Physician Training Manual. LASE Endoscopic Discectomy

Transcription

1 Physician Training Manual LASE Endoscopic Discectomy

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3 DISCLAIMER This manual contains information about the LASE procedure. Clarus Medical, LLC recommends, that before performing a LASE procedure you attend a perceptorship to learn from experienced physicians patient selection and care. Refer to the package insert for a complete list of cautions and warnings. Customer Service: The internet: For More Information LASE is a registered trademark of Clarus Medical, LLC 3

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5 Table of Contents Chapter 1: Introduction... 7 Chapter 2: Selecting Candidates for LASE Endoscopic Discectomy... 9 Patient Selection Criteria: Contraindications: Relative contraindications: Contained Herniations LASE is Better than Conventional Surgery on Contained Disc Herniation Chapter 3: LASE Kit Components Introduction LASE Endoscope Flexible Guiding Needle Dilator Straight Working Channel Straight Working Channel with Dilator Curved Working Channel Trephine Stylet Scalpel Skin Maker Ruler Irrigation Tubing Chapter 4: Connecting LASE The "Endoscope Coupler" Types of Video Cameras C-Mount Cameras V-Mount Cameras

6 Focusing C and V-Mount Cameras B-Mount Cameras Focusing B-Mount Cameras Image Orientation Illumination The Laser Connection Irrigation Aspiration Chapter 5: LASE Technique Introduction A Summary Of Resources Required Sample List of Disposables And Supplies: Patient And Equipment Positioning: Preparation Sequence Needle Placement Introduction of the Working Channel - Technique Important Safety and Patient Comfort Notes..46 Tissue Removal with the LASE Endoscope Sequence of Movements..47 Determining the Endpoint The Patient Chart Chapter 6: LASE Technique & Heating Table 1: Identifying and Solving Heat Problems with Clarus= LASE Kit...51 Table 2: Thermal Problems...52 Chapter 7: Endoscopy Pump Pump Notes Chapter 8 Sterilization

7 Chapter 1: Introduction This manual explains the LASE endoscopic discectomy procedure. After you study this manual you should have a good understanding of the procedure. Be sure, though, to study the LASE package insert for a complete set of cautions and warnings. When performing LASE endoscopic discectomy you will be using a posterolateral approach through a tiny incision to remove a portion of the nucleus pulposus of a lumbar disc. The mechanism of removal is laser ablation, although you can also use mechanical means through the LASE kit's working channel. This procedure is performed under endoscopic and fluoroscopic control. LASE accomplishes discectomy in a minimally-invasive way. It is a same-day procedure, performed under local anesthesia. LASE does not damage the posterior spinal elements, or enter the epidural space. In Chapter 2 you will learn about LASE's indications and contraindications. Chapter 3 of this manual describes the LASE kit components. Chapter 4 shows how to hook up the LASE endoscope. Chapter 5 tells you how to perform the discectomy. Chapter 6 describes the Clarus endoscopy pump used with LASE. Chapter 7 tells you how the reusable components can be sterilized. 7

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9 Chapter 2: Selecting Candidates for LASE Endoscopic Discectomy 9

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11 The LASE technique is indicated for treating patients with contained herniated lumbar discs who fail conservative treatment for six weeks or more and who present with clinical and radiologic evidence of nerve root impingement. Patient Selection Criteria: Unilateral leg pain greater than back pain Positive straight leg raising test, crossover pain or bowstring sign Positive CT, MRI or discography study showing a subligamentous herniation at a location consistent with the clinical findings Possible neurologic findings including weakness, sensory alteration and reflex alteration Contraindications: Patients with any of the following clinical or radiologic findings are not considered candidates for this procedure at this time: Radiological evidence of severe degenerative facet disease, severe lateral recess stenosis, ligamentum flavum hypertrophy or free fragments within the spinal canal Any other pathologies or conditions that would place the patient at undue risk Relative contraindications: Unstable spine Full thickness annular tears. Caution when performing LASE on patients with full thickness annular tears may be warranted because the irrigation fluid may leak into the epidural space, and over-pressurize it. 11

12 Contained Herniations The LASE procedure is indicated for patients with contained herniated and bulging lumbar discs. Contained herniated discs are defined as an extension of the nucleus that has not perforated the posterior longitudinal ligament. Figure 1 Contained Herniation (Focal protrusion) Figure 2 Contained Herniation (Prolapsed disc) Reference: Clinical Appearance of Contained and Noncontained Lumbar Disc Herniation Jonsson and Stromqvist, Journal of Spinal Disorders vol. 9, No. 1, pp 32-38, (1996). 12

13 LASE is Better than Conventional Surgery on Contained Disc Herniation Conventional surgery Jonsson and Stromqvist stratified surgical outcomes by type of disc and obtained these results: Status Outcome (%) at 4 and 12 months follow-up. The latter separated into effect on back pain and leg pain. 4 months (overall) Follow-up period 12 months (back pain) 12 months (sciatica) S P FP S P FP S P FP Excellent Fair Unchanged Worse p value (Kruskal- Wallis, H corrected for ties) S=sequestered/extruded disc herniation; P=prolapse; FP=focal protrusion. This study shows that 25 to 30 percent of surgical patients with focal protrusions got worse or were unchanged after conventional surgery. LASE procedure LASE success rate is better than 80% without surgery s morbidity. Clarus can supply you with material about the long-term success rates for laser discectomy. Material is also available about the science behind the use of lasers in the disc. Contact Clarus or your sales representative for more information. 13

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15 Chapter 3: LASE Kit Components 15

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17 Introduction This chapter describes the components of the LASE kit. The LASE kit is a single use kit, packaged with most of the items needed to perform endoscopic discectomy. The tray containing the LASE kit is packaged sterile and is double bagged. A description of the LASE technique is shipped with every LASE kit. Additionally, instructions on proper connection and focusing are printed on the lid of each LASE kit. The following describes the features and benefits of all the components of the LASE kit. 17

18 LASE Endoscope The LASE endoscope removes disc tissue with laser energy under direct visualization. The endoscope has a deflectable steerable tip that facilitates the removal of more disc tissue than can be removed with a rigid device. An integrated laser fiber, within the steerable device, makes the direction of laser energy to the desired location easier. A built-in endoscope allows a physician to see tissue in the disc space being removed and to determine when a sufficient cavity has been created. This increases the safety and efficacy of the procedure. Irrigation is provided from the distal tip of the device to control the temperature in the disc, improve vision, and provide a medium through which debris is aspirated. The LASE endoscope has a 1.7 mm diameter. Distance markings on the device provide the physician a means of determining where the tip of the LASE is located. The LASE system utilizes Holmium: YAG laser energy. Holmium has proven to be a safe and effective laser wavelength for laser discectomy due to its shallow 0.5 mm tissue penetration. 18

19 Flexible Guiding Needle Used to initiate access to the intervertebral disc. The proximal portion of the guiding needle is flexible to accommodate the C-arm of the fluoroscope used during guiding needle placement. The guiding needle is pliable making it more steerable - assisting placement into the intervertebral disc. Dilator Yellow Dot Locks inside either working channel to make the working channel s distal tip less traumatic. 19

20 Straight Working Channel 1. Skin Stop 2. Skin Stop Screw 3. Working channel Aspiration Port 4. Compression fitting This working channel dilator assembly is passed over the flexible guiding needle to create working channel access to the intervertebral disc An aspiration port on the working channel permits removal of irrigation fluid. A compression fitting on the working channel creates a seal around the LASE endoscope to facilitate aspiration. An adjustable skin stop is attached to the working channel to control the depth of the working channel's penetration into the intervertebral disc. 20

21 Straight Working Channel with Dilator This picture shows the dilator inserted into the straight working channel. When properly locked into position, the dilator's tip protrudes from the working channel's distal end, making it smoother and less traumatic. Curved Working Channel The working channel/dilator assembly is passed over the flexible guiding needle to create working channel access to the L5-S1 intervertebral disc. The curve is designed to accommodate the iliac crest of the pelvis that sometimes obstructs guiding needle access to the L5-S1 disc. The curved working channel is packed separately from the LASE kit. Its order number is

22 Trephine Red Dot This instrument is passed through the straight or curved working channel to core the annulus of the intervertebral disc and to facilitate placing the working channel. The trephine is marked with a red dot for easy indentification. The trephine is packaged attached to the blunt stylet. Stylet This instrument can be passed through the working channel to free tissue that may obstruct the working channel. It can also be used as a sterile pointer to help locate the disc level and the entry point for the flexible guiding needle. The stylet is packaged attached to the trephine. 22

23 Scalpel Available for use to incise the skin to facilitate easy passage of the dilator/working channel assembly through the skin and fascia. Skin Maker Used to mark the entry site on the patient during preparation for flexible guiding needle placement. Ruler The ruler is provided to assist in marking the patient for flexible guiding needle placement. 23

24 Irrigation Tubing Attaches to a Luer lock fitting on the LASE endoscope to provide irrigation. 24

25 Chapter 4: Connecting LASE 25

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27 Introduction This chapter explains how to hook up LASE. Five connections are necessary: Image - to display the endoscope's image on a TV monitor Illumination - provide light for the endoscope Laser - connect the kit's laser fiber to the laser Irrigation - provide for cooling irrigant inflow Aspiration - removes irrigant and ablated nucleus pulposus from patient. The "Endoscope Coupler" The "endoscope coupler" connects the endoscope to the camera. The connection of the image fiber is simple: Align the pins on the coupler with the sockets on the LASE Image connector, push, and twist clockwise. LASE Image Connector Align Push Twist Endoscope Coupler Image Make sure the cap on the coupler is dry. Unscrew the cap if the coupler was washed or sterilized by a method that involves a fluid, and Dry the cap thoroughly, inducing the thread Dry the window Screw the cap back on tightly (A hint to drying the inside of the silver "cap" is to hook it up to the suction. The water will be drawn out and air-dried.) Sterilizing the endoscope coupler is discussed in Chapter 7. 27

28 Types of Video Cameras All endoscopes require some sort of image coupling system to attach to cameras commonly used in operating rooms. There are three common configurations of camera heads: The C-mount, the B-mount and the V-mount. The Clarus optical coupling system can easily accommodate all three configurations. There are three common camera types: C-mount (the best) B-mount (cumbersome, but common) V-mount (uncommon, but good) C-Mount Cameras The C-mount configuration is best. It has only one focus ring. The endoscope coupler is directly screwed to the camera body. Screw it in snugly. 28

29 V-Mount Cameras The V-mount optics offers the benefits of the C-mount configuration. The V-mount thread is smaller than the C-mount thread, so a V to C adapter is needed. Screw everything in snugly. V to C Adapter Focusing C and V-Mount Cameras To prevent yourself from unscrewing the camera from the coupler body hold the part of the coupler where "CLARUS" is printed with one hand, and turn the focus knob with the other hand, so that: The picture gets smaller The edge of the picture is razor sharp With good video systems, you will be able to see the pixels (individual fibers) of the endoscope when the focus is perfect 'In Focus' Out of Focus' 29

30 B-Mount Cameras The B-mount is common. It is more cumbersome than the other methods. The B- mount requires an eyepiece to allow the endoscope coupler to connect with the video camera. Eyepiece Focusing B-Mount Cameras The B-mount optic has two focus rings On the endoscope coupler- acts as a fine focus. 2. On the video camera - acts as a zoom lens. Proper focus of the B-mount is easy: First, turn the camera knob so that the image is as small as possible Then using the same methods as for the C and V-mounts, use the endoscope coupler knob for final focus. 30

31 Image Orientation In order to effectively use the LASE endoscope, many doctors orient the image so that the laser fiber appears at the three o'clock position on the television monitor. In this case, if the endoscopies is held with the deflection knob up, "up" on the television monitor corresponds to "up" in the procedure room. Image orientation is achieved by turning the blue cuff at the connection of the image fiber to the coupler so the image on the video monitor has the laser fiber at the 3 o'clock position Twist 31

32 Illumination In order to get an image, the field must be adequately illuminated. The fiberoptic light cable connected to a light source provides this illumination. In order to use a Clarus endoscope, a Clarus-brand light cable must be used. The Clarus light cable matches the amount of light required by the endoscope to the amount of light delivered from the light source. This eliminates excess heat from being delivered to the endoscope from the light source, which can damage the endoscope s proximal end. The Clarus light cable is provided in four configurations. The four light cables adapt to the types of light sources commonly utilized by hospitals. The proximal configurations of the light cables are: ACMI Olympus Storz Wolf/Dyonics and these four styles can be used with many other brands of light source. The connections are easy: Insert Push 32

33 The Laser Connection The laser fiber connection is easy to make. Pass the proximal end of the laser fiber off the sterile field. There is a protective cap on the laser fiber. Remove it. Screw the laser fiber connector into the laser. LASE uses a "Holmium YAG" laser, also written "Ho:YAG". This laser is commonly used for fragmenting ureteral and bladder calculi, and is sometimes used in shoulder and knee surgery. Its light is strongly absorbed by water, the principle component of the nucleus pulposus. LASE is most commonly performed with lasers manufactured by Coherent or Trimedyne. For Coherent lasers (or for other lasers having a "905 SMA" connector), use order the LASE model; for Trimedyne lasers order model Clarus can supply you with training material about the various lasers that have been used for laser discectomy. Contact Clarus or your sales representative for more information. 33

34 Irrigation The Clarus 5169 Endoscopy Pump is specially designed for use with the Clarus LASE device. Constant irrigation is critical to the proper functioning of the LASE endoscope. The Clarus Endoscopy Pump is a high pressure, low volume irrigation source. Details are found in Chapter Endoscopy pump lever 2. Irrigation tubing set 3. Lock down tab 1. Securely attach the power cord to the pump and plug the power cord into a wall socket or extension cord. 2. Verify that the power switch, located on the backside of the pump, is in the "on" position. 3. Open the pump head using the lever on top of the pump head. 4. Place the tubing set into the pump head. 5. Note the arrow on the face of the pump head that indicates the direction of flow. Verify the tubing set is placed into the pump head such that fluid flows from the saline bag towards the LASE endoscope. 34

35 6. Lower the tubing guides, or black plastic "forks", located on each side of the pump head by pushing the lock-down tabs in and down. 7. Close the pump head on the tubing set using the lever on top of the pump head. Verify that the tubing guides are trapping the tubing set. 8. Attach the Luer -lock end of the tubing set to the LASE endoscope and pierce the saline bag with the other end. 9. Activate the fluid pump by using the flow start/stop button located on the face of the fluid pump. The physician also has the option of using the footswitch instead of the flow Start/Stop button. The footswitch attaches to a receptacle on the backside of the fluid pump. 10. Using the flow rate adjustment knob on the face of the fluid pump, adjust the flow rate of irrigation to approximately 30 ml/minute as indicated on the LCD flow rate indicator. 11. Remove air from the tubing set by depressing and holding the prime button located on the face of the fluid pump. 12. Be sure there is an adequate flow of saline from the tip of the LASE endoscope before the LASE device is inserted into the working channel. Aspiration Wall suction is used to remove the irrigating fluid from a port on the kit's working channel. Turn the aspiration to maximum. 35

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37 Chapter 5: LASE Technique 37

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39 Introduction This chapter explains how to complete the LASE procedure. A Summary Of Resources Required The following list is a summary of resources required for a typical LASE procedure. This list was derived from a review of "procedure cards" from various facilities where the LASE procedure is performed. Staff Required: Physician Anesthetist Scrub Nurse/Technician Circulating Nurse Laser Technician C-arm Operator Equipment Required: C-arm (portable fluoroscopy unit) A radiolucent operation table (must accommodate A-P and lateral views of the lumbar spine with the C-arm) Video system (camera, light source, and monitor) Coherent or Trimedyne Holmium: YAG laser Pulse oximetry equipment Oxygen A Clarus light cable The Clarus Endoscopy Pump The Clarus camera head adapter equipment (optic coupler and eyepiece) A Mayo stand An IV pole 39

40 Sample List of Disposables And Supplies: Oty. Description 1 Clarus LASE kit 1 Clarus Curved Working channel Kit (required for some L5/S1 cases) 2 Anesthesiology - Versed 4 mg (2-2 mg vials) 2 Anesthesiology - Fentanyl (200 mcg (2-100 microgram ampules) 1 Pharmacy-IV LR 1000ml 1 Pharmacy - ANCEF (Cefazolin) 1.0 g 1 Pharmacy - Marcaine 0.5% With Epinephrine 2 Pharmacy - Irrigation sterile water 1000 ml 1 Pharmacy - Xylocaine 1% Plain 50 ml vial 1 Pharmacy - Sodium bicarbonate 50 ml 1 Pharmacy - Omnipaque dye 240,50 ml vial 1 Oxygen tubing 1 Set of 3 EKG pads 1 Basin - Pull set, S.S. 1 Angiography procedure pack 1 EZ Prep 27G small 1 Drape laparotomy 2 Surgical gowns 1 Drape (57x77) 1 Gloves 7 Neutralon 1 Suction tubing connection (l0ft.) 1 IV Leur lock connective tubing 1 Drape - Mayo stand cover 1 Drape- C-arm cover 1 Gloves -8 Triflex 1 Suction canister (3000 CC) 2 Under pads 1 Needle Chiba (.22GA x 6in.) 1 Needle Spinal (.20 GA x 3½ in.) 1 Needle Spinal (.18 GA x 3½ in.) 1 Dressing - Band-Aid sheer (1 x 3) 1 Ice pack cloth holder (medium) 40

41 Patient And Equipment Positioning: The patient is positioned in the lateral position with their most symptomatic, or painful, side up. (NOTE: Many physicians prefer to place the patient in the prone position. This will alter the equipment positioning described below.) The physician will be standing posterior to the patient to work on the patient's back. The C-arm is positioned on the opposite side of the table from the physician (the patient's anterior side) such that A-P and lateral views of the patient's lumbar spine can be achieved. The C-arm monitors are placed next to the C-arm towards the patient's head (Between the C-arm and the anesthesiology equipment). The video system is placed next to the C-arm towards the feet of the patient The laser can be placed at the patient's feet near the video system. The Mayo stand is sterile draped and placed such that it can be moved into position over the patient's legs or near the physician. This Mayo stand will hold the assembled and connected LASE kit and video connectors. The IV pole is placed between the laser and the video system. The Endoscopy Pump is placed on top of the laser or on a second Mayo stand near the video system. Patient in lateral or prone position at physician preference. 41

42 Preparation Sequence 1. The endoscope coupler/camera head assembly and light cable are sterilized by an approved method. A camera drape may also be used. 2. Clarus endoscope coupler and light cable, and optionally the eyepiece are properly adapted to the video system. 3. The patient is positioned in the lateral decubitus position. True A-P and lateral X-rays are obtained. The patient is secured to the table in the appropriate position with all pressure points padded. (Tip: secure the patient with 3" adhesive tape across the shoulder, hip and calf.) 4. The patient is prepped, draped and the C-arm is draped in sterile fashion. 5. The LASE endoscope should be connected to: a. The endoscope coupler/camera b. The proper light cable c. The irrigation tubing d. The Coherent or Trimedyne Holmium: YAG laser 6. Properly focus the image. 7. Orient the image so that the laser fiber appears in the "3 o'clock position". 8. Confirm passage of irrigation. 9. Attach an aspiration line to the working channel. All components of the LASE kit are explained later. Many of the components are color coded to facilitate easy identification. The physician should now proceed with needle placement. A flexible guiding needle is supplied in the kit. It is the introduction needle. 42

43 Needle Placement The technique of needle placement for percutaneous disc decompression is exactly the same as the needle placement for lumbar discography. Note: There are two methods, one using oblique, AP and lateral described in Appendix 1, the other using only AP and lateral, described in Appendix 2. Be sure to read the LASE kit package insert (Appendix 3). Introduction of the Working Channel - Technique 1. After correct position of the flexible guiding needle has been confirmed on A-P and lateral fluoroscopy, first lock the dilator on the working channel by twisting the dilator s hub clockwise. Then the pair (working channel with dilator) is passed over the flexible guiding needle and monitored fluoroscopically as it is inserted to the annulus. Caution: Caution: Take care to monitor the flexible guiding needle to ensure that it does not advance further or migrate from the disc. The patient should be carefully monitored for radicular pain during insertion of the working channel. If pain is experienced, reposition the Guiding needle and/or the working channel/dilator. 2. Upon confirmation of proper working channel placement the dilator is rotated counterclockwise to unlock it from the working channel and removed. Note: The flexible guiding needle is not removed. The working channel should remain positioned at the annulus. 3. The trephine (red dot) should be separated from the obturator and the obturator set aside. Slide the trephine over the guiding needle. 4. Confirmation of the working channel placement at the annulus should be performed before the trephine is advanced through the working channel over the flexible guiding needle. 43

44 5. Incise the annulus with the trephine to provide an entry to the nucleus by the LASE device. 6. The trephine is removed, leaving the flexible guiding needle behind. 7. Reattach the dilator to the working channel. 8. The working channel/dilator pair should be advanced gently so that the distal tip is inserted inside the outer edge of the annulus. The skin stop on the working channel is loosened, lowered to the skin and secured by the screw to prevent the inadvertent advancement of the working channel. 9. Remove the dilator. 44

45 10. Prior to removal of the flexible guiding needle the LASE endoscope should be checked for: Focus of image Irrigation (30 ml/minute.) Aiming beam confirmation 11. Remove the guiding needle. 12. Aspiration should be hooked up to the working channel. Turn on irrigation. Note: Constant irrigation and aspiration must be maintained throughout the procedure. 13. The laser settings are adjusted to the desired levels. The maximum recommended "average power setting" for the LASE procedure is 30 watts. This may best be achieved with an energy setting of 2.0 joules/pulse at a rate of 15 pulses/second. It may be more comfortable for the patient to begin the procedure at a lower average power setting and increase the settings during the procedure. 14 Watts (l.4 joules/pulse and 10 pulses/second) is a common starting average power setting. 14. The LASE endoscope inserted down to the nucleus. 15. The laser fiber is advanced with a clockwise rotation of the fiber advancement knob located at the proximal end of the handle of the LASE endoscope. The fiber can be advanced from 1 mm to 5 mm beyond the tip of the endoscope (recommended advancement is 2.5mm-3mm,or about halfway). Be certain that the tip of the laser fiber is always in view. 16. Frequently use fluoroscopy to verify the positions of the endoscope tip and the working channel. 45

46 Important Safety and Patient Comfort Notes Proper irrigation and aspiration are crucial to safety and patient comfort. The laser delivers a large amount of energy into a small volume, and the irrigating fluid is required to cool the disc and the endoscope. Over-heating causes patient discomfort or injury and can damage or destroy the endoscope tip. Inadequate aspiration impedes cooling, and causes increased intradiscal pressure and patient discomfort. Tissue Removal with the LASE Endoscope Using the LASE endoscope to vaporize the nucleus pulposus safely and effectively requires some practice. Keep in mind the following guidelines: The tip of the laser fiber should be in constant view while the laser is being fired. The laser will only ablate tissue effectively if the tip of the laser fiber is very close to, or touching, the nucleus. The laser fiber is located eccentrically in the endoscope body, so by rotating the undeflected endoscope you will be able to increase the volume of tissue vaporized. You can increase the volume ablated by deflecting the endoscope, but do not pull back a deflected endoscope because the endoscope can be sheared off by the working channel tip. (This situation is analogous to shearing off an epidural catheter in a Touhy needle.) 46

47 Sequence of Movements Manipulating the endoscope in the disc is easy. You will probably spend most of your time performing sequence A, below. Towards the end of the case sequence B might be appropriate. A. A good first step is to perform a series of Advance, undeflected, while firing. Withdraw, undeflected, not firing. Rotate to a new quadrant, and repeat. Periodically, while carrying out this first step, stop firing, pull the endoscope back into the working channel, and look to see that the working channel is not blocked by tissue. Note: While you are performing the first step, it seems as if the cavity is not enlarging. Why? As you ablate tissue, the herniation begins to relax, filling the cavity with fresh nucleus. Thus the cavity will not increase in size until near the end of the case. B. Second, as the cavity begins to enlarge, begin deflecting the endoscope. Do not withdraw a deflected endoscope. While firing the laser, constantly be on the alert for signs that the endoscope is overheating. A detailed description of these signs is found in Appendix 4. 47

48 Determining the Endpoint How do you know when to finish the case? Consider these three guidelines. 1. After you withdraw the endoscope from the laser created cavity, the cavity will initially close up. As you finally remove enough nucleus, you will see the cavity remain open as you withdraw the endoscope. This sign is the best one that you have removed enough disc. 2. Many experienced LASE uses make sure they deliver at least 15 KJ total energy. The laser operator should read out the total energy delivered every 1 KJ (1000 Joules). 3. Relying on the patent s symptoms is unreliable. Many patients obtain relief on the table, but even if relief is obtained on the table, please refer to guideline #2 above. When utilizing the deflection capabilities of the LASE endoscope, many physicians choose to only deflect parallel to the endplates of the vertebral bodies. These physicians prefer not to direct laser energy towards the endplates. The Patient Chart Be sure to record the total energy used in the patient chart. You should also note the pulse energies and repetition. 48

49 Chapter 6: LASE Technique & Heating 49

50 Dear LASE User: This memo provides you with information about the safe and effective use of LASE. There are two lessons in it. LASE uses heat to vaporize the nucleus pulposus. This heating is normal, and is normally reduced by cooling and aspiration, each of which is crucial for the procedure. Too much heat can be a bad thing, and there are simple ways to identify any problem, to prevent a heat problem from progressing, and there are simple ways to recover from any heat problem. No clinical problem with heat in a LASE case has ever been reported. However, thermal damage (softening of the plastic tubing at the tip of the endoscope) to the endoscope can ruin it, requiring use of a second endoscope in a case, raising patient costs. If you find that your physicians are experiencing heating problems, you should consider the following tables. Table 1: Identifying and Solving Heat Problems with Clarus= LASE Kit This table lists the warning signs of overheating, so you can identify that a problem is arising. Table 2: Thermal Problems This table lists the causes of overheating, and gives suggested actions. 50

51 Thermal Problems Classification Cause Action Laser Technique Tip overheated Do not bury the tip of the endoscope into tissue while lasing. The distal end of the laser fiber should be visible at all times. Too much laser power Too little cooling fluid Too much laser power Too much laser power early in case, before an adequate cavity has been developed Pump off Reduce energy or repetition rate Use lower power early in the case; many users start at 1.4 J and 10 Hz. Turn pump on. Hints: $ Once the pump is on, leave it on for the entire case $ Consider giving responsibility to the laser operator to be certain that the pump is running if the laser is firing. $ Make sure that the pump=s front panel is in clear view. Tubing installed incorrectly $ Verify the pump is pumping towards the patient by observing fluid flow from the top of the endoscope before inserting into cannula $ Verify that the tubing is mounted between the pump rollers $ Tubing is not kinked or clamped shut. Bag is empty Replace bag Flow rate too low $ Set pump to 30 ml/min $ If pump has a tubing-selector knob, set it to A14" Inadequate aspiration Irrigation is leaving the endoscope through a side-hole leak Aspiration is off or too low Cannula is not seated in annulotomy hole Cannula is blocked Replace LASE endoscope. A side-hole leak can be caused by scraping the LASE endoscope shaft on the cannula. DO NOT withdraw the endoscope inside the cannula while the endoscope is deflected. Check aspiration line is hooked up, unkinked, and that the aspiration level is set to the maximum If the cannula has moved (e.g. due to patient movement), reposition it. Use the trephine again if necessary. Use the endoscope=s irrigation to dislodge blockage. Fire the laser beam at the blockage, using intermittent firing, and low power levels. Push the block aside using the kit s stylet. 51

52 Identifying and Solving Heat Problems with Clarus= LASE Kit Progression What happens Symptoms that this is happening What to do about it Initial LASE tip softens 1. Distal tubing softens and deforms 2. Distal tip tubing discolors 3. Endoscopic image darkens 1. Stop firing the laser 2. Verify irrigation is coming out the LASE tip 3. Verify proper irrigation rate (30 ml/min) 4. Verify aspiration is on 5. Use endoscope to make sure that the cannula is not blocked by tissue debris 6. Verify that the cannula is aligned with the hole in the nucleus pulposus 7. Consider switching to a new LASE kit Adhesive in tip weakens 1. Endoscopic image becomes Acracked@ or fuzzy As above, consider switching to a new LASE kit Lens disconnects from fibers 1. Loss of endoscopic image Switch to a new LASE kit. It is not safe to proceed without Endoscopic vision. Final Endoscope tip disconnects from endoscope 1. Endoscope does not deflect 2. Radiopaque marker remains in disc after endoscope is withdrawn 1. Remove endoscope 2. Using C-Arm guidance, use 2 mm diameter forceps to remove radiopaque ring from nucleus 3. Switch to a new LASE kit 52

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55 Chapter 7: Endoscopy Pump 55

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57 The Clarus 5169 Endoscopy Pump is specially designed for use with the LASE device for minimally invasive laser disc surgery. The pump is a high pressure, low volume, peristaltic pump that supplies a constant flow of irrigation. Maintenance of a continuous flow of irrigation through the LASE device during a procedure is critical. The use of any other source of irrigation with the LASE endoscope voids the warranty on the device. Pump Notes The flow rate of the pump is easily changeable by turning the flow rate adjustment knob on the face of the pump. The flow rate of the irrigation is readily determined by reading the LCD flow rate indicator on the face of the pump. Air can be quickly bled from the irrigation tubing by pressing the prime button on the face of the pump. The prime button generates a high speed bolus of irrigation through the tubing. The physician can opt for personal control of the flow start/stop function of the pump through the use of the footswitch. Most physicians leave the irrigation on throughout a case, to minimize the chance of firing the laser without irrigation. Tubing guides on each side of the pump head lock-down on the tubing to prevent the tubing from "walking through" the pump head and becoming damaged. Be sure the irrigant is flowing towards the patient. 57

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59 Chapter 8: Sterilization 59

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61 The following table shows how the reusable equipment can be sterilized. Tip: water is the enemy of video cameras and other optical equipment. You can maximize the life of your equipment, and help ensure that you obtain the best quality images by using a sterile camera drape for the camera, endoscope coupler, eyepiece and light cable instead of sterilizing these items. Using a camera drape is slightly less convenient than sterilizing this equipment, but it greatly reduces the chances of having a bad video picture. Item Sterilization Method ETO gas Steris Sterrad Autoclave Camera drape Endoscope coupler NO! Best Eyepiece NO! Best Expansion ring acceptable Best Light cable acceptable Best 61