2 Biopsy and Mass Removal IndicationsBiopsy is usually recommended before mass removalGives information about the behavior of the mass and allows for development of a treatment plan and prognosis
3 Biopsy and Mass Removal: Fine-Needle Aspiration FNA is on of the simplest methods for cytologic evaluation of a mass.Easy to performMinimal morbidityNo sedation requiredDisadvantage: low diagnostic yield
4 Biopsy and Mass Removal: Impression Smears Indications, appropriate useAs simple to perform as FNAUseful for ulcerated surface tumors & freshly cut surfacesCan be made from excised masses prior to placing in formalin
5 Biopsy and Mass Removal: Needle Punch Indications, appropriate useGenerally requires sedationUsually guided by ultrasound to take samples of internal organs such as liver, spleen, prostate
10 Biopsy and Mass Removal: Bone Indications, appropriate useOften painful and require general anesthesiaMichele Trephine:Larger sample size, but increases likelihood ofPathologic fracture at the biopsy siteJamshidi needle:less invasive, but smaller sample size
14 Biopsy and Mass Removal: Incisional vs. Excisional Indications, appropriate useINCISIONAL BIOPSYGenerally performed only after cytology or needle core biopsies have failed to provide a diagnositic sampleA small wedge of the tumor is removed from the mass and submitted for histopathologyEXCISIONAL BIOPSYInvolves complete removal of the massGenerally performed only on benign skin tumors or when removal of the organ is indicated
15 Biopsy and Mass Removal: Excisional Indications, appropriate use
16 Biopsy Sample Handling and Fixation Importance of proper handling:Impression smearsMark margins of surgical excision sampleAllow sample to dry for at least 20 minPlace sample in fixative10% neutral buffered formalin1 part tissue to 10 parts formalinLarge samples (>1cm in thickness) should be sliced like a loaf of bread prior to fixingProperly label sample container (date, patient name, site of sample removal) Paperwork should include the history, signalment, clinical findings, and tentative diagnosis
17 Laser Surgery How it works Clinical functions: ablation, incision, excisionLaser light is absorbed and transformed into heat within the tissueDifferent tissues/substances absorb different wavelengths of light causing the tissue to heatAppropriate useFrom minor to more extensive procedures (feline declaw, lumpectomy, castration, amputation)Three types: CO2, diode, & Nd:YAG (neodymium:yttrium-aluminum-garnet) will not be discussed hereLasers are classified as I-IV according to the degree of possible safety hazards to patients and users
18 Laser Surgery: CO2 Class IV laser Available at wavelength of 10,600nm Most use a noncontact mode in which the laser tip never comes in contact with the tissueHighly absorbed by water – most tissues have high water content, so the laser energy is absorbed very close to the surface
19 Laser Surgery: Diode Class IV laser Available at wavelengths of 805nm to980nmCan be used as a contact or noncontactModeAbsorbed better in hemoglobin andMelaninMore collateral thermal damage may occur due to the deeper penetrationMay provide more efficient hemostasisAnd incisions
20 Laser SurgeryDifferences between CO2 and diode (e.g., contact vs. noncontact, wavelengths)Mode tipsBoth come with a variety of tips that are chosen based on the procedureSpot sizeRefers to the diameter of the aperture on the tipMoving the tip closer to the target tissue decreases the spot size; moving the tip further from the target tissue increases the spot sizeExposureRefers to the duration of the laser beam or how long the tissue is exposed to the beamCharringrefers to carbonization of tissue – char, that occurs at temps greater than 100°COccurs when tissue absorbs heat faster than it can be releasedThe clinician uses spot size, power, and exposure to control the interaction of the CO2 laser beam and its effects on the tissue.
22 Laser SurgerySafety standards: Set by the American National Standard Institute (ANSI)Warning sign should be posted on the surgery room door and all doors leading to itDangers associated with class IV lasers include eye, skin, fire, and smoke plume hazardsA record or log should be kept of each procedure performed as well as the power and duration settingsThis will help the surgeon choose settings to use for future procedures.
23 Laser Surgery Precautions Eye gogglesEveryone in the laser surgery room must wearEye goggles specific for the particular laser lightcorneal or retinal damage can occur from scatteredReflectionsThe eyes of the patient should be protected as wellMoistened sponges can be placed over the eyesPatient eye shields are available
24 Laser Surgery Precautions Skin – damage may occur from direct or scattered laser beams.Clinicians should wear gloves and a gown for added protectionFire in surgery room – hazards include the surgical drapes, anesthetic agents, oxygen, animal’s fur, alcohol, methane from flatulencePlace moistened sponges around the surgical areaBe sure ET tube cuff is properly inflatedHave fire extinguishers readily availableSmoke plumeContains toxic and carcinogenic chemicals as well as bacteria and viral particles.An evacuator is usually purchased with the laser machine & should be placed within 1-2 inches of the smoke’s originWear laser surgery masks as regular surgical masks may not be sufficient
25 Laparoscopy To examine peritoneal cavity and its viscera A type of endoscope called a laparoscope is placed through a small midline incision or opening into the abdominal wall (lateral to midline)Necessary equipmentLaparascopeTrocar-cannula unitFiberoptic light cableLight sourceVeress insufflation needleGas insufflatorCamera/video system (optional)
28 Laparoscopic Equipment Trocar–cannula unitsTrocar punctures through theabdominal wall, and the cannula for the insertion of a laparacope
29 Laparoscopic Equipment Fiberoptic light cable and light sourceThe fiber optic light cable emits light from the light source to the scope
30 Laparoscopic Equipment Veress insufflation needleUsed for insufflation of the peritoneal cavity. This lifts the abdominal wall away from the abdominal organs.
31 Laparoscopic Equipment Gas insufflatorsCO2 – recommended due to rapid absorptionNitrous oxideRoom airTubing is connected from the gas insufflator to the Veress needle. Insufflation should not exceed 15mmHg
34 Laparoscopic Equipment Special instrumentsThese instruments can bePassed through cannulas of accessory ports to aid in biopsy retrieval or toPerform surgical procedures.
35 Laparoscopic Equipment Special instrumentsBiopsy and grasping instrument tips
36 Laparoscopy Procedure Patient prep: fasting, bladder expressedClip from xiphoid process to pubisRecumbency depends on procedureDrapingRemove scope from glutaraldehyde solutionSterile saline over scope and light cableDried by member of surgical teamSterile sleeve used to cover the camera; scope placed on the head of the cameraEntry of Veress needle
37 Laparoscopy Procedure Outer trocar of needled is retractedInsufflation tubing can be connected to the needleNOTE: Insufflation of the abdomen can never exceed 15 mm HgPlace trocar–cannulaView abdominal wall on the monitorMove scope as neededAdditional cannula introduced if needed
45 Types of Endoscopes Fiberoptic If any images are to be taken, a camera headcan be attached fromthe eyepiece on theendoscope to theendoscopy unit
46 Types of Endoscopes Video Similar to the fiberoptic endosdcopes except they do not have a directviewing lens aidedby an eyepiece.
47 Types of Endoscopes Rigid Best use – for procedures involving a direct pathway that are better viewed with a straight or direct line of sight such as the ears, nose, bladder, joint spaces
48 Endoscopy Preparation Veterinary technician is responsible for prep:Hook up endoscopeEnter patient data on computerTurn on machine and check light sourceTest machineGet distilled water for flushingAir–water valve covered, distal end of insertion tube submerged in water, check for bubblesLeave tip submerged in water and test for suctioning
63 DuodenoscopyDiagnosis and treatment of small intestine disease
64 ColonoscopyExamine rectum, large intestine, and cecum
65 Colonoscopy Patient preparation: Biopsy sampling Fecal examination for parasitesFecal cytologyAssaysFasted for 24 to 36 hoursLavage colonBiopsy samplingSo all tests prior to administering the lavage solution