Subfascia1 Implantation of Implantable
Cardioverter Defibrillator Generator
David M. Shahian, MD, Warren A. Williamson, MD, John M. Streitz, Jr, MD, and Ferdinand J. Venditti, MD Department of Thoracic and Cardiovascular Surgery -~ and Section of Cardiology, Lahey Clinic Medical Center, Burlington, Massachusetts
The automatic cardioverter defibrillator generator is a relatively large unit, which has most often been implanted in a subcutaneous pocket. In a consecutive series of 120 primary implantations, we employed a subrectus fascia pocket that has resulted in a cosmetically superior result with a 0.8% incidence of system infection. The technique of subfascial implantation is described. (Ann Thorac Surg 1992;54:1734)
C
ompared with modern permanent pacemakers, automatic implantable cardioverter defibrillator (AICD) generators are relatively large. The surgical challenge of constructing a pocket for such a generator is analogous to that of placing a pacemaker in a child. The unit itself is large in relation to body size, it must be replaced periodically, erosion must be prevented, and the result must be cosmetically acceptable. A subcutaneous generator pocket is currently the most popular approach for adult AICD placement [ 1 3 ] and is technically the easiest approach. However, this method leaves little protection between the generator and the skin, particularly in thin patients. It thus produces the least appealing cosmetic result and may be more susceptible to infection. To avoid the disadvantages of these other techniques, we have adopted routine use of the subrectus fascia pocket for all AICD generator implantations. Our techniques and results are described.
Material and Methods A transverse skin incision is made at or slightly cephalad to the level of the umbilicus (Fig l),extending from the midline to a point several centimeters lateral to the lateral edge of the rectus sheath. The subcutaneous tissue is dissected with the electrocautery, and the rectus sheath is opened. At the lateral margin of the rectus sheath, the external and internal oblique components of the sheath are easily identified as they split. The external oblique component is left intact, whereas the internal oblique fascia may be divided with the electrocautery to increase the lateral dimensions of the pocket beyond that of the Accepted for publication March 20, 1992. Address reprint requests to Dr Shahian, Department of Thoracic and Cardiovascular Surgery, Lahey Clinic Medical Center, 41 Mall Rd, Burlington, MA 01805.
0 1992 by The Society of Thoracic Surgeons
rectus sheath itself (Fig 2). This maneuver is especially useful in thin patients or when the rectus sheath is narrow. Kocher clamps are used to grasp the superior cut edge of the anterior sheath and external oblique aponeurosis, and the electrocautery is used to dissect away the rectus muscle. Small perforating vessels are carefully electrocoagulated. Larger vessels are suture ligated to prevent subsequent bleeding and formation of a hematoma. The same procedure is carried out in a caudad direction after grasping the inferior cut edge of the anterior sheath. Lateral to the lateral edge of the rectus muscle, care is taken to avoid inadvertent entry into the peritoneal cavity. When the inferior epigastric artery is exposed and appears to be susceptible to erosion by the generator, the artery is oversewn. With a combination of digital exploration and, occasionally, a long straight clamp, a tunnel is made from the superior portion of the pocket to connect with the chest cavity just at the anterior attachments of the diaphragm. A chest tube is placed through this tract, and the leads are extracted from the chest cavity into the pocket. Defibrillation threshold testing is carried out. During this testing, laparotomy pads soaked with an antimicrobial solution, such as bacitracin, are packed into the pocket. When defibrillation threshold testing is complete, the packs are removed, and the pocket is carefully evaluated for hemostasis. The generator is implanted, and the anterior fascia and external oblique aponeurosis are closed with interrupted sutures of absorbable material, such as Vicryl. The subcutaneous tissue is approximated, and the skin is closed with a subcuticular closure (Fig 3). We believe the latter method is preferable to either interrupted stitches or staples because it provides the most effective seal of the wound. Other methods are more likely to permit local separation of the skin and external communication of the pocket. We have performed numerous generator replacements after subfascial AICD implantation. The pocket is simply reopened, and the generator is extracted. Extraction or reimplantation of the new generator may require splitting the lateral border of the fibrous pocket, but this can be repaired easily after the new generator is in place.
Results We have employed the technique of subfascial AICD placement in a series of 120 consecutive primary implan0003-4975/92/$5.00
174
HOW TO DO IT SHAHIAN ET AL SUBFASCIAL AICD POCKET
Ann Thorac Surg 1992;54:1734
Fig 1. Broken line indicates typical location of the horizontal skin incision at or slightly cephalad to the umbilicus. The incision extends just lateral to the lateral edge of the rectus sheath. The layers of the abdominal wall at that level are depicted. (Reprinted by permission of the Lahey Clinic.)
tations. This method has resulted in a good cosmetic and functional result in all patients. One system infection (0.8%), three early pocket hematomas in patients who Fig 3 . The typical final position of the automatic implantable cardio verter defibrillator generator shown in both (A)frontal and ( B ) horizontal planes. (Reprinted by permission of the Lahey Clinic.)
were being treated with anticoagulants (2.5%), and one sterile erosion from pressure necrosis in a paraplegic patient (0.8%)have occurred.
Comment We believe the subfascial pocket is cosmetically superior and offers excellent protection against system erosion and infection. With lateral extension under the external oblique aponeurosis, the generator can be implanted in a patient of any size. It is possible that the increased dissection necessary for a subfacial pocket may make formation of a postoperative hematoma more likely, and early anticoagulation should be postponed, when possible.
References
Fig 2. (A) The anterior rectus sheath is opened, and the rectus muscle is dissected away from the underside of the sheath using the electrocautey. Larger perforating vessels are ligated. ( B ) Often, it is helpful to divide the internal oblique aponeurosis to gain additional lateral dimension, while maintaining the external oblique aponeurosis intact. (Reprinted by permission of the Lahey Clinic.)
1. Slater AD, Singer I, Stavens CS, et al. Treatment of malignant ventricular arrhythmias with the automatic implantable cardioverter defibrillator. Ann Surg 1989;209:635-41. 2. Winkle RA, Mead RH, Ruder MA, et al. Long-term outcome with the automatic implantable cardioverter-defibrillator. J Am Coll Cardiol 1989;13:1353-61. 3. Winkle RA, Stinson EB, Echt DS, Mead RH, Schmidt P. Practical aspects of automatic cardioverteridefibrillator implantation. Am Heart J 1984;108:133!%46.
Cardioverter Defibrillator Generator
David M. Shahian, MD, Warren A. Williamson, MD, John M. Streitz, Jr, MD, and Ferdinand J. Venditti, MD Department of Thoracic and Cardiovascular Surgery -~ and Section of Cardiology, Lahey Clinic Medical Center, Burlington, Massachusetts
The automatic cardioverter defibrillator generator is a relatively large unit, which has most often been implanted in a subcutaneous pocket. In a consecutive series of 120 primary implantations, we employed a subrectus fascia pocket that has resulted in a cosmetically superior result with a 0.8% incidence of system infection. The technique of subfascial implantation is described. (Ann Thorac Surg 1992;54:1734)
C
ompared with modern permanent pacemakers, automatic implantable cardioverter defibrillator (AICD) generators are relatively large. The surgical challenge of constructing a pocket for such a generator is analogous to that of placing a pacemaker in a child. The unit itself is large in relation to body size, it must be replaced periodically, erosion must be prevented, and the result must be cosmetically acceptable. A subcutaneous generator pocket is currently the most popular approach for adult AICD placement [ 1 3 ] and is technically the easiest approach. However, this method leaves little protection between the generator and the skin, particularly in thin patients. It thus produces the least appealing cosmetic result and may be more susceptible to infection. To avoid the disadvantages of these other techniques, we have adopted routine use of the subrectus fascia pocket for all AICD generator implantations. Our techniques and results are described.
Material and Methods A transverse skin incision is made at or slightly cephalad to the level of the umbilicus (Fig l),extending from the midline to a point several centimeters lateral to the lateral edge of the rectus sheath. The subcutaneous tissue is dissected with the electrocautery, and the rectus sheath is opened. At the lateral margin of the rectus sheath, the external and internal oblique components of the sheath are easily identified as they split. The external oblique component is left intact, whereas the internal oblique fascia may be divided with the electrocautery to increase the lateral dimensions of the pocket beyond that of the Accepted for publication March 20, 1992. Address reprint requests to Dr Shahian, Department of Thoracic and Cardiovascular Surgery, Lahey Clinic Medical Center, 41 Mall Rd, Burlington, MA 01805.
0 1992 by The Society of Thoracic Surgeons
rectus sheath itself (Fig 2). This maneuver is especially useful in thin patients or when the rectus sheath is narrow. Kocher clamps are used to grasp the superior cut edge of the anterior sheath and external oblique aponeurosis, and the electrocautery is used to dissect away the rectus muscle. Small perforating vessels are carefully electrocoagulated. Larger vessels are suture ligated to prevent subsequent bleeding and formation of a hematoma. The same procedure is carried out in a caudad direction after grasping the inferior cut edge of the anterior sheath. Lateral to the lateral edge of the rectus muscle, care is taken to avoid inadvertent entry into the peritoneal cavity. When the inferior epigastric artery is exposed and appears to be susceptible to erosion by the generator, the artery is oversewn. With a combination of digital exploration and, occasionally, a long straight clamp, a tunnel is made from the superior portion of the pocket to connect with the chest cavity just at the anterior attachments of the diaphragm. A chest tube is placed through this tract, and the leads are extracted from the chest cavity into the pocket. Defibrillation threshold testing is carried out. During this testing, laparotomy pads soaked with an antimicrobial solution, such as bacitracin, are packed into the pocket. When defibrillation threshold testing is complete, the packs are removed, and the pocket is carefully evaluated for hemostasis. The generator is implanted, and the anterior fascia and external oblique aponeurosis are closed with interrupted sutures of absorbable material, such as Vicryl. The subcutaneous tissue is approximated, and the skin is closed with a subcuticular closure (Fig 3). We believe the latter method is preferable to either interrupted stitches or staples because it provides the most effective seal of the wound. Other methods are more likely to permit local separation of the skin and external communication of the pocket. We have performed numerous generator replacements after subfascial AICD implantation. The pocket is simply reopened, and the generator is extracted. Extraction or reimplantation of the new generator may require splitting the lateral border of the fibrous pocket, but this can be repaired easily after the new generator is in place.
Results We have employed the technique of subfascial AICD placement in a series of 120 consecutive primary implan0003-4975/92/$5.00
174
HOW TO DO IT SHAHIAN ET AL SUBFASCIAL AICD POCKET
Ann Thorac Surg 1992;54:1734
Fig 1. Broken line indicates typical location of the horizontal skin incision at or slightly cephalad to the umbilicus. The incision extends just lateral to the lateral edge of the rectus sheath. The layers of the abdominal wall at that level are depicted. (Reprinted by permission of the Lahey Clinic.)
tations. This method has resulted in a good cosmetic and functional result in all patients. One system infection (0.8%), three early pocket hematomas in patients who Fig 3 . The typical final position of the automatic implantable cardio verter defibrillator generator shown in both (A)frontal and ( B ) horizontal planes. (Reprinted by permission of the Lahey Clinic.)
were being treated with anticoagulants (2.5%), and one sterile erosion from pressure necrosis in a paraplegic patient (0.8%)have occurred.
Comment We believe the subfascial pocket is cosmetically superior and offers excellent protection against system erosion and infection. With lateral extension under the external oblique aponeurosis, the generator can be implanted in a patient of any size. It is possible that the increased dissection necessary for a subfacial pocket may make formation of a postoperative hematoma more likely, and early anticoagulation should be postponed, when possible.
References
Fig 2. (A) The anterior rectus sheath is opened, and the rectus muscle is dissected away from the underside of the sheath using the electrocautey. Larger perforating vessels are ligated. ( B ) Often, it is helpful to divide the internal oblique aponeurosis to gain additional lateral dimension, while maintaining the external oblique aponeurosis intact. (Reprinted by permission of the Lahey Clinic.)
1. Slater AD, Singer I, Stavens CS, et al. Treatment of malignant ventricular arrhythmias with the automatic implantable cardioverter defibrillator. Ann Surg 1989;209:635-41. 2. Winkle RA, Mead RH, Ruder MA, et al. Long-term outcome with the automatic implantable cardioverter-defibrillator. J Am Coll Cardiol 1989;13:1353-61. 3. Winkle RA, Stinson EB, Echt DS, Mead RH, Schmidt P. Practical aspects of automatic cardioverteridefibrillator implantation. Am Heart J 1984;108:133!%46.
