Robotic-Assisted Endoscopic Thoracic Aortic Anastomosis in Juvenile Lambs

Background: Advances in robotic technology have enabled a wider range of applications for minimally invasive techniques in cardiac surgery, including mitral valve repair and coronary artery bypass grafting. With increased technical sophistication, robotic-assisted techniques can be developed for the endoscopic repair of certain congenital cardiac lesions. Objective: The purpose of this study was to assess the feasibility of closed chest thoracic aortic anastomosis in a juvenile ovine model. Methods: Lambs, aged 45 to 55 days, underwent surgery that was performed using the da Vinci robotic surgical system. Using 3 ports, the surgeon dissected the descending thoracic aorta and mobilized it free from attachments, using single-lung ventilation and CO2 insufflation. Snares were introduced through 2 stab wounds for aortic occlusion proximally and distally. In 4 lambs, the aorta was completely transected and reanastomosed using interrupted nitinol sutures. One lamb underwent longitudinal aortotomy, and patch aortoplasty was performed with the placement of a Gore-Tex patch. Snares were released and the animals were recovered once hemodynamically stable. Animals were sacrificed at 6 to 12 hours after surgery and the descending aorta was harvested. Burst-pressure testing was performed on the anastomoses. Results: All 5 lambs survived the procedure with stabilization of hemodynamic parameters following surgery. The mean aortic clamp time was 47 � 17 minutes, and the anastomosis was completed in 26 � 5 minutes. The mean burst pressure was 163 � 9 mm Hg. Conclusions: Endoscopic thoracic aortic anastomosis can be performed safely and with adequate exposure in a juvenile large-animal model using computer-assisted surgical techniques. With further refinements, these approaches could be applied to the repair of congenital anomalies of the aorta, including interrupted aortic arch and aortic coarctation.

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Ex vivo evaluation of a multilayered sealant patch for watertight dural closure: cranial and spinal models

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-021-06552-4 ◽

2021 ◽

Vol 32 (8) ◽

Author(s):

A. Kinaci ◽

S. van Thoor ◽

S. Redegeld ◽

M. Tooren ◽

T. P. C. van Doormaal

Keyword(s):

Ex Vivo ◽

Resistance Test ◽

Burst Pressure ◽

Cerebrospinal Fluid Leakage ◽

Computer Assisted ◽

Dural Defect ◽

Test Results ◽

Physiological Conditions ◽

Dural Attachment ◽

The Mean

AbstractCerebrospinal fluid leakage is a frequent complication after cranial and spinal surgery. To prevent this complication and seal the dura watertight, we developed Liqoseal, a dural sealant patch comprising a watertight polyesterurethane layer and an adhesive layer consisting of poly(DL-lactide-co-ε-caprolactone) copolymer and multiarmed N-hydroxylsuccinimide functionalized polyethylene glycol. We compared acute burst pressure and resistance to physiological conditions for 72 h of Liqoseal, Adherus, Duraseal, Tachosil, and Tisseel using computer-assisted models and fresh porcine dura. The mean acute burst pressure of Liqoseal in the cranial model (145 ± 39 mmHg) was higher than that of Adherus (87 ± 47 mmHg), Duraseal (51 ± 42 mmHg) and Tachosil (71 ± 16 mmHg). Under physiological conditions, cranial model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment during 72 hours as opposed to 3 of 3 for Adherus and Duraseal and 0 of 3 for Tachosil. The mean burst pressure of Liqoseal in the spinal model (233 ± 81 mmHg) was higher than that of Tachosil (123 ± 63 mmHg) and Tisseel (23 ± 16 mmHg). Under physiological conditions, spinal model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment for 72 hours as opposed to 3 of 3 for Adherus and 0 of 3 for Duraseal and Tachosil. This novel study showed that Liqoseal is capable of achieving a strong watertight seal over a dural defect in ex vivo models.

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Tamoxifen as an effective neuroprotectant in an endovascular canine model of stroke

Journal of Neurosurgery ◽

10.3171/2010.8.jns09352 ◽

2011 ◽

Vol 114 (4) ◽

pp. 1117-1126 ◽

Cited By ~ 17

Author(s):

Alan S. Boulos ◽

Eric M. Deshaies ◽

John C. Dalfino ◽

Paul J. Feustel ◽

A. John Popp ◽

...

Keyword(s):

Mr Imaging ◽

Infarct Size ◽

Vertebral Artery ◽

Cerebral Artery ◽

Infarct Volume ◽

Randomized Study ◽

Neurological Deficits ◽

Large Animal Model ◽

Large Animal ◽

The Mean

Object Tamoxifen has been shown to be a potent neuroprotectant against stroke in rodents. Because other neuroprotectant medications have failed in human trials, a study of tamoxifen in a large-animal model was necessary to further assess the drug's effectiveness. For this study, the authors developed an endovascular model of anterior circulation infarction in canines to mimic the human clinical condition. They assessed the following hypotheses: 1) that they will be able to consistently produce an internal carotid artery (ICA) terminus infarction and 2) that tamoxifen is an effective neuroprotectant against stroke in canines. Methods In 24 male beagles (weight 9–11 kg), bilateral femoral artery cutdowns were performed, and the vertebral artery and left ICA were each selectively catheterized. Under fluoroscopic guidance, a microcatheter was introduced via the vertebral artery, guiding the catheter into the basilar artery, posterior communicating artery, and ICA terminus. A 1-ml clot was injected in the terminus, occluding the middle cerebral artery (MCA) and anterior cerebral artery (ACA) origin. In the first 12 canines, the occlusions were confirmed by angiography. A Canine Stroke Score (CSS) was assigned (score range 0–18 [0 = intact on examination, 18 = comatose]). The animals were then killed and their brains stained with 2,3,5-triphenyltetrazolium chloride (TTC). The subsequent 12 canines underwent a blinded randomized study in which the authors compared the results of tamoxifen (5 mg/kg) infused intravenously 1 hour after clot injection with an equal volume of vehicle (dimethylsulfoxide). After 3 hours, the animals underwent MR imaging, were extubated, and clinical examinations were performed. The canines were killed at 8 hours after clot injection, and TTC staining was used. Results In the first group, infarct volume and CSSs were consistent with the extent of the occlusion of the angiographic vessels. An occlusion of the ACA, MCA, and posterior cerebral artery resulted in larger infarcts and higher stroke scores than occlusion of the ACA and MCA. In the second group, tamoxifen significantly reduced infarct size and improved clinical outcomes. In tamoxifen-treated animals, the mean infarct volume reduction was 40% (p < 0.05) and the mean CSS was significantly less than vehicle-treated animals (p < 0.001). There were significant correlations among MR imaging-determined volume, TTC-determined volume, and neurological clinical outcome (p < 0.05). Conclusions Using this endovascular model of stroke, the authors were able to consistently produce an infarction in the canines that was similar in scope to a carotid terminus occlusion in humans. Also, angiography could predict subsequent clinical course and infarct size. Tamoxifen was effective at significantly improving the canine neurological deficits and reducing the size of the stroke. This study took the first step in demonstrating the effectiveness of a promising human neuroprotectant in a large animal.

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Clot accumulation at the tip of hemodialysis catheters in a large animal model

The Journal of Vascular Access ◽

10.1177/1129729820983617 ◽

2020 ◽

pp. 112972982098361

Author(s):

Michael G. Tal ◽

Ron Livne ◽

Rotem Neeman

Keyword(s):

Large Animal Model ◽

Large Animal ◽

Central Venous ◽

Jugular Veins ◽

Entire Study ◽

Side Hole ◽

Hemodialysis Catheter ◽

The Mean ◽

The Difference

Background: The issue of side holes in the tips of the tunneled cuffed central venous catheters is complex and has been subject to longstanding debate. This study sought to compare the clotting potential of the side-hole-free Pristine hemodialysis catheter with that of a symmetric catheter with side holes. Methods: Both jugular veins of five goats were catheterized with the two different catheters. The catheters were left in place for 4 weeks and were flushed and locked with heparin thrice weekly. The aspirated intraluminal clot length was assessed visually prior to each flushing. In addition, the size and weight of the clot were recorded upon catheter extraction at the end of the 4-week follow-up Results: The mean intraluminal clot length observed during the entire study follow-up measured up to a mean of 0.66 cm in the GlidePath (95% CI, 0.14–1.18) and 0.19 cm in the Pristine hemodialysis catheter (95% CI, −0.33 to 0.71), the difference being statistically significant ( p = 0.026). On average, 0.01 g and 0.07 g of intraluminal clot were retrieved from the Pristine and GlidePath catheters, respectively ( p = 0.052). Conclusion: The Pristine hemodialysis catheter was largely superior to a standard side hole catheter in impeding clot formation, and, contrary to the side hole catheter, allowed for complete aspiration of the intraluminal clot.

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Abstract 15143: Painless Epicardial Implantable Cardioverter Defibrillator Net System With Electric Conductive Fibers

Circulation ◽

10.1161/circ.142.suppl_3.15143 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Toshiaki Akita

Keyword(s):

Ventricular Fibrillation ◽

Implantable Cardioverter Defibrillator ◽

Middle Part ◽

Low Energy ◽

Large Animal Model ◽

Computer Assisted ◽

Large Animal ◽

Lower Electrode ◽

Cardioverter Defibrillator ◽

Conductive Fibers

Introduction: Current Implantable cardioverter-defibrillator (ICD) needs high CD shock (35J), which is not tolerable under consciousness. Our multi-physics computer-simulation demonstrated extra-low energy defibrillation (0.36J)can be possible if sheet electrodes are arranged upper (base) and lower (apex) side of the heart. Hypothesis: We developed the epicardial ICD net electrodes system (Ep-ICD) made of upper and lower parts with fine conductive fibers. The objective of this study was to test whether Ep-ICD can stop ventricular fibrillation with painless level (<0.7J) in large animal model. Methods: Ep-ICD was constructed by fine tungsten fibers using computer-assisted knitting machine (Shimaseiki Co., Japan). Middle part was knitted by polyester fibers. Upper and lower electrode nets were connected to RV and SVC coils of DF-1 lead (Medtronic), respectively. Five beagle dogs were used for this experiment. The Ep-ICD net was directly attached to the heart, and electrodes were connected to commercially available ICD system. DC discharges were controlled by telemetry controller. Vf was induced by attaching 9V battery onto the heart surface. Ten seconds after Vf induction, DC was delievered from minimal energy 0.4J (Medtronic Viva XT) or 0.1J (Boston Scientific Perciva). DC energy was gradually increased until defibrillation was accomplished. After 3 minutes of recovery, the ventricular fibrillation induction and defibrillation tests were repeated. Defibrillation threshold (DFT) was defined as 75% of success of defibrillation. To compare current ICD system, commercial ICD lead was inserted in one dog through internal juglar vein, and defibrillation test was conducted. Results: Defibrillation was accomplished by 0.1J~1J, All hearts recovered instantaneously to sinus rhythm. DFT were 0.6J for 4 dogs and 0.8J for one dog. Current ICD system needed 30J for defibrillation. Conclusions: Our preliminary results shows that the Ep-ICD accomplished defibrillation with painless level of DC energy (<0.7J). Extra-low energy DC can avoid electroporation which causes conduction abnormality or malignant arrhythmia. Ep-ICD can apply DC shock before losing consciousness, which has a huge merit for QOL.

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Automatic Air Volume Control System for Ventilation of Two Patients Using a Single Ventilator: A Large Animal Model Study

10.21203/rs.3.rs-1112029/v1 ◽

2021 ◽

Author(s):

Krzysztof Zielinski ◽

Barbara Lisowska ◽

Katarzyna Siewruk ◽

Maria Sady ◽

Karolina Ferenc ◽

...

Keyword(s):

Animal Model ◽

Lung Ventilation ◽

Volume Control ◽

Large Animal Model ◽

Large Animal ◽

Physiological Level ◽

Model Study ◽

Respiratory Parameters ◽

Animal Model Study ◽

Gas Volume

Abstract The COVID-19 pandemic outbreak led to a global ventilator shortage. Hence, different strategies to use a single ventilator to support multiple patients are considered. A mechatronic system Ventil divides and automatically controls gas volume pumped through two channels and was successfully validated in independent lung ventilation. We used Ventil in a series of experiments on a large animal model to verify its usability for ventilation in two patients using a single ventilator. The results of investigations on 12 pigs showed that the physiological level of respiratory parameters was maintained for 24 hours. Application of Ventil did not lead to injuries in the lungs, as indicated by CT scan analysis. We conclude that ventilation using Ventil can be considered safe in patients subjected to deep sedation without spontaneous breathing efforts.

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Acute and Chronic Changes in Platelet Volume and Count After Cardiopulmonary Bypass Induced Thrombocytopenia in Man

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651061 ◽

1987 ◽

Vol 57 (01) ◽

pp. 55-58 ◽

Cited By ~ 37

Author(s):

J F Martin ◽

T D Daniel ◽

E A Trowbridge

Keyword(s):

Platelet Count ◽

Mean Platelet Volume ◽

Artery Bypass ◽

Bypass Graft ◽

Control Group ◽

Artery Bypass Graft ◽

Platelet Volume ◽

Young Males ◽

The Mean

SummaryPatients undergoing surgery for coronary artery bypass graft or heart valve replacement had their platelet count and mean volume measured pre-operatively, immediately post-operatively and serially for up to 48 days after the surgical procedure. The mean pre-operative platelet count of 1.95 ± 0.11 × 1011/1 (n = 26) fell significantly to 1.35 ± 0.09 × 1011/1 immediately post-operatively (p <0.001) (n = 22), without a significant alteration in the mean platelet volume. The average platelet count rose to a maximum of 5.07 ± 0.66 × 1011/1 between days 14 and 17 after surgery while the average mean platelet volume fell from preparative and post-operative values of 7.25 ± 0.14 and 7.20 ± 0.14 fl respectively to a minimum of 6.16 ± 0.16 fl by day 20. Seven patients were followed for 32 days or longer after the operation. By this time they had achieved steady state thrombopoiesis and their average platelet count was 2.44 ± 0.33 × 1011/1, significantly higher than the pre-operative value (p <0.05), while their average mean platelet volume was 6.63 ± 0.21 fl, significantly lower than before surgery (p <0.001). The pre-operative values for the platelet volume and counts of these patients were significantly different from a control group of 32 young males, while the chronic post-operative values were not. These long term changes in platelet volume and count may reflect changes in the thrombopoietic control system secondary to the corrective surgery.

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