Obturator Foramen Bypass in the Management of Infected Vascular Prostheses Marc Rudich, MD, Buffalo, New York lrineo 2. Gutierrez, MD, Buffalo, New York Andrew A. Gage, MD, Buffalo, New York
The management of infection in a vascular prosthesis remains one of the most difficult problems in vascular reconstructive surgery. The most frequent site of infection is the upper thigh and groin, where sepsis in a femoral prosthesis is a life-threatening process that usually leads to catastrophic hemorrhage or systemic sepsis if not treated. Conservative management, such as opening the wound or administering local and systemic antibiotics, is usually ineffective and often permits continuation of infection and thrombosis of vessels, resulting in amputation of the extremity or death. The classic treatment of infected foreign bodies anywhere in the body usually requires surgical removal of all foreign material, and vascular prostheses are no exception. The basic principles for management of infected arterial prostheses, that is, the removal of all foreign material, drainage of the infected area, and provision of blood supply to the extremity by new vascular prostheses in an uncontaminated area, were described by Shaw and Baue [l], who originally suggested obturator foramen bypass as a technic for extraanatomic reconstruction in a clean operative field. The extent of this problem was demonstrated recently in a 5 year survey (1972 to 1976) of 295 femoral arterial reconstructions performed with a knitted Dacron@ prosthesis at the Veterans Administration Hospital, Buffalo, New York. Eight prostheses became infected, for an incidence rate of 2.7 per cent, which is greater than the 1 per cent rate for all clean surgical wounds at this hospital. The true incidence From the Department of Surgery, Veterans Administration Hospital, and the State University of New York at Buffalo School of Medicine. Buffalo. New York. Reprint requests should be addressed to Andrew A. Gage, MD, 3495 Bailey Avenue, Buffalo. New York 14215.
Volume 137, May 1979
of vascular prosthesis infection is difficult to determine because some infections are not apparent until 5 or more years after operation. Nevertheless, late onset is uncommon, and the incidence of infection after a follow-up of at least 2 years is representative. Of the eight patients with infection, five were treated with obturator foramen bypass, one was treated successfully with conservative nonsurgical measures, and two patients were treated with local surgical measures and amputation because of advanced distal arteriosclerotic disease. The purpose of this report is to review the management of infected femoropopliteal prostheses with obturator foramen bypass because the technic offers significant advantages in the management of this complication. In addition to the five patients treated with obturator foramen bypass in the 5 year study period, two additional patients from a later period are included. Six operations had been performed for severe occlusive arteriosclerotic disease and one for removal of a femoral arterial aneurysm. The infection occurred in clean wounds, and no patient had distant ulcerations of the legs at the time of operation. Only two patients had diabetes mellitus, and both depended on insulin for control. The time from vascular operation to the appearance of prosthetic infection ranged from 2 weeks to an extraordinary 26 months. Because of the older age of the veterans studied and the presence of severe associated disease, prolonged hospitalization was common, and in four patients the wound infection was discovered while the patient was still under observation and treatment for unrelated chronic disease. The initial event was often inflammatory change in the operative site, followed by breakdown of the skin and the formation of a draining sinus. The
657
Rudich et al
TABLE I
Manifestation and Infecting Bacteria in Femoral Prosthetic Infection
Case No.
Operative Procedure
Presentation
Onset*
1 2 3
Excision femoral artery aneurysm Femoropopliteal bypass Femoropopliteal bypass Femoropopliteal bypass Femoropopliteal bypass Femoropopliteal bypass Aortofemoral bypass
Draining sinus Groin wound infection Erosion of graft (mid thigh) Groin abscess Groin wound infection Groin wound infection False aneurysm in groin
26 mo 4wk 5mo 4 wk 8 wk 2 wk 24 mo
4 5 6
7 l
Interval from implantation to clinical recognition
Culture Staphylococcus aureus Escherichia co/i
Pseudomonas Staphylococcus aureus Staphylococcus aweus Staphylococcus aureus, Serratia Staphyloccus aureus, Enterococci
of graft infection.
appearance of infection was often delayed, all but one of the infections appeared 1 month or longer after vascular operation. Three infections appeared after long intervals when the patient was no longer hospitalized: the prosthesis eroded through the skin 5 months after operation in one patient, a false aneurysm developed in the femoral region 24 months after operation in one patient, and a draining sinus formed in the femoral region 26 months after operation in the third patient. The vascular prostheses in all seven patients were patent and functioning so that the involved leg was viable when the first sign of infection appeared. No bacteremia or signs of systemic sepsis were found. No hemorrhage occurred because the patients were treated promptly once the problem was identified. Treatment
Operative treatment was preceded by careful bacteriologic studies and by aggressive local measures to control or eliminate infection, including identification of the infecting organism, sensitivity studies, and the use of appropriate antibiotics. Culture of the groin wounds before operation showed that Staphylococcus aureus was the dominant organism, but E. coli, Pseudomonas, and Serratia were also present (Table I). There was no correlation between the interval from the first operation to the development of infection; however, Serratia infection occurred as early as 2 weeks after operation.
Infected Area
Figure 1. Diagram showing the position of the obturator foramen bypass, remote from the infected femoral area.
Therapeutic management was complicated by the necessity of maintaining blood flow to the extremity while removing the infected prosthesis. The insertion of a new prosthesis through an uncontaminated field was the first phase of the operation (Figure 1). Our technic of obturator foramen bypass was a modification of that described by Guida and Moore [2]. The infected prosthesis was carefully isolated from the clean areas with adhesive drapes and towels. Then, remote from the contaminated area, the common iliac artery was exposed through a lower midline abdominal incision and the popliteal artery exposed through an incision in the lower thigh. Through both incisions, the extraanatomic tunnel was created by blunt dissection from above and below. From above, the incision in the aponeurotic fascia of the obturator foramen was made precisely inferior to the.obturator vessels but superior to the obturator internis muscle. The frequent anomalies of the obturator vessels demanded caution in the placement of this incision. During the creation of the tunnel posterior to the pectineus muscle and the short and long adductor muscles and anterior to the hamstring muscles, care was taken not to breach the contaminated femoral region. A Spark’s Mandril tunneler was used to pass the preclotted 8 mm knitted Dacron prosthesis from the area of the iliac artery to that of the popliteal artery below. To prevent obstruction of the ureter, it was placed anterior to the prosthesis. Anastomoses of.the prosthesis to iliac and popliteal arteries were made with polypropylene sutures. Both wounds were closed in layers using a subcuticular suture technic and were protected with adhesive drapes to isolate the wounds during work in the infected area. The infected prosthesis was removed, including the proximal and distal suture lines, which were submitted separately for culture. The femoral arteriotomy was closed and the sartorius muscle mobilized medially to cover the anastomosis. The wounds were irrigated with cephalothin solution and the groin wound loosely packed with fine mesh gauze. At the end of the procedure the distal circulation was evaluated with Doppler ultrasound to ascertain that blood flow was reestablished. After operation, the administration of systemic antibiotics was continued until the groin wound had healed. The groin wound was irrigated with antibiotic solutions daily, and necrotic tissue was debrided as necessary at the time
The American Journal of Surgery
Obturator Foramen Bypass
of the frequent dressing changes. The wounds required 4
to 12 weeks to heal, which partly accounted for prolonged hospitalization. There was no evidence of sepsis in this period, and blood cultures were negative. In spite of the open infected groin wound, none of the newly implanted prostheses became infected. Results
After the infected prosthesis was removed and obturator foramen bypass performed, the clinical course of the patients demonstrated the severity of the remaining problems even after the elimination of infection and successful reconstruction. One man died 3 days after operation from aspiration pneumonia. In another patient an unusual complication developed: necrosis of the entire thigh with a viable lower leg. This patient had severe narrowing of the profunda femoris artery and occluded external and internal iliac arteries. When the infected prosthesis was removed, ligation of the popliteal artery was believed necessary to secure a good distal anastomosis, but this was a technical error. The profunda femoral artery was not sufficiently large to maintain viability of the thigh, and the muscles of the thigh became obviously necrotic on the third day while the viability of the distal leg was maintained by good flow through the prosthesis. A hip disarticulation was performed and the patient survived. The five remaining patients recovered from operation and the prostheses were patent. Three prosthetic grafts became occluded as long as 8 months after operation, and below-knee amputation was necessary. The basic problem in these three patients was extremely poor circulation to the distal extremity caused by severe arteriosclerotic changes in the arteries of the lower leg. The remaining two patients had good distal circulation with good functioning vessels below the knee. Nevertheless after 3 years of function, amputation of the involved leg became necessary in one patient, and the other patient with a functioning bypass died of carcinoma of the prostate. Thus only two of the patients in this study achieved long-term benefit. Comments
The reported incidence of infection after vascular arterial reconstruction ranges from 1.8 to 6 per cent [3-61, which is higher than the rate usually considered acceptable for clean wounds. In part, this is because the groin is associated with a high incidence of wound complications, especially in vascular surgery. Goldstone and Moore [7] attributed this to proximity to the perineum, the transportation of microorganisms from distal ulcerations on the legs
Volume 137, May 1979
through the lymphatic vessels, and factors in operative technic, such as extensive undermining of skin flaps and improper wound closure. The resultant mortality rate, from deaths due largely to hemorrhage, sepsis, multiple operative procedures, and prosthetic thrombosis, is 37 to 75 per cent [81, which is ample reason for an aggressive surgical approach. The incidence of prosthetic infection in this study, although not unusually large compared with that reported in other studies, is sufficiently large to cause concern. The basic methods of management include removing the source of infection, treating the infecting microorganism with appropriate antibiotics, and maintaining the circulation of the distal limb through an uncontaminated extraanatomic route. In the femoral region, the obturator foramen bypass is perhaps the best approach, although close proximity to the contaminated femoral triangle is unavoidable. Reports by DiPalma and Hubay [9], Spiro and Cotton [IO], and Mahoney and Whelan [11] emphasized the utility of obturator foramen bypass in complicated cases involving groin wound sepsis, which may be associated with vascular injury, previous radical groin dissection, radiotherapy, or intraabdominal sepsis. Because such infections threaten a patient’s limbs and well as his life, it is not surprising that even more extensive bypass procedures have been performed [12]. We have not ligated all the femoral vessels and donor iliac artery as recommended by Leather and Karmody [13]. Experimental work in dogs by Jacobson and McAllister [14] suggests that a patent prosthesis causes the gradual disappearance of existing collateral circulation. Any preexistent circulation through the iliac and femoral vessels has caused no difficulties in debriding and closing the infected artery and may be essential in some cases for viability of the thigh. The one case of thigh necrosis observed after operation emphasizes that caution should be used in ligating the proximal popliteal artery above the distal anastomosis and the profunda femoris artery should be carefully scrutinized. In our patients, early operative treatment averted hemorrhage from the infected suture line and systemic sepsis. The generalization made by Shaw and Baue [I] that sepsis does not propagate up and down a patent prosthesis was confirmed in our patients. Culture of the removed prosthetic materials showed no growth in the distal suture lines, which were not involved clinically in the infection, but the proximal suture lines grew the organisms shown in Table I. The short-term patency of most of the prostheses in this series was due to poor distal circulation. NO
659
Rudich
et al
limb survived after prosthetic occlusion. The incidence of later amputation stresses the serious nature of the infection and the progressive nature of the disease. Most of the patients in this small series had advanced disease with limbs at risk due to ischemia, so reestablishing blood flow provided only short-term benefit in most patients. The most effective treatment is prevention of infection. Ulcers of the distal extremity should be healed as much as possible before reconstruction. Appropriate antibiotic coverage is determined by the individual cultures and sensitivities. There is evidence that soaking the prosthesis in antibiotic solution may lessen the incidence of infection [15], and this procedure is recommended. Other factors in the prevention of infection include careful preoperative cleansing of the skin and a meticulous operative technic, which includes avoiding excessive prosthetic length, preventing hematoma, closing the subcuticular groin wound, and preserving all existing collateral circulation. Care should be taken to implant the prosthesis sufficiently deep to reduce the chance of erosion through the skin, which inevitably leads to infection. The preoperative administration of antibiotics is considered effective in reducing wound infection. Because Staphylococcus aureus is the organism responsible for most graft infections [6], inoculation is assumed to occur at the time of implantation in such patients. Antibiotic coverage with a parenteral cephalosporin, a broad spectrum antibiotic with bactericidal effect on staphylococci as well as most gram negative bacilli, must begin before inoculation to help prevent wound infection. The intravenous route just before surgery insures rapid distribution and adequate tissue levels. Antibiotics should be continued postoperatively until the groin infection is resolved. Prostheses are susceptible to bacteremic seeding in the immediate postoperative period. Experimental studies in dogs by Malone et al [16] revealed a 100 per cent susceptibility to bacteremic seeding 1 month after operation and a 30 per cent susceptibility 1 year after prosthetic implantation. The primary determinant of susceptibility to bacteremic infection was considered by those authors to be related to the integrity of the pseudointima. When a new intima has formed completely, as rarely occurs with prosthetic materials, the prosthesis is relatively immune to bacteremic infection. The sources of transient bacteremia are well known to be urinary catheters, intravenous cannulas, pulmonary infection, carious teeth, and ischemic ulcerations of the legs; these sources probably cause the infections that appear months after operation in some patients. Prophylactic administration of antibiotics is advisable 660
during illness or procedures with transient bacteremia.
known to be associated
Summary
Seven patients with infected vascular prostheses in the femoral region were treated by removal of the prosthesis and extraanatomic reconstruction by way of the obturator foramen. Because the operation avoided entry into the infected area, it was considered the best surgical treatment for these patients. Although catastrophic hemorrhage and systemic sepsis were averted, amputation was eventually necessary in five patients, usually because of severe arteriosclerotic disease in distal arteries. Short-term benefit was gained by only two patients. The prevention of infection demands intensive preoperative preparation using prophylactic antibiotics and meticulous operating room technic. References 1. Shaw RS, Baue AE: Management of sepsis complicating arterial reconstructive procedures. Surgery53: 75, 1983. 2. Guida PM, Moore SW: Obturator bypass technique. Surg Gynecol Obstet 128: 1307, 1989. 3. Szilagyi DE, Smith RF, Elliott FP. Vrandecic MP: Infection in arterial reconstruction with synthetic grafts. Ann Surg 178: 321, 1972. 4. Fry WJ. Lindenauer SM: Infection complicating the use of plastic arterial implants. Arch Surg 94: 800, 1987. 5. Conn JH, Hardy JD, Chavez CM. Fain WR: Infected arterial grafts: experience with 22 cases with emphasis on unusual bacteria and technics. Ann Surg 171: 704, 1970. 8. Liekweg WG JR, Greenfield LJ: Vascular prosthetic infections: collected experience and results of treatment. Surgery 81: 335.1977. 7. Goldstone J, Moore WS: Infection in vascular prostheses. Clinical manifestations and surgical management. Am J Surg 128: 225. 1974. 8. DiGiglia JW, Leonard GL. Ochsner JL: Local irrigation with antibiotic solution in the prevention of infection in vascular prostheses. Surgery87: 838, 1970. 9. DePalma RG, Hubay CA: Arterial bypass via the obturator foramen. An alternative in complicated vascular problems. Am J Surg 115: 323, 1988. 10. Spiro M, Cotton LT: The obturator canal as a route for iliofemoral bypass. Br J Surg 57: 188, 1970. 11. Mahoney WD, Whelan TJ: Use of obturator foramen in iliofemoral artery grafting-case reports. Ann Surg 183: 215, 1988. 12. Smith R, Perdue G, Hyatt H, Ansley J: Management of infected aortofemoral prosthesis including use of an axillopopliteal bypass. Am Surg 42: 85, 1977. 13. Leather RP, Karmody AM: A lateral route for extra-anatomical bypass of the femoral artery. Surgery 81: 307, 1977. 14. Jacobson JH II, McAllister FF: The harmful effect of arterial grafting on existing collateral circulation. Surgery42: 148. 1957. 15. Richardson RL Jr, Pate JW, Wolf RY, Ledes C, Hopson WB: The outcome of antibiotic-soaked arterial grafts in guinea pig wounds contaminated with E. coli or Staph aureus. J Thorac Cardiovasc Surg 59: 835. 1970. 18. Malone JM, Moore WS, Campagna G, Bean B: Bacteremic infectability of vascular grafts: the influence of pseudointimal integrity and duration of graft function. Surgery 78: 211, 1975. The American Journal of Surgery
The management of infection in a vascular prosthesis remains one of the most difficult problems in vascular reconstructive surgery. The most frequent site of infection is the upper thigh and groin, where sepsis in a femoral prosthesis is a life-threatening process that usually leads to catastrophic hemorrhage or systemic sepsis if not treated. Conservative management, such as opening the wound or administering local and systemic antibiotics, is usually ineffective and often permits continuation of infection and thrombosis of vessels, resulting in amputation of the extremity or death. The classic treatment of infected foreign bodies anywhere in the body usually requires surgical removal of all foreign material, and vascular prostheses are no exception. The basic principles for management of infected arterial prostheses, that is, the removal of all foreign material, drainage of the infected area, and provision of blood supply to the extremity by new vascular prostheses in an uncontaminated area, were described by Shaw and Baue [l], who originally suggested obturator foramen bypass as a technic for extraanatomic reconstruction in a clean operative field. The extent of this problem was demonstrated recently in a 5 year survey (1972 to 1976) of 295 femoral arterial reconstructions performed with a knitted Dacron@ prosthesis at the Veterans Administration Hospital, Buffalo, New York. Eight prostheses became infected, for an incidence rate of 2.7 per cent, which is greater than the 1 per cent rate for all clean surgical wounds at this hospital. The true incidence From the Department of Surgery, Veterans Administration Hospital, and the State University of New York at Buffalo School of Medicine. Buffalo. New York. Reprint requests should be addressed to Andrew A. Gage, MD, 3495 Bailey Avenue, Buffalo. New York 14215.
Volume 137, May 1979
of vascular prosthesis infection is difficult to determine because some infections are not apparent until 5 or more years after operation. Nevertheless, late onset is uncommon, and the incidence of infection after a follow-up of at least 2 years is representative. Of the eight patients with infection, five were treated with obturator foramen bypass, one was treated successfully with conservative nonsurgical measures, and two patients were treated with local surgical measures and amputation because of advanced distal arteriosclerotic disease. The purpose of this report is to review the management of infected femoropopliteal prostheses with obturator foramen bypass because the technic offers significant advantages in the management of this complication. In addition to the five patients treated with obturator foramen bypass in the 5 year study period, two additional patients from a later period are included. Six operations had been performed for severe occlusive arteriosclerotic disease and one for removal of a femoral arterial aneurysm. The infection occurred in clean wounds, and no patient had distant ulcerations of the legs at the time of operation. Only two patients had diabetes mellitus, and both depended on insulin for control. The time from vascular operation to the appearance of prosthetic infection ranged from 2 weeks to an extraordinary 26 months. Because of the older age of the veterans studied and the presence of severe associated disease, prolonged hospitalization was common, and in four patients the wound infection was discovered while the patient was still under observation and treatment for unrelated chronic disease. The initial event was often inflammatory change in the operative site, followed by breakdown of the skin and the formation of a draining sinus. The
657
Rudich et al
TABLE I
Manifestation and Infecting Bacteria in Femoral Prosthetic Infection
Case No.
Operative Procedure
Presentation
Onset*
1 2 3
Excision femoral artery aneurysm Femoropopliteal bypass Femoropopliteal bypass Femoropopliteal bypass Femoropopliteal bypass Femoropopliteal bypass Aortofemoral bypass
Draining sinus Groin wound infection Erosion of graft (mid thigh) Groin abscess Groin wound infection Groin wound infection False aneurysm in groin
26 mo 4wk 5mo 4 wk 8 wk 2 wk 24 mo
4 5 6
7 l
Interval from implantation to clinical recognition
Culture Staphylococcus aureus Escherichia co/i
Pseudomonas Staphylococcus aureus Staphylococcus aweus Staphylococcus aureus, Serratia Staphyloccus aureus, Enterococci
of graft infection.
appearance of infection was often delayed, all but one of the infections appeared 1 month or longer after vascular operation. Three infections appeared after long intervals when the patient was no longer hospitalized: the prosthesis eroded through the skin 5 months after operation in one patient, a false aneurysm developed in the femoral region 24 months after operation in one patient, and a draining sinus formed in the femoral region 26 months after operation in the third patient. The vascular prostheses in all seven patients were patent and functioning so that the involved leg was viable when the first sign of infection appeared. No bacteremia or signs of systemic sepsis were found. No hemorrhage occurred because the patients were treated promptly once the problem was identified. Treatment
Operative treatment was preceded by careful bacteriologic studies and by aggressive local measures to control or eliminate infection, including identification of the infecting organism, sensitivity studies, and the use of appropriate antibiotics. Culture of the groin wounds before operation showed that Staphylococcus aureus was the dominant organism, but E. coli, Pseudomonas, and Serratia were also present (Table I). There was no correlation between the interval from the first operation to the development of infection; however, Serratia infection occurred as early as 2 weeks after operation.
Infected Area
Figure 1. Diagram showing the position of the obturator foramen bypass, remote from the infected femoral area.
Therapeutic management was complicated by the necessity of maintaining blood flow to the extremity while removing the infected prosthesis. The insertion of a new prosthesis through an uncontaminated field was the first phase of the operation (Figure 1). Our technic of obturator foramen bypass was a modification of that described by Guida and Moore [2]. The infected prosthesis was carefully isolated from the clean areas with adhesive drapes and towels. Then, remote from the contaminated area, the common iliac artery was exposed through a lower midline abdominal incision and the popliteal artery exposed through an incision in the lower thigh. Through both incisions, the extraanatomic tunnel was created by blunt dissection from above and below. From above, the incision in the aponeurotic fascia of the obturator foramen was made precisely inferior to the.obturator vessels but superior to the obturator internis muscle. The frequent anomalies of the obturator vessels demanded caution in the placement of this incision. During the creation of the tunnel posterior to the pectineus muscle and the short and long adductor muscles and anterior to the hamstring muscles, care was taken not to breach the contaminated femoral region. A Spark’s Mandril tunneler was used to pass the preclotted 8 mm knitted Dacron prosthesis from the area of the iliac artery to that of the popliteal artery below. To prevent obstruction of the ureter, it was placed anterior to the prosthesis. Anastomoses of.the prosthesis to iliac and popliteal arteries were made with polypropylene sutures. Both wounds were closed in layers using a subcuticular suture technic and were protected with adhesive drapes to isolate the wounds during work in the infected area. The infected prosthesis was removed, including the proximal and distal suture lines, which were submitted separately for culture. The femoral arteriotomy was closed and the sartorius muscle mobilized medially to cover the anastomosis. The wounds were irrigated with cephalothin solution and the groin wound loosely packed with fine mesh gauze. At the end of the procedure the distal circulation was evaluated with Doppler ultrasound to ascertain that blood flow was reestablished. After operation, the administration of systemic antibiotics was continued until the groin wound had healed. The groin wound was irrigated with antibiotic solutions daily, and necrotic tissue was debrided as necessary at the time
The American Journal of Surgery
Obturator Foramen Bypass
of the frequent dressing changes. The wounds required 4
to 12 weeks to heal, which partly accounted for prolonged hospitalization. There was no evidence of sepsis in this period, and blood cultures were negative. In spite of the open infected groin wound, none of the newly implanted prostheses became infected. Results
After the infected prosthesis was removed and obturator foramen bypass performed, the clinical course of the patients demonstrated the severity of the remaining problems even after the elimination of infection and successful reconstruction. One man died 3 days after operation from aspiration pneumonia. In another patient an unusual complication developed: necrosis of the entire thigh with a viable lower leg. This patient had severe narrowing of the profunda femoris artery and occluded external and internal iliac arteries. When the infected prosthesis was removed, ligation of the popliteal artery was believed necessary to secure a good distal anastomosis, but this was a technical error. The profunda femoral artery was not sufficiently large to maintain viability of the thigh, and the muscles of the thigh became obviously necrotic on the third day while the viability of the distal leg was maintained by good flow through the prosthesis. A hip disarticulation was performed and the patient survived. The five remaining patients recovered from operation and the prostheses were patent. Three prosthetic grafts became occluded as long as 8 months after operation, and below-knee amputation was necessary. The basic problem in these three patients was extremely poor circulation to the distal extremity caused by severe arteriosclerotic changes in the arteries of the lower leg. The remaining two patients had good distal circulation with good functioning vessels below the knee. Nevertheless after 3 years of function, amputation of the involved leg became necessary in one patient, and the other patient with a functioning bypass died of carcinoma of the prostate. Thus only two of the patients in this study achieved long-term benefit. Comments
The reported incidence of infection after vascular arterial reconstruction ranges from 1.8 to 6 per cent [3-61, which is higher than the rate usually considered acceptable for clean wounds. In part, this is because the groin is associated with a high incidence of wound complications, especially in vascular surgery. Goldstone and Moore [7] attributed this to proximity to the perineum, the transportation of microorganisms from distal ulcerations on the legs
Volume 137, May 1979
through the lymphatic vessels, and factors in operative technic, such as extensive undermining of skin flaps and improper wound closure. The resultant mortality rate, from deaths due largely to hemorrhage, sepsis, multiple operative procedures, and prosthetic thrombosis, is 37 to 75 per cent [81, which is ample reason for an aggressive surgical approach. The incidence of prosthetic infection in this study, although not unusually large compared with that reported in other studies, is sufficiently large to cause concern. The basic methods of management include removing the source of infection, treating the infecting microorganism with appropriate antibiotics, and maintaining the circulation of the distal limb through an uncontaminated extraanatomic route. In the femoral region, the obturator foramen bypass is perhaps the best approach, although close proximity to the contaminated femoral triangle is unavoidable. Reports by DiPalma and Hubay [9], Spiro and Cotton [IO], and Mahoney and Whelan [11] emphasized the utility of obturator foramen bypass in complicated cases involving groin wound sepsis, which may be associated with vascular injury, previous radical groin dissection, radiotherapy, or intraabdominal sepsis. Because such infections threaten a patient’s limbs and well as his life, it is not surprising that even more extensive bypass procedures have been performed [12]. We have not ligated all the femoral vessels and donor iliac artery as recommended by Leather and Karmody [13]. Experimental work in dogs by Jacobson and McAllister [14] suggests that a patent prosthesis causes the gradual disappearance of existing collateral circulation. Any preexistent circulation through the iliac and femoral vessels has caused no difficulties in debriding and closing the infected artery and may be essential in some cases for viability of the thigh. The one case of thigh necrosis observed after operation emphasizes that caution should be used in ligating the proximal popliteal artery above the distal anastomosis and the profunda femoris artery should be carefully scrutinized. In our patients, early operative treatment averted hemorrhage from the infected suture line and systemic sepsis. The generalization made by Shaw and Baue [I] that sepsis does not propagate up and down a patent prosthesis was confirmed in our patients. Culture of the removed prosthetic materials showed no growth in the distal suture lines, which were not involved clinically in the infection, but the proximal suture lines grew the organisms shown in Table I. The short-term patency of most of the prostheses in this series was due to poor distal circulation. NO
659
Rudich
et al
limb survived after prosthetic occlusion. The incidence of later amputation stresses the serious nature of the infection and the progressive nature of the disease. Most of the patients in this small series had advanced disease with limbs at risk due to ischemia, so reestablishing blood flow provided only short-term benefit in most patients. The most effective treatment is prevention of infection. Ulcers of the distal extremity should be healed as much as possible before reconstruction. Appropriate antibiotic coverage is determined by the individual cultures and sensitivities. There is evidence that soaking the prosthesis in antibiotic solution may lessen the incidence of infection [15], and this procedure is recommended. Other factors in the prevention of infection include careful preoperative cleansing of the skin and a meticulous operative technic, which includes avoiding excessive prosthetic length, preventing hematoma, closing the subcuticular groin wound, and preserving all existing collateral circulation. Care should be taken to implant the prosthesis sufficiently deep to reduce the chance of erosion through the skin, which inevitably leads to infection. The preoperative administration of antibiotics is considered effective in reducing wound infection. Because Staphylococcus aureus is the organism responsible for most graft infections [6], inoculation is assumed to occur at the time of implantation in such patients. Antibiotic coverage with a parenteral cephalosporin, a broad spectrum antibiotic with bactericidal effect on staphylococci as well as most gram negative bacilli, must begin before inoculation to help prevent wound infection. The intravenous route just before surgery insures rapid distribution and adequate tissue levels. Antibiotics should be continued postoperatively until the groin infection is resolved. Prostheses are susceptible to bacteremic seeding in the immediate postoperative period. Experimental studies in dogs by Malone et al [16] revealed a 100 per cent susceptibility to bacteremic seeding 1 month after operation and a 30 per cent susceptibility 1 year after prosthetic implantation. The primary determinant of susceptibility to bacteremic infection was considered by those authors to be related to the integrity of the pseudointima. When a new intima has formed completely, as rarely occurs with prosthetic materials, the prosthesis is relatively immune to bacteremic infection. The sources of transient bacteremia are well known to be urinary catheters, intravenous cannulas, pulmonary infection, carious teeth, and ischemic ulcerations of the legs; these sources probably cause the infections that appear months after operation in some patients. Prophylactic administration of antibiotics is advisable 660
during illness or procedures with transient bacteremia.
known to be associated
Summary
Seven patients with infected vascular prostheses in the femoral region were treated by removal of the prosthesis and extraanatomic reconstruction by way of the obturator foramen. Because the operation avoided entry into the infected area, it was considered the best surgical treatment for these patients. Although catastrophic hemorrhage and systemic sepsis were averted, amputation was eventually necessary in five patients, usually because of severe arteriosclerotic disease in distal arteries. Short-term benefit was gained by only two patients. The prevention of infection demands intensive preoperative preparation using prophylactic antibiotics and meticulous operating room technic. References 1. Shaw RS, Baue AE: Management of sepsis complicating arterial reconstructive procedures. Surgery53: 75, 1983. 2. Guida PM, Moore SW: Obturator bypass technique. Surg Gynecol Obstet 128: 1307, 1989. 3. Szilagyi DE, Smith RF, Elliott FP. Vrandecic MP: Infection in arterial reconstruction with synthetic grafts. Ann Surg 178: 321, 1972. 4. Fry WJ. Lindenauer SM: Infection complicating the use of plastic arterial implants. Arch Surg 94: 800, 1987. 5. Conn JH, Hardy JD, Chavez CM. Fain WR: Infected arterial grafts: experience with 22 cases with emphasis on unusual bacteria and technics. Ann Surg 171: 704, 1970. 8. Liekweg WG JR, Greenfield LJ: Vascular prosthetic infections: collected experience and results of treatment. Surgery 81: 335.1977. 7. Goldstone J, Moore WS: Infection in vascular prostheses. Clinical manifestations and surgical management. Am J Surg 128: 225. 1974. 8. DiGiglia JW, Leonard GL. Ochsner JL: Local irrigation with antibiotic solution in the prevention of infection in vascular prostheses. Surgery87: 838, 1970. 9. DePalma RG, Hubay CA: Arterial bypass via the obturator foramen. An alternative in complicated vascular problems. Am J Surg 115: 323, 1988. 10. Spiro M, Cotton LT: The obturator canal as a route for iliofemoral bypass. Br J Surg 57: 188, 1970. 11. Mahoney WD, Whelan TJ: Use of obturator foramen in iliofemoral artery grafting-case reports. Ann Surg 183: 215, 1988. 12. Smith R, Perdue G, Hyatt H, Ansley J: Management of infected aortofemoral prosthesis including use of an axillopopliteal bypass. Am Surg 42: 85, 1977. 13. Leather RP, Karmody AM: A lateral route for extra-anatomical bypass of the femoral artery. Surgery 81: 307, 1977. 14. Jacobson JH II, McAllister FF: The harmful effect of arterial grafting on existing collateral circulation. Surgery42: 148. 1957. 15. Richardson RL Jr, Pate JW, Wolf RY, Ledes C, Hopson WB: The outcome of antibiotic-soaked arterial grafts in guinea pig wounds contaminated with E. coli or Staph aureus. J Thorac Cardiovasc Surg 59: 835. 1970. 18. Malone JM, Moore WS, Campagna G, Bean B: Bacteremic infectability of vascular grafts: the influence of pseudointimal integrity and duration of graft function. Surgery 78: 211, 1975. The American Journal of Surgery
