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- Author or Editor: Michelle Oblak x
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Abstract
OBJECTIVE
To compare the effect of volume and solution on transit time and fluorescence intensity (FI) using near-infrared fluorescence imaging (NIRF) in a simulated tumor model in cats. Secondarily, to describe SLN mapping with indocyanine green (ICG) NIRF and report any adverse effects of intradermally injected ICG in cats.
ANIMALS
7 healthy purpose-bred domestic shorthaired male cats.
METHODS
Cats were randomly divided into 2 groups (ICG or ICG + methylene blue [MB]). Transit time and FI were determined for 1 or 2 mL solutions injected intradermally in 4 quadrants around a simulated tumor. Following massage, fluorescence intensity was quantified by calculating the corrected total ROI fluorescence using ImageJ software. Cats were monitored for adverse effects up to 4 weeks post-injection.
RESULTS
A larger solution volume had decreased transit times to the SLN (P = .001). There was no significant difference in transit times between ICG and ICG-MB. ICG demonstrated a greater FI (P = .001) in the SLN compared to ICG-MB. Methylene blue did not percutaneously fluoresce under NIRF. The volume of the solution did not significantly affect FI. No adverse reactions were reported.
CLINICAL RELEVANCE
Increased volume of ICG may aid in rapid percutaneous lymphatic tracking from tumor to SLN. Indocyanine green alone may be preferred over ICG-MB for greater visualization of the SLN. Intradermal injections of ICG and ICG-MB were well-tolerated in healthy cats with no significant complications. Clinical evaluation of this technique in an impaired lymphatic system, as seen in cancer patients, should be assessed in future research.
Abstract
OBJECTIVE
To determine whether conservative lateral surgical margins (equal to tumor diameter for tumors < 2 cm in diameter or 2 cm for larger tumors) were noninferior to wide (3-cm) lateral surgical margins for achieving tumor-free histologic margins following excision of grade I and II cutaneous mast cell tumors (MCTs) in dogs.
ANIMALS
83 grade I and II MCTs excised with a deep surgical fascial margin and requisite lateral surgical margins from 68 dogs from 2007 to 2017. Tumors representing scar revision or local recurrence were excluded.
PROCEDURES
A pathology department database was searched to identify qualifying MCTs, and medical records were cross-referenced to obtain data regarding patients and tumors. Outcome (complete vs incomplete excision as histologically determined) was compared between conservative- and wide-margin groups. A noninferiority margin of ≥ 0.9 was used for the risk ratio (probability of complete excision for the conservative- vs wide-margin group), implying that noninferiority would be established if the data indicated that the true risk of complete excision with the conservative-margin approach was at worst 90% of that for the wide-margin approach.
RESULTS
The proportion of excised MCTs with tumor-free histologic margins was similar between the conservative- (43/46 [93%]) and wide- (34/37 [92%]) margin groups. There were no differences in tumor diameter or location between treatment groups. The risk ratio (1.02; 95% confidence interval, 0.89 to 1.19) met the criterion for noninferiority.
CONCLUSIONS AND CLINICAL RELEVANCE
The conservative-margin approach appeared to be noninferior to the wide-margin approach for achieving tumor-free histologic margins in the dogs of this study, and its use could potentially reduce the risk of postoperative complications. (J Am Vet Med Assoc 2020;256:567-572
Abstract
CASE DESCRIPTION A 13-year-old female green iguana (Iguana iguana) was examined because of a 6-day history of vomiting, anorexia, and lethargy and a 4-day history of decreased fecal and urate output.
CLINICAL FINDINGS Physical examination revealed a distended abdomen, signs of depression, pallor, tachycardia, harsh lung sounds, and vomiting. Abdominal radiographs revealed gas distention of the stomach and small intestine with fluid lines evident on the lateral view. Plasma biochemical analysis indicated hypochloremic metabolic alkalosis, hyperglycemia, and hyperuricemia.
TREATMENT AND OUTCOME Exploratory laparotomy confirmed a diagnosis of small intestinal entrapment and 170° volvulus involving approximately 80% (20 to 30 cm) of the small intestine. The portion of the small intestine extending from the middle portion of the duodenum to the caudal extent of the ileum was resected, and end-to-end anastomosis of the remaining small intestine was performed. The iguana recovered without apparent complications and was reportedly doing well 1 year after surgery.
CLINICAL RELEVANCE Findings suggested that iguanas, as hindgut fermenters, may tolerate > 70% resection of the small intestine with a good outcome and no clinical evidence of residual gastrointestinal dysfunction.
Abstract
OBJECTIVE
To evaluate short- and long-term outcomes for dogs undergoing anal sacculectomy for massive (> 5 cm) apocrine gland anal sac adenocarcinoma (AGASACA).
ANIMALS
28 client-owned dogs with massive AGASACA.
PROCEDURES
A retrospective multi-institutional study was performed. Pre-, intra-, and post-operative data was collected, and variables were statistically analyzed for associations with progression-free interval (PFI) and overall survival (OS).
RESULTS
At the time of anal sacculectomy, 19 (68%) dogs underwent concurrent iliosacral lymph node extirpation, including 17 of 18 (94%) dogs with suspected nodal metastasis preoperatively. Five (18%) dogs experienced grade 2 intraoperative complications. Ten (36%) dogs experienced postoperative complications, including 1 grade 3 and 1 grade 4 complication. No dogs had permanent fecal incontinence, tenesmus, or anal stenosis. Nineteen dogs received adjuvant chemotherapy, radiation, or both. Local recurrence occurred in 37% of dogs. Dogs with lymph node metastasis at surgery were more likely than dogs without metastasis to develop new/progressive lymph node metastasis (10/17 [59%] vs 0/10 [0%]; P = .003) and distant metastasis (7/17 [41%] vs 0/10 [0%]; P = .026). Median PFI was 204 days (95% CI, 145 to 392). Median OS was 671 days (95% CI, 225 to upper limit not reached). Nodal metastasis at the time of surgery was associated with shorter PFI (P = .017) but not OS (P = .26). Adjuvant therapy was not associated with outcome.
CLINICAL RELEVANCE
Dogs with massive AGASACA experienced prolonged survival following anal sacculectomy despite a high incidence of local recurrence and metastasis. Lymph node metastasis at the time of surgery was a negative prognostic indicator for PFI but not OS.
Abstract
OBJECTIVE
To compare the long-term outcomes of a ventral versus lateral surgical approach for mandibular and sublingual sialoadenectomy in dogs with a unilateral sialocele.
ANIMALS
46 client-owned dogs.
PROCEDURES
Medical records of dogs that underwent unilateral sialoadenectomy between 1999 and 2019 were retrospectively reviewed, and information was collected regarding signalment, clinical signs, historical treatment, swelling location, diagnostic imaging findings, sialoadenectomy approach, adjunctive treatments, intraoperative complications, hospitalization time, postoperative complications, recurrence, and contralateral sialocele development.
RESULTS
There were no significant differences in incidences of intraoperative complications, recurrence, or postoperative complications between dogs in which a lateral versus ventral approach was used. Clinically important intraoperative complications included iatrogenic tears in the oral mucosa, ligature slippage from the duct end, hemorrhage, and possible lingual nerve transection. Surgical experience was associated with the likelihood that intraoperative complications would develop. Suspected recurrence was reported in 2 of 26 (8%) dogs that underwent a lateral approach and 2 of 12 (17%) dogs that underwent a ventral approach. Hospitalization time was significantly shorter with the lateral approach than with the ventral approach. Postoperative complications had a short-term onset and occurred in 4 of 25 (16%) dogs that underwent a lateral approach and 3 of 12 (25%) dogs that underwent a ventral approach. Age and presence of a pharyngeal sialocele were associated with development of postoperative complications.
CLINICAL RELEVANCE
Long-term outcomes for ventral and lateral approaches to sialoadenectomy were favorable and appeared to be comparable. Further prospective study into potential associations of sialoadenectomy approach, age, and pharyngeal sialoceles on outcome is needed.
Abstract
OBJECTIVE To describe the operative technique and perioperative outcome for laparoscopic-assisted splenectomy (LAS) in dogs.
DESIGN Retrospective case series.
ANIMALS 18 client-owned dogs.
PROCEDURES Medical records of dogs with naturally occurring disease of the spleen treated by means of LAS between 2012 and 2014 were reviewed. History, signalment, results of physical examination, results of preoperative diagnostic testing, details of surgical technique, intraoperative findings including results of abdominal exploration and staging, concurrent surgical procedures, complications, histopathologic diagnoses, duration of postoperative hospitalization, and perioperative outcome were recorded. The perioperative period was defined as the time from hospital admission for LAS until discharge or death (within the same visit).
RESULTS All dogs underwent initial abdominal exploration and staging via multiple 5-mm laparoscopic ports (n = 2) or a single commercially available multichannel port (16), followed by minilaparotomy with insertion of a wound retraction device, progressive exteriorization of the spleen, sealing of hilar vessels, and splenectomy. Splenectomy was performed for treatment of a splenic mass (n = 15), suspected neoplasia (2), or refractory immune-mediated disease (1). Median size (width × length) of splenic masses was 5 × 5 cm (range, 1.6 to 11.0 cm × 1.5 to 14.5 cm). Complications were limited to minor intraoperative hemorrhage in 1 dog; no patient required conversion to open laparotomy.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that LAS was technically feasible in dogs and not associated with major complications. Further evaluation is required; however, in appropriately selected patients, LAS may offer the benefits of a minimally invasive technique, including a smaller incision and improved illumination and magnification during exploration and staging.
Abstract
OBJECTIVE To compare perioperative characteristics of dogs with cystic calculi treated via open versus laparoscopic-assisted cystotomy (LAC).
DESIGN Retrospective case series.
ANIMALS 89 client-owned dogs that underwent open cystotomy (n = 39) or LAC (50).
PROCEDURES Medical records of dogs that underwent cystotomy between 2011 and 2015 were reviewed. History, signalment, surgery date, results of physical examination, results of preoperative diagnostic testing, details of surgical treatment, duration of surgery, perioperative complications, treatment costs, and duration of hospitalization were recorded.
RESULTS 5 of 50 (10%) dogs required conversion from LAC to open cystotomy (OC). There was no significant difference between the LAC (1/50) and OC (2/39) groups with regard to percentage of patients with incomplete removal of calculi. Duration of surgery was not significantly different between the LAC (median, 80 min; range, 35 to 145 min) and OC (median, 70 min; range, 45 to 120 min) groups. Postoperative duration of hospitalization was significantly shorter for dogs that underwent LAC (median, 24 hours; range, 12 to 48 hours) versus OC (median, 26 hours; range, 12 to 63 hours). Surgical and total procedural costs were significantly higher for patients undergoing LAC.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that LAC may be an acceptable minimally invasive technique for treatment of cystic calculi in dogs. Surgery times were similar to those for dogs undergoing OC; however, surgical and total procedural costs were higher. Further investigation is suggested to determine which patients may benefit from LAC versus traditional OC.
OBJECTIVE
To describe surgical management and associated outcomes for dogs with primary spontaneous pneumothorax.
ANIMALS
110 client-owned dogs with primary spontaneous pneumothorax that underwent surgical management.
PROCEDURES
Medical records at 7 veterinary teaching hospitals were reviewed. Data collected included signalment, history, clinical signs, radiographic and CT findings, surgical methods, intraoperative and postoperative complications, outcomes, and histopathologic findings. Follow-up information was obtained by contacting the referring veterinarian or owner.
RESULTS
110 dogs were included, with a median follow-up time of 508 days (range, 3 to 2,377 days). Ninety-nine (90%) dogs underwent median sternotomy, 9 (8%) underwent intercostal thoracotomy, and 2 (2%) underwent thoracoscopy as the sole intervention. Bullous lesions were most commonly found in the left cranial lung lobe (51/156 [33%] lesions) and right cranial lung lobe (37/156 [24%] lesions). Of the 100 dogs followed up for > 30 days, 13 (13%) had a recurrence of pneumothorax, with median time between surgery and recurrence of 9 days. Recurrence was significantly more likely to occur ≤ 30 days after surgery, compared with > 30 days after surgery. Recurrence > 30 days after surgery was rare (3 [3%]). No risk factors for recurrence were identified.
CONCLUSIONS AND CLINICAL RELEVANCE
Lung lobectomy via median sternotomy resulted in resolution of pneumothorax in most dogs with primary spontaneous pneumothorax. Recurrence of pneumothorax was most common in the immediate postoperative period, which may have reflected failure to identify lesions during the initial thoracic exploration, rather than development of additional bullae.
Abstract
OBJECTIVE
To assess histologic evaluation of mandibular lymph nodes (MLNs) and medial retropharyngeal lymph nodes (MRLNs) for metastatic disease during tumor staging for dogs with oral malignant melanoma (OMM) and oral squamous cell carcinoma (OSCC).
DESIGN
Retrospective multi-institutional study.
ANIMALS
27 dogs with OMM and 21 dogs with OSCC.
PROCEDURES
Medical record databases of 8 institutions were searched to identify dogs with OMM or OSCC that underwent unilateral or bilateral extirpation of the MLNs and MRLNs during the same procedure between January 2004 and April 2016. Information extracted from the records included signalment, primary mass location and size, diagnostic imaging results, histologic results for the primary tumor and all lymph nodes evaluated, and whether distant metastasis developed.
RESULTS
Prevalence of lymph node metastasis did not differ significantly between dogs with OMM (10/27 [37%]) and dogs with OSCC (6/21 [29%]). Distant metastasis was identified in 11 (41%) dogs with OMM and was suspected in 1 dog with OSCC. The MRLN was affected in 13 of 16 dogs with lymph node metastasis, and 3 of those dogs had metastasis to the MRLN without concurrent metastasis to an MLN. Metastasis was identified in lymph nodes contralateral to the primary tumor in 4 of 17 dogs that underwent contralateral lymph node removal.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated histologic evaluation of only 1 MLN was insufficient to definitively rule out lymph node metastasis in dogs with OMM or OSCC; therefore, bilateral lymphadenectomy of the MLN and MRLN lymphocentra is recommended for such dogs.
Abstract
OBJECTIVE To characterize clinical findings, surgical procedures, complications, and outcomes in dogs undergoing extirpation of masses from the cranial mediastinum via video-assisted thoracic surgery (VATS) and establish preliminary guidelines for case selection when considering VATS for thymectomy in dogs.
DESIGN Retrospective case series.
ANIMALS 18 client-owned dogs that underwent extirpation of a cranial mediastinal mass by means of VATS at 5 academic referral hospitals from 2009 through 2014.
PROCEDURES Medical records were reviewed and data extracted regarding signalment, clinical signs, physical examination findings, diagnostic imaging results, surgical approach and duration, cytologic and histologic examination results, complications, outcome, and cause of death, when applicable.
RESULTS 16 dogs had a thymoma, 1 had thymic anaplastic carcinoma, and 1 had hemangiosarcoma. Seven had both megaesophagus and myasthenia gravis. Median approximate tumor volume was 113.1 cm3 (interquartile range, 33.5 to 313.3 cm3). Median duration of VATS was 117.5 minutes (interquartile range, 91.5 to 136.3 minutes). Conversion to an open thoracic surgical procedure was required for 2 dogs, 1 of which died during surgery. Median survival time following VATS for dogs with thymoma and concurrent myasthenia gravis and megaesophagus was 20 days. Dogs with thymoma without paraneoplastic syndrome survived for ≥ 60 days, and none of these dogs died of disease-related causes.
CONCLUSIONS AND CLINICAL RELEVANCE VATS appeared to be an acceptable approach for extirpation of masses from the cranial mediastinum in dogs under certain conditions. Dogs with myasthenia gravis and megaesophagus had a poor postoperative outcome.
