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.

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.

Serum amylase and lipase activities after exploratory laparotomy in dogs.

Serum amylase and lipase activities and creatinine concentration were determined before surgery, and at 1 and 2 days after exploratory laparotomy in 24 dogs. Examination of all viscera was done during each laparotomy, but a surgical procedure was not performed. The mean serum activities for lipase were: before surgery, 0.71 (0.0 to 2.0) Cherry Crandall units (CCU)/L; 1 day after surgery, 2.1 (0.0 to 4.5) CCU/L; and 2 days after surgery, 1.19 (0.0 to 3.9) CCU/L. The mean serum activities for amylase were: before surgery, 1,958 (1,027 to 3,426) IU/L; 1 day after surgery, 1,538 (937 to 2,659) IU/L; and 2 days after surgery, 1,663 (1,066 to 2,274) IU/L. Serum creatinine concentrations before surgery, 1 day after surgery, and 2 days after surgery were 0.88 (0.2 to 1.7) mg/dl, 0.78 (0.4 to 1.3) mg/dl, and 0.78 (0.3 to 1.3) mg/dl, respectively. Mean preoperative, day-1, and day-2 serum amylase activities and serum creatinine concentrations did not differ significantly from each other. Mean preoperative and day-2 serum lipase activities did not differ significantly; however, mean serum lipase activity was significantly greater when day 1 activities were compared with preoperative activities (P = 0.0002). Post-mortem examinations revealed no gross or histologic evidence of pancreatitis in any dog. The results of this study show that a 3 or more fold increase in serum lipase activity may occur after routine exploratory laparotomy in dogs without clinical signs or gross evidence of pancreatitis. Histologic evidence of pancreatitis was not found in the right pancreatic lobes in any dog.

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.

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.

Colonic perforation after corticosteroid and surgical treatment of intervertebral disk disease in a dog.

Colonic perforation after corticosteroid and surgical treatment of intervertebral disk disease in a dog Perforation of the distal segment of the descending colon, after corticosteroid and neurosurgical treatment for an intervertebral disk herniation, resulted in the death of a 3-year-old, male, Lhasa Apso. Initially, the dog was paraparetic in the hindlimbs, but became paraplegic after 4 days of conservative treatment. Corticosteroids were administered before referral and during decompressive hemilaminectomy. Six days after surgery, the dog had improved neurologically, but was depressed, anorectic, and vomiting. Abdominocentesis revealed septic peritonitis. The dog died shortly after a perforation in the descending colon was surgically corrected.

Nonweightbearing lameness secondary to synovial sarcoma in a young dog.

Synovial sarcoma was diagnosed in the right carpus of a 2 1/2-year-old mixed-breed dog. The dog had developed a right forelimb lameness before one year of age. The lameness was progressive for nearly 2 years, resulting in severe disuse atrophy of the right forelimb musculature and pronounced osteopenia. A definitive diagnosis was not made until the dog was referred after 2 years of conservative treatment was ineffectual. Right forelimb amputation was done and the dog survived an additional 15 months. The protracted clinical course before definitive diagnosis underscores the need for aggressive pursuit of a diagnosis when conservative treatment of a lameness is not efficacious.

Use of a double-hook plate to repair a subtrochanteric femoral fracture in an immature dog.

A subtrochanteric femoral fracture in a 5-month-old Doberman Pinscher was repaired by use of a 5-hole, 3.5-mm, double-hook plate. The double-hook plate afforded rigid 3-point fixation of the short proximal metaphyseal segment without impingement of the proximal femoral physis and allowed compression of the fracture fragments by placement of an interfragmentary screw through its pendulum hole. The fracture healed without complications, and the dog had a rapid return to function. Although designed for use in performing femoral osteotomies in dogs afflicted with hip dysplasia, the double-hook plate can be used to repair fractures with short proximal or distal segments.

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.

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.

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.

Ehrlichia canis-related polyarthritis in a dog.

Ehrlichia canis-related polyarthritis was diagnosed in a 7-month-old Boxer. The diagnosis was based on intraneutrophilic morulae found in synovial fluid specimens, thrombocytopenia, a positive result for indirect fluorescent antibody testing for E canis, the presence on the dog of the known vector of E canis infection (Rhipicephalus sanguineus), and a favorable response to treatment with tetracycline hydrochloride. The dog has had no recurrence of lameness for 18 months after cessation of treatment.

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.

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.

Medical and surgical management of esophageal foreign body in a ferret.

A ferret was examined because of anorexia, repeated episodes of regurgitation, and subsequent dehydration. Radiography had revealed a radiodense midesophageal foreign body. Results of endoscopy of the esophagus, however, could not confirm the diagnosis. Contrast radiography revealed esophageal perforation, with subsequent penetration of the foreign body into the right pleural space, causing pleural effusion. Surgical repair of the esophagus was performed, and a gastrostomy feeding tube was inserted to provide adequate nutrition during esophageal healing. Nine days after surgery, radiography revealed a severe stricture at the esophageal surgical site. Surgery was repeated; the esophagus was transected, the stricture was removed, and esophageal tissues were closed in 2 layers. Systemically administered antibiotics and gastrostomy tube feedings were continued throughout the post-operative healing period. The esophagus healed with a mild stricture that diminished over time in response to corticosteroid administration.

Thymoma in the dog: two case reports and review of 20 additional cases.

A 7-year-old German Shepherd Dog had a large cranial mediastinal mass that had resulted in chronic weight loss. A diagnosis of benign thymoma was made by transthoracic needle biopsy. The thymoma was removed surgically and the dog recovered without complications. At 4 months after surgery, the dog's activity was improved and it had gained weight. A 12-year-old mixed-breed dog was admitted for evaluation of dependent edema of the neck. Thoracic radiography revealed pleural effusion and lesions in the right lung and left scapula. Neoplastic epithelial cells were found in a needle aspiration specimen from the scapular lesion. The dog was euthanatized and necropsied. The primary tumor, a malignant thymoma, filled the cranial mediastinum and had invaded the cranial vena cava. Metastasis was confirmed in the right lung, liver, and left scapula. Eight cases of thymoma in the dog were retrieved from the Veterinary Medical Data Program. In 5 of the cases, the tumor was benign. The 3 dogs with malignant thymoma developed cranial vena caval syndrome, and they were euthanatized or died. Four of the dogs with benign thymoma were euthanatized for reasons unrelated to the tumor. One dog with benign thymoma was free of tumor when examined 5 years after surgical removal of the tumor.

Repair of sixth lumbar vertebral fracture-luxations, using transilial pins and plastic spinous-process plates in six dogs.

Transilial pins and paired plastic spinous-process plates were used to repair fracture-luxations of the sixth lumbar vertebra in 6 dogs. All dogs had signs of lumbar pain and variable lower motor neuron deficits to the hindquarters (including hind limbs, tail, and pelvic region). Lumbar pain was decreased or resolved the day after surgery in all dogs, and 3 dogs were able to walk without assistance. One dog initially deteriorated neurologically after surgery and 2 dogs with multiple concurrent orthopedic injuries had no improvement in neurologic function and remained nonambulatory. Pin migration associated with improper bending of the transilial pins and requiring early implant removal was the most common postoperative complication. Four dogs had no neurologic abnormalities 1 to 3 months after surgery. One dog had a resolving unilateral sciatic nerve deficit 9 months after surgery, and another dog was euthanatized 3 months after surgery because of continued paraparesis and urinary and fecal incontinence. These 6 cases illustrate the efficacy of plastic spinous-process plates in combination with transilial pins for the repair of fracture-luxation of the sixth lumbar vertebra.

Congenital cranioventral abdominal wall, caudal sternal, diaphragmatic, pericardial, and intracardiac defects in cocker spaniel littermates.

Five littermate Cocker Spaniels were born with concomitant pericardial, diaphragmatic, caudal sternal, and cranioventral abdominal wall defects. Three of the 5 pups had ventricular septal defects. A sixth pup with a cranioventral abdominal wall defect died 4 days after birth. No history of teratogen exposure was reported, and none of the pups from previous litters of the dam was affected. Each pup underwent successful surgical correction (without median sternotomy) of the diaphragmatic and cranial abdominal wall defects when they were 10 to 12 weeks old. The ventricular septal defects were not corrected. In 2 of 3 pups with ventricular septal defects, thoracic radiography 6 months after surgery revealed moderate generalized cardiomegaly. All pups were healthy one year after surgery.

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.

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.