Matan Or

Pedicle digital pad transfer and negative pressure wound therapy for reconstruction of the weight-bearing surface after complete digital loss in a dog

A young Labrador Retriever was presented for treatment of severe distal hindlimb necrosis caused by bandage ischemia. During digit amputation at the metatarsophalangeal joints, the third and fourth digital pads were salvaged and transferred to the metatarsal stump to create a weight-bearing surface. Negative pressure wound therapy (NPWT) was utilized for flap immobilization and to promote granulation tissue in the remaining wound defect. Sturdy adherence of the digital pads was achieved after only four days. The skin defect healed completely by second intention and the stump was epithelialized with a thin pad after three months. At the nine month follow-up examination, the stump had a thick hyperkeratinized pad. The dog walked and ran without any apparent signs of discomfort and compensated for the loss of limb length by extending the stifle and tarsocrural joints. Despite a challenging wound in a difficult anatomical location, digital pad flap transfer and NPWT proved successful in restoring long-term ambulation in an active large breed dog.

Regional cerebral blood flow assessed by single photon emission computed tomography (SPECT) in dogs with congenital portosystemic shunt and hepatic encephalopathy

Regional cerebral blood flow (rCBF) in eight dogs with congenital portosystemic shunt (PSS) and hepatic encephalopathy (HE) was compared with rCBF in eight healthy control dogs using single photon emission computed tomography (SPECT) with a 99mtechnetium-hexamethylpropylene amine oxime (99mTc-HMPAO) tracer. SPECT scans were abnormal in all PSS dogs. Compared to the control group, rCBF in PSS dogs was significantly decreased in the temporal lobes and increased in the subcortical (thalamic and striatal) area. Brain perfusion imaging alterations observed in the dogs with PSS and HE are similar to those in human patients with HE. These findings suggest that dogs with HE and PSS have altered perfusion of mainly the subcortical and the temporal regions of the brain.

Determination of Porto-Azygos Shunt Anatomy in Dogs by Computed Tomography Angiography

OBJECTIVE To describe the morphology of porto-azygos shunts in a large series of dogs using computed tomography (CT) angiography. STUDY DESIGN Retrospective study. ANIMALS Dogs (n=36) with porto-azygos shunts. METHODS CT angiography was performed in dogs subsequently proven to have a porto-azygos shunt. The origin and insertion of the shunts were assessed on native images. The diameter of the porto-azygos shunt and the portal vein, cranial and caudal to the shunt origin, were measured. The porto-azygos shunt anatomy was studied on three-dimensional images. RESULTS All porto-azygos shunts originated either in the left gastric vein (33 left gastro-azygos shunts) or the right gastric vein (3 right gastro-azygos shunts). Two left gastro-azygos shunts had concurrent caval-azygos continuation and 2 right gastro-azygos shunts had a caudal splenic loop. All shunts crossed the diaphragm through the esophageal hiatus. The majority of porto-azygos shunts (32) followed a straight pathway after traversing the diaphragm, although 4 shunts followed a tortuous route. All shunts terminated in the thoracic part of the azygos vein, perpendicular to the aorta. The shunt diameter at insertion was only 3 mm on average. The insertion site was consistently the narrowest part of the shunt. CONCLUSION CT angiography was well suited to provide anatomic details of porto-azygos shunts and comprehensively documented that all porto-azygos shunts had a thoracic terminus, after crossing the diaphragm through the esophageal hiatus. Different shunt types existed with minor variations.

Negative pressure wound therapy using polyvinyl alcohol foam to bolster full-thickness mesh skin grafts in dogs

Objective: To report the use of negative pressure wound therapy (NPWT) with polyvinyl alcohol (PVA) foam to bolster full‐thickness mesh skin grafts in dogs. Study Design: Retrospective case series. Animals: Client‐owned dogs (n = 8). Material and Methods: Full‐thickness mesh skin graft was directly covered with PVA foam. NPWT was maintained for 5 days (in 1 or 2 cycles). Grafts were evaluated on days 2, 5, 10, 15, and 30 for graft appearance and graft take, granulation tissue formation, and complications. Results: Firm attachment of the graft to the recipient bed was accomplished in 7 dogs with granulation tissue quickly filling the mesh holes, and graft take considered excellent. One dog had bandage complications after cessation of the NPWT, causing partial graft loss. The PVA foam did not adhere to the graft or damage the surrounding skin. Conclusion: The application of NPWT with a PVA foam after full‐thickness mesh skin grafting in dogs provides an effective method for securing skin grafts, with good graft acceptance. PVA foam can be used as a primary dressing for skin grafts, obviating the need for other interposing materials to protect the graft and the surrounding skin.

Comparison of a 5-mm and 10-mm vessel sealing device in an open ovariectomy model in dogs

The objectives of this study were to compare (1) the extent of thermal damage and (2) the time between the 5-mm LigaSure V (LS5) and 10-mm LigaSure Atlas (LS10) vessel sealing devices (VSD) when performing open ovariectomy in dogs. A prospective, randomised, clinical trial was performed in 40 client-owned sexually entire female dogs. In each dog, one ovary was randomly assigned to be surgically removed using LS5 and the contralateral using LS10. The depth of thermal spread, measured on histopathological preparations, was significantly larger for LS10 (LS10 1.35±0.23 mm v LS5 0.82±0.10 mm; P<0.001). Mean ovariectomy time was significantly faster when using LS10 (LS5 2.58±1.32 minutes v LS10 2.07±1.27 minutes; P=0.008). Bodyweight was positively correlated with the time required for ovariectomy using LS5 (P=0.004), but no such correlation was present for LS10 (P=0.611). In conclusion, during open ovariectomy using VSD, LS10 causes significantly more thermal spread but surgical time is shorter compared with LS5. When using LS5, the ovariectomy time increases with increasing bodyweight.

Transdiaphragmatic pericardiectomy in dogs

In patients with recurrent pericardial effusions, pericardiectomy is indicated. The purpose of this study was to describe a transdiaphragmatic approach for subtotal pericardiectomy in dogs and to evaluate its feasibility. In total, 20 canine cadavers weighing less than 10 kg (group S) and 20 weighing more than 20 kg (group L) were used. Within each group, half underwent a subphrenic pericardiectomy via an intercostal approach and half via a transdiaphragmatic approach. For each approach and within each weight group, the percentage of resected pericardium was calculated and compared. Additionally, a case series of nine consecutive client-owned dogs that underwent a transdiaphragmatic pericardiectomy for pericardial effusion was reported. Exposure of pericardium and associated phrenic nerves was excellent in cadavers and clinical patients. In group S, the percentage of resected pericardium was not significantly different between the two approaches. In group L, on the other hand, the percentage of resected pericardium was lower with the transdiaphragmatic approach compared with the intercostal approach (P=0.001). In the clinical patients, no intraoperative complications were encountered and no recurrence of pericardial effusion was seen. Subtotal pericardiectomy via a transdiaphragmatic approach is straightforward and a safe surgical procedure to obtain permanent pericardial drainage in small and large breed dogs.

Transdiaphragmatic Approach to Attenuate Porto‐Azygos Shunts Inserting in the Thorax

OBJECTIVE To describe the surgical technique and document the application of a transdiaphragmatic approach to attenuate porto-azygos shunts inserting in the thoracic section of the azygos vein. STUDY DESIGN Cadaveric study and prospective case series. ANIMALS Canine cadavers (n=6) and client-owned dogs with porto-azygos shunts inserting in the thoracic section of the azygos vein (n=9). METHODS In the cadavers, the azygos vein was filled with aqueous latex. Landmarks were established for creating a safe transdiaphragmatic approach to the caudal intrathoracic portion of the azygos vein. In the clinical cases, porto-azygos communication was diagnosed by trans-splenic portal scintigraphy. All shunts were attenuated close to their insertion site via ventral midline celiotomy and a transdiaphragmatic approach to the shunt. Perioperative complications were recorded. RESULTS A 3-5 cm incision, 0.5-1 cm ventral and lateral to the level of the aortic hiatus, was made in the pars lumbalis part of the diaphragm. Stay sutures at both sides of the diaphragmatic incision were placed to open up the incision and a retractor was used to push the esophagus away from the aorta. Intrathoracic insertion of the shunt was confirmed intraoperative. Exposure of the shunt insertion site at the azygos vein was excellent in all clinical cases. No intraoperative or postoperative complications were encountered. CONCLUSION If thoracic attenuation of a porto-azygos shunt is considered, a transdiaphragmatic approach exposes the insertion site for shunt attenuation. This approach is straightforward, without unnecessary abdominal organ manipulation, and since attenuates at the insertion, avoids missing additional contributing branches.

Biomechanical properties of celiotomy wounds closed with tape and cyanoacrylate versus intradermal sutures

OBJECTIVE To compare cutaneous wound closure with mesh and 2-octyl cyanoacrylate (MOC) vs an intradermal suture pattern (ISP) in terms of time of application and biomechanical properties. SAMPLE POPULATION Experimental study with 12 female beagle dogs. METHODS A skin incision was created from the xiphoid to the pubis as part of an ovariohysterectomy; the linea alba and subcutaneous tissue were closed routinely. Half of the skin incision was closed with MOC, and the other half was closed with an ISP. Tissue samples were collected from both sections at days 14 and 28 and tested for ultimate strength and stiffness. RESULTS Closure with MOC (72.8 ± 14.0 s) was faster than with an ISP (398.4 ± 36.4 s; P = .001). The ultimate load and stiffness increased with time for MOC (P = .005 and P = .005, respectively) and ISP (P < .001 and P < .001, respectively). On day 14, ultimate load and stiffness were greater in wounds closed with MOC compared with ISP (P = .014 and P = .02, respectively). No difference between groups was detected at day 28. CONCLUSION Cutaneous wound closure with MOC was faster and resulted in superior strength at 14 days compared with closure with an ISP in this healthy population. CLINICAL SIGNIFICANCE Mesh and 2-octyl cyanoacrylate offers an attractive alternative to ISP for skin closure after celiotomy in dogs, especially if surgical/anesthesia time is a concern.

Inaccuracy of serum bile acids to predict closure after surgical attenuation of a portosystemic shunt

A four-month-old entire female miniature schnauzer became clinically normal after surgical attenuation of a portosystemic shunt was conducted using thin film banding. Postoperatively, preprandial and postprandial serum bile acids were within normal limits at repeated occasions. On the contrary, trans-splenic portal scintigraphy at 3 and at 28 months postoperatively showed a shunt fraction of 7 and 89 per cent, respectively. This case report illustrates that preprandial and postprandial serum bile acids are not always reliable in determining shunt closure after surgical attenuation.

Ammonia concentrations in arterial blood, venous blood, and cerebrospinal fluid of dogs with and without congenital extrahepatic portosystemic shunts

OBJECTIVE To compare ammonia concentrations in arterial blood, venous blood, and CSF samples of dogs with and without extrahepatic portosystemic shunts (EHPSS). ANIMALS 19 dogs with congenital EHPSS and 6 healthy control dogs. PROCEDURES All dogs underwent a physical examination and then were anesthetized for transsplenic portal scintigraphy to confirm the presence or absence of EHPSS. While dogs were anesthetized, arterial and venous blood samples and a CSF sample were simultaneously collected for determination of ammonia concentration, which was measured by use of a portable blood ammonia analyzer (device A) and a nonportable biochemical analyzer (device B). Results were compared between dogs with EHPSS and control dogs. RESULTS Arterial, venous, and CSF ammonia concentrations for dogs with EHPSS were significantly greater than those for control dogs. For dogs with EHPSS, ammonia concentrations in both arterial and venous blood samples were markedly increased from the reference range. There was a strong positive correlation between arterial and venous ammonia concentrations and between blood (arterial or venous) and CSF ammonia concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that blood and CSF ammonia concentrations in dogs with EHPSS were greater than those for healthy dogs and were strongly and positively correlated, albeit in a nonlinear manner. This suggested that the permeability of the blood-brain barrier to ammonia may be abnormally increased in dogs with EHPSS, but further investigation of the relationship between blood or CSF ammonia concentration and clinical signs of hepatic encephalopathy or the surgical outcome for dogs with EHPSS is warranted.