Evaluation of improved transvenous heartworm extraction brush in dogs with caval syndrome.

BACKGROUND: Heartworm infection in dogs is caused by Dirofilaria immitis and common in shelter animals and outdoors dogs. Caval syndrome can develop with severe infection and physical heartworm removal is essential with heartworm burdens. In this study, we used an improved transvenous heartworm extraction brush, which was expected to cause less cardiovascular damage and allow easier manipulation. OBJECTIVES: This study aims to evaluate efficacy of this improved transvenous heartworm extraction brush. METHODS: The brush was designed to improve upon the limitations of the previous brush-type devices. The brush was made of a polyvinyl chloride tube and threads of polyamides or polyglyconates. Metal material was inserted at the front tip for easy visualization under fluoroscopy. The eight dogs diagnosed with caval syndrome with large numbers of heartworms and pulmonary hypertension were used in this study. The removal procedure began with the dissection of the subcutaneous tissue around the right jugular vein. The device was inserted through the jugular vein. After insertion, the tube was rotated to catch the heartworms and extracted with the heartworms hanging on the threads. The procedure was repeated several times. Lastly, jugular vein and skin sutures were made. Adulticidal therapy was administered after heartworm removal. RESULTS: The mean number of removed heartworms was 10.5 ± 4.24 and mean number of remaining heartworms was 0.63 ± 1.06. Total procedure time was 72.63 ± 51.36. Except for three cases, heartworms were not detected on ultrasonography after the procedure. No procedure-related side effects were observed within the 1- to 2-mon. CONCLUSIONS: An improved transvenous heartworm extraction brush is efficient for heartworm removal in dogs with caval syndrome.

Accuracy of the Surface Contour of Three-Dimensional-Printed Canine Pelvic Replicas.

OBJECTIVE: The aim of this study was to determine the differences in surface contour between models of native pelvic bones and their corresponding three-dimensional (3D)-printed replicas. STUDY DESIGN: Digital 3D models of five cadaveric hemipelves and five live dogs with contralateral pelvic fractures were generated based on computed tomographic images and 3D printed. The 3D-printed replicas underwent 3D scanning and digital 3D models of the replicas were created. The digital 3D model of each replica was superimposed onto the model of the native hemipelvis. Errors in the replicas were determined by comparing the distances of 120,000 corresponding surface points between models. The medial surface, lateral surface and dorsal surface of the acetabulum (DSA) of each hemipelvis were selected for further analysis. The root mean square error (RMSE) was compared between various selected areas using a one-way repeated measures analysis of variance, followed by a Bonferroni post-hoc test. RESULTS: The RMSE of the hemipelvis was 0.25 ± 0.05 mm. The RMSE significantly decreased from the medial surface (0.28 ± 0.06mm), to the lateral surface (0.23 ± 0.06mm), to the DSA (0.04 ± 0.02mm) (p < 0.001). CONCLUSION: The 3D-printed replicas were adequate in serving as a template for the pre-contouring of bone plates in fracture repair of pelvic fractures, particularly those that demand accurate reduction such as acetabular fractures.

Long-term clinical outcomes of dogs with single congenital extrahepatic portosystemic shunts attenuated with thin film banding or ameroid ring constrictors.

OBJECTIVE: To compare long-term clinical outcomes of dogs with single congenital extrahepatic portosystemic shunts (CEHPSS) treated with thin film banding (TFB) consisting of polyolefin fiber or ameroid ring constrictor (ARC) placement in dogs. DESIGN: Retrospective, two-center clinical study. ANIMALS: Client-owned dogs (n = 123) with single CEHPSS undergoing gradual attenuation via TFB (n = 85) or ARC (n = 38). METHODS: Medical records of dogs with CEHPSS were reviewed. Follow-up data were collected from the referring veterinarian and/or owner via standardized questionnaire. Data were analyzed to compare short-term mortality rate and long-term outcome (>6 months). RESULTS: Dogs in the TFB group were older than dogs in the ARC group (median age, 19 vs 12 months, respectively; P = .01). There was no difference in survival to discharge between dogs in the TFB (81/85 [95.3%]) and ARC (37/38 [97.4%]; P > .99) groups. Preoperative levetiracetam was more frequently administered to dogs treated with TFB (64/85 [75.3%]) than to dogs treated with ARC (15/38 [39.5%;] P = .0002). Postoperative seizures were reported in 10 (8.1%) dogs; their prevalence did not differ between dogs treated with TFB (9/85 [10.6%]) and dogs treated with ARC (1/38 [2.6%]; P = .17). Median follow-up time for dogs treated with TFB (58.0 months, range 8-130) and ARC (63.3 months, range 7-138; P = .24) did not differ. CONCLUSION: Gradual attenuation of a single CEHPSS with either TFB or ARC resulted in similar long-term clinical outcomes and low postoperative morbidity and mortality rates. CLINICAL SIGNIFICANCE: Thin film banding (polyolefin fiber) offers an alternative leading to clinical outcomes similar to ARC in dogs with single CEHPSS.

Cardiopulmonary changes induced by retroperitoneal insufflation in healthy dogs in sternal recumbency with the abdomen unsupported.

This study assessed the effects of retroperitoneal carbon dioxide (CO2) insufflation on cardiopulmonary variables and intra-abdominal pressure (IAP) in mechanically ventilated dogs in sternal recumbency with the abdomen unsupported, following placement of a positioning kit and towels under the pectoral and pelvic regions. General anesthesia was induced in eight healthy adult male Beagles. A Swan-Ganz catheter was placed in the pulmonary artery via the jugular vein for cardiac output measurements. A Foley urethral catheter was placed to monitor transvesical IAP. A 10 mm balloon blunt-tip trocar was inserted into the retroperitoneal space. With a fixed respiratory rate and tidal volume by mechanical ventilation, insufflation pressure was sequentially increased from 0 to 10 mmHg in 5 mmHg increments, followed by desufflation. All variables were measured before insufflation, 5 min after the establishment of each insufflation pressure, and after desufflation. At 10 mmHg, the IAP was nearly equal to insufflation pressure. Cardiopulmonary function was not compromised at any point, although the cardiac index (CI), heart rate, mean arterial pressure (MAP), and mean pulmonary arterial pressure increased within normal ranges. End-tidal CO2 concentration, arterial CO2 partial pressure, and oxygen delivery index (DO2I) increased, whereas pH decreased, at 10 mmHg. CI, MAP, and DO2I did not recover to baseline after decompression. Thus, retroperitoneal CO2 insufflation up to 10 mmHg is well tolerated by mechanically ventilated dogs positioned in sternal recumbency with the abdomen unsupported, although sympathetic changes may occur with an insufflation pressure increase.

Feasibility of single-port retroperitoneoscopic adrenalectomy in dogs.

OBJECTIVE: To evaluate the feasibility of single-port retroperitoneoscopic adrenalectomy (SPRA) in dogs. STUDY DESIGN: A pilot experimental study. ANIMALS: Eight healthy beagle dogs. METHODS: SPRA was performed on the left and right sides (4 dogs each). Resection of the adrenal gland was performed through a SILS port using a retroperitoneal approach. Operative time was defined from skin incision to the completion of skin suture. Postoperative pain was evaluated by using 3 pain scores. Integrity of the adrenal gland capsule was evaluated by histologic assessment. RESULTS: Mean time taken to complete the SPRA was 44.1 minutes (range, 37-51) and was significantly longer on the right side than on the left side (P < .05). There were no complications intraoperatively or during 14 days of postoperative monitoring. The adrenal gland capsule was found to be injured in 3 of the 8 dogs by histologic assessment. CONCLUSION: This is the first report of SPRA in the veterinary literature. With this technique it is possible to perform adrenalectomy with some risk of capsule penetration and with excellent visibility. CLINICAL SIGNIFICANCE: This study suggests that SPRA is feasible and can be used to resect small adrenal tumors with minimal complications.

Bilateral medial iliac lymph node excision by a ventral laparoscopic approach: technique description.

The aim of this study was to describe a ventral laparoscopic technique for bilateral medial iliac lymphadenectomy in dogs. Twelve intact male purpose-bred research dogs, weighing less than 15 kg, were positioned in dorsal recumbency, and a 3-portal technique was used. Bilateral dissection was performed with vessel-sealing devices while tilting the surgical table by up to 30° towards the contralateral side of the target medial iliac lymph node (MILN) without changing the surgeon's position. Using a ventral laparoscopic approach, bilateral MILNs were identified and excised in all dogs. The mean times for unilateral and bilateral MILN dissections were 9.7 ± 3.8 and 21.0 ± 6.0 min, respectively. The mean times for the right and left MILN dissections were 10.8 ± 4.3 and 9.8 ± 2.5 min, respectively. The mean total surgery time was 43.7 ± 7.7 min. In total, 26 MILNs were dissected. Several complications, including mild to moderate capillary hemorrhage from perinodal fat and vessels (controlled laparoscopically), mild spleen trauma caused by the first trocar insertion and capsular damage of MILNs, were observed. However, there were no other major complications. All MILN samples were evaluated and deemed suitable for histopathologic diagnosis. Laparoscopic excision of MILNs is a useful method of excisional biopsy for histopathologic diagnosis. Using this ventral laparoscopic approach with the 3-portal technique, bilateral MILN dissection suitable for obtaining histopathologic samples could be achieved in a short time in dogs weighing less than 15 kg.

Retroperitoneal Laparoscopy in Dogs: Access Technique, Working Space, and Surgical Anatomy.

OBJECTIVE: To develop and describe a laparoscopic retroperitoneal access technique, investigate working space establishment, and describe the surgical anatomy in the retroperitoneal space as an initial step for clinical application of retroperitoneal laparoscopy in dogs. STUDY DESIGN: Cadaveric and experimental study. ANIMALS: Cadaveric (n=8) and healthy (n=6) adult dogs. METHODS: The retroperitoneal access technique was developed in 3 cadavers based on the human technique and transperitoneal observation. Its application and working space establishment with carbon dioxide (CO2 ) insufflation alone was evaluated in 5 cadavers by observing with a transperitoneal telescope and in 6 live dogs by repeated computed tomography (CT) scans at pressure of 0, 5, 10, and 15 mmHg. Recordings of retroperitoneoscopy as well as working space volume and linear dimensions measured on CT images were analyzed. RESULTS: Retroperitoneal access and working space establishment with CO2 insufflation alone were successfully performed in all 6 live dogs. The only complication observed was in 1 dog that developed subclinical pneumomediastinum. As pressure increased, working space was established from the ipsilateral to the contralateral side, and peritoneal tearing eventually developed. Working space volume increased significantly from 5 mmHg and linear dimensions increased significantly from 0 to 10 mmHg. With pneumo-retroperitoneum above 5 mmHg, retroperitoneal organs, including kidneys and adrenal glands, were easily visualized. CONCLUSION: The retroperitoneal access technique and working space establishment with CO2 insufflation starting with 5 mmHg and increasing to 10 mmHg provided adequate working space and visualization of retroperitoneal organs, which may allow direct access for retroperitoneal laparoscopy in dogs.