Surgical approaches to recipient vessels of the head and neck for microvascular free tissue transfer in dogs

Effects of different subcutaneous sites on heterotopic autotransplantation of canine ovarian tissue

Ovarian tissue transplantation makes it possible to restore fertility; however, the success of this technique depends on the transplant region used. Therefore, this study aimed to evaluate the effect of two subcutaneous regions on canine ovarian transplantation, pinna (Pi) and neck (Ne), for 7 and 15 days. Ovaries collected by ovariosalpingohysterectomy were fragmented using a punch device. Fresh fragments were fixed, and the others were immediately grafted onto the animal itself in the Pi and Ne regions for 7 and 15 days. Recovered fragments were evaluated for histology (morphology, development and stromal density), picrosirius (collagen fibers), and immunohistochemistry (fibrosis and cell proliferation). The results showed that follicular normality rates were lower in Pi-7 (78%) vs. control (90%) and Pi-15 (86%), similar in Ne-7 (92%) and superior in Ne-15 (97%) compared to the control, with the effect of the region Ne (94%) superior (P < 0.05) to Pi (82%). Stromal density reduced in both regions vs. control but was similar within 15 days. Fragments from both regions showed higher fibronectin labeling and deposition of type I and lower type III collagen fibers (P < 0.05) vs. control. Proliferation rates in Ne-7 were higher (P < 0.05) than in control, and Pi-15 was higher (P < 0.05) than Ne-15. In conclusion, the pinna may be a region with greater potential than the neck after a 15-day autotransplantation of canine ovarian tissue.

Locoregional Flap Reconstruction Following Oromaxillofacial Oncologic Surgery in Dogs and Cats: A Review and Decisional Algorithm

Primary treatment of most oromaxillofacial tumors in dogs and cats is resective surgery. Management of malignant tumors may be very challenging as wide/radical free-margin surgical removal must be achieved while preserving vital functions. Removal of orofacial tumors may result in large defects exposing the oral cavity or creating a communication with the nasal, pharyngeal, or orbital cavities. Such defects require orofacial reconstruction in order to restore respiratory and manducatory functions. The veterinary surgeon must be familiar with reconstructive techniques in order to prevent the inability of closing the defect, which could lead to an insufficient resection. Small oral defects exposing the nasal cavity are best closed with local random mucosal flaps. Closure of large oral defects may be better achieved with a facial or major palatine-based axial-pattern flap. Small to moderate facial defects can be closed with local advancement or transposition skin flaps. Reconstruction of large facial defects often requires the use of locoregional axial pattern flaps such as the caudal auricular, the superficial temporal, or the facial (angularis oris) myocutaneous axial pattern flaps. Recent publications have shown that the facial (angularis oris) flap is a very versatile and reliable flap in orofacial reconstructive surgery. A surgical decision algorithm based on the size, nature, and location of the defect is proposed.

Ex vivo evaluation of the effect of various surgical procedures on blood delivery to the patellar tendon of dogs

OBJECTIVE To determine the effect of arthrotomy alone or in combination with osteotomy of the proximal portion of the tibia on blood delivery to the patellar tendon of dogs. SAMPLE 24 canine cadavers. PROCEDURES One hind limb from each cadaver was assigned to 1 of 4 treatment groups: medial arthrotomy (MA; MA group), lateral arthrotomy (LA; LA group), MA and LA with tibial tuberosity transposition (MALA group), and MA with tibial plateau leveling osteotomy (TPLO; TPLO group). The contralateral hind limb served as the control sample. Contrast solution (barium [33%], India ink [17%], and saline [0.9% NaCl] solution [50%]) was injected through an 8F catheter inserted in the caudal portion of the abdominal aorta. Limbs were radiographed to allow examination of vascular filling. The patella, patellar tendon, and tibial crest were harvested, radiographed to allow examination of tissue vascular filling, and fixed in 4% paraformaldehyde. Vessels perfused with contrast solution were counted in sections obtained from the proximal, middle, and distal regions of each patellar tendon. RESULTS Vessel counts did not differ significantly among the 3 tendon regions. Compared with results for the control group, delivery of contrast solution to the patellar tendon was significantly decreased in the MALA and TPLO groups but was not changed in the MA or LA groups. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that surgical procedures used to treat cranial cruciate injuries (ie, TPLO) and patellar luxation decreased blood delivery to the patellar tendon of canine cadavers, at least acutely.

Rectus Abdominis Free Muscle Flap for Reconstruction in Nine Dogs

OBJECTIVE

To evaluate the clinical use and outcome of a rectus abdominis microvascular free flap for wound closure in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n=9) with complex extremity or oral wounds.

METHODS

Medical records (2002-2006) of dogs that had a rectus abdominis free tissue transfer to close an extremity or oral wound were reviewed.

RESULTS

Nine dogs were identified: 5 had distal extremity wounds, 3 had oral palatal defects, and 1 had a large hygroma excised. A rectus abdominis free tissue transfer with a caudal epigastric vascular pedicle was successfully used for management of these wounds. No major complications occurred with the donor site and a good cosmetic and functional outcome occurred in all dogs.

CONCLUSION

The rectus abdominis is a versatile muscle that can be used for reconstructing cutaneous and oral defects with repeatable success.

CLINICAL RELEVANCE

Free tissue transfer of the rectus abdominis muscle is a clinically useful technique for closure of a variety of difficult soft tissue wounds.

Surgical Approaches to Recipient Vessels of the Fore- and HindLimbs for Microvascular Free Tissue Transfer in Dogs

OBJECTIVE

To develop and evaluate surgical approaches to the arteries and veins of the fore- and hindlimbs for use as potential recipient vessels for free tissue transfer.

STUDY DESIGN

Experimental anatomic study.

SAMPLE POPULATION

Canine cadavers (11): 2 preserved and 9 fresh cadavers.

METHODS

Fore- and hindlimbs from 1 preserved cadaver injected with a pigmented silicone/barium mixture, through the common carotid artery and external jugular vein, were cut in 1 cm cross-sections. Tissue sections were used to identify the location of vessels >1 mm that could be used as recipient vessels for free tissue transfer. The other preserved cadaver was used to develop surgical approaches to these vessels. Three surgeons evaluated the written descriptions and illustrations for these approaches using fresh cadavers. Modifications to the surgical approaches were made based on recommendations from these surgeons.

RESULTS

Six approaches were developed to isolate forelimb recipient vessels: palmar access, distal medial antebrachial, mid-antebrachial, proximal antebrachial, distal humeral, and mid-humeral vascular access. Twelve approaches were developed to isolate recipient vessels of the hindlimb: plantar access, dorsal tarsal, cranial distal tibial, craniomedial distal tibial, lateral distal tibial, medial distal tibial, medial femorotibial, lateral distal femoral, medial femoral, proximal medial femoral, groin, and proximal lateral femoral vascular access.

CONCLUSIONS

Six forelimb and 12 hindlimb sites were identified for surgical access to recipient vessels (>1 mm diameter) suitable for use in free tissue transfer for wound reconstruction.

CLINICAL RELEVANCE

For reconstruction of complex wounds of the extremities of dogs, surgeons should consider use of readily accessible recipient vessels that would allow for free tissue transfer to the fore- and hindlimbs.