Adrenal tumors treated by adrenalectomy following spontaneous rupture carry an overall favorable prognosis: retrospective evaluation of outcomes in 59 dogs and 3 cats (2000-2021).

OBJECTIVE: To conduct a retrospective multi-institutional study reporting short- and long-term outcomes of adrenalectomy in patients presenting with acute hemorrhage secondary to spontaneous adrenal rupture. ANIMALS: 59 dogs and 3 cats. METHODS: Medical records of dogs and cats undergoing adrenalectomy between 2000 and 2021 for ruptured adrenal masses were reviewed. Data collected included clinical presentation, preoperative diagnostics, surgical report, anesthesia and hospitalization findings, histopathology, adjuvant treatments, and long-term outcome (recurrence, metastasis, and survival). RESULTS: Median time from hospital admission to surgery was 3 days, with 34% of surgeries being performed emergently (within 1 day of presentation). Need for intraoperative blood transfusion was significantly associated with emergent surgery and presence of active intraoperative hemorrhage. The short-term (≤ 14 days) complication and mortality rates were 42% and 21%, respectively. Negative prognostic factors for short-term survival included emergent surgery, intraoperative hypotension, and performing additional surgical procedures. Diagnoses included adrenocortical neoplasia (malignant [41%], benign [12%], and undetermined [5%]), pheochromocytoma (38%), a single case of adrenal fibrosis and hemorrhage (2%), and a single case of hemangiosarcoma (2%). Local recurrence and metastasis of adrenocortical carcinoma were confirmed in 1 and 3 cases, respectively. Overall median survival time was 574 days and 900 days when short-term mortality was censored. No significant relationship was found between histopathological diagnosis and survival. CLINICAL RELEVANCE: Adrenalectomy for ruptured adrenal gland masses was associated with similar short- and long-term outcomes as compared with previously reported nonruptured cases. If hemodynamic stability can be achieved, delaying surgery and limiting additional procedures appear indicated to optimize short-term survival.

Risk factors influencing death prior to discharge in 302 dogs undergoing unilateral adrenalectomy for treatment of primary adrenal gland tumours.

Adrenalectomies for canine adrenal tumours are associated with peri-operative morbidity and mortality. Objectives of this study included assessing the prognostic value of tumour- or surgery-related variables in predicting peri-operative mortality and overall survival in dogs undergoing adrenalectomies for primary adrenal tumours as well as pre-treatment with phenoxybenzamine on survival to discharge with pheochromocytomas specifically. A multi-institutional retrospective cohort study was performed across nine institutions. Electronic medical record searches identified 302 dogs which met the inclusion criteria. Data collected included dog-related, tumour-related, treatment-related, surgery-related, and outcome variables. Univariate and multivariable logistic regression and cox proportional hazards models were used to identify variables associated with death prior to discharge and tumour-related survival. Overall, 87% of dogs survived to discharge with a tumour-related survival time of 3.96 years. Post-operative complications were reported in 25%. Increased surgical time (p = 0.002) and pre-surgical medical treatment other than phenoxybenzamine (p = 0.024) were significantly associated with increased peri-operative mortality while ureteronephrectomy (p = 0.021), post-operative pancreatitis (p = 0.025), and post-operative aspiration pneumonia (p < 0.001) were significantly associated with decreased overall survival. Phenoxybenzamine pretreatment had no effect on peri-operative mortality. Thirty-seven of 45 (82%) dogs with pheochromocytomas not pretreated survived to discharge, and 50 of 59 (85%) dogs with pheochromocytomas pretreated with phenoxybenzamine survived to discharge (p = 0.730). This study provides information on risk factors for death prior to discharge and tumour-related survival that may help guide clinical management and owner expectations. In addition, the study findings challenge the previously reported benefit of phenoxybenzamine for pretreatment of dogs undergoing adrenalectomies for pheochromocytomas.

Novel 3D Custom-Made Silicone Tumor Model as a Support for Teaching Surgical Oncology Principles.

Alternative laboratory teaching methods are becoming increasingly desirable and effective in medical education environments. While ethical concerns associated with the use of live animals in terminal surgery laboratories have been reduced with cadaveric models, availability, and lack of pathology can limit their ability to adequately convey surgical principles and replicate clinical training. We have developed a three-dimensional (3D) custom-made silicone soft tissue tumor model using 3D-printed molds derived from canine soft tissue sarcoma computed tomography images. This novel teaching model allows users to apply surgical oncology principles and perform basic technical tasks such as incisional biopsy, margin demarcation, marginal and wide surgical excision, and inking of surgical margins. A large cohort of students in addition to a small number of professional veterinarians at different levels of specialty training followed the laboratory guidelines and evaluated the simulated tumor model based on a qualitative survey. All participants were able to successfully complete the practical training. The model also allowed the students to identify and correct technical errors associated with biopsy sampling and margin dissection, and to understand the clinical impacts related to those errors. Face and content validity of the model were assessed using Likert-style questionnaires with overall average instructors' scores of 3.8/5 and 4.6/5, respectively. Content validity assessment of the model by the students approximated instructors' evaluation with an overall average score of 4.4/5. This model development emphasizes the efficacy of alternative non-cadaveric laboratory teaching tools and could become a valuable aid in the veterinary curricula.

Performances of novel custom 3D-printed cutting guide in canine caudal maxillectomy: a cadaveric study.

Introduction: Caudal maxillectomies are challenging procedures for most veterinary surgeons. Custom guides may allow the procedure to become more accessible. Methods: A cadaveric study was performed to evaluate the accuracy and efficiency of stereolithography guided (3D-printed) caudal maxillectomy. Mean absolute linear deviation from planned to performed cuts and mean procedure duration were compared pairwise between three study groups, with 10 canine cadaver head sides per group: 3D-printed guided caudal maxillectomy performed by an experienced surgeon (ESG) and a novice surgery resident (NSG), and freehand procedure performed by an experienced surgeon (ESF). Results: Accuracy was systematically higher for ESG versus ESF, and statistically significant for 4 of 5 osteotomies (p < 0.05). There was no statistical difference in accuracy between ESG and NSG. The highest absolute mean linear deviation for ESG was <2 mm and >5 mm for ESF. Procedure duration was statistically significantly longer for ESG than ESF (p < 0.001), and for NSG than ESG (p < 0.001). Discussion: Surgical accuracy of canine caudal maxillectomy was improved with the use of our novel custom cutting guide, despite a longer duration procedure. Improved accuracy obtained with the use of the custom cutting guide could prove beneficial in achieving complete oncologic margins. The time increase might be acceptable if hemorrhage can be adequately controlled in vivo. Further development in custom guides may improve the overall efficacy of the procedure.

Complications associated with iliosacral lymphadenectomy in dogs with metastatic apocrine gland anal sac adenocarcinoma.

Objective: To report intraoperative and immediate postoperative complications associated with removal of metastatic iliosacral lymph nodes in dogs with apocrine gland anal sac adenocarcinoma. Animals: There were 136 client-owned dogs in the study. Procedure: Retrospective multi-institutional study. The database of collaborating institutions was searched for dogs with metastatic apocrine gland anal sac adenocarcinoma that underwent lymphadenectomy for removal of one or more iliosacral lymph nodes. Information of signalment, hematological abnormalities, abdominal computed tomography or ultrasound findings, number and size of enlarged lymph nodes, intraoperative and postoperative complications, treatment and outcome were collected. Results: The overall complication rate associated with metastatic iliosacral lymphadenectomy was 26.1%. The only intraoperative complication recorded was hemorrhage and was reported in 24 (17.6%) surgeries, 11 (45.8%) of which received a blood transfusion. Postoperative complications were reported in 10.4% of surgeries, and included edema formation (n = 4, 2.6%), unilateral or bilateral paraparesis (n = 4, 2.6%), hypotension (n = 3, 2.0%), surgical site infection (n = 2, 1.3%), abdominal incision dehiscence (n = 1, 0.6%), urinary incontinence (n = 1, 0.6%), and death (n = 1, 0.6%). The size of the iliosacral lymph nodes was significantly associated with a greater risk of complications, hemorrhage, and the need of transfusion during lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma. Conclusion: Complications associated with iliosacral lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma are relatively common and mostly relate to hemorrhage. These complications are significantly associated with the size of the extirpated metastatic lymph nodes. Clinical relevance: This retrospective study provides information for the clinician regarding the potential surgical complications for extirpation of metastatic iliosacral lymph nodes. These complications, although not common, can be severe and should be discussed with owners before surgery.

Objectif: Rapporter les complications peropératoires et postopératoires immédiates associées à l'ablation des ganglions lymphatiques ilio-sacrés métastatiques chez les chiens atteints d'un adénocarcinome des glandes apocrines des sacs anaux. Animaux: Il y avait 136 chiens appartenant à des clients dans l'étude. Procédure: Étude multi-institutionnelle rétrospective. La base de données des institutions collaboratrices a été recherchée pour les chiens atteints d'un adénocarcinome métastatique des glandes apocrines des sacs anaux qui ont subi une lymphadénectomie pour l'ablation d'un ou plusieurs ganglions lymphatiques ilio-sacrés. Des informations sur le signalement, les anomalies hématologiques, les résultats de la tomodensitométrie abdominale ou de l'échographie, le nombre et la taille des ganglions élargis, les complications peropératoires et postopératoires, le traitement et les résultats ont été recueillis. Résultats: Le taux global de complications associées à la lymphadénectomie ilio-sacrée métastatique était de 26,1 %. La seule complication peropératoire enregistrée était une hémorragie et a été rapportée dans 24 (17,6 %) chirurgies, dont 11 (45,8 %) ont reçu une transfusion sanguine. Des complications postopératoires ont été signalées dans 10,4 % des interventions chirurgicales et comprenaient la formation d'oedème (n = 4, 2,6 %), la paraparésie unilatérale ou bilatérale (n = 4, 2,6 %), l'hypotension (n = 3, 2,0 %), l'infection du site opératoire (n = 2, 1,3 %), la déhiscence de l'incision abdominale (n = 1, 0,6 %), l'incontinence urinaire (n = 1, 0,6 %) et le décès (n = 1, 0,6 %). La taille des ganglions ilio-sacrés était significativement associée à un risque accru de complications, d'hémorragie et à la nécessité d'une transfusion lors d'une lymphadénectomie pour un adénocarcinome métastatique des glandes apocrines des sacs anaux. Conclusion: Les complications associées à la lymphadénectomie ilio-sacrée pour l'adénocarcinome métastatique des glandes apocrines des sacs anaux sont relativement fréquentes et concernent principalement l'hémorragie. Ces complications sont significativement associées à la taille des ganglions lymphatiques métastatiques retirés. Pertinence clinique: Cette étude rétrospective fournit des informations au clinicien concernant les complications chirurgicales potentielles pour le retrait des ganglions lymphatiques ilio-sacrés métastatiques. Ces complications, bien que rares, peuvent être graves et doivent être discutées avec les propriétaires avant la chirurgie.(Traduit par Dr Serge Messier).

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Evaluation of outcomes following subtotal colectomy for the treatment of idiopathic megacolon in cats.

OBJECTIVE: To evaluate outcomes in cats undergoing subtotal colectomy for the treatment of idiopathic megacolon and to determine whether removal versus nonremoval of the ileocecocolic junction (ICJ) was associated with differences in outcome. ANIMALS: 166 client-owned cats. PROCEDURES: For this retrospective cohort study, medical records databases of 18 participating veterinary hospitals were searched to identify records of cats with idiopathic megacolon treated by subtotal colectomy from January 2000 to December 2018. Data collection included perioperative and surgical variables, complications, outcome, and owner perception of the procedure. Data were analyzed for associations with outcomes of interest, and Kaplan-Meier survival time analysis was performed. RESULTS: Major perioperative complications occurred in 9.9% (15/151) of cats, and 14% (12/87) of cats died as a direct result of treatment or complications of megacolon. The median survival time was not reached. Cats with (vs without) a body condition score < 4/9 (hazard ratio [HR], 5.97), preexisting heart disease (HR, 3.21), major perioperative complications (HR, 27.8), or long-term postoperative liquid feces (HR, 10.4) had greater hazard of shorter survival time. Constipation recurrence occurred in 32% (24/74) of cats at a median time of 344 days and was not associated with retention versus removal of the ICJ; however, ICJ removal was associated with long-term liquid feces (OR, 3.45), and a fair or poor outcome on owner assessment (OR, 3.6). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that subtotal colectomy was associated with long survival times and a high rate of owner satisfaction. Removal of the ICJ was associated with less favorable outcomes in cats of the present study.

Investigation of the use of microwave ablation with and without cooling urethral perfusion for thermal ablation of the prostate gland in canine cadavers.

OBJECTIVE: To investigate the use of microwave ablation (MWA) with cooling urethral perfusion and with no perfusion (MWA-UP and MWA-NP, respectively) for prostate gland ablation in canine cadavers. ANIMALS: Cadavers of 18 sexually intact male dogs. PROCEDURES: After technique refinement in 2 cadavers, laparotomy with ultrasound-guided MWA-UP (n = 8) or MWA-NP (8) of the prostate gland was performed in 16 cadavers. Normograde cystourethroscopy was performed before and after treatment; recorded images were reviewed in a blinded manner for scoring of urethral mucosal discoloration and loss of integrity. Difficulty with cystoscope insertion was recorded if present. Excised prostate glands were fixed for serial sectioning, gross measurements, and calculation of percentage ablation. Percentages of prostate tissue necrosis from MWA, denuded urethral mucosa, and depth of epithelial surface loss in an adjacent section of the colon were estimated histologically. Variables of interest were statistically analyzed. RESULTS: Difficulty with cystoscope insertion after treatment was significantly more common and scores for urethral mucosal discoloration and loss of integrity were significantly higher (indicating more severe lesions) for the MWA-NP group than for the MWA-UP group. The histologically assessed percentage of denuded urethral mucosa was also greater for the MWA-NP group. Overall median percentage prostate gland ablation was 73%; this result was not associated with prostate gland volume or chronological order of treatment. CONCLUSIONS AND CLINICAL RELEVANCE: MWA-UP induced subtotal thermal necrosis of prostate glands in canine cadavers while limiting urethral mucosal injury. Further study is required to optimize the technique and evaluate its safety and efficacy in vivo as a future curative-intent treatment for prostatic tumors in dogs.

Evaluation of bioabsorbable calcium sulfate hemihydrate beads for local delivery of carboplatin.

The objectives of this study were to evaluate a novel kit of resorbable calcium sulfate beads marketed specifically for use in veterinary medicine and generally used for local delivery of antimicrobials as carboplatin-delivery system. The study characterized the elution of carboplatin in vitro, and investigated whether the initial dose and formulation of carboplatin, or the bead size significantly influences carboplatin elution in vitro. Calcium sulfate hemihydrate beads of 3- and 5-mm diameter were prepared. Five doses and two formulations of carboplatin (20, 50, 100, and 500 mg carboplatin per kit in powder formulation; 20 mg in liquid formulation) were tested in triplicates for each diameter beads. Beads were placed in 37°C phosphate buffered saline for 72 hours. Carboplatin concentrations in the eluent were measured by high-performance liquid chromatography at 11 time points with a modified United States Pharmacopeia assay. Concentrations of carboplatin in the eluent proportionally increased with the initial dose and peaked between 13 and 52 hours, ranging from 42.1% to 79.3% of the incorporated load. Higher peak concentrations, percentages released, and elution rates were observed with the liquid formulation and with higher carboplatin doses. There was no significant difference in maximum carboplatin concentrations between 3- and 5-mm diameter beads, but 5-mm diameter beads had slower elution rates. The novel kit can be used for preparation of carboplatin-impregnated resorbable calcium sulfate beads at variable doses, sizes and formulations. Further study is warranted to define the in vivo requirements and effective carboplatin dose, spatial diffusion and desired duration of elution.

Outcomes associated with vaginectomy and vulvovaginectomy in 21 dogs.

OBJECTIVE: To report the outcomes of dogs with lesions of the genitourinary tract treated by vaginectomy or vulvovaginectomy. STUDY DESIGN: Multi-institutional retrospective study. ANIMALS: Female dogs that underwent vulvovaginectomy, complete vaginectomy, or subtotal vaginectomy from 2003 to 2018 with complete medical records and a minimum of 60 days follow-up. METHODS: Data collected from medical records included preoperative, intraoperative, and postoperative data, such as the occurrence of urinary incontinence (UIC), disease recurrence, and death/euthanasia. RESULTS: This study included 21 dogs. Four dogs had vulvovaginectomy, six had complete vaginectomy, and 11 had a subtotal vaginectomy performed. The mean age at surgery was 9.2 years (SD, 3.3). Thirteen dogs were intact at presentation. Smooth muscle tumors were diagnosed most commonly (10 leiomyomata, three leiomyosarcomas, two leiomyofibromas). The median duration of follow-up was 520 days (range, 71-1955). Major complications requiring revision surgery were recorded in two dogs. Postoperative UIC occurred in six of 21 dogs, resolving spontaneously within 60 days in three dogs. Dogs with malignant tumors (n = 6) survived at least 71 days (median, 626; 95% CI, 71-1245), and recurrence of disease occurred in two dogs. In dogs with benign tumors (n = 15), the median survival time was not reached. These dogs survived at least 104 days and had no recurrence of the disease. CONCLUSION: Vaginectomy and vulvovaginectomy resulted in prolonged survival and low rates of major complications and UIC. CLINICAL SIGNIFICANCE: This study provides evidence to recommend that the risks of this procedure and expectations should be discussed with clients.

Combination of blood and biphasic calcium phosphate microparticles for the reconstruction of large bone defects in dog: A pilot study.

We previously reported that biphasic calcium phosphate (BCP) microparticles embedded in a blood clot induces ectopic bone formation in mice and repairs a critical femoral defect in rat. The present pilot study aimed to evaluate in dog and in two models of large defects the efficacy of this composite named "blood for reconstruction of bone" (BRB). We show here that BRB is a cohesive biomaterial easy to prepare from dog autologous blood and to mold to fill large bone defects. First in a model of cylindrical femoral condyle defect, the BRB was compared with BCP particles alone. After 8 weeks, this revealed that the amount of mature bone was slightly and significantly higher with BRB than with BCP particles. Second, in a model consisting in a 2 cm-long critical interruptive defect of the ulna, the BRB was compared with autologous bone. After 6 months, we observed that implantation of BRB can induce the complete reconstruction of the defect and that newly formed bone exhibits high regenerative potential. Comparison with the results obtained with autologous bone grafting strongly suggests that the BRB might be an efficient biomaterial to repair large bone defects, as an alternative or in addition to autologous bone. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1842-1850, 2018.

In Vivo Evaluation of Biodegradability and Biocompatibility of Fe30Mn Alloy.

OBJECTIVES: This study aims to evaluate the biodegradability and biocompatibility of an alloy of iron and manganese (Fe30Mn) in a bone model in vivo. METHODS: Resorption of a Fe30Mn wire was compared with traditional permanent 316L stainless steel (SS) wire after bilateral transcondylar femoral implantation in 12 rats. Evaluation of biodegradation over 6 months was performed using radiography, post-mortem histology and microscopic implant surface analysis. RESULTS: Corrosion and resorption of the novel iron-manganese implant with formation of an iron oxide corrosion layer was noted on all post-mortem histological sections and macroscopic specimens (corrosion fraction of 0.84 and 0 for Fe30Mn and 316L SS, respectively). Increased bone ongrowth was observed at the wire-bone interface (bone ongrowth fraction of 0.61 and 0.34 for Fe30Mn and 316L SS, respectively). Occasionally, poorly stained newly formed bone and necrotic bone in contact with corrosion was seen. In bone marrow, Fe30Mn alloy was scored as a mild local irritant compared with 316L SS (biocompatibility score of 8.8 and 5.3, respectively). There was no evidence of systemic adverse reaction. CLINICAL SIGNIFICANCE: Resorbable iron-manganese alloys may offer a promising alternative to permanent metallic implants. Further in vivo studies to control implant resorption at a rate suitable for fracture healing and to confirm the biocompatibility and biosafety of the resorbable Fe30Mn metallic implant are necessary prior to use in clinical settings.

Comparative outcomes between ameroid ring constrictor and cellophane banding for treatment of single congenital extrahepatic portosystemic shunts in 49 dogs (1998-2012).

OBJECTIVE: To compare outcomes and identify prognostic factors in dogs with single congenital extrahepatic portosystemic shunt (CEHPSS) gradually attenuated with an ameroid ring constrictor (ARC) or cellophane banding (CB). STUDY DESIGN: Retrospective, multi-institutional study. ANIMALS: Forty-nine dogs with CEHPSS (n = 23 for ARC; n = 26 for CB). METHODS: Medical records of dogs with CEHPSS treated by ARC or CB were reviewed for postoperative (<1 month), midterm (1-6 months), and long-term (> 6 months) outcomes. Data were evaluated to detect factors associated with postoperative complications, residual shunting, and long-term outcome. RESULTS: Postoperative complication rates did not differ between ARC (26.1%) and CB (23.1%, P = .89) and were negatively associated with body weight (P = .03). Overall, postoperative mortality was low (2.0%). Clinical long-term outcome was excellent in 45.0% and 39.1% and good in 55.0% and 60.9% of dogs after ARC and CB, respectively. Suspected residual shunting rate upon abdominal ultrasonography was greater after CB (31.6%) than after ARC (0%). CONCLUSION: ARC and CB were both effective for attenuation of CEHPSS, resulting in good to excellent outcomes with low morbidity and mortality. Residual shunting was suspected in a higher proportion of dogs treated with CB on the basis of abdominal ultrasonography results. However, further prospective randomized studies must be conducted with validated evaluation methods to verify this assumption.