VSR 421: Regional Veterinary Surgery (2+1)

TREATMENT

Surgery

• Surgery is the most feasible therapeutic option in India and cost effective also. The procedures done include
  • Lumpectomy which involves removing the tumor mass alone
  • Simple Mastectomy wherein the affected mammary glands are removed
• Regional Mastectomy: wherein the affected mammary gland and ipsilateral glands are also removed.
• Enbloc resection wherein the affected mammary gland, regional lymphnode and all interfering glands and lymphatics are removed
• Unilateral Mastectomy: The affected glands with all other mammary glands on that side is removed
• Bilateral mastectomy: Removing all the mammary glands on both sides. This could be done as staged process to prevent complications like dehiscence and also to reduce the pain to the animal

Procedure

• The procedure is performed with the patient in general anesthesia.
• The Surgical technique involves proper aseptic preparation of the site from ulcerative discharges, dirt and casting the animal in dorsoventral recumbency.
• A elliptical skin incision is made around the affected gland including 1-2 cm of normal tissue on all planes and careful hemostasis is adhered. The principles of surgical oncology states that we need to isolate the major blood vessels supplying the tumor mass and ligate them so that we prevent the tumor cells draining into these vessels and causing tumor seeding or metastasis post operatively.
• If the tumor mass is malignant it can produce excessive VEGF (Vascular endothelial growth factor) causing more blood vessels originating from the normal anatomical course and need to be double ligated as well. Incise through the subcutaneous tissue and using a metzenbaum scissors with gentle traction to one end of the tumor start resecting the tumor.
• If the subcutaneous tissue or muscle is involved then include them also and make necessary reconstructive procedures. Ligate all major blood vessels and remove the regional lymphnodes if they are enlarged. The subcutaneous tissue is apposed with 3-0 or 4-0 absorbable suture materials and skin apposed with silk 2-0 or 3-0 in cruciate pattern.

Postoperative care

• The animal is bandaged with a absorbent gauze material and the surgical site is dressed with antiseptic every 2 days and a course of antibiotic is given for a period of 5 to 7 days.
• The sutures of skin are removed on the 10^th post operative day.

Chemoptherapy

• Anti estrogenic compounds like tamoxifen is effective in controlling the tumorogenesis associated with the action of estrogen on mammary acinar cells.
• Antineoplastic agents administered include Doxorubicin  IV at 30mg/m² on day 1 and Cyclophosphamide at 100 mg/m² on days 3 to 6 of a 21 day cycle and repeated based on response to therapy
• Radiation therapy is effective for carcinomas unresponsive to chemoterapy as well as sarcomas

Immunotherapy

• Intravenous BCG therpay on 1^st, 2^nd, 4^th week for every 8 weeks.
• Gamma interferon therapy

Complications

• Hemorrhage, Pain, Inflammation, Seroma, Infection, Wound dehiscence and tumor recurrence

Prognosis

• It is influenced by tumor size, histology, mode of growth and clinical stage of the disease.

Note:- Feline mammary tumors are more infiltrative and are best treated by extensive surgery by removing all the glands.