Evaluation of three approaches to meniscal release.

Three approaches to medial meniscal release (MMR) were compared using 48 canine cadaver stifles. The approaches included a caudomedial arthrotomy approach, a blind stab incision based on anatomic landmarks, and an arthroscopic guided approach. The cranial cruciate ligament was intact in all specimens. The time required to perform the meniscal release and joint capsule closure was recorded, as well as completeness and location of the meniscal transection. Damage to the caudal cruciate ligament, femoral cartilage, and medial collateral ligament were recorded. The mini-arthrotomy was 81% successful in accomplishment of MMR with a 4% rate of iatrogenic damage. The blind technique was 56% successful in the accomplishment of MMR with a 4% rate of iatrogenic damage. The arthroscopic guided approach was 62.5% successful in accomplishment of MMR, with a 10% rate of iatrogenic damage. Accomplishment and iatrogenic damage rates were not significantly different among procedures (p > 0.05). Significantly less time was required to perform the blind technique, and significantly greater time was required to perform the arthroscopic guided technique (p > 0.05). Significant differences were not noted among the procedures regarding the ability to accomplish the meniscal release or damage surrounding structures. None of the evaluated approaches for meniscal release resulted in a complete and accurate meniscal release for over 81% of the time.

Congenital unilateral cleft of the soft palate in six dogs.

Unilateral cleft of the soft palate occurs sporadically in dogs, and there are few reports in the veterinary literature regarding its aetiology and management. This report describes six dogs with the condition. The dogs' primary presenting problem was rhinitis. The defects were successfully repaired using a two-layer closure technique with absorbable suture in five of the cases. Surgical correction was not performed in the remaining case.

Surgical treatment of septic peritonitis without abdominal drainage in 28 dogs.

The purpose of this study was to evaluate the surgical outcomes of 28 dogs with generalized septic peritonitis treated without postoperative abdominal drainage. The overall mortality rate was 46%, with most cases of peritonitis being caused by leakage of the gastrointestinal tract (75%). Etiology of peritonitis, abdominal cytopathology, total white blood cell count, packed cell volume, total protein, and results of serum biochemistries were not statistically different between survivors and nonsurvivors. The mortality rate of 46% is similar to other studies in which the abdomen was left open postoperatively for the management of septic peritonitis, although more advanced medical treatment than that used in earlier studies may have positively affected the outcome. The results of this study show that closure of the abdomen after the source of contamination has been successfully corrected, in combination with thorough intraoperative peritoneal lavage and appropriate postoperative medical management, may be an acceptable alternative method for the management of septic peritonitis.

Omentalization of cystic sublumbar lymph node metastases for long-term palliation of tenesmus and dysuria in a dog with anal sac adenocarcinoma.

A 13-year-old castrated male Bassett Hound was examined because of a 2-week history of severe constipation and tenesmus. Radiography revealed a large cystic mass in the caudal portion of the abdomen that was compressing the urethra and obstructing the pelvic canal. A small perianal mass was also noticed in the region of the left anal sac. Exploratory surgery was performed, but the mass was deemed unresectable. Instead, the mass was incised, drained, and omentalized in an attempt to establish continuous drainage after surgery. Cytologic evaluation of the perianal mass was consistent with a diagnosis of anal sac adenocarcinoma. Histologic evaluation of the abdominal mass revealed it was a lymph node effaced by adenocarcinoma. Despite the poor prognosis for anal sac adenocarcinoma with metastatic spread to the sublumbar lymph nodes, tenesmus and dysuria in this dog remained palliated until the dog's death 18 months after surgery. Omentalization was successful in providing a continuous method of fluid drainage for this cystopapillary abdominal tumor.

Removal of a thymoma via median sternotomy in a rabbit with recurrent appendicular neurofibrosarcoma.

A 9-year-old rabbit was evaluated for a mass on the right elbow. As a result of preoperative radiography, another mass was identified in the cranial portion of the mediastinum. Ultrasound guided fine needle aspiration was used for cytologic evaluation of the mass in the mediastinum and resulted in a presumptive diagnosis of thymoma. A median sternotomy approach was chosen to allow wide exposure for meticulous dissection in the cranial portion of the thoracic region. Histologic examination and immunoperoxidase labeling of lymphocytes with CD3 (a T cell marker) confirmed the diagnosis. The mass on the right elbow was subsequently removed and identified as a neurofibrosarcoma. Multiple appendicular masses that developed at separate locations and distinct times were excised and classified as locally invasive primary neurofibrosarcomas. Postmortem examination 9 months after initial evaluation confirmed recurrence of the neurofibrosarcoma at previous surgical sites. Gross or histologic evidence of thymoma was not evident. Prognosis is dismal for incompletely excised soft tissue sarcomas, because they are locally invasive and often recur.

Clinical, urodynamic, and histologic effects of urethral intussusception in clinically normal dogs.

OBJECTIVE: To evaluate clinical and histologic effects of surgically created urethral intussusception and determine whether it creates a high-pressure zone that resists passive urine flow in clinically normal dogs. ANIMALS: 8 healthy adult sexually intact female dogs. PROCEDURE: Urethral pressure profilometry was used to measure maximal urethral closure pressure (MUCP) and functional profile length (FPL) in dogs sedated with xylazine hydrochloride and atropine before and 2, 4, 7, 14, 28, 60, and 90 days after surgery. Cystourethral leak point pressure (CLPP) and cystourethral leak point volume (CLPV) were determined in anesthetized dogs immediately before and after surgery. Dogs were assigned to 4 groups of 2 dogs each; groups were euthanatized 4, 14, 28, and 90 days later, and representative tissues were examined. RESULTS: Dog 1 developed complete postoperative urethral obstruction. The procedure was altered, and all dogs recovered without complication. Mild inflammation attributable to surgical manipulation, but not ischemic damage or reduction of the intussusception, was evident. Comparison of preoperative MUCP and FPL with postoperative values did not yield significant differences. Immediate postoperative CLPP and CLPV were significantly higher than preoperative values, but were not significantly increased at euthanasia. A distinct but nonsignificant pressure spike was observed in postoperative urethral pressure profiles and persisted in 7 of 8 dogs. CONCLUSIONS: Urethral intussusception does not have deleterious effects when performed as described. Urodynamic data do not support the premise that urethral intussusception will create a high-pressure zone in the urethra that will resist passive urine flow long term in clinically normal dogs.

Biphasic thymus response by kittens inoculated with feline immunodeficiency virus during fetal development.

The objective of this study was to assess the response of the feline thymus to fetal infection with feline immunodeficiency virus (FIV), an animal model for human immunodeficiency virus infection. Thirteen feline embryos from four litters were directly inoculated with FIV during the sixth week postbreeding, a period corresponding to the late second trimester of pregnancy. Thymus tissue was collected and analyzed from randomly selected kittens at 2, 4, and 16 weeks postinoculation (PI) and compared to age-matched control kittens that did not receive fetal inoculations. Of three kittens evaluated at 2 weeks PI (week 8 of gestation), neither thymus:body weight ratio nor histologic structure differed from five age-matched control animals. However, analysis of thymocyte subpopulations by flow cytometry revealed a significant (P = 0.011) reduction in the percentage of cluster of differentiation (CD)4+/CD8+ cells from an average of 66% in control fetuses to 45% in infected fetuses. FIV RNA transcription, assessed by in situ hybridization using an FIVgag RNA probe, was widely distributed throughout the thymus in patterns suggestive of both stromal and parenchymal infection. By 4 weeks PI (week 1 postpartum), the thymus:body weight ratio was significantly reduced (P = 0.007) from 0.36% in five control kittens to 0.13% in four fetal inoculates. Severely atrophied thymus lobules supported minimal virus transcription and mean CD4+/CD8+ thymocyte percentages were lower (P = 0.021) in infected kittens (15%) compared to age-matched controls (66%). By 16 weeks PI (week 12 postpartum), thymus:body weight ratios of six inoculated kittens were not significantly different from six age-matched controls, suggesting that partial postnatal thymus regeneration had occurred. However, despite similar size, the regenerative thymus contained reduced percentages of CD4+/CD8+ thymocytes (infected: 40% versus control: 76%; P = 0.009) and increased percentages of CD4+/CD8- (11% versus 5%; P = 0.002) and CD4-/CD8+ (16% versus 9%; P = 0.035) lymphocytes. These changes were associated with widespread FIV transcription within thymic lymphocytes. Thus, the thymus of kittens infected with FIV during late fetal development is characterized by two distinct changes: neonatal atrophy and postnatal regeneration. Despite a recovery in thymus weight, thymus regeneration ineffectively restores the normal phenotypic distribution of thymocytes and supports FIV transcription.

Pulmonary lobectomy in the management of pneumonia in five cats.

Five cats underwent lobectomy for the management of pneumonia. The mean presurgical duration of treatment was eight months. A potentially immunosuppressive disease process was present preoperatively in two of the five cats. Preoperatively, two of the cats had radiographically diffuse pneumonia, while three had focal pneumonia. A single pulmonary lobe was removed in four cats, with one cat having two pulmonary lobes removed. There were no life-threatening complications and no clinical recurrence noted during a mean follow-up period of 37.8 months. The benefit of pulmonary lobectomy in focal pneumonia may lie in removing the nidus of infection. In diffuse, chronic or medically refractory pneumonia, obtaining an aetiological diagnosis may be the main benefit of lobectomy. Selective lobectomy for the treatment of pneumonia may be beneficial but a thorough preoperative evaluation is warranted.

Chlorhexidine gluconate versus chloroxylenol for preoperative skin preparation in dogs.

The efficacy of 3% chloroxylenol (PCMX) or 4% chlorhexidine gluconate (CG) for preoperative skin preparation was assessed in 100 dogs undergoing clean or clean-contaminated surgical procedures. Replication Organism Detection and Counting (RODAC) plates were used to quantify skin bacteria colony forming units (CFU) at the operative site before and after skin preparation and immediately postoperatively. Reduction of CFU after skin preparation and immediately postoperatively was significant for each agent. However, CFU levels were significantly lower in the CG group than in the PCMX group after surgical preparation, regardless of initial CFU numbers. No significant difference in CFU counts was observed between antiseptic groups postoperatively. Within-group comparisons showed PCMX to be significantly less efficacious when the prescrub CFU number was greater than 1,000. Bacterial reduction was similar in the CG group regardless of prescrub CFU levels. The number of negative cultures after skin preparation was significantly greater with CG than with PCMX. Chlorhexidine gluconate also had fewer cultures with heavy bacterial growth (> 5 CFUs) after surgical preparation. There was no significant difference between antiseptics in the number of negative cultures or cultures with more than 5 CFUs immediately after surgery. The number of skin reactions and postoperative wound infections that occurred with each technique were similar. Three percent PCMX, as used in this study, was less effective than 4% CG in its immediate antimicrobial activity, however, this difference was not associated with an increased wound infection rate.

Gastric leiomyosarcoma associated with hypoglycemia in a dog.

Hypoglycemia associated with a large, gastric leiomyosarcoma was diagnosed in an 11-year-old, yellow Labrador retriever. The dog had persistent hypoglycemia and low serum insulin levels. Although radiological and ultrasonographical evaluations suggested an abdominal mass involving the liver, a large, nonresectable, gastric mass was found during exploratory laparotomy. Metastasis was not identified on gross inspection of the liver or abdomen, and no metastatic lesions were seen on thoracic radiographs. The dog was euthanized. Histopathological examination of the mass revealed a poorly differentiated, gastric leiomyosarcoma that extended into the mesentery without regional lymph-node involvement.

Treatment of perianal fistulas with ND:YAG laser--results in twenty cases.

Excision of perianal fistulas using a 1.064 micron wavelength neodymium:yttrium aluminum garnet (ND:YAG) contact tipped laser with primary wound closure was used to treat 20 dogs with perianal fistulas. Overall, 19 of 20 (95%) dogs had resolution of fistulas after one or more ND:YAG treatments. The period of resolution ranged from 10 to 42 months with a mean of 22.9 months. Sixteen of 20 (80%) dogs had resolved fistulas after one laser excision. Three of the four recurrences underwent additional laser treatments with successful results. The total number of laser procedures ranged from one to three with a mean of 1.2 procedures. Postoperatively, anal tone as judged by digital rectal examination was reduced in about 60% of the cases, but clinical evidence of fecal incontinence only occurred in four of 20 cases. This was managed effectively with diet modification. The tendency toward loss of anal tone or fecal incontinence depended on the severity of preexisting anal stenosis. On a client survey, 19 of 20 owners believed that their animals experienced less pain during defecation after surgery and rated the results as excellent or good. The overall success rate using ND:YAG laser excision compared very favorably with previously reported studies of other methods of treatment for perianal fistulas in dogs.

Surgical stapling of the spleen, pancreas, liver, and urogenital tract.

Stapling instrumentation designed primarily for specific gastrointestinal procedures and transection of vascular pedicles have been adapted for use in parenchymal organs of the abdomen and urogenital tract. This article reviews current veterinary clinical and experimental use of stapling instrumentation for splenic, pancreatic, hepatic, and urogenital surgery.

Results of surgical management of portosystemic shunts in dogs: 20 cases (1985-1990).

Serum bile acid (SBA) values were obtained in 20 dogs, 2.5 to 60 months (mean, 18.6 months) after surgery for occlusion of a congenital portosystemic shunt. The SBA values obtained after food was withheld were significantly (P < 0.005) reduced at follow-up, compared with preoperative values. In 85% of the dogs (17/20), response to surgery was graded by the owners as excellent or good, although most dogs had abnormal SBA values at follow-up. Significant difference in clinical results or follow-up SBA values was not found in dogs that had complete or partial occlusion of the shunting vessel. Correlation between clinical results and SBA values also was not detected. Dogs that were > 2 years old at the time of diagnosis and surgery had a significantly (P = 0.012) poorer clinical result than that of dogs < 1 year old.

Temporary bile diversion in cats with experimental extrahepatic bile duct obstruction.

The use of a cholecystostomy catheter for temporary bile diversion was investigated in four cats with experimentally induced extrahepatic bile duct obstruction. Eighteen days after ligation of the common bile duct, a 6.5 F accordion catheter was placed in the gallbladder with a 22 g Hawkins needle-guide system through a paracostal incision. Biochemical parameters and fasting serum bile acids were monitored for 16 days. There were significant decreases in mean total bilirubin, aspartate aminotransferase, and fasting serum bile acids within 72 hours of bile diversion, and in mean alanine aminotransferase within 96 hours. Attitude and appetite improved, and the catheter was tolerated well. Positive bile cultures developed in three cats. Histologic changes in the gallbladder included mucosal ulcerations, a mixed inflammatory cellular infiltration, and fibrosis of the submucosa.

192iridium brachytherapy, using an intracavitary afterload device, for treatment of intranasal neoplasms in dogs.

After surgical removal of a primary intranasal neoplasm, an implant device, designed to deliver 192iridium (192Ir) brachytherapy, was positioned in the nasal cavity of 8 dogs. Ribbons containing 192Ir seeds were placed in the device, using an afterloading technique. Dosimetry, to a dose of 7,000 to 10,000 centiGray (cGy), was calculated to encompass the site previously occupied by the tumor and a 1-cm margin of surrounding normal tissue. The quantity of 192Ir implanted varied between 16.69 and 100.80 mg of radium equivalent. The duration of implantation ranged from 90 to 168 hours. All dogs tolerated the implant well, but had a mucoid nasal discharge after radiotherapy. The implant device allowed rapid application and removal of the radioactive ribbons. Mean (+/- SD) radiation exposure to each radiotherapist during seed loading and unloading was 14.4 (+/- 5.3) and 4.5 (+/- 0.9) mrem, respectively. A uniform dose distribution around the intranasal implant device was achieved; however, dogs that received doses in excess of 9,400 cGy at the dorsolateral surface of the nose and/or hard palate had bone and soft tissue necrosis between 70 and 120 days after treatment. One dog was euthanatized 50 days after treatment because of metastatic disease, and 2 dogs were euthanatized because of local tumor recurrence at 125 and 212 days. Death, considered unrelated to treatment, occurred in 1 dog that was euthanatized 27 days after treatment and in 3 dogs that died 30, 93, and 456 days after treatment. Necropsy was performed on 3 of these dogs and evidence of intranasal neoplasia was not observed. One dog remained disease-free at 587 days after treatment.

Inspiratory resistive load detection in conscious dogs.

The physiological mechanisms mediating the detection of mechanical loads are unknown. This is, in part, due to the lack of an animal model of load detection that could be used to investigate specific sensory systems. We used American Foxhounds with tracheal stomata to behaviorally condition the detection of inspiratory occlusion and graded resistive loads. The resistive loads were presented with a loading manifold connected to the inspiratory port of a non-rebreathing valve. The dogs signaled detection of the load by lifting their front paw off a lever. Inspiratory occlusion was used as the initial training stimulus, and the dogs could reliably respond within the first or second inspiratory effort to 100% of the occlusion presentations after 13 trials. Graded resistances that spanned the 50% detection threshold were then presented. The detection threshold resistances (delta R50) were 0.96 and 1.70 cmH2O.l-1.s. Ratios of delta R50 to background resistance were 0.15 and 0.30. The near-threshold resistive loads did not significantly change expired PCO2 or breathing patterns. These results demonstrate that dogs can be conditioned to reliably and specifically signal the detection of graded inspiratory mechanical loads. Inspiration through the tracheal stoma excludes afferents in the upper extrathoracic trachea, larynx, pharynx, nasal passages, and mouth from mediating load detection in these dogs. It is unknown which remaining afferents (vagal or respiratory muscle) are responsible for load detection.

Unilateral congenital aneurysm of the jugular, linguofacial, and maxillary veins in a dog.

A 5-month-old female Gordon Setter was examined because of a soft, fluctuant, subcutaneous swelling in the right submandibular region. Clinical problems were not associated with the mass. Cytologic examination and blood gas analysis of an aspirate from the mass confirmed its contents to be venous blood. Venous angiography delineated a fusiform dilatation of the right jugular, maxillary, and linguofacial veins, with no evidence of obstruction or anomalous venous return to the heart. The dilated segments were surgically excised, and the tissue was submitted for histologic examination. The clinical, radiographic, and histologic features of this lesion supported the diagnosis of congenital venous aneurysm.

Calcinosis circumscripta of the metacarpal pad in a dog.

Calcinosis circumscripta was found in the metacarpal pad of an otherwise healthy young German Shepherd Dog. The lesion caused progressive lameness. Incomplete surgical excision alleviated pain, while preserving a functional metacarpal pad. There were no clinical or laboratory data to indicate impaired renal function in this dog. Five months after surgery, the lameness had not returned. Footpad calcinosis circumscripta has been previously described in older dogs with renal insufficiency.

Surgical correction of concomitant cranioventral abdominal wall, caudal sternal, diaphragmatic, and pericardial defects in young dogs.

Seven puppies with concomitant congenital cranioventral abdominal wall, caudal sternal, diaphragmatic, and pericardial defects were treated surgically when they were between 10 and 12 weeks old. Three pups had ventricular septal defects that were not corrected. Diaphragmatic herniorrhaphy without extension of the diaphragmatic defect was performed in 6 pups. In one pup, paracostal extension of the diaphragmatic defect was necessary to decrease tension on the diaphragmatic closure. All pups were healthy at 6-month follow-up examinations, but 2 of 3 pups with ventricular septal defects had moderate generalized cardiomegaly evident on thoracic radiography. Early surgical correction of the congenital defects in these pups was usually simple because there were few or no thoracic adhesions, the dogs were small, the defects were small in 6 of 7 dogs, and the costal arch was pliable in each dog.