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A modified classification and approach to the management of infections involving peripheral arterial prosthetic grafts
A modified classification and approach management of infections involving peripheral arterial prosthetic grafts
to
the
Russell H. Samson, M D , Frank J. Veith, M D , Gary S. Janko, M D , Sushil K. Gupta, M D , and Larry A. Scher, M D , New York, N . Y . During the past 15 years, we have employed a modified classification and management plan to treat infections involving nonaortic peripheral arterial prosthetic grafts (PAPGs) without graft removal whenever possible. Sixty-eight infected wounds potentially involving PAPGs were initially treated by excision of necrotic and infected wound tissue in the operating room (wound excision). This was sufficient for all 34 minor infections that did not directly involve the graft. In the 34 remaining infected wounds with graft involvement (major infections), partial removal of a PAPG in 13 cases allowed preservation for up to 15 years of a functioning arterial segment and its collaterals. Ten other grafts were entirely saved. Only 11 of 34 major graft infections ultimately required total graft removal. This approach to infection complicating PAPGs resulted in only two deaths (6%) and directly led to limb loss or amputation at a higher level in eight patients (24%), Total removal of an infected PAPG is often unnecessary and may increase mortality and morbidity. (I VAsc SURG 1988;8:147-53.)
Although there are anecdotal reports to the contraiT, conventional therapy for infected prosthetic arterial grafts involves total graft excision with autogenous or extraanatomic reconstruction. This treatment approach is primarily based on data derived from the management of a0rtoiliac or aort0femoral graft infections and limited specific data are available regarding prosthetic graft infections in other anatomic locations. Fifteen years ago, we 1 began to explore the hypothesis that graft removal was not always required or optimal, even when a graftto-artery anastomosis of an infected arterial pros,thetic graft was surrounded by purulence. On the basis of our early experience, we have developed an approach to infected wounds surrounding nonaortic peripheral arterial prothetic grafts (PAPGs). This article reports our experience with this modified classification and approach to the management of infected arterial grafts located distal to the clavicle or inguinal ligament. METHOD
The records of 68 patients who were treated for infection related to a PAPG at our hospitals from From the Division of Vascular Surgery, MontefioreMedicalCenter, Bronx Municipal Hospital Center and the Albert Einstein College of Medicine. Supported in part by agrant from the Manning Foundation. Reprint requests:Frank J. Veith, MD, MontefioreMedicalCenter, 111 East 210 St., New York, NY 10467.
January 1972 through May 1985 were reviewed and analyzed. Grafts for hemodialysis access and those involving the aorta or its intrabdominal branches were excluded. Classification o f graft infection
Infection o f wounds containing 68 PAPGs (66 polytetrafluoroethylene [PTFE] and two Dacron) were classified according t o the depth o f infection and degree of graft involvement: group I: infections (purulence and bacteria) extended no deeper than the dermis (20 cases); group II: infections involved subcutaneous tissue but did not come i n grossly 0bservable direct contact with the graft (14 cases); group iII: infections involved the body of the graft but not an anastomosis (five cases); group IV: infections surrounded an exposed anastomosis but bacteremia or anastomotic bleeding had not occurred (25 cases); group V: infections involved a graft-toartery anastomosis and were associated with septicemia and/or anastomotic bleeding at the time of presentation (four cases). All 34 "minor" infections (groups I and II) were adequately and completely healed by operative debridement, local wound care, and intravenous antibiotics. The rest of this article deals only with the five group III, 25 group iV, and four group V infections, making a total of 34 grafts involved by what we term major graft infections. Included in this experience were 21 men and 13 women with an age 147
Journal of VASCULAR SURGERY
148 Samson et al.
Table I. Location of graft in which major infection ultimately developed
Table II. Bacteriology of graft infections No. No.
Femoropopliteal Femoral-anterior tibial Femoral-posterior tibial Femorofemoral Axillofemoral Axillopopliteal Sequential femoropopliteal-tibial Popliteal- anterior final Total
9 8 5 4~ 4 1 2 1 34
*One graft was extemal iliac-femoral and was placed entirely through an infrainguinal approach.
distribution of 60 to 91 years (mean 71 years). Sixteen patients were diabetic. Thirty-two of the grafts were expanded PTFE and two were Dacron fabric. Twenty-six of the patients had had one or more previous ipsilateral vascular reconstructive operations before the one in which the infection was noted (mean 2.7, median 2, range zero to six vascular operations involving the same operative area). The anatomic placements of the grafts that ultimately became infected are listed in Table I. Infection manifested itself from 3 days to 300 weeks after the first or original vascular reconstruction (median 12 weeks, mean 56 weeks). The onset of infection from the last vascular operation varied from 3 days to 79 weeks (median 2 weeks, mean 10 weeks). Sixteen of the 34 patients (47%) had infected toe or foot lesions at the time of their last vascular reconstruction before graft infection. The bacterial organisms that were cultured are listed in Table II. A single organism was encountered in 24 cultures and multiple organisms in 10. Antibiotic prophylaxis was routinely used during the study period. A cephalosporin antibiotic was usually given intravenously the night before operation, intraoperatively, and for the first 24 hours postoperatively. Patients who had infected pedal lesions at the time of surgery were given an antibiotic effective against cultured organisms. The actual incidence of infection complicating peripheral arterial reconstructions performed in our institutions was difficult to assess because of inadequate record keeping in one period of the study, 1972 to 1975. However, of the 34 major infections (groups III, IV, and V), 26 complicated surgery primarily performed in our institution and eight were referred to us for management of a wound infection involving an arterial graft that had been inserted elsewhere. In a review of 592 infrainguinal reconstructions (fern-
Pseudomonas aeruginosa Staphylococcus aureus Proteus mirabilis Enterococcus S. epidermidis Serratia marcescens J~-Hemolytic streptococcus IGebsiella pneumoniae Escherichia coli Corynebacterium Acinetobacter Streptococcusfaecalis Bacteroides fragilis Morganella n~rganii
18 17 3 3 3 2 2 1 2 I 1 1 1 1
oropopliteal and femorotibial) that we performed between November 1975 and March i983, 12 patients had infections of grade III severity or greater for a major infection rate of 2%. Of these, only three had the graft infection after a primary vascular reconstruction, for a major infection rate in primary arterial operations of 0.5%. 2 During a similar period, 57 axillofemoral and 44 femorofemoral bypasses were performed, with only one patient having a grade HI groin infection, thereby providing a major infection rate of i% for these operations. Management protocol W o u n d excision. If the presentation was soft tissue infection with or without obvious graft involvement, wide debridement of all infected and necrotic tissue was accomplished in the operating room with the patient under general or regional anesthesia. This was done for therapeutic reasons and to allow accurate classification. Every effort was made to preserve functioning grafts even when the graft and any graft-to-artery anastomosis was exposed and surrounded by purulent material. Open wounds were managed by daily minor debridement and frequent (every 4 to 6 hours) irrigations and/or dressing changes with 0.1% kanamycin in saline solution or a povidone-iodine solution. Continuous irrigation was not done. Repeat operative debridement was performed as necessary; final wound closure was accomplished by granulation and secondary closure, split-thickness skin grafts, or myocutaneous flaps. Constant intensive care nursing and observation were required because sudden hemorrhage was a threat and in reality occurred in two patients. If the infection involved a graft tunnel, the wound was widely incised and debrided. Smear for Gram stain and aero-
Volume 8 Nuraber 2
Infected prosthetic arterial grains 149
August1988
Table I l L Summary of treatment and outcome of 34 major graft infections in groups III, IV, and V Initial treatment
Ultimate treatment or outcome
No. of patients
Total graft salvage
Partial graft removal
Total graft removal
Total graft salvage
Partial graft removal
Total graft removal
Amputation*
Deaths
IV
5 25
5 6
0 19
0 0
4 6
1 (1)t 12
0 7 (1)~-
0 7
0 2
V
__4
O
O
4
O
O
4 (3)t
!
0
34
11
19
4
10
13
11
8
2
Group No.
III Total
*Amputations or repeat amputation at a higher level directly resulting from treatment of infection. An additional 10 amputations had been required for graft thrombosis before the onset of graft infection. tNumbers in parentheses indicate the number of patients who required an arterial reconstruction in a noninfectcd field to maintain limb viability or maintain healing of a below-knee amputation stump.
bic and anaerobic cultures were taken during surgical debridement and appropriate antibiotics were started as soon as culture results were available. Total graft salvage. As shown in Table III, 11 patients were treated initially by complete preservation of the infected PAPG (five in group Ili, six in group IV). When infection occurred, one of these grafts in group III was known to be thrombosed. The remaining 10 grafts treated in this fashion were patent and functional at the time the infection was detected and treated. Partial graft removal. Often total graft removal of an infected thrombosed graft would have necessitated obliteration of the adjacent donor artery and its collaterals. However, if anastomotic bleeding had not occurred and the artery adjacent to the anastomosis was not obviously infected at the time of wound excision, a small oversewn stump of graft was left attached at the site of the original anastomosis. This allowed preservation of arterial flow into critical distal vessels such as the axillary or deep femoral arteries, thereby preventing more severe distal ischcmia. Furthermore, the complexity of the surgery required to treat the graft infection was greatly re; duced and operative time was shortened. Because of these considerations, partial graft removal was used as the initial treatment in 19 of the patients with major graft infections (Table III). All were group IV infections in which an artery-to-graft anastomosis was involved, and all grafts so treated were thrombosed at the time of their partial removal as initial treatment. Total graft removal. Total graft removal was performed as the initial treatment for the four group V infections (Table III). All these grafts were fimctional at the time that the graft infection manifested and all limbs were viable. Three required perfor-
mance of a secondary extraanatomic prosthetic graft in a clean operative field to assure continued limb viability. RESULTS Results of this classification and management plan in the treatment of major PAPG infection are summarized in Table III. Treatment bascd on the initial classification alone was sufficient to eradicatc all evidence of major infection in 25 of the 34 patients with major graft infection. During a follow-up period of 1 to 15 years (mean 4 years) none of these 25 patients had subsequent complications directly related to this management of their graft infection. In the remaining nine patients, one with group III infection and eight with group IV graft infections had treatment complications or progression of the infection despite initial management by this protocol. One of these patients died and the other eight required further operative treatment consisting of partial (one case) or total (seven cases) graft removal. This progression became apparent within 5 months of the original graft salvage, wound excision operation. Total graft salvage. Of the 11 graft infections initially treated by total graft salvage, only one patient with a group III graft infection ultimately required excision of most of the midportion of a functioning external iliac-femoral graft originally placed via an infrainguinal approach. It was replaced by an extraanatomic PTFE graft, which was routed through a clean field and which resulted in limb salvage and eradication of the infection with follow-up for more than 2 years. Anastomotic involvement never occurred. No patient required an amputation as a direct result of this form of treatment for graft infection, although one other patient with group 11I infection had a below-knee amputation for uncontrolled foot infec-
lournal of VASCULAR SURGERY
150 Samson et al.
Table IV. Amputations, patient survival, and extremiqr preservation related to infection grade and salvage of all or a portion of the infected graft
Infection group
III
1V
V Total
Major amputation ~ (No. ofpatients)
Major repeat amputation s (No. ofpatients)
1 (BK)
0
0
4
4
1
0
0
0
1
I
6
0
0
0
6
6
3 (2 BK, 1 AK)
0
11
i1
6
1
Ultimate treatment
No. of patients
Total graft salvage Partial graft removal Total graft salvage Partial graft removal Total graft removal Total graft removal
4
12
Previouslimb loss (No. of patients)
Patient survival (No. of patients)
Salvage of all or a major portion of involved limb (No. of patients)
2 (AK)
2 (AK)
4
5 (3 BK, 2 AK) 4 (2 BK, 2 AK) O
1 (BK)
0
4
3
34
10
6
2
32 (94%)
26 (81%)
7
BK, Below-knee;AK, above-knee. ~Amputation resulting from treatment. tion before the graft infection became apparent. This was the only amputation required in the five patients with a group III infection or in the six group IV infections with patent grafts treated by total graft salvage. Moreover, no deaths occurred in any of the 11 patients so treated (Table III). Partial graft removal. O f the 19 patients with group IV infected grafts initially treated by partial graft removal, seven ultimately required total graft removal (37%). The remaining 12 infected occluded grafts ultimately treated by partial graft excision had the following outcome: Five were already associated with a major lower extremity amputation (three below-knee and two above-knee). However, preservation of a portion of the graft on the common femoral artery in all five patients permitted salvage of an important portion of the extremity by preserving direct flow to the deep femoral artery. In the remaining seven patients who had manifested a group IV infection in an occluded graft, partial graft excision permitted preservation of a portion of the graft with maintenance of circulation to the arm or thigh via the axillary or common and deep femoral arteries. The involved limb (one upper and three lower) was saved in four patients. Although a major amputation of the involved lower limb was required in the three other patients (two below-knee and one above-knee), the level of amputation was lowered and preservation of an important portion of the extremity was possible because of the maintained arterial flow. There was one death in this group of i2 patients (discussed later).
Thus the treatment of major graft infection by partial graft removal was effective as definitive treatment in l I , or 58%, of the 19 cases in which it was initially attcmptcd. When this was the only form of treatment required, it resulted in one death and major limb loss in 3 of 12 patients. However, it permitted simplified maintenance of sufficient arterial flow to save all (five cases) or an important portion (seven cases) of the involved extremity. In the 20 patients in w h o m partial graft removal was attempted as definitive treatment of a major graft infection (19 initial and one ultimate), there were two deaths (10%). One patient bled from the graft remnant-femoral arte U anastomosis. This necessitated total graft removal and ligation of all femoral vessels. The paticnt ultimately died of general cachexia and sepsis after a high above-knee amputation that failed to heal. The other patient, whose graft infection was controlled, died of an aplastic agranulocy~osis from the antibiotic ticarcillin. Total graft removal. As already described, the four group V infections were initially treated by total graft removal, and an additional seven group IV infections treated originally by" partial graft removal ultimately required and were treated by total removal of the graft remnant (Table III). Four of these I1 grafts (all group V infections) were patent at the time of infection and initial treatment by total graft removal. One limb remained viable without the need for further arterial reconstruction. A new extraanatomic PTFE graft placed in a noninfected field saved two of three limbs in which
Volume 8 Number 2 August 1988
Such treatment was attempted. Thus only one limb required a major below-knee amputation in this setting and this occurred when the extraanatomic bypass performed after total removal of an infected patent graft failed. No deaths occurred among these four patients. There were seven patients with occluded grafts and group IV infections initially treated by partial graft removal whose treatment failed and who required total graft removal. Treatment in three cases failed because of anastomotic bleeding and in four cases the failure was due to the lack of healing of a groin wound. Two of these seven patients had already undergone above-knee amputation. Of the remaining five patients, one patient had the lower extremity saved by placement of an extraanatomic PTFE graft in a clean field after an autogcnous vein graft placed in the infected field disrupted and bled. There was one death as described earlier. The other three patients, two of whom had already had belowknee amputation, all ultimately required an aboveknee amputation. Thus, when treatment of graft infection by total removal of an occluded graft was required after failure of partial graft removal, the leg could only be saved in One case and treatment of the graft infection directly resulted in four above-knee amputations and one death. Mortality. In the entire group of major graft infections treated by this approach, there were two deaths. Thus the overall mortality rate was 6%. Amputation. As shown in Table IV, overall 10 amputations (six below-knee and four above-knee) had been required before graft infection became apparent. Ultimately, six other patients required a major amputation and two patients with previous amputations required revision to a higher level as a result Of the treatment of the infected PAPG. Thus, although the overall amputation rate was 47%, amputation or repeat amputation at a higher level as a direct result of treatment occurred in only 8 of 34 patients (24%); salvage of all or a major portion of the patient's limb was made possible by use of our protocol in 26 of 32 surviving patients (81%) with major graft infection. DISCUSSION Management of prosthetic graft infections is complicated by the many variables that may affect outcome. Because graft infection is fortunately an infrequent complication, most investigators do not gain a large experience with such patients. Accordingly, most reports combine experience with infections related to different graft materials and graft locations.
Infected prosthetic arterialgrafts 151 It is conceivable that basic tenets and dictums that apply to management of infected aortic grafts do not necessarily apply to infected PAPGs. In fact, a literature review demonstrates a difference in the final outcome for graft infection depending on the original site of graft insertion. The mortality rate for infected aortofemoral bypasses is higher than that for infected PAPGs such as femoropopliteal, femorofemoral, or axillofemoral bypassesY However, the amputation rate appears higher with infection of PAPGs treated by standard methods with total graft excisionY Fifteen years ago, we 1 realized that in the periphery, total graft excision necessitated difficult complex revascularization procedures and even with these often resulted in high thigh amputation and Sometimes the death of the patient. Furthermore, total excision in many cases required sacrifice of the proximal donor or inflow artery, thereby significantly compromising distal collateral flow. Accordingly, in patients in whom graft infection had occurred but in whom infection of the host artery or graft wall was not obviously present (as manifested by either septicemia or bleeding), attempts were made either to preserve the graft entirely or partially. Such partial graft excision was easier to perform and often permitted preservation of the proximal donor artery and its collaterals so that urgent complex revascularization was not required. This selective approach to arterial graft infection was also supported by an earlier report by Carter et al.6 Subsequently, several other authors 7-I4 have also suggested nonexcisional treatment of infected g~afts. Furthermore, our experience in the management of infected PTFE hemodialysis access grafts has shown the benefits of such nonexcisional treatment particularly when the graft is still patent, is The data presented in this article show that, by adhering to the management approach outlined, it is often possible to save all or a critical portion of a PAPG that is involved by infection and that such graft salvage may be maintained up t o 15 years. Crucial to this approach is the performance of operative debridement of the associated infected wound. This procedure, which is always performed with the patient under anesthesia in the operating room, cannot be termed conservative. Rather it is a radical debridement of all grossly infected, necrotic soft tissue from the wound, a procedure we describe as wound excision. This is not only therapeutic in facilitating elimination of the infection, it also has diagnostic value and permits accurate application of our new, modified classification scheme. This in turn determines prognosis and further treatment.
152 Samsonet al.
Minor infections (groups I and II) are analogous to grade I and grade II infections described by Szilagyi et al. a in 1972. These minor infections involve only the dermis and subcutaneous tissue of the wound containing the arterial prosthesis, but the graft itself is not in contact with purulence or involved directly by the infection. Once the extent o f these minor infections is known, the treatment is simple and consists of antibiotics, local wound care with povidone-iodine solution dressings, and subcutaneous wound closure by second intention or, rarely, skin grafts. The prognosis for healing and continned graft function is uniformly good. The wound excision operation also allows diagnosis of a major graft infection in which purnlence comes in contact with the graft. These major graft infections are analogous to the grade Ili infections of Szilagyi et al.3 for which complete graft removal is widely thought to be necessary. Wound excision facilitates further subdivision of these major graft infections in a way designed to define which grafts must be excised and which grafts may be totally or partially saved. Our modified classification system divides major infections into three groups with different prognoses and requiring different treatments. Group III infections involve the body of the graft but not a graft-artery anastomosis. Others s'7-~2 have reported successful treatment 0fsuch infections without removal of the graft, and our experience confirms that graft salvaging techniques can be used successfully for such infections with a low risk to life and limb. Our group V graft infections are manifested either by signs of arterial or anastomotic bacterial involvement such as anastomotic bleeding or septicemia with positive blood cultures, or, at the time of wound excision, by evidence of arterial wall softening such as loose sutures or discoloration of the artery at the anastomosis. Standard treatment consisting of total graft removal with arterial ligation proximal and distal to the sites of anastomosis is mandatory for such group V infections. Some form of remote extraanatomic revascularization with a new prosthetic graft is usually- required for limb salvage and this can be performed before or after graft removal. Aside from facilitating earlier diagnosis in some cases at the time of wound excision, our management plan contributes little that is new to patients with this type of graft infection. Although some authors 16'17recommend anatomic arterial reconstruction with autogenous grafts or patches to permit total excision of the prosthetic graft, we are reluctant to
Journal of VASCULAR SURGERY
use this approach if anastomotic involvement with bleeding has occurred. We believe that this implies a virulent infection with arterial wall involvement and suggests that a repeat anastomosis or local autogenous repair in the infected field has a high likelihood of disrupting again. Such suture line disruption occurred in one of our patients and in 8 of 14 patients with positive arterial wall cultures reported by Macbeth et al. 18 Group IV infections were those with purulent material in direct contact with the prosthetic graft at an artery-to-graft anastomosis. This type of infection was the commonest in our series and afflicted 74% of our 34 patients with major graft infection. It is also the type of infection for which our modified approach to classification and management offers some potential benefit in terms of simplifying treatment and improving results. Salvage of an infected functioning patent graft may greatly simplify treatment and avoid the complex revascularization procedure that would be required if the graft was totally excised. Similarly, salvage of a portion of an infected nonfunctioning thrombosed graft may maintain the flow through a patent inflow or outflow artery and the perfusion of important collateral vessels arising from it. This is particularly true when the common femoral artery was used to provide inflow for a distal bypass. In this case the maintenance of normal flow to the deep femoral artery is crucial for sustaining viability of all or a portion of the limb. One risk of leaving all or a part of a graft in place when purulence surrounds an anastomosis is that bleeding from this site may occur; a second risk is that healing will not take place. These undesirable events occurred in seven of our 19 patients (37%) with group IV infections of a thrombosed graft, a portion of which was left in the infected field. They never occurred in the six patients with grade IV infections of patent grafts, all of which were left in place. Thus our graft salvage approach to grade IV infections was locally successful in 18 of the 25 instances (72%) in which it was attempted. Despite this relatively good success rate, this approach has some obvious disadvantages. First, it failed to ablate the infection in 28% of attcmpts. Healing could not be obtained in four cases, and bleeding occurred in three. If the graft or a portion of it is left in place attached to a functioning arterial segment, the patient must be constantly observed for bleeding until the wound is healed. This may require several weeks of costly hospitalization and intensive care. In the present series, although anastomotic
Volume 8 Number 2 August 1988
bleeding occurred in three patients, none exsanguinated; only one patient's death could be related even remotely to this event. Although this graft preservation approach was successful in achieving healing in 22 of the 30 group III and group IV infections (73%) in which its use was attempted, it is difficult to be certain that this form of treatment is superior to more standard graft excision methods. The overall amputation and higher repeat amputation rate for treatment of major graft infection was 24%. The partial or complete limb salvage rate with the described graft preservation approach to major graft infections was 81%. These rates compare favorably with statistics from series treated by more standard methods. However, the relatively small numbers of patients in various series and the influence of many other variables prevent conclusive comparisons. The same difficulties prevent comparison of mortality rates, although the 6% overall mortality rate associated with treatment of major graft infections with our graft preservation approach when feasible also compares favorably with mortality rates associated with infected PAPGs treated in more standard fashion. Although the modified classification and treatment plan described herein has been used primarily on infected PAPGs, some may wonder whether it could be used to simplify the treatment of infected intraabdominal grafts. To date we have used the same principles selectively in two very poor-risk patients. In one a small stump of an infected Dacron graft was left attached to the aorta; in the other a similar graft stump was left attached to the proximal external iliac artery. Healing of wounds and preservation of arterial continuity have been maintained for 3 and 5 years, respectively. However, the larger size and impaired accessibility of retroperitoneal arteries for wound care and control mandate that this approach to infections of grafts to these arteries be viewed with skepticism and used only with the utmost caution. Even in peripheral arteries, our modified treatment plan has risks and disadvantages that must be weighed before its use is attempted in the management of major graft infections. Finally, since graft preservation treatment was not uniformly successful in managing group IV graft infections with thrombosed grafts, it would be helpful if methods could be developed to predict cases in which this new approach was destined to succeed or fail. Such methods and accurate comparisons of results with the graft salvage approach and more standard treatment plans demand further investigation.
Infected prosthetic arterial grafts
153
However, the greater simplicity of this modified approach, its feasibility in 89% of our major graft infections, and its effective results in 73% of the 30 patients in whom it was attempted establish it as a reasonable alternative to standard methods of treatment for infected PAPGs. REFERENCES
1. Veith H- Surgery of the infected aortic graft. In: Bergan IJ, Yao JST, eds. Surgery of the aorta and its body branches. New York: Grune & Stratton, Inc, 1979:532-3. 2. Veith FJ, Gupta SK, Samson RH, et al. Progress in limb salvage by reconstructive arterial surgery combined with new or improved adjunctive procedures. Ann Surg 1981; 194:336401. 3. Szilagyi DE, Smith RF, Elliot JP, Vrandecic MP. Infection in arterial reconstruction with synthetic grafts. Ann Surg 1972;176:321-33. 4. Bunt TJ. Synthetic vascular graft infections. I. Graft infections. Surgery 1983;93:733-46. 5. Liekweg WG Jr, Greenfield LJ. Vascular prosthetic infections: collected experience and results of treatment. Surgery 1977; 81:335-42. 6. Carter SC, Cohen A, Whelan TJ. Clinical experience with management of the infected Dacron graft. Aim Surg 1963; 158:249-55. 7. Kwaan JHM, Counolly JE. Successful management of prosthetic graft infection with continuous povidone-iodine irrigation. Arch Surg 1981;116:716-20. 8. Popovsky J, SingerS. Infected prosthetic grafts: localtherapy with graft preservation. Arch Surg 1980;115:203-5. 9. Johansen H, Hipp R. Healing of exposed prosthetic vascular grafts by vigorous wound care and povidone-iodine. Vase Surg 1981;15:421-4. 10. Schaberg FJ, Wong R, Phillips MR, Healey EH, Healey PJM. Management of draining wounds in vascular surgery. Vasc Surg 1982;16:213-8. 11. Casali RE, Tucker WE, Thompson BW, Read RC. Infected prosthetic grafts. Arch Surg 1980;115:557-80. 12. Hepp W, Schulze T. The management of infected grafts in reconstructive vascular surgery. Thorac Cardiovasc Surg 1986;34:265-8. 13. Sweeney TF, Piorkowski R, Ariyan S, Kerstein M. An alternative in the management of the infected vascular prosthesis. Vase Surg 1983;17:195-8. 14. Ehrenfeld WK. Prosthetic vascular graft infection. In: Hairnovici H, ed. Vascular emergencies. New York: AppletonCentury-Crofts, 1982:515-6. 15. Bhat DJ, Tellis VA, Kohlberg WI, Driscoll B, Veith FJ. Management of sepsis involving expanded polytetrafluoroethylene grafts for hemodialysis access. Surgery 1980;87:445-50. 16. Reilly LM, Altman H, Lusby RJ, Kersh RA, Ehrenfeld WK, Stoney RJ. Late results following surgical management of vascular graft infection. J Vase SuRe 1984;1:36-44. 17. Seeger JR, Wheeler JR, Gregory RT, Snyder SO, Gayle RG. Autogenous graft replacement of infected prosthetic grafts in the femoral position. Surgery 1983;93:39-45. 18. Macbeth GA, Rubin JR, McIntyre ICE Jr, Goldstone J, Malone JM. The relevance of arterial wall microbiology to the treatment of prosthetic graft infections: graft infection vs arterial infection. J Vasc SURG 1984;1:750-4.
to
the
Russell H. Samson, M D , Frank J. Veith, M D , Gary S. Janko, M D , Sushil K. Gupta, M D , and Larry A. Scher, M D , New York, N . Y . During the past 15 years, we have employed a modified classification and management plan to treat infections involving nonaortic peripheral arterial prosthetic grafts (PAPGs) without graft removal whenever possible. Sixty-eight infected wounds potentially involving PAPGs were initially treated by excision of necrotic and infected wound tissue in the operating room (wound excision). This was sufficient for all 34 minor infections that did not directly involve the graft. In the 34 remaining infected wounds with graft involvement (major infections), partial removal of a PAPG in 13 cases allowed preservation for up to 15 years of a functioning arterial segment and its collaterals. Ten other grafts were entirely saved. Only 11 of 34 major graft infections ultimately required total graft removal. This approach to infection complicating PAPGs resulted in only two deaths (6%) and directly led to limb loss or amputation at a higher level in eight patients (24%), Total removal of an infected PAPG is often unnecessary and may increase mortality and morbidity. (I VAsc SURG 1988;8:147-53.)
Although there are anecdotal reports to the contraiT, conventional therapy for infected prosthetic arterial grafts involves total graft excision with autogenous or extraanatomic reconstruction. This treatment approach is primarily based on data derived from the management of a0rtoiliac or aort0femoral graft infections and limited specific data are available regarding prosthetic graft infections in other anatomic locations. Fifteen years ago, we 1 began to explore the hypothesis that graft removal was not always required or optimal, even when a graftto-artery anastomosis of an infected arterial pros,thetic graft was surrounded by purulence. On the basis of our early experience, we have developed an approach to infected wounds surrounding nonaortic peripheral arterial prothetic grafts (PAPGs). This article reports our experience with this modified classification and approach to the management of infected arterial grafts located distal to the clavicle or inguinal ligament. METHOD
The records of 68 patients who were treated for infection related to a PAPG at our hospitals from From the Division of Vascular Surgery, MontefioreMedicalCenter, Bronx Municipal Hospital Center and the Albert Einstein College of Medicine. Supported in part by agrant from the Manning Foundation. Reprint requests:Frank J. Veith, MD, MontefioreMedicalCenter, 111 East 210 St., New York, NY 10467.
January 1972 through May 1985 were reviewed and analyzed. Grafts for hemodialysis access and those involving the aorta or its intrabdominal branches were excluded. Classification o f graft infection
Infection o f wounds containing 68 PAPGs (66 polytetrafluoroethylene [PTFE] and two Dacron) were classified according t o the depth o f infection and degree of graft involvement: group I: infections (purulence and bacteria) extended no deeper than the dermis (20 cases); group II: infections involved subcutaneous tissue but did not come i n grossly 0bservable direct contact with the graft (14 cases); group iII: infections involved the body of the graft but not an anastomosis (five cases); group IV: infections surrounded an exposed anastomosis but bacteremia or anastomotic bleeding had not occurred (25 cases); group V: infections involved a graft-toartery anastomosis and were associated with septicemia and/or anastomotic bleeding at the time of presentation (four cases). All 34 "minor" infections (groups I and II) were adequately and completely healed by operative debridement, local wound care, and intravenous antibiotics. The rest of this article deals only with the five group III, 25 group iV, and four group V infections, making a total of 34 grafts involved by what we term major graft infections. Included in this experience were 21 men and 13 women with an age 147
Journal of VASCULAR SURGERY
148 Samson et al.
Table I. Location of graft in which major infection ultimately developed
Table II. Bacteriology of graft infections No. No.
Femoropopliteal Femoral-anterior tibial Femoral-posterior tibial Femorofemoral Axillofemoral Axillopopliteal Sequential femoropopliteal-tibial Popliteal- anterior final Total
9 8 5 4~ 4 1 2 1 34
*One graft was extemal iliac-femoral and was placed entirely through an infrainguinal approach.
distribution of 60 to 91 years (mean 71 years). Sixteen patients were diabetic. Thirty-two of the grafts were expanded PTFE and two were Dacron fabric. Twenty-six of the patients had had one or more previous ipsilateral vascular reconstructive operations before the one in which the infection was noted (mean 2.7, median 2, range zero to six vascular operations involving the same operative area). The anatomic placements of the grafts that ultimately became infected are listed in Table I. Infection manifested itself from 3 days to 300 weeks after the first or original vascular reconstruction (median 12 weeks, mean 56 weeks). The onset of infection from the last vascular operation varied from 3 days to 79 weeks (median 2 weeks, mean 10 weeks). Sixteen of the 34 patients (47%) had infected toe or foot lesions at the time of their last vascular reconstruction before graft infection. The bacterial organisms that were cultured are listed in Table II. A single organism was encountered in 24 cultures and multiple organisms in 10. Antibiotic prophylaxis was routinely used during the study period. A cephalosporin antibiotic was usually given intravenously the night before operation, intraoperatively, and for the first 24 hours postoperatively. Patients who had infected pedal lesions at the time of surgery were given an antibiotic effective against cultured organisms. The actual incidence of infection complicating peripheral arterial reconstructions performed in our institutions was difficult to assess because of inadequate record keeping in one period of the study, 1972 to 1975. However, of the 34 major infections (groups III, IV, and V), 26 complicated surgery primarily performed in our institution and eight were referred to us for management of a wound infection involving an arterial graft that had been inserted elsewhere. In a review of 592 infrainguinal reconstructions (fern-
Pseudomonas aeruginosa Staphylococcus aureus Proteus mirabilis Enterococcus S. epidermidis Serratia marcescens J~-Hemolytic streptococcus IGebsiella pneumoniae Escherichia coli Corynebacterium Acinetobacter Streptococcusfaecalis Bacteroides fragilis Morganella n~rganii
18 17 3 3 3 2 2 1 2 I 1 1 1 1
oropopliteal and femorotibial) that we performed between November 1975 and March i983, 12 patients had infections of grade III severity or greater for a major infection rate of 2%. Of these, only three had the graft infection after a primary vascular reconstruction, for a major infection rate in primary arterial operations of 0.5%. 2 During a similar period, 57 axillofemoral and 44 femorofemoral bypasses were performed, with only one patient having a grade HI groin infection, thereby providing a major infection rate of i% for these operations. Management protocol W o u n d excision. If the presentation was soft tissue infection with or without obvious graft involvement, wide debridement of all infected and necrotic tissue was accomplished in the operating room with the patient under general or regional anesthesia. This was done for therapeutic reasons and to allow accurate classification. Every effort was made to preserve functioning grafts even when the graft and any graft-to-artery anastomosis was exposed and surrounded by purulent material. Open wounds were managed by daily minor debridement and frequent (every 4 to 6 hours) irrigations and/or dressing changes with 0.1% kanamycin in saline solution or a povidone-iodine solution. Continuous irrigation was not done. Repeat operative debridement was performed as necessary; final wound closure was accomplished by granulation and secondary closure, split-thickness skin grafts, or myocutaneous flaps. Constant intensive care nursing and observation were required because sudden hemorrhage was a threat and in reality occurred in two patients. If the infection involved a graft tunnel, the wound was widely incised and debrided. Smear for Gram stain and aero-
Volume 8 Nuraber 2
Infected prosthetic arterial grains 149
August1988
Table I l L Summary of treatment and outcome of 34 major graft infections in groups III, IV, and V Initial treatment
Ultimate treatment or outcome
No. of patients
Total graft salvage
Partial graft removal
Total graft removal
Total graft salvage
Partial graft removal
Total graft removal
Amputation*
Deaths
IV
5 25
5 6
0 19
0 0
4 6
1 (1)t 12
0 7 (1)~-
0 7
0 2
V
__4
O
O
4
O
O
4 (3)t
!
0
34
11
19
4
10
13
11
8
2
Group No.
III Total
*Amputations or repeat amputation at a higher level directly resulting from treatment of infection. An additional 10 amputations had been required for graft thrombosis before the onset of graft infection. tNumbers in parentheses indicate the number of patients who required an arterial reconstruction in a noninfectcd field to maintain limb viability or maintain healing of a below-knee amputation stump.
bic and anaerobic cultures were taken during surgical debridement and appropriate antibiotics were started as soon as culture results were available. Total graft salvage. As shown in Table III, 11 patients were treated initially by complete preservation of the infected PAPG (five in group Ili, six in group IV). When infection occurred, one of these grafts in group III was known to be thrombosed. The remaining 10 grafts treated in this fashion were patent and functional at the time the infection was detected and treated. Partial graft removal. Often total graft removal of an infected thrombosed graft would have necessitated obliteration of the adjacent donor artery and its collaterals. However, if anastomotic bleeding had not occurred and the artery adjacent to the anastomosis was not obviously infected at the time of wound excision, a small oversewn stump of graft was left attached at the site of the original anastomosis. This allowed preservation of arterial flow into critical distal vessels such as the axillary or deep femoral arteries, thereby preventing more severe distal ischcmia. Furthermore, the complexity of the surgery required to treat the graft infection was greatly re; duced and operative time was shortened. Because of these considerations, partial graft removal was used as the initial treatment in 19 of the patients with major graft infections (Table III). All were group IV infections in which an artery-to-graft anastomosis was involved, and all grafts so treated were thrombosed at the time of their partial removal as initial treatment. Total graft removal. Total graft removal was performed as the initial treatment for the four group V infections (Table III). All these grafts were fimctional at the time that the graft infection manifested and all limbs were viable. Three required perfor-
mance of a secondary extraanatomic prosthetic graft in a clean operative field to assure continued limb viability. RESULTS Results of this classification and management plan in the treatment of major PAPG infection are summarized in Table III. Treatment bascd on the initial classification alone was sufficient to eradicatc all evidence of major infection in 25 of the 34 patients with major graft infection. During a follow-up period of 1 to 15 years (mean 4 years) none of these 25 patients had subsequent complications directly related to this management of their graft infection. In the remaining nine patients, one with group III infection and eight with group IV graft infections had treatment complications or progression of the infection despite initial management by this protocol. One of these patients died and the other eight required further operative treatment consisting of partial (one case) or total (seven cases) graft removal. This progression became apparent within 5 months of the original graft salvage, wound excision operation. Total graft salvage. Of the 11 graft infections initially treated by total graft salvage, only one patient with a group III graft infection ultimately required excision of most of the midportion of a functioning external iliac-femoral graft originally placed via an infrainguinal approach. It was replaced by an extraanatomic PTFE graft, which was routed through a clean field and which resulted in limb salvage and eradication of the infection with follow-up for more than 2 years. Anastomotic involvement never occurred. No patient required an amputation as a direct result of this form of treatment for graft infection, although one other patient with group 11I infection had a below-knee amputation for uncontrolled foot infec-
lournal of VASCULAR SURGERY
150 Samson et al.
Table IV. Amputations, patient survival, and extremiqr preservation related to infection grade and salvage of all or a portion of the infected graft
Infection group
III
1V
V Total
Major amputation ~ (No. ofpatients)
Major repeat amputation s (No. ofpatients)
1 (BK)
0
0
4
4
1
0
0
0
1
I
6
0
0
0
6
6
3 (2 BK, 1 AK)
0
11
i1
6
1
Ultimate treatment
No. of patients
Total graft salvage Partial graft removal Total graft salvage Partial graft removal Total graft removal Total graft removal
4
12
Previouslimb loss (No. of patients)
Patient survival (No. of patients)
Salvage of all or a major portion of involved limb (No. of patients)
2 (AK)
2 (AK)
4
5 (3 BK, 2 AK) 4 (2 BK, 2 AK) O
1 (BK)
0
4
3
34
10
6
2
32 (94%)
26 (81%)
7
BK, Below-knee;AK, above-knee. ~Amputation resulting from treatment. tion before the graft infection became apparent. This was the only amputation required in the five patients with a group III infection or in the six group IV infections with patent grafts treated by total graft salvage. Moreover, no deaths occurred in any of the 11 patients so treated (Table III). Partial graft removal. O f the 19 patients with group IV infected grafts initially treated by partial graft removal, seven ultimately required total graft removal (37%). The remaining 12 infected occluded grafts ultimately treated by partial graft excision had the following outcome: Five were already associated with a major lower extremity amputation (three below-knee and two above-knee). However, preservation of a portion of the graft on the common femoral artery in all five patients permitted salvage of an important portion of the extremity by preserving direct flow to the deep femoral artery. In the remaining seven patients who had manifested a group IV infection in an occluded graft, partial graft excision permitted preservation of a portion of the graft with maintenance of circulation to the arm or thigh via the axillary or common and deep femoral arteries. The involved limb (one upper and three lower) was saved in four patients. Although a major amputation of the involved lower limb was required in the three other patients (two below-knee and one above-knee), the level of amputation was lowered and preservation of an important portion of the extremity was possible because of the maintained arterial flow. There was one death in this group of i2 patients (discussed later).
Thus the treatment of major graft infection by partial graft removal was effective as definitive treatment in l I , or 58%, of the 19 cases in which it was initially attcmptcd. When this was the only form of treatment required, it resulted in one death and major limb loss in 3 of 12 patients. However, it permitted simplified maintenance of sufficient arterial flow to save all (five cases) or an important portion (seven cases) of the involved extremity. In the 20 patients in w h o m partial graft removal was attempted as definitive treatment of a major graft infection (19 initial and one ultimate), there were two deaths (10%). One patient bled from the graft remnant-femoral arte U anastomosis. This necessitated total graft removal and ligation of all femoral vessels. The paticnt ultimately died of general cachexia and sepsis after a high above-knee amputation that failed to heal. The other patient, whose graft infection was controlled, died of an aplastic agranulocy~osis from the antibiotic ticarcillin. Total graft removal. As already described, the four group V infections were initially treated by total graft removal, and an additional seven group IV infections treated originally by" partial graft removal ultimately required and were treated by total removal of the graft remnant (Table III). Four of these I1 grafts (all group V infections) were patent at the time of infection and initial treatment by total graft removal. One limb remained viable without the need for further arterial reconstruction. A new extraanatomic PTFE graft placed in a noninfected field saved two of three limbs in which
Volume 8 Number 2 August 1988
Such treatment was attempted. Thus only one limb required a major below-knee amputation in this setting and this occurred when the extraanatomic bypass performed after total removal of an infected patent graft failed. No deaths occurred among these four patients. There were seven patients with occluded grafts and group IV infections initially treated by partial graft removal whose treatment failed and who required total graft removal. Treatment in three cases failed because of anastomotic bleeding and in four cases the failure was due to the lack of healing of a groin wound. Two of these seven patients had already undergone above-knee amputation. Of the remaining five patients, one patient had the lower extremity saved by placement of an extraanatomic PTFE graft in a clean field after an autogcnous vein graft placed in the infected field disrupted and bled. There was one death as described earlier. The other three patients, two of whom had already had belowknee amputation, all ultimately required an aboveknee amputation. Thus, when treatment of graft infection by total removal of an occluded graft was required after failure of partial graft removal, the leg could only be saved in One case and treatment of the graft infection directly resulted in four above-knee amputations and one death. Mortality. In the entire group of major graft infections treated by this approach, there were two deaths. Thus the overall mortality rate was 6%. Amputation. As shown in Table IV, overall 10 amputations (six below-knee and four above-knee) had been required before graft infection became apparent. Ultimately, six other patients required a major amputation and two patients with previous amputations required revision to a higher level as a result Of the treatment of the infected PAPG. Thus, although the overall amputation rate was 47%, amputation or repeat amputation at a higher level as a direct result of treatment occurred in only 8 of 34 patients (24%); salvage of all or a major portion of the patient's limb was made possible by use of our protocol in 26 of 32 surviving patients (81%) with major graft infection. DISCUSSION Management of prosthetic graft infections is complicated by the many variables that may affect outcome. Because graft infection is fortunately an infrequent complication, most investigators do not gain a large experience with such patients. Accordingly, most reports combine experience with infections related to different graft materials and graft locations.
Infected prosthetic arterialgrafts 151 It is conceivable that basic tenets and dictums that apply to management of infected aortic grafts do not necessarily apply to infected PAPGs. In fact, a literature review demonstrates a difference in the final outcome for graft infection depending on the original site of graft insertion. The mortality rate for infected aortofemoral bypasses is higher than that for infected PAPGs such as femoropopliteal, femorofemoral, or axillofemoral bypassesY However, the amputation rate appears higher with infection of PAPGs treated by standard methods with total graft excisionY Fifteen years ago, we 1 realized that in the periphery, total graft excision necessitated difficult complex revascularization procedures and even with these often resulted in high thigh amputation and Sometimes the death of the patient. Furthermore, total excision in many cases required sacrifice of the proximal donor or inflow artery, thereby significantly compromising distal collateral flow. Accordingly, in patients in whom graft infection had occurred but in whom infection of the host artery or graft wall was not obviously present (as manifested by either septicemia or bleeding), attempts were made either to preserve the graft entirely or partially. Such partial graft excision was easier to perform and often permitted preservation of the proximal donor artery and its collaterals so that urgent complex revascularization was not required. This selective approach to arterial graft infection was also supported by an earlier report by Carter et al.6 Subsequently, several other authors 7-I4 have also suggested nonexcisional treatment of infected g~afts. Furthermore, our experience in the management of infected PTFE hemodialysis access grafts has shown the benefits of such nonexcisional treatment particularly when the graft is still patent, is The data presented in this article show that, by adhering to the management approach outlined, it is often possible to save all or a critical portion of a PAPG that is involved by infection and that such graft salvage may be maintained up t o 15 years. Crucial to this approach is the performance of operative debridement of the associated infected wound. This procedure, which is always performed with the patient under anesthesia in the operating room, cannot be termed conservative. Rather it is a radical debridement of all grossly infected, necrotic soft tissue from the wound, a procedure we describe as wound excision. This is not only therapeutic in facilitating elimination of the infection, it also has diagnostic value and permits accurate application of our new, modified classification scheme. This in turn determines prognosis and further treatment.
152 Samsonet al.
Minor infections (groups I and II) are analogous to grade I and grade II infections described by Szilagyi et al. a in 1972. These minor infections involve only the dermis and subcutaneous tissue of the wound containing the arterial prosthesis, but the graft itself is not in contact with purulence or involved directly by the infection. Once the extent o f these minor infections is known, the treatment is simple and consists of antibiotics, local wound care with povidone-iodine solution dressings, and subcutaneous wound closure by second intention or, rarely, skin grafts. The prognosis for healing and continned graft function is uniformly good. The wound excision operation also allows diagnosis of a major graft infection in which purnlence comes in contact with the graft. These major graft infections are analogous to the grade Ili infections of Szilagyi et al.3 for which complete graft removal is widely thought to be necessary. Wound excision facilitates further subdivision of these major graft infections in a way designed to define which grafts must be excised and which grafts may be totally or partially saved. Our modified classification system divides major infections into three groups with different prognoses and requiring different treatments. Group III infections involve the body of the graft but not a graft-artery anastomosis. Others s'7-~2 have reported successful treatment 0fsuch infections without removal of the graft, and our experience confirms that graft salvaging techniques can be used successfully for such infections with a low risk to life and limb. Our group V graft infections are manifested either by signs of arterial or anastomotic bacterial involvement such as anastomotic bleeding or septicemia with positive blood cultures, or, at the time of wound excision, by evidence of arterial wall softening such as loose sutures or discoloration of the artery at the anastomosis. Standard treatment consisting of total graft removal with arterial ligation proximal and distal to the sites of anastomosis is mandatory for such group V infections. Some form of remote extraanatomic revascularization with a new prosthetic graft is usually- required for limb salvage and this can be performed before or after graft removal. Aside from facilitating earlier diagnosis in some cases at the time of wound excision, our management plan contributes little that is new to patients with this type of graft infection. Although some authors 16'17recommend anatomic arterial reconstruction with autogenous grafts or patches to permit total excision of the prosthetic graft, we are reluctant to
Journal of VASCULAR SURGERY
use this approach if anastomotic involvement with bleeding has occurred. We believe that this implies a virulent infection with arterial wall involvement and suggests that a repeat anastomosis or local autogenous repair in the infected field has a high likelihood of disrupting again. Such suture line disruption occurred in one of our patients and in 8 of 14 patients with positive arterial wall cultures reported by Macbeth et al. 18 Group IV infections were those with purulent material in direct contact with the prosthetic graft at an artery-to-graft anastomosis. This type of infection was the commonest in our series and afflicted 74% of our 34 patients with major graft infection. It is also the type of infection for which our modified approach to classification and management offers some potential benefit in terms of simplifying treatment and improving results. Salvage of an infected functioning patent graft may greatly simplify treatment and avoid the complex revascularization procedure that would be required if the graft was totally excised. Similarly, salvage of a portion of an infected nonfunctioning thrombosed graft may maintain the flow through a patent inflow or outflow artery and the perfusion of important collateral vessels arising from it. This is particularly true when the common femoral artery was used to provide inflow for a distal bypass. In this case the maintenance of normal flow to the deep femoral artery is crucial for sustaining viability of all or a portion of the limb. One risk of leaving all or a part of a graft in place when purulence surrounds an anastomosis is that bleeding from this site may occur; a second risk is that healing will not take place. These undesirable events occurred in seven of our 19 patients (37%) with group IV infections of a thrombosed graft, a portion of which was left in the infected field. They never occurred in the six patients with grade IV infections of patent grafts, all of which were left in place. Thus our graft salvage approach to grade IV infections was locally successful in 18 of the 25 instances (72%) in which it was attempted. Despite this relatively good success rate, this approach has some obvious disadvantages. First, it failed to ablate the infection in 28% of attcmpts. Healing could not be obtained in four cases, and bleeding occurred in three. If the graft or a portion of it is left in place attached to a functioning arterial segment, the patient must be constantly observed for bleeding until the wound is healed. This may require several weeks of costly hospitalization and intensive care. In the present series, although anastomotic
Volume 8 Number 2 August 1988
bleeding occurred in three patients, none exsanguinated; only one patient's death could be related even remotely to this event. Although this graft preservation approach was successful in achieving healing in 22 of the 30 group III and group IV infections (73%) in which its use was attempted, it is difficult to be certain that this form of treatment is superior to more standard graft excision methods. The overall amputation and higher repeat amputation rate for treatment of major graft infection was 24%. The partial or complete limb salvage rate with the described graft preservation approach to major graft infections was 81%. These rates compare favorably with statistics from series treated by more standard methods. However, the relatively small numbers of patients in various series and the influence of many other variables prevent conclusive comparisons. The same difficulties prevent comparison of mortality rates, although the 6% overall mortality rate associated with treatment of major graft infections with our graft preservation approach when feasible also compares favorably with mortality rates associated with infected PAPGs treated in more standard fashion. Although the modified classification and treatment plan described herein has been used primarily on infected PAPGs, some may wonder whether it could be used to simplify the treatment of infected intraabdominal grafts. To date we have used the same principles selectively in two very poor-risk patients. In one a small stump of an infected Dacron graft was left attached to the aorta; in the other a similar graft stump was left attached to the proximal external iliac artery. Healing of wounds and preservation of arterial continuity have been maintained for 3 and 5 years, respectively. However, the larger size and impaired accessibility of retroperitoneal arteries for wound care and control mandate that this approach to infections of grafts to these arteries be viewed with skepticism and used only with the utmost caution. Even in peripheral arteries, our modified treatment plan has risks and disadvantages that must be weighed before its use is attempted in the management of major graft infections. Finally, since graft preservation treatment was not uniformly successful in managing group IV graft infections with thrombosed grafts, it would be helpful if methods could be developed to predict cases in which this new approach was destined to succeed or fail. Such methods and accurate comparisons of results with the graft salvage approach and more standard treatment plans demand further investigation.
Infected prosthetic arterial grafts
153
However, the greater simplicity of this modified approach, its feasibility in 89% of our major graft infections, and its effective results in 73% of the 30 patients in whom it was attempted establish it as a reasonable alternative to standard methods of treatment for infected PAPGs. REFERENCES
1. Veith H- Surgery of the infected aortic graft. In: Bergan IJ, Yao JST, eds. Surgery of the aorta and its body branches. New York: Grune & Stratton, Inc, 1979:532-3. 2. Veith FJ, Gupta SK, Samson RH, et al. Progress in limb salvage by reconstructive arterial surgery combined with new or improved adjunctive procedures. Ann Surg 1981; 194:336401. 3. Szilagyi DE, Smith RF, Elliot JP, Vrandecic MP. Infection in arterial reconstruction with synthetic grafts. Ann Surg 1972;176:321-33. 4. Bunt TJ. Synthetic vascular graft infections. I. Graft infections. Surgery 1983;93:733-46. 5. Liekweg WG Jr, Greenfield LJ. Vascular prosthetic infections: collected experience and results of treatment. Surgery 1977; 81:335-42. 6. Carter SC, Cohen A, Whelan TJ. Clinical experience with management of the infected Dacron graft. Aim Surg 1963; 158:249-55. 7. Kwaan JHM, Counolly JE. Successful management of prosthetic graft infection with continuous povidone-iodine irrigation. Arch Surg 1981;116:716-20. 8. Popovsky J, SingerS. Infected prosthetic grafts: localtherapy with graft preservation. Arch Surg 1980;115:203-5. 9. Johansen H, Hipp R. Healing of exposed prosthetic vascular grafts by vigorous wound care and povidone-iodine. Vase Surg 1981;15:421-4. 10. Schaberg FJ, Wong R, Phillips MR, Healey EH, Healey PJM. Management of draining wounds in vascular surgery. Vasc Surg 1982;16:213-8. 11. Casali RE, Tucker WE, Thompson BW, Read RC. Infected prosthetic grafts. Arch Surg 1980;115:557-80. 12. Hepp W, Schulze T. The management of infected grafts in reconstructive vascular surgery. Thorac Cardiovasc Surg 1986;34:265-8. 13. Sweeney TF, Piorkowski R, Ariyan S, Kerstein M. An alternative in the management of the infected vascular prosthesis. Vase Surg 1983;17:195-8. 14. Ehrenfeld WK. Prosthetic vascular graft infection. In: Hairnovici H, ed. Vascular emergencies. New York: AppletonCentury-Crofts, 1982:515-6. 15. Bhat DJ, Tellis VA, Kohlberg WI, Driscoll B, Veith FJ. Management of sepsis involving expanded polytetrafluoroethylene grafts for hemodialysis access. Surgery 1980;87:445-50. 16. Reilly LM, Altman H, Lusby RJ, Kersh RA, Ehrenfeld WK, Stoney RJ. Late results following surgical management of vascular graft infection. J Vase SuRe 1984;1:36-44. 17. Seeger JR, Wheeler JR, Gregory RT, Snyder SO, Gayle RG. Autogenous graft replacement of infected prosthetic grafts in the femoral position. Surgery 1983;93:39-45. 18. Macbeth GA, Rubin JR, McIntyre ICE Jr, Goldstone J, Malone JM. The relevance of arterial wall microbiology to the treatment of prosthetic graft infections: graft infection vs arterial infection. J Vasc SURG 1984;1:750-4.