgeries. By summarily classifying all laparoscopic procedures as major surgeries, IACUCs that adopt this paradigm may promote unintended consequences that seem counter to the biomedical research community's goals. This classification necessitates the use of additional animals to be sampled at various time-points and encourages researchers to opt for collecting single biopsy samples by laparotomy or after performing a humane euthanasia, rather than having to justify multiple survival surgeries. The UK's Animals (Scientific Procedures) Act of 1986 does not distinguish between major and minor surgery. The Act regulates both the severity of procedures and whether or not animals can be re-used for multiple surgical procedures. The severity of the surgical procedure is determined by the degree of departure from the normal physiological state caused by the procedure. The UK's Animals Act of 1986 requires justification for any ‘re-use’ or ‘continual use’ of animals.¹⁰⁷ The European Union's regulations are similar to that of the UK with respect to the re-use of animals and the determination of the severity of surgical procedures.¹⁰⁸ The ability to perform serial laparoscopic biopsies can be a superior, humane and cost-effective surgical approach that reduces trauma, postoperative pain and adhesion formation in individual subjects, as well as the total number of animals needed for a study. This approach is consistent with the veterinary medical canon of ethics and provides reasonable scientific justification for performing multiple laparoscopic surgeries per animal at institutions, regardless of how they classify laparoscopic biopsies, as major or minor surgical procedures.

Addressing laparoscopic limitations

The principal disadvantages of laparoscopy are the need for specialized equipment and training. Adequate training on how to use laparoscopic equipment effectively is imperative to perform laparoscopic procedures successfully. The cost of rodent laparoscopic equipment has decreased dramatically in the last few years, and training is becoming more available during annual meetings such as the Academy of Surgical Research and American Association for Laboratory Animal Sciences.^109,110 As to anaesthesia, the preferred method for rodent laparoscopic procedures is isoflurane through a calibrated vaporizer. This significantly decreases the anaesthesia time compared with injectable anaesthesia protocols thereby allowing mice and rats to recover quickly. The amount of analgesia required for laparoscopic procedures is significantly less relative to laparotomies.^111–115 It has been suggested that laparoscopy may lead to port site tumour seeding due to the intra-abdominal pressure;^116–119 however, this is more likely the result of intraoperative instrument contamination.¹²⁰ Most reports of metastases associated with laparoscopy are clinical cases with many variables and lacking adequate controls.^121,122 Mutter et al.¹¹⁹ have demonstrated that manipulation of the tumour is one of the factors affecting metastasis. The benefits of laparoscopy over laparotomy in this study appear to be the ability to decrease tumour manipulation, leading to a lower incidence of local regional dissemination and less tumour growth suggesting a potential lower recurrence rate in human practice.¹¹⁹

Conclusion

Rodents serve as invaluable experimental models for investigating the pathogenesis of and evaluating potential therapeutic treatments of neoplastic, inflammatory and metabolic diseases. The scientific community has made considerable refinements in how rodents are used in research. These refinements have improved rodent welfare, while allowing researchers to reach their study objectives more reproducibly. However, we must continually strive to refine experimental techniques and identify new methodologies to improve animal welfare as required by regulatory and accrediting bodies, and as part of our ethical responsibility.^104,109

In this article, we have tried to provide the most compelling evidence that demonstrates the benefits of rodent laparoscopic surgery. Rodent laparoscopy presents an opportunity for significant refinement of rodent surgical procedures by reducing tissue damage and inflammation, postsurgical pain and recovery time, and by preserving the immune system when compared with open surgery. Manipulations such as direct injection of reagents or the taking of biopsies from target organs or tissues can easily be performed with precision, allowing the researcher to assess and manipulate disease progression in mice and rats in vivo. Rodent laparoscopy is in keeping with the three Rs and complies with the refinement recommendations of cost-benefit assessment in animal-based research, described in the Appendix I of the Guidance on the Operation of Animals (Scientific Procedures) Act.¹⁰⁷ Laproscopy not only improves individual animal welfare, but also reduces the number of animals and associated costs required to gain significant and reliable data. When amortized, these savings can offset the initial investment required to purchase equipment and train personnel. Incorporation of rodent laparoscopy into studies can provide a cost-effective and powerful tool for the development and continuous assessment of inflammatory, metabolic and neoplastic diseases in rodent models. Laparoscopy can be used as a standalone technology or in conjunction with other imaging methods to study disease progression in rodent models. In conclusion, recent advances in rodent laparoscopy should facilitate the widespread adoption of this superior surgical approach and promote the goals of the biomedical research community.

References

Russell

WMS

, Burch

RL.

The Principles of Humane Experimental Technique. London: Methuen, 1959

De Boo

, Rennie

, Buchanan-Smith

, Hendriksen

CFM.

The interplay between replacement, reduction and refinement. Anim Welf 2005; 14: 327–32

Zeller

, Weber

, Panoussis

, Burge

, Bergmann

Refinement of blood sampling from the sublingual vein of rats. Lab Anim 1998; 32: 369–76

Flecknell

PA.

Refinement of animal use - assessment and alleviation of pain and distress. Lab Anim 1994; 28: 222–31

Jennings

, Batchelor

, Brain

PF.

Refining rodent husbandry: the mouse. Report of the Rodent Refinement Working Party. Lab Anim 1998; 32: 233–59

Curwen

, Wedge

SR.

The use and refinement of rodent models in anti-cancer drug discovery: a review. Altern Lab Anim 2009; 37: 173–80

Waller

, Fairhall

, Xu

, Robinson

, Murphy

Neurohypophyseal and fluid homeostasis in transgenic rats expressing a tagged rat vasopressin prepropeptide in hypothalamic neurons. Endocrinology 1996; 137: 5068–77

Hirabayashi

, Takahashi

, Sekiguchi

, Ueda

Viability of transgenic rat embryos after freezing and thawing. Exp Anim 1997; 46: 111–15

Palmiter

, Brinster

, Hammer

RE.

Dramatic growth of mice that develop from eggs microinjected with metallothionein-growth hormone fusion genes. Nature 1982; 300: 611–15

10.

Palmiter

, Chen

, Brinster

RL.

Differential regulation of metallothionein-thymidine kinase fusion genes in transgenic mice and their offspring. Cell 1982; 29: 701–10

11.

Stratton

, Kucera

, Micha

JP.

The subrenal capsule tumor implant assay as a predictor of clinical response to chemotherapy: 3 years of experience. Gynecol Oncol 1984; 19: 336–47

12.

Griffin

, Bogden

, Reich

SD.

Initial clinical trials of the subrenal capsule assay as a predictor of tumor response to chemotherapy. Cancer 1983; 52: 2185–92

13.

Tan

, Holyoke

, Goldrosen

MH.

Murine colon adenocarcinoma: syngeneic orthotopic transplantation and subsequent hepatic metastases. J Natl Cancer Inst 1977; 59: 1537–44

14.

Rygaard

, Povlsen

CO.

Heterotransplantation of a human malignant tumour to ‘Nude’ mice. Acta Pathol Microbiol Scand 1969; 77: 758–60

15.

Corbett

, Valeriote

, Baker

LH.

Is the P388 murine tumor no longer adequate as a drug discovery model?

Invest New Drugs 1987; 5: 3–20

16.

Tseng

, Leong

, Engleman

Orthotopic mouse model of colorectal cancer. J Vis Exp 2007; (10):484

17.

Sasaki

, Miura

, Horii

Orthotopic implantation mouse model and cDNA microarray analysis indicates several genes potentially involved in lymph node metastasis of colorectal cancer. Cancer Sci 2008; 99: 711–19

18.

Dong

, Radinsky

, Fan

Organ-specific modulation of steady-state mdr gene expression and drug resistance in murine colon cancer cells. J Natl Cancer Inst 1994; 86: 913–20

19.

Ahn

, Jung

, Kim

, Lee

, Yoon

SS.

Behavior of murine renal carcinoma cells grown in ectopic or orthotopic sites in syngeneic mice. Tumour Biol 2001; 22: 146–53

20.

Yang

, Rescorla

, Reilly

CR.

A reproducible rat liver cancer model for experimental therapy: introducing a technique of intrahepatic tumor implantation. J Surg Res 1992; 52: 193–8

21.

Morikawa

, Walker

, Nakajima

, Pathak

, Jessup

, Fidler

IJ.

Influence of organ environment on the growth, selection, and metastasis of human colon carcinoma cells in nude mice. Cancer Res 1988; 48: 6863–71

22.

Fidler

, Wilmanns

, Staroselsky

, Radinsky

, Dong

, Fan

Modulation of tumor cell response to chemotherapy by the organ environment. Cancer Metastasis Rev 1994; 13: 209–22

23.

Schnater

, Bruder

, Bertschin

Subcutaneous and intrahepatic growth of human hepatoblastoma in immunodeficient mice. J Hepatol 2006; 45: 377–86

24.

Lin

, Lin

, He

, Gao

, Xue

ES.

Experimental study on ultrasound-guided intratumoral injection of ‘Star-99’ in treatment of hepatocellular carcinoma of nude mice. World J Gastroenterol 2003; 9: 701–5

25.

Shapira

, Katz

, Ali

Utilization of murine laparoscopy for continuous in-vivo assessment of the liver in multiple disease models. PLoS One 2009; 4: e4776

26.

Cowey

, Szafran

, Kappes

Breast cancer metastasis to bone: evaluation of bioluminescent imaging and microSPECT/CT for detecting bone metastasis in immunodeficient mice. Clin Exp Metastasis 2007; 24: 389–401

27.

Ohsawa

, Murakami

, Uemoto

, Kobayashi

In vivo luminescent imaging of cyclosporin A-mediated cancer progression in rats. Transplantation 2006; 81: 1558–67

28.

Murakami

, Kobayashi

Color-engineered rats and luminescent LacZ imaging: a new platform to visualize biological processes. J Biomed Opt 2005; 10: 41204

29.

Mook

, Van Marie

, Vreeling-Sindelarova

, Jonges

, Frederiks

, Van Noorden

CJ.

Visualization of early events in tumor formation of eGFP-transfected rat colon cancer cells in liver. Hepatology 2003; 38: 295–304

30.

Zhang

, Lyons

, Lim

, Lassota

A spontaneous acinar cell carcinoma model for monitoring progression of pancreatic lesions and response to treatment through noninvasive bioluminescence imaging. Clin Cancer Res 2009; 15: 4915–24

31.

Chang

, Chang

, Ho

TY.

Noninvasive bioluminescent and microPET imaging for the regulation of NF-kappaB in human hepatoma-bearing mice. Anticancer Res 2009; 29: 987–94

32.

Fante

, Boldrin

, Polito

Refinement of a transplantation project in the non-human primate by the use of a humane endpoint. Lab Anim 2007; 41: 456–69

33.

Litwin

, Cahan

MA.

Laparoscopic cholecystectomy. Surg Clin North Am 2008; 88: 1295–313, ix

34.

Gurlich

, Maruna

, Lindner

, Fidler

[Evaluation of laparoscopic and laparotomy cholecystectomy by comparing the dynamics of acute phase proteins]. Rozhl Chir 1994; 73: 214–17

35.

Sain

AH.

Laparoscopic cholecystectomy is the current ‘gold standard’ for the treatment of gallstone disease. Ann Surg 1996; 224: 689–90

36.

Soper

, Stockmann

, Dunnegan

, Ashley

SW.

Laparoscopic cholecystectomy. The new ‘gold standard'?

Arch Surg 1992; 127: 917–21; discussion 21-3

37.

Takada

, Fukumoto

, Ichihara

, Ku

, Kuroda

Comparison of intestinal transit recovery between laparoscopic and open surgery using a rat model. Surg Endosc 2003; 17: 1237–40

38.

Mayhew

Surgical views: laparoscopic and laparoscopic-assisted cryptorchidectomy in dogs and cats. Compend Contin Educ Vet 2009; 31: 274–81

39.

Davidson

, Moll

, Payton

ME.

Comparison of laparoscopic ovariohysterectomy and ovariohysterectomy in dogs. Vet Surg 2004; 33: 62–9

40.

Miller

, Van Lue

, Rawlings

CA.

Use of laparoscopic-assisted cryptorchidectomy in dogs and cats. J Am Vet Med Assoc 2004; 224: 875–8, 865

41.

Denzer

, Arnoldy

, Kanzler

, Galle

, Dienes

, Lohse

AW.

Prospective randomized comparison of minilaparoscopy and percutaneous liver biopsy: diagnosis of cirrhosis and complications. J Clin Gastroenterol 2007; 41: 103–10

42.

Schneider

, Riemann

, Arnold

JC.

[Value of minilaparoscopy in comparison with conventional laparoscopy in diagnosis of liver diseases - intermediate term results of a prospective, randomized study]. Z Gastroenterol 2001; 39(1 Suppl):15–18

43.

Orlando

, Lirussi

Laparoscopy and guided liver biopsy in the diagnosis of cirrhosis: conventional technique vs minilaparoscopy. Endoscopy 2003; 35: 1079–80

44.

Manns

, Schneider

, Meier

PN.

Minilaparoscopy for early diagnosis of cirrhosis: is the endoscopist's eye better than the histopathologist's?

Endoscopy 2003; 35: 74–5

45.

Helmreich-Becker

, Schumacher

, Denzer

, Hensel

, Meyer zum Buschenfelde

, Lohse

AW.

Minilaparoscopy in the diagnosis of cirrhosis: superiority in patients with Child-Pugh A and macronodular disease. Endoscopy 2003; 35: 55–60

46.

Ratziu

, Charlotte

, Heurtier

Sampling variability of liver biopsy in nonalcoholic fatty liver disease. Gastroenterology 2005; 128: 1898–906

47.

Gluud

Sampling variability in percutaneous liver biopsy. Lancet 1986; 1: 975

48.

Ratziu

, Bugianesi

, Dixon

Histological progression of non-alcoholic fatty liver disease: a critical reassessment based on liver sampling variability. Aliment Pharmacol Ther 2007; 26: 821–30

49.

Van Dongen

JJ.

Manual of Microsurgery on the Laboratory Rat. Amsterdam: Elsevier, 1990

50.

van Dongen

, Remie

, Rensema

, van Wunnik

GHJ.

Manual of Microsurgery on the Laboratory Rat. Amsterdam: Elsevier, 2004

51.

Jones

BD.

Veterinary Endoscopy. Philadelphia: Saunders, 1990

52.

McCarthy

TC.

Veterinary Endoscopy for the Small Animal Practitioner. St Louis, MO: Elsevier Saunders, 2005

53.

Hulka

, Reich

Textbook of Laparoscopy. 3rd edn. Philadelphia: Saunders, 1998

54.

Salky

, Berci

Laparoscopy for Surgeons. New York: Igaku-Shoin, 1990

55.

International Organization for Standardization. ISO 9000: International Standards for Quality Management. 3rd edn. Geneva, Switzerland: International Organization for Standardization, 1993

56.

Stengl

, Bronson

, Gouch

, Rumsey

, Sullivan

, Wilbourn

CL.

Good Laboratory Practices, Total Quality Management, and International Organization for Standardization: a foundation for excellence. Qual Assur 1995; 4: 316–18

57.

Krinke

The Laboratory Rat. San Diego: Academic Press, 2000

58.

Sharp

, La Regina

, Suckow

MA.

The Laboratory Rat. Boca Raton, FL: CRC Press, 1998

59.

Suckow

, Weisbroth

, Franklin

CL.

The Laboratory Rat. 2nd edn. Amsterdam: Elsevier, 2006

60.

Hedrich

, Bullock

GR.

The Laboratory Mouse. Amsterdam: Elsevier Academic Press, 2004

61.

Suckow

, Danneman

, Brayton

The Laboratory Mouse. Boca Raton, FL: CRC Press, 2001

62.

Allendorf

, Bessler

, Whelan

RL.

A murine model of laparoscopic-assisted intervention. Surg Endosc 1997; 11: 622–4

63.

Mercier

, Jasmin

, Pavlides

Clinical and translational implications of the caveolin gene family: lessons from mouse models and human genetic disorders. Lab Invest 2009; 89: 614–23

64.

Zachau

HG.

The immunoglobulin kappa gene families of human and mouse: a cottage industry approach. Biol Chem 2000; 381: 951–4

65.

Clark

, Arden

, Kabelitz

, Mak

TW.

Comparison of human and mouse T-cell receptor variable gene segment subfamilies. Immunogenetics 1995; 42: 531–40

66.

Lan

, Ma

, Liu

, Shen

Adenovirus-mediated CTLA4Ig gene transfer improves the survival of grafted human hepatic progenitors in mouse liver. Transplant Proc 2009; 41: 1862–4

67.

Balls

Replacement of animal procedures: alternatives in research, education and testing. Lab Anim 1994; 28: 193–211

68.

Weihe

WH.

Use and misuse of an imprecise concept: alternative methods in animal experiments. Lab Anim 1985; 19: 19–26

69.

Office of Laboratory Animal Welfare. Frequently Asked Questions -Protocol Review - Question 13: Are laparoscopic procedures considered major surgery? See http://grants.nih.gov/grants/olaw/faqs. htm#f13 (last checked 16 May 2010)

70.

Tung

, Smith

CD.

Laparoscopic insufflation with room air causes exaggerated interleukin-6 response. Surg Endosc 1999; 13: 473–5

71.

Hanly

, Aurora

, Shih

SP.

Peritoneal acidosis mediates immunoprotection in laparoscopic surgery. Surgery 2007; 142: 357–64

72.

Hanly

, Fuentes

, Aurora

AR.

Carbon dioxide pneumoperitoneum prevents mortality from sepsis. Surg Endosc 2006; 20: 1482–7

73.

Hanly

, Aurora

, Fuentes

JM.

Abdominal insufflation with CO₂ causes peritoneal acidosis independent of systemic pH. J Gastrointest Surg 2005; 9: 1245–51; discussion 51-2

74.

Hanly

, Bachman

, Marohn

MR.

Carbon dioxide pneumoperitoneum-mediated attenuation of the inflammatory response is independent of systemic acidosis. Surgery 2005; 137: 559–66

75.

Kuntz

, Wunsch

, Bodeker

Effect of pressure and gas type on intraabdominal, subcutaneous, and blood pH in laparoscopy. Surg Endosc 2000; 14: 367–71

76.

Mealy

, O'Farrelly

, Stephens

, Feighery

Impaired neutrophil function during anesthesia and surgery is due to serum factors. J Surg Res 1987; 43: 393–7

77.

Christou

, Superina

, Broadhead

, Meakins

JL.

Postoperative depression of host resistance: determinants and effect of peripheral protein-sparing therapy. Surgery 1982; 92: 786–92

78.

Hjortso

, Kehlet

Influence of surgery, age and serum albumin on delayed hypersensitivity. Acta Chir Scand 1986; 152: 175–9

79.

Lennard

, Shenton

, Borzotta

The influence of surgical operations on components of the human immune system. Br J Surg 1985; 72: 771–6

80.

Nielsen

, Pedersen

, Moesgaard

, Haahr

, Kehlet

Effect of ranitidine on postoperative suppression of natural killer cell activity and delayed hypersensitivity. Acta Chir Scand 1989; 155: 377–82

81.

Nielsen

, Moesgaard

, Kehlet

Ranitidine for prevention of postoperative suppression of delayed hypersensitivity. Am J Surg 1989; 157: 291–4

82.

Lasson

, Berling

, Goransson

, Ohlsson

Alpha-2-macroglobulin decreases parallel to albumin and haemoglobin after elective surgery. Scand J Clin Lab Invest 1991; 51: 225–33

83.

Allendorf

, Bessler

, Whelan

Postoperative immune function varies inversely with the degree of surgical trauma in a murine model. Surg Endosc 1997; 11: 427–30

84.

Hammer

, Nielsen

, Moesgaard

, Kehlet

Duration of postoperative immunosuppression assessed by repeated delayed type hypersensitivity skin tests. Eur Surg Res 1992; 24: 133–7

85.

Schwab

, Eissele

, Bruckner

, Gebhard

, Becker

HP.

Systemic inflammatory response after endoscopic (TEP) vs Shouldice groin hernia repair. Hernia 2004; 8: 226–32

86.

Kobayashi

, Yoshida

, Yamauchi

, Suminaga

, Miyata

Immune function in patients undergoing open vs laparoscopic cholecystectomy. Arch Surg 1995; 130: 676

87.

Redmond

, Watson

, Houghton

, Condron

, Watson

, Bouchier-Hayes

Immune function in patients undergoing open vs laparoscopic cholecystectomy. Arch Surg 1994; 129: 1240–6

88.

Iwanaka

, Arkovitz

, Arya

, Ziegler

MM.

Evaluation of operative stress and peritoneal macrophage function in minimally invasive operations. J Am Coll Surg 1997; 184: 357–63

89.

Ellis

The clinical significance of adhesions: focus on intestinal obstruction. Eur J Surg Suppl 1997; 577: 5–9

90.

Zhang

, Yao

, Wu

, Chi

, Zhang

, Li

Topical application of halcinonide cream reduces the severity and incidence of intraperitoneal adhesions in a rat model. Am J Surg 2002; 184: 74–7

91.

Duffy

, diZerega

GS.

Adhesion controversies: pelvic pain as a cause of adhesions, crystalloids in preventing them. J Reprod Med 1996; 41: 19–26

92.

Guvenal

, Cetin

, Ozdemir

, Yanar

, Kaya

Prevention of postoperative adhesion formation in rat uterine horn model by nimesulide: a selective COX-2 inhibitor. Hum Reprod 2001; 16: 1732–5

93.

Rapkin

AJ.

Adhesions and pelvic pain: a retrospective study. Obstet Gynecol 1986; 68: 13–15

94.

Elkelani

, Binda

, Molinas

, Koninckx

PR.

Effect of adding more than 3% oxygen to carbon dioxide pneumoperitoneum on adhesion formation in a laparoscopic mouse model. Fertil Steril 2004; 82: 1616–22

95.

Bogden

, Haskell

, LePage

, Kelton

, Cobb

, Esber

HJ.

Growth of human tumor xenografts implanted under the renal capsule of normal immunocompetent mice. Exp Cell Biol 1979; 47: 281–93

96.

Bennett

, Pilon

, MacDowell

RT.

Evaluation of growth and histology of human tumor xenografts implanted under the renal capsule of immunocompetent and immunodeficient mice. Cancer Res 1985; 45: 4963–9

97.

Aamdal

, Fodstad

, Pihl

Human tumor xenografts transplanted under the renal capsule of conventional mice. Growth rates and host immune response. Int J Cancer 1984; 34: 725–30

98.

Watson

, Redmond

, McCarthy

, Burke

, Bouchier-Hayes

Exposure of the peritoneal cavity to air regulates early inflammatory responses to surgery in a murine model. Br J Surg 1995; 82: 1060–5

99.

Jacobi

, Ordemann

, Bohm

The influence of laparotomy and laparoscopy on tumor growth in a rat model. Surg Endosc 1997; 11: 618–21

100.

Shiromizu

, Suematsu

, Yamaguchi

, Shiraishi

, Adachi

, Kitano

Effect of laparotomy and laparoscopy on the establishment of lung metastasis in a murine model. Surgery 2000; 128: 799–805

101.

Pollock

, Lotzova

Surgical-stress-related suppression of natural killer cell activity: a possible role in tumor metastasis. Nat Immun Cell Growth Regul 1987; 6: 269–78

102.

Saba

, Antikatzides

TG.

Decreased resistance to intravenous tumour-cell challenge during reticuloendothelial depression following surgery. Br J Cancer 1976; 34: 381–9

103.

Tsuchiya

, Sawada

, Yoshioka

Increased surgical stress promotes tumor metastasis. Surgery 2003; 133: 547–55

104.

Institute of Laboratory Animal Resources (US). Guide for the Care and Use of Laboratory Animals. 7th edn. Washington, DC: National Academy Press, 1996

105.

Code of Federal Regulations. 9CFR3. Washington, DC,1995. Revised 2009

106.

United States Animal and Plant Health Inspection Service. Animal Welfare Act and Animal Welfare Regulations. Washington, DC: US Department of Agriculture, Animal and Plant Health Inspection Service, 2005

107.

Home Office. Guidance on the Operation of the Animals (Scientific Procedures) Act 1986. London: The Stationery Office, 2000

108.

Council of The European Union. Directive of the European Parliament and the Council on The Protection of Animals used for Scientific Purposes, 2010. See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:276:0033:0079:EN:PDF

109.

Baran

, Perret-Gentil

, eds. Introduction to Basic Principles of Large Animal and Rodent Laparoscopy through Inanimate Object Training. American Association for Laboratory Animal Science Annual Meeting. Denver, CO, 2009

110.

Baran

, Perret-Gentil

, eds. Laparoscopic Techniques. Academy of Surgical Research Annual Meeting. New Orleans, LA, 2009

111.

Perret-Gentil

, Sinanan

, Dennis

MB.

Videoendoscopy: an effective and efficient way to perform multiple visceral biopsies in small animals. J Invest Surg 1999; 12: 157–65

112.

Perret-Gentil

, Sinanan

, Dennis

MB.

Videoendoscopic techniques for collection of multiple, serial intra-abdominal biopsy specimens in HIV-negative and HIV-positive pigtail macaques (Macaca nemestrina). J Invest Surg 2000; 13: 181–95

113.

Kerbl

, Clayman

, Petros

, Chandhoke

, Gill

IS.

Staging pelvic lymphadenectomy for prostate cancer: a comparison of laparoscopic and open techniques. J Urol 1993; 150(2 Part 1):396–8; discussion 9

114.

Maruszynski

, Pojda

Interleukin 6 (IL-6) levels in the monitoring of surgical trauma. A comparison of serum IL-6 concentrations in patients treated by cholecystectomy via laparotomy or laparoscopy. Surg Endosc 1995; 9: 882–5

115.

Glaser

, Sannwald

, Buhr

HJ.

General stress response to conventional and laparoscopic cholecystectomy. Ann Surg 1995; 221: 372–80

116.

Clair

, Lautz

, Brooks

DC.

Rapid development of umbilical metastases after laparoscopic cholecystectomy for unsuspected gallbladder carcinoma. Surgery 1993; 113: 355–8

117.

Fligelstone

, Rhodes

, Flook

, Puntis

, Crosby

Tumour inoculation during laparoscopy. Lancet 1993; 342: 368–9

118.

O'Rourke

, Price

, Kelly

, Sikora

Tumour inoculation during laparoscopy. Lancet 1993; 342: 368

119.

Mutter

, Hajri

, Tassetti

, Solis-Caxaj

, Aprahamian

, Marescaux

Increased tumor growth and spread after laparoscopy vs laparotomy: influence of tumor manipulation in a rat model. Surg Endosc 1999; 13: 365–70

120.

Gertsch

, Baer

, Kraft

, Maddern

, Altermatt

HJ.

Malignant cells are collected on circular staplers. Dis Colon Rectum 1992; 35: 238–41

121.

Gleeson

, Nicosia

, Mark

, Hoffman

, Cavanagh

Abdominal wall metastases from ovarian cancer after laparoscopy. Am J Obstet Gynecol 1993; 169: 522–3

122.

Prasad

, Avery

, Foley

RJ.

Abdominal wall metastases following laparoscopy. Br J Surg 1994; 81: 1697

Rodent laparoscopy: Refinement for rodent drug studies and model development,and monitoring of neoplastic,inflammatory and metabolic diseases

Abstract

Keywords

Overview of laparoscopic surgery

Rodent laparoscopy

Harm–benefit and financials–benefit

Scientific aspects

Gas exposure

Immune function

Faster return to normal physiological status

Tumour development and metastasis

Multiple surgeries

Addressing laparoscopic limitations

Conclusion

References