Iatrogenic dissection of the abdominal aorta

Abstract

Abdominal aortic dissections are much less common than dissections of the thoracic aorta. Despite the increasing use of arterial catheterization for endovascular procedures and radiologic examinations, iatrogenic dissections of the abdominal aorta are paradoxically much rarer than spontaneous dissections. We describe two new cases of iatrogenic abdominal aortic dissection and analyze the clinical and radiologic signs and indications for treatment. A 66-year-old man arrived for evaluation in May 1987 with intermittent claudication of the lower left limb. Fifteen years earlier he had undergone left transfemoral catheter arteriography by Seldinger's method in another center to explore pain in the right lower extremity. The films from this period have been lost, but the report of the examination mentioned a localized dissection at the end of the left external iliac artery. After arteriography was performed, both right and left femoral pulses were palpable. Eventually the patient underwent an operation for a lumbar disk herniation, which was causing the right lower extremity pain. During the subsequent years the patient had claudication of the left lower limb. A diagnosis of lumbar disk herniation was made, but the patient refused surgery. At this time the patient consulted at our center for the worsening of the left lower limb claudication. On clinical examination the left femoral pulse was absent. Abdominal palpation revealed an aneurysm of the abdominal aorta. Abdominal ultrasonography showed a transversal diameter of 50 mm (no computed tomography [CT] scan was performed). Arteriography showed extensive stenosis of the infrarenal aorta, occlusion of the left iliac artery, and a normal right iliac artery. The pararenal aorta was normal, and the origins of the renal arteries were well visualized. The left lumbar arteries and the inferior mesenteric artery were not opacified (Fig. 1). The middle sacral artery supplied a rich collateral network within the left pelvis but did not reconstitute the occluded left internal iliac artery (Fig. 2). Fig. 2Case 1: arteriogram. 1. Middle sacral artery. 2. Collateral network within left pelvis.View Large Image Figure ViewerDownload (PPT) Surgery was performed by midline transperitoneal laparotomy. The upper pole of the abdominal aortic aneurysm was located level with the renal arteries. After suprarenal clamping was performed, the aneurysmal sac was opened to reveal a dissection of the abdominal aorta with thrombosis of the false lumen. The dissection extended in a retrograde manner up to the renal arteries. The false channel of the dissection extended beyond the renal arteries. It was posterior and medial and respected the origin of the renal arteries. The dissection extended to the left iliac axis and the left internal iliac artery. It terminated 4 cm before the end of the external iliac artery. No reentry tear was present. Treatment consisted of insertion of a Dacron graft that underwent anastomosis in end-to-end fashion with the infrarenal aorta by a running suture; this procedure closed the false lumen by fixing the two coats of the dissected aorta. The right limb underwent end-to-end anastomosis with the mid-portion of the right common iliac artery. The left limb underwent end-to-end anastomosis with the left common femoral artery, thereby excluding the dissected left iliac artery. After surgery the patient had left lower limb paresis caused by ischemia of the lumbar plexus after exclusion of the middle sacral artery, which supplies a rich collateral network within the left pelvis, particularly by its radicular branches for the lumbar plexus (Fig. 2). This motor deficit completely regressed in 12 months. No other signs of pelvic, colon, or left buttock ischemia were seen. When last seen in March 1996, the patient had no symptoms, and abdominal ultrasonography was normal. A 52-year-old corpulent patient presented in August 1995 with intermittent claudication of the left lower limb. Three years previously arteriography had been performed by a right femoral approach according to Seldinger's method for an exploration. At the time of the procedure the patient was reporting severe right lumbar pain. The dissection was noted at the time of arteriography, because the films taken at the time had been lost. On clinical examination all lower limb pulses were palpable, but vascular function tests revealed left iliac stenosis with a drop in ankle/brachial index on exercise. CT demonstrated a dissection of the abdominal aorta extending up to the celiac artery (Fig. 3). Arteriography demonstrated the false lumen, which originated at the right iliac artery and extended up in a retrograde manner 2 cm above the celiac artery; the visceral arteries were not involved. The catheter was placed above the level of the dissection (Fig. 4). Fig. 4Case 2: arteriogram. 1. False lumen. 2. Stenosis of left common lilac artery.View Large Image Figure ViewerDownload (PPT)Retrograde flow in the dissection showed opacification of the abdominal aorta before the dissection plane completely filled. The left common iliac artery had stenosis at its origin (Fig. 5). Fig. 5Case 2: arteriogram. 1. Catheter above level of dissection. 2. Opacification of abdominal aorta before dissection plane completely filled.View Large Image Figure ViewerDownload (PPT)Surgery was performed by an extraperitoneal thoracolumbar approach because of the corpulence of the patient and the existence of the retrograde dissection beyond the celiac trunk. A clamp was applied to the suprarenal aorta because the false aneurysm extended above the renal arteries. No reentry tear was present. Primary aortobiliac revascularization was performed with a Dacron graft. The proximal anastomosis at the level of the infrarenal abdominal aorta was performed in end-to-end fashion by a running suture that closed the false lumen by fixing the two coats of the dissected aortic wall. The entry tear was located 2 cm from the origin of the right external iliac artery. The stenosis of the left common iliac artery corresponded to extrinsic compression by the false lumen (Fig. 4). At the most recent checkup in September 1996, the patient had no symptoms. Dissections limited to the abdominal aorta are rare, accounting for only 2% to 4% of all aortic dissections.1Hirst AE Johns VJ Kime SW. Dissecting aneurysm of the aorta. A review of 505 cases.Medicine. 1958; 37: 217-239Crossref PubMed Scopus (1046) Google Scholar Despite the increasingly widespread use of endovascular techniques and arterial catheterization procedures, iatrogenic dissections of the abdominal aorta are paradoxically more rarely described than spontaneous dissections. Most cases reported to date occurred after aortography performed according to the technique of Dos Santos.2Gaylis H Laws JW. Dissection of aorta as a complication of translumbard aortography.BMJ. 1956; 2: 1141-1146Crossref PubMed Scopus (21) Google Scholar With progress in vascular radiology techniques, postcatheterization dissections of the abdominal aorta have become exceptional. McCann et al.3McCann RL Schwartz LB Pieper KS. Vascular complications of cardiac catheterization.J Vasc Surg. 1991; 14: 375-381Abstract Full Text Full Text PDF PubMed Scopus (128) Google Scholar failed to find any cases of iatrogenic dissection in a series of 16,350 femoral catheterizations. A review of the English language literature disclosed only 45 cases of spontaneous dissection of the abdominal aorta,4Graham D Alexander JJ Franceschi D Rashad F. The management of localized abdominal aortic dissections.J Vasc Surg. 1988; 8: 582-591PubMed Scopus (50) Google Scholar, 5Becquemin JP Deleuze P Watelet J Testard J Mellière D Acute and chronic dissection of the abdominal aorta: clinical features and treatment.J Vasc Surg. 1990; 11: 397-402PubMed Scopus (48) Google Scholar, 6Busuttil S Hall L Hines GL Brook M Brook S Dissections spontanées de l'aorte abdominale: 5 observations.Ann Chir Vasc. 1993; 7: 414-418Abstract Full Text PDF PubMed Scopus (11) Google Scholar and only 6 cases of abdominal aortic dissection after aortography have been reported since 1956.2Gaylis H Laws JW. Dissection of aorta as a complication of translumbard aortography.BMJ. 1956; 2: 1141-1146Crossref PubMed Scopus (21) Google Scholar, 4Graham D Alexander JJ Franceschi D Rashad F. The management of localized abdominal aortic dissections.J Vasc Surg. 1988; 8: 582-591PubMed Scopus (50) Google Scholar, 7Kocandrle V Kittle F Petasnick J. Percutaneous retrograde abdominal aortography complication.Intimal dissection. Arch Surg. 1970; 100: 611-613Crossref PubMed Scopus (4) Google Scholar, 8Sakamoto I Hayaski K Matsunaga N Matsuoka Y Uetani M Fukuda T et al.Aortic dissection caused by angiographic procedure.Radiology. 1994; 191: 467-471PubMed Google Scholar For Sakamoto et al.,8Sakamoto I Hayaski K Matsunaga N Matsuoka Y Uetani M Fukuda T et al.Aortic dissection caused by angiographic procedure.Radiology. 1994; 191: 467-471PubMed Google Scholar however, these lesions are underestimated, because most iatrogenic dissections of the abdominal aorta are asymptomatic and thus go unrecognized. The incidence of dissections after aortic catheterization is approximately 0.3 per 1000 angiographic procedures.8Sakamoto I Hayaski K Matsunaga N Matsuoka Y Uetani M Fukuda T et al.Aortic dissection caused by angiographic procedure.Radiology. 1994; 191: 467-471PubMed Google Scholar In the two cases reported aortic catheterization was performed by femoral cannulation and ilioaortic retrograde catheterization. Two entry sites to the dissection are possible either at the site of cannulation, by placing the tip of the puncture needle at the subintimal level, or as in our two cases, at the level of the external iliac artery. In its pelvic pathway this artery has a medial anteroconcavity. The retrograde insertion of the guide leads to it pressing against the posterior wall of the concave segment of the external iliac artery. The dissection is caused by an iatrogenic intimal tear by the guide and its retrograde intraparietal insertion. Rubbing may occur because of the existence of an atheromatous stenosis or by kinking of the artery, but it was not the case in our two patients. During catheterization extreme care must be taken in the passage of the guide. There must be no resistance when it is perfectly endoluminal. When it is intraparietal, a slight rubbing of the guide is usually noticed, and the radiologist perceives a dissection at the slightest manual injection of contrast material. The extent of the iatrogenic dissection in our two cases could suggest that the intraparietal passage of the guide had met with some weak resistance of a parietal fragility. In both of our cases the patients did not have signs supporting collagen-vascular disease, and their arterial blood pressure was stable and well controlled by medical treatment. When the entry site of the dissection is narrow and no reentry tear is present, the false channel is a cul-de-sac, and a thrombosis of the false channel may occur as in case 1. On the other hand, if the entry tear is wide, the flow in the false channel can increase, progressively leading to a reduction in caliber of the dissected arteries and retrograde progression of the dissection as in case 2. The clinical manifestations of iatrogenic dissections of the abdominal aorta are comparable to those of spontaneous dissections.5Becquemin JP Deleuze P Watelet J Testard J Mellière D Acute and chronic dissection of the abdominal aorta: clinical features and treatment.J Vasc Surg. 1990; 11: 397-402PubMed Scopus (48) Google Scholar Acute abdominal aortic dissections may be suggested by severe chest or abdominal pain immediately after contrast injection, associated with arterial hypotension and diminution or abolition of lower extremity pulses.8Sakamoto I Hayaski K Matsunaga N Matsuoka Y Uetani M Fukuda T et al.Aortic dissection caused by angiographic procedure.Radiology. 1994; 191: 467-471PubMed Google Scholar Chronic dissections may be revealed by the onset of intermittent lower extremity claudication after arteriography, as in our two cases, or discovery of an abdomina aortic aneurysm, as in case 1. Dissection may also be completely asymptomatic, however, and discovered fortuitously during subsequent arteriography or CT, as in our first case. Abdominal ultrasonography is diagnostic when an intimal flap is seen in the lumen of a dilated aorta.9Bresnihan ER Keates PG. Ultrasound and dissection of the abdominal aorta.Clin Radiol. 1980; 31: 105-108Abstract Full Text PDF PubMed Scopus (11) Google Scholar However, ultrasonography has its limits, particularly in obese individuals and when the false lumen has undergone thrombosis, as in case 1. Recently, intravascular ultrasonography has been used both to diagnose aortic dissection and to guide endovascular treatment.10Cavaye DM French WJ White RA Lerman RD Mehringer CM Tabbara MR et al.Intravascular ultrasound imaging of an acute dissecting aortic aneurysm: a case report.J Vasc Surg. 1991; 15: 510-513Abstract Full Text Full Text PDF Scopus (17) Google Scholar, 11Walker PJ Dake MD Mitchell RS Miller DC. The use of endovascular techniques for the treatment of complications of aortic dissections.J Vasc Surg. 1993; 18: 1042-1045Abstract Full Text Full Text PDF PubMed Scopus (110) Google Scholar Contrast-enhanced CT can demonstrate the intraluminal aortic flap, the false lumen, and its extent (Fig. 3), but the entry tear and the upper limit of the dissection may be difficult to see and require multiple contiguous scans. Magnetic resonance imaging provides the same information as CT but also allows scanning in the sagittal, coronal, and oblique planes, which facilitates determination of the extent of the dissection.12Petasnick JP. Radiologic evaluation of aortic dissection.Radiology. 1991; 180: 297-305PubMed Google Scholar Arteriography is the best technique to locate the site of entry and reentry necessary to plan the appropriate operation. It remains indispensable to confirm the extent of the dissection and its relations with the visceral arteries. A double lumen with or without an intimal flap is pathognomonic, as in case 2. Possible indirect signs include stenosis or occlusion caused by compression of the arterial lumen by the false lumen or an aneurysmal appearance or aortic stenosis, but with unusual signs as in case 1 (Fig. 1). The evolution of aortic dissections involves two risks: thrombosis, as in case 1, with the development of ischemia, or persistence of a false lumen with development of a false aneurysm and risk of compression, as in case 2, or rupture, especially if no reentry tear is present.7Kocandrle V Kittle F Petasnick J. Percutaneous retrograde abdominal aortography complication.Intimal dissection. Arch Surg. 1970; 100: 611-613Crossref PubMed Scopus (4) Google Scholar Aside from the onset of complications (lower limb ischemia or rupture of a false aneurysm), the indications for surgery depend on the course of the false aneurysm when circulation persists in a false lumen and the nature of the false aneurysms; saccular false aneurysms, for example, reportedly have a higher risk of rupture.7Kocandrle V Kittle F Petasnick J. Percutaneous retrograde abdominal aortography complication.Intimal dissection. Arch Surg. 1970; 100: 611-613Crossref PubMed Scopus (4) Google Scholar These patients should be monitored on a regular basis by CT or magnetic resonance imaging to assess any changes in the dissection. In the literature the surgical management of the dissection of the abdominal aorta has been variable: prosthetic replacement of the aorta, creation of a reentry site with both the true and false lumen as a combined source of inflow when the false channel is patent and the chronic septum is thick and has fibrosis, oversewing the dissection channel, and extraanatomic bypass without aortic repair.4Graham D Alexander JJ Franceschi D Rashad F. The management of localized abdominal aortic dissections.J Vasc Surg. 1988; 8: 582-591PubMed Scopus (50) Google Scholar The treatment of patients with iatrogenic dissections of the abdominal aorta is usually uncomplicated when the dissection does not extend beyond the renal arteries (as in our first case). The false lumen is closed by suturing a graft to the dissected walls of the infrarenal aorta, and the entry tear of the dissection is excluded downstream. When the dissection extends beyond the renal arteries, the indications for more selective surgical procedures must be assessed, but the complexity of reconstruction must be taken into account. However, if the dissection extends above the celiac artery but does not involve the visceral vessels, as in case 2, closure of the false lumen at the level of the proximal anastomosis solves the problem if no reentry tear is present. The use of endoprostheses has recently been proposed as a less invasive alternative to surgery in certain cases; intravascular ultrasonography, balloon angioplasty, stent placement, and endovascular septal fenestration have been used in the treatment of patients with traumatic or complicated aortic dissection in whom conventional treatment portends a high-risk mortality rate.11Walker PJ Dake MD Mitchell RS Miller DC. The use of endovascular techniques for the treatment of complications of aortic dissections.J Vasc Surg. 1993; 18: 1042-1045Abstract Full Text Full Text PDF PubMed Scopus (110) Google Scholar, 14Slonim SM Nyam U Semba CP Miller CD Mitchell RS Dake MO. Aortic dissection: percutaneous management of ischemic complications with endovascular stents and balloon fenestration.J Vasc Surg. 1996; 23: 241-253Abstract Full Text Full Text PDF PubMed Scopus (192) Google Scholar, 15Marty-Ané CH Alric P Prudhomme M Chircop R Serre-Cousine O Mary H Intravascular stenting of traumatic abdominal aortic dissection.J Vasc Surg. 1996; 23: 156-161Abstract Full Text PDF PubMed Scopus (46) Google Scholar Thoracic or thoracoabdominal pain after aortic catheterization should prompt a search for an iatrogenic aortic dissection. CT and arteriography are the examinations of choice to establish the diagnosis and determine whether the dissection involves the visceral arteries. Persistence of a progressive functioning false lumen or the onset of complications necessitate surgery, which gives satisfactory results for dissections that remain localized at the level of the infrarenal aorta.13Cambria RP Morse S August D Gusberg R. Acute dissection orginating in the abdominal aorta.J Vasc Surg. 1987; 5: 495-497PubMed Scopus (28) Google Scholar