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Aortic graft infections 2016-University of Arizona
- 1. Aortic Graft Infections BRAD TRINIDAD, MD
- 2. Incidence .8-6% InterGard silver bifurcated graft: Features and results of a multicenter clinical study. Ricco, Jean-Baptiste. Journal of Vascular Surgery , Volume 44 , Issue 2 , 339 - 346 O’Conner S, Andrew P, Batt M, Becquemin JP. A systematic review and meta-analysis of treatments for aortic graft infection. Journal of vascular surgery. Volume 44, Issue 1, July 2006, Pages 38–45.
- 3. 60 yo M with a history of DM, COPD and EVAR two weeks prior presents with back pain and associated intermittent fevers, chills, N/V, malaise, and fatigue for the last few days. Upon admission he had a fever of 102.4 F. He was hemodynamically stable. His exam was fairly unremarkable, but he does look “sick”. His WBC is 18K, and his ESR is 64. Due to his recent AAA repair history CT is ordered which shows the following…
- 5. Aortic Graft Infections Most serious and devastating Mortality 25-40%, likely higher Most 5 year survival of <50% Up to 20% receive an amputation 60% Pneumonia, renal failure, cardiac issues Vogel TR, Symons R, Flum DR. The incidence and factors associated with graft infection after aortic aneurysm repair. Journal of Vascular Surgery, Volume 47, Issue 2, February 2008, Pages 264–269.
- 6. Clinical Classifications of Prosthetic Graft Infections Time of appearance after implantation Early <4 months<Late Relationship to post-operative wound infection (Szilagyi classification) Group 1: cellulitis involving wound Group 2: infection involving subcutaneous tissues Group 3: infection involving the graft prosthesis Extent of graft involvement (Samson classification) Involvement of the anastomosis
- 7. Bunt’s Classification Cavitary vs noncavitary Extracavitary portion of graft originating in cavity Infection of patch angioplasty Graft-enteric fistula; graft erosion Aortic stump sepsis
- 8. Risk Factors/Pathogenesis Speculative at best Bacterial contamination at time of implantation Hematogenous or lymphogenous transfer of organisms from a remote site Prolonged preoperative hospitalization, extended operating time, break in aseptic technique, post-operative wound infection, etc Altered immune function, chronic steroid use, malnutrition Gelabert HA. Primary arterial infections and antibiotic prophylaxis. In: Moore WS, ed. Vascular Surgery: a comprehensive review. 6th ed. Philadelphia: WB Saunders;2002:179-199(191).
- 10. Vogel et al
- 11. Bacteriology Staph epidermidis 45% Staph aureus 40% E.coli 20% Others including pseudomonas, proteus, etc Timing and species matters Dr. Patrizio Castelli, Roberto Caronno, Sandro Ferrarese, Vittorio Mantovani, Gabriele Piffaretti, Matteo Tozzi, Chiara Lomazzi, Nicola Rivolta, and Andrea Sala. Surgical Infections. October 2006, 7(supplement 2): s-45-s-47. doi:10.1089/sur.2006.7.s2-45.
- 12. Presentation Early Systemic manifestations more likely(but variable) Staph aureus and gram (-) bacteria more likely Pseudomonas Marked inflammatory reactions Late Low-virulence more likely Staph epidermidis more likely Fever usually absent Glycocalyx biofilm layer More likely to have complications of aortic graft infection
- 13. Copyright © 1988 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions “Infection of vascular prostheses caused by bacterial biofilms” Thomas M. Bergamini, M.D., Dennis F. Bandyk, M.D., Dean Govostis, M.D., Hermann W. Kaebnick, M.D., Jonathan B. Towne, M.D. Journal of Vascular Surgery Volume 7, Issue 1, Pages 21-30 (January 1988)
- 14. Extracavitary vs Intracavitary Local signs common Fever, leukocytosis common Sometimes wound mass or drainage “Use of antibiotic-loaded polymethylmethacrylate beads for the treatment of extracavitary prosthetic vascular graft infections” Journal of Vascular Surgery 2006 44, 757-761DOI: (10.1016/j.jvs.2006.05.056) Copyright © 2006 The Society for Vascular Surgery Terms and Conditions
- 15. Diagnosis of Aortic Graft Infection History and physical Imaging: CT MRI PET scan Radionucleotide scanning Endoscopy
- 16. Diagnosis No universally accepted case presentation or diagnostic standard Combination of clinical, radiological, and laboratory findings. Diagnosis and treatment of prosthetic aortic graft infections: confusion and inconsistency in the absence of evidence or consensus . J. Antimicrob. Chemother. (December 2005) 56 (6): 996-999 first published online November 3, 2005 doi:10.1093/jac/dki382
- 19. CT Gold standard Sensitivity 64%, Specificity 86% Findings: Perigraft fluid, loss of tissue planes, focal bowel wall thickening, perigraft air These not pathognominic Detection of aortic graft infection by fluorodeoxyglucose positron emission tomography: Comparison with computed tomographic findings.Fukuchi, Kazuki et al.Journal of Vascular Surgery , Volume 42 , Issue 5 , 919 - 925 Published in: "Aortic Prosthetic Graft Infections: Radiologic Manifestations and Implications for Management1" Orton et al. RadioGraphics Vol. 20, No. 4: 977-993
- 20. Perigraft Air Fig. 1 Axial (A and B) and coronal (C) views of CTA done 3 weeks post-operatively. Arrows point to gas and fluid collections which occurred posteromedial and posterolateral in proximal and distal portions of the graft. Fig. 2. Axial (A and B) and coronal (C) views of CTA done 12 weeks post-operatively. Of note, gas is gone and fluid collections are much decreased in size.
- 21. MRI Sensitivity 68% Specificity 97% Superior to CT in differentiating fluid/inflammation from hematoma/fibrosis Detection of Abdominal Aortic Graft Infection: Comparison of Magnetic Resonance Imaging and Indium-Labeled White Blood Cell Scanning. Shahidi, Saeid et al.. Annals of Vascular Surgery , Volume 21 , Issue 5 , 586 - 592
- 22. Other imaging Endoscopy Labeled WBC scan
- 23. Fluorodeoxyglucose-PET/CT scan Sensitivity ~100%, specificity 64% Enables differentiation of graft vs soft tissue infection Combining anatomical modality with functional one Likely the future A 54-y-old man who had received right femoropopliteal bypass graft 3 mo previously. Zohar Keidar et al. J Nucl Med 2007;48:1230-1236
- 24. Treatment of Infected Vascular Grafts Extrananatomical bypass and removal of infected conduit Removal of infected prosthetic conduit followed by in situ reconstruction with another prosthetic graft w/ or w/out antimicrobial impregnation Removal and immediate in situ reconstruction using arterial allograft Removal and immediate in situ reconstruction using venous autograft or allograft Surgical debridement, tissue coverage, and partial or complete preservation of infected prosthesis (or conservative management)
- 25. Data shortcomings Rare No control groups Mixed pathologies Data reporting not consistent Limited power
- 26. Extra-anatomic Bypass Gold standard Greatest accumulated experience Type depends on location of infection Amputation 3-34% Aortic stump disruption rates 3-24% Post-op mortality 11%-40% Poor patency Timing of revascularization Two-staged approach most common Reid, JD et al. Removing the infected aortofemoral graft using a two-stage procedure with a delay between the stages. Ann Vasc Surg.2005.
- 27. In-situ Reconstruction w/ Prosthetic Graft
- 29. In-situ Prosthetic Graft Replacement with Antimicrobials Rifampin binds to collagen or gelatin impregnated graft Silver ion
- 31. The Leicester Experience 11 patients Prospective nonrandomized study 7 patients originally had elective repair, 4 emergent Two patients died within 30 days, two died in follow-up period 4 had hemorrhage from aortoenteric fistula 2 MRSA related deaths 7 patients experienced long-term survival and remained clinically free from infection
- 32. The Leicester Experience Their conclusions: Poorer long-term outcome associated with: Those who originally had emergency procedures Patients w/ MRSA-this study is why rifampin- bonded prosthesis are not first option in MRSA patients Aortoenteric fistulas*
- 33. Oderich et al. 2006 117 patients treated for AGI over 20 yrs 52 ISR vs 49 AXFR ISR patients comprised primary analysis Primary outcomes: Early and late procedure-related death Primary graft patency Limb loss Secondary outcomes: Operative mortality Patient survival Graft reinfection rates
- 34. Oderich et al. 2006 Primary patency at 5 yrs: 89%(vs 48% for AXFR P=.01) Limb salvage at 5 years: 100%(vs 89% for AXFR P=.06) 4 early, and no late procedure related deaths after a median follow up of 3.4 yrs Graft reinfection rate: 11.5% 18.5% in patients with perigraft purulence 5% w/ omental wrap Procedure-related death rate not different than those treated with AXFR Operative mortality rate of 8% 1 of 30 patients w/ AEF developed recurrent graft infection
- 36. Oderich et al 2011 Follow-up to last study “ISRGs have excellent patency and limb salvage rates in those with AGEF w/out excessive perigraft purulence
- 37. Silver-coated Dacron Grafts One study comparing silver-coated dacron grafts vs cryopreserved arterial homografts 11 treated with silver-coated dacron grafts 30 day mortality: 18% 2 year mortality: 27% After two years limb salvage and graft patency were 100% Major complication as graft reinfection in two patients
- 38. Cryopreserved Arterial Allograft The first conduits used in vascular reconstruction Allow inline flow, allow complete excision of infected conduit, eliminate use of prosthetic material Lack of availability Lots of potential for conduit failure Delicate with a learning curve to use
- 39. Keiffer et.al 2004 Previous largest study on arterial allografts (179 patients) Fresh vs cryopreserved 111 patients got fresh allografts 68 cryopreserved after Aug 1996 Mean follow-up was 46 months Early post-op mortality was 20% 2% allograft related (fresh)-rupture 3% had nonlethal allograft complications Rupture, thrombosis 2% allograft-related late deaths from rupture at 9,10, and 27 months 7% late non-lethal aortic events Occlusion,dilatation,aneurysm Cryopreserved better
- 40. Keiffer et.al 2004 Their take-away: • Allograft replacement: • Avoided aortic stump blowout • Less affinity for infection or occlusion than extra-anatomical bypass, • much less duration and demand than femoral vein reconstruction • cryopreserved over fresh allograft • Beware dilatation, rupture
- 42. Zhou et. Al 2006 Retrospective review of records for 4 large Academic Medical Centers in USA 42 patients over 6 year period 34 primary graft infections 6 Mycotic aneurysm 2 aortoenteric erosion 10 patients tube grafts, 32 bifurcated grafts Mean f/u 12.5 months
- 43. Zhou et. Al 2006 Results No intraoperative deaths 30 day operative mortality of 17% Due to multiorgan failure secondary to sepsis Overall treatment mortality rate of 21% 50% had nonlethal procedure related complications DVT (n=5) Renal failure requiring dialysis (n=2) Amputation (n=6) One patient required allograft revision for graft thrombosis No reinfections
- 44. Vascular Low-Frequency Disease Consortium 2014 Multicenter study 220 patients since 2002 Mean follow-up 30 months Looked at complications, patency, and survival following cryopreserved allograft
- 48. Vogt et. Al 2000
- 49. Venous Autograft Replacement Superficial femoral vein-popliteal vein complex (neoaortoiliac system procedure aka NAIS) Prior attempts were with saphenous vein failed Hemodynamic anatomical
- 50. Clagett in Dallas 1993 Fashioned their neo-aortoiliac systems exclusively from superficial and deep femoral veins Details experience over 5 year pd w/ 21 NAIS procedures Wanted to evaluate mortality, morbidity, and intermediate term follow-up of patients undergoing NAIS w/ either superficial or deep femoral veins
- 52. Clagett in Dallas 1993 In-hospital mortality 10% Amputation rates 10% Mean operative time was 6.5 hrs and mean requirement of 4 units of blood No reinfections Failure rate of 64% for GSV NAIS vs 0% for DV NAIS
- 53. Ali et al 2009 Goal: evaluate long-term outcomes in large cohort treated w/ NAIS 187 patients using 336 FPV grafts over 16 years 30 day mortality 10% Procedure-related mortality 14% Amputation rate 7.4% Reinfection 5% primary patency at 72 months was 81% (91% assisted primary) Limb salvage was 89% at 72 months
- 54. Concerns about FPV use for NAIS Predisposition to venous morbidity Chronic venous insufficiency in 15% of harvested limbs at a mean F/U of 70 months Majority is just minor limb swelling Venous ulceration rare 12% fasciotomies Technical demands
- 55. Option Advantages Disadvantages Extra-anatomic bypass • Staging possible • Less physiologic stress • Most known • Risk of aortic stump blowout • Reinfection risk (27%) • Poor long-term patency • anticoagulation • Potential compromise of blood supply to the pelvis and colon Redo in-situ prosthesis • Convenient • Expedient • No aortic stump • Good patency and limb salvage • Reinfection risk(11-15%) • Chronic antibiotics Arterial allograft • Shorter surgery(No harvesting) • Good limb salvage • No aortic stump • Cost and limited availability • Reinfection risk(though much less) • Acute thrombosis • Chronic Abx • Possible rupture or dilatation Venous autograft(NAIS) • Resistent to reinfection • Superior patency • No aortic stump • Availability of conduit • No need for longer term Abx • Procedure length • Consequences of deep vein harvesting-venous HTN, edema, compartment syndrome (high physiological stress) • Long lower-limb ischemia times
- 56. Smith & Clagett UTSW
- 58. Aortic Endograft Infection Increasingly reported Incidence .2% to 5% Often performed in patients unfit for open surgery already-mortality goes up even further Vascular Low-Frequency Disease Consortium
- 59. Aortic Endograft Infection 206 patients: 180 EVAR, 26 TEVAR
- 60. Smeds et al
- 61. Smeds et al Perioperative 30 day mortality 35% Overally mortality 11% Overall 5 year survival 51% TEVAR patients had worse overall outcomes with 5 year survival of 29% On multivariate analysis, use of a prosthetic graft was a predictor of overall graft-related mortality Why worse outcomes? Maybe the sac
- 64. A word on Antibiotics…
- 65. Thank you.
Editor's Notes
- Early mortality-sepsis, MSOF, hemorrhage, renal failure, MI Late mortality-graft related (recurrent infection), CV disease
- Szilagyi classification created in 1972. Group 1: infection involves dermis only Group 2: infection extends into subcutaneous tissue but doesn’t invade arterial implant Group 3: the arterial implant proper is involved in the infection Since then there has been modifications, including the Samson classification which divides the actual involvement of infection with the graft, i.e. involving body but not the anastomosis, or surrounding an exposed anastomosis (Mr. Benko), or involving the anastomosis with associated septicemia, bleeding or both at time of presentation Szilagyi DE, Smith RF, Elliott JP, Vrandecic MP. Infection in arterial reconstruction with synthetic grafts. Annals of Surgery. 1972;176(3):321-333. A modified classification and approach to the management of infections involving peripheral arterial prosthetic grafts. Samson, Russell H. et al. Journal of Vascular Surgery , Volume 8 , Issue 2 , 147 - 153 . 1988.
- TJ Blunt MD, was in Phoenix at VA and Maricopa Medical Center in mid 90s
- Factors associated with graft infection
- Vogel et al tried to look into factors associated with graft infection They hypothesized more common in those with associated nosocomial infections and in emergency repair Defined as: pneumonia, septicemia, surgical site infection Retrospective cohort study using a state-wide hospital discharge database between 1987-2005 The Charlson Comorbidity Index contains 19 categories of comorbidity and predicts the ten-year mortality for a patient who may have a range of co-morbid conditions. The incidence of AGI was low, presented most commonly in the first postoperative year, Patients with nosocomial infection had an earlier onset of AGI. The 2-year rate of AGI was significantly higher in patients who had blood stream septicemia and surgical site infection in the periprocedural hospitalization. These data may be helpful in directing surveillance programs for AIG. Odds ratio estimates risk of exposure i.e. how many times more likely the odds of finding an exposure in someone with disease is compared to finding the exposure in someone without the disease
- Dr. Patrizio Castelli, Roberto Caronno, Sandro Ferrarese, Vittorio Mantovani, Gabriele Piffaretti, Matteo Tozzi, Chiara Lomazzi, Nicola Rivolta, and Andrea Sala. Surgical Infections. October 2006, 7(supplement 2): s-45-s-47. doi:10.1089/sur.2006.7.s2-45. 2/3 are gram-positive organisms Aortoenteric fistula involved, mostly gram negative organisms Type of bacteria important Even when known bowel manipulation during aortic reconstruction, you yield low incidence of enteric organisms and continued high incidence of staph epidermidis
- Early infections more likely to have systemic infections because not yet isolated by the perigraft capsule or because most commonly involve staph aureus and gram negative bacteria. They are more toxic in general, may have leukocytosis Staph aureus has specific enzymes such as catalases, hyaluronidases, coagulases etc which result in that marked inflammatory reactionpus and abscess Gram negatives also get abscess, but are less virulent Pseudomonas particularly bad as it invades vascular walls leading to more pseudoaneurysmal formation and arterial wall disruption Late infections more indolent, likely due to lower virulent species like staph epidermidis Staph epidermidis produces a glycocalyx biofilm layer that basically sequesters the organism, and mutes the host response Late infections can be indolent for years without knowing- either found incidently, or because of draining wounds or a sinus tract or something The presentation of late-onset infections (those occurring more than 4 months after surgery) tends to be more subtle with non-specific signs and symptoms. Fever is usually absent. These patients are more likely to present with signs of complications of aortic graft infection, such as false aneurysm, gastrointestinal bleeding resulting from erosion of the graft into the gastrointestinal tract, hydronephrosis or osteomyelitis
- Scanning electron micrograph of knitted Dacron graft colonized in vitro with slime-producing S. epidermidis shows numerous adherent bacterial microcolonies enclosed within a surface biofilm. Area delineated by inset (A) is shown at higher magnification in (B) (bar indicates 10 μm). In situ replacement of vascular prostheses infected by bacterial biofilms. Bandyk, Dennis F. et al. Journal of Vascular Surgery , Volume 13 , Issue 5 , 575 - 583
- Will focus more on intracavitary graft infections, i.e. aortic graft infections Extracavitary graft infections include: femorfemoral, femoropopliteal, or axillofemoral grafts Tend to present earlier and will most commonly demonstrate local signs of infection such as cellulitis, induration, and inflammation A wound mass or drainage is common, as are fever and leukocytosis Stone PA, Back MR, Armstrong PA, Brumberg RS, Flaherty SK, Johnson BL, Shames ML, Bandyk DF. Evolving microbiology and treatment of extracavitary prosthetic graft infections. Vasc Endovascular Surg. 2008 Dec-2009 Jan;42(6):537-44.
- Failure to thrive?
- Diagnosis and treatment of prosthetic aortic graft infections: confusion and inconsistency in the absence of evidence or consensus . J. Antimicrob. Chemother. (December 2005) 56 (6): 996-999 first published online November 3, 2005 doi:10.1093/jac/dki382
- Attempted to propose a formal case definition derived by a process of multidisciplinary, expert consensus. The objective was to define a precise criteria for diagnosing AGI Idea is to have a definition readily applied in routine practice and to aid in early recognition, and to provide a diagnostic standard for development of evidence-based clinical guidelines that is essential for clinical trial design and meaningful comparison
- AGI suspected if a single major criterion or two or more minor criteria from different categories are present AGI is diagnosed if one major criterion plus any criterion(major or minor) from another category They even admit it requires validation which is planned in a multicenter, clinical service database supported by the vascular society of great Britain and Ireland. Im not suggesting we incorporate this into our clinical practice, but I wouldn’t to give an idea that we are still trying to find a uniform definition and there is work being done that will allow more standardization.
- Aortic Prosthetic Graft Infections: Radiologic Manifestations and Implications for Management. Donald F. Orton, Robert F. LeVeen, Jean A. Saigh, William C. Culp, Jeff L. Fidler, Thomas J. Lynch, Timothy C. Goertzen, and Timothy C. McCowan. RadioGraphics 2000 20:4, 977-993 Lots of confusion on the normalcy of perigraft air following aortic repair. This was brought up in a recent case with Dr. Hughes who performed an open aortic repair on a patient who came in with a symptomatic infrarenal aortic aneurysm. He had returned 12 days later to the ED with left side pain and a leukocytosis of 14k. When CT done, it showed posterior pockets of fluid and air concerning for infection. His picture just didn’t fit the bill of an infected aortic graft infection and observation was chosen. His leukocytosis returned to normal without antibiotic intervention. He still had perigraft air present on CT at 16 days post-op, with complete resolution by his 6 week follow-up. Interestingly it was noted the area of the air coincided with the location of gelfoam placement intraoperatively.
- Current literature has attempted to delineate a normal timeline for post-operative perigraft air, with or without gelfoam use, defining normalcy up to around 7 days post-operatively, with findings of air 4-7 weeks after surgery being fairly suggestive of graft infection3,4,5, and findings later than 2-3 months post-operatively likely suggestive of aortoenteric fistula6 As far as gelfoam’s role in perigraft air, the literature is sparse. A study has been done looking into differentiating CT findings of gelfoam from intraabdominal abscess, but that was following other types of surgeries including liver transplant, and hysterectomies. They suggested certain CT findings like more linear presentation, fixed spatial positioning throughout serial examinations, and lack of air-fluid levels would be unusual in the setting of an infection or abscess. (Sandrasegaran and colleagues11 at Indiana). There also has been a case report linking gelfoam to perigraft air findings, but in ascending aortic aneurysm repair
- Sensitivity and specificity slightly better than CT Not used because time consuming, expensive, and cant be used in patients with chronic renal insufficiency due to nephrogenic fibrosis possibility
- Endoscopy: only if suspicious for aortoentertic fistula. Someone with known past aortic aneurysm repair and GI bleeding should be suspected of having aortoenteric fistula until proven otherwise. Use pediatric colonoscope because most occur in the 3rd and 4rth portion of the duodenum Labeled white blood cell scan Indium or technetium-99m These better than gallium because no GI uptake and little platelet cross-labeling White cells present in both inflammation and infection and thus cant differentiate based off of this technique, and thus has fallen out of favor
- Enables precise localization of abnormal F-FDG uptake
- Due to rarity and limited frequency of graft infection, the length of time required to accumulate any sufficiently large amounts of clinical evidence is too long, and patient management is sure to change during that time. No control groups and mostly just retrospective with limited power Reports often have mixed pathologies-not just aortic graft infections. Sometimes patients with primary aortic infections or nonaortic graft infections are included Data reporting not consistent study to study so hard to make comparisons Bacteriology Associated erosions or fistulas The anatomy of the revascularization Stability at presentation
- Completely removes infected material and new revascularization is placed through uninfected tissue Preferred conduit usually PTFE and either a prosthetic or an autogenous cross-femoral or cross-ilialconduit including saphenous vein, superficial femoral vein autograft or allografts, or arterial allografts, depending on whether infection involves the graft at a femoral level or not Type depends on location of infection Axillofemoral graft anastomosis is performed to the CFA if no groin infection is present If groin infection, then SFA If SFA occluded, then profunda femoris May be a better option in older, sicker patients in whom long-term graft failure may be less important Limited by anatomy Not feasible in patients with severe profunda femoris and proximal superficial femoral arterial occlusive disease Must work around if have associated groin site infections If groin infected, instead of prosthetic use saphenous vein, femoral vein,endarterectomized SFA, or cryopreserved artery Used for patients with the most aggressive and invasive aortic graft infections Poor patency: Seeger et al found that the 5-year primary patency rate for axillofemoral bypasses was 64%, and no axillopopliteal bypasses in his series were patent beyond 7 months. 3-year graft patency quoted as 43% w/ 5 year amputation rate of 34% in paper by Quiones-Baldrich Two-stage approach w/ a delay between the stages may reduce the morbidity and mortality associated with removal of infected graft. Reid’s paper only 8 patients over a 6 year span. Idea is to give patient chance for resuscitation post-op in ICU and give IV Abx, then return to decrease one stage operative time. You do worry about thrombosis during that time though! Less physiologic stress Two-staged approach with initial revascularization FIRST, followed by graft excision in 1-2 days is associated with significant less morbidity/mortality Reilly and Colleagues showed that overally mortality was 53% if graft excision preceeded extranatomic bypass but was down to 17% if bypass preceeded graft excision One study attempted using rifampin soaked grafts for extra-anatomic bypass and found no evidence this decreases infection risks, which as we will see, is in contradistinction to treatment with in-line rifampin-soaked grafts
- Observation that unstable patients bleeding from an aortoenteric fistula were occasionally successfully managed with in situ replacement using prosthetic graft Looking for an alternative to the failure-prone extra-anatomic bypasses Lower mortality and lower amputation rates compared to extra-anatomic bypass, but still concerns for reinfection
- Paper monumental in the study of aortic graft infections One of the first to describe use of in-situ graft replacement for aortic graft infection-in their case they used PTFE without antibiotic And one of the first to discuss the biofilm formation brought on by staph epidermidis, and discussed the increased prevalence of Coagulase negative staff as the major player in graft infection, and its usually indolent nature. 17 patients with aortic graft infection All underwent graft excision, wide debridement and in-situ PTFE graft replacement No perioperative death, but re-infection rate was 22% in 21 months the conclusion was that this was an acceptable treatment option in low virulent organism infection and for those who were dissatisfied with thrombosis and infection in extranatomic bypass grafts, but reinfection rates of around 20% may still be an issue. They got by with a decent mortality rate of only 4% Speziale-European Journal of Vascular and Endovascular Surgery 1997- similar study 25 patients Conclusions: acceptable treatment option in low virulent organism infection
- Rifampin became a popular choice because it has broad-spectrum activity against staph species as well as other gram positive and gram negative organisms AND more importantly, it does not redistribute rapidly into the systemic circulation owing to its relative hydrophobic nature Rifampin NOT effective against MRSA Some suggest it binds better to dacron due to increased collagen
- Retrospective review, reporting their initial experience of 27 patients with life- or limb-threatening arterial infections who underwent in situ treatment using antibiotic-bonded graft 27 patients: of these. 22 prosthetic aortic graft infection and 20 were treated with in-situ rifampin-bonded prosthetic grafts),5 primary aortic infection). This was over a 5 year period Their elective surgical treatment paradigm was based on presenting signs and microbiology of the infectious process: They involved attempted rifampin-soaked prosthetic only in patients with indolent biofilm infections with staph epidermidis or aureus Rifampin soaked gelatin-sealed Dacron All low grade i.e. staph epi and non-MRSA staph aureus Measures of success included: patient survival, freedom from recurrent infection, patency of the graft, and avoidance of major amputation Mortality of 8% (two patients), and at a mean follow-up of 17 months, there were no deaths or lower limb amputations as a result of graft infection in the surviving patients 2 reinfections (but involved the aortofemoral segments) Concluded that in situ prosthetic graft replacement is a good treatment option in patients with low-grade S. aureus infection, Staph epidermidis biofilm infections, and gram-positive infections involving the aorta at sites that preclude conventional management. However, when they had more complicated cases or more virulent bacterial strains, their treatment paradigm focused more autogenous vein replacement, which I will talk about more later. Decreased reinfection rates compared to non-antimicrobial based grafts, but inferior to autogenous reconstruction
- Goal was to assess the outcome after graft excision and in situ replacement with a rifampin-bonded prosthesis for treatment of major aortic graft infection Both of the early death and one late death were in patients initially treated for ruptured abdominal aortic aneurysm
- Primary purpose: to analyze the clinical outcome in patients treated for aortic graft infection with ISR Secondary aim: outcomes compared between patients who had similar clinical characteristics and extent of infection, needed total graft exicision, and had either ISR or axillofemoral reconstruction
- Reiterating that it is a safe and effective alternative in select patients Graft patency and limb salvage rates were excellent, but graft reinfection still occurred in 11.5% of patients(which went down to 5% in those where 360 omental wrap was used) Patients with hemorrhage or systemic sepsis from aortic graft enteric fistula had a mortality rate of 22% (2/9) and only 1 of 30 who had an aortic graft enteric fistula at all developed recurrent graft infection Overall procedure related death rate is at least as good as that reported for any other method of treatment. Could be considered an acceptable option in patient with aortoenteric fistula Important to note no difference in patient survival at 5 years between the two groups
- Bisdas et al in Germany in 2011 looked at silver-coated dacron as an alternative to rifampin-bonded grafts. 11 treated with in-situ silver-coated Dacron grafts In situ arterial reconstruction with homografts is nearly 3x more expensive than with silver graft
- Used as early as the 1950s. Abandoned due to significant incidence of late degeneration, dilation, rupture, thrombosis Conduit failure includes rupture, aneurysmal degeneration, infection, or rejection due to immunogenicity
- Looked at early and late results of allografts, and particularly fresh vs cryopreserved Originally planned this to be a bridge to late repeat prosthetic grafting after infection subsided but noticed they faired pretty well Fresh allografts: stored from 48hrs to 37 days at 4 degrees celcius in 500 ml of preservation medium containing heparin and antibiotic agents Changes in French health regulations led to switch to cryopreserved allografts in 1996 A segment of descending thoracic aorta used in 10 patients, infrarenal and various lengths of iliac and femoral arteries in 140 patients Rest of deaths not allograft related and risk factors for mortality included septic shock, presence of AEF, emergency operation, and surgical or medical complications
- Prior concerns about rupture seem to have been alleviated by improved preservation techniques Is this procedure’s cost justified, when you could probably get better or same results with different procedure?
- Objective was to evaluate the efficacy of cryopreserved aortic allografts at multiple institutions in the USA
- Most studies done on arterial allograft use done in Europe to this point One of first American studies on this topic Majority were transabdominal midline incisions
- Conclusion was that in situ cryopreserved allograft reconstruction is an effective alternative with satisfactory mid-term outcomes
- Complications occurred in 24% of patients Include the complications pictured above Patients who had full graft excision had significantly better outcomes
- 10 patients (5%) required allograft explant for the following reasons as explained in the chart
- Freedom from graft-related complications, graft explant, and limb loss was 80%,88%,and 97% respectively, at 5 years Primary graft patency at 5 years was 97% Patient survival was 75% at one year, but only 51% at 5 years In the end for high risk patients they felt due to the lower early and long-term morbidity and mortality than other previously reported treatment options, this should be considered first line treatment for aortic graft infections
- Looked at cryopreserved vascular allograft use at his institution to look for technical pitfalls that could influence early and midterm mortality. 49 patients between 1990-1999 Allograft related technical problems occurred in 8 of them included: Intraoperative rupture Allograftenteric fistula formation Anastomotic failure caused by inappropriate mechanical stress Stricture Failure due to inadequate wound drainage Interestingly 7 of the 8 technical problems occurred in the first 10 patients and the 30 day mortality rate of 6%, but 2.6% for the last 39 patients. CREDITED this to various technical adaptations He noted distinct allograft-related technical problems had to be overcome to improve outcomes. In the end he emphasized the following technical points in handling arterial allograft conduits
- Saphenous vein was simply not large enough. Failures were both hemodynamic and anatomical Hemodynamic: inadequate caliber to support sufficient flow Anatomical: kinking, compression
- Landmark paper who coined the term “neo-aortoiliac system” Study to evaluate the morbidity, mortality, and intermediate term follow-up of patients undergoing replacement with lower extremity deep and superficial veins Earlier in-situ reconstruction were using both arterial and venous autografts. They were the first to use strictly superficial and deep femoral veins Removal of infected prosthetic material, harvest of vein and creation of NAIS was performed as a single-staged procedure
- Various configurations of femoropopliteal vein used for aortoiliac and aortofemoral reconstructions after excising infected aortic grafts Operative time one average was 6.5 hrs. Interestingly it was noted that the OR time was always less than 5 hours when two teams were used.
- NAIS constructed from GSVs were prone to development of focal stenosis requiring intervention or diffuse neointimal hyperplasia leading to occlusion In-hospital mortality-non NAIS related, instead sepsis and MSOF Interestingly, limb edema and other signs of venous hypertension were minimal A take away from this was that in order for a saphenous vein to be sufficient for use, it must be at least 7 or 8 mm in size and in general though femoral popliteal deep veins were greatly superior FPV offers several major advantages for in-situ repair It is a large-caliber autogenous conduit that is relatively resistant to reinfection and offers excellent long-term patency. It also obviates the need for long-term antibiotics post-operatively Mean follow-up time 22 months
- Ali paper wanted to look at more long-term outcomes of NAIS Hypothesizedt that NAIS offers superior long-term patency, durability, and freedom of secondary interventions Importantly all patients suffered AGI, unlike most other studies Data from a prospectively maintained database was analyzed over a 16 year period Charts reviewed Operative data like total operative time, IVFs, transfusion requirements, ASA class, adjunctive surgical procedures Patients divided into 3 groups according to location of their infected graft: AFBG; AIBG; AxFBG Operative complications divided into surgical and medical Operative time averaged 9 hrs Felt their mortality rate was quite respectable considering they considered their patient population disadvantaged, and a patient population in which 35% presented with sepsis or aortoenteric fistulas and a majority of who had advanced multilevel occlusive disease They also had a high proportion of extremely virulent organisms Aortic reconstruction reinfection occurred in 5% of patients with typical manifestations of graft disruption and hemorrhage within 2 weeks of graft implantation Perioperative risk factors for increased mortality included: use of platelets, blood loss >3L, pre-op sepsis Overall survival at 5 years was 52%
- Late incidence of chronic venous insufficiency after deep vein harvest. Presented at the Southern Association for Vascular Surgery, Rio Grande, Puerto Rico, Jan 20, 2007. J. Gregory Modrall, MDa, , , Jennie A. Hocking, PA-Cb, Carlos H. Timaran, MDa, Eric B. Rosero, MDa, Frank R. Arko III, MDa, R. James Valentine, MDa, G. Patrick Clagett, Mda. Modrall and Clagett looked at this Cohort of 350 FPV-harvested legs, only one to date developed venous ulceration In general, loss of the deep vein is compensated for over time. However, this may indicate why patients in earlier years with NAIS were having more trouble, due to the harvesting of both the deep femoral veins and the GSV, or damage or ligation of the profunda vein. Without these, less opportunity for collateralization
- O’Hara PJ et al. Surgical management of infected abdominal aortic grafts: review of a 25-year experience. JVS 1986;3:725-31. Reinfection risk of 27% Bacourt F et al. Axillobifemoral bypass and aortic exclusion for vascular septic lesions: a multicenter retrospective study of 98 cases. French University Association for Research in Surgery. Ann Vasc Surg 1992;6:119-26. Due to an inability to effectively revascularize the internal iliac arteries and IMA Bovine Pericardium?>
- No large multi-institutional studies The consortium aims to improve clinical care of patients with low frequency or uncommon vascular diseases
- Incidence of .2-5% Focusing on endovascular graft infection Examined the medical and surgical management and outcomes of patients with aortic endograft infection after EVAR or TEVAR 206 patients over 10 years at a mean 22 months after implant 196 surgical management: 111 prosthetic, 54 cryopreserved allograft, 21 NAIS, 11 Axbfbypass Perioperative 30 day mortality 35% Prosthetic graft replacement after explantation is associated with higher reinfectiona and graft-related complications and decreased survival compared with autogenous reconstruction
- Higher TEVAR mortality likely due to higher rates of aortic fistulization, need for left heart bypass, and higher cross-clamping level than EVAR patients They hypothesized that the presence of an aneuryms sac behaves similarly to an abscess, making prosthetic replacement less favorable than allograft Best outcomes occurred in patients who got NAIS
- Controversial No current guidelines exist Some recommend lifelong, some recommend 6 months, some recommend 6 weeks Probably best to go no shorter than 6 weeks Ultimate goal is no clinical, radiological, or laboratory signs of infection