Endovascular Stent-Graft Treatment of Traumatic Arterial Lesions

Original Articles

Endovascular Stent-Graft Treatment of Traumatic Arterial Lesions Juan C. Parodi, MD, Claudio Scho¨nholz, MD, Łuis M. Ferreira, MD, and John Bergan, MD, Hon. FRCS (Eng.), Buenos Aires, Argentina, and La Jolla, California

Twenty-nine cases of post-traumatic false aneurysms and arteriovenous fistulas (AVF), with a mean follow-up of 24 months (1-65 months), are presented here. Diagnosis was established by color duplex and arteriogram. The time between injury and treatment varied between 3 days and 61 months. Endovascular treatment was accomplished using a covered Palmaz stent [vein, polytetrafluoroethylene (PTFE), or polyester], Corvita endoluminal graft, or a Wallgraft. Complimentary treatment of a branch injury was performed using a detachable balloon in one patient. The initial result was favorable for all patients. One case of asymptomatic stenosis of an iliac stent graft and three occlusions of the stent (one subclavian, one axillary, and one internal carotid) were registered during the follow-up period, and no clinical manifestations of the occlusions were reported. Endovascular treatment of post-traumatic false aneurysms and AVF appears to be a promising alternative for treatment of these lesions. Less pain and disability as well as rapid recovery time and lower cost after endovascular treatment compare favorably to the standard surgical technique. (Ann Vasc Surg 1999;13:121-129.)

INTRODUCTION Traumatic arterial aneurysms may appear in isolation or be discovered with associated arteriovenous fistulas (AVF). Increasing experience with civilian arterial trauma has taught us that in some locations these lesions are dangerous to approach and difficult to repair. Large incisions and wide exposure are often required to achieve the proximal control and distal exposure required to close vascular defects and restore arterial and venous continuity.1,2 Yet, such false aneurysms and AVF are common. They may be diagnosed acutely and repaired. If not detected, they may undergo expansion and progresFrom the Department of Vascular Surgery, Instituto Cardiovascular de Buenos Aires (J.C.P., L.M.F.) and Department of Interventional Radiology, Clı´nica La Sagrada Familia (C.S.), Capital Federal, Argentina; Department of Surgery, Scripps Memorial Hospital, La Jolla, CA (J.B.). Correspondence to: J.C. Parodi, MD, Department of Vascular Surgery, Instituto Cardiovascular de Buenos Aires, Blanco Encalada 1543, 1428 Capital Federal, Argentina.

sion or they may persist and enlarge after incomplete treatment. They may be detected early and allowed to remain because of associated injuries. In each of these situations, access to the arterial trauma may be difficult and risky because of the possibility of surgical injury to blood-stained and hematoma-obscured adjacent structures. While the ultimate results of wide surgical exposure and vascular repair have been generally satisfactory, there are situations in which persistent pain and various degrees of disability have occurred. In particular, injuries to the subclavian vessels have necessitated clavicular resection with its attendant morbidity. Other vessels, such as the innominate trunk, visceral arteries, and vessels at the base of the skull, and the retrohepatic vena cava have provided surgical challenges. In the long-standing AVF, potentially difficult access has occurred because of massive enlargement of adjacent vessels and the possibility of nerve damage when dissecting through high-pressure caput medusa–like surrounding veins. Such veins are 121

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regularly enlarged, friable, and under high pressure. Inadvertant laceration of these large, thinwalled vessels with intraluminal pressures approaching systemic arterial pressure can lead to catastrophic complications including massive hemorrhage. Recognizing a need to address this situation, we began in 1976 to develop a system of endoluminal treatment of arterial aneurysms, dissections, obstructive disease, and arterial trauma. By 1990, it was possible to report the first clinical case of treatment of an aortic aneurysm by endoluminal techniques. Within the following 2 years, we used the endoluminal approach to treat a patient with a large, long-standing AVF in the subclavian axillary region. In that case, the patient was suffering from high-output congestive heart failure. The simplicity of the less-invasive technique of endoluminal repair led to rapid recovery of a very ill patient. This encouraged us to explore the technique further. The following report is based on an analysis of lessons learned in 29 cases of vascular trauma, which emphasize the utility of this novel endovascular approach.

PATIENTS AND METHODS Between January 1992 and May 1998, 29 patients were encountered with traumatic arterial lesions and treated with the stent-graft technique. Twentyfive of the patients were men and 4 were women. Their ages ranged from 15 to 67 years (mean 38 years). The lesions encountered included 19 posttraumatic AVFs and 10 false aneurysms. Acute, subacute, and chronic cases were included (Table I). These were located in the subclavian artery (9), axillary artery (3), aorta (2), common iliac artery (2), common carotid artery (5), the common femoral artery (1), superficial femoral artery (3), and the popliteal artery (1). The internal carotid artery was injured in three patients (Table I). The cause of the arterial lesions was penetrating trauma in all but one case. The penetrating trauma was gunshot (17), blunt trauma (1), stab injury (1), and iatrogenic (10). The iatrogenic injuries occurred during laparoscopic surgery, cardiac catheterization, orthopedic surgery, vein stripping, and inadvertent arterial puncture during central vein catheter introduction. The guiding principle of repairing vital arteries is occlusion of the arterial injury from within the arterial lumen without compromising arterial flow. This is not necessary with traumatic lesions involving nonessential vessels. These can be effectively treated by catheter-directed arterial embolization.

Annals of Vascular Surgery

This was accomplished by implanting a tubular metallic mesh (stent), covered by polyester fabric, polytetrafluoroethylene (PTFE), or vein (Fig. 1). As all of the procedures were similar to one another, all adhered to the basic principle of preservation of patency in essential vessels and total occlusion of nonessential arteries. Clinical diagnosis in each case was supported by objective imaging, including color duplex scanning and arteriography. These were used in every patient. All operations were conducted under local anesthesia, and the stent graft was introduced from a remote site into the arterial tree, percutaneously or through a small incision designed to expose the entry site. Arteries utilized for access included the common femoral (24), superficial femoral (1), common carotid (2), and axillary (2). Material used for stent coverage included polyester (9), thin-wall PTFE (3), polycarbonate urethane polymer (13) (Oravein威; Corvita, Miami, FL), and autogenous vein (4) (Fig. 2). The first stent predominantly employed was a Palmaz威 balloon-expandable stent (Johnson & Johnson Interventional Systems, Warren, NJ). The stent-graft was mounted on an angioplasty balloon catheter whose diameter exceeded the diameter of the artery by 10 to 15% to obtain secure fixation. The covering in each case was attached to the stent with four ‘‘U’’ stitches placed two at each end of the graft at 180° to one another. The stents varied between 2 and 3 cm in length. The entire device of balloon and stent graft was compressed into an 1112 French (Fr) introducer sheath. When an aortic extra-large Palmaz (Johnson & Johnson Interventional Systems) was needed, the size of the sheath used was 18 Fr (internal diameter). To avoid arterial damage during introduction and progression into the artery, a homemade tapered tip was used utilizing the nose cone technique. The nose cone technique consists of creating a cone outside the sheath using the distal tip of the balloon inflated with saline solution. In this way, the edge of the sheath is made smooth, preventing damage to the intima of the artery. In two patients, the first presenting with AIDS and the second with an infected false aneurysm, autogenous vein was used to cover the stent. It was believed that the vein would be more resistant to infection than the synthetic foreign body. An additional patient with a post-traumatic internal carotid dissection complicated with a false aneurysm received a vein-covered stent, which was deployed at the base of the skull. The objective in this case was to create a less thrombogenic surface with which to cover the false aneurysm. The false aneurysm had been the source of thrombus, which

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Table I. Vascular trauma treated with stent graft Age (years)

Sex

1 2

50 15

M F

61 23

3 4

20 23

M M

38 2

5 6 7

35 45 37

F M M

23 14 3

8

56

M

2

9 10 11 12 13

24 56 22 30 56

M M M M F

11 5 2 16 —b

14 15 16 17

26 31 28 32

M M M M

45 22 9 23

18

67

M

47

19

22

M

13

20 21 22 23 24 25 26

45 52 24 65 32 74 21

M M M M M M M

8 9 1 1 2 2 23

27

53

M

2

28

23

M

26

29

30

M

12

Patient

IRTI (months)

Device

Patency

Cause of injury

1 2

Palmaz Dacron Palmaz Dacron

42 65/46

Gunshot Iatrogenic

AVF FA

2 2

Palmaz Dacron Palmaz vein

60 58

Gunshot Gunshot

AVF AVF FA

1 2 4

Palmaz PTFE Palmaz Dacrona Palmaz vein

58 57 36 1

Gunshot Gunshot Blunt trauma Iatrogenic

48 41 40 32 <1

Gunshot Iatrogenic Gunshot Gunshot Iatrogenic

29 8 14 26

Gunshot Gunshot Gunshot Gunshot

Artery injured

Lesion

Axillary Common iliac-cava Aorto-cava Common carotid SFA Subclavian Internal carotid Common femoral Subclavian Subclavian Subclavian Aorto-cava Common carotid SFA Axillary Subclavian Common iliac Subclavian

AVF AVF

Common carotid Subclavian Subclavian Popliteal Subclavian Axillary SFA Common carotid Internal carotid Common carotid Internal carotid

FA

Hospital stay (days)

10

Palmaz vein

AVF AVF AVF AVF FA

3 3 2 3 1

Palmaz Palmaz Palmaz Palmaz CEG

Dacron Dacron PTFE Dacron

AVF FA AVF AVF

2 1 2 7

CEG CEG CEG CEG

AVF

8

AVF

2

CEG + Palmaz PTFE CEG

24

Stab wound

FA FA FA AVF FA AVF AVF

2 1 2 2 1 1 1

Palmaz Dacron CEG Palmaz vein CEG CEG CEG CEG

20 20 16 14 7 8 6

Iatrogenic Iatrogenic Iatrogenic Iatrogenic Gunshot Iatrogenic Gunshot

AVF

2

CEG

4

Gunshot

AVF

2

CEG

8

Gunshot

FA

1

Wall graft

1

Gunshot

9

Iatrogenic

AVF, arteriovenous fistula; CEG, Corvita endoluminal graft; FA, false aneurysms; IRTI, injury to repair time interval; SFA, superficial femoral artery. a Detachable balloon was deployed in an injured arterial branch (tyrocervical trunk) in addition to treatment of the subclavian artery. b 3 days.

caused five separate cerebral infarctions. The procedure was successful in preventing further cerebral embolization (Fig. 3). Currently, we favor the Corvita endoluminal graft (CEG) (Corvita, Miami, FL). CEG is produced by covering a stent with biocompatible elastomeric polycarbonate urethane (Corethane). These self-

expandable stent grafts are flexible and have a lower profile than the Palmaz stent; they are nondeformable and readily available on the market. They are manufactured in a variety of sizes and lengths to adapt to the injured vessel. Guiding catheters 9-10 Fr and pusher catheters 7-8 Fr are used over the wire for deployment of the stent. After

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Fig. 1. This artist’s drawing shows the concept of endoluminal graft stent repair of an AVF. Fig. 2. Corvita stent grafts are manufactured in a variety of sizes tailored to the size of the artery injured.

Fig. 3. Case 7. A Arteriogram showing an internal carotid artery false aneurysm that was treated by a vein-covered Palmaz stent. B The smooth nature of the post-stent vein graft is clearly seen.

mounting the stent graft, the entire assembly is introduced into a 11–12 Fr sheath (Figs. 4 and 5). Recently (case 29, Fig. 6), we had the opportunity to use a Wallgraft (Schneider Worldwide, MN), which is constructed with a Wallstent and a polyester fabric. It behaves very much like the Corvita endoluminal graft.

Statistical Analysis Stent-graft patency was evaluated by using the Kaplan Meyer survival curve.

RESULTS Fig. 4. Case 19. This patient’s problem was a very high– flow carotid-to-jugular AVF. A Diagnostic angiography confirms the AVF. B At 48 hr post-procedure, angiography shows a complete occlusion of the AVF.

The false aneurysm or AVFs were closed completely by one or more stent-graft devices in 28 of 29 cases as confirmed by clinical examination and both color duplex scans and angiography. In the single case of

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Fig. 5. Case 26. This patient’s problem was an iatrogenic common carotid false aneurysm. A Diagnostic arteriography illustrates the location and nature of the arterial trauma. B The post-deployment arteriogram of a CEG graft. Note the smooth lumen of the carotid artery.

Fig. 6. Case 29. A Arteriogram depicting an internal carotid false aneurysm caused by a gunshot injury. B Arteriogram after a Wallgraft application. C Wallgraft partially

released from the preloaded sheath. D Two sizes of Wallgrafts, 6 mm and 8 mm. E Plan X-ray of the neck showing the stent and bullet.

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Fig. 7. Case 6. A detachable balloon was used at a secondstage procedure after successful closure of a subclavian AVF. Note the smooth lumen of the stent-graft combination in the subclavian artery.

partial failure of the main stent graft, an additional procedure was necessitated because of an additional AVF located in a branch of the subclavian artery. This was closed by a detachable balloon placed in the scapular branch of the thyrocervical trunk (Fig. 7). Interestingly, all cases of long-standing AVF had a significant stenosis (>50% stenosis) of the artery at the site of injury, which required balloon dilatation before implanting the stent graft. The stenosis necessitated treatment by inflating a high-pressure balloon. In many of the AVFs, a false aneurysm was present in addition to the direct artery-to-vein connection. This finding did not change the fundamental strategy employed. That is, the arterial tear was covered with a stent graft in all of the cases. The Corvita endoluminal graft is porous. Therefore, high-flow AVFs usually remained open up to 24 hr after introduction and after heparin reversal. In one case, the fistula remained open for 7 days, which necessitated introduction of a Palmaz stent covered with PTFE. This achieved complete sealing. Complications One patient died 1 month following the stent-graft false-aneurysm closure. That death was due to uncorrectable severe coronary artery disease. This patient was treated for an infected false aneurysm of the common femoral artery and developed a hematoma at the site of vein harvesting. One other patient developed a hematoma in the inguinal area, which necessitated surgical drainage, and another one developed an asymptomatic deep venous

Annals of Vascular Surgery

thrombosis (DVT). One patient died after 3 months of implantation from a nonrelated cause. The follow-up protocol called for color duplex scanning 6 months following arterial repair and once yearly after the first year. Two patients with a Corvita stent graft (one axillary, one subclavian) had an occlusion 8 and 10 months after surgery. Both occlusions remained asymptomatic. One patient treated for an iatrogenic postlaparoscopic aortoiliac vein AVF had an asymptomatic stenosis of the common iliac in the middle of the stent. The color duplex scan showed an 80% stenosis, which was dilated successfully without further complications. Doppler follow-up examination of an internal carotid artery false aneurysm treated with a vein-covered Palmaz stent (case 7) showed flow alterations after 13 months of implantation; digital arteriography showed a 90% stenosis due to stent compression (a deformable Palmaz stent was used only in this case). The patient refused further treatment. Total occlusion was detected 23 months later and the patient remained asymptomatic on Coumadin anticoagulation. Spontaneous collateralization through the circle of Willis was seen. Another patient with an iatrogenic common carotid artery false aneurysm was successfully treated. Subsequent neurosurgery to correct an anterior cerebral artery aneurysm led to death from left cerebral infarction. In summary, 23 of 29 patients continue to demonstrate stent-graft patency and remain asymptomatic after 24 months of mean follow-up. Event-free survival at 3 years is 83% (Fig. 8).

DISCUSSION Arteriovenous fistulas and arterial false aneurysms remain a clinical challenge to vascular surgeons. Their diagnosis, pathophysiology, and treatment have stimulated the intellectual curiosity of surgeons for more than 200 years.2 In addition to the contributions of Shumaker and Freeman, other well-known vascular surgeons have been interested in the subject. These include Halsted, Matas, Mont Reid, Holman, and Elkin.1 Rich2 and colleagues established a Vietnam War Vascular Registry in 1966, which allowed long-term follow-up of all of the vascular injuries that occurred among American casualties during that war. In total, there were 558 AVFs and false aneurysms, which were treated over a 9-year period. Multiple fragments from various explosives created the penetrating trauma, which caused most cases of AVF and false aneurysms (87.3%). The idea of endoluminal repair of arterial lesions

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Endovascular stent-graft for traumatic arterial lesions 127

Fig. 8. Kaplan-Meyer survival curve (PL estimates).

conceptualized by Dotter has attracted the attention of several independent groups.3-8 In 1991, the first clinical applications of a temporary mean of sealing a false aneurysm was initially published by Becker et al.9 A balloon-expandable Palmaz iliac stent was covered with a thin layer of silicone and percutaneously deployed at the subclavian arteriovenous fistula which was treated afterwards with conventional surgery. The purpose of this preliminary attempt was not to permanently seal the false aneurysm but rather to use this method as a control maneuver. Our own experience began in 1976, culminating in a successful human implantation in September 1990. In that patient, as well as many others, an abdominal aortic aneurysm was corrected. Further experience with these cases led to the treatment of an AVF in 1992.10 According to our search of the medical literature, this is the first clinical case that permanently sealed an AVF. The advantage of the endoarterial technique is illustrated by case 3 in the present series. This patient, who had a gunshot wound affecting the aorta and vena cava, had been subjected to multiple surgical procedures at another hospital in an attempt to solve an aortoinferior vena cava AVF and other visceral injuries. All attempts failed because of the massive bleeding caused by the fragility of enlarged veins. The decision to repair the AVF under local anesthesia utilizing minimal intervention was at-

tractive to the patient as well as to the surgeons involved. An extra-large Palmaz stent covered by a polyester graft was placed at the site of the fistula through the right femoral artery. The patient was discharged the next day with the problem solved. There has been some concern about the longterm complications of the endoluminal stent-graft correction of AVFs and false aneurysms. These concerns include stenosis of the treated artery at the point of junction of the ends of the stent graft with the arterial lumen or the development of stenosis within the stent. Furthermore, as with direct arterial interventions, there has been fear of venous thrombosis on the venous side of the corrected AVF and false aneurysm. The incidence of such venous thrombosis has not been determined in either direct surgical repair or endovascular repair. This warrants further study. Only one of our patients had a venogram performed after exclusion of a superficial femoral AVF (Fig. 9). The study depicted occlusion of the dilated veins without any clinical manifestation. As experience with the technique develops, it may be possible to treat acute traumatic lesions by the endoluminal method. If associated injuries are not a problem, a stent graft can stop acute bleeding and restore continuity of the affected blood vessel. Avoidance of a major laparotomy or thoracotomy is obviously desirable in a multi-injured patient. In

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Fig. 9. Venogram of a patient who had a long-standing AVF of the superficial femoral artery treated by the endoluminal method: A before treatment, B after treatment (note absence of the enlarged veins).

Fig. 10. Case 27. A Arteriogram depicting an AVF between the internal carotid and jugular vein. Note the high location of the fistula at the base of the skull and a severe stenosis distal to arterial tear. B Result after CEG application.

such situations, associated injuries must be ruled out or treated. Further developments in stent design will improve technical aspects of the procedure. Longer, more flexible, covered stents may appear. Other coverings such as autogenous large veins, fascia, peritoneum, duramater, pleura, or synthetic materials resistant to infection will undoubtedly be considered in acute traumatic cases. Antibiotic-bonded graft/stent combinations may be useful in infected fields.

CONCLUSIONS This group of cases and the case reports have proved the feasibility of endoluminal repair of false

aneurysms and AVFs. The procedure is new, and time is needed to define the future role of this innovative approach. Thus, no definitive conclusion can be drawn yet. Advantages of the method are more evident in cases in which several previous unsuccessful surgical procedures (case 12) make reoperation very difficult and nerves and veins prone to injury. As some locations of false aneurysms or AVFs, such as the internal carotid artery near the base of the skull (case 27, Fig. 10), proximal carotid artery, or subclavian artery, require a major procedure to gain open access, the endovascular approach would have clear advantages in terms of facilitating the procedure. The technique is certainly less invasive, produces less post-procedural

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pain and disability, and costs less, largely because of a markedly shortened recovery time. In the future, stent grafts may be included in the armamentaria of trauma centers and be used in civilian arterial injury and the military environment. The potential of this technique to temporarily or permanently control massive bleeding is an attractive one. REFERENCES 1. Elkin DC, DeBakey ME. Surgery in World War II: Vascular Surgery. Washington, DC: Office of the Surgeon General, Dept. of Army, 1955. 2. Rich NM, Spencer FC (eds). Vascular Trauma. Philadelphia: WB Saunders, 1978. 3. Parodi JC, Barone HD, Schonholz CJ. Endovascular treatment of aortoiliac aneurysms and arteriovenous fistulas with stented dacron grafts. In Veith FJ, ed. Current Critical Problems in Vascular Surgery, Vol. 4. St. Louis: Quality Medical Publishing, 1993, p 264. 4. Terry PJ, Houser EE, Rivera FJ, Palmaz JC, Sarosdy MF. Percutaneous aortic stent placement for life threatening aor-

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tic rupture due to metastatic germ cell tumor. J Urol 1995; 153:1631-1634. 5. May J, White G, Waugh R, Yu W, Harris J. Transluminal placement of a prosthetic graft-stent device for treatment of subclavian artery aneurysm. J Vasc Surg 1993;18:10561059. 6. Chalmers RT, Brittenden J, Bradbury AW. The use of endovascular stented grafts in the management of traumatic false aneurysms: a caveat [letter]. J Vasc Surg 1995;22:337-338. 7. Marin ML, Veith FJ, Panetta TF, et al. Percutaneous transfemoral insertion of a stented graft to repair a traumatic femoral arteriovenous fistula. J Vasc Surgery 1993;18:299302. 8. Marin ML, Veith FJ, Panetta TF, et al. Transluminally placed endovascular stented graft repair for arterial trauma. J Vasc Surg 1994;20:466–472; discussion 472-473. 9. Becker GJ, Benenati JF, Zemel G, et al. Percutaneous placement of a balloon-expandable intraluminal graft for lifethreatening subclavian arterial hemorrhage. J Vasc Interv Radiol 1991;2:225-229. 10. Parodi JC. Endovascular repair of abdominal aortic aneurysms. Adv Vasc Surg 1993;1:85-106.