Efficacy of the Modified Tumescent Technique on Vascularization in Canine Mammary Tumors

Abstract

Background: Mammary tumors are among the most common neoplasms in dogs. As in various tumor types, angiogenesis plays a significant role in the development of mammary tumors. Since the nutritional requirements of newly formed tissues associated with malignancy increase, this situation is directly related to angiogenesis. The tumescent anesthesia technique, which is commonly used during this surgical procedure, involves the application of a sterile solution combined with a local anesthetic and vasoconstrictor. This approach aimed to determine the potential impact of the modified tumescent technique on tumor vascularization.

Materials, Methods & Results: The study included 28 dogs diagnosed with mammary tumors with medium breeds, aged over 8 to 13 years and weighing between 11-23 kg. For the preparation of the tumescent solution, 0.09% isotonic saline (Bioflex®, Turkey) was stored at 4°C for the cold group and kept at room temperature for the other group. After the prepared solution was dosed according to body weight, it was equally administered into the mammary tissue. Color Doppler was employed to assess the distribution of vascularization (peripheral, mixed), and diameter of the largest vessel at the pre- and posttumescent application. In colorflow mode, the frequency was set at 5 MHz, with a pulse repetition frequency (PRF) of 1 kHz and a gain of 38%. Finally, Pulsed Doppler was used to measure the PI and RI in both the pre- and post tumescent applications. After tumescent application, a significant reduction in VD and a significant increase in RI were observed in both temperature groups, indicating effective vasoconstriction. The decrease in VD was significantly greater in dogs receiving the cooled tumescent solution compared to those receiving the solution at room temperature. Statistical analyses were performed using SPSS version 23.0 (IBM Corp., USA). Normal distribution of data and homogeneity of variances were evaluated by Shaphiro wilk test and Levene’s test, respectively. The comparisons of the ultrasonography parameters between the groups (+4°C vs +20°C) and prior/after tumescent application within groups were performed by Student’s t-test and Mann-Whitney U test.  When ultrasonographic changes were analyzed according to histological grade, statistically significant vasoconstriction was primarily observed in grade 1 tumors, whereas grade 2 and grade 3 tumors demonstrated a reduced vascular response.

Discussion:The findings of the present study demonstrate that the modified tumescent anesthesia technique induces a significant vasoconstrictive effect in canine mammary tumors, as evidenced by reduced vessel diameter and increased vascular resistance following application.  Importantly, no postoperative complications such as delayed wound healing or wound dehiscence were observed, indicating that the modified formulation is safe and well tolerated. the consistent and significant vasoconstriction observed at different temperature settings (+4°C and +20°C) and across all histological grades clearly demonstrates the efficacy of the technique in reducing local vascular perfusion. Overall, the results suggest that cooled modified tumescent anesthesia, may be a reliable and effective approach for improving intraoperative vascular control and surgical field management during canine mastectomy procedures.

Keywords: dog, mammary tumor, tumescent, vascularization.