Vascular Prosthesis Infection Research Articles

Conservative treatment of vascular graft infections in the groin

Clinical implications of vascular graft infection vary according to the position of the implanted graft. The infected aortic bifurcation graft is associated with a high incidence of therapeutic failure and also a high mortality rate. 1-s In comparison, the mortality rate is low following infection of an infrainguinal bypass graft, but the risk of major amputation approaches 80%. 6'7 The close anatomical relation to the perineal area and the poor vascularisation of the subcutaneous tissue combined with a rich regional lymphatic supply predispose the groin to wound infection. Thus, not only local contamination, but also haematogenous and lymphogenic spread from other infectious sites may contribute to the high incidence of infectious complications in the groin. According to Herbst et al. s one out of three graft infections is caused by microorganisms originating from the patient's ischaemic ulcer, corroborating the observation by Lorentzen et al} that 20% of foot ulcers yield the same microorganism as isolated from the graft. Management of infected vascular prostheses is controversial. One approach is to remove the graft with a new extra-anatomic arterial reconstruction in one or two proceduresg; but it is associated with a high level of complications and bears a high mortality, especially with the involvement of an aortobifemoral graft, s'1°'1~ The other approach involves less extensive procedures in combination with administration of potent antibiotics.S,6,12 ~5 With this approach excellent results have been reported even in patients with aortic graft sepsis} 6 One such antibiotic is gentamicin applied to the region of the infection, e.g. the groin. 12'13 In our first reports on this treatment, results from 14 and 17 patients, respectively, were presented. 12'~3 In this report the number of patients has increased to 38 with a follow-up period of up to 6 years, mean 13 months.

Biofilms in device-related infections

The use of various medical devices including indwelling vascular catheters, cardiac pacemakers, prosthetic heart valves, chronic ambulatory peritoneal dialysis catheters and prosthetic joints has greatly facilitated the management of serious medical and surgical illness. However, the successful development of synthetic materials and introduction of these artificial devices into various body systems has been accompanied by the ability of microorganism to adhere to these devices in the environment of biofilms that protect them from the activity of antimicrobial agents and from host defense mechanisms. A number of host, biomaterial and microbial factors are unique to the initiation, persistence and treatment failures of device-related infections. Intravascular catheters are the most common devices used in clinical practice and interactions associated with these devices are the leading cause of nosocomial bacteremias. The infections associated with these devices include insertion site infection, septic thrombophlebitis, septicemia, endocarditis and metastatic abscesses. Other important device-related infections include infections of vascular prostheses, intracardiac prostheses, total artificial hearts, indwelling urinary catheters, orthopedic prostheses, endotracheal tubes and extended wear lenses. The diagnosis and management of biofilm-associated infections remain difficult but critical issues. Appropriate antimicrobial therapy is often not effective in eradicating these infections and the removal of the device becomes necessary. Several improved diagnostic and therapeutic modalities have been reported in recent experimental studies. The clinical usefulness of these strategies remains to be determined.

Muscle-Flap Coverage for Infected Peripheral Vascular Prostheses

Infection in a peripheral vascular prosthesis continues to be a serious complication in arterial reconstructive surgery and threatens the patient with loss of either limb or life. Infection rates at major centers are now low, ranging from 1 to 6 percent; however, limb loss and mortality rates for this complication range from 25 to 75 percent depending on the location of the graft and the extent of the infection. The use of muscle flaps in the management of acute wounds, infection-prone wounds, exposed orthopedic hardware, and osteomyelitis is now commonplace. Transposed muscle has been shown to be well-vascularized tissue that improves healing time and decreases local wound bacterial counts. After considering the preceding facts, we used muscle flaps for coverage of infected peripheral vascular prostheses in a highly select group of patients. These patients were "end of the line," and last-ditch efforts were made to salvage life or limb. Twenty-four infected vascular grafts in 20 patients have been analyzed. Ages ranged from 52 to 87 years. All patients had grade 3, stage I, II, or III peripheral graft infections, as previously defined by Szilagyi and modified by vonDongen. Aortofemoral reconstruction was the most common initial bypass procedure (14), followed by femoral popliteal (6), axillofemoral (2), iliofemoral (1), and subclavian/subclavian bypass (1). Staphylococcus aureus was the most common infecting organism. Muscles used for coverage were the rectus femoris (13), the sartorius (9), the rectus abdominis (1), and the pectoralis major (1). The graft material was composed of Dacron in 16 instances and polytetrafluoroethylene in 8.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of radiolabeled, nonspecific immunoglobulin in the detection of focal inflammation

The serendipitous discovery that radiolabeled nonspecific immunoglobulin G (IgG) accumulates at a site of focal inflammation has led to the development of a new radiopharmaceutical for inflammation scanning, 111In-IgG. This reagent has been extensively studied in humans with focal infection and has been shown to be both safe and effective. It has been especially useful in the evaluation of patients with possible abdominal and skeletal infection, with the ability to perform serial scans being an important attribute in terms of determining "proof of cure." Preliminary data suggest that this approach may be particularly useful in immuno-compromised patients and may find a role in the quantitative assessment of patients with such noninfectious inflammatory processes as rheumatoid arthritis and inflammatory bowel disease. A new method of labeling IgG with technetium, via the hydrazino nicotinamide derivative, holds promise in terms of substituting this more practical radionuclide for indium. However, caution must be directed against total substitution, because such processes as suspected vascular or skeletal prosthesis infection may require the longer half-life of 111In for satisfactory diagnosis. When one compares the results obtained with radiolabeled IgG against the ideal specifications for a radiopharmaceutical to be used for inflammation imaging, most of the requirements are met. The major weakness of this approach is that even with the technetium-labeled reagent, a minimum of 6 to 12 hours is necessary for a scan to become positive, which is not acceptable in the evaluation of acutely evolving processes. Development of other radiopharmaceuticals for this purpose remains to be accomplished.

In situ replacement of arterial prosthesis infected by bacterial biofilms: long-term follow-up.

Bacterial biofilm infections of vascular prostheses are characterized by an absence of systemic sepsis, a fluid-filled cavity surrounding the graft, a draining sinus tract, and microorganisms that must be removed from the fabric prosthesis for bacterial culture. Since 1987 we have treated 20 infected grafts with prosthetic excision and in situ replacement in 14 men and 6 women. The time from initial graft implantation to diagnosis of graft infection ranged from 3 months to 14 years (mean 4.5 years). The original graft (Dacron-17, polytetrafluoroethylene-3) was an aortobifemoral in 14, axillofemoral femorofemoral in 3, iliofemoral in 2, and femoropopliteal in 1 patient. Presenting symptoms were groin false aneurysm with perigraft fluid in 10, inflammatory mass in 6, and sinus tract in 4. At surgery all unincorporated graft material and the perigraft capsule were excised from a point where the proximal graft was incorporated, including debridement of vessels at the distal anastomosis. Of the 14 aortobifemoral grafts, only the femoral limbs were excised at the initial presentation of biofilm infection. The conduit was replaced with an in situ polytetrafluoroethylene interposition graft, which was covered with a gracilis or sartorius muscle flap when possible. All surgical sites healed, all grafts remained patent, and there was no limb loss. After ultrasonic oscillation of the explanted graft, bacterial cultures recovered coagulase-negative Staphylococcus species in 14, coagulase-positive Staphylococcus species in one, both species in three, with no growth from two specimens. During follow-up, two patients have had clinical involvement in the proximal intraabdominal portion of the graft that had not been previously resected. In all grafts, the in situ replacement graft remained well incorporated. In situ graft replacement is effective treatment for biofilm infections of vascular prostheses. Because of the indolent nature of these infections, subsequent infection of previously uninvolved graft segments may be expected.

In situ replacement of infected vascular prostheses with rifampin-soaked vascular grafts: Early results

Based on the excellent results of experimental studies with antibiotic-bonded vascular prostheses for prevention of graft infection, gelatin-sealed grafts soaked with rifampin were implanted in situ in five patients with vascular infection. All patients were at risk for limb loss or death and could not be treated by standard techniques such as graft excision and extra-anatomic bypass. In one patient an infected aortic stump aneurysm with involvement of both renal and visceral arteries was found. He was treated by implantation of a bifurcation rifampin-soaked graft between the subdiaphragmal aorta and both renal arteries and reimplantation of celiac and superior mesenteric artery into the graft. In four patients with in-flow or runoff problems on angiography, an antibiotic-soaked graft was used for replacement of a partially or totally infected graft. Cultures were positive for Staphylococcus aureus in three and coagulase-negative staphylococci in two patients. Wound healing was uncomplicated; there was no need for amputation. After a follow-up of at least 6 months, all grafts were patent without any evidence of reinfection on computed tomographic scan. We conclude that infected vascular prostheses can be replaced in situ by rifampin-soaked grafts in patients at high risk for death or major amputation.

In situ replacement of infected vascular prostheses with rifampin-soaked vascular grafts: Early results

Based on the excellent results of experimental studies with antibiotic-bonded vascular prostheses for prevention of graft infection, gelatin-sealed grafts soaked with rifampin were implanted in situ in five patients with vascular infection. All patients were at risk for limb loss or death and could not be treated by standard techniques such as graft excision and extraanatomic bypass. In one patient an infected aortic stump aneurysm with involvement of both renal and visceral arteries was found. He was treated by implantation of a bifurcation rifampin-soaked graft between the subdiaphragmal aorta and both renal arteries and reimplantation of celiac and superior mesenteric artery into the graft. In four patients with in-flow or runoff problems on angiography, an antibiotic-soaked graft was used for replacement of a partially or totally infected graft. Cultures were positive for Staphylococcus aureus in three and coagulase-negative staphylococci in two patients. Wound healing was uncomplicated; there was no need for amputation. After a follow-up of at least 6 months, all grafts were patent without any evidence of reinfection on computed tomographic scan. We conclude that infected vascular prostheses can be replaced in situ by rifampin-soaked grafts in patients at high risk for death or major amputation.

Chronic Q fever. Ninety-two cases from France, including 27 cases without endocarditis

Chronic Q fever is seldom recognized; before 1989, only 234 cases had been reported in the literature. The 92 cases of chronic Q fever collected at the French National Reference Center for Rickettsioses from 1982 through 1990 represent the largest series ever reported. The patients included in the study were diagnosed between July 31, 1982, and August 1, 1990, at the French National Reference Center for Rickettsioses as having chronic Q fever by the following criteria: presence of antibody against Coxiella burnetii phase I antigen at a titer greater than or equal to 800 for IgG and 50 for IgA by the indirect immunofluorescence test. Epidemiologic, clinical, laboratory, and treatment data were collected from 39 different collaborative hospitals throughout France. For each serologically selected patient, a computerized questionnaire was utilized to record 188 different items of demographic, epidemiologic, clinical, laboratory, and therapeutic data, which were analyzed. Chronic Q fever occurs more frequently in city dwellers than in rural inhabitants, and exposure to domestic ruminants and raw milk is an important feature. Immunocompromising conditions (20.2%) and underlying heart disease (88.4%) or vascular disease are the most important risk factors to consider in potential cases of chronic Q fever. The mortality in these patients with endocarditis was high (23.5%). The clinical spectrum of 84 patients included 57 cases of endocarditis, three cases of vascular prosthesis infection, three cases of aneurysmal infection, three cases of osteoarthritis, four cases with lung localizations, nine asymptomatic cases, three cases of hepatitis, and two cases with cutaneous forms of the disease. In patients with unexplained fever, negative blood cultures, and a history of underlying vascular or cardiac disease, Q fever should be considered.

In situ replacement of vascular prostheses infected by bacterial biofilms

Late prosthetic graft infections are commonly the result of coagulase-negative staphylococci that survive within a biofilm on prosthetic surfaces and provoke perigraft inflammation. The indolent nature and microbiologic characteristics of bacterial biofilm infections coupled with the morbidity of graft excision and extraanatomic bypass grafting prompted us to use in situ graft replacement in 15 patients admitted to the hospital with 17 infected graft segments at a mean (± SEM) time interval of 70 ± 16 months after graft implantation (n = 6) or revision (n = 9). Since 1986, 17 grafts (14 aortofemoral, 2 axillofemoral, and 1 femoropopliteal) infected by bacterial biofilms have been treated. Signs on admission included femoral pseudoaneurysm (n = 7), perigraft abscess (n = 6), or graft-cutaneous sinus tract (n = 4). No patient exhibited septicemia. At operation graft incorporation was absent and Gram's stain of perigraft exudate showed polymorphonuclear leukocytes but no bacteria. Culture of explanted graft material isolated coagulasenegative staphylococci (n = 12), Staphylococcus aureus (n = 1), and no growth (n = 2). All patients were successfully treated by a regimen that included parenteral antibiotics, removal of involved graft material, excision of inflamed perigraft tissue, and in situ replacement with an expanded polytetrafluoroethylene prosthesis. No deaths, graft thromboses, or deep wound infections occurred after operation. Recurrent graft infection did not develop during a follow-up interval that ranged from 5 to 50 months (mean, 21 months). Diagnosis of vascular prosthesis infection caused by bacterial biofilms can be based on signs at admission and operative findings. Complications of this perigraft infection can be eradicated by antibiotic administration, local debridement, and in situ graft replacement.

Experience with 60 inferior rectus abdominis flaps

We report on our experience with the inferior rectus abdominis flap. Since 1984, 60 patients have been operated on with this technique. The inferior rectus abdominis flap was used as a free flap, island flap or pedicle flap (inferiorly based). Pure muscle flaps served to fill bone defects in patients with chronic osteomyelitis or as a biologic cover of infected vascular prostheses following multiple vascular surgery in the groin. The myocutaneous and fasciocutaneous rectus flaps served to cover soft tissue defects of the upper and lower extremities after accidents, degloving and radical tumour surgery. We present data from our collective patients to document the benefits of the inferior rectus abdominis flap and recommend this technique as a safe surgical modality to manage large-surface soft tissue defects.

Gas in an infected vascular prosthesis. An unusual finding on plain radiographs

Infection of prosthetic vascular grafts is a potentially serious complication, which may prove difficult to diagnose despite modern imaging techniques. We report a case in which the diagnosis was strikingly obvious on plain radiographs, gas being present within the lumen of the graft. The clinical features and investigation of suspected graft infection are reviewed.

Management of aortic prosthetic infections

Infections of aortic vascular prostheses remain a dreaded complication. Although removal of the graft has generally been recommended in the literature, the role of lesser procedures, the need for alternate revascularization, and a precise plan of attack are ill defined. We have treated 18 patients with infection of aortic prostheses. Specific risk factors potentially promoting infection included reoperation, septic complications, or gastrointestinal entry at the time of graft placement. Clinical signs of infection included chronic draining sinus in eight patients, localized groin abscess in three patients, groin swelling in four patients, gastrointestinal bleeding in two patients, and pseudoaneurysm in one patient. Treatment by local therapy, including catheter irrigation of sinus tracts, debridement, and local antibiotics, resulted in failure in eight of nine patients. If the sinogram of a groin sinus showed no communication with the body of the graft, resection of a graft limb was successful in 66 percent of the patients. If the sinus communicated with the body of the graft, total resection was mandatory. When total excision was necessary, all patients required revascularization by means of an extraanatomic bypass. The mortality rate was 33 percent and was primarily due to bleeding fistulas. An aggressive approach to this serious problem with early graft excision is encouraged.

Infection of vascular prostheses caused by bacterial biofilms

A canine model was developed to study the efficacy of graft replacement as treatment for vascular prosthesis infections from Staphylococcus epidermidis. Infrarenal aortic graft infections were established in 18 dogs by implantation of Dacron prostheses colonized in vitro with a slime-producing strain of S. epidermidis to form an adherent bacteria-laden biofilm (5 × 106 colony-forming units/cm2 graft). Study animals developed a graft infection with anatomic and microbiologic characteristics typical of late prosthetic graft infections in humans (sterile perigraft exudate, absent graft incorporation, and normal serum leukocyte count and sedimentation rate). The S. epidermidis study strain was isolated from 14 of 18 explanted grafts (78%) by mechanical disruption of the graft surface biofilm and culture in broth media. Four dogs with sterile graft cultures had histologic evidence of bacterial infection. The established prosthetic surface biofilm infection was treated by graft excision, parenteral cefazolin, and graft replacement with a Dacron or polytetrafluoroethylene (PTFE) vascular prosthesis. One month after graft replacement, no PTFE graft had signs of infection, but perigraft exudate and inflammation involved three of nine Dacron grafts (33%). The study strain was recovered from four of nine PTFE grafts (44%) and two of nine Dacron (22%) replacement grafts (p > 0.05). Prosthetic replacement of Dacron prostheses infected by S. epidermidis as a bacteria-laden surface biofilm can result in early graft healing, but persistent colonization of one third of replacement grafts signify that recurrent clinical infection remains a risk.

Infection of vascular prostheses caused by bacterial biofilms

Infection of vascular prostheses caused by bacterial biofilms

Endocarditis and Infections of Intravascular Devices Due to Eikenella corrodens

Eikenella corrodens, a microaerophilic gram-negative rod, is a normal inhabitant of human mucosal surfaces. Infections involving Eikenella have been reported with increasing frequency during the past 10 years. Despite a demonstrated ability to invade the blood stream, Eikenella has rarely been implicated in endocarditis or other vascular space infections. Two patients are reported with prolonged illness due to infection of peripheral vascular prostheses with E. corrodens and prior reports of Eikenella vascular space infections are reviewed. When Eikenella is the sole infecting organism, vascular space infections tend to be indolent. However, removal of vascular prostheses may be required for cure.

Skin deep-fascia flap graft in infected vascular prosthesis

Skin deep-fascia flap graft in infected vascular prosthesis

An alternative in the management of the infected vascular prosthesis

An alternative in the management of the infected vascular prosthesis

Pathophysiology, diagnosis, and treatment of abdominal abscesses

The serendipitous discovery that radiolabeled nonspecific immunoglobulin G (IgG) accumulates at a site of focal inflammation has led to the development of a new radiopharmaceutical for inflammation scanning, 111In-IgG. This reagent has been extensively studied in humans with focal infection and has been shown to be both safe and effective. It has been especially useful in the evaluation of patients with possible abdominal and skeletal infection, with the ability to perform serial scans being an important attribute in terms of determining “proof of cure”. Preliminary data suggest that this approach may be particularly useful in immunocompromised patients and may find a role in the quantitative assessment of patietns with such nonfectious inflammatory processes as rheumatoid arthritis and inflammatory bowel disease. A new method of labeling IgG with technetium, via the hydrazino nicotinamide derivative, holds promise, in terms of substituting this more practical radionuclide for indium. However, caution must be directed against total substitution, because such processes as suspected vascular or skeletal prosthesis infection may required the longer half-life of 111In for satisfactory diagnosis. When one compares the results obtained with radiolabeled IgG against the ideal specifications for a radiopharmaceutical to be used for inflammation imaging, most of the requirements are met. The major weakness of this approach is that even with, the technetium-labeled reagent, a minimum of, 6 to 12 hours is necessary for a scant to become positive, which is not acceptable in the evaluation of acutely evolving processes. Development of other radiopharmaceuticals for this purpose remains to be accomplished.

Enteroprosthetic Fistula Associated with Hypertrophic Osteoarthropathy

Infected vascular grafts with aortoenteric fistulae can be difficult to diagnose. We describe an interesting patient who developed hypertrophic osteoarthropathy of the lower extremities. This occurred one year prior to the diagnosis of an infected vascular prosthesis. With definitive surgical therapy, all symptoms of hypertrophic osteoarth ropathy resolved. Patients with arterial prostheses who present with hypertrophic osteoarthropathy should be carefully evaluated for occult graft infections.

An Alternative in the Management of the Infected Vascular Prosthesis

Etude experimentale chez le chien, de modeles d'infection de protheses vasculaires. Le traitement par antibiotiques associe a une reintervention du niveau de la greffe a donne les meilleurs resultats