Effects of Heated Tumescence Solution in Bitches after Unilateral Mastectomy

Background: Mammary tumors, for which mastectomy is the main treatment, are the most common neoplasms in bitches. Mastectomy is painful and, in order to reduce the pain stimulus in the transoperative period, tumescent local anesthesia is associated with general inhalation anesthesia. However, despite the numerous benefits of tumescence, intraoperative hypothermia is the most common complication. In Medicine, especially in plastic and dermatological surgery, it is common to use a heated tumescence solution to prevent intraoperative hypothermia; however, in Veterinary medicine, no previous study has examined the advantages and disadvantages of using heated tumescence solution. Thus, this study aimed to investigate the transanesthetic cardiorespiratory effects of heated tumescence solution in bitches submitted to radical unilateral mastectomy.Materials, Methods & Results: Eight animals were treated with 0.1% lidocaine solution, warmed to 37-42°C, using a Klein’s cannula for administration. Chlorpromazine (0.3 mg/kg) and meperidine (3 mg/kg) were used as pre-anesthetic medication intramuscularly, and induction was performed with intravenous propofol and maintenance with isoflurane. The data collection times were as follows: 15 min after starting isoflurane administration (M1), 5 min after tumescence (M2), after beginning of surgical incision (M3), during breast pullout (M4), after clamping of the superficial caudal epigastric vein, and artery (M5), after the beginning of the approximation of the subcutaneous tissue (M6), after the beginning of the intradermal suture (M7), and at the end of the surgical procedure (Mfinal). The heart (HR) and respiratory (ƒ) rates, mean arterial pressure (MAP), end-tidal CO2 concentration (EtCO2), expired isoflurane concentration (EtISO), and rectal temperature (RT) were measured. The HR, ƒ, and EtCO2levels did not differ statistically. The mean EtISO presented in M2 (1.16 ± 0.41) was significantly lower than that in M3 (1.39 ± 0.40) and M4 (1.49 ± 0.49).Discussion: In the HR analysis, it was found that during all evaluation moments, the means remained within the reference range for the species. Moreover, the values during the breast pullout (M4) did not exceed 20% of those presented minutes before the beginning of the surgery (M2), which was indicative of analgesic rescue, suggesting that the animals did not experience pain. Hypoventilation resulted in an increase in EtCO2 values. Thus, it can be said that in this study, there was no respiratory depression during the transoperative period, as the values of the variables ƒ and EtCO2 were within the reference for the species. With regard to the EtISO variable, there was no reduction in the MAC of isoflurane with the use of heated tumescence solution, as reported by some authors (EtISO 0.8%). However, the EtISO values presented here are close to those found in the literature during breast pullout (EtISO between 1.3% and 1.52%), with the use of refrigerated tumescence solution. In addition, the values shown in M4 are within the equivalent of 1 MAC (1.41%) of isoflurane, proving that heated tumescent local anesthesia is a safe technique and an excellent adjunct to inhalation anesthesia, as it provides intraoperative analgesia. Therefore, heated tumescence solution is safe and an excellent adjuvant in general inhalational anesthesia for radical unilateral mastectomy as it did not increase inhaled anesthetic consumption during surgery.Keywords: tumescent local anesthesia, lidocaine, dogs, inhalation anesthesia, mammary tumors

Micropapillary carcinoma in a dog: case report

Mammary neoplasms in female dogs present a high incidence. Several histological types are observed, among them, micropapillary carcinoma is considered one of the most aggressive because it is related to vascular invasion, metastases and low survival time. Aimed to describe a case of micropapillary breast carcinoma, with cutaneous metastasis, in a dog. A canine, female, 14 years old, 8kg, not defined breed, uncastrated, nulliparous, with pseudocyesis and no contraceptives administration history was attended at the Veterinary Reproduction and Obstetrics Service from "Governador Laudo Natel” Hospital, FCAV, UNESP, Jaboticabal, presenting a breast ulcerated nodule, with one month estimated evolution. After stabilization and preoperative exams, radical unilateral mastectomy and ipsilateral axillary and inguinal lymphadenectomy were performed. Histopathologic diagnosis revealed micropapillary carcinoma and free surgical margins from neoplasm, however, there were metastasis in both lymph nodes. The tutors did not adhere to antineoplastic chemotherapy. In 60th post-surgical day, there was inflammatory reaction in the surgical scar region, with small cutaneous ulceration, where the elastogram  revealed  rigidity and shear velocity of 7.84m/s. Skin biopsy revealed metastasis of micropapillary breast carcinoma. There was progression of ulcerations, compromising animal’s welfare and its physiological activities, when on the 110th post-surgical day, it was decided to euthanize the patient.  The correct diagnosis and knowledge of tumor biological behavior are importants points to choose the correct treatment. The adjuvant chemotherapy treatment can impact on average survival time and ARFI elastography is an accurate predictor of rapid and non-invasive diagnosis of micropapillary carcinoma recurrence.Mammary neoplasms in female dogs have a high incidence. Among the several histological types observed, micropapillary carcinoma is considered one of the most aggressive due to vascular invasion, metastases, and short survival time. The present objective was to describe a case of mammary gland micropapillary carcinoma, with cutaneous metastasis, in a dog. A 14-year-old intact nulliparous mixed-breed bitch, weighing 8kg, with a history of pseudocyesis and no history of contraceptive administration, presented to the Veterinary Reproduction and Obstetrics Service from "Governador Laudo Natel” Hospital, FCAV, UNESP, Jaboticabal, with an ulcerated nodule in the mammary gland for approximately one month. After stabilization of clinical parameters and preoperative exams, a radical unilateral mastectomy and ipsilateral axillary and inguinal lymphadenectomy were performed. Histopathology revealed micropapillary carcinoma with clear surgical margins, however, there were metastases in both lymph nodes. Antineoplastic chemotherapy was refused by the owners. On the 60th day after surgery, there was an inflammatory reaction in the surgical scar region, with a small cutaneous ulceration, where elastography showed rigidity and shear velocity of 7.84m/s. Skin biopsy revealed metastasis of the micropapillary carcinoma. Even with continued treatment since the patient was first examined, the ulcerations progressed, compromising the animal’s welfare and physiological activities, and on the 110th day after surgery, euthanasia was decided on. A correct diagnosis and knowledge of tumor biological behavior are important points for choosing the correct treatment. Acoustic Radiation Force Image (ARFI) elastography has been shown to be a fast and non-invasive diagnostic method for detection of recurrent micropapillary carcinoma

Effects of Heated Tumescence Solution in Bitches after Unilateral Mastectomy

Background: Mammary tumors, for which mastectomy is the main treatment, are the most common neoplasms in bitches. Mastectomy is painful and, in order to reduce the pain stimulus in the transoperative period, tumescent local anesthesia is associated with general inhalation anesthesia. However, despite the numerous benefits of tumescence, intraoperative hypothermia is the most common complication. In Medicine, especially in plastic and dermatological surgery, it is common to use a heated tumescence solution to prevent intraoperative hypothermia; however, in Veterinary medicine, no previous study has examined the advantages and disadvantages of using heated tumescence solution. Thus, this study aimed to investigate the transanesthetic cardiorespiratory effects of heated tumescence solution in bitches submitted to radical unilateral mastectomy.Materials, Methods & Results: Eight animals were treated with 0.1% lidocaine solution, warmed to 37-42°C, using a Klein’s cannula for administration. Chlorpromazine (0.3 mg/kg) and meperidine (3 mg/kg) were used as pre-anesthetic medication intramuscularly, and induction was performed with intravenous propofol and maintenance with isoflurane. The data collection times were as follows: 15 min after starting isoflurane administration (M1), 5 min after tumescence (M2), after beginning of surgical incision (M3), during breast pullout (M4), after clamping of the superficial caudal epigastric vein, and artery (M5), after the beginning of the approximation of the subcutaneous tissue (M6), after the beginning of the intradermal suture (M7), and at the end of the surgical procedure (Mfinal). The heart (HR) and respiratory (ƒ) rates, mean arterial pressure (MAP), end-tidal CO2 concentration (EtCO2), expired isoflurane concentration (EtISO), and rectal temperature (RT) were measured. The HR, ƒ, and EtCO2levels did not differ statistically. The mean EtISO presented in M2 (1.16 ± 0.41) was significantly lower than that in M3 (1.39 ± 0.40) and M4 (1.49 ± 0.49).Discussion: In the HR analysis, it was found that during all evaluation moments, the means remained within the reference range for the species. Moreover, the values during the breast pullout (M4) did not exceed 20% of those presented minutes before the beginning of the surgery (M2), which was indicative of analgesic rescue, suggesting that the animals did not experience pain. Hypoventilation resulted in an increase in EtCO2 values. Thus, it can be said that in this study, there was no respiratory depression during the transoperative period, as the values of the variables ƒ and EtCO2 were within the reference for the species. With regard to the EtISO variable, there was no reduction in the MAC of isoflurane with the use of heated tumescence solution, as reported by some authors (EtISO 0.8%). However, the EtISO values presented here are close to those found in the literature during breast pullout (EtISO between 1.3% and 1.52%), with the use of refrigerated tumescence solution. In addition, the values shown in M4 are within the equivalent of 1 MAC (1.41%) of isoflurane, proving that heated tumescent local anesthesia is a safe technique and an excellent adjunct to inhalation anesthesia, as it provides intraoperative analgesia. Therefore, heated tumescence solution is safe and an excellent adjuvant in general inhalational anesthesia for radical unilateral mastectomy as it did not increase inhaled anesthetic consumption during surgery.Keywords: tumescent local anesthesia, lidocaine, dogs, inhalation anesthesia, mammary tumors