Reconstruction surgery using polypropylene mesh after extensive resection of a costal osteosarcoma in a dog.

Osteosarcoma is the most common tumour that develops in the chest wall of dogs; an extensive excision is the treatment of choice. Various methods have been reported for reconstruction of chest wall defects following extensive excision. The objective of this report was to describe the complete resection of an extensive costal osteosarcoma with an extended resection of the ribs and part of the diaphragm in a dog. An 11-year-old neutered, male, miniature pinscher was presented with dyspnoea: An extensive mass was observed, stretching from the right chest wall to the abdominal wall. On computed tomography, the mass originated from the right 9th rib and exceeded the 6th rib on the cranial side and the 13th rib on the caudal side; it was compressing the lungs, diaphragm, liver, stomach and duodenum. When the patient's condition was medically stabilized, the tumour was removed from the right 9th rib. In consideration of the surgical margin, the 5th-13th ribs were excised, and the tumour was resected with the thoracoabdominal wall and part of the diaphragm. The missing thoracoabdominal wall and section of the diaphragm were reconstructed using two sheets of a polypropylene mesh. Postoperatively, flail chest was observed, although dyspnoea was not observed in the patient. Histopathological examination confirmed the diagnosis of osteosarcoma with a clean margin. Although 60.6 months have passed post-surgery, no metastasis has reoccurred. In this case, complete resection and reconstruction of the chest wall and diaphragm were achieved using a polypropylene mesh without fatal postoperative complications, despite extensive osteosarcoma resection.

Retrospective analysis of perineal herniorrhaphy with cone-shaped polypropylene mesh in dogs: technique description and outcome.

Introduction: This study aimed to describe the technique for the surgical repair of perineal hernia (PH) in dogs using a polypropylene mesh (PM) and to evaluate its outcomes. Methods: All dogs were placed in the Trendelenburg position. Castration and caudal celiotomy for cystopexy and colopexy were performed as needed. Ipsilateral perianal incision was performed in the affected hernia side. A PM was formed a cone-shape with suturing and placed in hernial foramen. The PH was repaired with suturing between PH and pelvic diaphragm including the sacrotuberous ligament, internal obturator muscle, and external anal sphincter muscle. The medical records of all dogs were reviewed to evaluate signalment, perioperative findings, postoperative complications, and prognosis. Results: Of the 22 dogs, 15 were intact, and 7 were previously neutered. The median age and body weight were 10 years and 6.8 kg, respectively. The PH reconstruction using a cone-shaped PM was feasible in all dogs. The median operative time was 60.5 min for unilateral PH and 109 min for bilateral PH. Major postoperative complications occurred in seven dogs (32%), and three dogs (14%) had a recurrence of PH. In the long-term (> 2 weeks) follow-up period, 16 dogs (73%) had an excellent prognosis. Discussion: Our study suggests that PH reconstruction surgery using a cone-shaped PM may be a viable treatment method for PH in dogs. Therefore, a cone-shaped PM could serve as an alternative treatment option for canine PH reconstruction.

Percutaneous transvenous coil embolization (PTCE) for treatment of single extrahepatic portosystemic shunt in dogs.

BACKGROUND: There is limited information regarding percutaneous transvenous coil embolization (PTCE) for single extrahepatic portosystemic shunt (PSS). This study aimed to describe the procedure and outcome of PTCE in dogs with a single extrahepatic PSS. Forty-two privately owned dogs were included in this study. All dogs were diagnosed with extrahepatic PSS by computed tomography (CT). Preoperative CT images were used to evaluate the diameter of the PSS for coil placement. A multipurpose balloon catheter was percutaneously inserted into the PSS via the jugular vein, and transvenous retrograde portography (TRP) and measurement of blood pressure in the PSS (pPSS) were performed during balloon inflation; one or more embolization coils were implanted via the catheter. RESULTS: In most cases, preoperative median fasting and postprandial serum total bile acid (TBA) concentrations were high (fasting, 86.5 µmol/L [ 3.7-250.0 µmol/L]; postprandial, 165.5 µmol/L [ 1.5-565.0 µmol/L]). CT revealed that 30 dogs had left gastrophrenic shunt; eight had left gastroazygos shunt; and one each had left gastrocaval, splenocaval, splenophrenic, and left colocaval shunt. TRP revealed that intrahepatic portal vascularity was clearly detectable in all dogs. The median values of pPSS before and during the balloon occlusion were 4.8 mmHg [2.0-13.0 mmHg] and 8.6 mmHg [5.0-18.0 mmHg], respectively. The median number and diameter of coils used were 2 coils [1 - 5 coils] and 8.0 mm [4.0 - 12.0 mm], respectively. The median times of irradiation and PTCE were 9 min [4-26 min] and 40 min [23-75 min], respectively. The median fasting and postprandial TBAs significantly decreased to 8.2 µmol/L [0.3-45.1 µmol/L, n = 38, p = 0.0028] and 19.8 µmol/L [0.3-106.7 µmol/L, n = 38, p = 0.0018], respectively, approximately 1 month after PTCE. The clinical success rate of PTCE without requirement for a second surgery was 95.2% (40/42 dogs). During revision surgery, one dog underwent surgical ligation and, in another dog, an ameroid constrictor was placed. CONCLUSIONS: PTCE was clinically effective in treating single extrahepatic PSS in dogs. Preoperative CT and TRP prior to PTCE might be clinically valuable for choosing the size of embolization coils, deciding the appropriate location of coil implantation, and estimating the number of coils to be implanted. PTCE is a promising alternative to conventional surgical procedures for single extrahepatic PSS in dogs.

Preemptively planned en bloc resection of an extensive right adrenal pheochromocytoma involving the right hepatic division, caval thrombus and segmental caudal vena cava in a dog with Budd-Chiari-like syndrome.

BACKGROUND: Surgical resection is the treatment of choice for canine adrenal pheochromocytomas (PHEOs). Information on en bloc resection of adrenal PHEO with tumour thrombus, right hepatic division and segmental caudal vena cava (CVC) running through the adrenal tumour and right hepatic division is limited. OBJECTIVE: To describe the preemptively planned en bloc resection of an extensive right adrenal PHEO involving the right hepatic division, the caval thrombus and the segmental CVC in a dog with Budd-Chiari-like syndrome (BCLS). METHODS: A 13-year-old castrated male miniature dachshund was referred for surgical treatment due to anorexia, lethargy and severe abdominal distension caused by abundant ascites. Preoperative computed tomography (CT) revealed a large mass in the right adrenal gland with a large caval thrombus obstructing the CVC and hepatic veins, which caused BCLS. Additionally, collateral vessels were formed between the CVC and azygos veins. No findings suggested obvious metastases. Based on CT findings, an en bloc resection of the adrenal tumour with caval thrombus, right hepatic division and segmental CVC was planned. RESULTS: The preoperatively planned resection was feasible; the tumour was completely resected grossly. The operation time and total Pringle manoeuvre time were 162 min and 16 min 56 s, respectively. There was no postoperative hindlimb oedema, renal dysfunction, ascites or abdominal distention. The patient's clinical signs, including appetite, fully improved. Hospitalization lasted 16 days. However, the patient died on the 130th postoperative day due to suspected metastases and cachexia. CONCLUSIONS: Even in case of an extensive infiltration of adrenal PHEO causing BCLS, an en bloc resection might be successfully achieved based on the preoperative CT findings speculating the collateral vessels formed for caudal venous return.

Impact of near-infrared fluorescence imaging with indocyanine green on the surgical treatment of pulmonary masses in dogs.

Objectives: To investigate the intraoperative identification and complete resection of pulmonary masses, and to evaluate lymph node metastasis of pulmonary malignant tumors in dogs using indocyanine green (ICG) fluorescence imaging. Methods: Forty dogs with pulmonary masses were included, all of which underwent surgical treatment. ICG fluorescence imaging was performed on pulmonary masses before lobectomy and the resection margins after lobectomy. In addition, ICG fluorescence of the excised masses and lymph nodes was evaluated in the shaded box. The fluorescence findings were compared with the histopathological diagnosis. Results: Of 44 nodules resected from 40 dogs, 32 nodules were histopathologically diagnosed as lung adenocarcinoma, five were histiocytic sarcoma, three were undifferentiated sarcoma, two were malignant epithelial tumor metastases, one was carcinosarcoma, and one was a non-neoplastic lesion. Fluorescence was observed in all nodules. In addition to the main lesion, other fluorescent nodules were found in four dogs. Regarding the diagnostic accuracy of complete resection based on ICG fluorescence, the sensitivity was 67.7% and the specificity was 60.0%. The sensitivity and specificity of ICG fluorescence for the diagnosis of lymph node metastasis were 100 and 75.0%, respectively. Conclusions: ICG fluorescence imaging might be a useful intraoperative diagnostic method to identify the location of tumors and lymph node metastasis, but not to evaluate complete tumor resection, in dogs with pulmonary malignant tumors.

Glucoregulatory factors in canine hepatocellular carcinoma and leiomyosarcoma with non-islet cell tumour hypoglycaemia.

INTRODUCTION: Hypoglycaemia caused by malignant tumours other than insulinoma is referred to as non-islet cell tumour hypoglycaemia (NICTH), which may be caused by hepatocellular carcinoma (HCC) and leiomyosarcoma (LMS) in veterinary medicine. However, the pathogenetic mechanism of NICTH remains unclear. Therefore, this study aimed to evaluate the gene-expression levels of glucoregulatory factors in canine HCC and LMS accompanied by hypoglycaemia. MATERIALS & METHODS: Four patients (three with HCC and one with LMS) exhibiting hypoglycemia were included in the hypoglycemic (H) group, whereas ten patients not exhibiting hypoglycemia were in the non-hypoglycaemia (NH) group. The preoperative and postoperative blood glucose and serum insulin-like growth factor-2 (IGF-2) levels, as well as the expression of genes involved regulating blood glucose levels were analysed. RESULTS: Compared with the NH group, the H group exhibited significantly decreased blood-glucose levels, which increased to normal values after surgery. Compared with the NH group, the H group exhibited significantly increased gene expression of insulin-like growth factor 1, IGF-2, and insulin-like growth factor binding protein 3 in the tumours. Conversely, expression of genes encoding glucoregulatory factors including insulin, gastric inhibitory polypeptide and glucagon was not observed. Serum IGF-2 levels were significantly higher in the H group compared with that in the control group (healthy dogs) and NH group. In two cases in the H group, serum IGF-2 levels decreased after tumour resection. CONCLUSION: These results suggest that NICTH development in dogs with HCC and LMS is mechanistically associated with IGF-2 overexpression and elevated serum IGF-2 levels.

Clinical impact of near-infrared fluorescence imaging with indocyanine green on surgical treatment for hepatic masses in dogs.

BACKGROUND: Near-infrared fluorescence imaging using indocyanine green (ICG) is clinically applied to intraoperatively identify hepatic masses in humans. In addition, it is reported to be effective for assessing complete resection in human hepatocellular carcinoma (HCC). However, there is limited information on ICG fluorescence imaging for canine HCC, and its clinical usefulness is still unclear. Therefore, the purpose of this study was to evaluate the intraoperative identification and status of surgical margin for canine hepatic masses using near-infrared ICG fluorescence imaging. This clinical study included 104 dogs with hepatic masses. Between 12 and 24 h prior to surgery, ICG solution was injected intravenously at a dose of 0.5 mg/kg. The fluorescence intensity and pattern of each hepatic mass was investigated using an infrared camera before resection. After resection, the fluorescence intensity of the resection margin was also investigated. The resected masses were histopathologically diagnosed and compared using ICG fluorescence imaging. RESULTS: One hundred and twenty-two masses obtained from 104 dogs included 76 HCCs, 16 hepatocellular adenomas, 12 focal nodular hyperplasias, and 18 other lesions. Of the 122 masses, 106 (94 partial, 9 whole, and 3 ring fluorescence patterns), 7, and 9 masses showed increased, the same, or decreased fluorescence compared to the normal liver tissue, respectively. The fluorescence intensity and pattern were not significantly related to the histopathological diagnosis. The sensitivity and specificity of the margin evaluation in the 47 dogs were 100% and 77.3%, respectively. The median survival times in cases of HCC with complete and incomplete resection were 914 and 254 days, respectively. The median survival time of patients with a complete resection was significantly longer than that of patients with a incomplete resection (p = 0.043). CONCLUSION: ICG fluorescence imaging has potential clinical value for the identification and margin evaluation of canine hepatic masses. Although it is difficult to use fluorescence imaging for the differential diagnosis of liver tumours, it may be useful for assessing complete resection in cases of hepatic masses demonstrating increased fluorescence in dogs, and complete resection of HCC could have a survival benefit.

Perineal herniorrhaphy with pedunculated tunica vaginalis communis in dogs: Description of the technique and clinical case series.

Background: Perineal hernia (PH) in dogs is caused by the separation of the anal septal muscles and the displacement of pelvic/abdominal organs under the perineal skin. Reconstruction of the pelvic septum by surgical repositioning is the only curative treatment. Objectives: To describe the procedure and outcomes of surgical repair using the pedunculated tunica vaginalis communis (TVC) for PH in dogs. Methods: Intact male dogs diagnosed with PH were included in this study. For surgery, each dog was positioned in the Trendelenburg position. Castration was performed with the open technique, followed by colopexy and cystopexy via laparotomy. The remaining bilateral TVCs transposed to the opening of PH were used for the perineal herniorrhaphy. Intraoperative findings, complications, and outcomes were evaluated and recorded. Results: Eight dogs [median age 10.5 years (range, 9-13 years); median body weight 4.9 kg (range, 1.6-12.3 kg)] were treated using the TVC surgical technique. Perineal herniorrhaphy with the TVC was feasible in all dogs. The median operation time was 105.5 min (range, 46-149 min) in unilateral PH, and 92 and 122 min in two dogs with bilateral PH. Short-term postoperative complications during hospitalization did not occur in six dogs, whereas the residual two dogs had a temporary local infection as a minor complication. Postoperative recurrence occurred in one dog (13%) on postoperative day 136. Conclusions: Our study suggests that the herniorrhaphy technique using the pedunculated TVC is an alternative option for the repair of PH in dogs.

Gene expression of Nectin-4 and its clinical significance in dogs with primary lung adenocarcinoma.

BACKGROUND: Canine primary lung adenocarcinoma (CPLA) is suspected by radiography or computed tomography; however, since there are no tumour markers, early diagnosis is difficult, and the prognosis is poor due to increased tumour volume. Nectin-4 has been reported to be expressed in human lung, ovarian, and pancreatic cancers and promotes tumour growth. It has been reported to be a tumour marker and prognostic factor, and oncolytic virotherapy is being investigated using nectin-4 as a therapeutic target. OBJECTIVES: The purpose of this study was to investigate the expression of Nectin-4 in CPLA and its clinical significance in dogs with pulmonary adenocarcinomas. METHODS: The relationships between Nectin-4 expression and signalling, tumour volume, tumour weight, and prognosis were analyzed in 34 CPLA patients. RESULTS: The expression of canine Nectin-4 (high Nectin-4) was found in 25 of 34 cases (73%), and Nectin-4 expression levels did not show any significant associations with gender, body weight, and tumour stage. However, there was a significant positive correlation between Nectin-4 expression and tumour volume (r = 0.623, p < 0.05) and tumour weight (r = 0.735, p < 0.05). Regarding prognosis, the median survival time was 427 days in high Nectin-4 cases and 420 days in cases with no Nectin-4 expression. CONCLUSION: Our study demonstrated that Nectin-4 is highly expressed in CPLA. In addition, nectin-4 might be a tumour growth factor in CPLA and thus is a promising biomarker for CPLA. Further investigations on nectin-4 in CPLA are warranted for its diagnosis and novel targets for oncolytic virotherapy.

Quantitative analysis of contrast-enhanced ultrasound estimates intrahepatic portal vascularity in dogs with single extrahepatic portosystemic shunt.

OBJECTIVE: To evaluate the clinical impact on quantitative analysis of contrast-enhanced ultrasound (CEUS) on single extrahepatic portosystemic shunt (PSS) in dogs. ANIMALS: 21 client-owned dogs with single extrahepatic PSS and 5 healthy Beagles. PROCEDURES: In all dogs, CEUS was performed to calculate the rising time (RT), rising rate (RR), and portal vein-to-hepatic parenchyma transit time (ΔHP-PV) from the time-intensity curve obtained in the hepatic parenchyma and portal vein. All dogs in the PSS group underwent preoperative CT angiography (CTA) and surgery. The CEUS variables in the PSS group were compared with those in the healthy dogs (control group) and were analyzed for shunt types and grades of intrahepatic portal venous branches based on CTA findings, intraoperative portal pressure, and surgical procedures. RESULTS: All 3 CEUS variables showed no significant differences between the PSS and control groups. The RT and ΔHP-PV in the left gastrophrenic shunt group were significantly longer than in the other shunt types. In the intrahepatic portal vascularity, the RT in grade 1 was significantly shorter than in grades 3 and 4, and the RR in grade 1 was significantly higher than in grade 4. The RT and ΔHP-PV were significantly correlated with portal pressure variables. The RT in dogs with partial ligation was significantly shorter than in dogs with complete ligation and percutaneous transvenous coil embolization. CLINICAL RELEVANCE: Quantitative assessments of CEUS may be useful for estimating intrahepatic portal vascularity in dogs with single extrahepatic PSS.

Serum vascular endothelial growth factor in dogs with various proliferative diseases.

Angiogenesis plays an important role in the proliferation and metastasis mechanisms of malignant tumors. Vascular endothelial growth factor (VEGF), a group of cytokines that contribute to angiogenesis and vasculogenesis. This study aimed to investigate the serum VEGF-A concentrations in dogs with various proliferative diseases. A total of 202 dogs that were histopathologically diagnosed with proliferative diseases were included in the study. Serum VEGF-A concentrations were measured using enzyme-linked immunosorbent assay. Median serum VEGF-A concentrations in dogs were as follows: healthy dogs, 4 pg/ml [0-21 pg/ml]; hepatocellular carcinoma, 30 pg/ml [0-158 pg/ml, P=<0.001]; hepatocellular adenoma, 32 pg/ml [0-49 pg/ml, P=0.003]; hepatic nodular hyperplasia, 18 pg/ml [0-51 pg/ml, P=0.595]; adrenal pheochromocytoma, 32 pg/ml [0-187 pg/ml, P=<0.001]; adrenocortical carcinoma, 32 pg/ml [3-161 pg/ml, P=0.002]; adrenocortical adenoma, 27 pg/ml [0-106 pg/ml, P=0.005]; colorectal adenocarcinoma, 36 pg/ml [0-75 pg/ml, P=0.002]; colorectal adenoma, 43 pg/ml [0-48 pg/ml, P=0.144]; inflammatory colorectal polyps, 37 pg/ml [0-111 pg/ml, P=<0.001]; pulmonary adenocarcinoma, 35 pg/ml [4-107 pg/ml, P=0.002]; pulmonary histiocytic sarcoma, 35 pg/ml [0-131 pg/ml, P=0.016]; and follicular thyroid carcinoma, 35 pg/ml [0-106 pg/ml, P=0.009]. The serum VEGF-A concentrations were significantly higher in dogs with neoplastic lesions compared to healthy dogs, except for colorectal adenoma. High serum VEGF-A concentrations were observed in dogs with proliferative diseases. The present study suggests that angiogenesis-inhibiting therapy, which targets VEGF-A, may be useful for canine neoplastic diseases.

Clinical, diagnostic, and pathologic features and surgical outcomes of combined hepatocellular-cholangiocarcinoma in dogs: 14 cases (2009-2021).

OBJECTIVE: To describe the clinical, diagnostic, and pathological features and postoperative prognosis of canine combined hepatocellular-cholangiocarcinoma (cHCC-CCA). ANIMALS: 14 privately owned dogs that underwent surgical treatment. PROCEDURES: The medical records, including signalment, clinical signs, blood test, urine analysis, computed tomography (CT) findings, intraoperative findings, and pathological findings, were retrospectively reviewed in the dogs with cHCC-CCA. RESULTS: Of 306 dogs that underwent surgical removal of hepatic masses, 14 dogs (4.6%) were pathologically confirmed to have cHCC-CCA. Median age and body weight were 11.3 years and 7.3 kg, respectively. There were no specific clinicopathological findings for cHCC-CCA. CT revealed a massive hepatic mass in all dogs and the inclusion of cyst-like lesions within the mass in 13 dogs. Intrahepatic metastases were found at time of surgery in 2 dogs (14.3%). Of the residual 12 dogs, 1 dog showed postoperative formation of intrahepatic nodules suggestive of metastases and another had intrahepatic and pulmonary nodules and a forelimb skin mass, suggesting postoperative metastases. The median survival time of the patients with cHCC-CCA was 700 days (range, 10 to 869 days) after surgery. CLINICAL RELEVANCE: To the authors' knowledge, this is the first study to describe the clinical, diagnostic, and pathological features and postoperative prognosis of canine cHCC-CCA. The clinical and diagnostic features of canine cHCC-CCA might be more similar to those of HCC rather than to those of CCA, but the preoperative diagnosis differentiating between HCC and cHCC-CCA was challenging. Our study suggests that the postoperative prognosis of canine patients with cHCC-CCA is similar to that of dogs with HCC.