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Tools of the Trade
Scott J. Savader and Scott O. Trerotola, editors. Thieme, New York, 1996. Johnson A, Oppenheim BA. Vascular catheter-related sepsis: diagnosis and prevention. J Hosp Infect 1992;20:67-78. Pearson ML. Guideline for prevention of intravascular device-related infections. Infect Contr Hosp Epidemiol 1995;17:438-473. 4:00 pm
Guidelines for Rational Antibiotic Use in Minor Surgical Procedures Linda Mundy, MD 4:30 pm
Tools of the Trade Warren Gamer, MD Instruments The following are the instruments that I would use to do small surgical procedures in the subcutaneous space, such as create a pocket for the implantation of an access device. Develop a tray of instruments that can be used for all planned procedures. Have two of each critical instrument so if one is dropped, the procedure can proceed. Change your instruments as your preferences evolve. Needle Holders I prefer small instruments to use with the small sutures that are appropriate for most skin closures. Consider 4or 5-inch Webster needle holders. Avoid grooved jaws. Forceps Use fine forceps for holding the skin. Avoid forceps that do not allow you to hold the skin easily without repeatedly grasping, which traumatizes the tissue. I prefer single-toothed Adson forceps. The tooth improves my ability to grasp the skin without excessive tissue trauma. Scissors For dissecting scissors, try 7-inch Metzenbaum scissors. My personnel preference for dissecting scissors are Steven's tenotomy (6-inch) or Gorney facelift scissors, but these are more expensive. For suture scissors, use small (5-inch) straight Mayo scissors instead of larger instruments. Skin Hooks Skin hooks can be used to hold the skin when dissecting subcutaneously. They hold better than a forceps and prevent damage to the skin by repetitive grasping with a forceps. Retractors and Towel Clips An Army-Navy retractor might be useful for holding skin above deeper dissection, such as when making a subcutaneus pocket. Towel clips allow you to "square off" the dissection field.
Electrocautery Although expensive, electrocautery is useful for coagulating bleeding vessels and dissecting skin from deeper structures. Handheld devices do not usually work well. The smell of charred tissue can be disturbing to patients who are awake.
Sutures When sutures are used to reapproximate the skin, there are conflicting goals of secure closure versus ideal scar. The skin closure does not achieve significant tensile strength for 2 weeks after repair. Sutures left in place for this length of time will cause cross-hatching and worsen the scar appearance. If the final appearance of the incision is important, then a two-layer closure is useful. The deeper layer of absorbable suture holds the skin together for the necessary healing period. A superficial layer of sutures reapproximates the outer skin layers but is removed or dissolves within a week. A two-layer closure will also decrease the likelihood of wound breakdown with exposure of an underlying device or foreign body. Sutures come in different materials and sizes (thicknesses), and needles comes in different sizes and shapes. Any of them can be interchanged to make your procedure easier. In general, use the smallest suture that will do the job. Try different size and shape needles on the suture that you decide to use. Be sure to use clear sutures if they are to be placed permanently beneath the skin. Sutures are either absorbable, losing strength at a predictable rate and eventually disappearing, or permanent. Below are some standard skin sutures with recommendations for suture and needle size. Absorbable Chromic sutures are made from processed cat gut. They dissolve quickly and tend to illicit more tissue reaction than other sutures. Regular chromic sutures dissolve in 10 to 14 days. Fast-absorbing chromic sutures dissolve in 5 to 7 days. Monocryl (monofilament polyglecaprone 25) monofilament synthetic sutures dissolve in 10 to 14 days. They are good for single-layer skin closure when scarring is less important. Use 4-0 sutures with a PS-2 needle or 5-0 sutures with a P-3 needle. PDS/Maxon (polydioxanone) monofilament synthetic sutures dissolve slowly over the course of 3 months. They are useful for closing incisions under tension. Use 4-0 sutures with a PS-2 needle or 3-0 sutures with a PS-2 needle. Vicryl (Dexon, polyglactin 910) is a braided suture good for the deep layer of a two-layer closure. It dissolves in 6 weeks. Permanent Nylon is standard for removable skin closure sutures. Use 4-0 sutures with P-3 or FS-2 needles. Prolene is good for skin closure in the midst of dark hair. Use 4-0 sutures with a P-3 or FS-2 needle. Silk is not good for skin closure.
239
Skin Preparation Cleaning and disinfecting the skin are distinct processes. Shaving is not necessary and may increase infection rates. If you must remove hair in a surgical field, do so immediately before the procedure, shaving only the planned areas of incision in heavily haired individuals. My preference for prepping clean, intact normal skin is Betadine Gel-prep (Baxter Cat No. 4466, Preoperative skin prep tray). Anesthesia Procedures can be performed using local, regional, or general anesthesia. Individualize anesthesia based on patient age, comorbidity, and tolerance. It is very difficult to get children less than 12 years of age to remain still without general anesthesia. Many elderly people lose their inhibitions under the influence of excess benzodiazepines and become more difficult to manage.
Local Anesthesia Field blocks are best achieved by marking on the skin the dimensions of the planned area of dissection. The margins are then injected with relatively more agent and the remaining area of planned dissection with relatively less agent. Injection of the agent in the subcutaneous plain, not intradermally, substantially decreases pain. However, it takes several minutes for the agent to diffuse into the dermis and achieve anesthesia. I usually scrub or do paperwork during this interval. Allow 7 to 10 minutes and then check for anesthesia before proceeding. The textbook concentration of lidocaine resulting in toxicity is 5-7 mg/kg. However, the complications are based on intravenous injection rather than deposition in the subcutaneous space. Drug diffuses slowly from this location; therefore, the dose that can be administered safely is much higher. Epinephrine can be added to the injectate when vasoconstriction is desired to decrease bleeding. Epinephrine loses effectiveness if diluted more than 1:400,000. In deciding whether to use lidocaine or marcaine, consider the use of longer-acting agent, especially when working on children.
240
Regional Anesthesia Regional anesthesia is used for longer or more extensive procedures. Its benefit is that it is easier to discharge patients immediately after the procedure because no postprocedure drug effects result and there is excellent early pain control. The main disadvantage is the involvement of additional personnel, complicating scheduling and increasing costs. Bier blocks are achieved by exsanguinating the arm and with a tourniquet filled with a large volume of dilute lidocaine solution. The result is anesthesia below the tourniquet for 60 to 90 minutes. Regional blocks are achieved by injecting agent into the proximal nerve plexus to anesthetize regions of the body, for example, axillary blocks for upper extremity
procedures. A technically expert anesthesiologist is required.
Miscellaneous Other helpful equipment includes good, movable, focusable lights, a comfortable bed, a protocol for dealing with the anxious patient, and patient information sheets detailing postprocedure care.
Sunday, March 1, 1998
3:30 pm-5:30 pm Categorical Course: Vascular Imaging Part I (C102) Moderator: Gerald Zemel, MD 3:30 pm
Noninvasive Diagnosis of Peripheral Vascular Disease Geral Zemel, MD 4:00 pm
Abdominal and Renal MR Angiography A Comprehensive Approach Martin R. Prince, MD, PhD High-resolution renal artery imaging is utilized in several clinical settings, including renal artery stenosis (1), assessing renal function, and surgical planning for abdominal aortic aneurysm repair. Renal artery magnetic resonance angiography (MRA) must address all of the imaging needs presented in these situations, including: 1) determining the number and location of renal arteries; 2) identifying any renal artery stenoses, including orificial, proximal, midrenal artery or distal stenoses; 3) evaluating the hemodynamic significance of each stenosis; 4) providing a surgical road map by assessing atherosclerotic involvement of the aorta for locating bypass sites and evaluating the celiac and superior mesenteric artery origins; and 5) identifying neoplastic renal or perirenal masses that may supersede the clinical importance of renal revascularization. Magnetic Resonance Imaging Protocol Before the onset of imaging, an intravenous line is started, typically in the forearm, antecubital fossa, or wrist. For hand injections it is acceptable to use an existing central line, PICC line, or subcutaneous port, provided they are accessed with sterile technique and subsequently flushed with heparinized saline. It is useful to have a standard tubing set that has a known priming volume and allows simultaneous attachment of two syringes: one for gadolinium contrast and another for saline flush. This way the operator can become comfortable with a single IV tubing set that always has the same priming volume and flow. The patient is positioned feet first in the magnet with a respiratory monitoring device. It is acceptable to use the body coil on adults. Small children can often be
Guidelines for Rational Antibiotic Use in Minor Surgical Procedures Linda Mundy, MD 4:30 pm
Tools of the Trade Warren Gamer, MD Instruments The following are the instruments that I would use to do small surgical procedures in the subcutaneous space, such as create a pocket for the implantation of an access device. Develop a tray of instruments that can be used for all planned procedures. Have two of each critical instrument so if one is dropped, the procedure can proceed. Change your instruments as your preferences evolve. Needle Holders I prefer small instruments to use with the small sutures that are appropriate for most skin closures. Consider 4or 5-inch Webster needle holders. Avoid grooved jaws. Forceps Use fine forceps for holding the skin. Avoid forceps that do not allow you to hold the skin easily without repeatedly grasping, which traumatizes the tissue. I prefer single-toothed Adson forceps. The tooth improves my ability to grasp the skin without excessive tissue trauma. Scissors For dissecting scissors, try 7-inch Metzenbaum scissors. My personnel preference for dissecting scissors are Steven's tenotomy (6-inch) or Gorney facelift scissors, but these are more expensive. For suture scissors, use small (5-inch) straight Mayo scissors instead of larger instruments. Skin Hooks Skin hooks can be used to hold the skin when dissecting subcutaneously. They hold better than a forceps and prevent damage to the skin by repetitive grasping with a forceps. Retractors and Towel Clips An Army-Navy retractor might be useful for holding skin above deeper dissection, such as when making a subcutaneus pocket. Towel clips allow you to "square off" the dissection field.
Electrocautery Although expensive, electrocautery is useful for coagulating bleeding vessels and dissecting skin from deeper structures. Handheld devices do not usually work well. The smell of charred tissue can be disturbing to patients who are awake.
Sutures When sutures are used to reapproximate the skin, there are conflicting goals of secure closure versus ideal scar. The skin closure does not achieve significant tensile strength for 2 weeks after repair. Sutures left in place for this length of time will cause cross-hatching and worsen the scar appearance. If the final appearance of the incision is important, then a two-layer closure is useful. The deeper layer of absorbable suture holds the skin together for the necessary healing period. A superficial layer of sutures reapproximates the outer skin layers but is removed or dissolves within a week. A two-layer closure will also decrease the likelihood of wound breakdown with exposure of an underlying device or foreign body. Sutures come in different materials and sizes (thicknesses), and needles comes in different sizes and shapes. Any of them can be interchanged to make your procedure easier. In general, use the smallest suture that will do the job. Try different size and shape needles on the suture that you decide to use. Be sure to use clear sutures if they are to be placed permanently beneath the skin. Sutures are either absorbable, losing strength at a predictable rate and eventually disappearing, or permanent. Below are some standard skin sutures with recommendations for suture and needle size. Absorbable Chromic sutures are made from processed cat gut. They dissolve quickly and tend to illicit more tissue reaction than other sutures. Regular chromic sutures dissolve in 10 to 14 days. Fast-absorbing chromic sutures dissolve in 5 to 7 days. Monocryl (monofilament polyglecaprone 25) monofilament synthetic sutures dissolve in 10 to 14 days. They are good for single-layer skin closure when scarring is less important. Use 4-0 sutures with a PS-2 needle or 5-0 sutures with a P-3 needle. PDS/Maxon (polydioxanone) monofilament synthetic sutures dissolve slowly over the course of 3 months. They are useful for closing incisions under tension. Use 4-0 sutures with a PS-2 needle or 3-0 sutures with a PS-2 needle. Vicryl (Dexon, polyglactin 910) is a braided suture good for the deep layer of a two-layer closure. It dissolves in 6 weeks. Permanent Nylon is standard for removable skin closure sutures. Use 4-0 sutures with P-3 or FS-2 needles. Prolene is good for skin closure in the midst of dark hair. Use 4-0 sutures with a P-3 or FS-2 needle. Silk is not good for skin closure.
239
Skin Preparation Cleaning and disinfecting the skin are distinct processes. Shaving is not necessary and may increase infection rates. If you must remove hair in a surgical field, do so immediately before the procedure, shaving only the planned areas of incision in heavily haired individuals. My preference for prepping clean, intact normal skin is Betadine Gel-prep (Baxter Cat No. 4466, Preoperative skin prep tray). Anesthesia Procedures can be performed using local, regional, or general anesthesia. Individualize anesthesia based on patient age, comorbidity, and tolerance. It is very difficult to get children less than 12 years of age to remain still without general anesthesia. Many elderly people lose their inhibitions under the influence of excess benzodiazepines and become more difficult to manage.
Local Anesthesia Field blocks are best achieved by marking on the skin the dimensions of the planned area of dissection. The margins are then injected with relatively more agent and the remaining area of planned dissection with relatively less agent. Injection of the agent in the subcutaneous plain, not intradermally, substantially decreases pain. However, it takes several minutes for the agent to diffuse into the dermis and achieve anesthesia. I usually scrub or do paperwork during this interval. Allow 7 to 10 minutes and then check for anesthesia before proceeding. The textbook concentration of lidocaine resulting in toxicity is 5-7 mg/kg. However, the complications are based on intravenous injection rather than deposition in the subcutaneous space. Drug diffuses slowly from this location; therefore, the dose that can be administered safely is much higher. Epinephrine can be added to the injectate when vasoconstriction is desired to decrease bleeding. Epinephrine loses effectiveness if diluted more than 1:400,000. In deciding whether to use lidocaine or marcaine, consider the use of longer-acting agent, especially when working on children.
240
Regional Anesthesia Regional anesthesia is used for longer or more extensive procedures. Its benefit is that it is easier to discharge patients immediately after the procedure because no postprocedure drug effects result and there is excellent early pain control. The main disadvantage is the involvement of additional personnel, complicating scheduling and increasing costs. Bier blocks are achieved by exsanguinating the arm and with a tourniquet filled with a large volume of dilute lidocaine solution. The result is anesthesia below the tourniquet for 60 to 90 minutes. Regional blocks are achieved by injecting agent into the proximal nerve plexus to anesthetize regions of the body, for example, axillary blocks for upper extremity
procedures. A technically expert anesthesiologist is required.
Miscellaneous Other helpful equipment includes good, movable, focusable lights, a comfortable bed, a protocol for dealing with the anxious patient, and patient information sheets detailing postprocedure care.
Sunday, March 1, 1998
3:30 pm-5:30 pm Categorical Course: Vascular Imaging Part I (C102) Moderator: Gerald Zemel, MD 3:30 pm
Noninvasive Diagnosis of Peripheral Vascular Disease Geral Zemel, MD 4:00 pm
Abdominal and Renal MR Angiography A Comprehensive Approach Martin R. Prince, MD, PhD High-resolution renal artery imaging is utilized in several clinical settings, including renal artery stenosis (1), assessing renal function, and surgical planning for abdominal aortic aneurysm repair. Renal artery magnetic resonance angiography (MRA) must address all of the imaging needs presented in these situations, including: 1) determining the number and location of renal arteries; 2) identifying any renal artery stenoses, including orificial, proximal, midrenal artery or distal stenoses; 3) evaluating the hemodynamic significance of each stenosis; 4) providing a surgical road map by assessing atherosclerotic involvement of the aorta for locating bypass sites and evaluating the celiac and superior mesenteric artery origins; and 5) identifying neoplastic renal or perirenal masses that may supersede the clinical importance of renal revascularization. Magnetic Resonance Imaging Protocol Before the onset of imaging, an intravenous line is started, typically in the forearm, antecubital fossa, or wrist. For hand injections it is acceptable to use an existing central line, PICC line, or subcutaneous port, provided they are accessed with sterile technique and subsequently flushed with heparinized saline. It is useful to have a standard tubing set that has a known priming volume and allows simultaneous attachment of two syringes: one for gadolinium contrast and another for saline flush. This way the operator can become comfortable with a single IV tubing set that always has the same priming volume and flow. The patient is positioned feet first in the magnet with a respiratory monitoring device. It is acceptable to use the body coil on adults. Small children can often be