Virtual indigo carmine chromoendoscopy images: A novel modality for peroral cholangioscopy using artificial intelligence technology (with video).

BACKGROUND AND AIMS: Accurately diagnosing biliary strictures is crucial for surgical decisions, and although peroral cholangioscopy (POCS) aids in visual diagnosis, diagnosing malignancies or determining lesion margins via this route remains challenging. Indigo carmine is commonly used to evaluate lesions during gastrointestinal endoscopy. We aimed to establish the utility of virtual indigo carmine chromoendoscopy (VICI) converted from POCS images using artificial intelligence. METHODS: This single-center, retrospective study analyzed 40 patients with biliary strictures who underwent POCS using white light imaging (WLI) and narrow-band imaging (NBI). A "cycle-consistent adversarial network" (CycleGAN) was used to convert the WLI into VICI of POCS images. Three experienced endoscopists evaluated WLI, NBI, and VICI via POCS in all patients. The primary outcome was the visualization quality of surface structures, surface microvessels, and lesion margins. The secondary outcome was diagnostic accuracy. RESULTS: VICI showed superior visualization of the surface structures and lesion margins compared with WLI (P<0.001) and NBI (P<0.001). The diagnostic accuracies were 72.5%, 87.5%, and 90.0% in WLI alone, WLI and VICI simultaneously, and WLI and NBI simultaneously, respectively. WLI and VICI simultaneously tended to result in higher accuracy than WLI alone (P=0.083) and the results were not significantly different from WLI and NBI simultaneously (P=0.65). CONCLUSIONS: VICI in POCS proved valuable for visualizing surface structures and lesion margins and contributed to higher diagnostic accuracy comparable to NBI. In addition to NBI, VICI may be a novel supportive modality for POCS.

Immunophenotyping of Nonneoplastic and Neoplastic Histiocytes in Cats and Characterization of a Novel Cell Line Derived From Feline Progressive Histiocytosis.

Histiocytic proliferative diseases are rare in cats, and their pathogenesis is poorly understood. In the present study, 25 cases of histiocytic sarcoma (HS) and 6 of feline progressive histiocytosis (FPH) were examined, and survival times were recorded in 19 cases. The immunophenotypes of tumor cells in these cases as well as of nonneoplastic feline histiocytes were characterized using formalin-fixed, paraffin-embedded tissues. An FPH cell line (AS-FPH01) and xenotransplant mouse model of FPH were also established. The median survival time of HS (150 days) was significantly shorter than that of FPH (470 days). Immunohistochemically, nonneoplastic histiocytes were immunopositive for various combinations of Iba-1, HLA-DR, E-cadherin, CD204, CD163, CD208, and MAC387. By immunohistochemistry, dermal interstitial dendritic cells (iDCs) and macrophages were CD204+/E-cadherin-, while epidermal Langerhans cells (LCs) were CD204-/E-cadherin+. Neoplastic cells of 4 FPH and 18 HS were CD204+/E-cadherin- (iDC/macrophage immunophenotype), while 2 FPH and 2 HS were CD204-/E-cadherin+ (LC immunophenotype), and 5 HS were CD204+/E-cadherin+ (LC-like cell immunophenotype). Furthermore, immunohistochemical and western blot analyses of AS-FPH01 cells derived from E-cadherin-negative FPH revealed that cultured cells were immunopositive for both CD204 and E-cadherin in vitro and in vivo. These results indicate that the neoplastic cells of feline HS and FPH were variably positive for iDC/macrophage and LC markers, and their immunophenotype changed in different microenvironments. The novel cell line established in the present study may serve as an experimental model of FPH that will enable further molecular and therapeutic studies on this disease.

Efficacy of post-dilatation during carotid artery stenting for unstable plaque using closed-cell design stent evaluated by optical coherence tomography.

BACKGROUND AND PURPOSE: This study aimed to use optical coherence tomography (OCT) to evaluate the efficacy of post-dilatation (PD) after stent placement for unstable plaques during carotid artery stenting (CAS) using closed-cell design stent. MATERIALS AND METHODS: Twelve unstable carotid plaque lesions diagnosed by magnetic resonance imaging were evaluated by OCT during CAS. Pre-procedural minimum lumen diameter and area were 1.5 ± 0.6 mm and 2.6 ± 1.6 mm2, respectively. The lesion was pre-dilated with balloon catheters (diameter 4.8 ± 0.3 mm), and closed-cell stent was deployed. PD was performed with balloon catheters of the same size as those used for pre-dilatation. Minimum lumen diameter/area and in-stent tissue prolapse volume after stent placement and after PD were calculated by 2-dimensional cross section images. The number of the stent cells showing tissue prolapse and malapposition after stent-placement and after PD were calculated by 3-dimensional analysis. RESULTS: Compared to after stent placement, in-stent tissue prolapse volume (0.18 ± 0.10 to 0.22 ± 0.07 mm2/slice, P < 0.01), number of stent cells with any tissue prolapse (12.7 ± 8.2 to 21.0 ± 11.8%, P < 0.001) were significantly increased after PD; stent cells with ≥ 500-µm tissue prolapse (1.6 ± 1.1 to 0.7 ± 0.8%, P < 0.01) and stent malapposition (17.4 ± 7.2 to 14.0 ± 6.3%, P < 0.01) were significantly decreased. CONCLUSIONS: PD after carotid stent placement caused increase in in-stent tissue prolapse volume and small tissue prolapse, however, the in-stent large tissue prolapse decreased, as the in-stent tissue prolapse may have been crushed into debris.

Predictors of antegrade flow at internal carotid artery during carotid artery stenting with proximal protection.

BACKGROUND: Carotid artery stenting (CAS) with proximal occlusion effectively prevent distal cerebral embolism by flow arrest at internal carotid artery (ICA); however, the method can expose antegrade flow at ICA due to incomplete flow arrest. The aim of this study was to identify predictors of antegrade flow during CAS with proximal protection. METHODS: We retrospectively analyzed clinical and angiographic data among 143 lesions treated with CAS with proximal protection by occluding the common carotid artery (CCA) and external carotid artery (ECA). Flow arrest or antegrade flow at ICA was confirmed by contrast injection during proximal protection. RESULTS: Antegrade flow at ICA was observed in 12 lesions (8.4%). Compared with lesions in which flow arrest of ICA was achieved, the diameter of the superior thyroid artery (STA) was significantly larger (2.4 ± 0.34 vs. 1.4 ± 0.68 mm, p < 0.001), and the rate of ECA branches other than the STA located 0-10 mm above the bifurcation was significantly higher (50 vs. 8.4%, p < 0.001). Results of multivariate analysis revealed that a diameter of the STA ≥ 2.3 mm (OR 44, 95% CI 8.1-237; p < 0.001) and ECA branches other than the STA located 0-10 mm above the bifurcation (OR 6.0, 95% CI 1.1-32; p = 0.036) were independent predictors of antegrade flow. CONCLUSIONS: Distal filter protection should be combined with proximal protection for the lesions with antegrade flow to prevent distal migration of the carotid debris.

A case report of spondylectomy with circumference reconstruction for aggressive vertebral hemangioma covering the whole cervical spine (C4) with progressive spinal disorder.

PURPOSE: To describe the surgical experience of spondylectomy and spinal reconstruction for aggressive vertebral hemangioma (VH) induced at the C4 vertebra. No reports have described surgical strategy in cases covering an entire cervical vertebra presenting with progressive myelopathy. METHODS: A 28-year-old man presented with rapidly progressing skilled motor dysfunction and gait disorder. The Japanese Orthopedic Association (JOA) score was 6. Radiography showed a honeycomb appearance for the entire circumference of the C4 vertebra. Spinal computed tomography and magnetic resonance imaging showed vertebral tumor with extraosseous extension causing spinal cord compression. Results of diagnostic imaging were strongly suggestive of VH. Transarterial embolization of the spinal body branch was performed first to decrease intraoperative bleeding, followed by cervical posterior fixation to stabilize the unstable segment and excision biopsy to obtain a definitive diagnosis. After definitive diagnosis of cavernous hemangioma, two-stage surgery (anterior and posterior) was performed to complete total spondylectomy and 360° spinal reconstruction. RESULTS: Despite multiple operations, JOA scores were 8.5 after posterior fixation, 10.5 after anterior surgery, 11 after final surgery and 16 on postoperative day 90. The patient acquired excellent clinical results without complications and returned to society. CONCLUSIONS: The present three-stage surgery comprising fixation, biopsy, and final spondylectomy with circumferential fusion from anterior and posterior approaches may offer a useful choice for aggressive VH covering the entire cervical spine with rapidly progressive myelopathy.

Combination of flow reversal and distal filter for cerebral protection during carotid artery stenting.

BACKGROUND: Carotid artery stenting (CAS) with distal filter protection allows continuous cerebral perfusion, although it is associated with a greater risk of cerebral ischemic complications than other protection systems. To reduce cerebral ischemic complications, CAS was performed under combined cerebral protection using both flow reversal (FR) and a distal filter. METHODS: Fifty-six stenoses of 52 patients were treated with CAS using the combined protection of FR and a distal filter, with intermittent occlusion of both the common carotid artery (CCA) and the external carotid artery. The blood flow was reversed into the guiding catheter to the central venous system via an external filter, which collected the debris. Clinical outcomes, the rates of capturing visible debris, and new ischemic signals on diffusion-weighted magnetic resonance imaging (DWI-MRI) were evaluated. RESULTS: The overall technical success rate was 92.9% (52/56). Successful stent deployment was achieved in 100% (56/56) of the cases. No procedural-related emboli causing a neurologic deficit were observed. In 38.5% (20/52) of the cases, visible debris were captured by only the external filter, and in 17.3% (9/52), visible debris were captured by both external and distal filters. In no case was visible debris noted in only the distal filter. New ischemic signals on DWI-MRI were detected in 9.6% (5/52). The 30-day myocardial infarction, stroke, and death rates were 0%. CONCLUSIONS: The additional use of a distal filter captures emboli in 17.3% of cases, and because the occlusion is only intermittent, the procedure is potentially applicable even in those who cannot tolerate prolonged balloon occlusion of the CCA.

Spray-Type Adhesion Barrier Enhances Safety and Feasibility of Robotic Repeat Liver Resection: Initial Experience and Outcomes.

Background Although various types of adhesion barriers are widely utilized in liver surgery, the safety and feasibility of their use during repeat robotic liver resection (R-RLR) are still unknown. Methods Among the 68 patients undergoing RLR with the application of the spray-type adhesion barrier at Kokura Memorial Hospital, Kitakyushu, Japan, between 2021 and 2023, 24 cases that underwent R-RLR were included in this study. The included patients were divided into two groups: those who underwent previous hepatectomy with the use of a spray-type adhesion barrier (R-RLR-B, n = 14) and those without its previous use (R-RLR-NB, n = 10). The perioperative outcomes were compared between the groups. Results There were no differences between the R-RLR-B and R-RLR-NB groups in background characteristics, difficulty scores, operative and console time, or surgical blood loss. Although no difference was found between the groups in the time required for adhesiolysis before the robotic operation, both the time required for robotic adhesiolysis (75 minutes vs. 58 minutes, p = 0.034) and total time for adhesiolysis (192 minutes vs. 141 minutes, p = 0.014) were significantly shorter in the R-RLR-B group than in the R-RLR-NB group. Otherwise, there was no conversion to open hepatectomy, no intraoperative transfusion of red blood cells, no cases of grade B or C post-hepatectomy liver failure, and no mortality in the whole cohort. Conclusions The spray-type adhesion barrier may not be associated with an increase in the incidence of postoperative complications, including bile leakage or intraperitoneal abscess. In addition, its application during the previous hepatectomy can facilitate a secure R-RLR with reduced time for adhesiolysis. Thus, the use of the spray-type adhesion barrier for R-RLR is safe, effective, and time efficient.

An Efficient Saline-Linked Cautery (SLiC) Method for Robotic Liver Parenchymal Transection Using Simultaneous Activation of Saline-Linked Cautery and Robotic Suctioning: Detailed Technical Aspects and Short-Term Outcomes.

Introduction While there are several advantages to utilizing robotics in liver surgery compared to traditional open and laparoscopic approaches, the most challenging part of robotic liver resection (RLR) remains the liver parenchymal transection. This is primarily due to the constraints of the existing robotic tools and the absence of a standard procedure. This study presents detailed technical aspects of our novel saline-linked cautery (SLiC) method for RLR and assesses the short-term outcomes for both non-anatomical and anatomical RLRs. Methods In this study, 82 cases that underwent RLR utilizing the SLiC method at our hospital from September 2021 to December 2023 were examined. A novel SLiC method is introduced in this study for robotically transecting the liver parenchyma utilizing bipolar cautery or monopolar scissors. The technique involves activating the SLiC and robotic suctioning simultaneously. The included patients were divided into two groups: patients undergoing robotic anatomical hepatectomy (n=39), and those receiving robotic non-anatomical hepatectomy (n=43). Short-term outcomes, including intraoperative and postoperative complications, were assessed in patients receiving both anatomical and non-anatomical hepatectomies. Results In the whole cohort, 74% of patients had performance status 1 or 2, and 24% were classified as Child-Pugh class B. RLR was performed without Pringle's maneuver in more than 80% of cases in patients receiving robotic non-anatomical hepatectomy, and more than 80% of patients undergoing robotic anatomical hepatectomy required only four or fewer 15-minute Pringle's maneuvers. There was no conversion to open hepatectomy, no cases of grade B or C post-hepatectomy liver failure, and no mortality in the entire cohort. Four postoperative complications with CDC IIIa or higher occurred (small bowel obstruction in two cases, intraabdominal hemorrhage in one, and bile leak in another), but no differences in the frequency of complications were found between those undergoing non-anatomical and anatomical hepatectomy (p=0.342). Conclusions The SLiC method, which involves simultaneously activating SLiC and robotic suctioning with either monopolar scissors or bipolar cautery, appears to be a secure and convenient technique for liver parenchymal transection in RLR. This innovative method permits precise access to the major Glissonean and venous structures within the liver, making RLR more standardized and easily applicable in routine patient care.

Successful Multidisciplinary Treatment, Including Atezolizumab Plus Bevacizumab Biological Therapy, for Multiple Hepatocellular Carcinomas Adjacent to Major Vessels: A Case Report.

Multiple hepatocellular carcinomas (HCCs) are currently being treated with multimodal therapy that includes liver resection and local therapy. Although the necessity of multimodal therapy for multiple HCCs is evident, treating them is extremely difficult due to the complex nature of multiple HCCs and the frequent occurrence of underlying liver damage. We encountered a case in which long-term tumor control was achieved through multidisciplinary treatment, including atezolizumab plus bevacizumab combination biological therapy. As in the current case, less-invasive surgical resection combined with radiofrequency ablation after a combination of biological therapy may be one of the preferred options for the treatment of initially unresectable multiple HCCs.

Successful Multimodal Treatment of Pancreatic Cancer With Extensive Superior Mesenteric Vein Thrombosis Utilizing Chemotherapy Combined With Direct Oral Anticoagulant.

It is well known that portal vein thrombosis (PVT) sometimes occurs in pancreatic cancer (PC). However, no effective treatment plan for PVT in PC patients has yet been proposed. We experienced a successfully treated case of borderline resectable pancreatic cancer (PC-BR) with extensive superior mesenteric vein thrombosis utilizing intensive chemotherapy combined with direct oral anticoagulant. The thrombus disappeared and the tumor shrank, enabling curative surgery, and long-term survival for more than five years has been achieved. We report this successful case that we experienced as an option for the treatment of PC-BR with PVT in the future era when multimodal treatment is important.

Damage Control Surgery for Duodenal Ulcer Bleeding With Massive Hematoma and Perforation Due to Over-the-Scope Clip (OTSC).

Due to the advances in endoscopic technology, surgery for duodenal ulcer (DU) bleeding has decreased, although surgery is still necessary for more complicated cases. The concept of damage control surgery (DCS) has been established in the field of trauma, and a simple surgical approach may be preferable in serious cases such as uncontrolled DU bleeding. We present a successful case of bleeding with massive hematoma and perforation of the duodenum due to an over-the-scope clip that was treated by a less invasive surgical approach with consideration of the DCS.

Optical coherence tomography findings of balloon angioplasty/stenting for in-stent restenosis after carotid artery stenting.

OBJECTIVES: The optimal therapeutic methods for in-stent restenosis (ISR) after carotid artery stenting (CAS) remains controversial. This study aimed to use optical coherence tomography (OCT) to evaluate the in-stent architectures during endovascular angioplasty/stenting for ISR. MATERIALS AND METHODS: Six lesions of ISR after CAS were evaluated by OCT during endovascular angioplasty/stenting. RESULTS: In one lesion, the OCT system could not be crossed because of elongation distal to the ISR lesion. In five lesions, pre-procedural OCT clearly revealed neointimal hyperplasia or neoatherosclerosis. The mean in-stent area stenosis was 84%. After regular balloon angioplasty, tissue compression and dissection of various sizes and layers were detected. After balloon angioplasty (with a mean balloon size of 5.4 mm), the minimum lumen area (from 1.7 ± 0.6 to 11.4 ± 5.3 mm2, p < 0.01) and the minimum in-stent area (12.7 ± 2.6 to 21.8 ± 5.0 mm2, p < 0.01) showed a significant increase. Additional stent was placed in one lesion that developed into a flap by dissection after balloon angioplasty. In another lesion in which sufficient dilatation was not achieved by balloon angioplasty, a major stroke occurred by acute occlusion of the ISR lesion 10 months later. CONCLUSIONS: OCT can detect the in-stent architecture of ISR lesions after balloon angioplasty and additional stent placement. However, which dissection should be treated by additional stent remain problematic.

Gene expression profiles associated with early relapse during first remission induction in canine multicentric high-grade B-cell lymphoma.

Although chemotherapy using CHOP-based protocol induces remission in most cases of canine multicentric high-grade B-cell lymphoma (mhBCL), some cases develop early relapse during the first induction protocol. In this study, we examined the gene expression profiles of canine mhBCL before chemotherapy and investigated their associations with early relapse during the first whole CHOP-based protocol. Twenty-five cases of mhBCL treated with CHOP-based protocol as first induction chemotherapy were included in this study. Sixteen cases completed the first whole CHOP-based protocol without relapse (S-group), and nine developed relapse during the chemotherapy (R-group). RNA-seq was performed on samples from neoplastic lymph nodes. Differentially expressed genes (DEGs) were extracted by the comparison of gene expression profiles between S- and R-groups, and the differences in the expression levels of these genes were validated by RT-qPCR. Extracted 179 DEGs included the genes related to chemokine CC motif ligand, T-cell receptor signaling pathway, and PD-L1 expression and PD-1 checkpoint pathway. We focused on chemokine CC motif ligand, and CCL4 was confirmed to be significantly downregulated in the R-group (P=0.039). We also focused on the genes related to T-cell signaling pathway, and CD3E (P=0.039), ITK (P=0.023), and LAT (P=0.023) genes were confirmed to be significantly upregulated in the R-group. The current results suggest that both changes in tumor cells and the interactions between tumor cells and immune cells are associated with the efficacy of the chemotherapy for first remission induction.

Prevalence of unruptured intracranial aneurysms in healthy asymptomatic Japanese adults: differences in gender and age.

BACKGROUND: We aimed to assess the prevalence of unruptured intracranial aneurysms (UIAs) in healthy asymptomatic adults, and investigate the differences in incidence due to gender and age in Japan. METHODS: Magnetic resonance angiography (MRA) results of healthy asymptomatic adults who underwent the procedure for examination of the brain, from April 2010 to March 2012, were retrospectively examined. Patients with a history of ruptured aneurysm and UIAs were excluded. UIAs greater than 2.0 mm in size were counted. In accordance with these criteria, 8,696 people with a mean age of 52.2±9.5 years were examined, and 37.4 % of these individuals were women. RESULTS: The overall prevalence of UIAs was 3.2 %. The prevalence in women was higher than that in men (4.4 % versus 2.5 %, OR, 1.81; 95% CI, 1.4 to 2.31). The prevalence increased with age in both genders. In under 49 years, the prevalence in women and men were 2.7 % and 1.9 %, respectively, with no significant differences (OR, 1.47; CI, 0.91 to 2.37). In over 50 years, the prevalence in women was higher than that in men (5.4 % versus 2.8 %, OR, 2.01; CI, 1.52­2.67). There were significant differences in the locations of UIAs by gender (P <0.001); Internal carotid artery was more frequent in women, whereas anterior cerebral artery and middle cerebral artery were more common inmen. CONCLUSIONS: This study provides etiological data on the prevalence of UIAs in healthy asymptomatic Japanese adults, and may be useful in determining therapeutic managements for UIAs.

Carotid artery stenting using a 7 French Optimo balloon guide catheter combined with a distal filter.

OBJECTIVES: Carotid artery stenting (CAS) by proximal occlusion of the common carotid artery (CCA) using a balloon guide catheter (BGC) is a simple proximal protection method to prevent distal embolism, however, it requires at least an 8 French (F) system. A 7 F Optimo BGC is the smallest BGC with an inner lumen diameter of 0.071 inches, and which permits the passage of a 5 F carotid stent. We retrospectively investigated the clinical results and the safety of CAS by using a 7 F Optimo BGC combined with a distal filter. MATERIALS AND METHODS: One-hundred carotid arterial stenosis patients were treated with CAS using combined protection of a 7 F Optimo BGC and a distal filter. The BGC was navigated from the femoral and radial arteries in 85 and 15 patients, respectively. RESULTS: The 7 F Optimo BGC was successfully navigated into the CCA in all patients, and the technical success rate of CAS was 100%. Major adverse events of any death, stroke, or myocardial infarction within 30-day after the procedure were observed in one (1%). Post-procedural diffusion-weighted magnetic resonance imaging revealed high signals in 21% of the patients, all of whom were asymptomatic. CONCLUSIONS: The 7 F Optimo is the smallest BGC to achieve CAS using a proximal protection system. The combined use of a 7 F Optimo BGC and a distal filter is effective for navigating the BGC and distal embolic protection.

Long-Term Oncological Control by Repeated Minimally Invasive Hepatectomy for Intrahepatic Cholangiocarcinoma Exhibiting Atypical Marker Expression of CK7-CK20+: A Case Report.

There are few reports of repeated liver resections being performed multiple times for intrahepatic recurrence of intrahepatic cholangiocarcinoma (ICC). We performed five minimally invasive liver resections and two minimally invasive lung resections for ICC with metachronous intrahepatic recurrence and lung metastases. Pathological examination revealed that all resected tumors were moderately differentiated mass-forming ICC with immunohistochemical marker expression of CK7 negative and CK20 positive. We present this as a rare case of ICC with atypical marker expression in which long-term tumor control was achieved with multiple minimally invasive liver resections over 47 months from the initial diagnosis.

Long-term hemodynamic changes in cerebral proliferative angiopathy presenting with intracranial hemorrhage: illustrative case.

BACKGROUND: Cerebral proliferative angiopathy (CPA) is a rare vascular proliferative disease; however, long-term follow-up reports are scarce. The authors report a rare case and document a patient's medical history over 20 years. OBSERVATIONS: A 5-year-old girl developed left frontal lobe hemorrhage, presenting with headache. At 8 years of age, angiography showed diffuse capillary ectasia without an arteriovenous shunt. Single-photon emission computed tomography (SPECT) showed normal cerebral blood flow (CBF). She had normal growth without systemic disease. At 25 years of age, an intraventricular hemorrhage occurred, presenting with sudden headache. Angiography revealed vascular lesion enlargement, increased feeding arteries, dural supply to the nidus and peri-nidal lesion, and flow-related aneurysm. SPECT showed remarkable decreases in CBF in the nidus and peri-nidal lesion. Cerebral proliferative angiopathy (CPA) was diagnosed, and the aneurysm arising at the lateral posterior choroidal artery caused the hemorrhage. Coil embolization of the aneurysm was performed with a flow-guide catheter and extremely soft platinum coils. New aneurysms were not noted 1.5 years after the procedure. LESSONS: This is the first report to demonstrate hemodynamic changes in CPA on angiography and SPECT over 17 years. The development of endovascular devices has enabled the embolization of ruptured aneurysms at the peripheral cerebral artery.

Prognosis of primary pulmonary adenocarcinoma after surgical resection in small-breed dogs: 52 cases (2005-2021).

BACKGROUND: Tumor size is an important prognostic factor in lung cancer in dogs, and the canine lung carcinoma stage classification (CLCSC) recently has been proposed to subdivide tumor sizes. It is unclear if the same classification scheme can be used for small-breed dogs. OBJECTIVES: To investigate whether the tumor size classification of CLCS is prognostic for survival and progression outcomes in small-breed dogs with surgically resected pulmonary adenocarcinomas (PACs). ANIMALS: Fifty-two client-owned small-breed dogs with PAC. METHODS: Single-center retrospective cohort study conducted between 2005 and 2021. Medical records of dogs weighing <15 kg with surgically resected lung masses histologically diagnosed as PAC were examined. RESULTS: The numbers of dogs with tumor size ≤3 cm, >3 cm to ≤5 cm, >5 cm to ≤7 cm, or >7 cm were 15, 18, 14, and 5, respectively. The median progression-free interval (PFI) and overall survival time (OST) were 754 and 716 days, respectively. In univariable analysis, clinical signs, lymph node metastasis, margin, and histologic grade were associated with PFI, and age, clinical signs, margin, and lymph node metastasis were associated with OST. Tumor size classification of CLCS was associated with PFI in all categories, and tumor size >7 cm was associated with OST. In multivariable analysis, tumor size >5 cm to ≤7 cm and margin were associated with PFI, and age was associated with OST. CONCLUSIONS AND CLINICAL IMPORTANCE: The tumor size classification of CLCS would be an important prognostic factor in small-breed dogs with surgically resected PACs.

Retrospective study of feline tracheal mass lesions.

OBJECTIVES: This multicentre, retrospective observational study aimed to describe the clinical presentation, diagnostic methods, treatment and outcomes of cats with tracheal masses. METHODS: Eighteen cats from five academic or secondary/tertiary animal hospitals were included. RESULTS: The median age at diagnosis was 10.7 years (mean 9.5; range 1-17). There were nine castrated males, seven spayed females, one intact male and one intact female. Fourteen (78%) were domestic shorthairs, one (6%) was an Abyssinian, one (6%) was an American Shorthair, one (6%) was a Bengal and one (6%) was a Scottish Fold. The most common presenting complaints included chronic respiratory distress or dyspnoea (n = 14), followed by wheezing/gagging (n = 12), coughing (n = 5) and voice changes (n = 5). There was cervical tracheal involvement in 16/18, and two showed involvement of the intrathoracic trachea. The following methods were used for diagnosis: ultrasound-guided fine-needle biopsy (UG-FNB) and cytology (n = 8), bronchoscopic forceps biopsy and histopathology (n = 5), surgical resection and histopathology (n = 3), forceps biopsy via an endotracheal tube (n = 1) and histology of tissue sputtered from a cough (n = 1). Lymphoma was most often diagnosed (n = 15), followed by adenocarcinoma (n = 2) and squamous cell carcinoma (n = 1). Most lymphoma cases received chemotherapy with or without radiation according to various protocols, and partial (n = 5) or complete responses (n = 8) were noted. Kaplan-Meier survival data for cats with lymphoma revealed a median survival time of 214 days (95% confidence interval >149 days), which was significantly longer than that of other types of tumours (21 days). CONCLUSIONS AND RELEVANCE: Lymphoma was the most prevalent diagnosis, and showed a good response to chemotherapy with or without radiation therapy. Various diagnostic procedures were performed, and UG-FNB and cytology are good diagnostic procedures for cervical tracheal lesions. Owing to the variety of treatment protocols at different centres, it was impossible to compare outcomes.

Clinical features and prognosis of retroperitoneal hemangiosarcoma in dogs with surgical resection with or without adjuvant doxorubicin.

Retroperitoneal hemangiosarcoma (RPHSA) is a rare tumor in dogs with a poorly understood prognosis after surgery. The objectives of this study were to investigate the clinical features and prognosis of canine RPHSA that had undergone surgical resection. In this single-center, retrospective cohort study, we reviewed the medical records of dogs that had undergone surgical resection for retroperitoneal tumors and received a histopathologic diagnosis of HSA between 2005 and 2021. The median progression-free survival (PFS) and overall survival (OS) were 77.5 days and 168 days, respectively. In the present study, canine RPHSA had an aggressive biological behavior similar to visceral HSA. Further studies in larger canine populations are needed to evaluate the efficacy of adjuvant chemotherapy.