Examination of the thickness of the different components of gallbladder wall in cases with mucocele and or cholecystitis.

OBJECTIVE: To assess the thickness of each layer of the gallbladder wall with different diseases in dogs. SAMPLE: 72 gallbladders. METHODS: Retrospective study of dogs that underwent cholecystectomy. Histopathological specimens of the gallbladders were reviewed. Histopathological diagnosis was made as gallbladder mucocele or cholecystitis, and cholecystitis was further categorized into chronic cholecystitis, acute-on-chronic cholecystitis, acute cholecystitis, and necrotic cholecystitis. The thickness of each layer of the gallbladder wall was measured. RESULTS: 22 dogs were diagnosed with gallbladder mucocele without cholecystitis, 24 with gallbladder mucocele and cholecystitis, 20 with only cholecystitis, and 6 as normal. Histopathological subclassification of cholecystitis in 44 gallbladders led to diagnosis of chronic cholecystitis in 21 gallbladders, acute-on-chronic cholecystitis in 10 gallbladders, acute cholecystitis in 6 gallbladders, and necrotic cholecystitis in 7 gallbladders. The thickness of the entire wall of the gallbladder (P < .0001) and the thickness of the mucosa (P < .0001) and subserosa (P < .0001) were affected by the different disease processes. CLINICAL RELEVANCE: Layers of the gallbladder wall were affected by diseases present in the gallbladder. It resulted in a difference in the thickness of the wall of the gallbladder among the gallbladder diseases in this study. Histopathological changes should be taken into consideration before surgery while deciding what technique to use to perform a cholecystectomy.

Constrictive physiology is not present in all dogs with idiopathic chylothorax.

OBJECTIVE: To determine whether subtotal pericardectomy affects recurrence and long-term outcomes in dogs with idiopathic chylothorax (IC). ANIMALS: 12 client-owned dogs diagnosed with IC between July 26, 2016, and March 23, 2023. METHODS: The diagnosis of constrictive physiology (CP) was established with cardiac catheterization and defined as elevated and equal diastolic pressures in all 4 cardiac chambers. Dogs were then entered into the constrictive physiology (CP) group or non-CP (NCP) group. All dogs received at least a thoracic duct ligation (TDL). The dogs in the CP group had a subtotal pericardectomy performed in addition to TDL. Repeated surgical interventions, recurrence, long-term outcomes, and survival times were recorded. RESULTS: 8 dogs were entered into the CP group and underwent TDL and subtotal pericardectomy. Four dogs were entered in the NCP group and underwent only a TDL. Four dogs in the CP group and 1 in the NCP group required multiple surgeries for recurrent chylothorax. The 1-, 2-, and 3-year disease-free rates were, respectively, 100%, 100%, and 50% for the NCP group and 87.5%, 72.9%, and 72.9% for the CP group (P = .935). The 1-, 2-, and 3-year survival rates were, respectively, 100%, 100%, and 100% for the NCP group and 87.5%, 72.9%, and 72.9% for the CP group (P = .317). CLINICAL RELEVANCE: Constrictive physiology should be evaluated by cardiac catheterization before surgical treatment of IC in dogs. If CP is not diagnosed, subtotal pericardectomy may not be required.

The use of a minimally invasive integrated endoscopic system to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions.

Introduction: The objective was to evaluate the use of a minimally invasive surgical (MIS) approach to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions (IVDE). Additionally, we aimed to evaluate the degree of soft tissue trauma using the endoscopic procedure compared to the standard open approach. Methods: Eight client-owned dogs presented to the Colorado State University Veterinary Teaching Hospital with acute onset thoracolumbar IVDE were included in this study. This was a prospective, randomized case-series. Patients were assigned to undergo an endoscopic (group 1; n = 4) or a standard open approach (group 2; n = 4) for a hemilaminectomy. A post-operative MRI was performed in all cases. Results: Conversion to an open approach was not necessary for any case in group 1. All cases had adequate spinal cord decompression on post-operative MRI. There was no significant difference in soft tissue changes noted on post-operative MRI between the two groups. Discussion: The MIS approach to hemilaminectomies in chondrodystrophic dogs with thoracolumbar IVDE can successfully be performed to decompress the neural tissue and appears to lead to similar clinical outcomes in the early postoperative period compared to the standard open approach. Larger studies are needed to determine the potential advantages of the MIS technique compared to the standard open approach in veterinary medicine.

Laparoscopic Treatment of Sliding Hiatal Hernia.

Hiatal hernias result from a widening of the esophageal hiatus that leads to the displacement of the lower esophageal sphincter and stomach into the thoracic cavity. Clinical signs of regurgitation, gastroesophageal reflux, and esophagitis are managed medically, but surgery is considered in those that fail to respond to medical management. Surgical treatment of hiatal hernia can be performed laparoscopically. Treatment involves plication of the esophageal hiatus, as well as a pexy of the esophagus to the diaphragm and a left sided gastropexy. Outcomes with laparoscopic treatment are comparable to those performed via laparotomy.

Influence of a single locking throw on the in vitro holding security of five friction throws.

OBJECTIVE: To compare the in vitro security of four different friction throws (square, surgeon's, Miller's, and strangle), with and without a locking throw, and a slip knot, on a vascular ligation model. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Nine groups with nine samples per group. METHODS: Four throws (square, surgeon's, Miller's, and strangle), with and without a locking throw, and a square throw locked in slip knot fashion, were tested to measure leakage pressure. RESULTS: The square and surgeon's throws leaked at a lower pressure than the Miller's and strangle throws (p < .0001). The leakage pressure was below physiologic arterial pressure for the square and the surgeon's throws. After the addition of a locking throw, the five knots leaked at a similar pressure (p = .5233) above physiologic arterial pressure. CONCLUSION: Following the addition of a locking throw, all the constructs tested in this study leaked at a similar pressure. The leakage pressure for all knots exceeded physiologic arterial pressures. CLINICAL SIGNIFICANCE: Any throw tested may be appropriate for secure vascular ligation if the initial throw is applied correctly.

The Edwards Acumen IQ system using peripheral arterial catheter-based waveforms to estimate cardiac output is not accurate as compared to thermodilution in dogs.

OBJECTIVE: To assess the agreement between cardiac output (CO) estimated via evaluation of the arterial pressure waveform by a novel monitoring system (Edwards Acumen IQ sensor and HemoSphere Advanced Monitor Platform [HS-IQ]; Edwards LifeSciences) and measured by thermodilution (TD) in anesthetized, normovolemic, and hypovolemic dogs. To assess the agreement between the HS-IQ CO measurements in the radial artery and dorsal metatarsal artery. ANIMALS: 8 purpose-bred Beagles. METHODS: Dogs were placed under general anesthesia. CO was measured via TD and via the HS-IQ at radial and dorsal metatarsal arterial catheters. CO measurements were obtained at 4 time points including normovolemic and multiple hypovolemic states. Paired measurements of CO were evaluated via the method of Bland and Altman with acceptable limits of agreement (LOA) defined as < 30%. RESULTS: A total of 24 (dorsal metatarsal) and 21 (radial) paired measurements were collected in 8 dogs. The overall bias (CI) for comparison of TD to radial arterial HS-IQ CO measurements was -0.09 L/min. LOA and proportional LOA were -2.66 to 2.49 L/min and -140.72% to 104.94%. The overall bias (CI) for comparison of TD to dorsal metatarsal arterial HS-IQ CO measurements was -0.26 L/min. LOA and proportional LOA were -2.76 to 2.24 L/min and -135.96% to 93.25%. The overall proportional error for radial arterial was -17.9% and for dorsal metatarsal was -21.4%. CLINICAL RELEVANCE: CO measurements with the HS-IQ were easy to obtain but did not produce results within a clinically acceptable range for either measurement site, with a very wide LOA. The CO estimations from the HS-IQ are not appropriate for clinical use at this time.

Three-dimensional versus two-dimensional laparoscopy for cholecystectomy in a canine cadaveric study.

OBJECTIVE: To compare the effect of three-dimensional (3D) and two-dimensional (2D) laparoscopy on surgical time and intraoperative complications during cholecystectomies in canine cadavers. STUDY DESIGN: Experimental prospective study. ANIMALS: Twelve canine cadavers. METHODS: The laparoscopic cholecystectomies were performed in canine cadavers with four cannulas and with either 2D or 3D cameras by a single surgeon. The following surgical times were recorded: time from insertion of laparoscopic instruments to first endoclip placement, time from first endoclip placement to second endoclip placement, time from second endoclip placement to complete gall bladder dissection, and total surgical time. The cystic duct length distal to the first endoclip, intraoperative complications, and the amount of liver attached to the gall bladder were also recorded. RESULTS: Time from the insertion of the instruments to the application of the first endoclip was shorter for the 3D group than for the 2D group (p = .016). Other surgical times were not different between groups. There was no difference in the cystic duct length distal to the first endoclip, intraoperative complications, or the amount of liver attachment. CONCLUSION: Three-dimensional laparoscopy shortened the time from insertion of the laparoscopic instruments to placement of the first endoclip. However, total surgical time was not affected by the type of camera in laparoscopic cholecystectomy. CLINICAL SIGNIFICANCE: Three-dimensional laparoscopy may be beneficial when performing procedures requiring enhanced spatial orientation. However, this technique did not shorten the total surgical time in this cadaveric study. Further studies in a clinical setting are necessary for the optimization of the future use of 3D laparoscopy.

A vessel sealing device and an ultrasonic dissector are equally effective and safe for single port laparoscopic ovariectomy in dogs.

OBJECTIVE: To evaluate ovary removal surgery times and intraoperative complication rates between a 5-mm Sonicision cordless ultrasonic dissector (SCUD) and 5-mm vessel sealing device (VSD) for laparoscopic ovariectomy in dogs. ANIMALS: Client-owned, intact female dogs (n = 10) presented for elective laparoscopic ovariectomy. METHODS: In each dog, 1 ovarian pedicle was randomly assigned to the SCUD group and 1 to the VSD group. In the SCUD group (n = 10), the ovariectomy was performed using the SCUD device; the ovariectomy in the VSD group (10) was performed using a VSD. The number of applications of each device during ovariectomy, surgery time required for each ovary removal, total surgery duration, ovarian pedicle fat score, and intraoperative complications were recorded. RESULTS: Both left and right ovaries had median pedicle fat scores of 2 (range, 1 to 3). To complete an ovariectomy, the median number of SCUD applications was 9 (range, 7 to 13) times; the VSD had a median of 10 (range, 5 to 18) times (P = .98). Median surgery times for the removal of 1 ovary with the SCUD and VSD were 96 seconds (range, 45 to 417 seconds) and 110 seconds (range, 42 to 164 seconds), respectively (P = 1). No intraoperative complications were associated with either device. Therefore, the VSD was not required for rescue in the SCUD group, and no conversions to open ovariectomy were necessary. CLINICAL RELEVANCE: A standard approach laparoscopic ovariectomy performed with the SCUD was successful in our population of dogs, making the 5-mm SCUD safe for laparoscopic ovariectomy in healthy dogs, which provides a more affordable option for practitioners and clients.

Clinical outcomes of the use of unidirectional barbed sutures in gastrointestinal surgery for dogs and cats: A retrospective study.

OBJECTIVE: To report the clinical outcomes of gastrointestinal surgery using unidirectional barbed sutures in single-layer appositional closure in dogs and cats. STUDY DESIGN: Retrospective and descriptive study. SAMPLE POPULATION: Twenty-six client-owned dogs; three client-owned cats. METHODS: Medical records of dogs and cats that received gastrointestinal surgery closed with unidirectional barbed sutures were reviewed to collect information on signalment, physical examinations, diagnostics, surgical procedures, and complications. Short- and long-term follow-up information was collected from the medical records, the owners, or the referring veterinarians. RESULTS: Six gastrotomies, 21 enterotomies, and nine enterectomies were closed with a simple continuous pattern with unidirectional barbed glycomer 631 sutures. Nine dogs had multiple surgical sites closed with unidirectional barbed sutures. None of the cases in the study developed leakage, dehiscence, or septic peritonitis during the 14-day short-term follow up. Long-term follow up information was collected for 19 patients. The median long-term follow-up time was 1076 days (range: 20-2179 days). Two dogs had intestinal obstruction due to strictures at the surgical site 20 and 27 days after surgery. Both were resolved with an enterectomy of the original surgical site. CONCLUSION: Unidirectional barbed suture was not associated with a risk of leakage or dehiscence after gastrointestinal surgery in dogs and cats. However, strictures may develop in the long term. CLINICAL SIGNIFICANCE: Unidirectional barbed sutures can be used during gastrointestinal surgery in client-owned dogs and cats. Further investigation of the role of unidirectional barbed sutures leading to abscess, fibrosis, or stricture is necessary.

Effect of insufflation pressure during transanal minimally invasive surgery on surgical complications with dissection of the rectal submucosa in canine cadavers.

OBJECTIVE: To determine ideal insufflation pressures during transanal minimally invasive surgery (TAMIS) in canine cadavers for rectal submucosal transection and incisional closure. ANIMALS: 16 canine cadavers. PROCEDURES: Cadavers were placed in lateral recumbency. Urinary catheters were placed to measure intra-abdominal pressure (IAP). A single access port was placed to establish a pneumorectum. Cadavers were placed in insufflation groups of 6 mmHg to 8 mmHg (group 1), 10 mmHg to 12 mmHg (group 2), or 14 mmHg to 16 mmHg (group 3). Defects in the rectal submucosa were created and closed with a unidirectional barbed suture. Duration for each procedure and subjective ease of identifying the transection plane and performing incisional closure were assessed. RESULTS: The single access port was successfully placed in dogs weighing 22.7 kg to 48 kg. The ease of each step of the procedure was not influenced by the insufflation pressure. The median surgical duration for group 1 was 740 seconds (range = 564 to 951 seconds), 879 seconds (range = 678 to 991 seconds) for group 2, and 749 seconds (range = 630 to 1,244 seconds) for group 3 (P = .650). The insufflation pressure increased the IAP (P = .007). Perforation of the rectum happened in 2 cadavers in group 3. CLINICAL RELEVANCE: The duration of each step of the procedure was not significantly influenced by insufflation pressure. Defining the dissection plane and performing resection was more challenging in the highest-pressure group. Rectal perforation occurred only with the 14 mmHg to 16 mmHg insufflation pressure. Single access port usage with TAMIS may provide a readily available, minimally invasive approach for the resection of rectal tumors in dogs.

Influence of conventional versus unidirectional barbed suture on leakage pressures in canine vesicourethral anastomosis: An ex-vivo study.

OBJECTIVE: To compare leakage pressures of vesicourethral anastomosis (VUA) performed with conventional and unidirectional barbed sutures in canine cadaveric tissue. STUDY DESIGN: Experimental, ex-vivo, randomized study. ANIMALS: A total of 24 male canine bladders with the urethra. METHODS: Specimens after prostatectomy were randomly divided into a unidirectional barbed suture (UBS) or a conventional suture (C) group. For the UBS group, the VUA was performed with 4-0 unidirectional barbed sutures. For the C group, the VUA was performed with 4-0 monofilament absorbable suture. The VUA was completed with two simple continuous sutures. Surgical time, leakage pressure, site of leakage, and the number of suture bites were recorded. RESULTS: The median suturing time was 12.70 minutes (range: 7.50-16.10 min) for the UBS group and 17.30 minutes (range: 14.00-21.30 min) for the C group (p < .0002). The median leakage pressure was 8.60 mmHg (range: 5.00-17.20 mmHg) for the UBS group and 11.70 mmHg (range: 6.00-18.50 mmHg) for the C group (p = .236). The median number of suture bites was 14 (range:11-27) for the UBS group and 19 (range:17-28) for the C group (p = .012). CONCLUSION: Unidirectional barbed suture does not statistically affect the acute leakage pressure of VUA in normal cadaveric specimen. It resulted in a shorter surgical time and fewer suture bite placements. CLINICAL SIGNIFICANCE: A urinary catheter will still be required when a unidirectional barbed suture is used to complete a VUA in dogs to prevent extravasation of urine in the postoperative period.

Description of the technique for laparoscopic radical prostatectomy in canine cadavers: 2D vs. 3D camera.

OBJECTIVE: To describe the technique of laparoscopic radical prostatectomy in canine cadavers. STUDY DESIGN: Cadaveric study. ANIMALS: 8 canine cadavers. METHODS: Specimens were randomly divided into a 2D or 3D group. The vesicourethral anastomosis (VUA) was performed with 5 mm laparoscopic needle holders. A unidirectional barbed suture was used to complete the VUA with two simple continuous suture patterns. The number of stitches placed, the patency of the anastomosis, and the distance between the VUA and the ureters were recorded. RESULTS: Four dogs were entered into each group. The prostatectomy was completed in each dog following the same technique. VUA were completed with nine stitches (range: 8-10 stitches) for the 2D group and ten stitches (range: 9-11 stitches) for the 3D group (p<0.176). All the stitches were placed full thickness. The VUA was patent in each case. The left ureter was 1.05 cm (range: 0.5 to 1.1cm) from the VUA in the 2D group and 1.8 cm (range: 1.3-1.8 cm) for the 3D group (p< 0.025). The right ureter was 1.5 cm (range: 1 to 2 cm) from the VUA in the 2D group and 1.75 cm (range: 1.3-2 cm) for the 3D group (p< 0.55). CONCLUSION: Laparoscopic radical prostatectomy can be performed with a 2D or a 3D camera in canine cadavers. The 3D camera results in more accurate placement of the sutures since they were placed further away from the left ureter. CLINICAL SIGNIFICANCE: Radical prostatectomy with laparoscopy should be considered for dogs.

Comparison of leakage pressures of vesicourethral anastomosis performed with intracorporeal suturing in a simulator and conventional suturing ex vivo in canine cadaveric tissue.

OBJECTIVE: To compare conventional and intracorporeal vesicourethral anastomosis (VUA) in canine cadaveric tissue. STUDY DESIGN: Cadaveric ex vivo study. STUDY POPULATION: Twenty-eight canine bladders with urethra. METHODS: Specimens after prostatectomy were randomly divided into intracorporeal (I) group or conventional (C) group. For the I group, VUA was performed in a simulator with laparoscopic needle holders and telescope. For the C group, the anastomosis was performed in vitro with standard instruments. The VUA was performed with 4-0 monofilament absorbable suture and was completed with two simple continuous sutures. Surgical time, leakage pressure, site of leakage, and number of suture bites were recorded. RESULTS: Fourteen samples were entered in each group. The dorsal side of the anastomosis was initially performed, followed by the ventral side. The median suturing time was 30.8 minutes (range, 19.3-39.2) for the I group and 17.3 minutes (range, 9.2-21.3) for the C group (P < .0001). The median leakage pressure was 10.9 mm Hg (range, 4.1-29.7) for the I group and 10.8 mm Hg (range, 6.2-18.5) for the C group (P = .94). The median number of stitches was 20 (range, 14-26) for the I group and 19 (range, 11-28) for the C group (P = .96). The distribution of the site of leakage was similar between groups (P = .381). CONCLUSION: Vesicourethral anastomosis can be performed with leakage pressures similar to intracorporeal and conventional suturing. CLINICAL SIGNIFICANCE: This study represents the first step toward laparoscopic radical prostatectomy in dogs.

Thoracoscopic treatment of persistent right aortic arch in dogs with and without one lung ventilation.

OBJECTIVE: To evaluate thoracoscopic treatment of persistent right aortic arch (PRAA) in dogs with and without the use of one lung ventilation (OLV). STUDY DESIGN: Retrospective cohort study. ANIMALS: Twenty-two (client-owned and shelter) dogs diagnosed with PRAA. METHODS: Medical records were reviewed retrospectively and intraoperative and immediate postoperative data were compared between dogs that underwent thoracoscopic treatment of PRAA with (OLV+) and without (OLV-) OLV. RESULTS: Ten of the 12 dogs in the OLV+ group and 7/10 dogs in the OLV- group had their left ligamentum arteriosum successfully ligated during thoracoscopy. Median surgical time, surgery complications, anesthesia complications, and rate of conversion to an open thoracotomy due to limited visualization or surgical complications were similar between the two groups. CONCLUSION: Thoracoscopic treatment of PRAA can be performed with or without OLV. Surgical time, intraoperative complications, and conversion rates were similar between dogs that underwent thoracoscopic treatment of PRAA with and without OLV. OLV may not have contributed to improved visualization in this group of dogs. CLINICAL SIGNIFICANCE (OR IMPACT): The use of OLV is safe during thoracoscopic treatment of PRAA. OLV did not appear to provide significant benefits in this case series and thoracoscopic treatment of PRAA in dogs may be performed successfully with or without the use of OLV.

Premature death in dogs with nontraumatic hemoabdomen and splenectomy with benign histopathologic findings.

OBJECTIVE: To determine whether premature death occurred among dogs with nonmalignant splenic histopathologic findings after splenectomy for nontraumatic hemoabdomen. ANIMALS: 197 dogs with nontraumatic hemoabdomen that underwent splenectomy and histopathologic evaluation between 2005 and 2018. PROCEDURES: Information was obtained from electronic medical records, dog owners, and referring veterinarians to determine patient characteristics, histopathologic findings, survival information, and cause of death. Dogs were grouped based on histopathological diagnosis and outcome, and median survival times (MSTs) and risk factors for death were determined. RESULTS: Histopathologic findings indicated malignancy in 144 of the 197 (73.1%) dogs with nontraumatic hemoabdomen. Hemangiosarcoma was diagnosed in 126 dogs (87.5% of those with malignancies and 64.0% of all dogs). Nine of 53 (17%) dogs with nonmalignant histopathologic findings had an adverse outcome and premature death, with an MST of 49 days. Risk factors for this outcome included low plasma total solids concentration, an elevated hemangiosarcoma likelihood prediction score, and a medium or high hemangiosarcoma likelihood prediction score category. CONCLUSIONS AND CLINICAL RELEVANCE: This study showed that there is a group of dogs with nontraumatic hemoabdomen due to splenic disease that have nonmalignant histopathologic findings after splenectomy, but nonetheless suffer an adverse outcome and die prematurely of a suspected malignancy. Further evaluation of potential at-risk populations may yield detection of otherwise overlooked malignancies.

The Interventricular Septum Is Biomechanically Distinct from the Ventricular Free Walls.

The interventricular septum contributes to the pumping function of both ventricles. However, unlike the ventricular wall, its mechanical behavior remains largely unknown. To fill the knowledge gap, this study aims to characterize the biaxial and transmural variation of the mechanical properties of the septum and compare it to the free walls of the left and right ventricles (LV/RV). Fresh hearts were obtained from healthy, adult sheep. The septal wall was sliced along the mid-line into two septal sides and compared to the epicardial layers of the LV- and RV-free walls. Biaxial tensile mechanical tests and constitutive modeling were performed to obtain the passive mechanical properties of the LV- and RV-side of the septum and ventricular walls. We found that both sides of the septum were significantly softer than the respective ventricular walls, and that the septum presented significantly less collagen than the ventricular walls. At low strains, we observed the symmetric distribution of the fiber orientations and a similar anisotropic behavior between the LV-side and RV-side of the septum, with a stiffer material property in the longitudinal direction, rather than the circumferential direction. At high strains, both sides showed isotropic behavior. Both septal sides had similar intrinsic elasticity, as evidenced by experimental data and constitutive modeling. These new findings offer important knowledge of the biomechanics of the septum wall, which may deepen the understanding of heart physiology.

Cardiopulmonary function and intestinal blood flow in anaesthetised, experimentally endotoxaemic horses given a constant rate infusion of dexmedetomidine.

BACKGROUND: Endotoxaemia causes untoward inflammatory-mediated effects that might be attenuated by dexmedetomidine. OBJECTIVES: To evaluate the effects of a dexmedetomidine intravenous (IV) infusion on systemic and intestinal haemodynamics and arterial blood gas values in sevoflurane-anaesthetised horses administered Escherichia coli O55:B5 lipopolysaccharides (LPS). STUDY DESIGN: Randomised controlled in vivo experiment. METHODS: A total of 13 horses weighing 456 ± 86 kg (mean ± standard deviation) and aged 13.9 ± 9.0 years donated for euthanasia underwent ventral midline celiotomy using sevoflurane anaesthesia. Baseline physiological variables were recorded after a 90-minute equilibration period. All horses were given 0.1 mcg/kg bwt LPS IV. Horses were randomly assigned to no further treatment (group LPS; seven horses) or IV administration of dexmedetomidine (loading dose 1.75 mcg/kg bwt followed by 1.75 mcg/kg bwt/h; group LPS-Dex; six horses) with concurrent target sevoflurane dose reduction of 50%. Cardiac index (CI; thermodilution), intestinal blood flow, arterial blood parameters and plasma dexmedetomidine concentration measurements were recorded every 30 minutes until euthanasia at 390 minutes. Data were compared between and within groups to baseline using a mixed model analysis (significance P < .05). RESULTS: In LPS-Dex horses, intestinal blood flow and CI were transiently decreased after the dexmedetomidine loading dose, but no significant differences were found compared with baseline during the infusion. Sevoflurane dose was reliably reduced by approximately 40%. Significant differences were identified in creatinine (115  umol/L LPS-Dex; 195 umol/L LPS), bicarbonate (29.7 mmol/L LPS-Dex; 23 mmol/L LPS) and base excess (2.0 mmol/L LPS-Dex; -5.3 mmol/L LPS). Dexmedetomidine plasma concentrations were highest after the loading dose and stable during infusion dosing. MAIN LIMITATIONS: Experimental conditions are not reflective of clinical colic management. CONCLUSIONS: A dexmedetomidine infusion with sevoflurane dose reduction attenuated some deleterious changes in anaesthetised horses administered LPS without sustained negative cardiovascular effects and may be beneficial during colic surgery.

Ex vivo comparison of hand-sutured versus circular stapled anastomosis in canine large intestine.

OBJECTIVE: To compare leakage pressures of colonic anastomoses performed with circular staplers to conventional hand-sewn techniques in dogs. STUDY DESIGN: Ex-vivo study. ANIMALS: Colon from 11 canine cadavers. METHODS: Thirty-two colonic anastomoses were performed. Four segments from each colon were randomly assigned to one of four techniques: hand-sewn colonic anastomoses performed with 4-0 glycomer 631 (G) and 4-0 barbed glycomer 631 (BG), and circular stapled colonic anastomoses using 4.8 mm End-to-End Anastomosis (EEA C4.8mm) and 3.5 mm End-to-End Anastomosis (EEA C3.5mm), 21 mm diameter circular staples in cadaveric canine colon. Leakage pressure was defined as the pressure at which dye-containing solution was first observed to leak from the anastomosis site. RESULTS: Leakage pressures were 49.5 mmHg (range:16-72) in group G, 45.5 mmHg (range:19-80) in group BG, 5.3 mmHg (range:0-31) in group C3.5mm, and 29.5 mmHg (range:23-50.3) in group C4.8mm. Anastomoses leaked at lower pressures when stapled rather than hand-sewn (C4.8mm-G p = .0313, C4.8mm-BG p = .0131, C3.5mm-G p = .0469, C3.5mm-BG p = .0313). Two of the C3.5mm constructs leaked immediately after saline infusion with 4/6 leaking at <5.3 mmHg. CONCLUSION: End-to-end colonic anastomoses closed with circular stapler leaked at lower pressures than hand-sutured anastomoses. Use of the EEA stapler with a staple height of 3.5 mm did not result in safe colonic anastomoses. CLINICAL SIGNIFICANCE: These results provide evidence to support hand-suturing colonic anatomoses with G and BG in dogs. The 4.8 mm staples may be considered in anatomical locations difficult to reach.

Surgical treatment of persistent right aortic arch with combined ligamentum arteriosum transection and esophageal diverticulum resection in three dogs.

OBJECTIVE: To describe the treatment of persistent right aortic arch (PRAA) in dogs with combined ligamentum arteriosum (LA) transection and esophageal diverticulum resection. ANIMALS: Three client owned dogs. STUDY DESIGN: Short case series. METHODS: Medical records were reviewed for clinical signs, diagnostic procedures, surgical treatment, post-operative therapies including medications and feeding regime, outcomes, and follow-up imaging. RESULTS: Esophageal resection was performed using a thoracoabdominal (TA) stapler with suture overlay. All dogs recovered well from surgery and did not experience any peri- or post-operative complications. The last follow-up was performed between 64 and 1004 days post-operatively. In all cases, regurgitation resolved and did not recur in any dogs. No dogs required medical therapy or dietary modifications. In two cases, follow-up imaging was performed that revealed marked improvement of esophageal dilation. CONCLUSION: Resection of esophageal diverticulum secondary to PRAA utilizing a TA stapler with suture overlay was technically feasible and did not seem associated with early or late complications.