Repair of Mycotic Aneurysm of the Innominate Artery With Homograft Tissue Douglas Schuch, MD, and Larry Wolff, MD Department of Cardiovascular and Thoracic Surgery and Department of Cardiology, Sutter Memorial Hospital, Sacramento,
California
The case of a 46-year-old drug addict who underwent repair of a mycotic aneurysm of the innominate artery with a 12-mm homograft is presented. The homograft was obtained from the descending thoracic position in a young child. Replacement of infected arteries with various artificial grafts risks recurrent infection and anasto-
motic disruption. The use of a homograft conduit in this case was successful in restoring the appropriate blood flow without infection. We suggest that the homograft conduit can be used in other areas with similar results.
A
length of approximately 3 cm. The clavicular head of the sternocleidomastoid muscle was transected, and the innominate vein was also transected for adequate exposure. Control of the innominate artery was obtained distal to the left common carotid takeoff; the mycotic aneurysm was entered, and distal control was obtained by clamping the common carotid on the right and the subclavian artery on the right. The innominate artery was completely destroyed for a length of 3 cm, and a cavity was debrided measuring approximately 8 cm in diameter to the right of the superior vena cava extending posteriorly to the tracheal bifurcation. A 12-mm homograft descending thoracic aorta, procured and prepared by Cryo-Life (Marietta, GA) was thawed in the usual manner and sewn into place with end-to-end anastomosis on both the proximal and distal ends using a 5-0 Prolene (Ethicon, Somerville, NJ) continuous suture. The clamps were left for a total of 40 minutes, during which time the thawing process and anastomosing were performed. During this time the temperature was lowered to 28°C and the heart fibrillated. Rewarming was performed near the end of the anastomosis and the heart defibrillated at 32°C. Further rewarming was then accomplished to 38°C. The innominate vein was then repaired in an end-to-end fashion with a running 5-0 Prolene suture. The aneurysmal cavity was further debrided, and a small red Robinson catheter was placed into the cavity and brought out inferior to the sternotomy along with a No. 38 chest tube. Continuous mediastinal irrigation was begun with 0.5% Betadine irrigation and normal saline solution at 200 mL/h. The wound was then closed in the usual fashion. Mediastinal irrigation continued for 5 days postoperatively, and the patient underwent a total of 4 weeks of intravenous drug therapy with nafcillin for 2% weeks and then Kefzol (2 g intravenously every 8 hours) for 1% weeks. The change in antibiotics was thought necessary secondary to the increased sodium load and difficulty with persistent weight gain postoperatively. The patient was discharged from the hospital on postoperative day 30 with normal cardiac function and normal
46-year-old, insulin-dependent diabetic and known intravenous heroin user was seen at our emergency room on September 29, 1990, with a fever, swelling of the face and neck, dyspnea, and bilateral upper anterior chest pain described as sharp in nature. He had admitted to using intravenous heroin for approximately 5 years on a daily basis. A chest roentgenogram (Fig 1) showed a right peritracheal mass with deviation of the trachea to the left. The physical examination revealed severe venous distention in the upper extremities, face, and neck. Pulses were equal bilaterally, and his neurological examination was within normal limits. His temperature was 39"C, his white blood cell count was 14.8 x 109/L (14,800 pL), and a blood culture was positive for coagulase-positive Staphylococcus. Further workup included a computed tomographic scan (Fig 2), which revealed a large mass effect in the mediastinum displacing the trachea to the left side and appeared to be a mycotic aneurysm causing obstruction to the superior vena cava. The abnormal density in the mediastinum extended inferiorly into the pretracheal retrocaval space and appeared also to extend into the subcarinal region with no hilar adenopathy. The patient was given intravenous nafcillin, 2 g intravenously every 4 hours. Arteriography revealed a false aneurysm of the right innominate artery. The left common carotid took its origin from the base of the right innominate artery. A preoperative diagnosis of a mycotic aneurysm involving the right innominate artery after the takeoff of the anomalous left common carotid artery was made. On further questioning the patient admitted to an attempt at heroin injection in the right neck approximately 6 months before this hospitalization. The patient was taken to the operating room and placed on cardiopulmonary bypass through the left femoral artery and vein. The sternotomy was made while he was on bypass with low pump flow. The incision was extended superior to the clavicle for a Accepted for publication March 1, 1991 Address reprint requests to Dr Schuch, 5301 F St, Suite 312, Sacramento, CA 95819.
0 1991 by The Society of Thoracic Surgeons
(Ann Thorac Surg 1991;52:8634)
0003-4975/91/$3.50
864
Ann Thorac Surg 1991;52:86M
CASE REPORT SCHUCH AND WOLFF HOMOGRAFT TISSUE REPAIR
Fig I. Preoperative chest roentgenogram with right paratracheal mass.
neurological function, afebrile, and on no antibiotics. He has since completed a drug rehabilitation program, and at 5 months postoperatively he remains well.
Comment The use of homograft cryopreserved tissue has been extensive for a number of years with the use of aortic
valve, aortic and pulmonary valve conduits, and even saphenous veins in cardiac and peripheral vascular operations [l].Its durability is thought to be directly related to the viability of the tissue that is preserved with the cryopreserved process and maintenance [2]. The controlled rate of freezing, storage, and thawing procedures are well known for maximization of tissue viability. In the early days of aortic valve replacement with homograft tissue the incidence of prosthetic valve endocarditis was found to be exceptionally low [3]. In contrast to the early phase of prosthetic valve endocarditis seen with heterograft and mechanical valves, there is no early phase with homograft valves [4].At The University of Alabama at Birmingham the presence of native valve endocarditis was associated with a fivefold increase in the probability of acquiring prosthetic valve endocarditis unless a homograft was used [4]. Therefore, a greater resistance by the homograft valve to surface contamination was thought to exist than that by a mechanical or heterograft valve. The presence of an infection is therefore thought to be a major indication for the use of a homograft valve. In our case, in dealing with a mycotic aneurysm of the innominate artery, we believed replacement with an artificial conduit would present a high risk of recurrent infection. The use of saphenous vein was an alternative, but size mismatch would have been a problem. Ligation of the innominate artery was considered, but the possibility of neurological sequelae would have been real. The homograft vessel matched perfectly in size and was therefore selected and, in this case, proved to be quite successful in the repair. In conclusion, the use of homograft cryopreserved tissue should be strongly considered as a reparative conduit in the face of infection. Given the proper bank tissue, this might also be used in acute trauma. We thank Carolyn Harris for editorial assistance.
References
Fig 2. Preoperative computed tomographic scan.
1. Ross D. Application of homografts in clinical surgery. J Cardiac Surg 1987;l(Suppl):1775-83. 2. O’Brien MF, Stafford EG, Gardner MF, Pohlner PG, McGiffin DC. A comparison of aortic valve replacement with viable cryopreserved and fresh allograft valves, with a note on chromosomal studies. J Thorac Cardiovasc Surg 1987;94: 812-23. 3. Karp RB. The use of free-hand unstented aortic valve allografts for replacement of the aortic valve. J Cardiac Surg 1986;1:2>32. 4. Kirklin JK, Kirklin JW, Pacific0 AD. Homograft replacement of aortic valve. Cardiol Clin 1985;3:32941.
California
The case of a 46-year-old drug addict who underwent repair of a mycotic aneurysm of the innominate artery with a 12-mm homograft is presented. The homograft was obtained from the descending thoracic position in a young child. Replacement of infected arteries with various artificial grafts risks recurrent infection and anasto-
motic disruption. The use of a homograft conduit in this case was successful in restoring the appropriate blood flow without infection. We suggest that the homograft conduit can be used in other areas with similar results.
A
length of approximately 3 cm. The clavicular head of the sternocleidomastoid muscle was transected, and the innominate vein was also transected for adequate exposure. Control of the innominate artery was obtained distal to the left common carotid takeoff; the mycotic aneurysm was entered, and distal control was obtained by clamping the common carotid on the right and the subclavian artery on the right. The innominate artery was completely destroyed for a length of 3 cm, and a cavity was debrided measuring approximately 8 cm in diameter to the right of the superior vena cava extending posteriorly to the tracheal bifurcation. A 12-mm homograft descending thoracic aorta, procured and prepared by Cryo-Life (Marietta, GA) was thawed in the usual manner and sewn into place with end-to-end anastomosis on both the proximal and distal ends using a 5-0 Prolene (Ethicon, Somerville, NJ) continuous suture. The clamps were left for a total of 40 minutes, during which time the thawing process and anastomosing were performed. During this time the temperature was lowered to 28°C and the heart fibrillated. Rewarming was performed near the end of the anastomosis and the heart defibrillated at 32°C. Further rewarming was then accomplished to 38°C. The innominate vein was then repaired in an end-to-end fashion with a running 5-0 Prolene suture. The aneurysmal cavity was further debrided, and a small red Robinson catheter was placed into the cavity and brought out inferior to the sternotomy along with a No. 38 chest tube. Continuous mediastinal irrigation was begun with 0.5% Betadine irrigation and normal saline solution at 200 mL/h. The wound was then closed in the usual fashion. Mediastinal irrigation continued for 5 days postoperatively, and the patient underwent a total of 4 weeks of intravenous drug therapy with nafcillin for 2% weeks and then Kefzol (2 g intravenously every 8 hours) for 1% weeks. The change in antibiotics was thought necessary secondary to the increased sodium load and difficulty with persistent weight gain postoperatively. The patient was discharged from the hospital on postoperative day 30 with normal cardiac function and normal
46-year-old, insulin-dependent diabetic and known intravenous heroin user was seen at our emergency room on September 29, 1990, with a fever, swelling of the face and neck, dyspnea, and bilateral upper anterior chest pain described as sharp in nature. He had admitted to using intravenous heroin for approximately 5 years on a daily basis. A chest roentgenogram (Fig 1) showed a right peritracheal mass with deviation of the trachea to the left. The physical examination revealed severe venous distention in the upper extremities, face, and neck. Pulses were equal bilaterally, and his neurological examination was within normal limits. His temperature was 39"C, his white blood cell count was 14.8 x 109/L (14,800 pL), and a blood culture was positive for coagulase-positive Staphylococcus. Further workup included a computed tomographic scan (Fig 2), which revealed a large mass effect in the mediastinum displacing the trachea to the left side and appeared to be a mycotic aneurysm causing obstruction to the superior vena cava. The abnormal density in the mediastinum extended inferiorly into the pretracheal retrocaval space and appeared also to extend into the subcarinal region with no hilar adenopathy. The patient was given intravenous nafcillin, 2 g intravenously every 4 hours. Arteriography revealed a false aneurysm of the right innominate artery. The left common carotid took its origin from the base of the right innominate artery. A preoperative diagnosis of a mycotic aneurysm involving the right innominate artery after the takeoff of the anomalous left common carotid artery was made. On further questioning the patient admitted to an attempt at heroin injection in the right neck approximately 6 months before this hospitalization. The patient was taken to the operating room and placed on cardiopulmonary bypass through the left femoral artery and vein. The sternotomy was made while he was on bypass with low pump flow. The incision was extended superior to the clavicle for a Accepted for publication March 1, 1991 Address reprint requests to Dr Schuch, 5301 F St, Suite 312, Sacramento, CA 95819.
0 1991 by The Society of Thoracic Surgeons
(Ann Thorac Surg 1991;52:8634)
0003-4975/91/$3.50
864
Ann Thorac Surg 1991;52:86M
CASE REPORT SCHUCH AND WOLFF HOMOGRAFT TISSUE REPAIR
Fig I. Preoperative chest roentgenogram with right paratracheal mass.
neurological function, afebrile, and on no antibiotics. He has since completed a drug rehabilitation program, and at 5 months postoperatively he remains well.
Comment The use of homograft cryopreserved tissue has been extensive for a number of years with the use of aortic
valve, aortic and pulmonary valve conduits, and even saphenous veins in cardiac and peripheral vascular operations [l].Its durability is thought to be directly related to the viability of the tissue that is preserved with the cryopreserved process and maintenance [2]. The controlled rate of freezing, storage, and thawing procedures are well known for maximization of tissue viability. In the early days of aortic valve replacement with homograft tissue the incidence of prosthetic valve endocarditis was found to be exceptionally low [3]. In contrast to the early phase of prosthetic valve endocarditis seen with heterograft and mechanical valves, there is no early phase with homograft valves [4].At The University of Alabama at Birmingham the presence of native valve endocarditis was associated with a fivefold increase in the probability of acquiring prosthetic valve endocarditis unless a homograft was used [4]. Therefore, a greater resistance by the homograft valve to surface contamination was thought to exist than that by a mechanical or heterograft valve. The presence of an infection is therefore thought to be a major indication for the use of a homograft valve. In our case, in dealing with a mycotic aneurysm of the innominate artery, we believed replacement with an artificial conduit would present a high risk of recurrent infection. The use of saphenous vein was an alternative, but size mismatch would have been a problem. Ligation of the innominate artery was considered, but the possibility of neurological sequelae would have been real. The homograft vessel matched perfectly in size and was therefore selected and, in this case, proved to be quite successful in the repair. In conclusion, the use of homograft cryopreserved tissue should be strongly considered as a reparative conduit in the face of infection. Given the proper bank tissue, this might also be used in acute trauma. We thank Carolyn Harris for editorial assistance.
References
Fig 2. Preoperative computed tomographic scan.
1. Ross D. Application of homografts in clinical surgery. J Cardiac Surg 1987;l(Suppl):1775-83. 2. O’Brien MF, Stafford EG, Gardner MF, Pohlner PG, McGiffin DC. A comparison of aortic valve replacement with viable cryopreserved and fresh allograft valves, with a note on chromosomal studies. J Thorac Cardiovasc Surg 1987;94: 812-23. 3. Karp RB. The use of free-hand unstented aortic valve allografts for replacement of the aortic valve. J Cardiac Surg 1986;1:2>32. 4. Kirklin JK, Kirklin JW, Pacific0 AD. Homograft replacement of aortic valve. Cardiol Clin 1985;3:32941.
