Case Description—Two 6-year-old male dogs were evaluated for removal of midline occipito-temporal multilobular osteochondrosarcomas.
Clinical Findings—Physical examination revealed mild ataxia in 1 dog and large masses of the central occipitotemporal portion of the skull in both dogs. Computed tomography, magnetic resonance imaging (MRI), or both revealed large bone-origin occipitotemporal masses with impingement of the brain and the sagittal and transverse venous sinuses. Three-dimensional contrast magnetic resonance image reconstruction delineated collateral venous circulation around the tumor and venous sinus occlusion in 1 dog.
Treatment and Outcome—Tumors in both dogs were surgically removed and the skull defects repaired with polymethyl methacrylate prostheses. Twenty-four hours after surgery, 1 dog had normal mentation, cranial nerve function, and conscious proprioceptive responses, whereas the other dog had depressed mentation but no neurologic deficits. Both dogs were discharged 4 days after surgery with normal mentation and no neurologic deficits.
Clinical Relevance—Findings suggested that MRI and computed tomography can play a key role in assessment of essential cortical collateral circulation when surgical removal of tumors is likely to result in bilateral disruption of transverse venous sinuses. Without robust collateral circulation and proper preoperative planning, removal of massive skull tumors in the midline occipitotemporal region will likely result in substantial morbidity or death. However, results in the 2 dogs reported here indicate the feasibility of removing such tumors with good outcomes in the presence of well-developed collateral venous drainage.
A 6-year-old neutered male mixed-breed dog (dog 1) and 5-year-old neutered male Boston Terrier (dog 2) were evaluated because of lateralized multilobular osteochondrosarcoma (MLO) of the occiput.
Diagnostic imaging revealed proliferative bony occipital masses in both dogs and a nodule in the right caudal lung lobe of dog 1. For both dogs, MRI revealed intact flow through the dorsal sagittal sinus (DSS) into 1 transverse sinus.
TREATMENT AND OUTCOME
In dog 1, a 4F balloon catheter was introduced into the DSS to the confluens sinuum (CS) and inflated over 16 hours to occlude venous flow. The mass with the CS was removed 24 hours later, and the skull was reconstructed. The dog was discharged from the hospital 2 days after surgery and survived 17 months before euthanasia because of metastasis. In dog 2, balloon catheter insertion into the DSS failed, and a 3.5F rubber catheter was placed up to the CS to occlude flow. The occiput with MLO was removed 48 hours after catheterization, and the skull was reconstructed. Dog 2 was discharged from the hospital after 3 days and was doing well 15 months later.
Findings for these 2 dogs suggested that deliberate preoperative occlusion of the DSS and CS allows successful resection of occipital neoplasms across the midline. Without prior occlusion of the DSS, development of lethal cerebral edema would have been likely. Gradual balloon catheter occlusion of the CS may facilitate challenging occipital mass excisions.
Objective—To evaluate the effect of the duration of cold Ischemia on the renin-angiotensin system during renal transplantation In cats and to define the potential Influence of vasoactive factors in renal tissue following cold ischemic storage versus warm ischemic storage
Procedures—10 cats underwent renal autotransplantation after 30 minutes (n = 5) or 3 hours (5) of simple, ex vivo cold storage of renal autographs. Following autograft reperfusion, direct hemodynamic variables were measured with a telemetric Implant and samples were collected for plasma renin concentration. Activation of vascular-related genes (renin, endothelin, and angiotensin converting enzyme) relative to 2-hour simple cold or warm ischemia was also evaluated.
Results—No significant difference between groups was detected In any of the hemodynamic variables or postreperfusion plasma renin concentrations measured in this study relative to the duration of cold ischemic storage. There was also no difference between warm- and cold-stored kidneys in the expression of vascular-related genes
Conclusions and Clinical Relevance—Prolonged renal Ischemia for clinically relevant durations does not appear to predispose clinically normal cats to altered hemodynamics or high plasma renin concentrations following graft reperfusion. Activation of vasoactive genes does not appear to be Influenced by type of Ischemia over 2 hours. (Am J Vet Res 2010;71:1220-1227)
Objective—To evaluate efficacy and cost of using
cyclosporine and ketoconazole for the treatment of
perianal fistulas in dogs.
Animals—12 dogs with perianal fistulas.
Procedure—Dogs received cyclosporine and ketoconazole
orally (target whole blood trough
cyclosporine concentrations of 400 to 600 ng/ml).
Study endpoints were resolution of clinical signs,
remission, and recurrence of disease. Adverse
effects and cost of medications were reported.
Results were compared with those from previous
studies in humans and in dogs in which single agent
cyclosporine treatment for perianal fistulas was used.
Results—All dogs had resolution of clinical signs.
Eight dogs went into remission; however, 5 of those
8 had recurrence of fistulas. Adverse effects of
treatment were minimal and well tolerated. Cost of
treatment was comparable to traditional surgical
options and less than single agent cyclosporine
Conclusions and Clinical Relevance—Administration
of cyclosporine with ketoconazole is an effective
and cost-comparable treatment for perianal fistulas
in dogs. (J Am Vet Med Assoc 2002;220:1009–1016)
Objective—To evaluate the effect of renal autograft ischemia and reperfusion associated with renal transplantation on pulse rate and pressure and arterial blood pressure variables in clinically normal cats.
Procedures—A radiotelemetric implant was placed in each cat to measure hemodynamic variables; baseline data were recorded before surgery. Standard heterotopic renal implantation and contralateral nephrectomy were performed (day 0). Autografts were stored in cold sucrose phosphate solution for 30 minutes (n = 5) or 3 hours (5); cats were anephric during this period. Hemodynamic variables were recorded every 5 minutes for up to 16 days after surgery; mean daily values were calculated.
Results—Data from 6 cats were available for analysis. Two cats developed ureteral obstructions and became azotemic at 111 and 197 hours after kidney reperfusion. Mean serum creatinine and BUN concentrations were greater than baseline values on days 1 and 2. Although changes from baseline hemodynamic values were detected in some cats, arterial blood pressure measurements did not change significantly from baseline at any time point. Compared with baseline data, mean pulse rate was increased on days 1 and 2 and days 6 through 12; mean pulse pressure was increased on days 1 and 2.
Conclusions and Clinical Relevance—In clinically normal cats, hypertension was not induced by clinically relevant periods of ischemia-reperfusion injury of renal autografts and was not an inherent consequence of the transplantation process. Causes of marked posttransplantation hypertension in cats with chronic kidney disease require further investigation.
OBJECTIVE To assess the effect of cold storage (CS) on immediate posttransplantation function of renal autografts in cats.
ANIMALS 15 healthy 1-year-old cats.
PROCEDURES Cats were assigned to 2 groups and underwent autotransplantation of the left kidney followed by nephrectomy of the right kidney. The left kidney was autotransplanted either immediately (IT group; n = 6) or after being flushed with a cold sucrose phosphate solution and stored on ice while the implant site was prepared (CS group; 9). Serum creatinine and BUN concentrations were monitored daily and autografts were ultrasonographically examined intermittently for 14 days after surgery.
RESULTS Mean duration of CS was 24 minutes for the CS group. Posttransplantation serum creatinine and BUN concentrations for the CS group had lower peak values, returned to the respective reference ranges quicker, and were generally significantly lower than those for the IT group. Mean posttransplantation autograft size for the CS group was smaller than that for the IT group.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that immediate posttransplantation function of renal autografts following a short period of CS was better than that of renal autografts that did not undergo CS, which suggested CS protected grafts from ischemic injury and may decrease perioperative complications, speed recovery, and improve the long-term outcome for cats with renal transplants.
IMPACT FOR HUMAN MEDICINE Cats metabolize immunosuppressive drugs in a manner similar to humans; therefore, renal transplantation in cats may serve as a desirable model for investigating the effects of renal transplantation in human patients.
Objective—To compare long-term results of radiotherapy
alone versus radiotherapy followed by exenteration
of the nasal cavity in dogs with malignant
Animals—53 dogs with malignant intranasal neoplasia.
Procedure—All dogs underwent radiotherapy consisting
of administration of 10 fractions of 4.2 Gy each
on consecutive weekdays. For dogs in the surgery
group (n = 13), follow-up computed tomography was
performed, and dogs were scheduled for surgery if
persistent or recurrent tumor was seen.
Results—Perioperative complications for dogs that
underwent surgery included hemorrhage requiring
transfusion (2 dogs) and subcutaneous emphysema
(8). Rhinitis and osteomyelitis-osteonecrosis occurred
significantly more frequently in dogs in the radiotherapy
and surgery group (9 and 4 dogs, respectively)
than in dogs in the radiotherapy-only group (4 and 3
dogs, respectively). Two- and 3-year survival rates
were 44% and 24%, respectively, for dogs in the
radiotherapy group and 69% and 58%, respectively,
for dogs in the surgery group. Overall median survival
time for dogs in the radiotherapy and surgery group
(47.7 months) was significantly longer than time for
dogs in the radiotherapy-only group (19.7 months).
Conclusions and Clinical Relevance—Results suggest
that exenteration of the nasal cavity significantly
prolongs survival time in dogs with intranasal neoplasia
that have undergone radiotherapy. Exenteration after
radiotherapy may increase the risk of chronic complications.
(J Am Vet Med Assoc 2005;227:936–941)