Successful management of pelvic urethral strictures with balloon dilation in 3 cats.

OBJECTIVE: To describe the successful management of pelvic urethral strictures in 3 young cats (1 after perineal urethrostomy, 1 after a third-time urethral obstruction, and 1 with prolonged lower urinary tract signs post-urethral obstruction) using balloon dilation and a short-term, indwelling urethral catheter. CASE SUMMARIES: A 9-month-old neutered male domestic longhair cat with a urethral obstruction and a suspected congenitally narrowed urethra was treated via perineal urethrostomy. The cat later developed acute kidney injury, multidrug-resistant urinary tract infections, and a pelvic urethral stricture. A second case, a 2.3-year-old neutered male domestic shorthair cat, developed a stricture of the pelvic urethra after multiple obstructions and catheterizations. A third case, a 1.2-year-old neutered male domestic shorthair cat, had persistent and prolonged lower urinary tract signs after treatment for a urinary obstruction. The cat also had an abnormally small urethral opening and was ultimately found to have a proximal urethral stricture. The strictures in all 3 cases were successfully treated with a combination of fluoroscopic-guided balloon dilation and short-term indwelling urethral catheterization while managing any present infection. NEW OR UNIQUE INFORMATION PROVIDED: To the authors' knowledge, this is the first published case series of successful balloon dilations paired with the use of a short-term indwelling urethral catheter in cats that developed urethral strictures after catheterization due to urinary obstructions. This procedure appears safe and well tolerated and appears to offer a long-term, cost-effective solution to urethral strictures at the level of the pelvis.

Effect of a Predictive Model on Planned Surgical Duration Accuracy, Patient Wait Time, and Use of Presurgical Resources: A Randomized Clinical Trial.

Importance: Accurate surgical scheduling affects patients, clinical staff, and use of physical resources. Although numerous retrospective analyses have suggested a potential for improvement, the real-world outcome of implementing a machine learning model to predict surgical case duration appears not to have been studied. Objectives: To assess accuracy and real-world outcome from implementation of a machine learning model that predicts surgical case duration. Design, Setting, and Participants: This randomized clinical trial was conducted on 2 surgical campuses of a cancer specialty center. Patients undergoing colorectal and gynecology surgery at Memorial Sloan Kettering Cancer Center who were scheduled more than 1 day before surgery between April 7, 2018, and June 25, 2018, were included. The randomization process included 29 strata (11 gynecological surgeons at 2 campuses and 7 colorectal surgeons at a single campus) to ensure equal chance of selection for each surgeon and each campus. Patients undergoing more than 1 surgery during the study's timeframe were enrolled only once. Data analyses took place from July 2018 to November 2018. Interventions: Cases were assigned to machine learning-assisted surgical predictions 1 day before surgery and compared with a control group. Main Outcomes and Measures: The primary outcome measure was accurate prediction of the duration of each scheduled surgery, measured by (arithmetic) mean (SD) error and mean absolute error. Effects on patients and systems were measured by start time delay of following cases, the time between cases, and the time patients spent in presurgical area. Results: A total of 683 patients were included (mean [SD] age, 55.8 [13.8] years; 566 women [82.9%]); 72 were excluded. Of the 683 patients included, those assigned to the machine learning algorithm had significantly lower mean (SD) absolute error (control group, 59.3 [72] minutes; intervention group, 49.5 [66] minutes; difference, -9.8 minutes; P = .03) compared with the control group. Mean start-time delay for following cases (patient wait time in a presurgical area), dropped significantly: 62.4 minutes (from 70.2 minutes to 7.8 minutes) and 16.7 minutes (from 36.9 minutes to 20.2 minutes) for patients receiving colorectal and gynecology surgery, respectively. The overall mean (SD) reduction of wait time was 33.1 minutes per patient (from 49.4 minutes to 16.3 minutes per patient). Improved accuracy did not adversely inflate time between cases (surgeon wait time). There was marginal improvement (1.5 minutes, from a mean of 70.6 to 69.1 minutes) in time between the end of cases and start of to-follow cases using the predictive model, compared with the control group. Patients spent a mean of 25.2 fewer minutes in the facility before surgery (173.3 minutes vs 148.1 minutes), indicating a potential benefit vis-à-vis available resources for other patients before and after surgery. Conclusions and Relevance: Implementing machine learning-generated predictions for surgical case durations may improve case duration accuracy, presurgical resource use, and patient wait time, without increasing surgeon wait time between cases. Trial Registration: ClinicalTrials.gov Identifier: NCT03471377.

Arterial thrombosis after vehicular trauma and humeral fracture in a dog.

CASE DESCRIPTION: A 3-year-old 19-kg (42-lb) spayed female mixed-breed dog was referred after being hit by a car. Injuries included pneumothorax, hemothorax, pulmonary contusions, a full-thickness axillary skin wound, and a grade I transverse fracture of the midshaft of the right humerus. Following patient stabilization, open reduction and internal fixation of the fracture were performed. The dog had weight-bearing lameness at the time of discharge. Eight days after fracture repair, the dog was reevaluated for acute onset of signs of pain and non-weight-bearing lameness in the right forelimb. CLINICAL FINDINGS: Physical examination findings in the right forelimb (knuckling and coolness, with absent digital pulses) were suggestive of a thrombus. Ultrasonography confirmed a right brachial artery thrombus with minimal blood flow to the affected limb. TREATMENT AND OUTCOME: Unfractionated heparin was administered via continuous IV infusion for the first 36 hours of hospitalization. Clopidogrel administration was also started at this time. During hospitalization, rapid clinical improvement occurred, and the dog was discharged 48 hours after admission. The transition to outpatient therapy was achieved by discontinuation of the unfractionated heparin infusion at 36 hours and beginning SC administration of dalteparin. Outpatient treatment with dalteparin and clopidogrel was continued. Repeated physical examination and ultrasonography 5 weeks later revealed resolution of the thrombus and normal blood flow to the limb. Anticoagulant administration was discontinued at that time. CLINICAL RELEVANCE: Thrombosis should be suspected in any dog with signs of acute pain after severe trauma or fracture repair, with or without concurrent lameness, that do not resolve with appropriate treatment. Restoration of blood flow to the affected limb after initiation of unfractionated heparin and clopidogrel administration followed by outpatient treatment with dalteparin and clopidogrel was achieved in this case.

Spontaneous pneumothorax in 35 cats (2001-2010).

Thirty-five cases of spontaneous pneumothorax were reviewed. In contrast to dogs, cats with an established etiology all had spontaneous pneumothorax associated with lung disease. Underlying diseases identified in affected cats included inflammatory airway disease, neoplasia, heartworm infection, pulmonary abscess and lungworm infection. Many cats were managed successfully with observation alone or needle thoracocentesis and specific therapy for their primary lung disease. Cats who present with spontaneous pneumothorax may be treated successfully with non-surgical therapies and appear to have a better prognosis than previously extrapolated from canine studies.

Preclinical evaluation of the neuroprotective effect of soluble complement receptor type 1 in a nonhuman primate model of reperfused stroke.

OBJECT: Postischemic cerebral inflammatory injury has been extensively investigated in an effort to develop effective neuroprotective agents. The complement cascade has emerged as an important contributor to postischemic neuronal injury. Soluble complement receptor Type 1 (sCR1), a potent inhibitor of complement activation, has been shown to reduce infarct volume and improve functional outcome after murine stroke. Given numerous high-profile failures to translate promising antiinflammatory strategies from the laboratory to the clinic and given the known species-specificity of the complement cascade, the authors sought to evaluate the neuroprotective effect of sCR1 in a nonhuman primate model of stroke. METHODS: A total of 48 adult male baboons (Papio anubis) were randomly assigned to receive 15 mg/kg of sCR1 or vehicle. The animals were subjected to 75 minutes of middle cerebral artery occlusion/reperfusion. Perioperative blood samples were analyzed for total complement activity by using a CH50 assay. Infarct volume and neurological scores were assessed at the time the animals were killed, and immunohistochemistry was used to determine cerebral drug penetration and C1q deposition. An interim futility analysis led to termination of the trial after study of 12 animals. Total serum complement activity was significantly depressed in the sCR1-treated animals compared with the controls. Immunostaining also demonstrated sCR1 deposition in the ischemic hemispheres of treated animals. Despite these findings, there were no significant differences in infarct volume or neurological score between the sCR1--and vehicle-treated cohorts. CONCLUSIONS: A preischemic bolus infusion of sCR1, the most effective means of administration in mice, was not neuroprotective in a primate model. This study illustrates the utility of a translational primate model of stroke in the assessment of promising antiischemic agents prior to implementation of large-scale clinical trials.

Use of a flow-mediated vasodilation technique to assess endothelial function in dogs.

OBJECTIVE: To develop and assess the reproducibility of a protocol to noninvasively test endothelial function in dogs on the basis of the flow-mediated vasodilation (FMD) procedure used in humans. ANIMALS: 5 healthy spayed female dogs. PROCEDURES: Luminal arterial diameter and blood flow velocity in the brachial and femoral arteries were measured with ultrasonography. The within-dog reproducibility of these ultrasonographic measurements was tested. An occlusion period of 1, 3, or 5 minutes with an inflatable cuff was used to create the FMD response. Measurements made at 15, 30, and 60 seconds following release of the occlusion were compared with measurements made immediately prior to each occlusion to assess the FMD response. RESULTS: Within-dog reproducibility of measurements revealed moderate to high correlations. Change from baseline in luminal arterial diameter was most substantial when measured at 30 seconds following release of occlusion, whereas blood flow velocity changes were maximal when measured at 15 seconds following release. The brachial imaging site provided a larger number of significant FMD responses than the femoral site. The 3-minute occlusion period provided equal or better responses than the 5-minute occlusion period. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonographic measurement of the FMD responses was a feasible and reproducible technique and significant changes from baseline were detected. The FMD responses in dogs were most substantial when performed at the brachial artery with blood flow velocity and luminal arterial diameter changes from baseline measured at 15 and 30 seconds, respectively, following release of a 3-minute occlusion period.

A cerebroprotective dose of intravenous citrate/sorbitol-stabilized dehydroascorbic acid is correlated with increased cerebral ascorbic acid and inhibited lipid peroxidation after murine reperfused stroke.

OBJECTIVE: Oxidative damage has been implicated in the pathogenesis of cerebral ischemia. We previously demonstrated that exogenously supplied dehydroascorbic acid (DHA), an oxidized, blood-brain barrier transportable form of the antioxidant ascorbic acid (AA), improves outcome after experimental stroke. METHODS: To investigate the neuroprotective effect of DHA therapy, we measured cerebral AA levels using a novel assay, quantified markers of lipid peroxidation, and evaluated infarct volume after reperfused stroke in a murine model. All experiments were performed using a new citrate/sorbitol-stabilized DHA formulation to improve the stability of the compound. RESULTS: Intraparenchymal AA levels declined after cerebral ischemia/reperfusion and were repleted in a dose-dependent fashion by postischemic administration of intravenous DHA (P < 0.01). Repletion of these levels was associated with reductions in cerebral malondialdehyde levels (P < 0.05), which were also elevated after reperfused stroke. DHA repletion of interstitial AA levels and reduction in cerebral lipid peroxidation was associated with dose-dependent reductions in infarct volume (P < 0.05). CONCLUSION: Together, these results indicate that an intravenous cerebroprotective dose of citrate/sorbitol-stabilized DHA is correlated with increased brain ascorbate levels and a suppression of excessive oxidative metabolism.

Co-registration of radiographic and pathologic infarct territory in a non-human primate model of stroke.

OBJECTIVES: Infarct volume correlation using magnetic resonance imaging (MRI) and pathology specimens enables exact tissue localization of cerebral injury following experimental stroke. We describe a protocol that enables co-registration of radiographic signal change and histologic ischemia in a non-human primate model of stroke. METHODS: One male baboon underwent left middle cerebral artery territory occlusion/reperfusion. MRI [5 mm axial T2 weighted (T2W) slices] was carried out 9 days post-ischemia after which the animal was killed. Immediately post-mortem, the whole brain was perfused and fixed in paraformaldehyde and sliced into 5 mm axial sections that corresponded to those demonstrated on MRI. Slices (40 microm) were obtained from each section and were then stained using Luxol hematoxylin and eosin. RESULTS: The relative area of hyperintensity demonstrated on T2W MRI approximates, in size and location, the region of infarct on gross pathology. This was confirmed microscopically. DISCUSSION: With the use of advanced imaging modalities, this co-registration technique affords the capacity to differentiate ischemic core, penumbra, and uninjured cortex following experimental stroke. Such a precise delineation enables immunohistochemical analysis of a wide variety of substrates in each of the aforementioned regions.

Serial magnetic resonance imaging in experimental primate stroke: validation of MRI for pre-clinical cerebroprotective trials.

Precise assessment of stroke outcome is critical for pre-clinical testing of cerebroprotective strategies. Differences in stroke volume measured by various magnetic resonance imaging (MRI) techniques are documented in humans, but not well described in experimental primate stroke. This study characterizes changes in stroke volume using serial MRI scans in a baboon model of reperfused cerebral ischemia. The location/area of hyperintensity on MRI corresponded with the TTC-stained infarct region. T2-weighted fast spin echo (T2W FSE), fluid attenuated inversion recovery (FLAIR), and diffusion weighted imaging (DWI) showed a decrease in infarct volume between 72 h and nine days post-ischemia (p = ns, p = 0.029, and p = 0.006). T2W FSE and FLAIR demonstrated an increase in infarct volume from 24 h to nine days post-ischemia, while DWI displayed a decrease over the same period. While early T2W FSE, FLAIR, and DWI all correlated with late infarct volume (p < 0.001), 72 h T2W FSE was the best direct measure (2.39% +/- 1.40% unity deviation). Serial MRI in a nonhuman primate model of focal cerebral ischemia recapitulates findings in clinical stroke. MRI at 72 h accurately predicts late infarct volume.

An improved functional neurological examination for use in nonhuman primate studies of focal reperfused cerebral ischemia.

There is renewed interest in primate models of acute stroke for the evaluation of potential therapeutic agents prior to clinical trials. The development of more precise functional outcome measures would improve the pre-clinical assessment of neuroprotective strategies. We have constructed a grading scale that utilizes an increased number of goal-oriented tasks to assess both behavior and motor function. The new scoring system is designed to enhance precision and accuracy when compared to existing scales. Twenty-seven male baboons were subjected to 1 h of middle cerebral artery territory occlusion followed by reperfusion. Outcome was evaluated using both a standard neurological function scale and a new task-oriented scale. Each scoring system was assessed for reproducibility (inter-observer reliability) and for association with radiographic infarct volume. The task-oriented grading system was significantly less variable than the standard outcome measure (p < 0.0001). The task-oriented neurological scale demonstrated stronger correlation with radiographic infarct volume (p < 0.0001) than the standard scale (p < 0.01) and more accurately reflected infarct size in animals with small strokes. Compared to the accepted system for grading neurological function, the task-oriented scale demonstrates improved inter-observer variability and a better association with radiographic outcome measures. Incorporating this refined neurological evaluation into a baboon model of stroke may serve to increase the functional predictive value of pre-clinical studies.

Intracranial pressure following aneurysmal subarachnoid hemorrhage: monitoring practices and outcome data.

OBJECT: Elevated intracranial pressure (ICP) is an important consequence of aneurysmal subarachnoid hemorrhage (SAH) that often results in decreased cerebral perfusion and secondary clinical decline. No definitive guidelines exist regarding methods and techniques for ICP management following aneurysm rupture. The authors describe monitoring practices and outcome data in 621 patients with aneurysmal SAH admitted to their neurological intensive care unit during an 8-year period (1996-2003). METHODS: A fiberoptic catheter tip probe or external ventricular drain (EVD) was used to record ICP values. The percentage of monitored patients varied, as expected, according to admission Hunt and Hess grade (p < 0.0001). Intracranial pressure monitoring devices were used in 27 (10%) of 264 Grade I to II patients, 72 (38%) of 189 Grade III patients, and 134 (80%) of 168 Grade IV to V patients. There was a strong propensity to favor transduced ventricular drains over parenchymal fiberoptic bolts, with the former used in 221 (95%) of 233 cases. This tendency was particularly strong in the poor-grade cohort, in which EVDs were placed in 99% of monitored individuals. The rates of cerebrospinal fluid infection in patients in whom ICP probes (0%) and ventricular drains (12%) were placed accorded with those in the literature. CONCLUSIONS: Following aneurysmal SAH, ICP monitoring prevalence and techniques differ with respect to admission Hunt and Hess grade and are associated with the patient's functional status at discharge.