This manuscript describes the surgical technique and experimental approach to develop severe right ventricular pressure overload to model their adaptive and maladaptive phenotypes.
Decompensated right ventricular failure (RVF) in pulmonary hypertension (PH) is fatal, with limited medical treatment options. Developing and testing novel therapeutics for PH requires a clinically relevant large animal model of increased pulmonary vascular resistance and RVF. This manuscript discusses the latest development of the previously published ovine PH-RVF model that utilizes left pulmonary artery (PA) ligation and main PA occlusion. This model of PH-RVF is a versatile platform to control not only the disease severity but also the RV's phenotypic response.
Adult sheep (60-80 kg) underwent left PA (LPA) ligation, placement of main PA cuff, and insertion of RV pressure monitor. PA cuff and RV pressure monitor were connected to subcutaneous ports. Subjects underwent progressive PA banding twice per week for 9 weeks with sequential measures of RV pressure, PA cuff pressures, and mixed venous blood gas (SvO2). At the initiation and endpoint of this model, ventricular function and dimensions were assessed using echocardiography. In a representative group of 12 animal subjects, RV mean and systolic pressure increased from 28 ± 5 and 57 ± 7 mmHg at week 1, respectively, to 44 ± 7 and 93 ± 18 mmHg (mean ± standard deviation) by week 9. Echocardiography demonstrated characteristic findings of PH-RVF, notably RV dilation, increased wall thickness, and septal bowing. The longitudinal trend of SvO2 and PA cuff pressure demonstrates that the rate of PA banding can be titrated to elicit varying RV phenotypes. A faster PA banding strategy led to a precipitous decline in SvO2 < 65%, indicating RV decompensation, whereas a slower, more paced strategy led to the maintenance of physiologic SvO2 at 70%-80%. One animal that experienced the accelerated strategy developed several liters of pleural effusion and ascites by week 9. This chronic PH-RVF model provides a valuable tool for studying molecular mechanisms, developing diagnostic biomarkers, and enabling therapeutic innovation to manage RV adaptation and maladaptation from PH.
Decompensated right ventricular (RV) failure is the predominant cause of morbidity and mortality for patients with pulmonary hypertension (PH). RV failure is responsible for over 50% of hospitalizations in patients with PH and is a common cause of death in this patient population1,2. Although current medical treatments for PH can provide temporizing measures, they do not reverse the progression of the disease. As such, the only long-term treatment is lung transplantation. To explore and test novel medical treatments and interventions for PH and RVF, a clinically relevant animal model is needed to recapitulate the disease's complex pathophysiology. In particular, there is a great clinical need to develop RV-targeted therapeutics for PH patients to improve RV function. To date, most published animal studies of PH and RV dysfunction have relied on small mammals such as mice and rats3. On the other hand, there have only been a handful of large animal models to study the disease and RV pathophysiology from abnormal afterload4,5,6,7. In addition, none of the previously published large animal models include descriptions of experimental procedures for controlled titration of disease severity that differentially leads to compensated versus decompensated RV failure phenotypes. An animal model of PH that can be titrated to induce acute and chronic RV failure with varying degrees of compensation is needed to study disease mechanisms and to develop, test, and translate novel diagnostics and therapeutics for PH and RVF into clinical practice. Such a model in a large animal is especially valuable for the development of mechanical circulatory support devices8.
Here, a chronic, large animal PH-RVF model using left pulmonary artery (PA) ligation and progressive main PA banding in adult sheep is presented9,10. The ligation of the left PA (LPA) increases the pulmonary vascular resistance and decreases PA capacitance11,12. The progressive PA banding approach allows for precise titration of disease severity and RV adaptation. This platform can also be readily utilized for longitudinal investigation of disease progression toward RV decompensation. The procedures and processes required to execute this model are presented as a resource for investigators interested in a large animal platform to develop novel treatments for PH and RVF.
The Institutional Animal Care and Use Committee at Vanderbilt University Medical Center approved the protocol. The described procedures were conducted in accordance with the US National Research Council's Guide for the Care and Use of Laboratory Animals, 8th edition. The overview and the timeline of the experimental procedure are provided in Figure 1. Supplementary Table 1 describes the sheep’s sex, weight, breed, source of sheep, and other relevant information that may be helpful for reproducibility purposes.
1. One day before surgery, preparation of the animal
2. Day of the surgery, pre-operative steps in the preparation room
3. Day of surgery, pre-operative steps in the operating suite
4. Operative procedure
5. Postoperative recovery
6. Chronic PA banding (9 – 10 weeks)
A representative group of 12 sheep is used to show the efficacy of this model for developing varying degrees of PH-RVF. Among these sheep, the mean PA cuff pressure increased from 32 ± 20 mmHg at week 1 to 1002 ± 429 mmHg at week 9. This resulted in increasing the RV mean and systolic pressures from 28 ± 5 and 57 ± 7 mmHg at week 1, respectively, to 44 ± 7 and 93 ± 18 mmHg by week 9. Furthermore, PA cuff pressure profile was superimposed onto mixed venous oxygen saturation (SvO2) to demonstrate the efficacy of the model at fine-tuning disease phenotype (Figure 4). Specifically, faster PA banding led to a more rapid decline in SvO2. In comparison, those that experienced a more gradual PA banding strategy maintained a physiologic range of SvO2 between 70% and 80%. A representative transthoracic echocardiogram acquired after 9 weeks of progressive PA banding shows RV dilation and septal bowing due to pressure overload (Supplementary Video 1). In a previously published case report10, the model can also be used to induce end-stage RV failure, which leads to pleural effusions and abdominal ascites.
Figure 1: Overview and timeline for the overall experiment. (A) Experimental timeline for the chronic pulmonary hypertension (PH) right ventricular failure (RVF) model and the suggested data acquisition strategy. (B) The schematic diagram for the first survival surgery to establish the foundation for the chronic pulmonary hypertension (PH) right ventricular failure (RVF) model. The main pulmonary artery (PA) occluder is implanted, the left pulmonary artery (LPA) is ligated, and a pressure tubing is placed in the right ventricular outflow tract (RVOT). Finally, both RVOT and PA cuff pressure lines are connected to their respective ports, both of which are implanted subcutaneously for recurrent access and monitoring. (C) Photograph of the PA cuff, the subcutaneous port, and the plastic fitting to protect their barbed connection. Please click here to view a larger version of this figure.
Figure 2: Photographs of key surgical steps to establish the ovine pulmonary hypertension (PH) model. (A) Isolation of the main pulmonary artery (PA) and implantation of the PA cuff (circle). (B) Implanted PA cuff (circle), Penrose tubing (star), and right ventricular outflow tract (RVOT) pressure tubing (white triangle). (C) Subcutaneous implantation of ports for RVOT and PA cuff. (D) Tubular dressing and foam padding fitted around the sheep's body to protect the implanted ports. Please click here to view a larger version of this figure.
Figure 3: Experimental approach for chronic pulmonary artery (PA) banding. (A) Schematic for setting up pressure transducers to measure and adjust right ventricular (RV) and PA cuff pressure values. (B) Photograph depiction of accessing RV outflow tract (RVOT) and PA cuff ports. (C) Representative pressure tracing of RV and PA cuff pressures. Please click here to view a larger version of this figure.
Figure 4: Pulmonary artery (PA) cuff pressure and corresponding mixed venous oxygen saturation (SvO2). Longitudinal trends between pulmonary artery (PA) cuff pressure and corresponding mixed venous oxygen saturation (SvO2) show differentiation in right ventricular phenotype based on the PA banding strategy. The color profile varies considerably between subjects that experienced a more rapid PA banding strategy in comparison to subjects that underwent a more gradual banding strategy. Please click here to view a larger version of this figure.
Supplementary Video 1: Representative transthoracic echocardiograms between healthy baseline state and after the pulmonary hypertension right ventricular failure (PH-RVF) disease model. The PH-RVF model recapitulates key features of the disease, including RV dilation and hypertrophy, and septal bowing. Please click here to download this Video.
Supplementary File 1: Data acquisition setup and calibration steps. Please click here to download this File.
Source | Noble Life Sciences, Woodbine, MD |
Sex | Castrated male or female |
Strain | Dorset cross |
Weight | 55-70kg at receipt |
Diet | 3 lb of pellets each day. Timothy hay given in the provided feed bag, filled up to twice a day |
Light Cycle | Light cycle 12/12 hour light/dark periods; Lights on at 6:00am, off at 6:00pm unless otherwise indicated |
Housing Condition | Sheep are housed individually or in pairs. Housing enclosures measure 6.3’w X 5.7’d (35.4 sq ft.) unless otherwise specified by the facility manager. Multiple enclosures can be connected for additional floor space as needed. Rubber mats are provided to all sheep upon receipt by the animal care technician. Mat(s) is/are sanitized weekly. |
Supplementary Table 1: Relevant information on animal subject for this platform.
Cases/Events | N (%) |
Total | 28 (100) |
No complications | 22 (78) |
Infection, early termination | 1 (4) |
Compromise of implanted port | 2 (7) |
Compromise of implanted pulmonary artery cuff | 2 (7) |
RV decompensation at end of the model | 1 (4) |
Supplementary Table 2: Complications during the sheep pulmonary hypertension model.
The presented PH-RVF model can reliably induce varying levels of disease severity to match the goals of the investigation. Two different approaches are used in combination to induce this disease model. First, the LPA ligation serves to increase pulmonary vascular resistance and decrease PA capacitance11,12, thereby establishing the starting point of the chronic model at an already increased RV afterload state. Then, the implantation of the PA cuff and its progressive inflation serves to develop a targeted phenotype of PH-RVF. Controlling PA cuff pressure and its rate of change can differentially create compensating or decompensating RVs, demonstrated by either maintenance or decline of SvO2 (Figure 4). By increasing cuff pressure by 250-300 mmHg per week, the sheep will start to display early signs of decompensation around 5-6 weeks. Increasing the cuff pressure by 100-150 mmHg per week, on the other hand, allows for a more adaptive profile over the entire 9-week duration.
Few large animal models of chronic PH and RVF exist in the literature. Pulmonary artery embolization in sheep has been most extensively reported and discussed4,5. However, this approach has a high mortality rate, upward of 86%4 depending on dosage frequency and bead sizes, yet it yields only a marginal change in RV hemodynamics and function. On the other hand, the presented model can induce a much greater range of RV pressure overload with minimal procedurally related deaths. One animal that died due to this PH-RVF model developed several liters of pleural effusion and ascites10, correlating with the clinical and research findings of right heart failure in humans13,14,15 and large animals16. These signs were observed without any evidence of left heart failure. This model can therefore serve as a clinically translatable large animal platform with the ability to produce titratable pathophysiology.
There are several notable challenges to executing this model. First, while using a left mini-thoracotomy facilitates expedient postoperative recovery, simultaneous surgical exposure of both the main PA and the LPA is technically challenging via this minimally invasive incision. Selecting the optimal intercostal space is essential and ultrasonography can be a helpful guide. The PA bifurcation is more distal and posterior compared to human anatomy, making ligation of the LPA the most challenging step of this procedure. While the ligation serves as a critical step to increase pulmonary vascular resistance and decrease PA capacitance, it is feasible that the main PA banding alone might achieve sufficiently high RV pressure.
Infection of indwelling ports and port-site wound dehiscence can be difficult to address and lead to devastating complications. In this pulmonary hypertension model, infections could be the acute metabolic insult that triggers cardiopulmonary compromise, collapse, and early mortality. High standards for sterile technique, meticulous skin closure, and port site protection significantly limit the incidence and impact of these occurrences.
Cuff rupture is a specific issue with the model that could lead to decreased RV pressure. Though uncommon, this problem has been observed previously. There are a few preventative and remedial steps for this issue. First, care should be taken to avoid puncturing the cuff while securing it around the PA with suture. Testing the cuff prior to closing the chest ensures its integrity at the conclusion of the initial operation. Next, the PA cuff size should be chosen based on the main PA diameter size. If the cuff leaks, then it will be important to assess the magnitude of leakage. If more frequent inflation of the PA band can overcome the rate of leakage, then the model can still achieve moderate PH-RVF, although it may no longer induce the desired severity of PH-RVF.
In our experience, this model has an overall success rate of 78% (Supplementary Table 2), but most of the complications have been in the earlier half of these trials. The more recent cohort of 13 subject has had a success rate of 100%, which suggests that this model can be reproducible and free of complications with enough experience.
Finally, a key scientific limitation of the presented animal model is that it does not convey a key feature of pulmonary arterial hypertension, namely, pulmonary vascular remodeling. Hence, this model is not the ideal platform to develop and test therapeutics that are focused solely on the pulmonary vasculature. Instead, it is an effective platform to study RV dysfunction and failure from abnormal RV afterload. Patient outcomes in PH are largely driven by RV function, and favorable outcomes are associated with the preservation of this RV function17. Although this model does not capture all aspects of PH, it is a valuable model for understanding the molecular pathways leading to RVF and developing RV-targeted therapeutics to ameliorate RVF.
The LPA ligation and main incremental PA banding model can successfully recapitulate the complex pathophysiology of RVF secondary to PH. This model will provide investigators an experimental platform to develop new diagnostic biomarkers that differentiate between adaptive and maladaptive responses to PH on the RV, elucidate critical response pathways in RVF, and enable therapeutic innovations to treat RVF.
The authors have nothing to disclose.
This work was funded by the National Institutes of Health R01HL140231. We thank the Division of Animal Care for their animal husbandry and veterinary care. We thank the SR Light Laboratory and its staff, Jamie Adcock, Susan Fultz, Codi VanRooyen, and José Diaz, for their dedicated technical support with large animal surgeries.
0.9% Sodium Chloride Irrigation Pour Bottle by Baxter Healthcare, 1000 mL | Medline | BHL2F7124 | Surgical Disposable |
0.25% Bupivacaine | Hospira Inc | 0409-1160-18 | Medication, Intra-Operative |
0.9% Normal Saline, 1000 mL | Baxter Healthcare Corp | 0338-0049-04 | Medication, Intra-Operative |
0.9% Normal Saline, 500 mL | Baxter Healthcare Corp., | 0338-0049-03 | Medication, Chronic PH |
16 mm Heavy Duty Occluder with actuating tubing | Access Technologies | OC-16HD | Surgical Disposable |
3-mL Skin Prep Applicator | Medline | MDF260400 | Surgical Disposable |
70% isopropyl alcohol prep pads | Medline | MDS090670 | Disposable, Chronic PH |
Adhesive bandage tape | Patterson Veterinary | Disposable, Chronic PH | |
Adson forceps | V. Mueller | NL1400 | Surgical Instrument |
Allis tissue forceps | V. Mueller | CH1560 | Surgical Instrument |
Aortic clamp, straight (bainbridge forceps) | V. Mueller | SU6001 | Surgical Instrument |
Backhaus towel forceps | V. Mueller | SU2900 | Surgical Instrument |
Bags, Infusion: Nonsterile Novaplus Infusion Bag, 500 mL | Medline | TCV4005H | Disposable, Chronic PH |
Berry sternal needle holder | V. Mueller | CH2540 | Surgical Instrument |
Blades, Electrode: Electrode Blade, 6.5", with 0.24 cm Shaft | Medline | VALE15516 | Surgical Disposable |
Blades: Stainless-Steel Sterile Surgical Blade, Size #10 | Medline | B-D371210 | Surgical Disposable |
Blades: Stainless-Steel Sterile Surgical Blade, Size #11 | Medline | B-D371211 | Surgical Disposable |
Blades: Stainless-Steel Sterile Surgical Blade, Size #15 | Medline | B-D371215 | Surgical Disposable |
BNC Male to BNC Male Cable | Digi-Key | 415-0198-036 | Equipment |
Castroviejo needle holder | V. Mueller | CH8589 | Surgical Instrument |
Cefazolin | Apotex Corp | 60505-6142-0 | Medication, Intra-Operative |
Ceftiofur Crystalline Free Acid | Zoetis Inc | 54771-5223-1 | Medication, Post-Operative |
Chest Drain, with Dry Suction, Adult-Pediatric | Medline | DEKA6000LFH | Surgical Disposable |
Chest tube passer | V. Mueller | CH04189 | Surgical Instrument |
COnfidence Flowprobes for Research (PAU-Series) | Transonic | 24PAU | Equipment, Perivascular Flow Probe |
Cooley tangential occlusion clamp | V. Mueller | CH6572 | Surgical Instrument |
Data Acquisition Hardware | ADInstruments | PowerLab 16/30 | Equipment |
DeBakey Aorta clamp | V. Mueller | CH7247 | Surgical Instrument |
DeBakey multi-purpose clamp | V. Mueller | CH7276 | Surgical Instrument |
Debakey tissue forceps, 12’’ | V. Mueller | CH5906 | Surgical Instrument |
Debakey vascular tissue forceps 7 3/4’’ | V. Mueller | CH5902 | Surgical Instrument |
Debakey vascular tissue forceps, 9’’ | V. Mueller | CH5904 | Surgical Instrument |
Electrosurgical Generator | Covidien | Force FX-C | Equipment |
Endotracheal Tube, 10mm | Patterson Veterinary | 07-882-9008 | Surgical Disposable |
Enrofloxacin | Norbrook Laboratories Limited | 55529-152-05 | Medication, Intra-Operative |
Fentanyl Transdermal Patch | Apotex Corp | 60505-7007-2 | Medication, Pre-Operative |
Ferris smith tissue forceps | V. Mueller | SU2510 | Surgical Instrument |
Finochietto rib spreaders, large | V. Mueller | CH1220-1 | Surgical Instrument |
Finochietto rib spreaders, medium | V. Mueller | CH1215-1 | Surgical Instrument |
Flexsteel ribbon retractor, 1” x 13” | V. Mueller | SU3340 | Surgical Instrument |
Flexsteel ribbon retractor, 2” x 13” | V. Mueller | SU3346 | Surgical Instrument |
Foerster sponge forceps, curved | V. Mueller | GL660 | Surgical Instrument |
Gauze Sponges: Sterile X-ray Compatible Gauze Sponges, 16-Ply, 4" x 4" | Medline | PRM21430LFH | Surgical Disposable |
Gerald-DeBakey forceps | V. Mueller | CH04242 | Surgical Instrument |
Glassman Allis | V. Mueller | SU6152 | Surgical Instrument |
Halsted mosquito forceps | V. Mueller | SU2702 | Surgical Instrument |
Harken clamp | V. Mueller | CH6462 | Surgical Instrument |
Heat Therapy Pump | Gaymar/Stryker | TP-400 | Equipment |
Heparin | Fresenius Kabi, | 63323-540-31 | Medication, Chronic PH |
Hospira Primary IV Sets, 80" | Patterson Veterinary | 07-835-0123 | Surgical Disposable |
Hypertonic saline 3% | Baxter Healthcare Corp., | 0338-0054-03 | Medication, Chronic PH |
Hypodermic Needle with Bevel and Regular Wall, 20 G x 1" | Medline | B-D305175Z | Disposable, Chronic PH |
Interface Cable, Edwards LifeScience Transducer to ADInstruments Bridge Amplifier | Fogg System | 0395-2434 | Equipment |
Intravenous Infusion Pump | Heska | Vet/IV 2.2 Infusion Pump | Equipment |
Isoflurane | Patterson Veterinary | 14043-704-06 | Medication, Pre-Operative |
Kantrowitz thoracic clamp, 9-1/2” | V. Mueller | CH1722 | Surgical Instrument |
Kelly hemostats | V. Mueller | 88-0314 | Surgical Instrument |
Lidocaine HCl, 2.46% | PRN Pharmacal, | 49427-434-04 | Medication, Chronic PH |
Ligaclip Multiple-Clip Appliers by Ethicon | Medline | ETHMCS20 | Surgical Disposable |
Loop, Vessel, Mini, Red, 2/pk, Sterile | Medline | DYNJVL12 | Surgical Disposable |
Lorna non-perforating towel forceps | V. Mueller | SU2937 | Surgical Instrument |
Mayo dissecting scissors, curved | V. Mueller | SU1826 | Surgical Instrument |
Mayo dissecting scissors, straight | V. Mueller | SU1821 | Surgical Instrument |
Medipore Dress-It Pre-Cut Dressing Covers by 3M | Medline | MMM2955Z | Surgical Disposable |
Meloxicam | Patterson Veterinary | 14043-909-10 | Medication, Post-Operative |
Mixter thoracic forceps, 9” | V. Mueller | CH1730-003 | Surgical Instrument |
Mosquito hemostats | V. Mueller | 88-0301 | Surgical Instrument |
Multi-Channel Research Consoles | Transonic | T402/T403 | Equipment, Perivascular Flow Meter |
Multi-Lumen Central Venous Catheterization Kits | Medline | ARW45703XP1AH | Surgical Disposable |
Multi-Parameter Vital Signs Monitor | Smiths Medical | SurgiVet Advisor 3 | Equipment |
Needles: Hypodermic Needle with Regular Bevel, Sterile, 18 G x 1.5" | Medline | B-D305185Z | Surgical Disposable |
No. 3 knife handle | V. Mueller | SU1403-001 | Surgical Instrument |
No. 7 knife handle | V. Mueller | SU1407 | Surgical Instrument |
Non-Vented Male Luer Cap | Qosina | 13614 | Disposable, Chronic PH |
Octal Bridge Amplifier | ADInstruments | FE228 | Equipment |
Ophthalmic Ointment | Akorn Animal Health | 59399-162-35 | Medication, Pre-Operative |
Penrose Tubing, 6 mm x 46 cm, 11 mm Flat | Medline | SWD514604H | Surgical Disposable |
Perma-Hand Black Braided Silk: 2-0 SH Taperpoint Needle, Control Release, 30" | Medline | ETHD8552 | Surgical Disposable |
Perma-Hand Suture, Black Braided, Size 0, 6 x 30” | Medline | ETHA306H | Surgical Disposable |
Perma-Hand Suture, Black Braided, Size 4-0, 12 x 30" | Medline | ETHA303H | Surgical Disposable |
Phenylephrine | West-Ward | 0641-6142-25 | Medication, Intra-Operative |
Polyhesive Cordless Patient Return Electrodes, Adult | Medline | SWDE7509 | Surgical Disposable |
Port-A-Cath Huber Needle, Straight, 22 G x 1-1/2" | Medline | AAKM21200724 | Disposable, Chronic PH |
PROLENE Monofilament Suture, Blue, Size 4-0, 36", Double Arm, RB-1 Needle | Medline | ETHD7143 | Surgical Disposable |
PROLENE Polypropylene Monofilament Suture, Blue, Double-Armed, RB-1 Needle, Size 5-0, 24" | Medline | ETH8555H | Surgical Disposable |
Regional Block Needles, 22-gauge | Medline | B-D408348Z | Surgical Disposable |
Schnidt tonsil artery forceps | V. Mueller | M01700 | Surgical Instrument |
Skin staple extractor | Medline | CND3031 | Disposable, Chronic PH |
Skin stapler 35 wide, with counter | Medline | STAPLER35W | Surgical Disposable |
Sphygmomanometer | Medline | Equipment | |
Sponge bowl | V. Mueller | GE-75 | Surgical Instrument |
Sponge, Lap: X-Ray Detectable Sterile Lap Sponge, 18" x 18", 5/Pack | Medline | MDS241518HH | Surgical Disposable |
Sponge, Peanut: X-Ray Detectable Sterile Peanut Sponge, Small, 3/8" | Medline | MDS72038 | Surgical Disposable |
Sterile Disposable Deluxe OR Towel, Blue, 17'' x 27'', 2/Pack | Medline | MDT2168202 | Surgical Disposable |
Sterile Luer-Lock Syringe, 3 mL | Medline | SYR103010Z | Disposable, Chronic PH |
Sterile Luer-Lock Syringe, 5 mL | Medline | SYR105010Z | Disposable, Chronic PH |
Sterile Surgical Equipment Probe Covers | Medline | DYNJE5930 | Surgical Disposable |
Stopcock: 3-Way Stopcock with Handle in OFF Position, Rotating Adaptor Male Collar Fitting, 45 PSI | Medline | DYNJSC301 | Surgical Disposable |
Stopcock: 3-Way Stopcock with Handle in OFF Position, Rotating Adaptor Male Collar Fitting, 45 PSI | Medline | DYNJSC301 | Disposable, Chronic PH |
Subcutaneous Port with 5-French Connector and Blue Boot | Access Technologies | CP2AC-5NC | Surgical Disposable |
Super cut metzenbaum dissecting scissors | V. Mueller | CH2032-S | Surgical Instrument |
Super cut nelson-metzenbaum dissecting scissors | V. Mueller | CH2025-S | Surgical Instrument |
Syringes: Sterile Luer-Lock Syringe, 10 mL | Medline | SYR110010Z | Surgical Disposable |
Thoracic Catheter, Straight, 28 Fr x 20" | Medline | SWD570549H | Surgical Disposable |
Three-quarter surgical drape | Medline | DYNJP2414H | Surgical Disposable |
Tiletamine + Zolazepam | Zoetis Inc | 54771-9050-1 | Medication, Pre-Operative |
TourniKwik Tourniquet Set with Four 7.5" Bronze-Colored Tubes and 1 Snare, 12 French | Medline | CVR79013 | Surgical Disposable |
Transducer clip | Edwards LifeScience | TCLIP05 | Equipment |
Trigger Aneroid Gauge (Sphygmomanometer) | Patterson Veterinary | 07-815-0464 | Equipment |
TruWave Disposable Pressure Transducer Kits by Edwards Lifesciences | Medline | VSYPX260 | Surgical Disposable and Chronic PH |
TS420 Perivascular Flow Module | Transonic | TS420 | Equipment, Perivascular Flow Meter |
Tubing, Suction: Sterile Universal Suction Tubing with Straight Ribbed Connectors, 1/4" x 12' | Medline | OR612 | Surgical Disposable |
Tubing: Pressure Monitoring Tubing with Fixed Male Luer Lock and Female Fitting, Low Pressure, 72" L | Medline | DYNJPMTBG72MF | Surgical Disposable |
Tubing: Pressure Monitoring Tubing with Fixed Male Luer Lock and Female Fitting, Low Pressure, 72" L | Medline | DYNJPMTBG72MF | Disposable, Chronic PH |
Tubular Elastic Dressing Retainer | Medline | DERGL711 | Disposable, Chronic PH |
Tuffier rib retractor | V. Mueller | CD1101 | Surgical Instrument |
Tygon E-3603 Flexible Tubings | Fisher Scientific | 14-171-227 | Surgical Disposable |
U.S.A retractor | V. Mueller | SU3660 | Surgical Instrument |
Umbilical Tape, Cotton, 3-Strand, 1/8 x 36" | Medline | ETHU12TH | Surgical Disposable |
Valleylab Button Switch Pencil | Medline | VALE2516H | Surgical Disposable |
Vanderbilt deep vessel forceps | V. Mueller | CH1687 | Surgical Instrument |
Veterinary Anesthesia Machine | Midmark | Matrx VMC | Equipment |
Veterinary Anesthesia Ventilator | Hallowell EMC | Model 2000 | Equipment |
Vicryl: Undyed Coated Vicryl 0 CT-1 36" Suture | Medline | ETHVCP946H | Surgical Disposable |
Vicryl: Undyed Coated Vicryl 2 TP-1 Taper 54" Suture | Medline | ETHVCP880T | Surgical Disposable |
Vicryl: Undyed Coated Vicryl 2-0 CT-1 18" Suture | Medline | ETHVCP739D | Surgical Disposable |
Vital crile-wood needle holder, 10-3/8” | V. Mueller | CH2427 | Surgical Instrument |
Vital mayo-hegar needle holder, 7-1/4” | V. Mueller | CH2417 | Surgical Instrument |
Vital metzenbaum dissecting scissors, 14’’ | V. Mueller | CH2009 | Surgical Instrument |
Vital metzenbaum dissecting scissors, 9” | V. Mueller | CH2006 | Surgical Instrument |
Vital ryder needle holder, 9” | V. Mueller | CH2510 | Surgical Instrument |
Yankauer, Bulb Tip: Sterile Rigid Yankauer with Bulb Tip, No Vent | Medline | DYND50130 | Surgical Disposable |