Diagnostic laparoscopy in the cat: 2. Common procedures

Comparison of the diagnostic yield of 3 and 5 mm laparoscopic liver biopsy forceps in cats

OBJECTIVE

To determine whether 3 and 5 mm laparoscopic cup biopsy forceps provide samples of equivalent diagnostic quality in cats.

STUDY DESIGN

Experimental study.

ANIMALS

Twelve colony cats undergoing a concurrent nutrition study.

METHODS

Two biopsy forceps (3 and 5 mm) and three biopsy techniques (twist, pull, and twist + pull) were used to collect 68 laparoscopic liver samples. Biopsies were performed consecutively with the 3 and 5 mm biopsy sites adjacent to each other. Data analyzed included the number of portal triads and hepatic lobules, tissue crush and fragmentation, overall sample area (mm2 ), sample weight, and agreement regarding morphologic diagnosis.

RESULTS

The 5 mm forceps provided more hepatic lobules, portal triads, and a larger tissue weight and histologic area (mm2 ) (p < .01). The twist and pull techniques provide more hepatic lobules and portal triads compared to the twist + pull technique while the twist + pull technique resulted in greater tissue crush compared to the twist technique (p = .0097). There was good agreement for morphological diagnosis between the 3 and 5 mm samples using the twist + pull technique but not for the twist or pull techniques.

CONCLUSION

Liver samples can be safely collected with 3 or 5 mm laparoscopic biopsy forceps and provide sufficient tissue for histopathology analysis in cats, with minimal artifact. The diagnostic accuracy of 3 mm samples remains unknown.

CLINICAL SIGNIFICANCE

Although 3 mm laparoscopic cup biopsy forceps provided samples of sufficient diagnostic quality for histopathologic interpretation in cats, further studies are required to assess their diagnostic accuracy.

Intraoperative and early postoperative pain in cats that underwent ovariohysterectomy using a spay hook: a randomised, masked, experimental study

BACKGROUND

This study aimed to compare the feasibility and practicality of the ovariohysterectomy (OHE) technique in cats with or without a spay hook with respect to the incision size, surgical time, surgical variables, and intra- and postoperative pain. Twenty-nine female cats underwent OHE using a spay hook (spay hook group [SHG], n = 15) or without using a spay hook (control group [CG], n = 14) to achieve the ovaries and cervix. Physiological parameters were monitored during the intraoperative period, and postoperative pain was assessed using a multidimensional composite and visual analogue pain scales.

RESULTS

The SHG had a significantly shorter operative time than the CG. The variables in the intraoperative period showed no statistically significant difference between both groups, as well as the early postoperative pain.

CONCLUSIONS

Less invasive OHE using a spay hook could potentially be a viable and feasible technique when performed by an inexperienced surgeon with appropriate training, especially in sterilisation campaigns, reducing the time to perform the procedure and increasing the number of animals spayed per time.

3D printed cannulas for use in laparoscopic surgery in feline patients: A cadaveric study and case series

OBJECTIVE

To evaluate custom 3D printed laparoscopic cannulas (3DPC) in a feline cadaveric abdominal surgery model and report their use in two live feline subjects.

STUDY DESIGN

Experimental cadaver study, live subject case series.

ANIMALS

Ten feline cadavers; two feline subjects.

METHODS

Custom 3DPCs were initially modeled in a PLA filament material and then created in an autoclavable dental resin for use in live patients. The surgery time, number of surgical collisions and cannula complications were recorded during cadaver procedures before and after use of 3DPCs. Cannula complications were recorded during live procedures and patients were followed to suture removal to record any incisional complications.

RESULTS

There was a significant reduction in mean surgical time (125.6 vs. 95.2 min, p = 0.03), mean number of instrument collisions (6.8 vs. 2.6, p = 0.03), and mean number of cannula complications (10 vs. 2.2, p = 0.03) with the use of only 3DPCs during the procedure. During the live procedures the use of the 3DPCs was successful and no postoperative complications occurred at the incision sites.

CONCLUSION

The use of customized 3DPCs may improve surgical dexterity and decrease complications in advanced procedures and was not associated with any clinical complications in two cats. The use of 3DPCs in veterinary medicine may allow for wider practice of laparoscopic techniques in small animals.

Feline cholangitis/cholangiohepatitis complex - what have we learned?

Cholangitis/cholangiohepatitis complex in cats is commonly encountered in clinical practice worldwide. Diagnosis and management of cats with this complex is difficult because of the ambiguity of clinical signs, diagnostic test results and commonality of comorbid disorders. These impediments can delay disease identification and treatment, which can increase morbidity and mortality. ​In this narrative review, we aimed to provide a thorough review of the unique physioanatomic features of the biliary system as well as clinically relevant updates on cholangitis/cholangiohepatitis complex in cats.

Pressure-Volume Curve during Capnoperitoneum in Cats

Laparoscopy is a growing field in veterinary medicine, although guidelines are lacking. The objective of this study was to evaluate the pressure-volume curve during capnoperitoneum in cats. A total of 59 female cats were scheduled for routine laparoscopy. Pressure and volume data were recorded and processed, and the yield point of the curve was calculated using a method based on a capacitor discharging function. For the remaining 40 cats, a linear-like pressure-volume curve was observed until a yield point with a mean cutoff pressure (COP) of 6.44 ± 1.7 mmHg (SD) (range, 2.72-13.00 mmHg) and a mean cutoff volume (COV) of 387 ± 144.35 mL (SD) (range, 178.84-968.43 mL) was reached. The mean mL/kg CO₂ value in cats was 208 ± 34.69 mL/kg (range, 100.00-288.46 mL/kg). The COV correlated with COP and body weight but not with body condition score (BCS). COP correlated only with the COV. This study suggests that feline patients have a pressure-volume curve similar to that of canine patients, and the same pressure limit recommendations can be used for both species. After a yield point of 6.44 mmHg is reached, the increment in volume decreases exponentially as the intra-abdominal pressure (IAP) increases.

Assessment of postoperative inflammatory markers and pain in cats after laparoscopy and miniceliotomy ovariectomy

Videosurgery is increasingly used in veterinary medicine. Compared with open surgery, it has been shown to cause minimal pain and promote a more rapid recovery. There are various methods of assessing pain and postoperative inflammation in cats, although their particular behaviours may make these assessments difficult. The aim of this study was to compare levels of postoperative pain and inflammation after laparoscopic ovariectomy with an open minimally invasive technique. Twenty queens were randomly divided into two groups based on the method of haemostasis and surgical technique: (1) laparoscopic ovariectomy using a miniloop (miniloop group (MG)); and (2) minilaparotomy using a Snook hook (control group (CG)). Heart rate (HR), respiratory rate (RR), end tidal CO₂ (EtCO₂) and body temperature were assessed using a multiparametric monitor during anaesthesia and surgery at defined surgical time points (preincision, left ovary manipulation, right ovary manipulation and skin suture). Blood samples (2 mL each) were collected from the jugular vein before surgery and 1, 12, 24, 48 and 72 hours, and 10 days, after endotracheal extubation for blood count analysis and to assess total protein and acute phase proteins (APP). EtCO₂ and RR were significantly higher in MG patients (P<0.001). HR was higher in the CG group for the duration of surgery (P=0.01). Temperature was significantly lower in MG patients (P<0.001). Pain assessment by dynamic interactive visual analogue scale showed no difference between groups or at specific moments of time within groups. Segmented neutrophil counts increased at 24 hours postoperatively and peaked at 48 and 72 hours in MG (P=0.01). The most important result among APPs was haptoglobin, which peaked at 72 hours in MG patients (P=0.001). Patients undergoing minilaparotomy and laparoscopy showed comparable postoperative pain. However, inflammatory changes such as APPs and neutrophil counts were increased in the laparoscopic group.

Hepatic lipidosis: Clinical review drawn from collective effort

Practical relevance: Hepatic lipidosis (HL) is the most common form of liver dysfunction in cats. If recognized early and treated appropriately, the prognosis is good; if not, the prognosis is grave. Clinical challenges: Distinguishing HL as idiopathic or secondary is critical since the presence of a concurrent disease affects the therapeutic plan and the prognosis.

AUDIENCE

Despite the unique and severe nature of a cat's response to anorexia and the complexity of the metabolic changes underlying this condition, the clinical acumen and technical ability to effectively diagnose and treat HL are readily available to all small animal practitioners. Patient group: Although many species develop a 'fatty liver', the cat is one of relatively few species that suffer from HL. The classic presentation is that of an overweight cat that stops eating for days to weeks, losing weight in the process. Equipment: Abdominal ultrasound is frequently employed in the diagnostic work-up of an anorectic cat; ultrasonographic findings often support a presumptive diagnosis, provide samples for cytology and, perhaps most importantly, help identify concurrent conditions that must be addressed for therapeutic success. All of the equipment necessary for essential nutritional intervention in an anorectic cat is readily available and easily affordable. Evidence base: The material for this review draws heavily on a relatively large number of original studies, excellent reviews by recognized experts, and informative communication with experienced clinicians, hence the term 'collective effort'.

Laparoscopic-Assisted Surgical Procedures

Laparoscopic-assisted procedures allow a balance between the improved patient recoveries often associated with smaller incisions and the need for appropriate visualization of visceral organs/identification of lesions. The organ systems of small animal veterinary patients that are highly amenable to laparoscopic-assisted procedures include the urinary bladder, the gastrointestinal tract, and the reproductive tracts. Laparoscopic-assisted procedures are especially beneficial in the approach to luminal organs, allowing the organ incision to be exteriorized through the body wall, protecting the peritoneal cavity from contamination from luminal contents. Procedure-specific morbidities and patient selection should be considered when choosing between assisted laparoscopic and open approaches.

Use of laparoscopy for diagnosing experimentally induced acute pancreatitis in dogs

Diagnosis of acute pancreatitis in dogs remains a significant challenge despite the development of advanced diagnostic methodologies. Visual inspection and pancreas biopsy using laparoscopy are generally considered to be procedures free of complications when conducted on healthy animals. However, the usefulness of laparoscopy for diagnosing acute pancreatitis has not been assessed. In the present study, the efficacy of laparoscopy for diagnosing acute pancreatitis in dogs was evaluated in animals with experimentally induced acute pancreatitis. Gross appearance of the pancreatic area was examined by laparoscopy to survey for the presence of edema, adhesions, effusion, pseudocysts, hemorrhage, and fat necrosis. Laparoscopic biopsy was performed and the histopathologic results were compared to those of pancreatic samples obtained during necropsy. The correlation between laparoscopy and histopathologic findings of the pancreas was evaluated. The presence of adhesions, effusion, and hemorrhage in the pancreatic area observed by laparoscopy significantly correlated with the histopathologic results (p < 0.05). There was no significant relationship between the histopathologic and laparoscopic biopsy findings. Results of this study suggested that laparoscopic evaluation of gross lesions has clinical significance although the laparoscopic biopsy technique has some limitations. This method combined with additional diagnostic tools can be effective for diagnosing acute pancreatitis in dogs.

Investigation of parenchymal abdominal organ disease in cats: aiming for the ideal biopsy

PRACTICAL RELEVANCE

Definitive diagnosis of disease involving the parenchymal abdominal viscera often requires a representative specimen of affected tissue. Methods used to obtain tissue samples range from those that are minimally invasive, such as fine-needle aspiration (FNA), to more invasive techniques such as surgical biopsy.

CLINICAL CHALLENGES

FNA and cytological examination can be a useful diagnostic tool and is commonly used for hepatic, splenic and lymph node specimens. FNA is an easy and cheap procedure that is best suited to diffuse disease and can be performed at low risk to the patient. However, its accuracy and agreement with the histopathological findings vary depending on the underlying disease and it often fails to provide information on parenchymal architecture. Importantly, FNA for cytological examination of the liver has serious limitations when used to identify the primary disease process due to the small sample size obtained.

AUDIENCE

This review is aimed at clinicians undertaking more detailed and specialist investigation of diseases of feline parenchymal abdominal organs and provides practical guidance on the different methods used to obtain hepatic, renal, pancreatic and splenic specimens in cats.

EVIDENCE BASE

The information presented is based on peer-reviewed publications and the clinical experience of the author.