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A new technique to explant an infected aortic endograft

2015; Elsevier BV; Volume: 62; Issue: 2 Linguagem: Inglês

10.1016/j.jvs.2015.03.033

1097-6809

Matthew Popplewell, Andrew Garnham, S.D. Hobbs,

Aortic Disease and Treatment Approaches

The management of an infected aortic endograft can be challenging both operatively and clinically. Although aortic endograft infection is rare, the incidence is likely to increase in the coming years because of ever rising numbers of endovascular aneurysm repairs. Definitive management involves the removal of the endograft through laparotomy. Removal of the graft is technically challenging; no manufacturer's device is available to assist in disengagement of barbed hooks that hold the endograft in position. We present a new technique using the disposable proctoscope as a device to facilitate safe removal of the endograft with minimal damage to the aortic wall. The management of an infected aortic endograft can be challenging both operatively and clinically. Although aortic endograft infection is rare, the incidence is likely to increase in the coming years because of ever rising numbers of endovascular aneurysm repairs. Definitive management involves the removal of the endograft through laparotomy. Removal of the graft is technically challenging; no manufacturer's device is available to assist in disengagement of barbed hooks that hold the endograft in position. We present a new technique using the disposable proctoscope as a device to facilitate safe removal of the endograft with minimal damage to the aortic wall. Aortic endograft infection is a rare but life-threatening condition. The incidence of graft infection is likely to increase in the coming years because of the increasing number of endovascular aneurysm repairs.1Usatii A. Payne W. Santilli S. Removal of an infected aortic endograft and open aortic reconstruction: technical remarks.Ann Vasc Surg. 2013; 27: 679-683Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar Surgical removal of the graft with revascularization is the preferred management option,2Herdrich B.J. Fairman R.M. How to manage infected aortic endografts.J Cardiovasc Surg (Torino). 2013; 54: 595-604PubMed Google Scholar although 30-day mortality has been quoted as high as 30%.3Lyons O.T. Patel A.S. Saha P. Clough R.E. Price N. Taylor P.R. A 14-year experience with aortic endograft infection: management and results.Eur J Vasc Endovasc Surg. 2013; 46: 307-313Abstract Full Text Full Text PDF Scopus (67) Google Scholar Removal of endograft devices has been documented to be notoriously difficult because of hooked barbs that implant into the aortic wall, removal of which can lead to injury.4Lyons O. Patel A.S. Taylor P.R. Aortic endograft explantation.in: Davies M. Lumsden A.B. Contemporary endovascular management: aorta. Cardiotext Publishing, Minneapolis, Minn2013Google Scholar We report a variation not previously described for resheathing of the device, allowing safe removal, with a disposable proctoscope. An 83-year-old man underwent elective endovascular aneurysm repair for a 5.8-cm infrarenal abdominal aortic aneurysm. Written informed consent was obtained, and review by an Institutional Review Board was waived as it was not deemed appropriate by the authors. This was performed through groin cutdowns using a 36-mm Cook Zenith Flex stent graft system (Cook Medical, Bloomington, Ind), extended with Spiral-Z limbs (Cook Medical). The patient satisfied all anatomic requirements for this stent, and it is preferred at our center because of the low incidence of proximal graft migration. On the right side, this was extended to the external iliac artery, after internal iliac artery embolization, on account of a short ectatic common iliac artery, and reinforced with a Wallstent (Boston Scientific, Natick, Mass). The procedure was successful; the patient made an uneventful recovery and had a satisfactory postimplantation computed tomography (CT) scan at 1 month. The patient presented again 6 months later with nonspecific lethargy, right-sided abdominal pain, raised inflammatory markers (C-reactive protein level, 103 mg/L; white blood cell count, 14.3 × 109/L), and worsening renal function. CT identified right-sided hydroureteronephrosis secondary to inflammatory change anterior to the right iliac vessels. A technetium Tc 99m-labeled white blood cell scan revealed an accumulation of white blood cells at 3 hours adjacent to the proximal right limb extension of the initial endovascular aneurysm repair, consistent with a focus of infection. The source of infection was unclear; the operation was performed without complication, and no breaks in sterility were observed. The patient had a long-term catheter; however, urinary cultures were subsequently negative. Given that the focus of infection was located within the aneurysm sac, the assumption was made that the main body of the endograft was also at risk. After a multidisciplinary discussion, it was decided that given the patient's age, comorbidities, and risk of graft body infection, extra-anatomic reconstruction by axillobifemoral bypass and subsequent graft explantation was the most appropriate way of managing the problem, after right antegrade ureteric stent insertion. The right axillary artery was exposed along with both femoral arteries, and an 8-mm Dacron axillobifemoral bypass graft was performed. The distal right external iliac artery was ligated, and a Cook Zenith iliac plug (Cook Medical) was placed in the left limb of the previous endograft to maintain left internal iliac artery perfusion and to prevent competitive flow. This was performed to reduce the risk of bypass graft thrombosis and to prevent re-entry into the groin, which would increase the risk of prosthetic contamination after entering an infected abdominal surgical field. The wounds were all closed. After this, the patient was reprepared, and a midline laparotomy was performed. The aortic sac was opened, and purulent fluid was found surrounding the graft, which had a biofilm on its surface. Before use, a standard disposable proctoscope was soaked in 2% chlorhexidine solution for 20 minutes. A brief suprarenal cross-clamp was applied, ensuring that the suprarenal barb hooks where distal to the site of occlusion. Initially, the graft limbs were disengaged from the main body of the endograft. To facilitate resheathing into the proctoscope, a length of nylon tape was tied on to the distal portion of the endograft to collapse the expandable stents. One end of the nylon tape was then passed through the lumen of the proctoscope to act as a point of traction, and the other end was gradually tightly wrapped around the endograft to collapse it down to a size at which the proctoscope could be passed over it. Particular attention was paid to the junctional zones between individual stents as this is the most likely site for snagging to occur. Once the proximal sealing stent was resheathed, advancement of the proctoscope in a cranial direction into the lumen of the aortic neck, while holding the endograft firmly with the other hand, allowed resheathing of the bare-metal suprarenal component and disengagement of the barbs from the aortic wall with little trauma (Figs 1 and 2).Fig 2Disengagement of the suprarenal barb hooks. Traction on the surgical tape while stabilizing the proctoscope allows the graft to be "resheathed" and safely removed.View Large Image Figure ViewerDownload Hi-res image Download (PPT) After explantation of the infected endograft, the aortic neck was oversewn with two layers of running mattress sutures and the aortic stump covered with an omental pedicle. The iliac limbs and Wallstent were easily explanted from the iliac vessels by gentle traction, and both common iliac arteries were ligated at their origin. The aortic sac was débrided, irrigated with rifampicin, and packed with Collatamp (Collatamp G; EUSA Pharma [Europe], Oxford, United Kingdom). Postoperatively, the patient received 14 days of intravenous meropenem and vancomycin, followed by a 4-week course of oral flucloxacillin and rifampicin. Subsequent graft culture was reported as negative. At recent follow-up 12 months postoperatively, the patient had recovered well, with return to normal levels of activity for him, with inflammatory markers within normal range. Mortality from the removal of infected endografts has been reported in approximately 14% to 40% of surgically managed cases from a host of different series.3Lyons O.T. Patel A.S. Saha P. Clough R.E. Price N. Taylor P.R. A 14-year experience with aortic endograft infection: management and results.Eur J Vasc Endovasc Surg. 2013; 46: 307-313Abstract Full Text Full Text PDF Scopus (67) Google Scholar Variable incidences have been reported in the current literature ranging from 0.05% to 4%.5Heyer K.S. Modi P. Morasch M.D. Matsumura J.S. Kibbe M.R. Pearce W.H. et al.Secondary infections of thoracic and abdominal aortic endografts.J Vasc Interv Radiol. 2009; 20: 173-179Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar, 6Ducasse E. Calisti A. Speziale F. Rizzo L. Misuraca M. Fioriani P. Aortoiliac stent graft infection: current problems and management.Ann Vasc Surg. 2004; 18: 521-526Abstract Full Text Full Text PDF PubMed Scopus (168) Google Scholar, 7Hobbs S.D. Kumar S. Gilling-Smith G.L. Epidemiology and endograft infection.J Cardiovasc Surg (Torino). 2010; 51: 5-14PubMed Google Scholar Endograft infection can be complicated by rupture, aortoenteric fistulization, and sepsis. The cause in the majority of cases is thought to be secondary seeding of microorganisms from other primary infections causing bacteremia, such as in the renal and respiratory tracts.8Murphy E.H. Szeto W.Y. Herdrich B.J. Jackson B.M. Wang G.J. Bavaria J.E. et al.The management of endograft infections following endovascular thoracic and abdominal aneurysm repair.J Vasc Surg. 2013; 58: 1179-1185Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar Multiple small series have documented their experience with mortality from endograft explantation, demonstrating varied outcomes. Sharif et al9Sharif M.A. Lee B. Lau L.L. Ellis P.K. Collins A.J. Blair P.H. et al.Prosthetic stent graft infection after endovascular abdominal aortic aneurysm repair.J Vasc Surg. 2007; 46: 442-448Abstract Full Text Full Text PDF PubMed Scopus (126) Google Scholar reported on 6 endograft infections from a case series of 509 patients, 50% of which were managed operatively, all of whom were alive at differing follow-up intervals. Murphy et al8Murphy E.H. Szeto W.Y. Herdrich B.J. Jackson B.M. Wang G.J. Bavaria J.E. et al.The management of endograft infections following endovascular thoracic and abdominal aneurysm repair.J Vasc Surg. 2013; 58: 1179-1185Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar reported similar findings, with 50% of patients with an infected endograft receiving surgery; mortality from aorta-related causes in this series was reported at 38.9%. A larger series of 100 patients undergoing late graft explantation >1 month from initial surgery had comparable rates of mortality in those patients in whom infection was present (n = 13; 38% mortality).10Turney E.J. Steenberge S.P. Lyden S.P. Eagleton M.J. Srivastava S.D. Sarac T.P. et al.Late graft explants in endovascular aneurysm repair.J Vasc Surg. 2014; 59: 886-893Abstract Full Text Full Text PDF PubMed Scopus (91) Google Scholar Fatima et al11Fatima J. Duncan A.A. de Grandis E. Oderich G.S. Kalra M. Gloviczki P. et al.Treatment strategies and outcomes in patients with infected aortic endografts.J Vasc Surg. 2013; 58: 371-379Abstract Full Text Full Text PDF PubMed Scopus (99) Google Scholar reported on their series of 24 explants due to infected endograft in 2013; mortality in this cohort was much less at 21% at last follow-up. Options for management are dependent on patient-related factors, in particular fitness for a surgical procedure on a background of sepsis. Conservative options include aspiration of the sac, translumbar CT-guided thrombin injection,12Hulin S.J. Morris G.E. Aortic endograft infection: open surgical management with endograft preservation.Eur J Vasc Endovasc Surg. 2007; 34: 191-193Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar and lifelong antibiosis. Conservative treatment has reported differing outcomes; some reported 100% mortality,9Sharif M.A. Lee B. Lau L.L. Ellis P.K. Collins A.J. Blair P.H. et al.Prosthetic stent graft infection after endovascular abdominal aortic aneurysm repair.J Vasc Surg. 2007; 46: 442-448Abstract Full Text Full Text PDF PubMed Scopus (126) Google Scholar whereas other small series have shown good survival in selected patients.8Murphy E.H. Szeto W.Y. Herdrich B.J. Jackson B.M. Wang G.J. Bavaria J.E. et al.The management of endograft infections following endovascular thoracic and abdominal aneurysm repair.J Vasc Surg. 2013; 58: 1179-1185Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar Others have published a technique of removal using a cut 20-mL syringe as a barrel to provide a similar method of removal as described here.1Usatii A. Payne W. Santilli S. Removal of an infected aortic endograft and open aortic reconstruction: technical remarks.Ann Vasc Surg. 2013; 27: 679-683Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar, 13Koning O.H. Hinnen J.W. van Baalen J.M. Technique for safe removal of an aortic endograft with suprarenal fixation.J Vasc Surg. 2006; 43: 855-857Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar This technique involves cutting or sawing off the end of a syringe, which may leave a rough edge that could predispose to aortic wall damage. The technique using the proctoscope as described here solves this problem by using a preformed device with a smooth tapered end without the need for modification with sharp instrumentation (Fig 3). The principle is identical in that resheathing of the device through a smaller lumen allows disengagement of the hooks, meaning that the graft can be removed in its entirety, protecting the operator from sharp injury. Other methods for the removal of an infected aortic endograft with suprarenal fixation include cutting of the suprarenal struts, leaving the barbs in situ, and manual pressure application to the proximal graft with proximal directional force to disengage the barbed hooks from the aortic wall.14Sternberg W.C. Conners M.S. Money S.R. Explantation of an infected aortic endograft with suprarenal barb fixation.J Vasc Surg. 2003; 38: 1136Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar However, leaving foreign material behind is likely to increase the rate of reinfection, and manual pressure disengagement could lead to wall injury. As the graft we removed was large (36 mm in diameter), we think that the instrument would be able to facilitate removal of thoracic stents if necessary. Although it is rare, aortic endograft infection carries significant mortality and morbidity. Removal of an infected endograft is technically challenging for the surgeon. We provide an alternative, safe, and effective variation of a previously described technique for removal of an infected endograft using the disposable proctoscope.