Daniel A. Degner

Hilar liver resection in dogs.

OBJECTIVE To describe hepatic vasculobiliary anatomy important to hilar liver lobe resection in the dog. STUDY DESIGN Experimental study. ANIMALS Canine cadavers (n=7). METHODS The vasculobiliary system of 7 fresh canine livers was injected with a polymer. The parenchyma was dissected at the level of the hilus to determine the vascular and biliary supply to each liver lobe, and then macerated with a corrosion preparation. The information gathered was used to describe a surgical approach for hilar liver lobe resection. RESULTS Each liver lobe had a single hepatic artery and biliary duct. The location of these structures was consistent, although minor variations existed (dorsal versus ventral to the lobar portal vein) in the left lateral lobe and papillary process in 2 specimens. Most liver lobes (34/49) were supplied by 1 lobar portal vein and drained by 1 lobar hepatic vein (39/49). The location of the portal and hepatic veins was consistent among specimens. CONCLUSIONS The left division is the most mobile of the liver lobes and each lobe can be removed separately or en bloc. Because of the location of the hepatic veins, the central division is best removed as a single unit. The right lateral lobe can be removed individually or together with the caudate process. The papillary process is removed by itself. CLINICAL RELEVANCE A hilar liver lobectomy technique can provide an alternative approach to conventional procedures for tumors that encroach upon the hilus of the liver.

Vascularized Ulnar Bone Grafts for Limb-Sparing Surgery for the Treatment of Distal Radial Osteosarcoma

The objective of this retrospective study was to compare vascularized free or roll-in ulnar bone grafts for limb-sparing surgery in dogs with radial osteosarcoma with the cortical allograft, metal endoprosthesis, or distraction osteogenesis techniques. Overall, the ulnar graft techniques used in this study demonstrated excellent healing properties. Complications included recurrence of the tumor in 25% (2/8) of the dogs, metastasis in 50% (4/8) of the dogs, implant loosening in 37.5% (3/8) of the dogs, implant failure in 12.5% (1/8) of the dogs, and infection in 62.5% (5/8) of the dogs. Mean survival time was 29.3 mo (range, 9 to 61 mo). The mean metastasis-free interval was 33.67 mo (range, 8 to 54 mo). Tumors recurred locally in two dogs at 10 mo and 20 mo postoperatively. This study yielded similar long-term complications as other limb-sparing options (such as cortical allografts and metal endoprostheses) and allowed dogs to bear weight on the operated limb with acceptable limb function. More research is needed regarding specific healing times for ulnar vascularized grafts, time until implant removal, and the extent of radial bone that could ultimately be replaced by the ulna.

Cutaneopulmonary Fistula in a Dog Caused by Migration of a Toothpick

A 6-year-old, neutered male, mixed-breed dog was presented for a chronic draining tract and cough. A contrast fistulogram demonstrated a cutaneopulmonary fistula. Excision of the fistulous tract retrieved a migrating foreign body (i.e., a toothpick) within the tract. Clinical signs resolved 2 weeks following surgery. Foreign body migration is a common problem seen in dogs, resulting in many different clinical syndromes. Definitive surgery depends upon complete removal of the foreign body and the diseased tissue. Sinography is an inexpensive, readily available diagnostic tool that can help define a draining tract and confirm a foreign body.

Histomorphometric Analysis and Regional Variations of Full Thickness Skin Grafts in Dogs

OBJECTIVE To (1) compare thickness of the epidermis and dermis of anatomically different donor sites in dogs, and (2) evaluate hair follicle damage during full thickness skin grafts (FTSG) preparation from anatomically different donor sites. Another objective was to compare the extent of agreement between gross and histologic quality of graft preparation. STUDY DESIGN Ex vivo study. ANIMALS Healthy Beagle dogs (n = 12). METHODS Skin samples were harvested from fresh cadavers free of gross dermatopathology and FTSG prepared. Regional, epidermal and dermal thickness, and hair follicle density in intact skin and FTSG specimens from different regions were determined by histomorphometric analysis. Hair follicle density in intact skin and FTSG specimens, and skin thickness measurements were compared among regions. RESULTS Mean epidermis and dermis thickness of the dorsal lumbar and lateral neck regions were significantly greater when compared with other sites. Total hair follicle (superficial and deep dermis) densities were significantly less in prepared FTSG versus intact skin specimens. The dorsal lumbar region had the highest hair follicle density. CONCLUSIONS Thickness of the epidermis and dermis is dependent on body region. Hair follicle density in the FTSG specimens was decreased compared with intact skin specimens, which may affect hair regrowth in FTSG.