Eric Monnet

Gastric dilatation-volvulus syndrome in dogs

Gastric dilatation-volvulus is a medical and surgical emergency that principally affects large-breed dogs. Surgical treatment should be undertaken as soon as the patient has been stabilized with fluid therapy and decompression. A gastrectomy might be required if the stomach is becoming necrotic. A gastropexy is required to prevent recurrence.

Thoracoscopic correction of persistent right aortic arch in a dog.

A 15-week-old, male intact, miniature schnauzer presented for signs consistent with persistent right aortic arch (PRAA). Esophagram and esophagoscopy confirmed this diagnosis. Following selective intubation, the constricting ligamentum arteriosum was visualized and completely resected via thoracoscopy. No complications were noted with this procedure. Advantages of thoracoscopy for management of persistent right aortic arch observed in this case were better visualization of the ligamentum arteriosum, minor postoperative discomfort, and minimal intraoperative hypothermia. Therefore, thoracoscopy is a potential alternative to intercostal thoracotomy for correction of PRAA.

A canine model of heart failure by intracoronary adriamycin injection: Hemodynamic and energetic results☆

BACKGROUNDnTo eliminate the noncardiac toxicities associated with Adriamycin (Pharmacia Upjohn, Kalamazoo, MI) and to avoid the need for surgical implantation of a coronary artery catheter, we proposed serial intracoronary infusions of Adriamycin (Pharmacia Upjohn) with a Judkins catheter to develop a nonsurgical but selective model of dilated cardiomyopathy in dogs.nnnMETHODS AND RESULTSnTwenty-two dogs were entered onto the study. Each dog received four weekly injections of Adriamycin (Pharmacia Upjohn; 15 mg/wk) through a Judkins catheter and verapamil orally (5 mg/kg twice daily) for 4 weeks. Dogs were evaluated with echocardiography, right-sided cardiac catheterization, and endomyocardial biopsy at times 0 and 10 weeks. The left ventricular ejection fraction decreased from 0.65 +/- 0.04 to 0.48 +/- 0.11 (P = .0006). The left ventricular end-diastolic and end-systolic diameter indices increased from 42.00 +/- 2.17 to 46.92 +/- 5.81 mm (P = .0029) and from 27.65 +/- 2.59 to 35.00 +/- 6.84 mm, respectively (P = .0210). The mechanical cardiac efficiency decreased from 28.55% +/- 13.30% at baseline and 15.64% +/- 9.09% at 10 weeks (P = .001). Cardiac myocyte vacuolation was present on histological examination at 10 weeks. The mortality rate was 41%. Minimal systemic Adriamycin (Pharmacia Upjohn) toxicity was noticed.nnnCONCLUSIONnIntracoronary injection of Adriamycin (Pharmacia Upjohn) in dogs induced a chronic dilated cardiomyopathy.

Interventional thoracoscopy in small animals.

Thoracoscopy is a minimally invasive technique for viewing the internal structures of the thoracic cavity. The procedure uses a rigid telescope placed through a portal and positioned in the thoracic wall to examine the contents of the pleural cavity. Once the telescope is in place, either biopsy forceps or an assortment of surgical instruments can be introduced into the thoracic cavity through adjacent portals in the thoracic wall to perform various diagnostic or surgical procedures. The minimal invasiveness of the procedure, the rapid patient recovery, and the diagnostic accuracy make thoracoscopy an ideal technique compared with other more invasive procedures. This article discusses the use of interventional thoracoscopy (an emerging surgical technique) in veterinary surgery to perform pericardial window, subtotal pericardiectomy, or lung lobectomy to correct vascular ring anomalies, to ligate patent ductus arteriosus and the thoracic duct, and to aid in the treatment of pyothorax. Most procedures are performed under thoracoscopy, and some procedures can be thoracoscopically assisted.

Treatment of suture line bleeding with a novel synthetic surgical sealant in a canine iliac PTFE graft model

CoSeal mark surgical sealant (CoSeal) was evaluated for inhibiting suture line bleeding using a canine iliac PTFE graft model. Both iliac arteries of 12 heparinized canines were grafted with PTFE. CoSeal was applied to the suture lines of one graft in each animal. The contra-lateral graft served as a control and bleeding was controlled with gauze and pressure (tamponade). The cross-clamps were removed 30 s following application of CoSeal. Times to hemostasis and volume of blood loss at each graft site were determined. Compared to tamponade control, CoSeal significantly reduced the time to hemostasis (average of 5 min vs. greater than 15 min, p < 0.05) and blood loss (19 g vs. 284 g, p < 0.05). Small amounts of CoSeal were visible grossly or histologically at day 7. Histology showed moderate to marked inflammation in CoSeal sites and moderate inflammation in control sites at day 7. At 30 and 60 days, no CoSeal was visible grossly or histologically. Histology showed moderate inflammation in both CoSeal treated sites and in control sites at day 30 and mild to moderate inflammation in both CoSeal and control sites at day 60. CoSeal significantly reduced the time to hemostasis and blood loss in comparison to tamponade.

Polymerized bovine hemoglobin decreases oxygen delivery during normoxia and acute hypoxia in the rat.

Hemoglobin-based oxygen carriers (HBOC) have been primarily studied for blood loss treatment. More recently infusions of HBOC in euvolemic subjects have been proposed for a wide variety of potential therapies in which increased tissue oxygenation would be beneficial. However, compared with the exchange transfusion models to study blood loss, less is known about HBOC oxygen delivery and vasoacitvity when it is infused in euvolemic subjects. We hypothesized that HBOC [polymerized bovine hemoglobin (PBvHb)] infusion creating hypervolemia would increase oxygen delivery to tissues during acute global hypoxia. Vascular oxygen content and hemodynamics were determined after euvolemic rats were infused with 3 ml of either lactated Ringer or PBvHb solution (13 g/dl, 1.3 g/kg) during acute hypoxia (FIO2 = 10%, 4 h) or normoxia (FIO2 = 21%) exposure. Our data demonstrated that compared with Ringer-infused animals, in hypoxia and normoxia, PBvHb treatment improved oxygen content but raised mean arterial pressure, lowered stroke volume, heart rate, and cardiac index, which resulted in a net reduction in blood flow and oxygen delivery to the tissues. The PBvHb vasoactive effect was similar in magnitude and direction as to the Ringer-infused animals treated with a nitric oxide synthase inhibitor nitro-l-arginine, suggesting the PBvHb effect is mediated via nitric oxide scavenging. We conclude that infusion of PBvHb is not likely to be useful in treating global hypoxia under these conditions.

A dog model to study ovary, ovarian ligament and visceral pain

OBJECTIVEnA dog model was developed to study visceral pain by stimulating the ovarian ligament.nnnSTUDY DESIGNnProspective experimental trial.nnnANIMALSnTwelve 1-year old female hound dogs weighing 25.7 ± 3.6 kg.nnnMETHODSnDogs were anesthetized with sevoflurane. The right ovary was accessed via laparoscopy. A suture was placed around the ovarian ligament and exteriorized through the abdominal wall for stimulation. The noxious stimulus consisted of pulling the ovary and ovarian ligament with a force transducer. The response to noxious stimulation was determined using the anesthetic minimum alveolar concentration requirement (MAC) for sevoflurane. The ovarian MAC was compared to the standardized somatic noxious stimulation tail clamp MAC. The results are depicted as mean ± SD and corrected to sea-level.nnnRESULTSnThe stimulus-response curve during ovarian stimulation in three dogs was hyperbolic and best represented by a three-parameter logistic growth curve model. The curve plateaued at 7.12 ± 4.19 N. From the stimulus-response curve, we chose 6.61 N to test the consistency and repeatability of the model in nine dogs. The ovarian stimulation MAC for sevoflurane in these dogs was 2.16 ± 0.46%. The ovarian stimulation confidence interval and limits are comparable to the results from tail stimulation MAC. The tail stimulation MACs before and after laparoscopy surgery were not different (1.86 ± 0.28% and 1.77 ± 0.38% respectively; p > 0.05) but lower when compared to the ovarian MAC (p < 0.01). The dogs recovered from anesthesia without complications.nnnCONCLUSIONS AND CLINICAL RELEVANCEnThe ovarian stimulation model is an adequate and repeatable means of producing visceral stimulation to determine MAC. The model may provide a humane mechanism to study the effectiveness of analgesics for acute ovarian pain.

Biomechanical comparison of glycomer 631 and glycomer 631 knotless for use in canine incisional gastropexy.

OBJECTIVEnTo compare the load to failure of incisional gastropexy performed with standard glycomer 631 (G) and with knotless glycomer 631 (GV) in ex vivo model of gastropexy.nnnSTUDY DESIGNnCadaveric study.nnnSAMPLE POPULATIONnCadaveric canine stomach and body wall (n = 24).nnnMETHODSnSpecimens were divided into 4 groups based on suture type (G, GV) and size (3 metric, 2 metric). An incisional gastropexy was performed on all samples, and load to failure evaluated.nnnRESULTSnGastropexy with GV had significantly higher load to failure than gastropexy performed with G (P = .0006). Suture size had no significant effect on maximum load to failure (P = .36). The interaction between size of the suture and suture materials had a significant effect on the load to failure of the gastropexy (P = .0474). Knotless glycomer 631, 3 metric had significantly greater load to failure than G 3 metric (P = .0016) and G 2 metric (P = .0107).nnnCONCLUSIONnA knotless suture appears to have comparable, if not greater load to failure than a standard suture of similar composition when used in canine incisional gastropexy in an acute ex vivo model.Objective nTo compare the load to failure of incisional gastropexy performed with standard glycomer 631 (G) and with knotless glycomer 631 (GV) in ex vivo model of gastropexy. n nStudy Design nCadaveric study. n nSample Population nCadaveric canine stomach and body wall (n = 24). n nMethods nSpecimens were divided into 4 groups based on suture type (G, GV) and size (3 metric, 2 metric). An incisional gastropexy was performed on all samples, and load to failure evaluated. n nResults nGastropexy with GV had significantly higher load to failure than gastropexy performed with G (P = .0006). Suture size had no significant effect on maximum load to failure (P = .36). The interaction between size of the suture and suture materials had a significant effect on the load to failure of the gastropexy (P = .0474). Knotless glycomer 631, 3 metric had significantly greater load to failure than G 3 metric (P = .0016) and G 2 metric (P = .0107). n nConclusion nA knotless suture appears to have comparable, if not greater load to failure than a standard suture of similar composition when used in canine incisional gastropexy in an acute ex vivo model.

Clinical management of flail chest in dogs and cats: A retrospective study of 24 cases (1989-1999)

Cases of flail chest injury for 24 client-owned companion animals following various traumas were evaluated. Concurrently sustained injuries, initial emergency treatments, and definitive treatment and outcome for regimens that utilize stabilization of the flail segment were compared with cases treated with no stabilization. Flail chest was confirmed in 24 animals: 21 dogs and three cats. There was an even division (12 each) of right and left flail segments. The median number of ribs involved was three (range, two to seven). Flail segment stabilization was performed in nine, and 15 were treated with no stabilization. Statistical analysis using multiple data permutations evaluating all combinations failed to reveal a significant difference in outcome between stabilized and unstabilized cases.

Closure of median sternotomy in dogs: suture versus wire.

Twenty normal, large-breed dogs underwent median sternotomy. Median sternotomies were closed with 20-gauge orthopedic wire in 10 dogs and no. 2 polybutester in 10 dogs. Closure with suture was faster than with wire (6.7 +/- 1.8 minutes versus 9.1 +/- 1.9 minutes, respectively). Significant differences were not observed in degree of postoperative pain or wound complication rates. Sternotomies closed with wire showed a trend to be more stable and had significantly less displacement on radiographic evaluation at 28 days. All sterna closed with wire examined histopathologically showed evidence of chondral or osteochondral bridging, while sterna closed with suture only showed fibrous union.