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Flashcards in Principles of oncological surgery Deck (39)
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List 5 roles of surgery in cancer management

Diagnosis (biospy)
Resection for cure (definitive excision)
Palliation (remove clinical signs)
Debulking (cytoreductive therapy)
Prophylaxis of neoplasia


Define biopsy

retrieval of cells or tissues form tumour to allow a Dx and prognosis (grading and staging) to plan appropriate therapy and allow owner to make decision about therapeutic options


Indications - biopsy - 3

- If treatment type (surgery/radiation/chemo) or extent (conservative/aggressive) would be altered by knowing the tumour type
- If owner's willingness to treat animal would be altered ny knowledge of tumour type, grade, prognosis and clinical stage.
- If lesion is in 'difficult' area


What information can be gained from biopsy?

Neoplastic or non-neoplastic
Cytological or histologic type
Margins (if excisional biopsy)
Potential sites for metastases (if LNs or other organs sampled)


Guidelines - tumour biopsy

Site should lie within likely surgical field
Minimal risk of tumour dissemination
Fresh instruments for each site
Don't worsen the prognosis
Longitudinal incisions for distal locations
Avoid tissue that would be difficult to resect or close
Large biopsy more likely to reach diagnosis
Careful tissue handling - avoid forceps and electrocautery
10% formalin fixation, tissues < 1cm thick
Detailed history


Define and outlien prophylactic tumour surgery

Remove tissue to reduce incidence of tumour occurence and recurrence rate
Normal or abnormal tissue


What does elective gonadectomy reduce the incidence of?

Decreases the incidence of mamary tumours, perianal adenomas, testicular tumours and willr educe the rate of recurrence of vaginal leiomyomas.


What might removal of lesions suspected to be pre-cancerous do?

May prevent the development of malignant disease susbsequently - eg. SCC in-situ from the skin of white cats and adenomatous rectal polyps.


Contraindications - tumour biopsy - 3

If treatment plan wouldn't be changed
No change in owner's willingness to treat
If biopsy is difficult


Indication - surgery with curative intent

Localised disease (only)


Advantages/disadvantages of complete surgical excision

ADVANTAGES: immediate cure, not carcinogenic, no local toxic effects, not immunosuppressive, better for large masses

DISADVANTAGES: local cure only, change in cosmesis, change in function


Principles - surgical excision - 5

- Establish Dx, plan surgery
- Perform surgery early in disease course
- First surgery has the best chance of success
- Adequate margins needed in 3D
- Margin of excision shouldn't be compromised by concerns regarding closure


Why is it important to get tumour removal surgery right first time?

- untreated tumours have normal regional anatomy
- recurrent tumours may have seeded into previously non-involved tissue planes and it can't be predicted where tumour cells will extend and a wider resection may be required.
- The most active and invasive parts of the tumour are at the periphery - incomplete excision leaves aggressive cells behind
- There is less normal tissue if surgery has been performed previously


Common reasons for failure of definitive tumour excision

Failure to plan surgery (usually failure to biopsy)
Failure to stick to the plan, usually concerns over closure


What information should be available before surgical procedure is selected?

Histologic type, grade and clinical stage
Expected local and systemic effects of above
Surgery indicated?
Cure possible?
Alternative and adjunctive procedures


What additional practical considerations are there for oncologic surgery? 9

Consideration of effect on cosmesis and function
Pre-operative patient prep
Dissection technique
Reduction of tumour cell contamination in surgical field
Avoidance of wound complications
Vascular occlusion techniques
Management of regional LNs
Reconstruction of resulting deficit
Evaluation of the resected tissue


What may interfere with local defence mechanisms to removal any remaining tumour cells after surgery?

haematoma, seroma or wound infection


Outline vascular and lymphati occlusion techniques

Ligate as early as possibly
Particularly important for tumours where exfoliation or dissemination of cells is likely or for tumours which usually metastasise via the haematogenous (sarcomas) or lymphatic (carcinomas) routes.
Theoretically, ligation of venous and lymphatic drainage should be performed before arterial suppy


Which tumour type is more likely to metastasise to regional LNs?

epithelial tumours much more likely than mesenchymal tumours.


Causes - regional lymphadenopathy

Metastasis - poor prognosis
Reactive hyperplasia - infection, inflammation, release of factors - may be indicative of a beneficial response


Result of lymphadenopathy due to tumour metastasis

generally results in complete effacement by tumour cells and a Dx may be made by FNA


Indications - LN removal

- If positive for a tumour and is not fixed to surrounding tissues (generally alone, en bloc resection of tumour, LN and intervening lymphatics may be performed in some cases)

- Normal-appearning LNs which drain the primary tumour maybe sampled to stage the tumour


Contraindications - LN removal

- LNs in critical areas which are fixed to the surrounding tissue. Biopsy or leave in situ

***Prophylactic removal of normal-appearing LNs without intention of sampling them to stage the tumour has no benefit and may reduce any beneficial host response to the tumour.***


Name 3 common types of surgical margin

Local excision
Wide local excision
Radical local excision


Define local excision

the tumour is removed through its natural capsule, immediate boundaries or with the minimum of adjacent tissue



INDICATIONS: benign tumours with no tendency for local infiltration - lipoma, histiocytoma, sebaceous adenoma

CONTRA-INDICATIONS: invasive benign tumours, all malignant tumours.


Define wide local excision

tumour is removed with a substantial margin of surrounding tissue, margins depend on individual tumour.

Anatomical determinants may dictate whether the selected margins will be feasible from a practical point of view, but they should never be the primary determinant in the selection of the appropriate margin.



INDICATIONS: benign tumours with the capacity for local infiltration (infiltrating lipoma), malignant tumours with limited potential for infiltration (WD SCC)

CONTRA-INDICATIONS: malignant tumours with the potential for local infiltration


Define radical local excision

tumour is removed together with margins that extend into adjacent fascial planes which are undisturbed by tumour growth.



INDICATIONS: tumours whose rapid radial expansion results in teh development of a circumferential zone of compressed tissue or pseudocapsule

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