Pharmacokinetic study comparing doxorubicin concentrations after chemoembolization or intravenous administration in dogs with naturally occurring nonresectable hepatic carcinoma.

BACKGROUND: Chemoembolization is a viable treatment option for patients with nonresectable hepatic carcinoma (HC) and may allow delivery of chemotherapeutic drugs with decreased systemic toxicity. HYPOTHESIS/OBJECTIVE: Compare the serum concentrations of doxorubicin after chemoembolization or IV administration in the same patient. We hypothesized that locoregional delivery may result in increased tumor chemotherapeutic drug concentrations, reflected by decreased measurable serum drug concentrations. Adverse hematological events were hypothesized to be decreased after locoregional delivery. ANIMALS: Seventeen client-owned dogs with incompletely resectable HC. METHODS: Prospective, single-arm clinical trial. Drug-eluting bead transarterial chemoembolization was performed to varying levels of blood flow stasis (NO STASIS, STASIS). Intravenous doxorubicin (IVC) subsequently was administered in selected patients. Systemic exposure was quantified by area under the serum doxorubicin concentration time curve (AUC), maximum serum doxorubicin concentration (Cmax ), and time doxorubicin was last above the limit of quantitation (Tlast ). Nadir test results after treatments were used to evaluate adverse hematological events. RESULTS: Thirteen NO STASIS treatments, 15 STASIS treatments, and 9 IVC treatments were performed. Maximum serum doxorubicin concentration, AUC, and Tlast were significantly lower when comparing NO STASIS or STASIS to IVC treatments. Of the patients with nadir results available, no adverse hematological events were observed after NO STASIS or STASIS treatments. Two patients developed adverse hematological events after IVC treatment. CONCLUSIONS/CLINICAL RELEVANCE: Drug-eluting bead transarterial chemoembolization offers a viable treatment option for patients with incompletely resectable HC with the potential for increased local tumor doxorubicin concentrations, decreased systemic chemotherapeutic exposure, and fewer adverse hematological events.

Drug-eluting bead chemoembolization for the treatment of nonresectable hepatic carcinoma in dogs: A prospective clinical trial.

BACKGROUND: Effective treatment options for nonresectable hepatic carcinoma (HC) in dogs are limited. HYPOTHESIS/OBJECTIVE: Objectives were to report outcomes, complications, and tumor responses via computed tomography (CT) assessment after drug-eluting bead transarterial chemoembolization (DEB-TACE) for nonresectable HC in dogs. The authors hypothesized that major complications would be uncommon and short-term CT assessment would demonstrate stable disease or partial response. ANIMALS: Client-owned dogs (n = 16) with nonresectable HC. METHODS: Prospective, single-arm clinical trial. Drug-eluting bead transarterial chemoembolization was performed to varying levels of blood flow stasis. Computed tomography imaging was compared before and approximately 12 weeks after initial treatment. RESULTS: Drug-eluting bead transarterial chemoembolization was successfully administered in all attempts. Based on percent change in elliptical tumor volume response (mL), stable disease (8/13; 62%) was the most common outcome followed by partial response (3/13; 23%) and progressive disease (2/13; 15%) with a median of 74 days (range, 39-125) after initial treatment. Median tumor volume (mL) after DEB-TACE decreased in volume by 13% (range, 56% decrease to 77% increase). Mild complications consistent with postembolization syndrome occurred after 7/27 (26%) treatments. Major complications occurred after 3/27 (11%) treatments: hepatic abscess/septicemia (2) and cholecystitis/death (1), resulting in treatment-induced death after 2/27 (7%) treatments. Median survival time after treatment was 337 days (range, 22-1061). Dogs with a presenting complaint of weight loss (P = .02) had a significantly shorter median survival time (126 days; range, 46-337) than those dogs without prior history of weight loss (582 days; range, 22-1061). CONCLUSIONS: Drug-eluting bead transarterial chemoembolization for nonresectable HC is a feasible procedure, which promoted stable disease or partial response in 85% of dogs in this study sample.

Endoscopic laser-ablation for the treatment of orthotopic and ectopic ureteroceles in dogs: 13 cases (2008-2017).

BACKGROUND: Ureteroceles are a rare condition in dogs in which conventional treatments can result in substantial morbidity. Cystoscopic and fluoroscopic-guided laser ablation (CLA) of ureteroceles can successfully relieve obstruction. OBJECTIVES: To describe the technique and outcomes of attempting CLA for treatment of ureteroceles in dogs. ANIMALS: Thirteen client-owned dogs that underwent CLA for treatment of ureteroceles. METHODS: Retrospective multicentered study. Medical records were reviewed in all dogs that underwent CLA for ureterocele(s). A laser was used to extend the opening of the ureteral orifice (UO) unless surgical conversion was necessary. Data collected included signalment, clinicopathologic data, imaging, procedural findings, complications, and short- and long-term outcome. RESULTS: Thirteen dogs with 13 ureteroceles associated with 14 UOs resulting in ureteral obstruction were included. One ureterocele extended bilaterally. Treatment was initiated via retrograde cystoscopy (7 females), percutaneous perineal urethrocystoscopy (4 males), or percutaneous antegrade cystoscopy (2 males). Surgical conversion was necessary in 2 males. Ten of 14 (71%) UOs associated with the ureteroceles were ectopic. Thirteen of 14 had stenotic or imperforate UOs. No postoperative complications were noted. Preoperative incontinence or pollakiuria was present in 9 of 13 and 3 of 13 dogs and resolved in 8 of 9 and 3 of 3 dogs, respectively. Follow-up imaging showed resolution of all ureteroceles and improved ureteral/renal pelvic dilatation. Median follow-up time was 27 months (range, 3-96 months). CONCLUSIONS AND CLINICAL IMPORTANCE: Cystoscopic-guided laser ablation was effective for the treatment of ureteroceles(s) in 11 of 13 dogs.

Comparison of iatrogenic articular cartilage injury in canine stifle arthroscopy versus medial parapatellar mini-arthrotomy in a cadaveric model.

OBJECTIVE: To assess iatrogenic articular cartilage injury (IACI) resulting from arthroscopy versus medial parapatellar mini-arthrotomy of the stifle. STUDY DESIGN: Paired comparison of canine cadaver stifles treated with arthroscopy or mini-arthrotomy ANIMALS: Paired canine stifles from 14 cadavers (≥20 kg). METHODS: Stifles (N = 28) were assigned to arthroscopy or arthrotomy. Full stifle joint exploration and meniscal probing were performed. Joints were disarticulated and India ink assay performed. IACI was defined as sharply delineated lesions with India ink uptake. Incidence, number, and lesion area in defects articular cartilage, incision length, surgery duration, and joint structures visualized were recorded. RESULTS: Arthroscopy resulted in greater IACI than mini-arthrotomy, including incidence of IACI (arthroscopy: 13 stifles, mini-arthrotomy: 4 stifles; P = .009), number of IACI per stifle (arthroscopy: 3.4 ± 2.90, mini-arthrotomy: 0.9 ± 1.96; P = .04), and IACI area (arthroscopy: 5.9 ± 7.58 mm2 , mini-arthrotomy: 1.7 ± 4.50 mm2 ; P = .003). Incision length was shorter with arthroscopy (1.0 ± 0.38 cm) versus mini-arthrotomy (5.3 ± 0.61 cm; P < .0001). Surgical duration was not significantly different between groups (arthroscopy: 12.5 ± 3.49 minutes, mini-arthrotomy: 11.05 ± 1.60 minutes; P = .21). Visualization of articular structures was incomplete in 14/14 mini-arthrotomy stifles and 1/14 arthroscopy stifles (P < .001). CONCLUSION: Incidence, number, and area of IACI were greater in the arthroscopy group versus the mini-arthrotomy group. Mini-arthrotomy resulted in a longer incision and incomplete joint visualization. Methods of preventing IACI and clinical significance of IACI warrant further investigation.

Preoperative low level laser therapy in dogs undergoing tibial plateau levelling osteotomy: A blinded, prospective, randomized clinical trial.

OBJECTIVES: To evaluate the influence of preoperative low-level laser therapy (LLLT) on therapeutic outcomes of dogs undergoing tibial plateau levelling osteotomy (TPLO). METHODS: Healthy dogs undergoing TPLO were randomly assigned to receive either a single preoperative LLLT treatment (800-900 nm dual wavelength, 6 W, 3.5 J/cm2, 100 cm2 area) or a sham treatment. Lameness assessment and response to manipulation, as well as force plate analysis, were performed preoperatively, then again at 24 hours, two weeks, and eight weeks postoperatively. Radiographic signs of healing of the osteo-tomy were assessed at eight weeks postoperatively. RESULTS: Twenty-seven dogs (27 stifles) were included and no major complications occurred. At eight weeks postoperatively, a significant difference in peak vertical force analysis was noted between the LLLT (39.6% ± 4.7%) and sham groups (28.9% ± 2.6%), (p <0.01 Time, p <0.01 L). There were no significant differences noted between groups for all other parameters. The age of dogs in the LLLT group (6.6 ± 1.6 years) was greater than that for the sham group (4.5 ± 2.0, p <0.01). Although not significant, a greater proportion of LLLT dogs (5/8) had healed at the eight-week time point than in the sham group (3/12) despite the age difference (p = 0.11) Clinical significance: The results of this study demonstrate that improved peak vertical force could be related to the preoperative use of LLLT for dogs undergoing TPLO at eight weeks postoperatively. The use of LLLT may improve postoperative return to function following canine osteotomies and its use is recommended.

Use of botulinum toxin type A for the treatment of radiation therapy-induced myokymia and neuromyotonia in a dog.

CASE DESCRIPTION A 5-year-old castrated male Maltese was evaluated for intermittent clinical signs of muscle cramping and abnormal movements of the skin of the right pelvic limb at the site where an infiltrative lipoma had twice been resected. After the second surgery, the surgical field was treated with radiation therapy (RT). The clinical signs developed approximately 14 months after completion of RT. CLINICAL FINDINGS When clinical signs were present, the right biceps femoris and semitendinosus muscles in the area that received RT were firm and had frequently visible contractions, and the skin overlying those muscles had episodic vermiform movements. Electromyography of those muscles revealed abnormal spontaneous activity with characteristics consistent with myokymic discharges and neuromyotonia. Magnetic resonance imaging of the affected leg revealed no evidence of tumor regrowth. The myokymia and neuromyotonia were considered secondary to RT. TREATMENT AND OUTCOME 4 U of Clostridium botulinum toxin type A (BoNT-A) neurotoxin complex was injected into the affected muscles at each of 6 sites twice during a 24-hour period (ie, 48 U of BoNT-A were administered). The clinical signs were completely resolved 10 days after BoNT-A treatment and were controlled by repeated BoNT-A treatment every 3 to 4 months for > 1 year. CLINICAL RELEVANCE To our knowledge, this is the first report of myokymia and neuromyotonia secondary to RT in a dog. For the dog of this report, injection of BoNT-A into the affected muscles was safe, effective, and easy to perform.