Charles A. Kuntz

Improved survival associated with postoperative wound infection in dogs treated with limb-salvage surgery for osteosarcoma.

BackgroundLimb-salvage surgery and adjuvant chemotherapy are performed as a treatment of appendicular osteosarcoma in dogs. Approximately 50% of dogs that undergo limb-salvage surgery develop postoperative surgical wound infections. Postoperative surgical infections may affect survival in cancer patients. The purposes of this study were to examine the effect of surgical wound infection on survival, local recurrence, and metastasis in relation to other prognostic factors for dogs with spontaneous osteosarcoma treated with limb-salvage surgery.MethodsForty-seven client-owned dogs with osteosarcoma of the distal radius were treated with limb-salvage surgery and adjuvant chemotherapy—either carboplatin or carboplatin and doxorubicin. Hazard ratios were estimated by using the Cox proportional hazard model, and survival functions were estimated by using the Kaplan-Meier product-limit life-table method.ResultsOf the 47 dogs in this study, 32 (68%) developed a postoperative wound infection. Infection, dog weight, and extent of the primary tumor (percentage of length) significantly affected survival, and infection and percentage of length significantly affected time to metastasis. None of the variables considered in this study affected local recurrence. Dogs that were diagnosed with an infection were less likely to die (hazard ratio, .446), and dogs with greater body weight and greater percentage length involvement were more likely to die (hazard ratios of 3.37 and 3.66, respectively).ConclusionsIn dogs with osteosarcoma treated with limb-salvage surgery, infection has a positive influence on survival, as does a smaller initial length of radius involved and lower body weight.

Radical excision with five-centimeter margins for treatment of feline injection-site sarcomas: 91 cases (1998–2002)

OBJECTIVE To evaluate outcomes of radical excision of feline injection-site sarcomas (ISS) via assessment of local recurrence and metastasis rates, survival times, and complications associated with surgery. DESIGN Retrospective case series. ANIMALS 91 cats with ISS. PROCEDURES Medical records of cats that had radical excision of ISS without adjunctive treatment were reviewed. Information extracted included sex, type of surgical procedure, histologic tumor grade, tumor diameter, time from tumor detection to definitive surgery, complications associated with surgery, whether tumors recurred locally or metastasized, and survival times. Diagnosis of ISS was histologically confirmed, and additional follow-up was performed. RESULTS Overall median survival time was 901 days. Thirteen of 91 (14%) cats had local tumor recurrence; 18 (20%) cats had evidence of metastasis after surgery. Median survival time of cats with and without recurrence was 499 and 1,461 days, respectively. Median survival time of cats with and without metastasis was 388 and 1,528 days, respectively. Tumor recurrence and metastasis were significantly associated with survival time, whereas other examined variables were not. Major complications occurred in 10 cats, including 7 with incisional dehiscence. CONCLUSIONS AND CLINICAL RELEVANCE Radical excision of ISS resulted in a metastasis rate similar to rates reported previously; the local recurrence rate appeared to be substantially less than rates reported after less aggressive surgeries, with or without adjuvant treatment. Major complication rates were similar to rates reported previously after aggressive surgical resection of ISS. Radical excision may be a valuable means of attaining an improved outcome in the treatment of feline ISS.

Effect of gas-plasma sterilization on the osteoinductive capacity of demineralized bone matrix

The current study evaluated the effect of low-temperature hydrogen peroxide gas plasma sterilization on the osteoinductive capability of human demineralized bone matrix using a rat model. Twelve athymic rats received three separate implants consisting of steam-sterilized demineralized bone matrix (negative control), sterile-harvest demineralized bone matrix (positive control), and gas-plasma–sterilized demineralized bone matrix. A demineralized bone matrix pellet from each sterilization group was placed individually into one of three separate soft tissue pockets created in the epaxial musculature of each rat. All 12 rats were euthanized 9 weeks after implantation. Each implantation site was removed along with 0.5-cm normal tissue around the implant. Histologic examination was done on each implant site to determine the presence or absence of new bone, cartilage, or bone marrow elements. All 12 sterile harvest demineralized bone matrix sites histologically contained new bone elements, whereas none of the negative control or gas plasma sterilized demineralized bone matrix sites contained any of these same elements. The results of this study indicate that demineralized bone matrix sterilized with low-temperature, gas-plasma sterilization loses its osteoinductive capacity in a manner similar to that of steam-sterilized demineralized bone matrix, making low-temperature, gas-plasma sterilization unsuitable as a method of secondary sterilization of demineralized bone matrix.

Thoracic surgical oncology

Thoracic surgical oncology involves surgical treatment of lesions of the thoracic wall, pulmonary parenchyma, or mediastinum (also including heart, esophagus, or trachea). The most common neoplasms of the thoracic wall are osteosarcoma and chondrosarcoma. Histopathologic type, the use of chemotherapy for osteosarcoma, and completeness of surgical margins are prognostic for survival. Relative to solitary pulmonary masses, carcinomas are most common, with histopathologic type, tumor size, tumor grade, and lymph node status prognostic for survival. Of the aforementioned variables, lymph node status is the most significant. Extensive preoperative workup, including bronchoscopy and transthoracic fine needle aspiration of solitary lung masses, is usually not recommended. Thymomas are the most common surgical mediastinal mass. Patients are frequently affected with paraneoplastic syndromes including myasthenia gravis, polymyositis, and nonthymic neoplasia. Patients without megaesophagus with surgically resectable masses have an excellent prognosis for survival. Provision of analgesia after surgery in thoracotomy patients is extremely important. Carefully selected analgesic agents in thoracotomy patients are far less damaging to cardiovascular status than is tachycardia from excessive pain. Given these and other guidelines, perioperative mortality in thoracotomy patients is minimal, and long-term survival in selected patients is excellent.

Evaluation of a single subcutaneous infusion of carboplatin as adjuvant chemotherapy for dogs with osteosarcoma: 17 cases (2006 -2010)

OBJECTIVE To evaluate adverse effects and survival times in dogs with osteosarcoma that received a single SC infusion of carboplatin as adjunctive chemotherapeutic treatment following limb amputation or limb-sparing surgery. DESIGN Retrospective case series. ANIMALS 17 client-owned dogs with spontaneously occurring osteosarcoma. PROCEDURES Medical records of dogs that underwent limb amputation or limb-sparing surgery followed by a single continuous SC infusion of carboplatin (total dose, 300 mg/m(2) infused over 3, 5, or 7 days) were evaluated. Signalment, tumor location, type of surgery (amputation or limb-sparing), duration of carboplatin infusion, results of hematologic and serum biochemical analyses, and adverse effects were recorded. Kaplan-Meier survival analysis was performed. RESULTS Median survival time for all dogs was 365 days. Nine dogs had adverse bone marrow-related (hematologic) effects, 1 had adverse gastrointestinal effects, and 7 had infections at the surgical site. No significant differences were detected in survival times of dogs grouped according to tumor location, type of surgery, duration of carboplatin infusion, or development of postoperative infection. CONCLUSIONS AND CLINICAL RELEVANCE Median survival time and adverse effects in dogs with osteosarcoma that received a single SC infusion of carboplatin over a 3-, 5-, or 7-day period as adjunctive treatment following limb amputation or limb-sparing surgery were comparable to those of previously reported chemotherapy protocols requiring IV drug administration over several weeks. Further investigation is needed to evaluate the efficacy of this protocol as adjunctive treatment for osteosarcoma and other tumors in dogs.

Second intention healing after wide local excision of soft tissue sarcomas in the distal aspects of the limbs in dogs: 31 cases (2005-2012)

OBJECTIVE To determine outcomes for dogs with soft tissue sarcomas in the distal aspects of the limbs that underwent second intention healing after wide excision (2-cm lateral surgical margins and a margin 1 fascial plane deep) of the tumors. DESIGN Retrospective case series. ANIMALS 31 dogs with soft tissue sarcomas in the distal aspects of the limbs that underwent second intention healing following wide local excision of their tumors. PROCEDURES Tumors were excised with 2-cm lateral margins and a margin 1 fascial plane deep to tumors. Wounds healed by means of second intention. Time to healing, complications during healing, and information regarding tumor recurrence were recorded. RESULTS All tumors were excised with histologically tumor-free margins. Twenty-nine (93.5%) wounds healed completely by second intention (median time, 53 days). Two (6.5%) dogs required free skin graft procedures to facilitate healing. Complications during open wound management developed for 7 (22.6%) dogs. Long-term complications were detected for 8 (25.8%) dogs, including intermittent epidermal disruption (5/31 [16.1%]) and wound contracture (3/31 [9.7%]). All complications were managed conservatively. Local tumor recurrence was detected for 1 (3.2%) dog. Median follow-up time was 980 days (range, 380 to 2,356 days). No patients died because of tumor-related causes. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study indicated second intention healing of large wounds in the distal aspects of the limbs was complete and typically without complications for dogs that underwent wide excision of soft tissue sarcomas. Wide local excision of soft tissue sarcomas in the distal aspects of the limbs with 2-cm lateral margins and margins 1 fascial plane deep to the tumors provided excellent long-term local tumor control.

Evaluation of Cisplatin in Combination with a Biologic Response Modifier in a Murine Mammary Carcinoma Model

The purpose of this study was to determine the efficacy of intracavitary cisplatin against local regrowth and metastasis after resection of a murine mammary carcinoma and the ability of a biologic response modifier (Virulizin®) to enhance chemotherapy. C3H-HeJ mice were injected with Gollin-B tumor cells. Once growth reached 8 mm, tumors underwent marginal resection and the mice were assigned randomly to intraperitoneal (IP) cisplatin, Virulizin, a controlled release cisplatin-impregnated sponge (OPLA–Pt), a combination of treatments or no treatment and were evaluated for local regrowth, metastasis, and toxicity at 14 or 60 days after surgery. A possible beneficial interaction was seen between OPLA–Pt and Virulizin at 14 days. All cisplatin groups had significant advantages over controls in all variables measured with OPLA–Pt displaying significant advantages over IP cisplatin in local recurrence rate, tumor score, survival time, and delay in regrowth at 60 days. No toxicity related to either cisplatin or Virulizin was observed.

Successful treatment of malakoplakia of the bladder in a kitten

A 4-month-old female kitten presented with chronic lower urinary tract signs and Escherichia coli cystitis, and was diagnosed with urinary bladder malakoplakia based upon histopathology. The kitten was treated with a prolonged antibiotic course and the malakoplakia resolved. Malakoplakia is a chronic granulomatous reaction characterized by the formation of Michaelis–Gutman bodies within von Hansemann macrophages. It is well described in humans, but has never been documented in a living veterinary patient. This case report describes the first successful treatment of malakoplakia in veterinary medicine.