PhysioTel®Digital Device Surgical Manual Surgical Implantation of the PhysioTel®Digital Blood Pressure and Biopotential Telemetry Devices Doc-To-Help Standard Template Error! No text of specified style in document.
Acknowledgments Vetbond® and Bair Hugger® are registered trademarks of 3M. PhysioTel®Digital Device Surgical Manual Copyright 2012 Data Sciences International All Rights Reserved Printed in U.S.A. Part Number Rev. 01 Data Sciences International (DSI) 119 14th Street NW ● Suite 100 ● St. Paul, MN 55112 Telephone: (1-651) 481-7400 ● 1-800 262-9687 Fax: (1-651) 481-7417 Website: www.datasci.com Doc-To-Help Standard Template Error! No text of specified style in document.
Introduction PhysioTel®Digital telemetry devices are surgically implanted into large laboratory animals to acquire multiple types of physiologic measurements, process the information and transmit the data via radio-frequency signals. The PhysioTel®Digital device can measure pressure (such as systemic blood pressure or intra-ventricular pressure), a biopotential (such as ECG) temperature and physical activity.
o Trans-diaphragmatic Approach o Intercostal Thoracotomy Approach Solid Tip ECG Lead Placement o Internal Jugular Vein o External Jugular Vein Traditional ECG Lead Placement o Lead II o Base-Apex Appendix A: Additional Device Information Appendix B: Functional Specifications Appendix C: Care and Use Appendix D: Equipment and Supplies Appendix E: Checking the Offset of a Pressure Device Doc-To-Help Standard Template Error! No text of specified style in document.
Required Supplies for the PhysioTel®Digital Surgery EQUIPMENT Clippers Supplemental heating PhysioTel®Digital device Ponemah 5.
Magnet * Re-gel syringe Vetbond®Tissue adhesive (if placing systemic blood pressure catheter in iliac artery) Gel loading micropipette tip or insulin syringe (if placing systemic blood pressure catheter in iliac artery) * Contained in starter kit Doc-To-Help Standard Template Error! No text of specified style in document.
Anesthesia and Analgesia Guidelines Proper peri-operative pain control and anesthesia are critical to humane treatment of laboratory animals. Each institution’s staff veterinarian should be contacted for proper analgesic and anesthetic protocols and training before survival surgery is attempted. The use of pre- and post-surgical analgesics is strongly encouraged for all surgical manipulations performed on laboratory animals.
Peri-operative Antibiotics and Antiarrhythmic Medications The use of antibiotics may be elected at the discretion of the investigator. The combination of sterile device packaging and proper aseptic technique help increase the potential for successful surgical outcomes. Investigators should follow the guidelines of their own institution. Questions regarding the use of antibiotics should be directed to the institution’s staff veterinarian.
Thin-walled section: tip of the catheter farthest from the device body that senses the dynamic portion of the pressure wave. It is designed to be completely inserted into the vessel or space where the desired pressure can be sensed. It contains biocompatible gel at the very tip, which prevents the non-compressible fluid from leaving the catheter and blood from clotting in the catheter tip (see Figure2).
Biopotential Leads - Two silicon coated helices of medical grade stainless steel wire extending out of the device body. The positive (red) lead is designed to be cut to a length suitable for the biopotential signal to be monitored. The negative (clear) lead has a solid tip and is NOT meant to be cut (unless you require traditional lead placement). It is designed to be introduced into the right jugular vein and fed into the cranial vena cava to collect the ECG signal.
Figure 4. [MES8]Solid Tip Biopotential Lead Device Handling ALWAYS handle the device with care supporting both the device body and catheters from underneath when moving or placing the device. Allowing the catheters to hit a solid surface can damage the pressure sensor. Before removing the device from its sterile package Turn the device to the ON mode with a magnet and audibly verify proper device operation with a DSI receiver. 1.
Preoperative Patient Preparation 1. Administer the appropriate surgical anesthesia. 2. Apply Artificial Tears eye ointment to each eye. 3. Remove the body hair liberally from all intended incision sites. 4. Surgically scrub the incision sites with Chlorhexidine or Providine-iodine scrub. a. A series of at least three scrubs after all gross debris has been removed is recommended. b.
Device Implantation Site Selection The PhysioTel®Digital device can be implanted either intramuscularly, subcutaneously, intraperitoneally or subperitoneally in animals weighing at least 2.5 kilograms. Possible locations for placement of the device body vary with the species and size of animal that is implanted and the physiologic parameters that will be measured.
Intra-abdominal Placement: Intraperitoneal/Subperitoneal Intraperitoneal/subperitoneal placement is appropriate for canines and non-human primates weighing ≥ 2.5 kg. Due to potential device engulfment by the intestines, intraperitoneal placement is not recommended in swine; instead a modified subperitoneal approach is favored.
the device is placed on the left side of the linea alba the antennae will run along the abdominal wall, across the abdominal incision, towards the right side of the abdomen.) alba the antennae will run along the abdominal wall, across the abdominal incision, towards the right side of the abdomen.) 5a.
Figure 7. PhysioTel®Digital Device Placed Intraperitoneally[MES11] 11. Next a small pocket should be tunneled in the subperitioneal space using blunt dissection with a mayo scissors or a straight hemostat to provide a secure location for the antenna to sit. 12. The body wall can be temporarily apposed near the antenna (without including the antenna itself) using an interrupted suture or a towel clamp. 13. The body wall should be closed in 2-3 layers.
Subcutaneous 2a. Using a mayo scissors bluntly dissect under the skin to form a pocket approximately the size of the device body. Intramuscular 2b. Using a gridding technique, bluntly separate the superficial external abdominal oblique muscle along the fibers running craniodorsal to caudoventrally. Be cautious not to dissect too deeply and enter the abdominal cavity. 4a. Pass a trochar and cannula can between 4b. See 4a.
placement of the antenna should also be closed using an intradermal/subcuticular pattern. Dorsal Recumbency Figure 11. Subcutaneous/Intramuscular Placement in Dorsal Recumbency Intramuscular 1a. Place a longitudinal incision just axial (to the inside of) the fold of the flank. Make the incision long enough to allow for insertion of the device in whichever positioning will allow the antenna to sit at 90 degrees to the device body (with neither device body nor antenna placed over any bony structure).
of the heart. Remembering that during dorsal recumbency the animal’s heart shifts from its natural position so the incision should be placed slightly ventrally. 3a. The diaphragm may be kept open by placing stay sutures in the diaphragm on each side of the incision using 3-0 or 4-0 suture with a taper needle. Secure the ends of the stay suture with a hemostatic clamp which can then be held by an assistant.
4. Carefully remove the tip cover from the LV catheter (Channel 1, see description above). Removal of the tip cover should be done by alternating gentle traction and release. Take care to prevent gel loss due to compression of the catheter or sudden release of the tip cover. Always examine the catheter prior to implantation for gel loss or bubbles. If there is gel loss or bubbles, the catheter will need to be regelled.
Figure 15: Puncture the heart wall 8. Withdraw the needle and insert a micro-mosquito hemostat into the hole. Open the hemostat slightly to expand the hole. 9. Grasp the overlap section of the catheter using a Ddebakey forceps, vessel cannulation forceps or gently using the hand. 10. Insert the tip of the catheter into the perforation in the heart wall. Advance the catheter until the suture aid suture on the catheter is in direct contact with the heart wall (see Figure 16).
Figure 17: Left ventricular pressure signal 12. Once proper positioning is verified, draw the purse-string suture closed around the catheter. Ensure this suture is tight and multiple square knots are tied to prevent the catheter from withdrawing from the heart (see Figure 18). Figure 18. Tying the purse-string suture Doc-To-Help Standard Template Error! No text of specified style in document.
13. Tie one tail of each of the purse-string sutures to one tail of each of the suture aid sutures (this is why using different colored sutures can be helpful) to further secure the catheter in place. 14. Ensure that the catheter is placed securely in the heart wall and that all bleeding has stopped, and cut the stay suture aid suture and purse string suture tails. If necessary, an additional purse-string suture can be placed. 15.
of the diaphragm closed. 19a. Make sure there are no leaks in the diaphragmatic closure, and that the diaphragm maintains its concave appearance following catheter removal. Place additional sutures as needed to completely seal the diaphragm, and perform repeat thoracocentesis if additional air withdrawal is needed to correct pneumothorax. 19b.
Figure 20. Medial Saphenous Artery Exposure [MES14] Mesenteric Artery 1a. Locate an intestinal artery running through the mesentery closely associated with the vein and lymphatic vessel. Choose an artery that has nearby collateral blood supply to avoid compromise to the intestine. Using a fine tipped, curved forceps carefully isolate at least 2.5 cm of the artery. Medial Saphenous/Femoral Artery 1b.
sutures can be tied in loose knots to allow the suture to pass as it is inserted into the abdominal aorta. The proximal-most suture will be used to temporarily occlude blood flow when the artery is punctured (see Figure 21). Figure 21. Preparing Artery for Catheter Placement 4. Prepare a 20-gauge needle by bending the beveled tip (while holding the bevel up) to a 90 degree angle (see Figure 22). This will be used to puncture the vessel and can be used to introduce the catheter. Figure 22.
6. Gently and slowly remove the tip cover using gentle traction and release, without touching the distal thin-walled sensing portion of the catheter. Take care to prevent gel loss due to compression of the catheter or sudden release of the tip cover. Always examine the catheter prior to implantation for gel loss or bubbles. If there is gel loss or bubbles, the catheter will need to be re-gelled. For help with this process, refer to the Guidelines for the Re-gel of the PA-C40 Device on our website: www.
1. Carefully locate and isolate the iliac artery. The paired iliac arteries are located in the caudal abdomen and branch directly off of the caudal abdominal aorta and can be palpated by first detecting the aortic pulse and moving caudally (see Figure 25). Figure 25. Iliac Artery 2. Using fine tipped, curved forceps, carefully isolate at least 2.5 cm of the iliac artery from the surrounding tissue and the iliac vein. 3.
4. Fill four gel-loading micropipette tips with VetbondR tissue adhesive using capillary action and set aside. They will be used to dispense a very small amount of adhesive to seal the vessel. Using micropipettes to dispense the Vetbond will help control the amount of Vetbond applied to the artery. Excessive Vetbond can encircle the artery and compromise blood flow. This can result in hind limb paresis. 5.
11. Secure the catheter that is outside the vessel near the entry site to the lumbar muscles in at least two locations using non-absorbable suture. If the catheter is not secured to nearby muscles there is a high risk that the catheter will back out of the vessel postoperatively, which would result in internal bleeding and loss of the blood pressure signal. Thoracic Aorta Systemic Blood Pressure Catheter Placement 1.
nearby muscles there is a high risk that the catheter will back out of the vessel postoperatively, which would result in internal bleeding and loss of the blood pressure signal. Electrocardiogram (ECG) Lead Placement Positive Lead Placement The positive lead must be placed first so you can detect an ECG signal to guide placement of the negative solid tip lead.
Figure 30. Lead II ECG Placement Figure 31. Base-apex ECG Lead Placement 1c. If the positive ECG lead will be placed epicardially, it will need to be directed to the thoracic cavity and placed prior to closure of the chest following left ventricular pressure catheter ± thoracic aorta systemic blood pressure catheter placement. 2. Cut the lead to the appropriate length to reach the incision, allowing for growth if needed.
Figure 32. ECG Lead Modification 3. Take the suture still attached to the ECG lead and use this to tack the loop to the underlying muscle/tissue. Anchor the exposed portion of the lead to the underlying muscle using at least 3 simple interrupted knots using 2-0 to 0 3-0 non-absorbable suture. You can also tack the lead along its course if you are concerned about tension. Negative Solid Tip Lead Placement The PhysioTel®Digital device will come with a solid tip negative lead.
Figure 33. External Jugular Vein Figure 34. Internal Jugular Vein in Non-human Primate 2. Once the solid-tipped lead is exteriorized at the jugular incision via passing it through a cannula (as described above in device placement description), it’s time to prepare the vessel for cannulation. Pass 3 pieces of non-absorbable suture around the vessel. The cranial-most suture will be used to permanently ligate the vessel.
6. It is imperative to monitor the ECG signal while passing the negative lead. The appropriate location of the solid tip is dictated by the size of the P wave. The P wave will start out small and grow increasingly larger as it approaches the heart and may become negative when it is passed too far. The solid tip is in its optimal position when the P wave is approximately 1/3 the height of the QRS complex.
Appendix A: Additional Device Information Device Explantation When explanting DSI devices implanted intraperitoneally, intramuscularly or subcutaneously, consider the following: Carefully remove the device body. Be careful not to drop the device. If cutting the catheter is necessary, use only a new scalpel blade to cut the catheter at a 45degree angle away from the device body and approximately 3 cm from the device body. Do not use any instrument other than a scalpel blade to cut the catheter.
Appendix B: Functional Specifications Specifications Weight Volume Height Width Length Usable Catheter Length Catheter Diameter Temperature Range Pressure Range Initial Accuracy Battery Life Intended Cage Size PhysioTel®Digital Device 35 cm*** * Standard catheter length. Also available in 10 cm and 15 cm lengths. ** The diameter is 5.5 cm and the thickness is 1.5 cm. *** Standard catheter length. Also available in 25 cm and 40 cm lengths.
Appendix C: Device Care and Use Operational Modes TL implantable devices are equipped with two operational modes: ON and OFF. Devices are shipped to you in the OFF mode. The battery in the device is not activated. When switched to ON, the devices begin to sense and transmit data. The switch to change between these two modes is in the interior of each device and is therefore not visible. The switch is magnetically activated. To switch operational modes: 1. Power on a PhysioTel®Digital reader 2.
Storage of On-Site Sterilized Devices Occasionally there may be a delay between the device removal from the animal and return to DSI for refurbishment. Proper storage of the on-site sterilized device is necessary to ensure that the unit will not be damaged. Thoroughly clean and sterilize each device according to DSI's On-Site Re-sterilization procedure. If the original device sterile package was saved, place the device into the plastic packaging.
Appendix D: Equipment and Supplies The surgical instruments, along with their part numbers from Fine Science Tools, are listed below.
Gel-loading micropipette tips (Part Number 02-707-83) can also be purchased from Fisher Scientific. Fisher Scientific: Telephone: (1-800) 766-7000 Fax: (1-800) 926-1166 Website: www.fishersci.com \ Doc-To-Help Standard Template Error! No text of specified style in document.
Appendix E: Checking the Offset of a Pressure Device The following protocol will allow you to verify that the pressure device is functioning normally prior to surgical placement in an animal. NOTE: Turn the device on approximately 1-4 hours before taking the pressure offset measurement. This will allow the electronics time to warm up and stabilize. Pressure offsets can be affected by temperature and intense light.
After the device has been on for 1-4 hours, place the device in the packaging tray onto its assigned receiver. 3. From the Setup menu, choose PD Setup... and change the analysis module to BP for the pressure channel in the Channel Input Setup screen. 4. Close the Setup window and start an acquisition from Acquisition – Start Acquistion. 5. In the Status window, double-click on the blood pressure channel to open the Blood Pressure Analysis Attributes window. Select the Offsets tab. 6.
