Traumatic chylothorax in urbanized free-ranging black-tufted marmosets (Callithrix penicillata).

After fatal traumatic injuries, three urbanized free-ranging marmosets developed a milky white or pink-white thoracic alkaline effusion with high specific gravity, triglyceride levels, and predominance of small lymphocytes. Chylothorax is an uncommon thoracic fluid accumulation in animals and humans and has not been reported in free-ranging non-human primates.

Chylothorax secondary to subcutaneous cervical lipoma in a dog.

An 8-year-old male neutered American English Coonhound was presented for a 2-day history of increased respiratory effort and rate with an occasional cough. Thoracic radiographs noted pleural effusion, which was chylous based on cytological and chemical evaluation. The dog also had a 2-year history of a slow growing fatty mass in the right cervical region. A CT scan confirmed the large cervical fat attenuating mass extending from the base of the skull to the cranial thorax and right axillary region with compression of vascular structures. Severe bilateral effusion and secondary pulmonary atelectasis was noted within the thoracic cavity. It was elected to surgically remove the cervical mass and place a PleuralPort within the thoracic cavity. The mass was diagnosed as a lipoma and its removal led to rapid and complete resolution of chylothorax. Based on the literature search, this is the first case report of chylothorax secondary to a cervical mass or subcutaneous lipoma.

Chylothorax associated with pulmonary compressive atelectasis in an emperor tamarin (Saguinus imperator).

Chylothorax is the accumulation of lymph in the thoracic cavity, and it has never been reported in neotropical primates. An emperor tamarin died and at necropsy chylothorax associated with pulmonary compressive atelectasis was diagnosed. Idiopathic chylothorax can be a cause of respiratory insufficiency and death in tamarins.

Resolution, recurrence, and chyle redistribution after thoracic duct ligation with or without pericardiectomy in dogs with naturally occurring idiopathic chylothorax.

OBJECTIVE: To document outcomes of thoracoscopic treatment of idiopathic chylothorax (IC) in dogs with and without constrictive pericardial physiology (CPP) and evaluate patterns of chyle flow redistribution after thoracic duct ligation (TDL). ANIMALS: 26 client-owned dogs. PROCEDURES: In this prospective cohort study, echocardiography and cardiac catheterization were performed to document CPP in dogs with IC. Thoracoscopic TDL with pericardiectomy was performed if CPP was present (TDL/P group). Dogs without evidence of CPP underwent thoracoscopic TDL alone (TDL group). Dogs underwent preoperative, immediate postoperative, and 3-month postoperative CT lymphangiography studies when possible. Perioperative morbidity, resolution and late recurrence rates, and long-term outcome were recorded. RESULTS: 17 dogs underwent TDL, and 9 underwent TDL/P. Twenty-five of 26 (96%) survived the perioperative period. One dog died from ventricular fibrillation during pericardiectomy. Resolution rates for TDL and TDL/P were 94% and 88%, respectively (P = .55), with 1 late recurrence occurring in the TDL group in a median follow-up of 25 months (range, 4 to 60 months). On 3-month postoperative CT lymphangiography studies, ongoing chyle flow past the ligation site was demonstrated in 5 of 17 dogs, of which 1 dog developed recurrence at 13 months postoperatively. In 15 of 17 dogs, chylous redistribution after TDL was principally by retrograde flow to the lumbar lymphatic plexus. CLINICAL RELEVANCE: In dogs without evidence of CPP, TDL alone was associated with a very good prognosis for treatment of IC. In the absence of CPP, the additional benefit of pericardiectomy in the treatment of IC is questionable.

Triple-combination surgery with thoracic duct ligation, partial pericardiectomy, and cisterna chyli ablation for treatment of canine idiopathic chylothorax.

This study aimed to evaluate the outcomes and complications of triple-combination surgery consisting of thoracic duct ligation (TDL), partial pericardiectomy (PPC), and cisterna chyli ablation (CCA) for the treatment of idiopathic chylothorax in dogs. Eleven privately owned dogs with idiopathic chylothorax underwent the triple-combination surgery: TDL and PPC were performed in left recumbency, followed by CCA in dorsal recumbency. Of the 11 dogs, seven were Shiba, two were Afghan hounds, and one each was Borzoi and mixed-breed. TDL and PPC required two intercostal thoracotomies in five dogs, whereas they were performed through a single intercostal incision in the other dogs. None of the dogs showed major intraoperative complications. The median operation time was 190 min (range, 151-234 min). Nine dogs showed no pleural effusion after surgery without medical management. Another dog showed the disappearance of chylous effusion, followed by the pleural accumulation of modified transudate. However, the residual one dog in whom chylothorax did not improve postoperatively died 4 months after the combination surgery. The mortality rate at the conclusion of this study was 9.1%. Although the triple-combination surgery with TDL, PPC, and CCA was complex and required a prolonged operation time, the success rate of resolving chylothorax in our study was comparable to that of open surgery as previously reported. Therefore, this study suggests that such triple-combination surgery can become one of the therapeutic options for the management of canine idiopathic chylothorax.

Prospective evaluation of lymphatic embolization as part of the treatment in dogs with presumptive idiopathic chylothorax.

OBJECTIVE: To describe the embolization technique and short-term clinical outcome in dogs undergoing lymphatic embolization (LE) as part of treatment for presumptive idiopathic chylothorax (IC). Additionally, to document findings in computed tomography lymphangiography (CTLa) following embolization. STUDY DESIGN: Prospective case series. ANIMALS: Eight client-owned dogs. METHODS: Dogs underwent CTLa followed by thoracic duct ligation (TDL), pericardiectomy (PC) and LE. A mixture of 3:1 lipiodol: n-butyl cyanoacrylate embolic solution was injected through a catheterized mesenteric lymphatic vessel via limited abdominal approach using intraoperative fluoroscopy. CTLa was scheduled for 12 weeks postoperatively, and long-term follow-up was obtained via telephone contact. RESULTS: LE was technically successful in six of the eight dogs; and clinically successful in five of the six dogs. In the unsuccessful dog, a diagnosis of lymphangiosarcoma was determined, and the owners elected for euthanasia. Five dogs who underwent successful LE underwent CTLa at 12 weeks. Complete resolution of pleural effusion occurred in three dogs and scant pleural effusion in two dogs. A robust lymphatic embolus preventing antegrade continuation of radiocontrast was documented in all five dogs. Five of the six dogs that underwent LE, were alive and clinically normal at 358-960 days postoperatively. CONCLUSIONS: LE is a feasible part of treatment for dogs with IC. Additionally, a robust lymphatic embolus and lack of radiocontrast flow past the embolus was documented at 12 weeks following surgery. CLINICAL SIGNIFICANCE: LE has the potential to reduce surgical failure by reducing efferent lymphatic chyle flow, occluding missed lymphatic branches and preventing the development of collateral branches.

Decortication, thoracic omentalization, and pericardiectomy for treatment of severe fibrosing pleuritis in a cat.

CASE DESCRIPTION: A 5-year-old spayed female domestic shorthair cat was evaluated because of an acute onset of dyspnea and open-mouthed breathing. CLINICAL FINDINGS: Thoracic radiography revealed pleural effusion and signs consistent with restrictive pleuritis, and results of preoperative CT were consistent with diffuse, severe restrictive pleuritis, bilateral pleural effusion, and pulmonary atelectasis. Thoracocentesis yielded a red, turbid fluid that was identified as chylous effusion with chronic inflammation. TREATMENT AND OUTCOME: Exploratory thoracotomy revealed diffuse, severe fibrous adhesions between the mediastinum, heart, lung lobes, and thoracic wall, with a thick fibrous capsule enveloping all lung lobes. Surgical treatment consisted of complete pleural decortication, pericardiectomy, and thoracic omentalization. The cat remained hospitalized for 6 days, receiving oxygen supplementation, multimodal analgesia, and supportive care. Long-term home care consisted of prednisolone administration, rutin supplementation, and provision of a low-fat diet. At recheck examinations 3-, 7-, and 20-weeks postoperatively, the cat remained tachypneic, but was otherwise clinically normal without dyspnea or respiratory distress. Follow-up thoracic radiography revealed improved pulmonary expansion, decreased pleural effusion, and resolved pneumothorax. CLINICAL RELEVANCE: Surgical management of fibrosing pleuritis secondary to idiopathic chylothorax in cats has historically resulted in poor outcomes. This report details the first successful use of complete decortication in the surgical management of severe fibrosing pleuritis in a cat.

Computed tomography lymphangiography via intrametatarsal pad injection is feasible in cats with chylothorax.

OBJECTIVE: To evaluate the feasibility of CT lymphangiography via intrametatarsal pad injection in cats with chylothorax. ANIMALS: 7 client-owned cats. PROCEDURES: This was a multicenter, retrospective, descriptive study. Medical records and imaging data from 4 veterinary hospitals were reviewed to identify cats with chylothorax that had undergone intrametatarsal pad injection via CT lymphangiography. In total, 7 client-owned cats were included in the study. Signalment, history, image findings, and follow-up data were recorded. Descriptive statistics were used to analyze the success rate of thoracic duct (TD) enhancement and describe relevant clinical findings. RESULTS: Enhancement of TDs was successful in 6 of the 7 cats within 5 to 15 minutes after initiating intrametatarsal pad injection under general anesthesia. Successful migration of contrast medium into the lymphatic vessels cranial to the popliteal lymph nodes was observed in all cats within 5 minutes after injection. The recommended dose of contrast medium to achieve TD enhancement was 1 mL/kg (0.5 mL/kg/pad; concentration, 350 mg of iodine/kg). Only 1 cat had mild swelling of the paws after the procedure, and it recovered quickly without pain medication; no cats experienced lameness. Similar to dogs and unlike in previously published reports, 72% of TD branches were located in the right hemithorax. CLINICAL RELEVANCE: CT lymphangiography via intrametatarsal pad injection is a feasible and safe procedure for cats with chylothorax. This technique provides detailed information regarding the unique TD anatomy and cisterna chyli location. It also contributes to surgical planning.

Anatomical variations of the thoracic duct in the dog.

Anatomical variations can be frequently found in the lymphatic system, which is also true for the shape and course of the thoracic duct (ductus thoracicus), the biggest lymph vessel in the body. From 2012 to 2019, the thoracic duct was successfully dissected in 43 dog carcasses that were used in the anatomy course at the Faculty of Veterinary Medicine, University of Zagreb. The thoracic duct originated from the cranial border of the cisterna chyli as one lymph vessel in 36 dogs (83.7%), as two vessels in six dogs (14%) and as three vessels in one dog (2.3%). We divided the observed thoracic duct variations into six groups according to their anatomical similarities. Considering the specific embryonic development, we can conclude that all observed variations are the result of minor deviations from the standard ontogenesis. However, the importance of thoracic duct variations is significant in surgical procedures done in the thoracic cavity to prevent or cure the chylothorax. Since this research showed variations in 39 out of 43 dogs (90.7%) throughout the whole course of the thoracic duct, great care must be taken while performing the ligation or embolization of the thoracic duct.

Complications and management of a long-term pleural access port in a dog with chronic chylothorax associated with lung lobe torsion.

A 2-year-old neutered male 35-kg golden retriever mixed breed dog was presented because of a 3-day history of increased respiratory effort. The patient was subsequently diagnosed with a lung lobe torsion and underwent lung lobectomy. Chylothorax developed after surgery and persisted for 3.5 y. Pleural access port (PAP) placement was used for long-term medical management. Several complications were encountered, including 2 episodes of PAP occlusion that were successfully treated with unfractionated heparin. The dog had a surgical site seroma and 2 episodes of pleuritis; euthanasia was elected after the second episode. Key clinical message: This case demonstrates successful long-term management of chylothorax with a pleural access port and management of 3 complications. Instead of the less accessible and more expensive tissue plasminogen activator, unfractionated heparin was used as an effective treatment for PAP occlusions.

Complications et prise en charge d'un port d'accès pleural à long terme chez un chien atteint de chylothorax chronique associé à une torsion d'un lobe pulmonaire. Un chien de race mélangée golden retriever mâle stérilisé âgé de 2 ans de 35 kg a été présenté en raison d'une histoire de 3 jours d'effort respiratoire accru. Le patient a été diagnostiqué avec une torsion du lobe pulmonaire et a subi une lobectomie pulmonaire. Un chylothorax s'est développé après la chirurgie et a persisté pendant 3,5 ans. Le placement du port d'accès pleural (PAP) a été utilisé pour la prise en charge médicale à long terme. Plusieurs complications ont été rencontrées, dont deux épisodes d'occlusion du PAP qui ont été traités avec succès avec de l'héparine non fractionnée. Le chien avait un séroma au site opératoire et deux épisodes de pleurésie; l'euthanasie a été choisie après le deuxième épisode.Message clinique clé :Ce cas démontre une prise en charge à long terme réussie du chylothorax avec un port d'accès pleural et une prise en charge de trois complications. Au lieu de l'activateur de plasminogène tissulaire moins accessible et plus coûteux, l'héparine non fractionnée a été utilisée comme traitement efficace pour les occlusions du PAP.(Traduit par Dr Serge Messier).

Canine idiopathic chylothorax: Anatomic characterization of the pre- and postoperative thoracic duct using computed tomography lymphography.

Surgical treatment has improved the prognosis of canine idiopathic chylothorax, although a recurrence of the disease occurs occasionally after the procedure. An improved understanding of possible causes for this recurrence would be helpful for prognosis and treatment planning in affected patients. In this retrospective case series study, we described the detailed pre- and postoperative computed tomographic lymphography (CTLG) imaging characteristics for a group of dogs with surgically confirmed idiopathic chylothorax. Preoperative CTLG was performed in 12 of 14 dogs diagnosed with idiopathic chylothorax. Thoracic ducts were present on the right side in 10 dogs, left side in one dog, and bilaterally in one dog. All the 14 dogs received a combination therapy of pericardiectomy and thoracic duct ligation (TDL) by video-assisted thoracoscopic surgery. One week after surgery, a postoperative CTLG was performed, and the thoracic ducts were apparent in seven of 14 dogs. Three dogs had an unchanged course of the thoracic duct, which could have resulted from a missed duct. Four dogs were identified as having a bypass formation: the oblique duct originated at the ligation site and connected to the duct on the other side. Our findings indicated that one of the possible causes for postoperative recurrence of chylothorax in dogs could be "invisible or sleeping" fine ducts that are collapsed and not visible in preoperative CTLG scans. After TDL causes a change in the pressure of lymphatic flow, these fine thoracic ducts may become apparent using postoperative CTLG.

Treatment of a heart base tumor and chylothorax with endovascular stent, stereotactic body radiation therapy, and a tyrosine kinase inhibitor in a dog.

An 8-year-old 28-kg male castrated rough collie was evaluated for persistent chylothorax secondary to right atrial mass. Cardiac ultrasound and computed tomography revealed a right atrial intra- and extraluminal mass with partial obstruction of the cranial vena cava and secondary chylothorax. Vascular stent placement was elected to alleviate cranial vena cava obstruction and secondary chylothorax. An 18 mm × 180 mm self-expanding stent was deployed in the region of the stricture, spanning the cranial vena cava and right atrium. An intrathoracic drainage catheter and subcutaneous port were placed within the right hemithorax, and antiplatelet therapy was initiated. Four weeks later, the dog underwent stereotactic body radiation therapy. Three months following treatment, the dog was diagnosed with supraventricular tachycardia and received antiarrhythmic therapy and antiangiogenic/antiproliferative medication (Palladia™). Subsequent evaluations confirmed the resolution of arrhythmia and pleural effusion. Combined vascular stent placement and stereotactic body radiation therapy for the treatment of a right atrial intraluminal and extraluminal mass leading to cranial vena cava compression and subsequent chylothorax may lead to long-term survival. A good outcome was achieved in this patient due to resolution of pleural effusion, as well as cytoreduction and presumably delayed progression of tumor growth.

Lymphaticovenous anastomosis of the caudal thoracic duct to an intercostal vein: A canine cadaver study.

OBJECTIVE: To describe a technique for anastomosis of the thoracic duct (TD) to the 11th or 12th intercostal vein (ICV) using a microvascular anastomotic coupler (MAC) in the dog. STUDY DESIGN: Cadaveric study. ANIMALS: Eight beagles. METHODS: A right paracostal laparotomy and 10th intercostal thoracotomy were performed in each dog. Mesenteric contrast lymphography was used to identify the TD and its branches on fluoroscopy. The TD and adjacent 11th or 12th ICV were isolated, double ligated, and divided using a surgical microscope. The caudal TD and proximal ICV were anastomosed in an end-to-end fashion using a 1.5 mm or 2 mm MAC. Mesenteric lymphography was repeated to document patency of the anastomosis. RESULTS: The TD was identified via lymphography in all dogs; five dogs had a single duct, and three dogs had additional branches. The anastomosis was successful in all eight dogs, and flow into the azygos vein without leakage was confirmed via lymphography. CONCLUSION: End-to-end anastomosis of the TD to an ICV using a MAC was technically feasible in the canine cadaver. CLINICAL SIGNIFICANCE: Lymphaticovenous anastomosis combined with TD ligation may have application as a treatment for idiopathic chylothorax. By maintaining the flow of chyle from the abdominal lymphatics to the systemic circulation, this procedure may reduce the stimulus for collateral circulation and persistent flow to the cranial mediastinal lymphatics.

Morphology of the cisterna chyli in nine dogs with idiopathic chylothorax and in six healthy dogs assessed by computed tomographic lymphangiography.

OBJECTIVE: To describe the morphology of the lymphatics in the region of the cisterna chyli in healthy dogs and in dogs with idiopathic chylothorax by using computed tomographic lymphangiography. STUDY DESIGN: Retrospective study. ANIMALS: Nine dogs with idiopathic chylothorax and six healthy dogs. METHODS: Computed tomographic lymphangiograms were reviewed to evaluate the number of cisterna chyli branches, total cross-sectional area of the branches normalized to the cross-sectional area of the aorta, number of branches with cross-sectional area greater than 25% of the aorta cross-sectional area, and ratio of the total perimeter to the total cross-sectional area of the branches. Data (mean ± SD) were compared between unaffected dogs and dogs with idiopathic chylothorax. RESULTS: The cisterna chyli included more branches in dogs with chylothorax (4.30 ± 1.57) than in unaffected dogs (1.67 ± 0.56, P = .02), occupying a relative perimeter approximately double that in unaffected dogs (P < .001). The relative cross-sectional area of the cisterna chyli was approximately twofold smaller in affected (0.73 ± 0.35) than in unaffected (1.63 ± 0.91, P = .02) dogs. The fraction of dogs with branches greater than 25% of the cross-sectional area of the aorta tended to be larger in unaffected dogs (P = .07). Most larger branches were located dorsal or to the right of the aorta. CONCLUSION: The cisterna chyli of dogs with idiopathic chylothorax contained smaller and more numerous branches compared with that of unaffected dogs. CLINICAL SIGNIFICANCE: Altered cisterna chyli morphology may impact the surgical approach for cisterna chyli ablation in dogs with idiopathic chylothorax.

[Granulomatous pleuritis and chylothorax caused by calcite inhalation in a Galgo Español dog]. / Granulomatöse Pleuritis und Chylothorax durch Kalzitinhalation bei einem Galgo Español.

A 6-year-old, male Galgo Español dog was presented with severe dyspnea. Radiography and ultrasonography revealed pleural effusion. Approximately 4 l of a milky and slightly reddish fluid were aspirated and drained from the thoracic cavity. Clinical chemistry examination of the fluid indicated a modified transudate with a high amount of triglycerides. On cytological examination, degenerated neutrophilic granulocytes, small lymphocytes, macrophages and chylomicrons were found. A chest tube was placed and computed tomography was performed, which indicated thickening of parietal and visceral pleura and enlargement of the sternal lymph node without abnormal findings in the lungs. During subsequent thoracoscopy disseminated proliferative masses, appearing as small white nodules, covering nearly the entire pleural surface were found and biopsies were taken for further analysis. Histopathologic diagnosis was a granulomatous pleuritis with intralesional birefringent foreign material. Energy dispensive x-ray emission analysis was used to determine the origin of the material. Scanning electron microscopy revealed high amounts of calcium containing foreign material (calcite) within the granulomas. An extended clinical history of the dog gave evidence that the animal had lived next to a construction site 15 months earlier and may well have inhaled the calcium-containing dust. Treatment with prednisolone was initiated, however the dog developed gastro-intestinal side effects and treatment was stalled after 10 weeks. Dyspnea and liquidothorax re-occurred 4 months later. A further attempt of immunosupressive treatment was commenced, using a combination of prednisolone and ciclosporine, which again was not tolerated by the patient. The dog finally developed pneumonia and was euthanized by the owner's request.

Computed tomographic lymphangiography via intra-metatarsal pad injection is feasible in dogs with chylothorax.

Lymphangiography can be useful for preoperative planning in chylothorax. Conventional ultrasound-guided intranodal injection can be difficult in some cases and is dependent upon operator skill. Alternative methods have been proposed to simplify the procedure, but their feasibility has not been sufficiently evaluated in clinical cases. The primary purpose of this multicenter, retrospective, descriptive study was to assess the feasibility and describe the clinical findings of CT lymphangiography by intrametatarsal pad injection in dogs with naturally occurring chylothorax. Twenty dogs were analyzed, and enhancement of thoracic ducts (TDs) was successful in 18 (90%) dogs within 5-14 min after initiating the injection, while successful enhancement of the lymphatic vessels cranial to the popliteal lymph nodes was seen in all dogs within 5 min after injection. The dose with good success to achieve TD enhancement was 1 mL/kg (concentration 350 mg I/kg). Only two dogs had mild discomfort after recovery from general anesthesia. Computed tomography lymphangiography by intrametatarsal pad injection is a feasible, easy, and safe procedure, which could provide adequate TD and cisterna chyli enhancement, identify TD number and cisterna chyli location and structure, and contribute to surgical planning.

Anatomic and volumetric characterization of the cisterna chyli using CT lymphangiography and computer-assisted design software in dogs with idiopathic chylothorax.

The objectives of this retrospective, observational study were to characterize the anatomical features of the cisterna chyli (CC) in a cohort of dogs diagnosed with idiopathic chylothorax that underwent CT lymphangiography (CTLa), and to evaluate the feasibility of computer-assisted design (CAD) software to quantify volumetric measurements of the CC. Twenty-three client-owned dogs with idiopathic chylothorax were included. Additionally, CTLa was performed in three canine cadavers to assess the ability of CAD software to accurately acquire volumetric measurements. Injection sites, attenuation values, anatomic location, dimensions, and aortic diameter to CC ratio (Ao:CC) were recorded. Video records of video-assisted thoracic surgery (VATS) thoracic duct ligation (TDL) were reviewed in eight out of 23 dogs to compare operative and CTLa findings. The CC was dorsal and right-sided in 18 out of 23 dogs, located between L1 and L4 in 21 dogs, and extended as far cranially as T11 in two dogs. The median measurements for length, height, and width were 150.0, 5.5, and 13.3 mm, respectively. Median total volume was 1.82 mL. Median volumes to the right and left of the aorta were 1.46 and 0.49 mL, respectively (P = .014). Median total CC volume to body weight ratio (CC:bw) was 0.07 mL/kg. The presence of an intrathoracic CC was observed intraoperatively in six out of eight cases that underwent VATS TDL. Findings supported the use of CTLa and CAD as feasible methods for characterizing the CC in dogs diagnosed with chylothorax. These methods may facilitate interventional planning involving the CC such as embolization.

Treatment of idiopathic chylothorax in dogs and cats: A systematic review.

OBJECTIVE: To evaluate the evidence published on the treatment of idiopathic chylothorax (IC) in small animals. STUDY DESIGN: Systematic literature review. SAMPLE POPULATION: Dogs and cats with IC. METHODS: A literature search was performed in three bibliographic databases in July 2018 for publications on IC in dogs and cats. Articles meeting criteria for inclusion were evaluated for treatment, survival, outcome data, and level of evidence (LoE) with a modified Oxford Level of Evidence (mOLE) and GRADE (Grading of Recommendations, Assessment, Development and Evaluations) system. RESULTS: Eleven of 313 identified articles met the inclusion criteria. Only one study was identified in dogs as having higher LoE by using the mOLE system, whereas no study was identified as such in either species with the GRADE system. Surgery was the primary treatment in all dogs and in 93% (68/73) of cats. Medical therapy was the primary treatment in 7% (5/73) of cats. The most common surgical treatment combined thoracic duct ligation (TDL) and subtotal pericardiectomy (SP; 40%; 34/84) in dogs and TDL in cats (51% [37/73]). CONCLUSION: The body of literature for IC treatment in small animals was limited to one higher LoE study in dogs and none in cats. No strong conclusion could be drawn regarding the effectiveness of any one surgical method in dogs or cats, and no evidence was found to support medical therapy as a primary treatment. CLINICAL SIGNIFICANCE: The best available evidence regarding the treatment of IC is published in dogs and provides some support for surgical treatment with either TDL + cisterna chyli ablation or TDL + SP. Additional evidence is required to confirm this finding.

Computed tomographic lymphangiography of the thoracic duct by subcutaneous iohexol injection into the metatarsal region.

OBJECTIVE: To evaluate the efficacy of subcutaneous iohexol injection into the metatarsal region for thoracic duct lymphangiography in dogs and to determine the minimum effective dose. STUDY DESIGN: Experimental study and clinical report. ANIMALS: Five healthy beagle dogs and one dog with chylothorax. METHODS: For the experimental study, iohexol was injected subcutaneously into the metatarsal region of five dogs at three doses (0.5, 0.75, and 1 mL/kg), and the injection sites were massaged gently. Computed tomography (CT) was performed 1, 3, 5, 7, 10, 15, and 20 minutes after iohexol injection. Subjective quality was assessed, and Hounsfield unit values were measured at several regions of interest (T1, T4, T8, T13, and L3). In the dog with chylothorax, iohexol (1.0 mL/kg) was injected into the right metatarsal region prior to CT. RESULTS: The thoracic duct was visualized and enhanced by contrast in all dogs after injection of 0.75 and 1.0 mL/kg of iohexol, and in two dogs after injection of 0.5 mL/kg at 3, 5, and 7 minutes. The thoracic duct was gradually attenuated with increasing doses of iohexol. In the dog with chylothorax, the entire thoracic duct was well enhanced and dilated, and tortuous cranial mediastinal lymphatics were detected. CONCLUSION: The thoracic duct was visualized when at least 0.75 mL/kg of iohexol was injected subcutaneously into the metatarsal region of dogs. CLINICAL SIGNIFICANCE: Subcutaneous injection of iohexol into the metatarsal region offers a simple alternative to conventional thoracic duct lymphangiography.

Efficacy of en bloc thoracic duct ligation in combination with pericardiectomy by video-assisted thoracoscopic surgery for canine idiopathic chylothorax.

OBJECTIVE: To compare the outcomes of pericardiectomy performed with conventional clipping thoracic duct ligation (C-TDL) to those with en bloc thoracic duct ligation (EB-TDL) using video-assisted thoracoscopic surgery (VATS) for canine idiopathic chylothorax. STUDY DESIGN: Retrospective consecutive case series. ANIMALS: Thirteen client-owned dogs with idiopathic chylothorax. METHODS: Medical records of dogs treated with pericardiectomy in combination with TDL by VATS without intraoperative contrast were reviewed. Five and seven dogs underwent C-TDL and EB-TDL, respectively, and 11 dogs were evaluated by preoperative and 7- to 10-days-postoperative computed tomography-lymphography (CTLG). No clinical symptoms with absent or minimal pleural effusion was defined as clinical improvement. Long-term remission (LTR) was defined as rapid resolution of pleural effusion and no recurrence for more than 1 year. Anesthesia time, operation time, the duration of hospitalization, and time until pleural effusion resolution were compared. RESULTS: Clinical improvement was achieved in 91.7% of the cases (C-TDL, 4/5; EB-TDL, 7/7), excluding one case of intraoperative death. The LTR rate was significantly higher with EB-TDL (6/7 [85.7%]) than with C-TDL (1/5 [20%]). Anesthesia time, operation time, and time until pleural effusion resolution were significantly better with EB-TDL than with C-TDL. The rates of thoracic ducts visualization by postoperative CTLG were 100% (5/5) with C-TDL and 42.9% (3/7) with EB-TDL. CONCLUSION: En bloc TDL was an effective treatment for canine idiopathic chylothorax in this patient population. It compared favorably to C-TDL, although missed branches at the time of surgery may explain the difference between C-TDL and EB-TDL in this small population of cases. CLINICAL SIGNIFICANCE: En bloc TDL by VATS was an effective minimally invasive treatment for canine idiopathic chylothorax. Computed tomography-lymphography can be used for surgical planning and postoperative evaluation.