Instruments Surgical instruments of importance to the physician who is implanting cardiac rhythm devices include those designed for cutting, grasping, retracting, clamping, and suturing. Instruments for Cutting The scalpel, consisting of a handle and a blade, is the most basic of cutting instruments and is synonymous with surgeons and the art of surgery. The most common handles come in two sizes, Bard Parker (BP) #3 (most common) and BP #4. Most modern scalpel handles have a locking mechanism for safe blade placement and removal (Fig. 3.2). The BP #3 handle can accommodate smaller blade sizes from #10 to #15, while the BP #4 handle is designed for larger blades and is not typically used in device implantation cases. Commonly used scalpel blades include #10, #11, and #15. Some operators may use a #12 blade; however, this is unusual. An illustration of scalpel blades is shown in Fig. 3.3. The #10 blade is similar in shape to the #15 blade but larger. Both are used to incise the skin and for sharp dissection. The #15 blade, being smaller, allows for more precise incisions. The #11 blade is pointed and is used primarily for making a press cut or stab incision. Device implanters typically use press cuts when cutting sutures from an anchoring sleeve on the lead. The #12 blade is hooked with the cutting edge on the concave portion of the blade. Its most common use in device implantation is cutting suture sleeves away from surrounding tissue without disturbing the anchoring sleeve. The scalpel handle may be held in two ways: a pencil grip for short, fine incisions or backhand cutting, and the fingertip grip, which allows for a maximum amount of cutting edge contact for greater control when making longer incisions (Fig. 3.4). When making an incision, the knife is drawn from left to right (right-handed surgeon) or from away toward the operator. When incising the skin, three points of tension are provided with the fingers laterally and the knife blade longitudinally to provide a stable cutting surface and allow precise control of cutting depth (Fig. 3.5). Additionally, the knife blade must be held perpendicular to the skin to avoid beveling (Fig. 3.6). Fig. 3.2. Bard Parker #3 locking scalpel handle. Fig. 3.3. Scalpel blades (top to bottom: #10, #11, #12, #15). Download full-size image Fig. 3.4. Holding the scalpel: (A) pencil grip; (B) fingertip grip. Download full-size image Fig. 3.5. Incising with three points of tension. The surgeon’s free hand provides two points with the thumb and index finger, while the scalpel blade provides the third point. This provides an undistorted surface for the incision. Download full-size image Fig. 3.6. Holding the knife blade: (A) 90 degrees perpendicular to the skin; (B) angle less than 90 degrees, resulting in beveled incision. If the scalpel defines the surgeon, the scissors are arguably the most versatile of all the instruments. They may be used for tissue dissection, undermining skin to relieve tension when closing, cutting sutures or other surgical material, or spreading or opening tissue planes for such tasks as generator pocket formation, or as a blunt dissector if the blades are closed. There are two basic types of scissors, blunt tipped for dissection and sharp tipped for cutting. Curved blunt-tipped scissors such as Metzenbaum, McIndoe, or Mayo are designed for dissecting and have an advantage over other instruments as they allow for both blunt and sharp dissection without having to change instruments (Fig. 3.7). The curved blade also provides directional mobility, visibility, and flexibility in the angle of approach to the tissue, as well as allowing lifting and palpating of tissue compared to straight scissors. They are most effective when dissecting along tissue planes. Straight blunt-tipped scissors provide a greater mechanical advantage when dissecting through scar and tough tissue, but their use in device implantation is limited. Straight sharp-tipped scissors are typically used for cutting sutures or other ligatures (Fig. 3.8). They allow rapid and accurate positioning of the scissor tips before cutting. Regardless of the type of scissors used, pronation to neutral hand positions provides the greatest maneuverability of the instrument in all directions. Download full-size image Fig. 3.7. Curved, blunt-tipped scissors for dissecting. Download full-size image Fig. 3.8. Straight, sharp-tipped scissors for cutting. Instruments for Grasping Forceps are nonlocking grasping tools that function as an extension of the thumb and opposing fingers in the assisting hand to augment the instrument in the operating hand. Their primary purpose is to grasp, retract, or stabilize tissue. They may also be used to pack or extract sponges, pass ligatures, and stabilize and manipulate needles during suturing. Forceps are categorized by the presence and type of teeth that are designed for the specific tissue they are intended to hold. Fine-toothed forceps such as DeBakey forceps are considered atraumatic and are designed for soft tissue and vessels (Fig. 3.9). They may be used on leads without damaging the insulation if used gently. Toothed forceps include those with teeth designed for dense tissue (Russian), with a single tooth on the end (rat-tooth), and smaller versions designed for closing skin (Adson) (Fig. 3.10). Forceps with teeth should never be used to grasp a pacemaker or defibrillator lead as the teeth may compromise the integrity of its outer insulation. The choice of forceps should be dictated by the amount and nature of the tissue being handled. Forceps are held such that they become extensions of the thumb and index finger. A pencil-grip position provides the widest range of maneuverability. Holding the shank of the forceps in the palm of the hand significantly limits its use and requires extreme flexion of the wrist and should be avoided (Fig. 3.11). Download full-size image Fig. 3.9. DeBakey forceps. Download full-size image Fig. 3.10. Toothed forceps (top to bottom: Russian, rat-tooth, Adson). Download full-size image Fig. 3.11. Holding forceps: (A) pencil grip; (B) incorrect position, limiting use. Instruments for Retracting A key component for safe, efficient surgery is good exposure. For that reason, a number of instruments have been designed for this purpose and fall into one of two categories: manual (held by the surgeon or assistant) and self-retaining. Good exposure requires thorough planning and thoughtful execution. If a procedure is particularly difficult, it is likely that inadequate exposure played a significant role. Skin hooks are manual retractors with one or more small, sharp hooks designed to hook into the dermis without trauma to the epidermis and are used primarily for wound retraction (Fig. 3.12). They are useful for undermining dermis to reduce or remove tissue tension from the skin closure, but must be used with extreme caution as they may inadvertently pierce the insulation of an indwelling lead if not positioned under direct visualization. The Senn retractor (Fig. 3.13) is an alternative to the skin hook and is preferred by many operators as it consists of a rake on one end and a right-angled flat blade on the other. For visualization while creating the pocket for the device generator and lead(s), manual retractors such as the Army-Navy, small Deaver, Richardson, and Goulet may be used (Fig. 3.14). These instruments can provide traction if one is employed and traction/countertraction if more than one is used. Manual retractors allow for dynamic tissue retraction as they may be continuously adjusted based on the needs of the surgeon. The specific retractor chosen for device implantation depends on tissue depth, the width of the incision, and surgeon preference. Care must be taken to avoid traumatizing the tissues with overaggressive traction. It is preferable to have a variety of retractors on the surgical table or readily available to be able to adapt to various types of body habitus. Download full-size image Fig. 3.12. Skin hooks. Download full-size image Fig. 3.13. Senn retractor. Download full-size image Fig. 3.14. Manual retractors (left to right: Army-Navy, small Deaver, Richardson). Self-retaining retractors such as the Weitlaner, cerebellar, and Gelpi (Fig. 3.15) provide both traction and countertraction with a locking mechanism located on the handle. This is advantageous as it provides long-term continuous exposure and frees the hands of the surgeon or assistant to perform other functions without losing exposure. For most patients, the Weitlaner is sufficient to provide exposure to the anterior fascia of the underlying muscle; however, in obese patients and those with large breasts, the cerebellar retractor with its angled arms can provide deeper exposure without impeding the surgeon’s progress. The Gelpi retractor has single-pointed tips on the ends and is useful for small incisions such as those performed for tunneling a subcutaneous defibrillator lead (see Chapter 10). Care must be taken when using the Gelpi retractor as its pointed ends may damage the insulation of the lead or tear the surgeon’s glove. Download full-size image Fig. 3.15. Self-retaining retractors (left to right: Weitlaner, cerebellar, Gelpi). Instruments for Clamping Clamps are useful tools for occluding, gripping, dissecting, and retracting. The most commonly encountered clamp for physicians implanting cardiac rhythm devices is the hemostat, also known as a “snap” or a “mosquito.” It is a small ratchet-locking clamp designed to grasp or occlude blood vessels before cutting. It is also useful during dissection when bleeding is encountered. When used in this manner, care must be taken to clamp the culprit bleeding vessel and avoid clamping excessive surrounding tissue. Hemostats may be curved, be straight, or have a right angle at the tip (Fig. 3.16), which is advantageous for fine dissection around vessels such as the cephalic vein. Because clamps hold tissue and ligatures securely, they may also be used as retractors to maneuver layers of tissue or change the angle of a vessel such as the cephalic vein to provide easier access. Download full-size image Fig. 3.16. Hemostats (left to right: curved, straight, right-angled). Instruments for Suturing Instruments for holding and driving needles through tissue are referred to as either needle holders or needle drivers. The art of suturing is easier and more efficient when the needle holder is used correctly. Needle holders are available in different lengths with jaw sizes designed to accommodate needles of specific sizes and shapes (Fig. 3.17). Specialty needle holders such as the Gilles (Fig. 3.18) possess jaws to hold the needle and scissors designed to cut sutures built into a single instrument and are favored by plastic surgeons. The most common needle holders used by physicians implanting cardiac rhythm devices have a ratchet-locking mechanism designed to hold the needle firmly in place once positioned and either serrated or tungsten carbide–impregnated jaws to prevent needle slippage as it is driven into tissue (Fig. 3.19). The needle holder is positioned in the hand in a manner similar to that with scissors. Curved needles must be driven through tissue along its curved shape or the needle will bend or break. For forehand suturing, the needle point is directed toward the nondominant hand and pointing upward, and the forearm is supinated to drive the tip of the needle through tissue in a plane matching that of the curve of the needle. For backhand suturing, the direction of the needle is reversed in the needle holder and the forearm is pronated, again matching the curve of the needle. Download full-size image Fig. 3.17. Large and small needle drivers. Download full-size image Fig. 3.18. Gilles needle driver. Download full-size image Fig. 3.19. Carbide-tipped jaws of needle driver. These prevent needle from slipping or spinning when driven into tissue. Source
