Ultrasonographic evaluation of renal autografts in normal cats

The purpose of this study was to determine changes in resistive index (RI) and renal size that occur in normal feline kidney autografts in the immediate post-transplant period. Qualitative changes in renal parenchymal echogenicity and pelvic dilation were also noted, although this was not a major focus of the study. Fourteen domestic short-haired cats underwent bilateral nephrectomies followed by an autograft of the right kidney to either the aorta or external iliac artery. Due to post-operative complications, only nine of these cats completed the study. Ultrasonographic determination of the RI and renal size was made before transplantation and on days 1, 4, 7, 10, and 13 following transplantation. No significant changes in renal RI were identified during the study. Renal size increased significantly, peaking at 63% above baseline on day 7, and stayed elevated at 50% above baseline on day 13. There was no evidence of rejection or other abnormalities found on histologic evaluation of the transplanted kidneys. It was concluded that the RI of normal feline renal autografts does not significantly change in the immediate post-operative period. However, significant renal enlargement, likely due to a combination of post-operative edema and hypertrophy, does occur. This study provides baseline information for comparison with feline allografts in the immediate post-transplant period.

A comparison of transdermal fentanyl versus epidural morphine for analgesia in dogs undergoing major orthopedic surgery

Postoperative analgesia provided by transdermal fentanyl was compared with that provided by epidural morphine in dogs undergoing major orthopedic surgery. Dogs randomly were assigned to receive either a 100 microg per hour transdermal fentanyl patch 24 hours prior to surgery (n=8) or epidural morphine (0.1 mg/kg body weight) administered following induction of anesthesia (n=10). Temperature, heart rate, respiratory rate, and pain score were recorded prior to surgery and zero, six, 18, 30, and 42 hours after surgery. Blood samples were collected from the dogs in the transdermal fentanyl group beginning 24 hours preoperatively to 42 hours postoperatively. Fentanyl concentrations were determined by radioimmunoassay. When all time periods after surgery were combined, dogs in the transdermal fentanyl group were experiencing significantly less pain after surgery than dogs given epidural morphine. The transdermal fentanyl provided analgesia after major orthopedic surgery greater than or equivalent to that of epidural morphine.

Limb salvage surgery for osteosarcoma of the proximal humerus: outcome in 17 dogs

OBJECTIVE

To describe function and identify factors that affect outcome in dogs undergoing limb salvage surgery for osteosarcoma (OS) of the proximal humerus.

STUDY DESIGN

A retrospective study of dogs in which OS of the proximal humerus was treated with limb salvage surgery.

ANIMALS

17 client-owned dogs.

METHODS

Records were analyzed for functional outcome, recurrence, metastasis, and survival.

RESULTS

Outcome was good to excellent in 12% of dogs. Recurrence, metastasis, and survival were significantly affected by completeness of surgical margins. Double plating of the distal allograft-host junction significantly reduced frequency of biomechanical failure.

CONCLUSIONS

Limb salvage surgery for OS of the proximal humerus did not result in acceptable function and was fraught with postoperative complications. Outcome was significantly affected by completeness of surgical margins.

CLINICAL RELEVANCE

Limb salvage surgery for OS of the proximal humerus in dogs cannot be recommended until improvement in functional outcome and reduction in postoperative complications can be achieved. The dependence of outcome on completeness of surgical margins supports aggressive en bloc resection and marking and evaluating surgical margins.

Clinical renal allograft transplantation in a Dalmatian dog: case report

A case of successful renal allograft transplantation performed in a two-year-old female Dalmatian dog suffering from end-stage chronic renal failure is reported. A one-year-old male German shepherd with severely injured spinal cord was used as kidney donor. Simultaneous kidney allograft transplantation combined with hypothermic initial perfusion as graft conservation was done, placing the donor kidney into the right iliac fossa of the recipient. The immunosuppression protocol consisted of prednisolone and azathioprine. Regular physical, laboratory, ultrasonographic and scintigraphic examinations were used for assessing both the morphology and the function of the allograft. After a two-week period of hospitalisation the patient was discharged in a remarkably improving condition. The recipient died on postoperative day 45 of respiratory insufficiency resulting from secondary pneumonia and pulmonary oedema. Neither macroscopic nor microscopic abnormalities of the allograft were revealed by necropsy.

Renal transplants in cats: 66 cases (1987-1996)

OBJECTIVE

To document the morbidity and survival time after renal transplants in cats with end-stage renal failure.

DESIGN

Retrospective case series.

ANIMALS

66 cats that had renal transplants.

PROCEDURE

Information regarding signalment, history, diagnostic testing, and postoperative morbidity and mortality was retrieved from medical records of cats with renal failure that had renal transplants at the University of California School of Veterinary Medicine between 1987 and 1996.

RESULTS

47 of 66 (71%) cats that had renal transplants survived until discharge. Nineteen cats died in the perioperative period. Most common causes of death were seizure-related complications (7 cats) and renal pedicle complications (4). One discharged cat was unavailable for follow-up monitoring. Of the 46 cats discharged and available for follow-up monitoring, 28 died. Most common causes of death in these cats were renal complications (9 cats) and death related to immunosuppression (8; mean and median survival times, 15 and 12 months, respectively). Of the 18 cats that were still living at the time this report was written, mean and median survival times were 26 and 22 months, respectively.

CLINICAL IMPLICATIONS

Renal transplantation resulted in long-term survival of many cats that would have otherwise died from, or have been euthanatized as a result of, renal failure. Problems with ureteral obstruction can be minimized. Postoperative CNS disorders were the most prevalent complication.

Use of full cortical allograft to repair a metatarsal fracture in a foal

A 4-month-old Quarter Horse colt was admitted for repair of an open, comminuted fracture of the proximal portions of the diaphyses of the left second, third, and fourth metatarsal bones. Initial repair included internal fixation and cancellous bone graft. However, the third metatarsal bone became infected and failed to heal. After removal of infected portions of the bone, a 5-cm, fullthickness cortical allograft was placed in the defect. Rigid internal fixation provided stability for the allograft and remaining fracture fragments so that the horse was able to bear weight on the second and fourth metatarsal bones. The allograft was ultimately resorbed; however, appositional bone growth permitted a massive, functional metatarsal bone to form that incorporated the second, third, and fourth metatarsal bones. The colt went on to compete successfully, long term, as a show horse.

Central nervous system disorders after renal transplantation in cats

OBJECTIVE

This study describes the incidence and severity of postoperative central nervous system (pCNS) disorders in feline renal transplant recipients.

STUDY DESIGN

A retrospective study based on the medical records of cats that received renal allografts from 1987 to 1996.

ANIMALS OR SAMPLE POPULATION

Fifty-seven client-owned cats received renal allografts for the treatment of renal failure.

METHODS

The frequency, duration, severity, and treatment of episodes of pCNS disorders were recorded from the medical records.

RESULTS

Twelve (21%) of 57 cats had pCNS disorders 1 hour to 5 days after the surgical procedure. Seven cats survived; four had single or multiple seizure episodes, and two had seizure episodes or disorientation followed by a period of coma. One cat became temporarily ataxic and blind after restraint for venipuncture. Five cats died; all had episodes of disorientation or seizures, or both, that progressed to a nonrecoverable comatose state, respiratory arrest or cardiac arrest, or both. There were no significant differences between the two groups in preoperative serum creatinine, blood urea nitrogen, or cholesterol levels, and intraoperative blood pressure measurements. There were no significant differences in the postoperative serum glucose levels, electrolytes levels, or osmolality between the two groups. The cats with pCNS disorders had a mean preoperative trough cyclosporine A (CyA) whole blood level of 429 ng/mL; cats without pCNS disorders had a significantly (P = .0116) higher mean preoperative trough CyA whole blood level of 736 ng/mL.

CONCLUSION

Central nervous system disorders are a common and often fatal complication of renal transplantation in cats.

CLINICAL RELEVANCE

Recognition of pCNS disorders, and possible causes, will help develop hypotheses to investigate the problem.

Cranioplasty after en bloc resection of calvarial chondroma rodens in two dogs

The clinical features of chondroma rodens in two dogs and the treatment using radiation therapy, en bloc resection of the tumours and cranioplasties with a bone allograft (case 1) and a polymethylmethacrylate implant (case 2) are described. The dogs were still alive with no local recurrence of the tumours 30 and 18 months, respectively, after surgery. En bloc resection and calvarial reconstruction in the treatment of chondroma rodens are discussed.

Fate of allogeneic skin transplantations in a marsupial (Monodelphis domestica)

Previously we reported that the South American gray short-tailed opossum, Monodelphis domestica, had an MHC class-I locus similar to that of eutherian species. In addition to the detection of lymphocyte antigens by cytotoxic antisera, we concluded that this marsupial rejected allogeneic skin grafts, as would be expected of animals with MHC class-I polymorphism. However, this conclusion was based on a limited number of skin transplants that were assayed for only a short period. Here we report the results of 22 reciprocal skin grafts made between individuals of known genetic relationships. On the basis of gross inspection of the grafts and histologic examination, we found that the average time of the onset of graft rejection was about 19 days and that the average time for complete graft rejection was about 31 days. In general, it took longer for the onset of graft rejection among pairs of genetically related animals than among less related animals. These results indicate unequivocally that this marsupial species has a high degree of class-I polymorphism and rejects allogeneic skin transplants in a manner similar to but more slowly than eutherian mammals.

Homologous testis transplantation in dogs

There is growing interest in the possible use of homologous testis transplantation for the treatment of anorchia and male infertility. In order to test the surgical and immunological feasibility of this therapy, three series of experimental studies of homologous testis transplantation were carried out in dogs. In the first pilot study, four beagles from the same litter were transplanted using microsurgical techniques for end-to-end anastomosis of the testicular vessels and the vas deferens. These dogs received cyclosporin A (CyA) for 3 months after transplantation. The longest functional graft survival in this series was 163 days, strongly suggesting that long-term survival of a homologously transplanted testis graft is possible. A second series of operations was performed on ten mongrel dogs. The same surgical technique was employed and the series was divided into three groups. Group 1 received CyA monotherapy, group 2 a combination of CyA and prednisolone, and group 3 received no immunosuppression. The average graft survival time in this series was 28 days, significantly less than the 71 days in the first series. The dogs in group 2, however, had graft survival times that were three times longer than those in the other two groups, suggesting that CyA in combination with prednisolone yields the best graft survival. In the third series, five littermates received a testis graft after castration. Immunosuppression was achieved by administration of CyA and prednisolone for 3 months. In three out of five animals, the graft survived until the immunosuppressive therapy was suspended. Histological biopsies of the graft 3 months after transplantation showed the same maturation of sperm cells as in the control testis of the same dog. The results of the last series suggest that long-term survival of homologously transplanted testis grafts in dogs is, indeed, possible with the aid of CyA and prednisolone.

Acceptance of skin grafts by isogenic rainbow trout (Oncorhynchus mykiss)

OBJECTIVE

To test the immunocompetence of isogenic families of rainbow trout by measuring their ability to accept or reject skin grafts.

ANIMALS

3 families of isogenic rainbow trout (Oncorhynchus mykiss), produced by mating homozygous females and homozygous males, plus 4 chinook salmon (O tshawytscha) were used in these experiments.

PROCEDURE

Grafts (allografts, members of the same family; autografts, donor and recipient were the same fish; and xenografts, O tshawytscha as donor) were exchanged. Grafts were applied on day 0 and removed on day 21, placed in neutral-buffered formalin, and embedded in paraffin. Lymphocytes and nuclei were counted in representative stained sections in the epidermis, dermis, and hypodermis. Results were analyzed by univariate analysis, using the Shapiro-Wilk statistic.

RESULTS

Autografts were retained and minimal histologic changes were apparent. Allografts were histologically similar to autografts. Xenografts were rejected.

CONCLUSIONS

Results indicate that the immune system of isogenic rainbow trout is unable to distinguish between family members within isogenic families, but that a vigorous response is mounted against chinook salmon xenografts. The isogenic rainbow trout are immunocompetent with respect to the phenomenon of graft rejection.

Allogeneic marrow transplantation in a cat with acute myeloid leukemia

A listless, anorectic 2-year-old cat was found to have a normocytic, nonregenerative anemia. A diagnosis of acute myeloid leukemia type M6Er was made. Because the cat was young, had negative FeLV and feline immunodeficiency virus test results, had a sibling that could be used as a bone marrow donor, had received only 1 transfusion, and was in good health other than being anemic, allogeneic bone marrow transplantation (BMT) was attempted using marrow from the cat's sibling. The most life-threatening complication following BMT was hemorrhage caused by severe thrombocytopenia. Complete hematopoietic engraftment was evident 36 days after BMT. The cat then was discharged to its owner. In the first year, the cat continued to improve with the exception of an intractable dermatophytosis, which resolved eventually. The cat continues to do well 4 years after BMT. To our knowledge, this represents the first report of successful allogeneic BMT for a cat with acute myeloid leukemia.

Canine deciduoma induced by intralumenal insertion of uterine grafts

This report deals with evaluation of histological characteristics of the canine deciduoma induced by insertion of the uterine grafts as a biological stimulus. Autografts induced severe uterine cystic endometrial hyperplasia, and the grafts were organized by maternal endometrium. On the other hand, allografts induced more severe hyperplasia of the uterine endometrium with stronger inflammation than autografts. Almost all allografts became necrotic and lytic in the uterine lumen. These results suggest that uterine grafts could induce deciduoma and that the maternal endometrium, though under the functional corpora lutea, recognized the uterine grafts to be a stimulant and showed severe cystic endometrial hyperplasia.

Uterine carcinomas in mother cats after intrafetal inoculation of allogeneic tumor cells (K248 C and P)

Three out of 13 queens that had undergone injection of tumor cells from an allogeneic feline mammary carcinoma cell line through the wall of the pregnant uterus developed a carcinoma of the uterus. The possible role of immune tolerance associated with pregnancy and/or major histocompatibility complex (MHC) compatibility is discussed.

Renal allograft survival in outbred mongrel dogs using rabbit anti-dog thymocyte serum in combination with immunosuppressive drug therapy with or without donor bone marrow

Therapeutic renal transplantation in dogs is currently being investigated as a treatment for endstage renal disease. This pilot study examines the effect of donor bone marrow (DBM) infusion and antithymocyte serum (ATS) in combination with immunosuppressive drug therapy in prolonging renal allograft survival in dogs. Seven normal outbred mongrel dogs received an unmatched renal allograft. All dogs received rabbit anti-dog thymocyte serum (RADTS), prednisone (Pr), cyclosporine-A (CsA) and azathioprine (Aza). In addition, three dogs (group 1 test) received DBM and four dogs (group 2 control) did not receive DBM. Serum CsA levels were measured throughout the study. Immunosuppressive therapy was gradually reduced with Pr, CsA, and Aza withdrawn at 200, 450, and 680 days, respectively. Allograft rejection was treated with prednisolone sodium succinate. One dog in group 1 and one in group 2 died as a result of infectious canine rhinotracheitis and rejection early in the study. Renal allograft torsion occurred in one group 1 dog. The remaining four dogs survived the 2 years of the study. The dogs in group 2 (three dogs) all rejected the renal allograft after total drug withdrawal, the surviving dog in group 1 did not. This study demonstrates that RADTS, Pr, CsA, and Aza in combination can prolong renal allograft survival in mongrel dogs, whereas DBM may enhance the unresponsive state.

Evaluation of canine cortical bone graft remodeling

A stable cortical bone fracture model was developed to evaluate the remodeling rate of cortical bone grafts. Samples of cortical bone were harvested with a trephine and press fit into predrilled holes in the femoral diaphyses of four live dogs. The percentages of new bone, unremodeled graft bone, porosity, forming bone surface area, and resorbing bone surface area were determined morphometrically and compared in cortical autografts, cortical allografts sterilized with 84% ethylene oxide (EO), and allografts sterilized with 12% EO. The host-graft interfaces healed without formation of fibrous tissue or cartilage, indicating a stable fracture surface. The amount of new bone formed in cortical autografts and allografts sterilized with 84% EO was significantly greater than the amount of new bone in allografts sterilized with 12% EO. There was no significant difference between the amounts of new bone formed in the allografts sterilized with 84% EO and the cortical autografts. No significant differences were detected in percentages of porosity or bone surface areas.

Incorporation of Fresh and Cryopreserved Bone in Osteochondral Autografts in the Horse

The structural integrity of subchondral bone in fresh and frozen osteochondral autografts was investigated at month 3 in 10 horses. Two osteochondral autografts were harvested from the lateral aspect of the lateral trochlear ridge of the left talus in each of 10 anesthetized horses. Grafts were frozen in 7.5% DMSO. After 14 days, the thawed grafts were press-fitted into drill holes in the trochlear ridges of the right stifles. A fresh graft from the right hock was implanted in each left stifle. To control for the effects of surgery, a fresh graft was transferred from the right stifle to the left stifle. The end result was two grafts in each femoropatellar joint. Fresh and frozen bone grafts maintained a structurally intact support for the cartilage surface. Graft stability and surface congruency were determining factors in the outcome of the grafts. Incorporation of both types of graft was complete at month 3, but remodeling of the fresh grafts was more active.

Epiglottic augmentation in the horse

Epiglottic augmentation with injectable bovine collagen or an autogenous or allogenous auricular cartilage graft was performed in 12 horses with endoscopically and radiographically normal epiglottises. The grafting procedures were easy to perform and did not cause apparent discomfort. Cartilage graft extrusion or resorption may have occurred, but was not seen by endoscopy and lateral laryngeal radiography. Only collagen implants remained evident endoscopically, as smooth round submucosal bulges ventral to the epiglottic cartilage. Two horses with collagen implants, and all horses with cartilage autografts and allografts, were euthanatized at week 16. One horse with a collagen implant was euthanatized at week 4 and one at week 6. The epiglottis appeared thickened in three horses with collagen implants, two horses with autogenous grafts, and three horses with allogenous grafts. Pharyngeal lymphoid tissue was hyperplastic in two horses with autografts and three horses with allografts, but not in horses with collagen implants. Collagen grafts persisted as one or two smooth bulges 8 mm in diameter. Collagen incited a brisk foreign body reaction that was surrounded by a fibrous connective tissue capsule. Epiglottises of the horses with collagen implants were significantly thicker 20 mm from the tip than those of normal horses and horses with allografts. Cartilage graft incorporation was not evident grossly and was seen on microscopic examination in only one autograft. Thickening was caused by submucosal fibrosis.

Long-term survival of a cat receiving a renal allograft from an unrelated donor

A 6-year-old, spayed female Persian cat in terminal renal failure was referred to the Veterinary Medical Teaching Hospital for renal transplantation. An allograft from an unrelated donor was placed in the right iliac fossa and cyclosporine and prednisolone were administered as immunosuppressive agents. More than 18 months after surgery the cat was clinically normal and azotemia was absent.

Evaluation of full cortical allografts in 25 dogs

Twenty-five dogs received 26 cortical allografts from Apr 9, 1976 through Jan 31, 1982. Cortical allografts were used to reconstruct fractures of the femur, humerus, tibia, radius, and ulna. These grafts were used to replace comminuted fragments; to lengthen bones; to correct malunions, delayed unions, and nonunions; and in one case, to replace bone lost to sequestrum formation in an infected fracture site. All fractures were stabilized by use of standard ASIF techniques and dynamic compression plates. Frozen bone allografts were used in all cases. These were harvested aseptically and stored in a household freezer for 3 days to one year before use. Clinically normal function was achieved in 96% of the dogs.

Feline model for the study of frozen osteoarticular hemijoint transplantation: qualitative and quantitative assessment of bone healing

Twenty-four outbred cats underwent massive osteoarticular allograft and control autograft transplantation, using the right distal femur with its articular cartilage, capsule, and medial collateral ligament intact. The cats were monitored clinically and radiographically for 1 year. Groups of cats (4 allografts and 2 control autografts) were euthanatized at 3-, 6-, 9-, and 12-month intervals. At necropsy, the grafts were photographed and assessed for bone healing and replacement by standard radiography, quantitative 99mTc bone scans, microradiography, and histologic examination of decalcified and nondecalcified specimens. The osteosynthesis site of the allografts usually healed by 5 months, compared with the autografts that healed by 3 months. As illustrated by quantitative bone scans, creeping appositional new bone slowly invaded and replaced the allograft bone. Seemingly, the cat can be used as an acceptable and clinically comparable model for the massive osteoarticular allografts currently being used for the reconstruction of joints damaged or destroyed by neoplasm surgery in limb-sparing procedures in human beings. This model may also be used to assess the rate and method of bone healing.

Preliminary study of ethylene oxide sterilization of full-thickness cortical allografts used in segmental femoral fracture repair

Full-thickness canine cortical allografts were cleanly harvested, sterilized with ethylene oxide, and stored at room temperature. The allografts were incorporated into canine segmental femoral fracture repairs and compared clinically, radiographically, and morphologically with control femoral cortical autografts for function of the limb, graft acceptance, and bone union. Sterility was maintained and the cortical allografts were well accepted by the host animals, resulting in full use of the limb which was subjected to surgical operation. The allografts showed healing patterns similar to those of the autografts, as determined by radiographic, gross, and histologic evaluation of the proximal and distal host-graft interfaces. Evaluations were made monthly. The host-graft interfaces of the allografts and autograft were filled with woven bone with adjacent vascular invasion and remodeling of the graft at the final 4th-month evaluation.