A10-year-old 7.1-kg (15.6-lb) spayed female Jack Russell Terrier (dog 1) was referred to the CUHA for evaluation of pleural effusion. The dog was initially examined by the referring veterinarian because of cough and increased respiratory effort of several weeks' duration. Thoracic radiography revealed pleural effusion. Via thoracocentesis, 180 mL (25.3 mL/kg [11.5 mL/lb]) and 120 mL (16.9 mL/kg [7.7 mL/lb]) of fluid was removed from the left and right hemithorax, respectively. The fluid was characterized cytologically as a modified transudate.

Physical examination findings at the CUHA were unremarkable. Results of CBC, serum biochemical analyses, and urinalysis were within reference limits. No cause for the pleural effusion was identified by use of thoracic ultrasonography, echocardiography, or computed tomography of the thorax. Thoracoscopic evaluation revealed thickening of the mediastinum and the left cranial parietal pleura. Biopsy specimens of the abnormal tissue were obtained, and histologic evaluation revealed mild monocytic and neutrophilic fasciitis of the mediastinum and the left parietal pleura, with no evidence of neoplasia. The dog was discharged from CUHA. During the next 2 weeks, the referring veterinarian removed fluid via thoracocentesis on 4 occasions.

Eighteen days after the initial evaluation, the dog was returned to the CUHA for surgical treatment of persistent pleural effusion. A left, fifth intercostal thoracotomy was performed, and a small amount of pleural fluid was removed via suction. The mediastinum was perforated by use of blunt dissection, and a Jackson-Pratt drain^a was placed through the perforation so that it spanned from the left to the right pleural cavity. The Jackson-Pratt drain tubing was connected to the indwelling catheter portion of a VAP^b by insertion of the smaller-diameter catheter tubing into the Jackson-Pratt tubing. The connection was secured by placement of 2 to 3 encircling ligatures of nonabsorbable, monofilament suture material (Figure 1). A 4-cm-long dorsoventral skin incision was made over the left lateral cervical area, and a subcutaneous pocket was made just caudal to the skin incision. A VAP injection port was secured to left dorsal cervical muscle fascia within the subcutaneous pocket by use of nonabsorbable, monofilament suture material. The VAP catheter was passed out of the thorax through a small incision in the fourth intercostal space. The catheter was then tunneled through the intercostal muscles and subcutaneous tissue to the cervical site and connected to the injection port (Figure 2). Patency of the system was assessed via injection of sterile saline (0.9% NaCl) solution containing heparin into the injection port prior to closure. Routine closure of the thoracotomy was performed by use of interrupted, circumferential, absorbable sutures. The subcutaneous tissue over the injection port was closed with absorbable suture in a simple interrupted pattern. At the incision site, skin edges were apposed with nylon sutures in a simple interrupted pattern.

View Full Size

Photograph of a VAP designed for subcutaneous placement (circular device to right of image) that is connected to a Jackson-Pratt drain.

Citation: Journal of the American Veterinary Medical Association 230, 4; 10.2460/javma.230.4.527

• Download Figure
• Download figure as PowerPoint slide

View Full Size

Illustration depicting placement of a VAP and Jackson-Pratt drain for treatment of pleural effusion in a dog (viewed from left side). Notice the cervical subcutaneous location of the VAP and the intrathoracic location of the Jackson-Pratt drain.

Citation: Journal of the American Veterinary Medical Association 230, 4; 10.2460/javma.230.4.527

• Download Figure
• Download figure as PowerPoint slide

Beginning 7 days after placement, the VAP was used to drain 25 to 100 mL (3.5 to 14.1 mL/kg [1.6 to 6.4 mL/lb]) of pleural fluid once weekly for 36 weeks. For each use of the VAP, the overlying skin was scrubbed 3 times with antiseptic soap and alcohol rinses. The skin and septum of the VAP were then punctured with a 22-gauge Huber-point needle, and the effusion was drained. Following drainage, the VAP was flushed with 3 to 5 mL of saline solution containing heparin. On 2 occasions, the pleural fluid was more opaque in appearance and was submitted for microbial culture and anti-microbial susceptibility testing. Bacterial cultures of the fluid collected on the first and second occasion yielded growth of Proteus spp and Pseudomonas spp, respectively. Both infections were treated successfully with amoxicillin-clavulanic acid^c (17.5 mg/kg [8 mg/lb], PO, q 12 h, prescribed indefinitely). In addition, ampicillin (28 mg/kg [12.7 mg/lb]) was injected into the pleural space via the VAP once weekly. The VAP hub was reported to have shifted slightly from its original location during the first 6 months of its use, but no other VAP-associated complications developed. Follow-up was obtained 36 months after placement of the VAP; at that time, the VAP was still being aspirated every week, and approximately 25 mL of fluid was removed at each visit.

A 12-year-old 5.2-kg (11.4-lb) spayed female mixed-breed dog (dog 2) was referred to the CUHA for evaluation of a splenic mass. One week prior to evaluation, the dog was examined by the referring veterinarian because of inappetence. Radiographic and ultrasonographic evaluations of the abdomen revealed a splenic nodule. Physical examination findings at the CUHA revealed abdominal distension and sublumbar lymph node enlargement. Results of a CBC, serum biochemical analyses, and urinalysis were unremarkable. Similarly, findings of thoracic radiography were unremarkable. Abdominal ultrasonography revealed 3 to 5 heterogeneously echoic splenic nodules and multiple large lymph nodes. Aspirate specimens of the abnormal splenic and lymph node tissues underwent cytologic examination and immunophenotyping, and results were consistent with CD3-positive, T-cell lymphoblastic lymphoma. Results of cytologic examination of a bone marrow aspirate were negative for lymphoma.

A combination chemotherapy protocol involving L-asparaginase^d (400 U/kg [181.8 U/lb], SC) and vincristine^e (0.5 mg/m² of body surface area, IV) was initiated. Chemotherapy treatments were given once weekly for the first 4 treatments. The dog was hospitalized for observation during the first treatment and discharged to the owner's care 3 days later. One day after discharge, the dog was returned to the hospital for evaluation because of lethargy, dyspnea, and occasional cough. Evaluation of thoracic radiographs revealed moderate pleural fluid and consolidation of the accessory lung lobe. Results of cytologic examination of a bronchoalveolar lavage specimen were unremarkable. The dog was treated with cephalexin (22 mg/kg [10 mg/lb], PO, q 8 h). At scheduled recheck examination 1 week later, findings of thoracic radiography were consistent with moderate pleural effusion. Abdominal ultrasonography revealed progressive resolution of abdominal lymphadenopathy and splenic masses. No abnormalities were detected echocardiographically. Approximately 40 mL (7.7 mL/ kg [3.5 mL/lb]) of fluid was removed via thoracocentesis performed with a winged infusion set and syringe; cytologically, the fluid was a mature lymphocytic effusion, consistent with chyle. Results of bacterial culture of the pleural fluid were negative.

During the following 4 weeks, the dog required thoracocentesis on 6 occasions to relieve dyspnea. Because lymphoma appeared to be responding to chemotherapy but chylous effusion persisted, a subcutaneous VAP attached to a pleural Jackson-Pratt drain was implanted to facilitate fluid removal. The dog was anesthetized, and the thoracic duct was ligated through a right, ninth intercostal thoracotomy. The mediastinum was perforated for transpleural placement of Jackson-Pratt drain tubing, which was attached to a VAP, as described for dog 1. The VAP was implanted subcutaneously over the right 12th intercostal space. The skin overlying the VAP was aseptically prepared (as described for dog 1), and the VAP was used daily for pleural drainage for the first 2 weeks, then every other day for 1 week. The VAP was flushed with 3 to 5 mL of saline solution containing heparin after each use. Three weeks after implantation, it became difficult to aspirate fluid through the port. Fluoroscopic imaging revealed no obstruction when iodinated contrast material was injected through the port (Figure 3). Nevertheless, as a prophylactic measure, tissue plasminogen activator (0.15 mg/kg [0.07 mg/lb]) was injected into the port, followed 30 minutes later by a flush with saline solution containing heparin. The port continued to be patent, and pleural fluid was drained 1 to 5 times weekly (quantities of pleural fluid removed ranged from 0 to 250 mL (0 to 48.0 mL/kg [0 to 21.8 mL/lb]) until the dog was euthanized because of progressive lymphoma 11 weeks after port placement.

View Full Size

Ventrodorsal fluoroscopic view of the thorax of a dog in which an intrathoracic drain and subcutaneous VAP (not in view) had been placed for the treatment of pleural effusion.

Citation: Journal of the American Veterinary Medical Association 230, 4; 10.2460/javma.230.4.527

• Download Figure
• Download figure as PowerPoint slide

A 9-year-old 35-kg (77-lb) spayed female mixedbreed dog (dog 3) was referred to the CUHA for evaluation because of sudden onset of tachypnea and dyspnea. Findings of thoracic radiography were compatible with severe pleural effusion. By use of a closed system comprised of a winged infusion set, 3-way stopcock, and syringe, thoracocentesis was performed twice during the initial evaluation. The dog's clinical signs improved after 1,300 mL (37.1 mL/kg [16.9 mL/lb]) of opaque pleural fluid was drained from the thorax. Cytologic analysis of the fluid revealed a predominance of macrophages, small lymphocytes, and neutrophils. The cytologic diagnosis was inflammation, hemorrhage, and probable chylous pleural effusion. There was no cytologic evidence of neoplasia. Results of a CBC and serum biochemical analyses were unremarkable.

Echocardiographic findings were within reference limits. Abdominal ultrasonography revealed 1 cystic liver mass and numerous fluid-filled masses adjacent to the aorta and renal arteries as well as mild peritoneal fluid. Cytologic examination of an ultrasound-guided fineneedle aspirate of the liver mass revealed many small lymphocytes.

The dog was reexamined 2 weeks later, and mild dyspnea was again evident. Thoracocentesis was not performed at that time. The dog was anesthetized, and thoracostomy tubes^f were placed bilaterally. Approximately 2,700 mL (77.1 mL/kg [35.0 mL/lb]) of chylousappearing fluid was removed from the right tube, and 150 mL (4.3 mL/kg [2.0 mL/lb]) of similar fluid was removed from the left tube. A standard ventral midline surgical approach was made for exploration of the abdomen, which revealed a 2-cm, fluid-filled lesion on the surface of the left lateral liver lobe. Incisional biopsy of this cystlike structure was performed, and the wedgeshaped defect was sutured to control hemorrhage. The remainder of the abdominal organs appeared grossly normal. Histologic evaluation of the specimen of liver mass revealed markedly altered tissue architecture with broad, irregular mats of compacted fibrin and extravascular spaces containing free erythrocytes. A single layer of endothelium was comprised of cells that contained ovoid nuclei; those endothelial cells reacted positively with cytoplasmic stain against von Willebrand's factor (factor VIII-related antigen). Histomorphologic diagnosis was lymphangiosarcoma. Thoracostomy tubes were removed following intrapleural administration of carboplatin (250 mg/m² of body surface area, once only).

Following surgery, the dog was treated with doxorubicin (30 mg/m² of body surface area, IV, q 3 wk) and fed a homemade low-fat diet with supplements of rutin (43 mg/kg [19.5 mg/lb], PO, q 8 h) and medium-chain triglyceride oil (0.5 mL/kg [0.2 mL/lb], PO, q 24 h). Despite treatment, the dog became dyspneic 8 weeks later and 3 L (85.7 mL/kg [39.0 mL/lb]) of chylous fluid was removed from the pleural space via thoracocentesis performed with a winged infusion set and syringe. A second exploratory laparotomy and thoracotomy for ablation of the cisterna chyli and ligation of the thoracic duct, respectively, were performed. At the time of laparotomy, a peritoneal dialysis drain^g was placed in the abdomen to drain accumulated fluid and tunneled through the subcutaneous tissue to the caudal thoracic wall, where it was connected to a VAP. In addition, a Jackson-Pratt drain was placed in the pleural cavity via a right, seventh intercostal thoracotomy and connected to a subcutaneous VAP secured to the muscle fascia over the dorsal third portion of the second and third ribs on the right side of the thorax. The mediastinum was perforated so that the pleural drain spanned both sides of the pleural cavity.

Subsequent to placement of the drains, the dog was reexamined weekly for 5 weeks. On all occasions, the dog's behavior appeared normal and both the thoracic and peritoneal drains were successfully used to remove effusions. The overlying skin was prepared, and the VAP was accessed with a Huber-point needle, as described for dog 1. Saline solution containing heparin (3 to 5 mL) was used to flush the VAP after each use. The quantity of fluid drained from the thoracic port ranged from 1,700 to 3,000 mL/visit (48.6 to 85.7 mL/kg [22.1 to 39.0 mL/lb]/visit). After each port was used for drainage, the reservoirs were flushed with saline solution containing heparin.

Six weeks after placement of the drains, the dog became lethargic and inappetent and vomited once. On physical examination, the dog had signs of depression and was weak and febrile (rectal temperature, 39.5°C [103.1°F]). Abdominal ultrasonography revealed fluiddistended, corrugated loops of small intestines; diffusely hyperechoic mesenteric fat; and a hypoechoic pancreas, all of which were suggestive of peritonitis. Cytologic analysis of the abdominal effusion revealed a predominance of neutrophils and intracellular rodshaped bacteria. Cytologic diagnosis was consistent with septic peritonitis. Further treatment was declined by the owners, and the dog died at home 2 days later.