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Aneurysms of the Internal Iliac Artery: Management Strategy
Aneurysms of the Internal Iliac Artery: Management Strategy Patrick Soury, MD, Denis Brisset, MD, Fre´de´ric Gigou, MD, Christophe Saliou, MD, Fre´de´ric Angel, MD, and Claude Laurian, MD, Paris, France
With the widespread use of CT scans, detection and treatment of internal iliac artery aneurysms (IIA) have become more frequent. In the last few years, endovascular repair has been added to the therapeutic arsenal. We reviewed the records of 38 patients treated for 44 IIA between 1987 and 1997 to assess immediate and long-term outcome using various therapeutic methods. Aneurysms were divided into three groups according to the circumstances of treatment. Group I included 25 IIA treated at the same time as abdominal aortic aneurysm (AAA). The morbidity/ mortality rate in this group was comparable to that in patients who underwent isolated AAA repair. Group II included 14 IIA treated during follow-up of AAA repair. Most complications in this group were intraoperative. Group III included five isolated IIA not associated with AAA repair. Complications were similar to those in group I. On the basis of this retrospective analysis, we propose a management strategy in which open surgery, endovascular repair, or both are used, depending on the circumstances of treatment.
INTRODUCTION Atherosclerotic internal iliac artery aneurysms (IIA) are uncommon findings accounting for only an estimated 0.4% of all intraabdominal aneurysms.1,2 With widespread use of the computed tomography (CT) scan for assessment of abdominal aneurysmal disease, detection and treatment of IIA has become more frequent in the last 10 years. Discovery usually occurs during assessment for multiple aneurysmal disease or long-term surveillance after abdominal aortic aneurysm (AAA) repair. For many years after MacLaren reported the first ligation in 1913,3 open surgery was the only treatment available for IIA. A variety of techniques have been described, including exclusion, aneurysmorService de Chirurgie Vasculaire, Hoˆpital St Joseph, Paris, France. Correspondence to: P. Soury, MD, Service de Chirurgie Vasculaire, Hoˆpital Saint Joseph, 185 rue Raymond Losserand, 75014 Paris, France. Ann Vasc Surg 2001; 15: 321-325 DOI: 10.1007/s100160010075 © Annals of Vascular Surgery Inc. Published online: April 24, 2001
rhapy, resection, and bypass. Surgical morbidity and mortality have been high, especially in cases involving rupture.4,5 Recently, endovascular repair has been employed for the treatment of IIA.6-9 The purpose of this retrospective study was to attempt to clarify the role of these therapeutic modalities in light of the circumstances of treatment.
PATIENTS AND METHODS We reviewed the records of 38 patients treated for IIA between January 1987 and January 1997. All patients were male, and the mean age was 73.4 years (range, 59-88). Aneurysms were divided into three groups according to the circumstances of treatment. Group I included IIA diagnosed and treated at the same time as AAA repair. Group II included IIA treated during follow-up after AAA repair. In these cases, simultaneous treatment was not performed, either intentionally or unintentionally, for preexisting aneurysms or because the aneurysm developed after AAA repair. Group III included IIA that were the main or only indication for treatment. 321
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Group I A total of 21 patients with 25 IIA (56%) were included in group I. The aneurysm was located on the right in 16 patients and on the left in 9. Bilateral aneurysm was noted in four patients. The mean age in this group was 72.2 years (range, 59-88). The mean size of the aneurysm was 37.7 mm (range, 15-65) as determined by ultrasonography, CT scan, or intraoperative assessment. Rupture and symptoms were not observed in any patient in this group. Treatment modalities for the associated AAA included aorta-to-aorta bypass in 2 patients and placement of a Y-prosthesis in 19, with distal anastomoses on the external iliac arteries in 9 patients, on the common iliac and external iliac arteries in 9, and on the femoral arteries in 1 patient. A variety of techniques were used for treatment of IIA. Aneurysmorraphy or resection was performed in 11 patients. Proximal ligation was performed in seven patients by suture of either the ostium of the hypogastric artery or the adjacent common and external iliac arteries. Distal revascularization at the level of the anterior and/or posterior branch of the IIA was performed in six cases. In the remaining case, radiologically guided embolization was performed 10 days after AAA repair because immediate treatment of a right IIA was not possible via the left retroperitoneal exposure route, which had been chosen because of respiratory insufficiency and previous surgery. To prevent visceral ischemia, as many arteries as possible supplying the abdominal region (e.g., the iliac and inferior mesenteric arteries) were revascularized. The inferior mesenteric artery was always reimplanted, if patent, i.e., in 11 cases. If the contralateral internal iliac artery was patent and normal (absence of aneurysm), it was revascularized either directly or by retrograde perfusion from the external iliac artery. Revascularization of one side was performed in all patients with bilateral IIA. Use of these revascularization techniques resulted in one patent artery in 8 patients, two patent arteries in 12, and three patent arteries in 1 patient. Group II A total of 12 patients with 14 IIA were included in group II. One aneurysm was treated twice. The aneurysm was located on the right in five patients and on the left in nine. The mean age of these patients was 73.2 years (range, 59-85) and the mean size of the aneurysm was 57.6 mm (range, 16-110). The mean interval between AAA and IIA repair was 76.2 months (range, 21-132). Four aneurysms were
Annals of Vascular Surgery
ruptured but all patients were hemodynamically stable at the time of repair. The other 10 aneurysms were asymptomatic. Open surgery, performed in 11 cases, consisted of aneurysmorraphy or resection in 7 cases and proximal exclusion in 4. Embolization was the initial treatment in three cases. One patient initially treated by embolization required resection 24 months later. Group III A total of five patients with five aneurysms were included in group III. The mean age in this group was 71.9 years (range, 61-79). The aneurysm was located on the left in three cases and on the right in two. The mean diameter of the aneurysm was 52.5 mm (range, 20-100). One patient presented with rupture of the aneurysm but was hemodynamically stable. Surgical treatment consisted of distal revascularization in one case and aneurysmorraphy or resection in three. The patient with the ruptured aneurysm required three separate embolization sessions because his general condition did not permit singlestage surgical treatment. In two patients IIA repair was associated with aorta-to-biiliac reconstruction due to dystrophy of the common iliac artery.
RESULTS Three of the 38 patients (8.3%) in this series died during the immediate postoperative period, including 2 with ruptured IIA. Intestinal ischemia requiring colectomy was observed in two patients (5.5%), including one who died. One patient had visceral ischemia (2.7%). The mean follow-up period for surviving patients was 39.5 months (range, 2-146). Ten patients (27.7%) died during follow-up. Group I No intraoperative complications were observed in this group. Four patients had nonfatal early postoperative complications—i.e., evisceration at day 8 in one case, hematoma of the rectus abdominalis muscle at day 5 in one patient treated by surgical drainage, thrombosis of the superficial femoral artery at day 15 in one patient treated conservatively, and intestinal ischemia at day 2 in one patient treated by left colectomy. Two deaths (9.5%) occurred in the postoperative period. One, on day 3, was due to multiple organ failure secondary to hemoperitoneum treated by surgical drainage. The other, on day 1, involved a
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patient treated for ruptured aneurysm who died as a result of massive intraoperative hemorrhage and intestinal ischemia. In one patient, embolization failed and open surgery was required 24 months later for expansion of the aneurysm (10 mm in 2 years). The mean follow-up period in this group was 42.9 months (range, 2-118). Six patients died during follow-up. None of these deaths were directly related to vascular repair. Group II Due to difficulty in achieving exposure, numerous intraoperative complications were observed in this group, including injury of iliac veins in four patients, injury of the common iliac artery in one, and massive hemorrhage around these injuries in two. Injury of the ureter was not observed. No postoperative complications were observed. The mean follow-up period in this group was 38.7 months (range, 6.9-146). Two patients (15%) died during follow-up. Although causes were not clearly specified, no death was directly related to treatment of IIA. Group III In the postoperative period, one patient in this group had visceral ischemia, which resulted in necrosis of the bladder requiring resection followed by bilateral ureterostomy. This patient died during bladder reconstruction 18 months later. One patient died on day 8 after multiple embolization failed to achieve complete thrombosis of a ruptured aneurysm. The mean follow-up period in this group was 26.1 months (range, 18.1-50.9). A second patient died 1 month after infection of the left limb of an aorta-to-biiliac artery bypass in which a Yprosthesis secondary to D11-D12 spondylodiscitis was used. This patient was treated by removal of the prosthesis followed by extraanatomic axillofemoral bypass. Immediate postoperative recovery was uneventful with no vascular or infectious complications.
DISCUSSION There is a paucity of epidemiological data on IIA. Through an autopsy study, Lucke and Rea1 estimated that isolated IIA account for 0.4% of intraabdominal aneurysms. A review of the literature published in 198210 contained only 76 case reports, including 28% involving bilateral lesions. Although
Aneurysms of the internal iliac artery 323
Lowry and Kraft11 reported that 43% of the isolated iliac aneurysms were IIA, these lesions accounted for only 18.8%, 20%, and 39% of isolated isolated iliac aneurysms treated in the series of Sekkal et al.,12 Desiron et al.,13 and Minato et al.,14 respectively. Isolated IIA are frequently treated in elderly patients and/or after rupture (38%).15 In many of our patients, IIA were discovered in association with aortic aneurysm. A few isolated cases have been reported in the literature,16 but their incidence in series describing long-term follow-up after aortic surgery is low.17 In a total of 1112 AAA repairs, only 6 aneurysms of the common iliac artery or hypogastric artery were observed.18 This is four times less than the number of thoracic aortic aneurysms. A variety of treatment methods have been used for IIA. Proximal ligation and suture exclusion are the oldest and technically simplest modalities. However, both carry the risk of long-term complications since the aneurysm is still supplied by collaterals and can thus continue to expand and even rupture.10,19 One patient in our series required aneurysmorraphy for an expanding IIA 11 years after proximal exclusion. These techniques are probably indicated only for patients with high operative risks and short life expectancy. Better long-term results can be obtained by distal ligation of the anterior and posterior branches of the hypogastric arteries in association with aneurysmorraphy. However, while this technique eliminates the risk of expansion, control of collaterals may be difficult by the external route. Technical difficulties can arise in relation to the size of the aneurysm, the depth of the operative field, and the fragility of the venous plexus, which is tightly adherent to the wall of the aneurysm.5 To reduce the risk of massive hemorrhage, collaterals can be controlled by means of balloon catheters.4,20 However, endo-aneurysmal catheter placement is often difficult, especially if the aneurysm is large and filled with thrombus. Distal revascularization of the hypogastric branches is associated with the same hemorrhagic risks as those accompanying aneurysmorraphy. This technique should only be used in patients with poor collateral circulation or with bilateral aneurysms to preserve one of the arteries supplying abdominal organs. Endovascular techniques are the newest addition to the therapeutic arsenal for IIA. Some authors7 have proposed placement of a covered stent between the common and external iliac arteries, thereby occluding the ostium of the IIA. This technique is tantamount to proximal surgical exclusion and carries the same long-term risk of expansion
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due to continued perfusion of the aneurysm from residual collaterals. In addition, this method makes further endovascular treatment difficult, so that open surgery may be the only alternative in case of expansion of the excluded IIA. In 1985, Rogoff and Stock21 reported a case treated by nonselective embolization using thrombin and cyanoacrylate after direct puncture of the aneurysm under CT scan guidance. Like most authors,6,8,9 we recommend that selective embolization of the ostia of the branches of the hypogastric artery be performed before stenting. To avoid distal embolization, metallic coils of an appropriate size should be pushed into each of the feeding arteries. After durable obstruction has been achieved, the stent can be inserted. Therapeutic strategy depends on the circumstances of presentation, anatomical features, and patient condition. Although the patient population in our study was small, the morbidity/mortality rate in group I (treatment of IIA at the same time as AAA) was relatively low in cases involving unruptured aneurysms. It was comparable to that reported in the literature for isolated aortic or aortoiliac repair, i.e., 3.9%.22 Thus simultaneous treatment can be considered a reasonable strategy whenever possible. Visceral ischemia is the most common complication after simultaneous treatment,4 and its prevention depends on maintaining good hemodynamics during surgery and on preserving perfusion of the inferior mesenteric and internal iliac arteries.14,23 Major hemodynamic variations and prolonged hypotension have been implicated in the onset of intestinal ischemia. Anesthetic and surgical techniques should be tailored to minimize hemodynamic variations. This is particularly true in cases in which interruption in collateral circulation may have jeopardized vascularization. Abdominal ischemia is a life-threatening complication with high mortality, i.e., 63%, according to Iliopoulos.24 Death can result from ischemic organ dysfunction, necrosis of the bladder, or ischemia of the lumbosacral plexus.25,26 Manifestations of ischemia can appear late in the form of buttock claudication. Treatment may require secondary revascularizaion of the hypogastric artery.27 However, symptoms may resolve spontaneously with the development of collateral circulation from the branches of the end of the external iliac artery or, more importantly, according to Iliopoulos et al.,28 from the deep femoral artery. For this reason, preservation of these vessels is important after interruption of hypogastric vascularization. Preservation of the inferior mesenteric artery can also prevent or attenuate the impact of exclusion. Indeed, we feel
Annals of Vascular Surgery
that, in contrast to conventional aortic or aortoiliac repair, whose usefulness is debatable, preservation of the inferior mesenteric artery is a necessity in any procedure involving interruption of collateral flow. By heeding this guideline, we were able to keep the incidence of symptomatic visceral ischemia close to that of isolated AAA repair, i.e., 2%, according to the meta-analysis of Tollefson and Ernst.29 In our opinion, the indications for endovascular repair are limited in patients indicated for AAA repair. In high-risk patients, preoperative embolization may be useful to facilitate open surgery. Similarly, embolization may be useful to treat inaccessible right IIA in patients requiring exposure by the left retroperitoneal route because of respiratory insufficiency or previous surgery. Treatment of IIA after AAA repair (group II) appears to be associated with two major problems: a higher incidence of rupture and of intraoperative complications. The greater frequency of rupture underlines the need for regularly scheduled, longterm surveillance after AAA repair. The higher intraoperative complication rate can be attributed not only to the frequency of rupture but also to technical difficulties. Re-dissection of the hypogastric fossa can result in arterial or venous injury with sudden, massive hemorrhage. Another reported dissection-related complication is injury of the ureter, which clings tightly to the wall of the aneurysm.5 Although use of the Barraya approach, which provides wide exposure of the lesions, can reduce these risks, endovascular repair is probably safer for treatment of IIA after AAA repair. In our opinion, open surgery is indicated only if endovascular repair fails, if visceral revascularization is required, or if symptomatic compression of the ureter is involved. Embolization is unsuitable when the ureter is compressed because neither the size of the aneurysm nor the degree of compression, is reduced. Although Razavi et al.9 and Bacourt et al.30 have reported successful stent insertion in patients with compression of the ureter, we feel that surgery with uretolysis gives more reliable long-term results. Isolated IIA (group III) are uncommon.31 The treatment of choice is endovascular repair. However, as in cases associated with AAA, because of the failure of endovascular treatment, borderline abdominal perfusion, and compression of the ureter, open surgery may be indicated. Anatomic conditions can also warrant surgery. In cases involving aortoiliac dystrophy in patients in good overall condition, in our opinion, replacement of all aortoiliac vessels is preferable to avoid deterioration of the lesions. Depending on the surgical technique re-
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quired, exposure can be achieved by the retroperitoneal route for isolated IIA or by the intraperitoneal route if IIA is associated with other lesions.
CONCLUSION Selective use of open surgery and endovascular repair, depending on the circumstances of treatment, allows better therapeutic management of IIA. Using this approach, acceptable morbidity and mortality rates can be achieved for patients with this lifethreatening disease. REFERENCES 1. Lucke B, Rea MH. Studies on aneurysm. I. General statistical data on aneurysm. JAMA 1921;77:935-940. 2. Silver D, Anderson EE, Porter JM. Isolated hypogastric artery aneurysm: review and report of three cases. Arch Surg 1967;95:308-312. 3. MacLaren A. Aneurysm of the internal iliac, probably immediately following a severe instrumental delivery. Operation and partial cure. Ann Surg 1913;58:269-270. 4. Perdue GD, Mittenthal MJ, Smith III RB, Salam AA. Aneurysms of the internal iliac artery. Surgery 1983;93:243-246. 5. Wirthlin LS, Warshaw AL. Ruptured aneurysm of the hypogastric artery. Surgery 1973;73:629-633. 6. Cynamon J, Marin ML, Veith FJ. Endovascular repair of an internal iliac artery aneurysm with use of a stented graft and embolization coils. J Vasc Interv Radiol 1995;6:509-512. 7. Dorros G, Cohn JM, Jaff MR. Percutaneous endovascular stent-graft repair of iliac artery aneurysms. J Endovasc Surg 1997;4:370-375. 8. Coullet JM, Beregi JP, Stekelorom-Debacker C. Place des techniques endovasculaires dans le traitement des ane´vrysmes iliaques internes. Sang Thrombose Vaisseaux 1995;7:469-473. 9. Razavi MK, Dake MD, Semba CP. Percutaneous endoluminal placement of stent-grafts for the treatment of isolated iliac artery aneurysms. Radiology 1995;197:801-804. 10. Brin BJ, Busutil RW. Isolated hypogastric artery aneurysms. Arch Surg 1982;117:1329-1333. 11. Lowry SF, Kraft RO. Isolated aneurysms of the iliac artery. Arch Surg 1978;113:1289-1293. 12. Sekkal S, Cornu E, Christides C. Ane´vrysmes iliaques isole´s: a` propos de 77 cas chez 48 malades. J Mal Vasc 1993;18:1317. 13. Desiron Q, Detry O, Sakalihasan N. Isolated athe´rosclerotic aneurysms of the iliac arteries. Ann Vasc Surg 1995; 9(Suppl):62-66. 14. Minato N, Itoh I, Natsuaki M. Isolated iliac artery aneurysm and its management. Cardiovasc Surg 1994;2:489-494.
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15. Kasulke RJ, Clifford A, Nichols WK, Silver D. Isolated atherosclerotic aneurysms of the internal iliac arteries: report of two cases and review of the literature. Arch Surg 1932;117:73-77. 16. Brings HA, Murray JD, Light JT. Internal iliac artery aneurysm following aortic reconstruction. Ann Vasc Surg 1996;10:59-62. 17. Jausseran, JM, Ferdani, M, Cataudella, R. Long-term results of surgical repair of abdominal aortic aneurysms. In: Branchereau, A, Jacobs, M, eds. Long-Term Results of Arterial Interventions. Armonk, NY: Futura, 1997, pp 167-174. 18. Plate G, Hollier LA, O’Brien P. Recurrent aneurysm and late vascular complications following repair of abdominal aortic aneurysms. Arch Surg 1985;120:590-594. 19. Deb B, Benjamin M, Comerota A. Delayed rupture of an internal iliac artery aneurysm following proximal ligation for abdominal aortic aneurysm repair. Ann Vasc Surg 1992;6:537-540. 20. Sacks NPM, Huddy J, Wegner T, Giddings B. Management of solitary iliac aneurysms. J Cardiovasc Surg 1992;33:679683. 21. Rogoff PA, Stock JR. Percutaneous transabdominal embolization of an iliac artery aneurysm. AJR Am J Roentgenol 1985;145:1258-1260. 22. L’AURC, Kieffer, E, Koskas, F, Dewailly, J, Gouny, P. Mortalite´ pe´ri ope´ratoire de la chirurgie e´lective des ane´vrysmes de l’aorte abdominale: e´tude multicentrique de l’AURC. In: Kieffer, E, ed. Les Ane´vrysmes de l’Aorte Abdominale. Paris: AERCV, 1990, pp 235-243. 23. Byrne JL, Zaman SN, Meade JW, Aronski WP. Operative management of bilateral internal iliac artery aneurysms. J Cardiovasc Surg 1989;30:241-243. 24. Iliopoulos JI, Howanitz PE, Pierce GE. The critical hypogastric circulation. Am J Surg 1987;154:671-675. 25. Paty P, Shah D, Chang A. Pelvic ischemia following aortoiliac reconstruction. Ann Vasc Surg 1994;8:204-206. 26. Picone AL, Green RM, Ricotta JR. Spinal cord ischemia following operations on the abdominal aorta. J Vasc Surg 1986;3:94-103. 27. Seagraves A, Rutherfort RB. Isolated hypogastric artery revascularization after previous bypass for aortoiliac occlusive disease. J Vasc Surg 1987;5:472-474. 28. Iliopoulos JI, Hermreck AS, Thomas J, Pierce GE. Hemodynamics of the hypogastric arterial circulation. J Vasc Surg 1989;9:637-642. 29. Tollefson DFJ, Ernst CB. Colon ischemia following aortic reconstruction. Ann Vasc Surg 1991;5:561-563. 30. Bacourt F, Mercier F, Benoist M. Ane´vrysme rompu de l’arte`re hypogastrique re´ve´le´ par une paralysie sciatique: un cas et revue de la litte´rature. J Mal Vasc 1994;19:147-150. 31. Brunkwall J, Hauksson H, Bengtsson H. Solitary aneurysms of the iliac arterial system: an estimate of their frequency of occurrence. J Vasc Surg 1989;10:381-384.
With the widespread use of CT scans, detection and treatment of internal iliac artery aneurysms (IIA) have become more frequent. In the last few years, endovascular repair has been added to the therapeutic arsenal. We reviewed the records of 38 patients treated for 44 IIA between 1987 and 1997 to assess immediate and long-term outcome using various therapeutic methods. Aneurysms were divided into three groups according to the circumstances of treatment. Group I included 25 IIA treated at the same time as abdominal aortic aneurysm (AAA). The morbidity/ mortality rate in this group was comparable to that in patients who underwent isolated AAA repair. Group II included 14 IIA treated during follow-up of AAA repair. Most complications in this group were intraoperative. Group III included five isolated IIA not associated with AAA repair. Complications were similar to those in group I. On the basis of this retrospective analysis, we propose a management strategy in which open surgery, endovascular repair, or both are used, depending on the circumstances of treatment.
INTRODUCTION Atherosclerotic internal iliac artery aneurysms (IIA) are uncommon findings accounting for only an estimated 0.4% of all intraabdominal aneurysms.1,2 With widespread use of the computed tomography (CT) scan for assessment of abdominal aneurysmal disease, detection and treatment of IIA has become more frequent in the last 10 years. Discovery usually occurs during assessment for multiple aneurysmal disease or long-term surveillance after abdominal aortic aneurysm (AAA) repair. For many years after MacLaren reported the first ligation in 1913,3 open surgery was the only treatment available for IIA. A variety of techniques have been described, including exclusion, aneurysmorService de Chirurgie Vasculaire, Hoˆpital St Joseph, Paris, France. Correspondence to: P. Soury, MD, Service de Chirurgie Vasculaire, Hoˆpital Saint Joseph, 185 rue Raymond Losserand, 75014 Paris, France. Ann Vasc Surg 2001; 15: 321-325 DOI: 10.1007/s100160010075 © Annals of Vascular Surgery Inc. Published online: April 24, 2001
rhapy, resection, and bypass. Surgical morbidity and mortality have been high, especially in cases involving rupture.4,5 Recently, endovascular repair has been employed for the treatment of IIA.6-9 The purpose of this retrospective study was to attempt to clarify the role of these therapeutic modalities in light of the circumstances of treatment.
PATIENTS AND METHODS We reviewed the records of 38 patients treated for IIA between January 1987 and January 1997. All patients were male, and the mean age was 73.4 years (range, 59-88). Aneurysms were divided into three groups according to the circumstances of treatment. Group I included IIA diagnosed and treated at the same time as AAA repair. Group II included IIA treated during follow-up after AAA repair. In these cases, simultaneous treatment was not performed, either intentionally or unintentionally, for preexisting aneurysms or because the aneurysm developed after AAA repair. Group III included IIA that were the main or only indication for treatment. 321
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Group I A total of 21 patients with 25 IIA (56%) were included in group I. The aneurysm was located on the right in 16 patients and on the left in 9. Bilateral aneurysm was noted in four patients. The mean age in this group was 72.2 years (range, 59-88). The mean size of the aneurysm was 37.7 mm (range, 15-65) as determined by ultrasonography, CT scan, or intraoperative assessment. Rupture and symptoms were not observed in any patient in this group. Treatment modalities for the associated AAA included aorta-to-aorta bypass in 2 patients and placement of a Y-prosthesis in 19, with distal anastomoses on the external iliac arteries in 9 patients, on the common iliac and external iliac arteries in 9, and on the femoral arteries in 1 patient. A variety of techniques were used for treatment of IIA. Aneurysmorraphy or resection was performed in 11 patients. Proximal ligation was performed in seven patients by suture of either the ostium of the hypogastric artery or the adjacent common and external iliac arteries. Distal revascularization at the level of the anterior and/or posterior branch of the IIA was performed in six cases. In the remaining case, radiologically guided embolization was performed 10 days after AAA repair because immediate treatment of a right IIA was not possible via the left retroperitoneal exposure route, which had been chosen because of respiratory insufficiency and previous surgery. To prevent visceral ischemia, as many arteries as possible supplying the abdominal region (e.g., the iliac and inferior mesenteric arteries) were revascularized. The inferior mesenteric artery was always reimplanted, if patent, i.e., in 11 cases. If the contralateral internal iliac artery was patent and normal (absence of aneurysm), it was revascularized either directly or by retrograde perfusion from the external iliac artery. Revascularization of one side was performed in all patients with bilateral IIA. Use of these revascularization techniques resulted in one patent artery in 8 patients, two patent arteries in 12, and three patent arteries in 1 patient. Group II A total of 12 patients with 14 IIA were included in group II. One aneurysm was treated twice. The aneurysm was located on the right in five patients and on the left in nine. The mean age of these patients was 73.2 years (range, 59-85) and the mean size of the aneurysm was 57.6 mm (range, 16-110). The mean interval between AAA and IIA repair was 76.2 months (range, 21-132). Four aneurysms were
Annals of Vascular Surgery
ruptured but all patients were hemodynamically stable at the time of repair. The other 10 aneurysms were asymptomatic. Open surgery, performed in 11 cases, consisted of aneurysmorraphy or resection in 7 cases and proximal exclusion in 4. Embolization was the initial treatment in three cases. One patient initially treated by embolization required resection 24 months later. Group III A total of five patients with five aneurysms were included in group III. The mean age in this group was 71.9 years (range, 61-79). The aneurysm was located on the left in three cases and on the right in two. The mean diameter of the aneurysm was 52.5 mm (range, 20-100). One patient presented with rupture of the aneurysm but was hemodynamically stable. Surgical treatment consisted of distal revascularization in one case and aneurysmorraphy or resection in three. The patient with the ruptured aneurysm required three separate embolization sessions because his general condition did not permit singlestage surgical treatment. In two patients IIA repair was associated with aorta-to-biiliac reconstruction due to dystrophy of the common iliac artery.
RESULTS Three of the 38 patients (8.3%) in this series died during the immediate postoperative period, including 2 with ruptured IIA. Intestinal ischemia requiring colectomy was observed in two patients (5.5%), including one who died. One patient had visceral ischemia (2.7%). The mean follow-up period for surviving patients was 39.5 months (range, 2-146). Ten patients (27.7%) died during follow-up. Group I No intraoperative complications were observed in this group. Four patients had nonfatal early postoperative complications—i.e., evisceration at day 8 in one case, hematoma of the rectus abdominalis muscle at day 5 in one patient treated by surgical drainage, thrombosis of the superficial femoral artery at day 15 in one patient treated conservatively, and intestinal ischemia at day 2 in one patient treated by left colectomy. Two deaths (9.5%) occurred in the postoperative period. One, on day 3, was due to multiple organ failure secondary to hemoperitoneum treated by surgical drainage. The other, on day 1, involved a
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patient treated for ruptured aneurysm who died as a result of massive intraoperative hemorrhage and intestinal ischemia. In one patient, embolization failed and open surgery was required 24 months later for expansion of the aneurysm (10 mm in 2 years). The mean follow-up period in this group was 42.9 months (range, 2-118). Six patients died during follow-up. None of these deaths were directly related to vascular repair. Group II Due to difficulty in achieving exposure, numerous intraoperative complications were observed in this group, including injury of iliac veins in four patients, injury of the common iliac artery in one, and massive hemorrhage around these injuries in two. Injury of the ureter was not observed. No postoperative complications were observed. The mean follow-up period in this group was 38.7 months (range, 6.9-146). Two patients (15%) died during follow-up. Although causes were not clearly specified, no death was directly related to treatment of IIA. Group III In the postoperative period, one patient in this group had visceral ischemia, which resulted in necrosis of the bladder requiring resection followed by bilateral ureterostomy. This patient died during bladder reconstruction 18 months later. One patient died on day 8 after multiple embolization failed to achieve complete thrombosis of a ruptured aneurysm. The mean follow-up period in this group was 26.1 months (range, 18.1-50.9). A second patient died 1 month after infection of the left limb of an aorta-to-biiliac artery bypass in which a Yprosthesis secondary to D11-D12 spondylodiscitis was used. This patient was treated by removal of the prosthesis followed by extraanatomic axillofemoral bypass. Immediate postoperative recovery was uneventful with no vascular or infectious complications.
DISCUSSION There is a paucity of epidemiological data on IIA. Through an autopsy study, Lucke and Rea1 estimated that isolated IIA account for 0.4% of intraabdominal aneurysms. A review of the literature published in 198210 contained only 76 case reports, including 28% involving bilateral lesions. Although
Aneurysms of the internal iliac artery 323
Lowry and Kraft11 reported that 43% of the isolated iliac aneurysms were IIA, these lesions accounted for only 18.8%, 20%, and 39% of isolated isolated iliac aneurysms treated in the series of Sekkal et al.,12 Desiron et al.,13 and Minato et al.,14 respectively. Isolated IIA are frequently treated in elderly patients and/or after rupture (38%).15 In many of our patients, IIA were discovered in association with aortic aneurysm. A few isolated cases have been reported in the literature,16 but their incidence in series describing long-term follow-up after aortic surgery is low.17 In a total of 1112 AAA repairs, only 6 aneurysms of the common iliac artery or hypogastric artery were observed.18 This is four times less than the number of thoracic aortic aneurysms. A variety of treatment methods have been used for IIA. Proximal ligation and suture exclusion are the oldest and technically simplest modalities. However, both carry the risk of long-term complications since the aneurysm is still supplied by collaterals and can thus continue to expand and even rupture.10,19 One patient in our series required aneurysmorraphy for an expanding IIA 11 years after proximal exclusion. These techniques are probably indicated only for patients with high operative risks and short life expectancy. Better long-term results can be obtained by distal ligation of the anterior and posterior branches of the hypogastric arteries in association with aneurysmorraphy. However, while this technique eliminates the risk of expansion, control of collaterals may be difficult by the external route. Technical difficulties can arise in relation to the size of the aneurysm, the depth of the operative field, and the fragility of the venous plexus, which is tightly adherent to the wall of the aneurysm.5 To reduce the risk of massive hemorrhage, collaterals can be controlled by means of balloon catheters.4,20 However, endo-aneurysmal catheter placement is often difficult, especially if the aneurysm is large and filled with thrombus. Distal revascularization of the hypogastric branches is associated with the same hemorrhagic risks as those accompanying aneurysmorraphy. This technique should only be used in patients with poor collateral circulation or with bilateral aneurysms to preserve one of the arteries supplying abdominal organs. Endovascular techniques are the newest addition to the therapeutic arsenal for IIA. Some authors7 have proposed placement of a covered stent between the common and external iliac arteries, thereby occluding the ostium of the IIA. This technique is tantamount to proximal surgical exclusion and carries the same long-term risk of expansion
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due to continued perfusion of the aneurysm from residual collaterals. In addition, this method makes further endovascular treatment difficult, so that open surgery may be the only alternative in case of expansion of the excluded IIA. In 1985, Rogoff and Stock21 reported a case treated by nonselective embolization using thrombin and cyanoacrylate after direct puncture of the aneurysm under CT scan guidance. Like most authors,6,8,9 we recommend that selective embolization of the ostia of the branches of the hypogastric artery be performed before stenting. To avoid distal embolization, metallic coils of an appropriate size should be pushed into each of the feeding arteries. After durable obstruction has been achieved, the stent can be inserted. Therapeutic strategy depends on the circumstances of presentation, anatomical features, and patient condition. Although the patient population in our study was small, the morbidity/mortality rate in group I (treatment of IIA at the same time as AAA) was relatively low in cases involving unruptured aneurysms. It was comparable to that reported in the literature for isolated aortic or aortoiliac repair, i.e., 3.9%.22 Thus simultaneous treatment can be considered a reasonable strategy whenever possible. Visceral ischemia is the most common complication after simultaneous treatment,4 and its prevention depends on maintaining good hemodynamics during surgery and on preserving perfusion of the inferior mesenteric and internal iliac arteries.14,23 Major hemodynamic variations and prolonged hypotension have been implicated in the onset of intestinal ischemia. Anesthetic and surgical techniques should be tailored to minimize hemodynamic variations. This is particularly true in cases in which interruption in collateral circulation may have jeopardized vascularization. Abdominal ischemia is a life-threatening complication with high mortality, i.e., 63%, according to Iliopoulos.24 Death can result from ischemic organ dysfunction, necrosis of the bladder, or ischemia of the lumbosacral plexus.25,26 Manifestations of ischemia can appear late in the form of buttock claudication. Treatment may require secondary revascularizaion of the hypogastric artery.27 However, symptoms may resolve spontaneously with the development of collateral circulation from the branches of the end of the external iliac artery or, more importantly, according to Iliopoulos et al.,28 from the deep femoral artery. For this reason, preservation of these vessels is important after interruption of hypogastric vascularization. Preservation of the inferior mesenteric artery can also prevent or attenuate the impact of exclusion. Indeed, we feel
Annals of Vascular Surgery
that, in contrast to conventional aortic or aortoiliac repair, whose usefulness is debatable, preservation of the inferior mesenteric artery is a necessity in any procedure involving interruption of collateral flow. By heeding this guideline, we were able to keep the incidence of symptomatic visceral ischemia close to that of isolated AAA repair, i.e., 2%, according to the meta-analysis of Tollefson and Ernst.29 In our opinion, the indications for endovascular repair are limited in patients indicated for AAA repair. In high-risk patients, preoperative embolization may be useful to facilitate open surgery. Similarly, embolization may be useful to treat inaccessible right IIA in patients requiring exposure by the left retroperitoneal route because of respiratory insufficiency or previous surgery. Treatment of IIA after AAA repair (group II) appears to be associated with two major problems: a higher incidence of rupture and of intraoperative complications. The greater frequency of rupture underlines the need for regularly scheduled, longterm surveillance after AAA repair. The higher intraoperative complication rate can be attributed not only to the frequency of rupture but also to technical difficulties. Re-dissection of the hypogastric fossa can result in arterial or venous injury with sudden, massive hemorrhage. Another reported dissection-related complication is injury of the ureter, which clings tightly to the wall of the aneurysm.5 Although use of the Barraya approach, which provides wide exposure of the lesions, can reduce these risks, endovascular repair is probably safer for treatment of IIA after AAA repair. In our opinion, open surgery is indicated only if endovascular repair fails, if visceral revascularization is required, or if symptomatic compression of the ureter is involved. Embolization is unsuitable when the ureter is compressed because neither the size of the aneurysm nor the degree of compression, is reduced. Although Razavi et al.9 and Bacourt et al.30 have reported successful stent insertion in patients with compression of the ureter, we feel that surgery with uretolysis gives more reliable long-term results. Isolated IIA (group III) are uncommon.31 The treatment of choice is endovascular repair. However, as in cases associated with AAA, because of the failure of endovascular treatment, borderline abdominal perfusion, and compression of the ureter, open surgery may be indicated. Anatomic conditions can also warrant surgery. In cases involving aortoiliac dystrophy in patients in good overall condition, in our opinion, replacement of all aortoiliac vessels is preferable to avoid deterioration of the lesions. Depending on the surgical technique re-
Vol. 15, No. 3, 2001
quired, exposure can be achieved by the retroperitoneal route for isolated IIA or by the intraperitoneal route if IIA is associated with other lesions.
CONCLUSION Selective use of open surgery and endovascular repair, depending on the circumstances of treatment, allows better therapeutic management of IIA. Using this approach, acceptable morbidity and mortality rates can be achieved for patients with this lifethreatening disease. REFERENCES 1. Lucke B, Rea MH. Studies on aneurysm. I. General statistical data on aneurysm. JAMA 1921;77:935-940. 2. Silver D, Anderson EE, Porter JM. Isolated hypogastric artery aneurysm: review and report of three cases. Arch Surg 1967;95:308-312. 3. MacLaren A. Aneurysm of the internal iliac, probably immediately following a severe instrumental delivery. Operation and partial cure. Ann Surg 1913;58:269-270. 4. Perdue GD, Mittenthal MJ, Smith III RB, Salam AA. Aneurysms of the internal iliac artery. Surgery 1983;93:243-246. 5. Wirthlin LS, Warshaw AL. Ruptured aneurysm of the hypogastric artery. Surgery 1973;73:629-633. 6. Cynamon J, Marin ML, Veith FJ. Endovascular repair of an internal iliac artery aneurysm with use of a stented graft and embolization coils. J Vasc Interv Radiol 1995;6:509-512. 7. Dorros G, Cohn JM, Jaff MR. Percutaneous endovascular stent-graft repair of iliac artery aneurysms. J Endovasc Surg 1997;4:370-375. 8. Coullet JM, Beregi JP, Stekelorom-Debacker C. Place des techniques endovasculaires dans le traitement des ane´vrysmes iliaques internes. Sang Thrombose Vaisseaux 1995;7:469-473. 9. Razavi MK, Dake MD, Semba CP. Percutaneous endoluminal placement of stent-grafts for the treatment of isolated iliac artery aneurysms. Radiology 1995;197:801-804. 10. Brin BJ, Busutil RW. Isolated hypogastric artery aneurysms. Arch Surg 1982;117:1329-1333. 11. Lowry SF, Kraft RO. Isolated aneurysms of the iliac artery. Arch Surg 1978;113:1289-1293. 12. Sekkal S, Cornu E, Christides C. Ane´vrysmes iliaques isole´s: a` propos de 77 cas chez 48 malades. J Mal Vasc 1993;18:1317. 13. Desiron Q, Detry O, Sakalihasan N. Isolated athe´rosclerotic aneurysms of the iliac arteries. Ann Vasc Surg 1995; 9(Suppl):62-66. 14. Minato N, Itoh I, Natsuaki M. Isolated iliac artery aneurysm and its management. Cardiovasc Surg 1994;2:489-494.
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