Endovascular Leaks: Perioperative Nursing Implications
Article Outline
- Abstract
- Endovascular Aortic Aneurysm Repair Procedural Basics
- Endoleak Classification
- Monitoring Complications of Endoleaks
- Case Study One: Type I Endoleak
- Case Study Two: Type II Endoleak
- Case Study Three: Type III Endoleak
- Case Study Four: Type IV Endoleak
- Postoperative and Posthospitalization Care
- Conclusion
- Examination
- Answer Sheet
- Learner Evaluation
- References
- Copyright
Abstract
Endovascular repair is becoming the gold standard treatment for aortic aneurysm disease. With the development of new treatment modalities, however, new and unique complications arise. Endovascular stent graft leaks (ie, endoleaks) are one such complication.
Endoleaks occur when blood leaks into the aneurysm sac after an endovascular stent repair. Endoleaks are divided into four categories (ie, I through IV) depending on the site of origin; perioperative nurses must become familiar with treatment options for each type of endoleak. AORN J 89 (May 2009) 839–846. © AORN, Inc, 2009.
Key words: Endoleak , endovascular aneurysm repair , EVAR , abdominal aortic aneurysm , thoracic aortic aneurysm
The key components of the perioperative nurse's role involve demonstrating knowledge related to the surgical procedure, the expected patient outcome, and any potential complications that may occur. With the advent of minimally invasive vascular surgery and the integration of an interventional radiological component to the treatment of aortic aneurysmal disease, perioperative nurses have been challenged to expand their knowledge about vascular procedures.
As with most technologically advanced procedures, the nurse's assessment calls for extrapolation of information from multiple sources, not just what is seen on the cardiac monitor or visually at the field. Endovascular surgery requires interpretation of information obtained through radiographic images. Understanding the unique complications of endovascular aortic repair is essential for planning, providing a surgical intervention, and educating patients and staff members.
One of the most common endovascular complications is an endovascular stent graft leak (ie, endoleak), which is defined as leakage of blood into the aneurysm sac after an endovascular stent repair. Education of vascular and perioperative nurses regarding endoleaks is essential for ensuring initiation of the appropriate nursing care plan, planning for appropriate interventions, and providing accurate patient education.
Endovascular Aortic Aneurysm Repair Procedural Basics
Endovascular repair is becoming the gold standard treatment modality for aortic aneurysm disease. When an aortic aneurysm is identified either through physical examination, ultrasound screening, or a radiological procedure, the patient undergoes a 16-slice computed tomography (CT) scan or magnetic resonance angiography. After careful review of anatomical structures and landmark measurement, the surgeon determines which option (ie, endovascular or open aneurysm repair) is best for the patient.
Patient selection for endovascular abdominal aortic aneurysm repair is based on anatomic inclusion criteria related to the
Therefore, according to this inclusion criteria. there are no critical branches within the aneurysmal vessel.
Criteria for endovascular thoracic aneurysm repair are the same as for repair of abdominal aortic aneurysms; however, the surgeon also must plan for two additional factors. Depending on the location of aortic arch vessels, the surgeon must plan for landing zones or arch reconstruction. Landing zones are defined as the segment of aorta where the endograft will end. This segment of aorta must consist of normal arterial wall structure to ensure full apposition between aortic wall and endovascular stent graft. Arch reconstruction may be necessary if the landing zone covers an aortic branch vessel; bypass of that vessel will be completed either as a staged approach or on the same day.
Selection of the endovascular stent graft is based on the diameter of the aorta at the proximal landing point, tortuosity of the access vessels and aorta, and physician preference. The technical details of the endovascular repair vary with each specific device, but the general principles are similar.2
The surgical procedure consists of unilateral or bilateral femoral cut downs, which are device- and physician-dependent. The surgeon accesses the femoral artery with an entry needle and arterial sheath. Under fluoroscopic guidance, the surgeon advances a diagnostic angiocatheter over a guide wire, performs sequential diagnostic angiograms, and confirms aortic measurements. The surgeon advances the device deployment system over a stiff guide wire, and after confirming placement at the predetermined landing zone or neck of the aneurysm, the surgeon deploys the device.
Before device deployment, some surgeons deploy a pressure-sensing monitor. The monitoring device is deployed within the aneurysm sac between the stent graft and aneurysmal wall. This device measures pressure and is used to predict endoleaks that may contribute to an increase in the size of the aneurysm sac.
If a multicomponent system is being used, the surgeon deploys the contralateral limb via the contralateral femoral artery using similar procedural steps. When all components have been deployed, the surgeon expands the endovascular stent grafts for full apposition (ie, in juxtaposition or proximity) and seals them using an aortic balloon specific to the size of the device used.
A completion angiogram is an essential component of the procedure to ensure complete exclusion of the aneurysm and confirm the aneurysmal sac is no longer filling. If the completion angiogram demonstrates good apposition with normal flow restored, the surgeon removes the device, wires, and sheaths; closes the arteriotomy sites; closes the incisions; and applies the dressings.
Endoleak Classification
In the event that contrast is seen within the aneurysmal sac during the completion angiogram, the surgeon performs additional angiographic studies to determine whether an endoleak is present and its respective source. Persistent blood flow within the aneurysmal sac eventually may result in rupture despite the endovascular stent graft repair. Intervention is determined by the type of endoleak and the timing of occurrence. Not all endoleaks occur during the surgical procedure; some endoleaks may occur as late as two to five years after the repair.
Endoleaks can be classified based on the time of first detection.
Additionally, endoleaks are categorized according to their site of origination (Table 1).
Table 1. Endoleaks Classified According to Site of Origination1
| Type of endoleak | Source of perigraft flow |
|---|---|
| I | Attachment site leaks |
| A | Proximal end of endograft |
| B | Distal end of endograft |
| C | Iliac occluder (ie, plug) |
| II | Branch leaks without attachment site connection |
| A | Simple or to-and-fro (ie, from only one patent branch) |
| B | Complex or flow-through with two or more patent branches |
| III | Graft defect |
| A | Junctional leak or modular disconnect |
| B | Fabric disruption (eg, midgraft hole, suture holes) |
| Minor (< 2 mm) | |
| Major (> 2 mm) | |
| IV | Graft wall (fabric) porosity (< 30 days after graft placement) |
1 Veith FJ, Baum RA, eds. Endoleaks & Endotension: Current Consensus on Their Nature and Significance. New York, NY: Marcel Dekker, Inc; 2001:14. |
Diagnosis is made using ultrasound, angiogram, or CT. These examinations may be a component of the surgical procedure or postoperative follow up. Follow-up protocols are institution-specific and vendor-dependent. An example of a postoperative follow-up regimen would be as follows:
If an intra-aortic pressure sensor is implanted at the time of the initial endograft repair, pressure monitoring is performed by placing an electronic wand over the abdomen. Pressure monitoring is performed intraoperatively; at one month, three months, and six months; and annually thereafter. When the presence of an endoleak is confirmed, it is categorized and the need for and type of intervention is determined.
Monitoring Complications of Endoleaks
Perioperative nurses can use the Thompson-Bertling Complication Acuity Scale to assist them in identifying the indicated endoleak and understanding appropriate medical or surgical intervention options (Table 2). Monitoring for potential complications begins in the surgical suite and continues to the postanesthesia care unit and then to the surgical intensive care unit or surgical floor until discharge. The patient usually is discharged 24 to 48 hours after the procedure, which provides a short but critical time period in which to ensure a positive outcome.
Table 2. Thompson-Bertling Complication Acuity Scale
| Grade 1 | Grade 2 | Grade 3 | Grade 4 | |
|---|---|---|---|---|
| Description | Complications that require monitoring; observation; and, potentially, future interventions | Complications that require a planned second-stage procedure at the time of the first procedure or in the near future | Complications that require an urgent intervention | Complications that require an emergent intervention |
| Complications |
•Hematoma •Pseudoaneurysm •Decreased renal function •One or more toes become discolored •Type IV endoleak •Type II endoleak with slow filling during the surgical procedure |
•Absent distal pulse •Renal failure •Bowel ischemia •Graft migration •Type II endoleak with aneurysmal sac filling or expanding from retrograde or collateral flow |
•Endovascular graft infolds or collapses •Paresthesia •Occlusion or obstruction of distal vessels from injury or emboli •Type I endoleak •Type III endoleak |
•Aortic rupture •Avulsion of the iliac artery •Cardiac arrest •Abdominal compartment syndrome •Type I endoleak rupture |
| Equipment | • None |
•Direct puncture approach: spinal needle •Transvascular approach: micro-angiocatheter •Contrast •Fluoroscopy •Basic angiogram setup •Positioning prone or supine: have positioning equipment available •Embolic agents and ultrasound machine available |
•Endovascular set up •Fluoroscopy •Additional stent graft components •Equipment for open repair available |
•Complete combined open/endovascular repair; •Fluoroscopy and imaging table •Aortic occlusion balloon •Additional stent graft cuff/limb •Aortic bifurcated graft •Autotransfusion equipment |
| Nursing considerations |
•Observation •Postoperative education (eg, follow-up examinations are essential for monitoring potential expansion of the aneurysmal sac) |
•Fluoroscopic angiographic procedure •Importance of follow-up diagnostic examinations are emphasized •Radiological safety measures are maintained |
•Fluoroscopic angiographic or open procedure depending on the surgeon •Maintain radiological safety measures •Transfusion blood and endovascular and traditional vascular grafts available |
•Emergent combined open/percutaneous approach •Blood products available •Crash cart •Hemostasis supplies •Call a STAT page for additional nursing help |
Case Study One: Type I Endoleak
An 87-year-old man underwent a traditional endovascular repair of an abdominal aortic aneurysm with implantation of a bifurcated three-component endovascular stent graft. His postoperative follow-up had been uneventful for five years. At his annual CT, a type I endoleak was noted at the proximal attachment site (Figure 1).
Figure 1.
Type I endoleak at the proximal attachment site.
Type I endoleaks occur when there is blood flow originating from either the proximal or distal seal of the endograft into the aneurismal sac. This may occur as a result of a sizing discrepancy; poor approximation with balloon dilation; or, as in this case, postprocedural aortic dilation with graft migration. A proximal type I endoleak is associated with a high risk of early postoperative rupture.1 This endoleak was treated using an additional component called a cuff, a short segment of endograft used to extend the existing bifurcated graft at the proximal fixation. The cuff was inflated to ensure apposition. The completion angiogram demonstrated resolution of the patient's type I endoleak.
Case Study Two: Type II Endoleak
A 67-year-old man underwent an endovascular stent graft repair of a 7.5-cm abdominal aortic aneurysm. The procedure was uneventful with a completion angiogram that demonstrated full apposition of the grafts, proximal and distal seals, and no endoleak. At the six-month follow-up, an abdominal ultrasound demonstrated residual blood flow in the aneurysmal sac and a 0.5 cm increase in the diameter of the aneurysm. A CT scan was performed, which identified the presence of an endoleak. Subsequently, a diagnostic angiogram was scheduled with the possibility of surgical intervention.
A type II endoleak is attributed to flow from collateral vessels (eg, inferior mesenteric artery, lumbar arteries) into the aneurysm sac.4 Additionally, retrograde flow from the hypogastric artery can contribute to a type II leak. In the thoracic aorta, contributing vessels include any aortic arch branch vessel that may have been covered at the time of the procedure as well as spinal arteries. Type II endoleaks are the most frequently documented type of endoleak. The majority of type II endoleaks will resolve spontaneously on subsequent imaging studies and will not be associated with aneurysm expansion.5
Various techniques and devices are available for embolizing or occluding the vessel that is contributing to the endoleak. Techniques include coil embolization through selective angiocatheter placement, implantation of nitinol mesh occlusion plug devices, or an infusion of an occlusive pharmaceutical medication (eg, n-butyl-2-cyanoacrylate [n-BCA]) via direct puncture or placement of a coaxial microcatheter system into the offending vessel.
This patient was treated using a direct-puncture embolization technique. The surgeon performed a diagnostic angiogram by placing a selective angiocatheter at the proximal portion of the graft. During the angiographic run, the surgeon identified that the leak was indeed a type II leak because no contrast was seen entering the sac at the beginning of the angiographic run, but later, the contrast appeared during retrograde flow from a lumbar artery. The surgeon accessed the hypogastric (ie, internal iliac) artery using a microcatheter (eg, 3 Fr) in an attempt to access the lumbar vessel but decided that the artery was too small. The surgical team repositioned the patient in the prone position with the diagnostic catheter in place for running a road map. A road map is a contrast run that creates a map of the arterial flow. The surgeon inserted a 22-gauge, 15-cm spinal needle into the aneurysmal sac at the point of the endoleak and injected 0.5 mL of n-BCA to form a “glue” occlusion. The cast of the glue occlusion is demonstrated in Figure 2.
Figure 2.
Type II endoleak with an n-butyl-2-cyanoacrylate glue cast.
Case Study Three: Type III Endoleak
A 58-year-old woman with a type III endoleak presented with an enlarging aortic aneurysm. A type III endoleak is defined as a structural disconnect within the graft. This may be separation between components, fracture of the exoskeleton or endoskeleton of the stent graft, or a tear or hole in the fabric itself. These were more common with earlier versions of stent grafts.
The patient presented with back pain two years postimplantation of an abdominal aortic endovascular stent graft and was sent for a CT scan. The CT scan demonstrated a fractured strut in the structure of the graft, which had resulted in blood flow directly into the aneurysm sac. Removal of an endovascular stent graft is complicated, so the OR set up is similar to that for an open aortic aneurysm procedure. Cross clamping and occlusion of vessels during removal can be difficult because of the structure of the endograft and placement of the endograft in the aneurysm neck and iliac vessels. The surgical team planned accordingly, expecting additional blood loss and prolonged cross clamping time.
The surgeon placed the cross clamp juxta-renal (ie, between renal arteries) because the lower margin of the renal artery was included in the aneurysm neck. The surgeon placed 7-Fr embolectomy balloons in the external iliac arteries and inflated them until retrograde flow stopped. The surgeon removed the endovascular graft (Figure 3) and sewed a bifurcated aortic knitted graft into place. The patient tolerated this procedure well. Blood loss was approximately 7,500 mL. An autotransfusion device was used to capture, clean, and reinfuse the patient's own blood. The patient was discharged without event.
Figure 3.
Type III endoleak noted in an explanted graft with structural defect and a hole in the graft fabric.
Case Study Four: Type IV Endoleak
A 76-year-old woman experienced a type IV endoleak, which occurs when blood leaks from the stent graft into the aneurysm sac via the porosity of the graft fabric. This is a temporary condition that stops within the first 30 days postimplantation. This is more prevalent in fabric-covered stent grafts than grafts covered with polytetrafluorethylene (ie, Teflon®). During the completion angiogram, the surgeon noted a slight blush within the aneurysmal sac late in the angiogram run. The patient was monitored with ultrasound before discharge, at two weeks, and at four weeks, and the patient's type IV leak resolved within 30 days of initial implantation without further treatment. With continual improvement of endovascular stent graft design, this type of endoleak is being seen less frequently.
Overview
An endovascular stent graft leak, also called an endoleak, is a leak that occurs in or near an endovascular stent graft. An endovascular stent graft is placed in an aneurysm, which is an area of weakness or dilation that forms in the wall of a blood vessel. An endoleak may be classified according to the first time it is detected, its location (type I through IV), or its severity.
When do endoleaks occur?
Some endoleaks occur during the surgical procedure so they can be resolved at that time. Some endoleaks occur within 24 hours of the endovascular aneurysm repair or between 1 and 90 days after the procedure. But, some endoleaks have occurred as late as two to five years after the original procedure.
Signs and symptoms of an endoleak
Some endoleaks do not cause any signs or symptoms. Some endoleaks, such as type I and type III endoleaks, may cause the patient to have back pain or feel a pulsating mass in his or her abdomen.
Risk factors for developing an endoleak
You did not do anything to cause the endoleak to occur. Unlike the aneurysm, heredity, and lifestyle factors such as smoking, high cholesterol, and high blood pressure do not cause an endoleak to occur.
How is an endoleak discovered?
Health care providers usually identify an endoleak through diagnostic examinations using ultrasound, angiogram, or computed tomography (CT). These examinations may be part of the original surgical procedure or routine postoperative follow-up. These tests help your surgeon decide whether to treat the endoleak.
Treatment options
Treatment for an endoleak depends on its location and severity. Some endoleaks are expected to go away without any treatment so your health care providers will only have to observe you and the stent graft to make sure that the leak resolves. Other types of endoleaks may require surgery.
Postoperative care
What happens after I go home?
When you are discharged from the health care facility, you will have the same follow-up as you did after your original surgery. Typically, this means that you will have ultrasounds and CT scans every 3 months for the first year and then annually thereafter.
Call your physician immediately if you experience any of the following postoperative complications:
Type IV endoleaks occur when blood leaks through the graft wall; these can occur anywhere on the graft.
Reference
- . Endoleak following AAA repair. EVToday . http://www.evtoday.com/OldArchives/pastarchive/1102/151.html Accessed March 30, 2009.
Postoperative and Posthospitalization Care
The postoperative care for an endovascular leak is dependent on the type of intervention used. Surgical interventions and endovascular stent graft placements require the same postoperative care as the traditional procedure. Patients who undergo percutaneous and direct stick procedures are kept on bed rest for two hours after the sheath is removed from the groin and discharged the next day with traditional arterial puncture precautions. Potential complications can be evaluated using the Thompson-Bertling Complication Acuity Scale. A patient's posthospitalization course follows the traditional endovascular stent graft follow-up, so the patient is scheduled for ultrasounds and CT scans every three months for the first year and then annually thereafter.
Conclusion
With the increasing shift from traditional aortic repairs to endovascular aortic stent graft repairs, the perioperative nurse and postoperative surgical staff nurse caring for a vascular surgical patient are challenged to learn about new complications. The endoleak is by far the most common complication associated with this type of aortic aneurysm repair. Understanding the different types of endoleaks, how they are treated, and potential complications is important to ensure safe and successful patient outcomes.
Examination
Endovascular Leaks: Perioperative Nursing Implications
Purpose/GoalTo educate perioperative nurses about caring for patients who experience endovascular leaks (endoleaks) after undergoing endovascular aneurysm repair.
Behavioral ObjectivesAfter reading and studying the article on perioperative nursing implications of endoleaks, nurses will be able to
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Endovascular Leaks: Perioperative Nursing Implications
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Endovascular Leaks: Perioperative Nursing Implications
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References
- In: Rutherford RB editors. Vascular Surgery . 6th ed.. Philadelphia, PA: Elsevier/Saunders; 2005;p. 1458–1462
- . Vascular surgery . In: Rothrock JC editors. Alexander's Care of the Patient in Surgery . 13th ed.. St Louis, MO: Mosby, Elsevier; 2007;p. 938–970
- In: Veith FJ , Baum RA editor. Endoleaks & Endotension: Current Consensus on Their Nature and Significance . New York, NY: Marcel Dekker, Inc; 2003;p. 14
- . Changing trends in the management of abdominal and thoracic aortic aneurysms . Perioperative Nursing Clinics: Vascular Surgery . 2006;1(2):111–120
- . Hypogastric artery embolization and endografting: controversies and techniques on the prevention and treatment of endoleaks . Endovascular Today . 2007;2:82–85 http://www.evtoday.com/PDFarticles/0207/EVT0207_14.pdf Accessed March 3, 2009.
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indicates that continuing education contact hours are available for this activity. Earn the contact hours by reading this article and taking the examination on pages 847–848 and then completing the answer sheet and learner evaluation on pages 849–850. The contact hours for this article expire May 31, 2012.The behavioral objectives and examination for this program were prepared by Rebecca Holm, RN, MSN, CNOR, clinical editor, with consultation from Susan Bakewell, RN, MS, BC, director, Center for Perioperative Education. Ms Holm and Ms Bakewell have no declared affiliations that could be perceived as potential conflicts of interest in publishing this article.This program meets criteria for CNOR and CRNFA recertification, as well as other continuing education requirements.AORN is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation.AORN recognizes this activity as continuing education for registered nurses. This recognition does not imply that AORN or the American Nurses Credentialing Center approves or endorses products mentioned in the activity.AORN is provider-approved by the California Board of Registered Nursing, Provider Number CEP 13019. Check with your state board of nursing for acceptance of this activity for relicensure.
PII: S0001-2092(09)00105-7
doi:10.1016/j.aorn.2009.02.001
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